[Qemu-devel] [PATCH v4 00/22] re-factor softfloat and add fp16 functions

[Qemu-devel] [PATCH v4 00/22] re-factor softfloat and add fp16 functions

[Alex Bennée]

Hi,

The main change is applying the __attribute__((flatten)) to some of
the public functions that show up in Emilio's dbt-benchmark. This
seems to be a cleaner solution that squashing inlines higher up the
chain and still leaves the chance for re-use for the less widely used
functions. The results are an improvement over v3 by some margin:

                         NBench score; higher is better

    5 +-+-----------+-------------+------------+-------------+-----------+-+
      |                     ****### %%%%  +++                              |
  4.5 +-+...................*..*..#.%..%..****##..%%%%+ system-2.5       +-+
      |                     *  *  # %  %  *  * #  %  %      master         |
    4 +-+...................*..*..#.%..%..*..*.#..%..%softfloat-v3       +-+
  3.5 +-+...................*..*..#.%..%..*..*.#..%..%softfloat-%%%%.....+-+
      |                     *  *  # %  %  *  * #  %  %  * *  #  %  %       |
    3 +-+...................*..*..#.%..%..*..*.#..%..%..*.*..#..%..%.....+-+
      |                     *  *  #+%  %  *  * #$$$  %  * *  #  %  %       |
  2.5 +-+........####.......*..*..#$$..%..*..*.#..$..%..*.*..#..%..%.....+-+
      |       ****  #  %%%  *  *  # $  %  *  * #  $  %  * *  #$$$  %       |
    2 +-+.....*..*..#..%.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
      |       *  *  #  % %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
  1.5 +-+.....*..*..#$$$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
    1 +-+.....*..*..#..$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
      |       *  *  #  $ %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
  0.5 +-+.....*..*..#..$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
      |       *  *  #  $ %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
    0 +-+-----****###$$$%%--****###$$%%%--****##$$$%%%--***###$$$%%%-----+-+
                 FOURIER     NEURAL NETLU DECOMPOSITION    gmean

Slightly easier to read PNG:

    https://i.imgur.com/XEeL0bC.png

I think it's pretty ready for a merge. Shall I submit a pull myself or
does it make sense going via someone else? According to MAINTAINERS
Peter and Aurelien are responsible for this code...

Alex Bennée (22):
  fpu/softfloat: implement float16_squash_input_denormal
  include/fpu/softfloat: remove USE_SOFTFLOAT_STRUCT_TYPES
  fpu/softfloat-types: new header to prevent excessive re-builds
  target/*/cpu.h: remove softfloat.h
  include/fpu/softfloat: implement float16_abs helper
  include/fpu/softfloat: implement float16_chs helper
  include/fpu/softfloat: implement float16_set_sign helper
  include/fpu/softfloat: add some float16 constants
  fpu/softfloat: improve comments on ARM NaN propagation
  fpu/softfloat: move the extract functions to the top of the file
  fpu/softfloat: define decompose structures
  fpu/softfloat: re-factor add/sub
  fpu/softfloat: re-factor mul
  fpu/softfloat: re-factor div
  fpu/softfloat: re-factor muladd
  fpu/softfloat: re-factor round_to_int
  fpu/softfloat: re-factor float to int/uint
  fpu/softfloat: re-factor int/uint to float
  fpu/softfloat: re-factor scalbn
  fpu/softfloat: re-factor minmax
  fpu/softfloat: re-factor compare
  fpu/softfloat: re-factor sqrt

 fpu/softfloat-macros.h          |   48 +
 fpu/softfloat-specialize.h      |  109 +-
 fpu/softfloat.c                 | 4545 ++++++++++++++++-----------------------
 include/fpu/softfloat-types.h   |  179 ++
 include/fpu/softfloat.h         |  202 +-
 include/qemu/bswap.h            |    2 +-
 target/alpha/cpu.h              |    2 -
 target/arm/cpu.c                |    1 +
 target/arm/cpu.h                |    2 -
 target/arm/helper-a64.c         |    1 +
 target/arm/helper.c             |    1 +
 target/arm/neon_helper.c        |    1 +
 target/hppa/cpu.c               |    1 +
 target/hppa/cpu.h               |    1 -
 target/hppa/op_helper.c         |    2 +-
 target/i386/cpu.h               |    4 -
 target/i386/fpu_helper.c        |    1 +
 target/m68k/cpu.c               |    2 +-
 target/m68k/cpu.h               |    1 -
 target/m68k/fpu_helper.c        |    1 +
 target/m68k/helper.c            |    1 +
 target/m68k/translate.c         |    2 +
 target/microblaze/cpu.c         |    1 +
 target/microblaze/cpu.h         |    2 +-
 target/microblaze/op_helper.c   |    1 +
 target/moxie/cpu.h              |    1 -
 target/nios2/cpu.h              |    1 -
 target/openrisc/cpu.h           |    1 -
 target/openrisc/fpu_helper.c    |    1 +
 target/ppc/cpu.h                |    1 -
 target/ppc/fpu_helper.c         |    1 +
 target/ppc/int_helper.c         |    1 +
 target/ppc/translate_init.c     |    1 +
 target/s390x/cpu.c              |    1 +
 target/s390x/cpu.h              |    2 -
 target/s390x/fpu_helper.c       |    1 +
 target/sh4/cpu.c                |    1 +
 target/sh4/cpu.h                |    2 -
 target/sh4/op_helper.c          |    1 +
 target/sparc/cpu.h              |    2 -
 target/sparc/fop_helper.c       |    1 +
 target/tricore/cpu.h            |    1 -
 target/tricore/fpu_helper.c     |    1 +
 target/tricore/helper.c         |    1 +
 target/unicore32/cpu.c          |    1 +
 target/unicore32/cpu.h          |    1 -
 target/unicore32/ucf64_helper.c |    1 +
 target/xtensa/cpu.h             |    1 -
 target/xtensa/op_helper.c       |    1 +
 49 files changed, 2199 insertions(+), 2941 deletions(-)
 create mode 100644 include/fpu/softfloat-types.h

-- 
2.15.1

[Qemu-devel] [PATCH v4 01/22] fpu/softfloat: implement float16_squash_input_denormal

[Alex Bennée]

This will be required when expanding the MINMAX() macro for 16
bit/half-precision operations.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 fpu/softfloat.c         | 15 +++++++++++++++
 include/fpu/softfloat.h |  1 +
 2 files changed, 16 insertions(+)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 433c5dad2d..3a4ab1355f 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -3488,6 +3488,21 @@ static float16 roundAndPackFloat16(flag zSign, int zExp,
     return packFloat16(zSign, zExp, zSig >> 13);
 }
 
+/*----------------------------------------------------------------------------
+| If `a' is denormal and we are in flush-to-zero mode then set the
+| input-denormal exception and return zero. Otherwise just return the value.
+*----------------------------------------------------------------------------*/
+float16 float16_squash_input_denormal(float16 a, float_status *status)
+{
+    if (status->flush_inputs_to_zero) {
+        if (extractFloat16Exp(a) == 0 && extractFloat16Frac(a) != 0) {
+            float_raise(float_flag_input_denormal, status);
+            return make_float16(float16_val(a) & 0x8000);
+        }
+    }
+    return a;
+}
+
 static void normalizeFloat16Subnormal(uint32_t aSig, int *zExpPtr,
                                       uint32_t *zSigPtr)
 {
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 0f96a0edd1..d5e99667b6 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -277,6 +277,7 @@ void float_raise(uint8_t flags, float_status *status);
 | If `a' is denormal and we are in flush-to-zero mode then set the
 | input-denormal exception and return zero. Otherwise just return the value.
 *----------------------------------------------------------------------------*/
+float16 float16_squash_input_denormal(float16 a, float_status *status);
 float32 float32_squash_input_denormal(float32 a, float_status *status);
 float64 float64_squash_input_denormal(float64 a, float_status *status);
 
-- 
2.15.1

[Qemu-devel] [PATCH v4 02/22] include/fpu/softfloat: remove USE_SOFTFLOAT_STRUCT_TYPES

[Alex Bennée]

It's not actively built and when enabled things fail to compile. I'm
not sure the type-checking is really helping here. Seeing as we "own"
our softfloat now lets remove the cruft.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/fpu/softfloat.h | 27 ---------------------------
 1 file changed, 27 deletions(-)

diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index d5e99667b6..52af1412de 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -103,32 +103,6 @@ enum {
 /*----------------------------------------------------------------------------
 | Software IEC/IEEE floating-point types.
 *----------------------------------------------------------------------------*/
-/* Use structures for soft-float types.  This prevents accidentally mixing
-   them with native int/float types.  A sufficiently clever compiler and
-   sane ABI should be able to see though these structs.  However
-   x86/gcc 3.x seems to struggle a bit, so leave them disabled by default.  */
-//#define USE_SOFTFLOAT_STRUCT_TYPES
-#ifdef USE_SOFTFLOAT_STRUCT_TYPES
-typedef struct {
-    uint16_t v;
-} float16;
-#define float16_val(x) (((float16)(x)).v)
-#define make_float16(x) __extension__ ({ float16 f16_val = {x}; f16_val; })
-#define const_float16(x) { x }
-typedef struct {
-    uint32_t v;
-} float32;
-/* The cast ensures an error if the wrong type is passed.  */
-#define float32_val(x) (((float32)(x)).v)
-#define make_float32(x) __extension__ ({ float32 f32_val = {x}; f32_val; })
-#define const_float32(x) { x }
-typedef struct {
-    uint64_t v;
-} float64;
-#define float64_val(x) (((float64)(x)).v)
-#define make_float64(x) __extension__ ({ float64 f64_val = {x}; f64_val; })
-#define const_float64(x) { x }
-#else
 typedef uint16_t float16;
 typedef uint32_t float32;
 typedef uint64_t float64;
@@ -141,7 +115,6 @@ typedef uint64_t float64;
 #define const_float16(x) (x)
 #define const_float32(x) (x)
 #define const_float64(x) (x)
-#endif
 typedef struct {
     uint64_t low;
     uint16_t high;
-- 
2.15.1

[Qemu-devel] [PATCH v4 03/22] fpu/softfloat-types: new header to prevent excessive re-builds

[Alex Bennée]

The main culprit here is bswap.h which pulled in softfloat.h so it
could use the types in its CPU_Float* and ldfl/stfql functions. As
bswap.h is very widely included this added a compile dependency every
time we touch softfloat.h. Move the typedefs for each float type into
their own file so we don't re-build the world every time we tweak the
main softfloat.h header.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
v3
  - new in v3
---
 include/fpu/softfloat-types.h | 115 ++++++++++++++++++++++++++++++++++++++++++
 include/fpu/softfloat.h       |  31 +-----------
 include/qemu/bswap.h          |   2 +-
 3 files changed, 117 insertions(+), 31 deletions(-)
 create mode 100644 include/fpu/softfloat-types.h

diff --git a/include/fpu/softfloat-types.h b/include/fpu/softfloat-types.h
new file mode 100644
index 0000000000..8210a94ea1
--- /dev/null
+++ b/include/fpu/softfloat-types.h
@@ -0,0 +1,115 @@
+/*
+ * QEMU float support
+ *
+ * The code in this source file is derived from release 2a of the SoftFloat
+ * IEC/IEEE Floating-point Arithmetic Package. Those parts of the code (and
+ * some later contributions) are provided under that license, as detailed below.
+ * It has subsequently been modified by contributors to the QEMU Project,
+ * so some portions are provided under:
+ *  the SoftFloat-2a license
+ *  the BSD license
+ *  GPL-v2-or-later
+ *
+ * This header holds definitions for code that might be dealing with
+ * softfloat types but not need access to the actual library functions.
+ */
+/*
+===============================================================================
+This C header file is part of the SoftFloat IEC/IEEE Floating-point
+Arithmetic Package, Release 2a.
+
+Written by John R. Hauser.  This work was made possible in part by the
+International Computer Science Institute, located at Suite 600, 1947 Center
+Street, Berkeley, California 94704.  Funding was partially provided by the
+National Science Foundation under grant MIP-9311980.  The original version
+of this code was written as part of a project to build a fixed-point vector
+processor in collaboration with the University of California at Berkeley,
+overseen by Profs. Nelson Morgan and John Wawrzynek.  More information
+is available through the Web page `http://HTTP.CS.Berkeley.EDU/~jhauser/
+arithmetic/SoftFloat.html'.
+
+THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE.  Although reasonable effort
+has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT
+TIMES RESULT IN INCORRECT BEHAVIOR.  USE OF THIS SOFTWARE IS RESTRICTED TO
+PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY
+AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.
+
+Derivative works are acceptable, even for commercial purposes, so long as
+(1) they include prominent notice that the work is derivative, and (2) they
+include prominent notice akin to these four paragraphs for those parts of
+this code that are retained.
+
+===============================================================================
+*/
+
+/* BSD licensing:
+ * Copyright (c) 2006, Fabrice Bellard
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* Portions of this work are licensed under the terms of the GNU GPL,
+ * version 2 or later. See the COPYING file in the top-level directory.
+ */
+
+#ifndef SOFTFLOAT_TYPES_H
+#define SOFTFLOAT_TYPES_H
+
+/*
+ * Software IEC/IEEE floating-point types.
+ */
+
+typedef uint16_t float16;
+typedef uint32_t float32;
+typedef uint64_t float64;
+#define float16_val(x) (x)
+#define float32_val(x) (x)
+#define float64_val(x) (x)
+#define make_float16(x) (x)
+#define make_float32(x) (x)
+#define make_float64(x) (x)
+#define const_float16(x) (x)
+#define const_float32(x) (x)
+#define const_float64(x) (x)
+typedef struct {
+    uint64_t low;
+    uint16_t high;
+} floatx80;
+#define make_floatx80(exp, mant) ((floatx80) { mant, exp })
+#define make_floatx80_init(exp, mant) { .low = mant, .high = exp }
+typedef struct {
+#ifdef HOST_WORDS_BIGENDIAN
+    uint64_t high, low;
+#else
+    uint64_t low, high;
+#endif
+} float128;
+#define make_float128(high_, low_) ((float128) { .high = high_, .low = low_ })
+#define make_float128_init(high_, low_) { .high = high_, .low = low_ }
+
+#endif /* SOFTFLOAT_TYPES_H */
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 52af1412de..4e16e22e58 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -100,36 +100,7 @@ enum {
     float_relation_unordered =  2
 };
 
-/*----------------------------------------------------------------------------
-| Software IEC/IEEE floating-point types.
-*----------------------------------------------------------------------------*/
-typedef uint16_t float16;
-typedef uint32_t float32;
-typedef uint64_t float64;
-#define float16_val(x) (x)
-#define float32_val(x) (x)
-#define float64_val(x) (x)
-#define make_float16(x) (x)
-#define make_float32(x) (x)
-#define make_float64(x) (x)
-#define const_float16(x) (x)
-#define const_float32(x) (x)
-#define const_float64(x) (x)
-typedef struct {
-    uint64_t low;
-    uint16_t high;
-} floatx80;
-#define make_floatx80(exp, mant) ((floatx80) { mant, exp })
-#define make_floatx80_init(exp, mant) { .low = mant, .high = exp }
-typedef struct {
-#ifdef HOST_WORDS_BIGENDIAN
-    uint64_t high, low;
-#else
-    uint64_t low, high;
-#endif
-} float128;
-#define make_float128(high_, low_) ((float128) { .high = high_, .low = low_ })
-#define make_float128_init(high_, low_) { .high = high_, .low = low_ }
+#include "fpu/softfloat-types.h"
 
 /*----------------------------------------------------------------------------
 | Software IEC/IEEE floating-point underflow tininess-detection mode.
diff --git a/include/qemu/bswap.h b/include/qemu/bswap.h
index 09c78fd28a..3f28f661b1 100644
--- a/include/qemu/bswap.h
+++ b/include/qemu/bswap.h
@@ -1,7 +1,7 @@
 #ifndef BSWAP_H
 #define BSWAP_H
 
-#include "fpu/softfloat.h"
+#include "fpu/softfloat-types.h"
 
 #ifdef CONFIG_MACHINE_BSWAP_H
 # include <sys/endian.h>
-- 
2.15.1

[Qemu-devel] [PATCH v4 04/22] target/*/cpu.h: remove softfloat.h

[Alex Bennée]

As cpu.h is another typically widely included file which doesn't need
full access to the softfloat API we can remove the includes from here
as well. Where they do need types it's typically for float_status and
the rounding modes so we move that to softfloat-types.h as well.

As a result of not having softfloat in every cpu.h call we now need to
add it to various helpers that do need the full softfloat.h
definitions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[For PPC parts]
Acked-by: David Gibson <david@gibson.dropbear.id.au>
---
 include/fpu/softfloat-types.h   | 64 +++++++++++++++++++++++++++++++++++++++++
 include/fpu/softfloat.h         | 53 ----------------------------------
 target/alpha/cpu.h              |  2 --
 target/arm/cpu.c                |  1 +
 target/arm/cpu.h                |  2 --
 target/arm/helper-a64.c         |  1 +
 target/arm/helper.c             |  1 +
 target/arm/neon_helper.c        |  1 +
 target/hppa/cpu.c               |  1 +
 target/hppa/cpu.h               |  1 -
 target/hppa/op_helper.c         |  2 +-
 target/i386/cpu.h               |  4 ---
 target/i386/fpu_helper.c        |  1 +
 target/m68k/cpu.c               |  2 +-
 target/m68k/cpu.h               |  1 -
 target/m68k/fpu_helper.c        |  1 +
 target/m68k/helper.c            |  1 +
 target/m68k/translate.c         |  2 ++
 target/microblaze/cpu.c         |  1 +
 target/microblaze/cpu.h         |  2 +-
 target/microblaze/op_helper.c   |  1 +
 target/moxie/cpu.h              |  1 -
 target/nios2/cpu.h              |  1 -
 target/openrisc/cpu.h           |  1 -
 target/openrisc/fpu_helper.c    |  1 +
 target/ppc/cpu.h                |  1 -
 target/ppc/fpu_helper.c         |  1 +
 target/ppc/int_helper.c         |  1 +
 target/ppc/translate_init.c     |  1 +
 target/s390x/cpu.c              |  1 +
 target/s390x/cpu.h              |  2 --
 target/s390x/fpu_helper.c       |  1 +
 target/sh4/cpu.c                |  1 +
 target/sh4/cpu.h                |  2 --
 target/sh4/op_helper.c          |  1 +
 target/sparc/cpu.h              |  2 --
 target/sparc/fop_helper.c       |  1 +
 target/tricore/cpu.h            |  1 -
 target/tricore/fpu_helper.c     |  1 +
 target/tricore/helper.c         |  1 +
 target/unicore32/cpu.c          |  1 +
 target/unicore32/cpu.h          |  1 -
 target/unicore32/ucf64_helper.c |  1 +
 target/xtensa/cpu.h             |  1 -
 target/xtensa/op_helper.c       |  1 +
 45 files changed, 93 insertions(+), 79 deletions(-)

diff --git a/include/fpu/softfloat-types.h b/include/fpu/softfloat-types.h
index 8210a94ea1..4e378cb612 100644
--- a/include/fpu/softfloat-types.h
+++ b/include/fpu/softfloat-types.h
@@ -80,6 +80,12 @@ this code that are retained.
 #ifndef SOFTFLOAT_TYPES_H
 #define SOFTFLOAT_TYPES_H
 
+/* This 'flag' type must be able to hold at least 0 and 1. It should
+ * probably be replaced with 'bool' but the uses would need to be audited
+ * to check that they weren't accidentally relying on it being a larger type.
+ */
+typedef uint8_t flag;
+
 /*
  * Software IEC/IEEE floating-point types.
  */
@@ -112,4 +118,62 @@ typedef struct {
 #define make_float128(high_, low_) ((float128) { .high = high_, .low = low_ })
 #define make_float128_init(high_, low_) { .high = high_, .low = low_ }
 
+/*
+ * Software IEC/IEEE floating-point underflow tininess-detection mode.
+ */
+
+enum {
+    float_tininess_after_rounding  = 0,
+    float_tininess_before_rounding = 1
+};
+
+/*
+ *Software IEC/IEEE floating-point rounding mode.
+ */
+
+enum {
+    float_round_nearest_even = 0,
+    float_round_down         = 1,
+    float_round_up           = 2,
+    float_round_to_zero      = 3,
+    float_round_ties_away    = 4,
+    /* Not an IEEE rounding mode: round to the closest odd mantissa value */
+    float_round_to_odd       = 5,
+};
+
+/*
+ * Software IEC/IEEE floating-point exception flags.
+ */
+
+enum {
+    float_flag_invalid   =  1,
+    float_flag_divbyzero =  4,
+    float_flag_overflow  =  8,
+    float_flag_underflow = 16,
+    float_flag_inexact   = 32,
+    float_flag_input_denormal = 64,
+    float_flag_output_denormal = 128
+};
+
+
+/*
+ * Floating Point Status. Individual architectures may maintain
+ * several versions of float_status for different functions. The
+ * correct status for the operation is then passed by reference to
+ * most of the softfloat functions.
+ */
+
+typedef struct float_status {
+    signed char float_detect_tininess;
+    signed char float_rounding_mode;
+    uint8_t     float_exception_flags;
+    signed char floatx80_rounding_precision;
+    /* should denormalised results go to zero and set the inexact flag? */
+    flag flush_to_zero;
+    /* should denormalised inputs go to zero and set the input_denormal flag? */
+    flag flush_inputs_to_zero;
+    flag default_nan_mode;
+    flag snan_bit_is_one;
+} float_status;
+
 #endif /* SOFTFLOAT_TYPES_H */
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 4e16e22e58..f3b9008f78 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -82,12 +82,6 @@ this code that are retained.
 #ifndef SOFTFLOAT_H
 #define SOFTFLOAT_H
 
-/* This 'flag' type must be able to hold at least 0 and 1. It should
- * probably be replaced with 'bool' but the uses would need to be audited
- * to check that they weren't accidentally relying on it being a larger type.
- */
-typedef uint8_t flag;
-
 #define LIT64( a ) a##LL
 
 /*----------------------------------------------------------------------------
@@ -102,53 +96,6 @@ enum {
 
 #include "fpu/softfloat-types.h"
 
-/*----------------------------------------------------------------------------
-| Software IEC/IEEE floating-point underflow tininess-detection mode.
-*----------------------------------------------------------------------------*/
-enum {
-    float_tininess_after_rounding  = 0,
-    float_tininess_before_rounding = 1
-};
-
-/*----------------------------------------------------------------------------
-| Software IEC/IEEE floating-point rounding mode.
-*----------------------------------------------------------------------------*/
-enum {
-    float_round_nearest_even = 0,
-    float_round_down         = 1,
-    float_round_up           = 2,
-    float_round_to_zero      = 3,
-    float_round_ties_away    = 4,
-    /* Not an IEEE rounding mode: round to the closest odd mantissa value */
-    float_round_to_odd       = 5,
-};
-
-/*----------------------------------------------------------------------------
-| Software IEC/IEEE floating-point exception flags.
-*----------------------------------------------------------------------------*/
-enum {
-    float_flag_invalid   =  1,
-    float_flag_divbyzero =  4,
-    float_flag_overflow  =  8,
-    float_flag_underflow = 16,
-    float_flag_inexact   = 32,
-    float_flag_input_denormal = 64,
-    float_flag_output_denormal = 128
-};
-
-typedef struct float_status {
-    signed char float_detect_tininess;
-    signed char float_rounding_mode;
-    uint8_t     float_exception_flags;
-    signed char floatx80_rounding_precision;
-    /* should denormalised results go to zero and set the inexact flag? */
-    flag flush_to_zero;
-    /* should denormalised inputs go to zero and set the input_denormal flag? */
-    flag flush_inputs_to_zero;
-    flag default_nan_mode;
-    flag snan_bit_is_one;
-} float_status;
-
 static inline void set_float_detect_tininess(int val, float_status *status)
 {
     status->float_detect_tininess = val;
diff --git a/target/alpha/cpu.h b/target/alpha/cpu.h
index 09720c2f3b..a79fc2e780 100644
--- a/target/alpha/cpu.h
+++ b/target/alpha/cpu.h
@@ -33,8 +33,6 @@
 
 #include "exec/cpu-defs.h"
 
-#include "fpu/softfloat.h"
-
 #define ICACHE_LINE_SIZE 32
 #define DCACHE_LINE_SIZE 32
 
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 9da6ea505c..2d6ac054bd 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -34,6 +34,7 @@
 #include "sysemu/hw_accel.h"
 #include "kvm_arm.h"
 #include "disas/capstone.h"
+#include "fpu/softfloat.h"
 
 static void arm_cpu_set_pc(CPUState *cs, vaddr value)
 {
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index d2bb59eded..c7c922d79b 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -39,8 +39,6 @@
 #include "cpu-qom.h"
 #include "exec/cpu-defs.h"
 
-#include "fpu/softfloat.h"
-
 #define EXCP_UDEF            1   /* undefined instruction */
 #define EXCP_SWI             2   /* software interrupt */
 #define EXCP_PREFETCH_ABORT  3
diff --git a/target/arm/helper-a64.c b/target/arm/helper-a64.c
index 06fd321fae..10e08bdc1f 100644
--- a/target/arm/helper-a64.c
+++ b/target/arm/helper-a64.c
@@ -31,6 +31,7 @@
 #include "exec/cpu_ldst.h"
 #include "qemu/int128.h"
 #include "tcg.h"
+#include "fpu/softfloat.h"
 #include <zlib.h> /* For crc32 */
 
 /* C2.4.7 Multiply and divide */
diff --git a/target/arm/helper.c b/target/arm/helper.c
index bfce09643b..4ef99882c4 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -15,6 +15,7 @@
 #include <zlib.h> /* For crc32 */
 #include "exec/semihost.h"
 #include "sysemu/kvm.h"
+#include "fpu/softfloat.h"
 
 #define ARM_CPU_FREQ 1000000000 /* FIXME: 1 GHz, should be configurable */
 
diff --git a/target/arm/neon_helper.c b/target/arm/neon_helper.c
index 689491cad3..a1ec6537eb 100644
--- a/target/arm/neon_helper.c
+++ b/target/arm/neon_helper.c
@@ -11,6 +11,7 @@
 #include "cpu.h"
 #include "exec/exec-all.h"
 #include "exec/helper-proto.h"
+#include "fpu/softfloat.h"
 
 #define SIGNBIT (uint32_t)0x80000000
 #define SIGNBIT64 ((uint64_t)1 << 63)
diff --git a/target/hppa/cpu.c b/target/hppa/cpu.c
index 5213347720..9224331165 100644
--- a/target/hppa/cpu.c
+++ b/target/hppa/cpu.c
@@ -23,6 +23,7 @@
 #include "cpu.h"
 #include "qemu-common.h"
 #include "exec/exec-all.h"
+#include "fpu/softfloat.h"
 
 
 static void hppa_cpu_set_pc(CPUState *cs, vaddr value)
diff --git a/target/hppa/cpu.h b/target/hppa/cpu.h
index 7640c81221..c88d844938 100644
--- a/target/hppa/cpu.h
+++ b/target/hppa/cpu.h
@@ -51,7 +51,6 @@
 #define CPUArchState struct CPUHPPAState
 
 #include "exec/cpu-defs.h"
-#include "fpu/softfloat.h"
 
 #define TARGET_PAGE_BITS 12
 
diff --git a/target/hppa/op_helper.c b/target/hppa/op_helper.c
index 4ee936bf86..a3af62daf7 100644
--- a/target/hppa/op_helper.c
+++ b/target/hppa/op_helper.c
@@ -24,7 +24,7 @@
 #include "exec/cpu_ldst.h"
 #include "sysemu/sysemu.h"
 #include "qemu/timer.h"
-
+#include "fpu/softfloat.h"
 
 void QEMU_NORETURN HELPER(excp)(CPUHPPAState *env, int excp)
 {
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index f91e37d25d..faf39ec1ce 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -52,10 +52,6 @@
 
 #define CPUArchState struct CPUX86State
 
-#ifdef CONFIG_TCG
-#include "fpu/softfloat.h"
-#endif
-
 enum {
     R_EAX = 0,
     R_ECX = 1,
diff --git a/target/i386/fpu_helper.c b/target/i386/fpu_helper.c
index 9014b6f88a..ea5a0c4861 100644
--- a/target/i386/fpu_helper.c
+++ b/target/i386/fpu_helper.c
@@ -24,6 +24,7 @@
 #include "qemu/host-utils.h"
 #include "exec/exec-all.h"
 #include "exec/cpu_ldst.h"
+#include "fpu/softfloat.h"
 
 #define FPU_RC_MASK         0xc00
 #define FPU_RC_NEAR         0x000
diff --git a/target/m68k/cpu.c b/target/m68k/cpu.c
index 98919b358b..cbd5f08ce8 100644
--- a/target/m68k/cpu.c
+++ b/target/m68k/cpu.c
@@ -24,7 +24,7 @@
 #include "qemu-common.h"
 #include "migration/vmstate.h"
 #include "exec/exec-all.h"
-
+#include "fpu/softfloat.h"
 
 static void m68k_cpu_set_pc(CPUState *cs, vaddr value)
 {
diff --git a/target/m68k/cpu.h b/target/m68k/cpu.h
index 627fb787b6..e250dc5278 100644
--- a/target/m68k/cpu.h
+++ b/target/m68k/cpu.h
@@ -28,7 +28,6 @@
 #include "qemu-common.h"
 #include "exec/cpu-defs.h"
 #include "cpu-qom.h"
-#include "fpu/softfloat.h"
 
 #define OS_BYTE     0
 #define OS_WORD     1
diff --git a/target/m68k/fpu_helper.c b/target/m68k/fpu_helper.c
index 665e7609af..3c5a82aaa0 100644
--- a/target/m68k/fpu_helper.c
+++ b/target/m68k/fpu_helper.c
@@ -23,6 +23,7 @@
 #include "exec/helper-proto.h"
 #include "exec/exec-all.h"
 #include "exec/cpu_ldst.h"
+#include "fpu/softfloat.h"
 
 /* Undefined offsets may be different on various FPU.
  * On 68040 they return 0.0 (floatx80_zero)
diff --git a/target/m68k/helper.c b/target/m68k/helper.c
index 20155c7801..917d46efcc 100644
--- a/target/m68k/helper.c
+++ b/target/m68k/helper.c
@@ -24,6 +24,7 @@
 #include "exec/gdbstub.h"
 
 #include "exec/helper-proto.h"
+#include "fpu/softfloat.h"
 
 #define SIGNBIT (1u << 31)
 
diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index 34db97b8a0..bbbc3d8a0e 100644
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -32,6 +32,8 @@
 
 #include "trace-tcg.h"
 #include "exec/log.h"
+#include "fpu/softfloat.h"
+
 
 //#define DEBUG_DISPATCH 1
 
diff --git a/target/microblaze/cpu.c b/target/microblaze/cpu.c
index 5700652e06..393520f3ef 100644
--- a/target/microblaze/cpu.c
+++ b/target/microblaze/cpu.c
@@ -28,6 +28,7 @@
 #include "hw/qdev-properties.h"
 #include "migration/vmstate.h"
 #include "exec/exec-all.h"
+#include "fpu/softfloat.h"
 
 static const struct {
     const char *name;
diff --git a/target/microblaze/cpu.h b/target/microblaze/cpu.h
index f3e7405a62..1fe21c8539 100644
--- a/target/microblaze/cpu.h
+++ b/target/microblaze/cpu.h
@@ -28,7 +28,7 @@
 #define CPUArchState struct CPUMBState
 
 #include "exec/cpu-defs.h"
-#include "fpu/softfloat.h"
+#include "fpu/softfloat-types.h"
 struct CPUMBState;
 typedef struct CPUMBState CPUMBState;
 #if !defined(CONFIG_USER_ONLY)
diff --git a/target/microblaze/op_helper.c b/target/microblaze/op_helper.c
index 869072a2d1..1b4fe796e7 100644
--- a/target/microblaze/op_helper.c
+++ b/target/microblaze/op_helper.c
@@ -24,6 +24,7 @@
 #include "qemu/host-utils.h"
 #include "exec/exec-all.h"
 #include "exec/cpu_ldst.h"
+#include "fpu/softfloat.h"
 
 #define D(x)
 
diff --git a/target/moxie/cpu.h b/target/moxie/cpu.h
index a01f480821..d85e1fc061 100644
--- a/target/moxie/cpu.h
+++ b/target/moxie/cpu.h
@@ -34,7 +34,6 @@
 #define MOXIE_EX_BREAK      16
 
 #include "exec/cpu-defs.h"
-#include "fpu/softfloat.h"
 
 #define TARGET_PAGE_BITS 12     /* 4k */
 
diff --git a/target/nios2/cpu.h b/target/nios2/cpu.h
index 204b39add7..cd4e40d1b4 100644
--- a/target/nios2/cpu.h
+++ b/target/nios2/cpu.h
@@ -27,7 +27,6 @@
 #define CPUArchState struct CPUNios2State
 
 #include "exec/cpu-defs.h"
-#include "fpu/softfloat.h"
 #include "qom/cpu.h"
 struct CPUNios2State;
 typedef struct CPUNios2State CPUNios2State;
diff --git a/target/openrisc/cpu.h b/target/openrisc/cpu.h
index fb46cc9986..5050b1135c 100644
--- a/target/openrisc/cpu.h
+++ b/target/openrisc/cpu.h
@@ -29,7 +29,6 @@ struct OpenRISCCPU;
 
 #include "qemu-common.h"
 #include "exec/cpu-defs.h"
-#include "fpu/softfloat.h"
 #include "qom/cpu.h"
 
 #define TYPE_OPENRISC_CPU "or1k-cpu"
diff --git a/target/openrisc/fpu_helper.c b/target/openrisc/fpu_helper.c
index 1375cea948..977a1e8e55 100644
--- a/target/openrisc/fpu_helper.c
+++ b/target/openrisc/fpu_helper.c
@@ -22,6 +22,7 @@
 #include "cpu.h"
 #include "exec/helper-proto.h"
 #include "exception.h"
+#include "fpu/softfloat.h"
 
 static inline uint32_t ieee_ex_to_openrisc(OpenRISCCPU *cpu, int fexcp)
 {
diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index 9f8cbbe7aa..7bde1884a1 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -79,7 +79,6 @@
 
 #include "exec/cpu-defs.h"
 #include "cpu-qom.h"
-#include "fpu/softfloat.h"
 
 #if defined (TARGET_PPC64)
 #define PPC_ELF_MACHINE     EM_PPC64
diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c
index c4dab159e4..9ae418a577 100644
--- a/target/ppc/fpu_helper.c
+++ b/target/ppc/fpu_helper.c
@@ -21,6 +21,7 @@
 #include "exec/helper-proto.h"
 #include "exec/exec-all.h"
 #include "internal.h"
+#include "fpu/softfloat.h"
 
 static inline float128 float128_snan_to_qnan(float128 x)
 {
diff --git a/target/ppc/int_helper.c b/target/ppc/int_helper.c
index 3a50f1e1b7..35bdf09773 100644
--- a/target/ppc/int_helper.c
+++ b/target/ppc/int_helper.c
@@ -23,6 +23,7 @@
 #include "qemu/host-utils.h"
 #include "exec/helper-proto.h"
 #include "crypto/aes.h"
+#include "fpu/softfloat.h"
 
 #include "helper_regs.h"
 /*****************************************************************************/
diff --git a/target/ppc/translate_init.c b/target/ppc/translate_init.c
index 55c99c97e3..54ec2e122a 100644
--- a/target/ppc/translate_init.c
+++ b/target/ppc/translate_init.c
@@ -36,6 +36,7 @@
 #include "sysemu/qtest.h"
 #include "qemu/cutils.h"
 #include "disas/capstone.h"
+#include "fpu/softfloat.h"
 
 //#define PPC_DUMP_CPU
 //#define PPC_DEBUG_SPR
diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
index d2e6b9f5c7..7acb827f1b 100644
--- a/target/s390x/cpu.c
+++ b/target/s390x/cpu.c
@@ -42,6 +42,7 @@
 #include "sysemu/arch_init.h"
 #include "sysemu/sysemu.h"
 #endif
+#include "fpu/softfloat.h"
 
 #define CR0_RESET       0xE0UL
 #define CR14_RESET      0xC2000000UL;
diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index a1123ad621..96264ad4cb 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -41,8 +41,6 @@
 
 #include "exec/cpu-all.h"
 
-#include "fpu/softfloat.h"
-
 #define NB_MMU_MODES 4
 #define TARGET_INSN_START_EXTRA_WORDS 1
 
diff --git a/target/s390x/fpu_helper.c b/target/s390x/fpu_helper.c
index 334159119f..43f8bf1c94 100644
--- a/target/s390x/fpu_helper.c
+++ b/target/s390x/fpu_helper.c
@@ -24,6 +24,7 @@
 #include "exec/exec-all.h"
 #include "exec/cpu_ldst.h"
 #include "exec/helper-proto.h"
+#include "fpu/softfloat.h"
 
 /* #define DEBUG_HELPER */
 #ifdef DEBUG_HELPER
diff --git a/target/sh4/cpu.c b/target/sh4/cpu.c
index e0b99fbc89..4f8c830fe3 100644
--- a/target/sh4/cpu.c
+++ b/target/sh4/cpu.c
@@ -25,6 +25,7 @@
 #include "qemu-common.h"
 #include "migration/vmstate.h"
 #include "exec/exec-all.h"
+#include "fpu/softfloat.h"
 
 
 static void superh_cpu_set_pc(CPUState *cs, vaddr value)
diff --git a/target/sh4/cpu.h b/target/sh4/cpu.h
index 52a4568dd5..a649b68d78 100644
--- a/target/sh4/cpu.h
+++ b/target/sh4/cpu.h
@@ -40,8 +40,6 @@
 
 #include "exec/cpu-defs.h"
 
-#include "fpu/softfloat.h"
-
 #define TARGET_PAGE_BITS 12	/* 4k XXXXX */
 
 #define TARGET_PHYS_ADDR_SPACE_BITS 32
diff --git a/target/sh4/op_helper.c b/target/sh4/op_helper.c
index 4b8bbf63b4..4f825bae5a 100644
--- a/target/sh4/op_helper.c
+++ b/target/sh4/op_helper.c
@@ -21,6 +21,7 @@
 #include "exec/helper-proto.h"
 #include "exec/exec-all.h"
 #include "exec/cpu_ldst.h"
+#include "fpu/softfloat.h"
 
 #ifndef CONFIG_USER_ONLY
 
diff --git a/target/sparc/cpu.h b/target/sparc/cpu.h
index 3eaffb354e..9724134a5b 100644
--- a/target/sparc/cpu.h
+++ b/target/sparc/cpu.h
@@ -29,8 +29,6 @@
 
 #include "exec/cpu-defs.h"
 
-#include "fpu/softfloat.h"
-
 /*#define EXCP_INTERRUPT 0x100*/
 
 /* trap definitions */
diff --git a/target/sparc/fop_helper.c b/target/sparc/fop_helper.c
index c7fb176e4c..b6642fd1d7 100644
--- a/target/sparc/fop_helper.c
+++ b/target/sparc/fop_helper.c
@@ -21,6 +21,7 @@
 #include "cpu.h"
 #include "exec/exec-all.h"
 #include "exec/helper-proto.h"
+#include "fpu/softfloat.h"
 
 #define QT0 (env->qt0)
 #define QT1 (env->qt1)
diff --git a/target/tricore/cpu.h b/target/tricore/cpu.h
index f41d2ceb69..e7dfe4bcc6 100644
--- a/target/tricore/cpu.h
+++ b/target/tricore/cpu.h
@@ -24,7 +24,6 @@
 #include "qemu-common.h"
 #include "cpu-qom.h"
 #include "exec/cpu-defs.h"
-#include "fpu/softfloat.h"
 
 #define CPUArchState struct CPUTriCoreState
 
diff --git a/target/tricore/fpu_helper.c b/target/tricore/fpu_helper.c
index 7979bb6692..df162902d6 100644
--- a/target/tricore/fpu_helper.c
+++ b/target/tricore/fpu_helper.c
@@ -20,6 +20,7 @@
 #include "qemu/osdep.h"
 #include "cpu.h"
 #include "exec/helper-proto.h"
+#include "fpu/softfloat.h"
 
 #define QUIET_NAN 0x7fc00000
 #define ADD_NAN   0x7fc00001
diff --git a/target/tricore/helper.c b/target/tricore/helper.c
index 378c2a4a76..45276d3782 100644
--- a/target/tricore/helper.c
+++ b/target/tricore/helper.c
@@ -19,6 +19,7 @@
 
 #include "cpu.h"
 #include "exec/exec-all.h"
+#include "fpu/softfloat.h"
 
 enum {
     TLBRET_DIRTY = -4,
diff --git a/target/unicore32/cpu.c b/target/unicore32/cpu.c
index 17dc1504d7..93cbae39d9 100644
--- a/target/unicore32/cpu.c
+++ b/target/unicore32/cpu.c
@@ -18,6 +18,7 @@
 #include "qemu-common.h"
 #include "migration/vmstate.h"
 #include "exec/exec-all.h"
+#include "fpu/softfloat.h"
 
 static void uc32_cpu_set_pc(CPUState *cs, vaddr value)
 {
diff --git a/target/unicore32/cpu.h b/target/unicore32/cpu.h
index a3cc71416d..42e1d52478 100644
--- a/target/unicore32/cpu.h
+++ b/target/unicore32/cpu.h
@@ -23,7 +23,6 @@
 #include "qemu-common.h"
 #include "cpu-qom.h"
 #include "exec/cpu-defs.h"
-#include "fpu/softfloat.h"
 
 #define NB_MMU_MODES            2
 
diff --git a/target/unicore32/ucf64_helper.c b/target/unicore32/ucf64_helper.c
index 6c919010c3..fad3fa6618 100644
--- a/target/unicore32/ucf64_helper.c
+++ b/target/unicore32/ucf64_helper.c
@@ -11,6 +11,7 @@
 #include "qemu/osdep.h"
 #include "cpu.h"
 #include "exec/helper-proto.h"
+#include "fpu/softfloat.h"
 
 /*
  * The convention used for UniCore-F64 instructions:
diff --git a/target/xtensa/cpu.h b/target/xtensa/cpu.h
index f300c02c07..49c2e3cf9a 100644
--- a/target/xtensa/cpu.h
+++ b/target/xtensa/cpu.h
@@ -36,7 +36,6 @@
 #include "qemu-common.h"
 #include "cpu-qom.h"
 #include "exec/cpu-defs.h"
-#include "fpu/softfloat.h"
 #include "xtensa-isa.h"
 
 #define NB_MMU_MODES 4
diff --git a/target/xtensa/op_helper.c b/target/xtensa/op_helper.c
index 43182b113e..7486b99799 100644
--- a/target/xtensa/op_helper.c
+++ b/target/xtensa/op_helper.c
@@ -34,6 +34,7 @@
 #include "exec/cpu_ldst.h"
 #include "exec/address-spaces.h"
 #include "qemu/timer.h"
+#include "fpu/softfloat.h"
 
 void xtensa_cpu_do_unaligned_access(CPUState *cs,
         vaddr addr, MMUAccessType access_type,
-- 
2.15.1

[Qemu-devel] [PATCH v4 05/22] include/fpu/softfloat: implement float16_abs helper

[Alex Bennée]

This will be required when expanding the MINMAX() macro for 16
bit/half-precision operations.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/fpu/softfloat.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index f3b9008f78..1d34f2c3eb 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -265,6 +265,13 @@ static inline int float16_is_zero_or_denormal(float16 a)
     return (float16_val(a) & 0x7c00) == 0;
 }
 
+static inline float16 float16_abs(float16 a)
+{
+    /* Note that abs does *not* handle NaN specially, nor does
+     * it flush denormal inputs to zero.
+     */
+    return make_float16(float16_val(a) & 0x7fff);
+}
 /*----------------------------------------------------------------------------
 | The pattern for a default generated half-precision NaN.
 *----------------------------------------------------------------------------*/
-- 
2.15.1

[Qemu-devel] [PATCH v4 06/22] include/fpu/softfloat: implement float16_chs helper

[Alex Bennée]

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/fpu/softfloat.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 1d34f2c3eb..f75aa59100 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -272,6 +272,15 @@ static inline float16 float16_abs(float16 a)
      */
     return make_float16(float16_val(a) & 0x7fff);
 }
+
+static inline float16 float16_chs(float16 a)
+{
+    /* Note that chs does *not* handle NaN specially, nor does
+     * it flush denormal inputs to zero.
+     */
+    return make_float16(float16_val(a) ^ 0x8000);
+}
+
 /*----------------------------------------------------------------------------
 | The pattern for a default generated half-precision NaN.
 *----------------------------------------------------------------------------*/
-- 
2.15.1

[Qemu-devel] [PATCH v4 07/22] include/fpu/softfloat: implement float16_set_sign helper

[Alex Bennée]

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/fpu/softfloat.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index f75aa59100..59c06ef192 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -281,6 +281,11 @@ static inline float16 float16_chs(float16 a)
     return make_float16(float16_val(a) ^ 0x8000);
 }
 
+static inline float16 float16_set_sign(float16 a, int sign)
+{
+    return make_float16((float16_val(a) & 0x7fff) | (sign << 15));
+}
+
 /*----------------------------------------------------------------------------
 | The pattern for a default generated half-precision NaN.
 *----------------------------------------------------------------------------*/
-- 
2.15.1

[Qemu-devel] [PATCH v4 08/22] include/fpu/softfloat: add some float16 constants

[Alex Bennée]

This defines the same set of common constants for float 16 as defined
for 32 and 64 bit floats. These are often used by target helper
functions. I've also removed constants that are not used by anybody.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

---
v2
  - fixup constants, remove unused onces
---
 include/fpu/softfloat.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 59c06ef192..23824a3000 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -286,6 +286,11 @@ static inline float16 float16_set_sign(float16 a, int sign)
     return make_float16((float16_val(a) & 0x7fff) | (sign << 15));
 }
 
+#define float16_zero make_float16(0)
+#define float16_one make_float16(0x3c00)
+#define float16_half make_float16(0x3800)
+#define float16_infinity make_float16(0x7c00)
+
 /*----------------------------------------------------------------------------
 | The pattern for a default generated half-precision NaN.
 *----------------------------------------------------------------------------*/
@@ -392,8 +397,6 @@ static inline float32 float32_set_sign(float32 a, int sign)
 
 #define float32_zero make_float32(0)
 #define float32_one make_float32(0x3f800000)
-#define float32_ln2 make_float32(0x3f317218)
-#define float32_pi make_float32(0x40490fdb)
 #define float32_half make_float32(0x3f000000)
 #define float32_infinity make_float32(0x7f800000)
 
@@ -506,7 +509,6 @@ static inline float64 float64_set_sign(float64 a, int sign)
 #define float64_zero make_float64(0)
 #define float64_one make_float64(0x3ff0000000000000LL)
 #define float64_ln2 make_float64(0x3fe62e42fefa39efLL)
-#define float64_pi make_float64(0x400921fb54442d18LL)
 #define float64_half make_float64(0x3fe0000000000000LL)
 #define float64_infinity make_float64(0x7ff0000000000000LL)
 
-- 
2.15.1

[Qemu-devel] [PATCH v4 09/22] fpu/softfloat: improve comments on ARM NaN propagation

[Alex Bennée]

Mention the pseudo-code fragment from which this is based.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 fpu/softfloat-specialize.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h
index de2c5d5702..4be0fb21ba 100644
--- a/fpu/softfloat-specialize.h
+++ b/fpu/softfloat-specialize.h
@@ -445,9 +445,10 @@ static float32 commonNaNToFloat32(commonNaNT a, float_status *status)
 
 #if defined(TARGET_ARM)
 static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
-                    flag aIsLargerSignificand)
+                   flag aIsLargerSignificand)
 {
-    /* ARM mandated NaN propagation rules: take the first of:
+    /* ARM mandated NaN propagation rules (see FPProcessNaNs()), take
+     * the first of:
      *  1. A if it is signaling
      *  2. B if it is signaling
      *  3. A (quiet)
-- 
2.15.1

[Qemu-devel] [PATCH v4 10/22] fpu/softfloat: move the extract functions to the top of the file

[Alex Bennée]

This is pure code-motion during re-factoring as the helpers will be
needed earlier.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
v2
  - fix minor white space nit
---
 fpu/softfloat.c | 120 +++++++++++++++++++++++++-------------------------------
 1 file changed, 54 insertions(+), 66 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 3a4ab1355f..297e48f5c9 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -132,6 +132,60 @@ static inline flag extractFloat16Sign(float16 a)
     return float16_val(a)>>15;
 }
 
+/*----------------------------------------------------------------------------
+| Returns the fraction bits of the single-precision floating-point value `a'.
+*----------------------------------------------------------------------------*/
+
+static inline uint32_t extractFloat32Frac(float32 a)
+{
+    return float32_val(a) & 0x007FFFFF;
+}
+
+/*----------------------------------------------------------------------------
+| Returns the exponent bits of the single-precision floating-point value `a'.
+*----------------------------------------------------------------------------*/
+
+static inline int extractFloat32Exp(float32 a)
+{
+    return (float32_val(a) >> 23) & 0xFF;
+}
+
+/*----------------------------------------------------------------------------
+| Returns the sign bit of the single-precision floating-point value `a'.
+*----------------------------------------------------------------------------*/
+
+static inline flag extractFloat32Sign(float32 a)
+{
+    return float32_val(a) >> 31;
+}
+
+/*----------------------------------------------------------------------------
+| Returns the fraction bits of the double-precision floating-point value `a'.
+*----------------------------------------------------------------------------*/
+
+static inline uint64_t extractFloat64Frac(float64 a)
+{
+    return float64_val(a) & LIT64(0x000FFFFFFFFFFFFF);
+}
+
+/*----------------------------------------------------------------------------
+| Returns the exponent bits of the double-precision floating-point value `a'.
+*----------------------------------------------------------------------------*/
+
+static inline int extractFloat64Exp(float64 a)
+{
+    return (float64_val(a) >> 52) & 0x7FF;
+}
+
+/*----------------------------------------------------------------------------
+| Returns the sign bit of the double-precision floating-point value `a'.
+*----------------------------------------------------------------------------*/
+
+static inline flag extractFloat64Sign(float64 a)
+{
+    return float64_val(a) >> 63;
+}
+
 /*----------------------------------------------------------------------------
 | Takes a 64-bit fixed-point value `absZ' with binary point between bits 6
 | and 7, and returns the properly rounded 32-bit integer corresponding to the
@@ -299,39 +353,6 @@ static int64_t roundAndPackUint64(flag zSign, uint64_t absZ0,
     return absZ0;
 }
 
-/*----------------------------------------------------------------------------
-| Returns the fraction bits of the single-precision floating-point value `a'.
-*----------------------------------------------------------------------------*/
-
-static inline uint32_t extractFloat32Frac( float32 a )
-{
-
-    return float32_val(a) & 0x007FFFFF;
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the exponent bits of the single-precision floating-point value `a'.
-*----------------------------------------------------------------------------*/
-
-static inline int extractFloat32Exp(float32 a)
-{
-
-    return ( float32_val(a)>>23 ) & 0xFF;
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the sign bit of the single-precision floating-point value `a'.
-*----------------------------------------------------------------------------*/
-
-static inline flag extractFloat32Sign( float32 a )
-{
-
-    return float32_val(a)>>31;
-
-}
-
 /*----------------------------------------------------------------------------
 | If `a' is denormal and we are in flush-to-zero mode then set the
 | input-denormal exception and return zero. Otherwise just return the value.
@@ -492,39 +513,6 @@ static float32
 
 }
 
-/*----------------------------------------------------------------------------
-| Returns the fraction bits of the double-precision floating-point value `a'.
-*----------------------------------------------------------------------------*/
-
-static inline uint64_t extractFloat64Frac( float64 a )
-{
-
-    return float64_val(a) & LIT64( 0x000FFFFFFFFFFFFF );
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the exponent bits of the double-precision floating-point value `a'.
-*----------------------------------------------------------------------------*/
-
-static inline int extractFloat64Exp(float64 a)
-{
-
-    return ( float64_val(a)>>52 ) & 0x7FF;
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the sign bit of the double-precision floating-point value `a'.
-*----------------------------------------------------------------------------*/
-
-static inline flag extractFloat64Sign( float64 a )
-{
-
-    return float64_val(a)>>63;
-
-}
-
 /*----------------------------------------------------------------------------
 | If `a' is denormal and we are in flush-to-zero mode then set the
 | input-denormal exception and return zero. Otherwise just return the value.
-- 
2.15.1

[Qemu-devel] [PATCH v4 11/22] fpu/softfloat: define decompose structures

[Alex Bennée]

These structures pave the way for generic softfloat helper routines
that will operate on fully decomposed numbers.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

---
v3
 - comment box style
 - CamelCase structs
 - hide DECOMPOSED_BINARY_POINT - frac in macro
 - more comments
 - add exp_size, frac_size to FloatFmt
 - compute exp_bias and exp_max from FLOAT_PARAMS
 - remove include bitops (in next patch)
---
 fpu/softfloat.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 85 insertions(+), 1 deletion(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 297e48f5c9..568d555595 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -83,7 +83,6 @@ this code that are retained.
  * target-dependent and needs the TARGET_* macros.
  */
 #include "qemu/osdep.h"
-
 #include "fpu/softfloat.h"
 
 /* We only need stdlib for abort() */
@@ -186,6 +185,91 @@ static inline flag extractFloat64Sign(float64 a)
     return float64_val(a) >> 63;
 }
 
+/*
+ * Classify a floating point number. Everything above float_class_qnan
+ * is a NaN so cls >= float_class_qnan is any NaN.
+ */
+
+typedef enum __attribute__ ((__packed__)) {
+    float_class_unclassified,
+    float_class_zero,
+    float_class_normal,
+    float_class_inf,
+    float_class_qnan,  /* all NaNs from here */
+    float_class_snan,
+    float_class_dnan,
+    float_class_msnan, /* maybe silenced */
+} FloatClass;
+
+/*
+ * Structure holding all of the decomposed parts of a float. The
+ * exponent is unbiased and the fraction is normalized. All
+ * calculations are done with a 64 bit fraction and then rounded as
+ * appropriate for the final format.
+ *
+ * Thanks to the packed FloatClass a decent compiler should be able to
+ * fit the whole structure into registers and avoid using the stack
+ * for parameter passing.
+ */
+
+typedef struct {
+    uint64_t frac;
+    int32_t  exp;
+    FloatClass cls;
+    bool sign;
+} FloatParts;
+
+#define DECOMPOSED_BINARY_POINT    (64 - 2)
+#define DECOMPOSED_IMPLICIT_BIT    (1ull << DECOMPOSED_BINARY_POINT)
+#define DECOMPOSED_OVERFLOW_BIT    (DECOMPOSED_IMPLICIT_BIT << 1)
+
+/* Structure holding all of the relevant parameters for a format.
+ *   exp_size: the size of the exponent field
+ *   exp_bias: the offset applied to the exponent field
+ *   exp_max: the maximum normalised exponent
+ *   frac_size: the size of the fraction field
+ *   frac_shift: shift to normalise the fraction with DECOMPOSED_BINARY_POINT
+ * The following are computed based the size of fraction
+ *   frac_lsb: least significant bit of fraction
+ *   fram_lsbm1: the bit bellow the least significant bit (for rounding)
+ *   round_mask/roundeven_mask: masks used for rounding
+ */
+typedef struct {
+    int exp_size;
+    int exp_bias;
+    int exp_max;
+    int frac_size;
+    int frac_shift;
+    uint64_t frac_lsb;
+    uint64_t frac_lsbm1;
+    uint64_t round_mask;
+    uint64_t roundeven_mask;
+} FloatFmt;
+
+/* Expand fields based on the size of exponent and fraction */
+#define FLOAT_PARAMS(E, F)                                           \
+    .exp_size       = E,                                             \
+    .exp_bias       = ((1 << E) - 1) >> 1,                           \
+    .exp_max        = (1 << E) - 1,                                  \
+    .frac_size      = F,                                             \
+    .frac_shift     = DECOMPOSED_BINARY_POINT - F,                   \
+    .frac_lsb       = 1ull << (DECOMPOSED_BINARY_POINT - F),         \
+    .frac_lsbm1     = 1ull << ((DECOMPOSED_BINARY_POINT - F) - 1),   \
+    .round_mask     = (1ull << (DECOMPOSED_BINARY_POINT - F)) - 1,   \
+    .roundeven_mask = (2ull << (DECOMPOSED_BINARY_POINT - F)) - 1
+
+static const FloatFmt float16_params = {
+    FLOAT_PARAMS(5, 10)
+};
+
+static const FloatFmt float32_params = {
+    FLOAT_PARAMS(8, 23)
+};
+
+static const FloatFmt float64_params = {
+    FLOAT_PARAMS(11, 52)
+};
+
 /*----------------------------------------------------------------------------
 | Takes a 64-bit fixed-point value `absZ' with binary point between bits 6
 | and 7, and returns the properly rounded 32-bit integer corresponding to the
-- 
2.15.1

[Qemu-devel] [PATCH v4 12/22] fpu/softfloat: re-factor add/sub

[Alex Bennée]

We can now add float16_add/sub and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 add and sub functions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---

v3
 - renames for FloatParts
 - shorten internal names
 - fix comment style
 - use FloatFmt values for for extract/deposit in raw_pack/unpack
 - move #include bitops from previous patch
 - add is_nan helper
 - avoid temp variables where we can
v4
 - fewer lines for pack_raw
 - is_nan/is_snan/is_qnan with unlikey() annotation for is_nan
 - pick_nan_parts -> pick_nan
 - __attribute__((flatten)) for public facing functions
---
 fpu/softfloat.c         | 892 +++++++++++++++++++++++++-----------------------
 include/fpu/softfloat.h |   4 +
 2 files changed, 469 insertions(+), 427 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 568d555595..2190e7de56 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -83,6 +83,7 @@ this code that are retained.
  * target-dependent and needs the TARGET_* macros.
  */
 #include "qemu/osdep.h"
+#include "qemu/bitops.h"
 #include "fpu/softfloat.h"
 
 /* We only need stdlib for abort() */
@@ -270,6 +271,470 @@ static const FloatFmt float64_params = {
     FLOAT_PARAMS(11, 52)
 };
 
+/* Unpack a float to parts, but do not canonicalize.  */
+static inline FloatParts unpack_raw(FloatFmt fmt, uint64_t raw)
+{
+    const int sign_pos = fmt.frac_size + fmt.exp_size;
+
+    return (FloatParts) {
+        .cls = float_class_unclassified,
+        .sign = extract64(raw, sign_pos, 1),
+        .exp = extract64(raw, fmt.frac_size, fmt.exp_size),
+        .frac = extract64(raw, 0, fmt.frac_size),
+    };
+}
+
+static inline FloatParts float16_unpack_raw(float16 f)
+{
+    return unpack_raw(float16_params, f);
+}
+
+static inline FloatParts float32_unpack_raw(float32 f)
+{
+    return unpack_raw(float32_params, f);
+}
+
+static inline FloatParts float64_unpack_raw(float64 f)
+{
+    return unpack_raw(float64_params, f);
+}
+
+/* Pack a float from parts, but do not canonicalize.  */
+static inline uint64_t pack_raw(FloatFmt fmt, FloatParts p)
+{
+    const int sign_pos = fmt.frac_size + fmt.exp_size;
+    uint64_t ret = deposit64(p.frac, fmt.frac_size, fmt.exp_size, p.exp);
+    return deposit64(ret, sign_pos, 1, p.sign);
+}
+
+static inline float16 float16_pack_raw(FloatParts p)
+{
+    return make_float16(pack_raw(float16_params, p));
+}
+
+static inline float32 float32_pack_raw(FloatParts p)
+{
+    return make_float32(pack_raw(float32_params, p));
+}
+
+static inline float64 float64_pack_raw(FloatParts p)
+{
+    return make_float64(pack_raw(float64_params, p));
+}
+
+/* Canonicalize EXP and FRAC, setting CLS.  */
+static FloatParts canonicalize(FloatParts part, const FloatFmt *parm,
+                               float_status *status)
+{
+    if (part.exp == parm->exp_max) {
+        if (part.frac == 0) {
+            part.cls = float_class_inf;
+        } else {
+#ifdef NO_SIGNALING_NANS
+            part.cls = float_class_qnan;
+#else
+            int64_t msb = part.frac << (parm->frac_shift + 2);
+            if ((msb < 0) == status->snan_bit_is_one) {
+                part.cls = float_class_snan;
+            } else {
+                part.cls = float_class_qnan;
+            }
+#endif
+        }
+    } else if (part.exp == 0) {
+        if (likely(part.frac == 0)) {
+            part.cls = float_class_zero;
+        } else if (status->flush_inputs_to_zero) {
+            float_raise(float_flag_input_denormal, status);
+            part.cls = float_class_zero;
+            part.frac = 0;
+        } else {
+            int shift = clz64(part.frac) - 1;
+            part.cls = float_class_normal;
+            part.exp = parm->frac_shift - parm->exp_bias - shift + 1;
+            part.frac <<= shift;
+        }
+    } else {
+        part.cls = float_class_normal;
+        part.exp -= parm->exp_bias;
+        part.frac = DECOMPOSED_IMPLICIT_BIT + (part.frac << parm->frac_shift);
+    }
+    return part;
+}
+
+/* Round and uncanonicalize a floating-point number by parts. There
+ * are FRAC_SHIFT bits that may require rounding at the bottom of the
+ * fraction; these bits will be removed. The exponent will be biased
+ * by EXP_BIAS and must be bounded by [EXP_MAX-1, 0].
+ */
+
+static FloatParts round_canonical(FloatParts p, float_status *s,
+                                  const FloatFmt *parm)
+{
+    const uint64_t frac_lsbm1 = parm->frac_lsbm1;
+    const uint64_t round_mask = parm->round_mask;
+    const uint64_t roundeven_mask = parm->roundeven_mask;
+    const int exp_max = parm->exp_max;
+    const int frac_shift = parm->frac_shift;
+    uint64_t frac, inc;
+    int exp, flags = 0;
+    bool overflow_norm;
+
+    frac = p.frac;
+    exp = p.exp;
+
+    switch (p.cls) {
+    case float_class_normal:
+        switch (s->float_rounding_mode) {
+        case float_round_nearest_even:
+            overflow_norm = false;
+            inc = ((frac & roundeven_mask) != frac_lsbm1 ? frac_lsbm1 : 0);
+            break;
+        case float_round_ties_away:
+            overflow_norm = false;
+            inc = frac_lsbm1;
+            break;
+        case float_round_to_zero:
+            overflow_norm = true;
+            inc = 0;
+            break;
+        case float_round_up:
+            inc = p.sign ? 0 : round_mask;
+            overflow_norm = p.sign;
+            break;
+        case float_round_down:
+            inc = p.sign ? round_mask : 0;
+            overflow_norm = !p.sign;
+            break;
+        default:
+            g_assert_not_reached();
+        }
+
+        exp += parm->exp_bias;
+        if (likely(exp > 0)) {
+            if (frac & round_mask) {
+                flags |= float_flag_inexact;
+                frac += inc;
+                if (frac & DECOMPOSED_OVERFLOW_BIT) {
+                    frac >>= 1;
+                    exp++;
+                }
+            }
+            frac >>= frac_shift;
+
+            if (unlikely(exp >= exp_max)) {
+                flags |= float_flag_overflow | float_flag_inexact;
+                if (overflow_norm) {
+                    exp = exp_max - 1;
+                    frac = -1;
+                } else {
+                    p.cls = float_class_inf;
+                    goto do_inf;
+                }
+            }
+        } else if (s->flush_to_zero) {
+            flags |= float_flag_output_denormal;
+            p.cls = float_class_zero;
+            goto do_zero;
+        } else {
+            bool is_tiny = (s->float_detect_tininess
+                            == float_tininess_before_rounding)
+                        || (exp < 0)
+                        || !((frac + inc) & DECOMPOSED_OVERFLOW_BIT);
+
+            shift64RightJamming(frac, 1 - exp, &frac);
+            if (frac & round_mask) {
+                /* Need to recompute round-to-even.  */
+                if (s->float_rounding_mode == float_round_nearest_even) {
+                    inc = ((frac & roundeven_mask) != frac_lsbm1
+                           ? frac_lsbm1 : 0);
+                }
+                flags |= float_flag_inexact;
+                frac += inc;
+            }
+
+            exp = (frac & DECOMPOSED_IMPLICIT_BIT ? 1 : 0);
+            frac >>= frac_shift;
+
+            if (is_tiny && (flags & float_flag_inexact)) {
+                flags |= float_flag_underflow;
+            }
+            if (exp == 0 && frac == 0) {
+                p.cls = float_class_zero;
+            }
+        }
+        break;
+
+    case float_class_zero:
+    do_zero:
+        exp = 0;
+        frac = 0;
+        break;
+
+    case float_class_inf:
+    do_inf:
+        exp = exp_max;
+        frac = 0;
+        break;
+
+    case float_class_qnan:
+    case float_class_snan:
+        exp = exp_max;
+        break;
+
+    default:
+        g_assert_not_reached();
+    }
+
+    float_raise(flags, s);
+    p.exp = exp;
+    p.frac = frac;
+    return p;
+}
+
+static FloatParts float16_unpack_canonical(float16 f, float_status *s)
+{
+    return canonicalize(float16_unpack_raw(f), &float16_params, s);
+}
+
+static float16 float16_round_pack_canonical(FloatParts p, float_status *s)
+{
+    switch (p.cls) {
+    case float_class_dnan:
+        return float16_default_nan(s);
+    case float_class_msnan:
+        return float16_maybe_silence_nan(float16_pack_raw(p), s);
+    default:
+        p = round_canonical(p, s, &float16_params);
+        return float16_pack_raw(p);
+    }
+}
+
+static FloatParts float32_unpack_canonical(float32 f, float_status *s)
+{
+    return canonicalize(float32_unpack_raw(f), &float32_params, s);
+}
+
+static float32 float32_round_pack_canonical(FloatParts p, float_status *s)
+{
+    switch (p.cls) {
+    case float_class_dnan:
+        return float32_default_nan(s);
+    case float_class_msnan:
+        return float32_maybe_silence_nan(float32_pack_raw(p), s);
+    default:
+        p = round_canonical(p, s, &float32_params);
+        return float32_pack_raw(p);
+    }
+}
+
+static FloatParts float64_unpack_canonical(float64 f, float_status *s)
+{
+    return canonicalize(float64_unpack_raw(f), &float64_params, s);
+}
+
+static float64 float64_round_pack_canonical(FloatParts p, float_status *s)
+{
+    switch (p.cls) {
+    case float_class_dnan:
+        return float64_default_nan(s);
+    case float_class_msnan:
+        return float64_maybe_silence_nan(float64_pack_raw(p), s);
+    default:
+        p = round_canonical(p, s, &float64_params);
+        return float64_pack_raw(p);
+    }
+}
+
+/* Simple helpers for checking if what NaN we have */
+static bool is_nan(FloatClass c)
+{
+    return unlikely(c >= float_class_qnan);
+}
+static bool is_snan(FloatClass c)
+{
+    return c == float_class_snan;
+}
+static bool is_qnan(FloatClass c)
+{
+    return c == float_class_qnan;
+}
+
+static FloatParts pick_nan(FloatParts a, FloatParts b, float_status *s)
+{
+    if (is_snan(a.cls) || is_snan(b.cls)) {
+        s->float_exception_flags |= float_flag_invalid;
+    }
+
+    if (s->default_nan_mode) {
+        a.cls = float_class_dnan;
+    } else {
+        if (pickNaN(is_qnan(a.cls), is_snan(a.cls),
+                    is_qnan(b.cls), is_snan(b.cls),
+                    a.frac > b.frac ||
+                    (a.frac == b.frac && a.sign < b.sign))) {
+            a = b;
+        }
+        a.cls = float_class_msnan;
+    }
+    return a;
+}
+
+/*
+ * Returns the result of adding or subtracting the values of the
+ * floating-point values `a' and `b'. The operation is performed
+ * according to the IEC/IEEE Standard for Binary Floating-Point
+ * Arithmetic.
+ */
+
+static FloatParts addsub_floats(FloatParts a, FloatParts b, bool subtract,
+                                float_status *s)
+{
+    bool a_sign = a.sign;
+    bool b_sign = b.sign ^ subtract;
+
+    if (a_sign != b_sign) {
+        /* Subtraction */
+
+        if (a.cls == float_class_normal && b.cls == float_class_normal) {
+            if (a.exp > b.exp || (a.exp == b.exp && a.frac >= b.frac)) {
+                shift64RightJamming(b.frac, a.exp - b.exp, &b.frac);
+                a.frac = a.frac - b.frac;
+            } else {
+                shift64RightJamming(a.frac, b.exp - a.exp, &a.frac);
+                a.frac = b.frac - a.frac;
+                a.exp = b.exp;
+                a_sign ^= 1;
+            }
+
+            if (a.frac == 0) {
+                a.cls = float_class_zero;
+                a.sign = s->float_rounding_mode == float_round_down;
+            } else {
+                int shift = clz64(a.frac) - 1;
+                a.frac = a.frac << shift;
+                a.exp = a.exp - shift;
+                a.sign = a_sign;
+            }
+            return a;
+        }
+        if (is_nan(a.cls) || is_nan(b.cls)) {
+            return pick_nan(a, b, s);
+        }
+        if (a.cls == float_class_inf) {
+            if (b.cls == float_class_inf) {
+                float_raise(float_flag_invalid, s);
+                a.cls = float_class_dnan;
+            }
+            return a;
+        }
+        if (a.cls == float_class_zero && b.cls == float_class_zero) {
+            a.sign = s->float_rounding_mode == float_round_down;
+            return a;
+        }
+        if (a.cls == float_class_zero || b.cls == float_class_inf) {
+            b.sign = a_sign ^ 1;
+            return b;
+        }
+        if (b.cls == float_class_zero) {
+            return a;
+        }
+    } else {
+        /* Addition */
+        if (a.cls == float_class_normal && b.cls == float_class_normal) {
+            if (a.exp > b.exp) {
+                shift64RightJamming(b.frac, a.exp - b.exp, &b.frac);
+            } else if (a.exp < b.exp) {
+                shift64RightJamming(a.frac, b.exp - a.exp, &a.frac);
+                a.exp = b.exp;
+            }
+            a.frac += b.frac;
+            if (a.frac & DECOMPOSED_OVERFLOW_BIT) {
+                a.frac >>= 1;
+                a.exp += 1;
+            }
+            return a;
+        }
+        if (is_nan(a.cls) || is_nan(b.cls)) {
+            return pick_nan(a, b, s);
+        }
+        if (a.cls == float_class_inf || b.cls == float_class_zero) {
+            return a;
+        }
+        if (b.cls == float_class_inf || a.cls == float_class_zero) {
+            b.sign = b_sign;
+            return b;
+        }
+    }
+    g_assert_not_reached();
+}
+
+/*
+ * Returns the result of adding or subtracting the floating-point
+ * values `a' and `b'. The operation is performed according to the
+ * IEC/IEEE Standard for Binary Floating-Point Arithmetic.
+ */
+
+float16  __attribute__((flatten)) float16_add(float16 a, float16 b,
+                                              float_status *status)
+{
+    FloatParts pa = float16_unpack_canonical(a, status);
+    FloatParts pb = float16_unpack_canonical(b, status);
+    FloatParts pr = addsub_floats(pa, pb, false, status);
+
+    return float16_round_pack_canonical(pr, status);
+}
+
+float32 __attribute__((flatten)) float32_add(float32 a, float32 b,
+                                             float_status *status)
+{
+    FloatParts pa = float32_unpack_canonical(a, status);
+    FloatParts pb = float32_unpack_canonical(b, status);
+    FloatParts pr = addsub_floats(pa, pb, false, status);
+
+    return float32_round_pack_canonical(pr, status);
+}
+
+float64 __attribute__((flatten)) float64_add(float64 a, float64 b,
+                                             float_status *status)
+{
+    FloatParts pa = float64_unpack_canonical(a, status);
+    FloatParts pb = float64_unpack_canonical(b, status);
+    FloatParts pr = addsub_floats(pa, pb, false, status);
+
+    return float64_round_pack_canonical(pr, status);
+}
+
+float16 __attribute__((flatten)) float16_sub(float16 a, float16 b,
+                                             float_status *status)
+{
+    FloatParts pa = float16_unpack_canonical(a, status);
+    FloatParts pb = float16_unpack_canonical(b, status);
+    FloatParts pr = addsub_floats(pa, pb, true, status);
+
+    return float16_round_pack_canonical(pr, status);
+}
+
+float32 __attribute__((flatten)) float32_sub(float32 a, float32 b,
+                                             float_status *status)
+{
+    FloatParts pa = float32_unpack_canonical(a, status);
+    FloatParts pb = float32_unpack_canonical(b, status);
+    FloatParts pr = addsub_floats(pa, pb, true, status);
+
+    return float32_round_pack_canonical(pr, status);
+}
+
+float64 __attribute__((flatten)) float64_sub(float64 a, float64 b,
+                                             float_status *status)
+{
+    FloatParts pa = float64_unpack_canonical(a, status);
+    FloatParts pb = float64_unpack_canonical(b, status);
+    FloatParts pr = addsub_floats(pa, pb, true, status);
+
+    return float64_round_pack_canonical(pr, status);
+}
+
 /*----------------------------------------------------------------------------
 | Takes a 64-bit fixed-point value `absZ' with binary point between bits 6
 | and 7, and returns the properly rounded 32-bit integer corresponding to the
@@ -2081,220 +2546,6 @@ float32 float32_round_to_int(float32 a, float_status *status)
 
 }
 
-/*----------------------------------------------------------------------------
-| Returns the result of adding the absolute values of the single-precision
-| floating-point values `a' and `b'.  If `zSign' is 1, the sum is negated
-| before being returned.  `zSign' is ignored if the result is a NaN.
-| The addition is performed according to the IEC/IEEE Standard for Binary
-| Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-static float32 addFloat32Sigs(float32 a, float32 b, flag zSign,
-                              float_status *status)
-{
-    int aExp, bExp, zExp;
-    uint32_t aSig, bSig, zSig;
-    int expDiff;
-
-    aSig = extractFloat32Frac( a );
-    aExp = extractFloat32Exp( a );
-    bSig = extractFloat32Frac( b );
-    bExp = extractFloat32Exp( b );
-    expDiff = aExp - bExp;
-    aSig <<= 6;
-    bSig <<= 6;
-    if ( 0 < expDiff ) {
-        if ( aExp == 0xFF ) {
-            if (aSig) {
-                return propagateFloat32NaN(a, b, status);
-            }
-            return a;
-        }
-        if ( bExp == 0 ) {
-            --expDiff;
-        }
-        else {
-            bSig |= 0x20000000;
-        }
-        shift32RightJamming( bSig, expDiff, &bSig );
-        zExp = aExp;
-    }
-    else if ( expDiff < 0 ) {
-        if ( bExp == 0xFF ) {
-            if (bSig) {
-                return propagateFloat32NaN(a, b, status);
-            }
-            return packFloat32( zSign, 0xFF, 0 );
-        }
-        if ( aExp == 0 ) {
-            ++expDiff;
-        }
-        else {
-            aSig |= 0x20000000;
-        }
-        shift32RightJamming( aSig, - expDiff, &aSig );
-        zExp = bExp;
-    }
-    else {
-        if ( aExp == 0xFF ) {
-            if (aSig | bSig) {
-                return propagateFloat32NaN(a, b, status);
-            }
-            return a;
-        }
-        if ( aExp == 0 ) {
-            if (status->flush_to_zero) {
-                if (aSig | bSig) {
-                    float_raise(float_flag_output_denormal, status);
-                }
-                return packFloat32(zSign, 0, 0);
-            }
-            return packFloat32( zSign, 0, ( aSig + bSig )>>6 );
-        }
-        zSig = 0x40000000 + aSig + bSig;
-        zExp = aExp;
-        goto roundAndPack;
-    }
-    aSig |= 0x20000000;
-    zSig = ( aSig + bSig )<<1;
-    --zExp;
-    if ( (int32_t) zSig < 0 ) {
-        zSig = aSig + bSig;
-        ++zExp;
-    }
- roundAndPack:
-    return roundAndPackFloat32(zSign, zExp, zSig, status);
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of subtracting the absolute values of the single-
-| precision floating-point values `a' and `b'.  If `zSign' is 1, the
-| difference is negated before being returned.  `zSign' is ignored if the
-| result is a NaN.  The subtraction is performed according to the IEC/IEEE
-| Standard for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-static float32 subFloat32Sigs(float32 a, float32 b, flag zSign,
-                              float_status *status)
-{
-    int aExp, bExp, zExp;
-    uint32_t aSig, bSig, zSig;
-    int expDiff;
-
-    aSig = extractFloat32Frac( a );
-    aExp = extractFloat32Exp( a );
-    bSig = extractFloat32Frac( b );
-    bExp = extractFloat32Exp( b );
-    expDiff = aExp - bExp;
-    aSig <<= 7;
-    bSig <<= 7;
-    if ( 0 < expDiff ) goto aExpBigger;
-    if ( expDiff < 0 ) goto bExpBigger;
-    if ( aExp == 0xFF ) {
-        if (aSig | bSig) {
-            return propagateFloat32NaN(a, b, status);
-        }
-        float_raise(float_flag_invalid, status);
-        return float32_default_nan(status);
-    }
-    if ( aExp == 0 ) {
-        aExp = 1;
-        bExp = 1;
-    }
-    if ( bSig < aSig ) goto aBigger;
-    if ( aSig < bSig ) goto bBigger;
-    return packFloat32(status->float_rounding_mode == float_round_down, 0, 0);
- bExpBigger:
-    if ( bExp == 0xFF ) {
-        if (bSig) {
-            return propagateFloat32NaN(a, b, status);
-        }
-        return packFloat32( zSign ^ 1, 0xFF, 0 );
-    }
-    if ( aExp == 0 ) {
-        ++expDiff;
-    }
-    else {
-        aSig |= 0x40000000;
-    }
-    shift32RightJamming( aSig, - expDiff, &aSig );
-    bSig |= 0x40000000;
- bBigger:
-    zSig = bSig - aSig;
-    zExp = bExp;
-    zSign ^= 1;
-    goto normalizeRoundAndPack;
- aExpBigger:
-    if ( aExp == 0xFF ) {
-        if (aSig) {
-            return propagateFloat32NaN(a, b, status);
-        }
-        return a;
-    }
-    if ( bExp == 0 ) {
-        --expDiff;
-    }
-    else {
-        bSig |= 0x40000000;
-    }
-    shift32RightJamming( bSig, expDiff, &bSig );
-    aSig |= 0x40000000;
- aBigger:
-    zSig = aSig - bSig;
-    zExp = aExp;
- normalizeRoundAndPack:
-    --zExp;
-    return normalizeRoundAndPackFloat32(zSign, zExp, zSig, status);
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of adding the single-precision floating-point values `a'
-| and `b'.  The operation is performed according to the IEC/IEEE Standard for
-| Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float32 float32_add(float32 a, float32 b, float_status *status)
-{
-    flag aSign, bSign;
-    a = float32_squash_input_denormal(a, status);
-    b = float32_squash_input_denormal(b, status);
-
-    aSign = extractFloat32Sign( a );
-    bSign = extractFloat32Sign( b );
-    if ( aSign == bSign ) {
-        return addFloat32Sigs(a, b, aSign, status);
-    }
-    else {
-        return subFloat32Sigs(a, b, aSign, status);
-    }
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of subtracting the single-precision floating-point values
-| `a' and `b'.  The operation is performed according to the IEC/IEEE Standard
-| for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float32 float32_sub(float32 a, float32 b, float_status *status)
-{
-    flag aSign, bSign;
-    a = float32_squash_input_denormal(a, status);
-    b = float32_squash_input_denormal(b, status);
-
-    aSign = extractFloat32Sign( a );
-    bSign = extractFloat32Sign( b );
-    if ( aSign == bSign ) {
-        return subFloat32Sigs(a, b, aSign, status);
-    }
-    else {
-        return addFloat32Sigs(a, b, aSign, status);
-    }
-
-}
-
 /*----------------------------------------------------------------------------
 | Returns the result of multiplying the single-precision floating-point values
 | `a' and `b'.  The operation is performed according to the IEC/IEEE Standard
@@ -3891,219 +4142,6 @@ float64 float64_trunc_to_int(float64 a, float_status *status)
     return res;
 }
 
-/*----------------------------------------------------------------------------
-| Returns the result of adding the absolute values of the double-precision
-| floating-point values `a' and `b'.  If `zSign' is 1, the sum is negated
-| before being returned.  `zSign' is ignored if the result is a NaN.
-| The addition is performed according to the IEC/IEEE Standard for Binary
-| Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-static float64 addFloat64Sigs(float64 a, float64 b, flag zSign,
-                              float_status *status)
-{
-    int aExp, bExp, zExp;
-    uint64_t aSig, bSig, zSig;
-    int expDiff;
-
-    aSig = extractFloat64Frac( a );
-    aExp = extractFloat64Exp( a );
-    bSig = extractFloat64Frac( b );
-    bExp = extractFloat64Exp( b );
-    expDiff = aExp - bExp;
-    aSig <<= 9;
-    bSig <<= 9;
-    if ( 0 < expDiff ) {
-        if ( aExp == 0x7FF ) {
-            if (aSig) {
-                return propagateFloat64NaN(a, b, status);
-            }
-            return a;
-        }
-        if ( bExp == 0 ) {
-            --expDiff;
-        }
-        else {
-            bSig |= LIT64( 0x2000000000000000 );
-        }
-        shift64RightJamming( bSig, expDiff, &bSig );
-        zExp = aExp;
-    }
-    else if ( expDiff < 0 ) {
-        if ( bExp == 0x7FF ) {
-            if (bSig) {
-                return propagateFloat64NaN(a, b, status);
-            }
-            return packFloat64( zSign, 0x7FF, 0 );
-        }
-        if ( aExp == 0 ) {
-            ++expDiff;
-        }
-        else {
-            aSig |= LIT64( 0x2000000000000000 );
-        }
-        shift64RightJamming( aSig, - expDiff, &aSig );
-        zExp = bExp;
-    }
-    else {
-        if ( aExp == 0x7FF ) {
-            if (aSig | bSig) {
-                return propagateFloat64NaN(a, b, status);
-            }
-            return a;
-        }
-        if ( aExp == 0 ) {
-            if (status->flush_to_zero) {
-                if (aSig | bSig) {
-                    float_raise(float_flag_output_denormal, status);
-                }
-                return packFloat64(zSign, 0, 0);
-            }
-            return packFloat64( zSign, 0, ( aSig + bSig )>>9 );
-        }
-        zSig = LIT64( 0x4000000000000000 ) + aSig + bSig;
-        zExp = aExp;
-        goto roundAndPack;
-    }
-    aSig |= LIT64( 0x2000000000000000 );
-    zSig = ( aSig + bSig )<<1;
-    --zExp;
-    if ( (int64_t) zSig < 0 ) {
-        zSig = aSig + bSig;
-        ++zExp;
-    }
- roundAndPack:
-    return roundAndPackFloat64(zSign, zExp, zSig, status);
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of subtracting the absolute values of the double-
-| precision floating-point values `a' and `b'.  If `zSign' is 1, the
-| difference is negated before being returned.  `zSign' is ignored if the
-| result is a NaN.  The subtraction is performed according to the IEC/IEEE
-| Standard for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-static float64 subFloat64Sigs(float64 a, float64 b, flag zSign,
-                              float_status *status)
-{
-    int aExp, bExp, zExp;
-    uint64_t aSig, bSig, zSig;
-    int expDiff;
-
-    aSig = extractFloat64Frac( a );
-    aExp = extractFloat64Exp( a );
-    bSig = extractFloat64Frac( b );
-    bExp = extractFloat64Exp( b );
-    expDiff = aExp - bExp;
-    aSig <<= 10;
-    bSig <<= 10;
-    if ( 0 < expDiff ) goto aExpBigger;
-    if ( expDiff < 0 ) goto bExpBigger;
-    if ( aExp == 0x7FF ) {
-        if (aSig | bSig) {
-            return propagateFloat64NaN(a, b, status);
-        }
-        float_raise(float_flag_invalid, status);
-        return float64_default_nan(status);
-    }
-    if ( aExp == 0 ) {
-        aExp = 1;
-        bExp = 1;
-    }
-    if ( bSig < aSig ) goto aBigger;
-    if ( aSig < bSig ) goto bBigger;
-    return packFloat64(status->float_rounding_mode == float_round_down, 0, 0);
- bExpBigger:
-    if ( bExp == 0x7FF ) {
-        if (bSig) {
-            return propagateFloat64NaN(a, b, status);
-        }
-        return packFloat64( zSign ^ 1, 0x7FF, 0 );
-    }
-    if ( aExp == 0 ) {
-        ++expDiff;
-    }
-    else {
-        aSig |= LIT64( 0x4000000000000000 );
-    }
-    shift64RightJamming( aSig, - expDiff, &aSig );
-    bSig |= LIT64( 0x4000000000000000 );
- bBigger:
-    zSig = bSig - aSig;
-    zExp = bExp;
-    zSign ^= 1;
-    goto normalizeRoundAndPack;
- aExpBigger:
-    if ( aExp == 0x7FF ) {
-        if (aSig) {
-            return propagateFloat64NaN(a, b, status);
-        }
-        return a;
-    }
-    if ( bExp == 0 ) {
-        --expDiff;
-    }
-    else {
-        bSig |= LIT64( 0x4000000000000000 );
-    }
-    shift64RightJamming( bSig, expDiff, &bSig );
-    aSig |= LIT64( 0x4000000000000000 );
- aBigger:
-    zSig = aSig - bSig;
-    zExp = aExp;
- normalizeRoundAndPack:
-    --zExp;
-    return normalizeRoundAndPackFloat64(zSign, zExp, zSig, status);
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of adding the double-precision floating-point values `a'
-| and `b'.  The operation is performed according to the IEC/IEEE Standard for
-| Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float64 float64_add(float64 a, float64 b, float_status *status)
-{
-    flag aSign, bSign;
-    a = float64_squash_input_denormal(a, status);
-    b = float64_squash_input_denormal(b, status);
-
-    aSign = extractFloat64Sign( a );
-    bSign = extractFloat64Sign( b );
-    if ( aSign == bSign ) {
-        return addFloat64Sigs(a, b, aSign, status);
-    }
-    else {
-        return subFloat64Sigs(a, b, aSign, status);
-    }
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of subtracting the double-precision floating-point values
-| `a' and `b'.  The operation is performed according to the IEC/IEEE Standard
-| for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float64 float64_sub(float64 a, float64 b, float_status *status)
-{
-    flag aSign, bSign;
-    a = float64_squash_input_denormal(a, status);
-    b = float64_squash_input_denormal(b, status);
-
-    aSign = extractFloat64Sign( a );
-    bSign = extractFloat64Sign( b );
-    if ( aSign == bSign ) {
-        return subFloat64Sigs(a, b, aSign, status);
-    }
-    else {
-        return addFloat64Sigs(a, b, aSign, status);
-    }
-
-}
 
 /*----------------------------------------------------------------------------
 | Returns the result of multiplying the double-precision floating-point values
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 23824a3000..693ece0974 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -236,6 +236,10 @@ float64 float16_to_float64(float16 a, flag ieee, float_status *status);
 /*----------------------------------------------------------------------------
 | Software half-precision operations.
 *----------------------------------------------------------------------------*/
+
+float16 float16_add(float16, float16, float_status *status);
+float16 float16_sub(float16, float16, float_status *status);
+
 int float16_is_quiet_nan(float16, float_status *status);
 int float16_is_signaling_nan(float16, float_status *status);
 float16 float16_maybe_silence_nan(float16, float_status *status);
-- 
2.15.1

[Qemu-devel] [PATCH v4 13/22] fpu/softfloat: re-factor mul

[Alex Bennée]

We can now add float16_mul and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 versions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
v3
  - mul compile fixes for new names
  - remove duplicate s-o-b
  - more explicit inf * zero check
v4
  - use is_nan
  - pick_nan_parts/pick_nan
---
 fpu/softfloat.c         | 209 +++++++++++++++++++-----------------------------
 include/fpu/softfloat.h |   1 +
 2 files changed, 82 insertions(+), 128 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 2190e7de56..6d29e1a103 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -735,6 +735,87 @@ float64 __attribute__((flatten)) float64_sub(float64 a, float64 b,
     return float64_round_pack_canonical(pr, status);
 }
 
+/*
+ * Returns the result of multiplying the floating-point values `a' and
+ * `b'. The operation is performed according to the IEC/IEEE Standard
+ * for Binary Floating-Point Arithmetic.
+ */
+
+static FloatParts mul_floats(FloatParts a, FloatParts b, float_status *s)
+{
+    bool sign = a.sign ^ b.sign;
+
+    if (a.cls == float_class_normal && b.cls == float_class_normal) {
+        uint64_t hi, lo;
+        int exp = a.exp + b.exp;
+
+        mul64To128(a.frac, b.frac, &hi, &lo);
+        shift128RightJamming(hi, lo, DECOMPOSED_BINARY_POINT, &hi, &lo);
+        if (lo & DECOMPOSED_OVERFLOW_BIT) {
+            shift64RightJamming(lo, 1, &lo);
+            exp += 1;
+        }
+
+        /* Re-use a */
+        a.exp = exp;
+        a.sign = sign;
+        a.frac = lo;
+        return a;
+    }
+    /* handle all the NaN cases */
+    if (is_nan(a.cls) || is_nan(b.cls)) {
+        return pick_nan(a, b, s);
+    }
+    /* Inf * Zero == NaN */
+    if ((a.cls == float_class_inf && b.cls == float_class_zero) ||
+        (a.cls == float_class_zero && b.cls == float_class_inf)) {
+        s->float_exception_flags |= float_flag_invalid;
+        a.cls = float_class_dnan;
+        a.sign = sign;
+        return a;
+    }
+    /* Multiply by 0 or Inf */
+    if (a.cls == float_class_inf || a.cls == float_class_zero) {
+        a.sign = sign;
+        return a;
+    }
+    if (b.cls == float_class_inf || b.cls == float_class_zero) {
+        b.sign = sign;
+        return b;
+    }
+    g_assert_not_reached();
+}
+
+float16 __attribute__((flatten)) float16_mul(float16 a, float16 b,
+                                             float_status *status)
+{
+    FloatParts pa = float16_unpack_canonical(a, status);
+    FloatParts pb = float16_unpack_canonical(b, status);
+    FloatParts pr = mul_floats(pa, pb, status);
+
+    return float16_round_pack_canonical(pr, status);
+}
+
+float32 __attribute__((flatten)) float32_mul(float32 a, float32 b,
+                                             float_status *status)
+{
+    FloatParts pa = float32_unpack_canonical(a, status);
+    FloatParts pb = float32_unpack_canonical(b, status);
+    FloatParts pr = mul_floats(pa, pb, status);
+
+    return float32_round_pack_canonical(pr, status);
+}
+
+float64 __attribute__((flatten)) float64_mul(float64 a, float64 b,
+                                             float_status *status)
+{
+    FloatParts pa = float64_unpack_canonical(a, status);
+    FloatParts pb = float64_unpack_canonical(b, status);
+    FloatParts pr = mul_floats(pa, pb, status);
+
+    return float64_round_pack_canonical(pr, status);
+}
+
 /*----------------------------------------------------------------------------
 | Takes a 64-bit fixed-point value `absZ' with binary point between bits 6
 | and 7, and returns the properly rounded 32-bit integer corresponding to the
@@ -2546,70 +2627,6 @@ float32 float32_round_to_int(float32 a, float_status *status)
 
 }
 
-/*----------------------------------------------------------------------------
-| Returns the result of multiplying the single-precision floating-point values
-| `a' and `b'.  The operation is performed according to the IEC/IEEE Standard
-| for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float32 float32_mul(float32 a, float32 b, float_status *status)
-{
-    flag aSign, bSign, zSign;
-    int aExp, bExp, zExp;
-    uint32_t aSig, bSig;
-    uint64_t zSig64;
-    uint32_t zSig;
-
-    a = float32_squash_input_denormal(a, status);
-    b = float32_squash_input_denormal(b, status);
-
-    aSig = extractFloat32Frac( a );
-    aExp = extractFloat32Exp( a );
-    aSign = extractFloat32Sign( a );
-    bSig = extractFloat32Frac( b );
-    bExp = extractFloat32Exp( b );
-    bSign = extractFloat32Sign( b );
-    zSign = aSign ^ bSign;
-    if ( aExp == 0xFF ) {
-        if ( aSig || ( ( bExp == 0xFF ) && bSig ) ) {
-            return propagateFloat32NaN(a, b, status);
-        }
-        if ( ( bExp | bSig ) == 0 ) {
-            float_raise(float_flag_invalid, status);
-            return float32_default_nan(status);
-        }
-        return packFloat32( zSign, 0xFF, 0 );
-    }
-    if ( bExp == 0xFF ) {
-        if (bSig) {
-            return propagateFloat32NaN(a, b, status);
-        }
-        if ( ( aExp | aSig ) == 0 ) {
-            float_raise(float_flag_invalid, status);
-            return float32_default_nan(status);
-        }
-        return packFloat32( zSign, 0xFF, 0 );
-    }
-    if ( aExp == 0 ) {
-        if ( aSig == 0 ) return packFloat32( zSign, 0, 0 );
-        normalizeFloat32Subnormal( aSig, &aExp, &aSig );
-    }
-    if ( bExp == 0 ) {
-        if ( bSig == 0 ) return packFloat32( zSign, 0, 0 );
-        normalizeFloat32Subnormal( bSig, &bExp, &bSig );
-    }
-    zExp = aExp + bExp - 0x7F;
-    aSig = ( aSig | 0x00800000 )<<7;
-    bSig = ( bSig | 0x00800000 )<<8;
-    shift64RightJamming( ( (uint64_t) aSig ) * bSig, 32, &zSig64 );
-    zSig = zSig64;
-    if ( 0 <= (int32_t) ( zSig<<1 ) ) {
-        zSig <<= 1;
-        --zExp;
-    }
-    return roundAndPackFloat32(zSign, zExp, zSig, status);
-
-}
 
 /*----------------------------------------------------------------------------
 | Returns the result of dividing the single-precision floating-point value `a'
@@ -4142,70 +4159,6 @@ float64 float64_trunc_to_int(float64 a, float_status *status)
     return res;
 }
 
-
-/*----------------------------------------------------------------------------
-| Returns the result of multiplying the double-precision floating-point values
-| `a' and `b'.  The operation is performed according to the IEC/IEEE Standard
-| for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float64 float64_mul(float64 a, float64 b, float_status *status)
-{
-    flag aSign, bSign, zSign;
-    int aExp, bExp, zExp;
-    uint64_t aSig, bSig, zSig0, zSig1;
-
-    a = float64_squash_input_denormal(a, status);
-    b = float64_squash_input_denormal(b, status);
-
-    aSig = extractFloat64Frac( a );
-    aExp = extractFloat64Exp( a );
-    aSign = extractFloat64Sign( a );
-    bSig = extractFloat64Frac( b );
-    bExp = extractFloat64Exp( b );
-    bSign = extractFloat64Sign( b );
-    zSign = aSign ^ bSign;
-    if ( aExp == 0x7FF ) {
-        if ( aSig || ( ( bExp == 0x7FF ) && bSig ) ) {
-            return propagateFloat64NaN(a, b, status);
-        }
-        if ( ( bExp | bSig ) == 0 ) {
-            float_raise(float_flag_invalid, status);
-            return float64_default_nan(status);
-        }
-        return packFloat64( zSign, 0x7FF, 0 );
-    }
-    if ( bExp == 0x7FF ) {
-        if (bSig) {
-            return propagateFloat64NaN(a, b, status);
-        }
-        if ( ( aExp | aSig ) == 0 ) {
-            float_raise(float_flag_invalid, status);
-            return float64_default_nan(status);
-        }
-        return packFloat64( zSign, 0x7FF, 0 );
-    }
-    if ( aExp == 0 ) {
-        if ( aSig == 0 ) return packFloat64( zSign, 0, 0 );
-        normalizeFloat64Subnormal( aSig, &aExp, &aSig );
-    }
-    if ( bExp == 0 ) {
-        if ( bSig == 0 ) return packFloat64( zSign, 0, 0 );
-        normalizeFloat64Subnormal( bSig, &bExp, &bSig );
-    }
-    zExp = aExp + bExp - 0x3FF;
-    aSig = ( aSig | LIT64( 0x0010000000000000 ) )<<10;
-    bSig = ( bSig | LIT64( 0x0010000000000000 ) )<<11;
-    mul64To128( aSig, bSig, &zSig0, &zSig1 );
-    zSig0 |= ( zSig1 != 0 );
-    if ( 0 <= (int64_t) ( zSig0<<1 ) ) {
-        zSig0 <<= 1;
-        --zExp;
-    }
-    return roundAndPackFloat64(zSign, zExp, zSig0, status);
-
-}
-
 /*----------------------------------------------------------------------------
 | Returns the result of dividing the double-precision floating-point value `a'
 | by the corresponding value `b'.  The operation is performed according to
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 693ece0974..7fc63dd60f 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -239,6 +239,7 @@ float64 float16_to_float64(float16 a, flag ieee, float_status *status);
 
 float16 float16_add(float16, float16, float_status *status);
 float16 float16_sub(float16, float16, float_status *status);
+float16 float16_mul(float16, float16, float_status *status);
 
 int float16_is_quiet_nan(float16, float_status *status);
 int float16_is_signaling_nan(float16, float_status *status);
-- 
2.15.1

[Qemu-devel] [PATCH v4 14/22] fpu/softfloat: re-factor div

[Alex Bennée]

We can now add float16_div and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 versions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---

v3
  - rename functions and structures
v4
  - use is_nan
  - better attribution for div128To64
  - pick_nan_parts->pick_nan
---
 fpu/softfloat-macros.h  |  48 ++++++++++
 fpu/softfloat.c         | 236 ++++++++++++++++++------------------------------
 include/fpu/softfloat.h |   1 +
 3 files changed, 137 insertions(+), 148 deletions(-)

diff --git a/fpu/softfloat-macros.h b/fpu/softfloat-macros.h
index 9cc6158cb4..c45a23193e 100644
--- a/fpu/softfloat-macros.h
+++ b/fpu/softfloat-macros.h
@@ -625,6 +625,54 @@ static uint64_t estimateDiv128To64( uint64_t a0, uint64_t a1, uint64_t b )
 
 }
 
+/* From the GNU Multi Precision Library - longlong.h __udiv_qrnnd
+ * (https://gmplib.org/repo/gmp/file/tip/longlong.h)
+ *
+ * Licensed under the GPLv2/LGPLv3
+ */
+static uint64_t div128To64(uint64_t n0, uint64_t n1, uint64_t d)
+{
+    uint64_t d0, d1, q0, q1, r1, r0, m;
+
+    d0 = (uint32_t)d;
+    d1 = d >> 32;
+
+    r1 = n1 % d1;
+    q1 = n1 / d1;
+    m = q1 * d0;
+    r1 = (r1 << 32) | (n0 >> 32);
+    if (r1 < m) {
+        q1 -= 1;
+        r1 += d;
+        if (r1 >= d) {
+            if (r1 < m) {
+                q1 -= 1;
+                r1 += d;
+            }
+        }
+    }
+    r1 -= m;
+
+    r0 = r1 % d1;
+    q0 = r1 / d1;
+    m = q0 * d0;
+    r0 = (r0 << 32) | (uint32_t)n0;
+    if (r0 < m) {
+        q0 -= 1;
+        r0 += d;
+        if (r0 >= d) {
+            if (r0 < m) {
+                q0 -= 1;
+                r0 += d;
+            }
+        }
+    }
+    r0 -= m;
+
+    /* Return remainder in LSB */
+    return (q1 << 32) | q0 | (r0 != 0);
+}
+
 /*----------------------------------------------------------------------------
 | Returns an approximation to the square root of the 32-bit significand given
 | by `a'.  Considered as an integer, `a' must be at least 2^31.  If bit 0 of
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 6d29e1a103..4a859b2721 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -816,6 +816,94 @@ float64 __attribute__((flatten)) float64_mul(float64 a, float64 b,
     return float64_round_pack_canonical(pr, status);
 }
 
+/*
+ * Returns the result of dividing the floating-point value `a' by the
+ * corresponding value `b'. The operation is performed according to
+ * the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
+ */
+
+static FloatParts div_floats(FloatParts a, FloatParts b, float_status *s)
+{
+    bool sign = a.sign ^ b.sign;
+
+    if (a.cls == float_class_normal && b.cls == float_class_normal) {
+        uint64_t temp_lo, temp_hi;
+        int exp = a.exp - b.exp;
+        if (a.frac < b.frac) {
+            exp -= 1;
+            shortShift128Left(0, a.frac, DECOMPOSED_BINARY_POINT + 1,
+                              &temp_hi, &temp_lo);
+        } else {
+            shortShift128Left(0, a.frac, DECOMPOSED_BINARY_POINT,
+                              &temp_hi, &temp_lo);
+        }
+        /* LSB of quot is set if inexact which roundandpack will use
+         * to set flags. Yet again we re-use a for the result */
+        a.frac = div128To64(temp_lo, temp_hi, b.frac);
+        a.sign = sign;
+        a.exp = exp;
+        return a;
+    }
+    /* handle all the NaN cases */
+    if (is_nan(a.cls) || is_nan(b.cls)) {
+        return pick_nan(a, b, s);
+    }
+    /* 0/0 or Inf/Inf */
+    if (a.cls == b.cls
+        &&
+        (a.cls == float_class_inf || a.cls == float_class_zero)) {
+        s->float_exception_flags |= float_flag_invalid;
+        a.cls = float_class_dnan;
+        return a;
+    }
+    /* Div 0 => Inf */
+    if (b.cls == float_class_zero) {
+        s->float_exception_flags |= float_flag_divbyzero;
+        a.cls = float_class_inf;
+        a.sign = sign;
+        return a;
+    }
+    /* Inf / x or 0 / x */
+    if (a.cls == float_class_inf || a.cls == float_class_zero) {
+        a.sign = sign;
+        return a;
+    }
+    /* Div by Inf */
+    if (b.cls == float_class_inf) {
+        a.cls = float_class_zero;
+        a.sign = sign;
+        return a;
+    }
+    g_assert_not_reached();
+}
+
+float16 float16_div(float16 a, float16 b, float_status *status)
+{
+    FloatParts pa = float16_unpack_canonical(a, status);
+    FloatParts pb = float16_unpack_canonical(b, status);
+    FloatParts pr = div_floats(pa, pb, status);
+
+    return float16_round_pack_canonical(pr, status);
+}
+
+float32 float32_div(float32 a, float32 b, float_status *status)
+{
+    FloatParts pa = float32_unpack_canonical(a, status);
+    FloatParts pb = float32_unpack_canonical(b, status);
+    FloatParts pr = div_floats(pa, pb, status);
+
+    return float32_round_pack_canonical(pr, status);
+}
+
+float64 float64_div(float64 a, float64 b, float_status *status)
+{
+    FloatParts pa = float64_unpack_canonical(a, status);
+    FloatParts pb = float64_unpack_canonical(b, status);
+    FloatParts pr = div_floats(pa, pb, status);
+
+    return float64_round_pack_canonical(pr, status);
+}
+
 /*----------------------------------------------------------------------------
 | Takes a 64-bit fixed-point value `absZ' with binary point between bits 6
 | and 7, and returns the properly rounded 32-bit integer corresponding to the
@@ -2627,77 +2715,6 @@ float32 float32_round_to_int(float32 a, float_status *status)
 
 }
 
-
-/*----------------------------------------------------------------------------
-| Returns the result of dividing the single-precision floating-point value `a'
-| by the corresponding value `b'.  The operation is performed according to the
-| IEC/IEEE Standard for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float32 float32_div(float32 a, float32 b, float_status *status)
-{
-    flag aSign, bSign, zSign;
-    int aExp, bExp, zExp;
-    uint32_t aSig, bSig, zSig;
-    a = float32_squash_input_denormal(a, status);
-    b = float32_squash_input_denormal(b, status);
-
-    aSig = extractFloat32Frac( a );
-    aExp = extractFloat32Exp( a );
-    aSign = extractFloat32Sign( a );
-    bSig = extractFloat32Frac( b );
-    bExp = extractFloat32Exp( b );
-    bSign = extractFloat32Sign( b );
-    zSign = aSign ^ bSign;
-    if ( aExp == 0xFF ) {
-        if (aSig) {
-            return propagateFloat32NaN(a, b, status);
-        }
-        if ( bExp == 0xFF ) {
-            if (bSig) {
-                return propagateFloat32NaN(a, b, status);
-            }
-            float_raise(float_flag_invalid, status);
-            return float32_default_nan(status);
-        }
-        return packFloat32( zSign, 0xFF, 0 );
-    }
-    if ( bExp == 0xFF ) {
-        if (bSig) {
-            return propagateFloat32NaN(a, b, status);
-        }
-        return packFloat32( zSign, 0, 0 );
-    }
-    if ( bExp == 0 ) {
-        if ( bSig == 0 ) {
-            if ( ( aExp | aSig ) == 0 ) {
-                float_raise(float_flag_invalid, status);
-                return float32_default_nan(status);
-            }
-            float_raise(float_flag_divbyzero, status);
-            return packFloat32( zSign, 0xFF, 0 );
-        }
-        normalizeFloat32Subnormal( bSig, &bExp, &bSig );
-    }
-    if ( aExp == 0 ) {
-        if ( aSig == 0 ) return packFloat32( zSign, 0, 0 );
-        normalizeFloat32Subnormal( aSig, &aExp, &aSig );
-    }
-    zExp = aExp - bExp + 0x7D;
-    aSig = ( aSig | 0x00800000 )<<7;
-    bSig = ( bSig | 0x00800000 )<<8;
-    if ( bSig <= ( aSig + aSig ) ) {
-        aSig >>= 1;
-        ++zExp;
-    }
-    zSig = ( ( (uint64_t) aSig )<<32 ) / bSig;
-    if ( ( zSig & 0x3F ) == 0 ) {
-        zSig |= ( (uint64_t) bSig * zSig != ( (uint64_t) aSig )<<32 );
-    }
-    return roundAndPackFloat32(zSign, zExp, zSig, status);
-
-}
-
 /*----------------------------------------------------------------------------
 | Returns the remainder of the single-precision floating-point value `a'
 | with respect to the corresponding value `b'.  The operation is performed
@@ -4159,83 +4176,6 @@ float64 float64_trunc_to_int(float64 a, float_status *status)
     return res;
 }
 
-/*----------------------------------------------------------------------------
-| Returns the result of dividing the double-precision floating-point value `a'
-| by the corresponding value `b'.  The operation is performed according to
-| the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float64 float64_div(float64 a, float64 b, float_status *status)
-{
-    flag aSign, bSign, zSign;
-    int aExp, bExp, zExp;
-    uint64_t aSig, bSig, zSig;
-    uint64_t rem0, rem1;
-    uint64_t term0, term1;
-    a = float64_squash_input_denormal(a, status);
-    b = float64_squash_input_denormal(b, status);
-
-    aSig = extractFloat64Frac( a );
-    aExp = extractFloat64Exp( a );
-    aSign = extractFloat64Sign( a );
-    bSig = extractFloat64Frac( b );
-    bExp = extractFloat64Exp( b );
-    bSign = extractFloat64Sign( b );
-    zSign = aSign ^ bSign;
-    if ( aExp == 0x7FF ) {
-        if (aSig) {
-            return propagateFloat64NaN(a, b, status);
-        }
-        if ( bExp == 0x7FF ) {
-            if (bSig) {
-                return propagateFloat64NaN(a, b, status);
-            }
-            float_raise(float_flag_invalid, status);
-            return float64_default_nan(status);
-        }
-        return packFloat64( zSign, 0x7FF, 0 );
-    }
-    if ( bExp == 0x7FF ) {
-        if (bSig) {
-            return propagateFloat64NaN(a, b, status);
-        }
-        return packFloat64( zSign, 0, 0 );
-    }
-    if ( bExp == 0 ) {
-        if ( bSig == 0 ) {
-            if ( ( aExp | aSig ) == 0 ) {
-                float_raise(float_flag_invalid, status);
-                return float64_default_nan(status);
-            }
-            float_raise(float_flag_divbyzero, status);
-            return packFloat64( zSign, 0x7FF, 0 );
-        }
-        normalizeFloat64Subnormal( bSig, &bExp, &bSig );
-    }
-    if ( aExp == 0 ) {
-        if ( aSig == 0 ) return packFloat64( zSign, 0, 0 );
-        normalizeFloat64Subnormal( aSig, &aExp, &aSig );
-    }
-    zExp = aExp - bExp + 0x3FD;
-    aSig = ( aSig | LIT64( 0x0010000000000000 ) )<<10;
-    bSig = ( bSig | LIT64( 0x0010000000000000 ) )<<11;
-    if ( bSig <= ( aSig + aSig ) ) {
-        aSig >>= 1;
-        ++zExp;
-    }
-    zSig = estimateDiv128To64( aSig, 0, bSig );
-    if ( ( zSig & 0x1FF ) <= 2 ) {
-        mul64To128( bSig, zSig, &term0, &term1 );
-        sub128( aSig, 0, term0, term1, &rem0, &rem1 );
-        while ( (int64_t) rem0 < 0 ) {
-            --zSig;
-            add128( rem0, rem1, 0, bSig, &rem0, &rem1 );
-        }
-        zSig |= ( rem1 != 0 );
-    }
-    return roundAndPackFloat64(zSign, zExp, zSig, status);
-
-}
 
 /*----------------------------------------------------------------------------
 | Returns the remainder of the double-precision floating-point value `a'
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 7fc63dd60f..85e4a74f1b 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -240,6 +240,7 @@ float64 float16_to_float64(float16 a, flag ieee, float_status *status);
 float16 float16_add(float16, float16, float_status *status);
 float16 float16_sub(float16, float16, float_status *status);
 float16 float16_mul(float16, float16, float_status *status);
+float16 float16_div(float16, float16, float_status *status);
 
 int float16_is_quiet_nan(float16, float_status *status);
 int float16_is_signaling_nan(float16, float_status *status);
-- 
2.15.1

[Qemu-devel] [PATCH v4 15/22] fpu/softfloat: re-factor muladd

[Alex Bennée]

We can now add float16_muladd and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 muladd functions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
v3
  - rename functions and structures
v4
  - use is_nan
  - attribute(flatten)
---
 fpu/softfloat-specialize.h | 104 -------
 fpu/softfloat.c            | 742 +++++++++++++++++----------------------------
 include/fpu/softfloat.h    |   1 +
 3 files changed, 272 insertions(+), 575 deletions(-)

diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h
index 4be0fb21ba..e81ca001e1 100644
--- a/fpu/softfloat-specialize.h
+++ b/fpu/softfloat-specialize.h
@@ -729,58 +729,6 @@ static float32 propagateFloat32NaN(float32 a, float32 b, float_status *status)
     }
 }
 
-/*----------------------------------------------------------------------------
-| Takes three single-precision floating-point values `a', `b' and `c', one of
-| which is a NaN, and returns the appropriate NaN result.  If any of  `a',
-| `b' or `c' is a signaling NaN, the invalid exception is raised.
-| The input infzero indicates whether a*b was 0*inf or inf*0 (in which case
-| obviously c is a NaN, and whether to propagate c or some other NaN is
-| implementation defined).
-*----------------------------------------------------------------------------*/
-
-static float32 propagateFloat32MulAddNaN(float32 a, float32 b,
-                                         float32 c, flag infzero,
-                                         float_status *status)
-{
-    flag aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN,
-        cIsQuietNaN, cIsSignalingNaN;
-    int which;
-
-    aIsQuietNaN = float32_is_quiet_nan(a, status);
-    aIsSignalingNaN = float32_is_signaling_nan(a, status);
-    bIsQuietNaN = float32_is_quiet_nan(b, status);
-    bIsSignalingNaN = float32_is_signaling_nan(b, status);
-    cIsQuietNaN = float32_is_quiet_nan(c, status);
-    cIsSignalingNaN = float32_is_signaling_nan(c, status);
-
-    if (aIsSignalingNaN | bIsSignalingNaN | cIsSignalingNaN) {
-        float_raise(float_flag_invalid, status);
-    }
-
-    which = pickNaNMulAdd(aIsQuietNaN, aIsSignalingNaN,
-                          bIsQuietNaN, bIsSignalingNaN,
-                          cIsQuietNaN, cIsSignalingNaN, infzero, status);
-
-    if (status->default_nan_mode) {
-        /* Note that this check is after pickNaNMulAdd so that function
-         * has an opportunity to set the Invalid flag.
-         */
-        return float32_default_nan(status);
-    }
-
-    switch (which) {
-    case 0:
-        return float32_maybe_silence_nan(a, status);
-    case 1:
-        return float32_maybe_silence_nan(b, status);
-    case 2:
-        return float32_maybe_silence_nan(c, status);
-    case 3:
-    default:
-        return float32_default_nan(status);
-    }
-}
-
 #ifdef NO_SIGNALING_NANS
 int float64_is_quiet_nan(float64 a_, float_status *status)
 {
@@ -936,58 +884,6 @@ static float64 propagateFloat64NaN(float64 a, float64 b, float_status *status)
     }
 }
 
-/*----------------------------------------------------------------------------
-| Takes three double-precision floating-point values `a', `b' and `c', one of
-| which is a NaN, and returns the appropriate NaN result.  If any of  `a',
-| `b' or `c' is a signaling NaN, the invalid exception is raised.
-| The input infzero indicates whether a*b was 0*inf or inf*0 (in which case
-| obviously c is a NaN, and whether to propagate c or some other NaN is
-| implementation defined).
-*----------------------------------------------------------------------------*/
-
-static float64 propagateFloat64MulAddNaN(float64 a, float64 b,
-                                         float64 c, flag infzero,
-                                         float_status *status)
-{
-    flag aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN,
-        cIsQuietNaN, cIsSignalingNaN;
-    int which;
-
-    aIsQuietNaN = float64_is_quiet_nan(a, status);
-    aIsSignalingNaN = float64_is_signaling_nan(a, status);
-    bIsQuietNaN = float64_is_quiet_nan(b, status);
-    bIsSignalingNaN = float64_is_signaling_nan(b, status);
-    cIsQuietNaN = float64_is_quiet_nan(c, status);
-    cIsSignalingNaN = float64_is_signaling_nan(c, status);
-
-    if (aIsSignalingNaN | bIsSignalingNaN | cIsSignalingNaN) {
-        float_raise(float_flag_invalid, status);
-    }
-
-    which = pickNaNMulAdd(aIsQuietNaN, aIsSignalingNaN,
-                          bIsQuietNaN, bIsSignalingNaN,
-                          cIsQuietNaN, cIsSignalingNaN, infzero, status);
-
-    if (status->default_nan_mode) {
-        /* Note that this check is after pickNaNMulAdd so that function
-         * has an opportunity to set the Invalid flag.
-         */
-        return float64_default_nan(status);
-    }
-
-    switch (which) {
-    case 0:
-        return float64_maybe_silence_nan(a, status);
-    case 1:
-        return float64_maybe_silence_nan(b, status);
-    case 2:
-        return float64_maybe_silence_nan(c, status);
-    case 3:
-    default:
-        return float64_default_nan(status);
-    }
-}
-
 #ifdef NO_SIGNALING_NANS
 int floatx80_is_quiet_nan(floatx80 a_, float_status *status)
 {
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 4a859b2721..ae4ba6de51 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -580,6 +580,40 @@ static FloatParts pick_nan(FloatParts a, FloatParts b, float_status *s)
     return a;
 }
 
+static FloatParts pick_nan_muladd(FloatParts a, FloatParts b, FloatParts c,
+                                  bool inf_zero, float_status *s)
+{
+    if (is_snan(a.cls) || is_snan(b.cls) || is_snan(c.cls)) {
+        s->float_exception_flags |= float_flag_invalid;
+    }
+
+    if (s->default_nan_mode) {
+        a.cls = float_class_dnan;
+    } else {
+        switch (pickNaNMulAdd(is_qnan(a.cls), is_snan(a.cls),
+                              is_qnan(b.cls), is_snan(b.cls),
+                              is_qnan(c.cls), is_snan(c.cls),
+                              inf_zero, s)) {
+        case 0:
+            break;
+        case 1:
+            a = b;
+            break;
+        case 2:
+            a = c;
+            break;
+        case 3:
+            a.cls = float_class_dnan;
+            return a;
+        default:
+            g_assert_not_reached();
+        }
+
+        a.cls = float_class_msnan;
+    }
+    return a;
+}
+
 /*
  * Returns the result of adding or subtracting the values of the
  * floating-point values `a' and `b'. The operation is performed
@@ -816,6 +850,243 @@ float64 __attribute__((flatten)) float64_mul(float64 a, float64 b,
     return float64_round_pack_canonical(pr, status);
 }
 
+/*
+ * Returns the result of multiplying the floating-point values `a' and
+ * `b' then adding 'c', with no intermediate rounding step after the
+ * multiplication. The operation is performed according to the
+ * IEC/IEEE Standard for Binary Floating-Point Arithmetic 754-2008.
+ * The flags argument allows the caller to select negation of the
+ * addend, the intermediate product, or the final result. (The
+ * difference between this and having the caller do a separate
+ * negation is that negating externally will flip the sign bit on
+ * NaNs.)
+ */
+
+static FloatParts muladd_floats(FloatParts a, FloatParts b, FloatParts c,
+                                int flags, float_status *s)
+{
+    bool inf_zero = ((1 << a.cls) | (1 << b.cls)) ==
+                    ((1 << float_class_inf) | (1 << float_class_zero));
+    bool p_sign;
+    bool sign_flip = flags & float_muladd_negate_result;
+    FloatClass p_class;
+    uint64_t hi, lo;
+    int p_exp;
+
+    /* It is implementation-defined whether the cases of (0,inf,qnan)
+     * and (inf,0,qnan) raise InvalidOperation or not (and what QNaN
+     * they return if they do), so we have to hand this information
+     * off to the target-specific pick-a-NaN routine.
+     */
+    if (is_nan(a.cls) || is_nan(b.cls) || is_nan(c.cls)) {
+        return pick_nan_muladd(a, b, c, inf_zero, s);
+    }
+
+    if (inf_zero) {
+        s->float_exception_flags |= float_flag_invalid;
+        a.cls = float_class_dnan;
+        return a;
+    }
+
+    if (flags & float_muladd_negate_c) {
+        c.sign ^= 1;
+    }
+
+    p_sign = a.sign ^ b.sign;
+
+    if (flags & float_muladd_negate_product) {
+        p_sign ^= 1;
+    }
+
+    if (a.cls == float_class_inf || b.cls == float_class_inf) {
+        p_class = float_class_inf;
+    } else if (a.cls == float_class_zero || b.cls == float_class_zero) {
+        p_class = float_class_zero;
+    } else {
+        p_class = float_class_normal;
+    }
+
+    if (c.cls == float_class_inf) {
+        if (p_class == float_class_inf && p_sign != c.sign) {
+            s->float_exception_flags |= float_flag_invalid;
+            a.cls = float_class_dnan;
+        } else {
+            a.cls = float_class_inf;
+            a.sign = c.sign ^ sign_flip;
+        }
+        return a;
+    }
+
+    if (p_class == float_class_inf) {
+        a.cls = float_class_inf;
+        a.sign = p_sign ^ sign_flip;
+        return a;
+    }
+
+    if (p_class == float_class_zero) {
+        if (c.cls == float_class_zero) {
+            if (p_sign != c.sign) {
+                p_sign = s->float_rounding_mode == float_round_down;
+            }
+            c.sign = p_sign;
+        } else if (flags & float_muladd_halve_result) {
+            c.exp -= 1;
+        }
+        c.sign ^= sign_flip;
+        return c;
+    }
+
+    /* a & b should be normals now... */
+    assert(a.cls == float_class_normal &&
+           b.cls == float_class_normal);
+
+    p_exp = a.exp + b.exp;
+
+    /* Multiply of 2 62-bit numbers produces a (2*62) == 124-bit
+     * result.
+     */
+    mul64To128(a.frac, b.frac, &hi, &lo);
+    /* binary point now at bit 124 */
+
+    /* check for overflow */
+    if (hi & (1ULL << (DECOMPOSED_BINARY_POINT * 2 + 1 - 64))) {
+        shift128RightJamming(hi, lo, 1, &hi, &lo);
+        p_exp += 1;
+    }
+
+    /* + add/sub */
+    if (c.cls == float_class_zero) {
+        /* move binary point back to 62 */
+        shift128RightJamming(hi, lo, DECOMPOSED_BINARY_POINT, &hi, &lo);
+    } else {
+        int exp_diff = p_exp - c.exp;
+        if (p_sign == c.sign) {
+            /* Addition */
+            if (exp_diff <= 0) {
+                shift128RightJamming(hi, lo,
+                                     DECOMPOSED_BINARY_POINT - exp_diff,
+                                     &hi, &lo);
+                lo += c.frac;
+                p_exp = c.exp;
+            } else {
+                uint64_t c_hi, c_lo;
+                /* shift c to the same binary point as the product (124) */
+                c_hi = c.frac >> 2;
+                c_lo = 0;
+                shift128RightJamming(c_hi, c_lo,
+                                     exp_diff,
+                                     &c_hi, &c_lo);
+                add128(hi, lo, c_hi, c_lo, &hi, &lo);
+                /* move binary point back to 62 */
+                shift128RightJamming(hi, lo, DECOMPOSED_BINARY_POINT, &hi, &lo);
+            }
+
+            if (lo & DECOMPOSED_OVERFLOW_BIT) {
+                shift64RightJamming(lo, 1, &lo);
+                p_exp += 1;
+            }
+
+        } else {
+            /* Subtraction */
+            uint64_t c_hi, c_lo;
+            /* make C binary point match product at bit 124 */
+            c_hi = c.frac >> 2;
+            c_lo = 0;
+
+            if (exp_diff <= 0) {
+                shift128RightJamming(hi, lo, -exp_diff, &hi, &lo);
+                if (exp_diff == 0
+                    &&
+                    (hi > c_hi || (hi == c_hi && lo >= c_lo))) {
+                    sub128(hi, lo, c_hi, c_lo, &hi, &lo);
+                } else {
+                    sub128(c_hi, c_lo, hi, lo, &hi, &lo);
+                    p_sign ^= 1;
+                    p_exp = c.exp;
+                }
+            } else {
+                shift128RightJamming(c_hi, c_lo,
+                                     exp_diff,
+                                     &c_hi, &c_lo);
+                sub128(hi, lo, c_hi, c_lo, &hi, &lo);
+            }
+
+            if (hi == 0 && lo == 0) {
+                a.cls = float_class_zero;
+                a.sign = s->float_rounding_mode == float_round_down;
+                a.sign ^= sign_flip;
+                return a;
+            } else {
+                int shift;
+                if (hi != 0) {
+                    shift = clz64(hi);
+                } else {
+                    shift = clz64(lo) + 64;
+                }
+                /* Normalizing to a binary point of 124 is the
+                   correct adjust for the exponent.  However since we're
+                   shifting, we might as well put the binary point back
+                   at 62 where we really want it.  Therefore shift as
+                   if we're leaving 1 bit at the top of the word, but
+                   adjust the exponent as if we're leaving 3 bits.  */
+                shift -= 1;
+                if (shift >= 64) {
+                    lo = lo << (shift - 64);
+                } else {
+                    hi = (hi << shift) | (lo >> (64 - shift));
+                    lo = hi | ((lo << shift) != 0);
+                }
+                p_exp -= shift - 2;
+            }
+        }
+    }
+
+    if (flags & float_muladd_halve_result) {
+        p_exp -= 1;
+    }
+
+    /* finally prepare our result */
+    a.cls = float_class_normal;
+    a.sign = p_sign ^ sign_flip;
+    a.exp = p_exp;
+    a.frac = lo;
+
+    return a;
+}
+
+float16 __attribute__((flatten)) float16_muladd(float16 a, float16 b, float16 c,
+                                                int flags, float_status *status)
+{
+    FloatParts pa = float16_unpack_canonical(a, status);
+    FloatParts pb = float16_unpack_canonical(b, status);
+    FloatParts pc = float16_unpack_canonical(c, status);
+    FloatParts pr = muladd_floats(pa, pb, pc, flags, status);
+
+    return float16_round_pack_canonical(pr, status);
+}
+
+float32 __attribute__((flatten)) float32_muladd(float32 a, float32 b, float32 c,
+                                                int flags, float_status *status)
+{
+    FloatParts pa = float32_unpack_canonical(a, status);
+    FloatParts pb = float32_unpack_canonical(b, status);
+    FloatParts pc = float32_unpack_canonical(c, status);
+    FloatParts pr = muladd_floats(pa, pb, pc, flags, status);
+
+    return float32_round_pack_canonical(pr, status);
+}
+
+float64 __attribute__((flatten)) float64_muladd(float64 a, float64 b, float64 c,
+                                                int flags, float_status *status)
+{
+    FloatParts pa = float64_unpack_canonical(a, status);
+    FloatParts pb = float64_unpack_canonical(b, status);
+    FloatParts pc = float64_unpack_canonical(c, status);
+    FloatParts pr = muladd_floats(pa, pb, pc, flags, status);
+
+    return float64_round_pack_canonical(pr, status);
+}
+
 /*
  * Returns the result of dividing the floating-point value `a' by the
  * corresponding value `b'. The operation is performed according to
@@ -2817,231 +3088,6 @@ float32 float32_rem(float32 a, float32 b, float_status *status)
     return normalizeRoundAndPackFloat32(aSign ^ zSign, bExp, aSig, status);
 }
 
-/*----------------------------------------------------------------------------
-| Returns the result of multiplying the single-precision floating-point values
-| `a' and `b' then adding 'c', with no intermediate rounding step after the
-| multiplication.  The operation is performed according to the IEC/IEEE
-| Standard for Binary Floating-Point Arithmetic 754-2008.
-| The flags argument allows the caller to select negation of the
-| addend, the intermediate product, or the final result. (The difference
-| between this and having the caller do a separate negation is that negating
-| externally will flip the sign bit on NaNs.)
-*----------------------------------------------------------------------------*/
-
-float32 float32_muladd(float32 a, float32 b, float32 c, int flags,
-                       float_status *status)
-{
-    flag aSign, bSign, cSign, zSign;
-    int aExp, bExp, cExp, pExp, zExp, expDiff;
-    uint32_t aSig, bSig, cSig;
-    flag pInf, pZero, pSign;
-    uint64_t pSig64, cSig64, zSig64;
-    uint32_t pSig;
-    int shiftcount;
-    flag signflip, infzero;
-
-    a = float32_squash_input_denormal(a, status);
-    b = float32_squash_input_denormal(b, status);
-    c = float32_squash_input_denormal(c, status);
-    aSig = extractFloat32Frac(a);
-    aExp = extractFloat32Exp(a);
-    aSign = extractFloat32Sign(a);
-    bSig = extractFloat32Frac(b);
-    bExp = extractFloat32Exp(b);
-    bSign = extractFloat32Sign(b);
-    cSig = extractFloat32Frac(c);
-    cExp = extractFloat32Exp(c);
-    cSign = extractFloat32Sign(c);
-
-    infzero = ((aExp == 0 && aSig == 0 && bExp == 0xff && bSig == 0) ||
-               (aExp == 0xff && aSig == 0 && bExp == 0 && bSig == 0));
-
-    /* It is implementation-defined whether the cases of (0,inf,qnan)
-     * and (inf,0,qnan) raise InvalidOperation or not (and what QNaN
-     * they return if they do), so we have to hand this information
-     * off to the target-specific pick-a-NaN routine.
-     */
-    if (((aExp == 0xff) && aSig) ||
-        ((bExp == 0xff) && bSig) ||
-        ((cExp == 0xff) && cSig)) {
-        return propagateFloat32MulAddNaN(a, b, c, infzero, status);
-    }
-
-    if (infzero) {
-        float_raise(float_flag_invalid, status);
-        return float32_default_nan(status);
-    }
-
-    if (flags & float_muladd_negate_c) {
-        cSign ^= 1;
-    }
-
-    signflip = (flags & float_muladd_negate_result) ? 1 : 0;
-
-    /* Work out the sign and type of the product */
-    pSign = aSign ^ bSign;
-    if (flags & float_muladd_negate_product) {
-        pSign ^= 1;
-    }
-    pInf = (aExp == 0xff) || (bExp == 0xff);
-    pZero = ((aExp | aSig) == 0) || ((bExp | bSig) == 0);
-
-    if (cExp == 0xff) {
-        if (pInf && (pSign ^ cSign)) {
-            /* addition of opposite-signed infinities => InvalidOperation */
-            float_raise(float_flag_invalid, status);
-            return float32_default_nan(status);
-        }
-        /* Otherwise generate an infinity of the same sign */
-        return packFloat32(cSign ^ signflip, 0xff, 0);
-    }
-
-    if (pInf) {
-        return packFloat32(pSign ^ signflip, 0xff, 0);
-    }
-
-    if (pZero) {
-        if (cExp == 0) {
-            if (cSig == 0) {
-                /* Adding two exact zeroes */
-                if (pSign == cSign) {
-                    zSign = pSign;
-                } else if (status->float_rounding_mode == float_round_down) {
-                    zSign = 1;
-                } else {
-                    zSign = 0;
-                }
-                return packFloat32(zSign ^ signflip, 0, 0);
-            }
-            /* Exact zero plus a denorm */
-            if (status->flush_to_zero) {
-                float_raise(float_flag_output_denormal, status);
-                return packFloat32(cSign ^ signflip, 0, 0);
-            }
-        }
-        /* Zero plus something non-zero : just return the something */
-        if (flags & float_muladd_halve_result) {
-            if (cExp == 0) {
-                normalizeFloat32Subnormal(cSig, &cExp, &cSig);
-            }
-            /* Subtract one to halve, and one again because roundAndPackFloat32
-             * wants one less than the true exponent.
-             */
-            cExp -= 2;
-            cSig = (cSig | 0x00800000) << 7;
-            return roundAndPackFloat32(cSign ^ signflip, cExp, cSig, status);
-        }
-        return packFloat32(cSign ^ signflip, cExp, cSig);
-    }
-
-    if (aExp == 0) {
-        normalizeFloat32Subnormal(aSig, &aExp, &aSig);
-    }
-    if (bExp == 0) {
-        normalizeFloat32Subnormal(bSig, &bExp, &bSig);
-    }
-
-    /* Calculate the actual result a * b + c */
-
-    /* Multiply first; this is easy. */
-    /* NB: we subtract 0x7e where float32_mul() subtracts 0x7f
-     * because we want the true exponent, not the "one-less-than"
-     * flavour that roundAndPackFloat32() takes.
-     */
-    pExp = aExp + bExp - 0x7e;
-    aSig = (aSig | 0x00800000) << 7;
-    bSig = (bSig | 0x00800000) << 8;
-    pSig64 = (uint64_t)aSig * bSig;
-    if ((int64_t)(pSig64 << 1) >= 0) {
-        pSig64 <<= 1;
-        pExp--;
-    }
-
-    zSign = pSign ^ signflip;
-
-    /* Now pSig64 is the significand of the multiply, with the explicit bit in
-     * position 62.
-     */
-    if (cExp == 0) {
-        if (!cSig) {
-            /* Throw out the special case of c being an exact zero now */
-            shift64RightJamming(pSig64, 32, &pSig64);
-            pSig = pSig64;
-            if (flags & float_muladd_halve_result) {
-                pExp--;
-            }
-            return roundAndPackFloat32(zSign, pExp - 1,
-                                       pSig, status);
-        }
-        normalizeFloat32Subnormal(cSig, &cExp, &cSig);
-    }
-
-    cSig64 = (uint64_t)cSig << (62 - 23);
-    cSig64 |= LIT64(0x4000000000000000);
-    expDiff = pExp - cExp;
-
-    if (pSign == cSign) {
-        /* Addition */
-        if (expDiff > 0) {
-            /* scale c to match p */
-            shift64RightJamming(cSig64, expDiff, &cSig64);
-            zExp = pExp;
-        } else if (expDiff < 0) {
-            /* scale p to match c */
-            shift64RightJamming(pSig64, -expDiff, &pSig64);
-            zExp = cExp;
-        } else {
-            /* no scaling needed */
-            zExp = cExp;
-        }
-        /* Add significands and make sure explicit bit ends up in posn 62 */
-        zSig64 = pSig64 + cSig64;
-        if ((int64_t)zSig64 < 0) {
-            shift64RightJamming(zSig64, 1, &zSig64);
-        } else {
-            zExp--;
-        }
-    } else {
-        /* Subtraction */
-        if (expDiff > 0) {
-            shift64RightJamming(cSig64, expDiff, &cSig64);
-            zSig64 = pSig64 - cSig64;
-            zExp = pExp;
-        } else if (expDiff < 0) {
-            shift64RightJamming(pSig64, -expDiff, &pSig64);
-            zSig64 = cSig64 - pSig64;
-            zExp = cExp;
-            zSign ^= 1;
-        } else {
-            zExp = pExp;
-            if (cSig64 < pSig64) {
-                zSig64 = pSig64 - cSig64;
-            } else if (pSig64 < cSig64) {
-                zSig64 = cSig64 - pSig64;
-                zSign ^= 1;
-            } else {
-                /* Exact zero */
-                zSign = signflip;
-                if (status->float_rounding_mode == float_round_down) {
-                    zSign ^= 1;
-                }
-                return packFloat32(zSign, 0, 0);
-            }
-        }
-        --zExp;
-        /* Normalize to put the explicit bit back into bit 62. */
-        shiftcount = countLeadingZeros64(zSig64) - 1;
-        zSig64 <<= shiftcount;
-        zExp -= shiftcount;
-    }
-    if (flags & float_muladd_halve_result) {
-        zExp--;
-    }
-
-    shift64RightJamming(zSig64, 32, &zSig64);
-    return roundAndPackFloat32(zSign, zExp, zSig64, status);
-}
-
 
 /*----------------------------------------------------------------------------
 | Returns the square root of the single-precision floating-point value `a'.
@@ -4265,252 +4311,6 @@ float64 float64_rem(float64 a, float64 b, float_status *status)
 
 }
 
-/*----------------------------------------------------------------------------
-| Returns the result of multiplying the double-precision floating-point values
-| `a' and `b' then adding 'c', with no intermediate rounding step after the
-| multiplication.  The operation is performed according to the IEC/IEEE
-| Standard for Binary Floating-Point Arithmetic 754-2008.
-| The flags argument allows the caller to select negation of the
-| addend, the intermediate product, or the final result. (The difference
-| between this and having the caller do a separate negation is that negating
-| externally will flip the sign bit on NaNs.)
-*----------------------------------------------------------------------------*/
-
-float64 float64_muladd(float64 a, float64 b, float64 c, int flags,
-                       float_status *status)
-{
-    flag aSign, bSign, cSign, zSign;
-    int aExp, bExp, cExp, pExp, zExp, expDiff;
-    uint64_t aSig, bSig, cSig;
-    flag pInf, pZero, pSign;
-    uint64_t pSig0, pSig1, cSig0, cSig1, zSig0, zSig1;
-    int shiftcount;
-    flag signflip, infzero;
-
-    a = float64_squash_input_denormal(a, status);
-    b = float64_squash_input_denormal(b, status);
-    c = float64_squash_input_denormal(c, status);
-    aSig = extractFloat64Frac(a);
-    aExp = extractFloat64Exp(a);
-    aSign = extractFloat64Sign(a);
-    bSig = extractFloat64Frac(b);
-    bExp = extractFloat64Exp(b);
-    bSign = extractFloat64Sign(b);
-    cSig = extractFloat64Frac(c);
-    cExp = extractFloat64Exp(c);
-    cSign = extractFloat64Sign(c);
-
-    infzero = ((aExp == 0 && aSig == 0 && bExp == 0x7ff && bSig == 0) ||
-               (aExp == 0x7ff && aSig == 0 && bExp == 0 && bSig == 0));
-
-    /* It is implementation-defined whether the cases of (0,inf,qnan)
-     * and (inf,0,qnan) raise InvalidOperation or not (and what QNaN
-     * they return if they do), so we have to hand this information
-     * off to the target-specific pick-a-NaN routine.
-     */
-    if (((aExp == 0x7ff) && aSig) ||
-        ((bExp == 0x7ff) && bSig) ||
-        ((cExp == 0x7ff) && cSig)) {
-        return propagateFloat64MulAddNaN(a, b, c, infzero, status);
-    }
-
-    if (infzero) {
-        float_raise(float_flag_invalid, status);
-        return float64_default_nan(status);
-    }
-
-    if (flags & float_muladd_negate_c) {
-        cSign ^= 1;
-    }
-
-    signflip = (flags & float_muladd_negate_result) ? 1 : 0;
-
-    /* Work out the sign and type of the product */
-    pSign = aSign ^ bSign;
-    if (flags & float_muladd_negate_product) {
-        pSign ^= 1;
-    }
-    pInf = (aExp == 0x7ff) || (bExp == 0x7ff);
-    pZero = ((aExp | aSig) == 0) || ((bExp | bSig) == 0);
-
-    if (cExp == 0x7ff) {
-        if (pInf && (pSign ^ cSign)) {
-            /* addition of opposite-signed infinities => InvalidOperation */
-            float_raise(float_flag_invalid, status);
-            return float64_default_nan(status);
-        }
-        /* Otherwise generate an infinity of the same sign */
-        return packFloat64(cSign ^ signflip, 0x7ff, 0);
-    }
-
-    if (pInf) {
-        return packFloat64(pSign ^ signflip, 0x7ff, 0);
-    }
-
-    if (pZero) {
-        if (cExp == 0) {
-            if (cSig == 0) {
-                /* Adding two exact zeroes */
-                if (pSign == cSign) {
-                    zSign = pSign;
-                } else if (status->float_rounding_mode == float_round_down) {
-                    zSign = 1;
-                } else {
-                    zSign = 0;
-                }
-                return packFloat64(zSign ^ signflip, 0, 0);
-            }
-            /* Exact zero plus a denorm */
-            if (status->flush_to_zero) {
-                float_raise(float_flag_output_denormal, status);
-                return packFloat64(cSign ^ signflip, 0, 0);
-            }
-        }
-        /* Zero plus something non-zero : just return the something */
-        if (flags & float_muladd_halve_result) {
-            if (cExp == 0) {
-                normalizeFloat64Subnormal(cSig, &cExp, &cSig);
-            }
-            /* Subtract one to halve, and one again because roundAndPackFloat64
-             * wants one less than the true exponent.
-             */
-            cExp -= 2;
-            cSig = (cSig | 0x0010000000000000ULL) << 10;
-            return roundAndPackFloat64(cSign ^ signflip, cExp, cSig, status);
-        }
-        return packFloat64(cSign ^ signflip, cExp, cSig);
-    }
-
-    if (aExp == 0) {
-        normalizeFloat64Subnormal(aSig, &aExp, &aSig);
-    }
-    if (bExp == 0) {
-        normalizeFloat64Subnormal(bSig, &bExp, &bSig);
-    }
-
-    /* Calculate the actual result a * b + c */
-
-    /* Multiply first; this is easy. */
-    /* NB: we subtract 0x3fe where float64_mul() subtracts 0x3ff
-     * because we want the true exponent, not the "one-less-than"
-     * flavour that roundAndPackFloat64() takes.
-     */
-    pExp = aExp + bExp - 0x3fe;
-    aSig = (aSig | LIT64(0x0010000000000000))<<10;
-    bSig = (bSig | LIT64(0x0010000000000000))<<11;
-    mul64To128(aSig, bSig, &pSig0, &pSig1);
-    if ((int64_t)(pSig0 << 1) >= 0) {
-        shortShift128Left(pSig0, pSig1, 1, &pSig0, &pSig1);
-        pExp--;
-    }
-
-    zSign = pSign ^ signflip;
-
-    /* Now [pSig0:pSig1] is the significand of the multiply, with the explicit
-     * bit in position 126.
-     */
-    if (cExp == 0) {
-        if (!cSig) {
-            /* Throw out the special case of c being an exact zero now */
-            shift128RightJamming(pSig0, pSig1, 64, &pSig0, &pSig1);
-            if (flags & float_muladd_halve_result) {
-                pExp--;
-            }
-            return roundAndPackFloat64(zSign, pExp - 1,
-                                       pSig1, status);
-        }
-        normalizeFloat64Subnormal(cSig, &cExp, &cSig);
-    }
-
-    /* Shift cSig and add the explicit bit so [cSig0:cSig1] is the
-     * significand of the addend, with the explicit bit in position 126.
-     */
-    cSig0 = cSig << (126 - 64 - 52);
-    cSig1 = 0;
-    cSig0 |= LIT64(0x4000000000000000);
-    expDiff = pExp - cExp;
-
-    if (pSign == cSign) {
-        /* Addition */
-        if (expDiff > 0) {
-            /* scale c to match p */
-            shift128RightJamming(cSig0, cSig1, expDiff, &cSig0, &cSig1);
-            zExp = pExp;
-        } else if (expDiff < 0) {
-            /* scale p to match c */
-            shift128RightJamming(pSig0, pSig1, -expDiff, &pSig0, &pSig1);
-            zExp = cExp;
-        } else {
-            /* no scaling needed */
-            zExp = cExp;
-        }
-        /* Add significands and make sure explicit bit ends up in posn 126 */
-        add128(pSig0, pSig1, cSig0, cSig1, &zSig0, &zSig1);
-        if ((int64_t)zSig0 < 0) {
-            shift128RightJamming(zSig0, zSig1, 1, &zSig0, &zSig1);
-        } else {
-            zExp--;
-        }
-        shift128RightJamming(zSig0, zSig1, 64, &zSig0, &zSig1);
-        if (flags & float_muladd_halve_result) {
-            zExp--;
-        }
-        return roundAndPackFloat64(zSign, zExp, zSig1, status);
-    } else {
-        /* Subtraction */
-        if (expDiff > 0) {
-            shift128RightJamming(cSig0, cSig1, expDiff, &cSig0, &cSig1);
-            sub128(pSig0, pSig1, cSig0, cSig1, &zSig0, &zSig1);
-            zExp = pExp;
-        } else if (expDiff < 0) {
-            shift128RightJamming(pSig0, pSig1, -expDiff, &pSig0, &pSig1);
-            sub128(cSig0, cSig1, pSig0, pSig1, &zSig0, &zSig1);
-            zExp = cExp;
-            zSign ^= 1;
-        } else {
-            zExp = pExp;
-            if (lt128(cSig0, cSig1, pSig0, pSig1)) {
-                sub128(pSig0, pSig1, cSig0, cSig1, &zSig0, &zSig1);
-            } else if (lt128(pSig0, pSig1, cSig0, cSig1)) {
-                sub128(cSig0, cSig1, pSig0, pSig1, &zSig0, &zSig1);
-                zSign ^= 1;
-            } else {
-                /* Exact zero */
-                zSign = signflip;
-                if (status->float_rounding_mode == float_round_down) {
-                    zSign ^= 1;
-                }
-                return packFloat64(zSign, 0, 0);
-            }
-        }
-        --zExp;
-        /* Do the equivalent of normalizeRoundAndPackFloat64() but
-         * starting with the significand in a pair of uint64_t.
-         */
-        if (zSig0) {
-            shiftcount = countLeadingZeros64(zSig0) - 1;
-            shortShift128Left(zSig0, zSig1, shiftcount, &zSig0, &zSig1);
-            if (zSig1) {
-                zSig0 |= 1;
-            }
-            zExp -= shiftcount;
-        } else {
-            shiftcount = countLeadingZeros64(zSig1);
-            if (shiftcount == 0) {
-                zSig0 = (zSig1 >> 1) | (zSig1 & 1);
-                zExp -= 63;
-            } else {
-                shiftcount--;
-                zSig0 = zSig1 << shiftcount;
-                zExp -= (shiftcount + 64);
-            }
-        }
-        if (flags & float_muladd_halve_result) {
-            zExp--;
-        }
-        return roundAndPackFloat64(zSign, zExp, zSig0, status);
-    }
-}
 
 /*----------------------------------------------------------------------------
 | Returns the square root of the double-precision floating-point value `a'.
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 85e4a74f1b..65bc7442d2 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -240,6 +240,7 @@ float64 float16_to_float64(float16 a, flag ieee, float_status *status);
 float16 float16_add(float16, float16, float_status *status);
 float16 float16_sub(float16, float16, float_status *status);
 float16 float16_mul(float16, float16, float_status *status);
+float16 float16_muladd(float16, float16, float16, int, float_status *status);
 float16 float16_div(float16, float16, float_status *status);
 
 int float16_is_quiet_nan(float16, float_status *status);
-- 
2.15.1

[Qemu-devel] [PATCH v4 16/22] fpu/softfloat: re-factor round_to_int

[Alex Bennée]

We can now add float16_round_to_int and use the common round_decomposed and
canonicalize functions to have a single implementation for
float16/32/64 round_to_int functions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
v3
  - rename structures and functions
v4
  - move NaN handling to return NaN
---
 fpu/softfloat.c         | 322 ++++++++++++++++++++++--------------------------
 include/fpu/softfloat.h |   1 +
 2 files changed, 148 insertions(+), 175 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index ae4ba6de51..5d04e65538 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -560,7 +560,26 @@ static bool is_qnan(FloatClass c)
     return c == float_class_qnan;
 }
 
-static FloatParts pick_nan(FloatParts a, FloatParts b, float_status *s)
+static inline FloatParts return_nan(FloatParts a, float_status *s)
+{
+    switch (a.cls) {
+    case float_class_snan:
+        s->float_exception_flags |= float_flag_invalid;
+        a.cls = float_class_msnan;
+        /* FALLTHRU */
+    case float_class_qnan:
+        if (s->default_nan_mode) {
+            a.cls = float_class_dnan;
+        }
+        break;
+
+    default:
+        g_assert_not_reached();
+    }
+    return a;
+}
+
+static inline FloatParts pick_nan(FloatParts a, FloatParts b, float_status *s)
 {
     if (is_snan(a.cls) || is_snan(b.cls)) {
         s->float_exception_flags |= float_flag_invalid;
@@ -1175,6 +1194,133 @@ float64 float64_div(float64 a, float64 b, float_status *status)
     return float64_round_pack_canonical(pr, status);
 }
 
+/*
+ * Rounds the floating-point value `a' to an integer, and returns the
+ * result as a floating-point value. The operation is performed
+ * according to the IEC/IEEE Standard for Binary Floating-Point
+ * Arithmetic.
+ */
+
+static FloatParts round_to_int(FloatParts a, int rounding_mode, float_status *s)
+{
+    if (is_nan(a.cls)) {
+        return return_nan(a, s);
+    }
+
+    switch (a.cls) {
+    case float_class_zero:
+    case float_class_inf:
+    case float_class_qnan:
+        /* already "integral" */
+        break;
+    case float_class_normal:
+        if (a.exp >= DECOMPOSED_BINARY_POINT) {
+            /* already integral */
+            break;
+        }
+        if (a.exp < 0) {
+            bool one;
+            /* all fractional */
+            s->float_exception_flags |= float_flag_inexact;
+            switch (rounding_mode) {
+            case float_round_nearest_even:
+                one = a.exp == -1 && a.frac > DECOMPOSED_IMPLICIT_BIT;
+                break;
+            case float_round_ties_away:
+                one = a.exp == -1 && a.frac >= DECOMPOSED_IMPLICIT_BIT;
+                break;
+            case float_round_to_zero:
+                one = false;
+                break;
+            case float_round_up:
+                one = !a.sign;
+                break;
+            case float_round_down:
+                one = a.sign;
+                break;
+            default:
+                g_assert_not_reached();
+            }
+
+            if (one) {
+                a.frac = DECOMPOSED_IMPLICIT_BIT;
+                a.exp = 0;
+            } else {
+                a.cls = float_class_zero;
+            }
+        } else {
+            uint64_t frac_lsb, frac_lsbm1, round_mask, roundeven_mask, inc;
+
+            frac_lsb = DECOMPOSED_IMPLICIT_BIT >> a.exp;
+            frac_lsbm1 = frac_lsb >> 1;
+            roundeven_mask = (frac_lsb - 1) | frac_lsb;
+            round_mask = roundeven_mask >> 1;
+
+            switch (rounding_mode) {
+            case float_round_nearest_even:
+                inc = ((a.frac & roundeven_mask) != frac_lsbm1 ? frac_lsbm1 : 0);
+                break;
+            case float_round_ties_away:
+                inc = frac_lsbm1;
+                break;
+            case float_round_to_zero:
+                inc = 0;
+                break;
+            case float_round_up:
+                inc = a.sign ? 0 : round_mask;
+                break;
+            case float_round_down:
+                inc = a.sign ? round_mask : 0;
+                break;
+            default:
+                g_assert_not_reached();
+            }
+
+            if (a.frac & round_mask) {
+                s->float_exception_flags |= float_flag_inexact;
+                a.frac += inc;
+                a.frac &= ~round_mask;
+                if (a.frac & DECOMPOSED_OVERFLOW_BIT) {
+                    a.frac >>= 1;
+                    a.exp++;
+                }
+            }
+        }
+        break;
+    default:
+        g_assert_not_reached();
+    }
+    return a;
+}
+
+float16 float16_round_to_int(float16 a, float_status *s)
+{
+    FloatParts pa = float16_unpack_canonical(a, s);
+    FloatParts pr = round_to_int(pa, s->float_rounding_mode, s);
+    return float16_round_pack_canonical(pr, s);
+}
+
+float32 float32_round_to_int(float32 a, float_status *s)
+{
+    FloatParts pa = float32_unpack_canonical(a, s);
+    FloatParts pr = round_to_int(pa, s->float_rounding_mode, s);
+    return float32_round_pack_canonical(pr, s);
+}
+
+float64 float64_round_to_int(float64 a, float_status *s)
+{
+    FloatParts pa = float64_unpack_canonical(a, s);
+    FloatParts pr = round_to_int(pa, s->float_rounding_mode, s);
+    return float64_round_pack_canonical(pr, s);
+}
+
+float64 float64_trunc_to_int(float64 a, float_status *s)
+{
+    FloatParts pa = float64_unpack_canonical(a, s);
+    FloatParts pr = round_to_int(pa, float_round_to_zero, s);
+    return float64_round_pack_canonical(pr, s);
+}
+
 /*----------------------------------------------------------------------------
 | Takes a 64-bit fixed-point value `absZ' with binary point between bits 6
 | and 7, and returns the properly rounded 32-bit integer corresponding to the
@@ -2905,87 +3051,6 @@ float128 float32_to_float128(float32 a, float_status *status)
 
 }
 
-/*----------------------------------------------------------------------------
-| Rounds the single-precision floating-point value `a' to an integer, and
-| returns the result as a single-precision floating-point value.  The
-| operation is performed according to the IEC/IEEE Standard for Binary
-| Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float32 float32_round_to_int(float32 a, float_status *status)
-{
-    flag aSign;
-    int aExp;
-    uint32_t lastBitMask, roundBitsMask;
-    uint32_t z;
-    a = float32_squash_input_denormal(a, status);
-
-    aExp = extractFloat32Exp( a );
-    if ( 0x96 <= aExp ) {
-        if ( ( aExp == 0xFF ) && extractFloat32Frac( a ) ) {
-            return propagateFloat32NaN(a, a, status);
-        }
-        return a;
-    }
-    if ( aExp <= 0x7E ) {
-        if ( (uint32_t) ( float32_val(a)<<1 ) == 0 ) return a;
-        status->float_exception_flags |= float_flag_inexact;
-        aSign = extractFloat32Sign( a );
-        switch (status->float_rounding_mode) {
-         case float_round_nearest_even:
-            if ( ( aExp == 0x7E ) && extractFloat32Frac( a ) ) {
-                return packFloat32( aSign, 0x7F, 0 );
-            }
-            break;
-        case float_round_ties_away:
-            if (aExp == 0x7E) {
-                return packFloat32(aSign, 0x7F, 0);
-            }
-            break;
-         case float_round_down:
-            return make_float32(aSign ? 0xBF800000 : 0);
-         case float_round_up:
-            return make_float32(aSign ? 0x80000000 : 0x3F800000);
-        }
-        return packFloat32( aSign, 0, 0 );
-    }
-    lastBitMask = 1;
-    lastBitMask <<= 0x96 - aExp;
-    roundBitsMask = lastBitMask - 1;
-    z = float32_val(a);
-    switch (status->float_rounding_mode) {
-    case float_round_nearest_even:
-        z += lastBitMask>>1;
-        if ((z & roundBitsMask) == 0) {
-            z &= ~lastBitMask;
-        }
-        break;
-    case float_round_ties_away:
-        z += lastBitMask >> 1;
-        break;
-    case float_round_to_zero:
-        break;
-    case float_round_up:
-        if (!extractFloat32Sign(make_float32(z))) {
-            z += roundBitsMask;
-        }
-        break;
-    case float_round_down:
-        if (extractFloat32Sign(make_float32(z))) {
-            z += roundBitsMask;
-        }
-        break;
-    default:
-        abort();
-    }
-    z &= ~ roundBitsMask;
-    if (z != float32_val(a)) {
-        status->float_exception_flags |= float_flag_inexact;
-    }
-    return make_float32(z);
-
-}
-
 /*----------------------------------------------------------------------------
 | Returns the remainder of the single-precision floating-point value `a'
 | with respect to the corresponding value `b'.  The operation is performed
@@ -4129,99 +4194,6 @@ float128 float64_to_float128(float64 a, float_status *status)
 
 }
 
-/*----------------------------------------------------------------------------
-| Rounds the double-precision floating-point value `a' to an integer, and
-| returns the result as a double-precision floating-point value.  The
-| operation is performed according to the IEC/IEEE Standard for Binary
-| Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float64 float64_round_to_int(float64 a, float_status *status)
-{
-    flag aSign;
-    int aExp;
-    uint64_t lastBitMask, roundBitsMask;
-    uint64_t z;
-    a = float64_squash_input_denormal(a, status);
-
-    aExp = extractFloat64Exp( a );
-    if ( 0x433 <= aExp ) {
-        if ( ( aExp == 0x7FF ) && extractFloat64Frac( a ) ) {
-            return propagateFloat64NaN(a, a, status);
-        }
-        return a;
-    }
-    if ( aExp < 0x3FF ) {
-        if ( (uint64_t) ( float64_val(a)<<1 ) == 0 ) return a;
-        status->float_exception_flags |= float_flag_inexact;
-        aSign = extractFloat64Sign( a );
-        switch (status->float_rounding_mode) {
-         case float_round_nearest_even:
-            if ( ( aExp == 0x3FE ) && extractFloat64Frac( a ) ) {
-                return packFloat64( aSign, 0x3FF, 0 );
-            }
-            break;
-        case float_round_ties_away:
-            if (aExp == 0x3FE) {
-                return packFloat64(aSign, 0x3ff, 0);
-            }
-            break;
-         case float_round_down:
-            return make_float64(aSign ? LIT64( 0xBFF0000000000000 ) : 0);
-         case float_round_up:
-            return make_float64(
-            aSign ? LIT64( 0x8000000000000000 ) : LIT64( 0x3FF0000000000000 ));
-        }
-        return packFloat64( aSign, 0, 0 );
-    }
-    lastBitMask = 1;
-    lastBitMask <<= 0x433 - aExp;
-    roundBitsMask = lastBitMask - 1;
-    z = float64_val(a);
-    switch (status->float_rounding_mode) {
-    case float_round_nearest_even:
-        z += lastBitMask >> 1;
-        if ((z & roundBitsMask) == 0) {
-            z &= ~lastBitMask;
-        }
-        break;
-    case float_round_ties_away:
-        z += lastBitMask >> 1;
-        break;
-    case float_round_to_zero:
-        break;
-    case float_round_up:
-        if (!extractFloat64Sign(make_float64(z))) {
-            z += roundBitsMask;
-        }
-        break;
-    case float_round_down:
-        if (extractFloat64Sign(make_float64(z))) {
-            z += roundBitsMask;
-        }
-        break;
-    default:
-        abort();
-    }
-    z &= ~ roundBitsMask;
-    if (z != float64_val(a)) {
-        status->float_exception_flags |= float_flag_inexact;
-    }
-    return make_float64(z);
-
-}
-
-float64 float64_trunc_to_int(float64 a, float_status *status)
-{
-    int oldmode;
-    float64 res;
-    oldmode = status->float_rounding_mode;
-    status->float_rounding_mode = float_round_to_zero;
-    res = float64_round_to_int(a, status);
-    status->float_rounding_mode = oldmode;
-    return res;
-}
-
 
 /*----------------------------------------------------------------------------
 | Returns the remainder of the double-precision floating-point value `a'
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 65bc7442d2..4650758c23 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -237,6 +237,7 @@ float64 float16_to_float64(float16 a, flag ieee, float_status *status);
 | Software half-precision operations.
 *----------------------------------------------------------------------------*/
 
+float16 float16_round_to_int(float16, float_status *status);
 float16 float16_add(float16, float16, float_status *status);
 float16 float16_sub(float16, float16, float_status *status);
 float16 float16_mul(float16, float16, float_status *status);
-- 
2.15.1

[Qemu-devel] [PATCH v4 17/22] fpu/softfloat: re-factor float to int/uint

[Alex Bennée]

We share the common int64/uint64_pack_decomposed function across all
the helpers and simply limit the final result depending on the final
size.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

---
v2
  - apply float_flg_invalid fixes next patch
v3
  - re-factor to common round_to_int/uint_and_pack
  - save flag state so invalid can override inexact
  - float to int/uint naming fixes
---
 fpu/softfloat.c         | 935 ++++++++++--------------------------------------
 include/fpu/softfloat.h |  13 +
 2 files changed, 193 insertions(+), 755 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 5d04e65538..216d60df6e 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1321,6 +1321,186 @@ float64 float64_trunc_to_int(float64 a, float_status *s)
     return float64_round_pack_canonical(pr, s);
 }
 
+/*
+ * Returns the result of converting the floating-point value `a' to
+ * the two's complement integer format. The conversion is performed
+ * according to the IEC/IEEE Standard for Binary Floating-Point
+ * Arithmetic---which means in particular that the conversion is
+ * rounded according to the current rounding mode. If `a' is a NaN,
+ * the largest positive integer is returned. Otherwise, if the
+ * conversion overflows, the largest integer with the same sign as `a'
+ * is returned.
+*/
+
+static int64_t round_to_int_and_pack(FloatParts in, int rmode,
+                                     int64_t min, int64_t max,
+                                     float_status *s)
+{
+    uint64_t r;
+    int orig_flags = get_float_exception_flags(s);
+    FloatParts p = round_to_int(in, rmode, s);
+
+    switch (p.cls) {
+    case float_class_snan:
+    case float_class_qnan:
+        return max;
+    case float_class_inf:
+        return p.sign ? min : max;
+    case float_class_zero:
+        return 0;
+    case float_class_normal:
+        if (p.exp < DECOMPOSED_BINARY_POINT) {
+            r = p.frac >> (DECOMPOSED_BINARY_POINT - p.exp);
+        } else if (p.exp - DECOMPOSED_BINARY_POINT < 2) {
+            r = p.frac << (p.exp - DECOMPOSED_BINARY_POINT);
+        } else {
+            r = UINT64_MAX;
+        }
+        if (p.sign) {
+            if (r < -(uint64_t) min) {
+                return -r;
+            } else {
+                s->float_exception_flags = orig_flags | float_flag_invalid;
+                return min;
+            }
+        } else {
+            if (r < max) {
+                return r;
+            } else {
+                s->float_exception_flags = orig_flags | float_flag_invalid;
+                return max;
+            }
+        }
+    default:
+        g_assert_not_reached();
+    }
+}
+
+#define FLOAT_TO_INT(fsz, isz)                                          \
+int ## isz ## _t float ## fsz ## _to_int ## isz(float ## fsz a,         \
+                                                float_status *s)        \
+{                                                                       \
+    FloatParts p = float ## fsz ## _unpack_canonical(a, s);             \
+    return round_to_int_and_pack(p, s->float_rounding_mode,             \
+                                 INT ## isz ## _MIN, INT ## isz ## _MAX,\
+                                 s);                                    \
+}                                                                       \
+                                                                        \
+int ## isz ## _t float ## fsz ## _to_int ## isz ## _round_to_zero       \
+ (float ## fsz a, float_status *s)                                      \
+{                                                                       \
+    FloatParts p = float ## fsz ## _unpack_canonical(a, s);             \
+    return round_to_int_and_pack(p, float_round_to_zero,                \
+                                 INT ## isz ## _MIN, INT ## isz ## _MAX,\
+                                 s);                                    \
+}
+
+FLOAT_TO_INT(16, 16)
+FLOAT_TO_INT(16, 32)
+FLOAT_TO_INT(16, 64)
+
+FLOAT_TO_INT(32, 16)
+FLOAT_TO_INT(32, 32)
+FLOAT_TO_INT(32, 64)
+
+FLOAT_TO_INT(64, 16)
+FLOAT_TO_INT(64, 32)
+FLOAT_TO_INT(64, 64)
+
+#undef FLOAT_TO_INT
+
+/*
+ *  Returns the result of converting the floating-point value `a' to
+ *  the unsigned integer format. The conversion is performed according
+ *  to the IEC/IEEE Standard for Binary Floating-Point
+ *  Arithmetic---which means in particular that the conversion is
+ *  rounded according to the current rounding mode. If `a' is a NaN,
+ *  the largest unsigned integer is returned. Otherwise, if the
+ *  conversion overflows, the largest unsigned integer is returned. If
+ *  the 'a' is negative, the result is rounded and zero is returned;
+ *  values that do not round to zero will raise the inexact exception
+ *  flag.
+ */
+
+static uint64_t round_to_uint_and_pack(FloatParts in, int rmode, uint64_t max,
+                                       float_status *s)
+{
+    int orig_flags = get_float_exception_flags(s);
+    FloatParts p = round_to_int(in, rmode, s);
+
+    switch (p.cls) {
+    case float_class_snan:
+    case float_class_qnan:
+        s->float_exception_flags = orig_flags | float_flag_invalid;
+        return max;
+    case float_class_inf:
+        return p.sign ? 0 : max;
+    case float_class_zero:
+        return 0;
+    case float_class_normal:
+    {
+        uint64_t r;
+        if (p.sign) {
+            s->float_exception_flags = orig_flags | float_flag_invalid;
+            return 0;
+        }
+
+        if (p.exp < DECOMPOSED_BINARY_POINT) {
+            r = p.frac >> (DECOMPOSED_BINARY_POINT - p.exp);
+        } else if (p.exp - DECOMPOSED_BINARY_POINT < 2) {
+            r = p.frac << (p.exp - DECOMPOSED_BINARY_POINT);
+        } else {
+            s->float_exception_flags = orig_flags | float_flag_invalid;
+            return max;
+        }
+
+        /* For uint64 this will never trip, but if p.exp is too large
+         * to shift a decomposed fraction we shall have exited via the
+         * 3rd leg above.
+         */
+        if (r > max) {
+            s->float_exception_flags = orig_flags | float_flag_invalid;
+            return max;
+        } else {
+            return r;
+        }
+    }
+    default:
+        g_assert_not_reached();
+    }
+}
+
+#define FLOAT_TO_UINT(fsz, isz) \
+uint ## isz ## _t float ## fsz ## _to_uint ## isz(float ## fsz a,       \
+                                                  float_status *s)      \
+{                                                                       \
+    FloatParts p = float ## fsz ## _unpack_canonical(a, s);             \
+    return round_to_uint_and_pack(p, s->float_rounding_mode,            \
+                                 UINT ## isz ## _MAX, s);               \
+}                                                                       \
+                                                                        \
+uint ## isz ## _t float ## fsz ## _to_uint ## isz ## _round_to_zero     \
+ (float ## fsz a, float_status *s)                                      \
+{                                                                       \
+    FloatParts p = float ## fsz ## _unpack_canonical(a, s);             \
+    return round_to_uint_and_pack(p, s->float_rounding_mode,            \
+                                 UINT ## isz ## _MAX, s);               \
+}
+
+FLOAT_TO_UINT(16, 16)
+FLOAT_TO_UINT(16, 32)
+FLOAT_TO_UINT(16, 64)
+
+FLOAT_TO_UINT(32, 16)
+FLOAT_TO_UINT(32, 32)
+FLOAT_TO_UINT(32, 64)
+
+FLOAT_TO_UINT(64, 16)
+FLOAT_TO_UINT(64, 32)
+FLOAT_TO_UINT(64, 64)
+
+#undef FLOAT_TO_UINT
+
 /*----------------------------------------------------------------------------
 | Takes a 64-bit fixed-point value `absZ' with binary point between bits 6
 | and 7, and returns the properly rounded 32-bit integer corresponding to the
@@ -2672,288 +2852,8 @@ float128 uint64_to_float128(uint64_t a, float_status *status)
     return normalizeRoundAndPackFloat128(0, 0x406E, a, 0, status);
 }
 
-/*----------------------------------------------------------------------------
-| Returns the result of converting the single-precision floating-point value
-| `a' to the 32-bit two's complement integer format.  The conversion is
-| performed according to the IEC/IEEE Standard for Binary Floating-Point
-| Arithmetic---which means in particular that the conversion is rounded
-| according to the current rounding mode.  If `a' is a NaN, the largest
-| positive integer is returned.  Otherwise, if the conversion overflows, the
-| largest integer with the same sign as `a' is returned.
-*----------------------------------------------------------------------------*/
-
-int32_t float32_to_int32(float32 a, float_status *status)
-{
-    flag aSign;
-    int aExp;
-    int shiftCount;
-    uint32_t aSig;
-    uint64_t aSig64;
-
-    a = float32_squash_input_denormal(a, status);
-    aSig = extractFloat32Frac( a );
-    aExp = extractFloat32Exp( a );
-    aSign = extractFloat32Sign( a );
-    if ( ( aExp == 0xFF ) && aSig ) aSign = 0;
-    if ( aExp ) aSig |= 0x00800000;
-    shiftCount = 0xAF - aExp;
-    aSig64 = aSig;
-    aSig64 <<= 32;
-    if ( 0 < shiftCount ) shift64RightJamming( aSig64, shiftCount, &aSig64 );
-    return roundAndPackInt32(aSign, aSig64, status);
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of converting the single-precision floating-point value
-| `a' to the 32-bit two's complement integer format.  The conversion is
-| performed according to the IEC/IEEE Standard for Binary Floating-Point
-| Arithmetic, except that the conversion is always rounded toward zero.
-| If `a' is a NaN, the largest positive integer is returned.  Otherwise, if
-| the conversion overflows, the largest integer with the same sign as `a' is
-| returned.
-*----------------------------------------------------------------------------*/
 
-int32_t float32_to_int32_round_to_zero(float32 a, float_status *status)
-{
-    flag aSign;
-    int aExp;
-    int shiftCount;
-    uint32_t aSig;
-    int32_t z;
-    a = float32_squash_input_denormal(a, status);
 
-    aSig = extractFloat32Frac( a );
-    aExp = extractFloat32Exp( a );
-    aSign = extractFloat32Sign( a );
-    shiftCount = aExp - 0x9E;
-    if ( 0 <= shiftCount ) {
-        if ( float32_val(a) != 0xCF000000 ) {
-            float_raise(float_flag_invalid, status);
-            if ( ! aSign || ( ( aExp == 0xFF ) && aSig ) ) return 0x7FFFFFFF;
-        }
-        return (int32_t) 0x80000000;
-    }
-    else if ( aExp <= 0x7E ) {
-        if (aExp | aSig) {
-            status->float_exception_flags |= float_flag_inexact;
-        }
-        return 0;
-    }
-    aSig = ( aSig | 0x00800000 )<<8;
-    z = aSig>>( - shiftCount );
-    if ( (uint32_t) ( aSig<<( shiftCount & 31 ) ) ) {
-        status->float_exception_flags |= float_flag_inexact;
-    }
-    if ( aSign ) z = - z;
-    return z;
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of converting the single-precision floating-point value
-| `a' to the 16-bit two's complement integer format.  The conversion is
-| performed according to the IEC/IEEE Standard for Binary Floating-Point
-| Arithmetic, except that the conversion is always rounded toward zero.
-| If `a' is a NaN, the largest positive integer is returned.  Otherwise, if
-| the conversion overflows, the largest integer with the same sign as `a' is
-| returned.
-*----------------------------------------------------------------------------*/
-
-int16_t float32_to_int16_round_to_zero(float32 a, float_status *status)
-{
-    flag aSign;
-    int aExp;
-    int shiftCount;
-    uint32_t aSig;
-    int32_t z;
-
-    aSig = extractFloat32Frac( a );
-    aExp = extractFloat32Exp( a );
-    aSign = extractFloat32Sign( a );
-    shiftCount = aExp - 0x8E;
-    if ( 0 <= shiftCount ) {
-        if ( float32_val(a) != 0xC7000000 ) {
-            float_raise(float_flag_invalid, status);
-            if ( ! aSign || ( ( aExp == 0xFF ) && aSig ) ) {
-                return 0x7FFF;
-            }
-        }
-        return (int32_t) 0xffff8000;
-    }
-    else if ( aExp <= 0x7E ) {
-        if ( aExp | aSig ) {
-            status->float_exception_flags |= float_flag_inexact;
-        }
-        return 0;
-    }
-    shiftCount -= 0x10;
-    aSig = ( aSig | 0x00800000 )<<8;
-    z = aSig>>( - shiftCount );
-    if ( (uint32_t) ( aSig<<( shiftCount & 31 ) ) ) {
-        status->float_exception_flags |= float_flag_inexact;
-    }
-    if ( aSign ) {
-        z = - z;
-    }
-    return z;
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of converting the single-precision floating-point value
-| `a' to the 64-bit two's complement integer format.  The conversion is
-| performed according to the IEC/IEEE Standard for Binary Floating-Point
-| Arithmetic---which means in particular that the conversion is rounded
-| according to the current rounding mode.  If `a' is a NaN, the largest
-| positive integer is returned.  Otherwise, if the conversion overflows, the
-| largest integer with the same sign as `a' is returned.
-*----------------------------------------------------------------------------*/
-
-int64_t float32_to_int64(float32 a, float_status *status)
-{
-    flag aSign;
-    int aExp;
-    int shiftCount;
-    uint32_t aSig;
-    uint64_t aSig64, aSigExtra;
-    a = float32_squash_input_denormal(a, status);
-
-    aSig = extractFloat32Frac( a );
-    aExp = extractFloat32Exp( a );
-    aSign = extractFloat32Sign( a );
-    shiftCount = 0xBE - aExp;
-    if ( shiftCount < 0 ) {
-        float_raise(float_flag_invalid, status);
-        if ( ! aSign || ( ( aExp == 0xFF ) && aSig ) ) {
-            return LIT64( 0x7FFFFFFFFFFFFFFF );
-        }
-        return (int64_t) LIT64( 0x8000000000000000 );
-    }
-    if ( aExp ) aSig |= 0x00800000;
-    aSig64 = aSig;
-    aSig64 <<= 40;
-    shift64ExtraRightJamming( aSig64, 0, shiftCount, &aSig64, &aSigExtra );
-    return roundAndPackInt64(aSign, aSig64, aSigExtra, status);
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of converting the single-precision floating-point value
-| `a' to the 64-bit unsigned integer format.  The conversion is
-| performed according to the IEC/IEEE Standard for Binary Floating-Point
-| Arithmetic---which means in particular that the conversion is rounded
-| according to the current rounding mode.  If `a' is a NaN, the largest
-| unsigned integer is returned.  Otherwise, if the conversion overflows, the
-| largest unsigned integer is returned.  If the 'a' is negative, the result
-| is rounded and zero is returned; values that do not round to zero will
-| raise the inexact exception flag.
-*----------------------------------------------------------------------------*/
-
-uint64_t float32_to_uint64(float32 a, float_status *status)
-{
-    flag aSign;
-    int aExp;
-    int shiftCount;
-    uint32_t aSig;
-    uint64_t aSig64, aSigExtra;
-    a = float32_squash_input_denormal(a, status);
-
-    aSig = extractFloat32Frac(a);
-    aExp = extractFloat32Exp(a);
-    aSign = extractFloat32Sign(a);
-    if ((aSign) && (aExp > 126)) {
-        float_raise(float_flag_invalid, status);
-        if (float32_is_any_nan(a)) {
-            return LIT64(0xFFFFFFFFFFFFFFFF);
-        } else {
-            return 0;
-        }
-    }
-    shiftCount = 0xBE - aExp;
-    if (aExp) {
-        aSig |= 0x00800000;
-    }
-    if (shiftCount < 0) {
-        float_raise(float_flag_invalid, status);
-        return LIT64(0xFFFFFFFFFFFFFFFF);
-    }
-
-    aSig64 = aSig;
-    aSig64 <<= 40;
-    shift64ExtraRightJamming(aSig64, 0, shiftCount, &aSig64, &aSigExtra);
-    return roundAndPackUint64(aSign, aSig64, aSigExtra, status);
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of converting the single-precision floating-point value
-| `a' to the 64-bit unsigned integer format.  The conversion is
-| performed according to the IEC/IEEE Standard for Binary Floating-Point
-| Arithmetic, except that the conversion is always rounded toward zero.  If
-| `a' is a NaN, the largest unsigned integer is returned.  Otherwise, if the
-| conversion overflows, the largest unsigned integer is returned.  If the
-| 'a' is negative, the result is rounded and zero is returned; values that do
-| not round to zero will raise the inexact flag.
-*----------------------------------------------------------------------------*/
-
-uint64_t float32_to_uint64_round_to_zero(float32 a, float_status *status)
-{
-    signed char current_rounding_mode = status->float_rounding_mode;
-    set_float_rounding_mode(float_round_to_zero, status);
-    int64_t v = float32_to_uint64(a, status);
-    set_float_rounding_mode(current_rounding_mode, status);
-    return v;
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of converting the single-precision floating-point value
-| `a' to the 64-bit two's complement integer format.  The conversion is
-| performed according to the IEC/IEEE Standard for Binary Floating-Point
-| Arithmetic, except that the conversion is always rounded toward zero.  If
-| `a' is a NaN, the largest positive integer is returned.  Otherwise, if the
-| conversion overflows, the largest integer with the same sign as `a' is
-| returned.
-*----------------------------------------------------------------------------*/
-
-int64_t float32_to_int64_round_to_zero(float32 a, float_status *status)
-{
-    flag aSign;
-    int aExp;
-    int shiftCount;
-    uint32_t aSig;
-    uint64_t aSig64;
-    int64_t z;
-    a = float32_squash_input_denormal(a, status);
-
-    aSig = extractFloat32Frac( a );
-    aExp = extractFloat32Exp( a );
-    aSign = extractFloat32Sign( a );
-    shiftCount = aExp - 0xBE;
-    if ( 0 <= shiftCount ) {
-        if ( float32_val(a) != 0xDF000000 ) {
-            float_raise(float_flag_invalid, status);
-            if ( ! aSign || ( ( aExp == 0xFF ) && aSig ) ) {
-                return LIT64( 0x7FFFFFFFFFFFFFFF );
-            }
-        }
-        return (int64_t) LIT64( 0x8000000000000000 );
-    }
-    else if ( aExp <= 0x7E ) {
-        if (aExp | aSig) {
-            status->float_exception_flags |= float_flag_inexact;
-        }
-        return 0;
-    }
-    aSig64 = aSig | 0x00800000;
-    aSig64 <<= 40;
-    z = aSig64>>( - shiftCount );
-    if ( (uint64_t) ( aSig64<<( shiftCount & 63 ) ) ) {
-        status->float_exception_flags |= float_flag_inexact;
-    }
-    if ( aSign ) z = - z;
-    return z;
-
-}
 
 /*----------------------------------------------------------------------------
 | Returns the result of converting the single-precision floating-point value
@@ -3559,236 +3459,6 @@ int float32_unordered_quiet(float32 a, float32 b, float_status *status)
     return 0;
 }
 
-/*----------------------------------------------------------------------------
-| Returns the result of converting the double-precision floating-point value
-| `a' to the 32-bit two's complement integer format.  The conversion is
-| performed according to the IEC/IEEE Standard for Binary Floating-Point
-| Arithmetic---which means in particular that the conversion is rounded
-| according to the current rounding mode.  If `a' is a NaN, the largest
-| positive integer is returned.  Otherwise, if the conversion overflows, the
-| largest integer with the same sign as `a' is returned.
-*----------------------------------------------------------------------------*/
-
-int32_t float64_to_int32(float64 a, float_status *status)
-{
-    flag aSign;
-    int aExp;
-    int shiftCount;
-    uint64_t aSig;
-    a = float64_squash_input_denormal(a, status);
-
-    aSig = extractFloat64Frac( a );
-    aExp = extractFloat64Exp( a );
-    aSign = extractFloat64Sign( a );
-    if ( ( aExp == 0x7FF ) && aSig ) aSign = 0;
-    if ( aExp ) aSig |= LIT64( 0x0010000000000000 );
-    shiftCount = 0x42C - aExp;
-    if ( 0 < shiftCount ) shift64RightJamming( aSig, shiftCount, &aSig );
-    return roundAndPackInt32(aSign, aSig, status);
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of converting the double-precision floating-point value
-| `a' to the 32-bit two's complement integer format.  The conversion is
-| performed according to the IEC/IEEE Standard for Binary Floating-Point
-| Arithmetic, except that the conversion is always rounded toward zero.
-| If `a' is a NaN, the largest positive integer is returned.  Otherwise, if
-| the conversion overflows, the largest integer with the same sign as `a' is
-| returned.
-*----------------------------------------------------------------------------*/
-
-int32_t float64_to_int32_round_to_zero(float64 a, float_status *status)
-{
-    flag aSign;
-    int aExp;
-    int shiftCount;
-    uint64_t aSig, savedASig;
-    int32_t z;
-    a = float64_squash_input_denormal(a, status);
-
-    aSig = extractFloat64Frac( a );
-    aExp = extractFloat64Exp( a );
-    aSign = extractFloat64Sign( a );
-    if ( 0x41E < aExp ) {
-        if ( ( aExp == 0x7FF ) && aSig ) aSign = 0;
-        goto invalid;
-    }
-    else if ( aExp < 0x3FF ) {
-        if (aExp || aSig) {
-            status->float_exception_flags |= float_flag_inexact;
-        }
-        return 0;
-    }
-    aSig |= LIT64( 0x0010000000000000 );
-    shiftCount = 0x433 - aExp;
-    savedASig = aSig;
-    aSig >>= shiftCount;
-    z = aSig;
-    if ( aSign ) z = - z;
-    if ( ( z < 0 ) ^ aSign ) {
- invalid:
-        float_raise(float_flag_invalid, status);
-        return aSign ? (int32_t) 0x80000000 : 0x7FFFFFFF;
-    }
-    if ( ( aSig<<shiftCount ) != savedASig ) {
-        status->float_exception_flags |= float_flag_inexact;
-    }
-    return z;
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of converting the double-precision floating-point value
-| `a' to the 16-bit two's complement integer format.  The conversion is
-| performed according to the IEC/IEEE Standard for Binary Floating-Point
-| Arithmetic, except that the conversion is always rounded toward zero.
-| If `a' is a NaN, the largest positive integer is returned.  Otherwise, if
-| the conversion overflows, the largest integer with the same sign as `a' is
-| returned.
-*----------------------------------------------------------------------------*/
-
-int16_t float64_to_int16_round_to_zero(float64 a, float_status *status)
-{
-    flag aSign;
-    int aExp;
-    int shiftCount;
-    uint64_t aSig, savedASig;
-    int32_t z;
-
-    aSig = extractFloat64Frac( a );
-    aExp = extractFloat64Exp( a );
-    aSign = extractFloat64Sign( a );
-    if ( 0x40E < aExp ) {
-        if ( ( aExp == 0x7FF ) && aSig ) {
-            aSign = 0;
-        }
-        goto invalid;
-    }
-    else if ( aExp < 0x3FF ) {
-        if ( aExp || aSig ) {
-            status->float_exception_flags |= float_flag_inexact;
-        }
-        return 0;
-    }
-    aSig |= LIT64( 0x0010000000000000 );
-    shiftCount = 0x433 - aExp;
-    savedASig = aSig;
-    aSig >>= shiftCount;
-    z = aSig;
-    if ( aSign ) {
-        z = - z;
-    }
-    if ( ( (int16_t)z < 0 ) ^ aSign ) {
- invalid:
-        float_raise(float_flag_invalid, status);
-        return aSign ? (int32_t) 0xffff8000 : 0x7FFF;
-    }
-    if ( ( aSig<<shiftCount ) != savedASig ) {
-        status->float_exception_flags |= float_flag_inexact;
-    }
-    return z;
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of converting the double-precision floating-point value
-| `a' to the 64-bit two's complement integer format.  The conversion is
-| performed according to the IEC/IEEE Standard for Binary Floating-Point
-| Arithmetic---which means in particular that the conversion is rounded
-| according to the current rounding mode.  If `a' is a NaN, the largest
-| positive integer is returned.  Otherwise, if the conversion overflows, the
-| largest integer with the same sign as `a' is returned.
-*----------------------------------------------------------------------------*/
-
-int64_t float64_to_int64(float64 a, float_status *status)
-{
-    flag aSign;
-    int aExp;
-    int shiftCount;
-    uint64_t aSig, aSigExtra;
-    a = float64_squash_input_denormal(a, status);
-
-    aSig = extractFloat64Frac( a );
-    aExp = extractFloat64Exp( a );
-    aSign = extractFloat64Sign( a );
-    if ( aExp ) aSig |= LIT64( 0x0010000000000000 );
-    shiftCount = 0x433 - aExp;
-    if ( shiftCount <= 0 ) {
-        if ( 0x43E < aExp ) {
-            float_raise(float_flag_invalid, status);
-            if (    ! aSign
-                 || (    ( aExp == 0x7FF )
-                      && ( aSig != LIT64( 0x0010000000000000 ) ) )
-               ) {
-                return LIT64( 0x7FFFFFFFFFFFFFFF );
-            }
-            return (int64_t) LIT64( 0x8000000000000000 );
-        }
-        aSigExtra = 0;
-        aSig <<= - shiftCount;
-    }
-    else {
-        shift64ExtraRightJamming( aSig, 0, shiftCount, &aSig, &aSigExtra );
-    }
-    return roundAndPackInt64(aSign, aSig, aSigExtra, status);
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of converting the double-precision floating-point value
-| `a' to the 64-bit two's complement integer format.  The conversion is
-| performed according to the IEC/IEEE Standard for Binary Floating-Point
-| Arithmetic, except that the conversion is always rounded toward zero.
-| If `a' is a NaN, the largest positive integer is returned.  Otherwise, if
-| the conversion overflows, the largest integer with the same sign as `a' is
-| returned.
-*----------------------------------------------------------------------------*/
-
-int64_t float64_to_int64_round_to_zero(float64 a, float_status *status)
-{
-    flag aSign;
-    int aExp;
-    int shiftCount;
-    uint64_t aSig;
-    int64_t z;
-    a = float64_squash_input_denormal(a, status);
-
-    aSig = extractFloat64Frac( a );
-    aExp = extractFloat64Exp( a );
-    aSign = extractFloat64Sign( a );
-    if ( aExp ) aSig |= LIT64( 0x0010000000000000 );
-    shiftCount = aExp - 0x433;
-    if ( 0 <= shiftCount ) {
-        if ( 0x43E <= aExp ) {
-            if ( float64_val(a) != LIT64( 0xC3E0000000000000 ) ) {
-                float_raise(float_flag_invalid, status);
-                if (    ! aSign
-                     || (    ( aExp == 0x7FF )
-                          && ( aSig != LIT64( 0x0010000000000000 ) ) )
-                   ) {
-                    return LIT64( 0x7FFFFFFFFFFFFFFF );
-                }
-            }
-            return (int64_t) LIT64( 0x8000000000000000 );
-        }
-        z = aSig<<shiftCount;
-    }
-    else {
-        if ( aExp < 0x3FE ) {
-            if (aExp | aSig) {
-                status->float_exception_flags |= float_flag_inexact;
-            }
-            return 0;
-        }
-        z = aSig>>( - shiftCount );
-        if ( (uint64_t) ( aSig<<( shiftCount & 63 ) ) ) {
-            status->float_exception_flags |= float_flag_inexact;
-        }
-    }
-    if ( aSign ) z = - z;
-    return z;
-
-}
 
 /*----------------------------------------------------------------------------
 | Returns the result of converting the double-precision floating-point value
@@ -7056,252 +6726,7 @@ float64 uint32_to_float64(uint32_t a, float_status *status)
     return int64_to_float64(a, status);
 }
 
-uint32_t float32_to_uint32(float32 a, float_status *status)
-{
-    int64_t v;
-    uint32_t res;
-    int old_exc_flags = get_float_exception_flags(status);
 
-    v = float32_to_int64(a, status);
-    if (v < 0) {
-        res = 0;
-    } else if (v > 0xffffffff) {
-        res = 0xffffffff;
-    } else {
-        return v;
-    }
-    set_float_exception_flags(old_exc_flags, status);
-    float_raise(float_flag_invalid, status);
-    return res;
-}
-
-uint32_t float32_to_uint32_round_to_zero(float32 a, float_status *status)
-{
-    int64_t v;
-    uint32_t res;
-    int old_exc_flags = get_float_exception_flags(status);
-
-    v = float32_to_int64_round_to_zero(a, status);
-    if (v < 0) {
-        res = 0;
-    } else if (v > 0xffffffff) {
-        res = 0xffffffff;
-    } else {
-        return v;
-    }
-    set_float_exception_flags(old_exc_flags, status);
-    float_raise(float_flag_invalid, status);
-    return res;
-}
-
-int16_t float32_to_int16(float32 a, float_status *status)
-{
-    int32_t v;
-    int16_t res;
-    int old_exc_flags = get_float_exception_flags(status);
-
-    v = float32_to_int32(a, status);
-    if (v < -0x8000) {
-        res = -0x8000;
-    } else if (v > 0x7fff) {
-        res = 0x7fff;
-    } else {
-        return v;
-    }
-
-    set_float_exception_flags(old_exc_flags, status);
-    float_raise(float_flag_invalid, status);
-    return res;
-}
-
-uint16_t float32_to_uint16(float32 a, float_status *status)
-{
-    int32_t v;
-    uint16_t res;
-    int old_exc_flags = get_float_exception_flags(status);
-
-    v = float32_to_int32(a, status);
-    if (v < 0) {
-        res = 0;
-    } else if (v > 0xffff) {
-        res = 0xffff;
-    } else {
-        return v;
-    }
-
-    set_float_exception_flags(old_exc_flags, status);
-    float_raise(float_flag_invalid, status);
-    return res;
-}
-
-uint16_t float32_to_uint16_round_to_zero(float32 a, float_status *status)
-{
-    int64_t v;
-    uint16_t res;
-    int old_exc_flags = get_float_exception_flags(status);
-
-    v = float32_to_int64_round_to_zero(a, status);
-    if (v < 0) {
-        res = 0;
-    } else if (v > 0xffff) {
-        res = 0xffff;
-    } else {
-        return v;
-    }
-    set_float_exception_flags(old_exc_flags, status);
-    float_raise(float_flag_invalid, status);
-    return res;
-}
-
-uint32_t float64_to_uint32(float64 a, float_status *status)
-{
-    uint64_t v;
-    uint32_t res;
-    int old_exc_flags = get_float_exception_flags(status);
-
-    v = float64_to_uint64(a, status);
-    if (v > 0xffffffff) {
-        res = 0xffffffff;
-    } else {
-        return v;
-    }
-    set_float_exception_flags(old_exc_flags, status);
-    float_raise(float_flag_invalid, status);
-    return res;
-}
-
-uint32_t float64_to_uint32_round_to_zero(float64 a, float_status *status)
-{
-    uint64_t v;
-    uint32_t res;
-    int old_exc_flags = get_float_exception_flags(status);
-
-    v = float64_to_uint64_round_to_zero(a, status);
-    if (v > 0xffffffff) {
-        res = 0xffffffff;
-    } else {
-        return v;
-    }
-    set_float_exception_flags(old_exc_flags, status);
-    float_raise(float_flag_invalid, status);
-    return res;
-}
-
-int16_t float64_to_int16(float64 a, float_status *status)
-{
-    int64_t v;
-    int16_t res;
-    int old_exc_flags = get_float_exception_flags(status);
-
-    v = float64_to_int32(a, status);
-    if (v < -0x8000) {
-        res = -0x8000;
-    } else if (v > 0x7fff) {
-        res = 0x7fff;
-    } else {
-        return v;
-    }
-
-    set_float_exception_flags(old_exc_flags, status);
-    float_raise(float_flag_invalid, status);
-    return res;
-}
-
-uint16_t float64_to_uint16(float64 a, float_status *status)
-{
-    int64_t v;
-    uint16_t res;
-    int old_exc_flags = get_float_exception_flags(status);
-
-    v = float64_to_int32(a, status);
-    if (v < 0) {
-        res = 0;
-    } else if (v > 0xffff) {
-        res = 0xffff;
-    } else {
-        return v;
-    }
-
-    set_float_exception_flags(old_exc_flags, status);
-    float_raise(float_flag_invalid, status);
-    return res;
-}
-
-uint16_t float64_to_uint16_round_to_zero(float64 a, float_status *status)
-{
-    int64_t v;
-    uint16_t res;
-    int old_exc_flags = get_float_exception_flags(status);
-
-    v = float64_to_int64_round_to_zero(a, status);
-    if (v < 0) {
-        res = 0;
-    } else if (v > 0xffff) {
-        res = 0xffff;
-    } else {
-        return v;
-    }
-    set_float_exception_flags(old_exc_flags, status);
-    float_raise(float_flag_invalid, status);
-    return res;
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of converting the double-precision floating-point value
-| `a' to the 64-bit unsigned integer format.  The conversion is
-| performed according to the IEC/IEEE Standard for Binary Floating-Point
-| Arithmetic---which means in particular that the conversion is rounded
-| according to the current rounding mode.  If `a' is a NaN, the largest
-| positive integer is returned.  If the conversion overflows, the
-| largest unsigned integer is returned.  If 'a' is negative, the value is
-| rounded and zero is returned; negative values that do not round to zero
-| will raise the inexact exception.
-*----------------------------------------------------------------------------*/
-
-uint64_t float64_to_uint64(float64 a, float_status *status)
-{
-    flag aSign;
-    int aExp;
-    int shiftCount;
-    uint64_t aSig, aSigExtra;
-    a = float64_squash_input_denormal(a, status);
-
-    aSig = extractFloat64Frac(a);
-    aExp = extractFloat64Exp(a);
-    aSign = extractFloat64Sign(a);
-    if (aSign && (aExp > 1022)) {
-        float_raise(float_flag_invalid, status);
-        if (float64_is_any_nan(a)) {
-            return LIT64(0xFFFFFFFFFFFFFFFF);
-        } else {
-            return 0;
-        }
-    }
-    if (aExp) {
-        aSig |= LIT64(0x0010000000000000);
-    }
-    shiftCount = 0x433 - aExp;
-    if (shiftCount <= 0) {
-        if (0x43E < aExp) {
-            float_raise(float_flag_invalid, status);
-            return LIT64(0xFFFFFFFFFFFFFFFF);
-        }
-        aSigExtra = 0;
-        aSig <<= -shiftCount;
-    } else {
-        shift64ExtraRightJamming(aSig, 0, shiftCount, &aSig, &aSigExtra);
-    }
-    return roundAndPackUint64(aSign, aSig, aSigExtra, status);
-}
-
-uint64_t float64_to_uint64_round_to_zero(float64 a, float_status *status)
-{
-    signed char current_rounding_mode = status->float_rounding_mode;
-    set_float_rounding_mode(float_round_to_zero, status);
-    uint64_t v = float64_to_uint64(a, status);
-    set_float_rounding_mode(current_rounding_mode, status);
-    return v;
-}
 
 #define COMPARE(s, nan_exp)                                                  \
 static inline int float ## s ## _compare_internal(float ## s a, float ## s b,\
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 4650758c23..ec1e701c26 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -232,6 +232,19 @@ float16 float32_to_float16(float32, flag, float_status *status);
 float32 float16_to_float32(float16, flag, float_status *status);
 float16 float64_to_float16(float64 a, flag ieee, float_status *status);
 float64 float16_to_float64(float16 a, flag ieee, float_status *status);
+int16_t float16_to_int16(float16, float_status *status);
+uint16_t float16_to_uint16(float16 a, float_status *status);
+int16_t float16_to_int16_round_to_zero(float16, float_status *status);
+uint16_t float16_to_uint16_round_to_zero(float16 a, float_status *status);
+int32_t float16_to_int32(float16, float_status *status);
+uint32_t float16_to_uint32(float16 a, float_status *status);
+int32_t float16_to_int32_round_to_zero(float16, float_status *status);
+uint32_t float16_to_uint32_round_to_zero(float16 a, float_status *status);
+int64_t float16_to_int64(float16, float_status *status);
+uint64_t float16_to_uint64(float16 a, float_status *status);
+int64_t float16_to_int64_round_to_zero(float16, float_status *status);
+uint64_t float16_to_uint64_round_to_zero(float16 a, float_status *status);
+float16 int16_to_float16(int16_t a, float_status *status);
 
 /*----------------------------------------------------------------------------
 | Software half-precision operations.
-- 
2.15.1

[Qemu-devel] [PATCH v4 18/22] fpu/softfloat: re-factor int/uint to float

[Alex Bennée]

These are considerably simpler as the lower order integers can just
use the higher order conversion function. As the decomposed fractional
part is a full 64 bit rounding and inexact handling comes from the
pack functions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
v2
  - explicit setting of r.sign
v3
  - renaming of functions/structs
---
 fpu/softfloat.c         | 322 ++++++++++++++++++++++++------------------------
 include/fpu/softfloat.h |  30 ++---
 2 files changed, 172 insertions(+), 180 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 216d60df6e..9f9f101d35 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1501,6 +1501,169 @@ FLOAT_TO_UINT(64, 64)
 
 #undef FLOAT_TO_UINT
 
+/*
+ * Integer to float conversions
+ *
+ * Returns the result of converting the two's complement integer `a'
+ * to the floating-point format. The conversion is performed according
+ * to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
+ */
+
+static FloatParts int_to_float(int64_t a, float_status *status)
+{
+    FloatParts r;
+    if (a == 0) {
+        r.cls = float_class_zero;
+        r.sign = false;
+    } else if (a == (1ULL << 63)) {
+        r.cls = float_class_normal;
+        r.sign = true;
+        r.frac = DECOMPOSED_IMPLICIT_BIT;
+        r.exp = 63;
+    } else {
+        uint64_t f;
+        if (a < 0) {
+            f = -a;
+            r.sign = true;
+        } else {
+            f = a;
+            r.sign = false;
+        }
+        int shift = clz64(f) - 1;
+        r.cls = float_class_normal;
+        r.exp = (DECOMPOSED_BINARY_POINT - shift);
+        r.frac = f << shift;
+    }
+
+    return r;
+}
+
+float16 int64_to_float16(int64_t a, float_status *status)
+{
+    FloatParts pa = int_to_float(a, status);
+    return float16_round_pack_canonical(pa, status);
+}
+
+float16 int32_to_float16(int32_t a, float_status *status)
+{
+    return int64_to_float16(a, status);
+}
+
+float16 int16_to_float16(int16_t a, float_status *status)
+{
+    return int64_to_float16(a, status);
+}
+
+float32 int64_to_float32(int64_t a, float_status *status)
+{
+    FloatParts pa = int_to_float(a, status);
+    return float32_round_pack_canonical(pa, status);
+}
+
+float32 int32_to_float32(int32_t a, float_status *status)
+{
+    return int64_to_float32(a, status);
+}
+
+float32 int16_to_float32(int16_t a, float_status *status)
+{
+    return int64_to_float32(a, status);
+}
+
+float64 int64_to_float64(int64_t a, float_status *status)
+{
+    FloatParts pa = int_to_float(a, status);
+    return float64_round_pack_canonical(pa, status);
+}
+
+float64 int32_to_float64(int32_t a, float_status *status)
+{
+    return int64_to_float64(a, status);
+}
+
+float64 int16_to_float64(int16_t a, float_status *status)
+{
+    return int64_to_float64(a, status);
+}
+
+
+/*
+ * Unsigned Integer to float conversions
+ *
+ * Returns the result of converting the unsigned integer `a' to the
+ * floating-point format. The conversion is performed according to the
+ * IEC/IEEE Standard for Binary Floating-Point Arithmetic.
+ */
+
+static FloatParts uint_to_float(uint64_t a, float_status *status)
+{
+    FloatParts r = { .sign = false};
+
+    if (a == 0) {
+        r.cls = float_class_zero;
+    } else {
+        int spare_bits = clz64(a) - 1;
+        r.cls = float_class_normal;
+        r.exp = DECOMPOSED_BINARY_POINT - spare_bits;
+        if (spare_bits < 0) {
+            shift64RightJamming(a, -spare_bits, &a);
+            r.frac = a;
+        } else {
+            r.frac = a << spare_bits;
+        }
+    }
+
+    return r;
+}
+
+float16 uint64_to_float16(uint64_t a, float_status *status)
+{
+    FloatParts pa = uint_to_float(a, status);
+    return float16_round_pack_canonical(pa, status);
+}
+
+float16 uint32_to_float16(uint32_t a, float_status *status)
+{
+    return uint64_to_float16(a, status);
+}
+
+float16 uint16_to_float16(uint16_t a, float_status *status)
+{
+    return uint64_to_float16(a, status);
+}
+
+float32 uint64_to_float32(uint64_t a, float_status *status)
+{
+    FloatParts pa = uint_to_float(a, status);
+    return float32_round_pack_canonical(pa, status);
+}
+
+float32 uint32_to_float32(uint32_t a, float_status *status)
+{
+    return uint64_to_float32(a, status);
+}
+
+float32 uint16_to_float32(uint16_t a, float_status *status)
+{
+    return uint64_to_float32(a, status);
+}
+
+float64 uint64_to_float64(uint64_t a, float_status *status)
+{
+    FloatParts pa = uint_to_float(a, status);
+    return float64_round_pack_canonical(pa, status);
+}
+
+float64 uint32_to_float64(uint32_t a, float_status *status)
+{
+    return uint64_to_float64(a, status);
+}
+
+float64 uint16_to_float64(uint16_t a, float_status *status)
+{
+    return uint64_to_float64(a, status);
+}
+
 /*----------------------------------------------------------------------------
 | Takes a 64-bit fixed-point value `absZ' with binary point between bits 6
 | and 7, and returns the properly rounded 32-bit integer corresponding to the
@@ -2592,43 +2755,6 @@ static float128 normalizeRoundAndPackFloat128(flag zSign, int32_t zExp,
 
 }
 
-/*----------------------------------------------------------------------------
-| Returns the result of converting the 32-bit two's complement integer `a'
-| to the single-precision floating-point format.  The conversion is performed
-| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float32 int32_to_float32(int32_t a, float_status *status)
-{
-    flag zSign;
-
-    if ( a == 0 ) return float32_zero;
-    if ( a == (int32_t) 0x80000000 ) return packFloat32( 1, 0x9E, 0 );
-    zSign = ( a < 0 );
-    return normalizeRoundAndPackFloat32(zSign, 0x9C, zSign ? -a : a, status);
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of converting the 32-bit two's complement integer `a'
-| to the double-precision floating-point format.  The conversion is performed
-| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float64 int32_to_float64(int32_t a, float_status *status)
-{
-    flag zSign;
-    uint32_t absA;
-    int8_t shiftCount;
-    uint64_t zSig;
-
-    if ( a == 0 ) return float64_zero;
-    zSign = ( a < 0 );
-    absA = zSign ? - a : a;
-    shiftCount = countLeadingZeros32( absA ) + 21;
-    zSig = absA;
-    return packFloat64( zSign, 0x432 - shiftCount, zSig<<shiftCount );
-
-}
 
 /*----------------------------------------------------------------------------
 | Returns the result of converting the 32-bit two's complement integer `a'
@@ -2675,56 +2801,6 @@ float128 int32_to_float128(int32_t a, float_status *status)
 
 }
 
-/*----------------------------------------------------------------------------
-| Returns the result of converting the 64-bit two's complement integer `a'
-| to the single-precision floating-point format.  The conversion is performed
-| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float32 int64_to_float32(int64_t a, float_status *status)
-{
-    flag zSign;
-    uint64_t absA;
-    int8_t shiftCount;
-
-    if ( a == 0 ) return float32_zero;
-    zSign = ( a < 0 );
-    absA = zSign ? - a : a;
-    shiftCount = countLeadingZeros64( absA ) - 40;
-    if ( 0 <= shiftCount ) {
-        return packFloat32( zSign, 0x95 - shiftCount, absA<<shiftCount );
-    }
-    else {
-        shiftCount += 7;
-        if ( shiftCount < 0 ) {
-            shift64RightJamming( absA, - shiftCount, &absA );
-        }
-        else {
-            absA <<= shiftCount;
-        }
-        return roundAndPackFloat32(zSign, 0x9C - shiftCount, absA, status);
-    }
-
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of converting the 64-bit two's complement integer `a'
-| to the double-precision floating-point format.  The conversion is performed
-| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float64 int64_to_float64(int64_t a, float_status *status)
-{
-    flag zSign;
-
-    if ( a == 0 ) return float64_zero;
-    if ( a == (int64_t) LIT64( 0x8000000000000000 ) ) {
-        return packFloat64( 1, 0x43E, 0 );
-    }
-    zSign = ( a < 0 );
-    return normalizeRoundAndPackFloat64(zSign, 0x43C, zSign ? -a : a, status);
-}
-
 /*----------------------------------------------------------------------------
 | Returns the result of converting the 64-bit two's complement integer `a'
 | to the extended double-precision floating-point format.  The conversion
@@ -2779,65 +2855,6 @@ float128 int64_to_float128(int64_t a, float_status *status)
 
 }
 
-/*----------------------------------------------------------------------------
-| Returns the result of converting the 64-bit unsigned integer `a'
-| to the single-precision floating-point format.  The conversion is performed
-| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float32 uint64_to_float32(uint64_t a, float_status *status)
-{
-    int shiftcount;
-
-    if (a == 0) {
-        return float32_zero;
-    }
-
-    /* Determine (left) shift needed to put first set bit into bit posn 23
-     * (since packFloat32() expects the binary point between bits 23 and 22);
-     * this is the fast case for smallish numbers.
-     */
-    shiftcount = countLeadingZeros64(a) - 40;
-    if (shiftcount >= 0) {
-        return packFloat32(0, 0x95 - shiftcount, a << shiftcount);
-    }
-    /* Otherwise we need to do a round-and-pack. roundAndPackFloat32()
-     * expects the binary point between bits 30 and 29, hence the + 7.
-     */
-    shiftcount += 7;
-    if (shiftcount < 0) {
-        shift64RightJamming(a, -shiftcount, &a);
-    } else {
-        a <<= shiftcount;
-    }
-
-    return roundAndPackFloat32(0, 0x9c - shiftcount, a, status);
-}
-
-/*----------------------------------------------------------------------------
-| Returns the result of converting the 64-bit unsigned integer `a'
-| to the double-precision floating-point format.  The conversion is performed
-| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float64 uint64_to_float64(uint64_t a, float_status *status)
-{
-    int exp = 0x43C;
-    int shiftcount;
-
-    if (a == 0) {
-        return float64_zero;
-    }
-
-    shiftcount = countLeadingZeros64(a) - 1;
-    if (shiftcount < 0) {
-        shift64RightJamming(a, -shiftcount, &a);
-    } else {
-        a <<= shiftcount;
-    }
-    return roundAndPackFloat64(0, exp - shiftcount, a, status);
-}
-
 /*----------------------------------------------------------------------------
 | Returns the result of converting the 64-bit unsigned integer `a'
 | to the quadruple-precision floating-point format.  The conversion is performed
@@ -6715,19 +6732,6 @@ int float128_unordered_quiet(float128 a, float128 b, float_status *status)
     return 0;
 }
 
-/* misc functions */
-float32 uint32_to_float32(uint32_t a, float_status *status)
-{
-    return int64_to_float32(a, status);
-}
-
-float64 uint32_to_float64(uint32_t a, float_status *status)
-{
-    return int64_to_float64(a, status);
-}
-
-
-
 #define COMPARE(s, nan_exp)                                                  \
 static inline int float ## s ## _compare_internal(float ## s a, float ## s b,\
                                       int is_quiet, float_status *status)    \
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index ec1e701c26..3e6fdd756a 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -190,9 +190,13 @@ enum {
 /*----------------------------------------------------------------------------
 | Software IEC/IEEE integer-to-floating-point conversion routines.
 *----------------------------------------------------------------------------*/
+float32 int16_to_float32(int16_t, float_status *status);
 float32 int32_to_float32(int32_t, float_status *status);
+float64 int16_to_float64(int16_t, float_status *status);
 float64 int32_to_float64(int32_t, float_status *status);
+float32 uint16_to_float32(uint16_t, float_status *status);
 float32 uint32_to_float32(uint32_t, float_status *status);
+float64 uint16_to_float64(uint16_t, float_status *status);
 float64 uint32_to_float64(uint32_t, float_status *status);
 floatx80 int32_to_floatx80(int32_t, float_status *status);
 float128 int32_to_float128(int32_t, float_status *status);
@@ -204,27 +208,6 @@ float32 uint64_to_float32(uint64_t, float_status *status);
 float64 uint64_to_float64(uint64_t, float_status *status);
 float128 uint64_to_float128(uint64_t, float_status *status);
 
-/* We provide the int16 versions for symmetry of API with float-to-int */
-static inline float32 int16_to_float32(int16_t v, float_status *status)
-{
-    return int32_to_float32(v, status);
-}
-
-static inline float32 uint16_to_float32(uint16_t v, float_status *status)
-{
-    return uint32_to_float32(v, status);
-}
-
-static inline float64 int16_to_float64(int16_t v, float_status *status)
-{
-    return int32_to_float64(v, status);
-}
-
-static inline float64 uint16_to_float64(uint16_t v, float_status *status)
-{
-    return uint32_to_float64(v, status);
-}
-
 /*----------------------------------------------------------------------------
 | Software half-precision conversion routines.
 *----------------------------------------------------------------------------*/
@@ -245,6 +228,11 @@ uint64_t float16_to_uint64(float16 a, float_status *status);
 int64_t float16_to_int64_round_to_zero(float16, float_status *status);
 uint64_t float16_to_uint64_round_to_zero(float16 a, float_status *status);
 float16 int16_to_float16(int16_t a, float_status *status);
+float16 int32_to_float16(int32_t a, float_status *status);
+float16 int64_to_float16(int64_t a, float_status *status);
+float16 uint16_to_float16(uint16_t a, float_status *status);
+float16 uint32_to_float16(uint32_t a, float_status *status);
+float16 uint64_to_float16(uint64_t a, float_status *status);
 
 /*----------------------------------------------------------------------------
 | Software half-precision operations.
-- 
2.15.1

[Qemu-devel] [PATCH v4 19/22] fpu/softfloat: re-factor scalbn

[Alex Bennée]

This is one of the simpler manipulations you could make to a floating
point number.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

---
v3
  - fix renames
v4
  - handle NaNs with return_nan
  - use unlikely(is_nan)
---
 fpu/softfloat.c         | 106 +++++++++++++++---------------------------------
 include/fpu/softfloat.h |   1 +
 2 files changed, 34 insertions(+), 73 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 9f9f101d35..558d37ecf9 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1664,6 +1664,39 @@ float64 uint16_to_float64(uint16_t a, float_status *status)
     return uint64_to_float64(a, status);
 }
 
+/* Multiply A by 2 raised to the power N.  */
+static FloatParts scalbn_decomposed(FloatParts a, int n, float_status *s)
+{
+    if (unlikely(is_nan(a.cls))) {
+        return return_nan(a, s);
+    }
+    if (a.cls == float_class_normal) {
+        a.exp += n;
+    }
+    return a;
+}
+
+float16 float16_scalbn(float16 a, int n, float_status *status)
+{
+    FloatParts pa = float16_unpack_canonical(a, status);
+    FloatParts pr = scalbn_decomposed(pa, n, status);
+    return float16_round_pack_canonical(pr, status);
+}
+
+float32 float32_scalbn(float32 a, int n, float_status *status)
+{
+    FloatParts pa = float32_unpack_canonical(a, status);
+    FloatParts pr = scalbn_decomposed(pa, n, status);
+    return float32_round_pack_canonical(pr, status);
+}
+
+float64 float64_scalbn(float64 a, int n, float_status *status)
+{
+    FloatParts pa = float64_unpack_canonical(a, status);
+    FloatParts pr = scalbn_decomposed(pa, n, status);
+    return float64_round_pack_canonical(pr, status);
+}
+
 /*----------------------------------------------------------------------------
 | Takes a 64-bit fixed-point value `absZ' with binary point between bits 6
 | and 7, and returns the properly rounded 32-bit integer corresponding to the
@@ -6987,79 +7020,6 @@ MINMAX(32)
 MINMAX(64)
 
 
-/* Multiply A by 2 raised to the power N.  */
-float32 float32_scalbn(float32 a, int n, float_status *status)
-{
-    flag aSign;
-    int16_t aExp;
-    uint32_t aSig;
-
-    a = float32_squash_input_denormal(a, status);
-    aSig = extractFloat32Frac( a );
-    aExp = extractFloat32Exp( a );
-    aSign = extractFloat32Sign( a );
-
-    if ( aExp == 0xFF ) {
-        if ( aSig ) {
-            return propagateFloat32NaN(a, a, status);
-        }
-        return a;
-    }
-    if (aExp != 0) {
-        aSig |= 0x00800000;
-    } else if (aSig == 0) {
-        return a;
-    } else {
-        aExp++;
-    }
-
-    if (n > 0x200) {
-        n = 0x200;
-    } else if (n < -0x200) {
-        n = -0x200;
-    }
-
-    aExp += n - 1;
-    aSig <<= 7;
-    return normalizeRoundAndPackFloat32(aSign, aExp, aSig, status);
-}
-
-float64 float64_scalbn(float64 a, int n, float_status *status)
-{
-    flag aSign;
-    int16_t aExp;
-    uint64_t aSig;
-
-    a = float64_squash_input_denormal(a, status);
-    aSig = extractFloat64Frac( a );
-    aExp = extractFloat64Exp( a );
-    aSign = extractFloat64Sign( a );
-
-    if ( aExp == 0x7FF ) {
-        if ( aSig ) {
-            return propagateFloat64NaN(a, a, status);
-        }
-        return a;
-    }
-    if (aExp != 0) {
-        aSig |= LIT64( 0x0010000000000000 );
-    } else if (aSig == 0) {
-        return a;
-    } else {
-        aExp++;
-    }
-
-    if (n > 0x1000) {
-        n = 0x1000;
-    } else if (n < -0x1000) {
-        n = -0x1000;
-    }
-
-    aExp += n - 1;
-    aSig <<= 10;
-    return normalizeRoundAndPackFloat64(aSign, aExp, aSig, status);
-}
-
 floatx80 floatx80_scalbn(floatx80 a, int n, float_status *status)
 {
     flag aSign;
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 3e6fdd756a..52621e0b79 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -244,6 +244,7 @@ float16 float16_sub(float16, float16, float_status *status);
 float16 float16_mul(float16, float16, float_status *status);
 float16 float16_muladd(float16, float16, float16, int, float_status *status);
 float16 float16_div(float16, float16, float_status *status);
+float16 float16_scalbn(float16, int, float_status *status);
 
 int float16_is_quiet_nan(float16, float_status *status);
 int float16_is_signaling_nan(float16, float_status *status);
-- 
2.15.1

[Qemu-devel] [PATCH v4 20/22] fpu/softfloat: re-factor minmax

[Alex Bennée]

Let's do the same re-factor treatment for minmax functions. I still
use the MACRO trick to expand but now all the checking code is common.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
v2
  - minor indentation fix
v3
  - fix merge conflicts from dropping MINMAX patch
  - fix naming of structs
v4
  - use is_nan/is_snan
  - pick_nan_parts->pick_nan
  - minmax_decomposed->minmax_floats
---
 fpu/softfloat.c         | 227 +++++++++++++++++++++++++-----------------------
 include/fpu/softfloat.h |   6 ++
 2 files changed, 126 insertions(+), 107 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 558d37ecf9..cb889a7a84 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1664,6 +1664,126 @@ float64 uint16_to_float64(uint16_t a, float_status *status)
     return uint64_to_float64(a, status);
 }
 
+/* Float Min/Max */
+/* min() and max() functions. These can't be implemented as
+ * 'compare and pick one input' because that would mishandle
+ * NaNs and +0 vs -0.
+ *
+ * minnum() and maxnum() functions. These are similar to the min()
+ * and max() functions but if one of the arguments is a QNaN and
+ * the other is numerical then the numerical argument is returned.
+ * SNaNs will get quietened before being returned.
+ * minnum() and maxnum correspond to the IEEE 754-2008 minNum()
+ * and maxNum() operations. min() and max() are the typical min/max
+ * semantics provided by many CPUs which predate that specification.
+ *
+ * minnummag() and maxnummag() functions correspond to minNumMag()
+ * and minNumMag() from the IEEE-754 2008.
+ */
+static FloatParts minmax_floats(FloatParts a, FloatParts b, bool ismin,
+                                bool ieee, bool ismag, float_status *s)
+{
+    if (unlikely(is_nan(a.cls) || is_nan(b.cls))) {
+        if (ieee) {
+            /* Takes two floating-point values `a' and `b', one of
+             * which is a NaN, and returns the appropriate NaN
+             * result. If either `a' or `b' is a signaling NaN,
+             * the invalid exception is raised.
+             */
+            if (is_snan(a.cls) || is_snan(b.cls)) {
+                return pick_nan(a, b, s);
+            } else if (is_nan(a.cls) && !is_nan(b.cls)) {
+                return b;
+            } else if (is_nan(b.cls) && !is_nan(a.cls)) {
+                return a;
+            }
+        }
+        return pick_nan(a, b, s);
+    } else {
+        int a_exp, b_exp;
+        bool a_sign, b_sign;
+
+        switch (a.cls) {
+        case float_class_normal:
+            a_exp = a.exp;
+            break;
+        case float_class_inf:
+            a_exp = INT_MAX;
+            break;
+        case float_class_zero:
+            a_exp = INT_MIN;
+            break;
+        default:
+            g_assert_not_reached();
+            break;
+        }
+        switch (b.cls) {
+        case float_class_normal:
+            b_exp = b.exp;
+            break;
+        case float_class_inf:
+            b_exp = INT_MAX;
+            break;
+        case float_class_zero:
+            b_exp = INT_MIN;
+            break;
+        default:
+            g_assert_not_reached();
+            break;
+        }
+
+        a_sign = a.sign;
+        b_sign = b.sign;
+        if (ismag) {
+            a_sign = b_sign = 0;
+        }
+
+        if (a_sign == b_sign) {
+            bool a_less = a_exp < b_exp;
+            if (a_exp == b_exp) {
+                a_less = a.frac < b.frac;
+            }
+            return a_sign ^ a_less ^ ismin ? b : a;
+        } else {
+            return a_sign ^ ismin ? b : a;
+        }
+    }
+}
+
+#define MINMAX(sz, name, ismin, isiee, ismag)                           \
+float ## sz float ## sz ## _ ## name(float ## sz a, float ## sz b,      \
+                                     float_status *s)                   \
+{                                                                       \
+    FloatParts pa = float ## sz ## _unpack_canonical(a, s);             \
+    FloatParts pb = float ## sz ## _unpack_canonical(b, s);             \
+    FloatParts pr = minmax_floats(pa, pb, ismin, isiee, ismag, s);      \
+                                                                        \
+    return float ## sz ## _round_pack_canonical(pr, s);                 \
+}
+
+MINMAX(16, min, true, false, false)
+MINMAX(16, minnum, true, true, false)
+MINMAX(16, minnummag, true, true, true)
+MINMAX(16, max, false, false, false)
+MINMAX(16, maxnum, false, true, false)
+MINMAX(16, maxnummag, false, true, true)
+
+MINMAX(32, min, true, false, false)
+MINMAX(32, minnum, true, true, false)
+MINMAX(32, minnummag, true, true, true)
+MINMAX(32, max, false, false, false)
+MINMAX(32, maxnum, false, true, false)
+MINMAX(32, maxnummag, false, true, true)
+
+MINMAX(64, min, true, false, false)
+MINMAX(64, minnum, true, true, false)
+MINMAX(64, minnummag, true, true, true)
+MINMAX(64, max, false, false, false)
+MINMAX(64, maxnum, false, true, false)
+MINMAX(64, maxnummag, false, true, true)
+
+#undef MINMAX
+
 /* Multiply A by 2 raised to the power N.  */
 static FloatParts scalbn_decomposed(FloatParts a, int n, float_status *s)
 {
@@ -6913,113 +7033,6 @@ int float128_compare_quiet(float128 a, float128 b, float_status *status)
     return float128_compare_internal(a, b, 1, status);
 }
 
-/* min() and max() functions. These can't be implemented as
- * 'compare and pick one input' because that would mishandle
- * NaNs and +0 vs -0.
- *
- * minnum() and maxnum() functions. These are similar to the min()
- * and max() functions but if one of the arguments is a QNaN and
- * the other is numerical then the numerical argument is returned.
- * minnum() and maxnum correspond to the IEEE 754-2008 minNum()
- * and maxNum() operations. min() and max() are the typical min/max
- * semantics provided by many CPUs which predate that specification.
- *
- * minnummag() and maxnummag() functions correspond to minNumMag()
- * and minNumMag() from the IEEE-754 2008.
- */
-#define MINMAX(s)                                                       \
-static inline float ## s float ## s ## _minmax(float ## s a, float ## s b,     \
-                                               int ismin, int isieee,   \
-                                               int ismag,               \
-                                               float_status *status)    \
-{                                                                       \
-    flag aSign, bSign;                                                  \
-    uint ## s ## _t av, bv, aav, abv;                                   \
-    a = float ## s ## _squash_input_denormal(a, status);                \
-    b = float ## s ## _squash_input_denormal(b, status);                \
-    if (float ## s ## _is_any_nan(a) ||                                 \
-        float ## s ## _is_any_nan(b)) {                                 \
-        if (isieee) {                                                   \
-            if (float ## s ## _is_quiet_nan(a, status) &&               \
-                !float ## s ##_is_any_nan(b)) {                         \
-                return b;                                               \
-            } else if (float ## s ## _is_quiet_nan(b, status) &&        \
-                       !float ## s ## _is_any_nan(a)) {                \
-                return a;                                               \
-            }                                                           \
-        }                                                               \
-        return propagateFloat ## s ## NaN(a, b, status);                \
-    }                                                                   \
-    aSign = extractFloat ## s ## Sign(a);                               \
-    bSign = extractFloat ## s ## Sign(b);                               \
-    av = float ## s ## _val(a);                                         \
-    bv = float ## s ## _val(b);                                         \
-    if (ismag) {                                                        \
-        aav = float ## s ## _abs(av);                                   \
-        abv = float ## s ## _abs(bv);                                   \
-        if (aav != abv) {                                               \
-            if (ismin) {                                                \
-                return (aav < abv) ? a : b;                             \
-            } else {                                                    \
-                return (aav < abv) ? b : a;                             \
-            }                                                           \
-        }                                                               \
-    }                                                                   \
-    if (aSign != bSign) {                                               \
-        if (ismin) {                                                    \
-            return aSign ? a : b;                                       \
-        } else {                                                        \
-            return aSign ? b : a;                                       \
-        }                                                               \
-    } else {                                                            \
-        if (ismin) {                                                    \
-            return (aSign ^ (av < bv)) ? a : b;                         \
-        } else {                                                        \
-            return (aSign ^ (av < bv)) ? b : a;                         \
-        }                                                               \
-    }                                                                   \
-}                                                                       \
-                                                                        \
-float ## s float ## s ## _min(float ## s a, float ## s b,               \
-                              float_status *status)                     \
-{                                                                       \
-    return float ## s ## _minmax(a, b, 1, 0, 0, status);                \
-}                                                                       \
-                                                                        \
-float ## s float ## s ## _max(float ## s a, float ## s b,               \
-                              float_status *status)                     \
-{                                                                       \
-    return float ## s ## _minmax(a, b, 0, 0, 0, status);                \
-}                                                                       \
-                                                                        \
-float ## s float ## s ## _minnum(float ## s a, float ## s b,            \
-                                 float_status *status)                  \
-{                                                                       \
-    return float ## s ## _minmax(a, b, 1, 1, 0, status);                \
-}                                                                       \
-                                                                        \
-float ## s float ## s ## _maxnum(float ## s a, float ## s b,            \
-                                 float_status *status)                  \
-{                                                                       \
-    return float ## s ## _minmax(a, b, 0, 1, 0, status);                \
-}                                                                       \
-                                                                        \
-float ## s float ## s ## _minnummag(float ## s a, float ## s b,         \
-                                    float_status *status)               \
-{                                                                       \
-    return float ## s ## _minmax(a, b, 1, 1, 1, status);                \
-}                                                                       \
-                                                                        \
-float ## s float ## s ## _maxnummag(float ## s a, float ## s b,         \
-                                    float_status *status)               \
-{                                                                       \
-    return float ## s ## _minmax(a, b, 0, 1, 1, status);                \
-}
-
-MINMAX(32)
-MINMAX(64)
-
-
 floatx80 floatx80_scalbn(floatx80 a, int n, float_status *status)
 {
     flag aSign;
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 52621e0b79..35df225a55 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -245,6 +245,12 @@ float16 float16_mul(float16, float16, float_status *status);
 float16 float16_muladd(float16, float16, float16, int, float_status *status);
 float16 float16_div(float16, float16, float_status *status);
 float16 float16_scalbn(float16, int, float_status *status);
+float16 float16_min(float16, float16, float_status *status);
+float16 float16_max(float16, float16, float_status *status);
+float16 float16_minnum(float16, float16, float_status *status);
+float16 float16_maxnum(float16, float16, float_status *status);
+float16 float16_minnummag(float16, float16, float_status *status);
+float16 float16_maxnummag(float16, float16, float_status *status);
 
 int float16_is_quiet_nan(float16, float_status *status);
 int float16_is_signaling_nan(float16, float_status *status);
-- 
2.15.1

[Qemu-devel] [PATCH v4 21/22] fpu/softfloat: re-factor compare

[Alex Bennée]

The compare function was already expanded from a macro. I keep the
macro expansion but move most of the logic into a compare_decomposed.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
v2
  - minor re-factor for better inf handling
v3
  - fix renaming of structs/functions
v4
  - use is_nan
---
 fpu/softfloat.c         | 134 +++++++++++++++++++++++++++++-------------------
 include/fpu/softfloat.h |   2 +
 2 files changed, 82 insertions(+), 54 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index cb889a7a84..8fc1c2a8d9 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1784,6 +1784,86 @@ MINMAX(64, maxnummag, false, true, true)
 
 #undef MINMAX
 
+/* Floating point compare */
+static int compare_floats(FloatParts a, FloatParts b, bool is_quiet,
+                          float_status *s)
+{
+    if (is_nan(a.cls) || is_nan(b.cls)) {
+        if (!is_quiet ||
+            a.cls == float_class_snan ||
+            b.cls == float_class_snan) {
+            s->float_exception_flags |= float_flag_invalid;
+        }
+        return float_relation_unordered;
+    }
+
+    if (a.cls == float_class_zero) {
+        if (b.cls == float_class_zero) {
+            return float_relation_equal;
+        }
+        return b.sign ? float_relation_greater : float_relation_less;
+    } else if (b.cls == float_class_zero) {
+        return a.sign ? float_relation_less : float_relation_greater;
+    }
+
+    /* The only really important thing about infinity is its sign. If
+     * both are infinities the sign marks the smallest of the two.
+     */
+    if (a.cls == float_class_inf) {
+        if ((b.cls == float_class_inf) && (a.sign == b.sign)) {
+            return float_relation_equal;
+        }
+        return a.sign ? float_relation_less : float_relation_greater;
+    } else if (b.cls == float_class_inf) {
+        return b.sign ? float_relation_greater : float_relation_less;
+    }
+
+    if (a.sign != b.sign) {
+        return a.sign ? float_relation_less : float_relation_greater;
+    }
+
+    if (a.exp == b.exp) {
+        if (a.frac == b.frac) {
+            return float_relation_equal;
+        }
+        if (a.sign) {
+            return a.frac > b.frac ?
+                float_relation_less : float_relation_greater;
+        } else {
+            return a.frac > b.frac ?
+                float_relation_greater : float_relation_less;
+        }
+    } else {
+        if (a.sign) {
+            return a.exp > b.exp ? float_relation_less : float_relation_greater;
+        } else {
+            return a.exp > b.exp ? float_relation_greater : float_relation_less;
+        }
+    }
+}
+
+#define COMPARE(sz)                                                     \
+int float ## sz ## _compare(float ## sz a, float ## sz b,               \
+                            float_status *s)                            \
+{                                                                       \
+    FloatParts pa = float ## sz ## _unpack_canonical(a, s);             \
+    FloatParts pb = float ## sz ## _unpack_canonical(b, s);             \
+    return compare_floats(pa, pb, false, s);                            \
+}                                                                       \
+int float ## sz ## _compare_quiet(float ## sz a, float ## sz b,         \
+                                  float_status *s)                      \
+{                                                                       \
+    FloatParts pa = float ## sz ## _unpack_canonical(a, s);             \
+    FloatParts pb = float ## sz ## _unpack_canonical(b, s);             \
+    return compare_floats(pa, pb, true, s);                             \
+}
+
+COMPARE(16)
+COMPARE(32)
+COMPARE(64)
+
+#undef COMPARE
+
 /* Multiply A by 2 raised to the power N.  */
 static FloatParts scalbn_decomposed(FloatParts a, int n, float_status *s)
 {
@@ -6885,60 +6965,6 @@ int float128_unordered_quiet(float128 a, float128 b, float_status *status)
     return 0;
 }
 
-#define COMPARE(s, nan_exp)                                                  \
-static inline int float ## s ## _compare_internal(float ## s a, float ## s b,\
-                                      int is_quiet, float_status *status)    \
-{                                                                            \
-    flag aSign, bSign;                                                       \
-    uint ## s ## _t av, bv;                                                  \
-    a = float ## s ## _squash_input_denormal(a, status);                     \
-    b = float ## s ## _squash_input_denormal(b, status);                     \
-                                                                             \
-    if (( ( extractFloat ## s ## Exp( a ) == nan_exp ) &&                    \
-         extractFloat ## s ## Frac( a ) ) ||                                 \
-        ( ( extractFloat ## s ## Exp( b ) == nan_exp ) &&                    \
-          extractFloat ## s ## Frac( b ) )) {                                \
-        if (!is_quiet ||                                                     \
-            float ## s ## _is_signaling_nan(a, status) ||                  \
-            float ## s ## _is_signaling_nan(b, status)) {                 \
-            float_raise(float_flag_invalid, status);                         \
-        }                                                                    \
-        return float_relation_unordered;                                     \
-    }                                                                        \
-    aSign = extractFloat ## s ## Sign( a );                                  \
-    bSign = extractFloat ## s ## Sign( b );                                  \
-    av = float ## s ## _val(a);                                              \
-    bv = float ## s ## _val(b);                                              \
-    if ( aSign != bSign ) {                                                  \
-        if ( (uint ## s ## _t) ( ( av | bv )<<1 ) == 0 ) {                   \
-            /* zero case */                                                  \
-            return float_relation_equal;                                     \
-        } else {                                                             \
-            return 1 - (2 * aSign);                                          \
-        }                                                                    \
-    } else {                                                                 \
-        if (av == bv) {                                                      \
-            return float_relation_equal;                                     \
-        } else {                                                             \
-            return 1 - 2 * (aSign ^ ( av < bv ));                            \
-        }                                                                    \
-    }                                                                        \
-}                                                                            \
-                                                                             \
-int float ## s ## _compare(float ## s a, float ## s b, float_status *status) \
-{                                                                            \
-    return float ## s ## _compare_internal(a, b, 0, status);                 \
-}                                                                            \
-                                                                             \
-int float ## s ## _compare_quiet(float ## s a, float ## s b,                 \
-                                 float_status *status)                       \
-{                                                                            \
-    return float ## s ## _compare_internal(a, b, 1, status);                 \
-}
-
-COMPARE(32, 0xff)
-COMPARE(64, 0x7ff)
-
 static inline int floatx80_compare_internal(floatx80 a, floatx80 b,
                                             int is_quiet, float_status *status)
 {
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 35df225a55..cebe37b716 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -251,6 +251,8 @@ float16 float16_minnum(float16, float16, float_status *status);
 float16 float16_maxnum(float16, float16, float_status *status);
 float16 float16_minnummag(float16, float16, float_status *status);
 float16 float16_maxnummag(float16, float16, float_status *status);
+int float16_compare(float16, float16, float_status *status);
+int float16_compare_quiet(float16, float16, float_status *status);
 
 int float16_is_quiet_nan(float16, float_status *status);
 int float16_is_signaling_nan(float16, float_status *status);
-- 
2.15.1

[Qemu-devel] [PATCH v4 22/22] fpu/softfloat: re-factor sqrt

[Alex Bennée]

This is a little bit of a departure from softfloat's original approach
as we skip the estimate step in favour of a straight iteration.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

---
v3
  - added to series
  - fixed renames of structs
v4
  - fix up comments
  - use is_nan
  - use return_nan instead of pick_nan(a,a)
---
 fpu/softfloat.c         | 201 ++++++++++++++++++++++--------------------------
 include/fpu/softfloat.h |   1 +
 2 files changed, 91 insertions(+), 111 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 8fc1c2a8d9..80301d8e04 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1897,6 +1897,96 @@ float64 float64_scalbn(float64 a, int n, float_status *status)
     return float64_round_pack_canonical(pr, status);
 }
 
+/*
+ * Square Root
+ *
+ * The old softfloat code did an approximation step before zeroing in
+ * on the final result. However for simpleness we just compute the
+ * square root by iterating down from the implicit bit to enough extra
+ * bits to ensure we get a correctly rounded result.
+ */
+
+static FloatParts sqrt_float(FloatParts a, float_status *s, const FloatFmt *p)
+{
+    uint64_t a_frac, r_frac, s_frac;
+    int bit, last_bit;
+
+    if (is_nan(a.cls)) {
+        return return_nan(a, s);
+    }
+    if (a.cls == float_class_zero) {
+        return a;  /* sqrt(+-0) = +-0 */
+    }
+    if (a.sign) {
+        s->float_exception_flags |= float_flag_invalid;
+        a.cls = float_class_dnan;
+        return a;
+    }
+    if (a.cls == float_class_inf) {
+        return a;  /* sqrt(+inf) = +inf */
+    }
+
+    assert(a.cls == float_class_normal);
+
+    /* We need two overflow bits at the top.  Adding room for that is
+       a right shift.  If the exponent is odd, we can discard the low
+       bit by multiplying the fraction by 2; that's a left shift.
+       Combine those and we shift right if the exponent is even.  */
+    a_frac = a.frac;
+    if (!(a.exp & 1)) {
+        a_frac >>= 1;
+    }
+    a.exp >>= 1;
+
+    /* Bit-by-bit computation of sqrt.  */
+    r_frac = 0;
+    s_frac = 0;
+
+    /* Iterate from implicit bit down to the 3 extra bits to compute a
+     * properly rounded result.  Remember we've inserted one more bit
+     * at the top, so these positions are one less.  */
+    bit = DECOMPOSED_BINARY_POINT - 1;
+    last_bit = MAX(p->frac_shift - 4, 0);
+    do {
+        uint64_t q = 1ULL << bit;
+        uint64_t t_frac = s_frac + q;
+        if (t_frac <= a_frac) {
+            s_frac = t_frac + q;
+            a_frac -= t_frac;
+            r_frac += q;
+        }
+        a_frac <<= 1;
+    } while (--bit >= last_bit);
+
+    /* Undo the right shift done above.  If there is any remaining
+       fraction, the result is inexact.  Set the sticky bit.  */
+    a.frac = (r_frac << 1) + (a_frac != 0);
+
+    return a;
+}
+
+float16 float16_sqrt(float16 a, float_status *status)
+{
+    FloatParts pa = float16_unpack_canonical(a, status);
+    FloatParts pr = sqrt_float(pa, status, &float16_params);
+    return float16_round_pack_canonical(pr, status);
+}
+
+float32 float32_sqrt(float32 a, float_status *status)
+{
+    FloatParts pa = float32_unpack_canonical(a, status);
+    FloatParts pr = sqrt_float(pa, status, &float32_params);
+    return float32_round_pack_canonical(pr, status);
+}
+
+float64 float64_sqrt(float64 a, float_status *status)
+{
+    FloatParts pa = float64_unpack_canonical(a, status);
+    FloatParts pr = sqrt_float(pa, status, &float64_params);
+    return float64_round_pack_canonical(pr, status);
+}
+
+
 /*----------------------------------------------------------------------------
 | Takes a 64-bit fixed-point value `absZ' with binary point between bits 6
 | and 7, and returns the properly rounded 32-bit integer corresponding to the
@@ -3304,62 +3394,6 @@ float32 float32_rem(float32 a, float32 b, float_status *status)
 }
 
 
-/*----------------------------------------------------------------------------
-| Returns the square root of the single-precision floating-point value `a'.
-| The operation is performed according to the IEC/IEEE Standard for Binary
-| Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float32 float32_sqrt(float32 a, float_status *status)
-{
-    flag aSign;
-    int aExp, zExp;
-    uint32_t aSig, zSig;
-    uint64_t rem, term;
-    a = float32_squash_input_denormal(a, status);
-
-    aSig = extractFloat32Frac( a );
-    aExp = extractFloat32Exp( a );
-    aSign = extractFloat32Sign( a );
-    if ( aExp == 0xFF ) {
-        if (aSig) {
-            return propagateFloat32NaN(a, float32_zero, status);
-        }
-        if ( ! aSign ) return a;
-        float_raise(float_flag_invalid, status);
-        return float32_default_nan(status);
-    }
-    if ( aSign ) {
-        if ( ( aExp | aSig ) == 0 ) return a;
-        float_raise(float_flag_invalid, status);
-        return float32_default_nan(status);
-    }
-    if ( aExp == 0 ) {
-        if ( aSig == 0 ) return float32_zero;
-        normalizeFloat32Subnormal( aSig, &aExp, &aSig );
-    }
-    zExp = ( ( aExp - 0x7F )>>1 ) + 0x7E;
-    aSig = ( aSig | 0x00800000 )<<8;
-    zSig = estimateSqrt32( aExp, aSig ) + 2;
-    if ( ( zSig & 0x7F ) <= 5 ) {
-        if ( zSig < 2 ) {
-            zSig = 0x7FFFFFFF;
-            goto roundAndPack;
-        }
-        aSig >>= aExp & 1;
-        term = ( (uint64_t) zSig ) * zSig;
-        rem = ( ( (uint64_t) aSig )<<32 ) - term;
-        while ( (int64_t) rem < 0 ) {
-            --zSig;
-            rem += ( ( (uint64_t) zSig )<<1 ) | 1;
-        }
-        zSig |= ( rem != 0 );
-    }
-    shift32RightJamming( zSig, 1, &zSig );
- roundAndPack:
-    return roundAndPackFloat32(0, zExp, zSig, status);
-
-}
 
 /*----------------------------------------------------------------------------
 | Returns the binary exponential of the single-precision floating-point value
@@ -4203,61 +4237,6 @@ float64 float64_rem(float64 a, float64 b, float_status *status)
 
 }
 
-
-/*----------------------------------------------------------------------------
-| Returns the square root of the double-precision floating-point value `a'.
-| The operation is performed according to the IEC/IEEE Standard for Binary
-| Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-float64 float64_sqrt(float64 a, float_status *status)
-{
-    flag aSign;
-    int aExp, zExp;
-    uint64_t aSig, zSig, doubleZSig;
-    uint64_t rem0, rem1, term0, term1;
-    a = float64_squash_input_denormal(a, status);
-
-    aSig = extractFloat64Frac( a );
-    aExp = extractFloat64Exp( a );
-    aSign = extractFloat64Sign( a );
-    if ( aExp == 0x7FF ) {
-        if (aSig) {
-            return propagateFloat64NaN(a, a, status);
-        }
-        if ( ! aSign ) return a;
-        float_raise(float_flag_invalid, status);
-        return float64_default_nan(status);
-    }
-    if ( aSign ) {
-        if ( ( aExp | aSig ) == 0 ) return a;
-        float_raise(float_flag_invalid, status);
-        return float64_default_nan(status);
-    }
-    if ( aExp == 0 ) {
-        if ( aSig == 0 ) return float64_zero;
-        normalizeFloat64Subnormal( aSig, &aExp, &aSig );
-    }
-    zExp = ( ( aExp - 0x3FF )>>1 ) + 0x3FE;
-    aSig |= LIT64( 0x0010000000000000 );
-    zSig = estimateSqrt32( aExp, aSig>>21 );
-    aSig <<= 9 - ( aExp & 1 );
-    zSig = estimateDiv128To64( aSig, 0, zSig<<32 ) + ( zSig<<30 );
-    if ( ( zSig & 0x1FF ) <= 5 ) {
-        doubleZSig = zSig<<1;
-        mul64To128( zSig, zSig, &term0, &term1 );
-        sub128( aSig, 0, term0, term1, &rem0, &rem1 );
-        while ( (int64_t) rem0 < 0 ) {
-            --zSig;
-            doubleZSig -= 2;
-            add128( rem0, rem1, zSig>>63, doubleZSig | 1, &rem0, &rem1 );
-        }
-        zSig |= ( ( rem0 | rem1 ) != 0 );
-    }
-    return roundAndPackFloat64(0, zExp, zSig, status);
-
-}
-
 /*----------------------------------------------------------------------------
 | Returns the binary log of the double-precision floating-point value `a'.
 | The operation is performed according to the IEC/IEEE Standard for Binary
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index cebe37b716..9b7b5e34e2 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -251,6 +251,7 @@ float16 float16_minnum(float16, float16, float_status *status);
 float16 float16_maxnum(float16, float16, float_status *status);
 float16 float16_minnummag(float16, float16, float_status *status);
 float16 float16_maxnummag(float16, float16, float_status *status);
+float16 float16_sqrt(float16, float_status *status);
 int float16_compare(float16, float16, float_status *status);
 int float16_compare_quiet(float16, float16, float_status *status);
 
-- 
2.15.1

Re: [Qemu-devel] [PATCH v4 00/22] re-factor softfloat and add fp16 functions

[no-reply]

Hi,

This series seems to have some coding style problems. See output below for
more information:

Type: series
Message-id: 20180206164815.10084-1-alex.bennee@linaro.org
Subject: [Qemu-devel] [PATCH v4 00/22] re-factor softfloat and add fp16 functions

=== TEST SCRIPT BEGIN ===
#!/bin/bash

BASE=base
n=1
total=$(git log --oneline $BASE.. | wc -l)
failed=0

git config --local diff.renamelimit 0
git config --local diff.renames True

commits="$(git log --format=%H --reverse $BASE..)"
for c in $commits; do
    echo "Checking PATCH $n/$total: $(git log -n 1 --format=%s $c)..."
    if ! git show $c --format=email | ./scripts/checkpatch.pl --mailback -; then
        failed=1
        echo
    fi
    n=$((n+1))
done

exit $failed
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
Switched to a new branch 'test'
1e781206be fpu/softfloat: re-factor sqrt
e685ea8dc4 fpu/softfloat: re-factor compare
63b87bcb69 fpu/softfloat: re-factor minmax
669591c216 fpu/softfloat: re-factor scalbn
2ed6c7c81d fpu/softfloat: re-factor int/uint to float
d1bd89624f fpu/softfloat: re-factor float to int/uint
bc1a994506 fpu/softfloat: re-factor round_to_int
6485285f24 fpu/softfloat: re-factor muladd
e385a48184 fpu/softfloat: re-factor div
92464a80c3 fpu/softfloat: re-factor mul
ffd17dee64 fpu/softfloat: re-factor add/sub
7815017f4b fpu/softfloat: define decompose structures
30d6d92cb4 fpu/softfloat: move the extract functions to the top of the file
51361e8312 fpu/softfloat: improve comments on ARM NaN propagation
c585bf8e1d include/fpu/softfloat: add some float16 constants
e5feca0066 include/fpu/softfloat: implement float16_set_sign helper
28e817f796 include/fpu/softfloat: implement float16_chs helper
fecbf8dcc9 include/fpu/softfloat: implement float16_abs helper
294fc6dd01 target/*/cpu.h: remove softfloat.h
b712e8fbb6 fpu/softfloat-types: new header to prevent excessive re-builds
694133665c include/fpu/softfloat: remove USE_SOFTFLOAT_STRUCT_TYPES
cf60e4d868 fpu/softfloat: implement float16_squash_input_denormal

=== OUTPUT BEGIN ===
Checking PATCH 1/22: fpu/softfloat: implement float16_squash_input_denormal...
Checking PATCH 2/22: include/fpu/softfloat: remove USE_SOFTFLOAT_STRUCT_TYPES...
Checking PATCH 3/22: fpu/softfloat-types: new header to prevent excessive re-builds...
Checking PATCH 4/22: target/*/cpu.h: remove softfloat.h...
Checking PATCH 5/22: include/fpu/softfloat: implement float16_abs helper...
Checking PATCH 6/22: include/fpu/softfloat: implement float16_chs helper...
Checking PATCH 7/22: include/fpu/softfloat: implement float16_set_sign helper...
Checking PATCH 8/22: include/fpu/softfloat: add some float16 constants...
Checking PATCH 9/22: fpu/softfloat: improve comments on ARM NaN propagation...
Checking PATCH 10/22: fpu/softfloat: move the extract functions to the top of the file...
Checking PATCH 11/22: fpu/softfloat: define decompose structures...
Checking PATCH 12/22: fpu/softfloat: re-factor add/sub...
ERROR: space prohibited after that open parenthesis '('
#532: FILE: fpu/softfloat.c:2568:
+    aSign = extractFloat32Sign( a );

ERROR: space prohibited before that close parenthesis ')'
#532: FILE: fpu/softfloat.c:2568:
+    aSign = extractFloat32Sign( a );

ERROR: space prohibited after that open parenthesis '('
#563: FILE: fpu/softfloat.c:2571:
+    bSign = extractFloat32Sign( b );

ERROR: space prohibited before that close parenthesis ')'
#563: FILE: fpu/softfloat.c:2571:
+    bSign = extractFloat32Sign( b );

ERROR: space prohibited after that open parenthesis '('
#565: FILE: fpu/softfloat.c:2573:
+    if ( aExp == 0xFF ) {

ERROR: space prohibited before that close parenthesis ')'
#565: FILE: fpu/softfloat.c:2573:
+    if ( aExp == 0xFF ) {

ERROR: space prohibited after that open parenthesis '('
#566: FILE: fpu/softfloat.c:2574:
+        if ( aSig || ( ( bExp == 0xFF ) && bSig ) ) {

ERROR: space prohibited before that close parenthesis ')'
#566: FILE: fpu/softfloat.c:2574:
+        if ( aSig || ( ( bExp == 0xFF ) && bSig ) ) {

ERROR: space prohibited after that open parenthesis '('
#571: FILE: fpu/softfloat.c:2577:
+        if ( ( bExp | bSig ) == 0 ) {

ERROR: space prohibited before that close parenthesis ')'
#571: FILE: fpu/softfloat.c:2577:
+        if ( ( bExp | bSig ) == 0 ) {

ERROR: space prohibited after that open parenthesis '('
#577: FILE: fpu/softfloat.c:2581:
+        return packFloat32( zSign, 0xFF, 0 );

ERROR: space prohibited before that close parenthesis ')'
#577: FILE: fpu/softfloat.c:2581:
+        return packFloat32( zSign, 0xFF, 0 );

ERROR: space prohibited after that open parenthesis '('
#585: FILE: fpu/softfloat.c:2583:
+    if ( bExp == 0xFF ) {

ERROR: space prohibited before that close parenthesis ')'
#585: FILE: fpu/softfloat.c:2583:
+    if ( bExp == 0xFF ) {

ERROR: space prohibited after that open parenthesis '('
#597: FILE: fpu/softfloat.c:2587:
+        if ( ( aExp | aSig ) == 0 ) {

ERROR: space prohibited before that close parenthesis ')'
#597: FILE: fpu/softfloat.c:2587:
+        if ( ( aExp | aSig ) == 0 ) {

ERROR: space prohibited after that open parenthesis '('
#788: FILE: fpu/softfloat.c:2591:
+        return packFloat32( zSign, 0xFF, 0 );

ERROR: space prohibited before that close parenthesis ')'
#788: FILE: fpu/softfloat.c:2591:
+        return packFloat32( zSign, 0xFF, 0 );

total: 18 errors, 0 warnings, 996 lines checked

Your patch has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

Checking PATCH 13/22: fpu/softfloat: re-factor mul...
Checking PATCH 14/22: fpu/softfloat: re-factor div...
Checking PATCH 15/22: fpu/softfloat: re-factor muladd...
Checking PATCH 16/22: fpu/softfloat: re-factor round_to_int...
WARNING: line over 80 characters
#118: FILE: fpu/softfloat.c:1261:
+                inc = ((a.frac & roundeven_mask) != frac_lsbm1 ? frac_lsbm1 : 0);

total: 0 errors, 1 warnings, 353 lines checked

Your patch has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.
Checking PATCH 17/22: fpu/softfloat: re-factor float to int/uint...
ERROR: space prohibited after that open parenthesis '('
#716: FILE: fpu/softfloat.c:3420:
+    if (    ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) )

ERROR: space prohibited before that close parenthesis ')'
#716: FILE: fpu/softfloat.c:3420:
+    if (    ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) )

ERROR: space prohibited after that open parenthesis '('
#717: FILE: fpu/softfloat.c:3421:
+         || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) )

ERROR: space prohibited before that close parenthesis ')'
#717: FILE: fpu/softfloat.c:3421:
+         || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) )

ERROR: space prohibited after that open parenthesis '('
#738: FILE: fpu/softfloat.c:3429:
+    aSign = extractFloat32Sign( a );

ERROR: space prohibited before that close parenthesis ')'
#738: FILE: fpu/softfloat.c:3429:
+    aSign = extractFloat32Sign( a );

ERROR: space prohibited after that open parenthesis '('
#739: FILE: fpu/softfloat.c:3430:
+    bSign = extractFloat32Sign( b );

ERROR: space prohibited before that close parenthesis ')'
#739: FILE: fpu/softfloat.c:3430:
+    bSign = extractFloat32Sign( b );

WARNING: line over 80 characters
#742: FILE: fpu/softfloat.c:3433:
+    if ( aSign != bSign ) return aSign && ( (uint32_t) ( ( av | bv )<<1 ) != 0 );

ERROR: spaces required around that '<<' (ctx:VxV)
#742: FILE: fpu/softfloat.c:3433:
+    if ( aSign != bSign ) return aSign && ( (uint32_t) ( ( av | bv )<<1 ) != 0 );
                                                                     ^

ERROR: space prohibited after that open parenthesis '('
#742: FILE: fpu/softfloat.c:3433:
+    if ( aSign != bSign ) return aSign && ( (uint32_t) ( ( av | bv )<<1 ) != 0 );

ERROR: space prohibited before that close parenthesis ')'
#742: FILE: fpu/softfloat.c:3433:
+    if ( aSign != bSign ) return aSign && ( (uint32_t) ( ( av | bv )<<1 ) != 0 );

ERROR: trailing statements should be on next line
#742: FILE: fpu/softfloat.c:3433:
+    if ( aSign != bSign ) return aSign && ( (uint32_t) ( ( av | bv )<<1 ) != 0 );

ERROR: braces {} are necessary for all arms of this statement
#742: FILE: fpu/softfloat.c:3433:
+    if ( aSign != bSign ) return aSign && ( (uint32_t) ( ( av | bv )<<1 ) != 0 );
[...]

ERROR: space prohibited after that open parenthesis '('
#743: FILE: fpu/softfloat.c:3434:
+    return ( av != bv ) && ( aSign ^ ( av < bv ) );

ERROR: space prohibited before that close parenthesis ')'
#743: FILE: fpu/softfloat.c:3434:
+    return ( av != bv ) && ( aSign ^ ( av < bv ) );

ERROR: space prohibited after that open parenthesis '('
#803: FILE: fpu/softfloat.c:3450:
+    if (    ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) )

ERROR: space prohibited before that close parenthesis ')'
#803: FILE: fpu/softfloat.c:3450:
+    if (    ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) )

ERROR: space prohibited after that open parenthesis '('
#804: FILE: fpu/softfloat.c:3451:
+         || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) )

ERROR: space prohibited before that close parenthesis ')'
#804: FILE: fpu/softfloat.c:3451:
+         || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) )

total: 19 errors, 1 warnings, 1068 lines checked

Your patch has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

Checking PATCH 18/22: fpu/softfloat: re-factor int/uint to float...
Checking PATCH 19/22: fpu/softfloat: re-factor scalbn...
Checking PATCH 20/22: fpu/softfloat: re-factor minmax...
Checking PATCH 21/22: fpu/softfloat: re-factor compare...
Checking PATCH 22/22: fpu/softfloat: re-factor sqrt...
=== OUTPUT END ===

Test command exited with code: 1


---
Email generated automatically by Patchew [http://patchew.org/].
Please send your feedback to patchew-devel@freelists.org

Re: [Qemu-devel] [PATCH v4 00/22] re-factor softfloat and add fp16 functions

[Peter Maydell]

On 6 February 2018 at 16:47, Alex Bennée <alex.bennee@linaro.org> wrote:
> Hi,
>
> The main change is applying the __attribute__((flatten)) to some of
> the public functions that show up in Emilio's dbt-benchmark. This
> seems to be a cleaner solution that squashing inlines higher up the
> chain and still leaves the chance for re-use for the less widely used
> functions. The results are an improvement over v3 by some margin:
>
>                          NBench score; higher is better
>
>     5 +-+-----------+-------------+------------+-------------+-----------+-+
>       |                     ****### %%%%  +++                              |
>   4.5 +-+...................*..*..#.%..%..****##..%%%%+ system-2.5       +-+
>       |                     *  *  # %  %  *  * #  %  %      master         |
>     4 +-+...................*..*..#.%..%..*..*.#..%..%softfloat-v3       +-+
>   3.5 +-+...................*..*..#.%..%..*..*.#..%..%softfloat-%%%%.....+-+
>       |                     *  *  # %  %  *  * #  %  %  * *  #  %  %       |
>     3 +-+...................*..*..#.%..%..*..*.#..%..%..*.*..#..%..%.....+-+
>       |                     *  *  #+%  %  *  * #$$$  %  * *  #  %  %       |
>   2.5 +-+........####.......*..*..#$$..%..*..*.#..$..%..*.*..#..%..%.....+-+
>       |       ****  #  %%%  *  *  # $  %  *  * #  $  %  * *  #$$$  %       |
>     2 +-+.....*..*..#..%.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>       |       *  *  #  % %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>   1.5 +-+.....*..*..#$$$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>     1 +-+.....*..*..#..$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>       |       *  *  #  $ %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>   0.5 +-+.....*..*..#..$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>       |       *  *  #  $ %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>     0 +-+-----****###$$$%%--****###$$%%%--****##$$$%%%--***###$$$%%%-----+-+
>                  FOURIER     NEURAL NETLU DECOMPOSITION    gmean
>
> Slightly easier to read PNG:
>
>     https://i.imgur.com/XEeL0bC.png
>
> I think it's pretty ready for a merge. Shall I submit a pull myself or
> does it make sense going via someone else? According to MAINTAINERS
> Peter and Aurelien are responsible for this code...
>
> Alex Bennée (22):
>   fpu/softfloat: implement float16_squash_input_denormal
>   include/fpu/softfloat: remove USE_SOFTFLOAT_STRUCT_TYPES
>   fpu/softfloat-types: new header to prevent excessive re-builds
>   target/*/cpu.h: remove softfloat.h
>   include/fpu/softfloat: implement float16_abs helper
>   include/fpu/softfloat: implement float16_chs helper
>   include/fpu/softfloat: implement float16_set_sign helper
>   include/fpu/softfloat: add some float16 constants
>   fpu/softfloat: improve comments on ARM NaN propagation
>   fpu/softfloat: move the extract functions to the top of the file
>   fpu/softfloat: define decompose structures
>   fpu/softfloat: re-factor add/sub
>   fpu/softfloat: re-factor mul
>   fpu/softfloat: re-factor div
>   fpu/softfloat: re-factor muladd
>   fpu/softfloat: re-factor round_to_int
>   fpu/softfloat: re-factor float to int/uint
>   fpu/softfloat: re-factor int/uint to float
>   fpu/softfloat: re-factor scalbn
>   fpu/softfloat: re-factor minmax
>   fpu/softfloat: re-factor compare
>   fpu/softfloat: re-factor sqrt

If you persuade git to use the --minimal, --patience or --histogram
git diff option when generating these patches you'll find that it
doesn't produce unreadable patches that provoke all the checkpatch
warnings. That in turn will let you find the genuine warning that
got lost in all the spurious ones:

Checking PATCH 16/22: fpu/softfloat: re-factor round_to_int...
WARNING: line over 80 characters
#127: FILE: fpu/softfloat.c:1261:
+                inc = ((a.frac & roundeven_mask) != frac_lsbm1 ?
frac_lsbm1 : 0);


As far as I can tell from a quick search, the 'histogram'
algorithm is reckoned to be about as fast as the default but
much less likely to produce terrible diffs.

  git config --global diff.algorithm histogram

should set it up as the default for all diff-producing purposes
including generating patches for email.

thanks
-- PMM

Re: [Qemu-devel] [PATCH v4 16/22] fpu/softfloat: re-factor round_to_int

[Peter Maydell]

On 6 February 2018 at 16:48, Alex Bennée <alex.bennee@linaro.org> wrote:
> We can now add float16_round_to_int and use the common round_decomposed and
> canonicalize functions to have a single implementation for
> float16/32/64 round_to_int functions.
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>
> ---
> v3
>   - rename structures and functions
> v4
>   - move NaN handling to return NaN
> ---
>  fpu/softfloat.c         | 322 ++++++++++++++++++++++--------------------------
>  include/fpu/softfloat.h |   1 +
>  2 files changed, 148 insertions(+), 175 deletions(-)
>
> diff --git a/fpu/softfloat.c b/fpu/softfloat.c
> index ae4ba6de51..5d04e65538 100644
> --- a/fpu/softfloat.c
> +++ b/fpu/softfloat.c
> @@ -560,7 +560,26 @@ static bool is_qnan(FloatClass c)
>      return c == float_class_qnan;
>  }
>
> -static FloatParts pick_nan(FloatParts a, FloatParts b, float_status *s)
> +static inline FloatParts return_nan(FloatParts a, float_status *s)
> +{
> +    switch (a.cls) {
> +    case float_class_snan:
> +        s->float_exception_flags |= float_flag_invalid;
> +        a.cls = float_class_msnan;
> +        /* FALLTHRU */

"/* fall through */" is the usual way of spelling it in QEMU
(255 instances vs 60).

> +    case float_class_qnan:
> +        if (s->default_nan_mode) {
> +            a.cls = float_class_dnan;
> +        }
> +        break;
> +
> +    default:
> +        g_assert_not_reached();
> +    }
> +    return a;
> +}
> +
> +static inline FloatParts pick_nan(FloatParts a, FloatParts b, float_status *s)
>  {
>      if (is_snan(a.cls) || is_snan(b.cls)) {
>          s->float_exception_flags |= float_flag_invalid;

This hunk looks a bit weird because the patch is also adding
an "inline" qualifier to pick_nan(). Should that have been in an
earlier patch (eg "fpu/softfloat: re-factor add/sub" where the
pick_nan() function was added) ?

> @@ -1175,6 +1194,133 @@ float64 float64_div(float64 a, float64 b, float_status *status)
>      return float64_round_pack_canonical(pr, status);
>  }
>
> +/*
> + * Rounds the floating-point value `a' to an integer, and returns the
> + * result as a floating-point value. The operation is performed
> + * according to the IEC/IEEE Standard for Binary Floating-Point
> + * Arithmetic.
> + */
> +
> +static FloatParts round_to_int(FloatParts a, int rounding_mode, float_status *s)
> +{
> +    if (is_nan(a.cls)) {
> +        return return_nan(a, s);
> +    }
> +
> +    switch (a.cls) {
> +    case float_class_zero:
> +    case float_class_inf:
> +    case float_class_qnan:
> +        /* already "integral" */
> +        break;
> +    case float_class_normal:
> +        if (a.exp >= DECOMPOSED_BINARY_POINT) {
> +            /* already integral */
> +            break;
> +        }
> +        if (a.exp < 0) {
> +            bool one;
> +            /* all fractional */
> +            s->float_exception_flags |= float_flag_inexact;
> +            switch (rounding_mode) {
> +            case float_round_nearest_even:
> +                one = a.exp == -1 && a.frac > DECOMPOSED_IMPLICIT_BIT;
> +                break;
> +            case float_round_ties_away:
> +                one = a.exp == -1 && a.frac >= DECOMPOSED_IMPLICIT_BIT;
> +                break;
> +            case float_round_to_zero:
> +                one = false;
> +                break;
> +            case float_round_up:
> +                one = !a.sign;
> +                break;
> +            case float_round_down:
> +                one = a.sign;
> +                break;
> +            default:
> +                g_assert_not_reached();
> +            }
> +
> +            if (one) {
> +                a.frac = DECOMPOSED_IMPLICIT_BIT;
> +                a.exp = 0;
> +            } else {
> +                a.cls = float_class_zero;
> +            }
> +        } else {
> +            uint64_t frac_lsb, frac_lsbm1, round_mask, roundeven_mask, inc;
> +
> +            frac_lsb = DECOMPOSED_IMPLICIT_BIT >> a.exp;
> +            frac_lsbm1 = frac_lsb >> 1;
> +            roundeven_mask = (frac_lsb - 1) | frac_lsb;
> +            round_mask = roundeven_mask >> 1;
> +
> +            switch (rounding_mode) {
> +            case float_round_nearest_even:
> +                inc = ((a.frac & roundeven_mask) != frac_lsbm1 ? frac_lsbm1 : 0);

This is that long line...

> +                break;

Otherwise
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

Re: [Qemu-devel] [PATCH v4 13/22] fpu/softfloat: re-factor mul

[Peter Maydell]

On 6 February 2018 at 16:48, Alex Bennée <alex.bennee@linaro.org> wrote:
> We can now add float16_mul and use the common decompose and
> canonicalize functions to have a single implementation for
> float16/32/64 versions.
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>
> ---
> v3

> +/*
> + * Returns the result of multiplying the floating-point values `a' and
> + * `b'. The operation is performed according to the IEC/IEEE Standard
> + * for Binary Floating-Point Arithmetic.
> + */
> +
> +static FloatParts mul_floats(FloatParts a, FloatParts b, float_status *s)
> +{
> +    bool sign = a.sign ^ b.sign;
> +
> +    if (a.cls == float_class_normal && b.cls == float_class_normal) {
> +        uint64_t hi, lo;
> +        int exp = a.exp + b.exp;
> +
> +        mul64To128(a.frac, b.frac, &hi, &lo);

It seems a shame that we previously were able to use a
32x32->64 multiply for the float32 case, and now we have to
do an expensive 64x64->128 multiply regardless...

Regardless
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

Re: [Qemu-devel] [PATCH v4 14/22] fpu/softfloat: re-factor div

[Peter Maydell]

On 6 February 2018 at 16:48, Alex Bennée <alex.bennee@linaro.org> wrote:
> We can now add float16_div and use the common decompose and
> canonicalize functions to have a single implementation for
> float16/32/64 versions.
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

> +static FloatParts div_floats(FloatParts a, FloatParts b, float_status *s)
> +{
> +    bool sign = a.sign ^ b.sign;
> +
> +    if (a.cls == float_class_normal && b.cls == float_class_normal) {
> +        uint64_t temp_lo, temp_hi;
> +        int exp = a.exp - b.exp;
> +        if (a.frac < b.frac) {
> +            exp -= 1;
> +            shortShift128Left(0, a.frac, DECOMPOSED_BINARY_POINT + 1,
> +                              &temp_hi, &temp_lo);
> +        } else {
> +            shortShift128Left(0, a.frac, DECOMPOSED_BINARY_POINT,
> +                              &temp_hi, &temp_lo);
> +        }
> +        /* LSB of quot is set if inexact which roundandpack will use
> +         * to set flags. Yet again we re-use a for the result */
> +        a.frac = div128To64(temp_lo, temp_hi, b.frac);

...and this is even worse as a cost increase for the float32
and float16 cases. Still:

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

Re: [Qemu-devel] [PATCH v4 13/22] fpu/softfloat: re-factor mul

[Richard Henderson]

On 02/13/2018 07:20 AM, Peter Maydell wrote:
>> +static FloatParts mul_floats(FloatParts a, FloatParts b, float_status *s)
>> +{
>> +    bool sign = a.sign ^ b.sign;
>> +
>> +    if (a.cls == float_class_normal && b.cls == float_class_normal) {
>> +        uint64_t hi, lo;
>> +        int exp = a.exp + b.exp;
>> +
>> +        mul64To128(a.frac, b.frac, &hi, &lo);
> 
> It seems a shame that we previously were able to use a
> 32x32->64 multiply for the float32 case, and now we have to
> do an expensive 64x64->128 multiply regardless...

To be fair, I've proposed two different solutions addressing that -- c++
templates and glibc macros -- and you like neither.  Is there a third
alternative that does not involve code duplication?


r~

Re: [Qemu-devel] [PATCH v4 22/22] fpu/softfloat: re-factor sqrt

[Peter Maydell]

On 6 February 2018 at 16:48, Alex Bennée <alex.bennee@linaro.org> wrote:
> This is a little bit of a departure from softfloat's original approach
> as we skip the estimate step in favour of a straight iteration.
>
> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>
> ---
> v3
>   - added to series
>   - fixed renames of structs
> v4
>   - fix up comments
>   - use is_nan
>   - use return_nan instead of pick_nan(a,a)
> ---
>  fpu/softfloat.c         | 201 ++++++++++++++++++++++--------------------------
>  include/fpu/softfloat.h |   1 +
>  2 files changed, 91 insertions(+), 111 deletions(-)
>
> diff --git a/fpu/softfloat.c b/fpu/softfloat.c
> index 8fc1c2a8d9..80301d8e04 100644
> --- a/fpu/softfloat.c
> +++ b/fpu/softfloat.c
> @@ -1897,6 +1897,96 @@ float64 float64_scalbn(float64 a, int n, float_status *status)
>      return float64_round_pack_canonical(pr, status);
>  }
>
> +/*
> + * Square Root
> + *
> + * The old softfloat code did an approximation step before zeroing in
> + * on the final result. However for simpleness we just compute the
> + * square root by iterating down from the implicit bit to enough extra
> + * bits to ensure we get a correctly rounded result.

So is this new approach slower?

> + */
> +
> +static FloatParts sqrt_float(FloatParts a, float_status *s, const FloatFmt *p)
> +{
> +    uint64_t a_frac, r_frac, s_frac;
> +    int bit, last_bit;
> +
> +    if (is_nan(a.cls)) {
> +        return return_nan(a, s);
> +    }
> +    if (a.cls == float_class_zero) {
> +        return a;  /* sqrt(+-0) = +-0 */
> +    }
> +    if (a.sign) {
> +        s->float_exception_flags |= float_flag_invalid;
> +        a.cls = float_class_dnan;
> +        return a;
> +    }
> +    if (a.cls == float_class_inf) {
> +        return a;  /* sqrt(+inf) = +inf */
> +    }
> +
> +    assert(a.cls == float_class_normal);
> +
> +    /* We need two overflow bits at the top.  Adding room for that is
> +       a right shift.  If the exponent is odd, we can discard the low
> +       bit by multiplying the fraction by 2; that's a left shift.
> +       Combine those and we shift right if the exponent is even.  */
> +    a_frac = a.frac;
> +    if (!(a.exp & 1)) {
> +        a_frac >>= 1;
> +    }
> +    a.exp >>= 1;

Comment says "shift right if the exponent is even", but code
says "shift right by 1 if exponent is odd, by 2 if exponent is even".

> +
> +    /* Bit-by-bit computation of sqrt.  */
> +    r_frac = 0;
> +    s_frac = 0;
> +
> +    /* Iterate from implicit bit down to the 3 extra bits to compute a
> +     * properly rounded result.  Remember we've inserted one more bit
> +     * at the top, so these positions are one less.  */

Some consistency in multiline comment formatting would be nice.
The top-of-function header and these two in the body of
the function have 3 different styles between them...

Otherwise
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

Re: [Qemu-devel] [PATCH v4 00/22] re-factor softfloat and add fp16 functions

[Peter Maydell]

On 6 February 2018 at 16:47, Alex Bennée <alex.bennee@linaro.org> wrote:
> Hi,
>
> The main change is applying the __attribute__((flatten)) to some of
> the public functions that show up in Emilio's dbt-benchmark. This
> seems to be a cleaner solution that squashing inlines higher up the
> chain and still leaves the chance for re-use for the less widely used
> functions. The results are an improvement over v3 by some margin:
>
>                          NBench score; higher is better
>
>     5 +-+-----------+-------------+------------+-------------+-----------+-+
>       |                     ****### %%%%  +++                              |
>   4.5 +-+...................*..*..#.%..%..****##..%%%%+ system-2.5       +-+
>       |                     *  *  # %  %  *  * #  %  %      master         |
>     4 +-+...................*..*..#.%..%..*..*.#..%..%softfloat-v3       +-+
>   3.5 +-+...................*..*..#.%..%..*..*.#..%..%softfloat-%%%%.....+-+
>       |                     *  *  # %  %  *  * #  %  %  * *  #  %  %       |
>     3 +-+...................*..*..#.%..%..*..*.#..%..%..*.*..#..%..%.....+-+
>       |                     *  *  #+%  %  *  * #$$$  %  * *  #  %  %       |
>   2.5 +-+........####.......*..*..#$$..%..*..*.#..$..%..*.*..#..%..%.....+-+
>       |       ****  #  %%%  *  *  # $  %  *  * #  $  %  * *  #$$$  %       |
>     2 +-+.....*..*..#..%.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>       |       *  *  #  % %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>   1.5 +-+.....*..*..#$$$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>     1 +-+.....*..*..#..$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>       |       *  *  #  $ %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>   0.5 +-+.....*..*..#..$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>       |       *  *  #  $ %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>     0 +-+-----****###$$$%%--****###$$%%%--****##$$$%%%--***###$$$%%%-----+-+
>                  FOURIER     NEURAL NETLU DECOMPOSITION    gmean
>
> Slightly easier to read PNG:
>
>     https://i.imgur.com/XEeL0bC.png
>
> I think it's pretty ready for a merge. Shall I submit a pull myself or
> does it make sense going via someone else? According to MAINTAINERS
> Peter and Aurelien are responsible for this code...

I had some nits but I think the best thing to do is if you fix those
and then just send a pull request for this.

thanks
-- PMM

Re: [Qemu-devel] [PATCH v4 22/22] fpu/softfloat: re-factor sqrt

[Richard Henderson]

On 02/13/2018 07:50 AM, Peter Maydell wrote:
>> +    /* We need two overflow bits at the top.  Adding room for that is
>> +       a right shift.  If the exponent is odd, we can discard the low
>> +       bit by multiplying the fraction by 2; that's a left shift.
>> +       Combine those and we shift right if the exponent is even.  */
>> +    a_frac = a.frac;
>> +    if (!(a.exp & 1)) {
>> +        a_frac >>= 1;
>> +    }
>> +    a.exp >>= 1;
> Comment says "shift right if the exponent is even", but code
> says "shift right by 1 if exponent is odd, by 2 if exponent is even".
> 

The last line is dividing the exponent by 2, not shifting the fraction.


r~

Re: [Qemu-devel] [PATCH v4 22/22] fpu/softfloat: re-factor sqrt

[Peter Maydell]

On 13 February 2018 at 16:23, Richard Henderson
<richard.henderson@linaro.org> wrote:
> On 02/13/2018 07:50 AM, Peter Maydell wrote:
>>> +    /* We need two overflow bits at the top.  Adding room for that is
>>> +       a right shift.  If the exponent is odd, we can discard the low
>>> +       bit by multiplying the fraction by 2; that's a left shift.
>>> +       Combine those and we shift right if the exponent is even.  */
>>> +    a_frac = a.frac;
>>> +    if (!(a.exp & 1)) {
>>> +        a_frac >>= 1;
>>> +    }
>>> +    a.exp >>= 1;
>> Comment says "shift right if the exponent is even", but code
>> says "shift right by 1 if exponent is odd, by 2 if exponent is even".
>>
>
> The last line is dividing the exponent by 2, not shifting the fraction.

Doh, so it is.

-- PMM

Re: [Qemu-devel] [PATCH v4 00/22] re-factor softfloat and add fp16 functions

[Laurent Vivier]

Le 13/02/2018 à 16:51, Peter Maydell a écrit :
> On 6 February 2018 at 16:47, Alex Bennée <alex.bennee@linaro.org> wrote:
>> Hi,
>>
>> The main change is applying the __attribute__((flatten)) to some of
>> the public functions that show up in Emilio's dbt-benchmark. This
>> seems to be a cleaner solution that squashing inlines higher up the
>> chain and still leaves the chance for re-use for the less widely used
>> functions. The results are an improvement over v3 by some margin:
>>
>>                          NBench score; higher is better
>>
>>     5 +-+-----------+-------------+------------+-------------+-----------+-+
>>       |                     ****### %%%%  +++                              |
>>   4.5 +-+...................*..*..#.%..%..****##..%%%%+ system-2.5       +-+
>>       |                     *  *  # %  %  *  * #  %  %      master         |
>>     4 +-+...................*..*..#.%..%..*..*.#..%..%softfloat-v3       +-+
>>   3.5 +-+...................*..*..#.%..%..*..*.#..%..%softfloat-%%%%.....+-+
>>       |                     *  *  # %  %  *  * #  %  %  * *  #  %  %       |
>>     3 +-+...................*..*..#.%..%..*..*.#..%..%..*.*..#..%..%.....+-+
>>       |                     *  *  #+%  %  *  * #$$$  %  * *  #  %  %       |
>>   2.5 +-+........####.......*..*..#$$..%..*..*.#..$..%..*.*..#..%..%.....+-+
>>       |       ****  #  %%%  *  *  # $  %  *  * #  $  %  * *  #$$$  %       |
>>     2 +-+.....*..*..#..%.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>       |       *  *  #  % %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>>   1.5 +-+.....*..*..#$$$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>     1 +-+.....*..*..#..$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>       |       *  *  #  $ %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>>   0.5 +-+.....*..*..#..$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>       |       *  *  #  $ %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>>     0 +-+-----****###$$$%%--****###$$%%%--****##$$$%%%--***###$$$%%%-----+-+
>>                  FOURIER     NEURAL NETLU DECOMPOSITION    gmean
>>
>> Slightly easier to read PNG:
>>
>>     https://i.imgur.com/XEeL0bC.png
>>
>> I think it's pretty ready for a merge. Shall I submit a pull myself or
>> does it make sense going via someone else? According to MAINTAINERS
>> Peter and Aurelien are responsible for this code...
> 
> I had some nits but I think the best thing to do is if you fix those
> and then just send a pull request for this.

Just to be sure no one has missed that:

https://bellard.org/libbf/

I'm wondering if it can help for this work.

Thanks,
Laurent

Re: [Qemu-devel] [PATCH v4 22/22] fpu/softfloat: re-factor sqrt

[Richard Henderson]

On 02/06/2018 08:48 AM, Alex Bennée wrote:
> This is a little bit of a departure from softfloat's original approach
> as we skip the estimate step in favour of a straight iteration.
> 
> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> 
> ---
> v3
>   - added to series
>   - fixed renames of structs
> v4
>   - fix up comments
>   - use is_nan
>   - use return_nan instead of pick_nan(a,a)
> ---
>  fpu/softfloat.c         | 201 ++++++++++++++++++++++--------------------------
>  include/fpu/softfloat.h |   1 +
>  2 files changed, 91 insertions(+), 111 deletions(-)

Did I not give you an r-b for this before?  Anyway,

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~

Re: [Qemu-devel] [PATCH v4 00/22] re-factor softfloat and add fp16 functions

[Alex Bennée]

Peter Maydell <peter.maydell@linaro.org> writes:

> On 6 February 2018 at 16:47, Alex Bennée <alex.bennee@linaro.org> wrote:
>> Hi,
>>
>> The main change is applying the __attribute__((flatten)) to some of
>> the public functions that show up in Emilio's dbt-benchmark. This
>> seems to be a cleaner solution that squashing inlines higher up the
>> chain and still leaves the chance for re-use for the less widely used
>> functions. The results are an improvement over v3 by some margin:
>>
>>                          NBench score; higher is better
>>
>>     5 +-+-----------+-------------+------------+-------------+-----------+-+
>>       |                     ****### %%%%  +++                              |
>>   4.5 +-+...................*..*..#.%..%..****##..%%%%+ system-2.5       +-+
>>       |                     *  *  # %  %  *  * #  %  %      master         |
>>     4 +-+...................*..*..#.%..%..*..*.#..%..%softfloat-v3       +-+
>>   3.5 +-+...................*..*..#.%..%..*..*.#..%..%softfloat-%%%%.....+-+
>>       |                     *  *  # %  %  *  * #  %  %  * *  #  %  %       |
>>     3 +-+...................*..*..#.%..%..*..*.#..%..%..*.*..#..%..%.....+-+
>>       |                     *  *  #+%  %  *  * #$$$  %  * *  #  %  %       |
>>   2.5 +-+........####.......*..*..#$$..%..*..*.#..$..%..*.*..#..%..%.....+-+
>>       |       ****  #  %%%  *  *  # $  %  *  * #  $  %  * *  #$$$  %       |
>>     2 +-+.....*..*..#..%.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>       |       *  *  #  % %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>>   1.5 +-+.....*..*..#$$$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>     1 +-+.....*..*..#..$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>       |       *  *  #  $ %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>>   0.5 +-+.....*..*..#..$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>       |       *  *  #  $ %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>>     0 +-+-----****###$$$%%--****###$$%%%--****##$$$%%%--***###$$$%%%-----+-+
>>                  FOURIER     NEURAL NETLU DECOMPOSITION    gmean
>>
>> Slightly easier to read PNG:
>>
>>     https://i.imgur.com/XEeL0bC.png
>>
>> I think it's pretty ready for a merge. Shall I submit a pull myself or
>> does it make sense going via someone else? According to MAINTAINERS
>> Peter and Aurelien are responsible for this code...
>>
>> Alex Bennée (22):
>>   fpu/softfloat: implement float16_squash_input_denormal
>>   include/fpu/softfloat: remove USE_SOFTFLOAT_STRUCT_TYPES
>>   fpu/softfloat-types: new header to prevent excessive re-builds
>>   target/*/cpu.h: remove softfloat.h
>>   include/fpu/softfloat: implement float16_abs helper
>>   include/fpu/softfloat: implement float16_chs helper
>>   include/fpu/softfloat: implement float16_set_sign helper
>>   include/fpu/softfloat: add some float16 constants
>>   fpu/softfloat: improve comments on ARM NaN propagation
>>   fpu/softfloat: move the extract functions to the top of the file
>>   fpu/softfloat: define decompose structures
>>   fpu/softfloat: re-factor add/sub
>>   fpu/softfloat: re-factor mul
>>   fpu/softfloat: re-factor div
>>   fpu/softfloat: re-factor muladd
>>   fpu/softfloat: re-factor round_to_int
>>   fpu/softfloat: re-factor float to int/uint
>>   fpu/softfloat: re-factor int/uint to float
>>   fpu/softfloat: re-factor scalbn
>>   fpu/softfloat: re-factor minmax
>>   fpu/softfloat: re-factor compare
>>   fpu/softfloat: re-factor sqrt
>
> If you persuade git to use the --minimal, --patience or --histogram
> git diff option when generating these patches you'll find that it
> doesn't produce unreadable patches that provoke all the checkpatch
> warnings.

I think this is patchew getting confused as I generated the patches
with:

  [diff]
        algorithm = minimal

In my qemu.git/.git/config

> That in turn will let you find the genuine warning that
> got lost in all the spurious ones:
>
> Checking PATCH 16/22: fpu/softfloat: re-factor round_to_int...
> WARNING: line over 80 characters
> #127: FILE: fpu/softfloat.c:1261:
> +                inc = ((a.frac & roundeven_mask) != frac_lsbm1 ?
> frac_lsbm1 : 0);

Yeah that was in the release but the one character over is the ; and it
seemed nicer keeping all the logic on the same line.

> As far as I can tell from a quick search, the 'histogram'
> algorithm is reckoned to be about as fast as the default but
> much less likely to produce terrible diffs.
>
>   git config --global diff.algorithm histogram
>
> should set it up as the default for all diff-producing purposes
> including generating patches for email.
>
> thanks
> -- PMM


--
Alex Bennée

Re: [Qemu-devel] [PATCH v4 00/22] re-factor softfloat and add fp16 functions

[Peter Maydell]

On 17 February 2018 at 13:23, Alex Bennée <alex.bennee@linaro.org> wrote:
> Peter Maydell <peter.maydell@linaro.org> writes:
>> If you persuade git to use the --minimal, --patience or --histogram
>> git diff option when generating these patches you'll find that it
>> doesn't produce unreadable patches that provoke all the checkpatch
>> warnings.
>
> I think this is patchew getting confused

Oh yes, sorry. Fam, can we update patchew's git config to use
  git config --global diff.algorithm histogram
(equivalently, algorithm = histogram in the .gitconfig) -- that
way the patches it runs checkpatch on are more likely to be
formatted so that they minimise spurious checkpatch output, I think.

thanks
-- PMM

Re: [Qemu-devel] [PATCH v4 13/22] fpu/softfloat: re-factor mul

[Alex Bennée]

Peter Maydell <peter.maydell@linaro.org> writes:

> On 6 February 2018 at 16:48, Alex Bennée <alex.bennee@linaro.org> wrote:
>> We can now add float16_mul and use the common decompose and
>> canonicalize functions to have a single implementation for
>> float16/32/64 versions.
>>
>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>>
>> ---
>> v3
>
>> +/*
>> + * Returns the result of multiplying the floating-point values `a' and
>> + * `b'. The operation is performed according to the IEC/IEEE Standard
>> + * for Binary Floating-Point Arithmetic.
>> + */
>> +
>> +static FloatParts mul_floats(FloatParts a, FloatParts b, float_status *s)
>> +{
>> +    bool sign = a.sign ^ b.sign;
>> +
>> +    if (a.cls == float_class_normal && b.cls == float_class_normal) {
>> +        uint64_t hi, lo;
>> +        int exp = a.exp + b.exp;
>> +
>> +        mul64To128(a.frac, b.frac, &hi, &lo);
>
> It seems a shame that we previously were able to use a
> 32x32->64 multiply for the float32 case, and now we have to
> do an expensive 64x64->128 multiply regardless...

Actually for mul the hit isn't too bad. When we do a div however you do
notice a bit of a gulf:

 https://i.imgur.com/KMWceo8.png

We could start passing &floatN_params to the functions much like the
sqrt function and be a bit smarter when we do our multiply and let the
compiler figure it out as we go.

Another avenue worth exploring is ensuring we use native Int128 support
where we can so these wide operations can use wide registers where
available.

However both of these things for future optimisations given it doesn't
show up in dbt-bench timings.

>
> Regardless
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
>
> thanks
> -- PMM


--
Alex Bennée

Re: [Qemu-devel] [PATCH v4 00/22] re-factor softfloat and add fp16 functions

[Alex Bennée]

Laurent Vivier <laurent@vivier.eu> writes:

> Le 13/02/2018 à 16:51, Peter Maydell a écrit:
>> On 6 February 2018 at 16:47, Alex Bennée <alex.bennee@linaro.org> wrote:
>>> Hi,
>>>
>>> The main change is applying the __attribute__((flatten)) to some of
>>> the public functions that show up in Emilio's dbt-benchmark. This
>>> seems to be a cleaner solution that squashing inlines higher up the
>>> chain and still leaves the chance for re-use for the less widely used
>>> functions. The results are an improvement over v3 by some margin:
>>>
>>>                          NBench score; higher is better
>>>
>>>     5 +-+-----------+-------------+------------+-------------+-----------+-+
>>>       |                     ****### %%%%  +++                              |
>>>   4.5 +-+...................*..*..#.%..%..****##..%%%%+ system-2.5       +-+
>>>       |                     *  *  # %  %  *  * #  %  %      master         |
>>>     4 +-+...................*..*..#.%..%..*..*.#..%..%softfloat-v3       +-+
>>>   3.5 +-+...................*..*..#.%..%..*..*.#..%..%softfloat-%%%%.....+-+
>>>       |                     *  *  # %  %  *  * #  %  %  * *  #  %  %       |
>>>     3 +-+...................*..*..#.%..%..*..*.#..%..%..*.*..#..%..%.....+-+
>>>       |                     *  *  #+%  %  *  * #$$$  %  * *  #  %  %       |
>>>   2.5 +-+........####.......*..*..#$$..%..*..*.#..$..%..*.*..#..%..%.....+-+
>>>       |       ****  #  %%%  *  *  # $  %  *  * #  $  %  * *  #$$$  %       |
>>>     2 +-+.....*..*..#..%.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>>       |       *  *  #  % %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>>>   1.5 +-+.....*..*..#$$$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>>     1 +-+.....*..*..#..$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>>       |       *  *  #  $ %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>>>   0.5 +-+.....*..*..#..$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>>       |       *  *  #  $ %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>>>     0 +-+-----****###$$$%%--****###$$%%%--****##$$$%%%--***###$$$%%%-----+-+
>>>                  FOURIER     NEURAL NETLU DECOMPOSITION    gmean
>>>
>>> Slightly easier to read PNG:
>>>
>>>     https://i.imgur.com/XEeL0bC.png
>>>
>>> I think it's pretty ready for a merge. Shall I submit a pull myself or
>>> does it make sense going via someone else? According to MAINTAINERS
>>> Peter and Aurelien are responsible for this code...
>>
>> I had some nits but I think the best thing to do is if you fix those
>> and then just send a pull request for this.
>
> Just to be sure no one has missed that:
>
> https://bellard.org/libbf/
>
> I'm wondering if it can help for this work.

I did have a brief look through to get a sense of how it works. The
first thing it is missing however is half-precision. It only seems to
deal in 32 and 64 bit floats. The code is also fairly sparse in its
commenting.

The main approach seems to be somewhere between rth's glibc macro fest
and what we have now. It makes extensive use of every QEMU developers
favourite glue macro to instantiate code from a "template". This allows
some better usage of size appropriate types in each instantiation where
we just do most things at the highest precision.

However I think it also suffers the same problem as SoftFloat3 as in
it is not an upstream project so it is just another lump of code to
import into out code base. Based on that I favour our re-factor more as
I think it is easier to follow and hopefully will be easier to maintain.

I think we can address the inefficiencies in our mul/div code by passing
FloatFmt in and letting the compiler deal with it in each flattened
implementation. I prototyped mul:

  http://ix.io/MYw

However unless we are super worried about these inefficiencies I'm
proposing we merge what we have and deal with these in a later round.

>
> Thanks,
> Laurent


--
Alex Bennée

[Qemu-devel] [PATCH] fpu/softfloat: use hardware sqrt if we can (EXPERIMENT!)

[Alex Bennée]

This is an attempt to save some of the cost of sqrt by using the
inbuilt support of the host hardware. The idea is assuming we start
with a valid input we can use the hardware. If any tininess issues
occur this will trip and FPU exception where:

  - we turn off cpu->use_host_fpu
  - mask the FPU exceptions
  - return to what we were doing

Once we return we should pick up the fact that there was something
weird about the operation and fall-back to the pure software
implementation.

You could imagine this being extended for code generation but instead
of returning to the code we could exit and re-generate the TB but this
time with pure software helpers rather than any support from the
hardware.

This is a sort of fix-it-up after the fact approach because reading
the FP state is an expensive operation for everything so let's only
worry about exceptions when they trip...

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 cpus.c                        | 28 ++++++++++++++++++++++++++++
 fpu/softfloat.c               | 40 +++++++++++++++++++++++++++++++++++-----
 include/fpu/softfloat-types.h |  2 ++
 include/fpu/softfloat.h       |  4 ++++
 include/qom/cpu.h             |  1 +
 linux-user/main.c             |  8 ++++++++
 linux-user/signal.c           | 16 ++++++++++++++++
 target/arm/cpu.c              |  4 ++++
 8 files changed, 98 insertions(+), 5 deletions(-)

diff --git a/cpus.c b/cpus.c
index f298b659f4..e435f6737b 100644
--- a/cpus.c
+++ b/cpus.c
@@ -23,6 +23,7 @@
  */
 
 #include "qemu/osdep.h"
+#include <fenv.h>
 #include "qemu/config-file.h"
 #include "cpu.h"
 #include "monitor/monitor.h"
@@ -1078,10 +1079,36 @@ static void qemu_init_sigbus(void)
 
     prctl(PR_MCE_KILL, PR_MCE_KILL_SET, PR_MCE_KILL_EARLY, 0, 0);
 }
+
+static void sigfpu_handler(int n, siginfo_t *siginfo, void *ctx)
+{
+    fprintf(stderr, "%s: got %d, %p/%p\n", __func__, n, siginfo, ctx);
+
+    /* Called asynchronously in VCPU thread.  */
+    g_assert(current_cpu);
+}
+
+static void qemu_init_sigfpu(void)
+{
+    struct sigaction action;
+
+    memset(&action, 0, sizeof(action));
+    action.sa_flags = SA_SIGINFO;
+    action.sa_sigaction = sigfpu_handler;
+    sigaction(SIGBUS, &action, NULL);
+
+    feenableexcept(FE_INVALID   |
+                   FE_OVERFLOW  |
+                   FE_UNDERFLOW |
+                   FE_INEXACT);
+}
 #else /* !CONFIG_LINUX */
 static void qemu_init_sigbus(void)
 {
 }
+static void qemu_init_sigfpu(void)
+{
+}
 #endif /* !CONFIG_LINUX */
 
 static QemuMutex qemu_global_mutex;
@@ -1827,6 +1854,7 @@ static void qemu_tcg_init_vcpu(CPUState *cpu)
     if (!tcg_region_inited) {
         tcg_region_inited = 1;
         tcg_region_init();
+        qemu_init_sigfpu();
     }
 
     if (qemu_tcg_mttcg_enabled() || !single_tcg_cpu_thread) {
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index e7fb0d357a..ec9355af7a 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1905,10 +1905,12 @@ float64 float64_scalbn(float64 a, int n, float_status *status)
  * bits to ensure we get a correctly rounded result.
  *
  * This does mean however the calculation is slower than before,
- * especially for 64 bit floats.
+ * especially for 64 bit floats. However the caller can only do checks
+ * if they actually want to off-load to the library.
  */
 
-static FloatParts sqrt_float(FloatParts a, float_status *s, const FloatFmt *p)
+static FloatParts sqrt_float(FloatParts a, float_status *s,
+                             const FloatFmt *p, bool check_only)
 {
     uint64_t a_frac, r_frac, s_frac;
     int bit, last_bit;
@@ -1928,6 +1930,10 @@ static FloatParts sqrt_float(FloatParts a, float_status *s, const FloatFmt *p)
         return a;  /* sqrt(+inf) = +inf */
     }
 
+    if (check_only) {
+        return a;
+    }
+
     assert(a.cls == float_class_normal);
 
     /* We need two overflow bits at the top. Adding room for that is a
@@ -1973,21 +1979,45 @@ static FloatParts sqrt_float(FloatParts a, float_status *s, const FloatFmt *p)
 float16 __attribute__((flatten)) float16_sqrt(float16 a, float_status *status)
 {
     FloatParts pa = float16_unpack_canonical(a, status);
-    FloatParts pr = sqrt_float(pa, status, &float16_params);
+    FloatParts pr = sqrt_float(pa, status, &float16_params, false);
     return float16_round_pack_canonical(pr, status);
 }
 
 float32 __attribute__((flatten)) float32_sqrt(float32 a, float_status *status)
 {
     FloatParts pa = float32_unpack_canonical(a, status);
-    FloatParts pr = sqrt_float(pa, status, &float32_params);
+    FloatParts pr;
+
+    if (status->use_host_fpu && *status->use_host_fpu) {
+        pr = sqrt_float(pa, status, &float32_params, true);
+        if (pr.cls == float_class_normal) {
+            float32 r = __builtin_sqrt(a);
+            if (*status->use_host_fpu) {
+                return r;
+            }
+        }
+    }
+
+    pr = sqrt_float(pa, status, &float32_params, false);
     return float32_round_pack_canonical(pr, status);
 }
 
 float64 __attribute__((flatten)) float64_sqrt(float64 a, float_status *status)
 {
     FloatParts pa = float64_unpack_canonical(a, status);
-    FloatParts pr = sqrt_float(pa, status, &float64_params);
+    FloatParts pr = sqrt_float(pa, status, &float64_params, true);
+
+    if (status->use_host_fpu && *status->use_host_fpu) {
+        pr = sqrt_float(pa, status, &float64_params, true);
+        if (pr.cls == float_class_normal) {
+            float64 r = __builtin_sqrt(a);
+            if (*status->use_host_fpu) {
+                return r;
+            }
+        }
+    }
+
+    pr = sqrt_float(pa, status, &float64_params, false);
     return float64_round_pack_canonical(pr, status);
 }
 
diff --git a/include/fpu/softfloat-types.h b/include/fpu/softfloat-types.h
index 4e378cb612..4c32e56cad 100644
--- a/include/fpu/softfloat-types.h
+++ b/include/fpu/softfloat-types.h
@@ -174,6 +174,8 @@ typedef struct float_status {
     flag flush_inputs_to_zero;
     flag default_nan_mode;
     flag snan_bit_is_one;
+    /* can we use the host_fpu for some things? */
+    bool *use_host_fpu;
 } float_status;
 
 #endif /* SOFTFLOAT_TYPES_H */
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 9b7b5e34e2..f7ee0232a2 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -157,6 +157,10 @@ static inline flag get_default_nan_mode(float_status *status)
 {
     return status->default_nan_mode;
 }
+static inline void enable_host_fpu(bool *host_fpu_flag, float_status *status)
+{
+    status->use_host_fpu = host_fpu_flag;
+}
 
 /*----------------------------------------------------------------------------
 | Routine to raise any or all of the software IEC/IEEE floating-point
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index aff88fa16f..337ebef8b6 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -396,6 +396,7 @@ struct CPUState {
     uint32_t halted;
     uint32_t can_do_io;
     int32_t exception_index;
+    bool use_host_fpu;
 
     /* shared by kvm, hax and hvf */
     bool vcpu_dirty;
diff --git a/linux-user/main.c b/linux-user/main.c
index 7de0e02487..36b6be3b2b 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -20,6 +20,7 @@
 #include "qemu-version.h"
 #include <sys/syscall.h>
 #include <sys/resource.h>
+#include <fenv.h>
 
 #include "qapi/error.h"
 #include "qemu.h"
@@ -4927,6 +4928,13 @@ int main(int argc, char **argv, char **envp)
         }
         gdb_handlesig(cpu, 0);
     }
+
+    feenableexcept(FE_INVALID   |
+                   FE_OVERFLOW  |
+                   FE_UNDERFLOW |
+                   FE_INEXACT);
+    cpu->use_host_fpu = true;
+
     cpu_loop(env);
     /* never exits */
     return 0;
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 9a380b9e31..0773d3ef18 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -20,6 +20,7 @@
 #include "qemu/bitops.h"
 #include <sys/ucontext.h>
 #include <sys/resource.h>
+#include <fenv.h>
 
 #include "qemu.h"
 #include "qemu-common.h"
@@ -639,6 +640,21 @@ static void host_signal_handler(int host_signum, siginfo_t *info,
     ucontext_t *uc = puc;
     struct emulated_sigtable *k;
 
+    /* Catch any FPU exceptions we might get from having tried to use
+     * the host FPU to speed up some calculations
+     */
+    if (host_signum == SIGFPE && cpu->use_host_fpu) {
+        cpu->use_host_fpu = false;
+        /* sadly this gets lost on the context switch when we return */
+        fedisableexcept(FE_INVALID   |
+                        FE_OVERFLOW  |
+                        FE_UNDERFLOW |
+                        FE_INEXACT);
+        /* sigaddset(&uc->uc_sigmask, SIGFPE); */
+        uc->__fpregs_mem.mxcsr |= 0x1f80;
+        return;
+    }
+
     /* the CPU emulator uses some host signals to detect exceptions,
        we forward to it some signals */
     if ((host_signum == SIGSEGV || host_signum == SIGBUS)
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 1b3ae62db6..67dce53a68 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -306,6 +306,10 @@ static void arm_cpu_reset(CPUState *s)
                               &env->vfp.fp_status);
     set_float_detect_tininess(float_tininess_before_rounding,
                               &env->vfp.standard_fp_status);
+
+    enable_host_fpu(&s->use_host_fpu, &env->vfp.fp_status);
+    enable_host_fpu(&s->use_host_fpu, &env->vfp.standard_fp_status);
+
 #ifndef CONFIG_USER_ONLY
     if (kvm_enabled()) {
         kvm_arm_reset_vcpu(cpu);
-- 
2.15.1

Re: [Qemu-devel] [PATCH] fpu/softfloat: use hardware sqrt if we can (EXPERIMENT!)

[Alex Bennée]

Alex Bennée <alex.bennee@linaro.org> writes:

> This is an attempt to save some of the cost of sqrt by using the
> inbuilt support of the host hardware. The idea is assuming we start
> with a valid input we can use the hardware. If any tininess issues
> occur this will trip and FPU exception where:
>
>   - we turn off cpu->use_host_fpu
>   - mask the FPU exceptions
>   - return to what we were doing
>
> Once we return we should pick up the fact that there was something
> weird about the operation and fall-back to the pure software
> implementation.
>
> You could imagine this being extended for code generation but instead
> of returning to the code we could exit and re-generate the TB but this
> time with pure software helpers rather than any support from the
> hardware.
>
> This is a sort of fix-it-up after the fact approach because reading
> the FP state is an expensive operation for everything so let's only
> worry about exceptions when they trip...
>
<snip>
> --- a/linux-user/signal.c
> +++ b/linux-user/signal.c
> @@ -20,6 +20,7 @@
>  #include "qemu/bitops.h"
>  #include <sys/ucontext.h>
>  #include <sys/resource.h>
> +#include <fenv.h>
>
>  #include "qemu.h"
>  #include "qemu-common.h"
> @@ -639,6 +640,21 @@ static void host_signal_handler(int host_signum, siginfo_t *info,
>      ucontext_t *uc = puc;
>      struct emulated_sigtable *k;
>
> +    /* Catch any FPU exceptions we might get from having tried to use
> +     * the host FPU to speed up some calculations
> +     */
> +    if (host_signum == SIGFPE && cpu->use_host_fpu) {
> +        cpu->use_host_fpu = false;
> +        /* sadly this gets lost on the context switch when we return */
> +        fedisableexcept(FE_INVALID   |
> +                        FE_OVERFLOW  |
> +                        FE_UNDERFLOW |
> +                        FE_INEXACT);
> +        /* sigaddset(&uc->uc_sigmask, SIGFPE); */
> +        uc->__fpregs_mem.mxcsr |= 0x1f80;

This is a bug, the correct place to reset mxcsr for the return is:

        (uc->uc_mcontext.fpregs)->mxcsr |= 0x1f80;

--
Alex Bennée

Re: [Qemu-devel] [PATCH v4 00/22] re-factor softfloat and add fp16 functions

[Fam Zheng]

On Mon, 02/19 13:56, Peter Maydell wrote:
> On 17 February 2018 at 13:23, Alex Bennée <alex.bennee@linaro.org> wrote:
> > Peter Maydell <peter.maydell@linaro.org> writes:
> >> If you persuade git to use the --minimal, --patience or --histogram
> >> git diff option when generating these patches you'll find that it
> >> doesn't produce unreadable patches that provoke all the checkpatch
> >> warnings.
> >
> > I think this is patchew getting confused
> 
> Oh yes, sorry. Fam, can we update patchew's git config to use
>   git config --global diff.algorithm histogram
> (equivalently, algorithm = histogram in the .gitconfig) -- that
> way the patches it runs checkpatch on are more likely to be
> formatted so that they minimise spurious checkpatch output, I think.

Updated. (With s/--global/--local/ along with other diff options, in the testing
command list:

git config --local diff.renamelimit 0
git config --local diff.renames True
git config --local diff.algorithm histogram

)

Fam

Re: [Qemu-devel] [PATCH] fpu/softfloat: use hardware sqrt if we can (EXPERIMENT!)

[Emilio G. Cota]

On Tue, Feb 20, 2018 at 21:01:37 +0000, Alex Bennée wrote:
> This is an attempt to save some of the cost of sqrt by using the
> inbuilt support of the host hardware. The idea is assuming we start
> with a valid input we can use the hardware. If any tininess issues
> occur this will trip and FPU exception where:
> 
>   - we turn off cpu->use_host_fpu
>   - mask the FPU exceptions
>   - return to what we were doing

Please see this thread for an alternative approach:

  [Qemu-devel] [PATCH v1 00/14] fp-test + hostfloat
  https://lists.gnu.org/archive/html/qemu-devel/2018-03/msg05908.html

		Emilio