diff mbox

Multiarch optimization for strspn on POWERPC

Message ID 53199E07.6040009@linux.vnet.ibm.com
State Committed
Delegated to: Adhemerval Zanella Netto
Headers show

Commit Message

R Vidya March 7, 2014, 10:23 a.m. UTC
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)

Comments

Adhemerval Zanella Netto March 10, 2014, 2:39 p.m. UTC | #1
Hi Vidya,

Sorry if I didn't catch it early, but just noted some line are not respecting the 80 column
requirement from code guidelines, please fix these (example below). Also, I just also noted
since you are touching 'string/strspn.c' it is worth of cleanup the old C-style (comment
below). With this change I think it is good to push upstream.


On 07-03-2014 07:23, 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;
>  {

There is no need on using old K&R style, just convert it to STRSPN (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

Here it is an example of the column limit limit, please break it to fix 80 column.
Also check for all file, since there are other issues relating to this.

> +   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)
diff mbox

Patch

>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