minix/lib/nbsd_libc/arch/powerpc64/string/bzero.S
Gianluca Guida b6cbf7203b Import unmodified NetBSD libc in trunk
This patch imports the unmodified current version of NetBSD libc.
The NetBSD includes are in /nbsd_include, while the libc code itself is 
split between lib/nbsd_libc and common/lib/libc.
2011-02-14 19:36:03 +00:00

100 lines
2.6 KiB
ArmAsm

/* $NetBSD: bzero.S,v 1.4 2008/04/28 20:22:57 martin Exp $ */
/*-
* Copyright (c) 2006 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Ross Harvey.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
.file "bzero.c"
ENTRY(bzero)
mr 5, 4 # translate to memcpy signature
li 4, 0 # add missing memcpy param
ENTRY(memset)
cmpldi 7, 5, 7 # only optimize if len >= 8
mr 9, 3
ble 7, 2f
rldicl. 0, 3, 0, 61 # only optimize if aligned
beq 0, 4f
2:
cmpdi 7, 5, 0
beqlr 7
3:
mtctr 5
rldicl 0, 4, 0, 56
.p2align 4,, 15
2:
stb 0, 0(9) # byte-at-a-time loop
addi 9, 9, 1
bdnz 2b
blr # done
4:
rldicl 4, 4, 0, 56 # construct parallel store
cmpldi 7, 5, 31
mr 10, 3
sldi 0, 4, 8
or 0, 0, 4
sldi 9, 0, 16
or 0, 0, 9
sldi 11, 0, 32
or 0, 0, 11
ble 7, 5f
addi 9, 5, -32
srdi 9, 9, 5
addi 9, 9, 1
mtctr 9
.p2align 4,, 15
2:
std 0, 0(10) # 8-way + unrolled store loop
std 0, 8(10)
addi 5, 5, -32 # schedule count decrement
std 0, 16(10)
std 0, 24(10)
addi 10, 10, 32
bdnz 2b
cmpldi 7, 5, 7
ble 7, 8f
5:
addi 9, 5, -8
srdi 9, 9, 3
addi 9, 9, 1
mtctr 9
.p2align 4,, 15
14:
std 0, 0(10) # 8-way not-unrolled loop
addi 5, 5, -8
addi 10, 10, 8
bdnz 14b
8:
cmpdi 7, 5, 0
mr 9, 10
bne 7, 3b
blr
.long 0
.byte 0, 0, 0, 0, 0, 0, 0, 0
.size .memset, .-.memset