The protection against segfaults does not completely solve
crashes and breaks test/fixedbugs/bug365.go

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6615058

R=ken2
CC=golang-dev
https://golang.org/cl/6609052

See issue 3970 (it's already marked as Fixed).

R=rsc, minux.ma
CC=golang-dev
https://golang.org/cl/6624059

This is a part of a bigger change that adds data race detection feature:
https://golang.org/cl/6456044

R=rsc, remyoudompheng
CC=gobot, golang-dev
https://golang.org/cl/6536059

This is a part of a bigger change that adds data race detection feature:
https://golang.org/cl/6456044

R=rsc, minux.ma
CC=gobot, golang-dev
https://golang.org/cl/6529053

This is a part of a bigger change that adds data race detection feature:
https://golang.org/cl/6456044

R=rsc
CC=gobot, golang-dev
https://golang.org/cl/6535050

Also add call to GC() to make it easier to re-enable the test.

Update #4155.
When we have precise GC merged, re-enable this test.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6622058

R=golang-dev, daniel.morsing
CC=golang-dev
https://golang.org/cl/6624060

Don't assume the test has a clean environment within /tmp.
Use an actual new tempdir for its tests.

Fixes FreeBSD build failure as seen at:
http://build.golang.org/log/396738676356d7fb6bab6eaf1b97cac820f8a90f

--- FAIL: TestMkdirAllWithSymlink (0.00 seconds)
path_test.go:178:                 Mkdir /tmp/dir: mkdir /tmp/dir: file exists
FAIL
FAIL    os      1.091s

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/6615057

Also adds tests, which didn't exist before.

Fixes #4188

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6613062

Update #4139.

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/6620070

t.Log("line 1\nline 2\nline 3")

Old output:
=== RUN TestLine3
--- PASS: TestLine3 (0.00 seconds)
testing_test.go:25: 	line 1
		line 2
		line 3
		PASS

New output:
=== RUN TestLine3
--- PASS: TestLine3 (0.00 seconds)
testing_test.go:24: 	line 1
		line 2
		line 3
PASS

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6613069

R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/6615055

For issue 3757:
BEFORE:  test/fixedbugs/bug463.go:12: typechecking loop involving a
             test/fixedbugs/bug463.go:12 a
             test/fixedbugs/bug463.go:12 <node DCLCONST>
AFTER:   test/fixedbugs/bug463.go:12: constant definition loop
             test/fixedbugs/bug463.go:12: a uses a

For issue 3937:
BEFORE: test/fixedbugs/bug464.go:12: typechecking loop involving foo
            test/fixedbugs/bug464.go:12 <T>
            test/fixedbugs/bug464.go:12 foo
            test/fixedbugs/bug464.go:12 <node DCLFUNC>
AFTER:  test/fixedbugs/bug464.go:12: foo is not a type

Fixes #3757.
Fixes #3937.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6614058

Fixes #4067.

R=golang-dev, minux.ma, dave, rsc
CC=golang-dev
https://golang.org/cl/6622056

decoder struct, inside the unmappedzero limit, to eliminate some
TESTB instructions in the inner decoding loop.

benchmark          old ns/op    new ns/op    delta
BenchmarkDecode      2943204      2746360   -6.69%

R=r, dave
CC=golang-dev
https://golang.org/cl/6625058

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6610060

The nil dereference in the next few lines doesn't seem
to cause a segmentation fault on Unix, but does seem
to halt the Go compiler.

The following is a test case:

>>>
package main

func mine(int b) int {
        return b + 2
}

func main() {
        mine()

        c = mine()
}
<<<

Without this change only the following is caught:

typecheck.go:3: undefined: b
typecheck.go:4: undefined: b

with it, we catch all the errors:

typecheck.go:3: undefined: b
typecheck.go:4: undefined: b
typecheck.go:10: undefined: c
typecheck.go:10: cannot assign to c .

R=rsc, minux.ma
CC=golang-dev
https://golang.org/cl/6542060

Fixes #4124.

R=golang-dev, dave, minux.ma, remyoudompheng, rsc
CC=golang-dev
https://golang.org/cl/6543057

before

func addr(s[]int) *int {
        return &s[2]
   10c1c:       e28d0008        add     r0, sp, #8
   10c20:       e5901004        ldr     r1, [r0, #4]
   10c24:       e3a02002        mov     r2, #2
   10c28:       e1510002        cmp     r1, r2
   10c2c:       8a000000        bhi     10c34 <main.addr+0x34>
   10c30:       eb0035e6        bl      1e3d0 <runtime.panicindex>
   10c34:       e5900000        ldr     r0, [r0]
   10c38:       e2800008        add     r0, r0, #8
   10c3c:       e58d0014        str     r0, [sp, #20]
   10c40:       e49df004        pop     {pc}            ; (ldr pc, [sp], #4)

after

func addr(s[]int) *int {
	return &s[2]
   10c1c:       e28d0008        add     r0, sp, #8
   10c20:       e5901004        ldr     r1, [r0, #4]
   10c24:       e3510002        cmp     r1, #2
   10c28:       8a000000        bhi     10c30 <main.addr+0x30>
   10c2c:       eb0035e6        bl      1e3cc <runtime.panicindex>
   10c30:       e5900000        ldr     r0, [r0]
   10c34:       e2800008        add     r0, r0, #8
   10c38:       e58d0014        str     r0, [sp, #20]
   10c3c:       e49df004        pop     {pc}            ; (ldr pc, [sp], #4)

Also, relax gcmp restriction that 2nd operand must be a register. A followup
CL will address the remaining TODO items.

R=rsc, remyoudompheng, minux.ma
CC=golang-dev
https://golang.org/cl/6620064

to be consistent with the fdct function, and to ease any future
idct rewrites in assembly.

The BenchmarkIDCT delta is obviously just an accounting change and not
a real saving, but it does give an indication of what proportion of
time was spent in the actual IDCT and what proportion was in shift and
clip. The idct time taken is now comparable to fdct.

The BenchmarkFDCT delta is an estimate of benchmark noise.

benchmark                   old ns/op    new ns/op    delta
BenchmarkFDCT                    3842         3837   -0.13%
BenchmarkIDCT                    5611         3478  -38.01%
BenchmarkDecodeRGBOpaque      2932785      2929751   -0.10%

R=r
CC=golang-dev
https://golang.org/cl/6625057

refer to opacity. Those references were copy/pasted from the
image/png encoding benchmarks, which cares whether or not the
source image is opaque, but the JPEG encoder does not care.

R=r
CC=golang-dev
https://golang.org/cl/6623052

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6610061

elimination) in idct.go.

benchmark                   old ns/op    new ns/op    delta
BenchmarkIDCT                    5649         5610   -0.69%
BenchmarkDecodeRGBOpaque      2948607      2941051   -0.26%

The "type block" declaration moved so that idct.go is compilable
as a stand-alone file: "go tool 6g -S idct.go" works.

R=r
CC=golang-dev
https://golang.org/cl/6619056

It confused the detection of init loops when involving
method calls.

Fixes #3890.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6620067

Fixes #4201.

R=golang-dev, rsc
CC=golang-dev, remy
https://golang.org/cl/6622055

Fixes #4200.

R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/6619057

Fixes #3872.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6612060

Protects the package a little against undesirable clients.

R=golang-dev, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/6624054

func add() int {
        var a int
        a += 10
        a += 20
        a += 30
        a -= 10
        a -= 20
        a -= 30
        return a
}

before

--- prog list "add" ---
0000 (/home/dfc/src/add.go:5) TEXT      add+0(SB),$0-4
0001 (/home/dfc/src/add.go:6) MOVW      $0,R2
0002 (/home/dfc/src/add.go:7) MOVW      $10,R0
0003 (/home/dfc/src/add.go:7) ADD       R0,R2,R1
0004 (/home/dfc/src/add.go:8) MOVW      $20,R0
0005 (/home/dfc/src/add.go:8) ADD       R0,R1
0006 (/home/dfc/src/add.go:9) MOVW      $30,R0
0007 (/home/dfc/src/add.go:9) ADD       R0,R1
0008 (/home/dfc/src/add.go:10) MOVW     $10,R0
0009 (/home/dfc/src/add.go:10) SUB      R0,R1
0010 (/home/dfc/src/add.go:11) MOVW     $20,R0
0011 (/home/dfc/src/add.go:11) SUB      R0,R1
0012 (/home/dfc/src/add.go:12) MOVW     $30,R0
0013 (/home/dfc/src/add.go:12) SUB      R0,R1,R2
0014 (/home/dfc/src/add.go:12) MOVW     R2,R0
0015 (/home/dfc/src/add.go:13) MOVW     R2,R1
0016 (/home/dfc/src/add.go:13) MOVW     R2,.noname+0(FP)
0017 (/home/dfc/src/add.go:13) RET      ,

after

--- prog list "add" ---
0000 (/home/dfc/src/add.go:5) TEXT      add+0(SB),$0-4
0001 (/home/dfc/src/add.go:6) MOVW      $0,R0
0002 (/home/dfc/src/add.go:7) ADD       $10,R0
0003 (/home/dfc/src/add.go:8) ADD       $20,R0
0004 (/home/dfc/src/add.go:9) ADD       $30,R0
0005 (/home/dfc/src/add.go:10) SUB      $10,R0
0006 (/home/dfc/src/add.go:11) SUB      $20,R0
0007 (/home/dfc/src/add.go:12) SUB      $30,R0,R2
0008 (/home/dfc/src/add.go:13) MOVW     R2,R0
0009 (/home/dfc/src/add.go:13) MOVW     R2,.noname+0(FP)
0010 (/home/dfc/src/add.go:13) RET      ,

R=rsc, minux.ma, remyoudompheng
CC=golang-dev
https://golang.org/cl/6584056

Fixes #4197.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6611056

The profiler collects goroutine blocking information similar to Google Perf Tools.
You may see an example of the profile (converted to svg) attached to
http://code.google.com/p/go/issues/detail?id=3946
The public API changes are:
+pkg runtime, func BlockProfile([]BlockProfileRecord) (int, bool)
+pkg runtime, func SetBlockProfileRate(int)
+pkg runtime, method (*BlockProfileRecord) Stack() []uintptr
+pkg runtime, type BlockProfileRecord struct
+pkg runtime, type BlockProfileRecord struct, Count int64
+pkg runtime, type BlockProfileRecord struct, Cycles int64
+pkg runtime, type BlockProfileRecord struct, embedded StackRecord

R=rsc, dave, minux.ma, r
CC=gobot, golang-dev, r, remyoudompheng
https://golang.org/cl/6443115

rundir will compile each file in the directory in lexicographic order, link the last file as the main package and run the resulting program. rundircmpout is an related command, that will compare the output of the program to an corresponding .out file

errorcheckdir will compile each file in a directory in lexicographic order, running errorcheck on each file as it compiles. All compilations are assumed to be successful except for the last file. However, If a -0 flag is present on the command, the last compilation will also be assumed successful

This CL also includes a small refactoring of run.go. It was getting unwieldy and the meaning of the run commands was hidden behind argument line formatting.

Fixes #4058.

R=rsc, minux.ma, remyoudompheng, iant
CC=golang-dev
https://golang.org/cl/6554071

R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6621052

func addr(s[]int) *int {
	return &s[2]
}

--- prog list "addr" ---
0000 (/home/dfc/src/addr.go:5) TEXT     addr+0(SB),$0-16
0001 (/home/dfc/src/addr.go:6) MOVW     $s+0(FP),R0
0002 (/home/dfc/src/addr.go:6) MOVW     4(R0),R1
0003 (/home/dfc/src/addr.go:6) MOVW     $2,R2
0004 (/home/dfc/src/addr.go:6) CMP      R2,R1,
0005 (/home/dfc/src/addr.go:6) BHI      ,7(APC)
0006 (/home/dfc/src/addr.go:6) BL       ,runtime.panicindex+0(SB)
0007 (/home/dfc/src/addr.go:6) MOVW     0(R0),R0
0008 (/home/dfc/src/addr.go:6) MOVW     $8,R1
0009 (/home/dfc/src/addr.go:6) ADD      R1,R0
0010 (/home/dfc/src/addr.go:6) MOVW     R0,.noname+12(FP)
0011 (/home/dfc/src/addr.go:6) RET      ,

becomes

--- prog list "addr" ---
0000 (/home/dfc/src/addr.go:5) TEXT     addr+0(SB),$0-16
0001 (/home/dfc/src/addr.go:6) MOVW     $s+0(FP),R0
0002 (/home/dfc/src/addr.go:6) MOVW     4(R0),R1
0003 (/home/dfc/src/addr.go:6) MOVW     $2,R2
0004 (/home/dfc/src/addr.go:6) CMP      R2,R1,
0005 (/home/dfc/src/addr.go:6) BHI      ,7(APC)
0006 (/home/dfc/src/addr.go:6) BL       ,runtime.panicindex+0(SB)
0007 (/home/dfc/src/addr.go:6) MOVW     0(R0),R0
0008 (/home/dfc/src/addr.go:6) ADD      $8,R0
0009 (/home/dfc/src/addr.go:6) MOVW     R0,.noname+12(FP)
0010 (/home/dfc/src/addr.go:6) RET      ,

R=rsc, remyoudompheng, minux.ma
CC=golang-dev
https://golang.org/cl/6590056

R=golang-dev, dave, daniel.morsing, rsc
CC=golang-dev, remy
https://golang.org/cl/6586072

SHA-256:

benchmark          old ns/op    new ns/op    delta
BenchmarkHash1K        21686        16912  -22.01%
BenchmarkHash8K       173216       135020  -22.05%

benchmark           old MB/s     new MB/s  speedup
BenchmarkHash1K        47.22        60.55    1.28x
BenchmarkHash8K        47.29        60.67    1.28x

SHA-512:

benchmark          old ns/op    new ns/op    delta
BenchmarkHash1K        14323        11163  -22.06%
BenchmarkHash8K       114120        88693  -22.28%

benchmark           old MB/s     new MB/s  speedup
BenchmarkHash1K        71.49        91.73    1.28x
BenchmarkHash8K        71.78        92.36    1.29x

R=golang-dev, agl
CC=golang-dev
https://golang.org/cl/6584071

The Go run-time assumes that all SSE floating-point exceptions
are masked so that Go programs are not broken by such invalid
operations. By default, the 64-bit version of the Plan 9 kernel
masks only some SSE floating-point exceptions. Here, we mask
them all on a per-thread basis.

R=rsc, rminnich, minux.ma
CC=golang-dev
https://golang.org/cl/6592056

    so that it could work with the bundled jQuery.

R=adg
CC=golang-dev
https://golang.org/cl/6592073

(use floating-point rather then integer constant division)

gofmt -w src misc

Fixes #3965.

R=r, bsiegert, 0xjnml
CC=bradfitz, golang-dev
https://golang.org/cl/6610051