- minor unrelated cleanups
- performance impact in the noise

benchmark                       old ns/op    new ns/op    delta
BenchmarkReadSlice1000Int32s        83462        83346   -0.14%
BenchmarkReadStruct                  4141         4247   +2.56%
BenchmarkReadInts                    1588         1586   -0.13%
BenchmarkWriteInts                   1550         1489   -3.94%
BenchmarkPutUvarint32                  39           39   +1.02%
BenchmarkPutUvarint64                 142          144   +1.41%

benchmark                        old MB/s     new MB/s  speedup
BenchmarkReadSlice1000Int32s        47.93        47.99    1.00x
BenchmarkReadStruct                 16.90        16.48    0.98x
BenchmarkReadInts                   18.89        18.91    1.00x
BenchmarkWriteInts                  19.35        20.15    1.04x
BenchmarkPutUvarint32              101.90       100.82    0.99x
BenchmarkPutUvarint64               56.11        55.45    0.99x

Fixes #4185.

R=r, rsc
CC=golang-dev
https://golang.org/cl/6750053

R=dvyukov
CC=golang-dev
https://golang.org/cl/6810067

R=golang-dev
CC=golang-dev
https://golang.org/cl/6826047

1. Prepend racefuncenter() to fn->enter -- fn->enter can contain new() calls,
and we want them to be in the scope of the function.
2. Dump fn->enter and fn->exit.
3. Add TODO that OTYPESW expression can contain interesting memory accesses.
4. Ignore only _ names instead of all names starting with _.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6822048

R=golang-dev, minux.ma, fullung, dave, rsc, hanwenn
CC=golang-dev
https://golang.org/cl/6350074

go test -race -run none -bench . encoding/json
benchmark                      old ns/op    new ns/op    delta
BenchmarkCodeEncoder          3207689000   1716149000  -46.50%
BenchmarkCodeMarshal          3206761000   1715677000  -46.50%
BenchmarkCodeDecoder          8647304000   4482709000  -48.16%
BenchmarkCodeUnmarshal        8032217000   3451248000  -57.03%
BenchmarkCodeUnmarshalReuse   8016722000   3480502000  -56.58%
BenchmarkSkipValue           10340453000   4560313000  -55.90%

benchmark                       old MB/s     new MB/s  speedup
BenchmarkCodeEncoder                0.60         1.13    1.88x
BenchmarkCodeMarshal                0.61         1.13    1.85x
BenchmarkCodeDecoder                0.22         0.43    1.95x
BenchmarkCodeUnmarshal              0.24         0.56    2.33x
BenchmarkCodeUnmarshalReuse         0.24         0.56    2.33x
BenchmarkSkipValue                  0.19         0.44    2.32x

Fixes #4248.

R=dvyukov, golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6815066

- simplified assignment checking by removing duplicate code
- implemented field lookup (methods, structs, embedded fields)
- importing methods (not just parsing them)
- type-checking functions and methods
- typechecking more statements (inc/dec, select, return)
- tracing support for easier debugging
- handling nil more correctly (comparisons)
- initial support for [...]T{} arrays
- initial support for method expressions
- lots of bug fixes

All packages under pkg/go as well as pkg/exp/types typecheck
now with pkg/exp/gotype applied to them; i.e., a significant
amount of typechecking works now (several statements are not
implemented yet, but handling statements is almost trivial in
comparison with typechecking expressions).

R=rsc
CC=golang-dev
https://golang.org/cl/6768063

Use wrapper functions to tell scheduler what we are doing.

With this patch, and a separate patch to the go tool, all the
cgo tests pass with gccgo.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6812058

* Use -fgo-pkgpath and -gccgopkgpath rather than -fgo-prefix
  and -gccgoprefix.
* Define GOPKGPATH when compiling .c or .s files for gccgo.
* Use -fgo-relative-import-path.
* Produce .o files for gccgo, not .[568] files.
* Pass -E when linking if using cgo.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6820064

This supports writing different .c/.s code when using gccgo.

R=golang-dev, dsymonds, iant, rsc
CC=golang-dev
https://golang.org/cl/6823055

The idea is to (1) process ninit of all nodes,
and (2) put instrumentation of ninit into the nodes themselves (not the top-level statement ninit).
Fixes #4304.

R=golang-dev, rsc
CC=golang-dev, lvd
https://golang.org/cl/6818049

When local declarations needed unexported types, these could
be missing in the export data.

Fixes build with -gcflags -lll, except for exp/gotype.

R=golang-dev, rsc, lvd
CC=golang-dev
https://golang.org/cl/6813067

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6612064

Fixes #4323.

R=rsc, lvd, golang-dev
CC=golang-dev
https://golang.org/cl/6815061

Helps with issue 2703.

R=dave, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/5536078

This should make the compiler emit errors specific to the bounds checking instead of overflow errors on the underlying types.

Updates #4232.

R=rsc
CC=golang-dev
https://golang.org/cl/6783054

This is an attempt at making the interaction between
these three constructs clearer. Specifically:

- return statements terminate a function, execute deferred
  functions, return to the caller, and then execution
  continues after the call

- panic calls terminate a function, execute deferred
  functions, return to the caller, and then re-panic

- deferred functions are executed before a function _returns_
  to its caller

The hope is that with this change it becomes clear when a
deferred function is executed (when a function returns),
and when it is not (when a program exits).

R=r, rsc, iant, ken, iant
CC=golang-dev
https://golang.org/cl/6736071

The 'type' field of Itab will be used by the garbage collector.

R=rsc
CC=golang-dev
https://golang.org/cl/6815059

Incorrect cast was causing panics when
calling String() on dnsMsg with dnsRR_A
answers.

R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/6818043

R=golang-dev
CC=golang-dev, remyoudompheng, rsc
https://golang.org/cl/6780059

Plan 9 and Go's lib9/fmt disagree on whether %#x includes the 0x prefix
when printing 0, because ANSI C gave bad advice long ago.

Avoiding that case makes binaries compiled on different systems compatible.

R=ken2
CC=akumar, golang-dev
https://golang.org/cl/6814066

This caused more problems than it was worth.

Fixes #4301.
Fixes #4317.

R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6818076

The move to 64-bit ints in 6g made componentgen ineffective.
In componentgen, the code already selects which values it can handle.

On amd64:
benchmark                 old ns/op    new ns/op    delta
BenchmarkBinaryTree17    9477970000   9582314000   +1.10%
BenchmarkFannkuch11      5928750000   5255080000  -11.36%
BenchmarkGobDecode         37103040     31451120  -15.23%
BenchmarkGobEncode         16042490     16844730   +5.00%
BenchmarkGzip             811337400    741373600   -8.62%
BenchmarkGunzip           197928700    192844500   -2.57%
BenchmarkJSONEncode       224164100    140064200  -37.52%
BenchmarkJSONDecode       258346800    231829000  -10.26%
BenchmarkMandelbrot200      7561780      7601615   +0.53%
BenchmarkParse             12970340     11624360  -10.38%
BenchmarkRevcomp         1969917000   1699137000  -13.75%
BenchmarkTemplate         296182000    263117400  -11.16%

R=nigeltao, dave, daniel.morsing
CC=golang-dev
https://golang.org/cl/6821052

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/6811059

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6826044

defined by the PLTE chunk. Such pixels decode to opaque black,
which matches what libpng does.

Fixes #4319.

On my reading, the PNG spec isn't clear whether palette index values
outside of those defined by the PLTE chunk is an error, and if not,
what to do.

Libpng 1.5.3 falls back to opaque black. png_set_PLTE says:

/* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead
 * of num_palette entries, in case of an invalid PNG file that has
 * too-large sample values.
 */
png_ptr->palette = (png_colorp)png_calloc(png_ptr,
        PNG_MAX_PALETTE_LENGTH * png_sizeof(png_color));

ImageMagick 6.5.7 returns an error:

$ convert -version
Version: ImageMagick 6.5.7-8 2012-08-17 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2009 ImageMagick Studio LLC
Features: OpenMP
$ convert packetloss.png x.bmp
convert: Invalid colormap index `packetloss.png' @ image.c/SyncImage/3849.

R=r
CC=golang-dev
https://golang.org/cl/6822065

Fixes #4297.

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/6817045

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6815062

Fixes #4324.

R=r
CC=golang-dev
https://golang.org/cl/6822062

Fixes #1390.

R=golang-dev, minux.ma, adg, agl
CC=golang-dev
https://golang.org/cl/6631044

Fixes #4314.

R=r, rsc
CC=golang-dev
https://golang.org/cl/6822059

Fixes #2874.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6820068

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6812060

Fixes build, too.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6775088

R=r, mpvl
CC=golang-dev
https://golang.org/cl/6818067

Tailorings are represented by removing and reinserting entries from a linked list.
After all tailorings are done, missing weights are computed and verified.
This implementation assumes that entries that are used in expansions are not
reinserted at a later point.  This considerably simplifies the implementation.

R=r
CC=golang-dev
https://golang.org/cl/6739052

incremental comparisons. Instead, processing is now done directly on colElems.
As a result, the size of the weights array is now reduced by 75%.
Details:
- Primary value of type 1 colElem is shifted by 1 bit so that primaries
  of all types can be compared without shifting.
- Quaternary values are now stored in the colElem itself. This is possible
  as quaternary values other than 0 or maxQuaternary are only needed when other
  values are ignored.
- Simplified processWeights by removing cases that are needed for ICU but not
  for us (our CJK primary values fit in a single value).

R=r
CC=golang-dev
https://golang.org/cl/6817054

R=r
CC=golang-dev
https://golang.org/cl/6727049

I fixed a bug in gccgo that was causing it to only give an
error for the first package that was imported and not used.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6813058

As discussed in the following thread:
https://groups.google.com/forum/?fromgroups=#!topic/golang-dev/emeJffxWhVo

This is required to enable applications such as `less` to use something
other than stdin as the controlling terminal.

R=dave, iant
CC=bradfitz, golang-dev
https://golang.org/cl/6785057