summaryrefslogtreecommitdiff
path: root/sysdeps/powerpc/powerpc64/strpbrk.S
diff options
context:
space:
mode:
authorAdhemerval Zanella <azanella@linux.vnet.ibm.com>2014-11-19 16:27:56 -0500
committerAdhemerval Zanella <azanella@linux.vnet.ibm.com>2014-12-02 13:34:02 -0500
commit0f0a1c82f5d8e7b8d24f9eddc2b7728abd3d5bc4 (patch)
tree4c0490845d3af2ee55f351c32741fac1af18d8ef /sysdeps/powerpc/powerpc64/strpbrk.S
parentbb2542e0ae6f82197e804e7e9b78fed461553fc0 (diff)
downloadglibc-0f0a1c82f5d8e7b8d24f9eddc2b7728abd3d5bc4.tar.gz
powerpc: Add powerpc64 strpbrk optimization
This patch makes the POWER7 optimized strpbrk generic by using default doubleword stores to zero the hash, instead of VSX instructions. Performance on POWER7/POWER8 does not change.
Diffstat (limited to 'sysdeps/powerpc/powerpc64/strpbrk.S')
-rw-r--r--sysdeps/powerpc/powerpc64/strpbrk.S135
1 files changed, 135 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc64/strpbrk.S b/sysdeps/powerpc/powerpc64/strpbrk.S
new file mode 100644
index 0000000000..6b2ad4d1aa
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/strpbrk.S
@@ -0,0 +1,135 @@
+/* Optimized strpbrk implementation for PowerPC64.
+ 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>
+
+/* char [r3] *strpbrk(const char [r4] *s, const char [r5] *accept) */
+
+EALIGN (strpbrk, 4, 0)
+ CALL_MCOUNT 3
+
+ lbz r10,0(r4)
+ cmpdi cr7,r10,0 /* accept[0] == '\0' ? */
+ beq cr7,L(nullfound)
+
+ /* The idea to speed up the algorithm is to create a lookup table
+ for fast check if input character should be considered. For ASCII
+ or ISO-8859-X character sets it has 256 positions. */
+
+ /* PPC64 ELF ABI stack is aligned to 16 bytes. */
+ addi r9,r1,-256
+ /* Clear the table with 0 values */
+ li r6, 0
+ li r7, 4
+ mtctr r7
+ mr r8, r9
+ .align 4
+L(zerohash):
+ std r6, 0(r8)
+ std r6, 8(r8)
+ std r6, 16(r8)
+ std r6, 24(r8)
+ std r6, 32(r8)
+ std r6, 40(r8)
+ std r6, 48(r8)
+ std r6, 56(r8)
+ addi r8, r8, 64
+ bdnz L(zerohash)
+
+ /* Initialize the table as:
+ for (i=0; accept[i]; i++
+ table[accept[i]]] = 1 */
+ li r0,1
+ .align 4
+L(init_table):
+ stbx r0,r9,r10
+ lbzu r10,1(r4)
+ cmpdi r0,r10,0
+ bne cr0,L(init_table)
+L(finish_table):
+ /* set table[0] = 1 */
+ li r4,1
+ stb r4,0(r9)
+ b L(mainloop)
+
+ /* Unrool the loop 4 times and check using the table as:
+ i = 0;
+ while (1)
+ {
+ if (table[input[i++]] == 1)
+ return (s[i -1] ? s + i - 1: NULL);
+ if (table[input[i++]] == 1)
+ return (s[i -1] ? s + i - 1: NULL);
+ if (table[input[i++]] == 1)
+ return (s[i -1] ? s + i - 1: NULL);
+ if (table[input[i++]] == 1)
+ return (s[i -1] ? s + i - 1: NULL);
+ } */
+ .align 4
+L(unroll):
+ lbz r0,1(r3)
+ lbzx r8,r9,r0
+ cmpwi cr6,r8,1
+ beq cr6,L(checkend2)
+ lbz r10,2(r3)
+ lbzx r4,r9,r10
+ cmpwi cr7,r4,1
+ beq cr7,L(checkend3)
+ lbz r12,3(r3)
+ addi r3,r3,4
+ lbzx r11,r9,r12
+ cmpwi cr0,r11,1
+ beq cr0,L(checkend)
+L(mainloop):
+ lbz r12,0(r3)
+ addi r11,r3,1
+ addi r5,r3,2
+ addi r7,r3,3
+ lbzx r6,r9,r12
+ cmpwi cr1,r6,1
+ bne cr1,L(unroll)
+ cmpdi cr0,r12,0
+ beq cr0,L(nullfound)
+L(end):
+ blr
+
+ .align 4
+L(checkend):
+ cmpdi cr1,r12,0
+ mr r3,r7
+ bne cr1,L(end)
+L(nullfound):
+ /* return NULL */
+ li 3,0
+ blr
+
+ .align 4
+L(checkend2):
+ cmpdi cr7,r0,0
+ mr r3,r11
+ beq cr7,L(nullfound)
+ blr
+
+ .align 4
+L(checkend3):
+ cmpdi cr6,r10,0
+ mr r3,r5
+ beq cr6,L(nullfound)
+ blr
+END (strpbrk)
+libc_hidden_builtin_def (strpbrk)