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lavu/intmath.h: Add msvc/icl ctzll optimisations. 

Signed-off-by: Matt Oliver <protogonoi@gmail.com>
This commit is contained in:
Matt Oliver 2015-10-16 16:58:43 +11:00
parent ce0a117ed4
commit 216cc1f6fe
1 changed files with 35 additions and 0 deletions
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35
libavutil/x86/intmath.h
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@ -24,6 +24,41 @@
#include <stdint.h>
#include "config.h"
#if HAVE_FAST_CLZ
#if defined(__INTEL_COMPILER)
# define ff_ctzll ff_ctzll_x86
static av_always_inline av_const int ff_ctzll_x86(long long v)
{
# if ARCH_X86_64
uint64_t c;
__asm__("bsfq %1,%0" : "=r" (c) : "r" (v));
return c;
# else
return ((uint32_t)v == 0) ? _bit_scan_forward((uint32_t)(v >> 32)) + 32 : _bit_scan_forward((uint32_t)v);
# endif
}
#elif defined(_MSC_VER)
# define ff_ctzll ff_ctzll_x86
static av_always_inline av_const int ff_ctzll_x86(long long v)
{
unsigned long c;
# if ARCH_X86_64
_BitScanForward64(&c, v);
# else
if ((uint32_t)v == 0) {
_BitScanForward(&c, (uint32_t)(v >> 32));
c += 32;
} else {
_BitScanForward(&c, (uint32_t)v);
}
# endif
return c;
}
#endif /* __INTEL_COMPILER */
#endif /* HAVE_FAST_CLZ */
#if defined(__GNUC__)
/* Our generic version of av_popcount is faster than GCC's built-in on