| 1 | /* |
| 2 | SDL - Simple DirectMedia Layer |
| 3 | Copyright (C) 1997-2009 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 SDL_MixAudio_m68k_U8(char* dst, char* src, long len, long volume, char* mix8) |
| 32 | { |
| 33 | __asm__ __volatile__ ( |
| 34 | |
| 35 | "tstl %2\n" |
| 36 | " beqs stoploop_u8\n" |
| 37 | "mixloop_u8:\n" |
| 38 | |
| 39 | /* Mix a sample */ |
| 40 | |
| 41 | " moveq #0,%%d0\n" |
| 42 | " moveq #0,%%d1\n" |
| 43 | |
| 44 | " moveb %1@+,%%d0\n" /* d0 = *src++ */ |
| 45 | " sub #128,%%d0\n" /* d0 -= 128 */ |
| 46 | " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ |
| 47 | " moveb %0@,%%d1\n" /* d1 = *dst */ |
| 48 | " asr #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ |
| 49 | " add #128,%%d0\n" /* d0 += 128 */ |
| 50 | |
| 51 | " add %%d1,%%d0\n" |
| 52 | |
| 53 | " moveb %4@(%%d0:w),%0@+\n" |
| 54 | |
| 55 | /* Loop till done */ |
| 56 | |
| 57 | " subql #1,%2\n" |
| 58 | " bhis mixloop_u8\n" |
| 59 | "stoploop_u8:\n" |
| 60 | |
| 61 | : /* no return value */ |
| 62 | : /* input */ |
| 63 | "a"(dst), "a"(src), "d"(len), "d"(volume), "a"(mix8) |
| 64 | : /* clobbered registers */ |
| 65 | "d0", "d1", "cc", "memory" |
| 66 | ); |
| 67 | } |
| 68 | |
| 69 | void SDL_MixAudio_m68k_S8(char* dst, char* src, long len, long volume) |
| 70 | { |
| 71 | __asm__ __volatile__ ( |
| 72 | |
| 73 | "tstl %2\n" |
| 74 | " beqs stoploop_s8\n" |
| 75 | " moveq #-128,%%d2\n" |
| 76 | " moveq #127,%%d3\n" |
| 77 | "mixloop_s8:\n" |
| 78 | |
| 79 | /* Mix a sample */ |
| 80 | |
| 81 | " moveq #0,%%d0\n" |
| 82 | " moveq #0,%%d1\n" |
| 83 | |
| 84 | " moveb %1@+,%%d0\n" /* d0 = *src++ */ |
| 85 | " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ |
| 86 | " moveb %0@,%%d1\n" /* d1 = *dst */ |
| 87 | " asr #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ |
| 88 | |
| 89 | " add %%d1,%%d0\n" |
| 90 | |
| 91 | " cmp %%d2,%%d0\n" |
| 92 | " bges lower_limit_s8\n" |
| 93 | " move %%d2,%%d0\n" |
| 94 | "lower_limit_s8:\n" |
| 95 | |
| 96 | " cmp %%d3,%%d0\n" |
| 97 | " bles upper_limit_s8\n" |
| 98 | " move %%d3,%%d0\n" |
| 99 | "upper_limit_s8:\n" |
| 100 | " moveb %%d0,%0@+\n" |
| 101 | |
| 102 | /* Loop till done */ |
| 103 | |
| 104 | " subql #1,%2\n" |
| 105 | " bhis mixloop_s8\n" |
| 106 | "stoploop_s8:\n" |
| 107 | |
| 108 | : /* no return value */ |
| 109 | : /* input */ |
| 110 | "a"(dst), "a"(src), "d"(len), "d"(volume) |
| 111 | : /* clobbered registers */ |
| 112 | "d0", "d1", "d2", "d3", "cc", "memory" |
| 113 | ); |
| 114 | } |
| 115 | |
| 116 | void SDL_MixAudio_m68k_S16MSB(short* dst, short* src, long len, long volume) |
| 117 | { |
| 118 | __asm__ __volatile__ ( |
| 119 | |
| 120 | "tstl %2\n" |
| 121 | " beqs stoploop_s16msb\n" |
| 122 | " movel #-32768,%%d2\n" |
| 123 | " movel #32767,%%d3\n" |
| 124 | " lsrl #1,%2\n" |
| 125 | "mixloop_s16msb:\n" |
| 126 | |
| 127 | /* Mix a sample */ |
| 128 | |
| 129 | " move %1@+,%%d0\n" /* d0 = *src++ */ |
| 130 | " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ |
| 131 | " move %0@,%%d1\n" /* d1 = *dst */ |
| 132 | " extl %%d1\n" /* extend d1 to 32 bits */ |
| 133 | " asrl #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ |
| 134 | |
| 135 | " addl %%d1,%%d0\n" |
| 136 | |
| 137 | " cmpl %%d2,%%d0\n" |
| 138 | " bges lower_limit_s16msb\n" |
| 139 | " move %%d2,%%d0\n" |
| 140 | "lower_limit_s16msb:\n" |
| 141 | |
| 142 | " cmpl %%d3,%%d0\n" |
| 143 | " bles upper_limit_s16msb\n" |
| 144 | " move %%d3,%%d0\n" |
| 145 | "upper_limit_s16msb:\n" |
| 146 | " move %%d0,%0@+\n" |
| 147 | |
| 148 | /* Loop till done */ |
| 149 | |
| 150 | " subql #1,%2\n" |
| 151 | " bhis mixloop_s16msb\n" |
| 152 | "stoploop_s16msb:\n" |
| 153 | |
| 154 | : /* no return value */ |
| 155 | : /* input */ |
| 156 | "a"(dst), "a"(src), "d"(len), "d"(volume) |
| 157 | : /* clobbered registers */ |
| 158 | "d0", "d1", "d2", "d3", "cc", "memory" |
| 159 | ); |
| 160 | } |
| 161 | |
| 162 | void SDL_MixAudio_m68k_S16LSB(short* dst, short* src, long len, long volume) |
| 163 | { |
| 164 | __asm__ __volatile__ ( |
| 165 | |
| 166 | "tstl %2\n" |
| 167 | " beqs stoploop_s16lsb\n" |
| 168 | " movel #-32768,%%d2\n" |
| 169 | " movel #32767,%%d3\n" |
| 170 | " lsrl #1,%2\n" |
| 171 | "mixloop_s16lsb:\n" |
| 172 | |
| 173 | /* Mix a sample */ |
| 174 | |
| 175 | " move %1@+,%%d0\n" /* d0 = *src++ */ |
| 176 | " rorw #8,%%d0\n" |
| 177 | " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ |
| 178 | " move %0@,%%d1\n" /* d1 = *dst */ |
| 179 | " rorw #8,%%d1\n" |
| 180 | " extl %%d1\n" /* extend d1 to 32 bits */ |
| 181 | " asrl #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ |
| 182 | |
| 183 | " addl %%d1,%%d0\n" |
| 184 | |
| 185 | " cmpl %%d2,%%d0\n" |
| 186 | " bges lower_limit_s16lsb\n" |
| 187 | " move %%d2,%%d0\n" |
| 188 | "lower_limit_s16lsb:\n" |
| 189 | |
| 190 | " cmpl %%d3,%%d0\n" |
| 191 | " bles upper_limit_s16lsb\n" |
| 192 | " move %%d3,%%d0\n" |
| 193 | "upper_limit_s16lsb:\n" |
| 194 | " rorw #8,%%d0\n" |
| 195 | " move %%d0,%0@+\n" |
| 196 | |
| 197 | /* Loop till done */ |
| 198 | |
| 199 | " subql #1,%2\n" |
| 200 | " bhis mixloop_s16lsb\n" |
| 201 | "stoploop_s16lsb:\n" |
| 202 | |
| 203 | : /* no return value */ |
| 204 | : /* input */ |
| 205 | "a"(dst), "a"(src), "d"(len), "d"(volume) |
| 206 | : /* clobbered registers */ |
| 207 | "d0", "d1", "d2", "d3", "cc", "memory" |
| 208 | ); |
| 209 | } |
| 210 | #endif |
| 211 | |