1/* $NetBSD: rasops_masks.h,v 1.8 2013/12/02 14:05:51 tsutsui Exp $ */
2
3/*-
4 * Copyright (c) 1999 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Andrew Doran.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#ifndef _RASOPS_MASKS_H_
33#define _RASOPS_MASKS_H_ 1
34
35#include <sys/types.h>
36#include <machine/endian.h>
37
38/*
39 * Convenience macros. To get around the problem of dealing with properly
40 * ordered bits on little-endian machines, we just convert everything to
41 * big-endian and back again when we're done.
42 *
43 * MBL: move bits left
44 * MBR: move bits right
45 * MBE: make big-endian
46 */
47#if BYTE_ORDER == BIG_ENDIAN
48
49#define MBL(x,y) ((y) > 31 ? 0 : (x) << (y))
50#define MBR(x,y) ((y) > 31 ? 0 : (x) >> (y))
51#define MBE(x) (x)
52
53#else
54
55#define MBL(x,y) ((y) > 31 ? 0 : MBE(MBE(x) << (y)))
56#define MBR(x,y) ((y) > 31 ? 0 : MBE(MBE(x) >> (y)))
57#define MBE(x) ( (((x) & 0x000000FFU) << 24) \
58 | (((x) & 0x0000FF00U) << 8) \
59 | (((x) & 0x00FF0000U) >> 8) \
60 | (((x) & 0xFF000000U) >> 24) )
61#endif
62
63/*
64 * Using GETBITS() and PUTBITS() inside a loop mightn't be such a good idea.
65 * There's probably some CSE and strength-reduction that the compiler won't
66 * even think about - really should have a few assumptions/separate cases.
67 */
68
69/* Get a number of bits ( <= 32 ) from *sp and store in dw */
70#define GETBITS(sp, x, w, dw) do { \
71 dw = MBL(*(sp), (x)); \
72 if (((x) + (w)) > 32) \
73 dw |= (MBR((sp)[1], 32 - (x))); \
74} while(0);
75
76/* Put a number of bits ( <= 32 ) from sw to *dp */
77#define PUTBITS(sw, x, w, dp) do { \
78 int n = (x) + (w) - 32; \
79 \
80 if (n <= 0) { \
81 n = rasops_pmask[x & 31][w & 31]; \
82 *(dp) = (*(dp) & ~n) | (MBR(sw, x) & n); \
83 } else { \
84 *(dp) = (*(dp) & rasops_rmask[x]) | (MBR((sw), x)); \
85 (dp)[1] = ((dp)[1] & rasops_rmask[n]) | \
86 (MBL(sw, 32-(x)) & rasops_lmask[n]); \
87 } \
88} while(0);
89
90/* rasops_masks.c */
91extern const uint32_t rasops_lmask[32+1];
92extern const uint32_t rasops_rmask[32+1];
93extern const uint32_t rasops_pmask[32][32];
94
95#endif /* _RASOPS_MASKS_H_ */
96