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  1. 17 Mar, 2017 12 commits
  3. 16 Mar, 2017 15 commits
    • Jeremy Jackins's avatar
      cmd/compile: further clarify assignment count mismatch error message · 73a44f04
      Jeremy Jackins authored 
      This is an evolution of https://go-review.googlesource.com/33616, as discussed
via email with Robert (gri):

$ cat foobar.go
package main

func main() {
        a := "foo", "bar"
}

before:
./foobar.go:4:4: assignment count mismatch: want 1 values, got 2

after:
./foobar.go:4:4: assignment count mismatch: cannot assign 2 values to 1 variables

We could likely also eliminate the "assignment count mismatch" prefix now
without losing any information, but that string is matched by a number of
tests.

Change-Id: Ie6fc8a7bbd0ebe841d53e66e5c2f49868decf761
Reviewed-on: https://go-review.googlesource.com/38313Reviewed-by: default avatarRobert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      73a44f04
    • Keith Randall's avatar
      cmd/compile: intrinsics for math/bits.{Len,LeadingZeros} · 495b1679
      Keith Randall authored 
      name              old time/op  new time/op  delta
LeadingZeros-4    2.00ns ± 0%  1.34ns ± 1%  -33.02%  (p=0.000 n=8+10)
LeadingZeros16-4  1.62ns ± 0%  1.57ns ± 0%   -3.09%  (p=0.001 n=8+9)
LeadingZeros32-4  2.14ns ± 0%  1.48ns ± 0%  -30.84%  (p=0.002 n=8+10)
LeadingZeros64-4  2.06ns ± 1%  1.33ns ± 0%  -35.08%  (p=0.000 n=8+8)

8-bit args is a special case - the Go code is really fast because
it is just a single table lookup.  So I've disabled that for now.
Intrinsics were actually slower:
LeadingZeros8-4   1.22ns ± 3%  1.58ns ± 1%  +29.56%  (p=0.000 n=10+10)

Update #18616

Change-Id: Ia9c289b9ba59c583ea64060470315fd637e814cf
Reviewed-on: https://go-review.googlesource.com/38311
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarRobert Griesemer <gri@golang.org>
      495b1679
    • Steve Francia's avatar
      doc: reorganize the contribution guidelines into a guide · 5f3e7aa7
      Steve Francia authored 
      Updates #17802

Change-Id: I65ea0f4cde973604c04051e7eb25d12e4facecd3
Reviewed-on: https://go-review.googlesource.com/36626Reviewed-by: default avatarIan Lance Taylor <iant@golang.org>
Reviewed-by: default avatarChris Broadfoot <cbro@golang.org>
      5f3e7aa7
    • Aliaksandr Valialkin's avatar
      strconv: optimize formatting for small decimal ints · bc8b9b23
      Aliaksandr Valialkin authored 
      Avoid memory allocations by returning pre-calculated strings
for decimal ints in the range 0..99.

Benchmark results:

name              old time/op    new time/op    delta
FormatInt-4         2.45µs ± 1%    2.40µs ± 1%    -1.86%  (p=0.000 n=8+9)
AppendInt-4         1.67µs ± 1%    1.65µs ± 0%    -0.92%  (p=0.000 n=10+10)
FormatUint-4         676ns ± 3%     669ns ± 1%      ~     (p=0.146 n=10+10)
AppendUint-4         467ns ± 2%     474ns ± 0%    +1.58%  (p=0.000 n=10+10)
FormatIntSmall-4    29.6ns ± 2%     3.3ns ± 0%   -88.98%  (p=0.000 n=10+9)
AppendIntSmall-4    16.0ns ± 1%     8.5ns ± 0%   -46.98%  (p=0.000 n=10+9)

name              old alloc/op   new alloc/op   delta
FormatInt-4           576B ± 0%      576B ± 0%      ~     (all equal)
AppendInt-4          0.00B          0.00B           ~     (all equal)
FormatUint-4          224B ± 0%      224B ± 0%      ~     (all equal)
AppendUint-4         0.00B          0.00B           ~     (all equal)
FormatIntSmall-4     2.00B ± 0%     0.00B       -100.00%  (p=0.000 n=10+10)
AppendIntSmall-4     0.00B          0.00B           ~     (all equal)

name              old allocs/op  new allocs/op  delta
FormatInt-4           37.0 ± 0%      35.0 ± 0%    -5.41%  (p=0.000 n=10+10)
AppendInt-4           0.00           0.00           ~     (all equal)
FormatUint-4          6.00 ± 0%      6.00 ± 0%      ~     (all equal)
AppendUint-4          0.00           0.00           ~     (all equal)
FormatIntSmall-4      1.00 ± 0%      0.00       -100.00%  (p=0.000 n=10+10)
AppendIntSmall-4      0.00           0.00           ~     (all equal)

Fixes #19445

Change-Id: Ib1f8922f2e0b13743c847ee9e703d1dab77f705c
Reviewed-on: https://go-review.googlesource.com/37963Reviewed-by: default avatarRobert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      bc8b9b23
    • Keith Randall's avatar
      cmd/compile: intrinsify math/bits.ReverseBytes · dd9892e3
      Keith Randall authored 
      Update #18616

Change-Id: I0c2d643cbbeb131b4c9b12194697afa4af48e1d2
Reviewed-on: https://go-review.googlesource.com/38166
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarRobert Griesemer <gri@golang.org>
      dd9892e3
    • Cherry Zhang's avatar
      cmd/compile: fix MIPS Zero lower rule · 793e4ec3
      Cherry Zhang authored 
      A copy-paste error in CL 38150. Fix build.

Change-Id: Ib2afc83564ebe7dab934d45522803e1a191dea18
Reviewed-on: https://go-review.googlesource.com/38292
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: default avatarKeith Randall <khr@golang.org>
      793e4ec3
    • Matthew Dempsky's avatar
      cmd/compile/internal/syntax: track column position at function end · f37ee0f3
      Matthew Dempsky authored 
      Fixes #19576.

Change-Id: I11034fb08e989f6eb7d54bde873b92804223598d
Reviewed-on: https://go-review.googlesource.com/38291
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: default avatarRobert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      f37ee0f3
    • Cherry Zhang's avatar
      cmd/compile: use type information in Aux for Store size · c8f38b33
      Cherry Zhang authored 
      Remove size AuxInt in Store, and alignment in Move/Zero. We still
pass size AuxInt to Move/Zero, as it is used for partial Move/Zero
lowering (e.g. cmd/compile/internal/ssa/gen/386.rules:288).
SizeAndAlign is gone.

Passes "toolstash -cmp" on std.

Change-Id: I1ca34652b65dd30de886940e789fcf41d521475d
Reviewed-on: https://go-review.googlesource.com/38150
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarKeith Randall <khr@golang.org>
      c8f38b33
    • Cherry Zhang's avatar
      cmd/compile: add a test for writebarrier pass with single-block loop · d75925d6
      Cherry Zhang authored 
      The old writebarrier implementation fails to handle single-block
loop where a memory Phi value depends on the write barrier store
in the same block. The new implementation (CL 36834) doesn't have
this problem. Add a test to ensure it.

Fix #19067.

Change-Id: Iab13c6817edc12be8a048d18699b4450fa7ed712
Reviewed-on: https://go-review.googlesource.com/36940Reviewed-by: default avatarDavid Chase <drchase@google.com>
      d75925d6
    • Cherry Zhang's avatar
      cmd/compile: clean up SSA-building code · 1b853006
      Cherry Zhang authored 
      Now that the write barrier insertion is moved to SSA, the SSA
building code can be simplified.

Updates #17583.

Change-Id: I5cacc034b11aa90b0abe6f8dd97e4e3994e2bc25
Reviewed-on: https://go-review.googlesource.com/36840
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarKeith Randall <khr@golang.org>
      1b853006
    • Cherry Zhang's avatar
      cmd/compile: move write barrier insertion to SSA · 9ebf3d51
      Cherry Zhang authored 
      When the compiler insert write barriers, the frontend makes
conservative decisions at an early stage. This sometimes have
false positives because of the lack of information, for example,
writes on stack. SSA's writebarrier pass identifies writes on
stack and eliminates write barriers for them.

This CL moves write barrier insertion into SSA. The frontend no
longer makes decisions about write barriers, and simply does
normal assignments and emits normal Store ops when building SSA.
SSA writebarrier pass inserts write barrier for Stores when needed.
There, it has better information about the store because Phi and
Copy propagation are done at that time.

This CL only changes StoreWB to Store in gc/ssa.go. A followup CL
simplifies SSA building code.

Updates #17583.

Change-Id: I4592d9bc0067503befc169c50b4e6f4765673bec
Reviewed-on: https://go-review.googlesource.com/36839
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarKeith Randall <khr@golang.org>
      9ebf3d51
    • Cherry Zhang's avatar
      cmd/compile: pass types on SSA Store/Move/Zero ops · 211c8c9f
      Cherry Zhang authored 
      For SSA Store/Move/Zero ops, attach the type of the value being
stored to the op as the Aux field. This type will be used for
write barrier insertion (in a followup CL). Since SSA passes
do not accurately propagate types of values (because of type
casting), we can't simply use type of the store's arguments
for write barrier insertion.

Passes "toolstash -cmp" on std.

Updates #17583.

Change-Id: I051d5e5c482931640d1d7d879b2a6bb91f2e0056
Reviewed-on: https://go-review.googlesource.com/36838
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarKeith Randall <khr@golang.org>
      211c8c9f
    • Daniel Martí's avatar
      runtime: remove unused g parameter · 77b09b8b
      Daniel Martí authored 
      Found by github.com/mvdan/unparam.

Change-Id: I20145440ff1bcd27fcf15a740354c52f313e536c
Reviewed-on: https://go-review.googlesource.com/37894
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarAustin Clements <austin@google.com>
      77b09b8b
    • Carlos Eduardo Seo's avatar
      runtime: improve IndexByte for ppc64x · d60166d5
      Carlos Eduardo Seo authored 
      This change adds a better implementation of IndexByte for ppc64x.

Improvement for bytes·IndexByte:

benchmark                             old ns/op     new ns/op     delta
BenchmarkIndexByte/10-16              12.5          8.48          -32.16%
BenchmarkIndexByte/32-16              34.4          9.85          -71.37%
BenchmarkIndexByte/4K-16              3089          217           -92.98%
BenchmarkIndexByte/4M-16              3154810       207051        -93.44%
BenchmarkIndexByte/64M-16             50564811      5579093       -88.97%

benchmark                             old MB/s     new MB/s     speedup
BenchmarkIndexByte/10-16              800.41       1179.64      1.47x
BenchmarkIndexByte/32-16              930.60       3249.10      3.49x
BenchmarkIndexByte/4K-16              1325.71      18832.53     14.21x
BenchmarkIndexByte/4M-16              1329.49      20257.29     15.24x
BenchmarkIndexByte/64M-16             1327.19      12028.63     9.06x

Improvement for strings·IndexByte:

benchmark                             old ns/op     new ns/op     delta
BenchmarkIndexByte-16                 25.9          7.69          -70.31%

Fixes #19030

Change-Id: Ifb82bbb3d643ec44b98eaa2d08a07f47e5c2fd11
Reviewed-on: https://go-review.googlesource.com/37670
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarLynn Boger <laboger@linux.vnet.ibm.com>
      d60166d5
    • Keith Randall's avatar
      cmd/compile: intrinsics for math/bits.TrailingZerosX · d5dc4905
      Keith Randall authored 
      Implement math/bits.TrailingZerosX using intrinsics.

Generally reorganize the intrinsic spec a bit.
The instrinsics data structure is now built at init time.
This will make doing the other functions in math/bits easier.

Update sys.CtzX to return int instead of uint{64,32} so it
matches math/bits.TrailingZerosX.

Improve the intrinsics a bit for amd64.  We don't need the CMOV
for <64 bit versions.

Update #18616

Change-Id: Ic1c5339c943f961d830ae56f12674d7b29d4ff39
Reviewed-on: https://go-review.googlesource.com/38155
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarRobert Griesemer <gri@golang.org>
      d5dc4905
  5. 15 Mar, 2017 10 commits
    • Martin Möhrmann's avatar
      runtime: make complex division c99 compatible · 16200c73
      Martin Möhrmann authored 
      - changes tests to check that the real and imaginary part of the go complex
  division result is equal to the result gcc produces for c99
- changes complex division code to satisfy new complex division test
- adds float functions isNan, isFinite, isInf, abs and copysign
  in the runtime package

Fixes #14644.

name                   old time/op  new time/op  delta
Complex128DivNormal-4  21.8ns ± 6%  13.9ns ± 6%  -36.37%  (p=0.000 n=20+20)
Complex128DivNisNaN-4  14.1ns ± 1%  15.0ns ± 1%   +5.86%  (p=0.000 n=20+19)
Complex128DivDisNaN-4  12.5ns ± 1%  16.7ns ± 1%  +33.79%  (p=0.000 n=19+20)
Complex128DivNisInf-4  10.1ns ± 1%  13.0ns ± 1%  +28.25%  (p=0.000 n=20+19)
Complex128DivDisInf-4  11.0ns ± 1%  20.9ns ± 1%  +90.69%  (p=0.000 n=16+19)
ComplexAlgMap-4        86.7ns ± 1%  86.8ns ± 2%     ~     (p=0.804 n=20+20)

Change-Id: I261f3b4a81f6cc858bc7ff48f6fd1b39c300abf0
Reviewed-on: https://go-review.googlesource.com/37441Reviewed-by: default avatarRobert Griesemer <gri@golang.org>
      16200c73
    • Austin Clements's avatar
      runtime: print user stack on other threads during GOTRACBEACK=crash · 4b8f41da
      Austin Clements authored 
      Currently, when printing tracebacks of other threads during
GOTRACEBACK=crash, if the thread is on the system stack we print only
the header for the user goroutine and fail to print its stack. This
happens because we passed the g0 to traceback instead of curg. The g0
never has anything set in its gobuf, so traceback doesn't print
anything.

Fix this by passing _g_.m.curg to traceback instead of the g0.

Fixes #19494.

Change-Id: Idfabf94d6a725e9cdf94a3923dead6455ef3b217
Reviewed-on: https://go-review.googlesource.com/38012
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarIan Lance Taylor <iant@golang.org>
      4b8f41da
    • Austin Clements's avatar
      runtime: make GOTRACEBACK=crash crash promptly in cgo binaries · f2e87158
      Austin Clements authored 
      GOTRACEBACK=crash works by bouncing a SIGQUIT around the process
sched.mcount times. However, sched.mcount includes the extra Ms
allocated by oneNewExtraM for cgo callbacks. Hence, if there are any
extra Ms that don't have real OS threads, we'll try to send SIGQUIT
more times than there are threads to catch it. Since nothing will
catch these extra signals, we'll fall back to blocking for five
seconds before aborting the process.

Avoid this five second delay by subtracting out the number of extra Ms
when sending SIGQUITs.

Of course, in a cgo binary, it's still possible for the SIGQUIT to go
to a cgo thread and cause some other failure mode. This does not fix
that.

Change-Id: I4fbf3c52dd721812796c4c1dcb2ab4cb7026d965
Reviewed-on: https://go-review.googlesource.com/38182
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarIan Lance Taylor <iant@golang.org>
      f2e87158
    • Josh Bleecher Snyder's avatar
      cmd/compile: check labels and gotos before building SSA · c03e75e5
      Josh Bleecher Snyder authored 
      This CL introduces yet another compiler pass,
which checks for correct control flow constructs
prior to converting from AST to SSA form.

It cannot be integrated with walk, since walk rewrites
switch and select statements on the fly.

To reduce code duplication, this CL also does some
minor refactoring.

With this pass in place, the AST to SSA converter
can now stop generating SSA for any known-dead code.
This minor savings pays for the minor cost of the new pass.

Performance is almost a wash:

name       old time/op     new time/op     delta
Template       206ms ± 4%      205ms ± 4%   ~     (p=0.108 n=43+43)
Unicode       84.0ms ± 4%     84.0ms ± 4%   ~     (p=0.979 n=43+43)
GoTypes        550ms ± 3%      553ms ± 3%   ~     (p=0.065 n=40+41)
Compiler       2.57s ± 4%      2.58s ± 2%   ~     (p=0.103 n=44+41)
SSA            3.94s ± 3%      3.93s ± 2%   ~     (p=0.833 n=44+42)
Flate          126ms ± 6%      125ms ± 4%   ~     (p=0.941 n=43+39)
GoParser       147ms ± 4%      148ms ± 3%   ~     (p=0.164 n=42+39)
Reflect        359ms ± 3%      357ms ± 5%   ~     (p=0.241 n=43+44)
Tar            106ms ± 5%      106ms ± 7%   ~     (p=0.853 n=40+43)
XML            202ms ± 3%      203ms ± 3%   ~     (p=0.488 n=42+41)

name       old user-ns/op  new user-ns/op  delta
Template        240M ± 4%       239M ± 4%   ~     (p=0.844 n=42+43)
Unicode         107M ± 5%       107M ± 4%   ~     (p=0.332 n=40+43)
GoTypes         735M ± 3%       731M ± 4%   ~     (p=0.141 n=43+44)
Compiler       3.51G ± 3%      3.52G ± 3%   ~     (p=0.208 n=42+43)
SSA            5.72G ± 4%      5.72G ± 3%   ~     (p=0.928 n=44+42)
Flate           151M ± 7%       150M ± 8%   ~     (p=0.662 n=44+43)
GoParser        181M ± 5%       181M ± 4%   ~     (p=0.379 n=41+44)
Reflect         447M ± 4%       445M ± 4%   ~     (p=0.344 n=43+43)
Tar             125M ± 7%       124M ± 6%   ~     (p=0.353 n=43+43)
XML             248M ± 4%       250M ± 6%   ~     (p=0.158 n=44+44)

name       old alloc/op    new alloc/op    delta
Template      40.3MB ± 0%     40.2MB ± 0%  -0.27%  (p=0.000 n=10+10)
Unicode       30.3MB ± 0%     30.2MB ± 0%  -0.10%  (p=0.015 n=10+10)
GoTypes        114MB ± 0%      114MB ± 0%  -0.06%  (p=0.000 n=7+9)
Compiler       480MB ± 0%      481MB ± 0%  +0.07%  (p=0.000 n=10+10)
SSA            864MB ± 0%      862MB ± 0%  -0.25%  (p=0.000 n=9+10)
Flate         25.9MB ± 0%     25.9MB ± 0%    ~     (p=0.123 n=10+10)
GoParser      32.1MB ± 0%     32.1MB ± 0%    ~     (p=0.631 n=10+10)
Reflect       79.9MB ± 0%     79.6MB ± 0%  -0.39%  (p=0.000 n=10+9)
Tar           27.1MB ± 0%     27.0MB ± 0%  -0.18%  (p=0.003 n=10+10)
XML           42.6MB ± 0%     42.6MB ± 0%    ~     (p=0.143 n=10+10)

name       old allocs/op   new allocs/op   delta
Template        401k ± 0%       401k ± 1%    ~     (p=0.353 n=10+10)
Unicode         322k ± 0%       322k ± 0%    ~     (p=0.739 n=10+10)
GoTypes        1.18M ± 0%      1.18M ± 0%  +0.25%  (p=0.001 n=7+8)
Compiler       4.51M ± 0%      4.53M ± 0%  +0.37%  (p=0.000 n=10+10)
SSA            7.91M ± 0%      7.93M ± 0%  +0.20%  (p=0.000 n=9+10)
Flate           244k ± 0%       245k ± 0%    ~     (p=0.123 n=10+10)
GoParser        323k ± 1%       324k ± 1%  +0.40%  (p=0.035 n=10+10)
Reflect        1.01M ± 0%      1.02M ± 0%  +0.37%  (p=0.000 n=10+9)
Tar             258k ± 1%       258k ± 1%    ~     (p=0.661 n=10+9)
XML             403k ± 0%       405k ± 0%  +0.47%  (p=0.004 n=10+10)

Updates #15756
Updates #19250

Change-Id: I647bfbb745c35630447eb79dfcaa994b490ce942
Reviewed-on: https://go-review.googlesource.com/38159
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarMatthew Dempsky <mdempsky@google.com>
      c03e75e5
    • Josh Bleecher Snyder's avatar
      cmd/compile: ensure TESTQconst AuxInt is in range · 604455a4
      Josh Bleecher Snyder authored 
      Fixes #19555

Change-Id: I7aa0551a90f6bb630c0ba721f3525a8a9cf793fd
Reviewed-on: https://go-review.googlesource.com/38164
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarKeith Randall <khr@golang.org>
      604455a4
    • Bryan C. Mills's avatar
      archive/zip: parallelize benchmarks · d0a045da
      Bryan C. Mills authored 
      Add subbenchmarks for BenchmarkZip64Test with different sizes to tease
apart construction costs vs. steady-state throughput.

Results remain comparable with the non-parallel version with -cpu=1:

benchmark                           old ns/op     new ns/op     delta
BenchmarkCompressedZipGarbage       26832835      27506953      +2.51%
BenchmarkCompressedZipGarbage-6     27172377      4321534       -84.10%
BenchmarkZip64Test                  196758732     197765510     +0.51%
BenchmarkZip64Test-6                193850605     192625458     -0.63%

benchmark                           old allocs     new allocs     delta
BenchmarkCompressedZipGarbage       44             44             +0.00%
BenchmarkCompressedZipGarbage-6     44             44             +0.00%

benchmark                           old bytes     new bytes     delta
BenchmarkCompressedZipGarbage       5592          5664          +1.29%
BenchmarkCompressedZipGarbage-6     5592          21946         +292.45%

updates #18177

Change-Id: Icfa359d9b1a8df5e085dacc07d2b9221b284764c
Reviewed-on: https://go-review.googlesource.com/36719Reviewed-by: default avatarBrad Fitzpatrick <bradfitz@golang.org>
      d0a045da
    • Cherry Zhang's avatar
      cmd/link: on PPC64, put plt stubs at beginning of Textp · 15b37655
      Cherry Zhang authored 
      Put call stubs at the beginning (instead of the end). So the
trampoline pass knows the addresses of the stubs, and it can
insert trampolines when necessary.

Fixes #19425.

Change-Id: I1e06529ef837a6130df58917315610d45a6819ca
Reviewed-on: https://go-review.googlesource.com/38131
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarLynn Boger <laboger@linux.vnet.ibm.com>
      15b37655
    • Josh Bleecher Snyder's avatar
      cmd/compile: define roles for ssa.Func, ssa.Config, and ssa.Cache · 43afcb5c
      Josh Bleecher Snyder authored 
      The line between ssa.Func and ssa.Config has blurred.
Concurrent compilation in the backend will require more precision.
This CL lays out an (aspirational) organization.
The implementation will come in follow-up CLs,
once the organization is settled.

ssa.Config holds basic compiler configuration,
mostly arch-specific information.
It is configured once, early on, and is readonly,
so it is safe for concurrent use.

ssa.Func is a single-shot object used for
compiling a single Func. It is not concurrency-safe
and not re-usable.

ssa.Cache is a multi-use object used to avoid
expensive allocations during compilation.
Each ssa.Func is given an ssa.Cache to use.
ssa.Cache is not concurrency-safe.

Change-Id: Id02809b6f3541541cac6c27bbb598834888ce1cc
Reviewed-on: https://go-review.googlesource.com/38160Reviewed-by: default avatarKeith Randall <khr@golang.org>
      43afcb5c
    • David Chase's avatar
      cmd/compile: put spills in better places · 886e9e60
      David Chase authored 
      Previously we always issued a spill right after the op
that was being spilled.  This CL pushes spills father away
from the generator, hopefully pushing them into unlikely branches.
For example:

  x = ...
  if unlikely {
    call ...
  }
  ... use x ...

Used to compile to

  x = ...
  spill x
  if unlikely {
    call ...
    restore x
  }

It now compiles to

  x = ...
  if unlikely {
    spill x
    call ...
    restore x
  }

This is particularly useful for code which appends, as the only
call is an unlikely call to growslice.  It also helps for the
spills needed around write barrier calls.

The basic algorithm is walk down the dominator tree following a
path where the block still dominates all of the restores.  We're
looking for a block that:
 1) dominates all restores
 2) has the value being spilled in a register
 3) has a loop depth no deeper than the value being spilled

The walking-down code is iterative.  I was forced to limit it to
searching 100 blocks so it doesn't become O(n^2).  Maybe one day
we'll find a better way.

I had to delete most of David's code which pushed spills out of loops.
I suspect this CL subsumes most of the cases that his code handled.

Generally positive performance improvements, but hard to tell for sure
with all the noise.  (compilebench times are unchanged.)

name                      old time/op    new time/op    delta
BinaryTree17-12              2.91s ±15%     2.80s ±12%    ~     (p=0.063 n=10+10)
Fannkuch11-12                3.47s ± 0%     3.30s ± 4%  -4.91%   (p=0.000 n=9+10)
FmtFprintfEmpty-12          48.0ns ± 1%    47.4ns ± 1%  -1.32%    (p=0.002 n=9+9)
FmtFprintfString-12         85.6ns ±11%    79.4ns ± 3%  -7.27%  (p=0.005 n=10+10)
FmtFprintfInt-12            91.8ns ±10%    85.9ns ± 4%    ~      (p=0.203 n=10+9)
FmtFprintfIntInt-12          135ns ±13%     127ns ± 1%  -5.72%   (p=0.025 n=10+9)
FmtFprintfPrefixedInt-12     167ns ± 1%     168ns ± 2%    ~      (p=0.580 n=9+10)
FmtFprintfFloat-12           249ns ±11%     230ns ± 1%  -7.32%  (p=0.000 n=10+10)
FmtManyArgs-12               504ns ± 7%     506ns ± 1%    ~       (p=0.198 n=9+9)
GobDecode-12                6.95ms ± 1%    7.04ms ± 1%  +1.37%  (p=0.001 n=10+10)
GobEncode-12                6.32ms ±13%    6.04ms ± 1%    ~     (p=0.063 n=10+10)
Gzip-12                      233ms ± 1%     235ms ± 0%  +1.01%   (p=0.000 n=10+9)
Gunzip-12                   40.1ms ± 1%    39.6ms ± 0%  -1.12%   (p=0.000 n=10+8)
HTTPClientServer-12          227µs ± 9%     221µs ± 5%    ~       (p=0.114 n=9+8)
JSONEncode-12               16.1ms ± 2%    15.8ms ± 1%  -2.09%    (p=0.002 n=9+8)
JSONDecode-12               61.8ms ±11%    57.9ms ± 1%  -6.30%   (p=0.000 n=10+9)
Mandelbrot200-12            4.30ms ± 3%    4.28ms ± 1%    ~      (p=0.203 n=10+8)
GoParse-12                  3.18ms ± 2%    3.18ms ± 2%    ~     (p=0.579 n=10+10)
RegexpMatchEasy0_32-12      76.7ns ± 1%    77.5ns ± 1%  +0.92%    (p=0.002 n=9+8)
RegexpMatchEasy0_1K-12       239ns ± 3%     239ns ± 1%    ~     (p=0.204 n=10+10)
RegexpMatchEasy1_32-12      71.4ns ± 1%    70.6ns ± 0%  -1.15%   (p=0.000 n=10+9)
RegexpMatchEasy1_1K-12       383ns ± 2%     390ns ±10%    ~       (p=0.181 n=8+9)
RegexpMatchMedium_32-12      114ns ± 0%     113ns ± 1%  -0.88%    (p=0.000 n=9+8)
RegexpMatchMedium_1K-12     36.3µs ± 1%    36.8µs ± 1%  +1.59%   (p=0.000 n=10+8)
RegexpMatchHard_32-12       1.90µs ± 1%    1.90µs ± 1%    ~     (p=0.341 n=10+10)
RegexpMatchHard_1K-12       59.4µs ±11%    57.8µs ± 1%    ~      (p=0.968 n=10+9)
Revcomp-12                   461ms ± 1%     462ms ± 1%    ~       (p=1.000 n=9+9)
Template-12                 67.5ms ± 1%    66.3ms ± 1%  -1.77%   (p=0.000 n=10+8)
TimeParse-12                 314ns ± 3%     309ns ± 0%  -1.56%    (p=0.000 n=9+8)
TimeFormat-12                340ns ± 2%     331ns ± 1%  -2.79%  (p=0.000 n=10+10)

The go binary is 0.2% larger.  Not really sure why the size
would change.

Change-Id: Ia5116e53a3aeb025ef350ffc51c14ae5cc17871c
Reviewed-on: https://go-review.googlesource.com/34822Reviewed-by: default avatarDavid Chase <drchase@google.com>
      886e9e60
    • Philip Hofer's avatar
      cmd/compile/internal/gc: mark generated wrappers as DUPOK · 710f4d3e
      Philip Hofer authored 
      Interface wrapper functions now get compiled eagerly in some cases.
Consequently, they may be present in multiple translation units.
Mark them as DUPOK, just like closures.

Fixes #19548
Fixes #19550

Change-Id: Ibe74adb5a62dbf6447db37fde22dcbb3479969ef
Reviewed-on: https://go-review.googlesource.com/38156Reviewed-by: default avatarDavid Chase <drchase@google.com>
      710f4d3e
  7. 14 Mar, 2017 3 commits
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