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      1 /*
      2     SDL - Simple DirectMedia Layer
      3     Copyright (C) 1997-2006 Sam Lantinga
      4 
      5     This library is free software; you can redistribute it and/or
      6     modify it under the terms of the GNU Lesser General Public
      7     License as published by the Free Software Foundation; either
      8     version 2.1 of the License, or (at your option) any later version.
      9 
     10     This library is distributed in the hope that it will be useful,
     11     but WITHOUT ANY WARRANTY; without even the implied warranty of
     12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13     Lesser General Public License for more details.
     14 
     15     You should have received a copy of the GNU Lesser General Public
     16     License along with this library; if not, write to the Free Software
     17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
     18 
     19     Sam Lantinga
     20     slouken (at) libsdl.org
     21 */
     22 #include "SDL_config.h"
     23 
     24 #include "SDL_mixer_MMX_VC.h"
     25 
     26 #if ((defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)) && defined(SDL_ASSEMBLY_ROUTINES)
     27 // MMX assembler version of SDL_MixAudio for signed little endian 16 bit samples and signed 8 bit samples
     28 // Copyright 2002 Stephane Marchesin (stephane.marchesin (at) wanadoo.fr)
     29 // Converted to Intel ASM notation by Cth
     30 // This code is licensed under the LGPL (see COPYING for details)
     31 //
     32 // Assumes buffer size in bytes is a multiple of 16
     33 // Assumes SDL_MIX_MAXVOLUME = 128
     34 
     35 
     36 ////////////////////////////////////////////////
     37 // Mixing for 16 bit signed buffers
     38 ////////////////////////////////////////////////
     39 
     40 void SDL_MixAudio_MMX_S16_VC(char* dst,char* src,unsigned int nSize,int volume)
     41 {
     42 	__asm
     43 	{
     44 
     45 		push	edi
     46 		push	esi
     47 		push	ebx
     48 
     49 		mov		edi, dst		// edi = dst
     50 		mov		esi, src		// esi = src
     51 		mov		eax, volume		// eax = volume
     52 		mov		ebx, nSize		// ebx = size
     53 		shr		ebx, 4			// process 16 bytes per iteration = 8 samples
     54 		jz		endS16
     55 
     56 		pxor	mm0, mm0
     57 		movd	mm0, eax		//%%eax,%%mm0
     58 		movq	mm1, mm0		//%%mm0,%%mm1
     59 		psllq	mm0, 16			//$16,%%mm0
     60 		por		mm0, mm1		//%%mm1,%%mm0
     61 		psllq	mm0, 16			//$16,%%mm0
     62 		por		mm0, mm1		//%%mm1,%%mm0
     63 		psllq	mm0, 16			//$16,%%mm0
     64 		por		mm0, mm1		//%%mm1,%%mm0			// mm0 = vol|vol|vol|vol
     65 
     66 		#ifndef __WATCOMC__
     67 		align	16
     68 		#endif
     69 mixloopS16:
     70 		movq	mm1, [esi]		//(%%esi),%%mm1\n" // mm1 = a|b|c|d
     71 		movq	mm2, mm1		//%%mm1,%%mm2\n" // mm2 = a|b|c|d
     72 		movq	mm4, [esi + 8]	//8(%%esi),%%mm4\n" // mm4 = e|f|g|h
     73 		// pre charger le buffer dst dans mm7
     74 		movq	mm7, [edi]		//(%%edi),%%mm7\n" // mm7 = dst[0]"
     75 		// multiplier par le volume
     76 		pmullw	mm1, mm0		//%%mm0,%%mm1\n" // mm1 = l(a*v)|l(b*v)|l(c*v)|l(d*v)
     77 		pmulhw	mm2, mm0		//%%mm0,%%mm2\n" // mm2 = h(a*v)|h(b*v)|h(c*v)|h(d*v)
     78 		movq	mm5, mm4		//%%mm4,%%mm5\n" // mm5 = e|f|g|h
     79 		pmullw	mm4, mm0		//%%mm0,%%mm4\n" // mm4 = l(e*v)|l(f*v)|l(g*v)|l(h*v)
     80 		pmulhw	mm5, mm0		//%%mm0,%%mm5\n" // mm5 = h(e*v)|h(f*v)|h(g*v)|h(h*v)
     81 		movq	mm3, mm1		//%%mm1,%%mm3\n" // mm3 = l(a*v)|l(b*v)|l(c*v)|l(d*v)
     82 		punpckhwd	mm1, mm2	//%%mm2,%%mm1\n" // mm1 = a*v|b*v
     83 		movq		mm6, mm4	//%%mm4,%%mm6\n" // mm6 = l(e*v)|l(f*v)|l(g*v)|l(h*v)
     84 		punpcklwd	mm3, mm2	//%%mm2,%%mm3\n" // mm3 = c*v|d*v
     85 		punpckhwd	mm4, mm5	//%%mm5,%%mm4\n" // mm4 = e*f|f*v
     86 		punpcklwd	mm6, mm5	//%%mm5,%%mm6\n" // mm6 = g*v|h*v
     87 		// pre charger le buffer dst dans mm5
     88 		movq	mm5, [edi + 8]	//8(%%edi),%%mm5\n" // mm5 = dst[1]
     89 		// diviser par 128
     90 		psrad	mm1, 7			//$7,%%mm1\n" // mm1 = a*v/128|b*v/128 , 128 = SDL_MIX_MAXVOLUME
     91 		add		esi, 16			//$16,%%esi\n"
     92 		psrad	mm3, 7			//$7,%%mm3\n" // mm3 = c*v/128|d*v/128
     93 		psrad	mm4, 7			//$7,%%mm4\n" // mm4 = e*v/128|f*v/128
     94 		// mm1 = le sample avec le volume modifie
     95 		packssdw	mm3, mm1	//%%mm1,%%mm3\n" // mm3 = s(a*v|b*v|c*v|d*v)
     96 		psrad	mm6, 7			//$7,%%mm6\n" // mm6= g*v/128|h*v/128
     97 		paddsw	mm3, mm7		//%%mm7,%%mm3\n" // mm3 = adjust_volume(src)+dst
     98 		// mm4 = le sample avec le volume modifie
     99 		packssdw	mm6, mm4	//%%mm4,%%mm6\n" // mm6 = s(e*v|f*v|g*v|h*v)
    100 		movq	[edi], mm3		//%%mm3,(%%edi)\n"
    101 		paddsw	mm6, mm5		//%%mm5,%%mm6\n" // mm6 = adjust_volume(src)+dst
    102 		movq	[edi + 8], mm6	//%%mm6,8(%%edi)\n"
    103 		add		edi, 16			//$16,%%edi\n"
    104 		dec		ebx				//%%ebx\n"
    105 		jnz mixloopS16
    106 
    107 ends16:
    108 		emms
    109 
    110 		pop		ebx
    111 		pop		esi
    112 		pop		edi
    113 	}
    114 
    115 }
    116 
    117 ////////////////////////////////////////////////
    118 // Mixing for 8 bit signed buffers
    119 ////////////////////////////////////////////////
    120 
    121 void SDL_MixAudio_MMX_S8_VC(char* dst,char* src,unsigned int nSize,int volume)
    122 {
    123 	_asm
    124 	{
    125 
    126 		push	edi
    127 		push	esi
    128 		push	ebx
    129 
    130 		mov		edi, dst	//movl	%0,%%edi	// edi = dst
    131 		mov		esi, src	//%1,%%esi	// esi = src
    132 		mov		eax, volume	//%3,%%eax	// eax = volume
    133 
    134 		movd	mm0, eax	//%%eax,%%mm0
    135 		movq	mm1, mm0	//%%mm0,%%mm1
    136 		psllq	mm0, 16		//$16,%%mm0
    137 		por		mm0, mm1	//%%mm1,%%mm0
    138 		psllq	mm0, 16		//$16,%%mm0
    139 		por		mm0, mm1	//%%mm1,%%mm0
    140 		psllq	mm0, 16		//$16,%%mm0
    141 		por		mm0, mm1	//%%mm1,%%mm0
    142 
    143 		mov		ebx, nSize	//%2,%%ebx	// ebx = size
    144 		shr		ebx, 3		//$3,%%ebx	// process 8 bytes per iteration = 8 samples
    145 		cmp		ebx, 0		//$0,%%ebx
    146 		je		endS8
    147 
    148 		#ifndef __WATCOMC__
    149 		align 16
    150 		#endif
    151 mixloopS8:
    152 		pxor	mm2, mm2	//%%mm2,%%mm2		// mm2 = 0
    153 		movq	mm1, [esi]	//(%%esi),%%mm1	// mm1 = a|b|c|d|e|f|g|h
    154 		movq	mm3, mm1	//%%mm1,%%mm3 	// mm3 = a|b|c|d|e|f|g|h
    155 		// on va faire le "sign extension" en faisant un cmp avec 0 qui retourne 1 si <0, 0 si >0
    156 		pcmpgtb		mm2, mm1	//%%mm1,%%mm2	// mm2 = 11111111|00000000|00000000....
    157 		punpckhbw	mm1, mm2	//%%mm2,%%mm1	// mm1 = 0|a|0|b|0|c|0|d
    158 		punpcklbw	mm3, mm2	//%%mm2,%%mm3	// mm3 = 0|e|0|f|0|g|0|h
    159 		movq	mm2, [edi]	//(%%edi),%%mm2	// mm2 = destination
    160 		pmullw	mm1, mm0	//%%mm0,%%mm1	// mm1 = v*a|v*b|v*c|v*d
    161 		add		esi, 8		//$8,%%esi
    162 		pmullw	mm3, mm0	//%%mm0,%%mm3	// mm3 = v*e|v*f|v*g|v*h
    163 		psraw	mm1, 7		//$7,%%mm1		// mm1 = v*a/128|v*b/128|v*c/128|v*d/128
    164 		psraw	mm3, 7		//$7,%%mm3		// mm3 = v*e/128|v*f/128|v*g/128|v*h/128
    165 		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
    166 		paddsb	mm3, mm2	//%%mm2,%%mm3	// add to destination buffer
    167 		movq	[edi], mm3	//%%mm3,(%%edi)	// store back to ram
    168 		add		edi, 8		//$8,%%edi
    169 		dec		ebx			//%%ebx
    170 		jnz		mixloopS8
    171 
    172 endS8:
    173 		emms
    174 
    175 		pop		ebx
    176 		pop		esi
    177 		pop		edi
    178 	}
    179 }
    180 
    181 #endif /* SDL_ASSEMBLY_ROUTINES */
    182