/* $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 |