--- /dev/null
+/*
+ * linux/arch/arm/lib/memmove.S
+ *
+ * Author: Nicolas Pitre
+ * Created: Sep 28, 2005
+ * Copyright: (C) MontaVista Software Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#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)
+ UNWIND( .fnstart )
+
+ subs ip, r0, r1
+ cmphi r2, ip
+ bls memcpy
+
+ stmfd sp!, {r0, r4, lr}
+ UNWIND( .fnend )
+
+ UNWIND( .fnstart )
+ UNWIND( .save {r0, r4, lr} ) @ in first stmfd block
+ 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 - r8}
+ UNWIND( .fnend )
+
+ UNWIND( .fnstart )
+ UNWIND( .save {r0, r4, lr} )
+ UNWIND( .save {r5 - r8} ) @ in second stmfd block
+ blt 5f
+
+ CALGN( ands ip, r0, #31 )
+ CALGN( sbcnes 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, r7, r8, ip, lr}
+ subs r2, r2, #32
+ stmdb r0!, {r3, r4, r5, r6, r7, r8, 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) r7, [r1, #-4]!
+ W(ldr) r8, [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) r7, [r0, #-4]!
+ W(str) r8, [r0, #-4]!
+ W(str) lr, [r0, #-4]!
+
+ CALGN( bcs 2b )
+
+7: ldmfd sp!, {r5 - r8}
+ UNWIND( .fnend ) @ end of second stmfd block
+
+ UNWIND( .fnstart )
+ UNWIND( .save {r0, r4, lr} ) @ still in first stmfd block
+
+8: movs r2, r2, lsl #31
+ ldrneb r3, [r1, #-1]!
+ ldrcsb r4, [r1, #-1]!
+ ldrcsb ip, [r1, #-1]
+ strneb r3, [r0, #-1]!
+ strcsb r4, [r0, #-1]!
+ strcsb ip, [r0, #-1]
+ ldmfd sp!, {r0, r4, pc}
+
+9: cmp ip, #2
+ ldrgtb r3, [r1, #-1]!
+ ldrgeb r4, [r1, #-1]!
+ ldrb lr, [r1, #-1]!
+ strgtb r3, [r0, #-1]!
+ strgeb 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
+ UNWIND( .fnend )
+
+
+ .macro backward_copy_shift push pull
+
+ UNWIND( .fnstart )
+ UNWIND( .save {r0, r4, lr} ) @ still in first stmfd block
+ subs r2, r2, #28
+ blt 14f
+
+ CALGN( ands ip, r0, #31 )
+ CALGN( sbcnes r4, ip, r2 ) @ C is always set here
+ CALGN( subcc r2, r2, ip )
+ CALGN( bcc 15f )
+
+11: stmfd sp!, {r5 - r9}
+ UNWIND( .fnend )
+
+ UNWIND( .fnstart )
+ UNWIND( .save {r0, r4, lr} )
+ UNWIND( .save {r5 - r9} ) @ in new second stmfd block
+
+ 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!, {r7, r8, r9, 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, r9, lspull #\pull
+ mov r9, r9, lspush #\push
+ orr r9, r9, r8, lspull #\pull
+ mov r8, r8, lspush #\push
+ orr r8, r8, r7, lspull #\pull
+ mov r7, r7, lspush #\push
+ orr r7, r7, 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 - r9, ip, lr}
+ bge 12b
+ PLD( cmn r2, #96 )
+ PLD( bge 13b )
+
+ ldmfd sp!, {r5 - r9}
+ UNWIND( .fnend ) @ end of the second stmfd block
+
+ UNWIND( .fnstart )
+ UNWIND( .save {r0, r4, lr} ) @ still in first stmfd block
+
+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
+ UNWIND( .fnend )
+
+ .endm
+
+
+ backward_copy_shift push=8 pull=24
+
+17: backward_copy_shift push=16 pull=16
+
+18: backward_copy_shift push=24 pull=8
+
+ENDPROC(memmove)
Code Review / kvmfornfv.git / blobdiff