1/*	$NetBSD$	*/
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:
41SCREEN LEFT				SCREEN RIGHT
42in this file and maskbits.c, left and right refer to screen coordinates,
43NOT bit numbering in registers.
44
45rasops_lmask[n]
46	bits[0,n-1] = 0	bits[n,31] = 1
47rasops_rmask[n] =
48	bits[0,n-1] = 1	bits[n,31] = 0
49
50maskbits(x, w, startmask, endmask, nlw)
51	for a span of width w starting at position x, returns
52a mask for ragged bits at start, mask for ragged bits at end,
53and the number of whole longwords between the ends.
54
55*/
56
57#define maskbits(x, w, startmask, endmask, nlw)				\
58do {									\
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)		\
77do {									\
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)					\
87do {									\
88        int _tmp;							\
89        FASTGETBITS(psrc, x, 32, _tmp);					\
90        dst = _tmp;							\
91} while (/* CONSTCOND */ 0)
92