Mercurial > sdl-ios-xcode
view src/audio/SDL_mixer_MMX.c @ 809:dba98fb391e7
Date: Tue, 13 Jan 2004 19:25:37 +0300
From: Dmitry Yakimov
Subject: [SDL] [PATCH] SDL bug patch
Let me introduce 2 fixes to SDL.
1. Preventing great slowdown on fast machines while hardware
flipping (it's obviously bug).
2. Setting up 85 Hz of monitor if supported. The reason is that
Win98 by default sets lowest frequency 60 Hz.
And we can't set up maximum frequency because some users can have
wrong monitor drivers.
This is important for shareware and commercial programs.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Wed, 11 Feb 2004 16:10:16 +0000 |
parents | a9e38f3b8e4d |
children | b4b64bb88f2f |
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// 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 %0,%%edi\n" // edi = dst " movl %1,%%esi\n" // esi = src " movl %3,%%eax\n" // eax = volume " movl %2,%%ebx\n" // ebx = size " shrl $4,%%ebx\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 (%%esi),%%mm1\n" // mm1 = a|b|c|d " movq %%mm1,%%mm2\n" // mm2 = a|b|c|d " movq 8(%%esi),%%mm4\n" // mm4 = e|f|g|h // pré charger le buffer dst dans mm7 " movq (%%edi),%%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(%%edi),%%mm5\n" // mm5 = dst[1] // diviser par 128 " psrad $7,%%mm1\n" // mm1 = a*v/128|b*v/128 , 128 = SDL_MIX_MAXVOLUME " addl $16,%%esi\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,(%%edi)\n" " paddsw %%mm5,%%mm6\n" // mm6 = adjust_volume(src)+dst " movq %%mm6,8(%%edi)\n" " addl $16,%%edi\n" " dec %%ebx\n" " jnz .mixloopS16\n" " emms\n" ".endS16:\n" : : "m" (dst), "m"(src),"m"(size), "m"(volume) : "eax","ebx", "esi", "edi","memory" ); } //////////////////////////////////////////////// // Mixing for 8 bit signed buffers //////////////////////////////////////////////// void SDL_MixAudio_MMX_S8(char* dst,char* src,unsigned int size,int volume) { __asm__ __volatile__ ( " movl %0,%%edi\n" // edi = dst " movl %1,%%esi\n" // esi = src " movl %3,%%eax\n" // eax = volume " movd %%ebx,%%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,%%ebx\n" // ebx = size " shr $3,%%ebx\n" // process 8 bytes per iteration = 8 samples " cmp $0,%%ebx\n" " je .endS8\n" ".align 16\n" " .mixloopS8:\n" " pxor %%mm2,%%mm2\n" // mm2 = 0 " movq (%%esi),%%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 (%%edi),%%mm2\n" // mm2 = destination " pmullw %%mm0,%%mm1\n" // mm1 = v*a|v*b|v*c|v*d " addl $8,%%esi\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,(%%edi)\n" // store back to ram " addl $8,%%edi\n" " dec %%ebx\n" " jnz .mixloopS8\n" ".endS8:\n" " emms\n" : : "m" (dst), "m"(src),"m"(size), "m"(volume) : "eax","ebx", "esi", "edi","memory" ); } #endif