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Added MMX audio mixing code for gcc (thanks Stephane!)

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--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%40540
This commit is contained in:
Sam Lantinga 2002-11-09 06:13:28 +00:00
parent ef6f54e336
commit 994f095e2e
5 changed files with 238 additions and 1 deletions
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36
src/audio/SDL_mixer.c
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@ -35,7 +35,24 @@ static char rcsid =
#include "SDL_mutex.h"
#include "SDL_timer.h"
#include "SDL_sysaudio.h"
#include "SDL_mixer_MMX.h"
/* Function to check the CPU flags */
#define MMX_CPU 0x800000
#ifdef USE_ASMBLIT
#define CPU_Flags() Hermes_X86_CPU()
#else
#define CPU_Flags() 0L
#endif
#ifdef USE_ASMBLIT
#define X86_ASSEMBLER
#define HermesConverterInterface void
#define HermesClearInterface void
#define STACKCALL
#include "HeadX86.h"
#endif
/* This table is used to add two sound values together and pin
* the value to avoid overflow. (used with permission from ARDI)
@ -130,6 +147,15 @@ void SDL_MixAudio (Uint8 *dst, const Uint8 *src, Uint32 len, int volume)
break;
case AUDIO_S8: {
#if defined(i386) && defined(__GNUC__) && defined(USE_ASMBLIT)
if (CPU_Flags() & MMX_CPU)
{
SDL_MixAudio_MMX_S8((char*)dst,(char*)src,(unsigned int)len,(int)volume);
}
else
#endif
{
Sint8 *dst8, *src8;
Sint8 src_sample;
int dst_sample;
@ -153,10 +179,19 @@ void SDL_MixAudio (Uint8 *dst, const Uint8 *src, Uint32 len, int volume)
++dst8;
++src8;
}
}
}
break;
case AUDIO_S16LSB: {
#if defined(i386) && defined(__GNUC__) && defined(USE_ASMBLIT)
if (CPU_Flags() & MMX_CPU)
{
SDL_MixAudio_MMX_S16((char*)dst,(char*)src,(unsigned int)len,(int)volume);
}
else
#endif
{
Sint16 src1, src2;
int dst_sample;
const int max_audioval = ((1<<(16-1))-1);
@ -180,6 +215,7 @@ void SDL_MixAudio (Uint8 *dst, const Uint8 *src, Uint32 len, int volume)
dst[1] = dst_sample&0xFF;
dst += 2;
}
}
}
break;