summaryrefslogtreecommitdiff
path: root/sysdeps/generic/memchr.c
diff options
context:
space:
mode:
authorJim Meyering <meyering@lucent.com>1995-03-13 03:38:06 +0000
committerJim Meyering <meyering@lucent.com>1995-03-13 03:38:06 +0000
commit7782ca54e1a3fc0a583febda9acd08cc63251a59 (patch)
treeedc68640ea777c6605f2eeeea14afa076884cd5a /sysdeps/generic/memchr.c
parent66e3dda448406399136e6f144a1b46679d5b2613 (diff)
Remove ansidecl.h and clean up for use by other packages. [LONG_MAX <= LONG_MAX_32_BITS]: Don't compile 64-bit code.
Diffstat (limited to 'sysdeps/generic/memchr.c')
-rw-r--r--sysdeps/generic/memchr.c101
1 files changed, 64 insertions, 37 deletions
diff --git a/sysdeps/generic/memchr.c b/sysdeps/generic/memchr.c
index d17f9c649e..1731574907 100644
--- a/sysdeps/generic/memchr.c
+++ b/sysdeps/generic/memchr.c
@@ -20,17 +20,44 @@ 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. */
-#include <ansidecl.h>
-#include <string.h>
+#ifdef HAVE_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 (HAVE_STRING_H) || defined (_LIBC)
+# include <string.h>
+#endif
+
+#if defined (HAVE_LIMIT_H) || defined (_LIBC)
+# include <limit.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. */
-PTR
-DEFUN(memchr, (s, c, n), CONST PTR s AND int c AND size_t n)
+__ptr_t
+memchr (s, c, n)
+ const __ptr_t s;
+ int c;
+ size_t n;
{
- CONST unsigned char *char_ptr;
- CONST unsigned long int *longword_ptr;
+ const unsigned char *char_ptr;
+ const unsigned long int *longword_ptr;
unsigned long int longword, magic_bits, charmask;
c = (unsigned char) c;
@@ -41,7 +68,7 @@ DEFUN(memchr, (s, c, n), CONST PTR s AND int c AND size_t n)
& (sizeof (longword) - 1)) != 0;
--n, ++char_ptr)
if (*char_ptr == c)
- return (PTR) 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. */
@@ -57,21 +84,22 @@ DEFUN(memchr, (s, c, n), CONST PTR s AND int c AND size_t n)
The 1-bits make sure that carries propagate to the next 0-bit.
The 0-bits provide holes for carries to fall into. */
- switch (sizeof (longword))
- {
- case 4: magic_bits = 0x7efefeffL; break;
- case 8: magic_bits = (0x7efefefeL << 32) | 0xfefefeffL; break;
- default:
- abort ();
- }
+
+ if (sizeof (longword) != 4 && sizeof (longword) != 8)
+ abort ();
+
+#if LONG_MAX <= LONG_MAX_32_BITS
+ magic_bits = 0x7efefeff;
+#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;
- if (sizeof (longword) > 4)
- charmask |= charmask << 32;
- if (sizeof (longword) > 8)
- abort ();
+#if LONG_MAX > LONG_MAX_32_BITS
+ charmask |= charmask << 32;
+#endif
/* Instead of the traditional loop which tests each character,
we will test a longword at a time. The tricky part is testing
@@ -128,41 +156,40 @@ DEFUN(memchr, (s, c, n), CONST PTR s AND int c AND size_t n)
/* Which of the bytes was C? If none of them were, it was
a misfire; continue the search. */
- CONST unsigned char *cp = (CONST unsigned char *) (longword_ptr - 1);
+ const unsigned char *cp = (const unsigned char *) (longword_ptr - 1);
if (cp[0] == c)
- return (PTR) cp;
+ return (__ptr_t) cp;
if (cp[1] == c)
- return (PTR) &cp[1];
+ return (__ptr_t) &cp[1];
if (cp[2] == c)
- return (PTR) &cp[2];
+ return (__ptr_t) &cp[2];
if (cp[3] == c)
- return (PTR) &cp[3];
- if (sizeof (longword) > 4)
- {
- if (cp[4] == c)
- return (PTR) &cp[4];
- if (cp[5] == c)
- return (PTR) &cp[5];
- if (cp[6] == c)
- return (PTR) &cp[6];
- if (cp[7] == c)
- return (PTR) &cp[7];
- }
+ return (__ptr_t) &cp[3];
+#if LONG_MAX > 2147483647
+ if (cp[4] == c)
+ return (__ptr_t) &cp[4];
+ if (cp[5] == c)
+ return (__ptr_t) &cp[5];
+ if (cp[6] == c)
+ return (__ptr_t) &cp[6];
+ if (cp[7] == c)
+ return (__ptr_t) &cp[7];
+#endif
}
n -= sizeof (longword);
}
- char_ptr = (CONST unsigned char *) longword_ptr;
+ char_ptr = (const unsigned char *) longword_ptr;
while (n-- > 0)
{
if (*char_ptr == c)
- return (PTR) char_ptr;
+ return (__ptr_t) char_ptr;
else
++char_ptr;
}
- return NULL;
+ return 0;
}