We compute a lot of stuff based off the CFG: postorder traversal,
dominators, dominator tree, loop nest.  Multiple phases use this
information and we end up recomputing some of it.  Add a cache
for this information so if the CFG hasn't changed, we can reuse
the previous computation.

Change-Id: I9b5b58af06830bd120afbee9cfab395a0a2f74b2
Reviewed-on: https://go-review.googlesource.com/29356Reviewed-by: David Chase <drchase@google.com>

Change-Id: I571f03af6f791e78e7e18addcc310eb25747cdcf
Reviewed-on: https://go-review.googlesource.com/29351Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

No point in calling a function when we can build the interface
using a known type (or itab) and the address of a local.

Get rid of third arg (preallocated stack space) to convT2{I,E}.

Makes go binary smaller by 0.2%

benchmark                   old ns/op     new ns/op     delta
BenchmarkEfaceInteger-8     16.7          10.1          -39.52%

Update #17118
Update #15375

Change-Id: I9724a1f802bfa1e3957bf1856b55558278e198a2
Reviewed-on: https://go-review.googlesource.com/29373
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Was missing a title in the documentation, so it formatted wrong.

Fixes #17124

Change-Id: Ie8a9c36fbc54eed7d8a761f89a088e582b8c062d
Reviewed-on: https://go-review.googlesource.com/29340Reviewed-by: Andrew Gerrand <adg@golang.org>

They are trivially available in the few places they are needed.

Change-Id: I6544692e9027076ec9e6e9a295c66457039e55e1
Reviewed-on: https://go-review.googlesource.com/29332
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Doing this revealed some dead code.

Change-Id: I5202fcc3f73e3dfddfea3ec7b772e16da51195da
Reviewed-on: https://go-review.googlesource.com/29331
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fix mips64le build.

Change-Id: Icf1b4901655463f582b49054a88edfb06ad6c676
Reviewed-on: https://go-review.googlesource.com/29281
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

This aliases to Xadd64.

Change-Id: I95d49e1d03eecc242e9e6fd4b2742b1c1a1d5ade
Reviewed-on: https://go-review.googlesource.com/29274
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Until a few weeks ago, bionic, the Andoid libc, incorrectly
returned const char* (instead of char*) from dlerror(3).

https://android.googlesource.com/platform/bionic/+/5e071a18ce88d93fcffaebb9e0f62524ae504908

Change-Id: I30d33240c63a9f35b6c20ca7e3928ad33bc5e33f
Reviewed-on: https://go-review.googlesource.com/29352
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

%s is no longer valid.  Use %v instead.

Change-Id: I5ec4fa6a9280082c1a0c75fd1cf94b4bb8096f5c
Reviewed-on: https://go-review.googlesource.com/29365Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Updates #16357.

Change-Id: I35f938d675ca5c31f65c4419ee0732bbc593b5cb
Reviewed-on: https://go-review.googlesource.com/29368
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Keep Plists in a slice instead of a linked list.
Eliminate unnecessary fields.
Also, while here remove gc's unused breakpc and continpc vars.

Change-Id: Ia04264036c0442843869965d247ccf68a5295115
Reviewed-on: https://go-review.googlesource.com/29367
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>

The compiler incorrectly will error when comparing a nil pointer
interface to a nil pointer of any other type. Example:
(*int)(nil) == interface{}(nil)
Will error with "gc: illegal constant expression: *int == interface {}"

Fixes #16702

Change-Id: I1a15d651df2cfca6762b1783a28b377b2e6ff8c6
Reviewed-on: https://go-review.googlesource.com/27591
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Replace the AGLOBL pseudo-op with a method to directly register an
LSym as a global. Similar to how we previously already replaced the
ADATA pseudo-op with directly writing out data bytes.

Passes toolstash -cmp.

Change-Id: I3631af0a2ab5798152d0c26b833dc309dbec5772
Reviewed-on: https://go-review.googlesource.com/29366
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Instead of ranging over servers in the config, grab an offset
from the config that is used to determine indices.

When the rotate option is enabled, the offset increases which
rotates queries through servers. Otherwise, it is always 0
which uses servers in config order.

Fixes #17126

Change-Id: If233f6de7bfa42f88570055b9ab631be08a76b3e
Reviewed-on: https://go-review.googlesource.com/29233Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Change-Id: I27b82d8c63a06ddf7e148b15853aba24a22a6282
Reviewed-on: https://go-review.googlesource.com/29336Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Mysterious error and no time or easy machine access to investigate
now, so disabling the -buildmode=plugin test on arm64. (The arm
version is working as expected.)

Updates #17138

Change-Id: I4cc56ddf47e7597213462e48d4934a765168bd07
Reviewed-on: https://go-review.googlesource.com/29363Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

I missed one in CL 29360.

Change-Id: I29fc6dcd920829a918c70734d646119133a0a9df
Reviewed-on: https://go-review.googlesource.com/29361Reviewed-by: Keith Randall <khr@golang.org>

This test was always being run with external linking on these
platforms because the linker was silently forcing external linking
until CL 28971. Now it produces an error instead.

Change-Id: I794e0812711e05b150daf805dc3451507bb4cae8
Reviewed-on: https://go-review.googlesource.com/29360
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

These are close to working, but untested and failing on
build.golang.org. So disable for now.

Change-Id: I330b8d1a91f0bf5139c894913868f01ec87e986d
Reviewed-on: https://go-review.googlesource.com/29359Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Update #16357.

Change-Id: I507676212d7137a62c76de7bfa0ba8dbd68e840f
Reviewed-on: https://go-review.googlesource.com/29358
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Dave Cheney <dave@cheney.net>

Change-Id: I3d64549b85b71bb63bcc815ce2276af6ca2eb215
Reviewed-on: https://go-review.googlesource.com/29354Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Similar idea to golang.org/cl/28970.

Change-Id: I9d2feb1a669d71ffda1d612cf39ee0d3c08d22d2
Reviewed-on: https://go-review.googlesource.com/29357
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Permits parsing of alias declarations with -newparser

	const/type/var/func T => p.T

but the compiler will reject it with an error. For now this
also accepts

	type T = p.T

so we can experiment with a type-alias only scenario.

- renamed _Arrow token to _Larrow (<-)
- introduced _Rarrow token (=>)
- introduced AliasDecl node
- extended scanner to accept _Rarrow
- extended parser and printer to handle alias declarations

Change-Id: I0170d10a87df8255db9186d466b6fd405228c38e
Reviewed-on: https://go-review.googlesource.com/29355
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Add some notes to main.go on what happens where.

Change-Id: I4fb0b6c280e5f990ddc5d749267372b86870af6d
Reviewed-on: https://go-review.googlesource.com/28970
TryBot-Result: Gobot Gobot <gobot@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

ppc64 has an extraneous variable live in some situations.
We need a better tighten pass to get rid of this extra variable.
I'm working on it, but fix the test in the meantime.

Fixes build for ppc64.

Change-Id: I1efb9ccb234a64f2a1c228abd2b3195f67fbeb41
Reviewed-on: https://go-review.googlesource.com/29353Reviewed-by: David Chase <drchase@google.com>

Updates #16357.

Change-Id: I37f04d83134b5e1e7f6ba44eb9a566758ef594d3
Reviewed-on: https://go-review.googlesource.com/29350
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Teach SSA about the cmd/internal/obj/$ARCH register numbering.
It can then return that numbering when requested.  Each architecture
now does not need to know anything about the internal SSA numbering
of registers.

Change-Id: I34472a2736227c15482e60994eebcdd2723fa52d
Reviewed-on: https://go-review.googlesource.com/29249Reviewed-by: David Chase <drchase@google.com>

Change-Id: Ib20263405a08674b5e160295fc965da4c8b54b34
Reviewed-on: https://go-review.googlesource.com/29248Reviewed-by: Ian Lance Taylor <iant@golang.org>

This CL gives Linkmode a type, switches it to the standard flag
handling mechanism, and deduplicates some logic.

There is a semantic change in this CL. Previously if a link was
invoked explicitly with -linkmode=internal, any condition that forced
external linking would silently override this and use external
linking. Instead it now fails with a reason why. I believe this is an
improvement, but will change it back if there's disagreement.

Fixes #12848

Change-Id: Ic80e341fff65ecfdd2b6fdd6079674cc7210fc5f
Reviewed-on: https://go-review.googlesource.com/28971
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: Ie9fea9814c850b084562ab2349b54d9ad9fa1f4a
Reviewed-on: https://go-review.googlesource.com/27825
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I0c8a04457db28c55c35c9a186b63c40f40730e39
Reviewed-on: https://go-review.googlesource.com/27824Reviewed-by: Ian Lance Taylor <iant@golang.org>

Includes a linux implementation.

Change-Id: Iacc2ed7da760ae9deebc928adf2b334b043b07ec
Reviewed-on: https://go-review.googlesource.com/27823
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Bias {Eq,Neq}{8,16} to prefer the extension likely to match
their operand's load (if loaded), and elide sign and zero
extending MOV{B,W}, MOV{B,W}Z when their operands are already
appropriately extended.

Change-Id: Ic01b9cab55e170f68fc2369688b50ce78a818608
Reviewed-on: https://go-review.googlesource.com/29236
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

A tentative fix of #16380. It adds "line" everywhere...

This also reduces binary size slightly (cmd/go on ARM as an example):

			before		after
total binary size	8068097		8018945 (-0.6%)
.gopclntab		1195341		1179929 (-1.3%)
.debug_line		 689692		 652017 (-5.5%)

Change-Id: Ibda657c6999783c5bac180cbbba487006dbf0ed7
Reviewed-on: https://go-review.googlesource.com/25082Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Old backends did not implement them, but SSA do.

Change-Id: I543b2281dcf4bab0da37c9b1f26a5ef55a0ea11b
Reviewed-on: https://go-review.googlesource.com/29278
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

For -buildmode=plugin, this lets the linker drop the main.main symbol
out of the binary while including most of the runtime.

(In the future it should be possible to drop the entire runtime
package from plugins.)

Change-Id: I3e7a024ddf5cc945e3d8b84bf37a0b7cb2a00eb6
Reviewed-on: https://go-review.googlesource.com/27821
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This CL contains several linker changes to support creating plugins.

It collects the exported plugin symbols provided by the compiler and
includes them in the moduledata.

It treats a binary as being dynamically linked if it imports the plugin
package. This lets the dynamic linker de-duplicate symbols.

Change-Id: I099b6f38dda26306eba5c41dbe7862f5a5918d95
Reviewed-on: https://go-review.googlesource.com/27820
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This adds examples showing the different ways of using sort.Search.

Change-Id: Iaa08b4501691f37908317fdcf2e618fbe9f99ade
Reviewed-on: https://go-review.googlesource.com/29131Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Andrew Gerrand <adg@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Gins, and in turn Naddr, is only used with ONAME and OLITERAL Nodes,
so we can drastically simplify Naddr.

Passes toolstash/buildall.

Change-Id: I2deb7eb771fd55e7c7f00040a9aee54588fcac11
Reviewed-on: https://go-review.googlesource.com/29247
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>