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authorAdhemerval Zanella <azanella@linux.vnet.ibm.com>2014-11-19 14:24:18 -0500
committerAdhemerval Zanella <azanella@linux.vnet.ibm.com>2014-12-02 07:15:58 -0500
commit2e8a2de2dafa3238b5b58eecb407af6825a780cd (patch)
tree0a89b6df52343efcbd359cb0c0c07b2f0a8bcbe7 /sysdeps/powerpc/powerpc64/power7
parent08f1e1d2bca9ef087813357780ec0bafe71c7d29 (diff)
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powerpc: Add powerpc64 strspn optimization
This patch makes the POWER7 optimized strspn generic by using default doubleword stores to zero the hash, instead of VSX instructions. Performance on POWER7/POWER8 machines does not changed.
Diffstat (limited to 'sysdeps/powerpc/powerpc64/power7')
-rw-r--r--sysdeps/powerpc/powerpc64/power7/strspn.S165
1 files changed, 0 insertions, 165 deletions
diff --git a/sysdeps/powerpc/powerpc64/power7/strspn.S b/sysdeps/powerpc/powerpc64/power7/strspn.S
deleted file mode 100644
index d587a67..0000000
--- a/sysdeps/powerpc/powerpc64/power7/strspn.S
+++ /dev/null
@@ -1,165 +0,0 @@
-/* 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)