/* memcpy.S: optimised assembly memcpy * * Copyright (C) 2003, 2004 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This 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 * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <features.h> .text .p2align 4 ############################################################################### # # void *memcpy(void *to, const char *from, size_t count) # # - NOTE: must not use any stack. exception detection performs function return # to caller's fixup routine, aborting the remainder of the copy # ############################################################################### .globl memcpy .type memcpy,@function memcpy: or.p gr8,gr9,gr4 orcc gr10,gr0,gr0,icc3 or.p gr10,gr4,gr4 beqlr icc3,#0 # optimise based on best common alignment for to, from & count andicc.p gr4,#0x1f,gr0,icc0 setlos #8,gr11 andicc.p gr4,#0x0f,gr0,icc1 beq icc0,#0,memcpy_32 andicc.p gr4,#0x07,gr0,icc0 beq icc1,#0,memcpy_16 andicc.p gr4,#0x03,gr0,icc1 beq icc0,#0,memcpy_8 andicc.p gr4,#0x01,gr0,icc0 beq icc1,#0,memcpy_4 setlos.p #1,gr11 beq icc0,#0,memcpy_2 # do byte by byte copy sub.p gr8,gr11,gr3 sub gr9,gr11,gr9 0: ldubu.p @(gr9,gr11),gr4 subicc gr10,#1,gr10,icc0 stbu.p gr4,@(gr3,gr11) bne icc0,#2,0b bralr # do halfword by halfword copy memcpy_2: setlos #2,gr11 sub.p gr8,gr11,gr3 sub gr9,gr11,gr9 0: lduhu.p @(gr9,gr11),gr4 subicc gr10,#2,gr10,icc0 sthu.p gr4,@(gr3,gr11) bne icc0,#2,0b bralr # do word by word copy memcpy_4: setlos #4,gr11 sub.p gr8,gr11,gr3 sub gr9,gr11,gr9 0: ldu.p @(gr9,gr11),gr4 subicc gr10,#4,gr10,icc0 stu.p gr4,@(gr3,gr11) bne icc0,#2,0b bralr # do double-word by double-word copy memcpy_8: sub.p gr8,gr11,gr3 sub gr9,gr11,gr9 0: lddu.p @(gr9,gr11),gr4 subicc gr10,#8,gr10,icc0 stdu.p gr4,@(gr3,gr11) bne icc0,#2,0b bralr # do quad-word by quad-word copy memcpy_16: sub.p gr8,gr11,gr3 sub gr9,gr11,gr9 0: lddu @(gr9,gr11),gr4 lddu.p @(gr9,gr11),gr6 subicc gr10,#16,gr10,icc0 stdu gr4,@(gr3,gr11) stdu.p gr6,@(gr3,gr11) bne icc0,#2,0b bralr # do eight-word by eight-word copy memcpy_32: sub.p gr8,gr11,gr3 sub gr9,gr11,gr9 0: lddu @(gr9,gr11),gr4 lddu @(gr9,gr11),gr6 lddu @(gr9,gr11),gr12 lddu.p @(gr9,gr11),gr14 subicc gr10,#32,gr10,icc0 stdu gr4,@(gr3,gr11) stdu gr6,@(gr3,gr11) stdu gr12,@(gr3,gr11) stdu.p gr14,@(gr3,gr11) bne icc0,#2,0b bralr .size memcpy, .-memcpy libc_hidden_def(memcpy)