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From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: alex.bennee@linaro.org, david@redhat.com
Subject: [PATCH 55/72] softfloat: Reduce FloatFmt
Date: Fri,  7 May 2021 18:47:45 -0700	[thread overview]
Message-ID: <20210508014802.892561-56-richard.henderson@linaro.org> (raw)
In-Reply-To: <20210508014802.892561-1-richard.henderson@linaro.org>

Remove frac_lsb, frac_lsbm1, roundeven_mask.  Compute
these from round_mask in parts$N_uncanon_normal.

With floatx80, round_mask will not be tied to frac_shift.
Everything else is easily computable.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 fpu/softfloat.c           | 29 ++++++++++++-----------------
 fpu/softfloat-parts.c.inc |  6 +++---
 2 files changed, 15 insertions(+), 20 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 4df69029ec..6a77e35663 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -562,9 +562,7 @@ typedef struct {
  *   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
- *   frac_lsbm1: the bit below the least significant bit (for rounding)
- *   round_mask/roundeven_mask: masks used for rounding
+ *   round_mask: bits below lsb which must be rounded
  * The following optional modifiers are available:
  *   arm_althp: handle ARM Alternative Half Precision
  */
@@ -574,24 +572,21 @@ typedef struct {
     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;
     bool arm_althp;
+    uint64_t round_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     = (-F - 1) & 63,                                 \
-    .frac_lsb       = 1ull << ((-F - 1) & 63),                       \
-    .frac_lsbm1     = 1ull << ((-F - 2) & 63),                       \
-    .round_mask     = (1ull << ((-F - 1) & 63)) - 1,                 \
-    .roundeven_mask = (2ull << ((-F - 1) & 63)) - 1
+#define FLOAT_PARAMS_(E, F)                             \
+    .exp_size       = E,                                \
+    .exp_bias       = ((1 << E) - 1) >> 1,              \
+    .exp_max        = (1 << E) - 1,                     \
+    .frac_size      = F
+
+#define FLOAT_PARAMS(E, F)                              \
+    FLOAT_PARAMS_(E, F),                                \
+    .frac_shift     = (-F - 1) & 63,                    \
+    .round_mask     = (1ull << ((-F - 1) & 63)) - 1
 
 static const FloatFmt float16_params = {
     FLOAT_PARAMS(5, 10)
diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc
index 65462bf6cb..3ee6552d5a 100644
--- a/fpu/softfloat-parts.c.inc
+++ b/fpu/softfloat-parts.c.inc
@@ -145,10 +145,10 @@ static void partsN(uncanon_normal)(FloatPartsN *p, float_status *s,
 {
     const int exp_max = fmt->exp_max;
     const int frac_shift = fmt->frac_shift;
-    const uint64_t frac_lsb = fmt->frac_lsb;
-    const uint64_t frac_lsbm1 = fmt->frac_lsbm1;
     const uint64_t round_mask = fmt->round_mask;
-    const uint64_t roundeven_mask = fmt->roundeven_mask;
+    const uint64_t frac_lsb = round_mask + 1;
+    const uint64_t frac_lsbm1 = round_mask ^ (round_mask >> 1);
+    const uint64_t roundeven_mask = round_mask | frac_lsb;
     uint64_t inc;
     bool overflow_norm;
     int exp, flags = 0;
-- 
2.25.1



  parent reply	other threads:[~2021-05-08  2:29 UTC|newest]

Thread overview: 151+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-08  1:46 [PATCH 00/72] Convert floatx80 and float128 to FloatParts Richard Henderson
2021-05-08  1:46 ` [PATCH 01/72] qemu/host-utils: Use __builtin_bitreverseN Richard Henderson
2021-05-10  9:59   ` Alex Bennée
2021-05-11  9:41   ` David Hildenbrand
2021-05-08  1:46 ` [PATCH 02/72] qemu/host-utils: Add wrappers for overflow builtins Richard Henderson
2021-05-10 10:22   ` Alex Bennée
2021-05-08  1:46 ` [PATCH 03/72] qemu/host-utils: Add wrappers for carry builtins Richard Henderson
2021-05-10 12:57   ` Alex Bennée
2021-05-11 20:10     ` Richard Henderson
2021-05-12 11:17       ` Alex Bennée
2021-05-08  1:46 ` [PATCH 04/72] accel/tcg: Use add/sub overflow routines in tcg-runtime-gvec.c Richard Henderson
2021-05-09  8:43   ` Philippe Mathieu-Daudé
2021-05-10 13:02   ` Alex Bennée
2021-05-11  9:46   ` David Hildenbrand
2021-05-08  1:46 ` [PATCH 05/72] tests/fp: add quad support to the benchmark utility Richard Henderson
2021-05-11 10:01   ` David Hildenbrand
2021-05-08  1:46 ` [PATCH 06/72] softfloat: Move the binary point to the msb Richard Henderson
2021-05-10 13:36   ` Alex Bennée
2021-05-08  1:46 ` [PATCH 07/72] softfloat: Inline float_raise Richard Henderson
2021-05-09  8:32   ` Philippe Mathieu-Daudé
2021-05-11 10:04   ` David Hildenbrand
2021-05-08  1:46 ` [PATCH 08/72] softfloat: Use float_raise in more places Richard Henderson
2021-05-09  8:34   ` Philippe Mathieu-Daudé
2021-05-11 10:06   ` David Hildenbrand
2021-05-08  1:46 ` [PATCH 09/72] softfloat: Tidy a * b + inf return Richard Henderson
2021-05-08  1:47 ` [PATCH 10/72] softfloat: Add float_cmask and constants Richard Henderson
2021-05-08  1:47 ` [PATCH 11/72] softfloat: Use return_nan in float_to_float Richard Henderson
2021-05-10 15:10   ` Alex Bennée
2021-05-11 10:10   ` David Hildenbrand
2021-05-08  1:47 ` [PATCH 12/72] softfloat: fix return_nan vs default_nan_mode Richard Henderson
2021-05-10 15:12   ` Alex Bennée
2021-05-11 10:12   ` David Hildenbrand
2021-05-08  1:47 ` [PATCH 13/72] target/mips: Set set_default_nan_mode with set_snan_bit_is_one Richard Henderson
2021-05-11  9:37   ` Alex Bennée
2021-05-11 10:16   ` David Hildenbrand
2021-05-08  1:47 ` [PATCH 14/72] softfloat: Do not produce a default_nan from parts_silence_nan Richard Henderson
2021-05-11 10:16   ` David Hildenbrand
2021-05-11 10:32   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 15/72] softfloat: Rename FloatParts to FloatParts64 Richard Henderson
2021-05-09  8:45   ` Philippe Mathieu-Daudé
2021-05-11 10:16   ` David Hildenbrand
2021-05-08  1:47 ` [PATCH 16/72] softfloat: Move type-specific pack/unpack routines Richard Henderson
2021-05-09  8:46   ` Philippe Mathieu-Daudé
2021-05-11 10:17   ` David Hildenbrand
2021-05-08  1:47 ` [PATCH 17/72] softfloat: Use pointers with parts_default_nan Richard Henderson
2021-05-11 10:22   ` David Hildenbrand
2021-05-11 20:19     ` Richard Henderson
2021-05-08  1:47 ` [PATCH 18/72] softfloat: Use pointers with unpack_raw Richard Henderson
2021-05-09  8:48   ` Philippe Mathieu-Daudé
2021-05-12 12:58   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 19/72] softfloat: Use pointers with ftype_unpack_raw Richard Henderson
2021-05-11 11:31   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 20/72] softfloat: Use pointers with pack_raw Richard Henderson
2021-05-11 11:32   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 21/72] softfloat: Use pointers with ftype_pack_raw Richard Henderson
2021-05-11 11:32   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 22/72] softfloat: Use pointers with ftype_unpack_canonical Richard Henderson
2021-05-11 13:54   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 23/72] softfloat: Use pointers with ftype_round_pack_canonical Richard Henderson
2021-05-11 13:55   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 24/72] softfloat: Use pointers with parts_silence_nan Richard Henderson
2021-05-11 13:56   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 25/72] softfloat: Rearrange FloatParts64 Richard Henderson
2021-05-11 13:57   ` Alex Bennée
2021-05-11 15:04     ` Richard Henderson
2021-05-12 11:08       ` Alex Bennée
2021-05-08  1:47 ` [PATCH 26/72] softfloat: Convert float128_silence_nan to parts Richard Henderson
2021-05-13  8:34   ` Alex Bennée
2021-05-13 12:25     ` Richard Henderson
2021-05-08  1:47 ` [PATCH 27/72] softfloat: Convert float128_default_nan " Richard Henderson
2021-05-13  8:56   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 28/72] softfloat: Move return_nan to softfloat-parts.c.inc Richard Henderson
2021-05-12 18:10   ` David Hildenbrand
2021-05-08  1:47 ` [PATCH 29/72] softfloat: Move pick_nan " Richard Henderson
2021-05-12 18:16   ` David Hildenbrand
2021-05-13 12:28     ` Richard Henderson
2021-05-08  1:47 ` [PATCH 30/72] softfloat: Move pick_nan_muladd " Richard Henderson
2021-05-12 18:18   ` David Hildenbrand
2021-05-08  1:47 ` [PATCH 31/72] softfloat: Move sf_canonicalize " Richard Henderson
2021-05-13  9:45   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 32/72] softfloat: Move round_canonical " Richard Henderson
2021-05-13  9:53   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 33/72] softfloat: Use uadd64_carry, usub64_borrow in softfloat-macros.h Richard Henderson
2021-05-13 10:00   ` Alex Bennée
2021-05-13 12:38     ` Richard Henderson
2021-05-08  1:47 ` [PATCH 34/72] softfloat: Move addsub_floats to softfloat-parts.c.inc Richard Henderson
2021-05-13 10:03   ` Alex Bennée
2021-05-13 10:05   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 35/72] softfloat: Implement float128_add/sub via parts Richard Henderson
2021-05-13 10:06   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 36/72] softfloat: Move mul_floats to softfloat-parts.c.inc Richard Henderson
2021-05-13 10:08   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 37/72] softfloat: Move muladd_floats " Richard Henderson
2021-05-13 10:43   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 38/72] softfloat: Use mulu64 for mul64To128 Richard Henderson
2021-05-08  1:47 ` [PATCH 39/72] softfloat: Use add192 in mul128To256 Richard Henderson
2021-05-13 10:49   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 40/72] softfloat: Tidy mul128By64To192 Richard Henderson
2021-05-13 10:50   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 41/72] softfloat: Introduce sh[lr]_double primitives Richard Henderson
2021-05-13 10:59   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 42/72] softfloat: Move div_floats to softfloat-parts.c.inc Richard Henderson
2021-05-13 11:02   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 43/72] softfloat: Split float_to_float Richard Henderson
2021-05-13 11:04   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 44/72] softfloat: Convert float-to-float conversions with float128 Richard Henderson
2021-05-13 11:17   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 45/72] softfloat: Move round_to_int to softfloat-parts.c.inc Richard Henderson
2021-05-13 14:10   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 46/72] softfloat: Move rount_to_int_and_pack " Richard Henderson
2021-05-13 14:11   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 47/72] softfloat: Move rount_to_uint_and_pack " Richard Henderson
2021-05-08  1:47 ` [PATCH 48/72] softfloat: Move int_to_float " Richard Henderson
2021-05-08  1:47 ` [PATCH 49/72] softfloat: Move uint_to_float " Richard Henderson
2021-05-08  1:47 ` [PATCH 50/72] softfloat: Move minmax_flags " Richard Henderson
2021-05-17 13:14   ` David Hildenbrand
2021-05-17 15:57     ` Richard Henderson
2021-05-08  1:47 ` [PATCH 51/72] softfloat: Move compare_floats " Richard Henderson
2021-05-08  1:47 ` [PATCH 52/72] softfloat: Move scalbn_decomposed " Richard Henderson
2021-05-08  1:47 ` [PATCH 53/72] softfloat: Move sqrt_float " Richard Henderson
2021-05-08  1:47 ` [PATCH 54/72] softfloat: Split out parts_uncanon_normal Richard Henderson
2021-05-08  1:47 ` Richard Henderson [this message]
2021-05-08  1:47 ` [PATCH 56/72] softfloat: Introduce Floatx80RoundPrec Richard Henderson
2021-05-08  1:47 ` [PATCH 57/72] softfloat: Adjust parts_uncanon_normal for floatx80 Richard Henderson
2021-05-08  1:47 ` [PATCH 58/72] tests/fp/fp-test: Reverse order of floatx80 precision tests Richard Henderson
2021-05-13 14:12   ` Alex Bennée
2021-05-08  1:47 ` [PATCH 59/72] softfloat: Convert floatx80_add/sub to FloatParts Richard Henderson
2021-05-08  1:47 ` [PATCH 60/72] softfloat: Convert floatx80_mul " Richard Henderson
2021-05-08  1:47 ` [PATCH 61/72] softfloat: Convert floatx80_div " Richard Henderson
2021-05-08  1:47 ` [PATCH 62/72] softfloat: Convert floatx80_sqrt " Richard Henderson
2021-05-08  1:47 ` [PATCH 63/72] softfloat: Convert floatx80_round " Richard Henderson
2021-05-08  1:47 ` [PATCH 64/72] softfloat: Convert floatx80_round_to_int " Richard Henderson
2021-05-08  1:47 ` [PATCH 65/72] softfloat: Convert integer to floatx80 " Richard Henderson
2021-05-08  1:47 ` [PATCH 66/72] softfloat: Convert floatx80 float conversions " Richard Henderson
2021-05-08  1:47 ` [PATCH 67/72] softfloat: Convert floatx80 to integer " Richard Henderson
2021-05-08  1:47 ` [PATCH 68/72] softfloat: Convert floatx80_scalbn " Richard Henderson
2021-05-08  1:47 ` [PATCH 69/72] softfloat: Convert floatx80 compare " Richard Henderson
2021-05-08  1:48 ` [PATCH 70/72] softfloat: Convert float32_exp2 " Richard Henderson
2021-05-08  1:48 ` [PATCH 71/72] softfloat: Move floatN_log2 to softfloat-parts.c.inc Richard Henderson
2021-05-08  1:48 ` [PATCH 72/72] softfloat: Convert modrem operations to FloatParts Richard Henderson
2021-05-08  2:52 ` [PATCH 00/72] Convert floatx80 and float128 " no-reply
2021-05-10 13:36 ` Alex Bennée
2021-05-12  1:52   ` Richard Henderson
2021-05-12 11:22     ` Alex Bennée
2021-05-12 15:28       ` Richard Henderson
2021-05-12 16:47 ` Alex Bennée
2021-05-12 19:23 ` Alex Bennée
2021-05-13 11:49   ` Richard Henderson
2021-05-13 13:33     ` Alex Bennée
2021-05-13 23:54       ` Richard Henderson
2021-05-13 14:13 ` Alex Bennée

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