[PATCH v1 2/2] x86: Add support for building str{c|p}{brk|spn} with explicit ISA level
Noah Goldstein
goldstein.w.n@gmail.com
Wed Jun 29 22:07:35 GMT 2022
On Wed, Jun 29, 2022 at 12:21 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Tue, Jun 28, 2022 at 8:27 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> >
> > The changes for these functions are different than the others because
> > the best implementation (sse4_2) requires the generic
> > implementation as a fallback to be built as well.
> >
> > Changes are:
> >
> > 1. Add non-multiarch functions for str{c|p}{brk|spn}.c to statically
> > select the best implementation based on the configured ISA build
> > level.
> >
> > 2. Add stubs for str{c|p}{brk|spn}-generic and varshift.c to in the
> > sysdeps/x86_64 directory so that the the sse4 implementation will
> > have all of its dependencies for the non-multiarch / rtld build
> > when ISA level >=
> Something is missing.
> > 3. Add new multiarch/rtld-strcspn.c that just include the
> > non-multiarch strcspn.c which will in turn select the best
> > implementation based on the compiled ISA level.
> >
> > 4. Refactor the ifunc selector and ifunc implementation list to use
> > the ISA level aware wrapper macros that allow functions below the
> > compiled ISA level (with a guranteed replacement) to be skipped.
> >
> > Tested with and without multiarch on x86_64 for ISA levels:
> > {generic, x86-64-v2, x86-64-v3, x86-64-v4}
> >
> > And m32 with and without multiarch.
> > ---
> > sysdeps/x86_64/Makefile | 9 +++++++-
> > sysdeps/x86_64/multiarch/ifunc-impl-list.c | 9 +++++++-
> > sysdeps/x86_64/multiarch/ifunc-sse4_2.h | 2 +-
> > sysdeps/x86_64/multiarch/rtld-strcspn.c | 18 +++++++++++++++
> > sysdeps/x86_64/multiarch/strcspn-generic.c | 11 +++++----
> > sysdeps/x86_64/multiarch/strcspn-sse4.c | 6 +++--
> > sysdeps/x86_64/multiarch/strpbrk-generic.c | 9 +++++---
> > sysdeps/x86_64/multiarch/strpbrk-sse4.c | 6 ++++-
> > sysdeps/x86_64/multiarch/strspn-generic.c | 8 ++++---
> > sysdeps/x86_64/multiarch/strspn-sse4.c | 6 ++++-
> > sysdeps/x86_64/strcspn-generic.c | 22 ++++++++++++++++++
> > sysdeps/x86_64/strcspn.c | 27 ++++++++++++++++++++++
> > sysdeps/x86_64/strpbrk-generic.c | 22 ++++++++++++++++++
> > sysdeps/x86_64/strpbrk.c | 27 ++++++++++++++++++++++
> > sysdeps/x86_64/strspn-generic.c | 23 ++++++++++++++++++
> > sysdeps/x86_64/strspn.c | 27 ++++++++++++++++++++++
> > sysdeps/x86_64/varshift.c | 23 ++++++++++++++++++
> > 17 files changed, 238 insertions(+), 17 deletions(-)
> > create mode 100644 sysdeps/x86_64/multiarch/rtld-strcspn.c
> > create mode 100644 sysdeps/x86_64/strcspn-generic.c
> > create mode 100644 sysdeps/x86_64/strcspn.c
> > create mode 100644 sysdeps/x86_64/strpbrk-generic.c
> > create mode 100644 sysdeps/x86_64/strpbrk.c
> > create mode 100644 sysdeps/x86_64/strspn-generic.c
> > create mode 100644 sysdeps/x86_64/strspn.c
> > create mode 100644 sysdeps/x86_64/varshift.c
> >
> > diff --git a/sysdeps/x86_64/Makefile b/sysdeps/x86_64/Makefile
> > index 79365aff2a..c130d56342 100644
> > --- a/sysdeps/x86_64/Makefile
> > +++ b/sysdeps/x86_64/Makefile
> > @@ -14,7 +14,14 @@ sysdep_noprof += _mcount
> > endif
> >
> > ifeq ($(subdir),string)
> > -sysdep_routines += strcasecmp_l-nonascii strncase_l-nonascii
> > +sysdep_routines += \
> > + strcasecmp_l-nonascii \
> > + strcspn-generic \
> > + strncase_l-nonascii \
> > + strpbrk-generic \
> > + strspn-generic \
> > + varshift \
> > +#sysdep_routines
>
> Add a space after #.
Fixed in V2.
>
> > gen-as-const-headers += locale-defines.sym
> > tests += \
> > tst-rsi-strlen
> > diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> > index 772b4ace6c..251b0022d9 100644
> > --- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> > +++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> > @@ -540,6 +540,8 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
> >
> > /* Support sysdeps/x86_64/multiarch/strcspn.c. */
> > IFUNC_IMPL (i, name, strcspn,
> > + /* All implementations of strcspn are built at all ISA
> > + levels. */
> > IFUNC_IMPL_ADD (array, i, strcspn, CPU_FEATURE_USABLE (SSE4_2),
> > __strcspn_sse42)
> > IFUNC_IMPL_ADD (array, i, strcspn, 1, __strcspn_generic))
> > @@ -616,6 +618,8 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
> >
> > /* Support sysdeps/x86_64/multiarch/strpbrk.c. */
> > IFUNC_IMPL (i, name, strpbrk,
> > + /* All implementations of strpbrk are built at all ISA
> > + levels. */
> > IFUNC_IMPL_ADD (array, i, strpbrk, CPU_FEATURE_USABLE (SSE4_2),
> > __strpbrk_sse42)
> > IFUNC_IMPL_ADD (array, i, strpbrk, 1, __strpbrk_generic))
> > @@ -623,13 +627,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
> >
> > /* Support sysdeps/x86_64/multiarch/strspn.c. */
> > IFUNC_IMPL (i, name, strspn,
> > + /* All implementations of strspn are built at all ISA
> > + levels. */
> > IFUNC_IMPL_ADD (array, i, strspn, CPU_FEATURE_USABLE (SSE4_2),
> > __strspn_sse42)
> > IFUNC_IMPL_ADD (array, i, strspn, 1, __strspn_generic))
> >
> > /* Support sysdeps/x86_64/multiarch/strstr.c. */
> > IFUNC_IMPL (i, name, strstr,
> > - /* All implementations of strstr are built at all ISA levels. */
> > + /* All implementations of strstr are built at all ISA
> > + levels. */
> > IFUNC_IMPL_ADD (array, i, strstr,
> > (CPU_FEATURE_USABLE (AVX512VL)
> > && CPU_FEATURE_USABLE (AVX512BW)
> > diff --git a/sysdeps/x86_64/multiarch/ifunc-sse4_2.h b/sysdeps/x86_64/multiarch/ifunc-sse4_2.h
> > index 204c4b5406..d642f54fac 100644
> > --- a/sysdeps/x86_64/multiarch/ifunc-sse4_2.h
> > +++ b/sysdeps/x86_64/multiarch/ifunc-sse4_2.h
> > @@ -31,7 +31,7 @@ IFUNC_SELECTOR (void)
> > there is no other optimized implementation keep using. If an
> > optimized fallback is added add a X86_ISA_CPU_FEATURE_USABLE_P
> > (cpu_features, SSE4_2) check. */
> > - if (ISA_CPU_FEATURE_USABLE_P (cpu_features, SSE4_2))
> > + if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, SSE4_2))
> > return OPTIMIZE (sse42);
> >
> > return OPTIMIZE (generic);
> > diff --git a/sysdeps/x86_64/multiarch/rtld-strcspn.c b/sysdeps/x86_64/multiarch/rtld-strcspn.c
> > new file mode 100644
> > index 0000000000..99e3c59e00
> > --- /dev/null
> > +++ b/sysdeps/x86_64/multiarch/rtld-strcspn.c
> > @@ -0,0 +1,18 @@
> > +/* 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/>. */
> > +
> > +#include "../strcspn.c"
> > diff --git a/sysdeps/x86_64/multiarch/strcspn-generic.c b/sysdeps/x86_64/multiarch/strcspn-generic.c
> > index 423de2e2b2..64e90a26bb 100644
> > --- a/sysdeps/x86_64/multiarch/strcspn-generic.c
> > +++ b/sysdeps/x86_64/multiarch/strcspn-generic.c
> > @@ -16,13 +16,16 @@
> > License along with the GNU C Library; if not, see
> > <https://www.gnu.org/licenses/>. */
> >
> > -#if IS_IN (libc)
> > -
> > +/* We always need to build this implementation as strcspn-sse4 needs
> > + to be able to fallback to it. */
> > +#include <isa-level.h>
> > +#if IS_IN (libc) || MINIMUM_X86_ISA_LEVEL >= 2
> > # include <sysdep.h>
> > # define STRCSPN __strcspn_generic
> >
> > # undef libc_hidden_builtin_def
> > # define libc_hidden_builtin_def(STRCSPN)
> > -#endif
> >
> > -#include <string/strcspn.c>
> > +# include <string/strcspn.c>
>
> <string/strcspn.c> will always be included. The only change
> should be
>
> #if IS_IN (libc) || MINIMUM_X86_ISA_LEVEL >= 2
>
> which controls __strcspn_generic vs strcspn.
>
Fixed in V2.
> > +
> > +#endif
> > diff --git a/sysdeps/x86_64/multiarch/strcspn-sse4.c b/sysdeps/x86_64/multiarch/strcspn-sse4.c
> > index 59f64f9fe8..becdaf05f3 100644
> > --- a/sysdeps/x86_64/multiarch/strcspn-sse4.c
> > +++ b/sysdeps/x86_64/multiarch/strcspn-sse4.c
> > @@ -52,9 +52,11 @@
> > when either CFlag or ZFlag is 1. If CFlag == 1, ECX has the offset
> > X for case 1. */
> >
> > +#ifndef STRCSPN
> > +# define STRCSPN __strcspn_sse42
> > +#endif
> > #ifndef STRCSPN_GENERIC
> > # define STRCSPN_GENERIC __strcspn_generic
> > -# define STRCSPN_SSE42 __strcspn_sse42
> > #endif
> >
> > #ifdef USE_AS_STRPBRK
> > @@ -78,7 +80,7 @@ char *
> > size_t
> > #endif
> > __attribute__ ((section (".text.sse4.2")))
> > -STRCSPN_SSE42 (const char *s, const char *a)
> > +STRCSPN (const char *s, const char *a)
> > {
> > if (*a == 0)
> > RETURN (NULL, strlen (s));
> > diff --git a/sysdeps/x86_64/multiarch/strpbrk-generic.c b/sysdeps/x86_64/multiarch/strpbrk-generic.c
> > index d31acfe495..7f3ea86e91 100644
> > --- a/sysdeps/x86_64/multiarch/strpbrk-generic.c
> > +++ b/sysdeps/x86_64/multiarch/strpbrk-generic.c
> > @@ -16,13 +16,16 @@
> > License along with the GNU C Library; if not, see
> > <https://www.gnu.org/licenses/>. */
> >
> > -#if IS_IN (libc)
> >
> > +/* We always need to build this implementation as strpbrk-sse4 needs
> > + to be able to fallback to it. */
> > +#include <isa-level.h>
> > +#if IS_IN (libc) || MINIMUM_X86_ISA_LEVEL >= 2
>
> Only this change is needed.
>
Fixed in V2.
> > # include <sysdep.h>
> > # define STRPBRK __strpbrk_generic
> >
> > # undef libc_hidden_builtin_def
> > # define libc_hidden_builtin_def(STRPBRK)
> > -#endif
> >
> > -#include <string/strpbrk.c>
> > +# include <string/strpbrk.c>
> > +#endif
> > diff --git a/sysdeps/x86_64/multiarch/strpbrk-sse4.c b/sysdeps/x86_64/multiarch/strpbrk-sse4.c
> > index bf74d660d5..0adb577955 100644
> > --- a/sysdeps/x86_64/multiarch/strpbrk-sse4.c
> > +++ b/sysdeps/x86_64/multiarch/strpbrk-sse4.c
> > @@ -16,7 +16,11 @@
> > License along with the GNU C Library; if not, see
> > <https://www.gnu.org/licenses/>. */
> >
> > +#ifndef STRPBRK
> > +# define STRPBRK __strpbrk_sse42
> > +#endif
> > +
> > #define USE_AS_STRPBRK
> > #define STRCSPN_GENERIC __strpbrk_generic
> > -#define STRCSPN_SSE42 __strpbrk_sse42
> > +#define STRCSPN STRPBRK
> > #include "strcspn-sse4.c"
> > diff --git a/sysdeps/x86_64/multiarch/strspn-generic.c b/sysdeps/x86_64/multiarch/strspn-generic.c
> > index 6b50c36432..f5632ad3b2 100644
> > --- a/sysdeps/x86_64/multiarch/strspn-generic.c
> > +++ b/sysdeps/x86_64/multiarch/strspn-generic.c
> > @@ -16,13 +16,15 @@
> > License along with the GNU C Library; if not, see
> > <https://www.gnu.org/licenses/>. */
> >
> > -#if IS_IN (libc)
> > -
> > +/* We always need to build this implementation as strspn-sse4 needs to
> > + be able to fallback to it. */
> > +#include <isa-level.h>
> > +#if IS_IN (libc) || MINIMUM_X86_ISA_LEVEL >= 2
>
> Only this change is needed.
>
> > # include <sysdep.h>
> > # define STRSPN __strspn_generic
> >
> > # undef libc_hidden_builtin_def
> > # define libc_hidden_builtin_def(STRSPN)
> > -#endif
> >
> > #include <string/strspn.c>
> > +#endif
> > diff --git a/sysdeps/x86_64/multiarch/strspn-sse4.c b/sysdeps/x86_64/multiarch/strspn-sse4.c
> > index d044916688..6263669b54 100644
> > --- a/sysdeps/x86_64/multiarch/strspn-sse4.c
> > +++ b/sysdeps/x86_64/multiarch/strspn-sse4.c
> > @@ -51,12 +51,16 @@
> >
> > We exit from the loop for case 1. */
> >
> > +
> > extern size_t __strspn_generic (const char *, const char *) attribute_hidden;
> >
> > +#ifndef STRSPN
> > +# define STRSPN __strspn_sse42
> > +#endif
> >
> > size_t
> > __attribute__ ((section (".text.sse4.2")))
> > -__strspn_sse42 (const char *s, const char *a)
> > +STRSPN (const char *s, const char *a)
> > {
> > if (*a == 0)
> > return 0;
> > diff --git a/sysdeps/x86_64/strcspn-generic.c b/sysdeps/x86_64/strcspn-generic.c
> > new file mode 100644
> > index 0000000000..082324e793
> > --- /dev/null
> > +++ b/sysdeps/x86_64/strcspn-generic.c
> > @@ -0,0 +1,22 @@
>
> Need a comment for its purpose.
>
Done in V2.
> > +/* 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/>. */
> > +
> > +#include <isa-level.h>
> > +
> > +#if !defined USE_MULTIARCH && MINIMUM_X86_ISA_LEVEL >= 2
>
> Do we need to check USE_MULTIARCH here? multiartch build will
> use multiarch/strcspn-generic.c.
>
No. Removed in V2. (All builds succeed)
> > +# include "multiarch/strcspn-generic.c"
> > +#endif
> > diff --git a/sysdeps/x86_64/strcspn.c b/sysdeps/x86_64/strcspn.c
> > new file mode 100644
> > index 0000000000..cd54eed869
> > --- /dev/null
> > +++ b/sysdeps/x86_64/strcspn.c
> > @@ -0,0 +1,27 @@
> > +/* strcspn hook for non-multiarch and RTLD build.
> > + 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/>. */
> > +
> > +#include <isa-level.h>
> > +
> > +#if MINIMUM_X86_ISA_LEVEL == 1
> > +#include <string/strcspn.c>
> > +#else
> > +#define STRCSPN strcspn
> > +#include "multiarch/strcspn-sse4.c"
> > +libc_hidden_builtin_def (strcspn)
> > +#endif
> > diff --git a/sysdeps/x86_64/strpbrk-generic.c b/sysdeps/x86_64/strpbrk-generic.c
> > new file mode 100644
> > index 0000000000..6bdbb2d164
> > --- /dev/null
> > +++ b/sysdeps/x86_64/strpbrk-generic.c
> > @@ -0,0 +1,22 @@
>
> Need a comment for its purpose.
>
Done in V2.
> > +/* 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/>. */
> > +
> > +#include <isa-level.h>
> > +
> > +#if !defined USE_MULTIARCH && MINIMUM_X86_ISA_LEVEL >= 2
> > +# include "multiarch/strpbrk-generic.c"
> > +#endif
> > diff --git a/sysdeps/x86_64/strpbrk.c b/sysdeps/x86_64/strpbrk.c
> > new file mode 100644
> > index 0000000000..e7ea1b334a
> > --- /dev/null
> > +++ b/sysdeps/x86_64/strpbrk.c
> > @@ -0,0 +1,27 @@
> > +/* strpbrk hook for non-multiarch and RTLD build.
> > + 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/>. */
> > +
> > +#include <isa-level.h>
> > +
> > +#if MINIMUM_X86_ISA_LEVEL == 1
> > +#include <string/strpbrk.c>
> > +#else
> > +#define STRPBRK strpbrk
> > +#include "multiarch/strpbrk-sse4.c"
> > +libc_hidden_builtin_def (strpbrk)
> > +#endif
> > diff --git a/sysdeps/x86_64/strspn-generic.c b/sysdeps/x86_64/strspn-generic.c
> > new file mode 100644
> > index 0000000000..0730972bbd
> > --- /dev/null
> > +++ b/sysdeps/x86_64/strspn-generic.c
> > @@ -0,0 +1,23 @@
>
> Need a comment for its purpose.
Done in V2.
>
> > +/* 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/>. */
> > +
> > +
> > +#include <isa-level.h>
> > +
> > +#if !defined USE_MULTIARCH && MINIMUM_X86_ISA_LEVEL >= 2
> > +# include "multiarch/strspn-generic.c"
> > +#endif
> > diff --git a/sysdeps/x86_64/strspn.c b/sysdeps/x86_64/strspn.c
> > new file mode 100644
> > index 0000000000..7b9ede26d9
> > --- /dev/null
> > +++ b/sysdeps/x86_64/strspn.c
> > @@ -0,0 +1,27 @@
> > +/* strspn hook for non-multiarch and RTLD build.
> > + 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/>. */
> > +
> > +#include <isa-level.h>
> > +
> > +#if MINIMUM_X86_ISA_LEVEL == 1
> > +#include <string/strspn.c>
> > +#else
> > +#define STRSPN strspn
> > +#include "multiarch/strspn-sse4.c"
> > +libc_hidden_builtin_def (strspn)
> > +#endif
> > diff --git a/sysdeps/x86_64/varshift.c b/sysdeps/x86_64/varshift.c
> > new file mode 100644
> > index 0000000000..ab3c506378
> > --- /dev/null
> > +++ b/sysdeps/x86_64/varshift.c
> > @@ -0,0 +1,23 @@
> > +/* 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/>. */
> > +
> > +
> > +#include <isa-level.h>
> > +
> > +#if !defined USE_MULTIARCH && MINIMUM_X86_ISA_LEVEL >= 2
> > +# include "multiarch/varshift.c"
> > +#endif
> > --
> > 2.34.1
> >
>
>
> --
> H.J.
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