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  1. 04 Apr, 2016 8 commits
    • Alexandru Moșoi's avatar
      cmd/compile: fold IsInBounds of modulo. · 68325b56
      Alexandru Moșoi authored 
      In b we only need the division by 0 check.

func b(i uint, v []byte) byte {
    return v[i%uint(len(v))]
}

Updates #15079.

Change-Id: Ic7491e677dd57cd6ba577efbce576dbb6e023cbd
Reviewed-on: https://go-review.googlesource.com/21502
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
Reviewed-by: 's avatarDavid Chase <drchase@google.com>
Reviewed-by: 's avatarAhmed Waheed <oneofone@gmail.com>
      68325b56
    • Austin Clements's avatar
      runtime: fix pagesInUse accounting · 61f56e92
      Austin Clements authored 
      When we grow the heap, we create a temporary "in use" span for the
memory acquired from the OS and then free that span to link it into
the heap. Hence, we (1) increase pagesInUse when we make the temporary
span so that (2) freeing the span will correctly decrease it.

However, currently step (1) increases pagesInUse by the number of
pages requested from the heap, while step (2) decreases it by the
number of pages requested from the OS (the size of the temporary
span). These aren't necessarily the same, since we round up the number
of pages we request from the OS, so steps 1 and 2 don't necessarily
cancel out like they're supposed to. Over time, this can add up and
cause pagesInUse to underflow and wrap around to 2^64. The garbage
collector computes the sweep ratio from this, so if this happens, the
sweep ratio becomes effectively infinite, causing the first allocation
on each P in a sweep cycle to sweep the entire heap. This makes
sweeping effectively STW.

Fix this by increasing pagesInUse in step 1 by the number of pages
requested from the OS, so that the two steps correctly cancel out. We
add a test that checks that the running total matches the actual state
of the heap.

Fixes #15022. For 1.6.x.

Change-Id: Iefd9d6abe37d0d447cbdbdf9941662e4f18eeffc
Reviewed-on: https://go-review.googlesource.com/21280
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarRuss Cox <rsc@golang.org>
      61f56e92
    • David Crawshaw's avatar
      cmd/link: keep types together when dynamic linking · 2d568895
      David Crawshaw authored 
      To refer to types and names by offsets, we want to keep the symbols in
the same sections. Do this by making all types .relro for now.

Once name offsets are further along, name data can move out of relro.

Change-Id: I1cbd2e914bd180cdf25c4aeb13d9c1c734febe69
Reviewed-on: https://go-review.googlesource.com/21394Reviewed-by: 's avatarMichael Hudson-Doyle <michael.hudson@canonical.com>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      2d568895
    • Caio Marcelo de Oliveira Filho's avatar
      go/types: better error when assigning to struct field in map · 74c0fea9
      Caio Marcelo de Oliveira Filho authored 
      Identify this assignment case and instead of the more general error

    prog.go:6: cannot assign to students["sally"].age (value of type int)

produce

    prog.go:6: cannot directly assign to struct field students["sally"].age in map

that explains why the assignment is not possible. Used ExprString
instead of String of operand since the type of the field is not relevant
to the error.

Updates #13779.

Change-Id: I581251145ae6336ddd181b9ddd77f657c51b5aff
Reviewed-on: https://go-review.googlesource.com/21463Reviewed-by: 's avatarDavid Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      74c0fea9
    • Caio Marcelo de Oliveira Filho's avatar
      cmd/compile: better error when assigning to struct field in map · f229e467
      Caio Marcelo de Oliveira Filho authored 
      Identify this assignment case and instead of the more general error

    prog.go:6: cannot assign to students["sally"].age

produce

    prog.go:6: cannot directly assign to struct field students["sally"].age in map

that explains why the assignment is not possible.

Fixes #13779.

Change-Id: I90c10b445f907834fc1735aa66e44a0f447aa74f
Reviewed-on: https://go-review.googlesource.com/21462Reviewed-by: 's avatarDavid Chase <drchase@google.com>
      f229e467
    • Alex Brainman's avatar
      runtime: change osyield to use Windows SwitchToThread · 1f5b1b2b
      Alex Brainman authored 
      It appears that windows osyield is just 15ms sleep on my computer
(see benchmarks below). Replace NtWaitForSingleObject in osyield
with SwitchToThread (as suggested by Dmitry).

Also add issue #14790 related benchmarks, so we can track perfomance
changes in CL 20834 and CL 20835 and beyond.

Update #14790

benchmark                             old ns/op     new ns/op     delta
BenchmarkChanToSyscallPing1ms         1953200       1953000       -0.01%
BenchmarkChanToSyscallPing15ms        31562904      31248400      -1.00%
BenchmarkSyscallToSyscallPing1ms      5247          4202          -19.92%
BenchmarkSyscallToSyscallPing15ms     5260          4374          -16.84%
BenchmarkChanToChanPing1ms            474           494           +4.22%
BenchmarkChanToChanPing15ms           468           489           +4.49%
BenchmarkOsYield1ms                   980018        75.5          -99.99%
BenchmarkOsYield15ms                  15625200      75.8          -100.00%

Change-Id: I1b4cc7caca784e2548ee3c846ca07ef152ebedce
Reviewed-on: https://go-review.googlesource.com/21294
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: 's avatarDmitry Vyukov <dvyukov@google.com>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      1f5b1b2b
    • Rob Pike's avatar
      html/template: prefix the internally-used FuncMap values with an underscore · 02adfa0b
      Rob Pike authored 
      This makes these names even less likely to collide with a real user-defined function.

Fixes #13852.

Change-Id: If5a8562c6797ced19c355c7ab2c86fc4401a8674
Reviewed-on: https://go-review.googlesource.com/21490
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarAndrew Gerrand <adg@golang.org>
      02adfa0b
    • Christopher Nelson's avatar
      cmd/go: fix -buildmode=c-archive should work on windows · ed8f0e5c
      Christopher Nelson authored 
      Add supporting code for runtime initialization, including both
32- and 64-bit x86 architectures.

Add .ctors section on Windows to PE .o files, and INITENTRY to .ctors
section to plug in to the GCC C/C++ startup initialization mechanism.
This allows the Go runtime to initialize itself. Add .text section
symbol for .ctor relocations. Note: This is unlikely to be useful for
MSVC-based toolchains.

Fixes #13494

Change-Id: I4286a96f70e5f5228acae88eef46e2bed95813f3
Reviewed-on: https://go-review.googlesource.com/18057Reviewed-by: 's avatarIan Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
      ed8f0e5c
  3. 03 Apr, 2016 12 commits
  5. 02 Apr, 2016 7 commits
  7. 01 Apr, 2016 13 commits
    • Brad Fitzpatrick's avatar
      runtime, syscall: only search for Windows DLLs in the System32 directory · 683448a3
      Brad Fitzpatrick authored 
      Make sure that for any DLL that Go uses itself, we only look for the
DLL in the Windows System32 directory, guarding against DLL preloading
attacks.

(Unless the Windows version is ancient and LoadLibraryEx is
unavailable, in which case the user probably has bigger security
problems anyway.)

This does not change the behavior of syscall.LoadLibrary or NewLazyDLL
if the DLL name is something unused by Go itself.

This change also intentionally does not add any new API surface. Instead,
x/sys is updated with a LoadLibraryEx function and LazyDLL.Flags in:
    https://golang.org/cl/21388

Updates #14959

Change-Id: I8d29200559cc19edf8dcf41dbdd39a389cd6aeb9
Reviewed-on: https://go-review.googlesource.com/21140Reviewed-by: 's avatarRuss Cox <rsc@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      683448a3
    • Ian Lance Taylor's avatar
      runtime: allocate mp.cgocallers earlier · 59fc42b2
      Ian Lance Taylor authored 
      Fixes #15061.

Change-Id: I71f69f398d1c5f3a884bbd044786f1a5600d0fae
Reviewed-on: https://go-review.googlesource.com/21398
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      59fc42b2
    • Josh Bleecher Snyder's avatar
      cmd/compile: rename Node.Int to Node.Int64 · 5cab0169
      Josh Bleecher Snyder authored 
      gorename -from '"cmd/compile/internal/gc".Node.Int' -to 'Int64'

Change-Id: I2fe3bf9a26ae6b0600d990d0c981e4b8b53020a4
Reviewed-on: https://go-review.googlesource.com/21426Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      5cab0169
    • Matthew Dempsky's avatar
      cmd/compile: more Isfoo Type cleanups · 00e5a68c
      Matthew Dempsky authored 
      Replace isideal(t) with t.IsUntyped().
Replace Istype(t, k) with t.IsKind(k).
Replace isnilinter(t) with t.IsEmptyInterface().

Also replace a lot of t.IsKind(TFOO) with t.IsFoo().

Replacements prepared mechanically with gofmt -w -r.

Passes toolstash -cmp.

Change-Id: Iba48058f3cc863e15af14277b5ff5e729e67e043
Reviewed-on: https://go-review.googlesource.com/21424Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
      00e5a68c
    • Josh Bleecher Snyder's avatar
      cmd/compile: add Type.SetNumElem · 5dd129bc
      Josh Bleecher Snyder authored 
      This removes all access to Type.Bound
from outside type.go.

Update sinit to make a new type rather than
copy and mutate.

Update bimport to create a new slice type
instead of mutating TDDDFIELD.
These are rare, so the extra allocs are nominal.

I’m not happy about having a setter,
but it appears the most practical route
forward at the moment, and it only has a few uses.

Passes toolstash -cmp.

Change-Id: I174f07c8f336afc656904bde4bdbde4f3ef0db96
Reviewed-on: https://go-review.googlesource.com/21423
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      5dd129bc
    • Josh Bleecher Snyder's avatar
      cmd/compile: use Node.Int more · e504055e
      Josh Bleecher Snyder authored 
      Generated by eg.

Passes toolstash -cmp.

Change-Id: I7516c211ca9aacf824f74894671dc62d31763b01
Reviewed-on: https://go-review.googlesource.com/21422
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      e504055e
    • Josh Bleecher Snyder's avatar
      cmd/compile: use NumElem instead of Type.Bound · 3a0783c5
      Josh Bleecher Snyder authored 
      This eliminates all direct reads of Type.Bound
outside type.go.

Change-Id: I0a9a72539f8f4c0de7f5e05e1821936bf7db5eb7
Reviewed-on: https://go-review.googlesource.com/21421
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      3a0783c5
    • Matthew Dempsky's avatar
      cmd/compile: cleanup algtype code · 077902d1
      Matthew Dempsky authored 
      Add AlgKind enum type to represent AFOO values.

Add IsComparable, IsRegularMemory, IncomparableField helper methods to
codify common higher-level idioms.

Passes toolstash -cmp.

Change-Id: I54c544953997a8ccc72396b3058897edcbbea392
Reviewed-on: https://go-review.googlesource.com/21420
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      077902d1
    • Ian Lance Taylor's avatar
      runtime/cgo: only build _cgo_callers if x_cgo_callers is defined · 58394fd7
      Ian Lance Taylor authored 
      Fixes a problem when using the external linker on Solaris.  The Solaris
external linker still doesn't work due to issue #14957.

The problem is, for example, with `go test cmd/objdump`:

        objdump_test.go:71: go build fmthello.go: exit status 2
                # command-line-arguments
                /var/gcc/iant/go/pkg/tool/solaris_amd64/link: running gcc failed: exit status 1
                Undefined                       first referenced
                 symbol                             in file
                x_cgo_callers                       /tmp/go-link-355600608/go.o
                ld: fatal: symbol referencing errors
                collect2: error: ld returned 1 exit status

Change-Id: I54917cfd5c288ee77ea25c439489bd2c9124fe73
Reviewed-on: https://go-review.googlesource.com/21392
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: 's avatarDavid Crawshaw <crawshaw@golang.org>
      58394fd7
    • Sebastien Binet's avatar
      reflect: implement StructOf · 633ab742
      Sebastien Binet authored 
      This change exposes a facility to create new struct types from a slice of
reflect.StructFields.

- reflect: first stab at implementing StructOf
- reflect: tests for StructOf

StructOf creates new struct types in the form of structTypeWithMethods
to accomodate the GC (especially the uncommonType.methods slice field.)

Creating struct types with embedded interfaces with unexported methods
is not supported yet and will panic.
Creating struct types with non-ASCII field names or types is not yet
supported (see #15064.)

Binaries' sizes for linux_amd64:

old=tip (0104a31b)

            old bytes     new bytes     delta
bin/go      9911336       9915456       +0.04%
reflect     781704        830048        +6.18%

Updates #5748.
Updates #15064.

Change-Id: I3b8fd4fadd6ce3b1b922e284f0ae72a3a8e3ce44
Reviewed-on: https://go-review.googlesource.com/9251Reviewed-by: 's avatarDavid Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
      633ab742
    • Shahar Kohanim's avatar
      cmd/internal/obj: more idiomatic object writer · 014f3e1e
      Shahar Kohanim authored 
      Change-Id: I41722ee605ea76a6b52e8a7e1e10f2293cef1a7a
Reviewed-on: https://go-review.googlesource.com/21371Reviewed-by: 's avatarDavid Crawshaw <crawshaw@golang.org>
      014f3e1e
    • Alexandru Moșoi's avatar
      cmd/compile/internal/ssa: BCE for induction variables · b91cc530
      Alexandru Moșoi authored 
      There are 5293 loop in the main go repository.
A survey of the top most common for loops:

     18 for __k__ := 0; i < len(sa.Addr); i++ {
     19 for __k__ := 0; ; i++ {
     19 for __k__ := 0; i < 16; i++ {
     25 for __k__ := 0; i < length; i++ {
     30 for __k__ := 0; i < 8; i++ {
     49 for __k__ := 0; i < len(s); i++ {
     67 for __k__ := 0; i < n; i++ {
    376 for __k__ := range __slice__ {
    685 for __k__, __v__ := range __slice__ {
   2074 for __, __v__ := range __slice__ {

The algorithm to find induction variables handles all cases
with an upper limit. It currently doesn't find related induction
variables such as c * ind or c + ind.

842 out of 22954 bound checks are removed for src/make.bash.
1957 out of 42952 bounds checks are removed for src/all.bash.

Things to do in follow-up CLs:
* Find the associated pointer for `for _, v := range a {}`
* Drop the NilChecks on the pointer.
* Replace the implicit induction variable by a loop over the pointer

Generated garbage can be reduced if we share the sdom between passes.

% benchstat old.txt new.txt
name       old time/op     new time/op     delta
Template       337ms ± 3%      333ms ± 3%    ~             (p=0.258 n=9+9)
GoTypes        1.11s ± 2%      1.10s ± 2%    ~           (p=0.912 n=10+10)
Compiler       5.25s ± 1%      5.29s ± 2%    ~             (p=0.077 n=9+9)
MakeBash       33.5s ± 1%      34.1s ± 2%  +1.85%          (p=0.011 n=9+9)

name       old alloc/op    new alloc/op    delta
Template      63.6MB ± 0%     63.9MB ± 0%  +0.52%         (p=0.000 n=10+9)
GoTypes        218MB ± 0%      219MB ± 0%  +0.59%         (p=0.000 n=10+9)
Compiler       978MB ± 0%      985MB ± 0%  +0.69%        (p=0.000 n=10+10)

name       old allocs/op   new allocs/op   delta
Template        582k ± 0%       583k ± 0%  +0.10%        (p=0.000 n=10+10)
GoTypes        1.78M ± 0%      1.78M ± 0%  +0.12%        (p=0.000 n=10+10)
Compiler       7.68M ± 0%      7.69M ± 0%  +0.05%        (p=0.000 n=10+10)

name       old text-bytes  new text-bytes  delta
HelloSize       581k ± 0%       581k ± 0%  -0.08%        (p=0.000 n=10+10)
CmdGoSize      6.40M ± 0%      6.39M ± 0%  -0.08%        (p=0.000 n=10+10)

name       old data-bytes  new data-bytes  delta
HelloSize      3.66k ± 0%      3.66k ± 0%    ~     (all samples are equal)
CmdGoSize       134k ± 0%       134k ± 0%    ~     (all samples are equal)

name       old bss-bytes   new bss-bytes   delta
HelloSize       126k ± 0%       126k ± 0%    ~     (all samples are equal)
CmdGoSize       149k ± 0%       149k ± 0%    ~     (all samples are equal)

name       old exe-bytes   new exe-bytes   delta
HelloSize       947k ± 0%       946k ± 0%  -0.01%        (p=0.000 n=10+10)
CmdGoSize      9.92M ± 0%      9.91M ± 0%  -0.06%        (p=0.000 n=10+10)

Change-Id: Ie74bdff46fd602db41bb457333d3a762a0c3dc4d
Reviewed-on: https://go-review.googlesource.com/20517Reviewed-by: 's avatarDavid Chase <drchase@google.com>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
      b91cc530
    • Ian Lance Taylor's avatar
      runtime: support symbolic backtrace of C code in a cgo crash · ea306ae6
      Ian Lance Taylor authored 
      The new function runtime.SetCgoTraceback may be used to register stack
traceback and symbolizer functions, written in C, to do a stack
traceback from cgo code.

There is a sample implementation of runtime.SetCgoSymbolizer at
github.com/ianlancetaylor/cgosymbolizer.  Just importing that package is
sufficient to get symbolic C backtraces.

Currently only supported on linux/amd64.

Change-Id: If96ee2eb41c6c7379d407b9561b87557bfe47341
Reviewed-on: https://go-review.googlesource.com/17761Reviewed-by: 's avatarAustin Clements <austin@google.com>
      ea306ae6