PowerPC: Optimized strcmp for PPC64/POWER7

Optimization is achieved on 8 byte aligned strings with double word
comparison using cmpb instruction. On unaligned strings loop unrolling
is applied for Power7 gain.

1 files changed, 40 insertions, 0 deletions

diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcmp-power7.S b/sysdeps/powerpc/powerpc64/multiarch/strcmp-power7.S
new file mode 100644
index 0000000..790ce8d
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strcmp-power7.S
@@ -0,0 +1,40 @@
+/* Optimized strcmp 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(__strcmp_power7)					\
+  .align ALIGNARG(alignt);					\
+  EALIGN_W_##words;						\
+  BODY_LABEL(__strcmp_power7):					\
+  cfi_startproc;						\
+  LOCALENTRY(__strcmp_power7)
+
+#undef END
+#define END(name)						\
+  cfi_endproc;							\
+  TRACEBACK(__strcmp_power7)					\
+  END_2(__strcmp_power7)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power7/strcmp.S>