MFp4: Pentium/Athlon-optimised implementation of wcslen().

2 files changed, 69 insertions, 1 deletions

diff --git a/lib/libc/i386/string/Makefile.inc b/lib/libc/i386/string/Makefile.inc
index b1a5277..28df6e7 100644
--- a/lib/libc/i386/string/Makefile.inc
+++ b/lib/libc/i386/string/Makefile.inc
@@ -3,4 +3,4 @@
 
 MDSRCS+=bcmp.S bcopy.S bzero.S ffs.S index.S memchr.S memcmp.S memcpy.S \
 	memmove.S memset.S rindex.S strcat.S strchr.S strcmp.S strcpy.S \
-	strlen.S strncmp.S strrchr.S swab.S wcscmp.S wmemchr.S
+	strlen.S strncmp.S strrchr.S swab.S wcscmp.S wcslen.S wmemchr.S
diff --git a/lib/libc/i386/string/wcslen.S b/lib/libc/i386/string/wcslen.S
new file mode 100644
index 0000000..2bebc1e
--- /dev/null
+++ b/lib/libc/i386/string/wcslen.S
@@ -0,0 +1,68 @@
+/*-
+ * Copyright (c) 2003 Tim J. Robbins.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <machine/asm.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * size_t
+ * wcslen(const wchar_t *s) --
+ *	Find the length of a wide character string.
+ */
+ENTRY(wcslen)
+	movl	4(%esp),%ecx		/* String */
+	pushl	%ebx
+	xorl	%ebx,%ebx
+	xorl	%eax,%eax
+.p2align 4,0x90
+L1:	cmpl	%ebx,(%ecx)
+	jz	found0
+	cmpl	%ebx,4(%ecx)
+	jz	found1
+	cmpl	%ebx,8(%ecx)
+	jz	found2
+	cmpl	%ebx,12(%ecx)
+	jz	found3
+	cmpl	%ebx,16(%ecx)
+	jz	found4
+	cmpl	%ebx,20(%ecx)
+	jz	found5
+	cmpl	%ebx,24(%ecx)
+	jz	found6
+	cmpl	%ebx,28(%ecx)
+	jz	found7
+	leal	32(%ecx),%ecx
+	addl	$8,%eax
+	jmp	L1
+found7:	incl	%eax
+found6:	incl	%eax
+found5:	incl	%eax
+found4:	incl	%eax
+found3:	incl	%eax
+found2:	incl	%eax
+found1:	incl	%eax
+found0:	popl	%ebx
+	ret