OpenCores
URL https://opencores.org/ocsvn/openrisc/openrisc/trunk

Subversion Repositories openrisc

[/] [openrisc/] [trunk/] [gnu-stable/] [gcc-4.5.1/] [libiberty/] [memmem.c] - Blame information for rev 847

Go to most recent revision | Details | Compare with Previous | View Log

Line No. Rev Author Line
1 274 jeremybenn
/* Copyright (C) 1991,92,93,94,96,97,98,2000,2004,2007 Free Software Foundation, Inc.
2
   This file is part of the GNU C Library.
3
 
4
   This program is free software; you can redistribute it and/or modify
5
   it under the terms of the GNU General Public License as published by
6
   the Free Software Foundation; either version 2, or (at your option)
7
   any later version.
8
 
9
   This program is distributed in the hope that it will be useful,
10
   but WITHOUT ANY WARRANTY; without even the implied warranty of
11
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12
   GNU General Public License for more details.
13
 
14
   You should have received a copy of the GNU General Public License along
15
   with this program; if not, write to the Free Software Foundation,
16
   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
17
 
18
/*
19
 
20
@deftypefn Supplemental void* memmem (const void *@var{haystack}, size_t @var{haystack_len} const void *@var{needle}, size_t @var{needle_len})
21
 
22
Returns a pointer to the first occurrence of @var{needle} (length
23
@var{needle_len}) in @var{haystack} (length @var{haystack_len}).
24
Returns @code{NULL} if not found.
25
 
26
@end deftypefn
27
 
28
*/
29
 
30
#ifndef _LIBC
31
# include <config.h>
32
#endif
33
 
34
#include <stddef.h>
35
#include <string.h>
36
 
37
#ifndef _LIBC
38
# define __builtin_expect(expr, val)   (expr)
39
#endif
40
 
41
#undef memmem
42
 
43
/* Return the first occurrence of NEEDLE in HAYSTACK.  */
44
void *
45
memmem (const void *haystack, size_t haystack_len, const void *needle,
46
        size_t needle_len)
47
{
48
  const char *begin;
49
  const char *const last_possible
50
    = (const char *) haystack + haystack_len - needle_len;
51
 
52
  if (needle_len == 0)
53
    /* The first occurrence of the empty string is deemed to occur at
54
       the beginning of the string.  */
55
    return (void *) haystack;
56
 
57
  /* Sanity check, otherwise the loop might search through the whole
58
     memory.  */
59
  if (__builtin_expect (haystack_len < needle_len, 0))
60
    return NULL;
61
 
62
  for (begin = (const char *) haystack; begin <= last_possible; ++begin)
63
    if (begin[0] == ((const char *) needle)[0] &&
64
        !memcmp ((const void *) &begin[1],
65
                 (const void *) ((const char *) needle + 1),
66
                 needle_len - 1))
67
      return (void *) begin;
68
 
69
  return NULL;
70
}

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.