about summary refs log tree commit diff
path: root/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S
diff options
context:
space:
mode:
authorVidya Ranganathan <vidya@linux.vnet.ibm.com>2014-05-05 19:10:45 -0500
committerAdhemerval Zanella <azanella@linux.vnet.ibm.com>2014-05-06 09:54:25 -0500
commitf360f94a05570045be615649e9a411cefba2e210 (patch)
treeac6fb86d01ea80b3bf914c2f74aa231b42bfda28 /sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S
parent978a41c35738dbe4592edb7dcaa155fec31dab50 (diff)
downloadglibc-f360f94a05570045be615649e9a411cefba2e210.tar.gz
glibc-f360f94a05570045be615649e9a411cefba2e210.tar.xz
glibc-f360f94a05570045be615649e9a411cefba2e210.zip
PowerPC: strncpy/stpncpy optimization for PPC64/POWER7
The optimization is achieved by following techniques:
  > data alignment [gain from aligned memory access on read/write]
  > POWER7 gains performance with loop unrolling/unwinding
    [gain by reduction of branch penalty].
  > zero padding done by calling optimized memset
Diffstat (limited to 'sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S')
-rw-r--r--sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S44
1 files changed, 44 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S b/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S
new file mode 100644
index 0000000000..e29674fbf4
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/stpncpy-power7.S
@@ -0,0 +1,44 @@
+/* Optimized stpncpy 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>
+
+#define USE_AS_STPNCPY
+
+#undef EALIGN
+#define EALIGN(name, alignt, words)				\
+  .section ".text";						\
+  ENTRY_2(__stpncpy_power7)					\
+  .align ALIGNARG(alignt);					\
+  EALIGN_W_##words;						\
+  BODY_LABEL(__stpncpy_power7):					\
+  cfi_startproc;						\
+  LOCALENTRY(__stpncpy_power7)
+
+#undef END
+#define END(name)						\
+  cfi_endproc;							\
+  TRACEBACK(__stpncpy_power7)					\
+  END_2(__stpncpy_power7)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#define MEMSET __memset_power7
+
+#include <sysdeps/powerpc/powerpc64/power7/stpncpy.S>