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.

1 files changed, 231 insertions, 0 deletions

diff --git a/sysdeps/arm/armv6/strcpy.S b/sysdeps/arm/armv6/strcpy.S
new file mode 100644
index 0000000000..833a83c28f
--- /dev/null
+++ b/sysdeps/arm/armv6/strcpy.S
@@ -0,0 +1,231 @@
+/* strcpy -- copy a nul-terminated string.
+   Copyright (C) 2013-2014 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/>.  */
+
+#include <sysdep.h>
+
+/* Endian independent macros for shifting bytes within registers.  */
+#ifdef __ARMEB__
+#define lsh_gt		lsr
+#define lsh_ls		lsl
+#else
+#define lsh_gt		lsl
+#define lsh_ls		lsr
+#endif
+
+	.syntax unified
+	.text
+
+ENTRY (__stpcpy)
+	@ Signal stpcpy with NULL in IP.
+	mov	ip, #0
+	b	0f
+END (__stpcpy)
+
+weak_alias (__stpcpy, stpcpy)
+libc_hidden_def (__stpcpy)
+libc_hidden_builtin_def (stpcpy)
+
+ENTRY (strcpy)
+	@ Signal strcpy with DEST in IP.
+	mov	ip, r0
+0:
+	sfi_pld	r0
+	sfi_pld	r1
+
+	@ To cater to long strings, we want 8 byte alignment in the source.
+	@ To cater to small strings, we don't want to start that right away.
+	@ Loop up to 16 times, less whatever it takes to reach alignment.
+	and	r3, r1, #7
+	rsb	r3, r3, #16
+
+	@ Loop until we find ...
+1:	sfi_breg r1, \
+	ldrb	r2, [\B], #1
+	subs	r3, r3, #1		@ ... the alignment point
+	sfi_breg r0, \
+	strb	r2, [\B], #1
+	it	ne
+	cmpne	r2, #0			@ ... or EOS
+	bne	1b
+
+	@ Disambiguate the exit possibilites above
+	cmp	r2, #0			@ Found EOS
+	beq	.Lreturn
+
+	@ Load the next two words asap
+	sfi_breg r1, \
+	ldrd	r2, r3, [\B], #8
+	sfi_pld	r0, #64
+	sfi_pld	r1, #64
+
+	@ For longer strings, we actaully need a stack frame.
+	push	{ r4, r5, r6, r7 }
+	cfi_adjust_cfa_offset (16)
+	cfi_rel_offset (r4, 0)
+	cfi_rel_offset (r5, 4)
+	cfi_rel_offset (r6, 8)
+	cfi_rel_offset (r7, 12)
+
+	@ Subtracting (unsigned saturating) from 1 for any byte means result
+	@ of 1 for any byte that was originally zero and 0 otherwise.
+	@ Therefore we consider the lsb of each byte the "found" bit.
+#ifdef ARCH_HAS_T2
+	movw	r7, #0x0101
+	tst	r0, #3			@ Test alignment of DEST
+	movt	r7, #0x0101
+#else
+	ldr	r7, =0x01010101
+	tst	r0, #3
+#endif
+	bne	.Lunaligned
+
+	@ So now source (r1) is aligned to 8, and dest (r0) is aligned to 4.
+	@ Loop, reading 8 bytes at a time, searching for EOS.
+	.balign	16
+2:	uqsub8	r4, r7, r2		@ Find EOS
+	uqsub8	r5, r7, r3
+	sfi_pld	r1, #128
+	cmp	r4, #0			@ EOS in first word?
+	sfi_pld	r0, #128
+	bne	3f
+	sfi_breg r0, \
+	str	r2, [\B], #4
+	cmp	r5, #0			@ EOS in second word?
+	bne	4f
+	sfi_breg r0, \
+	str	r3, [\B], #4
+	sfi_breg r1, \
+	ldrd	r2, r3, [\B], #8
+	b	2b
+
+3:	sub	r1, r1, #4		@ backup to first word
+4:	sub	r1, r1, #4		@ backup to second word
+
+	@ ... then finish up any tail a byte at a time.
+	@ Note that we generally back up and re-read source bytes,
+	@ but we'll not re-write dest bytes.
+.Lbyte_loop:
+	sfi_breg r1, \
+	ldrb	r2, [\B], #1
+	cmp	r2, #0
+	sfi_breg r0, \
+	strb	r2, [\B], #1
+	bne	.Lbyte_loop
+
+	pop	{ r4, r5, r6, r7 }
+	cfi_remember_state
+	cfi_adjust_cfa_offset (-16)
+	cfi_restore (r4)
+	cfi_restore (r5)
+	cfi_restore (r6)
+	cfi_restore (r7)
+
+.Lreturn:
+	cmp	ip, #0			@ Was this strcpy or stpcpy?
+	ite	eq
+	subeq	r0, r0, #1		@ stpcpy: undo post-inc from store
+	movne	r0, ip			@ strcpy: return original dest
+	bx	lr
+
+.Lunaligned:
+	cfi_restore_state
+	@ Here, source is aligned to 8, but the destination is not word
+	@ aligned.  Therefore we have to shift the data in order to be
+	@ able to perform aligned word stores.
+
+	@ Find out which misalignment we're dealing with.
+	tst	r0, #1
+	beq	.Lunaligned2
+	tst	r0, #2
+	bne	.Lunaligned3
+	@ Fallthru to .Lunaligned1.
+
+.macro unaligned_copy	unalign
+	@ Prologue to unaligned loop.  Seed shifted non-zero bytes.
+	uqsub8	r4, r7, r2		@ Find EOS
+	uqsub8	r5, r7, r3
+	mvns	r4, r4			@ EOS in first word?
+	it	ne
+	subne	r1, r1, #8
+	bne	.Lbyte_loop
+#ifdef __ARMEB__
+	rev	r2, r2			@ Byte stores below need LE data
+#endif
+	@ Store a few bytes from the first word.
+	@ At the same time we align r0 and shift out bytes from r2.
+.rept	4-\unalign
+	sfi_breg r0, \
+	strb	r2, [\B], #1
+	lsr	r2, r2, #8
+.endr
+#ifdef __ARMEB__
+	rev	r2, r2			@ Undo previous rev
+#endif
+	@ Rotated unaligned copy loop.  The tail of the prologue is
+	@ shared with the loop itself.
+	.balign 8
+1:	mvns	r5, r5			@ EOS in second word?
+	bne	4f
+	@ Combine first and second words
+	orr	r2, r2, r3, lsh_gt #(\unalign*8)
+	@ Save leftover bytes from the two words
+	lsh_ls	r6, r3, #((4-\unalign)*8)
+	sfi_breg r0, \
+	str	r2, [\B], #4
+	@ The "real" start of the unaligned copy loop.
+	sfi_breg r1, \
+	ldrd	r2, r3, [\B], #8	@ Load 8 more bytes
+	uqsub8	r4, r7, r2		@ Find EOS
+	sfi_pld	r1, #128
+	uqsub8	r5, r7, r3
+	sfi_pld	r0, #128
+	mvns	r4, r4			@ EOS in first word?
+	bne	3f
+	@ Combine the leftover and the first word
+	orr	r6, r6, r2, lsh_gt #(\unalign*8)
+	@ Discard used bytes from the first word.
+	lsh_ls	r2, r2, #((4-\unalign)*8)
+	sfi_breg r0, \
+	str	r6, [\B], #4
+	b	1b
+	@ Found EOS in one of the words; adjust backward
+3:	sub	r1, r1, #4
+	mov	r2, r6
+4:	sub	r1, r1, #4
+	@ And store the remaining bytes from the leftover
+#ifdef __ARMEB__
+	rev	r2, r2
+#endif
+.rept	\unalign
+	sfi_breg r0, \
+	strb	r2, [\B], #1
+	lsr	r2, r2, #8
+.endr
+	b	.Lbyte_loop
+.endm
+
+.Lunaligned1:
+	unaligned_copy	1
+.Lunaligned2:
+	unaligned_copy	2
+.Lunaligned3:
+	unaligned_copy	3
+
+END (strcpy)
+
+libc_hidden_builtin_def (strcpy)