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FFmpeg/libavutil/x86/intmath.h
Dale Curtis 50e30d9bb7 Don't use _tzcnt instrinics with clang for windows w/o BMI.
Technically _tzcnt* intrinsics are only available when the BMI
instruction set is present. However the instruction encoding
degrades to "rep bsf" on older processors.

Clang for Windows debatably restricts the _tzcnt* instrinics behind
the __BMI__ architecture define, so check for its presence or
exclude the usage of these intrinics when clang is present.

See also:
https://ffmpeg.org/pipermail/ffmpeg-devel/2015-November/183404.html
https://bugs.llvm.org/show_bug.cgi?id=30506
http://lists.llvm.org/pipermail/cfe-dev/2016-October/051034.html

Signed-off-by: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Matt Oliver <protogonoi@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2017-10-25 21:50:37 +02:00

140 lines
3.7 KiB
C

/*
* Copyright (c) 2015 James Almer
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVUTIL_X86_INTMATH_H
#define AVUTIL_X86_INTMATH_H
#include <stdint.h>
#include <stdlib.h>
#if HAVE_FAST_CLZ
#if defined(_MSC_VER)
#include <intrin.h>
#elif defined(__INTEL_COMPILER)
#include <immintrin.h>
#endif
#endif
#include "config.h"
#if HAVE_FAST_CLZ
#if (defined(__INTEL_COMPILER) && (__INTEL_COMPILER>=1216)) || defined(_MSC_VER)
# if defined(__INTEL_COMPILER)
# define ff_log2(x) (_bit_scan_reverse((x)|1))
# else
# define ff_log2 ff_log2_x86
static av_always_inline av_const int ff_log2_x86(unsigned int v)
{
unsigned long n;
_BitScanReverse(&n, v|1);
return n;
}
# endif
# define ff_log2_16bit av_log2
#if defined(__INTEL_COMPILER) || (defined(_MSC_VER) && (_MSC_VER >= 1700) && \
(defined(__BMI__) || !defined(__clang__)))
# define ff_ctz(v) _tzcnt_u32(v)
# if ARCH_X86_64
# define ff_ctzll(v) _tzcnt_u64(v)
# else
# define ff_ctzll ff_ctzll_x86
static av_always_inline av_const int ff_ctzll_x86(long long v)
{
return ((uint32_t)v == 0) ? _tzcnt_u32((uint32_t)(v >> 32)) + 32 : _tzcnt_u32((uint32_t)v);
}
# endif
#endif /* _MSC_VER */
#endif /* __INTEL_COMPILER */
#endif /* HAVE_FAST_CLZ */
#if defined(__GNUC__)
/* Our generic version of av_popcount is faster than GCC's built-in on
* CPUs that don't support the popcnt instruction.
*/
#if defined(__POPCNT__)
#define av_popcount __builtin_popcount
#if ARCH_X86_64
#define av_popcount64 __builtin_popcountll
#endif
#endif /* __POPCNT__ */
#if defined(__BMI2__)
#if AV_GCC_VERSION_AT_LEAST(5,1)
#define av_mod_uintp2 __builtin_ia32_bzhi_si
#elif HAVE_INLINE_ASM
/* GCC releases before 5.1.0 have a broken bzhi builtin, so for those we
* implement it using inline assembly
*/
#define av_mod_uintp2 av_mod_uintp2_bmi2
static av_always_inline av_const unsigned av_mod_uintp2_bmi2(unsigned a, unsigned p)
{
if (av_builtin_constant_p(p))
return a & ((1 << p) - 1);
else {
unsigned x;
__asm__ ("bzhi %2, %1, %0 \n\t" : "=r"(x) : "rm"(a), "r"(p));
return x;
}
}
#endif /* AV_GCC_VERSION_AT_LEAST */
#endif /* __BMI2__ */
#if defined(__SSE2__) && !defined(__INTEL_COMPILER)
#define av_clipd av_clipd_sse2
static av_always_inline av_const double av_clipd_sse2(double a, double amin, double amax)
{
#if defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
if (amin > amax) abort();
#endif
__asm__ ("minsd %2, %0 \n\t"
"maxsd %1, %0 \n\t"
: "+&x"(a) : "xm"(amin), "xm"(amax));
return a;
}
#endif /* __SSE2__ */
#if defined(__SSE__) && !defined(__INTEL_COMPILER)
#define av_clipf av_clipf_sse
static av_always_inline av_const float av_clipf_sse(float a, float amin, float amax)
{
#if defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
if (amin > amax) abort();
#endif
__asm__ ("minss %2, %0 \n\t"
"maxss %1, %0 \n\t"
: "+&x"(a) : "xm"(amin), "xm"(amax));
return a;
}
#endif /* __SSE__ */
#endif /* __GNUC__ */
#endif /* AVUTIL_X86_INTMATH_H */