| 1 | /* SPDX-License-Identifier: GPL-2.0-only */
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| 2 | /*
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| 3 | * linux/arch/arm/lib/memmove.S
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| 4 | *
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| 5 | * Author: Nicolas Pitre
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| 6 | * Created: Sep 28, 2005
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| 7 | * Copyright: (C) MontaVista Software Inc.
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| 8 | */
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| 9 |
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| 10 | |
| 11 | |
| 12 | |
| 13 |
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| 14 | .text
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| 15 |
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| 16 | /*
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| 17 | * Prototype: void *memmove(void *dest, const void *src, size_t n);
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| 18 | *
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| 19 | * Note:
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| 20 | *
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| 21 | * If the memory regions don't overlap, we simply branch to memcpy which is
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| 22 | * normally a bit faster. Otherwise the copy is done going downwards. This
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| 23 | * is a transposition of the code from copy_template.S but with the copy
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| 24 | * occurring in the opposite direction.
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| 25 | */
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| 26 |
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| 27 | ENTRY(__memmove)
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| 28 | WEAK(memmove)
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| 29 | UNWIND( .fnstart )
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| 30 |
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| 31 | subs ip, r0, r1
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| 32 | cmphi r2, ip
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| 33 | bls __memcpy
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| 34 | UNWIND( .fnend )
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| 35 |
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| 36 | UNWIND( .fnstart )
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| 37 | UNWIND( .save {r0, r4, fpreg, lr} )
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| 38 | stmfd sp!, {r0, r4, UNWIND(fpreg,) lr}
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| 39 | UNWIND( .setfp fpreg, sp )
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| 40 | UNWIND( mov fpreg, sp )
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| 41 | add r1, r1, r2
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| 42 | add r0, r0, r2
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| 43 | subs r2, r2, #4
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| 44 | blt 8f
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| 45 | ands ip, r0, #3
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| 46 | PLD( pld [r1, #-4] )
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| 47 | bne 9f
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| 48 | ands ip, r1, #3
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| 49 | bne 10f
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| 50 |
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| 51 | 1: subs r2, r2, #(28)
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| 52 | stmfd sp!, {r5, r6, r8, r9}
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| 53 | blt 5f
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| 54 |
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| 55 | CALGN( ands ip, r0, #31 )
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| 56 | CALGN( sbcsne r4, ip, r2 ) @ C is always set here
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| 57 | CALGN( bcs 2f )
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| 58 | CALGN( adr r4, 6f )
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| 59 | CALGN( subs r2, r2, ip ) @ C is set here
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| 60 | CALGN( rsb ip, ip, #32 )
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| 61 | CALGN( add pc, r4, ip )
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| 62 |
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| 63 | PLD( pld [r1, #-4] )
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| 64 | 2: PLD( subs r2, r2, #96 )
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| 65 | PLD( pld [r1, #-32] )
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| 66 | PLD( blt 4f )
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| 67 | PLD( pld [r1, #-64] )
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| 68 | PLD( pld [r1, #-96] )
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| 69 |
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| 70 | 3: PLD( pld [r1, #-128] )
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| 71 | 4: ldmdb r1!, {r3, r4, r5, r6, r8, r9, ip, lr}
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| 72 | subs r2, r2, #32
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| 73 | stmdb r0!, {r3, r4, r5, r6, r8, r9, ip, lr}
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| 74 | bge 3b
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| 75 | PLD( cmn r2, #96 )
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| 76 | PLD( bge 4b )
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| 77 |
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| 78 | 5: ands ip, r2, #28
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| 79 | rsb ip, ip, #32
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| 80 | addne pc, pc, ip @ C is always clear here
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| 81 | b 7f
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| 82 | 6: W(nop)
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| 83 | W(ldr) r3, [r1, #-4]!
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| 84 | W(ldr) r4, [r1, #-4]!
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| 85 | W(ldr) r5, [r1, #-4]!
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| 86 | W(ldr) r6, [r1, #-4]!
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| 87 | W(ldr) r8, [r1, #-4]!
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| 88 | W(ldr) r9, [r1, #-4]!
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| 89 | W(ldr) lr, [r1, #-4]!
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| 90 |
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| 91 | add pc, pc, ip
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| 92 | nop
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| 93 | W(nop)
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| 94 | W(str) r3, [r0, #-4]!
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| 95 | W(str) r4, [r0, #-4]!
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| 96 | W(str) r5, [r0, #-4]!
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| 97 | W(str) r6, [r0, #-4]!
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| 98 | W(str) r8, [r0, #-4]!
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| 99 | W(str) r9, [r0, #-4]!
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| 100 | W(str) lr, [r0, #-4]!
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| 101 |
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| 102 | CALGN( bcs 2b )
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| 103 |
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| 104 | 7: ldmfd sp!, {r5, r6, r8, r9}
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| 105 |
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| 106 | 8: movs r2, r2, lsl #31
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| 107 | ldrbne r3, [r1, #-1]!
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| 108 | ldrbcs r4, [r1, #-1]!
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| 109 | ldrbcs ip, [r1, #-1]
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| 110 | strbne r3, [r0, #-1]!
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| 111 | strbcs r4, [r0, #-1]!
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| 112 | strbcs ip, [r0, #-1]
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| 113 | ldmfd sp!, {r0, r4, UNWIND(fpreg,) pc}
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| 114 |
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| 115 | 9: cmp ip, #2
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| 116 | ldrbgt r3, [r1, #-1]!
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| 117 | ldrbge r4, [r1, #-1]!
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| 118 | ldrb lr, [r1, #-1]!
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| 119 | strbgt r3, [r0, #-1]!
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| 120 | strbge r4, [r0, #-1]!
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| 121 | subs r2, r2, ip
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| 122 | strb lr, [r0, #-1]!
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| 123 | blt 8b
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| 124 | ands ip, r1, #3
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| 125 | beq 1b
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| 126 |
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| 127 | 10: bic r1, r1, #3
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| 128 | cmp ip, #2
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| 129 | ldr r3, [r1, #0]
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| 130 | beq 17f
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| 131 | blt 18f
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| 132 |
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| 133 |
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| 134 | .macro backward_copy_shift push pull
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| 135 |
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| 136 | subs r2, r2, #28
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| 137 | blt 14f
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| 138 |
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| 139 | CALGN( ands ip, r0, #31 )
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| 140 | CALGN( sbcsne r4, ip, r2 ) @ C is always set here
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| 141 | CALGN( subcc r2, r2, ip )
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| 142 | CALGN( bcc 15f )
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| 143 |
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| 144 | 11: stmfd sp!, {r5, r6, r8 - r10}
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| 145 |
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| 146 | PLD( pld [r1, #-4] )
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| 147 | PLD( subs r2, r2, #96 )
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| 148 | PLD( pld [r1, #-32] )
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| 149 | PLD( blt 13f )
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| 150 | PLD( pld [r1, #-64] )
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| 151 | PLD( pld [r1, #-96] )
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| 152 |
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| 153 | 12: PLD( pld [r1, #-128] )
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| 154 | 13: ldmdb r1!, {r8, r9, r10, ip}
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| 155 | mov lr, r3, lspush #\push
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| 156 | subs r2, r2, #32
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| 157 | ldmdb r1!, {r3, r4, r5, r6}
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| 158 | orr lr, lr, ip, lspull #\pull
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| 159 | mov ip, ip, lspush #\push
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| 160 | orr ip, ip, r10, lspull #\pull
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| 161 | mov r10, r10, lspush #\push
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| 162 | orr r10, r10, r9, lspull #\pull
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| 163 | mov r9, r9, lspush #\push
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| 164 | orr r9, r9, r8, lspull #\pull
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| 165 | mov r8, r8, lspush #\push
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| 166 | orr r8, r8, r6, lspull #\pull
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| 167 | mov r6, r6, lspush #\push
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| 168 | orr r6, r6, r5, lspull #\pull
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| 169 | mov r5, r5, lspush #\push
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| 170 | orr r5, r5, r4, lspull #\pull
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| 171 | mov r4, r4, lspush #\push
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| 172 | orr r4, r4, r3, lspull #\pull
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| 173 | stmdb r0!, {r4 - r6, r8 - r10, ip, lr}
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| 174 | bge 12b
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| 175 | PLD( cmn r2, #96 )
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| 176 | PLD( bge 13b )
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| 177 |
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| 178 | ldmfd sp!, {r5, r6, r8 - r10}
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| 179 |
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| 180 | 14: ands ip, r2, #28
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| 181 | beq 16f
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| 182 |
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| 183 | 15: mov lr, r3, lspush #\push
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| 184 | ldr r3, [r1, #-4]!
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| 185 | subs ip, ip, #4
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| 186 | orr lr, lr, r3, lspull #\pull
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| 187 | str lr, [r0, #-4]!
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| 188 | bgt 15b
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| 189 | CALGN( cmp r2, #0 )
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| 190 | CALGN( bge 11b )
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| 191 |
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| 192 | 16: add r1, r1, #(\pull / 8)
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| 193 | b 8b
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| 194 |
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| 195 | .endm
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| 196 |
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| 197 |
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| 198 | backward_copy_shift push=8 pull=24
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| 199 |
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| 200 | 17: backward_copy_shift push=16 pull=16
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| 201 |
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| 202 | 18: backward_copy_shift push=24 pull=8
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| 203 |
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| 204 | UNWIND( .fnend )
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| 205 | ENDPROC(memmove)
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| 206 | ENDPROC(__memmove)
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