/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public

    License along with this library; if not, write to the Free Software

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken@libsdl.org

*/

#include "SDL_config.h"

#include "SDL_mixer_MMX_VC.h"

#if ((defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)) && defined(SDL_ASSEMBLY_ROUTINES)

// 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

////////////////////////////////////////////////

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

		#ifndef __WATCOMC__

		align	16

		#endif

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

		#ifndef __WATCOMC__

		align 16

		#endif

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 /* SDL_ASSEMBLY_ROUTINES */