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softfloat: Use mulu64 for mul64To128

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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>
This commit is contained in:
Richard Henderson 2020-09-23 08:57:01 -07:00
parent dedd123c56
commit b4d09b1794
1 changed files with 3 additions and 20 deletions
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23
include/fpu/softfloat-macros.h
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@ -470,27 +470,10 @@ static inline void sub192(uint64_t a0, uint64_t a1, uint64_t a2,
| `z0Ptr' and `z1Ptr'. | `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; mulu64(z1Ptr, z0Ptr, a, b);
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;
} }
/*---------------------------------------------------------------------------- /*----------------------------------------------------------------------------