Mercurial > sdl-ios-xcode
view src/audio/SDL_mixer_MMX.c @ 1224:f033d9589ca1
Debug code should check right function names.
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Wed, 04 Jan 2006 20:53:55 +0000 |
parents | b580f7201543 |
children | d910939febfa |
line wrap: on
line source
/* MMX assembler version of SDL_MixAudio for signed little endian 16 bit samples and signed 8 bit samples Copyright 2002 Stephane Marchesin (stephane.marchesin@wanadoo.fr) This code is licensed under the LGPL (see COPYING for details) Assumes buffer size in bytes is a multiple of 16 Assumes SDL_MIX_MAXVOLUME = 128 */ /*********************************************** * Mixing for 16 bit signed buffers ***********************************************/ #if defined(i386) && defined(__GNUC__) && defined(USE_ASMBLIT) void SDL_MixAudio_MMX_S16(char* dst,char* src,unsigned int size,int volume) { __asm__ __volatile__ ( " movl %3,%%eax\n" // eax = volume " movl %2,%%edx\n" // edx = size " shrl $4,%%edx\n" // process 16 bytes per iteration = 8 samples " jz .endS16\n" " pxor %%mm0,%%mm0\n" " movd %%eax,%%mm0\n" " movq %%mm0,%%mm1\n" " psllq $16,%%mm0\n" " por %%mm1,%%mm0\n" " psllq $16,%%mm0\n" " por %%mm1,%%mm0\n" " psllq $16,%%mm0\n" " por %%mm1,%%mm0\n" // mm0 = vol|vol|vol|vol ".align 16\n" " .mixloopS16:\n" " movq (%1),%%mm1\n" // mm1 = a|b|c|d " movq %%mm1,%%mm2\n" // mm2 = a|b|c|d " movq 8(%1),%%mm4\n" // mm4 = e|f|g|h // pré charger le buffer dst dans mm7 " movq (%0),%%mm7\n" // mm7 = dst[0]" // multiplier par le volume " pmullw %%mm0,%%mm1\n" // mm1 = l(a*v)|l(b*v)|l(c*v)|l(d*v) " pmulhw %%mm0,%%mm2\n" // mm2 = h(a*v)|h(b*v)|h(c*v)|h(d*v) " movq %%mm4,%%mm5\n" // mm5 = e|f|g|h " pmullw %%mm0,%%mm4\n" // mm4 = l(e*v)|l(f*v)|l(g*v)|l(h*v) " pmulhw %%mm0,%%mm5\n" // mm5 = h(e*v)|h(f*v)|h(g*v)|h(h*v) " movq %%mm1,%%mm3\n" // mm3 = l(a*v)|l(b*v)|l(c*v)|l(d*v) " punpckhwd %%mm2,%%mm1\n" // mm1 = a*v|b*v " movq %%mm4,%%mm6\n" // mm6 = l(e*v)|l(f*v)|l(g*v)|l(h*v) " punpcklwd %%mm2,%%mm3\n" // mm3 = c*v|d*v " punpckhwd %%mm5,%%mm4\n" // mm4 = e*f|f*v " punpcklwd %%mm5,%%mm6\n" // mm6 = g*v|h*v // pré charger le buffer dst dans mm5 " movq 8(%0),%%mm5\n" // mm5 = dst[1] // diviser par 128 " psrad $7,%%mm1\n" // mm1 = a*v/128|b*v/128 , 128 = SDL_MIX_MAXVOLUME " add $16,%1\n" " psrad $7,%%mm3\n" // mm3 = c*v/128|d*v/128 " psrad $7,%%mm4\n" // mm4 = e*v/128|f*v/128 // mm1 = le sample avec le volume modifié " packssdw %%mm1,%%mm3\n" // mm3 = s(a*v|b*v|c*v|d*v) " psrad $7,%%mm6\n" // mm6= g*v/128|h*v/128 " paddsw %%mm7,%%mm3\n" // mm3 = adjust_volume(src)+dst // mm4 = le sample avec le volume modifié " packssdw %%mm4,%%mm6\n" // mm6 = s(e*v|f*v|g*v|h*v) " movq %%mm3,(%0)\n" " paddsw %%mm5,%%mm6\n" // mm6 = adjust_volume(src)+dst " movq %%mm6,8(%0)\n" " add $16,%0\n" " dec %%edx\n" " jnz .mixloopS16\n" " emms\n" ".endS16:\n" : : "r" (dst), "r"(src),"m"(size), "m"(volume) : "eax","edx","memory" ); } //////////////////////////////////////////////// // Mixing for 8 bit signed buffers //////////////////////////////////////////////// void SDL_MixAudio_MMX_S8(char* dst,char* src,unsigned int size,int volume) { __asm__ __volatile__ ( " movl %3,%%eax\n" // eax = volume " movd %%eax,%%mm0\n" " movq %%mm0,%%mm1\n" " psllq $16,%%mm0\n" " por %%mm1,%%mm0\n" " psllq $16,%%mm0\n" " por %%mm1,%%mm0\n" " psllq $16,%%mm0\n" " por %%mm1,%%mm0\n" " movl %2,%%edx\n" // edx = size " shr $3,%%edx\n" // process 8 bytes per iteration = 8 samples " cmp $0,%%edx\n" " je .endS8\n" ".align 16\n" " .mixloopS8:\n" " pxor %%mm2,%%mm2\n" // mm2 = 0 " movq (%1),%%mm1\n" // mm1 = a|b|c|d|e|f|g|h " movq %%mm1,%%mm3\n" // mm3 = a|b|c|d|e|f|g|h // on va faire le "sign extension" en faisant un cmp avec 0 qui retourne 1 si <0, 0 si >0 " pcmpgtb %%mm1,%%mm2\n" // mm2 = 11111111|00000000|00000000.... " punpckhbw %%mm2,%%mm1\n" // mm1 = 0|a|0|b|0|c|0|d " punpcklbw %%mm2,%%mm3\n" // mm3 = 0|e|0|f|0|g|0|h " movq (%0),%%mm2\n" // mm2 = destination " pmullw %%mm0,%%mm1\n" // mm1 = v*a|v*b|v*c|v*d " add $8,%1\n" " pmullw %%mm0,%%mm3\n" // mm3 = v*e|v*f|v*g|v*h " psraw $7,%%mm1\n" // mm1 = v*a/128|v*b/128|v*c/128|v*d/128 " psraw $7,%%mm3\n" // mm3 = v*e/128|v*f/128|v*g/128|v*h/128 " packsswb %%mm1,%%mm3\n" // mm1 = v*a/128|v*b/128|v*c/128|v*d/128|v*e/128|v*f/128|v*g/128|v*h/128 " paddsb %%mm2,%%mm3\n" // add to destination buffer " movq %%mm3,(%0)\n" // store back to ram " add $8,%0\n" " dec %%edx\n" " jnz .mixloopS8\n" ".endS8:\n" " emms\n" : : "r" (dst), "r"(src),"m"(size), "m"(volume) : "eax","edx","memory" ); } #endif