SDL_mixer_MMX.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
// MMX assembler version of SDL_MixAudio for signed little endian 16 bit samples and signed 8 bit samples
// Copyright 2002 Stephane Marchesin (stephane.marchesin@wanadoo.fr)
// This code is licensed under the LGPL (see COPYING for details)
//
// Assumes buffer size in bytes is a multiple of 16
// Assumes SDL_MIX_MAXVOLUME = 128
////////////////////////////////////////////////
// Mixing for 16 bit signed buffers
////////////////////////////////////////////////
#if defined(i386) && defined(__GNUC__) && defined(USE_ASMBLIT)
void SDL_MixAudio_MMX_S16(char* dst,char* src,unsigned int size,int volume)
{
__asm__ __volatile__ (
" movl %0,%%edi\n" // edi = dst
" movl %1,%%esi\n" // esi = src
" movl %3,%%eax\n" // eax = volume
" movl %2,%%ebx\n" // ebx = size
" shrl $4,%%ebx\n" // process 16 bytes per iteration = 8 samples
" jz .endS16\n"
" pxor %%mm0,%%mm0\n"
" movd %%eax,%%mm0\n"
" movq %%mm0,%%mm1\n"
" psllq $16,%%mm0\n"
" por %%mm1,%%mm0\n"
" psllq $16,%%mm0\n"
" por %%mm1,%%mm0\n"
" psllq $16,%%mm0\n"
" por %%mm1,%%mm0\n" // mm0 = vol|vol|vol|vol
".align 16\n"
" .mixloopS16:\n"
" movq (%%esi),%%mm1\n" // mm1 = a|b|c|d
" movq %%mm1,%%mm2\n" // mm2 = a|b|c|d
" movq 8(%%esi),%%mm4\n" // mm4 = e|f|g|h
// pré charger le buffer dst dans mm7
" movq (%%edi),%%mm7\n" // mm7 = dst[0]"
// multiplier par le volume
" pmullw %%mm0,%%mm1\n" // mm1 = l(a*v)|l(b*v)|l(c*v)|l(d*v)
" pmulhw %%mm0,%%mm2\n" // mm2 = h(a*v)|h(b*v)|h(c*v)|h(d*v)
" movq %%mm4,%%mm5\n" // mm5 = e|f|g|h
" pmullw %%mm0,%%mm4\n" // mm4 = l(e*v)|l(f*v)|l(g*v)|l(h*v)
" pmulhw %%mm0,%%mm5\n" // mm5 = h(e*v)|h(f*v)|h(g*v)|h(h*v)
" movq %%mm1,%%mm3\n" // mm3 = l(a*v)|l(b*v)|l(c*v)|l(d*v)
" punpckhwd %%mm2,%%mm1\n" // mm1 = a*v|b*v
" movq %%mm4,%%mm6\n" // mm6 = l(e*v)|l(f*v)|l(g*v)|l(h*v)
" punpcklwd %%mm2,%%mm3\n" // mm3 = c*v|d*v
" punpckhwd %%mm5,%%mm4\n" // mm4 = e*f|f*v
" punpcklwd %%mm5,%%mm6\n" // mm6 = g*v|h*v
// pré charger le buffer dst dans mm5
" movq 8(%%edi),%%mm5\n" // mm5 = dst[1]
// diviser par 128
" psrad $7,%%mm1\n" // mm1 = a*v/128|b*v/128 , 128 = SDL_MIX_MAXVOLUME
" addl $16,%%esi\n"
" psrad $7,%%mm3\n" // mm3 = c*v/128|d*v/128
" psrad $7,%%mm4\n" // mm4 = e*v/128|f*v/128
// mm1 = le sample avec le volume modifié
" packssdw %%mm1,%%mm3\n" // mm3 = s(a*v|b*v|c*v|d*v)
" psrad $7,%%mm6\n" // mm6= g*v/128|h*v/128
" paddsw %%mm7,%%mm3\n" // mm3 = adjust_volume(src)+dst
// mm4 = le sample avec le volume modifié
" packssdw %%mm4,%%mm6\n" // mm6 = s(e*v|f*v|g*v|h*v)
" movq %%mm3,(%%edi)\n"
" paddsw %%mm5,%%mm6\n" // mm6 = adjust_volume(src)+dst
" movq %%mm6,8(%%edi)\n"
" addl $16,%%edi\n"
" dec %%ebx\n"
" jnz .mixloopS16\n"
" emms\n"
".endS16:\n"
:
: "m" (dst), "m"(src),"m"(size),
"m"(volume)
: "eax","ebx", "esi", "edi","memory"
);
}
////////////////////////////////////////////////
// Mixing for 8 bit signed buffers
////////////////////////////////////////////////
void SDL_MixAudio_MMX_S8(char* dst,char* src,unsigned int size,int volume)
{
__asm__ __volatile__ (
" movl %0,%%edi\n" // edi = dst
" movl %1,%%esi\n" // esi = src
" movl %3,%%eax\n" // eax = volume
" movd %%ebx,%%mm0\n"
" movq %%mm0,%%mm1\n"
" psllq $16,%%mm0\n"
" por %%mm1,%%mm0\n"
" psllq $16,%%mm0\n"
" por %%mm1,%%mm0\n"
" psllq $16,%%mm0\n"
" por %%mm1,%%mm0\n"
" movl %2,%%ebx\n" // ebx = size
" shr $3,%%ebx\n" // process 8 bytes per iteration = 8 samples
" cmp $0,%%ebx\n"
" je .endS8\n"
".align 16\n"
" .mixloopS8:\n"
" pxor %%mm2,%%mm2\n" // mm2 = 0
" movq (%%esi),%%mm1\n" // mm1 = a|b|c|d|e|f|g|h
" movq %%mm1,%%mm3\n" // mm3 = a|b|c|d|e|f|g|h
// on va faire le "sign extension" en faisant un cmp avec 0 qui retourne 1 si <0, 0 si >0
" pcmpgtb %%mm1,%%mm2\n" // mm2 = 11111111|00000000|00000000....
" punpckhbw %%mm2,%%mm1\n" // mm1 = 0|a|0|b|0|c|0|d
" punpcklbw %%mm2,%%mm3\n" // mm3 = 0|e|0|f|0|g|0|h
" movq (%%edi),%%mm2\n" // mm2 = destination
" pmullw %%mm0,%%mm1\n" // mm1 = v*a|v*b|v*c|v*d
" addl $8,%%esi\n"
" pmullw %%mm0,%%mm3\n" // mm3 = v*e|v*f|v*g|v*h
" psraw $7,%%mm1\n" // mm1 = v*a/128|v*b/128|v*c/128|v*d/128
" psraw $7,%%mm3\n" // mm3 = v*e/128|v*f/128|v*g/128|v*h/128
" packsswb %%mm1,%%mm3\n" // mm1 = v*a/128|v*b/128|v*c/128|v*d/128|v*e/128|v*f/128|v*g/128|v*h/128
" paddsb %%mm2,%%mm3\n" // add to destination buffer
" movq %%mm3,(%%edi)\n" // store back to ram
" addl $8,%%edi\n"
" dec %%ebx\n"
" jnz .mixloopS8\n"
".endS8:\n"
" emms\n"
:
: "m" (dst), "m"(src),"m"(size),
"m"(volume)
: "eax","ebx", "esi", "edi","memory"
);
}
#endif