xref: /src/sys/arch/hp300/stand/common/maskbits.h

/*	$NetBSD: maskbits.h,v 1.1.98.1 2025/08/02 05:55:39 perseant Exp $	*/

/*-
 * Copyright (c) 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)maskbits.h	8.2 (Berkeley) 3/21/94
 */

/*
 * Derived from X11R4
 */

/* the following notes use the following conventions:
 * SCREEN LEFT				SCREEN RIGHT
 * in this file and maskbits.c, left and right refer to screen coordinates,
 * NOT bit numbering in registers.
 *
 * starttab[n]
 * 	bits[0,n-1] = 0	bits[n,31] = 1
 * endtab[n] =
 * 	bits[0,n-1] = 1	bits[n,31] = 0
 *
 * maskbits(x, w, startmask, endmask, nlw)
 * 	for a span of width w starting at position x, returns
 * a mask for ragged bits at start, mask for ragged bits at end,
 * and the number of whole longwords between the ends.
 *
 */

#define maskbits(x, w, startmask, endmask, nlw)				\
do {									\
	startmask = starttab[(x) & 0x1f];				\
	endmask = endtab[((x) + (w)) & 0x1f];				\
	if (startmask)							\
		nlw = (((w) - (32 - ((x) & 0x1f))) >> 5);		\
	else								\
		nlw = (w) >> 5;						\
} while (/* CONSTCOND */ 0)

#define FASTGETBITS(psrc, x, w, dst)					\
    __asm ("bfextu %3{%1:%2},%0"					\
	: "=d" (dst) : "di" (x), "di" (w), "o" (*(uint8_t *)(psrc)))

#define FASTPUTBITS(src, x, w, pdst)					\
    __asm ("bfins %3,%0{%1:%2}"						\
	: "=o" (*(uint8_t *)(pdst))					\
	: "di" (x), "di" (w), "d" (src))

#define getandputrop(psrc, srcbit, dstbit, width, pdst, rop)		\
do {									\
	uint32_t _tmpsrc, _tmpdst;					\
	FASTGETBITS(pdst, dstbit, width, _tmpdst);			\
	FASTGETBITS(psrc, srcbit, width, _tmpsrc);			\
	DoRop(_tmpdst, rop, _tmpsrc, _tmpdst);				\
	FASTPUTBITS(_tmpdst, dstbit, width, pdst);			\
} while (/* CONSTCOND */ 0)

#define getandputrop0(psrc, srcbit, width, pdst, rop)			\
	getandputrop(psrc, srcbit, 0, width, pdst, rop)

#define getunalignedword(psrc, x, dst)					\
do {									\
	uint32_t _tmp;							\
	FASTGETBITS(psrc, x, 32, _tmp);					\
	dst = _tmp;							\
} while (/* CONSTCOND */ 0)

#define fnCLEAR(src, dst)       (0)
#define fnCOPY(src, dst)        (src)
#define fnXOR(src, dst)         ((src) ^ (dst))
#define fnCOPYINVERTED(src, dst)(~(src))

#define DoRop(result, alu, src, dst) \
do {									\
	if (alu == RR_COPY)						\
		result = fnCOPY(src, dst);				\
	else {								\
		switch (alu) {						\
		case RR_CLEAR:						\
			result = fnCLEAR(src, dst);			\
			break;						\
		case RR_XOR:						\
			result = fnXOR(src, dst);			\
			break;						\
		case RR_COPYINVERTED:					\
			result = fnCOPYINVERTED(src, dst);		\
			break;						\
		}							\
	}								\
} while (/* CONSTCOND */ 0)