memcpy.S revision 1.1.4.2
1 1.1.4.2 tls /* $NetBSD: memcpy.S,v 1.1.4.2 2014/08/19 23:45:12 tls Exp $ */ 2 1.1.4.2 tls 3 1.1.4.2 tls /*- 4 1.1.4.2 tls * Copyright (c) 2014 The NetBSD Foundation, Inc. 5 1.1.4.2 tls * All rights reserved. 6 1.1.4.2 tls * 7 1.1.4.2 tls * This code is derived from software contributed to The NetBSD Foundation 8 1.1.4.2 tls * by Matt Thomas of 3am Software Foundry. 9 1.1.4.2 tls * 10 1.1.4.2 tls * Redistribution and use in source and binary forms, with or without 11 1.1.4.2 tls * modification, are permitted provided that the following conditions 12 1.1.4.2 tls * are met: 13 1.1.4.2 tls * 1. Redistributions of source code must retain the above copyright 14 1.1.4.2 tls * notice, this list of conditions and the following disclaimer. 15 1.1.4.2 tls * 2. Redistributions in binary form must reproduce the above copyright 16 1.1.4.2 tls * notice, this list of conditions and the following disclaimer in the 17 1.1.4.2 tls * documentation and/or other materials provided with the distribution. 18 1.1.4.2 tls * 19 1.1.4.2 tls * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 1.1.4.2 tls * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.1.4.2 tls * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.1.4.2 tls * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 1.1.4.2 tls * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 1.1.4.2 tls * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 1.1.4.2 tls * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 1.1.4.2 tls * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 1.1.4.2 tls * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 1.1.4.2 tls * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 1.1.4.2 tls * POSSIBILITY OF SUCH DAMAGE. 30 1.1.4.2 tls */ 31 1.1.4.2 tls 32 1.1.4.2 tls #include <machine/asm.h> 33 1.1.4.2 tls 34 1.1.4.2 tls RCSID("$NetBSD: memcpy.S,v 1.1.4.2 2014/08/19 23:45:12 tls Exp $") 35 1.1.4.2 tls 36 1.1.4.2 tls /* LINTSTUB: void *memcpy(void * restrict, const void * restrict, size_t); */ 37 1.1.4.2 tls 38 1.1.4.2 tls ENTRY(memcpy) 39 1.1.4.2 tls mov x10, x0 40 1.1.4.2 tls mov x11, x1 41 1.1.4.2 tls cbz x2, .Lmemcpy_ret 42 1.1.4.2 tls 43 1.1.4.2 tls cmp x2, #7 44 1.1.4.2 tls b.ls .Lmemcpy_last_dword 45 1.1.4.2 tls 46 1.1.4.2 tls ands x3, x10, #7 47 1.1.4.2 tls b.eq .Lmemcpy_dword_aligned 48 1.1.4.2 tls 49 1.1.4.2 tls /* 50 1.1.4.2 tls * The dst address doesn't have dword alignment. The src address may or may 51 1.1.4.2 tls * not have the same alignment. Make dst dword aligned. Hope src will be 52 1.1.4.2 tls * dword aligned but if it isn't, take advantage of unaligned access. 53 1.1.4.2 tls */ 54 1.1.4.2 tls add x2, x2, x3 /* add unalignment to length */ 55 1.1.4.2 tls sub x2, x2, #8 /* now subtract a dword */ 56 1.1.4.2 tls 57 1.1.4.2 tls tbz x10, #0, .Lmemcpy_hword_aligned 58 1.1.4.2 tls ldrb w4, [x11], #1 59 1.1.4.2 tls strb w4, [x10], #1 60 1.1.4.2 tls .Lmemcpy_hword_aligned: 61 1.1.4.2 tls tbz x10, #1, .Lmemcpy_word_aligned 62 1.1.4.2 tls ldrh w4, [x11], #2 63 1.1.4.2 tls strh w4, [x10], #2 64 1.1.4.2 tls .Lmemcpy_word_aligned: 65 1.1.4.2 tls tbz x10, #2, .Lmemcpy_dword_aligned 66 1.1.4.2 tls ldr w4, [x11], #4 67 1.1.4.2 tls str w4, [x10], #4 68 1.1.4.2 tls .Lmemcpy_dword_aligned: 69 1.1.4.2 tls /* 70 1.1.4.2 tls * destination is now dword aligned. 71 1.1.4.2 tls */ 72 1.1.4.2 tls subs x2, x2, #32 73 1.1.4.2 tls b.mi .Lmemcpy_last_oword 74 1.1.4.2 tls 75 1.1.4.2 tls .Lmemcpy_oword_loop: 76 1.1.4.2 tls ldp x4, x5, [x11], #16 77 1.1.4.2 tls ldp x6, x7, [x11], #16 78 1.1.4.2 tls stp x4, x5, [x10], #16 79 1.1.4.2 tls stp x6, x7, [x10], #16 80 1.1.4.2 tls cbz x2, .Lmemcpy_ret 81 1.1.4.2 tls subs x2, x2, #32 82 1.1.4.2 tls b.pl .Lmemcpy_oword_loop 83 1.1.4.2 tls 84 1.1.4.2 tls .Lmemcpy_last_oword: 85 1.1.4.2 tls /* 86 1.1.4.2 tls * We have 31 bytes or less to copy. First see if we can write a qword 87 1.1.4.2 tls */ 88 1.1.4.2 tls tbz x2, #4, .Lmemcpy_last_qword 89 1.1.4.2 tls ldp x4, x5, [x11], #16 /* read word */ 90 1.1.4.2 tls stp x4, x5, [x10], #16 /* write word */ 91 1.1.4.2 tls 92 1.1.4.2 tls .Lmemcpy_last_qword: 93 1.1.4.2 tls /* 94 1.1.4.2 tls * We have 15 bytes or less to copy. First see if we can write a dword 95 1.1.4.2 tls */ 96 1.1.4.2 tls tbz x2, #3, .Lmemcpy_last_dword 97 1.1.4.2 tls ldr x4, [x11], #8 /* read word */ 98 1.1.4.2 tls str x4, [x10], #8 /* write word */ 99 1.1.4.2 tls 100 1.1.4.2 tls .Lmemcpy_last_dword: 101 1.1.4.2 tls /* 102 1.1.4.2 tls * We have 7 bytes or less to copy. First see if we can write a word 103 1.1.4.2 tls */ 104 1.1.4.2 tls tbz x2, #2, .Lmemcpy_last_word 105 1.1.4.2 tls ldr w4, [x11], #4 /* read word */ 106 1.1.4.2 tls str w4, [x10], #4 /* write word */ 107 1.1.4.2 tls 108 1.1.4.2 tls .Lmemcpy_last_word: 109 1.1.4.2 tls /* 110 1.1.4.2 tls * We have 3 bytes or less to copy. First see if we can write a hword 111 1.1.4.2 tls */ 112 1.1.4.2 tls tbz x2, #1, .Lmemcpy_last_hword 113 1.1.4.2 tls ldrh w4, [x11], #2 114 1.1.4.2 tls strh w4, [x10], #2 115 1.1.4.2 tls 116 1.1.4.2 tls .Lmemcpy_last_hword: 117 1.1.4.2 tls /* 118 1.1.4.2 tls * We have 1 or none bytes to copy. 119 1.1.4.2 tls */ 120 1.1.4.2 tls tbz x2, #0, .Lmemcpy_ret 121 1.1.4.2 tls ldrb w4, [x11] 122 1.1.4.2 tls strb w4, [x10] 123 1.1.4.2 tls 124 1.1.4.2 tls .Lmemcpy_ret: 125 1.1.4.2 tls ret 126 1.1.4.2 tls END(memcpy) 127
Indexes created Tue Sep 30 20:09:53 GMT 2025