[glibc] aarch64: Use memcpy_simd as the default memcpy

[glibc] aarch64: Use memcpy_simd as the default memcpy

[Wilco Dijkstra]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=e6f3fe362f1aab78b1448d69ecdbd9e3872636d3

commit e6f3fe362f1aab78b1448d69ecdbd9e3872636d3
Author: Wilco Dijkstra <wdijkstr@arm.com>
Date:   Wed Oct 26 14:16:50 2022 +0100

    aarch64: Use memcpy_simd as the default memcpy
    
    Since __memcpy_simd is the fastest memcpy on almost all cores, replace
    the generic memcpy with it.  If SVE is available, a SVE memcpy will be
    used by default (including for Neoverse N2).

Diff:
---
 sysdeps/aarch64/memcpy.S                    | 192 +++++++++------------
 sysdeps/aarch64/multiarch/Makefile          |   1 -
 sysdeps/aarch64/multiarch/ifunc-impl-list.c |   2 -
 sysdeps/aarch64/multiarch/memcpy.c          |   4 -
 sysdeps/aarch64/multiarch/memcpy_advsimd.S  | 248 ----------------------------
 sysdeps/aarch64/multiarch/memmove.c         |   4 -
 6 files changed, 81 insertions(+), 370 deletions(-)

diff --git a/sysdeps/aarch64/memcpy.S b/sysdeps/aarch64/memcpy.S
index 98d4e2c0e2..7b396b202f 100644
--- a/sysdeps/aarch64/memcpy.S
+++ b/sysdeps/aarch64/memcpy.S
@@ -1,4 +1,5 @@
-/* Copyright (C) 2012-2022 Free Software Foundation, Inc.
+/* Generic optimized memcpy using SIMD.
+   Copyright (C) 2012-2022 Free Software Foundation, Inc.
 
    This file is part of the GNU C Library.
 
@@ -20,7 +21,7 @@
 
 /* Assumptions:
  *
- * ARMv8-a, AArch64, unaligned accesses.
+ * ARMv8-a, AArch64, Advanced SIMD, unaligned accesses.
  *
  */
 
@@ -36,21 +37,18 @@
 #define B_l	x8
 #define B_lw	w8
 #define B_h	x9
-#define C_l	x10
 #define C_lw	w10
-#define C_h	x11
-#define D_l	x12
-#define D_h	x13
-#define E_l	x14
-#define E_h	x15
-#define F_l	x16
-#define F_h	x17
-#define G_l	count
-#define G_h	dst
-#define H_l	src
-#define H_h	srcend
 #define tmp1	x14
 
+#define A_q	q0
+#define B_q	q1
+#define C_q	q2
+#define D_q	q3
+#define E_q	q4
+#define F_q	q5
+#define G_q	q6
+#define H_q	q7
+
 #ifndef MEMMOVE
 # define MEMMOVE memmove
 #endif
@@ -69,10 +67,9 @@
    Large copies use a software pipelined loop processing 64 bytes per
    iteration.  The destination pointer is 16-byte aligned to minimize
    unaligned accesses.  The loop tail is handled by always copying 64 bytes
-   from the end.
-*/
+   from the end.  */
 
-ENTRY_ALIGN (MEMCPY, 6)
+ENTRY (MEMCPY)
 	PTR_ARG (0)
 	PTR_ARG (1)
 	SIZE_ARG (2)
@@ -87,10 +84,10 @@ ENTRY_ALIGN (MEMCPY, 6)
 	/* Small copies: 0..32 bytes.  */
 	cmp	count, 16
 	b.lo	L(copy16)
-	ldp	A_l, A_h, [src]
-	ldp	D_l, D_h, [srcend, -16]
-	stp	A_l, A_h, [dstin]
-	stp	D_l, D_h, [dstend, -16]
+	ldr	A_q, [src]
+	ldr	B_q, [srcend, -16]
+	str	A_q, [dstin]
+	str	B_q, [dstend, -16]
 	ret
 
 	/* Copy 8-15 bytes.  */
@@ -102,7 +99,6 @@ L(copy16):
 	str	A_h, [dstend, -8]
 	ret
 
-	.p2align 3
 	/* Copy 4-7 bytes.  */
 L(copy8):
 	tbz	count, 2, L(copy4)
@@ -128,87 +124,69 @@ L(copy0):
 	.p2align 4
 	/* Medium copies: 33..128 bytes.  */
 L(copy32_128):
-	ldp	A_l, A_h, [src]
-	ldp	B_l, B_h, [src, 16]
-	ldp	C_l, C_h, [srcend, -32]
-	ldp	D_l, D_h, [srcend, -16]
+	ldp	A_q, B_q, [src]
+	ldp	C_q, D_q, [srcend, -32]
 	cmp	count, 64
 	b.hi	L(copy128)
-	stp	A_l, A_h, [dstin]
-	stp	B_l, B_h, [dstin, 16]
-	stp	C_l, C_h, [dstend, -32]
-	stp	D_l, D_h, [dstend, -16]
+	stp	A_q, B_q, [dstin]
+	stp	C_q, D_q, [dstend, -32]
 	ret
 
 	.p2align 4
 	/* Copy 65..128 bytes.  */
 L(copy128):
-	ldp	E_l, E_h, [src, 32]
-	ldp	F_l, F_h, [src, 48]
+	ldp	E_q, F_q, [src, 32]
 	cmp	count, 96
 	b.ls	L(copy96)
-	ldp	G_l, G_h, [srcend, -64]
-	ldp	H_l, H_h, [srcend, -48]
-	stp	G_l, G_h, [dstend, -64]
-	stp	H_l, H_h, [dstend, -48]
+	ldp	G_q, H_q, [srcend, -64]
+	stp	G_q, H_q, [dstend, -64]
 L(copy96):
-	stp	A_l, A_h, [dstin]
-	stp	B_l, B_h, [dstin, 16]
-	stp	E_l, E_h, [dstin, 32]
-	stp	F_l, F_h, [dstin, 48]
-	stp	C_l, C_h, [dstend, -32]
-	stp	D_l, D_h, [dstend, -16]
+	stp	A_q, B_q, [dstin]
+	stp	E_q, F_q, [dstin, 32]
+	stp	C_q, D_q, [dstend, -32]
 	ret
 
-	.p2align 4
+	/* Align loop64 below to 16 bytes.  */
+	nop
+
 	/* Copy more than 128 bytes.  */
 L(copy_long):
-	/* Copy 16 bytes and then align dst to 16-byte alignment.  */
-	ldp	D_l, D_h, [src]
-	and	tmp1, dstin, 15
-	bic	dst, dstin, 15
-	sub	src, src, tmp1
+	/* Copy 16 bytes and then align src to 16-byte alignment.  */
+	ldr	D_q, [src]
+	and	tmp1, src, 15
+	bic	src, src, 15
+	sub	dst, dstin, tmp1
 	add	count, count, tmp1	/* Count is now 16 too large.  */
-	ldp	A_l, A_h, [src, 16]
-	stp	D_l, D_h, [dstin]
-	ldp	B_l, B_h, [src, 32]
-	ldp	C_l, C_h, [src, 48]
-	ldp	D_l, D_h, [src, 64]!
+	ldp	A_q, B_q, [src, 16]
+	str	D_q, [dstin]
+	ldp	C_q, D_q, [src, 48]
 	subs	count, count, 128 + 16	/* Test and readjust count.  */
 	b.ls	L(copy64_from_end)
-
 L(loop64):
-	stp	A_l, A_h, [dst, 16]
-	ldp	A_l, A_h, [src, 16]
-	stp	B_l, B_h, [dst, 32]
-	ldp	B_l, B_h, [src, 32]
-	stp	C_l, C_h, [dst, 48]
-	ldp	C_l, C_h, [src, 48]
-	stp	D_l, D_h, [dst, 64]!
-	ldp	D_l, D_h, [src, 64]!
+	stp	A_q, B_q, [dst, 16]
+	ldp	A_q, B_q, [src, 80]
+	stp	C_q, D_q, [dst, 48]
+	ldp	C_q, D_q, [src, 112]
+	add	src, src, 64
+	add	dst, dst, 64
 	subs	count, count, 64
 	b.hi	L(loop64)
 
 	/* Write the last iteration and copy 64 bytes from the end.  */
 L(copy64_from_end):
-	ldp	E_l, E_h, [srcend, -64]
-	stp	A_l, A_h, [dst, 16]
-	ldp	A_l, A_h, [srcend, -48]
-	stp	B_l, B_h, [dst, 32]
-	ldp	B_l, B_h, [srcend, -32]
-	stp	C_l, C_h, [dst, 48]
-	ldp	C_l, C_h, [srcend, -16]
-	stp	D_l, D_h, [dst, 64]
-	stp	E_l, E_h, [dstend, -64]
-	stp	A_l, A_h, [dstend, -48]
-	stp	B_l, B_h, [dstend, -32]
-	stp	C_l, C_h, [dstend, -16]
+	ldp	E_q, F_q, [srcend, -64]
+	stp	A_q, B_q, [dst, 16]
+	ldp	A_q, B_q, [srcend, -32]
+	stp	C_q, D_q, [dst, 48]
+	stp	E_q, F_q, [dstend, -64]
+	stp	A_q, B_q, [dstend, -32]
 	ret
 
 END (MEMCPY)
 libc_hidden_builtin_def (MEMCPY)
 
-ENTRY_ALIGN (MEMMOVE, 4)
+
+ENTRY (MEMMOVE)
 	PTR_ARG (0)
 	PTR_ARG (1)
 	SIZE_ARG (2)
@@ -220,64 +198,56 @@ ENTRY_ALIGN (MEMMOVE, 4)
 	cmp	count, 32
 	b.hi	L(copy32_128)
 
-	/* Small copies: 0..32 bytes.  */
+	/* Small moves: 0..32 bytes.  */
 	cmp	count, 16
 	b.lo	L(copy16)
-	ldp	A_l, A_h, [src]
-	ldp	D_l, D_h, [srcend, -16]
-	stp	A_l, A_h, [dstin]
-	stp	D_l, D_h, [dstend, -16]
+	ldr	A_q, [src]
+	ldr	B_q, [srcend, -16]
+	str	A_q, [dstin]
+	str	B_q, [dstend, -16]
 	ret
 
-	.p2align 4
 L(move_long):
 	/* Only use backward copy if there is an overlap.  */
 	sub	tmp1, dstin, src
-	cbz	tmp1, L(copy0)
+	cbz	tmp1, L(move0)
 	cmp	tmp1, count
 	b.hs	L(copy_long)
 
 	/* Large backwards copy for overlapping copies.
-	   Copy 16 bytes and then align dst to 16-byte alignment.  */
-	ldp	D_l, D_h, [srcend, -16]
-	and	tmp1, dstend, 15
-	sub	srcend, srcend, tmp1
+	   Copy 16 bytes and then align srcend to 16-byte alignment.  */
+L(copy_long_backwards):
+	ldr	D_q, [srcend, -16]
+	and	tmp1, srcend, 15
+	bic	srcend, srcend, 15
 	sub	count, count, tmp1
-	ldp	A_l, A_h, [srcend, -16]
-	stp	D_l, D_h, [dstend, -16]
-	ldp	B_l, B_h, [srcend, -32]
-	ldp	C_l, C_h, [srcend, -48]
-	ldp	D_l, D_h, [srcend, -64]!
+	ldp	A_q, B_q, [srcend, -32]
+	str	D_q, [dstend, -16]
+	ldp	C_q, D_q, [srcend, -64]
 	sub	dstend, dstend, tmp1
 	subs	count, count, 128
 	b.ls	L(copy64_from_start)
 
 L(loop64_backwards):
-	stp	A_l, A_h, [dstend, -16]
-	ldp	A_l, A_h, [srcend, -16]
-	stp	B_l, B_h, [dstend, -32]
-	ldp	B_l, B_h, [srcend, -32]
-	stp	C_l, C_h, [dstend, -48]
-	ldp	C_l, C_h, [srcend, -48]
-	stp	D_l, D_h, [dstend, -64]!
-	ldp	D_l, D_h, [srcend, -64]!
+	str	B_q, [dstend, -16]
+	str	A_q, [dstend, -32]
+	ldp	A_q, B_q, [srcend, -96]
+	str	D_q, [dstend, -48]
+	str	C_q, [dstend, -64]!
+	ldp	C_q, D_q, [srcend, -128]
+	sub	srcend, srcend, 64
 	subs	count, count, 64
 	b.hi	L(loop64_backwards)
 
 	/* Write the last iteration and copy 64 bytes from the start.  */
 L(copy64_from_start):
-	ldp	G_l, G_h, [src, 48]
-	stp	A_l, A_h, [dstend, -16]
-	ldp	A_l, A_h, [src, 32]
-	stp	B_l, B_h, [dstend, -32]
-	ldp	B_l, B_h, [src, 16]
-	stp	C_l, C_h, [dstend, -48]
-	ldp	C_l, C_h, [src]
-	stp	D_l, D_h, [dstend, -64]
-	stp	G_l, G_h, [dstin, 48]
-	stp	A_l, A_h, [dstin, 32]
-	stp	B_l, B_h, [dstin, 16]
-	stp	C_l, C_h, [dstin]
+	ldp	E_q, F_q, [src, 32]
+	stp	A_q, B_q, [dstend, -32]
+	ldp	A_q, B_q, [src]
+	stp	C_q, D_q, [dstend, -64]
+	stp	E_q, F_q, [dstin, 32]
+	stp	A_q, B_q, [dstin]
+L(move0):
 	ret
 
 END (MEMMOVE)
diff --git a/sysdeps/aarch64/multiarch/Makefile b/sysdeps/aarch64/multiarch/Makefile
index 16297192ee..223777d94e 100644
--- a/sysdeps/aarch64/multiarch/Makefile
+++ b/sysdeps/aarch64/multiarch/Makefile
@@ -3,7 +3,6 @@ sysdep_routines += \
   memchr_generic \
   memchr_nosimd \
   memcpy_a64fx \
-  memcpy_advsimd \
   memcpy_falkor \
   memcpy_generic \
   memcpy_sve \
diff --git a/sysdeps/aarch64/multiarch/ifunc-impl-list.c b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
index c6fe149a7c..ac8980288e 100644
--- a/sysdeps/aarch64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
@@ -37,7 +37,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 	      IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_thunderx)
 	      IFUNC_IMPL_ADD (array, i, memcpy, !bti, __memcpy_thunderx2)
 	      IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_falkor)
-	      IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_simd)
 #if HAVE_AARCH64_SVE_ASM
 	      IFUNC_IMPL_ADD (array, i, memcpy, sve, __memcpy_a64fx)
 	      IFUNC_IMPL_ADD (array, i, memcpy, sve, __memcpy_sve)
@@ -47,7 +46,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 	      IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_thunderx)
 	      IFUNC_IMPL_ADD (array, i, memmove, !bti, __memmove_thunderx2)
 	      IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_falkor)
-	      IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_simd)
 #if HAVE_AARCH64_SVE_ASM
 	      IFUNC_IMPL_ADD (array, i, memmove, sve, __memmove_a64fx)
 	      IFUNC_IMPL_ADD (array, i, memmove, sve, __memmove_sve)
diff --git a/sysdeps/aarch64/multiarch/memcpy.c b/sysdeps/aarch64/multiarch/memcpy.c
index 0486213f08..21d954e7f3 100644
--- a/sysdeps/aarch64/multiarch/memcpy.c
+++ b/sysdeps/aarch64/multiarch/memcpy.c
@@ -29,7 +29,6 @@
 extern __typeof (__redirect_memcpy) __libc_memcpy;
 
 extern __typeof (__redirect_memcpy) __memcpy_generic attribute_hidden;
-extern __typeof (__redirect_memcpy) __memcpy_simd attribute_hidden;
 extern __typeof (__redirect_memcpy) __memcpy_thunderx attribute_hidden;
 extern __typeof (__redirect_memcpy) __memcpy_thunderx2 attribute_hidden;
 extern __typeof (__redirect_memcpy) __memcpy_falkor attribute_hidden;
@@ -41,9 +40,6 @@ select_memcpy_ifunc (void)
 {
   INIT_ARCH ();
 
-  if (IS_NEOVERSE_N1 (midr) || IS_NEOVERSE_N2 (midr))
-    return __memcpy_simd;
-
   if (sve && HAVE_AARCH64_SVE_ASM)
     {
       if (IS_A64FX (midr))
diff --git a/sysdeps/aarch64/multiarch/memcpy_advsimd.S b/sysdeps/aarch64/multiarch/memcpy_advsimd.S
deleted file mode 100644
index fe9beaf5ea..0000000000
--- a/sysdeps/aarch64/multiarch/memcpy_advsimd.S
+++ /dev/null
@@ -1,248 +0,0 @@
-/* Generic optimized memcpy using SIMD.
-   Copyright (C) 2020-2022 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/>.  */
-
-#include <sysdep.h>
-
-/* Assumptions:
- *
- * ARMv8-a, AArch64, Advanced SIMD, unaligned accesses.
- *
- */
-
-#define dstin	x0
-#define src	x1
-#define count	x2
-#define dst	x3
-#define srcend	x4
-#define dstend	x5
-#define A_l	x6
-#define A_lw	w6
-#define A_h	x7
-#define B_l	x8
-#define B_lw	w8
-#define B_h	x9
-#define C_lw	w10
-#define tmp1	x14
-
-#define A_q	q0
-#define B_q	q1
-#define C_q	q2
-#define D_q	q3
-#define E_q	q4
-#define F_q	q5
-#define G_q	q6
-#define H_q	q7
-
-
-/* This implementation supports both memcpy and memmove and shares most code.
-   It uses unaligned accesses and branchless sequences to keep the code small,
-   simple and improve performance.
-
-   Copies are split into 3 main cases: small copies of up to 32 bytes, medium
-   copies of up to 128 bytes, and large copies.  The overhead of the overlap
-   check in memmove is negligible since it is only required for large copies.
-
-   Large copies use a software pipelined loop processing 64 bytes per
-   iteration.  The destination pointer is 16-byte aligned to minimize
-   unaligned accesses.  The loop tail is handled by always copying 64 bytes
-   from the end.  */
-
-ENTRY (__memcpy_simd)
-	PTR_ARG (0)
-	PTR_ARG (1)
-	SIZE_ARG (2)
-
-	add	srcend, src, count
-	add	dstend, dstin, count
-	cmp	count, 128
-	b.hi	L(copy_long)
-	cmp	count, 32
-	b.hi	L(copy32_128)
-
-	/* Small copies: 0..32 bytes.  */
-	cmp	count, 16
-	b.lo	L(copy16)
-	ldr	A_q, [src]
-	ldr	B_q, [srcend, -16]
-	str	A_q, [dstin]
-	str	B_q, [dstend, -16]
-	ret
-
-	/* Copy 8-15 bytes.  */
-L(copy16):
-	tbz	count, 3, L(copy8)
-	ldr	A_l, [src]
-	ldr	A_h, [srcend, -8]
-	str	A_l, [dstin]
-	str	A_h, [dstend, -8]
-	ret
-
-	/* Copy 4-7 bytes.  */
-L(copy8):
-	tbz	count, 2, L(copy4)
-	ldr	A_lw, [src]
-	ldr	B_lw, [srcend, -4]
-	str	A_lw, [dstin]
-	str	B_lw, [dstend, -4]
-	ret
-
-	/* Copy 0..3 bytes using a branchless sequence.  */
-L(copy4):
-	cbz	count, L(copy0)
-	lsr	tmp1, count, 1
-	ldrb	A_lw, [src]
-	ldrb	C_lw, [srcend, -1]
-	ldrb	B_lw, [src, tmp1]
-	strb	A_lw, [dstin]
-	strb	B_lw, [dstin, tmp1]
-	strb	C_lw, [dstend, -1]
-L(copy0):
-	ret
-
-	.p2align 4
-	/* Medium copies: 33..128 bytes.  */
-L(copy32_128):
-	ldp	A_q, B_q, [src]
-	ldp	C_q, D_q, [srcend, -32]
-	cmp	count, 64
-	b.hi	L(copy128)
-	stp	A_q, B_q, [dstin]
-	stp	C_q, D_q, [dstend, -32]
-	ret
-
-	.p2align 4
-	/* Copy 65..128 bytes.  */
-L(copy128):
-	ldp	E_q, F_q, [src, 32]
-	cmp	count, 96
-	b.ls	L(copy96)
-	ldp	G_q, H_q, [srcend, -64]
-	stp	G_q, H_q, [dstend, -64]
-L(copy96):
-	stp	A_q, B_q, [dstin]
-	stp	E_q, F_q, [dstin, 32]
-	stp	C_q, D_q, [dstend, -32]
-	ret
-
-	/* Align loop64 below to 16 bytes.  */
-	nop
-
-	/* Copy more than 128 bytes.  */
-L(copy_long):
-	/* Copy 16 bytes and then align src to 16-byte alignment.  */
-	ldr	D_q, [src]
-	and	tmp1, src, 15
-	bic	src, src, 15
-	sub	dst, dstin, tmp1
-	add	count, count, tmp1	/* Count is now 16 too large.  */
-	ldp	A_q, B_q, [src, 16]
-	str	D_q, [dstin]
-	ldp	C_q, D_q, [src, 48]
-	subs	count, count, 128 + 16	/* Test and readjust count.  */
-	b.ls	L(copy64_from_end)
-L(loop64):
-	stp	A_q, B_q, [dst, 16]
-	ldp	A_q, B_q, [src, 80]
-	stp	C_q, D_q, [dst, 48]
-	ldp	C_q, D_q, [src, 112]
-	add	src, src, 64
-	add	dst, dst, 64
-	subs	count, count, 64
-	b.hi	L(loop64)
-
-	/* Write the last iteration and copy 64 bytes from the end.  */
-L(copy64_from_end):
-	ldp	E_q, F_q, [srcend, -64]
-	stp	A_q, B_q, [dst, 16]
-	ldp	A_q, B_q, [srcend, -32]
-	stp	C_q, D_q, [dst, 48]
-	stp	E_q, F_q, [dstend, -64]
-	stp	A_q, B_q, [dstend, -32]
-	ret
-
-END (__memcpy_simd)
-libc_hidden_builtin_def (__memcpy_simd)
-
-
-ENTRY (__memmove_simd)
-	PTR_ARG (0)
-	PTR_ARG (1)
-	SIZE_ARG (2)
-
-	add	srcend, src, count
-	add	dstend, dstin, count
-	cmp	count, 128
-	b.hi	L(move_long)
-	cmp	count, 32
-	b.hi	L(copy32_128)
-
-	/* Small moves: 0..32 bytes.  */
-	cmp	count, 16
-	b.lo	L(copy16)
-	ldr	A_q, [src]
-	ldr	B_q, [srcend, -16]
-	str	A_q, [dstin]
-	str	B_q, [dstend, -16]
-	ret
-
-L(move_long):
-	/* Only use backward copy if there is an overlap.  */
-	sub	tmp1, dstin, src
-	cbz	tmp1, L(move0)
-	cmp	tmp1, count
-	b.hs	L(copy_long)
-
-	/* Large backwards copy for overlapping copies.
-	   Copy 16 bytes and then align srcend to 16-byte alignment.  */
-L(copy_long_backwards):
-	ldr	D_q, [srcend, -16]
-	and	tmp1, srcend, 15
-	bic	srcend, srcend, 15
-	sub	count, count, tmp1
-	ldp	A_q, B_q, [srcend, -32]
-	str	D_q, [dstend, -16]
-	ldp	C_q, D_q, [srcend, -64]
-	sub	dstend, dstend, tmp1
-	subs	count, count, 128
-	b.ls	L(copy64_from_start)
-
-L(loop64_backwards):
-	str	B_q, [dstend, -16]
-	str	A_q, [dstend, -32]
-	ldp	A_q, B_q, [srcend, -96]
-	str	D_q, [dstend, -48]
-	str	C_q, [dstend, -64]!
-	ldp	C_q, D_q, [srcend, -128]
-	sub	srcend, srcend, 64
-	subs	count, count, 64
-	b.hi	L(loop64_backwards)
-
-	/* Write the last iteration and copy 64 bytes from the start.  */
-L(copy64_from_start):
-	ldp	E_q, F_q, [src, 32]
-	stp	A_q, B_q, [dstend, -32]
-	ldp	A_q, B_q, [src]
-	stp	C_q, D_q, [dstend, -64]
-	stp	E_q, F_q, [dstin, 32]
-	stp	A_q, B_q, [dstin]
-L(move0):
-	ret
-
-END (__memmove_simd)
-libc_hidden_builtin_def (__memmove_simd)
diff --git a/sysdeps/aarch64/multiarch/memmove.c b/sysdeps/aarch64/multiarch/memmove.c
index 261996ecc4..70e8eaef7c 100644
--- a/sysdeps/aarch64/multiarch/memmove.c
+++ b/sysdeps/aarch64/multiarch/memmove.c
@@ -29,7 +29,6 @@
 extern __typeof (__redirect_memmove) __libc_memmove;
 
 extern __typeof (__redirect_memmove) __memmove_generic attribute_hidden;
-extern __typeof (__redirect_memmove) __memmove_simd attribute_hidden;
 extern __typeof (__redirect_memmove) __memmove_thunderx attribute_hidden;
 extern __typeof (__redirect_memmove) __memmove_thunderx2 attribute_hidden;
 extern __typeof (__redirect_memmove) __memmove_falkor attribute_hidden;
@@ -41,9 +40,6 @@ select_memmove_ifunc (void)
 {
   INIT_ARCH ();
 
-  if (IS_NEOVERSE_N1 (midr) || IS_NEOVERSE_N2 (midr))
-    return __memmove_simd;
-
   if (sve && HAVE_AARCH64_SVE_ASM)
     {
       if (IS_A64FX (midr))