-/* Copyright (C) 1991, 1993 Free Software Foundation, Inc.
- Based on strlen implemention by Torbjorn Granlund (tege@sics.se),
+/* Copyright (C) 1991, 1993, 1997, 1999 Free Software Foundation, Inc.
+ Based on strlen implementation by Torbjorn Granlund (tege@sics.se),
with help from Dan Sahlin (dan@sics.se) and
commentary by Jim Blandy (jimb@ai.mit.edu);
adaptation to memchr suggested by Dick Karpinski (dick@cca.ucsf.edu),
and implemented by Roland McGrath (roland@ai.mit.edu).
-The GNU C Library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public License as
-published by the Free Software Foundation; either version 2 of the
-License, or (at your option) any later version.
+NOTE: The canonical source of this file is maintained with the GNU C Library.
+Bugs can be reported to bug-glibc@prep.ai.mit.edu.
-The GNU C Library is distributed in the hope that it will be useful,
+This program is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 2, or (at your option) any
+later version.
+
+This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-Library General Public License for more details.
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB. If
-not, write to the Free Software Foundation, Inc., 675 Mass Ave,
-Cambridge, MA 02139, USA. */
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+USA. */
#ifdef HAVE_CONFIG_H
-#if defined (CONFIG_BROKETS)
-/* We use <config.h> instead of "config.h" so that a compilation
- using -I. -I$srcdir will use ./config.h rather than $srcdir/config.h
- (which it would do because it found this file in $srcdir). */
-#include <config.h>
-#else
-#include "config.h"
+# include <config.h>
+#endif
+
+#undef __ptr_t
+#if defined (__cplusplus) || (defined (__STDC__) && __STDC__)
+# define __ptr_t void *
+#else /* Not C++ or ANSI C. */
+# define __ptr_t char *
+#endif /* C++ or ANSI C. */
+
+#if defined (_LIBC)
+# include <string.h>
+#endif
+
+#if defined (HAVE_LIMITS_H) || defined (_LIBC)
+# include <limits.h>
#endif
+
+#define LONG_MAX_32_BITS 2147483647
+
+#ifndef LONG_MAX
+# define LONG_MAX LONG_MAX_32_BITS
#endif
+#include <sys/types.h>
+
+
/* Search no more than N bytes of S for C. */
-char *
+__ptr_t
memchr (s, c, n)
- unsigned char *s;
+ const __ptr_t s;
int c;
- unsigned n;
+ size_t n;
{
const unsigned char *char_ptr;
const unsigned long int *longword_ptr;
/* Handle the first few characters by reading one character at a time.
Do this until CHAR_PTR is aligned on a longword boundary. */
- for (char_ptr = s; n > 0 && ((unsigned long int) char_ptr
- & (sizeof (longword) - 1)) != 0;
+ for (char_ptr = (const unsigned char *) s;
+ n > 0 && ((unsigned long int) char_ptr
+ & (sizeof (longword) - 1)) != 0;
--n, ++char_ptr)
if (*char_ptr == c)
- return (char *) char_ptr;
+ return (__ptr_t) char_ptr;
/* All these elucidatory comments refer to 4-byte longwords,
but the theory applies equally well to 8-byte longwords. */
The 1-bits make sure that carries propagate to the next 0-bit.
The 0-bits provide holes for carries to fall into. */
-#ifdef LONG_64_BITS
- /* 64-bit version of the magic. */
- magic_bits = ((unsigned long int) 0x7efefefe << 32) | 0xfefefeff;
-#else
+
+ if (sizeof (longword) != 4 && sizeof (longword) != 8)
+ abort ();
+
+#if LONG_MAX <= LONG_MAX_32_BITS
magic_bits = 0x7efefeff;
-#endif /* LONG_64_BITS */
+#else
+ magic_bits = ((unsigned long int) 0x7efefefe << 32) | 0xfefefeff;
+#endif
/* Set up a longword, each of whose bytes is C. */
charmask = c | (c << 8);
charmask |= charmask << 16;
-#ifdef LONG_64_BITS
+#if LONG_MAX > LONG_MAX_32_BITS
charmask |= charmask << 32;
-#endif /* LONG_64_BITS */
- if (sizeof (longword) > 8)
- abort ();
-
+#endif
/* Instead of the traditional loop which tests each character,
we will test a longword at a time. The tricky part is testing
/* Add MAGIC_BITS to LONGWORD. */
if ((((longword + magic_bits)
- /* Set those bits that were unchanged by the addition. */
+ /* Set those bits that were unchanged by the addition. */
^ ~longword)
- /* Look at only the hole bits. If any of the hole bits
+ /* Look at only the hole bits. If any of the hole bits
are unchanged, most likely one of the bytes was a
zero. */
& ~magic_bits) != 0)
const unsigned char *cp = (const unsigned char *) (longword_ptr - 1);
if (cp[0] == c)
- return (char *) cp;
+ return (__ptr_t) cp;
if (cp[1] == c)
- return (char *) &cp[1];
+ return (__ptr_t) &cp[1];
if (cp[2] == c)
- return (char *) &cp[2];
+ return (__ptr_t) &cp[2];
if (cp[3] == c)
- return (char *) &cp[3];
-#ifdef LONG_64_BITS
+ return (__ptr_t) &cp[3];
+#if LONG_MAX > 2147483647
if (cp[4] == c)
- return (char *) &cp[4];
+ return (__ptr_t) &cp[4];
if (cp[5] == c)
- return (char *) &cp[5];
+ return (__ptr_t) &cp[5];
if (cp[6] == c)
- return (char *) &cp[6];
+ return (__ptr_t) &cp[6];
if (cp[7] == c)
- return (char *) &cp[7];
-#endif /* LONG_64_BITS */
+ return (__ptr_t) &cp[7];
+#endif
}
n -= sizeof (longword);
while (n-- > 0)
{
if (*char_ptr == c)
- return (char *) char_ptr;
+ return (__ptr_t) char_ptr;
else
++char_ptr;
}
projects / gnulib.git / blobdiff