about summary refs log tree commit diff
path: root/src/string/armel/memcpy.sub
diff options
context:
space:
mode:
authorRich Felker <dalias@aerifal.cx>2013-08-14 03:06:21 -0400
committerRich Felker <dalias@aerifal.cx>2013-08-14 03:06:21 -0400
commitcccc1844be95549e5b6c91ffc1f2c2ba3d3aab16 (patch)
treebf9cd7643d50131983f17d4631432b70db274d9c /src/string/armel/memcpy.sub
parentfb72a97df9222be61ec582ba7b1e9ce496b65e3e (diff)
downloadmusl-cccc1844be95549e5b6c91ffc1f2c2ba3d3aab16.tar.gz
musl-cccc1844be95549e5b6c91ffc1f2c2ba3d3aab16.tar.xz
musl-cccc1844be95549e5b6c91ffc1f2c2ba3d3aab16.zip
add arm-optimized memcpy implementation from bionic libc
the approach of this implementation was heavily investigated prior to
adopting it. attempts to obtain similar performance with pure C code
were capping out at about 75% of the performance of the asm, with
considerably larger code size, and were fragile in that the compiler
would sometimes compile part of memcpy into a call to itself.
therefore, just using the asm seems to be the best option.

this commit is the first to make use of the new subarch-specific asm
framework. the new armel directory is the location for arm asm that
should not be used for all arm subarchs, only the default one. armhf
is the name of the little-endian hardfloat-ABI subarch, which can use
the exact same asm. in both cases, the build system finds the asm by
following a memcpy.sub file.

the other two subarchs, armeb and armebhf, would need a big-endian
variant of this code. it would not be hard to adapt the code to big
endian, but I will hold off on doing so until there is demand for it.
Diffstat (limited to 'src/string/armel/memcpy.sub')
-rw-r--r--src/string/armel/memcpy.sub1
1 files changed, 1 insertions, 0 deletions
diff --git a/src/string/armel/memcpy.sub b/src/string/armel/memcpy.sub
new file mode 100644
index 00000000..543f583f
--- /dev/null
+++ b/src/string/armel/memcpy.sub
@@ -0,0 +1 @@
+memcpy.s