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.

18 files changed, 247 insertions, 13 deletions

diff --git a/sysdeps/x86_64/Makefile b/sysdeps/x86_64/Makefile
index 79365af..e597a48 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 9e07283..b84acfe 100644
--- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
@@ -533,6 +533,8 @@ __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))
@@ -609,6 +611,8 @@ __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))
@@ -616,6 +620,8 @@ __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 f8b5693..9a819ee 100644
--- a/sysdeps/x86_64/multiarch/ifunc-sse4_2.h
+++ b/sysdeps/x86_64/multiarch/ifunc-sse4_2.h
@@ -33,7 +33,7 @@ IFUNC_SELECTOR (void)
      implementation its best to keep it regardless.  If an optimized
      fallback is added add a X86_ISA_CPU_FEATURE_ARCH_P (cpu_features,
      Slow_SSE4_2) check.  */
-  if (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 0000000..99e3c59
--- /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 423de2e..86cda7b 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 d11e87a..873a416 100644
--- a/sysdeps/x86_64/multiarch/strcspn-sse4.c
+++ b/sysdeps/x86_64/multiarch/strcspn-sse4.c
@@ -16,7 +16,8 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#if IS_IN (libc)
+#include <isa-level.h>
+#if IS_IN (libc) || MINIMUM_X86_ISA_LEVEL >= 2
 
 # include <nmmintrin.h>
 # include <string.h>
@@ -54,9 +55,11 @@
    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
@@ -80,7 +83,7 @@ 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 d31acfe..058f635 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 bf74d66..0adb577 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 6b50c36..0f485ab 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 d044916..4d50507 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/multiarch/varshift.c b/sysdeps/x86_64/multiarch/varshift.c
index 5e2f2bd..a98311d 100644
--- a/sysdeps/x86_64/multiarch/varshift.c
+++ b/sysdeps/x86_64/multiarch/varshift.c
@@ -16,7 +16,9 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#if IS_IN (libc)
+#include <isa-level.h>
+#if IS_IN (libc) || MINIMUM_X86_ISA_LEVEL >= 2
+
 # include <stdint.h>
 
 const int8_t ___m128i_shift_right[31] attribute_hidden
diff --git a/sysdeps/x86_64/strcspn-generic.c b/sysdeps/x86_64/strcspn-generic.c
new file mode 100644
index 0000000..51fd70b
--- /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 0000000..cd54eed
--- /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 0000000..a7d8b11
--- /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 0000000..e7ea1b3
--- /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 0000000..1a2a576e
--- /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 0000000..7b9ede2
--- /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 0000000..8f9eb13
--- /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