For an unsigned integer, it's useful to convert its order test with 0/1
to its equality test with 0. We can save a comparison instruction that
followed by a conditional branch on arm64 since it supports
compare-with-zero-and-branch instructions. For example,
if x > 0 { ... } else { ... }
the original version:
CMP $0, R0
BLS 9
the optimized version:
CBZ R0, 8
Updates #21439
Change-Id: Id1de6f865f6aa72c5d45b29f7894818857288425
Reviewed-on: https://go-review.googlesource.com/c/go/+/246857
Reviewed-by: Keith Randall <khr@golang.org>
Corrects ErrReader's signature to what was accepted in the approved
proposal, and also removes an exported ErrIO which wasn't part of
the proposal and is unnecessary.
The new signature allows users to customize their own errors.
While here, started examples, with ErrReader leading the way.
Updates #38781
Change-Id: Ia7f84721f11061343cfef8b1adc2b7b69bc3f43c
Reviewed-on: https://go-review.googlesource.com/c/go/+/248898
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
We aren't using it for anything. The visited map will terminate
any recursion for us.
Change-Id: I36e6bd8e34952123c2ed46323067e42928ec7168
Reviewed-on: https://go-review.googlesource.com/c/go/+/238759
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
If the AND has other uses, we end up saving an argument to the AND
in another register, so we can use it for the TEST. No point in doing that.
Change-Id: I73444a6aeddd6f55e2328ce04d77c3e6cf4a83e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/241280
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Just like SIGILL, it might be useful to see what the instruction
that generated the SIGFPE is.
Update #39816
Change-Id: I8b2ff692998f0b770289339537dceab96b09d1ee
Reviewed-on: https://go-review.googlesource.com/c/go/+/239999
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
I noticed that there is a Todo comment here. This variable is only used for filename when dump a function's ssa passes result in details. It is no problem to print a function alone, but may be edited by not only one goroutine if dump multiple functions at the same time. Although it looks only dump one function's ssa passes now. As far as I am concerned this variable can be a member variable of the struct Func. I'm not sure if this change is necessary. Looking forward to your advices, thank you very much.
Change-Id: I35dd7247889e0cc7f19c0b400b597206592dee75
Reviewed-on: https://go-review.googlesource.com/c/go/+/244918
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
Use CBZ to replace the comparison and jump to the zero instruction in the arm64 assembly file.
Change-Id: Ie16fb52e27b4d327343e119ebc0f0ca756437bc4
Reviewed-on: https://go-review.googlesource.com/c/go/+/237477
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Use CBZ to replace the comparison and branch of arm64 and the zero instruction in the assembly file.
Change-Id: Id6c03e9af13aadafc3ad3953f82d2ffa29c12926
Reviewed-on: https://go-review.googlesource.com/c/go/+/237497
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This change deletes the old mcentral implementation from the code base
and the newMCentralImpl feature flag along with it.
Updates #37487.
Change-Id: Ibca8f722665f0865051f649ffe699cbdbfdcfcf2
Reviewed-on: https://go-review.googlesource.com/c/go/+/221184
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
This change removes the old markrootSpans implementation and deletes the
feature flag.
Updates #37487.
Change-Id: Idb5a2559abcc3be5a7da6f2ccce1a86e1d7634e3
Reviewed-on: https://go-review.googlesource.com/c/go/+/221183
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Austin Clements <austin@google.com>
There are some architecture-independent rules in #21439, since an
unsigned integer >= 0 is always true and < 0 is always false. This CL
adds these optimizations to generic rules.
Updates #21439
Change-Id: Iec7e3040b761ecb1e60908f764815fdd9bc62495
Reviewed-on: https://go-review.googlesource.com/c/go/+/246617
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This change does context propagation (and only context propagation)
necessary to add context to modfetch.Download and pkg.LoadImport.
This was done by adding context to their callers, and then
adding context to all call-sites, and then repeating adding
context to callers of those enclosing functions and their
callers until none were left. In some cases the call graph expansion
was pruned by using context.TODOs.
The next CL will add a span to Download. I kept it out of this
change to avoid making it any larger (and harder to review)
than it needs to be.
Updates #38714
Change-Id: I5bf2d599aafef67334c384dfccd5e255198c85b4
Reviewed-on: https://go-review.googlesource.com/c/go/+/248327
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
If we are parsing a test output, and the test does not end in the
usual PASS or FAIL line (say, because it panicked), then we need the
exit status of the test binary in order to determine whether the test
passed or failed. If we don't have that status available, we shouldn't
guess arbitrarily — instead, we should omit the final "pass" or "fail"
action entirely.
(In practice, we nearly always DO have the final status, such as when
running 'go test' or 'go tool test2json some.exe'.)
Fixes#40132
Change-Id: Iae482577361a6033395fe4a05d746b980e18c3de
Reviewed-on: https://go-review.googlesource.com/c/go/+/248624
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
par.Work is used in a number of places as a parallel
work queue. This change replaces it with goroutines
and channels in a number of simpler places where it's
used.
Change-Id: I0620eda46ec7b2c0599a8b9361639af7bb73a05a
Reviewed-on: https://go-review.googlesource.com/c/go/+/248326
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
This change adds context, and a span to modload.LoadBuildList and
propagates context into modload.BuildList. It's the start
of a run of CLs to add trace spans for module operations.
Updates #38714
Change-Id: I0d58dd394051526338092dc9a5ec29a9e087e4e4
Reviewed-on: https://go-review.googlesource.com/c/go/+/248325
Run-TryBot: Michael Matloob <matloob@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
These commands are build-like commands that do their own flag
processing, so the value of debug-trace isn't available until
the command starts running. Start tracing in the cmd's run
function.
Updates #38714
Change-Id: I4d633e6ee907bf09feac52c2aff3daceb9b20e12
Reviewed-on: https://go-review.googlesource.com/c/go/+/248324
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
This could help make it easier to identify blocking
dependencies when examining traces. Flows can be turned
off when viewing traces to remove potential distractions.
Updates #38714
Change-Id: Ibfd3f1a1861e3cac31addb053a2fca7ee796c4d7
Reviewed-on: https://go-review.googlesource.com/c/go/+/248322
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Action.Func is now a func(*Builder, context.Context, *Action), so that
contexts can be propagated into the action funcs. While context
is traditionally the first parameter of a function, it's the second
parameter of Action.Func's type to continue to allow for methods
on Builder to be used as functions taking a *Builder as the first
parameter. context.Context is instead the first parameter on
those functions.
Change-Id: I5f058d6a99a1e96fe2025f2e8ce30a033d12e935
Reviewed-on: https://go-review.googlesource.com/c/go/+/248321
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
This change adds a trace event for each action and also
annotates each of the action execution goroutines with trace.Goroutine
so that the actions eaxecuted by each goroutine appear on different threads in
the chrome trace viewer.
Updates #38714
Change-Id: I2e58dc5606b2e3f7f87076a61e1cc6a2014255c5
Reviewed-on: https://go-review.googlesource.com/c/go/+/248320
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
trace.StartGoroutine will associate the trace information on the context
with a new chrome profiler thread id. The chrome profiler doesn't
expect multiple trace events to have the same thread id, so this
will allow us to display concurrent events on the trace.
Updates #38714
Change-Id: I888b0cce15a5a01db66366716fdd85bf86c832cd
Reviewed-on: https://go-review.googlesource.com/c/go/+/248319
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
On ARM, for a JMP/CALL relocation, the instruction bytes is
encoded in Reloc.Add (issue #19811). I really hate it, but before
it is fixed we have to follow the rule and emit the right bits
from r.Add.
Fixes#40769.
Change-Id: I862e105408d344c5cc58ca9140d2e552e4364453
Reviewed-on: https://go-review.googlesource.com/c/go/+/248399
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Joel Sing <joel@sing.id.au>
Reviewed-by: Than McIntosh <thanm@google.com>
cgo_import_dynamic pragma indicates a symbol is imported from a
dynamic library. Currently, the linker does not actually link
against the dynamic library, so we have to "force" it by using
//go:cgo_import_dynamic _ _ "dylib"
syntax, which links in the library unconditionally.
This CL changes it to link in the library automatically when a
symbol is imported from the library, without using the "force"
syntax. (The "force" syntax is still supported.)
Remove the unconditional imports in the runtime. Now,
Security.framework and CoreFoundation.framework are only linked
when the x509 package is imported (or otherwise specified).
Fixes#40727.
Change-Id: Ied36b1f621cdcc5dc4a8f497cdf1c554a182d0e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/248333
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This reverts CL 247697.
Reason for revert: This change broke the linux-arm builder.
Change-Id: I8ca0d5b3b2ea0109ffbfadeab1406a1b60e7d18d
Reviewed-on: https://go-review.googlesource.com/c/go/+/248718
Reviewed-by: Michael Munday <mike.munday@ibm.com>
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Currently, the GC stores the object marks for checkmarks mode in the
heap bitmap using a rather complex encoding: for one word objects, the
checkmark is stored in the pointer/scalar bit since one word objects
must be pointers; for larger objects, the checkmark is stored in what
would be the scan/dead bit for the second word of the object. This
encoding made more sense when the runtime used the first scan/dead bit
as the regular mark bit, but we moved away from that long ago.
This encoding and overloading of the heap bitmap bits causes a great
deal of complexity in many parts of the allocator and garbage
collector and leads to some subtle bugs like #15903.
This CL moves the checkmarks mark bits into their own per-arena bitmap
and reclaims the second scan/dead bit as a regular scan/dead bit.
I tested this by enabling doubleCheck mode in heapBitsSetType and
running in both regular and GODEBUG=gccheckmark=1 mode.
Fixes#15903.
No performance degradation. (Very slight improvement on a few
benchmarks, but it's probably just noise.)
name old time/op new time/op delta
BiogoIgor 16.6s ± 1% 16.4s ± 1% -0.94% (p=0.000 n=25+24)
BiogoKrishna 19.2s ± 3% 19.2s ± 3% ~ (p=0.638 n=23+25)
BleveIndexBatch100 6.12s ± 5% 6.17s ± 4% ~ (p=0.170 n=25+25)
CompileTemplate 206ms ± 1% 205ms ± 1% -0.43% (p=0.005 n=24+24)
CompileUnicode 82.2ms ± 2% 81.5ms ± 2% -0.95% (p=0.001 n=22+22)
CompileGoTypes 755ms ± 3% 754ms ± 4% ~ (p=0.715 n=25+25)
CompileCompiler 3.73s ± 1% 3.73s ± 1% ~ (p=0.445 n=25+24)
CompileSSA 8.67s ± 1% 8.66s ± 1% ~ (p=0.836 n=24+22)
CompileFlate 134ms ± 2% 133ms ± 1% -0.66% (p=0.001 n=24+23)
CompileGoParser 164ms ± 1% 163ms ± 1% -0.85% (p=0.000 n=24+24)
CompileReflect 466ms ± 5% 466ms ± 3% ~ (p=0.863 n=25+25)
CompileTar 182ms ± 1% 182ms ± 1% -0.31% (p=0.048 n=24+24)
CompileXML 249ms ± 1% 248ms ± 1% -0.32% (p=0.031 n=21+25)
CompileStdCmd 10.3s ± 1% 10.3s ± 1% ~ (p=0.459 n=23+23)
FoglemanFauxGLRenderRotateBoat 8.66s ± 1% 8.62s ± 1% -0.47% (p=0.000 n=23+24)
FoglemanPathTraceRenderGopherIter1 20.3s ± 3% 20.2s ± 2% ~ (p=0.893 n=25+25)
GopherLuaKNucleotide 29.7s ± 1% 29.8s ± 2% ~ (p=0.421 n=24+25)
MarkdownRenderXHTML 246ms ± 1% 247ms ± 1% ~ (p=0.558 n=25+24)
Tile38WithinCircle100kmRequest 779µs ± 4% 779µs ± 3% ~ (p=0.954 n=25+25)
Tile38IntersectsCircle100kmRequest 1.02ms ± 3% 1.01ms ± 4% ~ (p=0.658 n=25+25)
Tile38KNearestLimit100Request 984µs ± 4% 986µs ± 4% ~ (p=0.627 n=24+25)
[Geo mean] 552ms 551ms -0.19%
https://perf.golang.org/search?q=upload:20200723.6
Change-Id: Ic703f26a83fb034941dc6f4788fc997d56890dec
Reviewed-on: https://go-review.googlesource.com/c/go/+/244539
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
The heapBitsSetType function has a slow doubleCheck debugging mode
that checks the bitmap written out by the rest of the function using
far more obvious logic. But even this has some surprisingly complex
logic in it. Simplify it a bit. This also happens to fix the logic on
32-bit.
Fixes#40335.
Change-Id: I5cee482ad8adbd01cf5b98e35a270fe941ba4940
Reviewed-on: https://go-review.googlesource.com/c/go/+/244538
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
The runtime has its own implementation of string indexing. To reduce
code duplication and cognitive load, replace this with calls to the
internal/bytealg package. We can't do this on Plan 9 because it needs
string indexing in a note handler (which isn't allowed to use the
optimized bytealg version because it uses SSE), so we can't just
eliminate the index function, but this CL does down-scope it so make
it clear it's only for note handlers on Plan 9.
Change-Id: Ie1a142678262048515c481e8c26313b80c5875df
Reviewed-on: https://go-review.googlesource.com/c/go/+/244537
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Makes sure the copyright notice is not interpreted as the package level
godoc.
Change-Id: I2afce7c9d620f19d51ec1438b1d0db1774b57146
Reviewed-on: https://go-review.googlesource.com/c/go/+/248760
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
On some machines, kern.maxfilesperproc is 4096. If Rlimit.Cur is larger
than that, Setrlimit will get an errEINVAL.
Fixes#40564.
Change-Id: Ib94303c790a489ff0559c88d41a021e514d18f8d
Reviewed-on: https://go-review.googlesource.com/c/go/+/246658
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Since NetBSD 7, hw.ncpuonline reports the number of CPUs online, while
hw.cpu reports the number of CPUs configured. Try hw.cpuonline first and
fall back to hw.ncpu in case it fails (which is the case on NetBSD
before 7.0).
This follows the behavior on OpenBSD (see CL 161757). Also, Go
in pkgsrc is patched to use hw.cpuonline, so this CL would allow said
patch to be dropped.
Updates #30824
Change-Id: Id1c19dff2c1e4401e6074179fae7c708ba0e3098
Reviewed-on: https://go-review.googlesource.com/c/go/+/231957
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
When adding a new library entry, ensure we record it as seen to avoid
adding duplicates of it.
Fixes#39256
Change-Id: Id309adf80c533d78fd485517c18bc9ab5f1d29fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/235257
Run-TryBot: Joel Sing <joel@sing.id.au>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Instead of returning a bad verb error format for runes above
utf8.Maxrune return a quoted utf8.RuneError rune (\ufffd).
This makes the behaviour consistent with the "c" verb and
aligns behaviour to not return bad verb error format when
a verb is applied to the correct argument type.
Fixes#14569
Change-Id: I679485f6bb90ebe408423ab68af16cce38816cd0
Reviewed-on: https://go-review.googlesource.com/c/go/+/248759
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
The two existing benchmarks encode randomized pixels, which isn't very
representative. The two new benchmarks encode a PNG photo as a GIF.
Also rename the benchmarks for consistency.
Also fix the bytes-per-op measure for paletted images, which are 1 (not
4) bytes per pixel.
Also simplify BenchmarkEncodeRandomPaletted (formerly just called
BenchmarkEncode). It doesn't need to generate a random palette (and the
GIF encoder largely doesn't care about the palette's RGBA values).
Use palette.Plan9 instead, a pre-existing 256-element color palette.
Change-Id: I10a6ea4e9590bb0d9f76e8cc0f4a88d43b1d650d
Reviewed-on: https://go-review.googlesource.com/c/go/+/248218
Reviewed-by: David Symonds <dsymonds@golang.org>
The log package is used with the net/http but was not in the import clause.
Change-Id: Ic45b987633adf0ee15defd4d136b5d37027e22b0
GitHub-Last-Rev: e74aff5337
GitHub-Pull-Request: golang/go#36674
Reviewed-on: https://go-review.googlesource.com/c/go/+/215618
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
There is an optimization rule that removes calls to racefuncenter and
racefuncexit, if there are no other race calls in the function. The
rule removes the call to racefuncenter, but it does *not* remove the
store of its argument to the outargs section of the frame. If the
outargs section is now size 0 (because the calls to racefuncenter/exit
were the only calls), then that argument store clobbers the frame
pointer instead.
The fix is to remove the argument store when removing the call to
racefuncenter. (Racefuncexit doesn't have an argument.)
Change-Id: I183ec4d92bbb4920200e1be27b7b8f66b89a2a0a
Reviewed-on: https://go-review.googlesource.com/c/go/+/248262
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
These operations are async unsafe on architectures that use
frame pointers.
The reason is they rely on data being safe when stored below the stack
pointer. They do:
45da69: 48 89 6c 24 f0 mov %rbp,-0x10(%rsp)
45da6e: 48 8d 6c 24 f0 lea -0x10(%rsp),%rbp
45da73: e8 7d d0 ff ff callq 45aaf5 <runtime.duffzero+0x115>
45da78: 48 8b 6d 00 mov 0x0(%rbp),%rbp
This dance ensures that inside duffzero, it looks like there is a
proper frame pointer set up, so that stack walkbacks work correctly if
the kernel samples during duffzero.
However, this instruction sequence depends on data not being clobbered
even though it is below the stack pointer.
If there is an async interrupt at any of those last 3 instructions,
and the interrupt decides to insert a call to asyncPreempt, then the
saved frame pointer on the stack gets clobbered. The last instruction
above then restores junk to the frame pointer.
To prevent this, mark these instructions as async unsafe.
(The body of duffzero is already async unsafe, as it is in package runtime.)
Change-Id: I5562e82f9f5bd2fb543dcf2b6b9133d87ff83032
Reviewed-on: https://go-review.googlesource.com/c/go/+/248261
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
BP should be callee-save. It will be saved automatically if
there is a nonzero frame size. Otherwise, we need to avoid this register.
Change-Id: If3f551efa42d830c8793d9f0183cb8daad7a2ab5
Reviewed-on: https://go-review.googlesource.com/c/go/+/248260
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
