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[PATCH 1/8] softfloat: Use mulu64 for mul64To128
From: |
Richard Henderson |
Subject: |
[PATCH 1/8] softfloat: Use mulu64 for mul64To128 |
Date: |
Wed, 23 Sep 2020 18:24:46 -0700 |
Via host-utils.h, we use a host widening multiply for
64-bit hosts, and a common subroutine for 32-bit hosts.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
include/fpu/softfloat-macros.h | 24 ++++--------------------
1 file changed, 4 insertions(+), 20 deletions(-)
diff --git a/include/fpu/softfloat-macros.h b/include/fpu/softfloat-macros.h
index a35ec2893a..57845f8af0 100644
--- a/include/fpu/softfloat-macros.h
+++ b/include/fpu/softfloat-macros.h
@@ -83,6 +83,7 @@ this code that are retained.
#define FPU_SOFTFLOAT_MACROS_H
#include "fpu/softfloat-types.h"
+#include "qemu/host-utils.h"
/*----------------------------------------------------------------------------
| Shifts `a' right by the number of bits given in `count'. If any nonzero
@@ -515,27 +516,10 @@ static inline void
| `z0Ptr' and `z1Ptr'.
*----------------------------------------------------------------------------*/
-static inline void mul64To128( uint64_t a, uint64_t b, uint64_t *z0Ptr,
uint64_t *z1Ptr )
+static inline void
+mul64To128(uint64_t a, uint64_t b, uint64_t *z0Ptr, uint64_t *z1Ptr)
{
- uint32_t aHigh, aLow, bHigh, bLow;
- uint64_t z0, zMiddleA, zMiddleB, z1;
-
- aLow = a;
- aHigh = a>>32;
- bLow = b;
- bHigh = b>>32;
- z1 = ( (uint64_t) aLow ) * bLow;
- zMiddleA = ( (uint64_t) aLow ) * bHigh;
- zMiddleB = ( (uint64_t) aHigh ) * bLow;
- z0 = ( (uint64_t) aHigh ) * bHigh;
- zMiddleA += zMiddleB;
- z0 += ( ( (uint64_t) ( zMiddleA < zMiddleB ) )<<32 ) + ( zMiddleA>>32 );
- zMiddleA <<= 32;
- z1 += zMiddleA;
- z0 += ( z1 < zMiddleA );
- *z1Ptr = z1;
- *z0Ptr = z0;
-
+ mulu64(z1Ptr, z0Ptr, a, b);
}
/*----------------------------------------------------------------------------
--
2.25.1
- [PATCH 0/8] softfloat: Implement float128_muladd, Richard Henderson, 2020/09/23
- [PATCH 1/8] softfloat: Use mulu64 for mul64To128,
Richard Henderson <=
- [PATCH 2/8] softfloat: Use int128.h for some operations, Richard Henderson, 2020/09/23
- [PATCH 3/8] softfloat: Tidy a * b + inf return, Richard Henderson, 2020/09/23
- [PATCH 4/8] softfloat: Add float_cmask and constants, Richard Henderson, 2020/09/23
- [PATCH 5/8] softfloat: Inline pick_nan_muladd into its caller, Richard Henderson, 2020/09/23
- [PATCH 6/8] softfloat: Implement float128_muladd, Richard Henderson, 2020/09/23