SDL/SDL_main/src/audio/SDL_mixer_MMX.c

   1 /*
   2     SDL - Simple DirectMedia Layer
   3     Copyright (C) 1997-2009 Sam Lantinga
   4
   5     This library is free software; you can redistribute it and/or
   6     modify it under the terms of the GNU Lesser General Public
   7     License as published by the Free Software Foundation; either
   8     version 2.1 of the License, or (at your option) any later version.
   9
  10     This library is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13     Lesser General Public License for more details.
  14
  15     You should have received a copy of the GNU Lesser General Public
  16     License along with this library; if not, write to the Free Software
  17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18
  19     Sam Lantinga
  20     slouken@libsdl.org
  21 */
  22 #include "SDL_config.h"
  23
  24 /*
  25     MMX assembler version of SDL_MixAudio for signed little endian 16 bit samples and signed 8 bit samples
  26     Copyright 2002 Stephane Marchesin (stephane.marchesin@wanadoo.fr)
  27     This code is licensed under the LGPL (see COPYING for details)
  28
  29     Assumes buffer size in bytes is a multiple of 16
  30     Assumes SDL_MIX_MAXVOLUME = 128
  31 */
  32
  33
  34 /***********************************************
  35 *   Mixing for 16 bit signed buffers
  36 ***********************************************/
  37
  38 #if defined(SDL_BUGGY_MMX_MIXERS) /* buggy, so we're disabling them. --ryan. */
  39 #if defined(__GNUC__) && defined(__i386__) && defined(SDL_ASSEMBLY_ROUTINES)
  40 void SDL_MixAudio_MMX_S16(char* dst,char* src,unsigned int size,int volume)
  41 {
  42     __asm__ __volatile__ (
  43
  44 "       movl %3,%%eax\n"        /* eax = volume */
  45
  46 "       movl %2,%%edx\n"        /* edx = size */
  47
  48 "       shrl $4,%%edx\n"        /* process 16 bytes per iteration = 8 samples */
  49
  50 "       jz .endS16\n"
  51
  52 "       pxor %%mm0,%%mm0\n"
  53
  54 "       movd %%eax,%%mm0\n"
  55 "       movq %%mm0,%%mm1\n"
  56 "       psllq $16,%%mm0\n"
  57 "       por %%mm1,%%mm0\n"
  58 "       psllq $16,%%mm0\n"
  59 "       por %%mm1,%%mm0\n"
  60 "       psllq $16,%%mm0\n"
  61 "       por %%mm1,%%mm0\n"              /* mm0 = vol|vol|vol|vol */
  62
  63 ".align 8\n"
  64 "       .mixloopS16:\n"
  65
  66 "       movq (%1),%%mm1\n" /* mm1 = a|b|c|d */
  67
  68 "       movq %%mm1,%%mm2\n" /* mm2 = a|b|c|d */
  69
  70 "       movq 8(%1),%%mm4\n" /* mm4 = e|f|g|h */
  71
  72         /* pré charger le buffer dst dans mm7 */
  73 "       movq (%0),%%mm7\n" /* mm7 = dst[0] */
  74
  75         /* multiplier par le volume */
  76 "       pmullw %%mm0,%%mm1\n" /* mm1 = l(a*v)|l(b*v)|l(c*v)|l(d*v) */
  77
  78 "       pmulhw %%mm0,%%mm2\n" /* mm2 = h(a*v)|h(b*v)|h(c*v)|h(d*v) */
  79 "       movq %%mm4,%%mm5\n" /* mm5 = e|f|g|h */
  80
  81 "       pmullw %%mm0,%%mm4\n" /* mm4 = l(e*v)|l(f*v)|l(g*v)|l(h*v) */
  82
  83 "       pmulhw %%mm0,%%mm5\n" /* mm5 = h(e*v)|h(f*v)|h(g*v)|h(h*v) */
  84 "       movq %%mm1,%%mm3\n" /* mm3 = l(a*v)|l(b*v)|l(c*v)|l(d*v) */
  85
  86 "       punpckhwd %%mm2,%%mm1\n" /* mm1 = a*v|b*v */
  87
  88 "       movq %%mm4,%%mm6\n" /* mm6 = l(e*v)|l(f*v)|l(g*v)|l(h*v) */
  89 "       punpcklwd %%mm2,%%mm3\n" /* mm3 = c*v|d*v */
  90
  91 "       punpckhwd %%mm5,%%mm4\n" /* mm4 = e*f|f*v */
  92
  93 "       punpcklwd %%mm5,%%mm6\n" /* mm6 = g*v|h*v */
  94
  95         /* pré charger le buffer dst dans mm5 */
  96 "       movq 8(%0),%%mm5\n" /* mm5 = dst[1] */
  97
  98         /* diviser par 128 */
  99 "       psrad $7,%%mm1\n" /* mm1 = a*v/128|b*v/128 , 128 = SDL_MIX_MAXVOLUME */
 100 "       add $16,%1\n"
 101
 102 "       psrad $7,%%mm3\n" /* mm3 = c*v/128|d*v/128 */
 103
 104 "       psrad $7,%%mm4\n" /* mm4 = e*v/128|f*v/128 */
 105
 106         /* mm1 = le sample avec le volume modifié */
 107 "       packssdw %%mm1,%%mm3\n" /* mm3 = s(a*v|b*v|c*v|d*v) */
 108
 109 "       psrad $7,%%mm6\n" /* mm6= g*v/128|h*v/128 */
 110 "       paddsw %%mm7,%%mm3\n" /* mm3 = adjust_volume(src)+dst */
 111
 112         /* mm4 = le sample avec le volume modifié */
 113 "       packssdw %%mm4,%%mm6\n" /* mm6 = s(e*v|f*v|g*v|h*v) */
 114 "       movq %%mm3,(%0)\n"
 115
 116 "       paddsw %%mm5,%%mm6\n" /* mm6 = adjust_volume(src)+dst */
 117
 118 "       movq %%mm6,8(%0)\n"
 119
 120 "       add $16,%0\n"
 121
 122 "       dec %%edx\n"
 123
 124 "       jnz .mixloopS16\n"
 125
 126 "       emms\n"
 127
 128 ".endS16:\n"
 129          :
 130          : "r" (dst), "r"(src),"m"(size),
 131          "m"(volume)
 132          : "eax","edx","memory"
 133          );
 134 }
 135
 136
 137
 138 /*////////////////////////////////////////////// */
 139 /* Mixing for 8 bit signed buffers */
 140 /*////////////////////////////////////////////// */
 141
 142 void SDL_MixAudio_MMX_S8(char* dst,char* src,unsigned int size,int volume)
 143 {
 144     __asm__ __volatile__ (
 145
 146 "       movl %3,%%eax\n"        /* eax = volume */
 147
 148 "       movd %%eax,%%mm0\n"
 149 "       movq %%mm0,%%mm1\n"
 150 "       psllq $16,%%mm0\n"
 151 "       por %%mm1,%%mm0\n"
 152 "       psllq $16,%%mm0\n"
 153 "       por %%mm1,%%mm0\n"
 154 "       psllq $16,%%mm0\n"
 155 "       por %%mm1,%%mm0\n"
 156
 157 "       movl %2,%%edx\n"        /* edx = size */
 158 "       shr $3,%%edx\n" /* process 8 bytes per iteration = 8 samples */
 159
 160 "       cmp $0,%%edx\n"
 161 "       je .endS8\n"
 162
 163 ".align 8\n"
 164 "       .mixloopS8:\n"
 165
 166 "       pxor %%mm2,%%mm2\n"             /* mm2 = 0 */
 167 "       movq (%1),%%mm1\n"      /* mm1 = a|b|c|d|e|f|g|h */
 168
 169 "       movq %%mm1,%%mm3\n"     /* mm3 = a|b|c|d|e|f|g|h */
 170
 171         /* on va faire le "sign extension" en faisant un cmp avec 0 qui retourne 1 si <0, 0 si >0 */
 172 "       pcmpgtb %%mm1,%%mm2\n"  /* mm2 = 11111111|00000000|00000000.... */
 173
 174 "       punpckhbw %%mm2,%%mm1\n"        /* mm1 = 0|a|0|b|0|c|0|d */
 175
 176 "       punpcklbw %%mm2,%%mm3\n"        /* mm3 = 0|e|0|f|0|g|0|h */
 177 "       movq (%0),%%mm2\n"      /* mm2 = destination */
 178
 179 "       pmullw %%mm0,%%mm1\n"   /* mm1 = v*a|v*b|v*c|v*d */
 180 "       add $8,%1\n"
 181
 182 "       pmullw %%mm0,%%mm3\n"   /* mm3 = v*e|v*f|v*g|v*h */
 183 "       psraw $7,%%mm1\n"               /* mm1 = v*a/128|v*b/128|v*c/128|v*d/128  */
 184
 185 "       psraw $7,%%mm3\n"               /* mm3 = v*e/128|v*f/128|v*g/128|v*h/128 */
 186
 187 "       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 */
 188
 189 "       paddsb %%mm2,%%mm3\n"   /* add to destination buffer */
 190
 191 "       movq %%mm3,(%0)\n"      /* store back to ram */
 192 "       add $8,%0\n"
 193
 194 "       dec %%edx\n"
 195
 196 "       jnz .mixloopS8\n"
 197
 198 ".endS8:\n"
 199 "       emms\n"
 200          :
 201          : "r" (dst), "r"(src),"m"(size),
 202          "m"(volume)
 203          : "eax","edx","memory"
 204          );
 205 }
 206 #endif
 207 #endif