xref: /netbsd-src/lib/libc/arch/powerpc64/string/bzero.S (revision ce099b40997c43048fb78bd578195f81d2456523)
1*ce099b40Smartin/*	$NetBSD: bzero.S,v 1.4 2008/04/28 20:22:57 martin Exp $	*/
2fefc484dSross
3d48f1466Sross/*-
47008de4cSross * Copyright (c) 2006 The NetBSD Foundation, Inc.
5d48f1466Sross * All rights reserved.
6d48f1466Sross *
77008de4cSross * This code is derived from software contributed to The NetBSD Foundation
87008de4cSross * by Ross Harvey.
97008de4cSross *
10d48f1466Sross * Redistribution and use in source and binary forms, with or without
11d48f1466Sross * modification, are permitted provided that the following conditions
12d48f1466Sross * are met:
13d48f1466Sross * 1. Redistributions of source code must retain the above copyright
14d48f1466Sross *    notice, this list of conditions and the following disclaimer.
15d48f1466Sross * 2. Redistributions in binary form must reproduce the above copyright
16d48f1466Sross *    notice, this list of conditions and the following disclaimer in the
17d48f1466Sross *    documentation and/or other materials provided with the distribution.
18d48f1466Sross *
197008de4cSross * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
207008de4cSross * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,  BUT NOT LIMITED
217008de4cSross * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
227008de4cSross * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
237008de4cSross * BE LIABLE FOR ANY DIRECT, INDIRECT,  INCIDENTAL,  SPECIAL,  EXEMPLARY,  OR
247008de4cSross * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,  PROCUREMENT OF
257008de4cSross * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,  OR PROFITS; OR BUSINESS
267008de4cSross * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
277008de4cSross * CONTRACT, STRICT LIABILITY,  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
287008de4cSross * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
297008de4cSross * POSSIBILITY OF SUCH DAMAGE.
30d48f1466Sross */
31d48f1466Sross
32d48f1466Sross#include	<machine/asm.h>
33d48f1466Sross
347008de4cSross	.file	"bzero.c"
35d48f1466SrossENTRY(bzero)
367008de4cSross	mr	5, 4		# translate to memcpy signature
377008de4cSross	li	4, 0		# add missing memcpy param
38d48f1466SrossENTRY(memset)
397008de4cSross	cmpldi	7, 5, 7		# only optimize if len >= 8
407008de4cSross	mr	9, 3
417008de4cSross	ble	7, 2f
427008de4cSross	rldicl.	0, 3, 0, 61	# only optimize if aligned
437008de4cSross	beq	0, 4f
447008de4cSross2:
457008de4cSross	cmpdi	7, 5, 0
467008de4cSross	beqlr	7
477008de4cSross3:
487008de4cSross	mtctr	5
497008de4cSross	rldicl	0, 4, 0, 56
507008de4cSross	.p2align 4,, 15
517008de4cSross2:
527008de4cSross	stb	0, 0(9)		# byte-at-a-time loop
537008de4cSross	addi	9, 9, 1
547008de4cSross	bdnz	2b
557008de4cSross	blr			# done
567008de4cSross4:
577008de4cSross	rldicl	4, 4, 0, 56	# construct parallel store
587008de4cSross	cmpldi	7, 5, 31
597008de4cSross	mr	10, 3
607008de4cSross	sldi	0, 4, 8
617008de4cSross	or	0, 0, 4
627008de4cSross	sldi	9, 0, 16
637008de4cSross	or	0, 0, 9
647008de4cSross	sldi	11, 0, 32
657008de4cSross	or	0, 0, 11
667008de4cSross	ble	7, 5f
677008de4cSross	addi	9, 5, -32
687008de4cSross	srdi	9, 9, 5
697008de4cSross	addi	9, 9, 1
707008de4cSross	mtctr	9
717008de4cSross	.p2align 4,, 15
727008de4cSross2:
737008de4cSross	std	0, 0(10)	# 8-way + unrolled store loop
747008de4cSross	std	0, 8(10)
757008de4cSross	addi	5, 5, -32	# schedule count decrement
767008de4cSross	std	0, 16(10)
777008de4cSross	std	0, 24(10)
787008de4cSross	addi	10, 10, 32
797008de4cSross	bdnz	2b
807008de4cSross	cmpldi	7, 5, 7
817008de4cSross	ble	7, 8f
827008de4cSross5:
837008de4cSross	addi	9, 5, -8
847008de4cSross	srdi	9, 9, 3
857008de4cSross	addi	9, 9, 1
867008de4cSross	mtctr	9
877008de4cSross	.p2align 4,, 15
887008de4cSross14:
897008de4cSross	std	0, 0(10)	# 8-way not-unrolled loop
907008de4cSross	addi	5, 5, -8
917008de4cSross	addi	10, 10, 8
927008de4cSross	bdnz	14b
937008de4cSross8:
947008de4cSross	cmpdi	7, 5, 0
957008de4cSross	mr	9, 10
967008de4cSross	bne	7, 3b
977008de4cSross	blr
987008de4cSross	.long	0
997008de4cSross	.byte	0, 0, 0, 0, 0, 0, 0, 0
1007008de4cSross	.size	.memset, .-.memset
101