From cca51a74315c37614042113b004505b150d305d7 Mon Sep 17 00:00:00 2001

From: Stefan Liebler <stli@linux.vnet.ibm.com>

Date: Thu, 8 Oct 2015 10:54:21 +0200

Subject: [PATCH 10/30] S390: Optimize strlen and wcslen.

upstream-commit-id: 9472f35a0a6dbbda82ce103aaf0f5013f5d46e34

https://www.sourceware.org/ml/libc-alpha/2015-07/msg00089.html

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.

---

 benchtests/Makefile                      |  3 +-

 benchtests/bench-wcslen.c                | 20 +++++++

 string/strlen.c                          |  7 ++-

 sysdeps/s390/multiarch/Makefile          |  7 +++

 sysdeps/s390/multiarch/ifunc-impl-list.c | 14 +++++

 sysdeps/s390/multiarch/strlen-c.c        | 28 ++++++++++

 sysdeps/s390/multiarch/strlen-vx.S       | 84 +++++++++++++++++++++++++++++

 sysdeps/s390/multiarch/strlen.c          | 27 ++++++++++

 sysdeps/s390/multiarch/wcslen-c.c        | 25 +++++++++

 sysdeps/s390/multiarch/wcslen-vx.S       | 91 ++++++++++++++++++++++++++++++++

 sysdeps/s390/multiarch/wcslen.c          | 28 ++++++++++

 11 files changed, 331 insertions(+), 3 deletions(-)

 create mode 100644 benchtests/bench-wcslen.c

 create mode 100644 sysdeps/s390/multiarch/Makefile

 create mode 100644 sysdeps/s390/multiarch/strlen-c.c

 create mode 100644 sysdeps/s390/multiarch/strlen-vx.S

 create mode 100644 sysdeps/s390/multiarch/strlen.c

 create mode 100644 sysdeps/s390/multiarch/wcslen-c.c

 create mode 100644 sysdeps/s390/multiarch/wcslen-vx.S

 create mode 100644 sysdeps/s390/multiarch/wcslen.c

diff --git a/benchtests/Makefile b/benchtests/Makefile

index 9b02bc7..09ab87f 100644

--- a/benchtests/Makefile

+++ b/benchtests/Makefile

@@ -38,7 +38,8 @@ string-bench := bcopy bzero memccpy memchr memcmp memcpy memmem memmove \

 		strcat strchr strchrnul strcmp strcpy strcspn strlen \

 		strncasecmp strncat strncmp strncpy strnlen strpbrk strrchr \

 		strspn strstr strcpy_chk stpcpy_chk memrchr strsep strtok

-string-bench-all := $(string-bench)

+wcsmbs-bench := wcslen

+string-bench-all := $(string-bench) ${wcsmbs-bench}

 stdlib-bench := strtod

diff --git a/benchtests/bench-wcslen.c b/benchtests/bench-wcslen.c

new file mode 100644

index 0000000..4e9d085

--- /dev/null

+++ b/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"

diff --git a/string/strlen.c b/string/strlen.c

index 5c1efda..d682693 100644

--- a/string/strlen.c

+++ b/string/strlen.c

@@ -23,11 +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 (str)

-     const char *str;

+STRLEN (const char *str)

 {

   const char *char_ptr;

   const unsigned long int *longword_ptr;

diff --git a/sysdeps/s390/multiarch/Makefile b/sysdeps/s390/multiarch/Makefile

new file mode 100644

index 0000000..3a98098

--- /dev/null

+++ b/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

diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c

index c330904..e9639ef 100644

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

+++ b/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;

 }

diff --git a/sysdeps/s390/multiarch/strlen-c.c b/sysdeps/s390/multiarch/strlen-c.c

new file mode 100644

index 0000000..1cbe959

--- /dev/null

+++ b/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 && !defined NOT_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 && !defined NOT_IN_libc */

diff --git a/sysdeps/s390/multiarch/strlen-vx.S b/sysdeps/s390/multiarch/strlen-vx.S

new file mode 100644

index 0000000..1a5cb23

--- /dev/null

+++ b/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 && !defined NOT_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 && !defined NOT_IN_libc */

diff --git a/sysdeps/s390/multiarch/strlen.c b/sysdeps/s390/multiarch/strlen.c

new file mode 100644

index 0000000..ba5863f

--- /dev/null

+++ b/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 && !defined NOT_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 && !defined NOT_IN_libc) */

diff --git a/sysdeps/s390/multiarch/wcslen-c.c b/sysdeps/s390/multiarch/wcslen-c.c

new file mode 100644

index 0000000..6dd011e

--- /dev/null

+++ b/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 && !defined NOT_IN_libc

+# define WCSLEN  __wcslen_c

+

+# include <wchar.h>

+extern __typeof (__wcslen) __wcslen_c;

+# include <wcsmbs/wcslen.c>

+#endif

diff --git a/sysdeps/s390/multiarch/wcslen-vx.S b/sysdeps/s390/multiarch/wcslen-vx.S

new file mode 100644

index 0000000..579e66b

--- /dev/null

+++ b/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 && !defined NOT_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 && !defined NOT_IN_libc */

diff --git a/sysdeps/s390/multiarch/wcslen.c b/sysdeps/s390/multiarch/wcslen.c

new file mode 100644

index 0000000..a7be73e

--- /dev/null

+++ b/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 && !defined NOT_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 && !defined NOT_IN_libc) */

-- 

2.3.0