Annotation of sys/dev/rasops/rasops_masks.h, Revision 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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