From 2b8e7757cdb8595181a01bb18756d60662c41fde Mon Sep 17 00:00:00 2001 From: Matt Oliver Date: Thu, 15 Oct 2015 19:42:31 +1100 Subject: [PATCH 1/2] lavu/intmath.h: Add msvc/icl ctzll optimisations. Signed-off-by: Matt Oliver --- libavutil/x86/intmath.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/libavutil/x86/intmath.h b/libavutil/x86/intmath.h index fefad20..613903b 100644 --- a/libavutil/x86/intmath.h +++ b/libavutil/x86/intmath.h @@ -60,6 +60,34 @@ static av_always_inline av_const unsigned av_mod_uintp2_bmi2(unsigned a, unsigne #endif /* __BMI2__ */ +#elif defined(_MSC_VER) +#define ff_ctzll ff_ctzll_c +static av_always_inline av_const int ff_ctzll_c(long long v) +{ +#if defined(__INTEL_COMPILER) +#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)[1]) + 32 : _bit_scan_forward((uint32_t)v); +#endif +#else + unsigned long c; +#if ARCH_X86_64 + _BitScanForward64(&c, v); +#else + if ((uint32_t)v == 0) { + _BitScanForward(&c, ((uint32_t *)&v)[1]); + c += 32; + } else { + _BitScanForward(&c, (uint32_t)v); + } +#endif + return c; +#endif +} + #endif /* __GNUC__ */ #endif /* AVUTIL_X86_INTMATH_H */ -- 1.9.5.github.0