view src/audio/SDL_mixer_MMX.c @ 1258:b2283b0ded26

Date: Thu, 19 Jan 2006 20:02:29 +0200 From: Vassilis Virvilis <vasvir@iit.demokritos.gr> Subject: [SDL] Request: Please reconsider adding tag in SDL_Event Hi, Patch in question: --- include/SDL_events.h 20 Aug 2004 18:57:01 -0000 1.11 +++ include/SDL_events.h 19 Jan 2006 17:35:09 -0000 @@ -214,7 +214,7 @@ } SDL_SysWMEvent; /* General event structure */ -typedef union { +typedef union SDL_Event { Uint8 type; SDL_ActiveEvent active; SDL_KeyboardEvent key; Reasoning: ---------- 1) Allows forward declaration of the SDL_Event union in C++. Please note that in plain C it is possible to forward declare it. 2) Forward declaration is good because it allows encapsulation. It hides the specific implementation and does not necessarily exposes SDL staff to my appication's namespace 3) It can't harm plain C because tags are living in a different namespace than typenames 4) It is already done like this in other places in SDL. Check for example SDL_KeySym, and SDL_.*Event structures. 5) Right now I have to include SDL/event.h from a C++ header file. See 2)
author Sam Lantinga <slouken@libsdl.org>
date Fri, 20 Jan 2006 13:07:25 +0000
parents b580f7201543
children d910939febfa
line wrap: on
line source

/*
    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 %3,%%eax\n"	// eax = volume

"	movl %2,%%edx\n"	// edx = size

"	shrl $4,%%edx\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 (%1),%%mm1\n" // mm1 = a|b|c|d

"	movq %%mm1,%%mm2\n" // mm2 = a|b|c|d

"	movq 8(%1),%%mm4\n" // mm4 = e|f|g|h

	// pré charger le buffer dst dans mm7
"	movq (%0),%%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(%0),%%mm5\n" // mm5 = dst[1]

	// diviser par 128
"	psrad $7,%%mm1\n" // mm1 = a*v/128|b*v/128 , 128 = SDL_MIX_MAXVOLUME
"	add $16,%1\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,(%0)\n"

"	paddsw %%mm5,%%mm6\n" // mm6 = adjust_volume(src)+dst

"	movq %%mm6,8(%0)\n"

"	add $16,%0\n"

"	dec %%edx\n"

"	jnz .mixloopS16\n"

"	emms\n"

".endS16:\n"
	 :
	 : "r" (dst), "r"(src),"m"(size),
	 "m"(volume)
	 : "eax","edx","memory"
	 );
}



////////////////////////////////////////////////
// Mixing for 8 bit signed buffers
////////////////////////////////////////////////

void SDL_MixAudio_MMX_S8(char* dst,char* src,unsigned int size,int volume)
{
    __asm__ __volatile__ (

"	movl %3,%%eax\n"	// eax = volume

"	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"

"	movl %2,%%edx\n"	// edx = size
"	shr $3,%%edx\n"	// process 8 bytes per iteration = 8 samples

"	cmp $0,%%edx\n"
"	je .endS8\n"

".align 16\n"
"	.mixloopS8:\n"

"	pxor %%mm2,%%mm2\n"		// mm2 = 0
"	movq (%1),%%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 (%0),%%mm2\n"	// mm2 = destination

"	pmullw %%mm0,%%mm1\n"	// mm1 = v*a|v*b|v*c|v*d
"	add $8,%1\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,(%0)\n"	// store back to ram
"	add $8,%0\n"

"	dec %%edx\n"

"	jnz .mixloopS8\n"

".endS8:\n"
"	emms\n"
	 :
	 : "r" (dst), "r"(src),"m"(size),
	 "m"(volume)
	 : "eax","edx","memory"
	 );
}
#endif