The Node type ODOT and its variants all represent a selector, with a
simple name to the right of the dot.  Before this change this was
represented by using an ONAME Node in the Right field.  This ONAME node
served no useful purpose.  This CL changes these Node types to store the
symbol in the Sym field instead, thus not requiring allocating a Node
for each selector.

When compiling x/tools/go/types this CL eliminates nearly 5000 calls to
newname and reduces the total number of Nodes allocated by about 6.6%.
It seems to cut compilation time by 1 to 2 percent.

Getting this right was somewhat subtle, and I added two dubious changes
to produce the exact same output as before.  One is to ishairy in
inl.go: the ONAME node increased the cost of ODOT and friends by 1, and
I retained that, although really ODOT is not more expensive than any
other node.  The other is to varexpr in walk.go: because the ONAME in
the Right field of an ODOT has no class, varexpr would always return
false for an ODOT, although in fact for some ODOT's it seemingly ought
to return true; I added an && false for now.  I will send separate CLs,
that will break toolstash -cmp, to clean these up.

This CL passes toolstash -cmp.

Change-Id: I4af8a10cc59078c436130ce472f25abc3a9b2f80
Reviewed-on: https://go-review.googlesource.com/20890
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Consider functions with an ODCLCONST for inlining and modify exprfmt to
ignore those nodes when exporting. Don't add symbols to the export list
if there is no definition.  This occurs when OLITERAL symbols are looked
up via Pkglookup for non-exported symbols.

Fixes #7655

Change-Id: I1de827850f4c69e58107447314fe7433e378e069
Reviewed-on: https://go-review.googlesource.com/20773
Run-TryBot: Todd Neal <todd@tneal.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

Change-Id: I5a43c354f36184ae64a52268023c3222da3026d8
Reviewed-on: https://go-review.googlesource.com/20880
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Todd Neal <todd@tneal.org>

Missed this in review of 20812

Change-Id: I01e220499dcd58e1a7205e2a577dd9630a8b7174
Reviewed-on: https://go-review.googlesource.com/20819Reviewed-by: Keith Randall <khr@golang.org>

Remove rewriting of flags before calling formatters.
Change Flag method to directly take plusV and sharpV flags
into account when reporting if plus or sharp flag is set.

Change-Id: Ic3423881ad89e5a5f9fff5ab59e842062394ef6d
Reviewed-on: https://go-review.googlesource.com/20859
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

benchmark                      old ns/op     new ns/op     delta
BenchmarkAlignedLoad-160       8.67          7.42          -14.42%
BenchmarkUnalignedLoad-160     8.63          7.37          -14.60%

Change-Id: Id4609d7b4038c4d2ec332efc4fe6f1adfb61b82b
Reviewed-on: https://go-review.googlesource.com/20812Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This ought to revert the bad effects of
https://go-review.googlesource.com/#/c/20775/
If you don't pass BOOT_GO_GCFLAGS, you get the
old behavior.

Tweaked to allow multiple space-separated flags in
BOOT_GO_GCFLAGS.

Change-Id: I2a22a04211b4535d1c5a8ec7a8a78cb051161c31
Reviewed-on: https://go-review.googlesource.com/20871
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: I0ec775c51f461c6f0cbff88e796a7af55b736fcb
Reviewed-on: https://go-review.googlesource.com/20838Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I6eb91ea73ef887b025e5a8de1dd55f30618e1aa6
Reviewed-on: https://go-review.googlesource.com/20857Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

(Corresponding x/tools/go/gcimporter change is https://go-review.googlesource.com/#/c/20827/)

Change-Id: I64e7fee2e273d387f1c51b87986294489978d250
Reviewed-on: https://go-review.googlesource.com/20828Reviewed-by: Robert Griesemer <gri@golang.org>

plan9, nacl, and netbsd to be precise.

Only the first test causes a hang, but just to be sure.

Change-Id: I400bb356ee2a0cf12c8666c95af79c924d1629aa
Reviewed-on: https://go-review.googlesource.com/20839
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: If45410a2d7e48d1c9e6800cd98f81dd89024832c
Reviewed-on: https://go-review.googlesource.com/20852Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: I2e26717f2563d7633ffd15f4adf63c3d0ee3403f
Reviewed-on: https://go-review.googlesource.com/20856
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: Ie79c16d6e61b3baa274069528cf883b22fd255fe
Reviewed-on: https://go-review.googlesource.com/20855
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: I58c4a75168fd1f797a25735c4151f501f0475332
Reviewed-on: https://go-review.googlesource.com/20854Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: I9e887a0b32baf0adc85fa9e4b85b319e8ef333e9
Reviewed-on: https://go-review.googlesource.com/20853Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: I0f4b6752ecc8b4945ecfde627cdec13fc4bb6a69
Reviewed-on: https://go-review.googlesource.com/20850Reviewed-by: Russ Cox <rsc@golang.org>

Phi splitting sometimes leads to a phi with only a single predecessor.
This must be replaced with a copy to maintain a valid SSA form.

Fixes #14857

Change-Id: I5ab2423fb6c85a061928e3206b02185ea8c79cd7
Reviewed-on: https://go-review.googlesource.com/20826Reviewed-by: Keith Randall <khr@golang.org>

API not exposed yet.

Change-Id: Iaba0adc0fa1ae8075e6b56796f99ee8db9177a78
Reviewed-on: https://go-review.googlesource.com/18896Reviewed-by: Russ Cox <rsc@golang.org>

API is not exposed yet.

Change-Id: I729360ef2be1d8ea683ca93cdb1763897cc8657c
Reviewed-on: https://go-review.googlesource.com/18895Reviewed-by: Russ Cox <rsc@golang.org>

testing.go:
- run method will evolve into the Run method.
- added level field in common

benchmark.go:
- benchContext will be central to distinguish handling of benchmarks
  between normal Run methods and ones called from within Benchmark
  function.
- expandCPU will evolve into the processing hook for Run methods
  called within normal processing.
- runBench will evolve into the Run method.

Change-Id: I1816f9985d5ba94deb0ad062302ea9aee0bb5338
Reviewed-on: https://go-review.googlesource.com/18894Reviewed-by: Russ Cox <rsc@golang.org>

The biggest change is that each test is now responsible for managing
the starting and stopping of its parallel subtests.

The "Main" test could be run as a tRunner as well. This shows that
the introduction of subtests is merely a generalization of and
consistent with the current semantics.

Change-Id: Ibf8388c08f85d4b2c0df69c069326762ed36a72e
Reviewed-on: https://go-review.googlesource.com/18893Reviewed-by: Russ Cox <rsc@golang.org>

There's nothing guaranteeing that the *Regexp isn't in active use,
and so copying the sync.Mutex value is invalid.

Updates #14839.

Change-Id: Iddf52bf69df1b563377922399f64a571f76b95dd
Reviewed-on: https://go-review.googlesource.com/20841Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>

This seems to help the problem reported in #14606; this
change seems to produce about a 4% improvement (mostly
for the 128-8192 shards).

Fixes #14789.

Change-Id: I1bd52c82d4ca81d9d5e9ab371fdfc860d7e8af50
Reviewed-on: https://go-review.googlesource.com/20660
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Improve the test by also translating " " to "_".

Fixes #14671.

Change-Id: Ie5997934b93c7663d7b8432244fad47bb5d3ffbe
Reviewed-on: https://go-review.googlesource.com/20714Reviewed-by: Ian Lance Taylor <iant@golang.org>

This is intended to help debug compiler problems that pop
up in the bootstrap phase of make.bash.  GO_GCFLAGS does not
normally apply there.  Options-for-all phases is intended
to allow crude tracing (and full timing) by turning on timing
for all phases, not just one.

Phase names can also be specified using a regular expression,
for example
BOOT_GO_GCFLAGS=-d='ssa/~^.*scc$/off' \
GO_GCFLAGS='-d=ssa/~^.*scc$/off' ./make.bash

I just added this because it was the fastest way to get
me to a place where I could easily debug the compiler.

Change-Id: I0781f3e7c19651ae7452fa25c2d54c9a245ef62d
Reviewed-on: https://go-review.googlesource.com/20775Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: Ic40449b2e4b4f18cbe5b5d4c3d51ea7b05ac674d
Reviewed-on: https://go-review.googlesource.com/20823
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This change makes unexposed methods start with lowercase letters for
avoiding unnecessary confusion because the net package uses many
embedding structures and intrefaces for controlling exposure of APIs.

Note that this change leaves DNS-related methods as they are.

Change-Id: I253758d1659175c5d0af6b2efcd30ce83f46543d
Reviewed-on: https://go-review.googlesource.com/20784
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: Ic5f62a7d0a5c090da69213d1d0187af0ea48e358
Reviewed-on: https://go-review.googlesource.com/20820Reviewed-by: Rob Pike <r@golang.org>

The critical phase did not correctly maintain the use count
when two predecessors of a new critical block transmit the
same value.

Change-Id: Iba802c98ebb84e36a410721ec32c867140efb6d4
Reviewed-on: https://go-review.googlesource.com/20822Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Todd Neal <todd@tneal.org>

* This the simplest solution I could came up with
that doesn't required changing the compiler.
* The bound checks become constants now
so they are removed during opt phase.

Updates #14808

Change-Id: If32c33d7ec08bb400321b465015d152f0a5d3001
Reviewed-on: https://go-review.googlesource.com/20654Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I3c6035559288cfdc33857216f50241b81932c8a4
Reviewed-on: https://go-review.googlesource.com/20811
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Make sure we don't generate write barriers in runtime
code that is marked to forbid write barriers.

Implement the optimization that if we're writing a sliced
slice back to the location it came from, we don't need a
write barrier.

Fixes #14784

Change-Id: I04b6a3b2ac303c19817e932a36a3b006de103aaa
Reviewed-on: https://go-review.googlesource.com/20791Reviewed-by: Austin Clements <austin@google.com>

Reduces size of archives in pkg/linux_amd64 by 1.4MB (3.2%),
slightly improving link time.

name       old s/op   new s/op   delta
LinkCmdGo  0.52 ± 3%  0.51 ± 2%  -0.65%  (p=0.000 n=98+99)

Change-Id: I7e265f4d4dd08967c5c5d55c1045e533466bbbec
Reviewed-on: https://go-review.googlesource.com/20802
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I32fd5c36f055fdb1dfe56524085676aa4111089a
Reviewed-on: https://go-review.googlesource.com/20830Reviewed-by: David Chase <drchase@google.com>

Boolean expressions involving t.Thistuple were converted to use
t.Recv(), because it's a bit clearer and will hopefully reveal cases
where we could remove redundant calls to t.Recv() (in followup CLs).

The other cases were all converted to use t.Recvs().NumFields(),
t.Params().NumFields(), or t.Results().NumFields().

Change-Id: I4df91762e7dc4b2ddae35995f8dd604a52c09b09
Reviewed-on: https://go-review.googlesource.com/20796Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>

We never need a type hash for a method type, so skip trying to
overwrite Thistuple.

Change-Id: I8de6480ba5fd321dfa134facf7661461d298840e
Reviewed-on: https://go-review.googlesource.com/20795Reviewed-by: Russ Cox <rsc@golang.org>

This is an automated rewrite of all the calls of the form:

    for f, it := IterFields(t); f != nil; f = it.Next() { ... }

Followup CLs will work on cleaning up the remaining cases.

Change-Id: Ic1005ad45ae0b50c63e815e34e507e2d2644ba1a
Reviewed-on: https://go-review.googlesource.com/20794Reviewed-by: David Crawshaw <crawshaw@golang.org>

Analogous to the Nodes type used as a more space efficient []*Node
representation.

Passes toolstash -cmp.

Change-Id: I8341e45304777d6e4200bd36dadc935b07ccf3ff
Reviewed-on: https://go-review.googlesource.com/20793Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I85c0bcf02842cc32dbc9bfdcea27efe871173574
Reviewed-on: https://go-review.googlesource.com/20774Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>