R=golang-dev, rsc, dave
CC=golang-dev
https://golang.org/cl/6569044

Apart from reducing the number of LEAL/LEAQ instructions by about
30%, it gives 8g easier registerization in several cases,
for example in strconv. Performance with 6g is not affected.

Before (386):
src/pkg/strconv/decimal.go:22   TEXT  (*decimal).String+0(SB),$240-12
src/pkg/strconv/extfloat.go:540 TEXT  (*extFloat).ShortestDecimal+0(SB),$584-20

After (386):
src/pkg/strconv/decimal.go:22   TEXT  (*decimal).String+0(SB),$196-12
src/pkg/strconv/extfloat.go:540 TEXT  (*extFloat).ShortestDecimal+0(SB),$420-20

Benchmarks with GOARCH=386 (on a Core 2).

benchmark                 old ns/op    new ns/op    delta
BenchmarkBinaryTree17    7110191000   7079644000   -0.43%
BenchmarkFannkuch11      7769274000   7766514000   -0.04%
BenchmarkGobDecode         33454820     34755400   +3.89%
BenchmarkGobEncode         11675710     11007050   -5.73%
BenchmarkGzip            2013519000   1593855000  -20.84%
BenchmarkGunzip           253368200    242667600   -4.22%
BenchmarkJSONEncode       152443900    120763400  -20.78%
BenchmarkJSONDecode       304112800    247461800  -18.63%
BenchmarkMandelbrot200     29245520     29240490   -0.02%
BenchmarkParse              8484105      8088660   -4.66%
BenchmarkRevcomp         2695688000   2841263000   +5.40%
BenchmarkTemplate         363759800    277271200  -23.78%

benchmark                       old ns/op    new ns/op    delta
BenchmarkAtof64Decimal                127          129   +1.57%
BenchmarkAtof64Float                  166          164   -1.20%
BenchmarkAtof64FloatExp               308          300   -2.60%
BenchmarkAtof64Big                    584          571   -2.23%
BenchmarkAppendFloatDecimal           440          430   -2.27%
BenchmarkAppendFloat                  995          776  -22.01%
BenchmarkAppendFloatExp               897          746  -16.83%
BenchmarkAppendFloatNegExp            900          752  -16.44%
BenchmarkAppendFloatBig              1528         1228  -19.63%
BenchmarkAppendFloat32Integer         443          453   +2.26%
BenchmarkAppendFloat32ExactFraction   812          661  -18.60%
BenchmarkAppendFloat32Point          1002          773  -22.85%
BenchmarkAppendFloat32Exp             858          725  -15.50%
BenchmarkAppendFloat32NegExp          848          728  -14.15%
BenchmarkAppendFloat64Fixed1          447          431   -3.58%
BenchmarkAppendFloat64Fixed2          480          462   -3.75%
BenchmarkAppendFloat64Fixed3          461          457   -0.87%
BenchmarkAppendFloat64Fixed4          509          484   -4.91%

Update #1914.

R=rsc, nigeltao
CC=golang-dev, remy
https://golang.org/cl/6494107

Session resumption saves a round trip and removes the need to perform
the public-key operations of a TLS handshake when both the client and
server support it (which is true of Firefox and Chrome, at least).

R=golang-dev, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/6555051

Fixes #4080.

R=rsc, adg
CC=golang-dev
https://golang.org/cl/6553068

Was not handling &x.y[0] and &x.y.z correctly where
y is an array or struct-valued field (not a pointer).

R=ken2
CC=golang-dev
https://golang.org/cl/6551059

Update #3953.

R=bradfitz, campoy
CC=golang-dev
https://golang.org/cl/6543068

Comparisons used to create temporaries for arguments
even if they were already variables or addressable.
Removing the extra ones reduces pressure on regopt.

benchmark                 old ns/op    new ns/op    delta
BenchmarkGobDecode         50787620     49908980   -1.73%
BenchmarkGobEncode         19870190     19473030   -2.00%
BenchmarkGzip            3214321000   3067929000   -4.55%
BenchmarkGunzip           496792800    465828600   -6.23%
BenchmarkJSONEncode       232524800    263864400  +13.48%
BenchmarkJSONDecode       622038400    506600600  -18.56%
BenchmarkMandelbrot200     23937310     45913060  +91.81%
BenchmarkParse             14364450     13997010   -2.56%
BenchmarkRevcomp         6919028000   6480009000   -6.35%
BenchmarkTemplate         594458800    539528200   -9.24%

benchmark                  old MB/s     new MB/s  speedup
BenchmarkGobDecode            15.11        15.38    1.02x
BenchmarkGobEncode            38.63        39.42    1.02x
BenchmarkGzip                  6.04         6.33    1.05x
BenchmarkGunzip               39.06        41.66    1.07x
BenchmarkJSONEncode            8.35         7.35    0.88x
BenchmarkJSONDecode            3.12         3.83    1.23x
BenchmarkParse                 4.03         4.14    1.03x
BenchmarkRevcomp              36.73        39.22    1.07x
BenchmarkTemplate              3.26         3.60    1.10x

R=mtj, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/6547064

R=rsc, nigeltao, dave, bradfitz, r, rogpeppe
CC=golang-dev
https://golang.org/cl/6497084

This CL makes the compiler understand that the type of
the len or cap of a map, slice, or string is 'int', not 'int32'.
It does not change the meaning of int, but it should make
the eventual change of the meaning of int in 6g a bit smoother.

Update #2188.

R=ken, dave, remyoudompheng
CC=golang-dev
https://golang.org/cl/6542059

Use explicit IntSize constant instead of 4.

This CL does not change the meaning of int, but it should make
the eventual change of the meaning of int on amd64 a bit
smoother.

Update #2188.

R=ken, dave
CC=golang-dev
https://golang.org/cl/6554076

This CL makes the size of an int controlled by a variable
in cgo instead of hard-coding 4 (or 32 bits) in various places.

Update #2188.

R=iant, r, dave
CC=golang-dev
https://golang.org/cl/6548061

In a few places, the existing cgo tests assume that a
Go int is the same as a C int. Making int 64 bits wide
on 64-bit platforms violates this assumption.
Change that code to assume that Go int32 and C int
are the same instead. That's still not great, but it's better,
and I am unaware of any systems we run on where it is not true.

Update #2188.

R=iant, r
CC=golang-dev
https://golang.org/cl/6552064

This CL makes the runtime understand that the type of
the len or cap of a map, slice, or string is 'int', not 'int32',
and it is also careful to distinguish between function arguments
and results of type 'int' vs type 'int32'.

In the runtime, the new typedefs 'intgo' and 'uintgo' refer
to Go int and uint. The C types int and uint continue to be
unavailable (cause intentional compile errors).

This CL does not change the meaning of int, but it should make
the eventual change of the meaning of int on amd64 a bit
smoother.

Update #2188.

R=iant, r, dave, remyoudompheng
CC=golang-dev
https://golang.org/cl/6551067

R=golang-dev, rsc
CC=golang-dev, remy
https://golang.org/cl/6554062

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6553067

R=rsc
CC=golang-dev
https://golang.org/cl/6543069

Fixes #4143.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6541064

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6541062

Was describing an old implementation.

R=ken2
CC=golang-dev
https://golang.org/cl/6553066

Using offsets from Tos is cumbersome and we've had problems
in the past. Since it's only being used to grab the PID, we'll just
get that from the default TLS instead.

R=rsc, rminnich, npe
CC=golang-dev
https://golang.org/cl/6543049

Pointed out by James Chalfant after submit of CL 65000655.

TBR=golang-dev
CC=golang-dev
https://golang.org/cl/6543067

The code was assuming that int = 32 bits. Don't.

Update #2188.

R=agl
CC=golang-dev
https://golang.org/cl/6543063

I'm not exactly sure why there's a performance gain, but it seems like
an easy win. Maybe it's a cache line thing. Maybe it's that
unsafe.Sizeof(decompressor{}) drops to below unmappedzero, so that
checkref/checkoffset don't need to insert TESTB instructions. Maybe
it's less noise for the conservative garbage collector. Maybe it's
something else.

compress/flate benchmarks:
BenchmarkDecodeDigitsSpeed1e4          378628       349906   -7.59%
BenchmarkDecodeDigitsSpeed1e5         3481976      3204898   -7.96%
BenchmarkDecodeDigitsSpeed1e6        34419500     31750660   -7.75%
BenchmarkDecodeDigitsDefault1e4        362317       335562   -7.38%
BenchmarkDecodeDigitsDefault1e5       3290032      3107624   -5.54%
BenchmarkDecodeDigitsDefault1e6      30542540     28937480   -5.26%
BenchmarkDecodeDigitsCompress1e4       362803       335158   -7.62%
BenchmarkDecodeDigitsCompress1e5      3294512      3114526   -5.46%
BenchmarkDecodeDigitsCompress1e6     30514940     28927090   -5.20%
BenchmarkDecodeTwainSpeed1e4           412818       389521   -5.64%
BenchmarkDecodeTwainSpeed1e5          3475780      3288908   -5.38%
BenchmarkDecodeTwainSpeed1e6         33629640     31931420   -5.05%
BenchmarkDecodeTwainDefault1e4         369736       348850   -5.65%
BenchmarkDecodeTwainDefault1e5        2861050      2721383   -4.88%
BenchmarkDecodeTwainDefault1e6       27120120     25862050   -4.64%
BenchmarkDecodeTwainCompress1e4        372057       350822   -5.71%
BenchmarkDecodeTwainCompress1e5       2855109      2718664   -4.78%
BenchmarkDecodeTwainCompress1e6      26987010     26336030   -2.41%

image/png benchmarks:
BenchmarkDecodeGray               1841839      1802251   -2.15%
BenchmarkDecodeNRGBAGradient      7115318      6933280   -2.56%
BenchmarkDecodeNRGBAOpaque        6135892      6013284   -2.00%
BenchmarkDecodePaletted           1153313      1114302   -3.38%
BenchmarkDecodeRGB                5619404      5511190   -1.93%

R=rsc, r
CC=golang-dev
https://golang.org/cl/6533048

various implementation of collation.  The tool provides commands for soring,
regressing one implementation against another, and benchmarking.
Currently it includes collation implementations for the Go collator, ICU,
and one using Darwin's CoreFoundation framework.
To avoid building this tool in the default build, the colcmp tag has been
added to all files. This allows other tools/colcmp in this directory (e.g. it may make
sense to move maketables here) to be put in this directory as well.

R=r, rsc, mpvl
CC=golang-dev
https://golang.org/cl/6496118

Minor tweaks to avoid assuming that int is always 32 bits.

Update #2188.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6553062

Can tell this doesn't get run very often, but it is still important
for when you've broken everything else.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6547065

This CL fixes code that incorrectly assumes that int is 32 bits wide.
Specifically, the socketpair system call expects a pointer to a pair
of int32s, not a pair of ints. Fix this inside the wrappers without
changing the APIs.

Update #2188.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6552063

Change the grammar so that field access is a proper operator.
This introduces a new node, ChainNode, into the public (but
actually internal) API of text/template/parse. For
compatibility, we only use the new node type for the specific
construct, which was not parseable before. Therefore this
should be backward-compatible.

Before, .X.Y was a token in the lexer; this CL breaks it out
into .Y applied to .X. But for compatibility we mush them
back together before delivering. One day we might remove
that hack; it's the simple TODO in parse.go/operand.

This change also provides grammatical distinction between
        f
and
        (f)
which might permit function values later, but not now.

Fixes #3999.

R=golang-dev, dsymonds, gri, rsc, mikesamuel
CC=golang-dev
https://golang.org/cl/6494119

The code was trying to interpret a uint32 n as a signed quantity
and then store it in an int. For this, int(n) currently works, but when
int becomes 64 bits one must write int(int32(n)) instead, to get
the 32-bit sign extension.

Update #2188.

R=golang-dev, nigeltao
CC=golang-dev
https://golang.org/cl/6551068

Fixes #3917.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6553061

After each line, ast.Print would do a zero-length write,
which would hit the boundary condition on Plan 9 when
reading over pipes (since message boundaries are
preserved). This change makes sure we only do positive-
length writes.

R=rsc, rminnich, dave, r
CC=golang-dev
https://golang.org/cl/6558046

This was misleading and often confusing for new users.

Leaving the actual weekly release history page for historical reference.

R=golang-dev, rsc, adg
CC=golang-dev
https://golang.org/cl/6555053

Today, if run.go doesn't understand a test header line it just ignores
the test, making it too easy to write or edit tests that are not actually
being run.

- expand errorcheck to accept flags, so that bounds.go and escape*.go can run.
- create a whitelist of skippable tests in run.go; skipping others is an error.
- mark all skipped tests at top of file.

Update #4139.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6549054

Revision 63f7abcae015 introduced a bug caused by
code assuming registers started at X5, not X0.

Fixes #4138.

R=rsc
CC=golang-dev, remy
https://golang.org/cl/6558043

R=rsc, r
CC=golang-dev
https://golang.org/cl/6552061

When I was a lad (and well past), users were in /usr;
now they're somewhere else, I'm told.
Kids today.

Fixes #4122.

R=golang-dev, dsymonds, rsc
CC=golang-dev
https://golang.org/cl/6552060

Fixes #3670.

R=ken2
CC=golang-dev
https://golang.org/cl/6542058

- remove ambiguous 'it'
- use a lower-case PackageName in the example

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6552057

The width was not being set on the address, which meant
that the optimizer could not find variables that overlapped
with it and mark them as having had their address taken.
This let to the compiler believing variables had been set
but never used and then optimizing away the set.

Fixes #4129.

R=ken2
CC=golang-dev
https://golang.org/cl/6552059

Fixes #4047.

R=iant, r
CC=golang-dev
https://golang.org/cl/6500065