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27946 Commits

Author SHA1 Message Date
Austin Clements
c8bd293e56 runtime: eliminate floating garbage estimate
Currently when we compute the trigger for the next GC, we do it based
on an estimate of the reachable heap size at the start of the GC
cycle, which is itself based on an estimate of the floating garbage.
This was introduced by 4655aad to fix a bad feedback loop that allowed
the heap to grow to many times the true reachable size.

However, this estimate gets easily confused by rapidly allocating
applications, and, worse it's different than the heap size the trigger
controller uses to compute the trigger itself. This results in the
trigger controller often thinking that GC finished before it started.
Since this would be a pretty great outcome from it's perspective, it
sets the trigger for the next cycle as close to the next goal as
possible (which is limited to 95% of the goal).

Furthermore, the bad feedback loop this estimate originally fixed
seems not to happen any more, suggesting it was fixed more correctly
by some other change in the mean time. Finally, with the change to
allocate black, it shouldn't even be theoretically possible for this
bad feedback loop to occur.

Hence, eliminate the floating garbage estimate and simply consider the
reachable heap to be the marked heap. This harms overall throughput
slightly for allocation-heavy benchmarks, but significantly improves
mutator availability.

Fixes #12204. This brings the average trigger in this benchmark from
0.95 (the cap) to 0.7 and the active GC utilization from ~90% to ~45%.

Updates #14951. This makes the trigger controller much better behaved,
so it pulls the trigger lower if assists are consuming a lot of CPU
like it's supposed to, increasing mutator availability.

name              old time/op  new time/op  delta
XBenchGarbage-12  2.21ms ± 1%  2.28ms ± 3%  +3.29%  (p=0.000 n=17+17)

Some of this slow down we paid for in earlier commits. Relative to the
start of the series to switch to allocate-black (the parent of "count
black allocations toward scan work"), the garbage benchmark is 2.62%
slower.

name                      old time/op    new time/op    delta
BinaryTree17-12              2.53s ± 3%     2.53s ± 3%    ~     (p=0.708 n=20+19)
Fannkuch11-12                2.08s ± 0%     2.08s ± 0%  -0.22%  (p=0.002 n=19+18)
FmtFprintfEmpty-12          45.3ns ± 2%    45.2ns ± 3%    ~     (p=0.505 n=20+20)
FmtFprintfString-12          129ns ± 0%     131ns ± 2%  +1.80%  (p=0.000 n=16+19)
FmtFprintfInt-12             121ns ± 2%     121ns ± 2%    ~     (p=0.768 n=19+19)
FmtFprintfIntInt-12          186ns ± 1%     188ns ± 3%  +0.99%  (p=0.000 n=19+19)
FmtFprintfPrefixedInt-12     188ns ± 1%     188ns ± 1%    ~     (p=0.947 n=18+16)
FmtFprintfFloat-12           254ns ± 1%     255ns ± 1%  +0.30%  (p=0.002 n=19+17)
FmtManyArgs-12               763ns ± 0%     770ns ± 0%  +0.92%  (p=0.000 n=18+18)
GobDecode-12                7.00ms ± 1%    7.04ms ± 1%  +0.61%  (p=0.049 n=20+20)
GobEncode-12                5.88ms ± 1%    5.88ms ± 0%    ~     (p=0.641 n=18+19)
Gzip-12                      214ms ± 1%     215ms ± 1%  +0.43%  (p=0.002 n=18+19)
Gunzip-12                   37.6ms ± 0%    37.6ms ± 0%  +0.11%  (p=0.015 n=17+18)
HTTPClientServer-12         76.9µs ± 2%    78.1µs ± 2%  +1.44%  (p=0.000 n=20+18)
JSONEncode-12               15.2ms ± 2%    15.1ms ± 1%    ~     (p=0.271 n=19+18)
JSONDecode-12               53.1ms ± 1%    53.3ms ± 0%  +0.49%  (p=0.000 n=18+19)
Mandelbrot200-12            4.04ms ± 1%    4.03ms ± 0%  -0.33%  (p=0.005 n=18+18)
GoParse-12                  3.29ms ± 1%    3.28ms ± 1%    ~     (p=0.146 n=16+17)
RegexpMatchEasy0_32-12      69.9ns ± 3%    69.5ns ± 1%    ~     (p=0.785 n=20+19)
RegexpMatchEasy0_1K-12       237ns ± 0%     237ns ± 0%    ~     (p=1.000 n=18+18)
RegexpMatchEasy1_32-12      69.5ns ± 1%    69.2ns ± 1%  -0.44%  (p=0.020 n=16+19)
RegexpMatchEasy1_1K-12       372ns ± 1%     371ns ± 2%    ~     (p=0.086 n=20+19)
RegexpMatchMedium_32-12      108ns ± 3%     107ns ± 1%  -1.00%  (p=0.004 n=19+14)
RegexpMatchMedium_1K-12     34.2µs ± 4%    34.0µs ± 2%    ~     (p=0.380 n=19+20)
RegexpMatchHard_32-12       1.77µs ± 4%    1.76µs ± 3%    ~     (p=0.558 n=18+20)
RegexpMatchHard_1K-12       53.4µs ± 4%    52.8µs ± 2%  -1.10%  (p=0.020 n=18+20)
Revcomp-12                   359ms ± 4%     377ms ± 0%  +5.19%  (p=0.000 n=20+18)
Template-12                 63.7ms ± 2%    62.9ms ± 2%  -1.27%  (p=0.005 n=18+20)
TimeParse-12                 316ns ± 2%     313ns ± 1%    ~     (p=0.059 n=20+16)
TimeFormat-12                329ns ± 0%     331ns ± 0%  +0.39%  (p=0.000 n=16+18)
[Geo mean]                  51.6µs         51.7µs       +0.18%

Change-Id: I1dce4640c8205d41717943b021039fffea863c57
Reviewed-on: https://go-review.googlesource.com/21324
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 20:07:25 +00:00
Austin Clements
6002e01e34 runtime: allocate black during GC
Currently we allocate white for most of concurrent marking. This is
based on the classical argument that it produces less floating
garbage, since allocations during GC may not get linked into the heap
and allocating white lets us reclaim these. However, it's not clear
how often this actually happens, especially since our write barrier
shades any pointer as soon as it's installed in the heap regardless of
the color of the slot.

On the other hand, allocating black has several advantages that seem
to significantly outweigh this downside.

1) It naturally bounds the total scan work to the live heap size at
the start of a GC cycle. Allocating white does not, and thus depends
entirely on assists to prevent the heap from growing faster than it
can be scanned.

2) It reduces the total amount of scan work per GC cycle by the size
of newly allocated objects that are linked into the heap graph, since
objects allocated black never need to be scanned.

3) It reduces total write barrier work since more objects will already
be black when they are linked into the heap graph.

This gives a slight overall improvement in benchmarks.

name              old time/op  new time/op  delta
XBenchGarbage-12  2.24ms ± 0%  2.21ms ± 1%  -1.32%  (p=0.000 n=18+17)

name                      old time/op    new time/op    delta
BinaryTree17-12              2.60s ± 3%     2.53s ± 3%  -2.56%  (p=0.000 n=20+20)
Fannkuch11-12                2.08s ± 1%     2.08s ± 0%    ~     (p=0.452 n=19+19)
FmtFprintfEmpty-12          45.1ns ± 2%    45.3ns ± 2%    ~     (p=0.367 n=19+20)
FmtFprintfString-12          131ns ± 3%     129ns ± 0%  -1.60%  (p=0.000 n=20+16)
FmtFprintfInt-12             122ns ± 0%     121ns ± 2%  -0.86%  (p=0.000 n=16+19)
FmtFprintfIntInt-12          187ns ± 1%     186ns ± 1%    ~     (p=0.514 n=18+19)
FmtFprintfPrefixedInt-12     189ns ± 0%     188ns ± 1%  -0.54%  (p=0.000 n=16+18)
FmtFprintfFloat-12           256ns ± 0%     254ns ± 1%  -0.43%  (p=0.000 n=17+19)
FmtManyArgs-12               769ns ± 0%     763ns ± 0%  -0.72%  (p=0.000 n=18+18)
GobDecode-12                7.08ms ± 2%    7.00ms ± 1%  -1.22%  (p=0.000 n=20+20)
GobEncode-12                5.88ms ± 0%    5.88ms ± 1%    ~     (p=0.406 n=18+18)
Gzip-12                      214ms ± 0%     214ms ± 1%    ~     (p=0.103 n=17+18)
Gunzip-12                   37.6ms ± 0%    37.6ms ± 0%    ~     (p=0.563 n=17+17)
HTTPClientServer-12         77.2µs ± 3%    76.9µs ± 2%    ~     (p=0.606 n=20+20)
JSONEncode-12               15.1ms ± 1%    15.2ms ± 2%    ~     (p=0.138 n=19+19)
JSONDecode-12               53.3ms ± 1%    53.1ms ± 1%  -0.33%  (p=0.000 n=19+18)
Mandelbrot200-12            4.04ms ± 1%    4.04ms ± 1%    ~     (p=0.075 n=19+18)
GoParse-12                  3.30ms ± 1%    3.29ms ± 1%  -0.57%  (p=0.000 n=18+16)
RegexpMatchEasy0_32-12      69.5ns ± 1%    69.9ns ± 3%    ~     (p=0.822 n=18+20)
RegexpMatchEasy0_1K-12       237ns ± 1%     237ns ± 0%    ~     (p=0.398 n=19+18)
RegexpMatchEasy1_32-12      69.8ns ± 2%    69.5ns ± 1%    ~     (p=0.090 n=20+16)
RegexpMatchEasy1_1K-12       371ns ± 1%     372ns ± 1%    ~     (p=0.178 n=19+20)
RegexpMatchMedium_32-12      108ns ± 2%     108ns ± 3%    ~     (p=0.124 n=20+19)
RegexpMatchMedium_1K-12     33.9µs ± 2%    34.2µs ± 4%    ~     (p=0.309 n=20+19)
RegexpMatchHard_32-12       1.75µs ± 2%    1.77µs ± 4%  +1.28%  (p=0.018 n=19+18)
RegexpMatchHard_1K-12       52.7µs ± 1%    53.4µs ± 4%  +1.23%  (p=0.013 n=15+18)
Revcomp-12                   354ms ± 1%     359ms ± 4%  +1.27%  (p=0.043 n=20+20)
Template-12                 63.6ms ± 2%    63.7ms ± 2%    ~     (p=0.654 n=20+18)
TimeParse-12                 313ns ± 1%     316ns ± 2%  +0.80%  (p=0.014 n=17+20)
TimeFormat-12                332ns ± 0%     329ns ± 0%  -0.66%  (p=0.000 n=16+16)
[Geo mean]                  51.7µs         51.6µs       -0.09%

Change-Id: I2214a6a0e4f544699ea166073249a8efdf080dc0
Reviewed-on: https://go-review.googlesource.com/21323
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 20:07:22 +00:00
Austin Clements
64a26b79ac runtime: simplify/optimize allocate-black a bit
Currently allocating black switches to the system stack (which is
probably a historical accident) and atomically updates the global
bytes marked stat. Since we're about to depend on this much more,
optimize it a bit by putting it back on the regular stack and updating
the per-P bytes marked stat, which gets lazily folded into the global
bytes marked stat.

Change-Id: Ibbe16e5382d3fd2256e4381f88af342bf7020b04
Reviewed-on: https://go-review.googlesource.com/22170
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 20:07:20 +00:00
Austin Clements
479501c14c runtime: count black allocations toward scan work
Currently we count black allocations toward the scannable heap size,
but not toward the scan work we've done so far. This is clearly
inconsistent (we have, in effect, scanned these allocations and since
they're already black, we're not going to scan them again). Worse, it
means we don't count black allocations toward the scannable heap size
as of the *next* GC because this is based on the amount of scan work
we did in this cycle.

Fix this by counting black allocations as scan work. Currently the GC
spends very little time in allocate-black mode, so this probably
hasn't been a problem, but this will become important when we switch
to always allocating black.

Change-Id: If6ff693b070c385b65b6ecbbbbf76283a0f9d990
Reviewed-on: https://go-review.googlesource.com/22119
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 20:07:17 +00:00
Marcel van Lohuizen
a683c385ad testing: add matching of subtest
Allows passing regexps per subtest to --test.run and --test.bench

Note that the documentation explicitly states that the split regular
expressions match the correpsonding parts (path components) of
the bench/test identifier. This is intended and slightly different
from the i'th RE matching the subtest/subbench at the respective
level.  Picking this semantics allows guaranteeing that a test or
benchmark identifier as printed by go test can be passed verbatim
(possibly quoted) to, respectively, -run or -bench: subtests and
subbenches might have a '/' in their name, causing a misaligment if
their ID is passed to -run or -bench as is.
This semantics has other benefits, but this is the main motivation.

Fixes golang.go#15126

Change-Id: If72e6d3f54db1df6bc2729ac6edc7ab3c740e7c3
Reviewed-on: https://go-review.googlesource.com/19122
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 19:58:31 +00:00
Keith Randall
f8fc3710fd cmd/compile: handle mem copies in amd64 backend
Fixes noopt builder.

Change-Id: If13373b2597f0fcc9b1b2f9c860f2bd043e43c6c
Reviewed-on: https://go-review.googlesource.com/22338
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-21 17:04:01 +00:00
Cherry Zhang
508a424eed cmd/compile/internal/gc: fix return value offset for SSA backend on ARM
Progress on SSA backend for ARM. Still not complete. It compiles a
Fibonacci function, but the caller picked the return value from an
incorrect offset. This CL adjusts it to match the stack frame layout
for architectures with link register.

Updates #15365.

Change-Id: I01e03c3e95f5503a185e8ac2b6d9caf4faf3d014
Reviewed-on: https://go-review.googlesource.com/22186
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 16:53:53 +00:00
Cherry Zhang
7c6b48ffba cmd/compile/internal/arm: fix comparison & conditional branch for SSA on ARM
Progress on SSA for ARM. Still not complete. Now Fibonacci function compiles
and runs correctly.

The old backend swaps the operands for CMP instruction. This CL does the same
on SSA backend, and uses conditional branch accordingly.

Updates #15365.

Change-Id: I117e17feb22f03d936608bd232f76970e4bbe21a
Reviewed-on: https://go-review.googlesource.com/22187
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-21 16:01:05 +00:00
David Crawshaw
7d56215bcb cmd/link: convert textp into a slice
Updates #15374

Change-Id: I3ea715735862fe9550b88d7a29def6cb9d4419a6
Reviewed-on: https://go-review.googlesource.com/22243
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
2016-04-21 12:02:20 +00:00
David Crawshaw
5a0881a1d1 cmd/link: calculate section alignment concurrently
Reduces link time for cmd/go by 1%.

Change-Id: Iad4a16db0aedc56f81ddf73ba9b632e418dc1b19
Reviewed-on: https://go-review.googlesource.com/22242
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 11:54:51 +00:00
Alex Brainman
45522a6a93 debug/pe: introduce Section.Relocs
cmd/link reads PE object files when building programs with cgo.
cmd/link accesses object relocations. Add new Section.Relocs that
provides similar functionality in debug/pe.

Updates #15345

Change-Id: I34de91b7f18cf1c9e4cdb3aedd685486a625ac92
Reviewed-on: https://go-review.googlesource.com/22332
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
2016-04-21 06:35:48 +00:00
Keith Randall
e48434887e cmd/compile: fix ssa/check/on build
Disable phielimValue from rewrite pass for now.

Change-Id: I9f3bb1f527b50bc7a21cc6b7cb89f6136efd81e8
Reviewed-on: https://go-review.googlesource.com/22335
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-21 06:29:21 +00:00
Martin Möhrmann
7e460e70d9 runtime: use type int to specify size for newarray
Consistently use type int for the size argument of
runtime.newarray, runtime.reflect_unsafe_NewArray
and reflect.unsafe_NewArray.

Change-Id: Ic77bf2dde216c92ca8c49462f8eedc0385b6314e
Reviewed-on: https://go-review.googlesource.com/22311
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Martin Möhrmann <martisch@uos.de>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 04:15:14 +00:00
Keith Randall
4938d7b5fc cmd/compile: fix dominator check in check()
Ancestor comparison was the wrong way around, effectively
disabling the def-must-dominate-use check.

Update #15084

Change-Id: Ic56d674c5000569d2cc855bbb000a60eae517c7c
Reviewed-on: https://go-review.googlesource.com/22330
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-21 02:53:53 +00:00
David Crawshaw
9568d54fb8 cmd/link: fix reordering of plt/rel
For the Solaris and S/390 builders.

Change-Id: Id9a83e0df91e6d0df8488ec5e2a546ba8e2d800e
Reviewed-on: https://go-review.googlesource.com/22327
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Michael Munday <munday@ca.ibm.com>
2016-04-21 02:19:11 +00:00
Alex Brainman
11f1041022 debug/pe: update cstring documentation
Updates #15345

Change-Id: If1fca1f6042571cb0ac689bbb3c294309dd6e7b4
Reviewed-on: https://go-review.googlesource.com/22331
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 01:23:50 +00:00
Alex Brainman
285a18436d debug/pe: pretty section.go code
Introduce (*SectionHeader32).fullName and add documentation comments.

Updates #15345

Change-Id: I8f3b8ab9492642d62e7aad010c91c68daea3f14b
Reviewed-on: https://go-review.googlesource.com/22301
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 01:03:17 +00:00
Tal Shprecher
75b886ab79 cmd/compile: reject embedded unsafe.Pointer values
Fixes #14729

Change-Id: Ied819aa7b23e25de30aa8cde049c97297b4cab11
Reviewed-on: https://go-review.googlesource.com/22325
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 00:32:01 +00:00
Robert Griesemer
f4f1b30749 cmd/compile: accept old and new import format for builtin declarations
Test with forceNewExport set to true (but continues to be disabled by
default for now).

Fixes #15322.

Change-Id: I3b893db2206cbb79e66339284f22f4a0b20bf137
Reviewed-on: https://go-review.googlesource.com/22328
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-04-21 00:10:08 +00:00
David Crawshaw
ed41054b6d cmd/link: process data symbols with slices
First (and largest single) step to switching cmd/link from linked
lists of symbols to slices.

Sort sections independently and concurrently.
This reduces jujud link times on linux/amd64 by ~4%.

Updates #15374

Change-Id: I452bc8f33081039468636502fe3c1cc8d6ed9efa
Reviewed-on: https://go-review.googlesource.com/22205
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
2016-04-20 22:45:03 +00:00
David Crawshaw
cda0aa1680 cmd/link: cleanup Datablk debug printing
(Split out from CL 22205.)

Change-Id: I45838dda8ea8c451b4388b8aade2c209cde2c0e1
Reviewed-on: https://go-review.googlesource.com/22299
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-20 21:56:47 +00:00
Lynn Boger
0fec75f5ca crypto/md5: add assembly implementation on ppc64le
This change improves the performance of the block
function used within crypto/md5 on ppc64le.  The following
improvement was seen:

BenchmarkHash8Bytes              8.39         26.04        3.10x
BenchmarkHash1K                  99.41        407.84       4.10x
BenchmarkHash8K                  108.87       460.00       4.23x
BenchmarkHash8BytesUnaligned     8.39         25.80        3.08x
BenchmarkHash1KUnaligned         89.94        407.81       4.53x
BenchmarkHash8KUnaligned         96.57        459.22       4.76x

Fixes #15385

Change-Id: I8af5af089cc3e3740c33c662003d104de5fe1d1b
Reviewed-on: https://go-review.googlesource.com/22294
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-20 21:38:01 +00:00
Robert Griesemer
aea224386e math/big: more tests, documentation for Flot gob marshalling
Follow-up to https://golang.org/cl/21755.
This turned out to be a bit more than just a few nits
as originally expected in that CL.

1) The actual mantissa may be shorter than required for the
   given precision (because of trailing 0's): no need to
   allocate space for it (and transmit 0's). This can save
   a lot of space when the precision is high: E.g., for
   prec == 1000, 16 words or 128 bytes are required at the
   most, but if the actual number is short, it may be much
   less (for the test cases present, it's significantly less).

2) The actual mantissa may be longer than the number of
   words required for the given precision: make sure to
   not overflow when encoding in bytes.

3) Add more documentation.

4) Add more tests.

Change-Id: I9f40c408cfdd9183a8e81076d2f7d6c75e7a00e9
Reviewed-on: https://go-review.googlesource.com/22324
Reviewed-by: Alan Donovan <adonovan@google.com>
2016-04-20 21:16:21 +00:00
Keith Randall
60fd32a47f cmd/compile: change the way we handle large map values
mapaccess{1,2} returns a pointer to the value.  When the key
is not in the map, it returns a pointer to zeroed memory.
Currently, for large map values we have a complicated scheme which
dynamically allocates zeroed memory for this purpose.  It is ugly
code and requires an atomic.Load in a bunch of places we'd rather
not have it.

Switch to a scheme where callsites of mapaccess{1,2} which expect
large return values pass in a pointer to zeroed memory that
mapaccess can return if the key is not found.  This avoids the
atomic.Load on all map accesses with a few extra instructions only
for the large value acccesses, plus a bit of bss space.

There was a time (1.4 & 1.5?) where we did something like this but
all the tricks to make the right size zero value were done by the
linker.  That scheme broke in the presence of dyamic linking.
The scheme in this CL works even when dynamic linking.

Fixes #12337

Change-Id: Ic2d0319944af33bbb59785938d9ab80958d1b4b1
Reviewed-on: https://go-review.googlesource.com/22221
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
2016-04-20 21:15:31 +00:00
Rob Pike
bc33dd7432 doc/faq: reword the link to the generics proposal
A late response to CL 22163.

Change-Id: I5275a22af7081875af0256da296811f4fe9832dc
Reviewed-on: https://go-review.googlesource.com/22296
Reviewed-by: David Symonds <dsymonds@golang.org>
2016-04-20 20:51:52 +00:00
David Crawshaw
79c527f4a7 cmd/link: move ppc64 genplt declarations into loop
(Split out from CL 22243.)

Change-Id: I07709a0c417e7a57e839e5085a37db7d5fbf3a35
Reviewed-on: https://go-review.googlesource.com/22322
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-20 19:10:59 +00:00
David Crawshaw
854ab14b7e cmd/link: move pcln declarations into loops
(Split out from CL 22243.)

Change-Id: Idac1748c8db2b2ed0484e4afadb105c471c6ce34
Reviewed-on: https://go-review.googlesource.com/22321
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-20 18:57:57 +00:00
David Crawshaw
1dad218da1 cmd/link: move declarations into loops
(Split out from CL 22205.)

Change-Id: Id32698f48ce02b55c15b6f2842215e0ffdbf425b
Reviewed-on: https://go-review.googlesource.com/22298
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-20 17:59:11 +00:00
OneOfOne
d8c9dd6048 math/big: implement GobDecode/Encode for big.Float
Added GobEncode/Decode and a test for them.

Fixes #14593

Change-Id: Ic8d3efd24d0313a1a66f01da293c4c1fd39764a8
Reviewed-on: https://go-review.googlesource.com/21755
Reviewed-by: Robert Griesemer <gri@golang.org>
2016-04-20 17:51:01 +00:00
David Crawshaw
7acb642e4f test: print output on link -X failure
(Split out from CL 22205.)

Change-Id: Iab66ac2a1cd3716966d8e59c570931bce95aba9b
Reviewed-on: https://go-review.googlesource.com/22297
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-20 17:37:35 +00:00
Michael Munday
46efe0bc7f crypto/aes: add s390x assembly implementation
Adds support for single block encryption using the cipher message
(KM) instruction. KM handles key expansion internally and
therefore it is not done up front when using the assembly
implementation on s390x.

Change-Id: I69954b8ae36d549e1dc40d7acd5a10bedfaaef9c
Reviewed-on: https://go-review.googlesource.com/22194
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bill O'Farrell <billotosyr@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-20 17:02:14 +00:00
Keith Randall
b57ac33331 cmd/compile: forward-looking desired register biasing
Improve forward-looking desired register calculations.
It is now inter-block and handles a bunch more cases.

Fixes #14504
Fixes #14828
Fixes #15254

Change-Id: Ic240fa0ec6a779d80f577f55c8a6c4ac8c1a940a
Reviewed-on: https://go-review.googlesource.com/22160
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-04-20 15:31:42 +00:00
Jamil Djadala
30c278dbe9 container/heap: correct number of elements in BenchmarkDup
In BenchmarkDup fuction, heap is created as h := make(myHeap, n)
and then n elements are added, so first time there are 2*n elements
in heap.

Fixes #15380

Change-Id: I0508486a847006b3cd545fd695e8b09af339134f
Reviewed-on: https://go-review.googlesource.com/22310
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-20 15:26:05 +00:00
Keith Randall
001e8e8070 runtime: simplify mallocgc flag argument
mallocgc can calculate noscan itself.  The only remaining
flag argument is needzero, so we just make that a boolean arg.

Fixes #15379

Change-Id: I839a70790b2a0c9dbcee2600052bfbd6c8148e20
Reviewed-on: https://go-review.googlesource.com/22290
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-20 14:02:22 +00:00
Alex Brainman
731531980a debug/pe: move some code into section.go and symbol.go
Just moving code. No code changes.

Updates #15345

Change-Id: I89c257b7aae4fbd78ce59a42909ecb3ff493659d
Reviewed-on: https://go-review.googlesource.com/22300
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-20 04:46:59 +00:00
Alex Brainman
d697a9d5d7 debug/pe: introduce StringTable type
PE specification requires that long section and symbol names
are stored in PE string table. Introduce StringTable that
implements this functionality. Only string table reading is
implemented.

Updates #15345

Change-Id: Ib9638617f2ab1881ad707111d96fc68b0e47340e
Reviewed-on: https://go-review.googlesource.com/22181
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
2016-04-20 02:01:36 +00:00
Alex Brainman
5183ad696c debug/pe: add some documentation and TODO
No code changes. Just moved ImportDirectory next to ImportedSymbols.
And moved useless FormatError to the bottom of file.go.

Updates #15345

Change-Id: I91ff243cefd18008b1c5ee9ec4326583deee431b
Reviewed-on: https://go-review.googlesource.com/22182
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-20 01:09:57 +00:00
Keith Randall
bfe0cbdc50 cmd/compile,runtime: pass elem type to {make,grow}slice
No point in passing the slice type to these functions.
All they need is the element type.  One less indirection,
maybe a few less []T type descriptors in the binary.

Change-Id: Ib0b83b5f14ca21d995ecc199ce8ac00c4eb375e6
Reviewed-on: https://go-review.googlesource.com/22275
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-20 00:31:16 +00:00
Josh Bleecher Snyder
0150f15a92 runtime: call mallocgc directly from makeslice and growslice
The extra checks provided by newarray are
redundant in these cases.

This shrinks by one frame the call stack expected
by the pprof test.

name                      old time/op  new time/op  delta
MakeSlice-8               34.3ns ± 2%  30.5ns ± 3%  -11.03%  (p=0.000 n=24+22)
GrowSlicePtr-8             134ns ± 2%   129ns ± 3%   -3.25%  (p=0.000 n=25+24)

Change-Id: Icd828655906b921c732701fd9d61da3fa217b0af
Reviewed-on: https://go-review.googlesource.com/22276
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-20 00:05:36 +00:00
Andrew Gerrand
7b0ba1cff8 doc: document go1.6.2
Change-Id: Ib3063719cf90dfad139dd723b3b16ef0b45e312e
Reviewed-on: https://go-review.googlesource.com/22251
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-19 23:20:57 +00:00
Matthew Dempsky
2244ae4173 cmd/compile/internal/gc: simplify typecheck's Efoo consts
There's no need for Eiota, Eindir, Eaddr, or Eproc; the values are
threaded through to denote various typechecking contexts, but they
don't actually influence typechecking behavior at all.

Also, while here, switch the Efoo const declarations to use iota.

Passes toolstash -cmp.

Change-Id: I5cea869ccd0755c481cf071978f863474bc9c1ed
Reviewed-on: https://go-review.googlesource.com/22271
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-19 22:57:26 +00:00
Julia Hansbrough
58012ea785 runtime: updated SIGSYS to cause a panic + stacktrace
On GNU/Linux, SIGSYS is specified to cause the process to terminate
without a core dump. In https://codereview.appspot.com/3749041 , it
appears that Golang accidentally introduced incorrect behavior for
this signal, which caused Golang processes to keep running after
receiving SIGSYS. This change reverts it to the old/correct behavior.

Updates #15204

Change-Id: I3aa48a9499c1bc36fa5d3f40c088fdd7599e0db5
Reviewed-on: https://go-review.googlesource.com/22202
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-04-19 22:48:31 +00:00
Robert Griesemer
5e74d40952 strconv: fix ParseFloat for special forms of zero values
Fixes #15364.

Change-Id: Id2a349896064c7c9e00e36c55162068bf18162b2
Reviewed-on: https://go-review.googlesource.com/22272
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-19 22:39:43 +00:00
Brad Fitzpatrick
ba7563019f crypto/x509: fix copy/paste-o in error message
Fixes #15371

Change-Id: Iff8d36e1bd9b5641f6b577a30ac6e967f973c939
Reviewed-on: https://go-review.googlesource.com/22240
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-04-19 22:31:49 +00:00
Keith Randall
998c8e034c cmd/compile: convT2{I,E} don't handle direct interfaces
We now inline type to interface conversions when the type
is pointer-shaped.  No need to keep code to handle that in
convT2{I,E}.

Change-Id: I3a6668259556077cbb2986a9e8fe42a625d506c9
Reviewed-on: https://go-review.googlesource.com/22249
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michel Lespinasse <walken@google.com>
2016-04-19 22:27:08 +00:00
Alexandru Moșoi
8b20fd000d cmd/compile: transform some Phis into Or8.
func f(a, b bool) bool {
          return a || b
}

is now a single instructions (excluding loading and unloading the arguments):
      v10 = ORB <bool> v11 v12 : AX

Change-Id: Iff63399410cb46909f4318ea1c3f45a029f4aa5e
Reviewed-on: https://go-review.googlesource.com/21872
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-19 22:04:30 +00:00
Robert Griesemer
082f464823 go/types: trailing semis are ok after valid fallthrough
Fixes #15376.

Change-Id: I9ece80f26b83be129671c961120c157da2ac0079
Reviewed-on: https://go-review.googlesource.com/22270
Reviewed-by: Alan Donovan <adonovan@google.com>
2016-04-19 21:44:44 +00:00
Josh Bleecher Snyder
a4dd6ea152 runtime: add maxSliceCap
This avoids expensive division calculations
for many common slice element sizes.

name                      old time/op  new time/op  delta
MakeSlice-8               51.9ns ± 3%  35.1ns ± 2%  -32.41%  (p=0.000 n=10+10)
GrowSliceBytes-8          44.1ns ± 2%  44.1ns ± 1%     ~     (p=0.984 n=10+10)
GrowSliceInts-8           60.9ns ± 3%  60.9ns ± 3%     ~     (p=0.698 n=10+10)
GrowSlicePtr-8             131ns ± 1%   120ns ± 2%   -8.41%   (p=0.000 n=8+10)
GrowSliceStruct24Bytes-8   111ns ± 2%   103ns ± 3%   -7.23%    (p=0.000 n=8+8)

Change-Id: I2630eb3d73c814db030cad16e620ea7fecbbd312
Reviewed-on: https://go-review.googlesource.com/22223
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-19 21:38:52 +00:00
Josh Bleecher Snyder
55ab07c224 cmd/compile: static composite literals are side-effect free
This extends CL 22192.

This removes the remaining performance disparity
between non-SSA and SSA on the AppendInPlace benchmarks.

Going from non-SSA to SSA:

AppendInPlace/NoGrow/2Ptr-8  1.60µs ± 5%  1.53µs ± 5%  -4.04%  (p=0.000 n=15+14)
AppendInPlace/NoGrow/3Ptr-8  2.04µs ± 3%  1.96µs ± 2%  -3.90%  (p=0.000 n=13+14)
AppendInPlace/NoGrow/4Ptr-8  2.83µs ± 8%  2.62µs ± 4%  -7.39%  (p=0.000 n=13+15)

Previously these were 20% regressions.

Change-Id: Ie87810bffd598730658e07585f5e2ef979a12b8f
Reviewed-on: https://go-review.googlesource.com/22248
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-19 20:56:00 +00:00
Josh Bleecher Snyder
3c6e60c0e4 cmd/compile: fix isStaticCompositeLiteral
Previously, isStaticCompositeLiteral would
return the wrong value for literals like:

[1]struct{ b []byte }{b: []byte{1}}

Note that the outermost component is an array,
but once we recurse into isStaticCompositeLiteral,
we never check again that arrays are actually arrays.

Instead of adding more logic to the guts of
isStaticCompositeLiteral, allow it to accept
any Node and return the correct answer.

Change-Id: I6af7814a9037bbc7043da9a96137fbee067bbe0e
Reviewed-on: https://go-review.googlesource.com/22247
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-19 20:55:41 +00:00