1 /* $NetBSD: rasops_masks.h,v 1.7 2008/04/28 20:23:57 martin 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 */ 91 extern const int32_t rasops_lmask[32+1]; 92 extern const int32_t rasops_rmask[32+1]; 93 extern const int32_t rasops_pmask[32][32]; 94 95 #endif /* _RASOPS_MASKS_H_ */ 96