15ed2564d9
(on an i486, 10 cycles (+ cache misses) instead of 15). The change should be a no-op if the compiler is any good. The best possible i*86 code for the same algorithm is only 1 more cycle faster on i486's so I don't want to bother implementing an assembler version. scanc() is a bottleneck for OPOST processing. It is naturally about 4 times as slow as bcopy() on 32-bit systems.
61 lines
2.3 KiB
C
61 lines
2.3 KiB
C
/*-
|
|
* Copyright (c) 1992, 1993
|
|
* 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. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. 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.
|
|
*
|
|
* @(#)scanc.c 8.1 (Berkeley) 6/10/93
|
|
*
|
|
* $Id: scanc.c,v 1.3 1995/03/17 06:15:39 phk Exp $
|
|
*/
|
|
|
|
#include <sys/libkern.h>
|
|
|
|
int
|
|
scanc(size, cp, table, mask0)
|
|
u_int size;
|
|
register u_char *cp, table[];
|
|
int mask0;
|
|
{
|
|
register u_char *end;
|
|
register u_char mask;
|
|
|
|
mask = mask0;
|
|
for (end = &cp[size]; cp < end; ++cp) {
|
|
/*
|
|
* gcc-2.6.3 generates poor (un)sign extension code on i386's.
|
|
* The cast to volatile should have no effect, but in fact it
|
|
* improves the code on i386's.
|
|
*/
|
|
if (table[*(volatile u_char *)cp] & mask)
|
|
break;
|
|
}
|
|
return (end - cp);
|
|
}
|