1 /*
2 * Copyright 2003-2007 Marcus Overhagen
3 * Copyright 2007 Haiku Inc. All rights reserved.
4 * Distributed under the terms of the MIT License.
5 */
6
7
8 #include "ByteSwap.h"
9
10 #include <ByteOrder.h>
11 #include <MediaDefs.h>
12
13 #include "MixerDebug.h"
14
15
16 static void swap_float(void *buffer, size_t bytecount);
17 static void swap_int32(void *buffer, size_t bytecount);
18 static void swap_int16(void *buffer, size_t bytecount);
19 static void do_nothing(void *buffer, size_t bytecount);
20
21
ByteSwap(uint32 format)22 ByteSwap::ByteSwap(uint32 format)
23 {
24 switch (format) {
25 case media_raw_audio_format::B_AUDIO_FLOAT:
26 fFunc = &swap_float;
27 break;
28 case media_raw_audio_format::B_AUDIO_INT:
29 fFunc = &swap_int32;
30 break;
31 case media_raw_audio_format::B_AUDIO_SHORT:
32 fFunc = &swap_int16;
33 break;
34 default:
35 fFunc = &do_nothing;
36 break;
37 }
38 }
39
40
~ByteSwap()41 ByteSwap::~ByteSwap()
42 {
43 }
44
45
46 void
do_nothing(void * buffer,size_t bytecount)47 do_nothing(void *buffer, size_t bytecount)
48 {
49 }
50
51
52 #if __i386__
53 // #pragma mark - optimized for IA32 platform
54
55
56 void
swap_float(void * buffer,size_t bytecount)57 swap_float(void *buffer, size_t bytecount)
58 {
59 // XXX Should be optimized
60 swap_data(B_FLOAT_TYPE, buffer, bytecount, B_SWAP_ALWAYS);
61 }
62
63
64 void
swap_int32(void * buffer,size_t bytecount)65 swap_int32(void *buffer, size_t bytecount)
66 {
67 // XXX Should be optimized
68 swap_data(B_INT32_TYPE, buffer, bytecount, B_SWAP_ALWAYS);
69 }
70
71
72 void
swap_int16(void * buffer,size_t bytecount)73 swap_int16(void *buffer, size_t bytecount)
74 {
75 // GCC FAQ: To write an asm which modifies an input operand but does
76 // not output anything usable, specify that operand as an
77 // output operand outputting to an unused dummy variable.
78 uint32 dummy1;
79 uint32 dummy2;
80 // GCC is way too smart and will remove the complete asm statement
81 // if we do not specify it as __volatile__. Don't remove that!
82 __asm__ __volatile__ (
83 "pushl %%ebx \n\t"
84 "movl %%eax, %%ebx \n\t"
85 "movl %%edx, %%eax \n\t"
86 "andl $0xFFFFFFE0,%%eax \n\t"
87 "pushl %%eax \n\t"
88 ".L_swap_loop: \n\t"
89 "rolw $8,-32(%%ebx,%%eax) \n\t"
90 "rolw $8,-30(%%ebx,%%eax) \n\t"
91 "rolw $8,-28(%%ebx,%%eax) \n\t"
92 "rolw $8,-26(%%ebx,%%eax) \n\t"
93 "rolw $8,-24(%%ebx,%%eax) \n\t"
94 "rolw $8,-22(%%ebx,%%eax) \n\t"
95 "rolw $8,-20(%%ebx,%%eax) \n\t"
96 "rolw $8,-18(%%ebx,%%eax) \n\t"
97 "rolw $8,-16(%%ebx,%%eax) \n\t"
98 "rolw $8,-14(%%ebx,%%eax) \n\t"
99 "rolw $8,-12(%%ebx,%%eax) \n\t"
100 "rolw $8,-10(%%ebx,%%eax) \n\t"
101 "rolw $8,-8(%%ebx,%%eax) \n\t"
102 "rolw $8,-6(%%ebx,%%eax) \n\t"
103 "rolw $8,-4(%%ebx,%%eax) \n\t"
104 "rolw $8,-2(%%ebx,%%eax) \n\t"
105 "subl $32,%%eax \n\t"
106 "jnz .L_swap_loop \n\t"
107 "popl %%eax \n\t"
108 "addl %%eax,%%ebx \n\t"
109 "andl $0x1F,%%edx \n\t"
110 "jz .L_swap_end \n\t"
111 "addl %%ebx, %%edx \n\t"
112 ".L_swap_loop_2: \n\t"
113 "rolw $8,(%%ebx) \n\t"
114 "addl $2,%%ebx \n\t"
115 "cmpl %%edx,%%ebx \n\t"
116 "jne .L_swap_loop_2 \n\t"
117 ".L_swap_end: \n\t"
118 "popl %%ebx \n\t"
119 : "=a" (dummy1), "=d" (dummy2)
120 : "d" (bytecount), "a" (buffer)
121 : "cc", "memory");
122 }
123
124
125 #else // !__i386__
126 // #pragma mark - generic versions
127
128
129 void
swap_float(void * buffer,size_t bytecount)130 swap_float(void *buffer, size_t bytecount)
131 {
132 swap_data(B_FLOAT_TYPE, buffer, bytecount, B_SWAP_ALWAYS);
133 }
134
135
136 void
swap_int32(void * buffer,size_t bytecount)137 swap_int32(void *buffer, size_t bytecount)
138 {
139 swap_data(B_INT32_TYPE, buffer, bytecount, B_SWAP_ALWAYS);
140 }
141
142
143 void
swap_int16(void * buffer,size_t bytecount)144 swap_int16(void *buffer, size_t bytecount)
145 {
146 swap_data(B_INT16_TYPE, buffer, bytecount, B_SWAP_ALWAYS);
147 }
148
149
150 #endif
151