AArch64: Add SVE memcpy

Add an initial SVE memcpy implementation.  Copies up to 32 bytes use SVE vectors
which improves the random memcpy benchmark significantly.
Enable it for Neoverse V1.

Passes GLIBC testsuite, OK for commit?

---

The 05/25/2022 17:04, Wilco Dijkstra wrote:
> diff --git a/sysdeps/aarch64/multiarch/ifunc-impl-list.c b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
> index 483fbbdb523c9a5b697a9b7f63153d2cefb482ac..e12c1a9fad3c2b1061f3f9d10accfe61ccc5ea50 100644
> --- a/sysdeps/aarch64/multiarch/ifunc-impl-list.c
> +++ b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
> @@ -45,6 +45,7 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
>               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)
>  #endif
>               IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_generic))
>    IFUNC_IMPL (i, name, memmove,
> @@ -54,6 +55,7 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
>               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)
>  #endif
>               IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_generic))
>    IFUNC_IMPL (i, name, memset,

i'd expect MAX_IFUNC to be updated whenever we add a new memcpy.


> diff --git a/sysdeps/aarch64/multiarch/memcpy.c b/sysdeps/aarch64/multiarch/memcpy.c
> index a476dd548fd04fddcd0b39cc3263866769bb309a..6172fddcb83baf91e78f621cae7cf4dd9aff822a 100644
> --- a/sysdeps/aarch64/multiarch/memcpy.c
> +++ b/sysdeps/aarch64/multiarch/memcpy.c
> @@ -35,6 +35,7 @@ extern __typeof (__redirect_memcpy) __memcpy_thunderx2 attribute_hidden;
>  extern __typeof (__redirect_memcpy) __memcpy_falkor attribute_hidden;
>  # if HAVE_AARCH64_SVE_ASM
>  extern __typeof (__redirect_memcpy) __memcpy_a64fx attribute_hidden;
> +extern __typeof (__redirect_memcpy) __memcpy_sve attribute_hidden;
>  # endif
> 
>  libc_ifunc (__libc_memcpy,
> @@ -45,15 +46,12 @@ libc_ifunc (__libc_memcpy,
>                 : (IS_THUNDERX2 (midr) || IS_THUNDERX2PA (midr)
>                    ? __memcpy_thunderx2
>                    : (IS_NEOVERSE_N1 (midr) || IS_NEOVERSE_N2 (midr)
> -                     || IS_NEOVERSE_V1 (midr)
>                       ? __memcpy_simd
> -# if HAVE_AARCH64_SVE_ASM
> -                    : (IS_A64FX (midr) && sve
> -                       ? __memcpy_a64fx
> -                       : __memcpy_generic))))));
> -# else
> -                    : __memcpy_generic)))));
> -# endif
> +                     : (sve && HAVE_AARCH64_SVE_ASM
> +                        ? (IS_A64FX (midr)
> +                           ? __memcpy_a64fx
> +                           : __memcpy_sve)
> +                        : __memcpy_generic))))));

i think if you remove the ifdef here, then the declaration
should be outside ifdef too.

same for memmove.

Hi Szabolcs,

> i'd expect MAX_IFUNC to be updated whenever we add a new memcpy.

Yes this macro is quite broken, the value 7 should be correct, but I've set it to 8 for now. The correct approach is to check for 'max' inside IFUNC_IMPL_ADD.

Here is v2 (which also improves the readability of the ifunc selectors):

Add an initial SVE memcpy implementation.  Copies up to 32 bytes use SVE vectors
which improves the random memcpy benchmark significantly.  Cleanup the memcpy
and memmove ifunc selectors.

---
diff --git a/sysdeps/aarch64/multiarch/Makefile b/sysdeps/aarch64/multiarch/Makefile
index 7500cf1e9369443daed1c5a938903dcff9d0a45e..490aaa0faf1e74fb7014e2ed6b574d92b8b83637 100644
--- a/sysdeps/aarch64/multiarch/Makefile
+++ b/sysdeps/aarch64/multiarch/Makefile
@@ -1,6 +1,6 @@
 ifeq ($(subdir),string)
 sysdep_routines += memcpy_generic memcpy_advsimd memcpy_thunderx memcpy_thunderx2 \
-		   memcpy_falkor memcpy_a64fx \
+		   memcpy_falkor memcpy_a64fx memcpy_sve \
 		   memset_generic memset_falkor memset_emag memset_kunpeng \
 		   memset_a64fx \
 		   memchr_generic memchr_nosimd \
diff --git a/sysdeps/aarch64/multiarch/ifunc-impl-list.c b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
index 483fbbdb523c9a5b697a9b7f63153d2cefb482ac..f6c6d008da285122cf3549efa5adf05d5e098680 100644
--- a/sysdeps/aarch64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
@@ -25,7 +25,7 @@
 #include <stdio.h>
 
 /* Maximum number of IFUNC implementations.  */
-#define MAX_IFUNC	7
+#define MAX_IFUNC	8
 
 size_t
 __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
@@ -45,6 +45,7 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 	      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)
 #endif
 	      IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_generic))
   IFUNC_IMPL (i, name, memmove,
@@ -54,6 +55,7 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 	      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)
 #endif
 	      IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_generic))
   IFUNC_IMPL (i, name, memset,
diff --git a/sysdeps/aarch64/multiarch/memcpy.c b/sysdeps/aarch64/multiarch/memcpy.c
index a476dd548fd04fddcd0b39cc3263866769bb309a..0486213f08db8ab08a903c4b9e6bdd19df6dccec 100644
--- a/sysdeps/aarch64/multiarch/memcpy.c
+++ b/sysdeps/aarch64/multiarch/memcpy.c
@@ -33,27 +33,38 @@ 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;
-# if HAVE_AARCH64_SVE_ASM
 extern __typeof (__redirect_memcpy) __memcpy_a64fx attribute_hidden;
-# endif
-
-libc_ifunc (__libc_memcpy,
-            (IS_THUNDERX (midr)
-	     ? __memcpy_thunderx
-	     : (IS_FALKOR (midr) || IS_PHECDA (midr)
-		? __memcpy_falkor
-		: (IS_THUNDERX2 (midr) || IS_THUNDERX2PA (midr)
-		   ? __memcpy_thunderx2
-		   : (IS_NEOVERSE_N1 (midr) || IS_NEOVERSE_N2 (midr)
-		      || IS_NEOVERSE_V1 (midr)
-		      ? __memcpy_simd
-# if HAVE_AARCH64_SVE_ASM
-		     : (IS_A64FX (midr) && sve
-			? __memcpy_a64fx
-			: __memcpy_generic))))));
-# else
-		     : __memcpy_generic)))));
-# endif
+extern __typeof (__redirect_memcpy) __memcpy_sve attribute_hidden;
+
+static inline __typeof (__redirect_memcpy) *
+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))
+	return __memcpy_a64fx;
+      return __memcpy_sve;
+    }
+
+  if (IS_THUNDERX (midr))
+    return __memcpy_thunderx;
+
+  if (IS_THUNDERX2 (midr) || IS_THUNDERX2PA (midr))
+    return __memcpy_thunderx2;
+
+  if (IS_FALKOR (midr) || IS_PHECDA (midr))
+    return __memcpy_falkor;
+
+  return __memcpy_generic;
+}
+
+libc_ifunc (__libc_memcpy, select_memcpy_ifunc ());
+
 # undef memcpy
 strong_alias (__libc_memcpy, memcpy);
 #endif
diff --git a/sysdeps/aarch64/multiarch/memcpy_sve.S b/sysdeps/aarch64/multiarch/memcpy_sve.S
new file mode 100644
index 0000000000000000000000000000000000000000..a70907ec5595114e4da35c54e932279c22e53cc6
--- /dev/null
+++ b/sysdeps/aarch64/multiarch/memcpy_sve.S
@@ -0,0 +1,218 @@
+/* Optimized memcpy for SVE.
+   Copyright (C) 2021-2022 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, SVE, unaligned accesses.
+ *
+ */
+
+#define dstin	x0
+#define src	x1
+#define count	x2
+#define dst	x3
+#define srcend	x4
+#define dstend	x5
+#define tmp1	x6
+#define vlen	x6
+
+#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 source pointer is 16-byte aligned to minimize unaligned accesses.
+   The loop tail is handled by always copying 64 bytes from the end.
+*/
+
+#if HAVE_AARCH64_SVE_ASM
+
+	.arch armv8.2-a+sve
+
+ENTRY (__memcpy_sve)
+	PTR_ARG (0)
+	PTR_ARG (1)
+	SIZE_ARG (2)
+
+	cmp	count, 128
+	b.hi	L(copy_long)
+	cmp	count, 32
+	b.hi	L(copy32_128)
+
+	whilelo p0.b, xzr, count
+	cntb	vlen
+	tbnz	vlen, 4, L(vlen128)
+	ld1b	z0.b, p0/z, [src]
+	st1b	z0.b, p0, [dstin]
+	ret
+
+	/* Medium copies: 33..128 bytes.  */
+L(copy32_128):
+	add	srcend, src, count
+	add	dstend, dstin, count
+	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
+
+	/* 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
+
+L(vlen128):
+	whilelo p1.b, vlen, count
+	ld1b	z0.b, p0/z, [src, 0, mul vl]
+	ld1b	z1.b, p1/z, [src, 1, mul vl]
+	st1b	z0.b, p0, [dstin, 0, mul vl]
+	st1b	z1.b, p1, [dstin, 1, mul vl]
+	ret
+
+	.p2align 4
+	/* Copy more than 128 bytes.  */
+L(copy_long):
+	add	srcend, src, count
+	add	dstend, dstin, count
+
+	/* 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_sve)
+libc_hidden_builtin_def (__memcpy_sve)
+
+
+ENTRY (__memmove_sve)
+	PTR_ARG (0)
+	PTR_ARG (1)
+	SIZE_ARG (2)
+
+	cmp	count, 128
+	b.hi	L(move_long)
+	cmp	count, 32
+	b.hi	L(copy32_128)
+
+	whilelo p0.b, xzr, count
+	cntb	vlen
+	tbnz	vlen, 4, L(vlen128)
+	ld1b	z0.b, p0/z, [src]
+	st1b	z0.b, p0, [dstin]
+	ret
+
+	.p2align 4
+L(move_long):
+	add	srcend, src, count
+	add	dstend, dstin, count
+	/* Only use backward copy if there is an overlap.  */
+	sub	tmp1, dstin, src
+	cbz	tmp1, L(return)
+	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.  */
+	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(return):
+	ret
+
+END (__memmove_sve)
+libc_hidden_builtin_def (__memmove_sve)
+#endif
diff --git a/sysdeps/aarch64/multiarch/memmove.c b/sysdeps/aarch64/multiarch/memmove.c
index 4f7d7eedfd943d1b6a54e90dc973406b30cc8db9..261996ecc4b36bdaf3c50598d910e9c7dcace08b 100644
--- a/sysdeps/aarch64/multiarch/memmove.c
+++ b/sysdeps/aarch64/multiarch/memmove.c
@@ -33,27 +33,38 @@ 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;
-# if HAVE_AARCH64_SVE_ASM
 extern __typeof (__redirect_memmove) __memmove_a64fx attribute_hidden;
-# endif
-
-libc_ifunc (__libc_memmove,
-            (IS_THUNDERX (midr)
-	     ? __memmove_thunderx
-	     : (IS_FALKOR (midr) || IS_PHECDA (midr)
-		? __memmove_falkor
-		: (IS_THUNDERX2 (midr) || IS_THUNDERX2PA (midr)
-		   ? __memmove_thunderx2
-		   : (IS_NEOVERSE_N1 (midr) || IS_NEOVERSE_N2 (midr)
-		      || IS_NEOVERSE_V1 (midr)
-		      ? __memmove_simd
-# if HAVE_AARCH64_SVE_ASM
-		     : (IS_A64FX (midr) && sve
-			? __memmove_a64fx
-			: __memmove_generic))))));
-# else
-		     : __memmove_generic)))));
-# endif
+extern __typeof (__redirect_memmove) __memmove_sve attribute_hidden;
+
+static inline __typeof (__redirect_memmove) *
+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))
+	return __memmove_a64fx;
+      return __memmove_sve;
+    }
+
+  if (IS_THUNDERX (midr))
+    return __memmove_thunderx;
+
+  if (IS_THUNDERX2 (midr) || IS_THUNDERX2PA (midr))
+    return __memmove_thunderx2;
+
+  if (IS_FALKOR (midr) || IS_PHECDA (midr))
+    return __memmove_falkor;
+
+  return __memmove_generic;
+}
+
+libc_ifunc (__libc_memmove, select_memmove_ifunc ());
+
 # undef memmove
 strong_alias (__libc_memmove, memmove);
 #endif

The 06/01/2022 17:03, Wilco Dijkstra wrote:
> Hi Szabolcs,
> 
> > i'd expect MAX_IFUNC to be updated whenever we add a new memcpy.
> 
> Yes this macro is quite broken, the value 7 should be correct, but I've set it to 8 for now. The correct approach is to check for 'max' inside IFUNC_IMPL_ADD.
> 
> Here is v2 (which also improves the readability of the ifunc selectors):
> 
> Add an initial SVE memcpy implementation.  Copies up to 32 bytes use SVE vectors
> which improves the random memcpy benchmark significantly.  Cleanup the memcpy
> and memmove ifunc selectors.
> 

thanks, this looks good.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>


> ---
> diff --git a/sysdeps/aarch64/multiarch/Makefile b/sysdeps/aarch64/multiarch/Makefile
> index 7500cf1e9369443daed1c5a938903dcff9d0a45e..490aaa0faf1e74fb7014e2ed6b574d92b8b83637 100644
> --- a/sysdeps/aarch64/multiarch/Makefile
> +++ b/sysdeps/aarch64/multiarch/Makefile
> @@ -1,6 +1,6 @@
>  ifeq ($(subdir),string)
>  sysdep_routines += memcpy_generic memcpy_advsimd memcpy_thunderx memcpy_thunderx2 \
> -                  memcpy_falkor memcpy_a64fx \
> +                  memcpy_falkor memcpy_a64fx memcpy_sve \
>                    memset_generic memset_falkor memset_emag memset_kunpeng \
>                    memset_a64fx \
>                    memchr_generic memchr_nosimd \
> diff --git a/sysdeps/aarch64/multiarch/ifunc-impl-list.c b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
> index 483fbbdb523c9a5b697a9b7f63153d2cefb482ac..f6c6d008da285122cf3549efa5adf05d5e098680 100644
> --- a/sysdeps/aarch64/multiarch/ifunc-impl-list.c
> +++ b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
> @@ -25,7 +25,7 @@
>  #include <stdio.h>
> 
>  /* Maximum number of IFUNC implementations.  */
> -#define MAX_IFUNC      7
> +#define MAX_IFUNC      8
> 
>  size_t
>  __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
> @@ -45,6 +45,7 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
>               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)
>  #endif
>               IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_generic))
>    IFUNC_IMPL (i, name, memmove,
> @@ -54,6 +55,7 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
>               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)
>  #endif
>               IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_generic))
>    IFUNC_IMPL (i, name, memset,
> diff --git a/sysdeps/aarch64/multiarch/memcpy.c b/sysdeps/aarch64/multiarch/memcpy.c
> index a476dd548fd04fddcd0b39cc3263866769bb309a..0486213f08db8ab08a903c4b9e6bdd19df6dccec 100644
> --- a/sysdeps/aarch64/multiarch/memcpy.c
> +++ b/sysdeps/aarch64/multiarch/memcpy.c
> @@ -33,27 +33,38 @@ 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;
> -# if HAVE_AARCH64_SVE_ASM
>  extern __typeof (__redirect_memcpy) __memcpy_a64fx attribute_hidden;
> -# endif
> -
> -libc_ifunc (__libc_memcpy,
> -            (IS_THUNDERX (midr)
> -            ? __memcpy_thunderx
> -            : (IS_FALKOR (midr) || IS_PHECDA (midr)
> -               ? __memcpy_falkor
> -               : (IS_THUNDERX2 (midr) || IS_THUNDERX2PA (midr)
> -                  ? __memcpy_thunderx2
> -                  : (IS_NEOVERSE_N1 (midr) || IS_NEOVERSE_N2 (midr)
> -                     || IS_NEOVERSE_V1 (midr)
> -                     ? __memcpy_simd
> -# if HAVE_AARCH64_SVE_ASM
> -                    : (IS_A64FX (midr) && sve
> -                       ? __memcpy_a64fx
> -                       : __memcpy_generic))))));
> -# else
> -                    : __memcpy_generic)))));
> -# endif
> +extern __typeof (__redirect_memcpy) __memcpy_sve attribute_hidden;
> +
> +static inline __typeof (__redirect_memcpy) *
> +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))
> +       return __memcpy_a64fx;
> +      return __memcpy_sve;
> +    }
> +
> +  if (IS_THUNDERX (midr))
> +    return __memcpy_thunderx;
> +
> +  if (IS_THUNDERX2 (midr) || IS_THUNDERX2PA (midr))
> +    return __memcpy_thunderx2;
> +
> +  if (IS_FALKOR (midr) || IS_PHECDA (midr))
> +    return __memcpy_falkor;
> +
> +  return __memcpy_generic;
> +}
> +
> +libc_ifunc (__libc_memcpy, select_memcpy_ifunc ());
> +
>  # undef memcpy
>  strong_alias (__libc_memcpy, memcpy);
>  #endif
> diff --git a/sysdeps/aarch64/multiarch/memcpy_sve.S b/sysdeps/aarch64/multiarch/memcpy_sve.S
> new file mode 100644
> index 0000000000000000000000000000000000000000..a70907ec5595114e4da35c54e932279c22e53cc6
> --- /dev/null
> +++ b/sysdeps/aarch64/multiarch/memcpy_sve.S
> @@ -0,0 +1,218 @@
> +/* Optimized memcpy for SVE.
> +   Copyright (C) 2021-2022 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, SVE, unaligned accesses.
> + *
> + */
> +
> +#define dstin  x0
> +#define src    x1
> +#define count  x2
> +#define dst    x3
> +#define srcend x4
> +#define dstend x5
> +#define tmp1   x6
> +#define vlen   x6
> +
> +#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 source pointer is 16-byte aligned to minimize unaligned accesses.
> +   The loop tail is handled by always copying 64 bytes from the end.
> +*/
> +
> +#if HAVE_AARCH64_SVE_ASM
> +
> +       .arch armv8.2-a+sve
> +
> +ENTRY (__memcpy_sve)
> +       PTR_ARG (0)
> +       PTR_ARG (1)
> +       SIZE_ARG (2)
> +
> +       cmp     count, 128
> +       b.hi    L(copy_long)
> +       cmp     count, 32
> +       b.hi    L(copy32_128)
> +
> +       whilelo p0.b, xzr, count
> +       cntb    vlen
> +       tbnz    vlen, 4, L(vlen128)
> +       ld1b    z0.b, p0/z, [src]
> +       st1b    z0.b, p0, [dstin]
> +       ret
> +
> +       /* Medium copies: 33..128 bytes.  */
> +L(copy32_128):
> +       add     srcend, src, count
> +       add     dstend, dstin, count
> +       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
> +
> +       /* 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
> +
> +L(vlen128):
> +       whilelo p1.b, vlen, count
> +       ld1b    z0.b, p0/z, [src, 0, mul vl]
> +       ld1b    z1.b, p1/z, [src, 1, mul vl]
> +       st1b    z0.b, p0, [dstin, 0, mul vl]
> +       st1b    z1.b, p1, [dstin, 1, mul vl]
> +       ret
> +
> +       .p2align 4
> +       /* Copy more than 128 bytes.  */
> +L(copy_long):
> +       add     srcend, src, count
> +       add     dstend, dstin, count
> +
> +       /* 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_sve)
> +libc_hidden_builtin_def (__memcpy_sve)
> +
> +
> +ENTRY (__memmove_sve)
> +       PTR_ARG (0)
> +       PTR_ARG (1)
> +       SIZE_ARG (2)
> +
> +       cmp     count, 128
> +       b.hi    L(move_long)
> +       cmp     count, 32
> +       b.hi    L(copy32_128)
> +
> +       whilelo p0.b, xzr, count
> +       cntb    vlen
> +       tbnz    vlen, 4, L(vlen128)
> +       ld1b    z0.b, p0/z, [src]
> +       st1b    z0.b, p0, [dstin]
> +       ret
> +
> +       .p2align 4
> +L(move_long):
> +       add     srcend, src, count
> +       add     dstend, dstin, count
> +       /* Only use backward copy if there is an overlap.  */
> +       sub     tmp1, dstin, src
> +       cbz     tmp1, L(return)
> +       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.  */
> +       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(return):
> +       ret
> +
> +END (__memmove_sve)
> +libc_hidden_builtin_def (__memmove_sve)
> +#endif
> diff --git a/sysdeps/aarch64/multiarch/memmove.c b/sysdeps/aarch64/multiarch/memmove.c
> index 4f7d7eedfd943d1b6a54e90dc973406b30cc8db9..261996ecc4b36bdaf3c50598d910e9c7dcace08b 100644
> --- a/sysdeps/aarch64/multiarch/memmove.c
> +++ b/sysdeps/aarch64/multiarch/memmove.c
> @@ -33,27 +33,38 @@ 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;
> -# if HAVE_AARCH64_SVE_ASM
>  extern __typeof (__redirect_memmove) __memmove_a64fx attribute_hidden;
> -# endif
> -
> -libc_ifunc (__libc_memmove,
> -            (IS_THUNDERX (midr)
> -            ? __memmove_thunderx
> -            : (IS_FALKOR (midr) || IS_PHECDA (midr)
> -               ? __memmove_falkor
> -               : (IS_THUNDERX2 (midr) || IS_THUNDERX2PA (midr)
> -                  ? __memmove_thunderx2
> -                  : (IS_NEOVERSE_N1 (midr) || IS_NEOVERSE_N2 (midr)
> -                     || IS_NEOVERSE_V1 (midr)
> -                     ? __memmove_simd
> -# if HAVE_AARCH64_SVE_ASM
> -                    : (IS_A64FX (midr) && sve
> -                       ? __memmove_a64fx
> -                       : __memmove_generic))))));
> -# else
> -                    : __memmove_generic)))));
> -# endif
> +extern __typeof (__redirect_memmove) __memmove_sve attribute_hidden;
> +
> +static inline __typeof (__redirect_memmove) *
> +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))
> +       return __memmove_a64fx;
> +      return __memmove_sve;
> +    }
> +
> +  if (IS_THUNDERX (midr))
> +    return __memmove_thunderx;
> +
> +  if (IS_THUNDERX2 (midr) || IS_THUNDERX2PA (midr))
> +    return __memmove_thunderx2;
> +
> +  if (IS_FALKOR (midr) || IS_PHECDA (midr))
> +    return __memmove_falkor;
> +
> +  return __memmove_generic;
> +}
> +
> +libc_ifunc (__libc_memmove, select_memmove_ifunc ());
> +
>  # undef memmove
>  strong_alias (__libc_memmove, memmove);
>  #endif
>