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fast memcpy() using x86 asm or mmxext 

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@359 b3059339-0415-0410-9bf9-f77b7e298cf2
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arpi_esp 2001-04-11 20:14:49 +00:00
parent 105f573b67
commit feb552b3de
1 changed files with 98 additions and 0 deletions
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libvo/fastmemcpy.h Normal file
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/*
This part of code was taken by from Linux-2.4.3 and slightly modified
for MMX2 instruction set. I have done it since linux uses page aligned
blocks but mplayer uses weakly ordered data and original sources can not
speedup their. Only using prefetch and movntq together have effect!
If you have questions please contact with me: Nick Kurshev: nickols_k@mail.ru.
*/
#ifndef HAVE_MMX2
//static inline void * __memcpy(void * to, const void * from, unsigned n)
inline static void * memcpy(void * to, const void * from, unsigned n)
{
int d0, d1, d2;
__asm__ __volatile__(
"rep ; movsl\n\t"
"testb $2,%b4\n\t"
"je 1f\n\t"
"movsw\n"
"1:\ttestb $1,%b4\n\t"
"je 2f\n\t"
"movsb\n"
"2:"
: "=&c" (d0), "=&D" (d1), "=&S" (d2)
:"0" (n/4), "q" (n),"1" ((long) to),"2" ((long) from)
: "memory");
return (to);
}
#else
//inline static void *__memcpy_mmx2(void *to, const void *from, unsigned len)
inline static void * memcpy(void * to, const void * from, unsigned n)
{
void *p;
int i;
if(len >= 0x200) /* 512-byte blocks */
{
p = to;
i = len >> 6; /* len/64 */
__asm__ __volatile__ (
"1: prefetch (%0)\n" /* This set is 28 bytes */
" prefetch 64(%0)\n"
" prefetch 128(%0)\n"
" prefetch 192(%0)\n"
" prefetch 256(%0)\n"
"2: \n"
".section .fixup, \"ax\"\n"
"3: movw $0x1AEB, 1b\n" /* jmp on 26 bytes */
" jmp 2b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b, 3b\n"
".previous"
: : "r" (from) );
for(; i>0; i--)
{
__asm__ __volatile__ (
"1: prefetch 320(%0)\n"
"2: movq (%0), %%mm0\n"
" movq 8(%0), %%mm1\n"
" movq 16(%0), %%mm2\n"
" movq 24(%0), %%mm3\n"
" movntq %%mm0, (%1)\n"
" movntq %%mm1, 8(%1)\n"
" movntq %%mm2, 16(%1)\n"
" movntq %%mm3, 24(%1)\n"
" movq 32(%0), %%mm0\n"
" movq 40(%0), %%mm1\n"
" movq 48(%0), %%mm2\n"
" movq 56(%0), %%mm3\n"
" movntq %%mm0, 32(%1)\n"
" movntq %%mm1, 40(%1)\n"
" movntq %%mm2, 48(%1)\n"
" movntq %%mm3, 56(%1)\n"
".section .fixup, \"ax\"\n"
"3: movw $0x05EB, 1b\n" /* jmp on 5 bytes */
" jmp 2b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b, 3b\n"
".previous"
: : "r" (from), "r" (to) : "memory");
from+=64;
to+=64;
}
__asm__ __volatile__ ("emms":::"memory");
}
/*
* Now do the tail of the block
*/
__memcpy(to, from, len&63);
return p;
}
#endif