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maskbits.h revision 1.2 
      1 /*	$NetBSD: maskbits.h,v 1.2 1994/10/26 07:24:43 cgd 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  *
     35  *	@(#)maskbits.h	8.2 (Berkeley) 3/21/94
     36  */
     37 
     38 /*
     39  * Derived from X11R4
     40  */
     41 
     42 /* the following notes use the following conventions:
     43 SCREEN LEFT				SCREEN RIGHT
     44 in this file and maskbits.c, left and right refer to screen coordinates,
     45 NOT bit numbering in registers.
     46 
     47 starttab[n]
     48 	bits[0,n-1] = 0	bits[n,31] = 1
     49 endtab[n] =
     50 	bits[0,n-1] = 1	bits[n,31] = 0
     51 
     52 maskbits(x, w, startmask, endmask, nlw)
     53 	for a span of width w starting at position x, returns
     54 a mask for ragged bits at start, mask for ragged bits at end,
     55 and the number of whole longwords between the ends.
     56 
     57 */
     58 
     59 #define maskbits(x, w, startmask, endmask, nlw) \
     60     startmask = starttab[(x)&0x1f]; \
     61     endmask = endtab[((x)+(w)) & 0x1f]; \
     62     if (startmask) \
     63 	nlw = (((w) - (32 - ((x)&0x1f))) >> 5); \
     64     else \
     65 	nlw = (w) >> 5;
     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), "0" (*(char *) (pdst)))
     75 
     76 #define getandputrop(psrc, srcbit, dstbit, width, pdst, rop) \
     77 { \
     78   register unsigned int _tmpsrc, _tmpdst; \
     79   FASTGETBITS(pdst, dstbit, width, _tmpdst); \
     80   FASTGETBITS(psrc, srcbit, width, _tmpsrc); \
     81   DoRop(_tmpdst, rop, _tmpsrc, _tmpdst); \
     82   FASTPUTBITS(_tmpdst, dstbit, width, pdst); \
     83 }
     84 
     85 #define getandputrop0(psrc, srcbit, width, pdst, rop) \
     86     	getandputrop(psrc, srcbit, 0, width, pdst, rop)
     87 
     88 #define getunalignedword(psrc, x, dst) { \
     89         register int _tmp; \
     90         FASTGETBITS(psrc, x, 32, _tmp); \
     91         dst = _tmp; \
     92 }
     93 
     94 #define fnCLEAR(src, dst)       (0)
     95 #define fnCOPY(src, dst)        (src)
     96 #define fnXOR(src, dst)         (src ^ dst)
     97 #define fnCOPYINVERTED(src, dst)(~src)
     98 
     99 #define DoRop(result, alu, src, dst) \
    100 { \
    101     if (alu == RR_COPY) \
    102         result = fnCOPY (src, dst); \
    103     else \
    104         switch (alu) \
    105         { \
    106           case RR_CLEAR: \
    107             result = fnCLEAR (src, dst); \
    108             break; \
    109           case RR_XOR: \
    110             result = fnXOR (src, dst); \
    111             break; \
    112           case RR_COPYINVERTED: \
    113             result = fnCOPYINVERTED (src, dst); \
    114             break; \
    115         } \
    116 }
    117