glibc/sysdeps/powerpc/powerpc64/multiarch/stpcpy-power8.S
Adhemerval Zanella 96d6fd6c40 powerpc: Optimized st{r,p}cpy for POWER8/PPC64
This patch adds an optimized POWER8 strcpy using unaligned accesses.
For strings up to 16 bytes the implementation first calculate the
string size, like strlen, and issues a memcpy.  For larger strings,
source is first aligned to 16 bytes and then tested over a loop that
reads 16 bytes am combine the cmpb results for speedup.  Special case is
added for page cross reads.

It shows 30%-60% improvement over the optimized POWER7 one that uses
only aligned accesses.
2015-01-13 11:28:30 -05:00

41 lines
1.3 KiB
ArmAsm

/* Optimized stpcpy implementation for POWER8/PPC64.
Copyright (C) 2015 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(__stpcpy_power8) \
.align ALIGNARG(alignt); \
EALIGN_W_##words; \
BODY_LABEL(__stpcpy_power8): \
cfi_startproc; \
LOCALENTRY(__stpcpy_power8)
#undef END
#define END(name) \
cfi_endproc; \
TRACEBACK(__stpcpy_power8) \
END_2(__stpcpy_power8)
#undef libc_hidden_builtin_def
#define libc_hidden_builtin_def(name)
#include <sysdeps/powerpc/powerpc64/power8/stpcpy.S>