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authorJoseph Myers <joseph@codesourcery.com>2014-02-08 01:49:39 +0000
committerJoseph Myers <joseph@codesourcery.com>2014-02-08 01:49:39 +0000
commitc6bfe5c4d756913297db03f55e42016d1c48918c (patch)
tree898d2910ef903f46b596ad54e519ed4495357766 /sysdeps/arm/armv6t2/strlen.S
parent852fa2dd3aa1a687780e27300df9eb0bdc433863 (diff)
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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.
Diffstat (limited to 'sysdeps/arm/armv6t2/strlen.S')
-rw-r--r--sysdeps/arm/armv6t2/strlen.S169
1 files changed, 169 insertions, 0 deletions
diff --git a/sysdeps/arm/armv6t2/strlen.S b/sysdeps/arm/armv6t2/strlen.S
new file mode 100644
index 0000000000..1706f6c6b8
--- /dev/null
+++ b/sysdeps/arm/armv6t2/strlen.S
@@ -0,0 +1,169 @@
+/* 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)