src/audio/SDL_mixer_m68k.c
author Sam Lantinga <slouken@libsdl.org>
Sun, 04 Jan 2004 16:49:27 +0000
changeset 769 b8d311d90021
parent 633 873c2598f969
child 1402 d910939febfa
permissions -rw-r--r--
Updated copyright information for 2004 (Happy New Year!)
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2004 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Library General Public
     7     License as published by the Free Software Foundation; either
     8     version 2 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     Library General Public License for more details.
    14 
    15     You should have received a copy of the GNU Library General Public
    16     License along with this library; if not, write to the Free
    17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 
    23 /*
    24 	m68k assembly mix routines
    25 
    26 	Patrice Mandin
    27 */
    28 
    29 #if defined(__M68000__) && defined(__GNUC__)
    30 void SDL_MixAudio_m68k_U8(char* dst, char* src, long len, long volume, char* mix8)
    31 {
    32     __asm__ __volatile__ (
    33 
    34 	"tstl	%2\n"
    35 "	beqs	stoploop_u8\n"
    36 "mixloop_u8:\n"
    37 
    38 	/* Mix a sample */
    39 
    40 "	moveq	#0,%%d0\n"
    41 "	moveq	#0,%%d1\n"
    42 
    43 "	moveb	%1@+,%%d0\n"	/* d0 = *src++ */
    44 "	sub	#128,%%d0\n"	/* d0 -= 128 */
    45 "	muls	%3,%%d0\n"	/* d0 *= volume (0<=volume<=128) */
    46 "	moveb	%0@,%%d1\n"	/* d1 = *dst */
    47 "	asr	#7,%%d0\n"	/* d0 /= 128 (SDL_MIX_MAXVOLUME) */
    48 "	add	#128,%%d0\n"	/* d0 += 128 */
    49 
    50 "	add	%%d1,%%d0\n"
    51 
    52 "	moveb	%4@(%%d0:w),%0@+\n"
    53 
    54 	/* Loop till done */
    55 
    56 "	subql	#1,%2\n"
    57 "	bhis	mixloop_u8\n"
    58 "stoploop_u8:\n"
    59 
    60 	 : /* no return value */
    61 	 : /* input */
    62 	 	"a"(dst), "a"(src), "d"(len), "d"(volume), "a"(mix8)	
    63 	 : /* clobbered registers */
    64 	 	"d0", "d1", "cc", "memory" 
    65 	 );
    66 }
    67 
    68 void SDL_MixAudio_m68k_S8(char* dst, char* src, long len, long volume)
    69 {
    70     __asm__ __volatile__ (
    71 
    72 	"tstl	%2\n"
    73 "	beqs	stoploop_s8\n"
    74 "	moveq	#-128,%%d2\n"
    75 "	moveq	#127,%%d3\n"
    76 "mixloop_s8:\n"
    77 
    78 	/* Mix a sample */
    79 
    80 "	moveq	#0,%%d0\n"
    81 "	moveq	#0,%%d1\n"
    82 
    83 "	moveb	%1@+,%%d0\n"	/* d0 = *src++ */
    84 "	muls	%3,%%d0\n"	/* d0 *= volume (0<=volume<=128) */
    85 "	moveb	%0@,%%d1\n"	/* d1 = *dst */
    86 "	asr	#7,%%d0\n"	/* d0 /= 128 (SDL_MIX_MAXVOLUME) */
    87 
    88 "	add	%%d1,%%d0\n"
    89 
    90 "	cmp	%%d2,%%d0\n"
    91 "	bges	lower_limit_s8\n"
    92 "	move	%%d2,%%d0\n"
    93 "lower_limit_s8:\n"
    94 
    95 "	cmp	%%d3,%%d0\n"
    96 "	bles	upper_limit_s8\n"
    97 "	move	%%d3,%%d0\n"
    98 "upper_limit_s8:\n"
    99 "	moveb	%%d0,%0@+\n"
   100 
   101 	/* Loop till done */
   102 
   103 "	subql	#1,%2\n"
   104 "	bhis	mixloop_s8\n"
   105 "stoploop_s8:\n"
   106 
   107 	 : /* no return value */
   108 	 : /* input */
   109 	 	"a"(dst), "a"(src), "d"(len), "d"(volume)	
   110 	 : /* clobbered registers */
   111 	 	"d0", "d1", "d2", "d3", "cc", "memory" 
   112 	 );
   113 }
   114 
   115 void SDL_MixAudio_m68k_S16MSB(short* dst, short* src, long len, long volume)
   116 {
   117     __asm__ __volatile__ (
   118 
   119 	"tstl	%2\n"
   120 "	beqs	stoploop_s16msb\n"
   121 "	movel	#-32768,%%d2\n"
   122 "	movel	#32767,%%d3\n"
   123 "	lsrl	#1,%2\n"
   124 "mixloop_s16msb:\n"
   125 
   126 	/* Mix a sample */
   127 
   128 "	move	%1@+,%%d0\n"	/* d0 = *src++ */
   129 "	muls	%3,%%d0\n"	/* d0 *= volume (0<=volume<=128) */
   130 "	move	%0@,%%d1\n"	/* d1 = *dst */
   131 "	extl	%%d1\n"		/* extend d1 to 32 bits */
   132 "	asrl	#7,%%d0\n"	/* d0 /= 128 (SDL_MIX_MAXVOLUME) */
   133 
   134 "	addl	%%d1,%%d0\n"
   135 
   136 "	cmpl	%%d2,%%d0\n"
   137 "	bges	lower_limit_s16msb\n"
   138 "	move	%%d2,%%d0\n"
   139 "lower_limit_s16msb:\n"
   140 
   141 "	cmpl	%%d3,%%d0\n"
   142 "	bles	upper_limit_s16msb\n"
   143 "	move	%%d3,%%d0\n"
   144 "upper_limit_s16msb:\n"
   145 "	move	%%d0,%0@+\n"
   146 
   147 	/* Loop till done */
   148 
   149 "	subql	#1,%2\n"
   150 "	bhis	mixloop_s16msb\n"
   151 "stoploop_s16msb:\n"
   152 
   153 	 : /* no return value */
   154 	 : /* input */
   155 	 	"a"(dst), "a"(src), "d"(len), "d"(volume)	
   156 	 : /* clobbered registers */
   157 	 	"d0", "d1", "d2", "d3", "cc", "memory" 
   158 	 );
   159 }
   160 
   161 void SDL_MixAudio_m68k_S16LSB(short* dst, short* src, long len, long volume)
   162 {
   163     __asm__ __volatile__ (
   164 
   165 	"tstl	%2\n"
   166 "	beqs	stoploop_s16lsb\n"
   167 "	movel	#-32768,%%d2\n"
   168 "	movel	#32767,%%d3\n"
   169 "	lsrl	#1,%2\n"
   170 "mixloop_s16lsb:\n"
   171 
   172 	/* Mix a sample */
   173 
   174 "	move	%1@+,%%d0\n"	/* d0 = *src++ */
   175 "	rorw	#8,%%d0\n"
   176 "	muls	%3,%%d0\n"	/* d0 *= volume (0<=volume<=128) */
   177 "	move	%0@,%%d1\n"	/* d1 = *dst */
   178 "	rorw	#8,%%d1\n"
   179 "	extl	%%d1\n"		/* extend d1 to 32 bits */
   180 "	asrl	#7,%%d0\n"	/* d0 /= 128 (SDL_MIX_MAXVOLUME) */
   181 
   182 "	addl	%%d1,%%d0\n"
   183 
   184 "	cmpl	%%d2,%%d0\n"
   185 "	bges	lower_limit_s16lsb\n"
   186 "	move	%%d2,%%d0\n"
   187 "lower_limit_s16lsb:\n"
   188 
   189 "	cmpl	%%d3,%%d0\n"
   190 "	bles	upper_limit_s16lsb\n"
   191 "	move	%%d3,%%d0\n"
   192 "upper_limit_s16lsb:\n"
   193 "	rorw	#8,%%d0\n"
   194 "	move	%%d0,%0@+\n"
   195 
   196 	/* Loop till done */
   197 
   198 "	subql	#1,%2\n"
   199 "	bhis	mixloop_s16lsb\n"
   200 "stoploop_s16lsb:\n"
   201 
   202 	 : /* no return value */
   203 	 : /* input */
   204 	 	"a"(dst), "a"(src), "d"(len), "d"(volume)	
   205 	 : /* clobbered registers */
   206 	 	"d0", "d1", "d2", "d3", "cc", "memory" 
   207 	 );
   208 }
   209 #endif
   210