PowerPC: optimized strcspn for PPC64/POWER7

This patch add a optimized strcspn for POWER7 by using a different
algorithm than default implementation: it constructs a table based on
the 'accept' argument and use this table to check for any occurance
on the input string. The idea is similar as x86_64 uses.
For PowerPC some tunings were added, such as unroll loops and align
stack memory to table to 16 bytes (so VSX clean can ran without
alignment issues).

Backport of 6eaf95cbfa0031ea267682dc2c9c17ed3e3dc167

8 files changed, 271 insertions, 16 deletions

diff --git a/ChangeLog b/ChangeLog
index fdfff77dd8..35d4aee06f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+2014-03-20  Adhemerval Zanella  <azanella@linux.vnet.ibm.com>
+
+	* string/strcspn.c (strcspn): Using macro to redefine symbol name.
+	* sysdeps/powerpc/powerpc64/multiarch/Makefile: Add strcspn-power7
+	and strcspn-ppc64 objects.
+	* sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+	(__libc_ifunc_impl_list): Add new strcspn optimized symbols.
+	* sysdeps/powerpc/powerpc64/multiarch/strcspn-power7.S: New file:
+	multiarch strcspn for POWER7.
+	* sysdeps/powerpc/powerpc64/multiarch/strcspn-ppc64.c: New file:
+	multiarch strcspn for PPC64.
+	* sysdeps/powerpc/powerpc64/multiarch/strcspn.c: New file: strcspn
+	ifunc selector.
+	* sysdeps/powerpc/powerpc64/power7/strcspn.S: New file: optimited
+	strcspn for POWER7.
+
 2014-03-14  Adhemerval Zanella  <azanella@linux.vnet.ibm.com>
 
 	[BZ #16707]
diff --git a/string/strcspn.c b/string/strcspn.c
index 7c39f793ea..431620521a 100644
--- a/string/strcspn.c
+++ b/string/strcspn.c
@@ -15,27 +15,18 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#if HAVE_CONFIG_H
-# include <config.h>
-#endif
-
-#if defined _LIBC || HAVE_STRING_H
-# include <string.h>
-#else
-# include <strings.h>
-# ifndef strchr
-#  define strchr index
-# endif
-#endif
+#include <string.h>
 
 #undef strcspn
 
+#ifndef STRCSPN
+# define STRCSPN strcspn
+#endif
+
 /* Return the length of the maximum initial segment of S
    which contains no characters from REJECT.  */
 size_t
-strcspn (s, reject)
-     const char *s;
-     const char *reject;
+STRCSPN (const char *s, const char *reject)
 {
   size_t count = 0;
 
diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index 3e8010c72d..c314e6f875 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -15,7 +15,7 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
 		   wordcopy-power7 wordcopy-power6 wordcopy-ppc64 \
 		   strcpy-power7 strcpy-ppc64 stpcpy-power7 stpcpy-ppc64 \
 		   strrchr-power7 strrchr-ppc64 strncat-power7 strncat-ppc64 \
-		   strspn-power7 strspn-ppc64
+		   strspn-power7 strspn-ppc64 strcspn-power7 strcspn-ppc64
 
 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 20d79186c5..328b87e5a9 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -262,5 +262,13 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 	      IFUNC_IMPL_ADD (array, i, strspn, 1,
 			      __strspn_ppc))
 
+  /* Support sysdeps/powerpc/powerpc64/multiarch/strcspn.c.  */
+  IFUNC_IMPL (i, name, strcspn,
+	      IFUNC_IMPL_ADD (array, i, strcspn,
+			      hwcap & PPC_FEATURE_HAS_VSX,
+			      __strcspn_power7)
+	      IFUNC_IMPL_ADD (array, i, strcspn, 1,
+			     __strcspn_ppc))
+
   return i;
 }
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcspn-power7.S b/sysdeps/powerpc/powerpc64/multiarch/strcspn-power7.S
new file mode 100644
index 0000000000..02ffcc89b8
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strcspn-power7.S
@@ -0,0 +1,40 @@
+/* Optimized strcspn implementation for POWER7.
+   Copyright (C) 2014 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/>.  */
+
+#include <sysdep.h>
+
+#undef EALIGN
+#define EALIGN(name, alignt, words)				\
+  .section ".text";						\
+  ENTRY_2(__strcspn_power7)					\
+  .align ALIGNARG(alignt);					\
+  EALIGN_W_##words;						\
+  BODY_LABEL(__strcspn_power7):					\
+  cfi_startproc;						\
+  LOCALENTRY(__strcspn_power7)
+
+#undef END
+#define END(name)						\
+  cfi_endproc;							\
+  TRACEBACK(__strcspn_power7)					\
+  END_2(__strcspn_power7)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power7/strcspn.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcspn-ppc64.c b/sysdeps/powerpc/powerpc64/multiarch/strcspn-ppc64.c
new file mode 100644
index 0000000000..5f8b61054d
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strcspn-ppc64.c
@@ -0,0 +1,30 @@
+/* Copyright (C) 2014 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/>.  */
+
+#include <string.h>
+
+#define STRCSPN __strcspn_ppc
+#ifdef SHARED
+
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(name) \
+  __hidden_ver1 (__strcspn_ppc, __GI_strcspn, __strcspn_ppc);
+#endif
+
+extern __typeof (strcspn) __strcspn_ppc attribute_hidden;
+
+#include <string/strcspn.c>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcspn.c b/sysdeps/powerpc/powerpc64/multiarch/strcspn.c
new file mode 100644
index 0000000000..3609d93ad2
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strcspn.c
@@ -0,0 +1,31 @@
+/* Multiple versions of strcspn. PowerPC64 version.
+   Copyright (C) 2014 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/>.  */
+
+#ifndef NOT_IN_libc
+# include <string.h>
+# include <shlib-compat.h>
+# include "init-arch.h"
+
+extern __typeof (strcspn) __strcspn_ppc attribute_hidden;
+extern __typeof (strcspn) __strcspn_power7 attribute_hidden;
+
+libc_ifunc (strcspn,
+	    (hwcap & PPC_FEATURE_HAS_VSX)
+	    ? __strcspn_power7
+	    : __strcspn_ppc);
+#endif
diff --git a/sysdeps/powerpc/powerpc64/power7/strcspn.S b/sysdeps/powerpc/powerpc64/power7/strcspn.S
new file mode 100644
index 0000000000..3f6aa0a506
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/power7/strcspn.S
@@ -0,0 +1,139 @@
+/* Optimized strcspn implementation for PowerPC64.
+   Copyright (C) 2014 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/>.  */
+
+#include <sysdep.h>
+
+/* size_t [r3] strcspn (const char [r4] *s, const char [r5] *reject)  */
+
+	.machine power7
+EALIGN (strcspn, 4, 0)
+	CALL_MCOUNT 3
+
+	/* The idea to speed up the algorithm is to create a lookup table
+	   for fast check if input character should be considered.  For ASCII
+	   or ISO-8859-X character sets it has 256 positions.  */
+	lbz	r10,0(r4)
+
+	/* First the table should be cleared and to avoid unaligned accesses
+	   when using the VSX stores the table address is aligned to 16
+	   bytes.  */
+	xxlxor	v0,v0,v0
+
+	/* PPC64 ELF ABI stack is aligned to 16 bytes.  */
+	addi 	r9,r1,-256
+
+	li	r8,48
+	li	r5,16
+	li	r6,32
+	cmpdi	cr7,r10,0	/* reject[0] == '\0' ?  */
+	addi	r12,r9,64
+	/* Clear the table with 0 values  */
+	stxvw4x	v0,r0,r9
+	addi	r11,r9,128
+	addi	r7,r9,192
+	stxvw4x v0,r9,r5
+	stxvw4x v0,r9,r6
+	stxvw4x v0,r9,r8
+	stxvw4x v0,r0,r12
+	stxvw4x v0,r12,r5
+	stxvw4x v0,r12,r6
+	stxvw4x v0,r12,r8
+	stxvw4x v0,r0,r11
+	stxvw4x v0,r11,r5
+	stxvw4x v0,r11,r6
+	stxvw4x v0,r11,r8
+	stxvw4x v0,r0,r7
+	stxvw4x v0,r7,r5
+	stxvw4x v0,r7,r6
+	stxvw4x v0,r7,r8
+	li	r8,1
+	beq     cr7,L(finish_table)  /* If reject[0] == '\0' skip  */
+
+	/* Initialize the table as:
+	   for (i=0; reject[i]; i++
+	     table[reject[i]]] = 1  */
+	.p2align 4,,15
+L(init_table):
+	stbx	r8,r9,r10
+	lbzu	r10,1(r4)
+	cmpdi	cr7,r10,0           /* If reject[0] == '\0' finish  */
+	bne	cr7,L(init_table)
+L(finish_table):
+	/* set table[0] = 1  */
+	li 	r10,1
+	stb	r10,0(r9)
+	li	r10,0
+	b	L(mainloop)
+
+	/* Unrool the loop 4 times and check using the table as:
+	   i = 0;
+	   while (1)
+	     {
+	       if (table[input[i++]] == 1)
+	         return i - 1;
+	       if (table[input[i++]] == 1)
+	         return i - 1;
+	       if (table[input[i++]] == 1)
+	         return i - 1;
+	       if (table[input[i++]] == 1)
+	         return i - 1;
+	     }  */
+	.p2align 4,,15
+L(unroll):
+	lbz	r8,1(r3)
+	addi	r10,r10,4
+	lbzx	r8,r9,r8
+	cmpwi	r7,r8,1
+	beq	cr7,L(end)
+	lbz	r8,2(r3)
+	addi	r3,r3,4
+	lbzx	r8,r9,r8
+	cmpwi	cr7,r8,1
+	beq	cr7,L(end2)
+	lbz	r8,3(r7)
+	lbzx	r8,r9,r8
+	cmpwi	cr7,r8,1
+	beq	cr7,L(end3)
+L(mainloop):
+	lbz	r8,0(r3)
+	mr	r7,r3
+	addi	r6,r10,1
+	addi	r4,r10,2
+	addi	r5,r10,3
+	lbzx	r8,r9,8
+	cmpwi	cr7,r8,1
+	bne	cr7,L(unroll)
+	mr	r3,r10
+	blr
+
+	.p2align 4,,15
+L(end):
+	mr	r3,r6
+	blr
+
+	.p2align 4,,15
+L(end2):
+	mr	r3,r4
+	blr
+
+	.p2align 4,,15
+L(end3):
+	mr	r3,r5
+	blr
+END (strcspn)
+libc_hidden_builtin_def (strcspn)