Add an initial set of arm optimized string functions. These

do seem to make noticable speed improvement...
 -Erik

1 files changed, 72 insertions, 0 deletions

diff --git a/libc/string/arm/memset.S b/libc/string/arm/memset.S
new file mode 100644
index 000000000..07d3913f9
--- /dev/null
+++ b/libc/string/arm/memset.S
@@ -0,0 +1,72 @@
+/* Copyright (C) 1998 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Philip Blundell <philb@gnu.org>
+
+   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 <sys/syscall.h>
+
+		.text
+		.global memset;
+		.type memset,%function
+		.align 4;                                                               \
+
+memset:
+	mov	a4, a1
+	cmp	a3, $8		@ at least 8 bytes to do?
+	blt	2f
+	orr	a2, a2, a2, lsl $8
+	orr	a2, a2, a2, lsl $16
+1:
+	tst	a4, $3		@ aligned yet?
+	strneb	a2, [a4], $1
+	subne	a3, a3, $1
+	bne	1b
+	mov	ip, a2
+1:
+	cmp	a3, $8		@ 8 bytes still to do?
+	blt	2f
+	stmia	a4!, {a2, ip}
+	sub	a3, a3, $8
+	cmp	a3, $8		@ 8 bytes still to do?
+	blt	2f
+	stmia	a4!, {a2, ip}
+	sub	a3, a3, $8
+	cmp	a3, $8		@ 8 bytes still to do?
+	blt	2f
+	stmia	a4!, {a2, ip}
+	sub	a3, a3, $8
+	cmp	a3, $8		@ 8 bytes still to do?
+	stmgeia	a4!, {a2, ip}
+	subge	a3, a3, $8
+	bge	1b
+2:
+	movs	a3, a3		@ anything left?
+	moveq	pc, lr		@ nope
+	rsb	a3, a3, $7
+	add	pc, pc, a3, lsl $2
+	mov	r0, r0
+	strb	a2, [a4], $1
+	strb	a2, [a4], $1
+	strb	a2, [a4], $1
+	strb	a2, [a4], $1
+	strb	a2, [a4], $1
+	strb	a2, [a4], $1
+	strb	a2, [a4], $1
+	mov	pc, lr
+
+.size memset,.-memset;
+