SDL: src/audio/SDL_mixer_m68k.c@c121d94672cb

     1 /*

     2     SDL - Simple DirectMedia Layer

     3     Copyright (C) 1997-2004 Sam Lantinga

     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.

    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.

    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

    19     Sam Lantinga

    20     slouken@libsdl.org

    21 */

    22 #include "SDL_config.h"

    24 /*

    25 	m68k assembly mix routines

    27 	Patrice Mandin

    28 */

    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 }

    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 }

    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 }

   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: */

author	Sam Lantinga <slouken@libsdl.org>
	Mon, 10 Jul 2006 21:04:37 +0000
changeset 1895	c121d94672cb
parent 1402	d910939febfa
child 2859	99210400e8b9
permissions	-rw-r--r--