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avcodec/x86/mathops: clip constants used with shift instructions with…
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…in inline assembly

Fixes assembling with binutil as >= 2.41

Signed-off-by: James Almer <jamrial@gmail.com>
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Rémi Denis-Courmont authored and jamrial committed Jul 20, 2023
1 parent ccc6849 commit effadce
Showing 1 changed file with 23 additions and 3 deletions.
26 changes: 23 additions & 3 deletions libavcodec/x86/mathops.h
Expand Up @@ -35,12 +35,20 @@
static av_always_inline av_const int MULL(int a, int b, unsigned shift)
{
int rt, dummy;
if (__builtin_constant_p(shift))
__asm__ (
"imull %3 \n\t"
"shrdl %4, %%edx, %%eax \n\t"
:"=a"(rt), "=d"(dummy)
:"a"(a), "rm"(b), "ci"((uint8_t)shift)
:"a"(a), "rm"(b), "i"(shift & 0x1F)
);
else
__asm__ (
"imull %3 \n\t"
"shrdl %4, %%edx, %%eax \n\t"
:"=a"(rt), "=d"(dummy)
:"a"(a), "rm"(b), "c"((uint8_t)shift)
);
return rt;
}

Expand Down Expand Up @@ -113,19 +121,31 @@ __asm__ volatile(\
// avoid +32 for shift optimization (gcc should do that ...)
#define NEG_SSR32 NEG_SSR32
static inline int32_t NEG_SSR32( int32_t a, int8_t s){
if (__builtin_constant_p(s))
__asm__ ("sarl %1, %0\n\t"
: "+r" (a)
: "ic" ((uint8_t)(-s))
: "i" (-s & 0x1F)
);
else
__asm__ ("sarl %1, %0\n\t"
: "+r" (a)
: "c" ((uint8_t)(-s))
);
return a;
}

#define NEG_USR32 NEG_USR32
static inline uint32_t NEG_USR32(uint32_t a, int8_t s){
if (__builtin_constant_p(s))
__asm__ ("shrl %1, %0\n\t"
: "+r" (a)
: "ic" ((uint8_t)(-s))
: "i" (-s & 0x1F)
);
else
__asm__ ("shrl %1, %0\n\t"
: "+r" (a)
: "c" ((uint8_t)(-s))
);
return a;
}

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