2239aff6ab
The implementation for memory copy functions on ARM had a (disabled) provision for aligning the source pointer before loading registers with data. Turns out that aligning the _destination_ pointer is much more useful, as the read side is already sufficiently helped with the use of preload. So this changes the definition of the CALGN() macro to target the destination pointer instead, and turns it on for Feroceon processors where the gain is very noticeable. Signed-off-by: Nicolas Pitre <nico@marvell.com> Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
199 lines
3.9 KiB
ArmAsm
199 lines
3.9 KiB
ArmAsm
/*
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* linux/arch/arm/lib/memmove.S
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*
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* Author: Nicolas Pitre
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* Created: Sep 28, 2005
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* Copyright: (C) MontaVista Software Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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.text
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/*
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* Prototype: void *memmove(void *dest, const void *src, size_t n);
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*
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* Note:
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*
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* If the memory regions don't overlap, we simply branch to memcpy which is
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* normally a bit faster. Otherwise the copy is done going downwards. This
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* is a transposition of the code from copy_template.S but with the copy
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* occurring in the opposite direction.
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*/
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ENTRY(memmove)
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subs ip, r0, r1
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cmphi r2, ip
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bls memcpy
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stmfd sp!, {r0, r4, lr}
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add r1, r1, r2
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add r0, r0, r2
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subs r2, r2, #4
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blt 8f
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ands ip, r0, #3
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PLD( pld [r1, #-4] )
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bne 9f
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ands ip, r1, #3
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bne 10f
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1: subs r2, r2, #(28)
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stmfd sp!, {r5 - r8}
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blt 5f
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CALGN( ands ip, r0, #31 )
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CALGN( sbcnes r4, ip, r2 ) @ C is always set here
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CALGN( bcs 2f )
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CALGN( adr r4, 6f )
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CALGN( subs r2, r2, ip ) @ C is set here
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CALGN( rsb ip, ip, #32 )
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CALGN( add pc, r4, ip )
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PLD( pld [r1, #-4] )
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2: PLD( subs r2, r2, #96 )
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PLD( pld [r1, #-32] )
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PLD( blt 4f )
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PLD( pld [r1, #-64] )
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PLD( pld [r1, #-96] )
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3: PLD( pld [r1, #-128] )
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4: ldmdb r1!, {r3, r4, r5, r6, r7, r8, ip, lr}
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subs r2, r2, #32
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stmdb r0!, {r3, r4, r5, r6, r7, r8, ip, lr}
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bge 3b
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PLD( cmn r2, #96 )
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PLD( bge 4b )
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5: ands ip, r2, #28
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rsb ip, ip, #32
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addne pc, pc, ip @ C is always clear here
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b 7f
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6: nop
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ldr r3, [r1, #-4]!
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ldr r4, [r1, #-4]!
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ldr r5, [r1, #-4]!
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ldr r6, [r1, #-4]!
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ldr r7, [r1, #-4]!
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ldr r8, [r1, #-4]!
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ldr lr, [r1, #-4]!
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add pc, pc, ip
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nop
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nop
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str r3, [r0, #-4]!
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str r4, [r0, #-4]!
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str r5, [r0, #-4]!
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str r6, [r0, #-4]!
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str r7, [r0, #-4]!
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str r8, [r0, #-4]!
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str lr, [r0, #-4]!
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CALGN( bcs 2b )
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7: ldmfd sp!, {r5 - r8}
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8: movs r2, r2, lsl #31
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ldrneb r3, [r1, #-1]!
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ldrcsb r4, [r1, #-1]!
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ldrcsb ip, [r1, #-1]
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strneb r3, [r0, #-1]!
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strcsb r4, [r0, #-1]!
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strcsb ip, [r0, #-1]
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ldmfd sp!, {r0, r4, pc}
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9: cmp ip, #2
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ldrgtb r3, [r1, #-1]!
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ldrgeb r4, [r1, #-1]!
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ldrb lr, [r1, #-1]!
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strgtb r3, [r0, #-1]!
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strgeb r4, [r0, #-1]!
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subs r2, r2, ip
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strb lr, [r0, #-1]!
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blt 8b
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ands ip, r1, #3
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beq 1b
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10: bic r1, r1, #3
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cmp ip, #2
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ldr r3, [r1, #0]
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beq 17f
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blt 18f
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.macro backward_copy_shift push pull
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subs r2, r2, #28
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blt 14f
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CALGN( ands ip, r0, #31 )
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CALGN( sbcnes r4, ip, r2 ) @ C is always set here
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CALGN( subcc r2, r2, ip )
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CALGN( bcc 15f )
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11: stmfd sp!, {r5 - r9}
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PLD( pld [r1, #-4] )
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PLD( subs r2, r2, #96 )
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PLD( pld [r1, #-32] )
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PLD( blt 13f )
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PLD( pld [r1, #-64] )
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PLD( pld [r1, #-96] )
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12: PLD( pld [r1, #-128] )
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13: ldmdb r1!, {r7, r8, r9, ip}
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mov lr, r3, push #\push
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subs r2, r2, #32
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ldmdb r1!, {r3, r4, r5, r6}
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orr lr, lr, ip, pull #\pull
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mov ip, ip, push #\push
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orr ip, ip, r9, pull #\pull
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mov r9, r9, push #\push
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orr r9, r9, r8, pull #\pull
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mov r8, r8, push #\push
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orr r8, r8, r7, pull #\pull
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mov r7, r7, push #\push
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orr r7, r7, r6, pull #\pull
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mov r6, r6, push #\push
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orr r6, r6, r5, pull #\pull
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mov r5, r5, push #\push
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orr r5, r5, r4, pull #\pull
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mov r4, r4, push #\push
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orr r4, r4, r3, pull #\pull
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stmdb r0!, {r4 - r9, ip, lr}
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bge 12b
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PLD( cmn r2, #96 )
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PLD( bge 13b )
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ldmfd sp!, {r5 - r9}
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14: ands ip, r2, #28
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beq 16f
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15: mov lr, r3, push #\push
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ldr r3, [r1, #-4]!
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subs ip, ip, #4
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orr lr, lr, r3, pull #\pull
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str lr, [r0, #-4]!
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bgt 15b
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CALGN( cmp r2, #0 )
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CALGN( bge 11b )
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16: add r1, r1, #(\pull / 8)
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b 8b
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.endm
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backward_copy_shift push=8 pull=24
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17: backward_copy_shift push=16 pull=16
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18: backward_copy_shift push=24 pull=8
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