OpenE2K
/
glibc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity
glibc/sysdeps/arm/memmove.S

361 lines
7.8 KiB
ArmAsm
Raw Blame History

/* Copyright (C) 2006-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by MontaVista Software, Inc. (written by Nicolas Pitre)
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library. If not, see
<http://www.gnu.org/licenses/>. */
/* Thumb requires excessive IT insns here. */
#define NO_THUMB
#include <sysdep.h>
#include <arm-features.h>
/*
* Data preload for architectures that support it (ARM V5TE and above)
*/
#if (!defined (__ARM_ARCH_2__) && !defined (__ARM_ARCH_3__) \
&& !defined (__ARM_ARCH_3M__) && !defined (__ARM_ARCH_4__) \
&& !defined (__ARM_ARCH_4T__) && !defined (__ARM_ARCH_5__) \
&& !defined (__ARM_ARCH_5T__))
#define PLD(code...) code
#else
#define PLD(code...)
#endif
/*
* This can be used to enable code to cacheline align the source pointer.
* Experiments on tested architectures (StrongARM and XScale) didn't show
* this a worthwhile thing to do. That might be different in the future.
*/
//#define CALGN(code...) code
#define CALGN(code...)
/*
* Endian independent macros for shifting bytes within registers.
*/
#ifndef __ARMEB__
#define PULL lsr
#define PUSH lsl
#else
#define PULL lsl
#define PUSH lsr
#endif
.text
.syntax unified
/*
* 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.
*/
ENTRY(memmove)
subs ip, r0, r1
cmphi r2, ip
#ifdef NOT_IN_libc
bls memcpy
#else
bls HIDDEN_JUMPTARGET(memcpy)
#endif
push {r0, r4, lr}
cfi_adjust_cfa_offset (12)
cfi_rel_offset (r4, 4)
cfi_rel_offset (lr, 8)
cfi_remember_state
add r1, r1, r2
add r0, r0, r2
subs r2, r2, #4
blt 8f
ands ip, r0, #3
PLD( sfi_pld r1, #-4 )
bne 9f
ands ip, r1, #3
bne 10f
1: subs r2, r2, #(28)
push {r5 - r8}
cfi_adjust_cfa_offset (16)
cfi_rel_offset (r5, 0)
cfi_rel_offset (r6, 4)
cfi_rel_offset (r7, 8)
cfi_rel_offset (r8, 12)
blt 5f
CALGN( ands ip, r1, #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
#ifndef ARM_ALWAYS_BX
CALGN( add pc, r4, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2))
#else
CALGN( add r4, r4, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2))
CALGN( bx r4 )
#endif
PLD( sfi_pld r1, #-4 )
2: PLD( subs r2, r2, #96 )
PLD( sfi_pld r1, #-32 )
PLD( blt 4f )
PLD( sfi_pld r1, #-64 )
PLD( sfi_pld r1, #-96 )
3: PLD( sfi_pld r1, #-128 )
4: sfi_breg r1, \
ldmdb \B!, {r3, r4, r5, r6, r7, r8, ip, lr}
subs r2, r2, #32
sfi_breg r0, \
stmdb \B!, {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
#ifndef ARM_ALWAYS_BX
/* C is always clear here. */
addne pc, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2)
b 7f
#else
beq 7f
push {r10}
cfi_adjust_cfa_offset (4)
cfi_rel_offset (r10, 0)
add r10, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2)
bx r10
#endif
.p2align ARM_BX_ALIGN_LOG2
6: nop
.p2align ARM_BX_ALIGN_LOG2
sfi_breg r1, \
ldr r3, [\B, #-4]!
.p2align ARM_BX_ALIGN_LOG2
sfi_breg r1, \
ldr r4, [\B, #-4]!
.p2align ARM_BX_ALIGN_LOG2
sfi_breg r1, \
ldr r5, [\B, #-4]!
.p2align ARM_BX_ALIGN_LOG2
sfi_breg r1, \
ldr r6, [\B, #-4]!
.p2align ARM_BX_ALIGN_LOG2
sfi_breg r1, \
ldr r7, [\B, #-4]!
.p2align ARM_BX_ALIGN_LOG2
sfi_breg r1, \
ldr r8, [\B, #-4]!
.p2align ARM_BX_ALIGN_LOG2
sfi_breg r1, \
ldr lr, [\B, #-4]!
#ifndef ARM_ALWAYS_BX
add pc, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2)
nop
#else
add r10, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2)
bx r10
#endif
.p2align ARM_BX_ALIGN_LOG2
nop
.p2align ARM_BX_ALIGN_LOG2
sfi_breg r0, \
str r3, [\B, #-4]!
.p2align ARM_BX_ALIGN_LOG2
sfi_breg r0, \
str r4, [\B, #-4]!
.p2align ARM_BX_ALIGN_LOG2
sfi_breg r0, \
str r5, [\B, #-4]!
.p2align ARM_BX_ALIGN_LOG2
sfi_breg r0, \
str r6, [\B, #-4]!
.p2align ARM_BX_ALIGN_LOG2
sfi_breg r0, \
str r7, [\B, #-4]!
.p2align ARM_BX_ALIGN_LOG2
sfi_breg r0, \
str r8, [\B, #-4]!
.p2align ARM_BX_ALIGN_LOG2
sfi_breg r0, \
str lr, [\B, #-4]!
#ifdef ARM_ALWAYS_BX
pop {r10}
cfi_adjust_cfa_offset (-4)
cfi_restore (r10)
#endif
CALGN( bcs 2b )
7: pop {r5 - r8}
cfi_adjust_cfa_offset (-16)
cfi_restore (r5)
cfi_restore (r6)
cfi_restore (r7)
cfi_restore (r8)
8: movs r2, r2, lsl #31
sfi_breg r1, \
ldrbne r3, [\B, #-1]!
sfi_breg r1, \
ldrbcs r4, [\B, #-1]!
sfi_breg r1, \
ldrbcs ip, [\B, #-1]
sfi_breg r0, \
strbne r3, [\B, #-1]!
sfi_breg r0, \
strbcs r4, [\B, #-1]!
sfi_breg r0, \
strbcs ip, [\B, #-1]
#if ((defined (__ARM_ARCH_4T__) && defined (__THUMB_INTERWORK__)) \
|| defined (ARM_ALWAYS_BX))
pop {r0, r4, lr}
cfi_adjust_cfa_offset (-12)
cfi_restore (r4)
cfi_restore (lr)
bx lr
#else
pop {r0, r4, pc}
#endif
cfi_restore_state
9: cmp ip, #2
sfi_breg r1, \
ldrbgt r3, [\B, #-1]!
sfi_breg r1, \
ldrbge r4, [\B, #-1]!
sfi_breg r1, \
ldrb lr, [\B, #-1]!
sfi_breg r0, \
strbgt r3, [\B, #-1]!
sfi_breg r0, \
strbge r4, [\B, #-1]!
subs r2, r2, ip
sfi_breg r0, \
strb lr, [\B, #-1]!
blt 8b
ands ip, r1, #3
beq 1b
10: bic r1, r1, #3
cmp ip, #2
sfi_breg r1, \
ldr r3, [\B, #0]
beq 17f
blt 18f
.macro backward_copy_shift push pull
subs r2, r2, #28
blt 14f
CALGN( ands ip, r1, #31 )
CALGN( rsb ip, ip, #32 )
CALGN( sbcsne r4, ip, r2 ) @ C is always set here
CALGN( subcc r2, r2, ip )
CALGN( bcc 15f )
11: push {r5 - r8, r10}
cfi_adjust_cfa_offset (20)
cfi_rel_offset (r5, 0)
cfi_rel_offset (r6, 4)
cfi_rel_offset (r7, 8)
cfi_rel_offset (r8, 12)
cfi_rel_offset (r10, 16)
PLD( sfi_pld r1, #-4 )
PLD( subs r2, r2, #96 )
PLD( sfi_pld r1, #-32 )
PLD( blt 13f )
PLD( sfi_pld r1, #-64 )
PLD( sfi_pld r1, #-96 )
12: PLD( sfi_pld r1, #-128 )
13: sfi_breg r1, \
ldmdb \B!, {r7, r8, r10, ip}
mov lr, r3, PUSH #\push
subs r2, r2, #32
sfi_breg r1, \
ldmdb \B!, {r3, r4, r5, r6}
orr lr, lr, ip, PULL #\pull
mov ip, ip, PUSH #\push
orr ip, ip, r10, PULL #\pull
mov r10, r10, PUSH #\push
orr r10, r10, r8, PULL #\pull
mov r8, r8, PUSH #\push
orr r8, r8, r7, PULL #\pull
mov r7, r7, PUSH #\push
orr r7, r7, r6, PULL #\pull
mov r6, r6, PUSH #\push
orr r6, r6, r5, PULL #\pull
mov r5, r5, PUSH #\push
orr r5, r5, r4, PULL #\pull
mov r4, r4, PUSH #\push
orr r4, r4, r3, PULL #\pull
sfi_breg r0, \
stmdb \B!, {r4 - r8, r10, ip, lr}
bge 12b
PLD( cmn r2, #96 )
PLD( bge 13b )
pop {r5 - r8, r10}
cfi_adjust_cfa_offset (-20)
cfi_restore (r5)
cfi_restore (r6)
cfi_restore (r7)
cfi_restore (r8)
cfi_restore (r10)
14: ands ip, r2, #28
beq 16f
15: mov lr, r3, PUSH #\push
sfi_breg r1, \
ldr r3, [\B, #-4]!
subs ip, ip, #4
orr lr, lr, r3, PULL #\pull
sfi_breg r0, \
str lr, [\B, #-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
END(memmove)
libc_hidden_builtin_def (memmove)
Reference in New Issue View Git Blame Copy Permalink