src/audio/SDL_mixer_MMX.c
changeset 539 a9e38f3b8e4d
child 887 b4b64bb88f2f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/audio/SDL_mixer_MMX.c	Sat Nov 09 06:13:28 2002 +0000
@@ -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
+