Loongarch: Add ifunc support for strchr{aligned, lsx, lasx} and strchrnul{aligned, lsx, lasx}

These implementations improve the time to run strchr{nul}
microbenchmark in glibc as below:
strchr-lasx       reduces the runtime about 50%-83%
strchr-lsx        reduces the runtime about 30%-67%
strchr-aligned    reduces the runtime about 10%-20%
strchrnul-lasx    reduces the runtime about 50%-83%
strchrnul-lsx     reduces the runtime about 36%-65%
strchrnul-aligned reduces the runtime about 6%-10%

12 files changed, 581 insertions, 0 deletions

diff --git a/sysdeps/loongarch/lp64/multiarch/Makefile b/sysdeps/loongarch/lp64/multiarch/Makefile
index 76c506c..110a8c5 100644
--- a/sysdeps/loongarch/lp64/multiarch/Makefile
+++ b/sysdeps/loongarch/lp64/multiarch/Makefile
@@ -3,5 +3,11 @@ sysdep_routines += \
   strlen-aligned \
   strlen-lsx \
   strlen-lasx \
+  strchr-aligned \
+  strchr-lsx \
+  strchr-lasx \
+  strchrnul-aligned \
+  strchrnul-lsx \
+  strchrnul-lasx \
 # sysdep_routines
 endif
diff --git a/sysdeps/loongarch/lp64/multiarch/ifunc-impl-list.c b/sysdeps/loongarch/lp64/multiarch/ifunc-impl-list.c
index 1a2a576f..c7164b4 100644
--- a/sysdeps/loongarch/lp64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/loongarch/lp64/multiarch/ifunc-impl-list.c
@@ -37,5 +37,21 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 #endif
 	      IFUNC_IMPL_ADD (array, i, strlen, 1, __strlen_aligned)
 	      )
+
+  IFUNC_IMPL (i, name, strchr,
+#if !defined __loongarch_soft_float
+	      IFUNC_IMPL_ADD (array, i, strchr, SUPPORT_LASX, __strchr_lasx)
+	      IFUNC_IMPL_ADD (array, i, strchr, SUPPORT_LSX, __strchr_lsx)
+#endif
+	      IFUNC_IMPL_ADD (array, i, strchr, 1, __strchr_aligned)
+	      )
+
+  IFUNC_IMPL (i, name, strchrnul,
+#if !defined __loongarch_soft_float
+	      IFUNC_IMPL_ADD (array, i, strchrnul, SUPPORT_LASX, __strchrnul_lasx)
+	      IFUNC_IMPL_ADD (array, i, strchrnul, SUPPORT_LSX, __strchrnul_lsx)
+#endif
+	      IFUNC_IMPL_ADD (array, i, strchrnul, 1, __strchrnul_aligned)
+	      )
   return i;
 }
diff --git a/sysdeps/loongarch/lp64/multiarch/ifunc-strchr.h b/sysdeps/loongarch/lp64/multiarch/ifunc-strchr.h
new file mode 100644
index 0000000..4494db7
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/ifunc-strchr.h
@@ -0,0 +1,41 @@
+/* Common definition for strchr ifunc selections.
+   All versions must be listed in ifunc-impl-list.c.
+   Copyright (C) 2023 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 <ldsodefs.h>
+#include <ifunc-init.h>
+
+#if !defined __loongarch_soft_float
+extern __typeof (REDIRECT_NAME) OPTIMIZE (lasx) attribute_hidden;
+extern __typeof (REDIRECT_NAME) OPTIMIZE (lsx) attribute_hidden;
+#endif
+
+extern __typeof (REDIRECT_NAME) OPTIMIZE (aligned) attribute_hidden;
+
+static inline void *
+IFUNC_SELECTOR (void)
+{
+#if !defined __loongarch_soft_float
+  if (SUPPORT_LASX)
+    return OPTIMIZE (lasx);
+  else if (SUPPORT_LSX)
+    return OPTIMIZE (lsx);
+  else
+#endif
+    return OPTIMIZE (aligned);
+}
diff --git a/sysdeps/loongarch/lp64/multiarch/ifunc-strchrnul.h b/sysdeps/loongarch/lp64/multiarch/ifunc-strchrnul.h
new file mode 100644
index 0000000..8a92512
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/ifunc-strchrnul.h
@@ -0,0 +1,41 @@
+/* Common definition for strchrnul ifunc selections.
+   All versions must be listed in ifunc-impl-list.c.
+   Copyright (C) 2023 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 <ldsodefs.h>
+#include <ifunc-init.h>
+
+#if !defined __loongarch_soft_float
+extern __typeof (REDIRECT_NAME) OPTIMIZE (lasx) attribute_hidden;
+extern __typeof (REDIRECT_NAME) OPTIMIZE (lsx) attribute_hidden;
+#endif
+
+extern __typeof (REDIRECT_NAME) OPTIMIZE (aligned) attribute_hidden;
+
+static inline void *
+IFUNC_SELECTOR (void)
+{
+#if !defined __loongarch_soft_float
+  if (SUPPORT_LASX)
+    return OPTIMIZE (lasx);
+  else if (SUPPORT_LSX)
+    return OPTIMIZE (lsx);
+  else
+#endif
+    return OPTIMIZE (aligned);
+}
diff --git a/sysdeps/loongarch/lp64/multiarch/strchr-aligned.S b/sysdeps/loongarch/lp64/multiarch/strchr-aligned.S
new file mode 100644
index 0000000..5fb0180
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strchr-aligned.S
@@ -0,0 +1,99 @@
+/* Optimized strchr implementation using basic Loongarch instructions.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+#include <sys/regdef.h>
+#include <sys/asm.h>
+
+#if IS_IN (libc)
+# define STRCHR_NAME __strchr_aligned
+#else
+# define STRCHR_NAME strchr
+#endif
+
+LEAF(STRCHR_NAME, 6)
+    slli.d      t1, a0, 3
+    bstrins.d   a0, zero, 2, 0
+    lu12i.w     a2, 0x01010
+    ld.d        t2, a0, 0
+
+    ori         a2, a2, 0x101
+    andi        a1, a1, 0xff
+    bstrins.d   a2, a2, 63, 32
+    li.w        t0, -1
+
+    mul.d       a1, a1, a2
+    sll.d       t0, t0, t1
+    slli.d      a3, a2, 7
+    orn         t2, t2, t0
+
+    sll.d       t3, a1, t1
+    xor         t4, t2, t3
+    sub.d       a4, t2, a2
+    sub.d       a5, t4, a2
+
+
+    andn        a4, a4, t2
+    andn        a5, a5, t4
+    or          t0, a4, a5
+    and         t0, t0, a3
+
+    bnez        t0, L(end)
+    addi.d      a0, a0, 8
+L(loop):
+    ld.d        t4, a0, 0
+    xor         t2, t4, a1
+
+    sub.d       a4, t4, a2
+    sub.d       a5, t2, a2
+    andn        a4, a4, t4
+    andn        a5, a5, t2
+
+    or          t0, a4, a5
+    and         t0, t0, a3
+    bnez        t0, L(end)
+    ld.d        t4, a0, 8
+
+
+    addi.d      a0, a0, 16
+    xor         t2, t4, a1
+    sub.d       a4, t4, a2
+    sub.d       a5, t2, a2
+
+    andn        a4, a4, t4
+    andn        a5, a5, t2
+    or          t0, a4, a5
+    and         t0, t0, a3
+
+    beqz        t0, L(loop)
+    addi.d      a0, a0, -8
+L(end):
+    and         t0, a5, a3
+    and         t1, a4, a3
+
+    ctz.d       t0, t0
+    ctz.d       t1, t1
+    srli.w      t2, t0, 3
+    sltu        t3, t1, t0
+
+
+    add.d       a0, a0, t2
+    masknez     a0, a0, t3
+    jr          ra
+END(STRCHR_NAME)
diff --git a/sysdeps/loongarch/lp64/multiarch/strchr-lasx.S b/sysdeps/loongarch/lp64/multiarch/strchr-lasx.S
new file mode 100644
index 0000000..254402d
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strchr-lasx.S
@@ -0,0 +1,91 @@
+/* Optimized strchr implementation using loongarch LASX SIMD instructions.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+#include <sys/regdef.h>
+#include <sys/asm.h>
+
+#if IS_IN (libc) && !defined __loongarch_soft_float
+
+#ifndef AS_STRCHRNUL
+# define STRCHR __strchr_lasx
+#endif
+
+LEAF(STRCHR, 6)
+    andi            t1, a0, 0x1f
+    bstrins.d       a0, zero, 4, 0
+    xvld            xr0, a0, 0
+    li.d            t2, -1
+
+    xvreplgr2vr.b   xr1, a1
+    sll.d           t1, t2, t1
+    xvxor.v         xr2, xr0, xr1
+    xvmin.bu        xr0, xr0, xr2
+
+    xvmsknz.b       xr0, xr0
+    xvpickve.w      xr3, xr0, 4
+    vilvl.h         vr0, vr3, vr0
+    movfr2gr.s      t0, fa0
+
+    orn             t0, t0, t1
+    bne             t0, t2, L(end)
+    addi.d          a0, a0, 32
+    nop
+
+
+L(loop):
+    xvld            xr0, a0, 0
+    xvxor.v         xr2, xr0, xr1
+    xvmin.bu        xr0, xr0, xr2
+    xvsetanyeqz.b   fcc0, xr0
+
+    bcnez           fcc0, L(loop_end)
+    xvld            xr0, a0, 32
+    addi.d          a0, a0, 64
+    xvxor.v         xr2, xr0, xr1
+
+    xvmin.bu        xr0, xr0, xr2
+    xvsetanyeqz.b   fcc0, xr0
+    bceqz           fcc0, L(loop)
+    addi.d          a0, a0, -32
+
+L(loop_end):
+    xvmsknz.b       xr0, xr0
+    xvpickve.w      xr1, xr0, 4
+    vilvl.h         vr0, vr1, vr0
+    movfr2gr.s      t0, fa0
+
+
+L(end):
+    cto.w           t0, t0
+    add.d           a0, a0, t0
+#ifndef AS_STRCHRNUL
+    vreplgr2vr.b    vr0, t0
+    xvpermi.q       xr3, xr2, 1
+
+    vshuf.b         vr0, vr3, vr2, vr0
+    vpickve2gr.bu   t0, vr0, 0
+    masknez         a0, a0, t0
+#endif
+    jr              ra
+
+END(STRCHR)
+
+libc_hidden_builtin_def(STRCHR)
+#endif
diff --git a/sysdeps/loongarch/lp64/multiarch/strchr-lsx.S b/sysdeps/loongarch/lp64/multiarch/strchr-lsx.S
new file mode 100644
index 0000000..dae98b0
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strchr-lsx.S
@@ -0,0 +1,73 @@
+/* Optimized strlen implementation using loongarch LSX SIMD instructions.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+#include <sys/regdef.h>
+#include <sys/asm.h>
+
+#if IS_IN (libc) && !defined __loongarch_soft_float
+
+#ifndef AS_STRCHRNUL
+# define STRCHR __strchr_lsx
+#endif
+
+LEAF(STRCHR, 6)
+    andi            t1, a0, 0xf
+    bstrins.d       a0, zero, 3, 0
+    vld             vr0, a0, 0
+    li.d            t2, -1
+
+    vreplgr2vr.b    vr1, a1
+    sll.d           t3, t2, t1
+    vxor.v          vr2, vr0, vr1
+    vmin.bu         vr0, vr0, vr2
+
+    vmsknz.b        vr0, vr0
+    movfr2gr.s      t0, fa0
+    ext.w.h         t0, t0
+    orn             t0, t0, t3
+
+    beq             t0, t2, L(loop)
+L(found):
+    cto.w           t0, t0
+    add.d           a0, a0, t0
+#ifndef AS_STRCHRNUL
+    vreplve.b       vr2, vr2, t0
+    vpickve2gr.bu   t1, vr2, 0
+    masknez         a0, a0, t1
+#endif
+    jr              ra
+
+
+L(loop):
+    vld             vr0, a0, 16
+    addi.d          a0, a0, 16
+    vxor.v          vr2, vr0, vr1
+    vmin.bu         vr0, vr0, vr2
+
+    vsetanyeqz.b    fcc0, vr0
+    bceqz           fcc0, L(loop)
+    vmsknz.b        vr0, vr0
+    movfr2gr.s      t0, fa0
+
+    b               L(found)
+END(STRCHR)
+
+libc_hidden_builtin_def (STRCHR)
+#endif
diff --git a/sysdeps/loongarch/lp64/multiarch/strchr.c b/sysdeps/loongarch/lp64/multiarch/strchr.c
new file mode 100644
index 0000000..404e97b
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strchr.c
@@ -0,0 +1,36 @@
+/* Multiple versions of strchr.
+   All versions must be listed in ifunc-impl-list.c.
+   Copyright (C) 2023 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/>.  */
+
+/* Define multiple versions only for the definition in libc.  */
+#if IS_IN (libc)
+# define strchr __redirect_strchr
+# include <string.h>
+# undef strchr
+
+# define SYMBOL_NAME strchr
+# include "ifunc-strchr.h"
+
+libc_ifunc_redirected (__redirect_strchr, strchr, IFUNC_SELECTOR ());
+weak_alias(strchr, index)
+# ifdef SHARED
+__hidden_ver1 (strchr, __GI_strchr, __redirect_strchr)
+  __attribute__ ((visibility ("hidden"))) __attribute_copy__ (strchr);
+# endif
+
+#endif
diff --git a/sysdeps/loongarch/lp64/multiarch/strchrnul-aligned.S b/sysdeps/loongarch/lp64/multiarch/strchrnul-aligned.S
new file mode 100644
index 0000000..1c01a02
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strchrnul-aligned.S
@@ -0,0 +1,95 @@
+/* Optimized strchrnul implementation using basic Loongarch instructions.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+#include <sys/regdef.h>
+#include <sys/asm.h>
+
+#if IS_IN (libc)
+# define STRCHRNUL_NAME __strchrnul_aligned
+#else
+# define STRCHRNUL_NAME __strchrnul
+#endif
+
+LEAF(STRCHRNUL_NAME, 6)
+    slli.d      t1, a0, 3
+    bstrins.d   a0, zero, 2, 0
+    lu12i.w     a2, 0x01010
+    ld.d        t2, a0, 0
+
+    ori         a2, a2, 0x101
+    andi        a1, a1, 0xff
+    bstrins.d   a2, a2, 63, 32
+    li.w        t0, -1
+
+    mul.d       a1, a1, a2
+    sll.d       t0, t0, t1
+    slli.d      a3, a2, 7
+    orn         t2, t2, t0
+
+    sll.d       t3, a1, t1
+    xor         t4, t2, t3
+    sub.d       a4, t2, a2
+    sub.d       a5, t4, a2
+
+
+    andn        a4, a4, t2
+    andn        a5, a5, t4
+    or          t0, a4, a5
+    and         t0, t0, a3
+
+    bnez        t0, L(end)
+    addi.d      a0, a0, 8
+L(loop):
+    ld.d        t4, a0, 0
+    xor         t2, t4, a1
+
+    sub.d       a4, t4, a2
+    sub.d       a5, t2, a2
+    andn        a4, a4, t4
+    andn        a5, a5, t2
+
+    or          t0, a4, a5
+    and         t0, t0, a3
+    bnez        t0, L(end)
+    ld.d        t4, a0, 8
+
+
+    addi.d      a0, a0, 16
+    xor         t2, t4, a1
+    sub.d       a4, t4, a2
+    sub.d       a5, t2, a2
+
+    andn        a4, a4, t4
+    andn        a5, a5, t2
+    or          t0, a4, a5
+    and         t0, t0, a3
+
+    beqz        t0, L(loop)
+    addi.d      a0, a0, -8
+L(end):
+    ctz.d       t0, t0
+    srli.w      t0, t0, 3
+
+
+    add.d       a0, a0, t0
+    jr          ra
+END(STRCHRNUL_NAME)
+
+libc_hidden_builtin_def (STRCHRNUL_NAME)
diff --git a/sysdeps/loongarch/lp64/multiarch/strchrnul-lasx.S b/sysdeps/loongarch/lp64/multiarch/strchrnul-lasx.S
new file mode 100644
index 0000000..d45495e
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strchrnul-lasx.S
@@ -0,0 +1,22 @@
+/* Optimized strchrnul implementation using loongarch LASX SIMD instructions.
+   Copyright (C) 2023 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/>.  */
+
+#define STRCHR __strchrnul_lasx
+#define AS_STRCHRNUL
+#include "strchr-lasx.S"
diff --git a/sysdeps/loongarch/lp64/multiarch/strchrnul-lsx.S b/sysdeps/loongarch/lp64/multiarch/strchrnul-lsx.S
new file mode 100644
index 0000000..07d793a
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strchrnul-lsx.S
@@ -0,0 +1,22 @@
+/* Optimized strchrnul implementation using loongarch LSX SIMD instructions.
+   Copyright (C) 2023 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/>.  */
+
+#define STRCHR __strchrnul_lsx
+#define AS_STRCHRNUL
+#include "strchr-lsx.S"
diff --git a/sysdeps/loongarch/lp64/multiarch/strchrnul.c b/sysdeps/loongarch/lp64/multiarch/strchrnul.c
new file mode 100644
index 0000000..f3b8296
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/strchrnul.c
@@ -0,0 +1,39 @@
+/* Multiple versions of strchrnul.
+   All versions must be listed in ifunc-impl-list.c.
+   Copyright (C) 2023 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
+   <http://www.gnu.org/licenses/>.  */
+
+/* Define multiple versions only for the definition in libc.  */
+
+#if IS_IN (libc)
+# define strchrnul __redirect_strchrnul
+# define __strchrnul __redirect___strchrnul
+# include <string.h>
+# undef __strchrnul
+# undef strchrnul
+
+# define SYMBOL_NAME strchrnul
+# include "ifunc-strchrnul.h"
+
+libc_ifunc_redirected (__redirect_strchrnul, __strchrnul,
+                       IFUNC_SELECTOR ());
+weak_alias (__strchrnul, strchrnul)
+# ifdef SHARED
+__hidden_ver1 (__strchrnul, __GI___strchrnul, __redirect_strchrnul)
+  __attribute__((visibility ("hidden"))) __attribute_copy__ (strchrnul);
+# endif
+#endif