diff --git a/docs.html b/docs.html
index cdced29e8..2f330d578 100644
--- a/docs.html
+++ b/docs.html
@@ -20,6 +20,7 @@ The latest stable release may be found on the
Major changes since SDL 1.0.0:
+ - 1.2.6: Added MMX audio mixing code for gcc (thanks Stephane!)
- 1.2.6: Fixed potential dropped events under DirectInput
- 1.2.6: Added Visual C++ 7 (.NET) projects (thanks James!)
- 1.2.5: Added an environment variable SDL_HAS3BUTTONMOUSE for Quartz
diff --git a/src/audio/Makefile.am b/src/audio/Makefile.am
index 9b3a2afa0..91fe93be4 100644
--- a/src/audio/Makefile.am
+++ b/src/audio/Makefile.am
@@ -22,7 +22,9 @@ COMMON_SRCS = \
SDL_mixer.c \
SDL_sysaudio.h \
SDL_wave.c \
- SDL_wave.h
+ SDL_wave.h \
+ SDL_mixer_MMX.c \
+ SDL_mixer_MMX.h
libaudio_la_SOURCES = $(COMMON_SRCS)
libaudio_la_LIBADD = $(DRIVERS)
diff --git a/src/audio/SDL_mixer.c b/src/audio/SDL_mixer.c
index 50839338f..c77391a04 100644
--- a/src/audio/SDL_mixer.c
+++ b/src/audio/SDL_mixer.c
@@ -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;
diff --git a/src/audio/SDL_mixer_MMX.c b/src/audio/SDL_mixer_MMX.c
new file mode 100644
index 000000000..179aa92be
--- /dev/null
+++ b/src/audio/SDL_mixer_MMX.c
@@ -0,0 +1,185 @@
+// 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
+
diff --git a/src/audio/SDL_mixer_MMX.h b/src/audio/SDL_mixer_MMX.h
new file mode 100644
index 000000000..8cd29235b
--- /dev/null
+++ b/src/audio/SDL_mixer_MMX.h
@@ -0,0 +1,13 @@
+// headers for MMX assembler version of SDL_MixAudio
+// 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
+
+
+#if defined(i386) && defined(__GNUC__) && defined(USE_ASMBLIT)
+void SDL_MixAudio_MMX_S16(char* ,char* ,unsigned int ,int );
+void SDL_MixAudio_MMX_S8(char* ,char* ,unsigned int ,int );
+#endif
+