From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: bharata@linux.ibm.com, alex.bennee@linaro.org, david@redhat.com
Subject: [PATCH v2 02/10] softfloat: Use int128.h for some operations
Date: Fri, 25 Sep 2020 08:20:39 -0700 [thread overview]
Message-ID: <20200925152047.709901-3-richard.henderson@linaro.org> (raw)
In-Reply-To: <20200925152047.709901-1-richard.henderson@linaro.org>
Use our Int128, which wraps the compiler's __int128_t,
instead of open-coding left shifts and arithmetic.
We'd need to extend Int128 to have unsigned operations
to replace more than these three.
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
include/fpu/softfloat-macros.h | 39 +++++++++++++++++-----------------
1 file changed, 20 insertions(+), 19 deletions(-)
diff --git a/include/fpu/softfloat-macros.h b/include/fpu/softfloat-macros.h
index 57845f8af0..95d88d05b8 100644
--- a/include/fpu/softfloat-macros.h
+++ b/include/fpu/softfloat-macros.h
@@ -84,6 +84,7 @@ this code that are retained.
#include "fpu/softfloat-types.h"
#include "qemu/host-utils.h"
+#include "qemu/int128.h"
/*----------------------------------------------------------------------------
| Shifts `a' right by the number of bits given in `count'. If any nonzero
@@ -352,13 +353,11 @@ static inline void shortShift128Left(uint64_t a0, uint64_t a1, int count,
static inline void shift128Left(uint64_t a0, uint64_t a1, int count,
uint64_t *z0Ptr, uint64_t *z1Ptr)
{
- if (count < 64) {
- *z1Ptr = a1 << count;
- *z0Ptr = count == 0 ? a0 : (a0 << count) | (a1 >> (-count & 63));
- } else {
- *z1Ptr = 0;
- *z0Ptr = a1 << (count - 64);
- }
+ Int128 a = int128_make128(a1, a0);
+ Int128 z = int128_lshift(a, count);
+
+ *z0Ptr = int128_gethi(z);
+ *z1Ptr = int128_getlo(z);
}
/*----------------------------------------------------------------------------
@@ -405,15 +404,15 @@ static inline void
*----------------------------------------------------------------------------*/
static inline void
- add128(
- uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1, uint64_t *z0Ptr, uint64_t *z1Ptr )
+add128(uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1,
+ uint64_t *z0Ptr, uint64_t *z1Ptr)
{
- uint64_t z1;
-
- z1 = a1 + b1;
- *z1Ptr = z1;
- *z0Ptr = a0 + b0 + ( z1 < a1 );
+ Int128 a = int128_make128(a1, a0);
+ Int128 b = int128_make128(b1, b0);
+ Int128 z = int128_add(a, b);
+ *z0Ptr = int128_gethi(z);
+ *z1Ptr = int128_getlo(z);
}
/*----------------------------------------------------------------------------
@@ -463,13 +462,15 @@ static inline void
*----------------------------------------------------------------------------*/
static inline void
- sub128(
- uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1, uint64_t *z0Ptr, uint64_t *z1Ptr )
+sub128(uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1,
+ uint64_t *z0Ptr, uint64_t *z1Ptr)
{
+ Int128 a = int128_make128(a1, a0);
+ Int128 b = int128_make128(b1, b0);
+ Int128 z = int128_sub(a, b);
- *z1Ptr = a1 - b1;
- *z0Ptr = a0 - b0 - ( a1 < b1 );
-
+ *z0Ptr = int128_gethi(z);
+ *z1Ptr = int128_getlo(z);
}
/*----------------------------------------------------------------------------
--
2.25.1
next prev parent reply other threads:[~2020-09-25 15:25 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-25 15:20 [PATCH v2 00/10] softfloat: Implement float128_muladd Richard Henderson
2020-09-25 15:20 ` [PATCH v2 01/10] softfloat: Use mulu64 for mul64To128 Richard Henderson
2020-10-15 19:08 ` Alex Bennée
2020-09-25 15:20 ` Richard Henderson [this message]
2020-10-15 19:10 ` [PATCH v2 02/10] softfloat: Use int128.h for some operations Alex Bennée
2020-09-25 15:20 ` [PATCH v2 03/10] softfloat: Tidy a * b + inf return Richard Henderson
2020-10-16 9:40 ` Alex Bennée
2020-10-16 17:04 ` Philippe Mathieu-Daudé
2020-09-25 15:20 ` [PATCH v2 04/10] softfloat: Add float_cmask and constants Richard Henderson
2020-10-16 9:44 ` Alex Bennée
2020-09-25 15:20 ` [PATCH v2 05/10] softfloat: Inline pick_nan_muladd into its caller Richard Henderson
2020-10-16 16:20 ` Alex Bennée
2020-10-16 16:36 ` Richard Henderson
2020-10-18 21:06 ` [PATCH] softfpu: Generalize pick_nan_muladd to opaque structures Richard Henderson
2020-10-19 9:57 ` Alex Bennée
2020-09-25 15:20 ` [PATCH v2 06/10] softfloat: Implement float128_muladd Richard Henderson
2020-10-16 16:31 ` Alex Bennée
2020-10-16 16:55 ` Richard Henderson
2020-09-25 15:20 ` [PATCH v2 07/10] softfloat: Use x86_64 assembly for {add, sub}{192, 256} Richard Henderson
2020-09-25 15:20 ` [PATCH v2 08/10] softfloat: Use x86_64 assembly for sh[rl]_double Richard Henderson
2020-09-25 15:20 ` [PATCH v2 09/10] softfloat: Use aarch64 assembly for {add, sub}{192, 256} Richard Henderson
2020-09-25 15:20 ` [PATCH v2 10/10] softfloat: Use ppc64 " Richard Henderson
2020-10-15 17:23 ` [PATCH v2 00/10] softfloat: Implement float128_muladd Richard Henderson
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