e14743d1 |
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 | |