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  1. 11 May, 2017 3 commits
    • Tom Bergan's avatar
      net/http: for http2, use the priority write scheduler by default · 8f366681
      Tom Bergan authored 
      Updates #18318

Change-Id: Ibd4ebc7708abf87eded8da9661378b5777b8a400
Reviewed-on: https://go-review.googlesource.com/43231
Run-TryBot: Tom Bergan <tombergan@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      8f366681
    • Ben Shi's avatar
      cmd/internal/obj: continue to optimize ARM's constant pool · 6897030f
      Ben Shi authored 
      Both Keith's https://go-review.googlesource.com/c/41612/ and
and Ben's https://go-review.googlesource.com/c/41679/ optimized ARM's
constant pool. But neither was complete.

First, BIC was forgotten.
1. "BIC $0xff00ff00, Reg" can be optimized to
   "BIC $0xff000000, Reg
    BIC $0x0000ff00, Reg"
2. "BIC $0xffff00ff, Reg" can be optimized to
   "AND $0x0000ff00, Reg"
3. "AND $0xffff00ff, Reg" can be optimized to
   "BIC $0x0000ff00, Reg"

Second, break a non-ARMImmRot to the subtraction of two ARMImmRots was
left as TODO.
1. "ADD $0x00fffff0, Reg" can be optimized to
   "ADD $0x01000000, Reg
    SUB $0x00000010, Reg"
2. "SUB $0x00fffff0, Reg" can be optimized to
   "SUB $0x01000000, Reg
    ADD $0x00000010, Reg"

This patch fixes them and issue #19844.

The go1 benchmark shows improvements.

name                     old time/op    new time/op    delta
BinaryTree17-4              41.4s ± 1%     41.7s ± 1%  +0.54%  (p=0.000 n=50+49)
Fannkuch11-4                24.7s ± 1%     25.1s ± 0%  +1.70%  (p=0.000 n=50+49)
FmtFprintfEmpty-4           853ns ± 1%     852ns ± 1%    ~     (p=0.833 n=50+50)
FmtFprintfString-4         1.33µs ± 1%    1.33µs ± 1%    ~     (p=0.163 n=50+50)
FmtFprintfInt-4            1.40µs ± 1%    1.40µs ± 0%    ~     (p=0.293 n=50+35)
FmtFprintfIntInt-4         2.09µs ± 1%    2.08µs ± 1%  -0.39%  (p=0.000 n=50+49)
FmtFprintfPrefixedInt-4    2.43µs ± 1%    2.43µs ± 1%    ~     (p=0.552 n=50+50)
FmtFprintfFloat-4          4.57µs ± 1%    4.42µs ± 1%  -3.18%  (p=0.000 n=50+50)
FmtManyArgs-4              8.62µs ± 1%    8.52µs ± 0%  -1.08%  (p=0.000 n=50+50)
GobDecode-4                 101ms ± 1%     101ms ± 2%  +0.45%  (p=0.001 n=49+49)
GobEncode-4                90.7ms ± 1%    91.1ms ± 2%  +0.51%  (p=0.001 n=50+50)
Gzip-4                      4.23s ± 1%     4.21s ± 1%  -0.62%  (p=0.000 n=50+50)
Gunzip-4                    623ms ± 1%     619ms ± 0%  -0.63%  (p=0.000 n=50+42)
HTTPClientServer-4          721µs ± 5%     683µs ± 3%  -5.25%  (p=0.000 n=50+47)
JSONEncode-4                251ms ± 1%     253ms ± 1%  +0.54%  (p=0.000 n=49+50)
JSONDecode-4                941ms ± 1%     944ms ± 1%  +0.30%  (p=0.001 n=49+50)
Mandelbrot200-4            49.3ms ± 1%    49.3ms ± 0%    ~     (p=0.918 n=50+48)
GoParse-4                  47.1ms ± 1%    47.2ms ± 1%  +0.18%  (p=0.025 n=50+50)
RegexpMatchEasy0_32-4      1.23µs ± 1%    1.24µs ± 1%  +0.30%  (p=0.000 n=49+50)
RegexpMatchEasy0_1K-4      7.74µs ± 7%    7.76µs ± 5%    ~     (p=0.888 n=50+50)
RegexpMatchEasy1_32-4      1.32µs ± 1%    1.32µs ± 1%  +0.23%  (p=0.003 n=50+50)
RegexpMatchEasy1_1K-4      10.6µs ± 2%    10.5µs ± 3%  -1.29%  (p=0.000 n=49+50)
RegexpMatchMedium_32-4     2.19µs ± 1%    2.10µs ± 1%  -3.79%  (p=0.000 n=49+49)
RegexpMatchMedium_1K-4      544µs ± 0%     545µs ± 0%    ~     (p=0.123 n=41+50)
RegexpMatchHard_32-4       28.8µs ± 0%    28.8µs ± 1%    ~     (p=0.580 n=46+50)
RegexpMatchHard_1K-4        863µs ± 1%     865µs ± 1%  +0.31%  (p=0.027 n=47+50)
Revcomp-4                  82.2ms ± 2%    82.3ms ± 2%    ~     (p=0.894 n=48+49)
Template-4                  1.06s ± 1%     1.04s ± 1%  -1.18%  (p=0.000 n=50+49)
TimeParse-4                7.25µs ± 1%    7.35µs ± 0%  +1.48%  (p=0.000 n=50+50)
TimeFormat-4               13.3µs ± 1%    13.2µs ± 1%  -0.13%  (p=0.007 n=50+50)
[Geo mean]                  736µs          733µs       -0.37%

name                     old speed      new speed      delta
GobDecode-4              7.60MB/s ± 1%  7.56MB/s ± 2%  -0.46%  (p=0.001 n=49+49)
GobEncode-4              8.47MB/s ± 1%  8.42MB/s ± 2%  -0.50%  (p=0.001 n=50+50)
Gzip-4                   4.58MB/s ± 1%  4.61MB/s ± 1%  +0.59%  (p=0.000 n=50+50)
Gunzip-4                 31.2MB/s ± 1%  31.4MB/s ± 0%  +0.63%  (p=0.000 n=50+42)
JSONEncode-4             7.73MB/s ± 1%  7.69MB/s ± 1%  -0.53%  (p=0.000 n=49+50)
JSONDecode-4             2.06MB/s ± 1%  2.06MB/s ± 1%    ~     (p=0.052 n=44+50)
GoParse-4                1.23MB/s ± 0%  1.23MB/s ± 2%    ~     (p=0.526 n=26+50)
RegexpMatchEasy0_32-4    25.9MB/s ± 1%  25.9MB/s ± 1%  -0.30%  (p=0.000 n=49+50)
RegexpMatchEasy0_1K-4     132MB/s ± 7%   132MB/s ± 6%    ~     (p=0.885 n=50+50)
RegexpMatchEasy1_32-4    24.2MB/s ± 1%  24.1MB/s ± 1%  -0.22%  (p=0.003 n=50+50)
RegexpMatchEasy1_1K-4    96.4MB/s ± 2%  97.8MB/s ± 3%  +1.36%  (p=0.000 n=50+50)
RegexpMatchMedium_32-4    460kB/s ± 0%   476kB/s ± 1%  +3.43%  (p=0.000 n=49+50)
RegexpMatchMedium_1K-4   1.88MB/s ± 0%  1.88MB/s ± 0%    ~     (all equal)
RegexpMatchHard_32-4     1.11MB/s ± 0%  1.11MB/s ± 1%  +0.34%  (p=0.000 n=45+50)
RegexpMatchHard_1K-4     1.19MB/s ± 1%  1.18MB/s ± 1%  -0.34%  (p=0.033 n=50+50)
Revcomp-4                30.9MB/s ± 2%  30.9MB/s ± 2%    ~     (p=0.894 n=48+49)
Template-4               1.84MB/s ± 1%  1.86MB/s ± 2%  +1.19%  (p=0.000 n=48+50)
[Geo mean]               6.63MB/s       6.65MB/s       +0.26%


Fixes #19844.

Change-Id: I5ad16cc0b29267bb4579aca3dcc10a0b8ade1aa4
Reviewed-on: https://go-review.googlesource.com/42430
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarCherry Zhang <cherryyz@google.com>
      6897030f
    • Daniel Martí's avatar
      reflect: remove dead v.typ assignment · 19b05acd
      Daniel Martí authored 
      v is not a pointer receiver, and v.typ isn't used in the lines below.
The assignment is dead. Remove it.

Keep the comment, as it refers to the whole case block and not just the
removed line.

Change-Id: Icb2d20c287d9a41bf620ebe5cdec764cd84178a7
Reviewed-on: https://go-review.googlesource.com/43134
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      19b05acd
  3. 10 May, 2017 15 commits
  5. 09 May, 2017 20 commits
    • Josh Bleecher Snyder's avatar
      cmd/compile: allow OpVarXXX calls to be duplicated in writebarrier blocks · 94a017f3
      Josh Bleecher Snyder authored 
      OpVarXXX Values don't generate instructions,
so there's no reason not to duplicate them,
and duplicating them generates better code
(fewer branches).

This requires changing the start/end accounting
to correctly handle the case in which we have run
of Values beginning with an OpVarXXX, e.g.
OpVarDef, OpZeroWB, OpMoveWB.
In that case, the sequence of values should begin
at the OpZeroWB, not the OpVarDef.

This also lays the groundwork for experimenting
with allowing duplication of some scalar stores.

Shrinks function text sizes a tiny amount:

name        old object-bytes  new object-bytes  delta
Template           381k ± 0%         381k ± 0%  -0.01%  (p=0.008 n=5+5)
Unicode            203k ± 0%         203k ± 0%  -0.04%  (p=0.008 n=5+5)
GoTypes           1.17M ± 0%        1.17M ± 0%  -0.01%  (p=0.008 n=5+5)
SSA               8.24M ± 0%        8.24M ± 0%  -0.00%  (p=0.008 n=5+5)
Flate              230k ± 0%         230k ± 0%    ~     (all equal)
GoParser           286k ± 0%         286k ± 0%    ~     (all equal)
Reflect           1.00M ± 0%        1.00M ± 0%    ~     (all equal)
Tar                189k ± 0%         189k ± 0%    ~     (all equal)
XML                415k ± 0%         415k ± 0%  -0.01%  (p=0.008 n=5+5)

Updates #19838

Change-Id: Ic5ef30855919f1468066eba08ae5c4bd9a01db27
Reviewed-on: https://go-review.googlesource.com/42011
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarCherry Zhang <cherryyz@google.com>
      94a017f3
    • Ian Lance Taylor's avatar
      cmd/internal/obj, cmd/link: fix st_other field on PPC64 · 5331e7e9
      Ian Lance Taylor authored 
      In PPC64 ELF files, the st_other field indicates the number of
prologue instructions between the global and local entry points.
We add the instructions in the compiler and assembler if -shared is used.
We were assuming that the instructions were present when building a
c-archive or PIE or doing dynamic linking, on the assumption that those
are the cases where the go tool would be building with -shared.
That assumption fails when using some other tool, such as Bazel,
that does not necessarily use -shared in exactly the same way.

This CL records in the object file whether a symbol was compiled
with -shared (this will be the same for all symbols in a given compilation)
and uses that information when setting the st_other field.

Fixes #20290.

Change-Id: Ib2b77e16aef38824871102e3c244fcf04a86c6ea
Reviewed-on: https://go-review.googlesource.com/43051
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarMichael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: 's avatarMatthew Dempsky <mdempsky@google.com>
      5331e7e9
    • Todd Neal's avatar
      cmd/compile: ignore types when considering tuple select for CSE · 08dca4c6
      Todd Neal authored 
      Fixes #20097

Change-Id: I3c9626ccc8cd0c46a7081ea8650b2ff07a5d4fcd
Reviewed-on: https://go-review.googlesource.com/41505
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarKeith Randall <khr@golang.org>
      08dca4c6
    • Josh Bleecher Snyder's avatar
      cmd/compile: change ssa.Type into *types.Type · 46b88c9f
      Josh Bleecher Snyder authored 
      When package ssa was created, Type was in package gc.
To avoid circular dependencies, we used an interface (ssa.Type)
to represent type information in SSA.

In the Go 1.9 cycle, gri extricated the Type type from package gc.
As a result, we can now use it in package ssa.
Now, instead of package types depending on package ssa,
it is the other way.
This is a more sensible dependency tree,
and helps compiler performance a bit.

Though this is a big CL, most of the changes are
mechanical and uninteresting.

Interesting bits:

* Add new singleton globals to package types for the special
  SSA types Memory, Void, Invalid, Flags, and Int128.
* Add two new Types, TSSA for the special types,
  and TTUPLE, for SSA tuple types.
  ssa.MakeTuple is now types.NewTuple.
* Move type comparison result constants CMPlt, CMPeq, and CMPgt
  to package types.
* We had picked the name "types" in our rules for the handy
  list of types provided by ssa.Config. That conflicted with
  the types package name, so change it to "typ".
* Update the type comparison routine to handle tuples and special
  types inline.
* Teach gc/fmt.go how to print special types.
* We can now eliminate ElemTypes in favor of just Elem,
  and probably also some other duplicated Type methods
  designed to return ssa.Type instead of *types.Type.
* The ssa tests were using their own dummy types,
  and they were not particularly careful about types in general.
  Of necessity, this CL switches them to use *types.Type;
  it does not make them more type-accurate.
  Unfortunately, using types.Type means initializing a bit
  of the types universe.
  This is prime for refactoring and improvement.

This shrinks ssa.Value; it now fits in a smaller size class
on 64 bit systems. This doesn't have a giant impact,
though, since most Values are preallocated in a chunk.

name        old alloc/op      new alloc/op      delta
Template         37.9MB ± 0%       37.7MB ± 0%  -0.57%  (p=0.000 n=10+8)
Unicode          28.9MB ± 0%       28.7MB ± 0%  -0.52%  (p=0.000 n=10+10)
GoTypes           110MB ± 0%        109MB ± 0%  -0.88%  (p=0.000 n=10+10)
Flate            24.7MB ± 0%       24.6MB ± 0%  -0.66%  (p=0.000 n=10+10)
GoParser         31.1MB ± 0%       30.9MB ± 0%  -0.61%  (p=0.000 n=10+9)
Reflect          73.9MB ± 0%       73.4MB ± 0%  -0.62%  (p=0.000 n=10+8)
Tar              25.8MB ± 0%       25.6MB ± 0%  -0.77%  (p=0.000 n=9+10)
XML              41.2MB ± 0%       40.9MB ± 0%  -0.80%  (p=0.000 n=10+10)
[Geo mean]       40.5MB            40.3MB       -0.68%

name        old allocs/op     new allocs/op     delta
Template           385k ± 0%         386k ± 0%    ~     (p=0.356 n=10+9)
Unicode            343k ± 1%         344k ± 0%    ~     (p=0.481 n=10+10)
GoTypes           1.16M ± 0%        1.16M ± 0%  -0.16%  (p=0.004 n=10+10)
Flate              238k ± 1%         238k ± 1%    ~     (p=0.853 n=10+10)
GoParser           320k ± 0%         320k ± 0%    ~     (p=0.720 n=10+9)
Reflect            957k ± 0%         957k ± 0%    ~     (p=0.460 n=10+8)
Tar                252k ± 0%         252k ± 0%    ~     (p=0.133 n=9+10)
XML                400k ± 0%         400k ± 0%    ~     (p=0.796 n=10+10)
[Geo mean]         428k              428k       -0.01%


Removing all the interface calls helps non-trivially with CPU, though.

name        old time/op       new time/op       delta
Template          178ms ± 4%        173ms ± 3%  -2.90%  (p=0.000 n=94+96)
Unicode          85.0ms ± 4%       83.9ms ± 4%  -1.23%  (p=0.000 n=96+96)
GoTypes           543ms ± 3%        528ms ± 3%  -2.73%  (p=0.000 n=98+96)
Flate             116ms ± 3%        113ms ± 4%  -2.34%  (p=0.000 n=96+99)
GoParser          144ms ± 3%        140ms ± 4%  -2.80%  (p=0.000 n=99+97)
Reflect           344ms ± 3%        334ms ± 4%  -3.02%  (p=0.000 n=100+99)
Tar               106ms ± 5%        103ms ± 4%  -3.30%  (p=0.000 n=98+94)
XML               198ms ± 5%        192ms ± 4%  -2.88%  (p=0.000 n=92+95)
[Geo mean]        178ms             173ms       -2.65%

name        old user-time/op  new user-time/op  delta
Template          229ms ± 5%        224ms ± 5%  -2.36%  (p=0.000 n=95+99)
Unicode           107ms ± 6%        106ms ± 5%  -1.13%  (p=0.001 n=93+95)
GoTypes           696ms ± 4%        679ms ± 4%  -2.45%  (p=0.000 n=97+99)
Flate             137ms ± 4%        134ms ± 5%  -2.66%  (p=0.000 n=99+96)
GoParser          176ms ± 5%        172ms ± 8%  -2.27%  (p=0.000 n=98+100)
Reflect           430ms ± 6%        411ms ± 5%  -4.46%  (p=0.000 n=100+92)
Tar               128ms ±13%        123ms ±13%  -4.21%  (p=0.000 n=100+100)
XML               239ms ± 6%        233ms ± 6%  -2.50%  (p=0.000 n=95+97)
[Geo mean]        220ms             213ms       -2.76%


Change-Id: I15c7d6268347f8358e75066dfdbd77db24e8d0c1
Reviewed-on: https://go-review.googlesource.com/42145
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarKeith Randall <khr@golang.org>
      46b88c9f
    • Josh Bleecher Snyder's avatar
      cmd/compile: add boolean simplification rules · 6a24b2d0
      Josh Bleecher Snyder authored 
      These collectively fire a few hundred times during make.bash,
mostly rewriting XOR SETNE -> SETEQ.

Fixes #17905.

Change-Id: Ic5eb241ee93ed67099da3de11f59e4df9fab64a3
Reviewed-on: https://go-review.googlesource.com/42491
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarKeith Randall <khr@golang.org>
      6a24b2d0
    • Marvin Stenger's avatar
      cmd/compile/internal/ssa: mark boolean instructions commutative · 9aeced65
      Marvin Stenger authored 
      Mark AndB, OrB, EqB, and NeqB as commutative.

Change-Id: Ife7cfcb9780cc5dd669617cb52339ab336667da4
Reviewed-on: https://go-review.googlesource.com/42515Reviewed-by: 's avatarGiovanni Bajo <rasky@develer.com>
Reviewed-by: 's avatarJosh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: 's avatarKeith Randall <khr@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      9aeced65
    • Josh Bleecher Snyder's avatar
      cmd/compile: make builds reproducible in presence of **byte and **int8 · 6f2ee0f3
      Josh Bleecher Snyder authored 
      CL 39915 introduced sorting of signats by ShortString
for reproducible builds. But ShortString treats types
byte and uint8 identically; same for rune and uint32.
CL 39915 attempted to compensate for this by only
adding the underlying type (uint8) to signats in addsignat.

This only works for byte and uint8. For e.g. *byte and *uint,
both get added, and their sort order is random,
leading to non-reproducible builds.

One fix would be to add yet another type printing mode
that doesn't eliminate byte and rune, and use it
for sorting signats. But the formatting routines
are complicated enough as it is.

Instead, just sort first by ShortString and then by String.
We can't just use String, because ShortString makes distinctions
that String doesn't. ShortString is really preferred here;
String is serving only as a backstop for handling of bytes and runes.

The long series of types in the test helps increase the odds of
failure, allowing a smaller number of iterations in the test.
On my machine, a full test takes 700ms.

Passes toolstash-check.

Updates #19961
Fixes #20272

name        old alloc/op      new alloc/op      delta
Template         37.9MB ± 0%       37.9MB ± 0%  +0.12%  (p=0.032 n=5+5)
Unicode          28.9MB ± 0%       28.9MB ± 0%    ~     (p=0.841 n=5+5)
GoTypes           110MB ± 0%        110MB ± 0%    ~     (p=0.841 n=5+5)
Compiler          463MB ± 0%        463MB ± 0%    ~     (p=0.056 n=5+5)
SSA              1.11GB ± 0%       1.11GB ± 0%  +0.02%  (p=0.016 n=5+5)
Flate            24.7MB ± 0%       24.8MB ± 0%  +0.14%  (p=0.032 n=5+5)
GoParser         31.1MB ± 0%       31.1MB ± 0%    ~     (p=0.421 n=5+5)
Reflect          73.9MB ± 0%       73.9MB ± 0%    ~     (p=1.000 n=5+5)
Tar              25.8MB ± 0%       25.8MB ± 0%  +0.15%  (p=0.016 n=5+5)
XML              41.2MB ± 0%       41.2MB ± 0%    ~     (p=0.310 n=5+5)
[Geo mean]       72.0MB            72.0MB       +0.07%

name        old allocs/op     new allocs/op     delta
Template           384k ± 0%         385k ± 1%    ~     (p=0.056 n=5+5)
Unicode            343k ± 0%         344k ± 0%    ~     (p=0.548 n=5+5)
GoTypes           1.16M ± 0%        1.16M ± 0%    ~     (p=0.421 n=5+5)
Compiler          4.43M ± 0%        4.44M ± 0%  +0.26%  (p=0.032 n=5+5)
SSA               9.86M ± 0%        9.87M ± 0%  +0.10%  (p=0.032 n=5+5)
Flate              237k ± 1%         238k ± 0%  +0.49%  (p=0.032 n=5+5)
GoParser           319k ± 1%         320k ± 1%    ~     (p=0.151 n=5+5)
Reflect            957k ± 0%         957k ± 0%    ~     (p=1.000 n=5+5)
Tar                251k ± 0%         252k ± 1%  +0.49%  (p=0.016 n=5+5)
XML                399k ± 0%         401k ± 1%    ~     (p=0.310 n=5+5)
[Geo mean]         739k              741k       +0.26%

Change-Id: Ic27995a8d374d012b8aca14546b1df9d28d30df7
Reviewed-on: https://go-review.googlesource.com/42955
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarRobert Griesemer <gri@golang.org>
      6f2ee0f3
    • Josh Bleecher Snyder's avatar
      cmd/compile: make "imported and not used" errors deterministic · 9fda4df9
      Josh Bleecher Snyder authored 
      If there were more unused imports than
the maximum default number of errors to report,
the set of reported imports was non-deterministic.

Fix by accumulating and sorting them prior to output.

Fixes #20298

Change-Id: Ib3d5a15fd7dc40009523fcdc1b93ddc62a1b05f2
Reviewed-on: https://go-review.googlesource.com/42954
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarRobert Griesemer <gri@golang.org>
      9fda4df9
    • Cherry Zhang's avatar
      cmd/internal/obj/arm64, cmd/compile: improve offset folding on ARM64 · fb0ccc5d
      Cherry Zhang authored 
      ARM64 assembler backend only accepts loads and stores with small
or aligned offset. The compiler therefore can only fold small or
aligned offsets into loads and stores. For locals and args, their
offsets to SP are not known until very late, and the compiler
makes conservative decision not folding some of them. However,
in most cases, the offset is indeed small or aligned, and can
be folded into load and store (but actually not).

This CL adds support of loads and stores with large and unaligned
offsets. When the offset doesn't fit into the instruction, it
uses two instructions and (for very large offset) the constant
pool. This way, the compiler doesn't need to be conservative,
and can simply fold the offset.

To make it work, the assembler's optab matching rules need to be
changed. Before, MOVD accepts C_UAUTO32K which matches multiple
of 8 between 0 and 32K, and also C_UAUTO16K, which may not be
multiple of 8 and does not fit into MOVD instruction. The
assembler errors in the latter case. This change makes it only
matches multiple of 8 (or offsets within ±256, which also fits
in instruction), and uses the large-or-unaligned-offset rule
for things doesn't fit (without error). Other sized move rules
are changed similarly.

Class C_UAUTO64K and C_UOREG64K are removed, as they are never
used.

In shared library, load/store of global is rewritten to using
GOT and temp register, which conflicts with the use of temp
register for assembling large offset. So the folding is disabled
for globals in shared library mode.

Reduce cmd/go binary size by 2%.

name                     old time/op    new time/op    delta
BinaryTree17-8              8.67s ± 0%     8.61s ± 0%   -0.60%  (p=0.000 n=9+10)
Fannkuch11-8                6.24s ± 0%     6.19s ± 0%   -0.83%  (p=0.000 n=10+9)
FmtFprintfEmpty-8           116ns ± 0%     116ns ± 0%     ~     (all equal)
FmtFprintfString-8          196ns ± 0%     192ns ± 0%   -1.89%  (p=0.000 n=10+10)
FmtFprintfInt-8             199ns ± 0%     198ns ± 0%   -0.35%  (p=0.001 n=9+10)
FmtFprintfIntInt-8          294ns ± 0%     293ns ± 0%   -0.34%  (p=0.000 n=8+8)
FmtFprintfPrefixedInt-8     318ns ± 1%     318ns ± 1%     ~     (p=1.000 n=10+10)
FmtFprintfFloat-8           537ns ± 0%     531ns ± 0%   -1.17%  (p=0.000 n=9+10)
FmtManyArgs-8              1.19µs ± 1%    1.18µs ± 1%   -1.41%  (p=0.001 n=10+10)
GobDecode-8                17.2ms ± 1%    17.3ms ± 2%     ~     (p=0.165 n=10+10)
GobEncode-8                14.7ms ± 1%    14.7ms ± 2%     ~     (p=0.631 n=10+10)
Gzip-8                      837ms ± 0%     836ms ± 0%   -0.14%  (p=0.006 n=9+10)
Gunzip-8                    141ms ± 0%     139ms ± 0%   -1.24%  (p=0.000 n=9+10)
HTTPClientServer-8          256µs ± 1%     253µs ± 1%   -1.35%  (p=0.000 n=10+10)
JSONEncode-8               40.1ms ± 1%    41.3ms ± 1%   +3.06%  (p=0.000 n=10+9)
JSONDecode-8                157ms ± 1%     156ms ± 1%   -0.83%  (p=0.001 n=9+8)
Mandelbrot200-8            8.94ms ± 0%    8.94ms ± 0%   +0.02%  (p=0.000 n=9+9)
GoParse-8                  8.69ms ± 0%    8.54ms ± 1%   -1.69%  (p=0.000 n=8+10)
RegexpMatchEasy0_32-8       227ns ± 1%     228ns ± 1%   +0.48%  (p=0.016 n=10+9)
RegexpMatchEasy0_1K-8      1.92µs ± 0%    1.63µs ± 0%  -15.08%  (p=0.000 n=10+9)
RegexpMatchEasy1_32-8       256ns ± 0%     251ns ± 0%   -2.19%  (p=0.000 n=10+9)
RegexpMatchEasy1_1K-8      2.38µs ± 0%    2.09µs ± 0%  -12.49%  (p=0.000 n=10+9)
RegexpMatchMedium_32-8      352ns ± 0%     354ns ± 0%   +0.39%  (p=0.002 n=10+9)
RegexpMatchMedium_1K-8      106µs ± 0%     106µs ± 0%   -0.05%  (p=0.005 n=10+9)
RegexpMatchHard_32-8       5.92µs ± 0%    5.89µs ± 0%   -0.40%  (p=0.000 n=9+8)
RegexpMatchHard_1K-8        180µs ± 0%     179µs ± 0%   -0.14%  (p=0.000 n=10+9)
Revcomp-8                   1.20s ± 0%     1.13s ± 0%   -6.29%  (p=0.000 n=9+8)
Template-8                  159ms ± 1%     154ms ± 1%   -3.14%  (p=0.000 n=9+10)
TimeParse-8                 800ns ± 3%     769ns ± 1%   -3.91%  (p=0.000 n=10+10)
TimeFormat-8                826ns ± 2%     817ns ± 2%   -1.04%  (p=0.050 n=10+10)
[Geo mean]                  145µs          143µs        -1.79%

Change-Id: I5fc42087cee9b54ea414f8ef6d6d020b80eb5985
Reviewed-on: https://go-review.googlesource.com/42172
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: 's avatarDavid Chase <drchase@google.com>
      fb0ccc5d
    • Josh Bleecher Snyder's avatar
      cmd/go: enable concurrent backend compilation by default · 5e0bcb38
      Josh Bleecher Snyder authored 
      It can be disabled by setting the environment variable
GO19CONCURRENTCOMPILATION=0, or with -gcflags=-c=1.

Fixes #15756.

Change-Id: I7acbf16330512b62ee14ecbab1f46b53ec5a67b6
Reviewed-on: https://go-review.googlesource.com/41820
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarKeith Randall <khr@golang.org>
      5e0bcb38
    • Josh Bleecher Snyder's avatar
      cmd/go: add support for concurrent backend compilation · f4e5bd48
      Josh Bleecher Snyder authored 
      It is disabled by default.
It can be enabled by setting the environment variable
GO19CONCURRENTCOMPILATION=1.

Benchmarking results are presented in a grid.
Columns are different values of c (compiler backend concurrency);
rows are different values of p (process concurrency).

'go build -a std cmd', a 4 core raspberry pi 3:

            c=1        c=2        c=4
StdCmd/p=1  504s ± 2%  413s ± 4%  367s ± 3%
StdCmd/p=2  314s ± 3%  266s ± 4%  267s ± 4%
StdCmd/p=4  254s ± 5%  241s ± 5%  238s ± 6%

'go build -a std cmd', an 8 core darwin/amd64 laptop:

            c=1         c=2         c=4         c=6         c=8
StdCmd/p=1  40.4s ± 7%  31.0s ± 1%  27.3s ± 1%  27.8s ± 0%  27.7s ± 0%
StdCmd/p=2  21.9s ± 1%  17.9s ± 1%  16.9s ± 1%  17.0s ± 1%  17.2s ± 0%
StdCmd/p=4  17.4s ± 2%  14.5s ± 2%  13.3s ± 2%  13.5s ± 2%  13.6s ± 2%
StdCmd/p=6  16.9s ± 1%  14.2s ± 2%  13.1s ± 2%  13.2s ± 2%  13.3s ± 2%
StdCmd/p=8  16.7s ± 2%  14.2s ± 2%  13.2s ± 3%  13.2s ± 2%  13.4s ± 2%

'go build -a std cmd', a 96 core arm64 server:

             c=1         c=2         c=4         c=6         c=8         c=16        c=32        c=64        c=96
StdCmd/p=1    173s ± 1%   133s ± 1%   114s ± 1%   109s ± 1%   106s ± 0%   106s ± 1%   107s ± 1%   110s ± 1%   113s ± 1%
StdCmd/p=2   94.2s ± 2%  71.5s ± 1%  61.7s ± 1%  58.7s ± 1%  57.5s ± 2%  56.9s ± 1%  58.0s ± 1%  59.6s ± 1%  61.0s ± 1%
StdCmd/p=4   74.1s ± 2%  53.5s ± 1%  43.7s ± 2%  40.5s ± 1%  39.2s ± 2%  38.9s ± 2%  39.5s ± 3%  40.3s ± 2%  40.8s ± 1%
StdCmd/p=6   69.3s ± 1%  50.2s ± 2%  40.3s ± 2%  37.3s ± 3%  36.0s ± 3%  35.3s ± 2%  36.0s ± 2%  36.8s ± 2%  37.5s ± 2%
StdCmd/p=8   66.1s ± 2%  47.7s ± 2%  38.6s ± 2%  35.7s ± 2%  34.4s ± 1%  33.6s ± 2%  34.2s ± 2%  34.6s ± 1%  35.0s ± 1%
StdCmd/p=16  63.4s ± 2%  45.3s ± 2%  36.3s ± 2%  33.3s ± 2%  32.0s ± 3%  31.6s ± 2%  32.1s ± 2%  32.5s ± 2%  32.7s ± 2%
StdCmd/p=32  62.2s ± 1%  44.2s ± 2%  35.3s ± 2%  32.4s ± 2%  31.2s ± 2%  30.9s ± 2%  31.1s ± 2%  31.7s ± 2%  32.0s ± 2%
StdCmd/p=64  62.2s ± 1%  44.3s ± 2%  35.4s ± 2%  32.4s ± 2%  31.2s ± 2%  30.9s ± 2%  31.2s ± 2%  31.8s ± 3%  32.2s ± 3%
StdCmd/p=96  62.2s ± 2%  44.4s ± 2%  35.3s ± 2%  32.3s ± 2%  31.1s ± 2%  30.9s ± 3%  31.3s ± 2%  31.7s ± 1%  32.1s ± 2%

benchjuju, an 8 core darwin/amd64 laptop:

               c=1         c=2         c=4         c=6         c=8
BuildJuju/p=1  55.3s ± 0%  46.3s ± 0%  41.9s ± 0%  41.4s ± 1%  41.3s ± 0%
BuildJuju/p=2  33.7s ± 1%  28.4s ± 1%  26.7s ± 1%  26.6s ± 1%  26.8s ± 1%
BuildJuju/p=4  24.7s ± 1%  22.3s ± 1%  21.4s ± 1%  21.7s ± 1%  21.8s ± 1%
BuildJuju/p=6  20.6s ± 1%  19.3s ± 2%  19.4s ± 1%  19.7s ± 1%  19.9s ± 1%
BuildJuju/p=8  20.6s ± 2%  19.5s ± 2%  19.3s ± 2%  19.6s ± 1%  19.8s ± 2%

Updates #15756

Change-Id: I8a56e88953071a05eee764002024c54cd888a56c
Reviewed-on: https://go-review.googlesource.com/41819
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      f4e5bd48
    • Robert Griesemer's avatar
      spec: clarify unsafe.Pointer conversions · 86f5f7fd
      Robert Griesemer authored 
      A pointer type of underlying type unsafe.Pointer can be used in
unsafe conversions. Document unfortunate status quo.

Fixes #19306.

Change-Id: I28172508a200561f8df366bbf2c2807ef3b48c97
Reviewed-on: https://go-review.googlesource.com/42132Reviewed-by: 's avatarMatthew Dempsky <mdempsky@google.com>
Reviewed-by: 's avatarRuss Cox <rsc@golang.org>
Reviewed-by: 's avatarIan Lance Taylor <iant@golang.org>
      86f5f7fd
    • Ibrahim AshShohail's avatar
      go/token: remove excess parenthesis in NoPos.IsValid() documentation · 54102963
      Ibrahim AshShohail authored 
      Fixes #20294

Change-Id: I32ac862fe00180210a04103cc94c4d9fef5d1b6c
Reviewed-on: https://go-review.googlesource.com/42992Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      54102963
    • Austin Clements's avatar
      runtime/pprof: deflake TestGoroutineCounts · d659682d
      Austin Clements authored 
      TestGoroutineCounts currently depends on timing to get 100 goroutines
to a known blocking point before taking a profile. This fails
frequently, with different goroutines captured at different stacks.
The test is disabled on openbsd because it was too flaky, but in fact
it flakes on all platforms.

Fix this by using Gosched instead of timing. This is both much more
reliable and makes the test run faster.

Fixes #15156.

Change-Id: Ia6e894196d717655b8fb4ee96df53f6cc8bc5f1f
Reviewed-on: https://go-review.googlesource.com/42953
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Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      d659682d
    • Ian Lance Taylor's avatar
      cmd/go: put user flags after code generation flag · 9eacd977
      Ian Lance Taylor authored 
      This permits the user to override the code generation flag when they
know better. This is always a good policy for all flags automatically
inserted by the build system.

Doing this now so that I can write a test for #20290.

Update #20290

Change-Id: I5c6708a277238d571b8d037993a5a59e2a442e98
Reviewed-on: https://go-review.googlesource.com/42952
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
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      9eacd977
    • Rob Phoenix's avatar
      net: fix ExampleParseCIDR IPv4 prefix length · 1e732ca3
      Rob Phoenix authored 
      Issue #15228 describes that reserved address blocks should be used for
documentation purposes. This change updates the prefix length so the
IPv4 address adheres to this.

Change-Id: I237d9cce1a71f4fd95f927ec894ce53fa806047f
Reviewed-on: https://go-review.googlesource.com/42991
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      1e732ca3
    • Alex Brainman's avatar
      cmd/go: run tests that require symlinks · 096e2bff
      Alex Brainman authored 
      Change-Id: I19a724ea4eb1ba0ff558721650c89a949e53b7c7
Reviewed-on: https://go-review.googlesource.com/42895Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
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      096e2bff
    • Alex Brainman's avatar
      os: avoid calulating fileStat.path until it is needed · 6dcaa095
      Alex Brainman authored 
      This CL improves

on my Windows 7

name         old time/op    new time/op    delta
Readdirname    58.1µs ± 1%    58.1µs ± 0%     ~     (p=0.817 n=8+8)
Readdir        58.0µs ± 3%    57.8µs ± 0%     ~     (p=0.944 n=9+8)

name         old alloc/op   new alloc/op   delta
Readdirname    3.03kB ± 0%    2.84kB ± 0%   -6.33%  (p=0.000 n=10+10)
Readdir        3.00kB ± 0%    2.81kB ± 0%   -6.40%  (p=0.000 n=10+10)

name         old allocs/op  new allocs/op  delta
Readdirname      34.0 ± 0%      30.0 ± 0%  -11.76%  (p=0.000 n=10+10)
Readdir          33.0 ± 0%      29.0 ± 0%  -12.12%  (p=0.000 n=10+10)

on my Windows XP

name           old time/op    new time/op    delta
Readdirname-2    85.5µs ± 0%    84.0µs ± 0%   -1.83%  (p=0.000 n=10+10)
Readdir-2        84.6µs ± 0%    83.5µs ± 0%   -1.31%  (p=0.000 n=10+9)

name           old alloc/op   new alloc/op   delta
Readdirname-2    6.52kB ± 0%    5.66kB ± 0%  -13.25%  (p=0.000 n=10+10)
Readdir-2        6.39kB ± 0%    5.53kB ± 0%  -13.52%  (p=0.000 n=10+10)

name           old allocs/op  new allocs/op  delta
Readdirname-2      78.0 ± 0%      66.0 ± 0%  -15.38%  (p=0.000 n=10+10)
Readdir-2          77.0 ± 0%      65.0 ± 0%  -15.58%  (p=0.000 n=10+10)

Change-Id: I5d698eca86b8e94a46b6cfbd5947898b7b3fbdbd
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      6dcaa095
    • ltnwgl's avatar
      container/heap: optimization when selecting smaller child · f5352a77
      ltnwgl authored 
      In down(), if two children are equal, we can choose either one.
Inspired by https://codereview.appspot.com/6613064/

Change-Id: Iaad4ca5e2f5111bf3abb87f606584e7d274c620b
Reviewed-on: https://go-review.googlesource.com/38612
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: 's avatarRobert Griesemer <gri@golang.org>
      f5352a77
    • Rob Phoenix's avatar
      net: add examples for IPv4, ParseCIDR & IPv4Mask · 716761b8
      Rob Phoenix authored 
      Further examples to support the net package.

See issue #5757

Change-Id: I839fd97a468c8d9195e8f4a0ee886ba50ca3f382
Reviewed-on: https://go-review.googlesource.com/42912Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
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      716761b8
  7. 08 May, 2017 2 commits
    • Robert Griesemer's avatar
      cmd/compile: better errors for float constants with large exponents · bcf2d74c
      Robert Griesemer authored 
      Also: Removed misleading comment.

Fixes #20232.

Change-Id: I0b141b1360ac53267b7ebfcec7a2e2a238f3f46c
Reviewed-on: https://go-review.googlesource.com/42930
Run-TryBot: Robert Griesemer <gri@golang.org>
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Reviewed-by: 's avatarMatthew Dempsky <mdempsky@google.com>
      bcf2d74c
    • Bill O'Farrell's avatar
      math: use SIMD to accelerate additional scalar math functions on s390x · 88672de7
      Bill O'Farrell authored 
      As necessary, math functions were structured to use stubs, so that they can
be accelerated with assembly on any platform.

Technique used was minimax polynomial approximation using tables of
polynomial coefficients, with argument range reduction.

Benchmark         New     Old     Speedup
BenchmarkAcos     12.2    47.5    3.89
BenchmarkAcosh    18.5    56.2    3.04
BenchmarkAsin     13.1    40.6    3.10
BenchmarkAsinh    19.4    62.8    3.24
BenchmarkAtan     10.1    23      2.28
BenchmarkAtanh    19.1    53.2    2.79
BenchmarkAtan2    16.5    33.9    2.05
BenchmarkCbrt     14.8    58      3.92
BenchmarkErf      10.8    20.1    1.86
BenchmarkErfc     11.2    23.5    2.10
BenchmarkExp      8.77    53.8    6.13
BenchmarkExpm1    10.1    38.3    3.79
BenchmarkLog      13.1    40.1    3.06
BenchmarkLog1p    12.7    38.3    3.02
BenchmarkPowInt   31.7    40.5    1.28
BenchmarkPowFrac  33.1    141     4.26
BenchmarkTan      11.5    30      2.61

Accuracy was tested against a high precision
reference function to determine maximum error.
Note: ulperr is error in "units in the last place"

       max
      ulperr
Acos  1.15
Acosh 1.07
Asin  2.22
Asinh 1.72
Atan  1.41
Atanh 3.00
Atan2 1.45
Cbrt  1.18
Erf   1.29
Erfc  4.82
Exp   1.00
Expm1 2.26
Log   0.94
Log1p 2.39
Tan   3.14

Pow will have 99.99% correctly rounded results with reasonable inputs
producing numeric (non Inf or NaN) results

Change-Id: I850e8cf7b70426e8b54ec49d74acd4cddc8c6cb2
Reviewed-on: https://go-review.googlesource.com/38585Reviewed-by: 's avatarMichael Munday <munday@ca.ibm.com>
Run-TryBot: Michael Munday <munday@ca.ibm.com>
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      88672de7