1 /* $OpenBSD: rasops_masks.h,v 1.3 2006/08/04 06:28:10 miod Exp $ */
2 /* $NetBSD: rasops_masks.h,v 1.5 2000/06/13 13:37:01 ad Exp $ */
3
4 /*-
5 * Copyright (c) 1999 The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Andrew Doran.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40 #ifndef _RASOPS_MASKS_H_
41 #define _RASOPS_MASKS_H_ 1
42
43 #include <sys/types.h>
44 #include <machine/endian.h>
45
46 /*
47 * Convenience macros. To get around the problem of dealing with properly
48 * ordered bits on little-endian machines, we just convert everything to
49 * big-endian and back again when we're done.
50 *
51 * MBL: move bits left
52 * MBR: move bits right
53 * MBE: make big-endian
54 */
55
56 #define MBL(x,y) ((y) > 31 ? 0 : (x) >> (y))
57 #define MBR(x,y) ((y) > 31 ? 0 : (x) << (y))
58
59 #if BYTE_ORDER == BIG_ENDIAN
60 #define MBE(x) (x)
61 #else
62 #define MBE(x) \
63 ({ \
64 u_int32_t tmp = (x); \
65 tmp = ((tmp >> 1) & 0x55555555) | ((tmp << 1) & 0xaaaaaaaa); \
66 tmp = ((tmp >> 2) & 0x33333333) | ((tmp << 2) & 0xcccccccc); \
67 tmp = ((tmp >> 4) & 0x0f0f0f0f) | ((tmp << 4) & 0xf0f0f0f0); \
68 tmp = ((tmp >> 8) & 0x00ff00ff) | ((tmp << 8) & 0xff00ff00); \
69 tmp = ((tmp >> 16) & 0x0000ffff) | ((tmp << 16) & 0xffff0000); \
70 tmp; \
71 })
72 #endif
73
74 /*
75 * Using GETBITS() and PUTBITS() inside a loop mightn't be such a good idea.
76 * There's probably some CSE and strength-reduction that the compiler won't
77 * even think about - really should have a few assumptions/separate cases.
78 */
79
80 /* Get a number of bits ( <= 32 ) from *sp and store in dw */
81 #define GETBITS(sp, x, w, dw) do { \
82 dw = MBL(*(sp), (x)); \
83 if (((x) + (w)) > 32) \
84 dw |= (MBR((sp)[1], 32 - (x))); \
85 } while(0);
86
87 /* Put a number of bits ( <= 32 ) from sw to *dp */
88 #define PUTBITS(sw, x, w, dp) do { \
89 int n = (x) + (w) - 32; \
90 \
91 if (n <= 0) { \
92 n = rasops_pmask[x & 31][w & 31]; \
93 *(dp) = (*(dp) & ~n) | (MBR(sw, x) & n); \
94 } else { \
95 *(dp) = (*(dp) & rasops_rmask[x]) | (MBR((sw), x)); \
96 (dp)[1] = ((dp)[1] & rasops_rmask[n]) | \
97 (MBL(sw, 32-(x)) & rasops_lmask[n]); \
98 } \
99 } while(0);
100
101 /* rasops_masks.c */
102 #if BYTE_ORDER == BIG_ENDIAN
103 extern const int32_t rasops_lmask[32+1];
104 extern const int32_t rasops_rmask[32+1];
105 extern const int32_t rasops_pmask[32][32];
106 #define rasops_masks_init() do { } while (0)
107 #else
108 extern int32_t rasops_lmask[32+1];
109 extern int32_t rasops_rmask[32+1];
110 extern int32_t rasops_pmask[32][32];
111 void rasops_masks_init(void);
112 #endif
113
114 #endif /* _RASOPS_MASKS_H_ */