1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* $Id: memmove.S,v 1.2 2001/07/27 11:51:09 gniibe Exp $ 3 * 4 * "memmove" implementation of SuperH 5 * 6 * Copyright (C) 1999 Niibe Yutaka 7 * 8 */ 9 10 /* 11 * void *memmove(void *dst, const void *src, size_t n); 12 * The memory areas may overlap. 13 */ 14 15 #include <linux/linkage.h> 16 ENTRY(memmove) 17 ! if dest > src, call memcpy (it copies in decreasing order) 18 cmp/hi r5,r4 19 bf 1f 20 mov.l 2f,r0 21 jmp @r0 22 nop 23 .balign 4 24 2: .long memcpy 25 1: 26 sub r5,r4 ! From here, r4 has the distance to r0 27 tst r6,r6 28 bt/s 9f ! if n=0, do nothing 29 mov r5,r0 30 add r6,r5 31 mov #12,r1 32 cmp/gt r6,r1 33 bt/s 8f ! if it's too small, copy a byte at once 34 add #-1,r4 35 add #1,r4 36 ! 37 ! [ ... ] DST [ ... ] SRC 38 ! [ ... ] [ ... ] 39 ! : : 40 ! r0+r4--> [ ... ] r0 --> [ ... ] 41 ! : : 42 ! [ ... ] [ ... ] 43 ! r5 --> 44 ! 45 mov r4,r1 46 mov #3,r2 47 and r2,r1 48 shll2 r1 49 mov r0,r3 ! Save the value on R0 to R3 50 mova jmptable,r0 51 add r1,r0 52 mov.l @r0,r1 53 jmp @r1 54 mov r3,r0 ! and back to R0 55 .balign 4 56 jmptable: 57 .long case0 58 .long case1 59 .long case2 60 .long case3 61 62 ! copy a byte at once 63 8: mov.b @r0+,r1 64 cmp/hs r5,r0 65 bf/s 8b ! while (r0<r5) 66 mov.b r1,@(r0,r4) 67 add #1,r4 68 9: 69 add r4,r0 70 rts 71 sub r6,r0 72 73 case_none: 74 bra 8b 75 add #-1,r4 76 77 case0: 78 ! 79 ! GHIJ KLMN OPQR --> GHIJ KLMN OPQR 80 ! 81 ! First, align to long word boundary 82 mov r0,r3 83 and r2,r3 84 tst r3,r3 85 bt/s 2f 86 add #-1,r4 87 mov #4,r2 88 sub r3,r2 89 1: dt r2 90 mov.b @r0+,r1 91 bf/s 1b 92 mov.b r1,@(r0,r4) 93 ! 94 2: ! Second, copy a long word at once 95 add #-3,r4 96 add #-3,r5 97 3: mov.l @r0+,r1 98 cmp/hs r5,r0 99 bf/s 3b 100 mov.l r1,@(r0,r4) 101 add #3,r5 102 ! 103 ! Third, copy a byte at once, if necessary 104 cmp/eq r5,r0 105 bt/s 9b 106 add #4,r4 107 bra 8b 108 add #-1,r4 109 110 case3: 111 ! 112 ! GHIJ KLMN OPQR --> ...G HIJK LMNO PQR. 113 ! 114 ! First, align to long word boundary 115 mov r0,r3 116 and r2,r3 117 tst r3,r3 118 bt/s 2f 119 add #-1,r4 120 mov #4,r2 121 sub r3,r2 122 1: dt r2 123 mov.b @r0+,r1 124 bf/s 1b 125 mov.b r1,@(r0,r4) 126 ! 127 2: ! Second, read a long word and write a long word at once 128 add #-2,r4 129 mov.l @(r0,r4),r1 130 add #-7,r5 131 add #-4,r4 132 ! 133 #ifdef __LITTLE_ENDIAN__ 134 shll8 r1 135 3: mov r1,r3 ! JIHG 136 shlr8 r3 ! xJIH 137 mov.l @r0+,r1 ! NMLK 138 mov r1,r2 139 shll16 r2 140 shll8 r2 ! Kxxx 141 or r2,r3 ! KJIH 142 cmp/hs r5,r0 143 bf/s 3b 144 mov.l r3,@(r0,r4) 145 #else 146 shlr8 r1 147 3: mov r1,r3 ! GHIJ 148 shll8 r3 ! HIJx 149 mov.l @r0+,r1 ! KLMN 150 mov r1,r2 151 shlr16 r2 152 shlr8 r2 ! xxxK 153 or r2,r3 ! HIJK 154 cmp/hs r5,r0 155 bf/s 3b 156 mov.l r3,@(r0,r4) 157 #endif 158 add #7,r5 159 ! 160 ! Third, copy a byte at once, if necessary 161 cmp/eq r5,r0 162 bt/s 9b 163 add #7,r4 164 add #-3,r0 165 bra 8b 166 add #-1,r4 167 168 case2: 169 ! 170 ! GHIJ KLMN OPQR --> ..GH IJKL MNOP QR.. 171 ! 172 ! First, align to word boundary 173 tst #1,r0 174 bt/s 2f 175 add #-1,r4 176 mov.b @r0+,r1 177 mov.b r1,@(r0,r4) 178 ! 179 2: ! Second, read a word and write a word at once 180 add #-1,r4 181 add #-1,r5 182 ! 183 3: mov.w @r0+,r1 184 cmp/hs r5,r0 185 bf/s 3b 186 mov.w r1,@(r0,r4) 187 add #1,r5 188 ! 189 ! Third, copy a byte at once, if necessary 190 cmp/eq r5,r0 191 bt/s 9b 192 add #2,r4 193 mov.b @r0,r1 194 mov.b r1,@(r0,r4) 195 bra 9b 196 add #1,r0 197 198 case1: 199 ! 200 ! GHIJ KLMN OPQR --> .GHI JKLM NOPQ R... 201 ! 202 ! First, align to long word boundary 203 mov r0,r3 204 and r2,r3 205 tst r3,r3 206 bt/s 2f 207 add #-1,r4 208 mov #4,r2 209 sub r3,r2 210 1: dt r2 211 mov.b @r0+,r1 212 bf/s 1b 213 mov.b r1,@(r0,r4) 214 ! 215 2: ! Second, read a long word and write a long word at once 216 mov.l @(r0,r4),r1 217 add #-7,r5 218 add #-4,r4 219 ! 220 #ifdef __LITTLE_ENDIAN__ 221 shll16 r1 222 shll8 r1 223 3: mov r1,r3 ! JIHG 224 shlr16 r3 225 shlr8 r3 ! xxxJ 226 mov.l @r0+,r1 ! NMLK 227 mov r1,r2 228 shll8 r2 ! MLKx 229 or r2,r3 ! MLKJ 230 cmp/hs r5,r0 231 bf/s 3b 232 mov.l r3,@(r0,r4) 233 #else 234 shlr16 r1 235 shlr8 r1 236 3: mov r1,r3 ! GHIJ 237 shll16 r3 238 shll8 r3 ! Jxxx 239 mov.l @r0+,r1 ! KLMN 240 mov r1,r2 241 shlr8 r2 ! xKLM 242 or r2,r3 ! JKLM 243 cmp/hs r5,r0 244 bf/s 3b ! while(r0<r5) 245 mov.l r3,@(r0,r4) 246 #endif 247 add #7,r5 248 ! 249 ! Third, copy a byte at once, if necessary 250 cmp/eq r5,r0 251 bt/s 9b 252 add #5,r4 253 add #-3,r0 254 bra 8b 255 add #-1,r4 256