powerpc : Add optimized memchr for POWER10

Optimized memchr for POWER10 based on existing rawmemchr and strlen.
Reordering instructions and loop unrolling helped in getting better performance.
Reviewed-by: Rajalakshmi Srinivasaraghavan <rajis@linux.ibm.com>

4 files changed, 52 insertions, 10 deletions

diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index d7824a922b..594fbb8058 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -31,10 +31,10 @@ sysdep_routines += memcpy-power8-cached memcpy-power7 memcpy-a2 memcpy-power6 \
 		   strncase-power8
 
 ifneq (,$(filter %le,$(config-machine)))
-sysdep_routines += memcmp-power10 memcpy-power10 memmove-power10 memset-power10 \
-		   rawmemchr-power9 rawmemchr-power10 \
-		   strcmp-power9 strcmp-power10 strncmp-power9 \
-		   strcpy-power9 stpcpy-power9 \
+sysdep_routines += memchr-power10 memcmp-power10 memcpy-power10 \
+		   memmove-power10 memset-power10 rawmemchr-power9 \
+		   rawmemchr-power10 strcmp-power9 strcmp-power10 \
+		   strncmp-power9 strcpy-power9 stpcpy-power9 \
 		   strlen-power9 strncpy-power9 stpncpy-power9 strlen-power10
 endif
 CFLAGS-strncase-power7.c += -mcpu=power7 -funroll-loops
diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
index 965dd17786..1a34629db9 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -226,6 +226,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
   /* Support sysdeps/powerpc/powerpc64/multiarch/memchr.c.  */
   IFUNC_IMPL (i, name, memchr,
+#ifdef __LITTLE_ENDIAN__
+	      IFUNC_IMPL_ADD (array, i, memchr,
+		              hwcap2 & PPC_FEATURE2_ARCH_3_1
+			      && hwcap & PPC_FEATURE_HAS_VSX,
+			      __memchr_power10)
+#endif
 	      IFUNC_IMPL_ADD (array, i, memchr,
 			      hwcap2 & PPC_FEATURE2_ARCH_2_07
 			      && hwcap & PPC_FEATURE_HAS_ALTIVEC,
diff --git a/sysdeps/powerpc/powerpc64/multiarch/memchr-power10.S b/sysdeps/powerpc/powerpc64/multiarch/memchr-power10.S
new file mode 100644
index 0000000000..b9ed792676
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/memchr-power10.S
@@ -0,0 +1,28 @@
+/* Optimized memchr implementation for POWER10/PPC64.
+   Copyright (C) 2016-2023 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/>.  */
+
+#if defined __LITTLE_ENDIAN__ && IS_IN (libc)
+#define MEMCHR __memchr_power10
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+#undef weak_alias
+#define weak_alias(name,alias)
+
+#include <sysdeps/powerpc/powerpc64/le/power10/memchr.S>
+#endif
diff --git a/sysdeps/powerpc/powerpc64/multiarch/memchr.c b/sysdeps/powerpc/powerpc64/multiarch/memchr.c
index a1a8f3eedd..dbb30fe51d 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/memchr.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/memchr.c
@@ -25,15 +25,23 @@ extern __typeof (__memchr) __memchr_ppc attribute_hidden;
 extern __typeof (__memchr) __memchr_power7 attribute_hidden;
 extern __typeof (__memchr) __memchr_power8 attribute_hidden;
 
+# ifdef __LITTLE_ENDIAN__
+extern __typeof (__memchr) __memchr_power10 attribute_hidden;
+# endif
 /* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
    ifunc symbol properly.  */
 libc_ifunc (__memchr,
-	    (hwcap2 & PPC_FEATURE2_ARCH_2_07
-	     && hwcap & PPC_FEATURE_HAS_ALTIVEC)
-	    ? __memchr_power8 :
-	    (hwcap & PPC_FEATURE_ARCH_2_06)
-            ? __memchr_power7
-            : __memchr_ppc);
+# ifdef __LITTLE_ENDIAN__
+	    (hwcap2 & PPC_FEATURE2_ARCH_3_1
+	     && hwcap & PPC_FEATURE_HAS_VSX)
+	    ? __memchr_power10 :
+# endif
+	      (hwcap2 & PPC_FEATURE2_ARCH_2_07
+	      && hwcap & PPC_FEATURE_HAS_ALTIVEC)
+	      ? __memchr_power8 :
+	        (hwcap & PPC_FEATURE_ARCH_2_06)
+	        ? __memchr_power7
+	        : __memchr_ppc);
 
 weak_alias (__memchr, memchr)
 libc_hidden_builtin_def (memchr)