/
SDL_mixer_m68k.c
210 lines (162 loc) · 4.53 KB
/
SDL_mixer_m68k.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
/*
SDL - Simple DirectMedia Layer
Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 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
*/
/*
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