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go / go / ea4e321d4daef32f4cd8df8ec799122ff3c6b9f0
commitea4e321d4daef32f4cd8df8ec799122ff3c6b9f0[log] [tgz]
authorDave Cheney <dave@cheney.net>Sat Sep 12 00:10:42 2015 +1000
committerDave Cheney <dave@cheney.net>Sat Sep 12 02:55:38 2015 +0000
treee224e2c91c0a61c9293ca6a00d8e8bbb3998542f
parent3b0224282cf84228d6bcd4b783eb164e579fbd9e [diff]
cmd/compile/internal/gc: avoid allocation in bnum

Although bnum was being called with a Bits value, a limitation
of the escape analyser (golang/go#12588) meant that taking the
address of the Bits.b array in the range statement caused the
formal parameter to escape to the heap.

Passing the a pointer to a Bits, as with all the other Bits helper
methods avoids the allocation.

Before:
BenchmarkBnum1-4        20000000                69.6 ns/op            32 B/op          1 allocs/op

After:
BenchmarkBnum1-4        100000000               10.1 ns/op             0 B/op          0 allocs/op

Change-Id: I673bd57ddc032ee67d09474156d795fb1ba72018
Reviewed-on: https://go-review.googlesource.com/14501
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
1 file changed
tree: e224e2c91c0a61c9293ca6a00d8e8bbb3998542f
  1. api/
  2. doc/
  3. lib/
  4. misc/
  5. src/
  6. test/
  7. .gitattributes
  8. .gitignore
  9. AUTHORS
  10. CONTRIBUTING.md
  11. CONTRIBUTORS
  12. favicon.ico
  13. LICENSE
  14. PATENTS
  15. README.md
  16. robots.txt
README.md

The Go Programming Language

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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 https://golang.org/doc/install or doc/install.html for more details.