Move all files into ports/ subdirectory in preparation for merge with glibc glibc-2.16-ports-before-merge

1 files changed, 163 insertions, 0 deletions

diff --git a/ports/sysdeps/arm/armv6t2/memchr.S b/ports/sysdeps/arm/armv6t2/memchr.S
new file mode 100644
index 0000000000..69ea320e89
--- /dev/null
+++ b/ports/sysdeps/arm/armv6t2/memchr.S
@@ -0,0 +1,163 @@
+/* Copyright (C) 2011 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Code contributed by Dave Gilbert <david.gilbert@linaro.org>
+
+   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>
+
+@ This memchr routine is optimised on a Cortex-A9 and should work on all ARMv7
+@ and ARMv6T2 processors.  It has a fast path for short sizes, and has an
+@ optimised path for large data sets; the worst case is finding the match early
+@ in a large data set.
+@ Note: The use of cbz/cbnz means it's Thumb only
+
+@ 2011-07-15 david.gilbert@linaro.org
+@    Copy from Cortex strings release 21 and change license
+@ http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/view/head:/src/linaro-a9/memchr.S
+@    Change function declarations/entry/exit
+@ 2011-12-01 david.gilbert@linaro.org
+@    Add some fixes from comments received (including use of ldrd instead ldm)
+@ 2011-12-07 david.gilbert@linaro.org
+@    Removed cbz from align loop - can't be taken
+
+@ this lets us check a flag in a 00/ff byte easily in either endianness
+#ifdef __ARMEB__
+#define CHARTSTMASK(c) 1<<(31-(c*8))
+#else
+#define CHARTSTMASK(c) 1<<(c*8)
+#endif
+	.syntax unified
+
+	.text
+	.thumb
+
+@ ---------------------------------------------------------------------------
+	.thumb_func
+	.global memchr
+	.type memchr,%function
+ENTRY(memchr)
+	@ r0 = start of memory to scan
+	@ r1 = character to look for
+	@ r2 = length
+	@ returns r0 = pointer to character or NULL if not found
+	and	r1,r1,#0xff	@ Don't think we can trust the caller to actually pass a char
+
+	cmp	r2,#16		@ If it's short don't bother with anything clever
+	blt	20f
+
+	tst	r0, #7		@ If it's already aligned skip the next bit
+	beq	10f
+
+	@ Work up to an aligned point
+5:
+	ldrb	r3, [r0],#1
+	subs	r2, r2, #1
+	cmp	r3, r1
+	beq	50f		@ If it matches exit found
+	tst	r0, #7
+	bne	5b		@ If not aligned yet then do next byte
+
+10:
+	@ At this point, we are aligned, we know we have at least 8 bytes to work with
+	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)
+
+	cfi_remember_state
+
+	orr	r1, r1, r1, lsl #8	@ expand the match word across to all bytes
+	orr	r1, r1, r1, lsl #16
+	bic	r4, r2, #7	@ Number of double words to work with * 8
+	mvns	r7, #0		@ all F's
+	movs	r3, #0
+
+15:
+	ldrd 	r5,r6, [r0],#8
+	subs	r4, r4, #8
+	eor	r5,r5, r1	@ Get it so that r5,r6 have 00's where the bytes match the target
+	eor	r6,r6, r1
+	uadd8	r5, r5, r7	@ Parallel add 0xff - sets the GE bits for anything that wasn't 0
+	sel	r5, r3, r7	@ bytes are 00 for none-00 bytes, or ff for 00 bytes - NOTE INVERSION
+	uadd8	r6, r6, r7	@ Parallel add 0xff - sets the GE bits for anything that wasn't 0
+	sel	r6, r5, r7	@ chained....bytes are 00 for none-00 bytes, or ff for 00 bytes - NOTE INVERSION
+	cbnz	r6, 60f
+	bne	15b		@ (Flags from the subs above) If not run out of bytes then go around again
+
+	pop	{r4,r5,r6,r7}
+	cfi_adjust_cfa_offset (-16)
+	cfi_restore (r4)
+	cfi_restore (r5)
+	cfi_restore (r6)
+	cfi_restore (r7)
+
+	and	r1,r1,#0xff	@ Get r1 back to a single character from the expansion above
+	and	r2,r2,#7	@ Leave the count remaining as the number after the double words have been done
+
+20:
+	cbz	r2, 40f		@ 0 length or hit the end already then not found
+
+21:  @ Post aligned section, or just a short call
+	ldrb	r3,[r0],#1
+	subs	r2,r2,#1
+	eor	r3,r3,r1	@ r3 = 0 if match - doesn't break flags from sub
+	cbz	r3, 50f
+	bne	21b		@ on r2 flags
+
+40:
+	movs	r0,#0		@ not found
+	DO_RET(lr)
+
+50:
+	subs	r0,r0,#1	@ found
+	DO_RET(lr)
+
+60:  @ We're here because the fast path found a hit - now we have to track down exactly which word it was
+     @ r0 points to the start of the double word after the one that was tested
+     @ r5 has the 00/ff pattern for the first word, r6 has the chained value
+	cfi_restore_state
+	cmp	r5, #0
+	itte	eq
+	moveq	r5, r6		@ the end is in the 2nd word
+	subeq	r0,r0,#3	@ Points to 2nd byte of 2nd word
+	subne	r0,r0,#7	@ or 2nd byte of 1st word
+
+	@ r0 currently points to the 2nd byte of the word containing the hit
+	tst	r5, # CHARTSTMASK(0)	@ 1st character
+	bne	61f
+	adds	r0,r0,#1
+	tst	r5, # CHARTSTMASK(1)	@ 2nd character
+	ittt	eq
+	addeq	r0,r0,#1
+	tsteq	r5, # (3<<15)		@ 2nd & 3rd character
+	@ If not the 3rd must be the last one
+	addeq	r0,r0,#1
+
+61:
+	pop	{r4,r5,r6,r7}
+	cfi_adjust_cfa_offset (-16)
+	cfi_restore (r4)
+	cfi_restore (r5)
+	cfi_restore (r6)
+	cfi_restore (r7)
+
+	subs	r0,r0,#1
+	DO_RET(lr)
+
+END(memchr)
+libc_hidden_builtin_def (memchr)