[PATCH v2 2/2] powerpc: Add optimized stpncpy for POWER9

Raphael Moreira Zinsly rzinsly@linux.ibm.com
Fri Sep 4 16:56:53 GMT 2020


Add stpncpy support into the POWER9 strncpy.
---
 sysdeps/powerpc/powerpc64/le/power9/stpncpy.S | 24 +++++++
 sysdeps/powerpc/powerpc64/le/power9/strncpy.S | 65 +++++++++++++++++++
 sysdeps/powerpc/powerpc64/multiarch/Makefile  |  2 +-
 .../powerpc64/multiarch/ifunc-impl-list.c     |  5 ++
 .../powerpc64/multiarch/stpncpy-power9.S      | 24 +++++++
 sysdeps/powerpc/powerpc64/multiarch/stpncpy.c |  7 ++
 6 files changed, 126 insertions(+), 1 deletion(-)
 create mode 100644 sysdeps/powerpc/powerpc64/le/power9/stpncpy.S
 create mode 100644 sysdeps/powerpc/powerpc64/multiarch/stpncpy-power9.S

diff --git a/sysdeps/powerpc/powerpc64/le/power9/stpncpy.S b/sysdeps/powerpc/powerpc64/le/power9/stpncpy.S
new file mode 100644
index 0000000000..81d9673d8b
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/le/power9/stpncpy.S
@@ -0,0 +1,24 @@
+/* Optimized stpncpy implementation for POWER9 LE.
+   Copyright (C) 2020 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 USE_AS_STPNCPY
+#include <sysdeps/powerpc/powerpc64/le/power9/strncpy.S>
+
+weak_alias (__stpncpy, stpncpy)
+libc_hidden_def (__stpncpy)
+libc_hidden_builtin_def (stpncpy)
diff --git a/sysdeps/powerpc/powerpc64/le/power9/strncpy.S b/sysdeps/powerpc/powerpc64/le/power9/strncpy.S
index 34fcdee913..f7265b11ec 100644
--- a/sysdeps/powerpc/powerpc64/le/power9/strncpy.S
+++ b/sysdeps/powerpc/powerpc64/le/power9/strncpy.S
@@ -18,16 +18,30 @@
 
 #include <sysdep.h>
 
+#ifdef USE_AS_STPNCPY
+# ifndef STPNCPY
+#   define FUNC_NAME __stpncpy
+# else
+#   define FUNC_NAME STPNCPY
+# endif
+#else
 # ifndef STRNCPY
 #  define FUNC_NAME strncpy
 # else
 #  define FUNC_NAME STRNCPY
 # endif
+#endif  /* !USE_AS_STPNCPY  */
 
 /* Implements the function
 
    char * [r3] strncpy (char *dest [r3], const char *src [r4], size_t n [r5])
 
+   or
+
+   char * [r3] stpncpy (char *dest [r3], const char *src [r4], size_t n [r5])
+
+   if USE_AS_STPNCPY is defined.
+
    The implementation can load bytes past a null terminator, but only
    up to the next 16-byte aligned address, so it never crosses a page.  */
 
@@ -49,7 +63,15 @@ ENTRY_TOCLESS (FUNC_NAME, 4)
 
 	/* Empty/1-byte string optimization  */
 	cmpdi	r5,0
+#ifdef USE_AS_STPNCPY
+	bgt	L(cont)
+	/* Compute pointer to last byte copied into dest.  */
+	addi	r3,r3,1
+	blr
+L(cont):
+#else
 	beqlr
+#endif
 
 	addi	r4,r4,1
 	neg	r7,r4
@@ -79,12 +101,20 @@ ENTRY_TOCLESS (FUNC_NAME, 4)
 	sldi	r10,r5,56	/* stxvl wants size in top 8 bits  */
 	stxvl	32+v0,r11,r10	/* Partial store  */
 
+#ifdef USE_AS_STPNCPY
+	/* Compute pointer to last byte copied into dest.  */
+	add	r3,r11,r5
+#endif
 	blr
 
 L(null):
 	sldi	r10,r8,56	/* stxvl wants size in top 8 bits  */
 	stxvl	32+v0,r11,r10	/* Partial store  */
 
+#ifdef USE_AS_STPNCPY
+	/* Compute pointer to last byte copied into dest.  */
+	add	r3,r11,r7
+#endif
 	add	r11,r11,r8
 	sub	r5,r5,r8
 	b L(zero_padding_loop)
@@ -168,6 +198,10 @@ L(n_tail4):
 	sldi	r10,r5,56	/* stxvl wants size in top 8 bits  */
 	addi	r11,r11,48	/* Offset */
 	stxvl	32+v3,r11,r10	/* Partial store  */
+#ifdef USE_AS_STPNCPY
+	/* Compute pointer to last byte copied into dest.  */
+	add	r3,r11,r5
+#endif
 	blr
 
 L(prep_n_tail1):
@@ -179,6 +213,10 @@ L(prep_n_tail1):
 L(n_tail1):
 	sldi	r10,r5,56	/* stxvl wants size in top 8 bits  */
 	stxvl	32+v0,r11,r10	/* Partial store  */
+#ifdef USE_AS_STPNCPY
+	/* Compute pointer to last byte copied into dest.  */
+	add	r3,r11,r5
+#endif
 	blr
 
 L(prep_n_tail2):
@@ -192,6 +230,10 @@ L(n_tail2):
 	sldi	r10,r5,56	/* stxvl wants size in top 8 bits  */
 	addi	r11,r11,16	/* offset */
 	stxvl	32+v1,r11,r10	/* Partial store  */
+#ifdef USE_AS_STPNCPY
+	/* Compute pointer to last byte copied into dest.  */
+	add	r3,r11,r5
+#endif
 	blr
 
 L(prep_n_tail3):
@@ -206,6 +248,10 @@ L(n_tail3):
 	sldi	r10,r5,56	/* stxvl wants size in top 8 bits  */
 	addi	r11,r11,32	/* Offset */
 	stxvl	32+v2,r11,r10	/* Partial store  */
+#ifdef USE_AS_STPNCPY
+	/* Compute pointer to last byte copied into dest.  */
+	add	r3,r11,r5
+#endif
 	blr
 
 L(prep_tail1):
@@ -215,6 +261,10 @@ L(tail1):
 	addi	r9,r8,1		/* Add null terminator  */
 	sldi	r10,r9,56	/* stxvl wants size in top 8 bits  */
 	stxvl	32+v0,r11,r10	/* Partial store  */
+#ifdef USE_AS_STPNCPY
+	/* Compute pointer to last byte copied into dest.  */
+	add	r3,r11,r8
+#endif
 	add	r11,r11,r9
 	sub	r5,r5,r9
 	b L(zero_padding_loop)
@@ -229,6 +279,10 @@ L(tail2):
 	sldi	r10,r9,56	/* stxvl wants size in top 8 bits  */
 	addi	r11,r11,16	/* offset */
 	stxvl	32+v1,r11,r10	/* Partial store  */
+#ifdef USE_AS_STPNCPY
+	/* Compute pointer to last byte copied into dest.  */
+	add	r3,r11,r8
+#endif
 	add	r11,r11,r9
 	sub	r5,r5,r9
 	b L(zero_padding_loop)
@@ -244,6 +298,10 @@ L(tail3):
 	sldi	r10,r9,56	/* stxvl wants size in top 8 bits  */
 	addi	r11,r11,32	/* offset */
 	stxvl	32+v2,r11,r10	/* Partial store  */
+#ifdef USE_AS_STPNCPY
+	/* Compute pointer to last byte copied into dest.  */
+	add	r3,r11,r8
+#endif
 	add	r11,r11,r9
 	sub	r5,r5,r9
 	b L(zero_padding_loop)
@@ -259,6 +317,10 @@ L(tail4):
 	sldi	r10,r9,56	/* stxvl wants size in top 8 bits  */
 	addi	r11,r11,48	/* offset */
 	stxvl	32+v3,r11,r10	/* Partial store  */
+#ifdef USE_AS_STPNCPY
+	/* Compute pointer to last byte copied into dest.  */
+	add	r3,r11,r8
+#endif
 	add	r11,r11,r9
 	sub	r5,r5,r9
 
@@ -279,3 +341,6 @@ L(zero_padding_end):
 	blr
 
 END (FUNC_NAME)
+#ifndef USE_AS_STPNCPY
+libc_hidden_builtin_def (strncpy)
+#endif
diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index cd2b47b403..f46bf50732 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -33,7 +33,7 @@ sysdep_routines += memcpy-power8-cached memcpy-power7 memcpy-a2 memcpy-power6 \
 
 ifneq (,$(filter %le,$(config-machine)))
 sysdep_routines += strcmp-power9 strncmp-power9 strcpy-power9 stpcpy-power9 \
-		   rawmemchr-power9 strlen-power9 strncpy-power9
+		   rawmemchr-power9 strlen-power9 strncpy-power9 stpncpy-power9
 endif
 CFLAGS-strncase-power7.c += -mcpu=power7 -funroll-loops
 CFLAGS-strncase_l-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 aa63e1c23f..56790bcfe3 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -317,6 +317,11 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
   /* Support sysdeps/powerpc/powerpc64/multiarch/stpncpy.c.  */
   IFUNC_IMPL (i, name, stpncpy,
+#ifdef __LITTLE_ENDIAN__
+	      IFUNC_IMPL_ADD (array, i, stpncpy,
+			      hwcap2 & PPC_FEATURE2_ARCH_3_00,
+			      __stpncpy_power9)
+#endif
 	      IFUNC_IMPL_ADD (array, i, stpncpy,
 			      hwcap2 & PPC_FEATURE2_ARCH_2_07,
 			      __stpncpy_power8)
diff --git a/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power9.S b/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power9.S
new file mode 100644
index 0000000000..ccbab55c31
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power9.S
@@ -0,0 +1,24 @@
+/* Optimized stpncpy implementation for POWER9 LE.
+   Copyright (C) 2020 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 STPNCPY __stpncpy_power9
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/le/power9/stpncpy.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/stpncpy.c b/sysdeps/powerpc/powerpc64/multiarch/stpncpy.c
index 17df886431..ac17b26650 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/stpncpy.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/stpncpy.c
@@ -26,10 +26,17 @@
 extern __typeof (__stpncpy) __stpncpy_ppc attribute_hidden;
 extern __typeof (__stpncpy) __stpncpy_power7 attribute_hidden;
 extern __typeof (__stpncpy) __stpncpy_power8 attribute_hidden;
+# ifdef __LITTLE_ENDIAN__
+extern __typeof (__stpncpy) __stpncpy_power9 attribute_hidden;
+# endif
 # undef stpncpy
 # undef __stpncpy
 
 libc_ifunc_redirected (__redirect___stpncpy, __stpncpy,
+# ifdef __LITTLE_ENDIAN__
+		     (hwcap2 & PPC_FEATURE2_ARCH_3_00)
+		     ? __stpncpy_power9 :
+# endif
 		       (hwcap2 & PPC_FEATURE2_ARCH_2_07)
 		       ? __stpncpy_power8
 		       : (hwcap & PPC_FEATURE_HAS_VSX)
-- 
2.26.2



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