[v2,2/2] x86: Add support for building str{c|p}{brk|spn} with explicit ISA level

  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 >= 2.

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 |  6 +++++
 sysdeps/x86_64/multiarch/ifunc-sse4_2.h    |  2 +-
 sysdeps/x86_64/multiarch/rtld-strcspn.c    | 18 +++++++++++++++
 sysdeps/x86_64/multiarch/strcspn-generic.c |  6 +++--
 sysdeps/x86_64/multiarch/strcspn-sse4.c    |  6 +++--
 sysdeps/x86_64/multiarch/strpbrk-generic.c |  5 +++-
 sysdeps/x86_64/multiarch/strpbrk-sse4.c    |  6 ++++-
 sysdeps/x86_64/multiarch/strspn-generic.c  |  7 ++++--
 sysdeps/x86_64/multiarch/strspn-sse4.c     |  5 +++-
 sysdeps/x86_64/strcspn-generic.c           | 25 ++++++++++++++++++++
 sysdeps/x86_64/strcspn.c                   | 27 ++++++++++++++++++++++
 sysdeps/x86_64/strpbrk-generic.c           | 25 ++++++++++++++++++++
 sysdeps/x86_64/strpbrk.c                   | 27 ++++++++++++++++++++++
 sysdeps/x86_64/strspn-generic.c            | 26 +++++++++++++++++++++
 sysdeps/x86_64/strspn.c                    | 27 ++++++++++++++++++++++
 sysdeps/x86_64/varshift.c                  | 26 +++++++++++++++++++++
 17 files changed, 242 insertions(+), 11 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
  

On Wed, Jun 29, 2022 at 3:05 PM 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 >= 2.
>
> 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 |  6 +++++
>  sysdeps/x86_64/multiarch/ifunc-sse4_2.h    |  2 +-
>  sysdeps/x86_64/multiarch/rtld-strcspn.c    | 18 +++++++++++++++
>  sysdeps/x86_64/multiarch/strcspn-generic.c |  6 +++--
>  sysdeps/x86_64/multiarch/strcspn-sse4.c    |  6 +++--
>  sysdeps/x86_64/multiarch/strpbrk-generic.c |  5 +++-
>  sysdeps/x86_64/multiarch/strpbrk-sse4.c    |  6 ++++-
>  sysdeps/x86_64/multiarch/strspn-generic.c  |  7 ++++--
>  sysdeps/x86_64/multiarch/strspn-sse4.c     |  5 +++-
>  sysdeps/x86_64/strcspn-generic.c           | 25 ++++++++++++++++++++
>  sysdeps/x86_64/strcspn.c                   | 27 ++++++++++++++++++++++
>  sysdeps/x86_64/strpbrk-generic.c           | 25 ++++++++++++++++++++
>  sysdeps/x86_64/strpbrk.c                   | 27 ++++++++++++++++++++++
>  sysdeps/x86_64/strspn-generic.c            | 26 +++++++++++++++++++++
>  sysdeps/x86_64/strspn.c                    | 27 ++++++++++++++++++++++
>  sysdeps/x86_64/varshift.c                  | 26 +++++++++++++++++++++
>  17 files changed, 242 insertions(+), 11 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..e597a4855f 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
>  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 0d28319905..6c03f53a8b 100644
> --- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> +++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> @@ -531,6 +531,8 @@ __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))
> @@ -607,6 +609,8 @@ __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))
> @@ -614,6 +618,8 @@ __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))
> diff --git a/sysdeps/x86_64/multiarch/ifunc-sse4_2.h b/sysdeps/x86_64/multiarch/ifunc-sse4_2.h
> index 973041d23b..f8943c8210 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_ARCH_P
>       (cpu_features, Slow_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..86cda7b037 100644
> --- a/sysdeps/x86_64/multiarch/strcspn-generic.c
> +++ b/sysdeps/x86_64/multiarch/strcspn-generic.c
> @@ -16,8 +16,10 @@
>     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
>
> 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..058f635774 100644
> --- a/sysdeps/x86_64/multiarch/strpbrk-generic.c
> +++ b/sysdeps/x86_64/multiarch/strpbrk-generic.c
> @@ -16,8 +16,11 @@
>     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
>  # include <sysdep.h>
>  # define STRPBRK __strpbrk_generic
>
> 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..0f485ab4da 100644
> --- a/sysdeps/x86_64/multiarch/strspn-generic.c
> +++ b/sysdeps/x86_64/multiarch/strspn-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 strspn-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 STRSPN __strspn_generic
>
>  # undef libc_hidden_builtin_def
>  # define libc_hidden_builtin_def(STRSPN)
> +
>  #endif
>
>  #include <string/strspn.c>
> diff --git a/sysdeps/x86_64/multiarch/strspn-sse4.c b/sysdeps/x86_64/multiarch/strspn-sse4.c
> index d044916688..4d50507a0d 100644
> --- a/sysdeps/x86_64/multiarch/strspn-sse4.c
> +++ b/sysdeps/x86_64/multiarch/strspn-sse4.c
> @@ -53,10 +53,13 @@
>
>  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..51fd70b63d
> --- /dev/null
> +++ b/sysdeps/x86_64/strcspn-generic.c
> @@ -0,0 +1,25 @@
> +/* Hook for build strcspn-generic for non-multiarch build.  Needed for
> +   the ISA level >= 2 because strcspn-sse4 has a dependency on
> +   strcspn-generic.
> +   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 >= 2
> +# 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..a7d8b11216
> --- /dev/null
> +++ b/sysdeps/x86_64/strpbrk-generic.c
> @@ -0,0 +1,25 @@
> +/* Hook for build strpbrk-generic for non-multiarch build.  Needed for
> +   the ISA level >= 2 because strpbrk-sse4 has a dependency on
> +   strpbrk-generic.
> +   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 >= 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..1a2a576e49
> --- /dev/null
> +++ b/sysdeps/x86_64/strspn-generic.c
> @@ -0,0 +1,26 @@
> +/* Hook for build strspn-generic for non-multiarch build.  Needed for
> +   the ISA level >= 2 because strspn-sse4 has a dependency on
> +   strspn-generic.
> +   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 >= 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..8f9eb13547
> --- /dev/null
> +++ b/sysdeps/x86_64/varshift.c
> @@ -0,0 +1,26 @@
> +/* Hook for build varshift for non-multiarch build.  Needed for the
> +   ISA level >= 2 because strspn-sse4, strcspn-sse4, and strpbrk-sse4
> +   all have a dependency on varshift.c.
> +   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 >= 2
> +# include "multiarch/varshift.c"
> +#endif
> --
> 2.34.1
>

LGTM.

Thanks.
  

On Wed, Jun 29, 2022 at 3:16 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Wed, Jun 29, 2022 at 3:05 PM 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 >= 2.
> >
> > 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 |  6 +++++
> >  sysdeps/x86_64/multiarch/ifunc-sse4_2.h    |  2 +-
> >  sysdeps/x86_64/multiarch/rtld-strcspn.c    | 18 +++++++++++++++
> >  sysdeps/x86_64/multiarch/strcspn-generic.c |  6 +++--
> >  sysdeps/x86_64/multiarch/strcspn-sse4.c    |  6 +++--
> >  sysdeps/x86_64/multiarch/strpbrk-generic.c |  5 +++-
> >  sysdeps/x86_64/multiarch/strpbrk-sse4.c    |  6 ++++-
> >  sysdeps/x86_64/multiarch/strspn-generic.c  |  7 ++++--
> >  sysdeps/x86_64/multiarch/strspn-sse4.c     |  5 +++-
> >  sysdeps/x86_64/strcspn-generic.c           | 25 ++++++++++++++++++++
> >  sysdeps/x86_64/strcspn.c                   | 27 ++++++++++++++++++++++
> >  sysdeps/x86_64/strpbrk-generic.c           | 25 ++++++++++++++++++++
> >  sysdeps/x86_64/strpbrk.c                   | 27 ++++++++++++++++++++++
> >  sysdeps/x86_64/strspn-generic.c            | 26 +++++++++++++++++++++
> >  sysdeps/x86_64/strspn.c                    | 27 ++++++++++++++++++++++
> >  sysdeps/x86_64/varshift.c                  | 26 +++++++++++++++++++++
> >  17 files changed, 242 insertions(+), 11 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..e597a4855f 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
> >  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 0d28319905..6c03f53a8b 100644
> > --- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> > +++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> > @@ -531,6 +531,8 @@ __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))
> > @@ -607,6 +609,8 @@ __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))
> > @@ -614,6 +618,8 @@ __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))
> > diff --git a/sysdeps/x86_64/multiarch/ifunc-sse4_2.h b/sysdeps/x86_64/multiarch/ifunc-sse4_2.h
> > index 973041d23b..f8943c8210 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_ARCH_P
> >       (cpu_features, Slow_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..86cda7b037 100644
> > --- a/sysdeps/x86_64/multiarch/strcspn-generic.c
> > +++ b/sysdeps/x86_64/multiarch/strcspn-generic.c
> > @@ -16,8 +16,10 @@
> >     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
> >
> > 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..058f635774 100644
> > --- a/sysdeps/x86_64/multiarch/strpbrk-generic.c
> > +++ b/sysdeps/x86_64/multiarch/strpbrk-generic.c
> > @@ -16,8 +16,11 @@
> >     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
> >  # include <sysdep.h>
> >  # define STRPBRK __strpbrk_generic
> >
> > 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..0f485ab4da 100644
> > --- a/sysdeps/x86_64/multiarch/strspn-generic.c
> > +++ b/sysdeps/x86_64/multiarch/strspn-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 strspn-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 STRSPN __strspn_generic
> >
> >  # undef libc_hidden_builtin_def
> >  # define libc_hidden_builtin_def(STRSPN)
> > +
> >  #endif
> >
> >  #include <string/strspn.c>
> > diff --git a/sysdeps/x86_64/multiarch/strspn-sse4.c b/sysdeps/x86_64/multiarch/strspn-sse4.c
> > index d044916688..4d50507a0d 100644
> > --- a/sysdeps/x86_64/multiarch/strspn-sse4.c
> > +++ b/sysdeps/x86_64/multiarch/strspn-sse4.c
> > @@ -53,10 +53,13 @@
> >
> >  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..51fd70b63d
> > --- /dev/null
> > +++ b/sysdeps/x86_64/strcspn-generic.c
> > @@ -0,0 +1,25 @@
> > +/* Hook for build strcspn-generic for non-multiarch build.  Needed for
> > +   the ISA level >= 2 because strcspn-sse4 has a dependency on
> > +   strcspn-generic.
> > +   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 >= 2
> > +# 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..a7d8b11216
> > --- /dev/null
> > +++ b/sysdeps/x86_64/strpbrk-generic.c
> > @@ -0,0 +1,25 @@
> > +/* Hook for build strpbrk-generic for non-multiarch build.  Needed for
> > +   the ISA level >= 2 because strpbrk-sse4 has a dependency on
> > +   strpbrk-generic.
> > +   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 >= 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..1a2a576e49
> > --- /dev/null
> > +++ b/sysdeps/x86_64/strspn-generic.c
> > @@ -0,0 +1,26 @@
> > +/* Hook for build strspn-generic for non-multiarch build.  Needed for
> > +   the ISA level >= 2 because strspn-sse4 has a dependency on
> > +   strspn-generic.
> > +   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 >= 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..8f9eb13547
> > --- /dev/null
> > +++ b/sysdeps/x86_64/varshift.c
> > @@ -0,0 +1,26 @@
> > +/* Hook for build varshift for non-multiarch build.  Needed for the
> > +   ISA level >= 2 because strspn-sse4, strcspn-sse4, and strpbrk-sse4
> > +   all have a dependency on varshift.c.
> > +   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 >= 2
> > +# include "multiarch/varshift.c"
> > +#endif
> > --
> > 2.34.1
> >
>
> LGTM.
>
> Thanks.
>
> --
> H.J.

Rebsubmitted in V5 after rebase ontop of:

commit 0aa294fb887bb5aae4cdfa4b764325466a329131
Author: Noah Goldstein <goldstein.w.n@gmail.com>
Date:   Wed Jun 29 18:56:17 2022 -0700

    x86: Add missing IS_IN (libc) check to strcspn-sse4.c
  

On Wed, Jun 29, 2022 at 8:11 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> On Wed, Jun 29, 2022 at 3:16 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> >
> > On Wed, Jun 29, 2022 at 3:05 PM 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 >= 2.
> > >
> > > 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 |  6 +++++
> > >  sysdeps/x86_64/multiarch/ifunc-sse4_2.h    |  2 +-
> > >  sysdeps/x86_64/multiarch/rtld-strcspn.c    | 18 +++++++++++++++
> > >  sysdeps/x86_64/multiarch/strcspn-generic.c |  6 +++--
> > >  sysdeps/x86_64/multiarch/strcspn-sse4.c    |  6 +++--
> > >  sysdeps/x86_64/multiarch/strpbrk-generic.c |  5 +++-
> > >  sysdeps/x86_64/multiarch/strpbrk-sse4.c    |  6 ++++-
> > >  sysdeps/x86_64/multiarch/strspn-generic.c  |  7 ++++--
> > >  sysdeps/x86_64/multiarch/strspn-sse4.c     |  5 +++-
> > >  sysdeps/x86_64/strcspn-generic.c           | 25 ++++++++++++++++++++
> > >  sysdeps/x86_64/strcspn.c                   | 27 ++++++++++++++++++++++
> > >  sysdeps/x86_64/strpbrk-generic.c           | 25 ++++++++++++++++++++
> > >  sysdeps/x86_64/strpbrk.c                   | 27 ++++++++++++++++++++++
> > >  sysdeps/x86_64/strspn-generic.c            | 26 +++++++++++++++++++++
> > >  sysdeps/x86_64/strspn.c                    | 27 ++++++++++++++++++++++
> > >  sysdeps/x86_64/varshift.c                  | 26 +++++++++++++++++++++
> > >  17 files changed, 242 insertions(+), 11 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..e597a4855f 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
> > >  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 0d28319905..6c03f53a8b 100644
> > > --- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> > > +++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> > > @@ -531,6 +531,8 @@ __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))
> > > @@ -607,6 +609,8 @@ __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))
> > > @@ -614,6 +618,8 @@ __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))
> > > diff --git a/sysdeps/x86_64/multiarch/ifunc-sse4_2.h b/sysdeps/x86_64/multiarch/ifunc-sse4_2.h
> > > index 973041d23b..f8943c8210 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_ARCH_P
> > >       (cpu_features, Slow_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..86cda7b037 100644
> > > --- a/sysdeps/x86_64/multiarch/strcspn-generic.c
> > > +++ b/sysdeps/x86_64/multiarch/strcspn-generic.c
> > > @@ -16,8 +16,10 @@
> > >     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
> > >
> > > 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..058f635774 100644
> > > --- a/sysdeps/x86_64/multiarch/strpbrk-generic.c
> > > +++ b/sysdeps/x86_64/multiarch/strpbrk-generic.c
> > > @@ -16,8 +16,11 @@
> > >     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
> > >  # include <sysdep.h>
> > >  # define STRPBRK __strpbrk_generic
> > >
> > > 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..0f485ab4da 100644
> > > --- a/sysdeps/x86_64/multiarch/strspn-generic.c
> > > +++ b/sysdeps/x86_64/multiarch/strspn-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 strspn-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 STRSPN __strspn_generic
> > >
> > >  # undef libc_hidden_builtin_def
> > >  # define libc_hidden_builtin_def(STRSPN)
> > > +
> > >  #endif
> > >
> > >  #include <string/strspn.c>
> > > diff --git a/sysdeps/x86_64/multiarch/strspn-sse4.c b/sysdeps/x86_64/multiarch/strspn-sse4.c
> > > index d044916688..4d50507a0d 100644
> > > --- a/sysdeps/x86_64/multiarch/strspn-sse4.c
> > > +++ b/sysdeps/x86_64/multiarch/strspn-sse4.c
> > > @@ -53,10 +53,13 @@
> > >
> > >  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..51fd70b63d
> > > --- /dev/null
> > > +++ b/sysdeps/x86_64/strcspn-generic.c
> > > @@ -0,0 +1,25 @@
> > > +/* Hook for build strcspn-generic for non-multiarch build.  Needed for
> > > +   the ISA level >= 2 because strcspn-sse4 has a dependency on
> > > +   strcspn-generic.
> > > +   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 >= 2
> > > +# 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..a7d8b11216
> > > --- /dev/null
> > > +++ b/sysdeps/x86_64/strpbrk-generic.c
> > > @@ -0,0 +1,25 @@
> > > +/* Hook for build strpbrk-generic for non-multiarch build.  Needed for
> > > +   the ISA level >= 2 because strpbrk-sse4 has a dependency on
> > > +   strpbrk-generic.
> > > +   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 >= 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..1a2a576e49
> > > --- /dev/null
> > > +++ b/sysdeps/x86_64/strspn-generic.c
> > > @@ -0,0 +1,26 @@
> > > +/* Hook for build strspn-generic for non-multiarch build.  Needed for
> > > +   the ISA level >= 2 because strspn-sse4 has a dependency on
> > > +   strspn-generic.
> > > +   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 >= 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..8f9eb13547
> > > --- /dev/null
> > > +++ b/sysdeps/x86_64/varshift.c
> > > @@ -0,0 +1,26 @@
> > > +/* Hook for build varshift for non-multiarch build.  Needed for the
> > > +   ISA level >= 2 because strspn-sse4, strcspn-sse4, and strpbrk-sse4
> > > +   all have a dependency on varshift.c.
> > > +   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 >= 2
> > > +# include "multiarch/varshift.c"
> > > +#endif
> > > --
> > > 2.34.1
> > >
> >
> > LGTM.
> >
> > Thanks.
> >
> > --
> > H.J.
>
> Rebsubmitted in V5 after rebase ontop of:
>
> commit 0aa294fb887bb5aae4cdfa4b764325466a329131
> Author: Noah Goldstein <goldstein.w.n@gmail.com>
> Date:   Wed Jun 29 18:56:17 2022 -0700
>
>     x86: Add missing IS_IN (libc) check to strcspn-sse4.c

There is an issue with this patch. Ignore it.