Commit | Line | Data |
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a09e091a JB |
1 | /* |
2 | * Fast C2P (Chunky-to-Planar) Conversion | |
3 | * | |
4 | * NOTES: | |
5 | * - This code was inspired by Scout's C2P tutorial | |
6 | * - It assumes to run on a big endian system | |
7 | * | |
8 | * Copyright © 2003-2008 Geert Uytterhoeven | |
9 | * | |
10 | * Permission is hereby granted, free of charge, to any person obtaining a | |
11 | * copy of this software and associated documentation files (the "Software"), | |
12 | * to deal in the Software without restriction, including without limitation | |
13 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
14 | * and/or sell copies of the Software, and to permit persons to whom the | |
15 | * Software is furnished to do so, subject to the following conditions: | |
16 | * | |
17 | * The above copyright notice and this permission notice (including the next | |
18 | * paragraph) shall be included in all copies or substantial portions of the | |
19 | * Software. | |
20 | * | |
21 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
22 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
23 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
24 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
25 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
26 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER | |
27 | * DEALINGS IN THE SOFTWARE. | |
28 | */ | |
29 | ||
30 | ||
31 | /* | |
32 | * Basic transpose step | |
33 | */ | |
34 | ||
35 | static inline void _transp(CARD32 d[], unsigned int i1, unsigned int i2, | |
36 | unsigned int shift, CARD32 mask) | |
37 | { | |
38 | CARD32 t = (d[i1] ^ (d[i2] >> shift)) & mask; | |
39 | ||
40 | d[i1] ^= t; | |
41 | d[i2] ^= t << shift; | |
42 | } | |
43 | ||
44 | ||
45 | static inline void c2p_unsupported(void) { | |
46 | BUG_WARN(1); | |
47 | } | |
48 | ||
49 | static inline CARD32 get_mask(unsigned int n) | |
50 | { | |
51 | switch (n) { | |
52 | case 1: | |
53 | return 0x55555555; | |
54 | ||
55 | case 2: | |
56 | return 0x33333333; | |
57 | ||
58 | case 4: | |
59 | return 0x0f0f0f0f; | |
60 | ||
61 | case 8: | |
62 | return 0x00ff00ff; | |
63 | ||
64 | case 16: | |
65 | return 0x0000ffff; | |
66 | } | |
67 | ||
68 | c2p_unsupported(); | |
69 | return 0; | |
70 | } | |
71 | ||
72 | ||
73 | /* | |
74 | * Transpose operations on 8 32-bit words | |
75 | */ | |
76 | ||
77 | static inline void transp8(CARD32 d[], unsigned int n, unsigned int m) | |
78 | { | |
79 | CARD32 mask = get_mask(n); | |
80 | ||
81 | switch (m) { | |
82 | case 1: | |
83 | /* First n x 1 block */ | |
84 | _transp(d, 0, 1, n, mask); | |
85 | /* Second n x 1 block */ | |
86 | _transp(d, 2, 3, n, mask); | |
87 | /* Third n x 1 block */ | |
88 | _transp(d, 4, 5, n, mask); | |
89 | /* Fourth n x 1 block */ | |
90 | _transp(d, 6, 7, n, mask); | |
91 | return; | |
92 | ||
93 | case 2: | |
94 | /* First n x 2 block */ | |
95 | _transp(d, 0, 2, n, mask); | |
96 | _transp(d, 1, 3, n, mask); | |
97 | /* Second n x 2 block */ | |
98 | _transp(d, 4, 6, n, mask); | |
99 | _transp(d, 5, 7, n, mask); | |
100 | return; | |
101 | ||
102 | case 4: | |
103 | /* Single n x 4 block */ | |
104 | _transp(d, 0, 4, n, mask); | |
105 | _transp(d, 1, 5, n, mask); | |
106 | _transp(d, 2, 6, n, mask); | |
107 | _transp(d, 3, 7, n, mask); | |
108 | return; | |
109 | } | |
110 | ||
111 | c2p_unsupported(); | |
112 | } | |
113 | ||
114 | ||
115 | /* | |
116 | * Transpose operations on 4 32-bit words | |
117 | */ | |
118 | ||
119 | static inline void transp4(CARD32 d[], unsigned int n, unsigned int m) | |
120 | { | |
121 | CARD32 mask = get_mask(n); | |
122 | ||
123 | switch (m) { | |
124 | case 1: | |
125 | /* First n x 1 block */ | |
126 | _transp(d, 0, 1, n, mask); | |
127 | /* Second n x 1 block */ | |
128 | _transp(d, 2, 3, n, mask); | |
129 | return; | |
130 | ||
131 | case 2: | |
132 | /* Single n x 2 block */ | |
133 | _transp(d, 0, 2, n, mask); | |
134 | _transp(d, 1, 3, n, mask); | |
135 | return; | |
136 | } | |
137 | ||
138 | c2p_unsupported(); | |
139 | } | |
140 | ||
141 | ||
142 | /* | |
143 | * Transpose operations on 4 32-bit words (reverse order) | |
144 | */ | |
145 | ||
146 | static inline void transp4x(CARD32 d[], unsigned int n, unsigned int m) | |
147 | { | |
148 | CARD32 mask = get_mask(n); | |
149 | ||
150 | switch (m) { | |
151 | case 2: | |
152 | /* Single n x 2 block */ | |
153 | _transp(d, 2, 0, n, mask); | |
154 | _transp(d, 3, 1, n, mask); | |
155 | return; | |
156 | } | |
157 | ||
158 | c2p_unsupported(); | |
159 | } | |
160 | ||
161 | ||
162 | /* | |
163 | * Transpose operations on 2 32-bit words | |
164 | */ | |
165 | ||
166 | static inline void transp2(CARD32 d[], unsigned int n) | |
167 | { | |
168 | CARD32 mask = get_mask(n); | |
169 | ||
170 | /* Single n x 1 block */ | |
171 | _transp(d, 0, 1, n, mask); | |
172 | return; | |
173 | } | |
174 | ||
175 | ||
176 | /* | |
177 | * Transpose operations on 2 32-bit words (reverse order) | |
178 | */ | |
179 | ||
180 | static inline void transp2x(CARD32 d[], unsigned int n) | |
181 | { | |
182 | CARD32 mask = get_mask(n); | |
183 | ||
184 | /* Single n x 1 block */ | |
185 | _transp(d, 1, 0, n, mask); | |
186 | return; | |
187 | } |