glibc/sysdeps/arm/armv6t2/strlen.S
Joseph Myers c6bfe5c4d7 Move arm from ports to libc.
I've moved the ARM port from ports to the main sysdeps hierarchy.
Beyond the README update, the move of the files was simply

git mv ports/sysdeps/arm sysdeps/arm
git mv ports/sysdeps/unix/arm sysdeps/unix/arm
git mv ports/sysdeps/unix/sysv/linux/arm sysdeps/unix/sysv/linux/arm

and in addition to the ChangeLog entries here, I put a note at the top
of ports/ChangeLog.arm similar to that at the top of
ChangeLog.powerpc.  There is deliberately no NEWS change, as I think
it makes the most sense to put in a general note above all ports
having moved if we can achieve that for 2.20.

Tested that disassembly of installed shared libraries for arm is the
same before and after this patch, except for data (not instructions)
in ld.so (there are assertions in sysdeps/arm/dl-machine.h, and the
path by which that file is found, and so by which it appears in the
assertion message, changes as a result of the move).

	* sysdeps/arm: Move directory from ports/sysdeps/arm.
	* sysdeps/unix/arm: Move directory from ports/sysdeps/unix/arm.
	* sysdeps/unix/sysv/linux/arm: Move directory from
	ports/sysdeps/unix/sysv/linux/arm.
	* README: Update listing for arm-*-linux-gnueabi.

ports/ChangeLog.arm:
	* sysdeps/arm: Move directory to ../sysdeps/arm.
	* sysdeps/unix/arm: Move directory to ../sysdeps.arm.
	* sysdeps/unix/sysv/linux/arm: Move directory to
	../sysdeps/unix/sysv/linux/arm.
2014-02-08 01:49:39 +00:00

170 lines
4.2 KiB
ArmAsm

/* Copyright (C) 2010-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>. */
/*
Assumes:
ARMv6T2, AArch32
*/
#include <arm-features.h> /* This might #define NO_THUMB. */
#include <sysdep.h>
#ifdef __ARMEB__
#define S2LO lsl
#define S2HI lsr
#else
#define S2LO lsr
#define S2HI lsl
#endif
#ifndef NO_THUMB
/* This code is best on Thumb. */
.thumb
#else
/* Using bne.w explicitly is desirable in Thumb mode because it helps
align the following label without a nop. In ARM mode there is no
such difference. */
.macro bne.w label
bne \label
.endm
/* This clobbers the condition codes, which the real Thumb cbnz instruction
does not do. But it doesn't matter for any of the uses here. */
.macro cbnz reg, label
cmp \reg, #0
bne \label
.endm
#endif
/* Parameters and result. */
#define srcin r0
#define result r0
/* Internal variables. */
#define src r1
#define data1a r2
#define data1b r3
#define const_m1 r12
#define const_0 r4
#define tmp1 r4 /* Overlaps const_0 */
#define tmp2 r5
.text
.p2align 6
ENTRY(strlen)
sfi_pld srcin, #0
strd r4, r5, [sp, #-8]!
cfi_adjust_cfa_offset (8)
cfi_rel_offset (r4, 0)
cfi_rel_offset (r5, 4)
cfi_remember_state
bic src, srcin, #7
mvn const_m1, #0
ands tmp1, srcin, #7 /* (8 - bytes) to alignment. */
sfi_pld src, #32
bne.w .Lmisaligned8
mov const_0, #0
mov result, #-8
.Lloop_aligned:
/* Bytes 0-7. */
sfi_breg src, \
ldrd data1a, data1b, [\B]
sfi_pld src, #64
add result, result, #8
.Lstart_realigned:
uadd8 data1a, data1a, const_m1 /* Saturating GE<0:3> set. */
sel data1a, const_0, const_m1 /* Select based on GE<0:3>. */
uadd8 data1b, data1b, const_m1
sel data1b, data1a, const_m1 /* Only used if d1a == 0. */
cbnz data1b, .Lnull_found
/* Bytes 8-15. */
sfi_breg src, \
ldrd data1a, data1b, [\B, #8]
uadd8 data1a, data1a, const_m1 /* Saturating GE<0:3> set. */
add result, result, #8
sel data1a, const_0, const_m1 /* Select based on GE<0:3>. */
uadd8 data1b, data1b, const_m1
sel data1b, data1a, const_m1 /* Only used if d1a == 0. */
cbnz data1b, .Lnull_found
/* Bytes 16-23. */
sfi_breg src, \
ldrd data1a, data1b, [\B, #16]
uadd8 data1a, data1a, const_m1 /* Saturating GE<0:3> set. */
add result, result, #8
sel data1a, const_0, const_m1 /* Select based on GE<0:3>. */
uadd8 data1b, data1b, const_m1
sel data1b, data1a, const_m1 /* Only used if d1a == 0. */
cbnz data1b, .Lnull_found
/* Bytes 24-31. */
sfi_breg src, \
ldrd data1a, data1b, [\B, #24]
add src, src, #32
uadd8 data1a, data1a, const_m1 /* Saturating GE<0:3> set. */
add result, result, #8
sel data1a, const_0, const_m1 /* Select based on GE<0:3>. */
uadd8 data1b, data1b, const_m1
sel data1b, data1a, const_m1 /* Only used if d1a == 0. */
cmp data1b, #0
beq .Lloop_aligned
.Lnull_found:
cmp data1a, #0
itt eq
addeq result, result, #4
moveq data1a, data1b
#ifndef __ARMEB__
rev data1a, data1a
#endif
clz data1a, data1a
ldrd r4, r5, [sp], #8
cfi_adjust_cfa_offset (-8)
cfi_restore (r4)
cfi_restore (r5)
add result, result, data1a, lsr #3 /* Bits -> Bytes. */
DO_RET(lr)
.Lmisaligned8:
cfi_restore_state
sfi_breg src, \
ldrd data1a, data1b, [\B]
and tmp2, tmp1, #3
rsb result, tmp1, #0
lsl tmp2, tmp2, #3 /* Bytes -> bits. */
tst tmp1, #4
sfi_pld src, #64
S2HI tmp2, const_m1, tmp2
#ifdef NO_THUMB
mvn tmp1, tmp2
orr data1a, data1a, tmp1
itt ne
orrne data1b, data1b, tmp1
#else
orn data1a, data1a, tmp2
itt ne
ornne data1b, data1b, tmp2
#endif
movne data1a, const_m1
mov const_0, #0
b .Lstart_realigned
END(strlen)
libc_hidden_builtin_def (strlen)