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, wchar_t is 4 bytes 58 */ 59 60 #include <private/bionic_asm.h> 61 62 /* Parameters and result. */ 63 #define dstin x0 64 #define src x1 65 #define count x2 66 #define srcend x3 67 #define dstend x4 68 #define tmp1 x5 69 #define A_l x6 70 #define A_h x7 71 #define B_l x8 72 #define B_h x9 73 #define C_l x10 74 #define C_h x11 75 #define D_l x12 76 #define D_h x13 77 #define E_l count 78 #define E_h tmp1 79 80 /* All memmoves up to 96 bytes are done by memcpy as it supports overlaps. 81 Larger backwards copies are also handled by memcpy. The only remaining 82 case is forward large copies. The destination is aligned, and an 83 unrolled loop processes 64 bytes per iteration. 84 */ 85 86 #if defined(WMEMMOVE) 87 ENTRY(wmemmove) 88 lsl count, count, #2 89 #else 90 ENTRY(memmove) 91 #endif 92 sub tmp1, dstin, src 93 cmp count, 96 94 ccmp tmp1, count, 2, hi 95 b.hs memcpy 96 97 cbz tmp1, 3f 98 add dstend, dstin, count 99 add srcend, src, count 100 101 /* Align dstend to 16 byte alignment so that we don't cross cache line 102 boundaries on both loads and stores. There are at least 96 bytes 103 to copy, so copy 16 bytes unaligned and then align. The loop 104 copies 64 bytes per iteration and prefetches one iteration ahead. */ 105 106 and tmp1, dstend, 15 107 ldp D_l, D_h, [srcend, -16] 108 sub srcend, srcend, tmp1 109 sub count, count, tmp1 110 ldp A_l, A_h, [srcend, -16] 111 stp D_l, D_h, [dstend, -16] 112 ldp B_l, B_h, [srcend, -32] 113 ldp C_l, C_h, [srcend, -48] 114 ldp D_l, D_h, [srcend, -64]! 115 sub dstend, dstend, tmp1 116 subs count, count, 128 117 b.ls 2f 118 nop 119 1: 120 stp A_l, A_h, [dstend, -16] 121 ldp A_l, A_h, [srcend, -16] 122 stp B_l, B_h, [dstend, -32] 123 ldp B_l, B_h, [srcend, -32] 124 stp C_l, C_h, [dstend, -48] 125 ldp C_l, C_h, [srcend, -48] 126 stp D_l, D_h, [dstend, -64]! 127 ldp D_l, D_h, [srcend, -64]! 128 subs count, count, 64 129 b.hi 1b 130 131 /* Write the last full set of 64 bytes. The remainder is at most 64 132 bytes, so it is safe to always copy 64 bytes from the start even if 133 there is just 1 byte left. */ 134 2: 135 ldp E_l, E_h, [src, 48] 136 stp A_l, A_h, [dstend, -16] 137 ldp A_l, A_h, [src, 32] 138 stp B_l, B_h, [dstend, -32] 139 ldp B_l, B_h, [src, 16] 140 stp C_l, C_h, [dstend, -48] 141 ldp C_l, C_h, [src] 142 stp D_l, D_h, [dstend, -64] 143 stp E_l, E_h, [dstin, 48] 144 stp A_l, A_h, [dstin, 32] 145 stp B_l, B_h, [dstin, 16] 146 stp C_l, C_h, [dstin] 147 3: ret 148 149 #if defined(WMEMMOVE) 150 END(wmemmove) 151 #else 152 END(memmove) 153 #endif 154
