[PATCH v2 2/3] AArch64: Remove eMAG memset ifunc

[Adhemerval Zanella Netto]

On 16/03/26 14:26, Wilco Dijkstra wrote:
> v2: Split patch
> 
> As a cleanup remove the eMAG ifunc for memset.
> 
> Passes regress, OK for commit?

LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> 
> ---
> 
> diff --git a/sysdeps/aarch64/multiarch/Makefile b/sysdeps/aarch64/multiarch/Makefile
> index bc497782555896bb030139eae3b219577728eb43..988f7cec2562127cdae463b449245aab2a0e00dc 100644
> --- a/sysdeps/aarch64/multiarch/Makefile
> +++ b/sysdeps/aarch64/multiarch/Makefile
> @@ -8,7 +8,6 @@ sysdep_routines += \
>    memcpy_sve \
>    memmove_mops \
>    memset_a64fx \
> -  memset_emag \
>    memset_generic \
>    memset_kunpeng \
>    memset_mops \
> diff --git a/sysdeps/aarch64/multiarch/ifunc-impl-list.c b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
> index b4416b044394f8811fc6f0c416b6580d23e4b0d2..ea5f5853c312e61fcf12458654a76740114c8a4d 100644
> --- a/sysdeps/aarch64/multiarch/ifunc-impl-list.c
> +++ b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
> @@ -50,7 +50,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
>    IFUNC_IMPL (i, name, memset,
>  	      IFUNC_IMPL_ADD (array, i, memset, (zva_size == 64), __memset_zva64)
>  	      IFUNC_IMPL_ADD (array, i, memset, (zva_size == 64), __memset_oryon1)
> -	      IFUNC_IMPL_ADD (array, i, memset, 1, __memset_emag)
>  	      IFUNC_IMPL_ADD (array, i, memset, 1, __memset_kunpeng)
>  	      IFUNC_IMPL_ADD (array, i, memset, sve && zva_size == 256, __memset_a64fx)
>  	      IFUNC_IMPL_ADD (array, i, memset, sve && zva_size == 64, __memset_sve_zva64)
> diff --git a/sysdeps/aarch64/multiarch/memset.c b/sysdeps/aarch64/multiarch/memset.c
> index 76c6532b811e3bfab31bb60b4270305c8b60a811..438845eec9e2d273272a270a0f87833e26ea8c84 100644
> --- a/sysdeps/aarch64/multiarch/memset.c
> +++ b/sysdeps/aarch64/multiarch/memset.c
> @@ -30,7 +30,6 @@
>  extern __typeof (__redirect_memset) __libc_memset;
>  
>  extern __typeof (__redirect_memset) __memset_zva64 attribute_hidden;
> -extern __typeof (__redirect_memset) __memset_emag attribute_hidden;
>  extern __typeof (__redirect_memset) __memset_kunpeng attribute_hidden;
>  extern __typeof (__redirect_memset) __memset_a64fx attribute_hidden;
>  extern __typeof (__redirect_memset) __memset_generic attribute_hidden;
> @@ -61,9 +60,6 @@ select_memset_ifunc (void)
>    if (IS_KUNPENG920 (midr))
>      return __memset_kunpeng;
>  
> -  if (IS_EMAG (midr))
> -    return __memset_emag;
> -
>    if (zva_size == 64)
>      return __memset_zva64;
>  
> diff --git a/sysdeps/aarch64/multiarch/memset_emag.S b/sysdeps/aarch64/multiarch/memset_emag.S
> deleted file mode 100644
> index 8f68de6f72d0f75acc068351c8689b004bdbab0d..0000000000000000000000000000000000000000
> --- a/sysdeps/aarch64/multiarch/memset_emag.S
> +++ /dev/null
> @@ -1,115 +0,0 @@
> -/* Optimized memset for AmpereComputing emag processor.
> -   Copyright (C) 2018-2026 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, unaligned accesses
> - *
> - */
> -
> -#define dstin	x0
> -#define val	x1
> -#define valw	w1
> -#define count	x2
> -#define dst	x3
> -#define dstend	x4
> -
> -ENTRY (__memset_emag)
> -
> -	bfi	valw, valw, 8, 8
> -	bfi	valw, valw, 16, 16
> -	bfi	val, val, 32, 32
> -
> -	add	dstend, dstin, count
> -
> -	cmp	count, 96
> -	b.hi	L(set_long)
> -	cmp	count, 16
> -	b.hs	L(set_medium)
> -
> -	/* Set 0..15 bytes.  */
> -	tbz	count, 3, 1f
> -	str	val, [dstin]
> -	str	val, [dstend, -8]
> -	ret
> -
> -	.p2align 3
> -1:	tbz	count, 2, 2f
> -	str	valw, [dstin]
> -	str	valw, [dstend, -4]
> -	ret
> -2:	cbz	count, 3f
> -	strb	valw, [dstin]
> -	tbz	count, 1, 3f
> -	strh	valw, [dstend, -2]
> -3:	ret
> -
> -	.p2align 3
> -	/* Set 16..96 bytes.  */
> -L(set_medium):
> -	stp	val, val, [dstin]
> -	tbnz	count, 6, L(set96)
> -	stp	val, val, [dstend, -16]
> -	tbz	count, 5, 1f
> -	stp	val, val, [dstin, 16]
> -	stp	val, val, [dstend, -32]
> -1:	ret
> -
> -	.p2align 4
> -	/* Set 64..96 bytes.  Write 64 bytes from the start and
> -	   32 bytes from the end.  */
> -L(set96):
> -	stp	val, val, [dstin, 16]
> -	stp	val, val, [dstin, 32]
> -	stp	val, val, [dstin, 48]
> -	stp	val, val, [dstend, -32]
> -	stp	val, val, [dstend, -16]
> -	ret
> -
> -	.p2align 4
> -L(set_long):
> -	stp	val, val, [dstin]
> -	bic	dst, dstin, 15
> -	/* Small-size or non-zero memset does not use DC ZVA. */
> -	sub	count, dstend, dst
> -
> -	/*
> -	 * Adjust count and bias for loop. By subtracting extra 1 from count,
> -	 * it is easy to use tbz instruction to check whether loop tailing
> -	 * count is less than 33 bytes, so as to bypass 2 unnecessary stps.
> -	 */
> -	sub	count, count, 64+16+1
> -
> -1:	stp	val, val, [dst, 16]
> -	stp	val, val, [dst, 32]
> -	stp	val, val, [dst, 48]
> -	stp	val, val, [dst, 64]!
> -	subs	count, count, 64
> -	b.hs	1b
> -
> -	tbz	count, 5, 1f	/* Remaining count is less than 33 bytes? */
> -	stp	val, val, [dst, 16]
> -	stp	val, val, [dst, 32]
> -1:	stp	val, val, [dstend, -32]
> -	stp	val, val, [dstend, -16]
> -	ret
> -
> -END (__memset_emag)
>