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      1 /*	$NetBSD: maskbits.h,v 1.2 2025/05/31 18:11:50 tsutsui Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1994
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  *
     31  *	@(#)maskbits.h	8.2 (Berkeley) 3/21/94
     32  */
     33 
     34 /*
     35  * Derived from X11R4
     36  */
     37 
     38 /* the following notes use the following conventions:
     39  * SCREEN LEFT				SCREEN RIGHT
     40  * in this file and maskbits.c, left and right refer to screen coordinates,
     41  * NOT bit numbering in registers.
     42  *
     43  * starttab[n]
     44  * 	bits[0,n-1] = 0	bits[n,31] = 1
     45  * endtab[n] =
     46  * 	bits[0,n-1] = 1	bits[n,31] = 0
     47  *
     48  * maskbits(x, w, startmask, endmask, nlw)
     49  * 	for a span of width w starting at position x, returns
     50  * a mask for ragged bits at start, mask for ragged bits at end,
     51  * and the number of whole longwords between the ends.
     52  *
     53  */
     54 
     55 #define maskbits(x, w, startmask, endmask, nlw)				\
     56 do {									\
     57 	startmask = starttab[(x) & 0x1f];				\
     58 	endmask = endtab[((x) + (w)) & 0x1f];				\
     59 	if (startmask)							\
     60 		nlw = (((w) - (32 - ((x) & 0x1f))) >> 5);		\
     61 	else								\
     62 		nlw = (w) >> 5;						\
     63 } while (/* CONSTCOND */ 0)
     64 
     65 #define FASTGETBITS(psrc, x, w, dst)					\
     66     __asm ("bfextu %3{%1:%2},%0"					\
     67 	: "=d" (dst) : "di" (x), "di" (w), "o" (*(uint8_t *)(psrc)))
     68 
     69 #define FASTPUTBITS(src, x, w, pdst)					\
     70     __asm ("bfins %3,%0{%1:%2}"						\
     71 	: "=o" (*(uint8_t *)(pdst))					\
     72 	: "di" (x), "di" (w), "d" (src))
     73 
     74 #define getandputrop(psrc, srcbit, dstbit, width, pdst, rop)		\
     75 do {									\
     76 	uint32_t _tmpsrc, _tmpdst;					\
     77 	FASTGETBITS(pdst, dstbit, width, _tmpdst);			\
     78 	FASTGETBITS(psrc, srcbit, width, _tmpsrc);			\
     79 	DoRop(_tmpdst, rop, _tmpsrc, _tmpdst);				\
     80 	FASTPUTBITS(_tmpdst, dstbit, width, pdst);			\
     81 } while (/* CONSTCOND */ 0)
     82 
     83 #define getandputrop0(psrc, srcbit, width, pdst, rop)			\
     84 	getandputrop(psrc, srcbit, 0, width, pdst, rop)
     85 
     86 #define getunalignedword(psrc, x, dst)					\
     87 do {									\
     88 	uint32_t _tmp;							\
     89 	FASTGETBITS(psrc, x, 32, _tmp);					\
     90 	dst = _tmp;							\
     91 } while (/* CONSTCOND */ 0)
     92 
     93 #define fnCLEAR(src, dst)       (0)
     94 #define fnCOPY(src, dst)        (src)
     95 #define fnXOR(src, dst)         ((src) ^ (dst))
     96 #define fnCOPYINVERTED(src, dst)(~(src))
     97 
     98 #define DoRop(result, alu, src, dst) \
     99 do {									\
    100 	if (alu == RR_COPY)						\
    101 		result = fnCOPY(src, dst);				\
    102 	else {								\
    103 		switch (alu) {						\
    104 		case RR_CLEAR:						\
    105 			result = fnCLEAR(src, dst);			\
    106 			break;						\
    107 		case RR_XOR:						\
    108 			result = fnXOR(src, dst);			\
    109 			break;						\
    110 		case RR_COPYINVERTED:					\
    111 			result = fnCOPYINVERTED(src, dst);		\
    112 			break;						\
    113 		}							\
    114 	}								\
    115 } while (/* CONSTCOND */ 0)
    116