Ensure that all errors (including io.EOF) are persistent across method
calls on zlib.Reader. Furthermore, ensure that these persistent errors
are properly cleared when Reset is called.

Fixes #14675

Change-Id: I15a20c7e25dc38219e7e0ff255d1ba775a86bb47
Reviewed-on: https://go-review.googlesource.com/20292Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Found by temporarily flipping fields from *NodeList to Nodes and fixing
all the compilation errors.  This CL does not actually change any
fields.

Passes toolstash -cmp.

Update #14473.

Change-Id: Ib98fa37e8752f96358224c973a743618a6a0e736
Reviewed-on: https://go-review.googlesource.com/20320
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Eliminates type conversions in a bunch of Oconv(int(n.Op), ...) calls.

Notably, this identified a misuse of Oconv in amd64/gsubr.go to try to
print an assembly instruction op instead of a compiler node op.

Change-Id: I93b5aa49fe14a5eaf868b05426d3b8cd8ab52bc5
Reviewed-on: https://go-review.googlesource.com/20298
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Implementation more or less follows plan9_386 version.
Revised 7 March to correct a bug in runtime.seek and
tidy whitespace for 8-column tabs.

Change-Id: I2e921558b5816502e8aafe330530c5a48a6c7537
Reviewed-on: https://go-review.googlesource.com/18966
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Plan 9 trap/signal handling differs on ARM from other architectures
because ARM has a link register.  Also trap message syntax varies
between different architectures (historical accident?).
Revised 7 March to clarify a comment.

Change-Id: Ib6485f82857a2f9a0d6b2c375cf0aaa230b83656
Reviewed-on: https://go-review.googlesource.com/18969
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

In increment and decrement statements, explicit check that the type
of operand is numeric earlier. This avoids a related but less clear
error about converting "1" to be emitted.

So, when compiling

	package main

	func main() {
		var x bool
		x++
	}

instead of emitting two errors

	prog.go:5: cannot convert 1 to type bool
	prog.go:5: invalid operation: x++ (non-numeric type bool)

just emits the second error.

Fixes #12525.

Change-Id: I6e81330703765bef0d6eb6c57098c1336af7c799
Reviewed-on: https://go-review.googlesource.com/20245Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Change-Id: Id0a12c76b0a6925f2926d38a1931157f9ef5f650
Reviewed-on: https://go-review.googlesource.com/20280Reviewed-by: Joe Tsai <joetsai@digital-static.net>
Run-TryBot: Joe Tsai <joetsai@digital-static.net>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This increases the number of matches in make.bash
from 853 to 984.

Change-Id: I12697697a50ecd86d49698200144a4c80dd3e5a4
Reviewed-on: https://go-review.googlesource.com/20274Reviewed-by: Todd Neal <todd@tneal.org>

We used to start background mark workers and assists at different
times, so we needed to keep track of these separately. They're now set
to exactly the same time, so clean things up by merging them in to one
value, markStartTime.

Change-Id: I17c9843c3ed2d6f07b4c8cd0b2c438fc6de23b53
Reviewed-on: https://go-review.googlesource.com/20143
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>

OffPtr allocates less and is easier to optimize.

With this change, the OffPtr collapsing opt
rule matches increase from 160k to 263k,
and the Load-after-Store opt rule matches
increase from 217 to 853.

Change-Id: I763426a3196900f22a367f7f6d8e8047b279653d
Reviewed-on: https://go-review.googlesource.com/20273
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Todd Neal <todd@tneal.org>
Reviewed-by: Keith Randall <khr@golang.org>

This triggers an astonishing 160k times
during make.bash. The second biggest
generic rewrite triggers 100k times.

However, this is really just moving
rewrites that were happening at the
architecture level to the generic level.

Change-Id: Ife06fe5234f31433328460cb2e0741c071deda41
Reviewed-on: https://go-review.googlesource.com/20235
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Todd Neal <todd@tneal.org>

This only deals with the loads themselves.  The bounds checks
are a separate issue.  Also doesn't handle stores, those are
harder because we need to make sure intermediate memory states
aren't observed (which is hard to do with rewrite rules).

Use one byte shorter instructions for zero-extending loads.

Update #14267

Change-Id: I40af25ab5208488151ba7db32bf96081878fa7d9
Reviewed-on: https://go-review.googlesource.com/20218Reviewed-by: Alexandru Moșoi <alexandru@mosoi.ro>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

They were only used for rtype.ptrToThis which David Crawshaw removed a couple
of weeks ago. Removes two traversals of Ctxt.Allsym from the linker but it
doesn't seem to make much difference to performance.

Change-Id: I5c305e0180186f643221d57822d301de4aa18827
Reviewed-on: https://go-review.googlesource.com/20287Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The new code is a bit less efficient,
but it does not involve altering the structure
of any linked lists.
This will make it easier to replace NodeLists
with Node slices.
We can return to a more efficient algorithm
when NodeLists have been replaced.

Passes toolstash -cmp.

Change-Id: I0bb5ee75e7c0646e6d37fe558c8f0548729d8aa1
Reviewed-on: https://go-review.googlesource.com/20277
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Iadb4aa016a7b361d01827787dbc59164d5d147f2
Reviewed-on: https://go-review.googlesource.com/20291Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

No immediate reduction in the size of Addr.

Passes toolstash -cmp.

Change-Id: I78ea4c6e181b6e571ce70a5f1ae8158844eb197d
Reviewed-on: https://go-review.googlesource.com/20276Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Add tests to ensure that the size of important types don't change
unexpectedly.

Skip the test on nacl platforms because of their unusual padding
requirements.

Change-Id: Iddb127a99499e089a309b721f5073356c0da8b24
Reviewed-on: https://go-review.googlesource.com/20285Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Dave Cheney <dave@cheney.net>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Removes specialized functions for each verb and float/complex size
and replaces them with generic variants fmtFloat and
fmtComplex similar to other generic fmt functions.

Simplifies the complex formatting by relying on fmtFloat
to handle the verb and default precision selection.

Complex imaginary formatting does not need to clear the f.space flag
because the set f.plus flag will force a sign instead of a space.

Sets default precision for %b to -1 (same as %g and %G)
since precision for %b has no affect in strconv.AppendFloat.

Add more tests and group them a bit better.
Use local copies of +Inf,-Inf and NaN instead
of math package functions for testing.

Saves around 8kb in the go binary.

name              old time/op  new time/op  delta
SprintfFloat-2     200ns ± 4%   196ns ± 4%  -1.55%  (p=0.007 n=20+20)
SprintfComplex-2   569ns ± 4%   570ns ± 3%    ~     (p=0.804 n=20+20)

Change-Id: I36d35dab6f835fc2bd2c042ac97705868eb2446f
Reviewed-on: https://go-review.googlesource.com/20252Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Rob Pike <r@golang.org>

Reuse the internal buffer and use append versions of
the strconv quote functions to avoid some allocations.

Add more tests.

name                  old time/op    new time/op    delta
SprintfQuoteString-2     486ns ± 2%     416ns ± 2%  -14.42%  (p=0.000 n=20+20)

name                  old allocs/op  new allocs/op  delta
SprintfQuoteString-2      4.00 ± 0%      2.00 ± 0%  -50.00%  (p=0.000 n=20+20)

Change-Id: I63795b51fd95c53c5993ec8e6e99b659941f9f54
Reviewed-on: https://go-review.googlesource.com/20251
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

Instead of calling printArg in fmtBytes to format each byte call
the byte formatting functions directly since it is known each
element is of type byte.

Add more tests for byte slice and array formatting.

name            old time/op  new time/op  delta
SprintfBytes-2   843ns ±16%   417ns ±11%  -50.58%  (p=0.000 n=20+20)

Change-Id: I5b907dbf52091e3de9710b09d67649c76f4c17e9
Reviewed-on: https://go-review.googlesource.com/20176
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

Current runtime.WriteHeapProfile() doesn't print correct
EnableGC. Even if GOGC=off, the result file has below line:
 # EnableGC = true

It is hard to print correct status of the variable because of corner
cases e.g. initialization. For avoiding confusion, this commit removes
the print.

Change-Id: Ia792454a6c650bdc50a06fbaff4df7b6330ae08a
Reviewed-on: https://go-review.googlesource.com/18600
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>

Updates #14473.

Change-Id: I88745c2a6119dea3b81b57299e70a2a7e4c584a8
Reviewed-on: https://go-review.googlesource.com/20272
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

formatFloat should restore the original f.wid value before
returning. Callers should not have to save and restore f.wid.

Fixes: #14642

Change-Id: I531dae15c7997fe8909e2ad1ef7c376654afb030
Reviewed-on: https://go-review.googlesource.com/20179
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

Passes toolstash -cmp.

Update #14473.

Change-Id: I0809c6b88643f04c7fc503f866ffe25e69f29910
Reviewed-on: https://go-review.googlesource.com/20260Reviewed-by: David Crawshaw <crawshaw@golang.org>

Passes toolstash -cmp.

Update #14473.

Change-Id: I836197810405cde72cbb49fef7e163a517601f9c
Reviewed-on: https://go-review.googlesource.com/20242Reviewed-by: David Crawshaw <crawshaw@golang.org>

The new check corresponds to the (etype != TANY || Debug['A'] != 0)
that was lost in golang.org/cl/19936.

Fixes #14652.

Change-Id: Iec3788ff02529b3b0f0d4dd92ec9f3ef20aec849
Reviewed-on: https://go-review.googlesource.com/20271Reviewed-by: Ian Lance Taylor <iant@golang.org>

Instead make substArgTypes responsible for cloning the function
definition Node and the function signature Type tree.

Passes toolstash -cmp.

Change-Id: I9ec84c90a7ae83d164d3f578e84a91cf1490d8ab
Reviewed-on: https://go-review.googlesource.com/20239
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Update supportsUnaligned in xor.go to be true for
GOARCH values ppc64le and ppc64.  This allows the
xor of long buffers to be done on double words
(8 bytes) instead of a single byte at a time, which
significantly improves performance.

Fixes #14350

Change-Id: Iccc6b9d3df2e604a55f4c1e4890bdd3bb0d77ab0
Reviewed-on: https://go-review.googlesource.com/19519Reviewed-by: Minux Ma <minux@golang.org>

Passes toolstash -cmp.

Update #14473.

Change-Id: I1b50fe981e7a266d4b14f31d849eb91afccdfda3
Reviewed-on: https://go-review.googlesource.com/20270
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: Ib632ee7ac893750bec4cfe223745bca5f31900ab
Reviewed-on: https://go-review.googlesource.com/20234Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Passes toolstash -cmp

Update #14473.

Change-Id: I15b35d40a5ec1f4355ee38bc6d131920933ac95c
Reviewed-on: https://go-review.googlesource.com/20237
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I01ec7d08884a1e0fbce94ea77281c1ee4a2cfd56
Reviewed-on: https://go-review.googlesource.com/20238Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Also fix some uses of nodeSeqIterator.Len, and fix the implementation in
nodesIterator.

Passes toolstash -cmp.

Update #14473.

Change-Id: I228871470234b7f1314ffd2aae8a4c0624c35f98
Reviewed-on: https://go-review.googlesource.com/20231
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

When the linker was written in C, command line arguments were passed
around as null-terminated byte arrays which encouraged checking
characters one at a time. In Go, that can easily lead to
out-of-bounds panics.

Use the more idiomatic strings.HasPrefix when checking cmd/link's -B
argument to avoid the panic, and replace the manual hex decode with
use of the encoding/hex package.

Fixes #14636

Change-Id: I45f765bbd8cf796fee1a9a3496178bf76b117827
Reviewed-on: https://go-review.googlesource.com/20211
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

gcMarkRootCheck takes ~10ns per goroutine. This is just a debugging
check, so disable it (plus, if something is going to go wrong, it's
more likely to go wrong during concurrent mark).

We may be able to re-enable this later, or move it to after we've
started the world again. (But not for 1.6.x.)

For 1.6.x.

Fixes #14419.

name / 95%ile-time/markTerm          old          new  delta
500kIdleGs-12                24.0ms ± 0%  18.9ms ± 6%  -21.46%  (p=0.000 n=15+20)

Change-Id: Idb2a2b1771449de772c159ef95920d6df1090666
Reviewed-on: https://go-review.googlesource.com/20148Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Currently we reset the mark state during STW sweep termination. This
involves looping over all of the goroutines. Each iteration of this
loop takes ~25ns, so at around 400k goroutines, we'll exceed our 10ms
pause goal.

However, it's safe to do this before we stop the world for sweep
termination because nothing is consuming this state yet. Hence, move
the reset to just before STW.

This isn't perfect: a long reset can still delay allocating goroutines
that block on GC starting. But it's certainly better to block some
things eventually than to block everything immediately.

For 1.6.x.

Fixes #14420.

name \ 95%ile-time/sweepTerm           old          new  delta
500kIdleGs-12                 11312µs ± 6%  18.9µs ± 6%  -99.83%  (p=0.000 n=16+20)

Change-Id: I9815c4d8d9b0d3c3e94dfdab78049cefe0dcc93c
Reviewed-on: https://go-review.googlesource.com/20147Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Also fix compiler-invoked panics to avoid a confusing "malloc deadlock"
crash if they are invoked while executing the runtime.

Fixes #14599.

Change-Id: I89436abcbf3587901909abbdca1973301654a76e
Reviewed-on: https://go-review.googlesource.com/20219
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Many read-only strings in Go binaries are substrings of other read-only
strings. A common source is the text form of type information, which
will include both "struct { X int }" and "*struct { X int }" or
"*bytes.Reader" and "func(*bytes.Reader)" in the same binary.

Because this character data is referred to by separate string headers,
we can skip writing the smaller string and modify the pointer
relocation to point to the larger string. This CL does this
deduplication in the linker after the reachable set of strings has
been determined.

This removes 765KB from juju (1.4% without DWARF).

Link time goes at tip goes form 4.6s to 6.3s, but note that this CL
is part of a series that recently reduced link time from 9.6s.

For #6853.

Change-Id: Ib2087cf627c9f1e9a1181f9b4c8f81d1a3f42191
Reviewed-on: https://go-review.googlesource.com/19987Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

go test github.com/onsi/gomega/gbytes now passes at tip, and tests
added to the reflect package.

Fixes #14645

Change-Id: I16216c1a86211a1103d913237fe6bca5000cf885
Reviewed-on: https://go-review.googlesource.com/20221
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Minalign > 1 implies that relocations inserted by the linker cannot
target arbitrary bytes.

Related to #14604

Change-Id: Ie68d14887bc4047d9b29b0cb1149a8d14b6c62e2
Reviewed-on: https://go-review.googlesource.com/20214Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>