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authorRajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>2014-03-03 08:06:41 -0600
committerAdhemerval Zanella <azanella@linux.vnet.ibm.com>2014-03-03 08:06:41 -0600
commitc7debbdfacbef150aaf9113eb05ccaf2b9e7af6c (patch)
treebaf78c9b58faa86b3996ae3745cb81fd50e2fb58
parent235eed8644eb2deebf839b13b418dbd47bb14c5a (diff)
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PowerPC: strrchr optimization for POWER7/PPC64
This patch optimizes strrchr() for ppc64. It uses aligned memory access along with cmpb instruction and CPU prefetch to avoid cache misses for speed improvement.
-rw-r--r--ChangeLog12
-rw-r--r--string/strrchr.c6
-rw-r--r--sysdeps/powerpc/powerpc64/multiarch/Makefile3
-rw-r--r--sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c8
-rw-r--r--sysdeps/powerpc/powerpc64/multiarch/strrchr-power7.S39
-rw-r--r--sysdeps/powerpc/powerpc64/multiarch/strrchr-ppc64.c33
-rw-r--r--sysdeps/powerpc/powerpc64/multiarch/strrchr.c35
-rw-r--r--sysdeps/powerpc/powerpc64/power7/strrchr.S255
8 files changed, 389 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog
index 45eb5ab..b4a7daa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2014-03-03 Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
+
+ * sysdeps/powerpc/powerpc64/power7/strrchr.S: New file.
+ * sysdeps/powerpc/powerpc64/multiarch/Makefile: Add strrchr multiarch
+ implementation.
+ * sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c:
+ (__libc_ifunc_impl_list): Likewise.
+ * sysdeps/powerpc/powerpc64/multiarch/strrchr.c: New file.
+ * sysdeps/powerpc/powerpc64/multiarch/strrchr-ppc64.c: New file.
+ * sysdeps/powerpc/powerpc64/multiarch/strrchr-power7.S: New file.
+ * string/strrchr.c: Define STRRCHR.
+
2014-02-28 Ondřej Bílka <neleai@seznam.cz>
* benchtest/bench-strtok.c (simple_strtok): Delete.
diff --git a/string/strrchr.c b/string/strrchr.c
index b5b4bc6..47ff08c 100644
--- a/string/strrchr.c
+++ b/string/strrchr.c
@@ -19,9 +19,13 @@
#undef strrchr
+#ifndef STRRCHR
+# define STRRCHR strrchr
+#endif
+
/* Find the last occurrence of C in S. */
char *
-strrchr (const char *s, int c)
+STRRCHR (const char *s, int c)
{
const char *found, *p;
diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index 3c47316..d09f2e3 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -13,7 +13,8 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
wcschr-power6 wcschr-ppc64 wcsrchr-power7 wcsrchr-power6 \
wcsrchr-ppc64 wcscpy-power7 wcscpy-power6 wcscpy-ppc64 \
wordcopy-power7 wordcopy-power6 wordcopy-ppc64 \
- strcpy-power7 strcpy-ppc64 stpcpy-power7 stpcpy-ppc64
+ strcpy-power7 strcpy-ppc64 stpcpy-power7 stpcpy-ppc64 \
+ strrchr-power7 strrchr-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 6bbdd4e..8789483 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -238,5 +238,13 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL_ADD (array, i, wcscpy, 1,
__wcscpy_ppc))
+ /* Support sysdeps/powerpc/powerpc64/multiarch/strrchr.c. */
+ IFUNC_IMPL (i, name, strrchr,
+ IFUNC_IMPL_ADD (array, i, strrchr,
+ hwcap & PPC_FEATURE_HAS_VSX,
+ __strrchr_power7)
+ IFUNC_IMPL_ADD (array, i, strrchr, 1,
+ __strrchr_ppc))
+
return i;
}
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strrchr-power7.S b/sysdeps/powerpc/powerpc64/multiarch/strrchr-power7.S
new file mode 100644
index 0000000..78e15e3
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strrchr-power7.S
@@ -0,0 +1,39 @@
+/* Optimized strrchr 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 ENTRY
+#define ENTRY(name) \
+ .section ".text"; \
+ ENTRY_2(__strrchr_power7) \
+ .align ALIGNARG(2); \
+ BODY_LABEL(__strrchr_power7): \
+ cfi_startproc; \
+ LOCALENTRY(__strrchr_power7)
+
+#undef END
+#define END(name) \
+ cfi_endproc; \
+ TRACEBACK(__strrchr_power7) \
+ END_2(__strrchr_power7)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power7/strrchr.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strrchr-ppc64.c b/sysdeps/powerpc/powerpc64/multiarch/strrchr-ppc64.c
new file mode 100644
index 0000000..5633a9f
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strrchr-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 STRRCHR __strrchr_ppc
+#undef weak_alias
+#define weak_alias(name, aliasname) \
+ extern __typeof (__strrchr_ppc) aliasname \
+ __attribute__ ((weak, alias ("__strrchr_ppc")));
+#if !defined(NOT_IN_libc) && defined(SHARED)
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(name) \
+ __hidden_ver1(__strrchr_ppc, __GI_strrchr, __strrchr_ppc);
+#endif
+
+extern __typeof (strrchr) __strrchr_ppc attribute_hidden;
+
+#include <string/strrchr.c>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strrchr.c b/sysdeps/powerpc/powerpc64/multiarch/strrchr.c
new file mode 100644
index 0000000..046162f
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strrchr.c
@@ -0,0 +1,35 @@
+/* Multiple versions of strrchr. 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/>. */
+
+/* Define multiple versions only for definition in libc. */
+#ifndef NOT_IN_libc
+# include <string.h>
+# include <shlib-compat.h>
+# include "init-arch.h"
+
+extern __typeof (strrchr) __strrchr_ppc attribute_hidden;
+extern __typeof (strrchr) __strrchr_power7 attribute_hidden;
+
+/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
+ ifunc symbol properly. */
+libc_ifunc (strrchr,
+ (hwcap & PPC_FEATURE_HAS_VSX)
+ ? __strrchr_power7
+ : __strrchr_ppc);
+weak_alias (strrchr, rindex)
+#endif
diff --git a/sysdeps/powerpc/powerpc64/power7/strrchr.S b/sysdeps/powerpc/powerpc64/power7/strrchr.S
new file mode 100644
index 0000000..e4a76c8
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/power7/strrchr.S
@@ -0,0 +1,255 @@
+/* Optimized strrchr implementation for PowerPC64/POWER7 using cmpb insn.
+ 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>
+
+/* int [r3] strrchr (char *s [r3], int c [r4]) */
+ .machine power7
+ENTRY (strrchr)
+ CALL_MCOUNT 2
+ dcbt 0,r3
+ clrrdi r8,r3,3 /* Align the address to doubleword boundary. */
+ cmpdi cr7,r4,0
+ ld r12,0(r8) /* Load doubleword from memory. */
+ li r9,0 /* used to store last occurence */
+ li r0,0 /* Doubleword with null chars to use
+ with cmpb. */
+
+ rlwinm r6,r3,3,26,28 /* Calculate padding. */
+
+ beq cr7,L(null_match)
+
+ /* Replicate byte to doubleword. */
+ insrdi r4,r4,8,48
+ insrdi r4,r4,16,32
+ insrdi r4,r4,32,0
+
+ /* r4 is changed now ,if its passed as more chars
+ check for null again */
+ cmpdi cr7,r4,0
+ beq cr7,L(null_match)
+ /* Now r4 has a doubleword of c bytes and r0 has
+ a doubleword of null bytes. */
+
+ cmpb r10,r12,r4 /* Compare each byte against c byte. */
+ cmpb r11,r12,r0 /* Compare each byte against null byte. */
+
+ /* Move the doublewords left and right to discard the bits that are
+ not part of the string and bring them back as zeros. */
+#ifdef __LITTLE_ENDIAN__
+ srd r10,r10,r6
+ srd r11,r11,r6
+ sld r10,r10,r6
+ sld r11,r11,r6
+#else
+ sld r10,r10,r6
+ sld r11,r11,r6
+ srd r10,r10,r6
+ srd r11,r11,r6
+#endif
+ or r5,r10,r11 /* OR the results to speed things up. */
+ cmpdi cr7,r5,0 /* If r5 == 0, no c or null bytes
+ have been found. */
+ bne cr7,L(done)
+
+L(align):
+ mtcrf 0x01,r8
+
+ /* Are we now aligned to a doubleword boundary? If so, skip to
+ the main loop. Otherwise, go through the alignment code. */
+
+ bt 28,L(loop)
+
+ /* Handle WORD2 of pair. */
+ ldu r12,8(r8)
+ cmpb r10,r12,r4
+ cmpb r11,r12,r0
+ or r5,r10,r11
+ cmpdi cr7,r5,0
+ bne cr7,L(done)
+ b L(loop) /* We branch here (rather than falling through)
+ to skip the nops due to heavy alignment
+ of the loop below. */
+ .p2align 5
+L(loop):
+ /* Load two doublewords, compare and merge in a
+ single register for speed. This is an attempt
+ to speed up the null-checking process for bigger strings. */
+ ld r12,8(r8)
+ ldu r7,16(r8)
+ cmpb r10,r12,r4
+ cmpb r11,r12,r0
+ cmpb r6,r7,r4
+ cmpb r7,r7,r0
+ or r12,r10,r11
+ or r5,r6,r7
+ or r5,r12,r5
+ cmpdi cr7,r5,0
+ beq cr7,L(loop)
+
+ /* OK, one (or both) of the doublewords contains a c/null byte. Check
+ the first doubleword and decrement the address in case the first
+ doubleword really contains a c/null byte. */
+ cmpdi cr6,r12,0
+ addi r8,r8,-8
+ bne cr6,L(done)
+
+ /* The c/null byte must be in the second doubleword. Adjust the
+ address again and move the result of cmpb to r10 so we can calculate
+ the pointer. */
+
+ mr r10,r6
+ mr r11,r7
+ addi r8,r8,8
+
+ /* r10/r11 have the output of the cmpb instructions, that is,
+ 0xff in the same position as the c/null byte in the original
+ doubleword from the string. Use that to calculate the pointer. */
+
+L(done):
+ /* if there are more than one 0xff in r11, find the first pos of ff
+ in r11 and fill r10 with 0 from that position */
+ cmpdi cr7,r11,0
+ beq cr7,L(no_null)
+#ifdef __LITTLE_ENDIAN__
+ addi r3,r11,-1
+ andc r3,r3,r11
+ popcntd r0,r3
+#else
+ cntlzd r0,r11
+#endif
+ subfic r0,r0,63
+ li r6,-1
+#ifdef __LITTLE_ENDIAN__
+ srd r0,r6,r0
+#else
+ sld r0,r6,r0
+#endif
+ and r10,r0,r10
+L(no_null):
+#ifdef __LITTLE_ENDIAN__
+ cntlzd r0,r10 /* Count leading zeros before c matches. */
+ addi r3,r10,-1
+ andc r3,r3,r10
+ addi r10,r11,-1
+ andc r10,r10,r11
+ cmpld cr7,r3,r10
+ bgt cr7,L(no_match)
+#else
+ addi r3,r10,-1 /* Count trailing zeros before c matches. */
+ andc r3,r3,r10
+ popcntd r0,r3
+ cmpld cr7,r11,r10
+ bgt cr7,L(no_match)
+#endif
+ srdi r0,r0,3 /* Convert trailing zeros to bytes. */
+ subfic r0,r0,7
+ add r9,r8,r0 /* Return address of the matching c byte
+ or null in case c was not found. */
+ li r0,0
+ cmpdi cr7,r11,0 /* If r11 == 0, no null's have been found. */
+ beq cr7,L(align)
+
+ .align 4
+L(no_match):
+ mr r3,r9
+ blr
+
+/* We are here because strrchr was called with a null byte. */
+ .align 4
+L(null_match):
+ /* r0 has a doubleword of null bytes. */
+
+ cmpb r5,r12,r0 /* Compare each byte against null bytes. */
+
+ /* Move the doublewords left and right to discard the bits that are
+ not part of the string and bring them back as zeros. */
+#ifdef __LITTLE_ENDIAN__
+ srd r5,r5,r6
+ sld r5,r5,r6
+#else
+ sld r5,r5,r6
+ srd r5,r5,r6
+#endif
+ cmpdi cr7,r5,0 /* If r10 == 0, no c or null bytes
+ have been found. */
+ bne cr7,L(done_null)
+
+ mtcrf 0x01,r8
+
+ /* Are we now aligned to a quadword boundary? If so, skip to
+ the main loop. Otherwise, go through the alignment code. */
+
+ bt 28,L(loop_null)
+
+ /* Handle WORD2 of pair. */
+ ldu r12,8(r8)
+ cmpb r5,r12,r0
+ cmpdi cr7,r5,0
+ bne cr7,L(done_null)
+ b L(loop_null) /* We branch here (rather than falling through)
+ to skip the nops due to heavy alignment
+ of the loop below. */
+
+ /* Main loop to look for the end of the string. Since it's a
+ small loop (< 8 instructions), align it to 32-bytes. */
+ .p2align 5
+L(loop_null):
+ /* Load two doublewords, compare and merge in a
+ single register for speed. This is an attempt
+ to speed up the null-checking process for bigger strings. */
+ ld r12,8(r8)
+ ldu r11,16(r8)
+ cmpb r5,r12,r0
+ cmpb r10,r11,r0
+ or r6,r5,r10
+ cmpdi cr7,r6,0
+ beq cr7,L(loop_null)
+
+ /* OK, one (or both) of the doublewords contains a null byte. Check
+ the first doubleword and decrement the address in case the first
+ doubleword really contains a null byte. */
+
+ cmpdi cr6,r5,0
+ addi r8,r8,-8
+ bne cr6,L(done_null)
+
+ /* The null byte must be in the second doubleword. Adjust the address
+ again and move the result of cmpb to r10 so we can calculate the
+ pointer. */
+
+ mr r5,r10
+ addi r8,r8,8
+
+ /* r5 has the output of the cmpb instruction, that is, it contains
+ 0xff in the same position as the null byte in the original
+ doubleword from the string. Use that to calculate the pointer. */
+L(done_null):
+#ifdef __LITTLE_ENDIAN__
+ addi r0,r5,-1
+ andc r0,r0,r5
+ popcntd r0,r0
+#else
+ cntlzd r0,r5 /* Count leading zeros before the match. */
+#endif
+ srdi r0,r0,3 /* Convert trailing zeros to bytes. */
+ add r3,r8,r0 /* Return address of the matching null byte. */
+ blr
+END (strrchr)
+weak_alias (strrchr, rindex)
+libc_hidden_builtin_def (strrchr)