1 /* $NetBSD: rasops_masks.h,v 1.6 2001/01/12 23:03:52 bjh21 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #ifndef _RASOPS_MASKS_H_ 40 #define _RASOPS_MASKS_H_ 1 41 42 #include <sys/types.h> 43 #include <machine/endian.h> 44 45 /* 46 * Convenience macros. To get around the problem of dealing with properly 47 * ordered bits on little-endian machines, we just convert everything to 48 * big-endian and back again when we're done. 49 * 50 * MBL: move bits left 51 * MBR: move bits right 52 * MBE: make big-endian 53 */ 54 #if BYTE_ORDER == BIG_ENDIAN 55 56 #define MBL(x,y) ((y) > 31 ? 0 : (x) >> (y)) 57 #define MBR(x,y) ((y) > 31 ? 0 : (x) << (y)) 58 #define MBE(x) (x) 59 60 #else 61 62 #define MBL(x,y) ((y) > 31 ? 0 : MBE(MBE(x) << (y))) 63 #define MBR(x,y) ((y) > 31 ? 0 : MBE(MBE(x) >> (y))) 64 #define MBE(x) ( (((x) & 0x000000FFU) << 24) \ 65 | (((x) & 0x0000FF00U) << 8) \ 66 | (((x) & 0x00FF0000U) >> 8) \ 67 | (((x) & 0xFF000000U) >> 24) ) 68 #endif 69 70 /* 71 * Using GETBITS() and PUTBITS() inside a loop mightn't be such a good idea. 72 * There's probably some CSE and strength-reduction that the compiler won't 73 * even think about - really should have a few assumptions/separate cases. 74 */ 75 76 /* Get a number of bits ( <= 32 ) from *sp and store in dw */ 77 #define GETBITS(sp, x, w, dw) do { \ 78 dw = MBL(*(sp), (x)); \ 79 if (((x) + (w)) > 32) \ 80 dw |= (MBR((sp)[1], 32 - (x))); \ 81 } while(0); 82 83 /* Put a number of bits ( <= 32 ) from sw to *dp */ 84 #define PUTBITS(sw, x, w, dp) do { \ 85 int n = (x) + (w) - 32; \ 86 \ 87 if (n <= 0) { \ 88 n = rasops_pmask[x & 31][w & 31]; \ 89 *(dp) = (*(dp) & ~n) | (MBR(sw, x) & n); \ 90 } else { \ 91 *(dp) = (*(dp) & rasops_rmask[x]) | (MBR((sw), x)); \ 92 (dp)[1] = ((dp)[1] & rasops_rmask[n]) | \ 93 (MBL(sw, 32-(x)) & rasops_lmask[n]); \ 94 } \ 95 } while(0); 96 97 /* rasops_masks.c */ 98 extern const int32_t rasops_lmask[32+1]; 99 extern const int32_t rasops_rmask[32+1]; 100 extern const int32_t rasops_pmask[32][32]; 101 102 #endif /* _RASOPS_MASKS_H_ */ 103