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Re: [PATCH] Multiarch optimization for strspn on POWERPC
- From: R Vidya <vidya at linux dot vnet dot ibm dot com>
- To: Adhemerval Zanella <azanella at linux dot vnet dot ibm dot com>, libc-alpha at sourceware dot org
- Date: Fri, 07 Mar 2014 15:53:03 +0530
- Subject: Re: [PATCH] Multiarch optimization for strspn on POWERPC
- Authentication-results: sourceware.org; auth=none
- References: <5315CD58 dot 5080002 at linux dot vnet dot ibm dot com> <53163BD1 dot 5000106 at linux dot vnet dot ibm dot com>
This patch has to be applied on top of strncat for multiarch support.
On Wednesday 05 March 2014 02:17 AM, Adhemerval Zanella wrote:
Hi Vidya,
The patch looks good, just some comments below.
On 04-03-2014 09:55, R Vidya wrote:
diff --git a/string/strspn.c b/string/strspn.c
index 37e8161..557eec5 100644
--- a/string/strspn.c
+++ b/string/strspn.c
@@ -18,11 +18,14 @@
#include <string.h>
#undef strspn
+#ifndef STRSPN
+#define STRSPN strspn
+#endif
/* Return the length of the maximum initial segment
of S which contains only characters in ACCEPT. */
size_t
-strspn (s, accept)
+STRSPN (s, accept)
const char *s;
const char *accept;
{
diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index d09f2e3..9821101 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -14,7 +14,7 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
wcsrchr-ppc64 wcscpy-power7 wcscpy-power6 wcscpy-ppc64 \
wordcopy-power7 wordcopy-power6 wordcopy-ppc64 \
strcpy-power7 strcpy-ppc64 stpcpy-power7 stpcpy-ppc64 \
- strrchr-power7 strrchr-ppc64
+ strrchr-power7 strrchr-ppc64 strspn-power7 strspn-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 8789483..7cf60f6 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -246,5 +246,13 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL_ADD (array, i, strrchr, 1,
__strrchr_ppc))
+ /* Support sysdeps/powerpc/powerpc64/multiarch/strspn.c. */
+ IFUNC_IMPL (i, name, strspn,
+ IFUNC_IMPL_ADD (array, i, strspn,
+ hwcap & PPC_FEATURE_HAS_VSX,
+ __strspn_power7)
+ IFUNC_IMPL_ADD (array, i, strspn, 1,
+ __strspn_ppc))
+
return i;
}
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strspn-power7.S b/sysdeps/powerpc/powerpc64/multiarch/strspn-power7.S
new file mode 100644
index 0000000..889dfee
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strspn-power7.S
@@ -0,0 +1,40 @@
+/* Optimized strspn 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(__strspn_power7) \
+ .align ALIGNARG(alignt); \
+ EALIGN_W_##words; \
+ BODY_LABEL(__strspn_power7): \
+ cfi_startproc; \
+ LOCALENTRY(__strspn_power7)
+
+#undef END
+#define END(name) \
+ cfi_endproc; \
+ TRACEBACK(__strspn_power7) \
+ END_2(__strspn_power7)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power7/strspn.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strspn-ppc64.c b/sysdeps/powerpc/powerpc64/multiarch/strspn-ppc64.c
new file mode 100644
index 0000000..d543772
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strspn-ppc64.c
@@ -0,0 +1,33 @@
+/* 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 STRSPN __strspn_ppc
+#undef weak_alias
+#define weak_alias(name, aliasname) \
+ extern __typeof (__strspn_ppc) aliasname \
+ __attribute__ ((weak, alias ("__strspn_ppc")));
+#if !defined(NOT_IN_libc) && defined(SHARED)
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(name) \
+ __hidden_ver1(__strspn_ppc, __GI_strspn, __strspn_ppc);
+#endif
+
+extern __typeof (strspn) __strspn_ppc attribute_hidden;
+
+#include <string/strspn.c>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strspn.c b/sysdeps/powerpc/powerpc64/multiarch/strspn.c
new file mode 100644
index 0000000..44945f3
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strspn.c
@@ -0,0 +1,31 @@
+/* Multiple versions of strspn. 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/>. */
+
+#if defined SHARED && !defined NOT_IN_libc
+# include <string.h>
+# include <shlib-compat.h>
+# include "init-arch.h"
+
+extern __typeof (strspn) __strspn_ppc attribute_hidden;
+extern __typeof (strspn) __strspn_power7 attribute_hidden;
+
+libc_ifunc (strspn,
+ (hwcap & PPC_FEATURE_HAS_VSX)
+ ? __strspn_power7
+ : __strspn_ppc);
+#endif
diff --git a/sysdeps/powerpc/powerpc64/power7/strspn.S b/sysdeps/powerpc/powerpc64/power7/strspn.S
new file mode 100644
index 0000000..a891768
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/power7/strspn.S
@@ -0,0 +1,149 @@
+/* Optimized strspn implementation for PowerPC64/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/>. */
+
+/* size_t [r3] strspn (const char *string [r3],
+ const char *needleAccept [r4] */
+
+/* Performance gains are grabbed through following techniques:
+
+ > hashing of needle.
+ > hashing avoids scanning of duplicate entries in needle across the string.
+ > initializing the hash table with Vector instructions by quadword access.
+ > unrolling when scanning for character in string across hash table. */
+
+/* Algorithm is as below:
+ 1. A empty hash table/dictionary is created comprising of 256 ascii character set
+ 2. When hash entry is found in needle , the hash index is initialized to 1
+ 3. The string is scanned until end and for every character, its corresponding
+ hash index is compared.
+ 4. initial length of string (count) until first hit of accept needle to be found
+ is set to 0
+ 4. If hash index is set to 1 for the index of string, count is returned.
+ 5. Otherwise count is incremented and scanning continues until end of string.
+*/
+
+#include <sysdep.h>
+
+#undef strspn
+
+ .machine power7
+EALIGN(strspn, 4, 0)
+ CALL_MCOUNT 2
+
+ lbz r10, 0(r4) /* load r10 with needle (r4) */
Comments with double-space ending, fix for the remaining ones.
+ addi r9, r1, -272 /* r9 is a hash of 272 bytes */
This is not really correct, check https://sourceware.org/ml/libc-alpha/2014-03/msg00071.html
+
+ li r5, 16 /* set r5 = 16 as offset */
+ li r6, 32 /* set r6 = 32 as offset */
+ li r8, 48 /* set r8 = 48 as offset */
+
+/*Iniatliaze hash table with Zeroes in double indexed quadword accesses */
+ xxlxor v0, v0, v0 /* prepare for initializing hash */
+
+ stxvd2x v0, r0, r9 /* initialize 1st quadword */
+ stxvd2x v0, r9, r5
+ stxvd2x v0, r9, r6
+ stxvd2x v0, r9, r8 /* initialize 4th quadword */
+
+ addi r11, r9, 64 /* r11 is index to hash */
+
+ stxvd2x v0, r0, r11 /* initialize 5th quadword */
+ stxvd2x v0, r11, r5
+ stxvd2x v0, r11, r6
+ stxvd2x v0, r11, r8 /* initialize 8th quadword */
+
+ addi r11, r9, 128 /* r11 is index to hash */
+
+ stxvd2x v0, r0, r11 /* initialize 9th quadword */
+ stxvd2x v0, r11, r5
+ stxvd2x v0, r11, r6
+ stxvd2x v0, r11, r8 /* initialize 12th quadword */
+
+ addi r11, r9, 192 /* r11 is index to hash */
+
+ stxvd2x v0, r0, r11 /* initialize 13th quadword */
+ stxvd2x v0, r11, r5
+ stxvd2x v0, r11, r6
+ stxvd2x v0, r11, r8 /* initialize 16th quadword */
+
+ li r8, 1 /* r8=1, marker into hash if found in needle */
+
+ cmpdi cr7, r10, 0 /* accept needle is NULL */
+ beq cr7, L(skipHashing) /* if needle is NULL, skip hashing */
+
+ .p2align 4 /* align section to 16 byte boundary */
+L(hashing):
+ stbx r8, r9, r10 /* update hash with marker for the pivot of the needle */
+ lbzu r10, 1(r4) /* load needle into r10 and update to next */
+ cmpdi cr7, r10, 0 /* if needle is has reached NULL, continue */
+ bne cr7, L(hashing) /* loop to hash the needle */
+
+L(skipHashing):
+ li r10, 0 /* load counter = 0 */
+ b L(beginScan)
+
+ .p2align 4 /* align section to 16 byte boundary */
+L(scanUnroll):
+ lbzx r8, r9, r8 /* load r8 with hash value at index */
+ cmpwi cr7, r8, 0 /* if we hit marker in hash, we have found accept needle */
+ beq cr7, L(ret1stIndex) /* we have hit accept needle, return the count */
+
+ lbz r8, 1(r3) /* load string[1] into r8 */
+ addi r10, r10, 4 /* increment counter */
+ lbzx r8, r9, r8 /* load r8 with hash value at index */
+ cmpwi cr7, r8, 0 /* if we hit marker in hash, we have found accept needle */
+ beq cr7, L(ret2ndIndex) /* we have hit accept needle, return the count */
+
+ lbz r8, 2(r3) /* load string[2] into r8 */
+ lbzx r8, r9, r8 /* load r8 with hash value at index */
+ cmpwi cr7, r8, 0 /* if we hit marker in hash, we have found accept needle */
+ beq cr7, L(ret3rdIndex) /* we have hit accept needle, return the count */
+
+ lbz r8, 3(r3) /* load string[3] into r8 */
+ lbzx r8, r9, r8 /* load r8 with hash value at index */
+ addi r3, r3, 4 /* unroll factor , increment string by 4 */
+ cmpwi cr7, r8, 0 /* if we hit marker in hash, we have found accept needle */
+ beq cr7,L(ret4thIndex) /* we have hit accept needle, return the count */
+
+L(beginScan):
+ lbz r8, 0(r3) /* load string[0] into r8 */
+ addi r6, r10, 1 /* place holder for counter + 1 */
+ addi r5, r10, 2 /* place holder for counter + 2 */
+ addi r4, r10, 3 /* place holder for counter + 3 */
+ cmpdi cr7, r8, 0 /* if we hit marker in hash, we have found accept needle */
+ bne cr7, L(scanUnroll) /* continue scanning */
+
+L(ret1stIndex):
+ mr r3, r10 /* update r3 for return */
+ blr /* return */
+
+L(ret2ndIndex):
+ mr r3, r6 /* update r3 for return */
+ blr /* return */
+
+L(ret3rdIndex):
+ mr r3, r5 /* update r3 for return */
+ blr /* return */
+
+L(ret4thIndex):
+ mr r3, r4 /* update r3 for return */
+ blr /* done */
+
+END(strspn)
+libc_hidden_builtin_def (strspn)
>From 48e7a71efeac09d77ad2bdefca886f61a59cbf39 Mon Sep 17 00:00:00 2001
From: Vidya Ranganathan <vidya@linux.vnet.ibm.com>
Date: Fri, 7 Mar 2014 03:15:06 -0500
Subject: [PATCH] Multiarch optimization for strspn() on PowerPC. I have
attached the benchtest output to show the performance improvement.
The optimization is achieved by following techniques:
> hashing of needle.
> hashing avoids scanning of duplicate entries in needle across the string.
> initializing the hash table with Vector instructions (VSX) by quadword access.
> unrolling when scanning for character in string across hash table.
ChangeLog:
2014-03-04 Vidya Ranganathan <vidya@linux.vnet.ibm.com>
* sysdeps/powerpc/powerpc64/power7/strspn.S: New file: Optimization.
* sysdeps/powerpc/powerpc64/multiarch/strspn.c: New file:
multiarch strspn for PPC64.
* sysdeps/powerpc/powerpc64/multiarch/strspn-ppc64.c: New file
* sysdeps/powerpc/powerpc64/multiarch/strspn-power7.S: New file
* sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c:
(__libc_ifunc_impl_list): Likewise.
* sysdeps/powerpc/powerpc64/multiarch/Makefile: Add strspn
multiarch optimizations
* string/strspn.c (strspn): Using macro to redefine symbol name.
Signed-off-by: Vidya Ranganathan <vidya@linux.vnet.ibm.com>
---
string/strspn.c | 5 +-
sysdeps/powerpc/powerpc64/multiarch/Makefile | 3 +-
.../powerpc/powerpc64/multiarch/ifunc-impl-list.c | 8 ++
.../powerpc/powerpc64/multiarch/strspn-power7.S | 40 ++++++
sysdeps/powerpc/powerpc64/multiarch/strspn-ppc64.c | 33 +++++
sysdeps/powerpc/powerpc64/multiarch/strspn.c | 31 +++++
sysdeps/powerpc/powerpc64/power7/strspn.S | 148 +++++++++++++++++++++
7 files changed, 266 insertions(+), 2 deletions(-)
create mode 100644 sysdeps/powerpc/powerpc64/multiarch/strspn-power7.S
create mode 100644 sysdeps/powerpc/powerpc64/multiarch/strspn-ppc64.c
create mode 100644 sysdeps/powerpc/powerpc64/multiarch/strspn.c
create mode 100644 sysdeps/powerpc/powerpc64/power7/strspn.S
diff --git a/string/strspn.c b/string/strspn.c
index 37e8161..557eec5 100644
--- a/string/strspn.c
+++ b/string/strspn.c
@@ -18,11 +18,14 @@
#include <string.h>
#undef strspn
+#ifndef STRSPN
+#define STRSPN strspn
+#endif
/* Return the length of the maximum initial segment
of S which contains only characters in ACCEPT. */
size_t
-strspn (s, accept)
+STRSPN (s, accept)
const char *s;
const char *accept;
{
diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index a03569e..3e8010c 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -14,7 +14,8 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
wcsrchr-ppc64 wcscpy-power7 wcscpy-power6 wcscpy-ppc64 \
wordcopy-power7 wordcopy-power6 wordcopy-ppc64 \
strcpy-power7 strcpy-ppc64 stpcpy-power7 stpcpy-ppc64 \
- strrchr-power7 strrchr-ppc64 strncat-power7 strncat-ppc64
+ strrchr-power7 strrchr-ppc64 strncat-power7 strncat-ppc64 \
+ strspn-power7 strspn-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 11a3bed..20d7918 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -254,5 +254,13 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL_ADD (array, i, strncat, 1,
__strncat_ppc))
+ /* Support sysdeps/powerpc/powerpc64/multiarch/strspn.c. */
+ IFUNC_IMPL (i, name, strspn,
+ IFUNC_IMPL_ADD (array, i, strspn,
+ hwcap & PPC_FEATURE_HAS_VSX,
+ __strspn_power7)
+ IFUNC_IMPL_ADD (array, i, strspn, 1,
+ __strspn_ppc))
+
return i;
}
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strspn-power7.S b/sysdeps/powerpc/powerpc64/multiarch/strspn-power7.S
new file mode 100644
index 0000000..889dfee
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strspn-power7.S
@@ -0,0 +1,40 @@
+/* Optimized strspn 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(__strspn_power7) \
+ .align ALIGNARG(alignt); \
+ EALIGN_W_##words; \
+ BODY_LABEL(__strspn_power7): \
+ cfi_startproc; \
+ LOCALENTRY(__strspn_power7)
+
+#undef END
+#define END(name) \
+ cfi_endproc; \
+ TRACEBACK(__strspn_power7) \
+ END_2(__strspn_power7)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power7/strspn.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strspn-ppc64.c b/sysdeps/powerpc/powerpc64/multiarch/strspn-ppc64.c
new file mode 100644
index 0000000..d543772
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strspn-ppc64.c
@@ -0,0 +1,33 @@
+/* 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 STRSPN __strspn_ppc
+#undef weak_alias
+#define weak_alias(name, aliasname) \
+ extern __typeof (__strspn_ppc) aliasname \
+ __attribute__ ((weak, alias ("__strspn_ppc")));
+#if !defined(NOT_IN_libc) && defined(SHARED)
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(name) \
+ __hidden_ver1(__strspn_ppc, __GI_strspn, __strspn_ppc);
+#endif
+
+extern __typeof (strspn) __strspn_ppc attribute_hidden;
+
+#include <string/strspn.c>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strspn.c b/sysdeps/powerpc/powerpc64/multiarch/strspn.c
new file mode 100644
index 0000000..44945f3
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strspn.c
@@ -0,0 +1,31 @@
+/* Multiple versions of strspn. 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/>. */
+
+#if defined SHARED && !defined NOT_IN_libc
+# include <string.h>
+# include <shlib-compat.h>
+# include "init-arch.h"
+
+extern __typeof (strspn) __strspn_ppc attribute_hidden;
+extern __typeof (strspn) __strspn_power7 attribute_hidden;
+
+libc_ifunc (strspn,
+ (hwcap & PPC_FEATURE_HAS_VSX)
+ ? __strspn_power7
+ : __strspn_ppc);
+#endif
diff --git a/sysdeps/powerpc/powerpc64/power7/strspn.S b/sysdeps/powerpc/powerpc64/power7/strspn.S
new file mode 100644
index 0000000..876e9cc
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/power7/strspn.S
@@ -0,0 +1,148 @@
+/* Optimized strspn implementation for PowerPC64/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/>. */
+
+/* size_t [r3] strspn (const char *string [r3],
+ const char *needleAccept [r4] */
+
+/* Performance gains are grabbed through following techniques:
+
+ > hashing of needle.
+ > hashing avoids scanning of duplicate entries in needle across the string.
+ > initializing the hash table with Vector instructions by quadword access.
+ > unrolling when scanning for character in string across hash table. */
+
+/* Algorithm is as below:
+ 1. A empty hash table/dictionary is created comprising of 256 ascii character set
+ 2. When hash entry is found in needle , the hash index is initialized to 1
+ 3. The string is scanned until end and for every character, its corresponding
+ hash index is compared.
+ 4. initial length of string (count) until first hit of accept needle to be found
+ is set to 0
+ 4. If hash index is set to 1 for the index of string, count is returned.
+ 5. Otherwise count is incremented and scanning continues until end of string. */
+
+#include <sysdep.h>
+
+#undef strspn
+
+ .machine power7
+EALIGN(strspn, 4, 0)
+ CALL_MCOUNT 2
+
+ lbz r10, 0(r4) /* load r10 with needle (r4) */
+ addi r9, r1, -256 /* r9 is a hash of 256 bytes */
+
+ li r5, 16 /* set r5 = 16 as offset */
+ li r6, 32 /* set r6 = 32 as offset */
+ li r8, 48 /* set r8 = 48 as offset */
+
+/*Iniatliaze hash table with Zeroes in double indexed quadword accesses */
+ xxlxor v0, v0, v0 /* prepare for initializing hash */
+
+ stxvd2x v0, r0, r9 /* initialize 1st quadword */
+ stxvd2x v0, r9, r5
+ stxvd2x v0, r9, r6
+ stxvd2x v0, r9, r8 /* initialize 4th quadword */
+
+ addi r11, r9, 64 /* r11 is index to hash */
+
+ stxvd2x v0, r0, r11 /* initialize 5th quadword */
+ stxvd2x v0, r11, r5
+ stxvd2x v0, r11, r6
+ stxvd2x v0, r11, r8 /* initialize 8th quadword */
+
+ addi r11, r9, 128 /* r11 is index to hash */
+
+ stxvd2x v0, r0, r11 /* initialize 9th quadword */
+ stxvd2x v0, r11, r5
+ stxvd2x v0, r11, r6
+ stxvd2x v0, r11, r8 /* initialize 12th quadword */
+
+ addi r11, r9, 192 /* r11 is index to hash */
+
+ stxvd2x v0, r0, r11 /* initialize 13th quadword */
+ stxvd2x v0, r11, r5
+ stxvd2x v0, r11, r6
+ stxvd2x v0, r11, r8 /* initialize 16th quadword */
+
+ li r8, 1 /* r8=1, marker into hash if found in needle */
+
+ cmpdi cr7, r10, 0 /* accept needle is NULL */
+ beq cr7, L(skipHashing) /* if needle is NULL, skip hashing */
+
+ .p2align 4 /* align section to 16 byte boundary */
+L(hashing):
+ stbx r8, r9, r10 /* update hash with marker for the pivot of the needle */
+ lbzu r10, 1(r4) /* load needle into r10 and update to next */
+ cmpdi cr7, r10, 0 /* if needle is has reached NULL, continue */
+ bne cr7, L(hashing) /* loop to hash the needle */
+
+L(skipHashing):
+ li r10, 0 /* load counter = 0 */
+ b L(beginScan)
+
+ .p2align 4 /* align section to 16 byte boundary */
+L(scanUnroll):
+ lbzx r8, r9, r8 /* load r8 with hash value at index */
+ cmpwi cr7, r8, 0 /* if we hit marker in hash, we have found accept needle */
+ beq cr7, L(ret1stIndex) /* we have hit accept needle, return the count */
+
+ lbz r8, 1(r3) /* load string[1] into r8 */
+ addi r10, r10, 4 /* increment counter */
+ lbzx r8, r9, r8 /* load r8 with hash value at index */
+ cmpwi cr7, r8, 0 /* if we hit marker in hash, we have found accept needle */
+ beq cr7, L(ret2ndIndex) /* we have hit accept needle, return the count */
+
+ lbz r8, 2(r3) /* load string[2] into r8 */
+ lbzx r8, r9, r8 /* load r8 with hash value at index */
+ cmpwi cr7, r8, 0 /* if we hit marker in hash, we have found accept needle */
+ beq cr7, L(ret3rdIndex) /* we have hit accept needle, return the count */
+
+ lbz r8, 3(r3) /* load string[3] into r8 */
+ lbzx r8, r9, r8 /* load r8 with hash value at index */
+ addi r3, r3, 4 /* unroll factor , increment string by 4 */
+ cmpwi cr7, r8, 0 /* if we hit marker in hash, we have found accept needle */
+ beq cr7,L(ret4thIndex) /* we have hit accept needle, return the count */
+
+L(beginScan):
+ lbz r8, 0(r3) /* load string[0] into r8 */
+ addi r6, r10, 1 /* place holder for counter + 1 */
+ addi r5, r10, 2 /* place holder for counter + 2 */
+ addi r4, r10, 3 /* place holder for counter + 3 */
+ cmpdi cr7, r8, 0 /* if we hit marker in hash, we have found accept needle */
+ bne cr7, L(scanUnroll) /* continue scanning */
+
+L(ret1stIndex):
+ mr r3, r10 /* update r3 for return */
+ blr /* return */
+
+L(ret2ndIndex):
+ mr r3, r6 /* update r3 for return */
+ blr /* return */
+
+L(ret3rdIndex):
+ mr r3, r5 /* update r3 for return */
+ blr /* return */
+
+L(ret4thIndex):
+ mr r3, r4 /* update r3 for return */
+ blr /* done */
+
+END(strspn)
+libc_hidden_builtin_def (strspn)
--
1.8.3.1