[PATCH, v5] ARM: Add Cortex-A15 optimized NEON and VFP memcpy routines, with IFUNC.

Will Newton will.newton@linaro.org
Tue Apr 30 16:54:00 GMT 2013


Add a high performance memcpy routine optimized for Cortex-A15 with
variants for use in the presence of NEON and VFP hardware selected
at runtime using indirect function support.

This was tested on armv7l-unknown-linux-gnueabihf. One new testsuite
failure was introduced (elf/ifuncmain5picstatic) which was caused by
a bug in ld. A fix for that ld issue has been committed to binutils
on 2012-04-29.

ports/ChangeLog.arm:

2013-04-30  Will Newton  <will.newton@linaro.org>

	* sysdeps/arm/armv7/multiarch/Makefile: New file.
	* sysdeps/arm/armv7/multiarch/aeabi_memcpy.c: Likewise.
	* sysdeps/arm/armv7/multiarch/ifunc-impl-list.c: Likewise.
	* sysdeps/arm/armv7/multiarch/memcpy.S: Likewise.
	* sysdeps/arm/armv7/multiarch/memcpy_impl.S: Likewise.
	* sysdeps/arm/armv7/multiarch/memcpy_neon.S: Likewise.
	* sysdeps/arm/armv7/multiarch/memcpy_vfp.S: Likewise.
	* sysdeps/arm/configure.in: Require binutils 2.21 to build
	for armv7.
---
 ports/sysdeps/arm/armv7/multiarch/Makefile         |   3 +
 ports/sysdeps/arm/armv7/multiarch/aeabi_memcpy.c   |  33 ++
 .../sysdeps/arm/armv7/multiarch/ifunc-impl-list.c  |  44 ++
 ports/sysdeps/arm/armv7/multiarch/memcpy.S         |  59 ++
 ports/sysdeps/arm/armv7/multiarch/memcpy_impl.S    | 640 +++++++++++++++++++++
 ports/sysdeps/arm/armv7/multiarch/memcpy_neon.S    |   3 +
 ports/sysdeps/arm/armv7/multiarch/memcpy_vfp.S     |   3 +
 ports/sysdeps/arm/configure.in                     |   8 +
 8 files changed, 793 insertions(+)
 create mode 100644 ports/sysdeps/arm/armv7/multiarch/Makefile
 create mode 100644 ports/sysdeps/arm/armv7/multiarch/aeabi_memcpy.c
 create mode 100644 ports/sysdeps/arm/armv7/multiarch/ifunc-impl-list.c
 create mode 100644 ports/sysdeps/arm/armv7/multiarch/memcpy.S
 create mode 100644 ports/sysdeps/arm/armv7/multiarch/memcpy_impl.S
 create mode 100644 ports/sysdeps/arm/armv7/multiarch/memcpy_neon.S
 create mode 100644 ports/sysdeps/arm/armv7/multiarch/memcpy_vfp.S

Changes in v5:
 - Move the configure check for binutils 2.21 to ports/sysdeps/arm.

diff --git a/ports/sysdeps/arm/armv7/multiarch/Makefile b/ports/sysdeps/arm/armv7/multiarch/Makefile
new file mode 100644
index 0000000..e834cc9
--- /dev/null
+++ b/ports/sysdeps/arm/armv7/multiarch/Makefile
@@ -0,0 +1,3 @@
+ifeq ($(subdir),string)
+sysdep_routines += memcpy_neon memcpy_vfp
+endif
diff --git a/ports/sysdeps/arm/armv7/multiarch/aeabi_memcpy.c b/ports/sysdeps/arm/armv7/multiarch/aeabi_memcpy.c
new file mode 100644
index 0000000..1f163b3
--- /dev/null
+++ b/ports/sysdeps/arm/armv7/multiarch/aeabi_memcpy.c
@@ -0,0 +1,33 @@
+/* Copyright (C) 2005-2013 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 <string.h>
+
+void *__memcpy_arm (void *dest, const void *src, size_t n);
+
+/* Copy memory like memcpy, but no return value required.  Can't alias
+   to memcpy because it's not defined in the same translation
+   unit.  */
+void
+__aeabi_memcpy (void *dest, const void *src, size_t n)
+{
+  __memcpy_arm (dest, src, n);
+}
+
+/* Versions of the above which may assume memory alignment.  */
+strong_alias (__aeabi_memcpy, __aeabi_memcpy4)
+strong_alias (__aeabi_memcpy, __aeabi_memcpy8)
diff --git a/ports/sysdeps/arm/armv7/multiarch/ifunc-impl-list.c b/ports/sysdeps/arm/armv7/multiarch/ifunc-impl-list.c
new file mode 100644
index 0000000..b877eba
--- /dev/null
+++ b/ports/sysdeps/arm/armv7/multiarch/ifunc-impl-list.c
@@ -0,0 +1,44 @@
+/* Enumerate available IFUNC implementations of a function.  arm version.
+   Copyright (C) 2013 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 <string.h>
+#include <ldsodefs.h>
+#include <sysdep.h>
+#include <ifunc-impl-list.h>
+
+/* Fill ARRAY of MAX elements with IFUNC implementations for function
+   NAME and return the number of valid entries.  */
+
+size_t
+__libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
+			size_t max)
+{
+  size_t i = 0;
+  int hwcap;
+
+  hwcap = GLRO(dl_hwcap);
+
+  IFUNC_IMPL (i, name, memcpy,
+	      IFUNC_IMPL_ADD (array, i, memcpy, hwcap & HWCAP_ARM_NEON,
+			      __memcpy_neon)
+	      IFUNC_IMPL_ADD (array, i, memcpy, hwcap & HWCAP_ARM_VFPv3,
+			      __memcpy_vfp)
+	      IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_arm));
+
+  return i;
+}
diff --git a/ports/sysdeps/arm/armv7/multiarch/memcpy.S b/ports/sysdeps/arm/armv7/multiarch/memcpy.S
new file mode 100644
index 0000000..9e423e6
--- /dev/null
+++ b/ports/sysdeps/arm/armv7/multiarch/memcpy.S
@@ -0,0 +1,59 @@
+/* Multiple versions of memcpy
+   All versions must be listed in ifunc-impl-list.c.
+   Copyright (C) 2013 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/>.  */
+
+#define NO_THUMB
+#include <sysdep.h>
+#include <rtld-global-offsets.h>
+
+#if !defined NOT_IN_libc
+	.text
+ENTRY(memcpy)
+	.type	memcpy, %gnu_indirect_function
+	ldr	r1, .Lmemcpy_arm
+	tst	r0, #HWCAP_ARM_VFP
+	ldrne	r1, .Lmemcpy_vfp
+	tst	r0, #HWCAP_ARM_NEON
+	ldrne	r1, .Lmemcpy_neon
+1:
+	add	r0, r1, pc
+	DO_RET(lr)
+
+.Lmemcpy_arm:
+	.long	C_SYMBOL_NAME(__memcpy_arm) - 1b - PC_OFS
+.Lmemcpy_neon:
+	.long	C_SYMBOL_NAME(__memcpy_neon) - 1b - PC_OFS
+.Lmemcpy_vfp:
+	.long	C_SYMBOL_NAME(__memcpy_vfp) - 1b - PC_OFS
+
+END(memcpy)
+
+libc_hidden_builtin_def (memcpy)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+#undef weak_alias
+#define weak_alias(x, y)
+#undef libc_hidden_def
+#define libc_hidden_def(name)
+
+#define memcpy __memcpy_arm
+
+#endif
+
+#include "memcpy_impl.S"
diff --git a/ports/sysdeps/arm/armv7/multiarch/memcpy_impl.S b/ports/sysdeps/arm/armv7/multiarch/memcpy_impl.S
new file mode 100644
index 0000000..5e4ba06
--- /dev/null
+++ b/ports/sysdeps/arm/armv7/multiarch/memcpy_impl.S
@@ -0,0 +1,640 @@
+/* NEON/VFP/ARM version of memcpy optimized for Cortex-A15.
+   Copyright (C) 2013 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/>.
+
+   This memcpy routine is optimised for Cortex-A15 cores and takes advantage
+   of VFP or NEON when built with the appropriate flags.
+
+   Assumptions:
+
+    ARMv6 (ARMv7-a if using Neon)
+    ARM state
+    Unaligned accesses
+    LDRD/STRD support unaligned word accesses
+
+ */
+#ifndef NO_THUMB
+#define NO_THUMB
+#endif
+#include <sysdep.h>
+
+	.syntax unified
+	/* This implementation requires ARM state.  */
+	.arm
+
+#ifdef MEMCPY_NEON
+
+	.fpu	neon
+	.arch	armv7-a
+# define FRAME_SIZE	4
+# define USE_VFP
+# define USE_NEON
+
+#elif defined (MEMCPY_VFP)
+
+	.arch	armv6
+	.fpu	vfpv2
+# define FRAME_SIZE	32
+# define USE_VFP
+
+#else
+	.arch	armv6
+# define FRAME_SIZE    32
+
+#endif
+
+#define ALIGN(addr, align) addr:align
+
+#define INSN_SIZE	4
+
+/* Call parameters.  */
+#define dstin	r0
+#define src	r1
+#define count	r2
+
+/* Locals.  */
+#define tmp1	r3
+#define dst	ip
+#define tmp2	r10
+
+#ifndef USE_NEON
+/* For bulk copies using GP registers.  */
+#define	A_l	r2		/* Call-clobbered.  */
+#define	A_h	r3		/* Call-clobbered.  */
+#define	B_l	r4
+#define	B_h	r5
+#define	C_l	r6
+#define	C_h	r7
+#define	D_l	r8
+#define	D_h	r9
+#endif
+
+/* Number of lines ahead to pre-fetch data.  If you change this the code
+   below will need adjustment to compensate.  */
+
+#define prefetch_lines	5
+
+#ifdef USE_VFP
+	.macro	cpy_line_vfp vreg, base
+	vstr	\vreg, [dst, #\base]
+	vldr	\vreg, [src, #\base]
+	vstr	d0, [dst, #\base + 8]
+	vldr	d0, [src, #\base + 8]
+	vstr	d1, [dst, #\base + 16]
+	vldr	d1, [src, #\base + 16]
+	vstr	d2, [dst, #\base + 24]
+	vldr	d2, [src, #\base + 24]
+	vstr	\vreg, [dst, #\base + 32]
+	vldr	\vreg, [src, #\base + prefetch_lines * 64 - 32]
+	vstr	d0, [dst, #\base + 40]
+	vldr	d0, [src, #\base + 40]
+	vstr	d1, [dst, #\base + 48]
+	vldr	d1, [src, #\base + 48]
+	vstr	d2, [dst, #\base + 56]
+	vldr	d2, [src, #\base + 56]
+	.endm
+
+	.macro	cpy_tail_vfp vreg, base
+	vstr	\vreg, [dst, #\base]
+	vldr	\vreg, [src, #\base]
+	vstr	d0, [dst, #\base + 8]
+	vldr	d0, [src, #\base + 8]
+	vstr	d1, [dst, #\base + 16]
+	vldr	d1, [src, #\base + 16]
+	vstr	d2, [dst, #\base + 24]
+	vldr	d2, [src, #\base + 24]
+	vstr	\vreg, [dst, #\base + 32]
+	vstr	d0, [dst, #\base + 40]
+	vldr	d0, [src, #\base + 40]
+	vstr	d1, [dst, #\base + 48]
+	vldr	d1, [src, #\base + 48]
+	vstr	d2, [dst, #\base + 56]
+	vldr	d2, [src, #\base + 56]
+	.endm
+#endif
+
+	.p2align 6
+ENTRY(memcpy)
+
+	mov	dst, dstin	/* Preserve dstin, we need to return it.  */
+	cmp	count, #64
+	bge	.Lcpy_not_short
+	/* Deal with small copies quickly by dropping straight into the
+	   exit block.  */
+
+.Ltail63unaligned:
+#ifdef USE_NEON
+	and	tmp1, count, #0x38
+	rsb	tmp1, tmp1, #(56 - PC_OFS + INSN_SIZE)
+	add	pc, pc, tmp1
+	vld1.8	{d0}, [src]!	/* 14 words to go.  */
+	vst1.8	{d0}, [dst]!
+	vld1.8	{d0}, [src]!	/* 12 words to go.  */
+	vst1.8	{d0}, [dst]!
+	vld1.8	{d0}, [src]!	/* 10 words to go.  */
+	vst1.8	{d0}, [dst]!
+	vld1.8	{d0}, [src]!	/* 8 words to go.  */
+	vst1.8	{d0}, [dst]!
+	vld1.8	{d0}, [src]!	/* 6 words to go.  */
+	vst1.8	{d0}, [dst]!
+	vld1.8	{d0}, [src]!	/* 4 words to go.  */
+	vst1.8	{d0}, [dst]!
+	vld1.8	{d0}, [src]!	/* 2 words to go.  */
+	vst1.8	{d0}, [dst]!
+
+	tst	count, #4
+	ldrne	tmp1, [src], #4
+	strne	tmp1, [dst], #4
+#else
+	/* Copy up to 15 full words of data.  May not be aligned.  */
+	/* Cannot use VFP for unaligned data.  */
+	and	tmp1, count, #0x3c
+	add	dst, dst, tmp1
+	add	src, src, tmp1
+	rsb	tmp1, tmp1, #(60 - PC_OFS/2 + INSN_SIZE/2)
+	/* Jump directly into the sequence below at the correct offset.  */
+	add	pc, pc, tmp1, lsl #1
+
+	ldr	tmp1, [src, #-60]	/* 15 words to go.  */
+	str	tmp1, [dst, #-60]
+
+	ldr	tmp1, [src, #-56]	/* 14 words to go.  */
+	str	tmp1, [dst, #-56]
+	ldr	tmp1, [src, #-52]
+	str	tmp1, [dst, #-52]
+
+	ldr	tmp1, [src, #-48]	/* 12 words to go.  */
+	str	tmp1, [dst, #-48]
+	ldr	tmp1, [src, #-44]
+	str	tmp1, [dst, #-44]
+
+	ldr	tmp1, [src, #-40]	/* 10 words to go.  */
+	str	tmp1, [dst, #-40]
+	ldr	tmp1, [src, #-36]
+	str	tmp1, [dst, #-36]
+
+	ldr	tmp1, [src, #-32]	/* 8 words to go.  */
+	str	tmp1, [dst, #-32]
+	ldr	tmp1, [src, #-28]
+	str	tmp1, [dst, #-28]
+
+	ldr	tmp1, [src, #-24]	/* 6 words to go.  */
+	str	tmp1, [dst, #-24]
+	ldr	tmp1, [src, #-20]
+	str	tmp1, [dst, #-20]
+
+	ldr	tmp1, [src, #-16]	/* 4 words to go.  */
+	str	tmp1, [dst, #-16]
+	ldr	tmp1, [src, #-12]
+	str	tmp1, [dst, #-12]
+
+	ldr	tmp1, [src, #-8]	/* 2 words to go.  */
+	str	tmp1, [dst, #-8]
+	ldr	tmp1, [src, #-4]
+	str	tmp1, [dst, #-4]
+#endif
+
+	lsls	count, count, #31
+	ldrhcs	tmp1, [src], #2
+	ldrbne	src, [src]		/* Src is dead, use as a scratch.  */
+	strhcs	tmp1, [dst], #2
+	strbne	src, [dst]
+	bx	lr
+
+.Lcpy_not_short:
+	/* At least 64 bytes to copy, but don't know the alignment yet.  */
+	str	tmp2, [sp, #-FRAME_SIZE]!
+	cfi_adjust_cfa_offset (FRAME_SIZE)
+	cfi_rel_offset (tmp2, 0)
+	cfi_remember_state
+	and	tmp2, src, #3
+	and	tmp1, dst, #3
+	cmp	tmp1, tmp2
+	bne	.Lcpy_notaligned
+
+#ifdef USE_VFP
+	/* Magic dust alert!  Force VFP on Cortex-A9.  Experiments show
+	   that the FP pipeline is much better at streaming loads and
+	   stores.  This is outside the critical loop.  */
+	vmov.f32	s0, s0
+#endif
+
+	/* SRC and DST have the same mutual 32-bit alignment, but we may
+	   still need to pre-copy some bytes to get to natural alignment.
+	   We bring DST into full 64-bit alignment.  */
+	lsls	tmp2, dst, #29
+	beq	1f
+	rsbs	tmp2, tmp2, #0
+	sub	count, count, tmp2, lsr #29
+	ldrmi	tmp1, [src], #4
+	strmi	tmp1, [dst], #4
+	lsls	tmp2, tmp2, #2
+	ldrhcs	tmp1, [src], #2
+	ldrbne	tmp2, [src], #1
+	strhcs	tmp1, [dst], #2
+	strbne	tmp2, [dst], #1
+
+1:
+	subs	tmp2, count, #64	/* Use tmp2 for count.  */
+	blt	.Ltail63aligned
+
+	cmp	tmp2, #512
+	bge	.Lcpy_body_long
+
+.Lcpy_body_medium:			/* Count in tmp2.  */
+#ifdef USE_VFP
+1:
+	vldr	d0, [src, #0]
+	subs	tmp2, tmp2, #64
+	vldr	d1, [src, #8]
+	vstr	d0, [dst, #0]
+	vldr	d0, [src, #16]
+	vstr	d1, [dst, #8]
+	vldr	d1, [src, #24]
+	vstr	d0, [dst, #16]
+	vldr	d0, [src, #32]
+	vstr	d1, [dst, #24]
+	vldr	d1, [src, #40]
+	vstr	d0, [dst, #32]
+	vldr	d0, [src, #48]
+	vstr	d1, [dst, #40]
+	vldr	d1, [src, #56]
+	vstr	d0, [dst, #48]
+	add	src, src, #64
+	vstr	d1, [dst, #56]
+	add	dst, dst, #64
+	bge	1b
+	tst	tmp2, #0x3f
+	beq	.Ldone
+
+.Ltail63aligned:			/* Count in tmp2.  */
+	and	tmp1, tmp2, #0x38
+	add	dst, dst, tmp1
+	add	src, src, tmp1
+	rsb	tmp1, tmp1, #(56 - PC_OFS + INSN_SIZE)
+	add	pc, pc, tmp1
+
+	vldr	d0, [src, #-56]	/* 14 words to go.  */
+	vstr	d0, [dst, #-56]
+	vldr	d0, [src, #-48]	/* 12 words to go.  */
+	vstr	d0, [dst, #-48]
+	vldr	d0, [src, #-40]	/* 10 words to go.  */
+	vstr	d0, [dst, #-40]
+	vldr	d0, [src, #-32]	/* 8 words to go.  */
+	vstr	d0, [dst, #-32]
+	vldr	d0, [src, #-24]	/* 6 words to go.  */
+	vstr	d0, [dst, #-24]
+	vldr	d0, [src, #-16]	/* 4 words to go.  */
+	vstr	d0, [dst, #-16]
+	vldr	d0, [src, #-8]	/* 2 words to go.  */
+	vstr	d0, [dst, #-8]
+#else
+	sub	src, src, #8
+	sub	dst, dst, #8
+1:
+	ldrd	A_l, A_h, [src, #8]
+	strd	A_l, A_h, [dst, #8]
+	ldrd	A_l, A_h, [src, #16]
+	strd	A_l, A_h, [dst, #16]
+	ldrd	A_l, A_h, [src, #24]
+	strd	A_l, A_h, [dst, #24]
+	ldrd	A_l, A_h, [src, #32]
+	strd	A_l, A_h, [dst, #32]
+	ldrd	A_l, A_h, [src, #40]
+	strd	A_l, A_h, [dst, #40]
+	ldrd	A_l, A_h, [src, #48]
+	strd	A_l, A_h, [dst, #48]
+	ldrd	A_l, A_h, [src, #56]
+	strd	A_l, A_h, [dst, #56]
+	ldrd	A_l, A_h, [src, #64]!
+	strd	A_l, A_h, [dst, #64]!
+	subs	tmp2, tmp2, #64
+	bge	1b
+	tst	tmp2, #0x3f
+	bne	1f
+	ldr	tmp2,[sp], #FRAME_SIZE
+	cfi_adjust_cfa_offset (-FRAME_SIZE)
+	cfi_restore (tmp2)
+	bx	lr
+
+	cfi_restore_state
+	cfi_remember_state
+1:
+	add	src, src, #8
+	add	dst, dst, #8
+
+.Ltail63aligned:			/* Count in tmp2.  */
+	/* Copy up to 7 d-words of data.  Similar to Ltail63unaligned, but
+	   we know that the src and dest are 32-bit aligned so we can use
+	   LDRD/STRD to improve efficiency.  */
+	/* TMP2 is now negative, but we don't care about that.  The bottom
+	   six bits still tell us how many bytes are left to copy.  */
+
+	and	tmp1, tmp2, #0x38
+	add	dst, dst, tmp1
+	add	src, src, tmp1
+	rsb	tmp1, tmp1, #(56 - PC_OFS + INSN_SIZE)
+	add	pc, pc, tmp1
+	ldrd	A_l, A_h, [src, #-56]	/* 14 words to go.  */
+	strd	A_l, A_h, [dst, #-56]
+	ldrd	A_l, A_h, [src, #-48]	/* 12 words to go.  */
+	strd	A_l, A_h, [dst, #-48]
+	ldrd	A_l, A_h, [src, #-40]	/* 10 words to go.  */
+	strd	A_l, A_h, [dst, #-40]
+	ldrd	A_l, A_h, [src, #-32]	/* 8 words to go.  */
+	strd	A_l, A_h, [dst, #-32]
+	ldrd	A_l, A_h, [src, #-24]	/* 6 words to go.  */
+	strd	A_l, A_h, [dst, #-24]
+	ldrd	A_l, A_h, [src, #-16]	/* 4 words to go.  */
+	strd	A_l, A_h, [dst, #-16]
+	ldrd	A_l, A_h, [src, #-8]	/* 2 words to go.  */
+	strd	A_l, A_h, [dst, #-8]
+
+#endif
+	tst	tmp2, #4
+	ldrne	tmp1, [src], #4
+	strne	tmp1, [dst], #4
+	lsls	tmp2, tmp2, #31		/* Count (tmp2) now dead. */
+	ldrhcs	tmp1, [src], #2
+	ldrbne	tmp2, [src]
+	strhcs	tmp1, [dst], #2
+	strbne	tmp2, [dst]
+
+.Ldone:
+	ldr	tmp2, [sp], #FRAME_SIZE
+	cfi_adjust_cfa_offset (-FRAME_SIZE)
+	cfi_restore (tmp2)
+	bx	lr
+
+	cfi_restore_state
+	cfi_remember_state
+
+.Lcpy_body_long:			/* Count in tmp2.  */
+
+	/* Long copy.  We know that there's at least (prefetch_lines * 64)
+	   bytes to go.  */
+#ifdef USE_VFP
+	/* Don't use PLD.  Instead, read some data in advance of the current
+	   copy position into a register.  This should act like a PLD
+	   operation but we won't have to repeat the transfer.  */
+
+	vldr	d3, [src, #0]
+	vldr	d4, [src, #64]
+	vldr	d5, [src, #128]
+	vldr	d6, [src, #192]
+	vldr	d7, [src, #256]
+
+	vldr	d0, [src, #8]
+	vldr	d1, [src, #16]
+	vldr	d2, [src, #24]
+	add	src, src, #32
+
+	subs	tmp2, tmp2, #prefetch_lines * 64 * 2
+	blt	2f
+1:
+	cpy_line_vfp	d3, 0
+	cpy_line_vfp	d4, 64
+	cpy_line_vfp	d5, 128
+	add	dst, dst, #3 * 64
+	add	src, src, #3 * 64
+	cpy_line_vfp	d6, 0
+	cpy_line_vfp	d7, 64
+	add	dst, dst, #2 * 64
+	add	src, src, #2 * 64
+	subs	tmp2, tmp2, #prefetch_lines * 64
+	bge	1b
+
+2:
+	cpy_tail_vfp	d3, 0
+	cpy_tail_vfp	d4, 64
+	cpy_tail_vfp	d5, 128
+	add	src, src, #3 * 64
+	add	dst, dst, #3 * 64
+	cpy_tail_vfp	d6, 0
+	vstr	d7, [dst, #64]
+	vldr	d7, [src, #64]
+	vstr	d0, [dst, #64 + 8]
+	vldr	d0, [src, #64 + 8]
+	vstr	d1, [dst, #64 + 16]
+	vldr	d1, [src, #64 + 16]
+	vstr	d2, [dst, #64 + 24]
+	vldr	d2, [src, #64 + 24]
+	vstr	d7, [dst, #64 + 32]
+	add	src, src, #96
+	vstr	d0, [dst, #64 + 40]
+	vstr	d1, [dst, #64 + 48]
+	vstr	d2, [dst, #64 + 56]
+	add	dst, dst, #128
+	add	tmp2, tmp2, #prefetch_lines * 64
+	b	.Lcpy_body_medium
+#else
+	/* Long copy.  Use an SMS style loop to maximize the I/O
+	   bandwidth of the core.  We don't have enough spare registers
+	   to synthesise prefetching, so use PLD operations.  */
+	/* Pre-bias src and dst.  */
+	sub	src, src, #8
+	sub	dst, dst, #8
+	pld	[src, #8]
+	pld	[src, #72]
+	subs	tmp2, tmp2, #64
+	pld	[src, #136]
+	ldrd	A_l, A_h, [src, #8]
+	strd	B_l, B_h, [sp, #8]
+	cfi_rel_offset (B_l, 8)
+	cfi_rel_offset (B_h, 12)
+	ldrd	B_l, B_h, [src, #16]
+	strd	C_l, C_h, [sp, #16]
+	cfi_rel_offset (C_l, 16)
+	cfi_rel_offset (C_h, 20)
+	ldrd	C_l, C_h, [src, #24]
+	strd	D_l, D_h, [sp, #24]
+	cfi_rel_offset (D_l, 24)
+	cfi_rel_offset (D_h, 28)
+	pld	[src, #200]
+	ldrd	D_l, D_h, [src, #32]!
+	b	1f
+	.p2align	6
+2:
+	pld	[src, #232]
+	strd	A_l, A_h, [dst, #40]
+	ldrd	A_l, A_h, [src, #40]
+	strd	B_l, B_h, [dst, #48]
+	ldrd	B_l, B_h, [src, #48]
+	strd	C_l, C_h, [dst, #56]
+	ldrd	C_l, C_h, [src, #56]
+	strd	D_l, D_h, [dst, #64]!
+	ldrd	D_l, D_h, [src, #64]!
+	subs	tmp2, tmp2, #64
+1:
+	strd	A_l, A_h, [dst, #8]
+	ldrd	A_l, A_h, [src, #8]
+	strd	B_l, B_h, [dst, #16]
+	ldrd	B_l, B_h, [src, #16]
+	strd	C_l, C_h, [dst, #24]
+	ldrd	C_l, C_h, [src, #24]
+	strd	D_l, D_h, [dst, #32]
+	ldrd	D_l, D_h, [src, #32]
+	bcs	2b
+	/* Save the remaining bytes and restore the callee-saved regs.  */
+	strd	A_l, A_h, [dst, #40]
+	add	src, src, #40
+	strd	B_l, B_h, [dst, #48]
+	ldrd	B_l, B_h, [sp, #8]
+	cfi_restore (B_l)
+	cfi_restore (B_h)
+	strd	C_l, C_h, [dst, #56]
+	ldrd	C_l, C_h, [sp, #16]
+	cfi_restore (C_l)
+	cfi_restore (C_h)
+	strd	D_l, D_h, [dst, #64]
+	ldrd	D_l, D_h, [sp, #24]
+	cfi_restore (D_l)
+	cfi_restore (D_h)
+	add	dst, dst, #72
+	tst	tmp2, #0x3f
+	bne	.Ltail63aligned
+	ldr	tmp2, [sp], #FRAME_SIZE
+	cfi_adjust_cfa_offset (-FRAME_SIZE)
+	cfi_restore (tmp2)
+	bx	lr
+#endif
+
+	cfi_restore_state
+	cfi_remember_state
+
+.Lcpy_notaligned:
+	pld	[src]
+	pld	[src, #64]
+	/* There's at least 64 bytes to copy, but there is no mutual
+	   alignment.  */
+	/* Bring DST to 64-bit alignment.  */
+	lsls	tmp2, dst, #29
+	pld	[src, #(2 * 64)]
+	beq	1f
+	rsbs	tmp2, tmp2, #0
+	sub	count, count, tmp2, lsr #29
+	ldrmi	tmp1, [src], #4
+	strmi	tmp1, [dst], #4
+	lsls	tmp2, tmp2, #2
+	ldrbne	tmp1, [src], #1
+	ldrhcs	tmp2, [src], #2
+	strbne	tmp1, [dst], #1
+	strhcs	tmp2, [dst], #2
+1:
+	pld	[src, #(3 * 64)]
+	subs	count, count, #64
+	ldrmi	tmp2, [sp], #FRAME_SIZE
+	bmi	.Ltail63unaligned
+	pld	[src, #(4 * 64)]
+
+#ifdef USE_NEON
+	vld1.8	{d0-d3}, [src]!
+	vld1.8	{d4-d7}, [src]!
+	subs	count, count, #64
+	bmi	2f
+1:
+	pld	[src, #(4 * 64)]
+	vst1.8	{d0-d3}, [ALIGN (dst, 64)]!
+	vld1.8	{d0-d3}, [src]!
+	vst1.8	{d4-d7}, [ALIGN (dst, 64)]!
+	vld1.8	{d4-d7}, [src]!
+	subs	count, count, #64
+	bpl	1b
+2:
+	vst1.8	{d0-d3}, [ALIGN (dst, 64)]!
+	vst1.8	{d4-d7}, [ALIGN (dst, 64)]!
+	ands	count, count, #0x3f
+#else
+	/* Use an SMS style loop to maximize the I/O bandwidth.  */
+	sub	src, src, #4
+	sub	dst, dst, #8
+	subs	tmp2, count, #64	/* Use tmp2 for count.  */
+	ldr	A_l, [src, #4]
+	ldr	A_h, [src, #8]
+	strd	B_l, B_h, [sp, #8]
+	cfi_rel_offset (B_l, 8)
+	cfi_rel_offset (B_h, 12)
+	ldr	B_l, [src, #12]
+	ldr	B_h, [src, #16]
+	strd	C_l, C_h, [sp, #16]
+	cfi_rel_offset (C_l, 16)
+	cfi_rel_offset (C_h, 20)
+	ldr	C_l, [src, #20]
+	ldr	C_h, [src, #24]
+	strd	D_l, D_h, [sp, #24]
+	cfi_rel_offset (D_l, 24)
+	cfi_rel_offset (D_h, 28)
+	ldr	D_l, [src, #28]
+	ldr	D_h, [src, #32]!
+	b	1f
+	.p2align	6
+2:
+	pld	[src, #(5 * 64) - (32 - 4)]
+	strd	A_l, A_h, [dst, #40]
+	ldr	A_l, [src, #36]
+	ldr	A_h, [src, #40]
+	strd	B_l, B_h, [dst, #48]
+	ldr	B_l, [src, #44]
+	ldr	B_h, [src, #48]
+	strd	C_l, C_h, [dst, #56]
+	ldr	C_l, [src, #52]
+	ldr	C_h, [src, #56]
+	strd	D_l, D_h, [dst, #64]!
+	ldr	D_l, [src, #60]
+	ldr	D_h, [src, #64]!
+	subs	tmp2, tmp2, #64
+1:
+	strd	A_l, A_h, [dst, #8]
+	ldr	A_l, [src, #4]
+	ldr	A_h, [src, #8]
+	strd	B_l, B_h, [dst, #16]
+	ldr	B_l, [src, #12]
+	ldr	B_h, [src, #16]
+	strd	C_l, C_h, [dst, #24]
+	ldr	C_l, [src, #20]
+	ldr	C_h, [src, #24]
+	strd	D_l, D_h, [dst, #32]
+	ldr	D_l, [src, #28]
+	ldr	D_h, [src, #32]
+	bcs	2b
+
+	/* Save the remaining bytes and restore the callee-saved regs.  */
+	strd	A_l, A_h, [dst, #40]
+	add	src, src, #36
+	strd	B_l, B_h, [dst, #48]
+	ldrd	B_l, B_h, [sp, #8]
+	cfi_restore (B_l)
+	cfi_restore (B_h)
+	strd	C_l, C_h, [dst, #56]
+	ldrd	C_l, C_h, [sp, #16]
+	cfi_restore (C_l)
+	cfi_restore (C_h)
+	strd	D_l, D_h, [dst, #64]
+	ldrd	D_l, D_h, [sp, #24]
+	cfi_restore (D_l)
+	cfi_restore (D_h)
+	add	dst, dst, #72
+	ands	count, tmp2, #0x3f
+#endif
+	ldr	tmp2, [sp], #FRAME_SIZE
+	cfi_adjust_cfa_offset (-FRAME_SIZE)
+	cfi_restore (tmp2)
+	bne	.Ltail63unaligned
+	bx	lr
+
+END(memcpy)
+libc_hidden_builtin_def (memcpy)
diff --git a/ports/sysdeps/arm/armv7/multiarch/memcpy_neon.S b/ports/sysdeps/arm/armv7/multiarch/memcpy_neon.S
new file mode 100644
index 0000000..c0ef1f8
--- /dev/null
+++ b/ports/sysdeps/arm/armv7/multiarch/memcpy_neon.S
@@ -0,0 +1,3 @@
+#define MEMCPY_NEON
+#define memcpy __memcpy_neon
+#include "memcpy_impl.S"
diff --git a/ports/sysdeps/arm/armv7/multiarch/memcpy_vfp.S b/ports/sysdeps/arm/armv7/multiarch/memcpy_vfp.S
new file mode 100644
index 0000000..d21b702
--- /dev/null
+++ b/ports/sysdeps/arm/armv7/multiarch/memcpy_vfp.S
@@ -0,0 +1,3 @@
+#define MEMCPY_VFP
+#define memcpy __memcpy_vfp
+#include "memcpy_impl.S"
diff --git a/ports/sysdeps/arm/configure.in b/ports/sysdeps/arm/configure.in
index d66500b..0d95cb9 100644
--- a/ports/sysdeps/arm/configure.in
+++ b/ports/sysdeps/arm/configure.in
@@ -44,3 +44,11 @@ if test $libc_cv_arm_pcs_vfp = yes; then
 else
   LIBC_CONFIG_VAR([default-abi], [soft])
 fi
+
+# If we are configuring for armv7 we need binutils 2.21 to ensure that
+# NEON alignments are assembled correctly.
+if test $machine = arm/armv7; then
+   AC_CHECK_PROG_VER(AS, $AS, --version,
+		  [GNU assembler.* \([0-9]*\.[0-9.]*\)],
+		  [2.1[0-9][0-9]*|2.[2-9][1-9]*|[3-9].*|[1-9][0-9]*], AS=: critic_missing="$critic_missing as")
+fi
-- 
1.8.1.4



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