With math/big supporting the new octal prefixes directly,
the compiler doesn't have to manually convert such numbers
into old-style 0-prefix octals anymore.

Updates #12711.

Change-Id: I300bdd095836595426a1478d68da179f39e5531a
Reviewed-on: https://go-review.googlesource.com/c/go/+/165861Reviewed-by: Matthew Dempsky <mdempsky@google.com>

This CL extends the various SetString and Parse methods for
Ints, Rats, and Floats to accept the new octal prefixes.

The main change is in natconv.go, all other changes are
documentation and test updates.

Finally, this CL also fixes TestRatSetString which silently
dropped certain failures.

Updates #12711.

Change-Id: I5ee5879e25013ba1e6eda93ff280915f25ab5d55
Reviewed-on: https://go-review.googlesource.com/c/go/+/165898Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>

Update the test in test/heapsampling.go to more thoroughly validate heap sampling.
Lower the sampling rate on the test to ensure allocations both smaller and
larger than the sampling rate are tested.

Tighten up the validation check to a 10% difference between the unsampled and correct value.
Because of the nature of random sampling, it is possible that the unsampled value fluctuates
over that range. To avoid flakes, run the experiment three times and only report an issue if the
same location consistently falls out of range on all experiments.

This tests the sampling fix in cl/158337.

Change-Id: I54a709e5c75827b8b1c2d87cdfb425ab09759677
GitHub-Last-Rev: 7c04f126034f9e323efc220c896d75e7984ffd39
GitHub-Pull-Request: golang/go#26944
Reviewed-on: https://go-review.googlesource.com/c/go/+/129117
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

net.TCPConn has the ability to send data out using system calls such as
sendfile when the source data comes from an *os.File. However, the way
that I/O has been laid out in the transport means that the File is
actually wrapped behind two outer io.Readers, and as such the TCP stack
cannot properly type-assert the reader, ensuring that it falls back to
genericReadFrom.

This commit does the following:

* Removes transferBodyReader and moves its functionality to a new
doBodyCopy helper. This is not an io.Reader implementation, but no
functionality is lost this way, and it allows us to unwrap one layer
from the body.

* The second layer of the body is unwrapped if the original reader
was wrapped with ioutil.NopCloser, which is what NewRequest wraps the
body in if it's not a ReadCloser on its own. The unwrap operation
passes through the existing body if there's no nopCloser.

Note that this depends on change https://golang.org/cl/163737 to
properly function, as the lack of ReaderFrom implementation otherwise
means that this functionality is essentially walled off.

Benchmarks between this commit and https://golang.org/cl/163862,
incorporating https://golang.org/cl/163737:

linux/amd64:
name                        old time/op    new time/op    delta
FileAndServer_1KB/NoTLS-4     53.2µs ± 0%    53.3µs ± 0%      ~     (p=0.075 n=10+9)
FileAndServer_1KB/TLS-4       61.2µs ± 0%    60.7µs ± 0%    -0.77%  (p=0.000 n=10+9)
FileAndServer_16MB/NoTLS-4    25.3ms ± 5%     3.8ms ± 6%   -84.95%  (p=0.000 n=10+10)
FileAndServer_16MB/TLS-4      33.2ms ± 2%    13.4ms ± 2%   -59.57%  (p=0.000 n=10+10)
FileAndServer_64MB/NoTLS-4     106ms ± 4%      16ms ± 2%   -84.45%  (p=0.000 n=10+10)
FileAndServer_64MB/TLS-4       129ms ± 1%      54ms ± 3%   -58.32%  (p=0.000 n=8+10)

name                        old speed      new speed      delta
FileAndServer_1KB/NoTLS-4   19.2MB/s ± 0%  19.2MB/s ± 0%      ~     (p=0.095 n=10+9)
FileAndServer_1KB/TLS-4     16.7MB/s ± 0%  16.9MB/s ± 0%    +0.78%  (p=0.000 n=10+9)
FileAndServer_16MB/NoTLS-4   664MB/s ± 5%  4415MB/s ± 6%  +565.27%  (p=0.000 n=10+10)
FileAndServer_16MB/TLS-4     505MB/s ± 2%  1250MB/s ± 2%  +147.32%  (p=0.000 n=10+10)
FileAndServer_64MB/NoTLS-4   636MB/s ± 4%  4090MB/s ± 2%  +542.81%  (p=0.000 n=10+10)
FileAndServer_64MB/TLS-4     522MB/s ± 1%  1251MB/s ± 3%  +139.95%  (p=0.000 n=8+10)

darwin/amd64:
name                        old time/op    new time/op     delta
FileAndServer_1KB/NoTLS-8     93.0µs ± 5%     96.6µs ±11%      ~     (p=0.190 n=10+10)
FileAndServer_1KB/TLS-8        105µs ± 7%      100µs ± 5%    -5.14%  (p=0.002 n=10+9)
FileAndServer_16MB/NoTLS-8    87.5ms ±19%     10.0ms ± 6%   -88.57%  (p=0.000 n=10+10)
FileAndServer_16MB/TLS-8      52.7ms ±11%     17.4ms ± 5%   -66.92%  (p=0.000 n=10+10)
FileAndServer_64MB/NoTLS-8     363ms ±54%       39ms ± 7%   -89.24%  (p=0.000 n=10+10)
FileAndServer_64MB/TLS-8       209ms ±13%       73ms ± 5%   -65.37%  (p=0.000 n=9+10)

name                        old speed      new speed       delta
FileAndServer_1KB/NoTLS-8   11.0MB/s ± 5%   10.6MB/s ±10%      ~     (p=0.184 n=10+10)
FileAndServer_1KB/TLS-8     9.75MB/s ± 7%  10.27MB/s ± 5%    +5.26%  (p=0.003 n=10+9)
FileAndServer_16MB/NoTLS-8   194MB/s ±16%   1680MB/s ± 6%  +767.83%  (p=0.000 n=10+10)
FileAndServer_16MB/TLS-8     319MB/s ±10%    963MB/s ± 4%  +201.36%  (p=0.000 n=10+10)
FileAndServer_64MB/NoTLS-8   180MB/s ±31%   1719MB/s ± 7%  +853.61%  (p=0.000 n=9+10)
FileAndServer_64MB/TLS-8     321MB/s ±12%    926MB/s ± 5%  +188.24%  (p=0.000 n=9+10)

Updates #30377.

Change-Id: I631a73cea75371dfbb418c9cd487c4aa35e73fcd
GitHub-Last-Rev: 4a77dd1b80140274bf3ed20ad7465ff3cc06febf
GitHub-Pull-Request: golang/go#30378
Reviewed-on: https://go-review.googlesource.com/c/go/+/163599
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>

Currently only CPU profile utilizes tag information.
This change documents that fact

Updates #23458

Change-Id: Ic893e85f63af0da9100d8cba7d3328c294e8c810
GitHub-Last-Rev: be99a126296493b3085aa5ade91895b36fb1de73
GitHub-Pull-Request: golang/go#27198
Reviewed-on: https://go-review.googlesource.com/c/go/+/131275Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>

Change-Id: Id0398b51336cc74f2172d9b8e18cb1dcb520b9a0
GitHub-Last-Rev: b5cf80bf9d7f79eab1a398ad3c03f3b424aafdf1
GitHub-Pull-Request: golang/go#29931
Reviewed-on: https://go-review.googlesource.com/c/go/+/159537Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This CL eliminates unnecessary type conversion operations: OpZeroExt16to64 and OpZeroExt8to64.
If the input argrument is a nonzero value, then ORconst operation can also be eliminated.

Benchmarks:

name               old time/op  new time/op  delta
TrailingZeros-8    2.75ns ± 0%  2.75ns ± 0%     ~     (all equal)
TrailingZeros8-8   3.49ns ± 1%  2.93ns ± 0%  -16.00%  (p=0.000 n=10+10)
TrailingZeros16-8  3.49ns ± 1%  2.93ns ± 0%  -16.05%  (p=0.000 n=9+10)
TrailingZeros32-8  2.67ns ± 1%  2.68ns ± 1%     ~     (p=0.468 n=10+10)
TrailingZeros64-8  2.67ns ± 1%  2.65ns ± 0%   -0.62%  (p=0.022 n=10+9)

code:

func f16(x uint) { z = bits.TrailingZeros16(uint16(x)) }

Before:

"".f16 STEXT size=48 args=0x8 locals=0x0 leaf
        0x0000 00000 (test.go:7)        TEXT    "".f16(SB), LEAF|NOFRAME|ABIInternal, $0-8
        0x0000 00000 (test.go:7)        FUNCDATA        ZR, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        FUNCDATA        $1, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        FUNCDATA        $3, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        PCDATA  $2, ZR
        0x0000 00000 (test.go:7)        PCDATA  ZR, ZR
        0x0000 00000 (test.go:7)        MOVD    "".x(FP), R0
        0x0004 00004 (test.go:7)        MOVHU   R0, R0
        0x0008 00008 (test.go:7)        ORR     $65536, R0, R0
        0x000c 00012 (test.go:7)        RBIT    R0, R0
        0x0010 00016 (test.go:7)        CLZ     R0, R0
        0x0014 00020 (test.go:7)        MOVD    R0, "".z(SB)
        0x0020 00032 (test.go:7)        RET     (R30)

This line of code is unnecessary:
        0x0004 00004 (test.go:7)        MOVHU   R0, R0

After:

"".f16 STEXT size=32 args=0x8 locals=0x0 leaf
        0x0000 00000 (test.go:7)        TEXT    "".f16(SB), LEAF|NOFRAME|ABIInternal, $0-8
        0x0000 00000 (test.go:7)        FUNCDATA        ZR, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        FUNCDATA        $1, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        FUNCDATA        $3, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        PCDATA  $2, ZR
        0x0000 00000 (test.go:7)        PCDATA  ZR, ZR
        0x0000 00000 (test.go:7)        MOVD    "".x(FP), R0
        0x0004 00004 (test.go:7)        ORR     $65536, R0, R0
        0x0008 00008 (test.go:7)        RBITW   R0, R0
        0x000c 00012 (test.go:7)        CLZW    R0, R0
        0x0010 00016 (test.go:7)        MOVD    R0, "".z(SB)
        0x001c 00028 (test.go:7)        RET     (R30)

The situation of TrailingZeros8 is similar to TrailingZeros16.

Change-Id: I473bdca06be8460a0be87abbae6fe640017e4c9d
Reviewed-on: https://go-review.googlesource.com/c/go/+/156999Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This CL adds two rules to turn patterns like ((x<<8) | (x>>8)) (the type of
x is uint16, "|" can also be "+" or "^") to a REV16 instruction on arm v6+.
This optimization rule can be used for math/bits.ReverseBytes16.

Benchmarks on arm v6:
name               old time/op  new time/op  delta
ReverseBytes-32    2.86ns ± 0%  2.86ns ± 0%   ~     (all equal)
ReverseBytes16-32  2.86ns ± 0%  2.86ns ± 0%   ~     (all equal)
ReverseBytes32-32  1.29ns ± 0%  1.29ns ± 0%   ~     (all equal)
ReverseBytes64-32  1.43ns ± 0%  1.43ns ± 0%   ~     (all equal)

Change-Id: I819e633c9a9d308f8e476fb0c82d73fb73dd019f
Reviewed-on: https://go-review.googlesource.com/c/go/+/159019Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Make persistConnWriter implement io.ReaderFrom, via an io.Copy on the
underlying net.Conn. This in turn enables it to use OS level
optimizations such as sendfile.

This has been observed giving performance gains even in the absence
of ReaderFrom, more than likely due to the difference in io's default
buffer (32 KB) versus bufio's (4 KB).

Speedups on linux/amd64:
benchmark                               old MB/s     new MB/s     speedup
BenchmarkFileAndServer_16MB/NoTLS-4     662.96       2703.74      4.08x
BenchmarkFileAndServer_16MB/TLS-4       552.76       1420.72      2.57x

Speedups on darwin/amd64:
benchmark                               old MB/s     new MB/s     speedup
BenchmarkFileAndServer_16MB/NoTLS-8     357.58       1972.86      5.52x
BenchmarkFileAndServer_16MB/TLS-8       346.20       1067.41      3.08x

Updates #30377.

Change-Id: Ic88d4ac254f665223536fcba4d551fc32ae105b6
GitHub-Last-Rev: a6f67cda2ed63ac61a1dffc87f0ea396363f72c6
GitHub-Pull-Request: golang/go#30390
Reviewed-on: https://go-review.googlesource.com/c/go/+/163737
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>

Change-Id: Ib03d7e5686e510152042e403b00fb2d65572f393
GitHub-Last-Rev: 57aeedf077cb4f82af68cc5cb2de5d53a447565e
GitHub-Pull-Request: golang/go#30156
Reviewed-on: https://go-review.googlesource.com/c/go/+/161723Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>

This CL removes runtime code working around missing ARM processor capability
information in the auxiliary vector in older FreeBSD versions.

As announced in the Go 1.12 release notes Go 1.13 will require FreeBSD 11.2+
or FreeBSD 12.0+. These FreeBSD versions support CPU capability detection
through AT_HWCAP and AT_HWCAP2 values stored in the auxiliary vector.

Updates #27619

Change-Id: I2a457b578d35101a7a5fd56ae9b81b300ad17da4
Reviewed-on: https://go-review.googlesource.com/c/go/+/165799Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Yuval Pavel Zholkover <paulzhol@gmail.com>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Martin Möhrmann <martisch@uos.de>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I92d8c93967c5ec57f07151affd0041f00e405057
GitHub-Last-Rev: 2dea977d938a504604aed6a9ae87986001f96acd
GitHub-Pull-Request: golang/go#30551
Reviewed-on: https://go-review.googlesource.com/c/go/+/164970Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

A recent edit broke the flow; add a paragraph break when the subject
switches from maps to structs.

No changes in wording.

Change-Id: I5df88ec36b9d81931cfdbc684424440d01ac06d1
Reviewed-on: https://go-review.googlesource.com/c/go/+/165917Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

As an experiment to better understand the impact of
having an authoritative source of truth for module hashes
before the real notary is available, this CL adds the basic
notary authorization checks using a partial whitelist of
known go.sum values for popular modules.

In addition to the temporary whitelist, this CL adds code
implementing $GONOVERIFY, a new 'go help modules-auth',
and clearer error messages for verification mismatches.

See #25530 for notary proposal.
Filed #30601 to remove whitelist when notary lands.

Change-Id: Ibcb6ac39c5e60455edf003d8c20af6932aeb7e88
Reviewed-on: https://go-review.googlesource.com/c/go/+/165380Reviewed-by: Bryan C. Mills <bcmills@google.com>

Fixes #30646

Change-Id: I5b7e986b0588e87b9781cce01445e3c55c06b6fc
Reviewed-on: https://go-review.googlesource.com/c/go/+/165897
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

First the insidious bug:

  var n uintptr
  for n := elemPtrs; n > 120; n -= 120 {
    prog = append(prog, 120)
    prog = append(prog, mask[:15]...)
    mask = mask[15:]
  }
  prog = append(prog, byte(n))
  prog = append(prog, mask[:(n+7)/8]...)

The := breaks this code, because the n after the loop is always 0!

We also do need to handle field padding correctly. In particular
the old padding code doesn't correctly handle fields that are not
a multiple of a pointer in size.

Fixes #30606.

Change-Id: Ifcab9494dc25c20116753c5d7e0145d6c2053ed8
Reviewed-on: https://go-review.googlesource.com/c/go/+/165860
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This change adds a Val accessor that returns the underlying type for a
given constant.Value. This change also adds a Make constructor that builds a
constant.Value given a value of a specific type.

Fixes #29820

Change-Id: I4fc3f5221408e24af42ffecd21ce4099ee75b47a
Reviewed-on: https://go-review.googlesource.com/c/go/+/164538Reviewed-by: Robert Griesemer <gri@golang.org>

The contents of debug_pubnames and debug_pubtypes have been wrong since
Go 1.12.
CL golang.org/cl/137235 moved global variables DIE to their respective
compilation unit, unfortunately writepub can't emit correct sections
for anything but the first compilation unit.

This commit moves the code generating debug_pubnames and debug_pubtypes
inside writeinfo and fixes it.
Gets rid of a number of unnecessary relocations as well as a hack that
writeinfo used to communicate to writepub the size of each compilation
unit.

Fixes #30573

Change-Id: Ibdaa80c02746ae81661c2cfe1d218092c5ae9236
Reviewed-on: https://go-review.googlesource.com/c/go/+/165337
Run-TryBot: Alessandro Arzilli <alessandro.arzilli@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>

The 'go version' statement was added during Go 1.11 development in
CL 125940. That CL added the GoVersion field to modinfo.ModulePublic
struct, but did not document it in cmd/go documentation. This was
consistent with the CL description, which stated "We aren't planning
to use this or advertise it much yet".

CL 147281, applied during Go 1.12 development, was a change to start
adding the 'go version' statement when initializing go.mod. The 'go
version' statement is now being used, and it has been documented in
the Go 1.12 release notes at https://golang.org/doc/go1.12#modules.
It's now due time to documement the GoVersion field in cmd/go as well.

Keep the Error field bottom-most, both because it makes sense not to
place it in the middle of other fields, and for consistency with the
field order in struct Package, where the Error information is located
at the very bottom.

Regenerate alldocs.go by running mkalldocs.sh.

Updates #28221
Updates #23969

Change-Id: Iaf43a0da4f6a2489d861092a1d4e002a532952cb
Reviewed-on: https://go-review.googlesource.com/c/go/+/164878
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

Change-Id: Ib391e019b1a7513d234fb1c8ff802efe8fa7c950
Reviewed-on: https://go-review.googlesource.com/c/go/+/163859
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

Instead of trying to guess type of constants in the AST,
which is hard, use the "var cgo%d Type = Constant"
so that typechecking is left to the Go compiler.

The previous code could still fail in some cases
for constants imported from other modules
or defined in other, non-cgo files.

Fixes #30527

Change-Id: I2120cd90e90a74b9d765eeec53f6a3d2cfc1b642
Reviewed-on: https://go-review.googlesource.com/c/go/+/164897
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Otherwise, when the 'cmd' module is added the test will run as if in module 'cmd'.

While we're here, remove an unnecessary os.Chdir in TestAbsolutePath:
we can instead set the Dir on the 'go build' command instead. Then we
can run the tests in this file in parallel with everything else.

Updates #30228

Change-Id: I13ecd7ec93bc1041010daec14d76bac10e0c89be
Reviewed-on: https://go-review.googlesource.com/c/go/+/165744
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Test case for a panic/crash in gccgoimporter caused by incorrect gccgo
export data emission. Note that the *.gox file checked in contains the
correct export data; the main intent of the test is to make sure that
gccgo produces the right export data when run on the Go source.

Updates #30628

Change-Id: I29c0c17b81a43f92ff64fbfcdc58fdb46a5be370
Reviewed-on: https://go-review.googlesource.com/c/go/+/165739
Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

They are missing a stop byte at the end.

Normally this doesn't matter, but when including a GC program
in another GC program, we strip the last byte. If that last byte
wasn't a stop byte, then we've thrown away part of the program
we actually need.

Fixes #30606

Change-Id: Ie9604beeb84f7f9442e77d31fe64c374ca132cce
Reviewed-on: https://go-review.googlesource.com/c/go/+/165857
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #28152

Change-Id: I98db923bdf8de7acf2df452313427bfea43b63c9
Reviewed-on: https://go-review.googlesource.com/c/go/+/165746
Run-TryBot: Jay Conrod <jayconrod@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

When running cmd/vet/all on multiple builders, the coordinator places
a copy of golang.org/x/tools at a consistent revision in the builders'
GOPATHs. Keep using the consistent revision in module mode by
executing the build from a working directory within that repository.

When not running on a builder, use 'go vet' directly instead of
building an arbitrarily stale vet tool from the user's GOPATH.

Updates #30228

Change-Id: I19bc809247378da98f3e6ac8572f61bda4518143
Reviewed-on: https://go-review.googlesource.com/c/go/+/165740
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Make sure the side effects inside short-circuited operations (&& and ||)
happen correctly.

Before this CL, we attached the side effects to the node itself using
exprInPlace. That caused other side effects in sibling expressions
to get reordered with respect to the short circuit side effect.

Instead, rewrite a && b like:

r := a
if r {
  r = b
}

That code we can keep correctly ordered with respect to other
side-effects extracted from part of a big expression.

exprInPlace seems generally unsafe. But this was the only case where
exprInPlace is called not at the top level of an expression, so I
don't think the other uses can actually trigger an issue (there can't
be a sibling expression). TODO: maybe those cases don't need "in
place", and we can retire that function generally.

This CL needed a small tweak to the SSA generation of OIF so that the
short circuit optimization still triggers. The short circuit optimization
looks for triangle but not diamonds, so don't bother allocating a block
if it will be empty.

Go 1 benchmarks are in the noise.

Fixes #30566

Change-Id: I19c04296bea63cbd6ad05f87a63b005029123610
Reviewed-on: https://go-review.googlesource.com/c/go/+/165617
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

TestGoGetInsecure verifies that 'go get -insecure' can fetch a
particular package. However, the GOPROXY protocol does not provide a
means for proxies to indicate packages as insecure; thus, proxies
cannot safely serve those packages.

Updates #30571

Change-Id: I447776dff98bd8ee6eb5055b897b9c7d293e3423
Reviewed-on: https://go-review.googlesource.com/c/go/+/165745
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Relative imports do not work in module mode. Use a fully-qualified
import path instead.

Updates #30228

Change-Id: I0a42ffa521a7b513395e7e1788022d24cbb1f31a
Reviewed-on: https://go-review.googlesource.com/c/go/+/165817
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

cmd/dist executes 'go test' within this directory, so it needs a
go.mod file to tell the compiler what package path to use in
diagnostic and debug information.

Updates #30228

Change-Id: Ia313ac06bc0ec4631d415faa20c56cce2ac8dbc5
Reviewed-on: https://go-review.googlesource.com/c/go/+/165498
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This change adds several arm64 v8.1 atomic instructions and test cases.
They are LDADDAx, LDADDLx, LDANDAx, LDANDALx, LDANDLx, LDEORAx, LDEORALx,
LDEORLx, LDORAx, LDORALx, LDORLx, SWPAx and SWPLx. Their form is consistent
with the form of the existing atomic instructions.

For instructions STXRx, STLXRx, STXPx and STLXPx, the second destination
register can't be RSP. This CL also adds a check for this.

LDADDx Rs, (Rb), Rt: *Rb -> Rt, Rs + *Rb -> *Rb
LDANDx Rs, (Rb), Rt: *Rb -> Rt, Rs AND NOT(*Rb) -> *Rb
LDEORx Rs, (Rb), Rt: *Rb -> Rt, Rs EOR *Rb -> *Rb
LDORx  Rs, (Rb), Rt: *Rb -> Rt, Rs OR *Rb -> *Rb

Change-Id: I9f9b0245958cb57ab7d88c66fb9159b23b9017fd
Reviewed-on: https://go-review.googlesource.com/c/go/+/157001Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

fd.l.Lock shouldn't be called in a loop.

Change-Id: I3afbc184aa06a60175c9a39319985b5810ecb144
Reviewed-on: https://go-review.googlesource.com/c/go/+/165598
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Before this change, if a directory was closed twice on Windows,
the returning error would be "use of closed network connection".

Some code assumes FD.isFile means whether the fd isn't a network
socket, which is true on Unix. But isFile reports whether
the fd is a normal file rather than directory or console on Windows.

With this change, isFile will have the same meaning on different
platforms. And the change adds a new field kind to replace isConsole
and isDir.

Change-Id: Ib12265f1e12fa3d0239ae925291128a84be59cc2
GitHub-Last-Rev: 3f031756de6ce0b96c1f102ad280950f4adbf6c2
GitHub-Pull-Request: golang/go#30589
Reviewed-on: https://go-review.googlesource.com/c/go/+/165257
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Use word-wise comparison for aligned buffers, otherwise fall back to the
current byte-wise comparison.

name                           old time/op    new time/op    delta
BytesCompare/1-4                 41.3ns ± 0%    36.4ns ± 1%   -11.73%  (p=0.008 n=5+5)
BytesCompare/2-4                 39.5ns ± 0%    39.5ns ± 1%      ~     (p=0.960 n=5+5)
BytesCompare/4-4                 45.3ns ± 0%    41.0ns ± 1%    -9.40%  (p=0.008 n=5+5)
BytesCompare/8-4                 64.8ns ± 1%    44.7ns ± 0%   -31.12%  (p=0.008 n=5+5)
BytesCompare/16-4                86.3ns ± 0%    55.1ns ± 0%   -36.21%  (p=0.008 n=5+5)
BytesCompare/32-4                 135ns ± 0%      70ns ± 1%   -47.73%  (p=0.008 n=5+5)
BytesCompare/64-4                 231ns ± 1%      99ns ± 0%   -57.27%  (p=0.016 n=5+4)
BytesCompare/128-4                424ns ± 0%     147ns ± 0%   -65.31%  (p=0.000 n=4+5)
BytesCompare/256-4                810ns ± 0%     243ns ± 0%   -69.96%  (p=0.008 n=5+5)
BytesCompare/512-4               1.59µs ± 0%    0.44µs ± 0%   -72.43%  (p=0.008 n=5+5)
BytesCompare/1024-4              3.14µs ± 1%    0.83µs ± 1%   -73.56%  (p=0.008 n=5+5)
BytesCompare/2048-4              6.23µs ± 0%    1.61µs ± 1%   -74.21%  (p=0.008 n=5+5)
CompareBytesEqual-4              79.4ns ± 0%    52.2ns ± 0%   -34.23%  (p=0.008 n=5+5)
CompareBytesToNil-4              31.0ns ± 0%    30.3ns ± 0%    -2.32%  (p=0.008 n=5+5)
CompareBytesEmpty-4              25.7ns ± 0%    25.7ns ± 0%      ~     (p=0.556 n=4+5)
CompareBytesIdentical-4          25.7ns ± 0%    25.7ns ± 0%      ~     (p=1.000 n=5+5)
CompareBytesSameLength-4         49.1ns ± 0%    48.5ns ± 0%    -1.26%  (p=0.008 n=5+5)
CompareBytesDifferentLength-4    49.8ns ± 1%    49.3ns ± 0%    -1.08%  (p=0.008 n=5+5)
CompareBytesBigUnaligned-4       5.71ms ± 1%    5.68ms ± 1%      ~     (p=0.222 n=5+5)
CompareBytesBig-4                4.95ms ± 0%    2.28ms ± 1%   -53.81%  (p=0.008 n=5+5)
CompareBytesBigIdentical-4       27.2ns ± 1%    27.3ns ± 1%      ~     (p=0.310 n=5+5)

name                           old speed      new speed      delta
CompareBytesBigUnaligned-4      184MB/s ± 1%   185MB/s ± 1%      ~     (p=0.222 n=5+5)
CompareBytesBig-4               212MB/s ± 0%   459MB/s ± 1%  +116.51%  (p=0.008 n=5+5)
CompareBytesBigIdentical-4     38.5TB/s ± 0%  38.4TB/s ± 1%      ~     (p=0.421 n=5+5)

Also, this reduces time for TestCompareBytes by about 20 sec on a
linux-arm builder via gomote.

Updates #29001

Change-Id: I25f148739b9ccb7cb1fc97b3d8763549b0a66c16
Reviewed-on: https://go-review.googlesource.com/c/go/+/165338
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Moduledata symbols like runtime.data or runtime.text must have the
same position in the final executable (as some symbol accesses are made
by offset from them).
ld on AIX might move them randomly if there are nil size symbols.

ld will also remove unreachable symbols like runtime.epclntab or
runtime.rodata. In order to keep them, R_REF relocations are created
between firstmoduledata and these symbols. This relocation tells ld to
keep these symbols even if there aren't reachable.

Change-Id: Ie5a28cf406977131cec6442f7f5b6fd89fb775a3
Reviewed-on: https://go-review.googlesource.com/c/go/+/164004
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This commit adds external linking in cmd/link for aix/ppc64.
As relocations on .text data aren't possible on AIX, Segrelrodata is
used to move all these datas to .data section.

Change-Id: I4d1361c1fc9290e11e6f5560864460c76551dbeb
Reviewed-on: https://go-review.googlesource.com/c/go/+/164003
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This commit rewrites if-else-if-else chain in scanBasePrefix function as a switch.

Based on Go style guide https://golang.org/doc/effective_go.html#switch

Change-Id: I6392bfd4ad0384f3dc8896de4763bb2164c3eead
GitHub-Last-Rev: 9bd8dfdac03c466bf8cacf3119f6245dfb61c009
GitHub-Pull-Request: golang/go#30621
Reviewed-on: https://go-review.googlesource.com/c/go/+/165619
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Note that this particular combination of properties still fails (EPERM), but it
no longer hangs.

Updates #29789

Change-Id: I29b15b85a25a7acd7ae89ffc5fed074bcdfe0a12
Reviewed-on: https://go-review.googlesource.com/c/go/+/158297
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

If the input was "John Doe", we're definitely missing "<email>", as
"John Doe@domain" isn't a valid email address.

However, if the input was "john.doe", it's possible that the user meant
"john.doe@domain", and not just "john.doe <email>". Make it clear in the
error that either could be the source of the problem.

Fixes #27064.

Change-Id: I1b8f1342775d711823dffc3db974898ee62d3a34
Reviewed-on: https://go-review.googlesource.com/c/go/+/165517
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The change fixes the following deviations between the existing implementation and the Spec:
1. Using pattern instead of "mask" for assertion and iteration in the Pattern Matching Algorithm.
2. Rename "image/vnd.microsoft.icon" to "image/x-icon" and add another signature for the same.
3. Using named strings instead of hexadecimal representation in "application/zip" and "application/x-rar-compressed".
4. Reordering "sniffSignatures" in accordance with the Spec section "Identifying a resource with an unknown MIME type".

In addition to the above fixes, unit tests for Image MIME type group are added.

Fixes #30570

Change-Id: I97d2ae22b426c3c57bf8efd2ed9396c0be983688
Reviewed-on: https://go-review.googlesource.com/c/go/+/165277Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
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