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29301 Commits

Author SHA1 Message Date
Kevin Burke
ed8f207940 encoding/json: Use a lookup table for safe characters
The previous check for characters inside of a JSON string that needed
to be escaped performed seven different boolean comparisons before
determining that a ASCII character did not need to be escaped. Most
characters do not need to be escaped, so this check can be done in a
more performant way.

Use the same strategy as the unicode package for precomputing a range
of characters that need to be escaped, then do a single lookup into a
character array to determine whether the character needs escaping.

On an AWS c4.large node:

$ benchstat benchmarks/master-bench benchmarks/json-table-bench
name                   old time/op    new time/op     delta
CodeEncoder-2            19.0ms ± 0%     15.5ms ± 1%  -18.16%        (p=0.000 n=19+20)
CodeMarshal-2            20.1ms ± 1%     16.8ms ± 2%  -16.35%        (p=0.000 n=20+21)
CodeDecoder-2            49.3ms ± 1%     49.5ms ± 2%     ~           (p=0.498 n=16+20)
DecoderStream-2           416ns ± 0%      416ns ± 1%     ~           (p=0.978 n=19+19)
CodeUnmarshal-2          51.0ms ± 1%     50.9ms ± 1%     ~           (p=0.490 n=19+17)
CodeUnmarshalReuse-2     48.5ms ± 2%     48.5ms ± 2%     ~           (p=0.989 n=20+19)
UnmarshalString-2         541ns ± 1%      532ns ± 1%   -1.75%        (p=0.000 n=20+21)
UnmarshalFloat64-2        485ns ± 1%      481ns ± 1%   -0.92%        (p=0.000 n=20+21)
UnmarshalInt64-2          429ns ± 1%      427ns ± 1%   -0.49%        (p=0.000 n=19+20)
Issue10335-2              631ns ± 1%      619ns ± 1%   -1.84%        (p=0.000 n=20+20)
NumberIsValid-2          19.1ns ± 0%     19.1ns ± 0%     ~     (all samples are equal)
NumberIsValidRegexp-2     689ns ± 1%      690ns ± 0%     ~           (p=0.150 n=20+20)
SkipValue-2              14.0ms ± 0%     14.0ms ± 0%   -0.05%        (p=0.000 n=18+18)
EncoderEncode-2           525ns ± 2%      512ns ± 1%   -2.33%        (p=0.000 n=20+18)

name                   old speed      new speed       delta
CodeEncoder-2           102MB/s ± 0%    125MB/s ± 1%  +22.20%        (p=0.000 n=19+20)
CodeMarshal-2          96.6MB/s ± 1%  115.6MB/s ± 2%  +19.56%        (p=0.000 n=20+21)
CodeDecoder-2          39.3MB/s ± 1%   39.2MB/s ± 2%     ~           (p=0.464 n=16+20)
CodeUnmarshal-2        38.1MB/s ± 1%   38.1MB/s ± 1%     ~           (p=0.525 n=19+17)
SkipValue-2             143MB/s ± 0%    143MB/s ± 0%   +0.05%        (p=0.000 n=18+18)

I also took the data set reported in #5683 (browser
telemetry data from Mozilla), added named structs for
the data set, and turned it into a proper benchmark:
https://github.com/kevinburke/jsonbench/blob/master/go/bench_test.go

The results from that test are similarly encouraging. On a 64-bit
Mac:

$ benchstat benchmarks/master-benchmark benchmarks/json-table-benchmark
name              old time/op    new time/op    delta
CodeMarshal-4       1.19ms ± 2%    1.08ms ± 2%   -9.33%  (p=0.000 n=21+17)
Unmarshal-4         3.09ms ± 3%    3.06ms ± 1%   -0.83%  (p=0.027 n=22+17)
UnmarshalReuse-4    3.04ms ± 1%    3.04ms ± 1%     ~     (p=0.169 n=20+15)

name              old speed      new speed      delta
CodeMarshal-4     80.3MB/s ± 1%  88.5MB/s ± 1%  +10.29%  (p=0.000 n=21+17)
Unmarshal-4       31.0MB/s ± 2%  31.2MB/s ± 1%   +0.83%  (p=0.025 n=22+17)

On the c4.large:

$ benchstat benchmarks/master-bench benchmarks/json-table-bench
name              old time/op    new time/op    delta
CodeMarshal-2       1.10ms ± 1%    0.98ms ± 1%  -10.12%  (p=0.000 n=20+54)
Unmarshal-2         2.82ms ± 1%    2.79ms ± 0%   -1.09%  (p=0.000 n=20+51)
UnmarshalReuse-2    2.80ms ± 0%    2.77ms ± 0%   -1.03%  (p=0.000 n=20+52)

name              old speed      new speed      delta
CodeMarshal-2     87.3MB/s ± 1%  97.1MB/s ± 1%  +11.27%  (p=0.000 n=20+54)
Unmarshal-2       33.9MB/s ± 1%  34.2MB/s ± 0%   +1.10%  (p=0.000 n=20+51)

For what it's worth, I tried other heuristics - short circuiting the
conditional for common ASCII characters, for example:

if (b >= 63 && b != 92) || (b >= 39 && b <= 59) || (rest of the conditional)

This offered a speedup around 7-9%, not as large as the submitted
change.

Change-Id: Idcf88f7b93bfcd1164cdd6a585160b7e407a0d9b
Reviewed-on: https://go-review.googlesource.com/24466
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-09-08 18:02:34 +00:00
Martin Möhrmann
2321895fe2 bytes: improve WriteRune performance
Remove the runeBytes buffer and write the utf8 encoding directly
to the internal buf byte slice.

name         old time/op   new time/op   delta
WriteRune-4   80.5µs ± 2%   57.1µs ± 2%  -29.06%  (p=0.000 n=20+20)

name         old speed     new speed     delta
WriteRune-4  153MB/s ± 2%  215MB/s ± 2%  +40.96%  (p=0.000 n=20+20)

Change-Id: Ic15f6e2d6e56a3d15c74f56159e2eae020ba73ba
Reviewed-on: https://go-review.googlesource.com/28816
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-09-08 17:15:28 +00:00
Josh Bleecher Snyder
07bcc16547 runtime: simplify getargp
Change-Id: I9ed62e8a6d8b9204c18748efd7845adabf3460b9
Reviewed-on: https://go-review.googlesource.com/28775
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-09-08 17:10:22 +00:00
Cherry Zhang
70fd814f53 cmd/compile/internal/ssa/gen: fix error message for wrong arg length
When arg length is wrong, op is not set, so it always prints
"should have 0 args".

Change-Id: If7bcb41d993919d0038d2a09e16188c79dfbd858
Reviewed-on: https://go-review.googlesource.com/28831
Reviewed-by: Keith Randall <khr@golang.org>
2016-09-08 16:28:02 +00:00
Michal Bohuslávek
bec84c728a doc: fix typo in the release notes
Change-Id: I003795d8dc2176532ee133740bf35e23a3aa3878
Reviewed-on: https://go-review.googlesource.com/28811
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-08 16:19:05 +00:00
Martin Möhrmann
252093f120 runtime: remove maxstring
Before this CL the runtime prevented printing of overlong strings with the print
function when the length of the string was determined to be corrupted.
Corruption was checked by comparing the string size against the limit
which was stored in maxstring.

However maxstring was not updated everywhere were go strings were created
e.g. for string constants during compile time. Thereby the check for maximum
string length prevented the printing of some valid strings.

The protection maxstring provided did not warrant the bookkeeping
and global synchronization needed to keep maxstring updated to the
correct limit everywhere.

Fixes #16999

Change-Id: I62cc2f4362f333f75b77f199ce1a71aac0ff7aeb
Reviewed-on: https://go-review.googlesource.com/28813
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-09-08 15:57:01 +00:00
Brad Fitzpatrick
fd975c6aa5 io/ioutil: return better error when TempDir called with non-extant dir
Fixes #14196

Change-Id: Ife7950289ac6adbcfc4d0f2fce31f20bc2657858
Reviewed-on: https://go-review.googlesource.com/28772
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-09-08 15:08:35 +00:00
Matthew Dempsky
3a59b5626d cmd/compile: remove unnecessary FuncType cloning
Since FuncTypes are represented as structs rather than linking the
parameter lists together, we no longer need to worry about duplicating
the parameter lists.

Change-Id: I3767aa3cd1cbeddfb80a6eef6b42290dc2ac14ae
Reviewed-on: https://go-review.googlesource.com/28574
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-09-08 05:38:46 +00:00
Sina Siadat
24d8f3fa4b net/http/httputil: copy header map if necessary in ReverseProxy
We were already making a copy of the map before removing
hop-by-hop headers. This commit does the same for proxied
headers mentioned in the "Connection" header.

A test is added to ensure request headers are not modified.

Updates #16875

Change-Id: I85329d212787958d5ad818915eb0538580a4653a
Reviewed-on: https://go-review.googlesource.com/28493
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-08 04:37:36 +00:00
Alberto Donizetti
b6f44923c0 go/format: add format.Node example
Updates #16360

Change-Id: I5927cffa961cd85539a3ba9606b116c5996d1096
Reviewed-on: https://go-review.googlesource.com/26696
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-08 04:12:35 +00:00
Brad Fitzpatrick
614dfe9b02 io: add test that MultiReader zeros exhausted Readers
Updates #16983
Updates #16996

Change-Id: I76390766385b2668632c95e172b2d243d7f66651
Reviewed-on: https://go-review.googlesource.com/28771
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-09-08 02:55:54 +00:00
Chris Broadfoot
9e040979bd doc: document go1.7.1
Change-Id: I4dc1ff7bfc67351a046f199dee8b7a9eadb1e524
Reviewed-on: https://go-review.googlesource.com/28693
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-07 19:07:38 +00:00
Joe Tsai
3ef0e8f823 net: remove parsing of negative decimals in IPv4 literal
https://golang.org/cl/27206 fixed the dtoi function such that
it now properly parses negative number. Ironically, this causes
several other functions that depended on dtoi to now (incorrectly)
parse negative numbers.

For example, ParseCIDR("-1.0.0.0/32") used to be rejected prior to the
above CL, but is now accepted even though it is an invalid CIDR notation.
This CL fixes that regression.

We fix this by removing the signed parsing logic entirely from dtoi.
It was introduced relatively recently in https://golang.org/cl/12447
to fix a bug where an invalid port was improperly being parsed as OK.
It seems to me that the fix in that CL to the port handling logic was
sufficient such that a change to dtoi was unnecessary.

Updates #16350

Change-Id: I414bb1aa27d0a226ebd4b05a09cb40d784691b43
Reviewed-on: https://go-review.googlesource.com/28414
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
2016-09-07 17:48:45 +00:00
Robert Griesemer
42433e27b0 cmd/compile: add format verification test
TestFormats finds potential (Printf, etc.) format strings.
If they are used in a call, the format verbs are verified
based on the matching argument type against a precomputed
table of valid formats (formatMapping, below). The table
can be used to automatically rewrite format strings with
the -u flag.

Run as: go test -run Formats [-u]

A formatMapping based on the existing formats is printed
when the test is run in verbose mode (-v flag). The table
needs to be updated whenever a new (type, format) combination
is found and the format verb is not 'v' (as in "%v").

Known bugs:
- indexed format strings ("%[2]s", etc.) are not suported
  (the test will fail)
- format strings that are not simple string literals cannot
  be updated automatically
  (the test will fail with respective warnings)

Change-Id: I1ca5bb6421d57ac78a00f1a80b9547a72837adc9
Reviewed-on: https://go-review.googlesource.com/28419
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-09-07 17:41:51 +00:00
Ilya Tocar
0cff219c12 strings: use AVX2 for Index if available
IndexHard4-4      1.50ms ± 2%  0.71ms ± 0%  -52.36%  (p=0.000 n=20+19)

This also fixes a bug, that caused a string of length 16 to use
two 8-byte comparisons instead of one 16-byte. And adds a test for
cases when partial_match fails.

Change-Id: I1ee8fc4e068bb36c95c45de78f067c822c0d9df0
Reviewed-on: https://go-review.googlesource.com/22551
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-09-07 10:43:13 +00:00
Keith Randall
83c73a85db cmd/compile: ignore contentEscapes for marking nodes as escaping
Redo of CL 28575 with fixed test.
We're in a pre-KeepAlive world for a bit yet, the old tests
were in a client which was in a post-KeepAlive world.

Change-Id: I114fd630339d761ab3306d1d99718d3cb973678d
Reviewed-on: https://go-review.googlesource.com/28582
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-07 06:59:22 +00:00
Brad Fitzpatrick
ca264cdc62 syscall: avoid convT2I allocs for common Windows error values
This is was already done for Unix in https://golang.org/cl/6701 +
https://golang.org/cl/8192. Do it for Windows also.

Fixes #16988

Change-Id: Ia7832b0d0d48566b0cd205652b85130df529592e
Reviewed-on: https://go-review.googlesource.com/28484
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-09-07 04:46:25 +00:00
Robert Griesemer
238274df4e go/constant: document that Value.String and ExactString return quoted strings
This has always been the case but it was not obvious from the documentation.
The reason for the quoting is that String() may return an abbreviated string,
starting with double-quote (") but ending in ... (w/o a quote). The missing
quote indicates the abbreviation (in contrast to a string ending in ...").

constant.StringVal can be used to obtain the unquoted string of a String Value.

Change-Id: Id0ba45b6ff62b3e024386ba8d907d6b3a4fcb6d7
Reviewed-on: https://go-review.googlesource.com/28576
Reviewed-by: Alan Donovan <adonovan@google.com>
2016-09-07 04:28:35 +00:00
Brad Fitzpatrick
bdb3b790c6 Revert of cmd/compile: ignore contentEscapes for marking nodes as escaping
Reason for revert: broke the build due to cherrypick;
relies on an unsubmitted parent CL.

Original issue's description:
> cmd/compile: ignore contentEscapes for marking nodes as escaping
> 
> We can still stack allocate and VarKill nodes which don't
> escape but their content does.
> 
> Fixes #16996
> 
> Change-Id: If8aa0fcf2c327b4cb880a3d5af8d213289e6f6bf
> Reviewed-on: https://go-review.googlesource.com/28575
> Run-TryBot: Keith Randall <khr@golang.org>
> TryBot-Result: Gobot Gobot <gobot@golang.org>
> Reviewed-by: David Chase <drchase@google.com>
> 

Change-Id: Ie1a325209de14d70af6acb2d78269b7a0450da7a
Reviewed-on: https://go-review.googlesource.com/28578
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-07 03:23:44 +00:00
Keith Randall
923a74ce77 cmd/compile: ignore contentEscapes for marking nodes as escaping
We can still stack allocate and VarKill nodes which don't
escape but their content does.

Fixes #16996

Change-Id: If8aa0fcf2c327b4cb880a3d5af8d213289e6f6bf
Reviewed-on: https://go-review.googlesource.com/28575
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-09-07 02:07:03 +00:00
David Chase
a6edffb286 cmd/compile: add BVC/BVS to branch ops in ppc64/prog.go
Includes test case shown to fail with unpatched compiler.

Fixes #17005.

Change-Id: I49b7b1a3f02736d85846a2588018b73f68d50320
Reviewed-on: https://go-review.googlesource.com/28573
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
2016-09-07 01:30:34 +00:00
Hiroshi Ioka
8737dac1f2 strings: make IndexRune faster
re-implement IndexRune by Index which is well optimized to get
performance gain.

name                   old time/op  new time/op  delta
IndexRune-4            30.2ns ± 1%  28.3ns ± 1%   -6.22%  (p=0.000 n=20+19)
IndexRuneLongString-4   156ns ± 1%    49ns ± 1%  -68.72%  (p=0.000 n=19+19)
IndexRuneFastPath-4    10.6ns ± 2%  10.0ns ± 1%   -6.30%  (p=0.000 n=18+18)

Change-Id: Ie663b8f7860ca51892dd4be182fca3caa5f8ae61
Reviewed-on: https://go-review.googlesource.com/28546
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-09-07 01:03:10 +00:00
Brad Fitzpatrick
a4bdd64555 syscall: use MNT_NOWAIT in TestGetfsstat
Fixes test failure when VMWare's shared folder filesystem is present.

MNT_NOWAIT is what the mount(8) command does.

Fixes #16937

Change-Id: Id436185f544b7069db46c8716d6a0bf580b31da0
Reviewed-on: https://go-review.googlesource.com/28550
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-09-07 00:58:19 +00:00
Josh Bleecher Snyder
9a243303b8 cmd/compile: omit some temp panicdivide calls
When the divisor is known to be a constant
non-zero, don't insert panicdivide calls
that will just be eliminated later.

The main benefit here is readability of the SSA
form for compiler developers.

Change-Id: Icb7d07fc996941fbaff84524ac3e4b53d8e75fda
Reviewed-on: https://go-review.googlesource.com/28530
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-09-07 00:30:10 +00:00
Hiroshi Ioka
e10286aeda bytes: make IndexRune faster
re-implement IndexRune by IndexByte and Index which are well optimized
to get performance gain.

name                  old time/op   new time/op     delta
IndexRune/10-4         53.2ns ± 1%     29.1ns ± 1%    -45.32%  (p=0.008 n=5+5)
IndexRune/32-4          191ns ± 1%       27ns ± 1%    -85.75%  (p=0.008 n=5+5)
IndexRune/4K-4         23.5µs ± 1%      1.0µs ± 1%    -95.77%  (p=0.008 n=5+5)
IndexRune/4M-4         23.8ms ± 0%      1.0ms ± 2%    -95.90%  (p=0.008 n=5+5)
IndexRune/64M-4         384ms ± 1%       15ms ± 1%    -95.98%  (p=0.008 n=5+5)
IndexRuneASCII/10-4    61.5ns ± 0%     10.3ns ± 4%    -83.17%  (p=0.008 n=5+5)
IndexRuneASCII/32-4     203ns ± 0%       11ns ± 5%    -94.68%  (p=0.008 n=5+5)
IndexRuneASCII/4K-4    23.4µs ± 0%      0.3µs ± 2%    -98.60%  (p=0.008 n=5+5)
IndexRuneASCII/4M-4    24.0ms ± 1%      0.3ms ± 1%    -98.60%  (p=0.008 n=5+5)
IndexRuneASCII/64M-4    386ms ± 2%        6ms ± 1%    -98.57%  (p=0.008 n=5+5)

name                  old speed     new speed       delta
IndexRune/10-4        188MB/s ± 1%    344MB/s ± 1%    +82.91%  (p=0.008 n=5+5)
IndexRune/32-4        167MB/s ± 0%   1175MB/s ± 1%   +603.52%  (p=0.008 n=5+5)
IndexRune/4K-4        174MB/s ± 1%   4117MB/s ± 1%  +2262.71%  (p=0.008 n=5+5)
IndexRune/4M-4        176MB/s ± 0%   4299MB/s ± 2%  +2340.46%  (p=0.008 n=5+5)
IndexRune/64M-4       175MB/s ± 1%   4354MB/s ± 1%  +2388.57%  (p=0.008 n=5+5)
IndexRuneASCII/10-4   163MB/s ± 0%    968MB/s ± 4%   +494.66%  (p=0.008 n=5+5)
IndexRuneASCII/32-4   157MB/s ± 0%   2974MB/s ± 4%  +1788.59%  (p=0.008 n=5+5)
IndexRuneASCII/4K-4   175MB/s ± 0%  12481MB/s ± 2%  +7027.71%  (p=0.008 n=5+5)
IndexRuneASCII/4M-4   175MB/s ± 1%  12510MB/s ± 1%  +7061.15%  (p=0.008 n=5+5)
IndexRuneASCII/64M-4  174MB/s ± 2%  12143MB/s ± 1%  +6881.70%  (p=0.008 n=5+5)

Change-Id: I0632eadb83937c2a9daa7f0ce79df1dee64f992e
Reviewed-on: https://go-review.googlesource.com/28537
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-06 23:32:57 +00:00
Austin Clements
8259cf3c72 runtime/debug: enable TestFreeOSMemory on all arches
TestFreeOSMemory was disabled on many arches because of issue #9993.
Since that's been fixed, enable the test everywhere.

Change-Id: I298c38c3e04128d9c8a1f558980939d5699bea03
Reviewed-on: https://go-review.googlesource.com/27403
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
2016-09-06 21:05:58 +00:00
Austin Clements
1b9499b069 syscall: make Getpagesize return page size from runtime
syscall.Getpagesize currently returns hard-coded page sizes on all
architectures (some of which are probably always wrong, and some of
which are definitely not always right). The runtime now has this
information, queried from the OS during runtime init, so make
syscall.Getpagesize return the page size that the runtime knows.

Updates #10180.

Change-Id: I4daa6fbc61a2193eb8fa9e7878960971205ac346
Reviewed-on: https://go-review.googlesource.com/25051
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-06 21:05:55 +00:00
Austin Clements
6dda7b2f5f runtime: don't hard-code physical page size
Now that the runtime fetches the true physical page size from the OS,
make the physical page size used by heap growth a variable instead of
a constant. This isn't used in any performance-critical paths, so it
shouldn't be an issue.

sys.PhysPageSize is also renamed to sys.DefaultPhysPageSize to make it
clear that it's not necessarily the true page size. There are no uses
of this constant any more, but we'll keep it around for now.

Updates #12480 and #10180.

Change-Id: I6c23b9df860db309c38c8287a703c53817754f03
Reviewed-on: https://go-review.googlesource.com/25022
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
2016-09-06 21:05:53 +00:00
Austin Clements
276a52de55 runtime: fetch physical page size from the OS
Currently the physical page size assumed by the runtime is hard-coded.
On Linux the runtime at least fetches the OS page size during init and
sanity checks against the hard-coded value, but they may still differ.
On other OSes we wouldn't even notice.

Add support on all OSes to fetch the actual OS physical page size
during runtime init and lift the sanity check of PhysPageSize from the
Linux init code to general malloc init. Currently this is the only use
of the retrieved page size, but we'll add more shortly.

Updates #12480 and #10180.

Change-Id: I065f2834bc97c71d3208edc17fd990ec9058b6da
Reviewed-on: https://go-review.googlesource.com/25050
Run-TryBot: Austin Clements <austin@google.com>
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Reviewed-by: Rick Hudson <rlh@golang.org>
2016-09-06 21:05:50 +00:00
Austin Clements
d7de8b6d23 runtime: assume 64kB physical pages on ARM
Currently we assume the physical page size on ARM is 4kB. While this
is usually true, the architecture also supports 16kB and 64kB physical
pages, and Linux (and possibly other OSes) can be configured to use
these larger page sizes.

With Go 1.6, such a configuration could potentially run, but generally
resulted in memory corruption or random panics. With current master,
this configuration will cause the runtime to panic during init on
Linux when it checks the true physical page size (and will still cause
corruption or panics on other OSes).

However, the assumed physical page size only has to be a multiple of
the true physical page size, the scavenger can now deal with large
physical page sizes, and the rest of the runtime can deal with a
larger assumed physical page size than the true size. Hence, there's
little disadvantage to conservatively setting the assumed physical
page size to 64kB on ARM.

This may result in some extra memory use, since we can only return
memory at multiples of the assumed physical page size. However, it is
a simple change that should make Go run on systems configured for
larger page sizes. The following commits will make the runtime query
the actual physical page size from the OS, but this is a simple step
there.

Updates #12480.

Change-Id: I851829595bc9e0c76235c847a7b5f62ad82b5302
Reviewed-on: https://go-review.googlesource.com/25021
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
2016-09-06 21:05:47 +00:00
Austin Clements
cf4f1d07a1 runtime: bound scanobject to ~100 µs
Currently the time spent in scanobject is proportional to the size of
the object being scanned. Since scanobject is non-preemptible, large
objects can cause significant goroutine (and even whole application)
delays through several means:

1. If a GC assist picks up a large object, the allocating goroutine is
   blocked for the whole scan, even if that scan well exceeds that
   goroutine's debt.

2. Since the scheduler does not run on the P performing a large object
   scan, goroutines in that P's run queue do not run unless they are
   stolen by another P (which can take some time). If there are a few
   large objects, all of the Ps may get tied up so the scheduler
   doesn't run anywhere.

3. Even if a large object is scanned by a background worker and other
   Ps are still running the scheduler, the large object scan doesn't
   flush background credit until the whole scan is done. This can
   easily cause all allocations to block in assists, waiting for
   credit, causing an effective STW.

Fix this by splitting large objects into 128 KB "oblets" and scanning
at most one oblet at a time. Since we can scan 1–2 MB/ms, this equates
to bounding scanobject at roughly 100 µs. This improves assist
behavior both because assists can no longer get "unlucky" and be stuck
scanning a large object, and because it causes the background worker
to flush credit and unblock assists more frequently when scanning
large objects. This also improves GC parallelism if the heap consists
primarily of a small number of very large objects by letting multiple
workers scan a large objects in parallel.

Fixes #10345. Fixes #16293.

This substantially improves goroutine latency in the benchmark from
issue #16293, which exercises several forms of very large objects:

name                 old max-latency    new max-latency    delta
SliceNoPointer-12           154µs ± 1%        155µs ±  2%     ~     (p=0.087 n=13+12)
SlicePointer-12             314ms ± 1%       5.94ms ±138%  -98.11%  (p=0.000 n=19+20)
SliceLivePointer-12        1148ms ± 0%       4.72ms ±167%  -99.59%  (p=0.000 n=19+20)
MapNoPointer-12           72509µs ± 1%        408µs ±325%  -99.44%  (p=0.000 n=19+18)
ChanPointer-12              313ms ± 0%       4.74ms ±140%  -98.49%  (p=0.000 n=18+20)
ChanLivePointer-12         1147ms ± 0%       3.30ms ±149%  -99.71%  (p=0.000 n=19+20)

name                 old P99.9-latency  new P99.9-latency  delta
SliceNoPointer-12           113µs ±25%         107µs ±12%     ~     (p=0.153 n=20+18)
SlicePointer-12          309450µs ± 0%         133µs ±23%  -99.96%  (p=0.000 n=20+20)
SliceLivePointer-12         961ms ± 0%        1.35ms ±27%  -99.86%  (p=0.000 n=20+20)
MapNoPointer-12            448µs ±288%         119µs ±18%  -73.34%  (p=0.000 n=18+20)
ChanPointer-12           309450µs ± 0%         134µs ±23%  -99.96%  (p=0.000 n=20+19)
ChanLivePointer-12          961ms ± 0%        1.35ms ±27%  -99.86%  (p=0.000 n=20+20)

This has negligible effect on all metrics from the garbage, JSON, and
HTTP x/benchmarks.

It shows slight improvement on some of the go1 benchmarks,
particularly Revcomp, which uses some multi-megabyte buffers:

name                      old time/op    new time/op    delta
BinaryTree17-12              2.46s ± 1%     2.47s ± 1%  +0.32%  (p=0.012 n=20+20)
Fannkuch11-12                2.82s ± 0%     2.81s ± 0%  -0.61%  (p=0.000 n=17+20)
FmtFprintfEmpty-12          50.8ns ± 5%    50.5ns ± 2%    ~     (p=0.197 n=17+19)
FmtFprintfString-12          131ns ± 1%     132ns ± 0%  +0.57%  (p=0.000 n=20+16)
FmtFprintfInt-12             117ns ± 0%     116ns ± 0%  -0.47%  (p=0.000 n=15+20)
FmtFprintfIntInt-12          180ns ± 0%     179ns ± 1%  -0.78%  (p=0.000 n=16+20)
FmtFprintfPrefixedInt-12     186ns ± 1%     185ns ± 1%  -0.55%  (p=0.000 n=19+20)
FmtFprintfFloat-12           263ns ± 1%     271ns ± 0%  +2.84%  (p=0.000 n=18+20)
FmtManyArgs-12               741ns ± 1%     742ns ± 1%    ~     (p=0.190 n=19+19)
GobDecode-12                7.44ms ± 0%    7.35ms ± 1%  -1.21%  (p=0.000 n=20+20)
GobEncode-12                6.22ms ± 1%    6.21ms ± 1%    ~     (p=0.336 n=20+19)
Gzip-12                      220ms ± 1%     219ms ± 1%    ~     (p=0.130 n=19+19)
Gunzip-12                   37.9ms ± 0%    37.9ms ± 1%    ~     (p=1.000 n=20+19)
HTTPClientServer-12         82.5µs ± 3%    82.6µs ± 3%    ~     (p=0.776 n=20+19)
JSONEncode-12               16.4ms ± 1%    16.5ms ± 2%  +0.49%  (p=0.003 n=18+19)
JSONDecode-12               53.7ms ± 1%    54.1ms ± 1%  +0.71%  (p=0.000 n=19+18)
Mandelbrot200-12            4.19ms ± 1%    4.20ms ± 1%    ~     (p=0.452 n=19+19)
GoParse-12                  3.38ms ± 1%    3.37ms ± 1%    ~     (p=0.123 n=19+19)
RegexpMatchEasy0_32-12      72.1ns ± 1%    71.8ns ± 1%    ~     (p=0.397 n=19+17)
RegexpMatchEasy0_1K-12       242ns ± 0%     242ns ± 0%    ~     (p=0.168 n=17+20)
RegexpMatchEasy1_32-12      72.1ns ± 1%    72.1ns ± 1%    ~     (p=0.538 n=18+19)
RegexpMatchEasy1_1K-12       385ns ± 1%     384ns ± 1%    ~     (p=0.388 n=20+20)
RegexpMatchMedium_32-12      112ns ± 1%     112ns ± 3%    ~     (p=0.539 n=20+20)
RegexpMatchMedium_1K-12     34.4µs ± 2%    34.4µs ± 2%    ~     (p=0.628 n=18+18)
RegexpMatchHard_32-12       1.80µs ± 1%    1.80µs ± 1%    ~     (p=0.522 n=18+19)
RegexpMatchHard_1K-12       54.0µs ± 1%    54.1µs ± 1%    ~     (p=0.647 n=20+19)
Revcomp-12                   387ms ± 1%     369ms ± 5%  -4.89%  (p=0.000 n=17+19)
Template-12                 62.3ms ± 1%    62.0ms ± 0%  -0.48%  (p=0.002 n=20+17)
TimeParse-12                 314ns ± 1%     314ns ± 0%    ~     (p=1.011 n=20+13)
TimeFormat-12                358ns ± 0%     354ns ± 0%  -1.12%  (p=0.000 n=17+20)
[Geo mean]                  53.5µs         53.3µs       -0.23%

Change-Id: I2a0a179d1d6bf7875dd054b7693dd12d2a340132
Reviewed-on: https://go-review.googlesource.com/23540
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
2016-09-06 19:27:33 +00:00
Austin Clements
b275e55d86 runtime: clean up more traces of the old mark bit
Commit 59877bf renamed bitMarked to bitScan, since the bitmap is no
longer used for marking. However, there were several other references
to this strewn about comments and in some other constant names. Fix
these up, too.

Change-Id: I4183d28c6b01977f1d75a99ad55b150f2211772d
Reviewed-on: https://go-review.googlesource.com/28450
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
2016-09-06 19:26:08 +00:00
Cherry Zhang
4d5bb76279 cmd/compile: remove nil check if followed by storezero on ARM64, MIPS64
Change-Id: Ib90c92056fa70b27feb734837794ef53e842c41a
Reviewed-on: https://go-review.googlesource.com/28513
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-09-06 19:01:26 +00:00
David Chase
0e0ab20334 cmd/compile: remove ld/st-followed nil checks for PPC64
Enabled checks (except for DUFF-ops which aren't implemented yet).
Added ppc64le to relevant test.

Also updated register list to reflect no-longer-reserved-
for-constants status (file was missed in that change).

Updates #16010.

Change-Id: I31b1aac19e14994f760f2ecd02edbeb1f78362e7
Reviewed-on: https://go-review.googlesource.com/28548
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2016-09-06 18:52:13 +00:00
David Crawshaw
b926bf83b0 cmd/link: remove outdated cast and comment
This program is written in Go now.

Change-Id: Ieec21a1bcac7c7a59e88cd1e1359977659de1757
Reviewed-on: https://go-review.googlesource.com/28549
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-09-06 17:21:22 +00:00
Aliaksandr Valialkin
bea39e63ec regexp: reduce mallocs in Regexp.Find* and Regexp.ReplaceAll*.
This improves Regexp.Find* and Regexp.ReplaceAll* speed:

name                  old time/op    new time/op    delta
Find-4                   345ns ± 1%     314ns ± 1%    -8.94%    (p=0.000 n=9+8)
FindString-4             341ns ± 1%     308ns ± 0%    -9.85%   (p=0.000 n=10+9)
FindSubmatch-4           440ns ± 1%     404ns ± 0%    -8.27%   (p=0.000 n=10+8)
FindStringSubmatch-4     426ns ± 0%     387ns ± 0%    -9.07%   (p=0.000 n=10+9)
ReplaceAll-4            1.75µs ± 1%    1.67µs ± 0%    -4.45%   (p=0.000 n=9+10)

name                  old alloc/op   new alloc/op   delta
Find-4                   16.0B ± 0%     0.0B ±NaN%  -100.00%  (p=0.000 n=10+10)
FindString-4             16.0B ± 0%     0.0B ±NaN%  -100.00%  (p=0.000 n=10+10)
FindSubmatch-4           80.0B ± 0%     48.0B ± 0%   -40.00%  (p=0.000 n=10+10)
FindStringSubmatch-4     64.0B ± 0%     32.0B ± 0%   -50.00%  (p=0.000 n=10+10)
ReplaceAll-4              152B ± 0%      104B ± 0%   -31.58%  (p=0.000 n=10+10)

name                  old allocs/op  new allocs/op  delta
Find-4                    1.00 ± 0%     0.00 ±NaN%  -100.00%  (p=0.000 n=10+10)
FindString-4              1.00 ± 0%     0.00 ±NaN%  -100.00%  (p=0.000 n=10+10)
FindSubmatch-4            2.00 ± 0%      1.00 ± 0%   -50.00%  (p=0.000 n=10+10)
FindStringSubmatch-4      2.00 ± 0%      1.00 ± 0%   -50.00%  (p=0.000 n=10+10)
ReplaceAll-4              8.00 ± 0%      5.00 ± 0%   -37.50%  (p=0.000 n=10+10)

Fixes #15643

Change-Id: I594fe51172373e2adb98d1d25c76ca2cde54ff48
Reviewed-on: https://go-review.googlesource.com/23030
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
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2016-09-06 17:04:31 +00:00
David Crawshaw
5923df1af9 cmd/compile: generate table of main symbol types
For each exported symbol in package main, add its name and type to
go.plugin.tabs symbol. This is used by the runtime when loading a
plugin to return a typed interface{} value.

Change-Id: I23c39583e57180acb8f7a74d218dae4368614f46
Reviewed-on: https://go-review.googlesource.com/27818
Run-TryBot: David Crawshaw <crawshaw@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-09-06 17:03:38 +00:00
Ilya Tocar
6e703ae709 math: fix sqrt regression on AMD64
1.7 introduced a significant regression compared to 1.6:

SqrtIndirect-4  2.32ns ± 0%  7.86ns ± 0%  +238.79%        (p=0.000 n=20+18)

This is caused by sqrtsd preserving upper part of destination register.
Which introduces dependency on previous  value of X0.
In 1.6 benchmark loop didn't use X0 immediately after call:

callq  *%rbx
movsd  0x8(%rsp),%xmm2
movsd  0x20(%rsp),%xmm1
addsd  %xmm2,%xmm1
mov    0x18(%rsp),%rax
inc    %rax
jmp    loop

In 1.7 however xmm0 is used just after call:

callq  *%rbx
mov    0x10(%rsp),%rcx
lea    0x1(%rcx),%rax
movsd  0x8(%rsp),%xmm0
movsd  0x18(%rsp),%xmm1

I've  verified that this is caused by dependency, by inserting
XORPS X0,X0 in the beginning of math.Sqrt, which puts performance back on 1.6 level.

Splitting SQRTSD mem,reg into:
MOVSD mem,reg
SQRTSD reg,reg

Removes dependency, because MOVSD (load version)
doesn't need to preserve upper part of a register.
And reg,reg operation is solved by renamer in CPU.

As a result of this change regression is gone:
SqrtIndirect-4  7.86ns ± 0%  2.33ns ± 0%  -70.36%  (p=0.000 n=18+17)

This also removes old Sqrt benchmarks, in favor of benchmarks measuring latency.
Only SqrtIndirect is kept, to show impact of this patch.

Change-Id: Ic7eebe8866445adff5bc38192fa8d64c9a6b8872
Reviewed-on: https://go-review.googlesource.com/28392
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
Reviewed-by: Keith Randall <khr@golang.org>
2016-09-06 15:45:02 +00:00
Josh Bleecher Snyder
6bcca5e918 cmd/go: run mkalldocs.sh
This should have happened as part of CL 28485.

Change-Id: I63cd31303e542ceaec3f4002c5573f186a1e9a52
Reviewed-on: https://go-review.googlesource.com/28547
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Reviewed-by: David Crawshaw <crawshaw@golang.org>
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2016-09-06 15:04:24 +00:00
Cherry Zhang
644c16c76c cmd/compile: fix intrinsifying sync/atomic.Swap* on AMD64
It should alias to Xchg instead of Swap. Found when testing #16985.

Change-Id: If9fd734a1f89b8b2656f421eb31b9d1b0d95a49f
Reviewed-on: https://go-review.googlesource.com/28512
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-09-06 14:44:50 +00:00
Cherry Zhang
f1ef5a06d2 cmd/compile: mark some AMD64 atomic ops as clobberFlags
Fixes #16985.

Change-Id: I5954db28f7b70dd3ac7768e471d5df871a5b20f9
Reviewed-on: https://go-review.googlesource.com/28510
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-09-06 14:26:18 +00:00
Brad Fitzpatrick
6db13e071b syscall: add yet more TestGetfsstat debugging
Updates #16937

Change-Id: I98aa203176f8f2ca2fcca6e334a65bc60d6f824d
Reviewed-on: https://go-review.googlesource.com/28535
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-09-06 04:16:42 +00:00
Erik Staab
66121ce8a9 runtime: remove redundant expression from SetFinalizer
The previous if condition already checks the same expression and doesn't
have side effects.

Change-Id: Ieaf30a786572b608d0a883052b45fd3f04bc6147
Reviewed-on: https://go-review.googlesource.com/28475
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-09-06 00:52:26 +00:00
Shenghou Ma
5514332ed9 os: deduplicate File definition
Fixes #16993.

Change-Id: Ibe406f97d2a49acae94531d969c56dbac8ce53b2
Reviewed-on: https://go-review.googlesource.com/28511
Run-TryBot: Minux Ma <minux@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
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Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-05 21:21:05 +00:00
Brad Fitzpatrick
269ff8e603 io: make MultiReader nil exhausted Readers for earlier GC
No test because the language spec makes no promises in this area.

Fixes #16983

Change-Id: I1a6aa7ff87dd14aa27e8400040a6f6fc908aa1fd
Reviewed-on: https://go-review.googlesource.com/28533
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2016-09-05 21:13:11 +00:00
Caio Marcelo de Oliveira Filho
29272b1e61 cmd/go: use httpGET helper in bug command
Use existing helper function instead of importing "net/http". This
allows the go_bootstrap build to not depend on "net/http" package.
See cmd/go/http.go for details.

Fixes build bootstrap build with all.bash.

Change-Id: I2fd0fb01af7774f1690a353af22137680ec78170
Reviewed-on: https://go-review.googlesource.com/28531
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
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2016-09-05 19:23:26 +00:00
Josh Bleecher Snyder
2939f395e0 cmd/go: add bug command
This is a slightly rough, skeletal implementation.
We will polish and add to it through use.

.github/ISSUE_TEMPLATE will be updated in a
separate CL.

Fixes #16635

Change-Id: Icf284170d87e61b5b643366c85cffc48f149f730
Reviewed-on: https://go-review.googlesource.com/28485
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-05 15:48:08 +00:00
Brad Fitzpatrick
d588864093 syscall: add more TestGetfsstat debugging
Updates #16937

Change-Id: I6d1b210c741269b58040bd68bf3b51644f891737
Reviewed-on: https://go-review.googlesource.com/28487
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-09-05 02:13:32 +00:00
Josh Bleecher Snyder
460b76aef9 cmd/compile: clean up ctxt params in sinit
The ctxt parameter is always set to 0 on entry into anylit so make this
parameter a literal constant, and where possibly remove ctxt as a parameter
where it is known to be a constant zero.

Passes toolstash -cmp.

This is a re-creation of CL 28221 by Dave Cheney.
That CL was graciously reverted in CL 28480
to make merging other CLs easier.

Change-Id: If7a57bf0e27774d9890adbc30af9fabb4aff1058
Reviewed-on: https://go-review.googlesource.com/28483
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
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Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
2016-09-05 01:58:47 +00:00
Hiroshi Ioka
199b17cca8 path/filepath: handle "C:." correctly in EvalSymlinks on Windows
Fixes #16886

Change-Id: Idfacb0cf44d9994559c8e09032b4595887e76433
Reviewed-on: https://go-review.googlesource.com/28214
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
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2016-09-05 00:53:32 +00:00