[PATCH] elf: Remove -fno-tree-loop-distribute-patterns usage on dl-support
H.J. Lu
hjl.tools@gmail.com
Mon Aug 8 22:16:00 GMT 2022
On Mon, Aug 8, 2022 at 1:00 PM Adhemerval Zanella via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> Besides the option being gcc specific, this approach is still fragile
> and not future proof since we do not if this will be the only
> optimization option gcc will add that transform loops to memset
> (or any libcall).
>
> The patch add a new internal __memset_generic internal symbol on all
> ports and an extra symbol redirection to header to include on TU that
> required it. The new header with the asm redirection is set per TU
> because the issue is very specific for glibc on binary loading, the
> default hidden_def symbol is used on default code.
>
> Checked on x86_64-linux-gnu and aarch64-linux-gnu.
> ---
> benchtests/bench-bzero-large.c | 1 +
> benchtests/bench-bzero-walk.c | 1 +
> benchtests/bench-bzero.c | 1 +
> benchtests/bench-memset-large.c | 1 +
> benchtests/bench-memset-walk.c | 1 +
> benchtests/bench-memset.c | 1 +
> elf/Makefile | 5 ----
> elf/dl-support.c | 1 +
> elf/dl-symbol-hacks.h | 29 +++++++++++++++++++
> string/memset.c | 1 +
> sysdeps/aarch64/multiarch/rtld-memset.S | 1 +
> sysdeps/alpha/memset.S | 1 +
> sysdeps/arm/memset.S | 1 +
> sysdeps/csky/abiv2/memset.S | 1 +
> sysdeps/i386/i586/memset.S | 1 +
> sysdeps/i386/i686/memset.S | 1 +
> sysdeps/i386/i686/multiarch/memset-ia32.S | 5 ++++
> sysdeps/i386/memset.S | 1 +
> sysdeps/ia64/memset.S | 1 +
> sysdeps/mips/memset.S | 1 +
> sysdeps/powerpc/powerpc32/memset.S | 1 +
> sysdeps/powerpc/powerpc32/power4/memset.S | 1 +
> .../powerpc32/power4/multiarch/memset-ppc32.S | 1 +
> sysdeps/powerpc/powerpc32/power6/memset.S | 1 +
> sysdeps/powerpc/powerpc32/power7/memset.S | 1 +
> sysdeps/powerpc/powerpc64/le/power10/memset.S | 1 +
> .../powerpc64/multiarch/memset-power4.S | 1 +
> .../powerpc64/multiarch/memset-ppc64.S | 1 +
> sysdeps/powerpc/powerpc64/power4/memset.S | 1 +
> sysdeps/powerpc/powerpc64/power6/memset.S | 1 +
> sysdeps/powerpc/powerpc64/power7/memset.S | 1 +
> sysdeps/powerpc/powerpc64/power8/memset.S | 1 +
> sysdeps/s390/memset-z900.S | 1 +
> sysdeps/sh/memset.S | 1 +
> sysdeps/sparc/sparc32/memset.S | 1 +
> .../sparc32/sparcv9/multiarch/memset-ultra1.S | 1 +
> sysdeps/sparc/sparc64/memset.S | 1 +
> .../sparc/sparc64/multiarch/memset-ultra1.S | 1 +
> sysdeps/x86_64/memset.S | 2 ++
> .../multiarch/memset-avx2-unaligned-erms.S | 3 ++
> .../multiarch/memset-evex-unaligned-erms.S | 3 ++
> .../multiarch/memset-sse2-unaligned-erms.S | 3 ++
> 42 files changed, 80 insertions(+), 5 deletions(-)
> create mode 100644 elf/dl-symbol-hacks.h
>
> diff --git a/benchtests/bench-bzero-large.c b/benchtests/bench-bzero-large.c
> index cfc7b81cdf..f016165d45 100644
> --- a/benchtests/bench-bzero-large.c
> +++ b/benchtests/bench-bzero-large.c
> @@ -137,6 +137,7 @@ test_main (void)
> # define libc_hidden_builtin_def(X)
> # define libc_hidden_def(X)
> # define libc_hidden_weak(X)
> +# define strong_alias(X,Y)
> # define weak_alias(X,Y)
> # undef MEMSET
> # define MEMSET generic_memset
> diff --git a/benchtests/bench-bzero-walk.c b/benchtests/bench-bzero-walk.c
> index 851a72b137..25a1a38fa3 100644
> --- a/benchtests/bench-bzero-walk.c
> +++ b/benchtests/bench-bzero-walk.c
> @@ -136,6 +136,7 @@ test_main (void)
> # define libc_hidden_builtin_def(X)
> # define libc_hidden_def(X)
> # define libc_hidden_weak(X)
> +# define strong_alias(X,Y)
> # define weak_alias(X,Y)
> # undef MEMSET
> # define MEMSET generic_memset
> diff --git a/benchtests/bench-bzero.c b/benchtests/bench-bzero.c
> index 500b7eba96..90b807c98a 100644
> --- a/benchtests/bench-bzero.c
> +++ b/benchtests/bench-bzero.c
> @@ -155,6 +155,7 @@ test_main (void)
> # define libc_hidden_builtin_def(X)
> # define libc_hidden_def(X)
> # define libc_hidden_weak(X)
> +# define strong_alias(X,Y)
> # define weak_alias(X,Y)
> # undef MEMSET
> # define MEMSET generic_memset
> diff --git a/benchtests/bench-memset-large.c b/benchtests/bench-memset-large.c
> index 0ea1e3811b..6605e2d414 100644
> --- a/benchtests/bench-memset-large.c
> +++ b/benchtests/bench-memset-large.c
> @@ -118,6 +118,7 @@ test_main (void)
> #define libc_hidden_builtin_def(X)
> #define libc_hidden_def(X)
> #define libc_hidden_weak(X)
> +#define strong_alias(X,Y)
> #define weak_alias(X,Y)
> #undef MEMSET
> #define MEMSET generic_memset
> diff --git a/benchtests/bench-memset-walk.c b/benchtests/bench-memset-walk.c
> index 466ee1b8d6..f7fcdf90ba 100644
> --- a/benchtests/bench-memset-walk.c
> +++ b/benchtests/bench-memset-walk.c
> @@ -116,6 +116,7 @@ test_main (void)
> #define libc_hidden_builtin_def(X)
> #define libc_hidden_def(X)
> #define libc_hidden_weak(X)
> +#define strong_alias(X,Y)
> #define weak_alias(X,Y)
> #undef MEMSET
> #define MEMSET generic_memset
> diff --git a/benchtests/bench-memset.c b/benchtests/bench-memset.c
> index 6c95a1e965..c801c86b73 100644
> --- a/benchtests/bench-memset.c
> +++ b/benchtests/bench-memset.c
> @@ -147,6 +147,7 @@ test_main (void)
> #define libc_hidden_builtin_def(X)
> #define libc_hidden_def(X)
> #define libc_hidden_weak(X)
> +#define strong_alias(X,Y)
> #define weak_alias(X,Y)
> #ifndef WIDE
> # undef MEMSET
> diff --git a/elf/Makefile b/elf/Makefile
> index 3386f0ce77..4b992bd348 100644
> --- a/elf/Makefile
> +++ b/elf/Makefile
> @@ -162,11 +162,6 @@ ifeq (yes,$(have-loop-to-function))
> CFLAGS-rtld.c += -fno-tree-loop-distribute-patterns
> endif
>
> -ifeq (yes,$(have-loop-to-function))
> -# Likewise, during static library startup, memset is not yet available.
> -CFLAGS-dl-support.c = -fno-tree-loop-distribute-patterns
> -endif
> -
> # Compile rtld itself without stack protection.
> # Also compile all routines in the static library that are elided from
> # the shared libc because they are in libc.a in the same way.
> diff --git a/elf/dl-support.c b/elf/dl-support.c
> index 4af0b5b2ce..6d1996ae6e 100644
> --- a/elf/dl-support.c
> +++ b/elf/dl-support.c
> @@ -44,6 +44,7 @@
> #include <dl-auxv.h>
> #include <dl-find_object.h>
> #include <array_length.h>
> +#include <dl-symbol-hacks.h>
>
> extern char *__progname;
> char **_dl_argv = &__progname; /* This is checked for some error messages. */
> diff --git a/elf/dl-symbol-hacks.h b/elf/dl-symbol-hacks.h
> new file mode 100644
> index 0000000000..b8caccb570
> --- /dev/null
> +++ b/elf/dl-symbol-hacks.h
> @@ -0,0 +1,29 @@
> +/* Symbol rediretion for loader/static initialization code.
> + Copyright (C) 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/>. */
> +
> +#ifndef _DL_SYMBOL_HACKS_H
> +#define _DL_SYMBOL_HACKS_H
> +
> +/* Some compiler optimizations may transform loops into memset/memmove
> + calls and without proper redirection it might call PLT throught
> + ifunc without relocations being processed. */
> +#ifndef SHARED
> +asm ("memset = __memset_generic");
> +#endif
> +
> +#endif
> diff --git a/string/memset.c b/string/memset.c
> index 1303dd7ad3..b98bad7095 100644
> --- a/string/memset.c
> +++ b/string/memset.c
> @@ -88,3 +88,4 @@ MEMSET (void *dstpp, int c, size_t len)
> return dstpp;
> }
> libc_hidden_builtin_def (MEMSET)
> +strong_alias (MEMSET, __memset_generic)
> diff --git a/sysdeps/aarch64/multiarch/rtld-memset.S b/sysdeps/aarch64/multiarch/rtld-memset.S
> index 7968d25e48..70591781d9 100644
> --- a/sysdeps/aarch64/multiarch/rtld-memset.S
> +++ b/sysdeps/aarch64/multiarch/rtld-memset.S
> @@ -22,4 +22,5 @@
> #if IS_IN (rtld)
> # define MEMSET memset
> # include <sysdeps/aarch64/memset.S>
> +strong_alias (memset, __memset_generic)
> #endif
> diff --git a/sysdeps/alpha/memset.S b/sysdeps/alpha/memset.S
> index 9249663d37..c5adae754b 100644
> --- a/sysdeps/alpha/memset.S
> +++ b/sysdeps/alpha/memset.S
> @@ -124,3 +124,4 @@ $done: ret
>
> cfi_endproc
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/arm/memset.S b/sysdeps/arm/memset.S
> index 9c05669864..9b9a3cb264 100644
> --- a/sysdeps/arm/memset.S
> +++ b/sysdeps/arm/memset.S
> @@ -66,3 +66,4 @@ ENTRY(memset)
> DO_RET(lr)
> END(memset)
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/csky/abiv2/memset.S b/sysdeps/csky/abiv2/memset.S
> index 41df8e2bb8..7e23edc787 100644
> --- a/sysdeps/csky/abiv2/memset.S
> +++ b/sysdeps/csky/abiv2/memset.S
> @@ -96,3 +96,4 @@ END (memset)
>
> libc_hidden_builtin_def (memset)
> .weak memset
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/i386/i586/memset.S b/sysdeps/i386/i586/memset.S
> index 672af41398..9d8dd40ad5 100644
> --- a/sysdeps/i386/i586/memset.S
> +++ b/sysdeps/i386/i586/memset.S
> @@ -101,3 +101,4 @@ L(2): shrl $2, %ecx /* convert byte count to longword count */
> ret
> END (memset)
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/i386/i686/memset.S b/sysdeps/i386/i686/memset.S
> index 3cb86c016d..3462cb99ab 100644
> --- a/sysdeps/i386/i686/memset.S
> +++ b/sysdeps/i386/i686/memset.S
> @@ -77,3 +77,4 @@ ENTRY (memset)
> ret
> END (memset)
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/i386/i686/multiarch/memset-ia32.S b/sysdeps/i386/i686/multiarch/memset-ia32.S
> index 8f0ae56cec..9a1b9c2b05 100644
> --- a/sysdeps/i386/i686/multiarch/memset-ia32.S
> +++ b/sysdeps/i386/i686/multiarch/memset-ia32.S
> @@ -31,3 +31,8 @@
> #endif
>
> #include <sysdeps/i386/i686/memset.S>
> +#if IS_IN(rtld)
> +strong_alias (memset, __memset_generic)
> +#else
> +strong_alias (__memset_ia32, __memset_generic)
> +#endif
> diff --git a/sysdeps/i386/memset.S b/sysdeps/i386/memset.S
> index db2753eb2f..c105090f03 100644
> --- a/sysdeps/i386/memset.S
> +++ b/sysdeps/i386/memset.S
> @@ -54,3 +54,4 @@ ENTRY (memset)
> END (memset)
>
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/ia64/memset.S b/sysdeps/ia64/memset.S
> index d52f23dd93..70ad1140b8 100644
> --- a/sysdeps/ia64/memset.S
> +++ b/sysdeps/ia64/memset.S
> @@ -395,3 +395,4 @@ store_words:
> ;; }
> END(memset)
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/mips/memset.S b/sysdeps/mips/memset.S
> index c5ffab1d8c..cb5c9a140f 100644
> --- a/sysdeps/mips/memset.S
> +++ b/sysdeps/mips/memset.S
> @@ -424,3 +424,4 @@ END(MEMSET_NAME)
> libc_hidden_builtin_def (MEMSET_NAME)
> # endif
> #endif
> +strong_alias(MEMSET_NAME, __memset_generic)
> diff --git a/sysdeps/powerpc/powerpc32/memset.S b/sysdeps/powerpc/powerpc32/memset.S
> index c125934f55..63ad3d2d2b 100644
> --- a/sysdeps/powerpc/powerpc32/memset.S
> +++ b/sysdeps/powerpc/powerpc32/memset.S
> @@ -302,3 +302,4 @@ L(handletail32):
>
> END (memset)
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/powerpc/powerpc32/power4/memset.S b/sysdeps/powerpc/powerpc32/power4/memset.S
> index 40b140c841..98811c1a66 100644
> --- a/sysdeps/powerpc/powerpc32/power4/memset.S
> +++ b/sysdeps/powerpc/powerpc32/power4/memset.S
> @@ -224,3 +224,4 @@ L(medium_28t):
> blr
> END (memset)
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/powerpc/powerpc32/power4/multiarch/memset-ppc32.S b/sysdeps/powerpc/powerpc32/power4/multiarch/memset-ppc32.S
> index 0937ba2215..4c5724bc60 100644
> --- a/sysdeps/powerpc/powerpc32/power4/multiarch/memset-ppc32.S
> +++ b/sysdeps/powerpc/powerpc32/power4/multiarch/memset-ppc32.S
> @@ -39,3 +39,4 @@
> #endif
>
> #include <sysdeps/powerpc/powerpc32/power4/memset.S>
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/powerpc/powerpc32/power6/memset.S b/sysdeps/powerpc/powerpc32/power6/memset.S
> index d86701ff7c..5f4c8518bd 100644
> --- a/sysdeps/powerpc/powerpc32/power6/memset.S
> +++ b/sysdeps/powerpc/powerpc32/power6/memset.S
> @@ -537,3 +537,4 @@ L(medium_28t):
> blr
> END (memset)
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/powerpc/powerpc32/power7/memset.S b/sysdeps/powerpc/powerpc32/power7/memset.S
> index 368e8b3939..68a6ec18d8 100644
> --- a/sysdeps/powerpc/powerpc32/power7/memset.S
> +++ b/sysdeps/powerpc/powerpc32/power7/memset.S
> @@ -428,3 +428,4 @@ L(small):
>
> END (memset)
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/powerpc/powerpc64/le/power10/memset.S b/sysdeps/powerpc/powerpc64/le/power10/memset.S
> index 0f43b002bf..551e221fd2 100644
> --- a/sysdeps/powerpc/powerpc64/le/power10/memset.S
> +++ b/sysdeps/powerpc/powerpc64/le/power10/memset.S
> @@ -242,3 +242,4 @@ L(bcdz_tail):
>
> END_GEN_TB (MEMSET,TB_TOCLESS)
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/powerpc/powerpc64/multiarch/memset-power4.S b/sysdeps/powerpc/powerpc64/multiarch/memset-power4.S
> index 4ee567c6f9..451de98f08 100644
> --- a/sysdeps/powerpc/powerpc64/multiarch/memset-power4.S
> +++ b/sysdeps/powerpc/powerpc64/multiarch/memset-power4.S
> @@ -22,3 +22,4 @@
> #define libc_hidden_builtin_def(name)
>
> #include <sysdeps/powerpc/powerpc64/power4/memset.S>
> +strong_alias (__memset_power4, __memset_generic)
> diff --git a/sysdeps/powerpc/powerpc64/multiarch/memset-ppc64.S b/sysdeps/powerpc/powerpc64/multiarch/memset-ppc64.S
> index 30b25ef15f..91b9775edd 100644
> --- a/sysdeps/powerpc/powerpc64/multiarch/memset-ppc64.S
> +++ b/sysdeps/powerpc/powerpc64/multiarch/memset-ppc64.S
> @@ -26,3 +26,4 @@
> #endif
>
> #include <sysdeps/powerpc/powerpc64/memset.S>
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/powerpc/powerpc64/power4/memset.S b/sysdeps/powerpc/powerpc64/power4/memset.S
> index 0f14a5198a..91557f0442 100644
> --- a/sysdeps/powerpc/powerpc64/power4/memset.S
> +++ b/sysdeps/powerpc/powerpc64/power4/memset.S
> @@ -237,3 +237,4 @@ L(medium_28t):
> blr
> END_GEN_TB (MEMSET,TB_TOCLESS)
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/powerpc/powerpc64/power6/memset.S b/sysdeps/powerpc/powerpc64/power6/memset.S
> index 140a756348..29ec7f200f 100644
> --- a/sysdeps/powerpc/powerpc64/power6/memset.S
> +++ b/sysdeps/powerpc/powerpc64/power6/memset.S
> @@ -381,3 +381,4 @@ L(medium_28t):
> blr
> END_GEN_TB (MEMSET,TB_TOCLESS)
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/powerpc/powerpc64/power7/memset.S b/sysdeps/powerpc/powerpc64/power7/memset.S
> index 358199a805..1afeaf754d 100644
> --- a/sysdeps/powerpc/powerpc64/power7/memset.S
> +++ b/sysdeps/powerpc/powerpc64/power7/memset.S
> @@ -384,3 +384,4 @@ L(small):
>
> END_GEN_TB (MEMSET,TB_TOCLESS)
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/powerpc/powerpc64/power8/memset.S b/sysdeps/powerpc/powerpc64/power8/memset.S
> index 70cace14ef..73676cdb88 100644
> --- a/sysdeps/powerpc/powerpc64/power8/memset.S
> +++ b/sysdeps/powerpc/powerpc64/power8/memset.S
> @@ -504,3 +504,4 @@ L(LE7_tail5):
>
> END_GEN_TB (MEMSET,TB_TOCLESS)
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/s390/memset-z900.S b/sysdeps/s390/memset-z900.S
> index 7adb466bb1..beecfa2815 100644
> --- a/sysdeps/s390/memset-z900.S
> +++ b/sysdeps/s390/memset-z900.S
> @@ -185,3 +185,4 @@ strong_alias (MEMSET_DEFAULT, memset)
> Compare to libc_hidden_builtin_def (memset) in string/memset.c. */
> strong_alias (MEMSET_DEFAULT, __GI_memset)
> #endif
> +strong_alias (MEMSET_DEFAULT, __memset_generic)
> diff --git a/sysdeps/sh/memset.S b/sysdeps/sh/memset.S
> index 7852b472eb..fc36bc836a 100644
> --- a/sysdeps/sh/memset.S
> +++ b/sysdeps/sh/memset.S
> @@ -84,3 +84,4 @@ L_byte_exit:
> mov r7,r0
> END(memset)
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
> diff --git a/sysdeps/sparc/sparc32/memset.S b/sysdeps/sparc/sparc32/memset.S
> index b1b67cb2d1..5026275239 100644
> --- a/sysdeps/sparc/sparc32/memset.S
> +++ b/sysdeps/sparc/sparc32/memset.S
> @@ -142,4 +142,5 @@ ENTRY(memset)
> b 4b
> sub %o0, %o2, %o0
> END(memset)
> +strong_alias (memset, __memset_generic)
> libc_hidden_builtin_def (memset)
> diff --git a/sysdeps/sparc/sparc32/sparcv9/multiarch/memset-ultra1.S b/sysdeps/sparc/sparc32/sparcv9/multiarch/memset-ultra1.S
> index 2dda6f1ed6..e5082fa161 100644
> --- a/sysdeps/sparc/sparc32/sparcv9/multiarch/memset-ultra1.S
> +++ b/sysdeps/sparc/sparc32/sparcv9/multiarch/memset-ultra1.S
> @@ -27,3 +27,4 @@
> # define memset __memset_ultra1
> # include <sysdeps/sparc/sparc32/sparcv9/memset.S>
> #endif
> +strong_alias (__memset_ultra1, __memset_generic)
> diff --git a/sysdeps/sparc/sparc64/memset.S b/sysdeps/sparc/sparc64/memset.S
> index 33ecbc93fe..6a68ab52cb 100644
> --- a/sysdeps/sparc/sparc64/memset.S
> +++ b/sysdeps/sparc/sparc64/memset.S
> @@ -303,4 +303,5 @@ ENTRY(memset)
> 0: retl
> mov %o5, %o0
> END(memset)
> +strong_alias (memset, __memset_generic)
> libc_hidden_builtin_def (memset)
> diff --git a/sysdeps/sparc/sparc64/multiarch/memset-ultra1.S b/sysdeps/sparc/sparc64/multiarch/memset-ultra1.S
> index 3c3add791e..478a106c83 100644
> --- a/sysdeps/sparc/sparc64/multiarch/memset-ultra1.S
> +++ b/sysdeps/sparc/sparc64/multiarch/memset-ultra1.S
> @@ -27,3 +27,4 @@
> # define memset __memset_ultra1
> # include <sysdeps/sparc/sparc64/memset.S>
> #endif
> +strong_alias (__memset_ultra1, __memset_generic)
> diff --git a/sysdeps/x86_64/memset.S b/sysdeps/x86_64/memset.S
> index f4e1bab601..52fb00b17b 100644
> --- a/sysdeps/x86_64/memset.S
> +++ b/sysdeps/x86_64/memset.S
> @@ -25,6 +25,7 @@
> #define WMEMSET_SYMBOL(p,s) __wmemset
> #define WMEMSET_CHK_SYMBOL(p,s) p
>
> +#define NO_MULTIARCH
> #define DEFAULT_IMPL_V1 "multiarch/memset-sse2-unaligned-erms.S"
> #define DEFAULT_IMPL_V3 "multiarch/memset-avx2-unaligned-erms.S"
> #define DEFAULT_IMPL_V4 "multiarch/memset-evex-unaligned-erms.S"
> @@ -32,6 +33,7 @@
> #include "isa-default-impl.h"
>
> libc_hidden_builtin_def (memset)
> +strong_alias (memset, __memset_generic)
>
> #if IS_IN (libc)
> libc_hidden_def (__wmemset)
> diff --git a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
> index a9054a9122..c2da716d7c 100644
> --- a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
> +++ b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
> @@ -38,4 +38,7 @@
>
> # define USE_XMM_LESS_VEC
> # include "memset-vec-unaligned-erms.S"
> +# if !defined NO_MULTIARCH && MINIMUM_X86_ISA_LEVEL >= 3
> +strong_alias (__memset_avx2_unaligned, __memset_generic)
> +# endif
> #endif
> diff --git a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
> index ac4b2d2d50..034d19b35e 100644
> --- a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
> +++ b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
> @@ -44,4 +44,7 @@
>
> # define USE_LESS_VEC_MASK_STORE 1
> # include "memset-vec-unaligned-erms.S"
> +# if !defined NO_MULTIARCH && MINIMUM_X86_ISA_LEVEL >= 4
> +strong_alias (__memset_evex_unaligned, __memset_generic)
> +# endif
> #endif
This will define 2 __memset_generic for -march=x86-64-v4.
> diff --git a/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S
> index 44f9b8888b..143055adff 100644
> --- a/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S
> +++ b/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S
> @@ -63,5 +63,8 @@
> # endif
>
> # include "memset-vec-unaligned-erms.S"
> +# if !defined NO_MULTIARCH && MINIMUM_X86_ISA_LEVEL <= 2
> +strong_alias (__memset_sse2_unaligned, __memset_generic)
> +# endif
>
> #endif
> --
> 2.34.1
>
--
H.J.
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