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[RFC PATCH 06/15] softfloat: Use mulu64 for mul64To128
From: |
Richard Henderson |
Subject: |
[RFC PATCH 06/15] softfloat: Use mulu64 for mul64To128 |
Date: |
Tue, 20 Oct 2020 21:51:40 -0700 |
Via host-utils.h, we use a host widening multiply for
64-bit hosts, and a common subroutine for 32-bit hosts.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
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
- [RFC PATCH 00/15] softfloat: alternate conversion of float128_addsub, Richard Henderson, 2020/10/21
- [RFC PATCH 01/15] qemu/int128: Add int128_or, Richard Henderson, 2020/10/21
- [RFC PATCH 02/15] qemu/int128: Add int128_clz, int128_ctz, Richard Henderson, 2020/10/21
- [RFC PATCH 03/15] qemu/int128: Rename int128_rshift, int128_lshift, Richard Henderson, 2020/10/21
- [RFC PATCH 05/15] qemu/int128: Add int128_geu, Richard Henderson, 2020/10/21
- [RFC PATCH 04/15] qemu/int128: Add int128_shr, Richard Henderson, 2020/10/21
- [RFC PATCH 06/15] softfloat: Use mulu64 for mul64To128,
Richard Henderson <=
- [RFC PATCH 07/15] softfloat: Use int128.h for some operations, Richard Henderson, 2020/10/21
- [RFC PATCH 08/15] softfloat: Tidy a * b + inf return, Richard Henderson, 2020/10/21
- [RFC PATCH 10/15] softfloat: Inline float_raise, Richard Henderson, 2020/10/21
- [RFC PATCH 09/15] softfloat: Add float_cmask and constants, Richard Henderson, 2020/10/21
- [RFC PATCH 12/15] softfloat: Streamline FloatFmt, Richard Henderson, 2020/10/21
- [RFC PATCH 11/15] Test split to softfloat-parts.c.inc, Richard Henderson, 2020/10/21
- [RFC PATCH 13/15] Test float128_addsub, Richard Henderson, 2020/10/21
- [RFC PATCH 15/15] softfloat: Improve subtraction of equal exponent, Richard Henderson, 2020/10/21
- [RFC PATCH 14/15] softfloat: Use float_cmask for addsub_floats, Richard Henderson, 2020/10/21