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-rw-r--r--sysdeps/generic/strncmp.c69
1 files changed, 69 insertions, 0 deletions
diff --git a/sysdeps/generic/strncmp.c b/sysdeps/generic/strncmp.c
new file mode 100644
index 0000000000..623d9c5714
--- /dev/null
+++ b/sysdeps/generic/strncmp.c
@@ -0,0 +1,69 @@
+/* Copyright (C) 1991 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 Library General Public License as
+published by the Free Software Foundation; either version 2 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
+Library 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. */
+
+#include <ansidecl.h>
+#include <string.h>
+#include <memcopy.h>
+
+/* Compare no more than N characters of S1 and S2,
+ returning less than, equal to or greater than zero
+ if S1 is lexiographically less than, equal to or
+ greater than S2. */
+int
+DEFUN(strncmp, (s1, s2, n),
+ CONST char *s1 AND CONST char *s2 AND 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;
+}