mirror of https://github.com/golang/go.git
7910cd68b5
On entry to a function, zero the results and zero the pointer section of the local variables. This is an intermediate step on the way to precise collection of Go frames. This can incur a significant (up to 30%) slowdown, but it also ensures that the garbage collector never looks at a word in a Go frame and sees a stale pointer value that could cause a space leak. (C frames and assembly frames are still possibly problematic.) This CL is required to start making collection of interface values as precise as collection of pointer values are today. Since we have to dereference the interface type to understand whether the value is a pointer, it is critical that the type field be initialized. A future CL by Carl will make the garbage collection pointer bitmaps context-sensitive. At that point it will be possible to remove most of the zeroing. The only values that will still need zeroing are values whose addresses escape the block scoping of the function but do not escape to the heap. benchmark old ns/op new ns/op delta BenchmarkBinaryTree17 4420289180 4331060459 -2.02% BenchmarkFannkuch11 3442469663 3277706251 -4.79% BenchmarkFmtFprintfEmpty 100 142 +42.00% BenchmarkFmtFprintfString 262 310 +18.32% BenchmarkFmtFprintfInt 213 281 +31.92% BenchmarkFmtFprintfIntInt 355 431 +21.41% BenchmarkFmtFprintfPrefixedInt 321 383 +19.31% BenchmarkFmtFprintfFloat 444 533 +20.05% BenchmarkFmtManyArgs 1380 1559 +12.97% BenchmarkGobDecode 10240054 11794915 +15.18% BenchmarkGobEncode 17350274 19970478 +15.10% BenchmarkGzip 455179460 460699139 +1.21% BenchmarkGunzip 114271814 119291574 +4.39% BenchmarkHTTPClientServer 89051 89894 +0.95% BenchmarkJSONEncode 40486799 52691558 +30.15% BenchmarkJSONDecode 94193361 112428781 +19.36% BenchmarkMandelbrot200 4747060 4748043 +0.02% BenchmarkGoParse 6363798 6675098 +4.89% BenchmarkRegexpMatchEasy0_32 129 171 +32.56% BenchmarkRegexpMatchEasy0_1K 365 395 +8.22% BenchmarkRegexpMatchEasy1_32 106 152 +43.40% BenchmarkRegexpMatchEasy1_1K 952 1245 +30.78% BenchmarkRegexpMatchMedium_32 198 283 +42.93% BenchmarkRegexpMatchMedium_1K 79006 101097 +27.96% BenchmarkRegexpMatchHard_32 3478 5115 +47.07% BenchmarkRegexpMatchHard_1K 110245 163582 +48.38% BenchmarkRevcomp 777384355 793270857 +2.04% BenchmarkTemplate 136713089 157093609 +14.91% BenchmarkTimeParse 1511 1761 +16.55% BenchmarkTimeFormat 535 850 +58.88% benchmark old MB/s new MB/s speedup BenchmarkGobDecode 74.95 65.07 0.87x BenchmarkGobEncode 44.24 38.43 0.87x BenchmarkGzip 42.63 42.12 0.99x BenchmarkGunzip 169.81 162.67 0.96x BenchmarkJSONEncode 47.93 36.83 0.77x BenchmarkJSONDecode 20.60 17.26 0.84x BenchmarkGoParse 9.10 8.68 0.95x BenchmarkRegexpMatchEasy0_32 247.24 186.31 0.75x BenchmarkRegexpMatchEasy0_1K 2799.20 2591.93 0.93x BenchmarkRegexpMatchEasy1_32 299.31 210.44 0.70x BenchmarkRegexpMatchEasy1_1K 1074.71 822.45 0.77x BenchmarkRegexpMatchMedium_32 5.04 3.53 0.70x BenchmarkRegexpMatchMedium_1K 12.96 10.13 0.78x BenchmarkRegexpMatchHard_32 9.20 6.26 0.68x BenchmarkRegexpMatchHard_1K 9.29 6.26 0.67x BenchmarkRevcomp 326.95 320.40 0.98x BenchmarkTemplate 14.19 12.35 0.87x R=cshapiro CC=golang-dev https://golang.org/cl/12616045 |
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| AUTHORS | ||
| CONTRIBUTORS | ||
| LICENSE | ||
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| README | ||
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README
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.html in your web browser.
After installing Go, you can view a nicely formatted
doc/install.html by running godoc --http=:6060
and then visiting http://localhost:6060/doc/install.html.
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.