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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 | /* SPDX-License-Identifier: GPL-2.0-only */ /* * linux/arch/arm/lib/memmove.S * * Author: Nicolas Pitre * Created: Sep 28, 2005 * Copyright: (C) MontaVista Software Inc. */ #include <linux/linkage.h> #include <asm/assembler.h> #include <asm/unwind.h> .text /* * Prototype: void *memmove(void *dest, const void *src, size_t n); * * Note: * * If the memory regions don't overlap, we simply branch to memcpy which is * normally a bit faster. Otherwise the copy is done going downwards. This * is a transposition of the code from copy_template.S but with the copy * occurring in the opposite direction. */ ENTRY(__memmove) WEAK(memmove) UNWIND( .fnstart ) subs ip, r0, r1 cmphi r2, ip bls __memcpy UNWIND( .fnend ) UNWIND( .fnstart ) UNWIND( .save {r0, r4, fpreg, lr} ) stmfd sp!, {r0, r4, UNWIND(fpreg,) lr} UNWIND( .setfp fpreg, sp ) UNWIND( mov fpreg, sp ) add r1, r1, r2 add r0, r0, r2 subs r2, r2, #4 blt 8f ands ip, r0, #3 PLD( pld [r1, #-4] ) bne 9f ands ip, r1, #3 bne 10f 1: subs r2, r2, #(28) stmfd sp!, {r5, r6, r8, r9} blt 5f CALGN( ands ip, r0, #31 ) CALGN( sbcsne r4, ip, r2 ) @ C is always set here CALGN( bcs 2f ) CALGN( adr r4, 6f ) CALGN( subs r2, r2, ip ) @ C is set here CALGN( rsb ip, ip, #32 ) CALGN( add pc, r4, ip ) PLD( pld [r1, #-4] ) 2: PLD( subs r2, r2, #96 ) PLD( pld [r1, #-32] ) PLD( blt 4f ) PLD( pld [r1, #-64] ) PLD( pld [r1, #-96] ) 3: PLD( pld [r1, #-128] ) 4: ldmdb r1!, {r3, r4, r5, r6, r8, r9, ip, lr} subs r2, r2, #32 stmdb r0!, {r3, r4, r5, r6, r8, r9, ip, lr} bge 3b PLD( cmn r2, #96 ) PLD( bge 4b ) 5: ands ip, r2, #28 rsb ip, ip, #32 addne pc, pc, ip @ C is always clear here b 7f 6: W(nop) W(ldr) r3, [r1, #-4]! W(ldr) r4, [r1, #-4]! W(ldr) r5, [r1, #-4]! W(ldr) r6, [r1, #-4]! W(ldr) r8, [r1, #-4]! W(ldr) r9, [r1, #-4]! W(ldr) lr, [r1, #-4]! add pc, pc, ip nop W(nop) W(str) r3, [r0, #-4]! W(str) r4, [r0, #-4]! W(str) r5, [r0, #-4]! W(str) r6, [r0, #-4]! W(str) r8, [r0, #-4]! W(str) r9, [r0, #-4]! W(str) lr, [r0, #-4]! CALGN( bcs 2b ) 7: ldmfd sp!, {r5, r6, r8, r9} 8: movs r2, r2, lsl #31 ldrbne r3, [r1, #-1]! ldrbcs r4, [r1, #-1]! ldrbcs ip, [r1, #-1] strbne r3, [r0, #-1]! strbcs r4, [r0, #-1]! strbcs ip, [r0, #-1] ldmfd sp!, {r0, r4, UNWIND(fpreg,) pc} 9: cmp ip, #2 ldrbgt r3, [r1, #-1]! ldrbge r4, [r1, #-1]! ldrb lr, [r1, #-1]! strbgt r3, [r0, #-1]! strbge r4, [r0, #-1]! subs r2, r2, ip strb lr, [r0, #-1]! blt 8b ands ip, r1, #3 beq 1b 10: bic r1, r1, #3 cmp ip, #2 ldr r3, [r1, #0] beq 17f blt 18f .macro backward_copy_shift push pull subs r2, r2, #28 blt 14f CALGN( ands ip, r0, #31 ) CALGN( sbcsne r4, ip, r2 ) @ C is always set here CALGN( subcc r2, r2, ip ) CALGN( bcc 15f ) 11: stmfd sp!, {r5, r6, r8 - r10} PLD( pld [r1, #-4] ) PLD( subs r2, r2, #96 ) PLD( pld [r1, #-32] ) PLD( blt 13f ) PLD( pld [r1, #-64] ) PLD( pld [r1, #-96] ) 12: PLD( pld [r1, #-128] ) 13: ldmdb r1!, {r8, r9, r10, ip} mov lr, r3, lspush #\push subs r2, r2, #32 ldmdb r1!, {r3, r4, r5, r6} orr lr, lr, ip, lspull #\pull mov ip, ip, lspush #\push orr ip, ip, r10, lspull #\pull mov r10, r10, lspush #\push orr r10, r10, r9, lspull #\pull mov r9, r9, lspush #\push orr r9, r9, r8, lspull #\pull mov r8, r8, lspush #\push orr r8, r8, r6, lspull #\pull mov r6, r6, lspush #\push orr r6, r6, r5, lspull #\pull mov r5, r5, lspush #\push orr r5, r5, r4, lspull #\pull mov r4, r4, lspush #\push orr r4, r4, r3, lspull #\pull stmdb r0!, {r4 - r6, r8 - r10, ip, lr} bge 12b PLD( cmn r2, #96 ) PLD( bge 13b ) ldmfd sp!, {r5, r6, r8 - r10} 14: ands ip, r2, #28 beq 16f 15: mov lr, r3, lspush #\push ldr r3, [r1, #-4]! subs ip, ip, #4 orr lr, lr, r3, lspull #\pull str lr, [r0, #-4]! bgt 15b CALGN( cmp r2, #0 ) CALGN( bge 11b ) 16: add r1, r1, #(\pull / 8) b 8b .endm backward_copy_shift push=8 pull=24 17: backward_copy_shift push=16 pull=16 18: backward_copy_shift push=24 pull=8 UNWIND( .fnend ) ENDPROC(memmove) ENDPROC(__memmove) |