S390: Optimize strlen and wcslen.

This patch provides optimized versions of strlen and wcslen with the z13 vector
instructions.
The helper macro IFUNC_VX_IMPL is introduced and is used to register all
__<func>_c() and __<func>_vx() functions within __libc_ifunc_impl_list()
to the ifunc test framework.

ChangeLog:

	* sysdeps/s390/multiarch/Makefile: New File.
	* sysdeps/s390/multiarch/strlen-c.c: Likewise.
	* sysdeps/s390/multiarch/strlen-vx.S: Likewise.
	* sysdeps/s390/multiarch/strlen.c: Likewise.
	* sysdeps/s390/multiarch/wcslen-c.c: Likewise.
	* sysdeps/s390/multiarch/wcslen-vx.S: Likewise.
	* sysdeps/s390/multiarch/wcslen.c: Likewise.
	* string/strlen.c (STRLEN): Define and use macro.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(IFUNC_VX_IMPL): New macro function.
	(__libc_ifunc_impl_list): Add ifunc test for strlen, wcslen.
	* benchtests/Makefile (wcsmbs-bench): New variable.
	(string-bench-all): Added wcsmbs-bench.
	* benchtests/bench-wcslen.c: New File.

ChangeLog

@@ -1,3 +1,20 @@
+2015-08-26  Stefan Liebler  <stli@linux.vnet.ibm.com>
+
+	* sysdeps/s390/multiarch/Makefile: New File.
+	* sysdeps/s390/multiarch/strlen-c.c: Likewise.
+	* sysdeps/s390/multiarch/strlen-vx.S: Likewise.
+	* sysdeps/s390/multiarch/strlen.c: Likewise.
+	* sysdeps/s390/multiarch/wcslen-c.c: Likewise.
+	* sysdeps/s390/multiarch/wcslen-vx.S: Likewise.
+	* sysdeps/s390/multiarch/wcslen.c: Likewise.
+	* string/strlen.c (STRLEN): Define and use macro.
+	* sysdeps/s390/multiarch/ifunc-impl-list.c
+	(IFUNC_VX_IMPL): New macro function.
+	(__libc_ifunc_impl_list): Add ifunc test for strlen, wcslen.
+	* benchtests/Makefile (wcsmbs-bench): New variable.
+	(string-bench-all): Added wcsmbs-bench.
+	* benchtests/bench-wcslen.c: New File.
+
 2015-08-26  Stefan Liebler  <stli@linux.vnet.ibm.com>
 
 	* sysdeps/s390/multiarch/ifunc-resolve.h (s390_vx_libc_ifunc,

benchtests/Makefile

@@ -36,7 +36,8 @@ string-bench := bcopy bzero memccpy memchr memcmp memcpy memmem memmove \
 		strncasecmp strncat strncmp strncpy strnlen strpbrk strrchr \
 		strspn strstr strcpy_chk stpcpy_chk memrchr strsep strtok \
 		strcoll
-string-bench-all := $(string-bench)
+wcsmbs-bench := wcslen
+string-bench-all := $(string-bench) ${wcsmbs-bench}
 
 # We have to generate locales
 LOCALES := en_US.UTF-8 tr_TR.UTF-8 cs_CZ.UTF-8 fa_IR.UTF-8 fr_FR.UTF-8 \

benchtests/bench-wcslen.c

@@ -0,0 +1,20 @@
+/* Measure wcslen functions.
+   Copyright (C) 2015 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 WIDE 1
+#include "bench-strlen.c"

string/strlen.c

@@ -23,10 +23,14 @@
 
 #undef strlen
 
+#ifndef STRLEN
+# define STRLEN strlen
+#endif
+
 /* Return the length of the null-terminated string STR.  Scan for
    the null terminator quickly by testing four bytes at a time.  */
 size_t
-strlen (const char *str)
+STRLEN (const char *str)
 {
   const char *char_ptr;
   const unsigned long int *longword_ptr;

sysdeps/s390/multiarch/Makefile

@@ -0,0 +1,7 @@
+ifeq ($(subdir),string)
+sysdep_routines += strlen strlen-vx strlen-c
+endif
+
+ifeq ($(subdir),wcsmbs)
+sysdep_routines += wcslen wcslen-vx wcslen-c
+endif

sysdeps/s390/multiarch/ifunc-impl-list.c

@@ -18,6 +18,7 @@
 
 #include <assert.h>
 #include <string.h>
+#include <wchar.h>
 #include <ifunc-impl-list.h>
 #include <ifunc-resolve.h>
 
@@ -70,5 +71,18 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
 #endif /* SHARED */
 
+#ifdef HAVE_S390_VX_ASM_SUPPORT
+
+# define IFUNC_VX_IMPL(FUNC)						\
+  IFUNC_IMPL (i, name, FUNC,						\
+	      IFUNC_IMPL_ADD (array, i, FUNC, dl_hwcap & HWCAP_S390_VX, \
+			      __##FUNC##_vx)				\
+	      IFUNC_IMPL_ADD (array, i, FUNC, 1, __##FUNC##_c))
+
+  IFUNC_VX_IMPL (strlen);
+  IFUNC_VX_IMPL (wcslen);
+
+#endif /* HAVE_S390_VX_ASM_SUPPORT */
+
   return i;
 }

sysdeps/s390/multiarch/strlen-c.c

@@ -0,0 +1,28 @@
+/* Default strlen implementation for S/390.
+   Copyright (C) 2015 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/>.  */
+
+#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
+# define STRLEN  __strlen_c
+# ifdef SHARED
+#  undef libc_hidden_builtin_def
+#  define libc_hidden_builtin_def(name)			\
+  __hidden_ver1 (__strlen_c, __GI_strlen, __strlen_c);
+# endif /* SHARED */
+
+# include <string/strlen.c>
+#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */

sysdeps/s390/multiarch/strlen-vx.S

@@ -0,0 +1,84 @@
+/* Vector optimized 32/64 bit S/390 version of strlen.
+   Copyright (C) 2015 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/>.  */
+
+#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
+
+# include "sysdep.h"
+# include "asm-syntax.h"
+
+	.text
+
+/* size_t strlen (const char *s)
+   Returns length of string s.
+
+   Register usage:
+   -r1=bytes to 4k-byte boundary
+   -r2=s
+   -r3=tmp
+   -r4=tmp
+   -r5=current_len and return_value
+   -v16=part of s
+*/
+ENTRY(__strlen_vx)
+	.machine "z13"
+	.machinemode "zarch_nohighgprs"
+
+	vlbb	%v16,0(%r2),6	/* Load s until next 4k-byte boundary.  */
+	lcbb	%r1,0(%r2),6	/* Get bytes to 4k-byte boundary or 16.  */
+
+	vfenezb	%v16,%v16,%v16	/* Find element not equal with zero search.  */
+	vlgvb	%r4,%v16,7	/* Load zero index or 16 if not found.  */
+	clr	%r4,%r1		/* If found zero within loaded bytes?  */
+	locgrl	%r2,%r4		/* Then copy return value.  */
+	blr	%r14		/* And return.  */
+
+	/* Align s to 16 byte.  */
+	risbgn	%r3,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15.  */
+	lghi	%r5,16		/* current_len = 16.  */
+	slr	%r5,%r3		/* Compute bytes to 16bytes boundary.  */
+
+	/* Find zero in 16 byte aligned loop.  */
+.Lloop:
+	vl	%v16,0(%r5,%r2)	/* Load s.  */
+	vfenezbs %v16,%v16,%v16 /* Find element not equal with zero search.  */
+	je	.Lfound		/* Jump away if zero was found.  */
+	vl	%v16,16(%r5,%r2)
+	vfenezbs %v16,%v16,%v16
+	je	.Lfound16
+	vl	%v16,32(%r5,%r2)
+	vfenezbs %v16,%v16,%v16
+	je	.Lfound32
+	vl	%v16,48(%r5,%r2)
+	vfenezbs %v16,%v16,%v16
+	je	.Lfound48
+
+	aghi	%r5,64
+	j	.Lloop		/* No zero found -> loop.  */
+
+.Lfound48:
+	aghi	%r5,16
+.Lfound32:
+	aghi	%r5,16
+.Lfound16:
+	aghi	%r5,16
+.Lfound:
+	vlgvb	%r2,%v16,7	/* Load byte index of zero.  */
+	algr	%r2,%r5
+	br	%r14
+END(__strlen_vx)
+#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */

sysdeps/s390/multiarch/strlen.c

@@ -0,0 +1,27 @@
+/* Multiple versions of strlen.
+   Copyright (C) 2015 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/>.  */
+
+#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
+# include <string.h>
+# include <ifunc-resolve.h>
+
+s390_vx_libc_ifunc2 (__strlen, strlen)
+
+#else
+# include <string/strlen.c>
+#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */

sysdeps/s390/multiarch/wcslen-c.c

@@ -0,0 +1,25 @@
+/* Default wcslen implementation for S/390.
+   Copyright (C) 2015 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/>.  */
+
+#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
+# define WCSLEN  __wcslen_c
+
+# include <wchar.h>
+extern __typeof (__wcslen) __wcslen_c;
+# include <wcsmbs/wcslen.c>
+#endif

sysdeps/s390/multiarch/wcslen-vx.S

@@ -0,0 +1,91 @@
+/* Vector optimized 32/64 bit S/390 version of wcslen.
+   Copyright (C) 2015 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/>.  */
+
+#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
+
+# include "sysdep.h"
+# include "asm-syntax.h"
+
+	.text
+
+/* size_t wcslen (const wchar_t *s)
+   Returns length of string s.
+
+   Register usage:
+   -r1=bytes to 4k-byte boundary
+   -r2=s
+   -r3=tmp
+   -r4=tmp
+   -r5=current_len and return_value
+   -v16=part of s
+*/
+ENTRY(__wcslen_vx)
+	.machine "z13"
+	.machinemode "zarch_nohighgprs"
+
+	vlbb	%v16,0(%r2),6	/* Load s until next 4k-byte boundary.  */
+	lcbb	%r1,0(%r2),6	/* Get bytes to 4k-byte boundary or 16.  */
+
+	tmll	%r2,3		/* Test if s is 4-byte aligned?   */
+	jne	.Lfallback	/* And use common-code variant if not.  */
+
+	vfenezf	%v16,%v16,%v16	/* Find element not equal with zero search.  */
+	vlgvb	%r4,%v16,7	/* Load zero index or 16 if not found.  */
+	clr	%r4,%r1		/* If found zero within loaded bytes?  */
+	locgrl	%r2,%r4		/* Then copy return value.  */
+	jl	.Lend		/* And return.  */
+
+	/* Align s to 16 byte.  */
+	risbgn	%r3,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15.  */
+	lghi	%r5,16		/* current_len = 16.  */
+	slr	%r5,%r3		/* Compute bytes to 16bytes boundary.  */
+
+	/* Find zero in 16byte aligned loop.  */
+.Lloop:
+	vl	%v16,0(%r5,%r2)	/* Load s.  */
+	vfenezfs %v16,%v16,%v16	/* Find element not equal with zero search.  */
+	je	.Lfound		/* Jump away if zero was found.  */
+	vl	%v16,16(%r5,%r2)
+	vfenezfs %v16,%v16,%v16
+	je	.Lfound16
+	vl	%v16,32(%r5,%r2)
+	vfenezfs %v16,%v16,%v16
+	je	.Lfound32
+	vl	%v16,48(%r5,%r2)
+	vfenezfs %v16,%v16,%v16
+	je	.Lfound48
+
+	aghi	%r5,64
+	j	.Lloop		/* No zero found -> loop.  */
+
+.Lfound48:
+	aghi	%r5,16
+.Lfound32:
+	aghi	%r5,16
+.Lfound16:
+	aghi	%r5,16
+.Lfound:
+	vlgvb	%r2,%v16,7	/* Load byte index of zero.  */
+	algr	%r2,%r5
+.Lend:
+	srlg	%r2,%r2,2	/* Convert byte-count to character-count.  */
+	br	%r14
+.Lfallback:
+	jg	__wcslen_c
+END(__wcslen_vx)
+#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */

sysdeps/s390/multiarch/wcslen.c

@@ -0,0 +1,28 @@
+/* Multiple versions of wcslen.
+   Copyright (C) 2015 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/>.  */
+
+#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
+# include <wchar.h>
+# include <ifunc-resolve.h>
+
+s390_vx_libc_ifunc (__wcslen)
+weak_alias (__wcslen, wcslen)
+
+#else
+# include <wcsmbs/wcslen.c>
+#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */