MFp4: Pentium-optimised implementation of wcscmp(). Performs significantly

better than the code generated by gcc in many cases.

2 files changed, 80 insertions, 1 deletions

diff --git a/lib/libc/i386/string/Makefile.inc b/lib/libc/i386/string/Makefile.inc
index 1b2de19..b3e0e56 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
+	strlen.S strncmp.S strrchr.S swab.S wcscmp.S
diff --git a/lib/libc/i386/string/wcscmp.S b/lib/libc/i386/string/wcscmp.S
new file mode 100644
index 0000000..aa44140
--- /dev/null
+++ b/lib/libc/i386/string/wcscmp.S
@@ -0,0 +1,79 @@
+/*-
+ * 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("$FreeBSD$");
+
+/*
+ * int
+ * wcscmp(const wchar_t *s1, const wchar_t *s2) --
+ *	Return an integer greater than, equal to, or less than 0, when
+ *	the string s1 is greater than, equal to, or less than the string s2.
+ */
+ENTRY(wcscmp)
+	pushl	%edi
+	pushl	%esi
+	movl	12(%esp),%edi		/* s1 */
+	movl	16(%esp),%esi		/* s2 */
+.p2align 4,0x90
+top:	movl	(%edi),%eax
+	cmpl	%eax,(%esi)
+	jne	no0
+	testl	%eax,%eax
+	jz	same
+	movl	4(%edi),%eax
+	cmpl	%eax,4(%esi)
+	jne	no4
+	testl	%eax,%eax
+	jz	same
+	movl	8(%edi),%eax
+	cmpl	%eax,8(%esi)
+	jne	no8
+	testl	%eax,%eax
+	jz	same
+	movl	12(%edi),%eax
+	cmpl	%eax,12(%esi)
+	jne	no12
+	leal	16(%edi),%edi
+	leal	16(%esi),%esi
+	testl	%eax,%eax
+	jnz	top
+.p2align 2,0x90
+same:	xorl	%eax,%eax
+	popl	%esi
+	popl	%edi
+	ret
+.p2align 2,0x90
+no12:	leal	4(%esi),%esi
+.p2align 2,0x90
+no8:	leal	4(%esi),%esi
+.p2align 2,0x90
+no4:	leal	4(%esi),%esi
+.p2align 2,0x90
+no0:	subl	(%esi),%eax
+	popl	%esi
+	popl	%edi
+	ret