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view src/audio/SDL_mixer_MMX.c @ 816:428f688f2ad2

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Date: Fri, 13 Feb 2004 17:03:16 +0100 From: Max Horn Subject: Modifier key fix The internal modifier state can get out of sync with reality. To trigger this, do for example this: 1) Launch an SDL app 2) Alt-click on the desktop (this will hide the SDL app). 3) Bring the SDL app back to the front 4) SDL will still think alt is pressed (and as such will treat left clicks like middle clicks). If you press and release alt, it'll be fine again. The attached patch cures this by rechecking the modifier state whenever we process an event.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 13 Feb 2004 17:57:16 +0000
parents a9e38f3b8e4d
children b4b64bb88f2f
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 %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