e779402d53
Just make this call BUG_WARN(1) to indicate that something unexpected happened Signed-off-by: Keith Packard <keithp@keithp.com>
187 lines
4.2 KiB
C
187 lines
4.2 KiB
C
/*
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* Fast C2P (Chunky-to-Planar) Conversion
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*
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* Copyright (C) 2003-2008 Geert Uytterhoeven
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*
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* NOTES:
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* - This code was inspired by Scout's C2P tutorial
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* - It assumes to run on a big endian system
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*
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* Permission to use, copy, modify, distribute, and sell this software and its
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* documentation for any purpose is hereby granted without fee, provided that
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* the above copyright notice appear in all copies and that both that
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* copyright notice and this permission notice appear in supporting
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* documentation, and that the name of Geert Uytterhoeven not be used in
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* advertising or publicity pertaining to distribution of the software without
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* specific, written prior permission. Geert Uytterhoeven makes no
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* representations about the suitability of this software for any purpose. It
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* is provided "as is" without express or implied warranty.
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*
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* GEERT UYTTERHOEVEN DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
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* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
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* EVENT SHALL GEERT UYTTERHOEVEN BE LIABLE FOR ANY SPECIAL, INDIRECT OR
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* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
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* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
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* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
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* PERFORMANCE OF THIS SOFTWARE.
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*/
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/*
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* Basic transpose step
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*/
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static inline void _transp(CARD32 d[], unsigned int i1, unsigned int i2,
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unsigned int shift, CARD32 mask)
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{
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CARD32 t = (d[i1] ^ (d[i2] >> shift)) & mask;
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d[i1] ^= t;
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d[i2] ^= t << shift;
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}
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static inline void c2p_unsupported(void) {
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BUG_WARN(1);
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}
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static inline CARD32 get_mask(unsigned int n)
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{
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switch (n) {
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case 1:
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return 0x55555555;
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case 2:
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return 0x33333333;
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case 4:
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return 0x0f0f0f0f;
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case 8:
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return 0x00ff00ff;
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case 16:
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return 0x0000ffff;
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}
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c2p_unsupported();
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return 0;
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}
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/*
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* Transpose operations on 8 32-bit words
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*/
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static inline void transp8(CARD32 d[], unsigned int n, unsigned int m)
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{
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CARD32 mask = get_mask(n);
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switch (m) {
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case 1:
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/* First n x 1 block */
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_transp(d, 0, 1, n, mask);
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/* Second n x 1 block */
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_transp(d, 2, 3, n, mask);
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/* Third n x 1 block */
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_transp(d, 4, 5, n, mask);
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/* Fourth n x 1 block */
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_transp(d, 6, 7, n, mask);
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return;
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case 2:
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/* First n x 2 block */
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_transp(d, 0, 2, n, mask);
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_transp(d, 1, 3, n, mask);
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/* Second n x 2 block */
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_transp(d, 4, 6, n, mask);
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_transp(d, 5, 7, n, mask);
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return;
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case 4:
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/* Single n x 4 block */
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_transp(d, 0, 4, n, mask);
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_transp(d, 1, 5, n, mask);
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_transp(d, 2, 6, n, mask);
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_transp(d, 3, 7, n, mask);
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return;
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}
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c2p_unsupported();
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}
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/*
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* Transpose operations on 4 32-bit words
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*/
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static inline void transp4(CARD32 d[], unsigned int n, unsigned int m)
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{
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CARD32 mask = get_mask(n);
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switch (m) {
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case 1:
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/* First n x 1 block */
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_transp(d, 0, 1, n, mask);
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/* Second n x 1 block */
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_transp(d, 2, 3, n, mask);
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return;
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case 2:
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/* Single n x 2 block */
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_transp(d, 0, 2, n, mask);
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_transp(d, 1, 3, n, mask);
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return;
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}
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c2p_unsupported();
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}
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/*
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* Transpose operations on 4 32-bit words (reverse order)
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*/
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static inline void transp4x(CARD32 d[], unsigned int n, unsigned int m)
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{
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CARD32 mask = get_mask(n);
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switch (m) {
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case 2:
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/* Single n x 2 block */
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_transp(d, 2, 0, n, mask);
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_transp(d, 3, 1, n, mask);
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return;
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}
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c2p_unsupported();
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}
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/*
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* Transpose operations on 2 32-bit words
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*/
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static inline void transp2(CARD32 d[], unsigned int n)
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{
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CARD32 mask = get_mask(n);
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/* Single n x 1 block */
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_transp(d, 0, 1, n, mask);
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return;
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}
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/*
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* Transpose operations on 2 32-bit words (reverse order)
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*/
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static inline void transp2x(CARD32 d[], unsigned int n)
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{
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CARD32 mask = get_mask(n);
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/* Single n x 1 block */
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_transp(d, 1, 0, n, mask);
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return;
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}
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