Mercurial > sdl-ios-xcode
view src/audio/SDL_mixer_m68k.c @ 4283:cd511a8560b7 SDL-1.2
Ozkan Sezer 2009-04-01 23:17:13 PDT
This change should be applied to the 1.2 branch, too, because the svn version
SDL_net requires it.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Thu, 08 Oct 2009 07:45:55 +0000 |
parents | a1b03ba2fcd0 |
children | 124629b76853 |
line wrap: on
line source
/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2009 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" /* m68k assembly mix routines Patrice Mandin */ #if defined(__M68000__) && defined(__GNUC__) void SDL_MixAudio_m68k_U8(char* dst, char* src, long len, long volume, char* mix8) { __asm__ __volatile__ ( "tstl %2\n" " beqs stoploop_u8\n" "mixloop_u8:\n" /* Mix a sample */ " moveq #0,%%d0\n" " moveq #0,%%d1\n" " moveb %1@+,%%d0\n" /* d0 = *src++ */ " sub #128,%%d0\n" /* d0 -= 128 */ " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ " moveb %0@,%%d1\n" /* d1 = *dst */ " asr #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ " add #128,%%d0\n" /* d0 += 128 */ " add %%d1,%%d0\n" " moveb %4@(%%d0:w),%0@+\n" /* Loop till done */ " subql #1,%2\n" " bhis mixloop_u8\n" "stoploop_u8:\n" : /* no return value */ : /* input */ "a"(dst), "a"(src), "d"(len), "d"(volume), "a"(mix8) : /* clobbered registers */ "d0", "d1", "cc", "memory" ); } void SDL_MixAudio_m68k_S8(char* dst, char* src, long len, long volume) { __asm__ __volatile__ ( "tstl %2\n" " beqs stoploop_s8\n" " moveq #-128,%%d2\n" " moveq #127,%%d3\n" "mixloop_s8:\n" /* Mix a sample */ " moveq #0,%%d0\n" " moveq #0,%%d1\n" " moveb %1@+,%%d0\n" /* d0 = *src++ */ " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ " moveb %0@,%%d1\n" /* d1 = *dst */ " asr #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ " add %%d1,%%d0\n" " cmp %%d2,%%d0\n" " bges lower_limit_s8\n" " move %%d2,%%d0\n" "lower_limit_s8:\n" " cmp %%d3,%%d0\n" " bles upper_limit_s8\n" " move %%d3,%%d0\n" "upper_limit_s8:\n" " moveb %%d0,%0@+\n" /* Loop till done */ " subql #1,%2\n" " bhis mixloop_s8\n" "stoploop_s8:\n" : /* no return value */ : /* input */ "a"(dst), "a"(src), "d"(len), "d"(volume) : /* clobbered registers */ "d0", "d1", "d2", "d3", "cc", "memory" ); } void SDL_MixAudio_m68k_S16MSB(short* dst, short* src, long len, long volume) { __asm__ __volatile__ ( "tstl %2\n" " beqs stoploop_s16msb\n" " movel #-32768,%%d2\n" " movel #32767,%%d3\n" " lsrl #1,%2\n" "mixloop_s16msb:\n" /* Mix a sample */ " move %1@+,%%d0\n" /* d0 = *src++ */ " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ " move %0@,%%d1\n" /* d1 = *dst */ " extl %%d1\n" /* extend d1 to 32 bits */ " asrl #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ " addl %%d1,%%d0\n" " cmpl %%d2,%%d0\n" " bges lower_limit_s16msb\n" " move %%d2,%%d0\n" "lower_limit_s16msb:\n" " cmpl %%d3,%%d0\n" " bles upper_limit_s16msb\n" " move %%d3,%%d0\n" "upper_limit_s16msb:\n" " move %%d0,%0@+\n" /* Loop till done */ " subql #1,%2\n" " bhis mixloop_s16msb\n" "stoploop_s16msb:\n" : /* no return value */ : /* input */ "a"(dst), "a"(src), "d"(len), "d"(volume) : /* clobbered registers */ "d0", "d1", "d2", "d3", "cc", "memory" ); } void SDL_MixAudio_m68k_S16LSB(short* dst, short* src, long len, long volume) { __asm__ __volatile__ ( "tstl %2\n" " beqs stoploop_s16lsb\n" " movel #-32768,%%d2\n" " movel #32767,%%d3\n" " lsrl #1,%2\n" "mixloop_s16lsb:\n" /* Mix a sample */ " move %1@+,%%d0\n" /* d0 = *src++ */ " rorw #8,%%d0\n" " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ " move %0@,%%d1\n" /* d1 = *dst */ " rorw #8,%%d1\n" " extl %%d1\n" /* extend d1 to 32 bits */ " asrl #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ " addl %%d1,%%d0\n" " cmpl %%d2,%%d0\n" " bges lower_limit_s16lsb\n" " move %%d2,%%d0\n" "lower_limit_s16lsb:\n" " cmpl %%d3,%%d0\n" " bles upper_limit_s16lsb\n" " move %%d3,%%d0\n" "upper_limit_s16lsb:\n" " rorw #8,%%d0\n" " move %%d0,%0@+\n" /* Loop till done */ " subql #1,%2\n" " bhis mixloop_s16lsb\n" "stoploop_s16lsb:\n" : /* no return value */ : /* input */ "a"(dst), "a"(src), "d"(len), "d"(volume) : /* clobbered registers */ "d0", "d1", "d2", "d3", "cc", "memory" ); } #endif