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The Go programming language
a712e20a1d
MOV with SSE registers seems faster than REP MOVSQ if the size being copied is less than about 2K. Previously we didn't use MOV if the memory region is larger than 256 byte. This patch improves the performance of 257 ~ 2048 byte non-overlapping copy by using MOV. Here is the benchmark result on Intel Xeon 3.5GHz (Nehalem). benchmark old ns/op new ns/op delta BenchmarkMemmove16 4 4 +0.42% BenchmarkMemmove32 5 5 -0.20% BenchmarkMemmove64 6 6 -0.81% BenchmarkMemmove128 7 7 -0.82% BenchmarkMemmove256 10 10 +1.92% BenchmarkMemmove512 29 16 -44.90% BenchmarkMemmove1024 37 25 -31.55% BenchmarkMemmove2048 55 44 -19.46% BenchmarkMemmove4096 92 91 -0.76% benchmark old MB/s new MB/s speedup BenchmarkMemmove16 3370.61 3356.88 1.00x BenchmarkMemmove32 6368.68 6386.99 1.00x BenchmarkMemmove64 10367.37 10462.62 1.01x BenchmarkMemmove128 17551.16 17713.48 1.01x BenchmarkMemmove256 24692.81 24142.99 0.98x BenchmarkMemmove512 17428.70 31687.72 1.82x BenchmarkMemmove1024 27401.82 40009.45 1.46x BenchmarkMemmove2048 36884.86 45766.98 1.24x BenchmarkMemmove4096 44295.91 44627.86 1.01x LGTM=khr R=golang-codereviews, gobot, khr CC=golang-codereviews https://golang.org/cl/90500043 |
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This is the source code repository for the Go programming language.
For documentation about how to install and use Go,
visit http://golang.org/ or load doc/install-source.html
in your web browser.
After installing Go, you can view a nicely formatted
doc/install-source.html by running godoc --http=:6060
and then visiting http://localhost:6060/doc/install/source.
Unless otherwise noted, the Go source files are distributed
under the BSD-style license found in the LICENSE file.
--
Binary Distribution Notes
If you have just untarred a binary Go distribution, you need to set
the environment variable $GOROOT to the full path of the go
directory (the one containing this README). You can omit the
variable if you unpack it into /usr/local/go, or if you rebuild
from sources by running all.bash (see doc/install.html).
You should also add the Go binary directory $GOROOT/bin
to your shell's path.
For example, if you extracted the tar file into $HOME/go, you might
put the following in your .profile:
export GOROOT=$HOME/go
export PATH=$PATH:$GOROOT/bin
See doc/install.html for more details.