1*0a6a1f1dSLionel Sambuc/* $NetBSD: memcpy.S,v 1.1 2014/08/10 05:47:35 matt Exp $ */ 2*0a6a1f1dSLionel Sambuc 3*0a6a1f1dSLionel Sambuc/*- 4*0a6a1f1dSLionel Sambuc * Copyright (c) 2014 The NetBSD Foundation, Inc. 5*0a6a1f1dSLionel Sambuc * All rights reserved. 6*0a6a1f1dSLionel Sambuc * 7*0a6a1f1dSLionel Sambuc * This code is derived from software contributed to The NetBSD Foundation 8*0a6a1f1dSLionel Sambuc * by Matt Thomas of 3am Software Foundry. 9*0a6a1f1dSLionel Sambuc * 10*0a6a1f1dSLionel Sambuc * Redistribution and use in source and binary forms, with or without 11*0a6a1f1dSLionel Sambuc * modification, are permitted provided that the following conditions 12*0a6a1f1dSLionel Sambuc * are met: 13*0a6a1f1dSLionel Sambuc * 1. Redistributions of source code must retain the above copyright 14*0a6a1f1dSLionel Sambuc * notice, this list of conditions and the following disclaimer. 15*0a6a1f1dSLionel Sambuc * 2. Redistributions in binary form must reproduce the above copyright 16*0a6a1f1dSLionel Sambuc * notice, this list of conditions and the following disclaimer in the 17*0a6a1f1dSLionel Sambuc * documentation and/or other materials provided with the distribution. 18*0a6a1f1dSLionel Sambuc * 19*0a6a1f1dSLionel Sambuc * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20*0a6a1f1dSLionel Sambuc * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21*0a6a1f1dSLionel Sambuc * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22*0a6a1f1dSLionel Sambuc * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23*0a6a1f1dSLionel Sambuc * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24*0a6a1f1dSLionel Sambuc * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25*0a6a1f1dSLionel Sambuc * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26*0a6a1f1dSLionel Sambuc * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27*0a6a1f1dSLionel Sambuc * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28*0a6a1f1dSLionel Sambuc * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29*0a6a1f1dSLionel Sambuc * POSSIBILITY OF SUCH DAMAGE. 30*0a6a1f1dSLionel Sambuc */ 31*0a6a1f1dSLionel Sambuc 32*0a6a1f1dSLionel Sambuc#include <machine/asm.h> 33*0a6a1f1dSLionel Sambuc 34*0a6a1f1dSLionel SambucRCSID("$NetBSD: memcpy.S,v 1.1 2014/08/10 05:47:35 matt Exp $") 35*0a6a1f1dSLionel Sambuc 36*0a6a1f1dSLionel Sambuc/* LINTSTUB: void *memcpy(void * restrict, const void * restrict, size_t); */ 37*0a6a1f1dSLionel Sambuc 38*0a6a1f1dSLionel SambucENTRY(memcpy) 39*0a6a1f1dSLionel Sambuc mov x10, x0 40*0a6a1f1dSLionel Sambuc mov x11, x1 41*0a6a1f1dSLionel Sambuc cbz x2, .Lmemcpy_ret 42*0a6a1f1dSLionel Sambuc 43*0a6a1f1dSLionel Sambuc cmp x2, #7 44*0a6a1f1dSLionel Sambuc b.ls .Lmemcpy_last_dword 45*0a6a1f1dSLionel Sambuc 46*0a6a1f1dSLionel Sambuc ands x3, x10, #7 47*0a6a1f1dSLionel Sambuc b.eq .Lmemcpy_dword_aligned 48*0a6a1f1dSLionel Sambuc 49*0a6a1f1dSLionel Sambuc/* 50*0a6a1f1dSLionel Sambuc * The dst address doesn't have dword alignment. The src address may or may 51*0a6a1f1dSLionel Sambuc * not have the same alignment. Make dst dword aligned. Hope src will be 52*0a6a1f1dSLionel Sambuc * dword aligned but if it isn't, take advantage of unaligned access. 53*0a6a1f1dSLionel Sambuc */ 54*0a6a1f1dSLionel Sambuc add x2, x2, x3 /* add unalignment to length */ 55*0a6a1f1dSLionel Sambuc sub x2, x2, #8 /* now subtract a dword */ 56*0a6a1f1dSLionel Sambuc 57*0a6a1f1dSLionel Sambuc tbz x10, #0, .Lmemcpy_hword_aligned 58*0a6a1f1dSLionel Sambuc ldrb w4, [x11], #1 59*0a6a1f1dSLionel Sambuc strb w4, [x10], #1 60*0a6a1f1dSLionel Sambuc.Lmemcpy_hword_aligned: 61*0a6a1f1dSLionel Sambuc tbz x10, #1, .Lmemcpy_word_aligned 62*0a6a1f1dSLionel Sambuc ldrh w4, [x11], #2 63*0a6a1f1dSLionel Sambuc strh w4, [x10], #2 64*0a6a1f1dSLionel Sambuc.Lmemcpy_word_aligned: 65*0a6a1f1dSLionel Sambuc tbz x10, #2, .Lmemcpy_dword_aligned 66*0a6a1f1dSLionel Sambuc ldr w4, [x11], #4 67*0a6a1f1dSLionel Sambuc str w4, [x10], #4 68*0a6a1f1dSLionel Sambuc.Lmemcpy_dword_aligned: 69*0a6a1f1dSLionel Sambuc /* 70*0a6a1f1dSLionel Sambuc * destination is now dword aligned. 71*0a6a1f1dSLionel Sambuc */ 72*0a6a1f1dSLionel Sambuc subs x2, x2, #32 73*0a6a1f1dSLionel Sambuc b.mi .Lmemcpy_last_oword 74*0a6a1f1dSLionel Sambuc 75*0a6a1f1dSLionel Sambuc.Lmemcpy_oword_loop: 76*0a6a1f1dSLionel Sambuc ldp x4, x5, [x11], #16 77*0a6a1f1dSLionel Sambuc ldp x6, x7, [x11], #16 78*0a6a1f1dSLionel Sambuc stp x4, x5, [x10], #16 79*0a6a1f1dSLionel Sambuc stp x6, x7, [x10], #16 80*0a6a1f1dSLionel Sambuc cbz x2, .Lmemcpy_ret 81*0a6a1f1dSLionel Sambuc subs x2, x2, #32 82*0a6a1f1dSLionel Sambuc b.pl .Lmemcpy_oword_loop 83*0a6a1f1dSLionel Sambuc 84*0a6a1f1dSLionel Sambuc.Lmemcpy_last_oword: 85*0a6a1f1dSLionel Sambuc /* 86*0a6a1f1dSLionel Sambuc * We have 31 bytes or less to copy. First see if we can write a qword 87*0a6a1f1dSLionel Sambuc */ 88*0a6a1f1dSLionel Sambuc tbz x2, #4, .Lmemcpy_last_qword 89*0a6a1f1dSLionel Sambuc ldp x4, x5, [x11], #16 /* read word */ 90*0a6a1f1dSLionel Sambuc stp x4, x5, [x10], #16 /* write word */ 91*0a6a1f1dSLionel Sambuc 92*0a6a1f1dSLionel Sambuc.Lmemcpy_last_qword: 93*0a6a1f1dSLionel Sambuc /* 94*0a6a1f1dSLionel Sambuc * We have 15 bytes or less to copy. First see if we can write a dword 95*0a6a1f1dSLionel Sambuc */ 96*0a6a1f1dSLionel Sambuc tbz x2, #3, .Lmemcpy_last_dword 97*0a6a1f1dSLionel Sambuc ldr x4, [x11], #8 /* read word */ 98*0a6a1f1dSLionel Sambuc str x4, [x10], #8 /* write word */ 99*0a6a1f1dSLionel Sambuc 100*0a6a1f1dSLionel Sambuc.Lmemcpy_last_dword: 101*0a6a1f1dSLionel Sambuc /* 102*0a6a1f1dSLionel Sambuc * We have 7 bytes or less to copy. First see if we can write a word 103*0a6a1f1dSLionel Sambuc */ 104*0a6a1f1dSLionel Sambuc tbz x2, #2, .Lmemcpy_last_word 105*0a6a1f1dSLionel Sambuc ldr w4, [x11], #4 /* read word */ 106*0a6a1f1dSLionel Sambuc str w4, [x10], #4 /* write word */ 107*0a6a1f1dSLionel Sambuc 108*0a6a1f1dSLionel Sambuc.Lmemcpy_last_word: 109*0a6a1f1dSLionel Sambuc /* 110*0a6a1f1dSLionel Sambuc * We have 3 bytes or less to copy. First see if we can write a hword 111*0a6a1f1dSLionel Sambuc */ 112*0a6a1f1dSLionel Sambuc tbz x2, #1, .Lmemcpy_last_hword 113*0a6a1f1dSLionel Sambuc ldrh w4, [x11], #2 114*0a6a1f1dSLionel Sambuc strh w4, [x10], #2 115*0a6a1f1dSLionel Sambuc 116*0a6a1f1dSLionel Sambuc.Lmemcpy_last_hword: 117*0a6a1f1dSLionel Sambuc /* 118*0a6a1f1dSLionel Sambuc * We have 1 or none bytes to copy. 119*0a6a1f1dSLionel Sambuc */ 120*0a6a1f1dSLionel Sambuc tbz x2, #0, .Lmemcpy_ret 121*0a6a1f1dSLionel Sambuc ldrb w4, [x11] 122*0a6a1f1dSLionel Sambuc strb w4, [x10] 123*0a6a1f1dSLionel Sambuc 124*0a6a1f1dSLionel Sambuc.Lmemcpy_ret: 125*0a6a1f1dSLionel Sambuc ret 126*0a6a1f1dSLionel SambucEND(memcpy) 127