Change-Id: I24374accf48d43edf4bf27ea6ba2245ddca558ad
Reviewed-on: https://go-review.googlesource.com/50910Reviewed-by: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Some debuggers use the declaration line to avoid showing variables
before they're declared. Emit them for local variables and function
parameters.

DW_AT_decl_file would be nice too, but since its value is an index
into a table built by the linker, that's dramatically harder. In
practice, with inlining disabled it's safe to assume that all a
function's variables are declared in the same file, so this should still
be pretty useful.

Change-Id: I8105818c8940cd71bc5473ec98797cce2f3f9872
Reviewed-on: https://go-review.googlesource.com/44350Reviewed-by: David Chase <drchase@google.com>

eqstring is only called for strings with equal lengths.
Instead of pushing a pointer and length for each argument string
on the stack we can omit pushing one of the lengths on the stack.

Changing eqstrings signature to eqstring(*uint8, *uint8, int) bool
to implement the above optimization would make it very similar to the
existing memequal(*any, *any, uintptr) bool function.

Since string lengths are positive we can avoid code redundancy and
use memequal instead of using eqstring with an optimized signature.

go command binary size reduced by 4128 bytes on amd64.

name                          old time/op    new time/op    delta
CompareStringEqual              6.03ns ± 1%    5.71ns ± 1%   -5.23%  (p=0.000 n=19+18)
CompareStringIdentical          2.88ns ± 1%    3.22ns ± 7%  +11.86%  (p=0.000 n=20+20)
CompareStringSameLength         4.31ns ± 1%    4.01ns ± 1%   -7.17%  (p=0.000 n=19+19)
CompareStringDifferentLength    0.29ns ± 2%    0.29ns ± 2%     ~     (p=1.000 n=20+20)
CompareStringBigUnaligned       64.3µs ± 2%    64.1µs ± 3%     ~     (p=0.164 n=20+19)
CompareStringBig                61.9µs ± 1%    61.6µs ± 2%   -0.46%  (p=0.033 n=20+19)

Change-Id: Ice15f3b937c981f0d3bc8479a9ea0d10658ac8df
Reviewed-on: https://go-review.googlesource.com/53650
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

If an error was already printed during LHS conversion step, we don't reprint
the "cannot convert" error.

In particular, this prevents `_ = int("1")` (and all similar casts) from
resulting in multiple identical error messages being printed.

Fixes #20812.

Change-Id: If6e52c59eab438599d641ecf6f110ebafca740a9
Reviewed-on: https://go-review.googlesource.com/46912Reviewed-by: Robert Griesemer <gri@golang.org>

Return an error when a bitSize below 0 or above 64 is specified.

Move bitSize 0 handling in ParseInt after the call to ParseUint
to avoid a spill.

AMD64:
name       old time/op  new time/op  delta
Atoi       28.9ns ± 6%  27.4ns ± 6%  -5.21%  (p=0.002 n=20+20)
AtoiNeg    24.6ns ± 2%  23.1ns ± 1%  -6.04%  (p=0.000 n=19+18)
Atoi64     38.8ns ± 1%  38.0ns ± 1%  -2.03%  (p=0.000 n=17+20)
Atoi64Neg  35.5ns ± 1%  34.3ns ± 1%  -3.42%  (p=0.000 n=19+20)

Updates #21275

Change-Id: I70f0e4a16fa003f7ea929ca4ef56bd1a4181660b
Reviewed-on: https://go-review.googlesource.com/55139Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>

Fixes: #6359

Change-Id: I6c697befd681a253e73a7091faa9f20ff3791201
Reviewed-on: https://go-review.googlesource.com/57090Reviewed-by: Robert Griesemer <gri@golang.org>

The current code gets shift arguments value from prog.From3.Offset.
But prog.From3.Offset is not assigned the shift arguments value in
instructions assemble process.

The fix calls movcon() function to get the correct value.

Uncomment the movk/movkw  cases.

Fixes #21398
Change-Id: I78d40c33c24bd4e3688a04622e4af7ddb5333fa6
Reviewed-on: https://go-review.googlesource.com/54990
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Previously, go/doc would only consider functions that return types of
T or any number of pointers to T: *T, **T, etc. This change expands
the definition of a constructor to also include functions that return
slices of a type (or pointer to that type) in its first return.

With this change, the following return types classify a function
as a constructor of type T:

T
*T
**T (and so on)
[]T
[]*T
[]**T (and so on)

Fixes #18063.

Change-Id: I9a1a689933e13c6b8eb80b74ceec85bd4cab236d
Reviewed-on: https://go-review.googlesource.com/54971Reviewed-by: Robert Griesemer <gri@golang.org>

Replace z.mul(x, x) calls on nats in internal code with z.sqr(x)
that employs optimized squaring routines. Benchmark results:

Exp-4                             12.9ms ± 2%  12.8ms ± 3%     ~     (p=0.165 n=10+10)
Exp2-4                            13.0ms ± 4%  12.8ms ± 2%   -2.14%  (p=0.015 n=8+9)
ModSqrt225_Tonelli-4               987µs ± 4%   989µs ± 2%     ~     (p=0.673 n=8+9)
ModSqrt224_3Mod4-4                 300µs ± 2%   301µs ± 3%     ~     (p=0.546 n=9+9)
ModSqrt5430_Tonelli-4              4.88s ± 6%   4.82s ± 5%     ~     (p=0.247 n=10+10)
ModSqrt5430_3Mod4-4                1.62s ±10%   1.57s ± 1%     ~     (p=0.094 n=9+9)
Exp3Power/0x10-4                   496ns ± 7%   426ns ± 7%  -14.21%  (p=0.000 n=10+10)
Exp3Power/0x40-4                   575ns ± 5%   470ns ± 7%  -18.20%  (p=0.000 n=9+10)
Exp3Power/0x100-4                  929ns ±19%   770ns ±10%  -17.13%  (p=0.000 n=10+10)
Exp3Power/0x400-4                 1.96µs ± 7%  1.79µs ± 5%   -8.68%  (p=0.000 n=10+10)
Exp3Power/0x1000-4                10.9µs ± 9%   7.9µs ± 5%  -28.02%  (p=0.000 n=10+10)
Exp3Power/0x4000-4                86.8µs ± 8%  67.3µs ± 8%  -22.41%  (p=0.000 n=10+10)
Exp3Power/0x10000-4                750µs ± 8%   731µs ± 1%     ~     (p=0.074 n=9+8)
Exp3Power/0x40000-4               7.07ms ± 7%  7.05ms ± 4%     ~     (p=0.931 n=9+9)
Exp3Power/0x100000-4              64.7ms ± 2%  65.6ms ± 6%     ~     (p=0.661 n=9+10)
Exp3Power/0x400000-4               577ms ± 2%   580ms ± 3%     ~     (p=0.931 n=9+9)
ProbablyPrime/n=0-4               9.08ms ±17%  9.09ms ±16%     ~     (p=0.447 n=9+10)
ProbablyPrime/n=1-4               10.8ms ± 4%  10.7ms ± 2%     ~     (p=0.243 n=10+9)
ProbablyPrime/n=5-4               18.5ms ± 3%  18.5ms ± 1%     ~     (p=0.863 n=9+9)
ProbablyPrime/n=10-4              28.6ms ± 6%  28.2ms ± 1%     ~     (p=0.050 n=9+9)
ProbablyPrime/n=20-4              48.4ms ± 4%  48.4ms ± 2%     ~     (p=0.739 n=10+10)
ProbablyPrime/Lucas-4             6.75ms ± 4%  6.75ms ± 2%     ~     (p=0.963 n=9+8)
ProbablyPrime/MillerRabinBase2-4  2.00ms ± 5%  2.00ms ± 7%     ~     (p=0.931 n=9+9)

Change-Id: Ibe9f58d11dbad25eb369faedf480b666a0250a6b
Reviewed-on: https://go-review.googlesource.com/56773Reviewed-by: Robert Griesemer <gri@golang.org>

name         old time/op    new time/op    delta
NewEmptyMap    53.2ns ± 7%    48.0ns ± 5%  -9.77%  (p=0.000 n=20+20)
NewSmallMap     111ns ± 1%     106ns ± 2%  -3.78%  (p=0.000 n=20+19)

Change-Id: I979d21ab16eae9f6893873becca517db57e054b5
Reviewed-on: https://go-review.googlesource.com/56290
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

If set, GOIOS_DEVICE_ID specifies the device id for the iOS exec
wrapper. With that, a single builder can host multiple iOS devices.

Change-Id: If3cc049552f5edbd7344befda7b8d7f73b4236e2
Reviewed-on: https://go-review.googlesource.com/57296
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: JBD <jbd@google.com>
Reviewed-by: Chris Broadfoot <cbro@golang.org>

Change-Id: I159bd1313e617c929008f6ac54ec7d702293360b
Reviewed-on: https://go-review.googlesource.com/57430Reviewed-by: Ian Lance Taylor <iant@golang.org>

BFX extracts given bits from the source register, sign extends them
to 32-bit, and writes to destination register. BFXU does the similar
operation with zero extention.

They were introduced in ARMv6T2.

Change-Id: I6822ebf663497a87a662d3645eddd7c611de2b1e
Reviewed-on: https://go-review.googlesource.com/56071
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

On arm64, all boolean-generating instructions (CSET, etc.) set the upper
63 bits of the destination register to zero, so there is no need
to zero-extend the lower 8 bits again.

Fixes #21445

Change-Id: I3b176baab706eb684105400bacbaa24175f721f3
Reviewed-on: https://go-review.googlesource.com/55671
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

The go tool assumed that -buildmode=pie implied internal linking on
linux-amd64. However, that was changed by CL 36417 for issue #18968.

Fixes #21452

Change-Id: I8ed13aea52959cc5c53223f4c41ba35329445545
Reviewed-on: https://go-review.googlesource.com/57231
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Avelino <t@avelino.xxx>
Reviewed-by: Rob Pike <r@golang.org>

Change-Id: I71bfff6a3462e6dfd7a65ef76ec56644bae37c34
Reviewed-on: https://go-review.googlesource.com/57272Reviewed-by: Avelino <t@avelino.xxx>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I79fee40370dc6758ca1869227f076c61d07f21a5
Reviewed-on: https://go-review.googlesource.com/57390Reviewed-by: Avelino <t@avelino.xxx>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I4377c478159129ab3f3b5ddc58d1944f8f4a4b07
Reviewed-on: https://go-review.googlesource.com/56320Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: Iecff99e85e2cca1127dca79747bb0d5362cd4125
Reviewed-on: https://go-review.googlesource.com/56319Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: Ia4abb76a8fa9e9ab280cd9162238ebd3fba79e4d
Reviewed-on: https://go-review.googlesource.com/56318Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I6a1d33a759deaa4788bafb1c288d9b0e2fe3b026
Reviewed-on: https://go-review.googlesource.com/56317Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I068e9bb6e692b5eff193ddb46af3f04785f98518
Reviewed-on: https://go-review.googlesource.com/56316Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: Idaab6516dae609e1707d4bce7bf7809ebfc8ec40
Reviewed-on: https://go-review.googlesource.com/56315Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I093b79a8dd298bce8e8774c51a86a4873718978a
Reviewed-on: https://go-review.googlesource.com/56314Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I8b23bfb85da9ece47e337f262bafd97f303dd1d1
Reviewed-on: https://go-review.googlesource.com/56313Reviewed-by: Ian Lance Taylor <iant@golang.org>

If there are no pointers, then clearing memory doesn't help GC,
and the memory is otherwise dead, so don't bother clearing it.

Change-Id: I953f4a3264939f2825e82292030eda2e835cbb97
Reviewed-on: https://go-review.googlesource.com/57350
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>

This reverts commit a6ffab6b.

Reason for revert: with CL 57290 the tests run on Android again.

Change-Id: Ifeb29762a4cd0178463acfeeb3696884d99d2993
Reviewed-on: https://go-review.googlesource.com/57310Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

The testcshared test.bash was rewritten in Go, but the rewritten script
broke on Android. Make the tests run on Android again by:

- Restoring the LD_LIBRARY_PATH path (.).
- Restoring the Android specific C flags (-pie -fuse-ld=gold).
- Adding runExe to run test executables. All other commands must run on
the host.

Fixes #21513.

Change-Id: I3ea617a943c686b15437cc5c118e9802a913d93a
Reviewed-on: https://go-review.googlesource.com/57290
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

For #21513

Change-Id: Ibe9479f8afc6f425779a737a807ff2f839a4f311
Reviewed-on: https://go-review.googlesource.com/57250
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

Ask whether the issue reproduces with the latest release.

'go bug' places the version and system details last,
in part because they're automatically filled.
I'd like to do the same here, but I worry
that they'll get ignored.

Change-Id: Iec636a27e6e36d61dca421deaf24ed6fe35d4b11
Reviewed-on: https://go-review.googlesource.com/50931Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Avelino <t@avelino.xxx>

Fixes #21522.

Change-Id: Ifec1681b265576c47a4d736f6f124cc25485c593
Reviewed-on: https://go-review.googlesource.com/57011
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Hopefully this will fix android build.

Maybe fixes #21513

Change-Id: I98f760562646f06b56e385c36927e79458465b92
Reviewed-on: https://go-review.googlesource.com/56790Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This CL is the first step (of two) for adding sparse file support
to the Writer. This CL only refactors the logic of sparse-file handling
in the Reader so that common logic can be easily shared by the Writer.

As a result of this CL, there are some new publicly visible API changes:
	type SparseEntry struct { Offset, Length int64 }
	type Header struct { ...; SparseHoles []SparseEntry }

A new type is defined to represent a sparse fragment and a new field
Header.SparseHoles is added to represent the sparse holes in a file.
The API intentionally represent sparse files using hole fragments,
rather than data fragments so that the zero value of SparseHoles
naturally represents a normal file (i.e., a file without any holes).
The Reader now populates SparseHoles for sparse files.

It is necessary to export the sparse hole information, otherwise it would
be impossible for the Writer to specify that it is trying to encode
a sparse file, and what it looks like.

Some unexported helper functions were added to common.go:
	func validateSparseEntries(sp []SparseEntry, size int64) bool
	func alignSparseEntries(src []SparseEntry, size int64) []SparseEntry
	func invertSparseEntries(src []SparseEntry, size int64) []SparseEntry

The validation logic that used to be in newSparseFileReader is now moved
to validateSparseEntries so that the Writer can use it in the future.
alignSparseEntries is currently unused by the Reader, but will be used
by the Writer in the future. Since TAR represents sparse files by
only recording the data fragments, we add the invertSparseEntries
function to convert a list of data fragments to a normalized list
of hole fragments (and vice-versa).

Some other high-level changes:
* skipUnread is deleted, where most of it's logic is moved to the
Discard methods on regFileReader and sparseFileReader.
* readGNUSparsePAXHeaders was rewritten to be simpler.
* regFileReader and sparseFileReader were completely rewritten
in simpler and easier to understand logic.
* A bug was fixed in sparseFileReader.Read where it failed to
report an error if the logical size of the file ends before
consuming all of the underlying data.
* The tests for sparse-file support was completely rewritten.

Updates #13548

Change-Id: Ic1233ae5daf3b3f4278fe1115d34a90c4aeaf0c2
Reviewed-on: https://go-review.googlesource.com/56771
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

By processing 8 blocks in parallel GHASH achieves higher throughput on amd64

Results on Skylake i7:

benchmark                   old ns/op     new ns/op     delta
BenchmarkAESGCMSeal1K-8     316           314           -0.63%
BenchmarkAESGCMOpen1K-8     282           281           -0.35%
BenchmarkAESGCMSign8K-8     5611          1099          -80.41%
BenchmarkAESGCMSeal8K-8     1869          1922          +2.84%
BenchmarkAESGCMOpen8K-8     1718          1724          +0.35%

benchmark                   old MB/s     new MB/s     speedup
BenchmarkAESGCMSeal1K-8     3237.10      3260.94      1.01x
BenchmarkAESGCMOpen1K-8     3629.74      3638.10      1.00x
BenchmarkAESGCMSign8K-8     1459.82      7452.99      5.11x
BenchmarkAESGCMSeal8K-8     4382.45      4260.93      0.97x
BenchmarkAESGCMOpen8K-8     4766.41      4750.54      1.00x

Change-Id: I479f2a791a968caa1c516115b0b6b96a791a20d2
Reviewed-on: https://go-review.googlesource.com/57150Reviewed-by: Adam Langley <agl@golang.org>

Because profile labels are copied from the goroutine into the tag
buffer by the signal handler, there's a carefully-crafted set of race
detector annotations to create the necessary happens-before edges
between setting a goroutine's profile label and retrieving it from the
profile tag buffer.

Given the constraints of the signal handler, we have to approximate
the true synchronization behavior. Currently, that approximation is
too weak.

Ideally, runtime_setProfLabel would perform a store-release on
&getg().labels and copying each label into the profile would perform a
load-acquire on &getg().labels. This would create the necessary
happens-before edges through each individual g.labels object.

Since we can't do this in the signal handler, we instead synchronize
on a "labelSync" global. The problem occurs with the following
sequence:

1. Goroutine 1 calls setProfLabel, which does a store-release on
   labelSync.

2. Goroutine 2 calls setProfLabel, which does a store-release on
   labelSync.

3. Goroutine 3 reads the profile, which does a load-acquire on
   labelSync.

The problem is that the load-acquire only synchronizes with the *most
recent* store-release to labelSync, and the two store-releases don't
synchronize with each other. So, once goroutine 3 touches the label
set by goroutine 1, we report a race.

The solution is to use racereleasemerge. This is like a
read-modify-write, rather than just a store-release. Each RMW of
labelSync in runtime_setProfLabel synchronizes with the previous RMW
of labelSync, and this ultimately carries forward to the load-acquire,
so it synchronizes with *all* setProfLabel operations, not just the
most recent.

Change-Id: Iab58329b156122002fff12cfe64fbeacb31c9613
Reviewed-on: https://go-review.googlesource.com/56670
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>

We can add a constant to loaction in memory with 1 instruction,
as opposed to load+add+store, so add a new op and relevent ssa rules.
Triggers in e. g. encoding/json isValidNumber:
NumberIsValid-6          36.4ns ± 0%    35.2ns ± 1%  -3.32%  (p=0.000 n=6+10)
Shaves ~2.5 kb from go tool.

Change-Id: I7ba576676c2522432360f77b290cecb9574a93c3
Reviewed-on: https://go-review.googlesource.com/54431
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

All of these are uints of different sizes, so checking >= 0 or < 0 are
effectively no-ops.

Found with staticcheck.

Change-Id: I16ac900eb7007bc8f9018b302136d42e483a4180
Reviewed-on: https://go-review.googlesource.com/56950Reviewed-by: Matt Layher <mdlayher@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Matt Layher <mdlayher@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This will reduce duplication when evacuate is specialized.

Change-Id: I34cdfb7103442d3e0ea908c970fb46334b86d5c4
Reviewed-on: https://go-review.googlesource.com/56934
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Avelino <t@avelino.xxx>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Minor refactoring. This is a step towards specializing evacuate
for mapfast key types.

Change-Id: Icffe2759b7d38e5c008d03941918d5a912ce62f6
Reviewed-on: https://go-review.googlesource.com/56933
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Since oldbucket == h.nevacuate, we can just increment h.nevacuate here.
This removes oldbucket from scope, which will be useful shortly.

Change-Id: I70f81ec3995f17845ebf5d77ccd20ea4338f23e6
Reviewed-on: https://go-review.googlesource.com/56932
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Avelino <t@avelino.xxx>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>