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softfloat: Use uadd64_carry, usub64_borrow in softfloat-macros.h

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Use compiler support for carry arithmetic.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2020-11-13 04:19:08 +00:00
parent ee6959f277
commit cb3ad0365f
1 changed files with 25 additions and 70 deletions
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95
include/fpu/softfloat-macros.h
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@ -83,6 +83,7 @@ this code that are retained.
#define FPU_SOFTFLOAT_MACROS_H #define FPU_SOFTFLOAT_MACROS_H
#include "fpu/softfloat-types.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 | Shifts `a' right by the number of bits given in `count'. If any nonzero
@ -403,16 +404,12 @@ static inline void
| are stored at the locations pointed to by `z0Ptr' and `z1Ptr'. | are stored at the locations pointed to by `z0Ptr' and `z1Ptr'.
*----------------------------------------------------------------------------*/ *----------------------------------------------------------------------------*/
static inline void static inline void add128(uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1,
add128( uint64_t *z0Ptr, uint64_t *z1Ptr)
uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1, uint64_t *z0Ptr, uint64_t *z1Ptr )
{ {
uint64_t z1; bool c = 0;
*z1Ptr = uadd64_carry(a1, b1, &c);
z1 = a1 + b1; *z0Ptr = uadd64_carry(a0, b0, &c);
*z1Ptr = z1;
*z0Ptr = a0 + b0 + ( z1 < a1 );
} }
/*---------------------------------------------------------------------------- /*----------------------------------------------------------------------------
@ -423,34 +420,14 @@ static inline void
| `z1Ptr', and `z2Ptr'. | `z1Ptr', and `z2Ptr'.
*----------------------------------------------------------------------------*/ *----------------------------------------------------------------------------*/
static inline void static inline void add192(uint64_t a0, uint64_t a1, uint64_t a2,
add192( uint64_t b0, uint64_t b1, uint64_t b2,
uint64_t a0, uint64_t *z0Ptr, uint64_t *z1Ptr, uint64_t *z2Ptr)
uint64_t a1,
uint64_t a2,
uint64_t b0,
uint64_t b1,
uint64_t b2,
uint64_t *z0Ptr,
uint64_t *z1Ptr,
uint64_t *z2Ptr
)
{ {
uint64_t z0, z1, z2; bool c = 0;
int8_t carry0, carry1; *z2Ptr = uadd64_carry(a2, b2, &c);
*z1Ptr = uadd64_carry(a1, b1, &c);
z2 = a2 + b2; *z0Ptr = uadd64_carry(a0, b0, &c);
carry1 = ( z2 < a2 );
z1 = a1 + b1;
carry0 = ( z1 < a1 );
z0 = a0 + b0;
z1 += carry1;
z0 += ( z1 < carry1 );
z0 += carry0;
*z2Ptr = z2;
*z1Ptr = z1;
*z0Ptr = z0;
} }
/*---------------------------------------------------------------------------- /*----------------------------------------------------------------------------
@ -461,14 +438,12 @@ static inline void
| `z1Ptr'. | `z1Ptr'.
*----------------------------------------------------------------------------*/ *----------------------------------------------------------------------------*/
static inline void static inline void sub128(uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1,
sub128( uint64_t *z0Ptr, uint64_t *z1Ptr)
uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1, uint64_t *z0Ptr, uint64_t *z1Ptr )
{ {
bool c = 0;
*z1Ptr = a1 - b1; *z1Ptr = usub64_borrow(a1, b1, &c);
*z0Ptr = a0 - b0 - ( a1 < b1 ); *z0Ptr = usub64_borrow(a0, b0, &c);
} }
/*---------------------------------------------------------------------------- /*----------------------------------------------------------------------------
@ -479,34 +454,14 @@ static inline void
| pointed to by `z0Ptr', `z1Ptr', and `z2Ptr'. | pointed to by `z0Ptr', `z1Ptr', and `z2Ptr'.
*----------------------------------------------------------------------------*/ *----------------------------------------------------------------------------*/
static inline void static inline void sub192(uint64_t a0, uint64_t a1, uint64_t a2,
sub192( uint64_t b0, uint64_t b1, uint64_t b2,
uint64_t a0, uint64_t *z0Ptr, uint64_t *z1Ptr, uint64_t *z2Ptr)
uint64_t a1,
uint64_t a2,
uint64_t b0,
uint64_t b1,
uint64_t b2,
uint64_t *z0Ptr,
uint64_t *z1Ptr,
uint64_t *z2Ptr
)
{ {
uint64_t z0, z1, z2; bool c = 0;
int8_t borrow0, borrow1; *z2Ptr = usub64_borrow(a2, b2, &c);
*z1Ptr = usub64_borrow(a1, b1, &c);
z2 = a2 - b2; *z0Ptr = usub64_borrow(a0, b0, &c);
borrow1 = ( a2 < b2 );
z1 = a1 - b1;
borrow0 = ( a1 < b1 );
z0 = a0 - b0;
z0 -= ( z1 < borrow1 );
z1 -= borrow1;
z0 -= borrow0;
*z2Ptr = z2;
*z1Ptr = z1;
*z0Ptr = z0;
} }
/*---------------------------------------------------------------------------- /*----------------------------------------------------------------------------