1/* Copyright (c) 2013, Linaro Limited 2 All rights reserved. 3 4 Redistribution and use in source and binary forms, with or without 5 modification, are permitted provided that the following conditions are met: 6 * Redistributions of source code must retain the above copyright 7 notice, this list of conditions and the following disclaimer. 8 * Redistributions in binary form must reproduce the above copyright 9 notice, this list of conditions and the following disclaimer in the 10 documentation and/or other materials provided with the distribution. 11 * Neither the name of the Linaro nor the 12 names of its contributors may be used to endorse or promote products 13 derived from this software without specific prior written permission. 14 15 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 18 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 19 HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 21 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 25 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ 26 27/* 28 * Copyright (c) 2015 ARM Ltd 29 * All rights reserved. 30 * 31 * Redistribution and use in source and binary forms, with or without 32 * modification, are permitted provided that the following conditions 33 * are met: 34 * 1. Redistributions of source code must retain the above copyright 35 * notice, this list of conditions and the following disclaimer. 36 * 2. Redistributions in binary form must reproduce the above copyright 37 * notice, this list of conditions and the following disclaimer in the 38 * documentation and/or other materials provided with the distribution. 39 * 3. The name of the company may not be used to endorse or promote 40 * products derived from this software without specific prior written 41 * permission. 42 * 43 * THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED 44 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 45 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 46 * IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 47 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 48 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 49 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 50 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 51 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 52 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 53 */ 54 55/* Assumptions: 56 * 57 * ARMv8-a, AArch64, unaligned accesses 58 */ 59 60 .macro def_fn f p2align=0 61 .text 62 .p2align \p2align 63 .global \f 64 .type \f, %function 65\f: 66 .endm 67 68/* Parameters and result. */ 69#define dstin x0 70#define src x1 71#define count x2 72#define srcend x3 73#define dstend x4 74#define tmp1 x5 75#define A_l x6 76#define A_h x7 77#define B_l x8 78#define B_h x9 79#define C_l x10 80#define C_h x11 81#define D_l x12 82#define D_h x13 83#define E_l count 84#define E_h tmp1 85 86/* All memmoves up to 96 bytes are done by memcpy as it supports overlaps. 87 Larger backwards copies are also handled by memcpy. The only remaining 88 case is forward large copies. The destination is aligned, and an 89 unrolled loop processes 64 bytes per iteration. 90*/ 91 92def_fn memmove, 6 93 sub tmp1, dstin, src 94 cmp count, 96 95 ccmp tmp1, count, 2, hi 96 b.hs memcpy 97 98 cbz tmp1, 3f 99 add dstend, dstin, count 100 add srcend, src, count 101 102 /* Align dstend to 16 byte alignment so that we don't cross cache line 103 boundaries on both loads and stores. There are at least 96 bytes 104 to copy, so copy 16 bytes unaligned and then align. The loop 105 copies 64 bytes per iteration and prefetches one iteration ahead. */ 106 107 and tmp1, dstend, 15 108 ldp D_l, D_h, [srcend, -16] 109 sub srcend, srcend, tmp1 110 sub count, count, tmp1 111 ldp A_l, A_h, [srcend, -16] 112 stp D_l, D_h, [dstend, -16] 113 ldp B_l, B_h, [srcend, -32] 114 ldp C_l, C_h, [srcend, -48] 115 ldp D_l, D_h, [srcend, -64]! 116 sub dstend, dstend, tmp1 117 subs count, count, 128 118 b.ls 2f 119 nop 1201: 121 stp A_l, A_h, [dstend, -16] 122 ldp A_l, A_h, [srcend, -16] 123 stp B_l, B_h, [dstend, -32] 124 ldp B_l, B_h, [srcend, -32] 125 stp C_l, C_h, [dstend, -48] 126 ldp C_l, C_h, [srcend, -48] 127 stp D_l, D_h, [dstend, -64]! 128 ldp D_l, D_h, [srcend, -64]! 129 subs count, count, 64 130 b.hi 1b 131 132 /* Write the last full set of 64 bytes. The remainder is at most 64 133 bytes, so it is safe to always copy 64 bytes from the start even if 134 there is just 1 byte left. */ 1352: 136 ldp E_l, E_h, [src, 48] 137 stp A_l, A_h, [dstend, -16] 138 ldp A_l, A_h, [src, 32] 139 stp B_l, B_h, [dstend, -32] 140 ldp B_l, B_h, [src, 16] 141 stp C_l, C_h, [dstend, -48] 142 ldp C_l, C_h, [src] 143 stp D_l, D_h, [dstend, -64] 144 stp E_l, E_h, [dstin, 48] 145 stp A_l, A_h, [dstin, 32] 146 stp B_l, B_h, [dstin, 16] 147 stp C_l, C_h, [dstin] 1483: ret 149 150 .size memmove, . - memmove 151