Currently, package obj reserves a range of 1<<12 opcodes for each
target architecture.  E.g., mips64 has [6<<12, 7<<12).

However, because mips.ABEQ and mips.ALAST are both within that range,
the expression mips.ABEQ+mips.ALAST in turn falls (far) outside that
range around 12<<12, meaning it could theoretically collide with
another arch's opcodes.

More practically, it's a problem because 12<<12 overflows an int16,
which hampers fixing #14692.  (We could also just switch to uint16 to
avoid the overflow, but that still leaves the first problem.)

As a workaround, use Michael Hudson-Doyle's solution from
https://golang.org/cl/20182 and use negative values for these variant
instructions.

Passes toolstash -cmp for GOARCH=arm and GOARCH=mips64.

Updates #14692.

Change-Id: Iad797d10652360109fa4db19d4d1edb6529fc2c0
Reviewed-on: https://go-review.googlesource.com/20345
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This is needed now for subrepos to be able to conditionally use
API symbols found only after Go 1.6.

Change-Id: Ie7d9301332aa1739b585d93f8025424ae72a2430
Reviewed-on: https://go-review.googlesource.com/20344Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

TimeoutHandler was starting the Timer when the handler was created,
instead of when serving a request. It also was sharing it between
multiple requests, which is incorrect, as the requests might start
at different times.

Store the timeout duration and create the Timer when ServeHTTP is
called. Different requests will have different timers.

The testing plumbing was simplified to store the channel used to
control when timeout happens. It overrides the regular timer.

Fixes #14568.

Change-Id: I4bd51a83f412396f208682d3ae5e382db5f8dc81
Reviewed-on: https://go-review.googlesource.com/20046Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Compile time is about the same.  Getting rid of the nodeSeq interfaces,
particularly nodeSeqIterate, should produce some improvements.

Passes toolstash -cmp.

Update #14473.

Change-Id: I678abafdd9129c6cccb0ec980511932eaed496a0
Reviewed-on: https://go-review.googlesource.com/20343Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

It is only necessary in a few places, and this inlining will
simplify the transition away from NodeLists.

Passes toolstash -cmp.

Change-Id: I4ee9b4bf56ffa04df23e20a0a83b302d36b33510
Reviewed-on: https://go-review.googlesource.com/20290Reviewed-by: Ian Lance Taylor <iant@golang.org>

-test flag is a testing only flag that enables all vet checks. It was needed
because there was no way to run all vet checks in a single command
invocation. However it is possible to do this now by combining -all and -shadow
flags.

Also a recently added -tests flag is similarly named, having both -test and
-tests can be confusing.

Change-Id: Ie5bacbe0bef5c8409eeace46f16141fa4e782c32
Reviewed-on: https://go-review.googlesource.com/20006Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Opt for replacements that avoid any assumptions
about the representations in use.

Passes toolstash -cmp.

Change-Id: Ia858a33abcae344e03fc1862fc9b0e192fde80c1
Reviewed-on: https://go-review.googlesource.com/20279
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fix some test output while we're here.

Change-Id: I265cedc222e078eff120f268b92451e12b0400b2
Reviewed-on: https://go-review.googlesource.com/20294Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #14693

Change-Id: Id0a6a80b4c37c0b0f1c2755667b7233ed8964e40
Reviewed-on: https://go-review.googlesource.com/20342Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Currently work.finalizersDone is reset only at the beginning of
gcStart. As a result, it will be set when checkmark runs, so checkmark
will skip scanning finalizers. Hence, if there are any bugs that cause
the regular scan of finalizers to miss pointers, checkmark will also
miss them and fail to detect the missed pointer.

Fix this by resetting finalizersDone in gcResetMarkState. This way it
gets reset before any full mark, which is exactly what we want.

Change-Id: I4ddb5eba5b3b97e52aaf3e08fd9aa692bda32b20
Reviewed-on: https://go-review.googlesource.com/20332
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Instead of abusing ALAST.

Passes GOARCH=mips64 toolstash -cmp.

Updates #14692.

Change-Id: Ie85e99cf76508c1d0f5847a4157056b614fd5cc6
Reviewed-on: https://go-review.googlesource.com/20341
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

In increment and decrement statements, explicit check that the type
of operand is numeric. This avoids a related but less clear error
about converting "1" to be emitted.

So, when checking

	package main

	func main() {
		var x bool
		x++
	}

instead of emitting the error

	prog.go:5:2: cannot convert 1 (untyped int constant) to bool

emits

	prog.go:5:2: invalid operation: x++ (non-numeric type bool).

Updates #12525.

Change-Id: I00aa6bd0bb23267a2fe10ea3f5a0b20bbf3552bc
Reviewed-on: https://go-review.googlesource.com/20244Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Automated refactoring produced using github.com/mdempsky/unconvert.

Change-Id: Iacf871a4f221ef17f48999a464ab2858b2bbaa90
Reviewed-on: https://go-review.googlesource.com/20071Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Move initproginfo and initvariants to ppc64.Main to avoid checking that
the tables are initialised every time.

Change-Id: I95ff4146a7abc18c42a20bfad716cc80ea8367e5
Reviewed-on: https://go-review.googlesource.com/20286Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #14626

Change-Id: I91c40407dc35355e5c5046f24111a126f99260d9
Reviewed-on: https://go-review.googlesource.com/20192Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>

Use slices as slices, instead of as clumsy pointers.

Passes toolstash/buildall.

Change-Id: If09eacc2d8805d7d5eaa5566f9b6305541074371
Reviewed-on: https://go-review.googlesource.com/20322
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

As part of local testing with a large group member list, I discovered
that the lookup functions don't resize their buffer if they receive
ERANGE.  I fixed this as a side-effect of this CL.

Thanks to @andrenth for the original CL.

Fixes #2617

Change-Id: Ie6aae2fe0a89eae5cce85786869a8acaa665ffe9
Reviewed-on: https://go-review.googlesource.com/19235Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The io.Reader contract makes no promises about how a Reader should
behave after it returns its first error. Usually the errors are
sticky, but they don't have to be. A regression in zlib.Reader (bug
accidentally relied on sticky errors.

Minimal fix: wrap the user's provided Reader in a Reader which
guarantees stickiness. The minimal fix is less scary than touching
the multipart state machine.

Fixes #14676

Change-Id: I8dd8814b13ae5530824ae0e68529f788974264a5
Reviewed-on: https://go-review.googlesource.com/20297
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I3eab54cd27c43bab38641fbead4adb6442481356
Reviewed-on: https://go-review.googlesource.com/20248
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Ensure that all errors (including io.EOF) are persistent across method
calls on zlib.Reader. Furthermore, ensure that these persistent errors
are properly cleared when Reset is called.

Fixes #14675

Change-Id: I15a20c7e25dc38219e7e0ff255d1ba775a86bb47
Reviewed-on: https://go-review.googlesource.com/20292Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Found by temporarily flipping fields from *NodeList to Nodes and fixing
all the compilation errors.  This CL does not actually change any
fields.

Passes toolstash -cmp.

Update #14473.

Change-Id: Ib98fa37e8752f96358224c973a743618a6a0e736
Reviewed-on: https://go-review.googlesource.com/20320
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Eliminates type conversions in a bunch of Oconv(int(n.Op), ...) calls.

Notably, this identified a misuse of Oconv in amd64/gsubr.go to try to
print an assembly instruction op instead of a compiler node op.

Change-Id: I93b5aa49fe14a5eaf868b05426d3b8cd8ab52bc5
Reviewed-on: https://go-review.googlesource.com/20298
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Implementation more or less follows plan9_386 version.
Revised 7 March to correct a bug in runtime.seek and
tidy whitespace for 8-column tabs.

Change-Id: I2e921558b5816502e8aafe330530c5a48a6c7537
Reviewed-on: https://go-review.googlesource.com/18966
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Plan 9 trap/signal handling differs on ARM from other architectures
because ARM has a link register.  Also trap message syntax varies
between different architectures (historical accident?).
Revised 7 March to clarify a comment.

Change-Id: Ib6485f82857a2f9a0d6b2c375cf0aaa230b83656
Reviewed-on: https://go-review.googlesource.com/18969
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

In increment and decrement statements, explicit check that the type
of operand is numeric earlier. This avoids a related but less clear
error about converting "1" to be emitted.

So, when compiling

	package main

	func main() {
		var x bool
		x++
	}

instead of emitting two errors

	prog.go:5: cannot convert 1 to type bool
	prog.go:5: invalid operation: x++ (non-numeric type bool)

just emits the second error.

Fixes #12525.

Change-Id: I6e81330703765bef0d6eb6c57098c1336af7c799
Reviewed-on: https://go-review.googlesource.com/20245Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Change-Id: Id0a12c76b0a6925f2926d38a1931157f9ef5f650
Reviewed-on: https://go-review.googlesource.com/20280Reviewed-by: Joe Tsai <joetsai@digital-static.net>
Run-TryBot: Joe Tsai <joetsai@digital-static.net>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This increases the number of matches in make.bash
from 853 to 984.

Change-Id: I12697697a50ecd86d49698200144a4c80dd3e5a4
Reviewed-on: https://go-review.googlesource.com/20274Reviewed-by: Todd Neal <todd@tneal.org>

We used to start background mark workers and assists at different
times, so we needed to keep track of these separately. They're now set
to exactly the same time, so clean things up by merging them in to one
value, markStartTime.

Change-Id: I17c9843c3ed2d6f07b4c8cd0b2c438fc6de23b53
Reviewed-on: https://go-review.googlesource.com/20143
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>

OffPtr allocates less and is easier to optimize.

With this change, the OffPtr collapsing opt
rule matches increase from 160k to 263k,
and the Load-after-Store opt rule matches
increase from 217 to 853.

Change-Id: I763426a3196900f22a367f7f6d8e8047b279653d
Reviewed-on: https://go-review.googlesource.com/20273
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Todd Neal <todd@tneal.org>
Reviewed-by: Keith Randall <khr@golang.org>

This triggers an astonishing 160k times
during make.bash. The second biggest
generic rewrite triggers 100k times.

However, this is really just moving
rewrites that were happening at the
architecture level to the generic level.

Change-Id: Ife06fe5234f31433328460cb2e0741c071deda41
Reviewed-on: https://go-review.googlesource.com/20235
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Todd Neal <todd@tneal.org>

This only deals with the loads themselves.  The bounds checks
are a separate issue.  Also doesn't handle stores, those are
harder because we need to make sure intermediate memory states
aren't observed (which is hard to do with rewrite rules).

Use one byte shorter instructions for zero-extending loads.

Update #14267

Change-Id: I40af25ab5208488151ba7db32bf96081878fa7d9
Reviewed-on: https://go-review.googlesource.com/20218Reviewed-by: Alexandru Moșoi <alexandru@mosoi.ro>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

They were only used for rtype.ptrToThis which David Crawshaw removed a couple
of weeks ago. Removes two traversals of Ctxt.Allsym from the linker but it
doesn't seem to make much difference to performance.

Change-Id: I5c305e0180186f643221d57822d301de4aa18827
Reviewed-on: https://go-review.googlesource.com/20287Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The new code is a bit less efficient,
but it does not involve altering the structure
of any linked lists.
This will make it easier to replace NodeLists
with Node slices.
We can return to a more efficient algorithm
when NodeLists have been replaced.

Passes toolstash -cmp.

Change-Id: I0bb5ee75e7c0646e6d37fe558c8f0548729d8aa1
Reviewed-on: https://go-review.googlesource.com/20277
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Iadb4aa016a7b361d01827787dbc59164d5d147f2
Reviewed-on: https://go-review.googlesource.com/20291Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

No immediate reduction in the size of Addr.

Passes toolstash -cmp.

Change-Id: I78ea4c6e181b6e571ce70a5f1ae8158844eb197d
Reviewed-on: https://go-review.googlesource.com/20276Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Add tests to ensure that the size of important types don't change
unexpectedly.

Skip the test on nacl platforms because of their unusual padding
requirements.

Change-Id: Iddb127a99499e089a309b721f5073356c0da8b24
Reviewed-on: https://go-review.googlesource.com/20285Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Dave Cheney <dave@cheney.net>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Removes specialized functions for each verb and float/complex size
and replaces them with generic variants fmtFloat and
fmtComplex similar to other generic fmt functions.

Simplifies the complex formatting by relying on fmtFloat
to handle the verb and default precision selection.

Complex imaginary formatting does not need to clear the f.space flag
because the set f.plus flag will force a sign instead of a space.

Sets default precision for %b to -1 (same as %g and %G)
since precision for %b has no affect in strconv.AppendFloat.

Add more tests and group them a bit better.
Use local copies of +Inf,-Inf and NaN instead
of math package functions for testing.

Saves around 8kb in the go binary.

name              old time/op  new time/op  delta
SprintfFloat-2     200ns ± 4%   196ns ± 4%  -1.55%  (p=0.007 n=20+20)
SprintfComplex-2   569ns ± 4%   570ns ± 3%    ~     (p=0.804 n=20+20)

Change-Id: I36d35dab6f835fc2bd2c042ac97705868eb2446f
Reviewed-on: https://go-review.googlesource.com/20252Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Rob Pike <r@golang.org>

Reuse the internal buffer and use append versions of
the strconv quote functions to avoid some allocations.

Add more tests.

name                  old time/op    new time/op    delta
SprintfQuoteString-2     486ns ± 2%     416ns ± 2%  -14.42%  (p=0.000 n=20+20)

name                  old allocs/op  new allocs/op  delta
SprintfQuoteString-2      4.00 ± 0%      2.00 ± 0%  -50.00%  (p=0.000 n=20+20)

Change-Id: I63795b51fd95c53c5993ec8e6e99b659941f9f54
Reviewed-on: https://go-review.googlesource.com/20251
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

Instead of calling printArg in fmtBytes to format each byte call
the byte formatting functions directly since it is known each
element is of type byte.

Add more tests for byte slice and array formatting.

name            old time/op  new time/op  delta
SprintfBytes-2   843ns ±16%   417ns ±11%  -50.58%  (p=0.000 n=20+20)

Change-Id: I5b907dbf52091e3de9710b09d67649c76f4c17e9
Reviewed-on: https://go-review.googlesource.com/20176
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

Current runtime.WriteHeapProfile() doesn't print correct
EnableGC. Even if GOGC=off, the result file has below line:
 # EnableGC = true

It is hard to print correct status of the variable because of corner
cases e.g. initialization. For avoiding confusion, this commit removes
the print.

Change-Id: Ia792454a6c650bdc50a06fbaff4df7b6330ae08a
Reviewed-on: https://go-review.googlesource.com/18600
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>