diff options
Diffstat (limited to 'sysdeps/generic/strncmp.c')
-rw-r--r-- | sysdeps/generic/strncmp.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/sysdeps/generic/strncmp.c b/sysdeps/generic/strncmp.c new file mode 100644 index 0000000..1adb2c0 --- /dev/null +++ b/sysdeps/generic/strncmp.c @@ -0,0 +1,73 @@ +/* Copyright (C) 1991, 1996, 1997, 2003 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <string.h> +#include <memcopy.h> + +#undef strncmp + +/* Compare no more than N characters of S1 and S2, + returning less than, equal to or greater than zero + if S1 is lexicographically less than, equal to or + greater than S2. */ +int +strncmp (s1, s2, n) + const char *s1; + const char *s2; + size_t n; +{ + unsigned reg_char c1 = '\0'; + unsigned reg_char c2 = '\0'; + + if (n >= 4) + { + size_t n4 = n >> 2; + do + { + c1 = (unsigned char) *s1++; + c2 = (unsigned char) *s2++; + if (c1 == '\0' || c1 != c2) + return c1 - c2; + c1 = (unsigned char) *s1++; + c2 = (unsigned char) *s2++; + if (c1 == '\0' || c1 != c2) + return c1 - c2; + c1 = (unsigned char) *s1++; + c2 = (unsigned char) *s2++; + if (c1 == '\0' || c1 != c2) + return c1 - c2; + c1 = (unsigned char) *s1++; + c2 = (unsigned char) *s2++; + if (c1 == '\0' || c1 != c2) + return c1 - c2; + } while (--n4 > 0); + n &= 3; + } + + while (n > 0) + { + c1 = (unsigned char) *s1++; + c2 = (unsigned char) *s2++; + if (c1 == '\0' || c1 != c2) + return c1 - c2; + n--; + } + + return c1 - c2; +} +libc_hidden_builtin_def (strncmp) |