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FFmpeg/libavcodec/x86/cpuid.c
Ronald S. Bultje 6526976f0c Remove FF_MM_SSE2/3 flags for CPUs where this is generally not faster than
regular MMX code. Examples of this are the Core1 CPU. Instead, set a new flag,
FF_MM_SSE2/3SLOW, which can be checked for particular SSE2/3 functions that
have been checked specifically on such CPUs and are actually faster than
their MMX counterparts.

In addition, use this flag to enable particular VP8 and LPC SSE2 functions
that are faster than their MMX counterparts.

Based on a patch by Loren Merritt <lorenm AT u washington edu>.

Originally committed as revision 24340 to svn://svn.ffmpeg.org/ffmpeg/trunk
2010-07-19 22:38:23 +00:00

151 lines
4.5 KiB
C

/*
* CPU detection code, extracted from mmx.h
* (c)1997-99 by H. Dietz and R. Fisher
* Converted to C and improved by Fabrice Bellard.
*
* 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
*/
#include <stdlib.h>
#include "libavutil/x86_cpu.h"
#include "libavcodec/dsputil.h"
#undef printf
/* ebx saving is necessary for PIC. gcc seems unable to see it alone */
#define cpuid(index,eax,ebx,ecx,edx)\
__asm__ volatile\
("mov %%"REG_b", %%"REG_S"\n\t"\
"cpuid\n\t"\
"xchg %%"REG_b", %%"REG_S\
: "=a" (eax), "=S" (ebx),\
"=c" (ecx), "=d" (edx)\
: "0" (index));
/* Function to test if multimedia instructions are supported... */
int mm_support(void)
{
int rval = 0;
int eax, ebx, ecx, edx;
int max_std_level, max_ext_level, std_caps=0, ext_caps=0;
int family=0, model=0;
union { int i[3]; char c[12]; } vendor;
#if ARCH_X86_32
x86_reg a, c;
__asm__ volatile (
/* See if CPUID instruction is supported ... */
/* ... Get copies of EFLAGS into eax and ecx */
"pushfl\n\t"
"pop %0\n\t"
"mov %0, %1\n\t"
/* ... Toggle the ID bit in one copy and store */
/* to the EFLAGS reg */
"xor $0x200000, %0\n\t"
"push %0\n\t"
"popfl\n\t"
/* ... Get the (hopefully modified) EFLAGS */
"pushfl\n\t"
"pop %0\n\t"
: "=a" (a), "=c" (c)
:
: "cc"
);
if (a == c)
return 0; /* CPUID not supported */
#endif
cpuid(0, max_std_level, vendor.i[0], vendor.i[2], vendor.i[1]);
if(max_std_level >= 1){
cpuid(1, eax, ebx, ecx, std_caps);
family = ((eax>>8)&0xf) + ((eax>>20)&0xff);
model = ((eax>>4)&0xf) + ((eax>>12)&0xf0);
if (std_caps & (1<<23))
rval |= FF_MM_MMX;
if (std_caps & (1<<25))
rval |= FF_MM_MMX2
#if HAVE_SSE
| FF_MM_SSE;
if (std_caps & (1<<26))
rval |= FF_MM_SSE2;
if (ecx & 1)
rval |= FF_MM_SSE3;
if (ecx & 0x00000200 )
rval |= FF_MM_SSSE3;
if (ecx & 0x00080000 )
rval |= FF_MM_SSE4;
if (ecx & 0x00100000 )
rval |= FF_MM_SSE42;
#endif
;
}
cpuid(0x80000000, max_ext_level, ebx, ecx, edx);
if(max_ext_level >= 0x80000001){
cpuid(0x80000001, eax, ebx, ecx, ext_caps);
if (ext_caps & (1<<31))
rval |= FF_MM_3DNOW;
if (ext_caps & (1<<30))
rval |= FF_MM_3DNOWEXT;
if (ext_caps & (1<<23))
rval |= FF_MM_MMX;
if (ext_caps & (1<<22))
rval |= FF_MM_MMX2;
}
if (!strncmp(vendor.c, "GenuineIntel", 12) &&
family == 6 && (model == 9 || model == 13 || model == 14)) {
/* 6/9 (pentium-m "banias"), 6/13 (pentium-m "dothan"), and 6/14 (core1 "yonah")
* theoretically support sse2, but it's usually slower than mmx,
* so let's just pretend they don't. */
if (rval & FF_MM_SSE2) rval ^= FF_MM_SSE2SLOW|FF_MM_SSE2;
if (rval & FF_MM_SSE3) rval ^= FF_MM_SSE3SLOW|FF_MM_SSE3;
}
#if 0
av_log(NULL, AV_LOG_DEBUG, "%s%s%s%s%s%s%s%s%s%s%s%s\n",
(rval&FF_MM_MMX) ? "MMX ":"",
(rval&FF_MM_MMX2) ? "MMX2 ":"",
(rval&FF_MM_SSE) ? "SSE ":"",
(rval&FF_MM_SSE2) ? "SSE2 ":"",
(rval&FF_MM_SSE2SLOW) ? "SSE2(slow) ":"",
(rval&FF_MM_SSE3) ? "SSE3 ":"",
(rval&FF_MM_SSE3SLOW) ? "SSE3(slow) ":"",
(rval&FF_MM_SSSE3) ? "SSSE3 ":"",
(rval&FF_MM_SSE4) ? "SSE4.1 ":"",
(rval&FF_MM_SSE42) ? "SSE4.2 ":"",
(rval&FF_MM_3DNOW) ? "3DNow ":"",
(rval&FF_MM_3DNOWEXT) ? "3DNowExt ":"");
#endif
return rval;
}
#ifdef TEST
int main ( void )
{
int mm_flags;
mm_flags = mm_support();
printf("mm_support = 0x%08X\n",mm_flags);
return 0;
}
#endif