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maskbits.h revision 1.9 
      1 /*	$NetBSD: maskbits.h,v 1.9 2011/02/06 18:26:52 tsutsui Exp $	*/
      2 /*	$OpenBSD: maskbits.h,v 1.6 2006/08/05 09:58:56 miod Exp $	*/
      3 /*	NetBSD: maskbits.h,v 1.3 1997/03/31 07:37:28 scottr Exp 	*/
      4 
      5 /*-
      6  * Copyright (c) 1994
      7  *	The Regents of the University of California.  All rights reserved.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  *
     33  *	@(#)maskbits.h	8.2 (Berkeley) 3/21/94
     34  */
     35 
     36 /*
     37  * Derived from X11R4
     38  */
     39 
     40 /* the following notes use the following conventions:
     41 SCREEN LEFT				SCREEN RIGHT
     42 in this file and maskbits.c, left and right refer to screen coordinates,
     43 NOT bit numbering in registers.
     44 
     45 rasops_lmask[n]
     46 	bits[0,n-1] = 0	bits[n,31] = 1
     47 rasops_rmask[n] =
     48 	bits[0,n-1] = 1	bits[n,31] = 0
     49 
     50 maskbits(x, w, startmask, endmask, nlw)
     51 	for a span of width w starting at position x, returns
     52 a mask for ragged bits at start, mask for ragged bits at end,
     53 and the number of whole longwords between the ends.
     54 
     55 */
     56 
     57 #define maskbits(x, w, startmask, endmask, nlw)				\
     58 do {									\
     59 	startmask = rasops_lmask[(x) & 0x1f];				\
     60 	endmask = rasops_rmask[((x) + (w)) & 0x1f];			\
     61 	if (startmask)							\
     62 		nlw = (((w) - (32 - ((x) & 0x1f))) >> 5);		\
     63 	else								\
     64 		nlw = (w) >> 5;						\
     65 } while (/* CONSTCOND */ 0)
     66 
     67 #define FASTGETBITS(psrc, x, w, dst)					\
     68     asm ("bfextu %3{%1:%2},%0"						\
     69     : "=d" (dst) : "di" (x), "di" (w), "o" (*(char *)(psrc)))
     70 
     71 #define FASTPUTBITS(src, x, w, pdst)					\
     72     asm ("bfins %3,%0{%1:%2}"						\
     73 	 : "=o" (*(char *)(pdst))					\
     74 	 : "di" (x), "di" (w), "d" (src))
     75 
     76 #define getandputrop(psrc, srcbit, dstbit, width, pdst, rop)		\
     77 do {									\
     78 	unsigned int _tmpdst;						\
     79 	if (rop == RR_CLEAR)						\
     80 		_tmpdst = 0;						\
     81 	else								\
     82 		FASTGETBITS(psrc, srcbit, width, _tmpdst);		\
     83 	FASTPUTBITS(_tmpdst, dstbit, width, pdst);			\
     84 } while (/* CONSTCOND */ 0)
     85 
     86 #define getunalignedword(psrc, x, dst)					\
     87 do {									\
     88         int _tmp;							\
     89         FASTGETBITS(psrc, x, 32, _tmp);					\
     90         dst = _tmp;							\
     91 } while (/* CONSTCOND */ 0)
     92