src/audio/SDL_mixer_m68k.c
author Sam Lantinga <slouken@libsdl.org>
Mon, 29 May 2006 04:04:35 +0000
branchSDL-1.3
changeset 1668 4da1ee79c9af
parent 1662 782fd950bd46
permissions -rw-r--r--
more tweaking indent options
     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 #include "SDL_config.h"
    23 
    24 /*
    25 	m68k assembly mix routines
    26 
    27 	Patrice Mandin
    28 */
    29 
    30 #if defined(__M68000__) && defined(__GNUC__)
    31 void
    32 SDL_MixAudio_m68k_U8(char *dst, char *src, long len, long volume, char *mix8)
    33 {
    34     __asm__ __volatile__("tstl	%2\n" "	beqs	stoploop_u8\n" "mixloop_u8:\n"
    35                          /* Mix a sample */
    36                          "	moveq	#0,%%d0\n" "	moveq	#0,%%d1\n" "	moveb	%1@+,%%d0\n"    /* d0 = *src++ */
    37                          "	sub	#128,%%d0\n"    /* d0 -= 128 */
    38                          "	muls	%3,%%d0\n"      /* d0 *= volume (0<=volume<=128) */
    39                          "	moveb	%0@,%%d1\n"     /* d1 = *dst */
    40                          "	asr	#7,%%d0\n"      /* d0 /= 128 (SDL_MIX_MAXVOLUME) */
    41                          "	add	#128,%%d0\n"    /* d0 += 128 */
    42                          "	add	%%d1,%%d0\n"
    43                          "	moveb	%4@(%%d0:w),%0@+\n"
    44                          /* Loop till done */
    45                          "	subql	#1,%2\n" "	bhis	mixloop_u8\n" "stoploop_u8:\n": /* no return value */
    46                          :      /* input */
    47                          "a"(dst), "a"(src), "d"(len), "d"(volume), "a"(mix8):  /* clobbered registers */
    48                          "d0", "d1", "cc", "memory");
    49 }
    50 
    51 void
    52 SDL_MixAudio_m68k_S8(char *dst, char *src, long len, long volume)
    53 {
    54     __asm__ __volatile__("tstl	%2\n"
    55                          "	beqs	stoploop_s8\n"
    56                          "	moveq	#-128,%%d2\n"
    57                          "	moveq	#127,%%d3\n" "mixloop_s8:\n"
    58                          /* Mix a sample */
    59                          "	moveq	#0,%%d0\n" "	moveq	#0,%%d1\n" "	moveb	%1@+,%%d0\n"    /* d0 = *src++ */
    60                          "	muls	%3,%%d0\n"      /* d0 *= volume (0<=volume<=128) */
    61                          "	moveb	%0@,%%d1\n"     /* d1 = *dst */
    62                          "	asr	#7,%%d0\n"      /* d0 /= 128 (SDL_MIX_MAXVOLUME) */
    63                          "	add	%%d1,%%d0\n"
    64                          "	cmp	%%d2,%%d0\n"
    65                          "	bges	lower_limit_s8\n"
    66                          "	move	%%d2,%%d0\n"
    67                          "lower_limit_s8:\n"
    68                          "	cmp	%%d3,%%d0\n"
    69                          "	bles	upper_limit_s8\n"
    70                          "	move	%%d3,%%d0\n"
    71                          "upper_limit_s8:\n" "	moveb	%%d0,%0@+\n"
    72                          /* Loop till done */
    73                          "	subql	#1,%2\n" "	bhis	mixloop_s8\n" "stoploop_s8:\n": /* no return value */
    74                          :      /* input */
    75                          "a"(dst), "a"(src), "d"(len), "d"(volume):     /* clobbered registers */
    76                          "d0", "d1", "d2", "d3", "cc", "memory");
    77 }
    78 
    79 void
    80 SDL_MixAudio_m68k_S16MSB(short *dst, short *src, long len, long volume)
    81 {
    82     __asm__ __volatile__("tstl	%2\n"
    83                          "	beqs	stoploop_s16msb\n"
    84                          "	movel	#-32768,%%d2\n"
    85                          "	movel	#32767,%%d3\n"
    86                          "	lsrl	#1,%2\n" "mixloop_s16msb:\n"
    87                          /* Mix a sample */
    88                          "	move	%1@+,%%d0\n"    /* d0 = *src++ */
    89                          "	muls	%3,%%d0\n"      /* d0 *= volume (0<=volume<=128) */
    90                          "	move	%0@,%%d1\n"     /* d1 = *dst */
    91                          "	extl	%%d1\n" /* extend d1 to 32 bits */
    92                          "	asrl	#7,%%d0\n"      /* d0 /= 128 (SDL_MIX_MAXVOLUME) */
    93                          "	addl	%%d1,%%d0\n"
    94                          "	cmpl	%%d2,%%d0\n"
    95                          "	bges	lower_limit_s16msb\n"
    96                          "	move	%%d2,%%d0\n"
    97                          "lower_limit_s16msb:\n"
    98                          "	cmpl	%%d3,%%d0\n"
    99                          "	bles	upper_limit_s16msb\n"
   100                          "	move	%%d3,%%d0\n"
   101                          "upper_limit_s16msb:\n" "	move	%%d0,%0@+\n"
   102                          /* Loop till done */
   103                          "	subql	#1,%2\n" "	bhis	mixloop_s16msb\n" "stoploop_s16msb:\n": /* no return value */
   104                          :      /* input */
   105                          "a"(dst), "a"(src), "d"(len), "d"(volume):     /* clobbered registers */
   106                          "d0", "d1", "d2", "d3", "cc", "memory");
   107 }
   108 
   109 void
   110 SDL_MixAudio_m68k_S16LSB(short *dst, short *src, long len, long volume)
   111 {
   112     __asm__ __volatile__("tstl	%2\n"
   113                          "	beqs	stoploop_s16lsb\n"
   114                          "	movel	#-32768,%%d2\n"
   115                          "	movel	#32767,%%d3\n"
   116                          "	lsrl	#1,%2\n" "mixloop_s16lsb:\n"
   117                          /* Mix a sample */
   118                          "	move	%1@+,%%d0\n"    /* d0 = *src++ */
   119                          "	rorw	#8,%%d0\n" "	muls	%3,%%d0\n"      /* d0 *= volume (0<=volume<=128) */
   120                          "	move	%0@,%%d1\n"     /* d1 = *dst */
   121                          "	rorw	#8,%%d1\n" "	extl	%%d1\n" /* extend d1 to 32 bits */
   122                          "	asrl	#7,%%d0\n"      /* d0 /= 128 (SDL_MIX_MAXVOLUME) */
   123                          "	addl	%%d1,%%d0\n"
   124                          "	cmpl	%%d2,%%d0\n"
   125                          "	bges	lower_limit_s16lsb\n"
   126                          "	move	%%d2,%%d0\n"
   127                          "lower_limit_s16lsb:\n"
   128                          "	cmpl	%%d3,%%d0\n"
   129                          "	bles	upper_limit_s16lsb\n"
   130                          "	move	%%d3,%%d0\n"
   131                          "upper_limit_s16lsb:\n"
   132                          "	rorw	#8,%%d0\n" "	move	%%d0,%0@+\n"
   133                          /* Loop till done */
   134                          "	subql	#1,%2\n" "	bhis	mixloop_s16lsb\n" "stoploop_s16lsb:\n": /* no return value */
   135                          :      /* input */
   136                          "a"(dst), "a"(src), "d"(len), "d"(volume):     /* clobbered registers */
   137                          "d0", "d1", "d2", "d3", "cc", "memory");
   138 }
   139 #endif
   140 /* vi: set ts=4 sw=4 expandtab: */