Issue 6754 reports that Go bzip2 Decode function is much slower
(about 2.5x in go1.5) than the Python equivalent (which is
actually just a wrapper around the usual C library) on random data.

Profiling the code shows that half a dozen of CMP instructions in a
tight loop are responsibile for most of the execution time.

This patch reduces the number of branches of the loop, greatly
improving performance on random data and speeding up decoding of
real data.

name            old time/op    new time/op    delta
DecodeDigits-4    9.28ms ± 1%    8.05ms ± 1%  -13.18%  (p=0.000 n=15+14)
DecodeTwain-4     28.9ms ± 2%    26.4ms ± 1%   -8.57%  (p=0.000 n=15+14)
DecodeRand-4      3.94ms ± 1%    3.06ms ± 1%  -22.45%  (p=0.000 n=15+14)

name            old speed      new speed      delta
DecodeDigits-4  4.65MB/s ± 1%  5.36MB/s ± 1%  +15.21%  (p=0.000 n=13+14)
DecodeTwain-4   4.32MB/s ± 2%  4.72MB/s ± 1%   +9.36%  (p=0.000 n=15+14)
DecodeRand-4    4.27MB/s ± 1%  5.51MB/s ± 1%  +28.86%  (p=0.000 n=15+14)

I've run some benchmark comparing Go bzip2 implementation with the
usual Linux bzip2 command (which is written in C). On my machine
this patch brings go1.5
  from ~2.26x to ~1.50x of bzip2 time (on 64MB  random data)
  from ~1.70x to ~1.50x of bzip2 time (on 100MB english text)
  from ~2.00x to ~1.88x of bzip2 time (on 64MB  /dev/zero data)

Fixes #6754

Change-Id: I3cb12d2c0c2243c1617edef1edc88f05f91d26d1
Reviewed-on: https://go-review.googlesource.com/13853Reviewed-by: Nigel Tao <nigeltao@golang.org>

This changed in https://golang.org/cl/10761.

Update #12203.

Change-Id: Ia37ebb7ecba689ad3cb2559213d675f21cf03a95
Reviewed-on: https://go-review.googlesource.com/13799Reviewed-by: Russ Cox <rsc@golang.org>

If we're going to do this for Go 1.6 we might as well do it now
and find out what breaks.

Change-Id: I8306b7829d8d13b564a1466c902ec6ba1a5a58c1
Reviewed-on: https://go-review.googlesource.com/13967Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This worked in Go 1.4 but was lost in the "pure Go" lookup
routines substituted late in the Go 1.5 cycle.

Fixes #12263.

Change-Id: I77ec9d97cd8e67ace99d6ac965e5bc16c151ba83
Reviewed-on: https://go-review.googlesource.com/13915Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Setgroups with zero-length groups is no-op for changing groups and
supposed to be used only for determining curent groups length. Also
because we deny setgroups by default if use GidMappings we have
unnecessary error from that no-op syscall.

Change-Id: I8f74fbca9190a3dcbbef1d886c518e01fa05eb62
Reviewed-on: https://go-review.googlesource.com/13938Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #12232.

Change-Id: Ide3fb7f5fc5ae377ae8683fbb94fd0dc01480549
Reviewed-on: https://go-review.googlesource.com/13924Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: I63bf6d2fdf41b49ff8783052d5d6c53b20e2f050
Reviewed-on: https://go-review.googlesource.com/13760Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>

For ARM machines, the assembler supports list of registers
operands such as [R1,R2].

A list missing a ']' results in the parser issuing many errors
and consuming all the tokens. At EOF (i.e. end of the line),
it still loops.

Normally, a counter is maintained to make sure the parser
stops after 10 errors. However, multiple errors occuring on the
same line are simply ignored. Only the first one is reported.
At most one error per line is accounted.

Missing ']' in a register list therefore results in an
infinite loop.

Fixed the parser by explicitly checking for ']' to interrupt
this loops

In the operand tests, also fixed a wrong entry which I think was
not set on purpose (but still led to a successful result).

Fixes #11764

Change-Id: Ie87773388ee0d21b3a2a4cb941d4d911d0230ba4
Reviewed-on: https://go-review.googlesource.com/13920Reviewed-by: Rob Pike <r@golang.org>

Useful to discriminate evaluation errors from write errors.

Fixes #11898.

Change-Id: I907d339a3820e887872d78e0e2d8fd011451fd19
Reviewed-on: https://go-review.googlesource.com/13957Reviewed-by: Andrew Gerrand <adg@golang.org>

I noticed that they were unimplemented on arm64 but then that they were
in fact not used at all.

Change-Id: Iee579feda2a5e374fa571bcc8c89e4ef607d50f6
Reviewed-on: https://go-review.googlesource.com/13951
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #11947.

Change-Id: I6225f96b8dea0cecb097f9c7452a1aa80ae4476d
Reviewed-on: https://go-review.googlesource.com/12939Reviewed-by: Alan Donovan <adonovan@google.com>

Accepting a request with a nil body was never explicitly supported but
happened to work in the past.

This doesn't happen in most cases because usually people pass
a Server's incoming Request to the ReverseProxy's ServeHTTP method,
and incoming server requests are guaranteed to have non-nil bodies.

Still, it's a regression, so fix.

Fixes #12344

Change-Id: Id9a5a47aea3f2875d195b66c9a5f8581c4ca2aed
Reviewed-on: https://go-review.googlesource.com/13935Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #11578.

Change-Id: I29a542be247127f470ba6c39aac0d0f6a18de553
Reviewed-on: https://go-review.googlesource.com/13285Reviewed-by: Alan Donovan <adonovan@google.com>

Not needed anymore since go/types is always built against the current
standard library.

Fixes #11538.

Change-Id: I2f07d73703f4e5661c4b5df5d487939dcf530b43
Reviewed-on: https://go-review.googlesource.com/13897Reviewed-by: Alan Donovan <adonovan@google.com>

byte is unsigned so the comparison against zero is always true.

Change-Id: I8fa60245972be362ae920507a291f92c0f9831ad
Reviewed-on: https://go-review.googlesource.com/13941
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The existing implementation fails to determine the correct time zone
abbreviations when the display language is non-English. This change adds
support for localized time zone names (standard- and daylightname)
by using the function RegLoadMUIString.

Fixes #12015

Change-Id: Ic0dc89c50993af8f292b199c20bc5932903e7e87
Reviewed-on: https://go-review.googlesource.com/13854Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This patch contains only loop unrolling change for size > 63B

Following are the performance numbers for various sizes on
On Haswell based system: Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz.

benchcmp go.head.8.25.15.txt go.head.8.25.15.opt.txt
benchmark                       old ns/op     new ns/op     delta
BenchmarkBytesCompare1-4        5.37          5.37          +0.00%
BenchmarkBytesCompare2-4        5.37          5.38          +0.19%
BenchmarkBytesCompare4-4        5.37          5.37          +0.00%
BenchmarkBytesCompare8-4        4.42          4.38          -0.90%
BenchmarkBytesCompare16-4       4.27          4.45          +4.22%
BenchmarkBytesCompare32-4       5.30          5.36          +1.13%
BenchmarkBytesCompare64-4       6.93          6.78          -2.16%
BenchmarkBytesCompare128-4      10.3          9.50          -7.77%
BenchmarkBytesCompare256-4      17.1          13.8          -19.30%
BenchmarkBytesCompare512-4      31.3          22.1          -29.39%
BenchmarkBytesCompare1024-4     62.5          39.0          -37.60%
BenchmarkBytesCompare2048-4     112           73.2          -34.64%

Change-Id: I4eeb1c22732fd62cbac97ba757b0d29f648d4ef1
Reviewed-on: https://go-review.googlesource.com/11871Reviewed-by: Keith Randall <khr@golang.org>

Fixes #12083

Change-Id: I8256739b33cf08d84dec23120d527667de2e6eea
Reviewed-on: https://go-review.googlesource.com/13822Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

s is a uint32 and can never be zero. It's max value is already tested
against sig.wanted, whose size is derived from _NSIG.  This also
matches the test in signal_enable.

Fixes #11282

Change-Id: I8eec9c7df8eb8682433616462fe51b264c092475
Reviewed-on: https://go-review.googlesource.com/13940Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

No longer used after previous hashmap change.

Change-Id: I558470f872281e84a78406132df4e391d077b833
Reviewed-on: https://go-review.googlesource.com/13785
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

If an exported function has named return variables, then show the names
as comments in the return struct we create in the header file.

Example here:

 https://groups.google.com/forum/#!topic/golang-nuts/r393ne4zIfY

Change-Id: I21fb4ca2673f6977bec35ccab0cef7d42b311f96
Reviewed-on: https://go-review.googlesource.com/13061Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Previously t.zero always pointed to runtime.zerovalue. Change the hashmap code
to always return a runtime pointer directly, and change that pointer to point
to a larger buffer if one is needed.

(It might be better to only copy from the pointer returned by the mapaccess
functions when the value type is small enough and have the compiler insert
explicit zeroing for larger value types, but I tried and failed to do this).

This removes all uses of the zero field of the type data; the field itself can
be removed in a separate change.

Fixes #11491

Change-Id: I5b81752ff4067d74a5a281c41e88f151bae0171e
Reviewed-on: https://go-review.googlesource.com/13784Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I3889eda72ae0f57117f1d4299e3574f8bf68be67
Reviewed-on: https://go-review.googlesource.com/13310Reviewed-by: Ian Lance Taylor <iant@golang.org>

This was always a bit confusing, but it also fixes a problem: runtime.firstmoduledata
was always overridden in the linker to be a local symbol but cmd/internal/obj had
already rewritten code accessing it to access it via the GOT. This works on amd64, but
causes link failures on other platforms (e.g. arm64).

Change-Id: I9b8153af74b4d0f092211d63a000d15818f39773
Reviewed-on: https://go-review.googlesource.com/13786Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The issue 12226 has been caused by the allocation of the same register
for the equality check of two byte values. The code in cgen.go freed the
register for the second operand before the allocation of the register
for the first operand.

Fixes #12226

Change-Id: Ie4dc33a488bd48a17f8ae9b497fd63c1ae390555
Reviewed-on: https://go-review.googlesource.com/13771Reviewed-by: Russ Cox <rsc@golang.org>

A comparison of the form l == r where l is an interface and r is
concrete performs a type assertion on l to convert it to r's type.
However, the compiler fails to zero the temporary where the result of
the type assertion is written, so if the type is a pointer type and a
stack scan occurs while in the type assertion, it may see an invalid
pointer on the stack.

Fix this by zeroing the temporary. This is equivalent to the fix for
type switches from c4092ac3.

Fixes #12253.

Change-Id: Iaf205d456b856c056b317b4e888ce892f0c555b9
Reviewed-on: https://go-review.googlesource.com/13872Reviewed-by: Russ Cox <rsc@golang.org>

Updates #11336

Follow the lead of amd64 by doing a pointer equality check
before comparing string/byte contents on arm64.

BenchmarkCompareBytesEqual-8               25.8           26.3           +1.94%
BenchmarkCompareBytesToNil-8               9.59           9.59           +0.00%
BenchmarkCompareBytesEmpty-8               9.59           9.17           -4.38%
BenchmarkCompareBytesIdentical-8           26.3           9.17           -65.13%
BenchmarkCompareBytesSameLength-8          16.3           16.3           +0.00%
BenchmarkCompareBytesDifferentLength-8     16.3           16.3           +0.00%
BenchmarkCompareBytesBigUnaligned-8        1132038        1131409        -0.06%
BenchmarkCompareBytesBig-8                 1126758        1128470        +0.15%
BenchmarkCompareBytesBigIdentical-8        1084366        9.17           -100.00%

Change-Id: Id7125c31957eff1ddb78897d4511bd50e79af3f7
Reviewed-on: https://go-review.googlesource.com/13885Reviewed-by: Keith Randall <khr@golang.org>

nmspinning has a value range of [0, 2^31-1].  Update the comment to
indicate this and fix the comparison so it's not always false.

Fixes #11280

Change-Id: Iedaf0654dcba5e2c800645f26b26a1a781ea1991
Reviewed-on: https://go-review.googlesource.com/13877Reviewed-by: Minux Ma <minux@golang.org>

gobuf.g is a guintptr, so without hex(), it will be printed as
a decimal, which is not very helpful and inconsistent with how
other pointers are printed.

Change-Id: I7c0432e9709e90a5c3b3e22ce799551a6242d017
Reviewed-on: https://go-review.googlesource.com/13879Reviewed-by: Ian Lance Taylor <iant@golang.org>

Simplify slice/map literal expressions.
Caught with gofmt -d -s, fixed with gofmt -w -s
Reformatted some expressions to improve readability.

Change-Id: Iaf123e6bd49162ec45c59297ad3b002ca59443bc
Reviewed-on: https://go-review.googlesource.com/13850Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

While we're at it, also fix a typo.

Change-Id: Id436f33cffa5683e2a8450cce5b545960cf2877e
Reviewed-on: https://go-review.googlesource.com/13878Reviewed-by: Ian Lance Taylor <iant@golang.org>

This is not a functional change. nr is a uint64 and can never be less
than zero, remove the no-op comparison.

Fixes #11279

Change-Id: Iebb36cc8fe97428b503e65d01b5e67d2b2bc7369
Reviewed-on: https://go-review.googlesource.com/13876
Run-TryBot: Todd Neal <todd@tneal.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The nohup command doesn't work in tmux on darwin.

Fixes #5135.

Change-Id: I1c21073d8bd54b49dd6b0bad86ef088d6d8e7a5f
Reviewed-on: https://go-review.googlesource.com/13883Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The URL is shown on go docs and is an eye-sore.

For go1.6.

Change-Id: I8b8ea3751200d06ed36acfe22f47ebb38107f8db
Reviewed-on: https://go-review.googlesource.com/13282Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Updates #11336

Follow the lead of amd64 do a pointer equality check
before comparing string/byte contents on arm.

BenchmarkCompareBytesEqual-4               208             211             +1.44%
BenchmarkCompareBytesToNil-4               83.6            81.8            -2.15%
BenchmarkCompareBytesEmpty-4               80.2            75.2            -6.23%
BenchmarkCompareBytesIdentical-4           208             75.2            -63.85%
BenchmarkCompareBytesSameLength-4          126             128             +1.59%
BenchmarkCompareBytesDifferentLength-4     128             130             +1.56%
BenchmarkCompareBytesBigUnaligned-4        14192804        14060971        -0.93%
BenchmarkCompareBytesBig-4                 12277313        12128193        -1.21%
BenchmarkCompareBytesBigIdentical-4        9385046         78.5            -100.00%

Change-Id: I5b24620018688c5fe04b6ff6743a24c4ce225788
Reviewed-on: https://go-review.googlesource.com/13881Reviewed-by: Keith Randall <khr@golang.org>

In short, %c should just give you the next rune, period.
Apparently this is the design. I use the term loosely.

Fixes #12275

Change-Id: I6f30bed442c0e88eac2244d465c7d151b29cf393
Reviewed-on: https://go-review.googlesource.com/13821Reviewed-by: Andrew Gerrand <adg@golang.org>

Fixes #12299

Change-Id: Id7b73d2935c9f7c0952f833613973ef455d02b0d
Reviewed-on: https://go-review.googlesource.com/13858Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Unused assignment for `err` encoding/asn1/marshal.go:622:3
Unused assignment for `err` encoding/asn1/marshal.go:650:5

Change-Id: I4226238645ce3640f25124cb405444e61439fd3f
Reviewed-on: https://go-review.googlesource.com/13847Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #11763

Change-Id: Ie291b36a8c29694e80940836d7e6fd96d2d76494
Reviewed-on: https://go-review.googlesource.com/12382Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Iaaecd8be9268c923f40cf0e5153cbf79f7015b8d
Reviewed-on: https://go-review.googlesource.com/13892Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>