Distinguish move/load/store ops.  Unify some of this code a bit.

Reduces Mandelbrot slowdown with SSA from 58% to 12%.

Change-Id: I3276eaebcbcdd9de3f8299c79b5f25c0429194c4
Reviewed-on: https://go-review.googlesource.com/18677
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>

If a failure occurs in SSA processing, we always report the
last line of the function we're compiling.  Modify the callbacks
from SSA to the GC compiler so we can pass a line number back
and use it in Fatalf.

Change-Id: Ifbfad50d5e167e997e0a96f0775bcc369f5c397e
Reviewed-on: https://go-review.googlesource.com/18599
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>

Pull the relevant part of https://go-review.googlesource.com/#/c/18304/
into the SSA branch.  This fixes the windows SSA build.

Change-Id: Iee3834d8e7019cd90307e32029f3d1032ceb46c1
Reviewed-on: https://go-review.googlesource.com/18673Reviewed-by: Austin Clements <austin@google.com>

Add new constant-flags opcodes.  These can be generated from
comparisons that we know the result of, like x&31 < 32.

Constant-fold the constant-flags opcodes into all flag users.

Reorder some CMPxconst args so they read in the comparison direction.

Reorg deadcode removal a bit - it needs to remove the OpCopy ops it
generates when strength-reducing Phi ops.  So it needs to splice out all
the dead blocks and do a copy elimination before it computes live
values.

Change-Id: Ie922602033592ad8212efe4345394973d3b94d9f
Reviewed-on: https://go-review.googlesource.com/18267
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>

In code that does:

    var x, z int32
    var y int64
    z = phi(x, int32(y))

We silently drop the int32 cast because truncation is a no-op.
The phi operation needs to make sure it uses the size of the
phi, not the size of its arguments, when generating spills.

Change-Id: I1f7baf44f019256977a46fdd3dad1972be209042
Reviewed-on: https://go-review.googlesource.com/18390Reviewed-by: David Chase <drchase@google.com>

Change-Id: If8b6b85d2165d6222b36f101adb95b7ee40371c1
Reviewed-on: https://go-review.googlesource.com/18300Reviewed-by: David Chase <drchase@google.com>

Semi-regular merge from tip into dev.ssa.

Change-Id: I1627d7c7e6892cd4f1f5da5f3e07389ff1d677ce

Updates http2 to x/net git rev 520af5de654d for
https://golang.org/cl/18370

Fixes #13659

Change-Id: I920eaff6036ac22c500a97449826c6b12f873d7f
Reviewed-on: https://go-review.googlesource.com/18371
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>

Change-Id: I995ac0559f89110662d79d136d710ef3a0bb1505
Reviewed-on: https://go-review.googlesource.com/18351Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #13731.

Change-Id: Iaf70a8b41c947f0d86013808564112ab676136e3
Reviewed-on: https://go-review.googlesource.com/18345Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

Fixes #13358

Change-Id: I57ed50c2610cab11fb3d9749f9e7d4a37daa7977
Reviewed-on: https://go-review.googlesource.com/18276Reviewed-by: Russ Cox <rsc@golang.org>

Now there are ARM downloads too.

Change-Id: I236381508c69d56748e672d184b92caa715e81ae
Reviewed-on: https://go-review.googlesource.com/18342Reviewed-by: Andrew Gerrand <adg@golang.org>

Update bundled http2 to git rev d1ba260648 (https://golang.org/cl/18288).

Fixes the flaky TestTransportAndServerSharedBodyRace_h2.

Also adds some debugging to TestTransportAndServerSharedBodyRace_h2
which I hope won't ever be necessary again, but I know will be.

Fixes #13556

Change-Id: Ibcf2fc23ec0122dcac8891fdc3bd7f8acddd880e
Reviewed-on: https://go-review.googlesource.com/18289Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes golang/go#12490

Change-Id: I0861e62aaa589fc63217c83e9c227c17e35cda75
Reviewed-on: https://go-review.googlesource.com/18277Reviewed-by: Russ Cox <rsc@golang.org>

After a failure on the build dashboard I tested testcarchive test 2 and
found that it failed an average of 1 in 475 runs on my laptop.  With
this change it ran over 50,000 times without failing.  I bumped up the
other iteration limits to correspond.

Change-Id: I0155c68161a2c2a09ae25c91e9269f1e8702628d
Reviewed-on: https://go-review.googlesource.com/18309
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Simply checking the exit code of `git rev-parse --git-dir` should
suffice here, but that requires deviating from the infrastructure
provided by `run`, so I've left that for a future change.

Originally by Tamir Duberstein but updated by iant & rsc to add
the filepath.Join logic.

Fixes #11211 (again).

Change-Id: I6d29b5ae39ba456088ae1fb5d41014cb91c86897
Reviewed-on: https://go-review.googlesource.com/18323Reviewed-by: Ian Lance Taylor <iant@golang.org>

The flag is already named -insecure. Make it more so.

If we're willing to accept HTTP, it's not much worse to accept
HTTPS man-in-the-middle attacks too. This allows servers
with self-signed certificates to work.

Fixes #13197.

Change-Id: Ia5491410bc886da0a26ef3bce4bf7d732f5e19e4
Reviewed-on: https://go-review.googlesource.com/18324Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Idf02428591f61dc58f654fdaf0e3a55f8b8a1060
Reviewed-on: https://go-review.googlesource.com/18350Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Read zip files that contain only 64-bit header offset, not 64-bit sizes.
Fixes #13367.

Read zip files that contain completely unexpected Extra fields,
provided we do not need to find 64-bit size or header offset information there.
Fixes #13166.

Write zip file entries with 0xFFFFFFFF uncompressed data bytes
correctly (must use zip64 header, since that's the magic indicator).
Fixes new TestZip64EdgeCase. (Noticed while working on the CL.)

Change-Id: I84a22b3995fafab8052b99de8094a9f35a25de5b
Reviewed-on: https://go-review.googlesource.com/18317Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #13673.

Change-Id: I60d1603ca0dfd2ae136117e0f89cee4b6fc6c3d3
Reviewed-on: https://go-review.googlesource.com/18332Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #13720.

Change-Id: I2e48454696f37db419370630f913590c435cd9f0
Reviewed-on: https://go-review.googlesource.com/18331Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>

Fixes #13845.

Change-Id: Ie83179b2d20c47a0296645d9e2fdc43271be495a
Reviewed-on: https://go-review.googlesource.com/18307Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

We were setting the signal mask of a new m to the signal mask of the m
that created it.  That failed when that m happened to be the one created
by ensureSigM, which sets its signal mask to only include the signals
being caught by os/signal.Notify.

Fixes #13164.
Update #9896.

Change-Id: I705c196fe9d11754e10bab9e9b2e7530ecdfa367
Reviewed-on: https://go-review.googlesource.com/18064Reviewed-by: Russ Cox <rsc@golang.org>

When calling a Go function on a C thread, if the C thread already has an
alternate signal stack, use that signal stack instead of installing a
new one.

Update #9896.

Change-Id: I62aa3a6a4a1dc4040fca050757299c8e6736987c
Reviewed-on: https://go-review.googlesource.com/18108Reviewed-by: Russ Cox <rsc@golang.org>

Just saw a few dragonfly failures here.

I'm tempted to preemptively add plan9 here too, but I'll wait until
I see it fail.

Change-Id: Ic99fc088dbfd1aa21f509148aee98ccfe7f640bf
Reviewed-on: https://go-review.googlesource.com/18306Reviewed-by: Russ Cox <rsc@golang.org>

Fixes #12790.

Change-Id: I0f231d198c76632c23692fc1337b57cfeafaf4c7
Reviewed-on: https://go-review.googlesource.com/18338Reviewed-by: Andrew Gerrand <adg@golang.org>

Fixes #13269.

Change-Id: I960d1825bda9d8873c2a9005872c45e4c7d30111
Reviewed-on: https://go-review.googlesource.com/18339Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #12059.

Change-Id: Ib5caf8133cd3ed888f9102dfbfeca11c506f3b5b
Reviewed-on: https://go-review.googlesource.com/18337Reviewed-by: Ian Lance Taylor <iant@golang.org>

This time with a test.
Also adjust another test to skip when hg is not present,
and delete no longer needed fixDetachedHead code.

Fixes #9032 (again).

Change-Id: I481717409e1d44b524f83c70a8dc377699d1a2a5
Reviewed-on: https://go-review.googlesource.com/18334Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #12542.

Change-Id: Icd0fa84d891d6b1feab9b4d4dd319cdf1e6d6c48
Reviewed-on: https://go-review.googlesource.com/18336Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

But also cache the previous parsed form and don't reread if the
size and modification time are both unchanged from before.

On systems with stable /etc/hosts this should result in more stat calls
but only a single parsing of /etc/hosts.

On systems with variable /etc/hosts files (like some Docker systems)
this should result in quicker adoption of changes.

Fixes #13340.

Change-Id: Iba93b204be73d6d903cd17c58038a4fcfd0952b9
Reviewed-on: https://go-review.googlesource.com/18258Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Add a couple more cases where we convert random network I/O errors
into errRequestCanceled if the request was forcefully aborted.

It failed ~1/1000 times without -race, or very easily with -race.
(due to -race randomizing some scheduling)

Fixes #11894

Change-Id: Ib1c123ce1eebdd88642da28a5948ca4f30581907
Reviewed-on: https://go-review.googlesource.com/18287Reviewed-by: Russ Cox <rsc@golang.org>

This shouldn't need to exist in general, but in practice I want something
like this a few times per year.

Change-Id: I9c220e58be44b7726f75d776f714212c570cf8bb
Reviewed-on: https://go-review.googlesource.com/18286Reviewed-by: Russ Cox <rsc@golang.org>

The old link died; replace with an archive.org copy.

Fixes #13345.

Change-Id: Ic4a7fdcf258e1ff3b4a02ecb4f237ae7db2686c7
Reviewed-on: https://go-review.googlesource.com/18335Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Adds a test that both http1 and http2's Transport send a default
User-Agent, with the same behavior.

Updates bundled http2 to golang.org/x/net git rev 1ade16a545 (for
https://go-review.googlesource.com/18285)

The http1 behavior changes slightly: if req.Header["User-Agent"] is
defined at all, even if it's nil or a zero-length slice, then the
User-Agent header is omitted. This is a slight behavior change for
http1, but is consistent with how http1 & http2 do optional headers
elsewhere (such as "Date", "Content-Type"). The old behavior (set it
explicitly to "", aka []string{""}) still works as before. And now
there are even tests.

Fixes #13685

Change-Id: I5786a6913b560de4a5f1f90e595fe320ff567adf
Reviewed-on: https://go-review.googlesource.com/18284
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

The textual export data generated by gc sometimes contains forward
references of packages. In rare cases such forward-referenced packages
were not created when needed because no package name was present.

Create unnamed packages in this case and set the name later when it
becomes known.

Fixes #13566.

Change-Id: I193e0ec712e874030b194ab8ecb3fca140f7997a
Reviewed-on: https://go-review.googlesource.com/18301Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>

This was supposed to be in CL 18204 but I submitted from the web
instead of my computer and lost this final edit.

Change-Id: I41598e936bb088d77f5e44752eda74222a4208c7
Reviewed-on: https://go-review.googlesource.com/18310Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This was supposed to be in CL 18205 but I submitted via the web
instead of from my computer, so it got lost.
May deflake some things.

Change-Id: I880fb74b5943b8a17f952a82639c60126701187a
Reviewed-on: https://go-review.googlesource.com/18259Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I8ee338c1244fc4e2fb75deec752a7f83239c33ea
Reviewed-on: https://go-review.googlesource.com/18257Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #13425.

Change-Id: I82f49d07841e89fc4f3fde9ea41e710a634579d0
Reviewed-on: https://go-review.googlesource.com/18313Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>