path: root/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S

/* memmove/memcpy/mempcpy with unaligned load/store and rep movsb
   Copyright (C) 2016-2019 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
   <https://www.gnu.org/licenses/>.  */

/* memmove/memcpy/mempcpy is implemented as:
   1. Use overlapping load and store to avoid branch.
   2. Load all sources into registers and store them together to avoid
      possible address overlap between source and destination.
   3. If size is 8 * VEC_SIZE or less, load all sources into registers
      and store them together.
   4. If address of destination > address of source, backward copy
      4 * VEC_SIZE at a time with unaligned load and aligned store.
      Load the first 4 * VEC and last VEC before the loop and store
      them after the loop to support overlapping addresses.
   5. Otherwise, forward copy 4 * VEC_SIZE at a time with unaligned
      load and aligned store.  Load the last 4 * VEC and first VEC
      before the loop and store them after the loop to support
      overlapping addresses.
   6. If size >= __x86_shared_non_temporal_threshold and there is no
      overlap between destination and source, use non-temporal store
      instead of aligned store.  */

#include <sysdep.h>

#ifndef MEMCPY_SYMBOL
# define MEMCPY_SYMBOL(p,s)		MEMMOVE_SYMBOL(p, s)
#endif

#ifndef MEMPCPY_SYMBOL
# define MEMPCPY_SYMBOL(p,s)		MEMMOVE_SYMBOL(p, s)
#endif

#ifndef MEMMOVE_CHK_SYMBOL
# define MEMMOVE_CHK_SYMBOL(p,s)	MEMMOVE_SYMBOL(p, s)
#endif

#ifndef VZEROUPPER
# if VEC_SIZE > 16
#  define VZEROUPPER vzeroupper
# else
#  define VZEROUPPER
# endif
#endif

/* Threshold to use Enhanced REP MOVSB.  Since there is overhead to set
   up REP MOVSB operation, REP MOVSB isn't faster on short data.  The
   memcpy micro benchmark in glibc shows that 2KB is the approximate
   value above which REP MOVSB becomes faster than SSE2 optimization
   on processors with Enhanced REP MOVSB.  Since larger register size
   can move more data with a single load and store, the threshold is
   higher with larger register size.  */
#ifndef REP_MOVSB_THRESHOLD
# define REP_MOVSB_THRESHOLD	(2048 * (VEC_SIZE / 16))
#endif

#ifndef PREFETCH
# define PREFETCH(addr) prefetcht0 addr
#endif

/* Assume 64-byte prefetch size.  */
#ifndef PREFETCH_SIZE
# define PREFETCH_SIZE 64
#endif

#define PREFETCHED_LOAD_SIZE (VEC_SIZE * 4)

#if PREFETCH_SIZE == 64
# if PREFETCHED_LOAD_SIZE == PREFETCH_SIZE
#  define PREFETCH_ONE_SET(dir, base, offset) \
	PREFETCH ((offset)base)
# elif PREFETCHED_LOAD_SIZE == 2 * PREFETCH_SIZE
#  define PREFETCH_ONE_SET(dir, base, offset) \
	PREFETCH ((offset)base); \
	PREFETCH ((offset + dir * PREFETCH_SIZE)base)
# elif PREFETCHED_LOAD_SIZE == 4 * PREFETCH_SIZE
#  define PREFETCH_ONE_SET(dir, base, offset) \
	PREFETCH ((offset)base); \
	PREFETCH ((offset + dir * PREFETCH_SIZE)base); \
	PREFETCH ((offset + dir * PREFETCH_SIZE * 2)base); \
	PREFETCH ((offset + dir * PREFETCH_SIZE * 3)base)
# else
#   error Unsupported PREFETCHED_LOAD_SIZE!
# endif
#else
# error Unsupported PREFETCH_SIZE!
#endif

#ifndef SECTION
# error SECTION is not defined!
#endif

	.section SECTION(.text),"ax",@progbits
#if defined SHARED && IS_IN (libc)
ENTRY (MEMMOVE_CHK_SYMBOL (__mempcpy_chk, unaligned))
	cmp	%RDX_LP, %RCX_LP
	jb	HIDDEN_JUMPTARGET (__chk_fail)
END (MEMMOVE_CHK_SYMBOL (__mempcpy_chk, unaligned))
#endif

ENTRY (MEMPCPY_SYMBOL (__mempcpy, unaligned))
	mov	%RDI_LP, %RAX_LP
	add	%RDX_LP, %RAX_LP
	jmp	L(start)
END (MEMPCPY_SYMBOL (__mempcpy, unaligned))

#if defined SHARED && IS_IN (libc)
ENTRY (MEMMOVE_CHK_SYMBOL (__memmove_chk, unaligned))
	cmp	%RDX_LP, %RCX_LP
	jb	HIDDEN_JUMPTARGET (__chk_fail)
END (MEMMOVE_CHK_SYMBOL (__memmove_chk, unaligned))
#endif

ENTRY (MEMMOVE_SYMBOL (__memmove, unaligned))
	movq	%rdi, %rax
L(start):
# ifdef __ILP32__
	/* Clear the upper 32 bits.  */
	movl	%edx, %edx
# endif
	cmp	$VEC_SIZE, %RDX_LP
	jb	L(less_vec)
	cmp	$(VEC_SIZE * 2), %RDX_LP
	ja	L(more_2x_vec)
#if !defined USE_MULTIARCH || !IS_IN (libc)
L(last_2x_vec):
#endif
	/* From VEC and to 2 * VEC.  No branch when size == VEC_SIZE.  */
	VMOVU	(%rsi), %VEC(0)
	VMOVU	-VEC_SIZE(%rsi,%rdx), %VEC(1)
	VMOVU	%VEC(0), (%rdi)
	VMOVU	%VEC(1), -VEC_SIZE(%rdi,%rdx)
	VZEROUPPER
#if !defined USE_MULTIARCH || !IS_IN (libc)
L(nop):
#endif
	ret
#if defined USE_MULTIARCH && IS_IN (libc)
END (MEMMOVE_SYMBOL (__memmove, unaligned))

# if VEC_SIZE == 16
ENTRY (__mempcpy_chk_erms)
	cmp	%RDX_LP, %RCX_LP
	jb	HIDDEN_JUMPTARGET (__chk_fail)
END (__mempcpy_chk_erms)

/* Only used to measure performance of REP MOVSB.  */
ENTRY (__mempcpy_erms)
	mov	%RDI_LP, %RAX_LP
	/* Skip zero length.  */
	test	%RDX_LP, %RDX_LP
	jz	2f
	add	%RDX_LP, %RAX_LP
	jmp	L(start_movsb)
END (__mempcpy_erms)

ENTRY (__memmove_chk_erms)
	cmp	%RDX_LP, %RCX_LP
	jb	HIDDEN_JUMPTARGET (__chk_fail)
END (__memmove_chk_erms)

ENTRY (__memmove_erms)
	movq	%rdi, %rax
	/* Skip zero length.  */
	test	%RDX_LP, %RDX_LP
	jz	2f
L(start_movsb):
	mov	%RDX_LP, %RCX_LP
	cmp	%RSI_LP, %RDI_LP
	jb	1f
	/* Source == destination is less common.  */
	je	2f
	lea	(%rsi,%rcx), %RDX_LP
	cmp	%RDX_LP, %RDI_LP
	jb	L(movsb_backward)
1:
	rep movsb
2:
	ret
L(movsb_backward):
	leaq	-1(%rdi,%rcx), %rdi
	leaq	-1(%rsi,%rcx), %rsi
	std
	rep movsb
	cld
	ret
END (__memmove_erms)
strong_alias (__memmove_erms, __memcpy_erms)
strong_alias (__memmove_chk_erms, __memcpy_chk_erms)
# endif

# ifdef SHARED
ENTRY (MEMMOVE_CHK_SYMBOL (__mempcpy_chk, unaligned_erms))
	cmp	%RDX_LP, %RCX_LP
	jb	HIDDEN_JUMPTARGET (__chk_fail)
END (MEMMOVE_CHK_SYMBOL (__mempcpy_chk, unaligned_erms))
# endif

ENTRY (MEMMOVE_SYMBOL (__mempcpy, unaligned_erms))
	mov	%RDI_LP, %RAX_LP
	add	%RDX_LP, %RAX_LP
	jmp	L(start_erms)
END (MEMMOVE_SYMBOL (__mempcpy, unaligned_erms))

# ifdef SHARED
ENTRY (MEMMOVE_CHK_SYMBOL (__memmove_chk, unaligned_erms))
	cmp	%RDX_LP, %RCX_LP
	jb	HIDDEN_JUMPTARGET (__chk_fail)
END (MEMMOVE_CHK_SYMBOL (__memmove_chk, unaligned_erms))
# endif

ENTRY (MEMMOVE_SYMBOL (__memmove, unaligned_erms))
	movq	%rdi, %rax
L(start_erms):
# ifdef __ILP32__
	/* Clear the upper 32 bits.  */
	movl	%edx, %edx
# endif
	cmp	$VEC_SIZE, %RDX_LP
	jb	L(less_vec)
	cmp	$(VEC_SIZE * 2), %RDX_LP
	ja	L(movsb_more_2x_vec)
L(last_2x_vec):
	/* From VEC and to 2 * VEC.  No branch when size == VEC_SIZE. */
	VMOVU	(%rsi), %VEC(0)
	VMOVU	-VEC_SIZE(%rsi,%rdx), %VEC(1)
	VMOVU	%VEC(0), (%rdi)
	VMOVU	%VEC(1), -VEC_SIZE(%rdi,%rdx)
L(return):
	VZEROUPPER
	ret

L(movsb):
	cmpq	__x86_shared_non_temporal_threshold(%rip), %rdx
	jae	L(more_8x_vec)
	cmpq	%rsi, %rdi
	jb	1f
	/* Source == destination is less common.  */
	je	L(nop)
	leaq	(%rsi,%rdx), %r9
	cmpq	%r9, %rdi
	/* Avoid slow backward REP MOVSB.  */
# if REP_MOVSB_THRESHOLD <= (VEC_SIZE * 8)
#  error Unsupported REP_MOVSB_THRESHOLD and VEC_SIZE!
# endif
	jb	L(more_8x_vec_backward)
1:
	mov	%RDX_LP, %RCX_LP
	rep movsb
L(nop):
	ret
#endif

L(less_vec):
	/* Less than 1 VEC.  */
#if VEC_SIZE != 16 && VEC_SIZE != 32 && VEC_SIZE != 64
# error Unsupported VEC_SIZE!
#endif
#if VEC_SIZE > 32
	cmpb	$32, %dl
	jae	L(between_32_63)
#endif
#if VEC_SIZE > 16
	cmpb	$16, %dl
	jae	L(between_16_31)
#endif
	cmpb	$8, %dl
	jae	L(between_8_15)
	cmpb	$4, %dl
	jae	L(between_4_7)
	cmpb	$1, %dl
	ja	L(between_2_3)
	jb	1f
	movzbl	(%rsi), %ecx
	movb	%cl, (%rdi)
1:
	ret
#if VEC_SIZE > 32
L(between_32_63):
	/* From 32 to 63.  No branch when size == 32.  */
	vmovdqu	(%rsi), %ymm0
	vmovdqu	-32(%rsi,%rdx), %ymm1
	vmovdqu	%ymm0, (%rdi)
	vmovdqu	%ymm1, -32(%rdi,%rdx)
	VZEROUPPER
	ret
#endif
#if VEC_SIZE > 16
	/* From 16 to 31.  No branch when size == 16.  */
L(between_16_31):
	vmovdqu	(%rsi), %xmm0
	vmovdqu	-16(%rsi,%rdx), %xmm1
	vmovdqu	%xmm0, (%rdi)
	vmovdqu	%xmm1, -16(%rdi,%rdx)
	ret
#endif
L(between_8_15):
	/* From 8 to 15.  No branch when size == 8.  */
	movq	-8(%rsi,%rdx), %rcx
	movq	(%rsi), %rsi
	movq	%rcx, -8(%rdi,%rdx)
	movq	%rsi, (%rdi)
	ret
L(between_4_7):
	/* From 4 to 7.  No branch when size == 4.  */
	movl	-4(%rsi,%rdx), %ecx
	movl	(%rsi), %esi
	movl	%ecx, -4(%rdi,%rdx)
	movl	%esi, (%rdi)
	ret
L(between_2_3):
	/* From 2 to 3.  No branch when size == 2.  */
	movzwl	-2(%rsi,%rdx), %ecx
	movzwl	(%rsi), %esi
	movw	%cx, -2(%rdi,%rdx)
	movw	%si, (%rdi)
	ret

#if defined USE_MULTIARCH && IS_IN (libc)
L(movsb_more_2x_vec):
	cmpq	$REP_MOVSB_THRESHOLD, %rdx
	ja	L(movsb)
#endif
L(more_2x_vec):
	/* More than 2 * VEC and there may be overlap between destination
	   and source.  */
	cmpq	$(VEC_SIZE * 8), %rdx
	ja	L(more_8x_vec)
	cmpq	$(VEC_SIZE * 4), %rdx
	jb	L(last_4x_vec)
	/* Copy from 4 * VEC to 8 * VEC, inclusively. */
	VMOVU	(%rsi), %VEC(0)
	VMOVU	VEC_SIZE(%rsi), %VEC(1)
	VMOVU	(VEC_SIZE * 2)(%rsi), %VEC(2)
	VMOVU	(VEC_SIZE * 3)(%rsi), %VEC(3)
	VMOVU	-VEC_SIZE(%rsi,%rdx), %VEC(4)
	VMOVU	-(VEC_SIZE * 2)(%rsi,%rdx), %VEC(5)
	VMOVU	-(VEC_SIZE * 3)(%rsi,%rdx), %VEC(6)
	VMOVU	-(VEC_SIZE * 4)(%rsi,%rdx), %VEC(7)
	VMOVU	%VEC(0), (%rdi)
	VMOVU	%VEC(1), VEC_SIZE(%rdi)
	VMOVU	%VEC(2), (VEC_SIZE * 2)(%rdi)
	VMOVU	%VEC(3), (VEC_SIZE * 3)(%rdi)
	VMOVU	%VEC(4), -VEC_SIZE(%rdi,%rdx)
	VMOVU	%VEC(5), -(VEC_SIZE * 2)(%rdi,%rdx)
	VMOVU	%VEC(6), -(VEC_SIZE * 3)(%rdi,%rdx)
	VMOVU	%VEC(7), -(VEC_SIZE * 4)(%rdi,%rdx)
	VZEROUPPER
	ret
L(last_4x_vec):
	/* Copy from 2 * VEC to 4 * VEC. */
	VMOVU	(%rsi), %VEC(0)
	VMOVU	VEC_SIZE(%rsi), %VEC(1)
	VMOVU	-VEC_SIZE(%rsi,%rdx), %VEC(2)
	VMOVU	-(VEC_SIZE * 2)(%rsi,%rdx), %VEC(3)
	VMOVU	%VEC(0), (%rdi)
	VMOVU	%VEC(1), VEC_SIZE(%rdi)
	VMOVU	%VEC(2), -VEC_SIZE(%rdi,%rdx)
	VMOVU	%VEC(3), -(VEC_SIZE * 2)(%rdi,%rdx)
	VZEROUPPER
	ret

L(more_8x_vec):
	cmpq	%rsi, %rdi
	ja	L(more_8x_vec_backward)
	/* Source == destination is less common.  */
	je	L(nop)
	/* Load the first VEC and last 4 * VEC to support overlapping
	   addresses.  */
	VMOVU	(%rsi), %VEC(4)
	VMOVU	-VEC_SIZE(%rsi, %rdx), %VEC(5)
	VMOVU	-(VEC_SIZE * 2)(%rsi, %rdx), %VEC(6)
	VMOVU	-(VEC_SIZE * 3)(%rsi, %rdx), %VEC(7)
	VMOVU	-(VEC_SIZE * 4)(%rsi, %rdx), %VEC(8)
	/* Save start and stop of the destination buffer.  */
	movq	%rdi, %r11
	leaq	-VEC_SIZE(%rdi, %rdx), %rcx
	/* Align destination for aligned stores in the loop.  Compute
	   how much destination is misaligned.  */
	movq	%rdi, %r8
	andq	$(VEC_SIZE - 1), %r8
	/* Get the negative of offset for alignment.  */
	subq	$VEC_SIZE, %r8
	/* Adjust source.  */
	subq	%r8, %rsi
	/* Adjust destination which should be aligned now.  */
	subq	%r8, %rdi
	/* Adjust length.  */
	addq	%r8, %rdx
#if (defined USE_MULTIARCH || VEC_SIZE == 16) && IS_IN (libc)
	/* Check non-temporal store threshold.  */
	cmpq	__x86_shared_non_temporal_threshold(%rip), %rdx
	ja	L(large_forward)
#endif
L(loop_4x_vec_forward):
	/* Copy 4 * VEC a time forward.  */
	VMOVU	(%rsi), %VEC(0)
	VMOVU	VEC_SIZE(%rsi), %VEC(1)
	VMOVU	(VEC_SIZE * 2)(%rsi), %VEC(2)
	VMOVU	(VEC_SIZE * 3)(%rsi), %VEC(3)
	addq	$(VEC_SIZE * 4), %rsi
	subq	$(VEC_SIZE * 4), %rdx
	VMOVA	%VEC(0), (%rdi)
	VMOVA	%VEC(1), VEC_SIZE(%rdi)
	VMOVA	%VEC(2), (VEC_SIZE * 2)(%rdi)
	VMOVA	%VEC(3), (VEC_SIZE * 3)(%rdi)
	addq	$(VEC_SIZE * 4), %rdi
	cmpq	$(VEC_SIZE * 4), %rdx
	ja	L(loop_4x_vec_forward)
	/* Store the last 4 * VEC.  */
	VMOVU	%VEC(5), (%rcx)
	VMOVU	%VEC(6), -VEC_SIZE(%rcx)
	VMOVU	%VEC(7), -(VEC_SIZE * 2)(%rcx)
	VMOVU	%VEC(8), -(VEC_SIZE * 3)(%rcx)
	/* Store the first VEC.  */
	VMOVU	%VEC(4), (%r11)
	VZEROUPPER
	ret

L(more_8x_vec_backward):
	/* Load the first 4 * VEC and last VEC to support overlapping
	   addresses.  */
	VMOVU	(%rsi), %VEC(4)
	VMOVU	VEC_SIZE(%rsi), %VEC(5)
	VMOVU	(VEC_SIZE * 2)(%rsi), %VEC(6)
	VMOVU	(VEC_SIZE * 3)(%rsi), %VEC(7)
	VMOVU	-VEC_SIZE(%rsi,%rdx), %VEC(8)
	/* Save stop of the destination buffer.  */
	leaq	-VEC_SIZE(%rdi, %rdx), %r11
	/* Align destination end for aligned stores in the loop.  Compute
	   how much destination end is misaligned.  */
	leaq	-VEC_SIZE(%rsi, %rdx), %rcx
	movq	%r11, %r9
	movq	%r11, %r8
	andq	$(VEC_SIZE - 1), %r8
	/* Adjust source.  */
	subq	%r8, %rcx
	/* Adjust the end of destination which should be aligned now.  */
	subq	%r8, %r9
	/* Adjust length.  */
	subq	%r8, %rdx
#if (defined USE_MULTIARCH || VEC_SIZE == 16) && IS_IN (libc)
	/* Check non-temporal store threshold.  */
	cmpq	__x86_shared_non_temporal_threshold(%rip), %rdx
	ja	L(large_backward)
#endif
L(loop_4x_vec_backward):
	/* Copy 4 * VEC a time backward.  */
	VMOVU	(%rcx), %VEC(0)
	VMOVU	-VEC_SIZE(%rcx), %VEC(1)
	VMOVU	-(VEC_SIZE * 2)(%rcx), %VEC(2)
	VMOVU	-(VEC_SIZE * 3)(%rcx), %VEC(3)
	subq	$(VEC_SIZE * 4), %rcx
	subq	$(VEC_SIZE * 4), %rdx
	VMOVA	%VEC(0), (%r9)
	VMOVA	%VEC(1), -VEC_SIZE(%r9)
	VMOVA	%VEC(2), -(VEC_SIZE * 2)(%r9)
	VMOVA	%VEC(3), -(VEC_SIZE * 3)(%r9)
	subq	$(VEC_SIZE * 4), %r9
	cmpq	$(VEC_SIZE * 4), %rdx
	ja	L(loop_4x_vec_backward)
	/* Store the first 4 * VEC.  */
	VMOVU	%VEC(4), (%rdi)
	VMOVU	%VEC(5), VEC_SIZE(%rdi)
	VMOVU	%VEC(6), (VEC_SIZE * 2)(%rdi)
	VMOVU	%VEC(7), (VEC_SIZE * 3)(%rdi)
	/* Store the last VEC.  */
	VMOVU	%VEC(8), (%r11)
	VZEROUPPER
	ret

#if (defined USE_MULTIARCH || VEC_SIZE == 16) && IS_IN (libc)
L(large_forward):
	/* Don't use non-temporal store if there is overlap between
	   destination and source since destination may be in cache
	   when source is loaded.  */
	leaq    (%rdi, %rdx), %r10
	cmpq    %r10, %rsi
	jb	L(loop_4x_vec_forward)
L(loop_large_forward):
	/* Copy 4 * VEC a time forward with non-temporal stores.  */
	PREFETCH_ONE_SET (1, (%rsi), PREFETCHED_LOAD_SIZE * 2)
	PREFETCH_ONE_SET (1, (%rsi), PREFETCHED_LOAD_SIZE * 3)
	VMOVU	(%rsi), %VEC(0)
	VMOVU	VEC_SIZE(%rsi), %VEC(1)
	VMOVU	(VEC_SIZE * 2)(%rsi), %VEC(2)
	VMOVU	(VEC_SIZE * 3)(%rsi), %VEC(3)
	addq	$PREFETCHED_LOAD_SIZE, %rsi
	subq	$PREFETCHED_LOAD_SIZE, %rdx
	VMOVNT	%VEC(0), (%rdi)
	VMOVNT	%VEC(1), VEC_SIZE(%rdi)
	VMOVNT	%VEC(2), (VEC_SIZE * 2)(%rdi)
	VMOVNT	%VEC(3), (VEC_SIZE * 3)(%rdi)
	addq	$PREFETCHED_LOAD_SIZE, %rdi
	cmpq	$PREFETCHED_LOAD_SIZE, %rdx
	ja	L(loop_large_forward)
	sfence
	/* Store the last 4 * VEC.  */
	VMOVU	%VEC(5), (%rcx)
	VMOVU	%VEC(6), -VEC_SIZE(%rcx)
	VMOVU	%VEC(7), -(VEC_SIZE * 2)(%rcx)
	VMOVU	%VEC(8), -(VEC_SIZE * 3)(%rcx)
	/* Store the first VEC.  */
	VMOVU	%VEC(4), (%r11)
	VZEROUPPER
	ret

L(large_backward):
	/* Don't use non-temporal store if there is overlap between
	   destination and source since destination may be in cache
	   when source is loaded.  */
	leaq    (%rcx, %rdx), %r10
	cmpq    %r10, %r9
	jb	L(loop_4x_vec_backward)
L(loop_large_backward):
	/* Copy 4 * VEC a time backward with non-temporal stores.  */
	PREFETCH_ONE_SET (-1, (%rcx), -PREFETCHED_LOAD_SIZE * 2)
	PREFETCH_ONE_SET (-1, (%rcx), -PREFETCHED_LOAD_SIZE * 3)
	VMOVU	(%rcx), %VEC(0)
	VMOVU	-VEC_SIZE(%rcx), %VEC(1)
	VMOVU	-(VEC_SIZE * 2)(%rcx), %VEC(2)
	VMOVU	-(VEC_SIZE * 3)(%rcx), %VEC(3)
	subq	$PREFETCHED_LOAD_SIZE, %rcx
	subq	$PREFETCHED_LOAD_SIZE, %rdx
	VMOVNT	%VEC(0), (%r9)
	VMOVNT	%VEC(1), -VEC_SIZE(%r9)
	VMOVNT	%VEC(2), -(VEC_SIZE * 2)(%r9)
	VMOVNT	%VEC(3), -(VEC_SIZE * 3)(%r9)
	subq	$PREFETCHED_LOAD_SIZE, %r9
	cmpq	$PREFETCHED_LOAD_SIZE, %rdx
	ja	L(loop_large_backward)
	sfence
	/* Store the first 4 * VEC.  */
	VMOVU	%VEC(4), (%rdi)
	VMOVU	%VEC(5), VEC_SIZE(%rdi)
	VMOVU	%VEC(6), (VEC_SIZE * 2)(%rdi)
	VMOVU	%VEC(7), (VEC_SIZE * 3)(%rdi)
	/* Store the last VEC.  */
	VMOVU	%VEC(8), (%r11)
	VZEROUPPER
	ret
#endif
END (MEMMOVE_SYMBOL (__memmove, unaligned_erms))

#if IS_IN (libc)
# ifdef USE_MULTIARCH
strong_alias (MEMMOVE_SYMBOL (__memmove, unaligned_erms),
	      MEMMOVE_SYMBOL (__memcpy, unaligned_erms))
#  ifdef SHARED
strong_alias (MEMMOVE_SYMBOL (__memmove_chk, unaligned_erms),
	      MEMMOVE_SYMBOL (__memcpy_chk, unaligned_erms))
#  endif
# endif
# ifdef SHARED
strong_alias (MEMMOVE_CHK_SYMBOL (__memmove_chk, unaligned),
	      MEMMOVE_CHK_SYMBOL (__memcpy_chk, unaligned))
# endif
#endif
strong_alias (MEMMOVE_SYMBOL (__memmove, unaligned),
	      MEMCPY_SYMBOL (__memcpy, unaligned))