summaryrefslogtreecommitdiff
path: root/libc/string/i386/strnlen.c
diff options
context:
space:
mode:
Diffstat (limited to 'libc/string/i386/strnlen.c')
-rw-r--r--libc/string/i386/strnlen.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/libc/string/i386/strnlen.c b/libc/string/i386/strnlen.c
new file mode 100644
index 000000000..be7ace51d
--- /dev/null
+++ b/libc/string/i386/strnlen.c
@@ -0,0 +1,55 @@
+/*
+ * This string-include defines all string functions as inline
+ * functions. Use gcc. It also assumes ds=es=data space, this should be
+ * normal. Most of the string-functions are rather heavily hand-optimized,
+ * see especially strtok,strstr,str[c]spn. They should work, but are not
+ * very easy to understand. Everything is done entirely within the register
+ * set, making the functions fast and clean. String instructions have been
+ * used through-out, making for "slightly" unclear code :-)
+ *
+ * NO Copyright (C) 1991, 1992 Linus Torvalds,
+ * consider these trivial functions to be PD.
+ */
+
+/*
+ * Copyright (C) 2000-2005 Erik Andersen <andersen@uclibc.org>
+ *
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/*
+ * Modified for uClibc by Erik Andersen <andersen@codepoet.org>
+ * These make no attempt to use nifty things like mmx/3dnow/etc.
+ * These are not inline, and will therefore not be as fast as
+ * modifying the headers to use inlines (and cannot therefore
+ * do tricky things when dealing with const memory). But they
+ * should (I hope!) be faster than their generic equivalents....
+ *
+ * More importantly, these should provide a good example for
+ * others to follow when adding arch specific optimizations.
+ * -Erik
+ */
+
+#define _GNU_SOURCE
+#include <string.h>
+
+size_t attribute_hidden __strnlen(const char *s, size_t count)
+{
+ int d0;
+ register int __res;
+ __asm__ __volatile__(
+ "movl %2,%0\n\t"
+ "incl %1\n"
+ "jmp 2f\n"
+ "1:\tcmpb $0,(%0)\n\t"
+ "je 3f\n\t"
+ "incl %0\n"
+ "2:\tdecl %1\n\t"
+ "jne 1b\n"
+ "3:\tsubl %2,%0"
+ :"=a" (__res), "=&d" (d0)
+ :"c" (s),"1" (count));
+ return __res;
+}
+
+strong_alias(__strnlen, strnlen)