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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 | /* SPDX-License-Identifier: GPL-2.0 */ /* $Id: memcpy.S,v 1.3 2001/07/27 11:50:52 gniibe Exp $ * * "memcpy" implementation of SuperH * * Copyright (C) 1999 Niibe Yutaka * */ /* * void *memcpy(void *dst, const void *src, size_t n); * No overlap between the memory of DST and of SRC are assumed. */ #include <linux/linkage.h> ENTRY(memcpy) tst r6,r6 bt/s 9f ! if n=0, do nothing mov r4,r0 sub r4,r5 ! From here, r5 has the distance to r0 add r6,r0 ! From here, r0 points the end of copying point mov #12,r1 cmp/gt r6,r1 bt/s 7f ! if it's too small, copy a byte at once add #-1,r5 add #1,r5 ! From here, r6 is free ! ! r4 --> [ ... ] DST [ ... ] SRC ! [ ... ] [ ... ] ! : : ! r0 --> [ ... ] r0+r5 --> [ ... ] ! ! mov r5,r1 mov #3,r2 and r2,r1 shll2 r1 mov r0,r3 ! Save the value on R0 to R3 mova jmptable,r0 add r1,r0 mov.l @r0,r1 jmp @r1 mov r3,r0 ! and back to R0 .balign 4 jmptable: .long case0 .long case1 .long case2 .long case3 ! copy a byte at once 7: mov r4,r2 add #1,r2 8: cmp/hi r2,r0 mov.b @(r0,r5),r1 bt/s 8b ! while (r0>r2) mov.b r1,@-r0 9: rts nop case0: ! ! GHIJ KLMN OPQR --> GHIJ KLMN OPQR ! ! First, align to long word boundary mov r0,r3 and r2,r3 tst r3,r3 bt/s 2f add #-4,r5 add #3,r5 1: dt r3 mov.b @(r0,r5),r1 bf/s 1b mov.b r1,@-r0 ! add #-3,r5 2: ! Second, copy a long word at once mov r4,r2 add #7,r2 3: mov.l @(r0,r5),r1 cmp/hi r2,r0 bt/s 3b mov.l r1,@-r0 ! ! Third, copy a byte at once, if necessary cmp/eq r4,r0 bt/s 9b add #3,r5 bra 8b add #-6,r2 case1: ! ! GHIJ KLMN OPQR --> ...G HIJK LMNO PQR. ! ! First, align to long word boundary mov r0,r3 and r2,r3 tst r3,r3 bt/s 2f add #-1,r5 1: dt r3 mov.b @(r0,r5),r1 bf/s 1b mov.b r1,@-r0 ! 2: ! Second, read a long word and write a long word at once mov.l @(r0,r5),r1 add #-4,r5 mov r4,r2 add #7,r2 ! #ifdef __LITTLE_ENDIAN__ 3: mov r1,r3 ! RQPO shll16 r3 shll8 r3 ! Oxxx mov.l @(r0,r5),r1 ! NMLK mov r1,r6 shlr8 r6 ! xNML or r6,r3 ! ONML cmp/hi r2,r0 bt/s 3b mov.l r3,@-r0 #else 3: mov r1,r3 ! OPQR shlr16 r3 shlr8 r3 ! xxxO mov.l @(r0,r5),r1 ! KLMN mov r1,r6 shll8 r6 ! LMNx or r6,r3 ! LMNO cmp/hi r2,r0 bt/s 3b mov.l r3,@-r0 #endif ! ! Third, copy a byte at once, if necessary cmp/eq r4,r0 bt/s 9b add #4,r5 bra 8b add #-6,r2 case2: ! ! GHIJ KLMN OPQR --> ..GH IJKL MNOP QR.. ! ! First, align to word boundary tst #1,r0 bt/s 2f add #-1,r5 mov.b @(r0,r5),r1 mov.b r1,@-r0 ! 2: ! Second, read a word and write a word at once add #-1,r5 mov r4,r2 add #3,r2 ! 3: mov.w @(r0,r5),r1 cmp/hi r2,r0 bt/s 3b mov.w r1,@-r0 ! ! Third, copy a byte at once, if necessary cmp/eq r4,r0 bt/s 9b add #1,r5 mov.b @(r0,r5),r1 rts mov.b r1,@-r0 case3: ! ! GHIJ KLMN OPQR --> .GHI JKLM NOPQ R... ! ! First, align to long word boundary mov r0,r3 and r2,r3 tst r3,r3 bt/s 2f add #-1,r5 1: dt r3 mov.b @(r0,r5),r1 bf/s 1b mov.b r1,@-r0 ! 2: ! Second, read a long word and write a long word at once add #-2,r5 mov.l @(r0,r5),r1 add #-4,r5 mov r4,r2 add #7,r2 ! #ifdef __LITTLE_ENDIAN__ 3: mov r1,r3 ! RQPO shll8 r3 ! QPOx mov.l @(r0,r5),r1 ! NMLK mov r1,r6 shlr16 r6 shlr8 r6 ! xxxN or r6,r3 ! QPON cmp/hi r2,r0 bt/s 3b mov.l r3,@-r0 #else 3: mov r1,r3 ! OPQR shlr8 r3 ! xOPQ mov.l @(r0,r5),r1 ! KLMN mov r1,r6 shll16 r6 shll8 r6 ! Nxxx or r6,r3 ! NOPQ cmp/hi r2,r0 bt/s 3b mov.l r3,@-r0 #endif ! ! Third, copy a byte at once, if necessary cmp/eq r4,r0 bt/s 9b add #6,r5 bra 8b add #-6,r2 |