[FFmpeg-devel] [PATCH]Remove test for cpuid instruction from cpuid.c

[Carl Eugen Hoyos]

Hi!

cpuid is an ia32 instruction that was added for later 80486 processors. 
I propose to remove the check for its existence from i386/cpuid.c.
ffmpeg can still be compiled for 80386 with --disable-mmx.

(Fixes compilation with icc 11.0)

Please comment, Carl Eugen
-------------- next part --------------
Index: libavcodec/i386/cpuid.c
===================================================================
--- libavcodec/i386/cpuid.c	(Revision 15910)
+++ libavcodec/i386/cpuid.c	(Arbeitskopie)
@@ -42,32 +42,7 @@
     int rval = 0;
     int eax, ebx, ecx, edx;
     int max_std_level, max_ext_level, std_caps=0, ext_caps=0;
-    x86_reg a, c;
 
-    __asm__ volatile (
-        /* See if CPUID instruction is supported ... */
-        /* ... Get copies of EFLAGS into eax and ecx */
-        "pushf\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"
-        "popf\n\t"
-
-        /* ... Get the (hopefully modified) EFLAGS */
-        "pushf\n\t"
-        "pop %0\n\t"
-        : "=a" (a), "=c" (c)
-        :
-        : "cc"
-        );
-
-    if (a == c)
-        return 0; /* CPUID not supported */
-
     cpuid(0, max_std_level, ebx, ecx, edx);
 
     if(max_std_level >= 1){