Thanks to Christopher Nelson for spearheading the effort.

Fixes #11058

Change-Id: Icafabac8dc697626ff1bd943cc577b0b1cc6b349
Reviewed-on: https://go-review.googlesource.com/69091
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This will be useful for debugging but is intentionally
undocumented and not guaranteed to persist in any
particular form.

Change-Id: I60710a1e94cfc2ce31fe91fc268c51985060f8df
Reviewed-on: https://go-review.googlesource.com/69330
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

* remove unnecessary explicit types
* remove dead assignments
* remove unused fields
* unindent code using early continues
* remove some unnecessary type conversions
* remove some unused func parameters

Change-Id: I202c67e92940beacbd80fc2dc179f9556dc5d9e5
Reviewed-on: https://go-review.googlesource.com/69118
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

The core dump reader would like a bunch of ideal int
constants to be available in dwarf.

Makes the go binary 0.9% bigger.

Update #14517

Change-Id: I00cdfc7f53bcdc56fccba576c1d33010f03bdd95
Reviewed-on: https://go-review.googlesource.com/69270
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

CL50610 broke the build for noopt (different inlining
behavior) and clang (no gdb) so it needs to catch those
cases and skip.

The run/no-run logic was slightly cleaned up,
the name of gdb on OSX was made more robust (tries gdb
first, then ggdb), and the file names were canonicalized
before loggging instead of in comparison to reduce
gratuitous noise in diffs when things aren't otherwise
equal.

This probably doesn't fix problems on Alpine, but it should
provide a cleaner and less confusing failure.

Change-Id: I26c65bff5a8d3d60f1cd6ae02a282558c53dda67
Reviewed-on: https://go-review.googlesource.com/69371
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>

These have never had a use - not even going back to when they were added
in C.

Change-Id: I143b6902b3bacb1fa83c56c9070a8adb9f61a844
Reviewed-on: https://go-review.googlesource.com/69119Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The '*' character is not allowed in ASN.1 PrintableString. However, due
to wide-spread use, we permit it so that we can parse many certificates
with wildcards. However, that also meant that generic strings with
asterisks in would be encoded as PrintableString.

This change makes the default for such strings to be UTF8String. Thus,
while the code PrintableStrings containing '*', it will not generate
them unless the string type was specified in the struct field tag.

Change-Id: I2d458da36649427352eeaa50a1b6020108b2ccbd
Reviewed-on: https://go-review.googlesource.com/68990Reviewed-by: Adam Langley <agl@golang.org>

The old code was seriously broken: It assumed that a constant
declaration without a type would always inherit the type of
the previous declaration, but in fact it only inherits the
type of the previous declaration when there's no type and no
constant value.

While fixing this bug, found that the result was not sorted
deterministically in all situations due to a poor choice of
order value (which led to spurious test failures since the
tests assume deterministic outputs). Fixed that as well.

Added new test cases and fixed some old (broken) tests.

Fixes #16153.

Change-Id: I95b480e019b0fd3538638caba02fe651c69e0513
Reviewed-on: https://go-review.googlesource.com/68730Reviewed-by: Alan Donovan <adonovan@google.com>

Change-Id: I9c75dee7e4498cc11c08cad1ae34ff2af75f1469
Reviewed-on: https://go-review.googlesource.com/69071Reviewed-by: Matthew Dempsky <mdempsky@google.com>

The //go:nosplit directive was visible in GoDoc because the function
that it preceeded (Gosched) is exported. This change moves the directive
above the documentation, hiding it from the output.

Change-Id: I281fd7573f11d977487809f74c9cc16b2af0dc88
Reviewed-on: https://go-review.googlesource.com/69120
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Optimize base64 decoding speed by adding 32-bits and 64-bits specialized
methods that don't perform any error checking and fall back to the more
complex decodeQuantum method when a non-base64 character is present.

On a 64-bits cpu:

name                 old time/op    new time/op     delta
DecodeString/2-4       70.0ns ± 6%     69.2ns ± 0%     ~     (p=0.169 n=5+8)
DecodeString/4-4       91.3ns ± 2%     80.4ns ± 0%  -11.89%  (p=0.001 n=5+10)
DecodeString/8-4        126ns ± 5%      106ns ± 0%  -16.14%  (p=0.000 n=5+7)
DecodeString/64-4       652ns ±21%      361ns ± 0%  -44.57%  (p=0.000 n=5+7)
DecodeString/8192-4    61.0µs ±13%     31.5µs ± 1%  -48.38%  (p=0.001 n=5+9)

name                 old speed      new speed       delta
DecodeString/2-4     57.2MB/s ± 6%   57.7MB/s ± 2%     ~     (p=0.419 n=5+9)
DecodeString/4-4     87.7MB/s ± 2%   99.5MB/s ± 0%  +13.45%  (p=0.001 n=5+10)
DecodeString/8-4     94.8MB/s ± 5%  112.6MB/s ± 1%  +18.82%  (p=0.001 n=5+9)
DecodeString/64-4     136MB/s ±19%    243MB/s ± 0%  +78.17%  (p=0.003 n=5+7)
DecodeString/8192-4   180MB/s ±11%    347MB/s ± 1%  +92.94%  (p=0.001 n=5+9)

Improves #19636

Change-Id: Ic10a454851093a7e1d46ca0c140deed73535d990
Reviewed-on: https://go-review.googlesource.com/38632
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

The existing logic for whether the left and right parts of an assignment
were equal only checked that the gofmt representation of the two was
equal. This only checks that the ASTs were equal.

However, that method is flawed. For example, if either of the
expressions contains a function call, the expressions may actually be
different even if their ASTs are the same. An obvious case is a func
call to math/rand to get a random integer, such as the one added in the
test.

If either of the expressions may have side effects, simply skip the
check. Reuse the logic from bool.go's hasSideEffects.

Fixes #22174.

Change-Id: Ied7f7543dc2bb8852e817230756c6d23bc801d90
Reviewed-on: https://go-review.googlesource.com/69116
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

Updates #19320.

Change-Id: Id38df033e3f0873986e668c8ff3855b6e08407a9
Reviewed-on: https://go-review.googlesource.com/69114
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #22176

Change-Id: If47ec9a25da6b480868d8eeccc518dc97d48bda7
Reviewed-on: https://go-review.googlesource.com/69230Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

Updates #11058

Change-Id: I2a8bf4403b680ab8bf06fff18291f3bf67261e27
Reviewed-on: https://go-review.googlesource.com/69090Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>

Restores linker behavior that existed before CL 68930.
Hopefully fixes the macOS 10.8 builder.

Change-Id: Ib8d6923b59543008cf71c4625addb4e2045cedf6
Reviewed-on: https://go-review.googlesource.com/69170
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Marvin Stenger <marvin.stenger94@gmail.com>

Change-Id: I6aee75a6ae1470dfc658d72a5b6508fb93503057
Reviewed-on: https://go-review.googlesource.com/69115Reviewed-by: Alberto Donizetti <alb.donizetti@gmail.com>

This attempts to choose better values for values that are
rematerialized (uses the XPos of the consumer, not the
original) and for unconditional branches (uses the last
assigned XPos in the block).

The JMP branches seem to sometimes end up with a PC in the
destination block, I think because of register movement
or rematerialization that gets placed in predecessor blocks.
This may be acceptable because (eyeball-empirically) that is
often the line number of the target block, so the line number
flow is correct.

Added proper test, that checks both -N -l and regular compilation.
The test is also capable (for gdb, delve soon) of tracking
variable printing based on comments in the source code.

There's substantial room for improvement in debugger behavior.

Updates #21098.

Change-Id: I13abd48a39141583b85576a015f561065819afd0
Reviewed-on: https://go-review.googlesource.com/50610
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Move some local declarations closer to their use, reducing their
respective lifetimes, also improve few error messages.
Follow up of CL 67370.

Updates #22095

Change-Id: I6131159ae8de571015ef5459b33d5c186e543a37
Reviewed-on: https://go-review.googlesource.com/69110Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Also add some b.ReportAllocs calls to other image codec benchmarks.

Change-Id: I0f055dc76bffb66329c621a5f1ccd239f0cdd30b
Reviewed-on: https://go-review.googlesource.com/68390Reviewed-by: Jed Denlea <jed@fastly.com>
Reviewed-by: Nigel Tao <nigeltao@golang.org>

Otherwise we end up with testp?.exe files after the tests run.

Updates #11058

Change-Id: Ieccfc42da6192622bdab1f9a411ccd50bb59fd5b
Reviewed-on: https://go-review.googlesource.com/68770
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

For #22095

Change-Id: I660080279692b74669c45f42c28cccff71bd33b5
Reviewed-on: https://go-review.googlesource.com/68930Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Also add -V=full to print a unique identifier of the specific tool being invoked.
This will be used for content-based staleness.

Also sort and clean up a few of the flag doc comments.

Change-Id: I786fe50be0b8e5f77af809d8d2dab721185c2abd
Reviewed-on: https://go-review.googlesource.com/68590
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

The BadCBCPadding255 test from bogo failed because at most 255 trailing
bytes were checked, but for a padding of 255 there are 255 padding bytes
plus 1 length byte with value 255.

Change-Id: I7dd237c013d2c7c8599067246e31b7ba93106cf7
Reviewed-on: https://go-review.googlesource.com/68070Reviewed-by: Adam Langley <agl@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Increase MaxBase from 36 to 62 and extend the conversion
alphabet with the upper-case letters 'A' to 'Z'. For int
conversions with bases <= 36, the letters 'A' to 'Z' have
the same values (10 to 35) as the corresponding lower-case
letters. For conversion bases > 36 up to 62, the upper-case
letters have the values 36 to 61.

Added MaxBase to api/except.txt: Clients should not make
assumptions about the value of MaxBase being constant.

The core of the change is in natconv.go. The remaining
changes are adjusted tests and documentation.

Fixes #21558.

Change-Id: I5f74da633caafca03993e13f32ac9546c572cc84
Reviewed-on: https://go-review.googlesource.com/65970Reviewed-by: Martin Möhrmann <moehrmann@google.com>

From a compact specification of control flow graphs,
generate complete set of possible assignment patterns to
output y, and also generate an interpretable specification.
Compiles (hoping for crash, or not) and then runs, where
the run checks function output against interpreted output
for various inputs observed to terminate in the interpreter.

In ssa_test.go, added ability to generate a test and run
(compile and run) the generated test, possibly with
modified environment variables.  The generated test is
compiled including the -D=ssa/check/on flag, and if the
interpreter terminates in a small number of steps, then it
is also run to check the result.

Change-Id: I392c828e36c543411b7733ca0799628452733276
Reviewed-on: https://go-review.googlesource.com/22751
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Change-Id: Icbe6885ffd3aa4e77441ab03a2b9a04a9276d5eb
Reviewed-on: https://go-review.googlesource.com/68311Reviewed-by: Martin Möhrmann <moehrmann@google.com>

Keep left-to-right order when referring to the number of
variables and values involved.

Fixes #22159.

Change-Id: Iccca12d3222f9d5e049939a9ccec07513c393faa
Reviewed-on: https://go-review.googlesource.com/68690Reviewed-by: Russ Cox <rsc@golang.org>

Fix ytab table for EXTRACTPS.
Related to https://go-review.googlesource.com/#/c/go/+/63490/.

Change-Id: I11672d6bb731a204a08905f8321450f02c5bed76
Reviewed-on: https://go-review.googlesource.com/68950
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

"VEX.vvvv" field (VSR, VEX-specified-register) made explicit
in Optab encoding.

vexNDS, vexNDD, vexDDS and vexNOVSR do nothing,
this change does not produce any noticeable effect.

Rationale behind this change:
- keep more information inside optab entries
- make encodings match SDM more closely
- one less special rule to keep in mind

Pvex optabs are updated based on the Intel SDM descriptions.

Unused VEX combinations are removed;
it is problematic to choose VSR combinations for them
without actual Optabs that use them.

The origin of this idea can be found in:
https://go-review.googlesource.com/#/c/arch/+/66972/

Change-Id: I54634a72b44d61f4b924a1e45f2240aab7384dc2
Reviewed-on: https://go-review.googlesource.com/67890
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Adds last missing SSE4 instruction.
Also introduces additional ytab set 'yextractps'.

See https://golang.org/cl/57470 that adds other SSE4 instructions
but skips this one due to 'yextractps'.

To make EXTRACTPS less "sloppy", Yu2 oclass added to forbid
usage of invalid offset values in immediate operand.

Part of the mission to add missing amd64 SSE4 instructions to Go asm.

Change-Id: I0e67e3497054f53257dd8eb4c6268da5118b4853
Reviewed-on: https://go-review.googlesource.com/57490
TryBot-Result: Gobot Gobot <gobot@golang.org>
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
Reviewed-by: Russ Cox <rsc@golang.org>

This CL optimizes assembly for len() or cap() division
by a power of 2 constants:

    func lenDiv(s []int) int {
        return len(s) / 16
    }

amd64 assembly before the CL:

    MOVQ    "".s+16(SP), AX
    MOVQ    AX, CX
    SARQ    $63, AX
    SHRQ    $60, AX
    ADDQ    CX, AX
    SARQ    $4, AX
    MOVQ    AX, "".~r1+32(SP)
    RET

amd64 assembly after the CL:

    MOVQ    "".s+16(SP), AX
    SHRQ    $4, AX
    MOVQ    AX, "".~r1+32(SP)
    RET

The CL relies on the fact that len() and cap() result cannot
be negative.

Trigger stats for the added SSA rules on linux/amd64 when running
make.bash:

     46 Div64
     12 Mod64

The added SSA rules may trigger on more cases in the future
when SSA values will be populated with the info on their
lower bounds.

For instance:

    func f(i int16) int16 {
        if i < 3 {
            return -1
        }

        // Lower bound of i is 3 here -> i is non-negative,
        // so unsigned arithmetics may be used here.
        return i % 16
    }

Change-Id: I8bc6be5a03e71157ced533c01416451ff6f1a7f0
Reviewed-on: https://go-review.googlesource.com/65530Reviewed-by: Keith Randall <khr@golang.org>

Replace Buildmode with BuildMode and Linkmode with LinkMode.

For #22095

Change-Id: I51a6f5719d107727bca29ec8e68e3e9d87e31e33
Reviewed-on: https://go-review.googlesource.com/68334
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

For #22095

Change-Id: Ie9ae84c758af99ac7daed26d0b3e3b0a47599edd
Reviewed-on: https://go-review.googlesource.com/67315
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

amd64 and 386 have rules to reduce multiplication by a positive power
of two, but a more general reduction (both for positive and negative
powers of two) is already performed by generic rules that were added
in CL 36323 to replace walkmul (see lines 166:173 in generic.rules).

The x86 and amd64 rules are never triggered during all.bash and can be
removed, reducing rules duplication.

The change also adds a few code generation tests for amd64 and 386.

Change-Id: I566d48186643bd722a4c0137fe94e513b8b20e36
Reviewed-on: https://go-review.googlesource.com/68450
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

This is only to aid in human debugging, and for that reason we maintain a panic, and not return an error.

Fixes #22097

Change-Id: If72e4d1e47ec9125ca7bc97d5fe4cedb7f76ae72
Reviewed-on: https://go-review.googlesource.com/67970Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I34008f56c191df0edcaafc20d569bbc6184f89fc
Reviewed-on: https://go-review.googlesource.com/68470
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This reverts https://golang.org/cl/66372.

Updates #22148

Change-Id: I3e94af3dfc11a2883bf28e1d5e1f32f98760b3ee
Reviewed-on: https://go-review.googlesource.com/68431Reviewed-by: Ian Lance Taylor <iant@golang.org>

This reverts https://golang.org/cl/65930.

Fixes #22148

Change-Id: Ie0712621ed89c43bef94417fc32de9af77607760
Reviewed-on: https://go-review.googlesource.com/68430Reviewed-by: Ian Lance Taylor <iant@golang.org>

TestUnexportedSymbols requires dup2 that
my gcc installation does not have.

TestSignalHandlersWithNotify fails with:
undefined: syscall.SIGIO.

TestSignalHandlers fails with:
sched.h: No such file or directory.

TestExportedSymbolsWithDynamicLoad fails with:
dlfcn.h: No such file or directory.

Also add t.Helper calls to better error messages.

Updates #11058

Change-Id: I7eb514968464256b8337e45f57fcb7d7fe0e4693
Reviewed-on: https://go-review.googlesource.com/68410
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>