Annotation of sys/dev/rasops/rasops_masks.h, Revision 1.1.1.1
1.1 nbrk 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_ */
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