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maskbits.h revision 1.1 
      1 /*-
      2  * Copyright (c) 1994
      3  *	The Regents of the University of California.  All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. 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  *	from: @(#)maskbits.h	8.2 (Berkeley) 3/21/94
     34  *	$Id: maskbits.h,v 1.1 1994/05/23 05:59:05 mycroft Exp $
     35  */
     36 
     37 /*
     38  * Derived from X11R4
     39  */
     40 
     41 /* the following notes use the following conventions:
     42 SCREEN LEFT				SCREEN RIGHT
     43 in this file and maskbits.c, left and right refer to screen coordinates,
     44 NOT bit numbering in registers.
     45 
     46 starttab[n]
     47 	bits[0,n-1] = 0	bits[n,31] = 1
     48 endtab[n] =
     49 	bits[0,n-1] = 1	bits[n,31] = 0
     50 
     51 maskbits(x, w, startmask, endmask, nlw)
     52 	for a span of width w starting at position x, returns
     53 a mask for ragged bits at start, mask for ragged bits at end,
     54 and the number of whole longwords between the ends.
     55 
     56 */
     57 
     58 #define maskbits(x, w, startmask, endmask, nlw) \
     59     startmask = starttab[(x)&0x1f]; \
     60     endmask = endtab[((x)+(w)) & 0x1f]; \
     61     if (startmask) \
     62 	nlw = (((w) - (32 - ((x)&0x1f))) >> 5); \
     63     else \
     64 	nlw = (w) >> 5;
     65 
     66 #define FASTGETBITS(psrc, x, w, dst) \
     67     asm ("bfextu %3{%1:%2},%0" \
     68     : "=d" (dst) : "di" (x), "di" (w), "o" (*(char *)(psrc)))
     69 
     70 #define FASTPUTBITS(src, x, w, pdst) \
     71     asm ("bfins %3,%0{%1:%2}" \
     72 	 : "=o" (*(char *)(pdst)) \
     73 	 : "di" (x), "di" (w), "d" (src), "0" (*(char *) (pdst)))
     74 
     75 #define getandputrop(psrc, srcbit, dstbit, width, pdst, rop) \
     76 { \
     77   register unsigned int _tmpsrc, _tmpdst; \
     78   FASTGETBITS(pdst, dstbit, width, _tmpdst); \
     79   FASTGETBITS(psrc, srcbit, width, _tmpsrc); \
     80   DoRop(_tmpdst, rop, _tmpsrc, _tmpdst); \
     81   FASTPUTBITS(_tmpdst, dstbit, width, pdst); \
     82 }
     83 
     84 #define getandputrop0(psrc, srcbit, width, pdst, rop) \
     85     	getandputrop(psrc, srcbit, 0, width, pdst, rop)
     86 
     87 #define getunalignedword(psrc, x, dst) { \
     88         register int _tmp; \
     89         FASTGETBITS(psrc, x, 32, _tmp); \
     90         dst = _tmp; \
     91 }
     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 { \
    100     if (alu == RR_COPY) \
    101         result = fnCOPY (src, dst); \
    102     else \
    103         switch (alu) \
    104         { \
    105           case RR_CLEAR: \
    106             result = fnCLEAR (src, dst); \
    107             break; \
    108           case RR_XOR: \
    109             result = fnXOR (src, dst); \
    110             break; \
    111           case RR_COPYINVERTED: \
    112             result = fnCOPYINVERTED (src, dst); \
    113             break; \
    114         } \
    115 }
    116