SDL-1.2/src/audio/SDL_mixer_MMX_VC.c

   1 /*
   2     SDL - Simple DirectMedia Layer
   3     Copyright (C) 1997-2006 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 #include "SDL_mixer_MMX_VC.h"
  25
  26 #if ((defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)) && defined(SDL_ASSEMBLY_ROUTINES)
  27 // MMX assembler version of SDL_MixAudio for signed little endian 16 bit samples and signed 8 bit samples
  28 // Copyright 2002 Stephane Marchesin (stephane.marchesin@wanadoo.fr)
  29 // Converted to Intel ASM notation by Cth
  30 // This code is licensed under the LGPL (see COPYING for details)
  31 //
  32 // Assumes buffer size in bytes is a multiple of 16
  33 // Assumes SDL_MIX_MAXVOLUME = 128
  34
  35
  36 ////////////////////////////////////////////////
  37 // Mixing for 16 bit signed buffers
  38 ////////////////////////////////////////////////
  39
  40 void SDL_MixAudio_MMX_S16_VC(char* dst,char* src,unsigned int nSize,int volume)
  41 {
  42         __asm
  43         {
  44
  45                 push    edi
  46                 push    esi
  47                 push    ebx
  48
  49                 mov             edi, dst                // edi = dst
  50                 mov             esi, src                // esi = src
  51                 mov             eax, volume             // eax = volume
  52                 mov             ebx, nSize              // ebx = size
  53                 shr             ebx, 4                  // process 16 bytes per iteration = 8 samples
  54                 jz              endS16
  55
  56                 pxor    mm0, mm0
  57                 movd    mm0, eax                //%%eax,%%mm0
  58                 movq    mm1, mm0                //%%mm0,%%mm1
  59                 psllq   mm0, 16                 //$16,%%mm0
  60                 por             mm0, mm1                //%%mm1,%%mm0
  61                 psllq   mm0, 16                 //$16,%%mm0
  62                 por             mm0, mm1                //%%mm1,%%mm0
  63                 psllq   mm0, 16                 //$16,%%mm0
  64                 por             mm0, mm1                //%%mm1,%%mm0                   // mm0 = vol|vol|vol|vol
  65
  66                 #ifndef __WATCOMC__
  67                 align   16
  68                 #endif
  69 mixloopS16:
  70                 movq    mm1, [esi]              //(%%esi),%%mm1\n" // mm1 = a|b|c|d
  71                 movq    mm2, mm1                //%%mm1,%%mm2\n" // mm2 = a|b|c|d
  72                 movq    mm4, [esi + 8]  //8(%%esi),%%mm4\n" // mm4 = e|f|g|h
  73                 // pre charger le buffer dst dans mm7
  74                 movq    mm7, [edi]              //(%%edi),%%mm7\n" // mm7 = dst[0]"
  75                 // multiplier par le volume
  76                 pmullw  mm1, mm0                //%%mm0,%%mm1\n" // mm1 = l(a*v)|l(b*v)|l(c*v)|l(d*v)
  77                 pmulhw  mm2, mm0                //%%mm0,%%mm2\n" // mm2 = h(a*v)|h(b*v)|h(c*v)|h(d*v)
  78                 movq    mm5, mm4                //%%mm4,%%mm5\n" // mm5 = e|f|g|h
  79                 pmullw  mm4, mm0                //%%mm0,%%mm4\n" // mm4 = l(e*v)|l(f*v)|l(g*v)|l(h*v)
  80                 pmulhw  mm5, mm0                //%%mm0,%%mm5\n" // mm5 = h(e*v)|h(f*v)|h(g*v)|h(h*v)
  81                 movq    mm3, mm1                //%%mm1,%%mm3\n" // mm3 = l(a*v)|l(b*v)|l(c*v)|l(d*v)
  82                 punpckhwd       mm1, mm2        //%%mm2,%%mm1\n" // mm1 = a*v|b*v
  83                 movq            mm6, mm4        //%%mm4,%%mm6\n" // mm6 = l(e*v)|l(f*v)|l(g*v)|l(h*v)
  84                 punpcklwd       mm3, mm2        //%%mm2,%%mm3\n" // mm3 = c*v|d*v
  85                 punpckhwd       mm4, mm5        //%%mm5,%%mm4\n" // mm4 = e*f|f*v
  86                 punpcklwd       mm6, mm5        //%%mm5,%%mm6\n" // mm6 = g*v|h*v
  87                 // pre charger le buffer dst dans mm5
  88                 movq    mm5, [edi + 8]  //8(%%edi),%%mm5\n" // mm5 = dst[1]
  89                 // diviser par 128
  90                 psrad   mm1, 7                  //$7,%%mm1\n" // mm1 = a*v/128|b*v/128 , 128 = SDL_MIX_MAXVOLUME
  91                 add             esi, 16                 //$16,%%esi\n"
  92                 psrad   mm3, 7                  //$7,%%mm3\n" // mm3 = c*v/128|d*v/128
  93                 psrad   mm4, 7                  //$7,%%mm4\n" // mm4 = e*v/128|f*v/128
  94                 // mm1 = le sample avec le volume modifie
  95                 packssdw        mm3, mm1        //%%mm1,%%mm3\n" // mm3 = s(a*v|b*v|c*v|d*v)
  96                 psrad   mm6, 7                  //$7,%%mm6\n" // mm6= g*v/128|h*v/128
  97                 paddsw  mm3, mm7                //%%mm7,%%mm3\n" // mm3 = adjust_volume(src)+dst
  98                 // mm4 = le sample avec le volume modifie
  99                 packssdw        mm6, mm4        //%%mm4,%%mm6\n" // mm6 = s(e*v|f*v|g*v|h*v)
 100                 movq    [edi], mm3              //%%mm3,(%%edi)\n"
 101                 paddsw  mm6, mm5                //%%mm5,%%mm6\n" // mm6 = adjust_volume(src)+dst
 102                 movq    [edi + 8], mm6  //%%mm6,8(%%edi)\n"
 103                 add             edi, 16                 //$16,%%edi\n"
 104                 dec             ebx                             //%%ebx\n"
 105                 jnz mixloopS16
 106
 107 endS16:
 108                 emms
 109
 110                 pop             ebx
 111                 pop             esi
 112                 pop             edi
 113         }
 114
 115 }
 116
 117 ////////////////////////////////////////////////
 118 // Mixing for 8 bit signed buffers
 119 ////////////////////////////////////////////////
 120
 121 void SDL_MixAudio_MMX_S8_VC(char* dst,char* src,unsigned int nSize,int volume)
 122 {
 123         _asm
 124         {
 125
 126                 push    edi
 127                 push    esi
 128                 push    ebx
 129
 130                 mov             edi, dst        //movl  %0,%%edi        // edi = dst
 131                 mov             esi, src        //%1,%%esi      // esi = src
 132                 mov             eax, volume     //%3,%%eax      // eax = volume
 133
 134                 movd    mm0, eax        //%%eax,%%mm0
 135                 movq    mm1, mm0        //%%mm0,%%mm1
 136                 psllq   mm0, 16         //$16,%%mm0
 137                 por             mm0, mm1        //%%mm1,%%mm0
 138                 psllq   mm0, 16         //$16,%%mm0
 139                 por             mm0, mm1        //%%mm1,%%mm0
 140                 psllq   mm0, 16         //$16,%%mm0
 141                 por             mm0, mm1        //%%mm1,%%mm0
 142
 143                 mov             ebx, nSize      //%2,%%ebx      // ebx = size
 144                 shr             ebx, 3          //$3,%%ebx      // process 8 bytes per iteration = 8 samples
 145                 cmp             ebx, 0          //$0,%%ebx
 146                 je              endS8
 147
 148                 #ifndef __WATCOMC__
 149                 align 16
 150                 #endif
 151 mixloopS8:
 152                 pxor    mm2, mm2        //%%mm2,%%mm2           // mm2 = 0
 153                 movq    mm1, [esi]      //(%%esi),%%mm1 // mm1 = a|b|c|d|e|f|g|h
 154                 movq    mm3, mm1        //%%mm1,%%mm3   // mm3 = a|b|c|d|e|f|g|h
 155                 // on va faire le "sign extension" en faisant un cmp avec 0 qui retourne 1 si <0, 0 si >0
 156                 pcmpgtb         mm2, mm1        //%%mm1,%%mm2   // mm2 = 11111111|00000000|00000000....
 157                 punpckhbw       mm1, mm2        //%%mm2,%%mm1   // mm1 = 0|a|0|b|0|c|0|d
 158                 punpcklbw       mm3, mm2        //%%mm2,%%mm3   // mm3 = 0|e|0|f|0|g|0|h
 159                 movq    mm2, [edi]      //(%%edi),%%mm2 // mm2 = destination
 160                 pmullw  mm1, mm0        //%%mm0,%%mm1   // mm1 = v*a|v*b|v*c|v*d
 161                 add             esi, 8          //$8,%%esi
 162                 pmullw  mm3, mm0        //%%mm0,%%mm3   // mm3 = v*e|v*f|v*g|v*h
 163                 psraw   mm1, 7          //$7,%%mm1              // mm1 = v*a/128|v*b/128|v*c/128|v*d/128
 164                 psraw   mm3, 7          //$7,%%mm3              // mm3 = v*e/128|v*f/128|v*g/128|v*h/128
 165                 packsswb mm3, mm1       //%%mm1,%%mm3   // 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
 166                 paddsb  mm3, mm2        //%%mm2,%%mm3   // add to destination buffer
 167                 movq    [edi], mm3      //%%mm3,(%%edi) // store back to ram
 168                 add             edi, 8          //$8,%%edi
 169                 dec             ebx                     //%%ebx
 170                 jnz             mixloopS8
 171
 172 endS8:
 173                 emms
 174
 175                 pop             ebx
 176                 pop             esi
 177                 pop             edi
 178         }
 179 }
 180
 181 #endif /* SDL_ASSEMBLY_ROUTINES */