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view src/audio/SDL_mixer_MMX_VC.c @ 1166:da33b7e6d181

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Date: Tue, 1 Nov 2005 20:25:10 +0100 From: Dirk Mueller Subject: [PATCH] build SDL with nonexecutable stack libSDL is by default marked with an executable stack, which it doesn't actually need. the reason for this is that there are assembler files in the source tree not properly annotated with the "noexec stack" section. As such the linker does a safe-fallback and marks the whole lib as "requires executable stack". the patch below removes this by adding annotations. As far as I can see it shouldn't break anything.
author Sam Lantinga <slouken@libsdl.org>
date Tue, 01 Nov 2005 23:19:59 +0000
parents ef03e8789d59
children 173c063d4f55
line wrap: on
line source

#if defined(USE_ASM_MIXER_VC)
// 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)
// Converted to Intel ASM notation by Cth
// 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
////////////////////////////////////////////////

#include <windows.h>
#include <stdio.h>

void SDL_MixAudio_MMX_S16_VC(char* dst,char* src,unsigned int nSize,int volume)
{
	__asm
	{

		push	edi
		push	esi
		push	ebx
		
		mov		edi, dst		// edi = dst
		mov		esi, src		// esi = src
		mov		eax, volume		// eax = volume
		mov		ebx, nSize		// ebx = size
		shr		ebx, 4			// process 16 bytes per iteration = 8 samples
		jz		endS16
		
		pxor	mm0, mm0
		movd	mm0, eax		//%%eax,%%mm0
		movq	mm1, mm0		//%%mm0,%%mm1
		psllq	mm0, 16			//$16,%%mm0
		por		mm0, mm1		//%%mm1,%%mm0
		psllq	mm0, 16			//$16,%%mm0
		por		mm0, mm1		//%%mm1,%%mm0
		psllq	mm0, 16			//$16,%%mm0
		por		mm0, mm1		//%%mm1,%%mm0			// mm0 = vol|vol|vol|vol

		align	16
mixloopS16:
		movq	mm1, [esi]		//(%%esi),%%mm1\n" // mm1 = a|b|c|d
		movq	mm2, mm1		//%%mm1,%%mm2\n" // mm2 = a|b|c|d
		movq	mm4, [esi + 8]	//8(%%esi),%%mm4\n" // mm4 = e|f|g|h
		// pre charger le buffer dst dans mm7
		movq	mm7, [edi]		//(%%edi),%%mm7\n" // mm7 = dst[0]"
		// multiplier par le volume
		pmullw	mm1, mm0		//%%mm0,%%mm1\n" // mm1 = l(a*v)|l(b*v)|l(c*v)|l(d*v)
		pmulhw	mm2, mm0		//%%mm0,%%mm2\n" // mm2 = h(a*v)|h(b*v)|h(c*v)|h(d*v)
		movq	mm5, mm4		//%%mm4,%%mm5\n" // mm5 = e|f|g|h
		pmullw	mm4, mm0		//%%mm0,%%mm4\n" // mm4 = l(e*v)|l(f*v)|l(g*v)|l(h*v)
		pmulhw	mm5, mm0		//%%mm0,%%mm5\n" // mm5 = h(e*v)|h(f*v)|h(g*v)|h(h*v)
		movq	mm3, mm1		//%%mm1,%%mm3\n" // mm3 = l(a*v)|l(b*v)|l(c*v)|l(d*v)
		punpckhwd	mm1, mm2	//%%mm2,%%mm1\n" // mm1 = a*v|b*v
		movq		mm6, mm4	//%%mm4,%%mm6\n" // mm6 = l(e*v)|l(f*v)|l(g*v)|l(h*v)
		punpcklwd	mm3, mm2	//%%mm2,%%mm3\n" // mm3 = c*v|d*v
		punpckhwd	mm4, mm5	//%%mm5,%%mm4\n" // mm4 = e*f|f*v
		punpcklwd	mm6, mm5	//%%mm5,%%mm6\n" // mm6 = g*v|h*v
		// pre charger le buffer dst dans mm5
		movq	mm5, [edi + 8]	//8(%%edi),%%mm5\n" // mm5 = dst[1]
		// diviser par 128
		psrad	mm1, 7			//$7,%%mm1\n" // mm1 = a*v/128|b*v/128 , 128 = SDL_MIX_MAXVOLUME
		add		esi, 16			//$16,%%esi\n"
		psrad	mm3, 7			//$7,%%mm3\n" // mm3 = c*v/128|d*v/128
		psrad	mm4, 7			//$7,%%mm4\n" // mm4 = e*v/128|f*v/128
		// mm1 = le sample avec le volume modifie
		packssdw	mm3, mm1	//%%mm1,%%mm3\n" // mm3 = s(a*v|b*v|c*v|d*v)
		psrad	mm6, 7			//$7,%%mm6\n" // mm6= g*v/128|h*v/128
		paddsw	mm3, mm7		//%%mm7,%%mm3\n" // mm3 = adjust_volume(src)+dst
		// mm4 = le sample avec le volume modifie
		packssdw	mm6, mm4	//%%mm4,%%mm6\n" // mm6 = s(e*v|f*v|g*v|h*v)
		movq	[edi], mm3		//%%mm3,(%%edi)\n"
		paddsw	mm6, mm5		//%%mm5,%%mm6\n" // mm6 = adjust_volume(src)+dst
		movq	[edi + 8], mm6	//%%mm6,8(%%edi)\n"
		add		edi, 16			//$16,%%edi\n"
		dec		ebx				//%%ebx\n"
		jnz mixloopS16

ends16:
		emms
		
		pop		ebx
		pop		esi
		pop		edi
	}

}

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

void SDL_MixAudio_MMX_S8_VC(char* dst,char* src,unsigned int nSize,int volume)
{
	_asm
	{

		push	edi
		push	esi
		push	ebx
		
		mov		edi, dst	//movl	%0,%%edi	// edi = dst
		mov		esi, src	//%1,%%esi	// esi = src
		mov		eax, volume	//%3,%%eax	// eax = volume

		movd	mm0, eax	//%%eax,%%mm0
		movq	mm1, mm0	//%%mm0,%%mm1
		psllq	mm0, 16		//$16,%%mm0
		por		mm0, mm1	//%%mm1,%%mm0
		psllq	mm0, 16		//$16,%%mm0
		por		mm0, mm1	//%%mm1,%%mm0
		psllq	mm0, 16		//$16,%%mm0
		por		mm0, mm1	//%%mm1,%%mm0
		
		mov		ebx, nSize	//%2,%%ebx	// ebx = size
		shr		ebx, 3		//$3,%%ebx	// process 8 bytes per iteration = 8 samples
		cmp		ebx, 0		//$0,%%ebx
		je		endS8

		align 16
mixloopS8:
		pxor	mm2, mm2	//%%mm2,%%mm2		// mm2 = 0
		movq	mm1, [esi]	//(%%esi),%%mm1	// mm1 = a|b|c|d|e|f|g|h
		movq	mm3, mm1	//%%mm1,%%mm3 	// 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		mm2, mm1	//%%mm1,%%mm2	// mm2 = 11111111|00000000|00000000....
		punpckhbw	mm1, mm2	//%%mm2,%%mm1	// mm1 = 0|a|0|b|0|c|0|d
		punpcklbw	mm3, mm2	//%%mm2,%%mm3	// mm3 = 0|e|0|f|0|g|0|h
		movq	mm2, [edi]	//(%%edi),%%mm2	// mm2 = destination
		pmullw	mm1, mm0	//%%mm0,%%mm1	// mm1 = v*a|v*b|v*c|v*d
		add		esi, 8		//$8,%%esi
		pmullw	mm3, mm0	//%%mm0,%%mm3	// mm3 = v*e|v*f|v*g|v*h
		psraw	mm1, 7		//$7,%%mm1		// mm1 = v*a/128|v*b/128|v*c/128|v*d/128 
		psraw	mm3, 7		//$7,%%mm3		// mm3 = v*e/128|v*f/128|v*g/128|v*h/128
		packsswb mm3, mm1	//%%mm1,%%mm3	// 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	mm3, mm2	//%%mm2,%%mm3	// add to destination buffer
		movq	[edi], mm3	//%%mm3,(%%edi)	// store back to ram
		add		edi, 8		//$8,%%edi
		dec		ebx			//%%ebx
		jnz		mixloopS8
		
endS8:
		emms
		
		pop		ebx
		pop		esi
		pop		edi
	}
}

#endif /* USE_ASM_MIXER_VC */