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Commit Graph

43785 Commits

Author SHA1 Message Date
Robert Griesemer
45d288718d bytes: simpler and faster FieldsFunc (apply same changes as for strings)
This change applies the recent changes to the strings package
(https://golang.org/cl/229765) to this package, with relevant
local adjustments.

In contrast to the changes in strings, for the bytes package
this change leads to a nice performance improvement of >10%.

Benchmarks run on a "quiet" MacBook Pro, 3.3GHz Dual-Core Intel Core i7,
with 16GB 2133MHz LPDDR3 RAM running macOS 10.15.4.

name                        old time/op    new time/op     delta
FieldsFunc/ASCII/16-4          191ns ± 9%      163ns ± 2%  -14.66%  (p=0.008 n=5+5)
FieldsFunc/ASCII/256-4        2.08µs ± 5%     1.80µs ± 8%  -13.51%  (p=0.008 n=5+5)
FieldsFunc/ASCII/4096-4       36.1µs ± 2%     31.7µs ± 7%  -12.34%  (p=0.008 n=5+5)
FieldsFunc/ASCII/65536-4       584µs ± 3%      517µs ± 3%  -11.52%  (p=0.008 n=5+5)
FieldsFunc/ASCII/1048576-4    9.45ms ± 3%     8.11ms ± 8%  -14.19%  (p=0.008 n=5+5)
FieldsFunc/Mixed/16-4          202ns ± 2%      181ns ± 2%  -10.02%  (p=0.008 n=5+5)
FieldsFunc/Mixed/256-4        2.12µs ± 6%     1.78µs ± 3%  -16.16%  (p=0.008 n=5+5)
FieldsFunc/Mixed/4096-4       40.4µs ± 2%     36.1µs ± 1%  -10.66%  (p=0.008 n=5+5)
FieldsFunc/Mixed/65536-4       700µs ± 5%      612µs ± 1%  -12.59%  (p=0.008 n=5+5)
FieldsFunc/Mixed/1048576-4    11.2ms ± 8%     10.3ms ± 4%   -8.15%  (p=0.008 n=5+5)

name                        old speed      new speed       delta
FieldsFunc/ASCII/16-4       84.0MB/s ± 9%   98.3MB/s ± 2%  +17.04%  (p=0.008 n=5+5)
FieldsFunc/ASCII/256-4       123MB/s ± 5%    143MB/s ± 8%  +15.74%  (p=0.008 n=5+5)
FieldsFunc/ASCII/4096-4      113MB/s ± 2%    130MB/s ± 6%  +14.20%  (p=0.008 n=5+5)
FieldsFunc/ASCII/65536-4     112MB/s ± 2%    127MB/s ± 3%  +13.05%  (p=0.008 n=5+5)
FieldsFunc/ASCII/1048576-4   111MB/s ± 3%    130MB/s ± 8%  +16.66%  (p=0.008 n=5+5)
FieldsFunc/Mixed/16-4       79.3MB/s ± 2%   88.2MB/s ± 2%  +11.15%  (p=0.008 n=5+5)
FieldsFunc/Mixed/256-4       121MB/s ± 5%    144MB/s ± 3%  +19.19%  (p=0.008 n=5+5)
FieldsFunc/Mixed/4096-4      101MB/s ± 2%    113MB/s ± 1%  +11.92%  (p=0.008 n=5+5)
FieldsFunc/Mixed/65536-4    93.7MB/s ± 5%  107.1MB/s ± 1%  +14.31%  (p=0.008 n=5+5)
FieldsFunc/Mixed/1048576-4  93.6MB/s ± 8%  101.8MB/s ± 4%   +8.77%  (p=0.008 n=5+5)

name                        old alloc/op   new alloc/op    delta
FieldsFunc/ASCII/16-4          80.0B ± 0%      80.0B ± 0%     ~     (all equal)
FieldsFunc/ASCII/256-4          768B ± 0%       768B ± 0%     ~     (all equal)
FieldsFunc/ASCII/4096-4       24.8kB ± 0%     24.8kB ± 0%     ~     (all equal)
FieldsFunc/ASCII/65536-4       497kB ± 0%      497kB ± 0%     ~     (p=0.444 n=5+5)
FieldsFunc/ASCII/1048576-4    9.61MB ± 0%     9.61MB ± 0%     ~     (p=0.500 n=5+5)
FieldsFunc/Mixed/16-4          96.0B ± 0%      96.0B ± 0%     ~     (all equal)
FieldsFunc/Mixed/256-4          768B ± 0%       768B ± 0%     ~     (all equal)
FieldsFunc/Mixed/4096-4       24.8kB ± 0%     24.8kB ± 0%     ~     (all equal)
FieldsFunc/Mixed/65536-4       497kB ± 0%      497kB ± 0%     ~     (all equal)
FieldsFunc/Mixed/1048576-4    9.61MB ± 0%     9.61MB ± 0%     ~     (p=0.881 n=5+5)

name                        old allocs/op  new allocs/op   delta
FieldsFunc/ASCII/16-4           1.00 ± 0%       1.00 ± 0%     ~     (all equal)
FieldsFunc/ASCII/256-4          1.00 ± 0%       1.00 ± 0%     ~     (all equal)
FieldsFunc/ASCII/4096-4         5.00 ± 0%       5.00 ± 0%     ~     (all equal)
FieldsFunc/ASCII/65536-4        12.0 ± 0%       12.0 ± 0%     ~     (all equal)
FieldsFunc/ASCII/1048576-4      24.0 ± 0%       24.0 ± 0%     ~     (all equal)
FieldsFunc/Mixed/16-4           1.00 ± 0%       1.00 ± 0%     ~     (all equal)
FieldsFunc/Mixed/256-4          1.00 ± 0%       1.00 ± 0%     ~     (all equal)
FieldsFunc/Mixed/4096-4         5.00 ± 0%       5.00 ± 0%     ~     (all equal)
FieldsFunc/Mixed/65536-4        12.0 ± 0%       12.0 ± 0%     ~     (all equal)
FieldsFunc/Mixed/1048576-4      24.0 ± 0%       24.0 ± 0%     ~     (all equal)

Change-Id: I59a2ed52563851c693b2c8dfce7e3cde640f62a9
Reviewed-on: https://go-review.googlesource.com/c/go/+/231120
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-05-01 03:49:21 +00:00
Brian Kessler
4209a9f65a math/cmplx: handle special cases
Implement special case handling and testing to ensure
conformance with the C99 standard annex G.6 Complex arithmetic.

Fixes #29320

Change-Id: Id72eb4c5a35d5a54b4b8690d2f7176ab11028f1b
Reviewed-on: https://go-review.googlesource.com/c/go/+/220689
Reviewed-by: Robert Griesemer <gri@golang.org>
2020-05-01 03:16:37 +00:00
Bryan C. Mills
da382a3978 internal/unsafeheader: consolidate stringHeader and sliceHeader declarations into an internal package
The new package "internal/unsafeheader" depends only on "unsafe", and
provides declarations equivalent to reflect.StringHeader and
reflect.SliceHeader but with Data fields of the proper unsafe.Pointer
type (instead of uintptr).

Unlike the types it replaces, the "internal/unsafeheader" package has
a regression test to ensure that its header types remain equivalent to
the declarations provided by the "reflect" package.

Since "internal/unsafeheader" has almost no dependencies, it can be
used in other low-level packages such as "syscall" and "reflect".

This change is based on the corresponding x/sys change in CL 231177.

Fixes #37805
Updates #19367

Change-Id: I7a6d93ef8dd6e235bcab94e7c47270aad047af31
Reviewed-on: https://go-review.googlesource.com/c/go/+/231223
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-05-01 02:31:29 +00:00
Anton Kuklin
4c78d54fdd cmd: disable *.go domains lookup in go get command
Using 'go get x.go' instead of 'go build x.go' or some other
go command is a common mistake. By that mistake, a user gets
a misleading error message about unsuccessful `x.go` domain lookup.
This improvement handles such cases, by validating, whether the
argument hasn't specified version, has .go suffix, and either has
no slashes or such file locally exists. Handled both GOPATH
and GOMOD modes.

Fixes #38478

Change-Id: I583a4ef7f7ca8901deb07ebc811e2b3c0e828fa6
Reviewed-on: https://go-review.googlesource.com/c/go/+/229938
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-30 22:06:07 +00:00
Gerrit Code Review
00753d5232 Merge "cmd: merge branch 'dev.link' into master" 2020-04-30 21:47:01 +00:00
Robert Griesemer
8740bdc5af strconv: fix for parseFloatPrefix
parseFloatPrefix accepts a string if it has a valid floating-point
number as prefix. Make sure that "infi", "infin", ... etc. are
accepted as valid numbers "inf" with suffix "i", "in", etc. This
is important for parsing complex numbers such as "0+infi".

This change does not affect the correctness of ParseFloat because
ParseFloat rejects strings that contain a suffix after a valid
floating-point number.

Updates #36771.

Change-Id: Ie1693a8ca2f8edf07b57688e0b35751b7100d39d
Reviewed-on: https://go-review.googlesource.com/c/go/+/231237
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-04-30 21:34:51 +00:00
Cherry Zhang
d0754cfe4a cmd: merge branch 'dev.link' into master
In the dev.link branch we continued developing the new object
file format support and the linker improvements described in
https://golang.org/s/better-linker . Since the last merge, more
progress has been made to improve the new linker.

This is a clean merge.

Change-Id: Ide5ad6fcec9cede99e9b21c4548929b4ba1f4185
2020-04-30 17:08:35 -04:00
Michael Anthony Knyszek
0f8fecaba7 runtime: add scavenge -> traceBuf to lock partial order
Under the scavenge lock it's possible to ready a goroutine (or now
injectglist, which has mostly the same effect) which could cause an
unpark trace event to be emitted. If there's no active trace buffer for
the P, then we might acquire the lock. The total order between the two
is correct, but there's no partial order edge between them. Add in the
edge.

Change-Id: I3fc5d86a3b6bdd0b5648181fb76b5ebc90c3d69f
Reviewed-on: https://go-review.googlesource.com/c/go/+/231197
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
2020-04-30 20:18:38 +00:00
Michael Anthony Knyszek
2491c5fd24 runtime: wake scavenger and update address on sweep done
This change modifies the semantics of waking the scavenger: rather than
wake on any update to pacing, wake when we know we will have work to do,
that is, when the sweeper is done. The current scavenger runs over the
address space just once per GC cycle, and we want to maximize the chance
that the scavenger observes the most attractive scavengable memory in
that pass (i.e. free memory with the highest address), so the timing is
important. By having the scavenger awaken and reset its search space
when the sweeper is done, we increase the chance that the scavenger will
observe the most attractive scavengable memory, because no more memory
will be freed that GC cycle (so the highest scavengable address should
now be available).

Furthermore, in applications that go idle, this means the background
scavenger will be awoken even if another GC doesn't happen, which isn't
true today.

However, we're unable to wake the scavenger directly from within the
sweeper; waking the scavenger involves modifying timers and readying
goroutines, the latter of which may trigger an allocation today (and the
sweeper may run during allocation!). Instead, we do the following:

1. Set a flag which is checked by sysmon. sysmon will clear the flag and
   wake the scavenger.
2. Wake the scavenger unconditionally at sweep termination.

The idea behind this policy is that it gets us close enough to the state
above without having to deal with the complexity of waking the scavenger
in deep parts of the runtime. If the application goes idle and sweeping
finishes (so we don't reach sweep termination), then sysmon will wake
the scavenger. sysmon has a worst-case 20 ms delay in responding to this
signal, which is probably fine if the application is completely idle
anyway, but if the application is actively allocating, then the
proportional sweeper should help ensure that sweeping ends very close to
sweep termination, so sweep termination is a perfectly reasonable time
to wake up the scavenger.

Updates #35788.

Change-Id: I84289b37816a7d595d803c72a71b7f5c59d47e6b
Reviewed-on: https://go-review.googlesource.com/c/go/+/207998
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2020-04-30 18:12:03 +00:00
Michael Anthony Knyszek
c7915376ce runtime: make the scavenger's pacing logic more defensive
This change adds two bits of logic to the scavenger's pacing. Firstly,
it checks to make sure we scavenged at least one physical page, if we
released a non-zero amount of memory. If we try to release less than one
physical page, most systems will release the whole page, which could
lead to memory corruption down the road, and this is a signal we're in
this situation.

Secondly, the scavenger's pacing logic now checks to see if the time a
scavenging operation takes is measured to be exactly zero or negative.
The exact zero case can happen if time update granularity is too large
to effectively capture the time the scavenging operation took, like on
Windows where the OS timer frequency is generally 1ms. The negative case
should not happen, but we're being defensive (against kernel bugs, bugs
in the runtime, etc.). If either of these cases happen, we fall back to
Go 1.13 behavior: assume the scavenge operation took around 10µs per
physical page. We ignore huge pages in this case because we're in
unknown territory, so we choose to be conservative about pacing (huge
pages could only increase the rate of scavenging).

Currently, the scavenger is broken on Windows because the granularity of
time measurement is around 1 ms, which is too coarse to measure how fast
we're scavenging, so we often end up with a scavenging time of zero,
followed by NaNs and garbage values in the pacing logic, which usually
leads to the scavenger sleeping forever.

Fixes #38617.

Change-Id: Iaaa2a4cbb21338e1258d010f7362ed58b7db1af7
Reviewed-on: https://go-review.googlesource.com/c/go/+/229997
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Austin Clements <austin@google.com>
2020-04-30 18:00:48 +00:00
Alberto Donizetti
666c9aedd4 cmd/compile: switch to typed auxint for arm64 TBZ/TBNZ block
This CL changes the arm64 TBZ/TBNZ block from using Aux to using
a (typed) AuxInt. The corresponding rules have also been changed
to be typed.

Passes

  GOARCH=arm64 gotip build -toolexec 'toolstash -cmp' -a std

Change-Id: I98d0cd2a791948f1db13259c17fb1b9b2807a043
Reviewed-on: https://go-review.googlesource.com/c/go/+/230839
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-30 17:30:54 +00:00
Keith Randall
9ed0fb42e3 cmd/compile: add indexed memory modification ops to amd64
name            old time/op  new time/op  delta
Modify-16        404ns ± 1%   365ns ± 1%  -9.73%  (p=0.000 n=10+10)
ConstModify-16   407ns ± 0%   385ns ± 2%  -5.56%  (p=0.000 n=9+10)

Seems to generally help generated code.

Binary size change is in the noise.

Change-Id: I57891bfaf0f7dfc5d143bb9f7ebafc7079d2614f
Reviewed-on: https://go-review.googlesource.com/c/go/+/228098
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2020-04-30 17:21:31 +00:00
Keith Randall
882ec701d2 cmd/compile: add indexed load+op operations to amd64
name        old time/op  new time/op  delta
LoadAdd-16   545ns ± 0%   456ns ± 0%  -16.31%  (p=0.000 n=10+10)

Update #36468

Change-Id: I84f390d55490648fa1f58cdbc24fd74c4f1bc8c1
Reviewed-on: https://go-review.googlesource.com/c/go/+/227960
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2020-04-30 17:19:57 +00:00
Brad Fitzpatrick
553e003414 doc/go1.15: add 32-bit darwin removal and Resolver.LookupIP
Change-Id: I3a67908de9c85bcd39fb03c1b674caa9f817606b
Reviewed-on: https://go-review.googlesource.com/c/go/+/231117
Reviewed-by: Andrew Bonventre <andybons@golang.org>
2020-04-30 16:40:38 +00:00
Brad Fitzpatrick
ecdbffd4ec net/http/httputil: don't append to X-Forwarded-For in ReverseProxy when nil
Fixes #38079

Change-Id: Iac02d7f9574061bb26d1d9a41bb6ee6cc38934e5
Reviewed-on: https://go-review.googlesource.com/c/go/+/230937
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-04-30 14:41:10 +00:00
Ruixin Bao
1d9801223e cmd/compile: adopt strong aux typing for some s390x rules
Convert the remaining lowering rules to strongly-typed versions.

Passes toolstash-check.
Change-Id: I583786806d55376f5463addab8fec32cb59fa7a6
Reviewed-on: https://go-review.googlesource.com/c/go/+/230939
Reviewed-by: Michael Munday <mike.munday@ibm.com>
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-30 13:46:20 +00:00
Alex Brainman
c76befe0f4 cmd/go: use -buildmode=pie as default on window
This change adjusts go command to pass -buildmode=pie to cmd/link,
if -buildmode is not explicitly provided.

Fixes #35192

Change-Id: Iec020131e676eb3e9a2df9eea1929b2af2b6df04
Reviewed-on: https://go-review.googlesource.com/c/go/+/230217
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-04-30 08:07:47 +00:00
Tobias Klauser
5c9a8c0761 lib/time, time/tzdata: update tz data to 2020a
Updates #22487

Change-Id: I691b4c8ced7bfb368f46ade0be46b2ab3f1820dd
Reviewed-on: https://go-review.googlesource.com/c/go/+/230360
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-04-30 08:07:39 +00:00
Daniel Martí
b7e54d8d07 cmd/go: make 'mod verify' use multiple CPUs
'go mod verify' checksums one module zip at a time, which is
CPU-intensive on most modern machines with fast disks. As a result, one
can see a CPU bottleneck when running the command on, for example, a
module where 'go list -m all' lists ~440 modules:

	$ /usr/bin/time go mod verify
	all modules verified
	11.47user 0.77system 0:09.41elapsed 130%CPU (0avgtext+0avgdata 24284maxresident)k
	0inputs+0outputs (0major+4156minor)pagefaults 0swaps

Instead, verify up to GOMAXPROCS zips at once, which should line up
pretty well with the amount of processors we can use on a machine. The
results below are obtained via 'benchcmd -n 5 GoModVerify go mod verify'
on the same large module.

	name         old time/op         new time/op         delta
	GoModVerify          9.35s ± 1%          3.03s ± 2%  -67.60%  (p=0.008 n=5+5)

	name         old user-time/op    new user-time/op    delta
	GoModVerify          11.2s ± 1%          16.3s ± 3%  +45.38%  (p=0.008 n=5+5)

	name         old sys-time/op     new sys-time/op     delta
	GoModVerify          841ms ± 9%          865ms ± 8%     ~     (p=0.548 n=5+5)

	name         old peak-RSS-bytes  new peak-RSS-bytes  delta
	GoModVerify         27.8MB ±13%         50.7MB ±27%  +82.01%  (p=0.008 n=5+5)

The peak memory usage nearly doubles, and there is some extra overhead,
but it seems clearly worth the tradeoff given that we see a ~3x speedup
on my laptop with 4 physical cores. The vast majority of developer
machines nowadays should have 2-4 cores at least.

No test or benchmark is included; one can benchmark 'go mod verify'
directly, as I did above. The existing tests also cover correctness,
including any data races via -race.

Fixes #38623.

Change-Id: I45d8154687a6f3a6a9fb0e2b13da4190f321246c
Reviewed-on: https://go-review.googlesource.com/c/go/+/229817
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2020-04-30 07:05:55 +00:00
Keyan Pishdadian
e87b0644db cmd/go: add error for cross-compiled -race builds
Race builds require C dependencies, but cross-compiled cgo builds are
not always possible, so don't suggest enabling CGO in those cases.

Fixes #37021

Change-Id: I1fd675efc9cef958a926bd63eac8e6858bc59d0a
GitHub-Last-Rev: cbf43c1bbb
GitHub-Pull-Request: golang/go#38670
Reviewed-on: https://go-review.googlesource.com/c/go/+/230202
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2020-04-30 04:02:34 +00:00
Rob Pike
41f6388e70 cmd/cover: include a package name in the HTML title
A recent change added a title to the HTML coverage report but
neglected to include the package name. Add the package name here.
It's a little trickier than you'd think because there may be multiple
packages and we don't want to parse the files, so we just extract
a directory name from the path of the first file.  This will almost
always be right, and has the advantage that it gives a better result
for package main. There are rare cases it will get wrong, but that
will be no hardship.

If this turns out not to be good enough, we can refine it.

Fixes #38609

Change-Id: I2201f6caef906e0b0258b90d7de518879041fe72
Reviewed-on: https://go-review.googlesource.com/c/go/+/230517
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-30 03:58:01 +00:00
Robert Griesemer
1d31f9b1e0 strconv: implement parseFloatPrefix returning no. of bytes consumed
parseFloatPrefix will make it easier to implement ParseComplex.

Verified that there's no relevant performance impact:
Benchmarks run on a "quiet" MacBook Pro, 3.3GHz Dual-Core Intel Core i7,
with 16GB 2133MHz LPDDR3 RAM running macOS 10.15.4.

name                  old time/op  new time/op  delta
Atof64Decimal-4       38.2ns ± 4%  38.4ns ± 3%    ~     (p=0.802 n=5+5)
Atof64Float-4         41.1ns ± 3%  43.0ns ± 1%  +4.77%  (p=0.008 n=5+5)
Atof64FloatExp-4      71.9ns ± 3%  70.1ns ± 1%    ~     (p=0.063 n=5+5)
Atof64Big-4            124ns ± 5%   119ns ± 0%    ~     (p=0.143 n=5+4)
Atof64RandomBits-4    57.2ns ± 1%  55.7ns ± 2%  -2.66%  (p=0.016 n=4+5)
Atof64RandomFloats-4  56.8ns ± 1%  56.9ns ± 4%    ~     (p=0.556 n=4+5)
Atof32Decimal-4       35.4ns ± 5%  35.9ns ± 0%    ~     (p=0.127 n=5+5)
Atof32Float-4         39.6ns ± 7%  40.3ns ± 1%    ~     (p=0.135 n=5+5)
Atof32FloatExp-4      73.7ns ± 7%  71.9ns ± 0%    ~     (p=0.175 n=5+4)
Atof32Random-4         103ns ± 6%    98ns ± 2%  -5.03%  (p=0.008 n=5+5)

Updates #36771.

Change-Id: I8ff66b582ae8b468d89c9ffc35c569c735cf0341
Reviewed-on: https://go-review.googlesource.com/c/go/+/230737
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-04-30 03:50:03 +00:00
Ian Lance Taylor
b255c12337 syscall: on linux-arm64, prefer prlimit to {g,s}etrlimit
Reportedly some Docker images accept the prlimit64 system call,
used by syscall.prlimit, but prohibit the getrlimit and setrlimit
system calls.

Fixes #38604

Change-Id: I91ff9370450b4869098cc8e335bbb7b863060508
Reviewed-on: https://go-review.googlesource.com/c/go/+/230339
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
2020-04-30 03:32:25 +00:00
Ian Lance Taylor
769a1cf7b6 debug/gosym: correct comments for Table.{Files,Objs}
The fields aren't too useful for Go 1.2 and later, but they aren't
actually nil.

Fixes #38754

Change-Id: Ia13a224f623697a00dea8ba0225633e1b9308c9f
Reviewed-on: https://go-review.googlesource.com/c/go/+/230940
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2020-04-30 03:07:49 +00:00
Austin Clements
eda6fe3572 Revert "cmd/compile: omit file:pos for non-existent, permission errors"
This reverts commit 4f7053c87f.

Reason for revert: Newly added test is failing on several builders.

Change-Id: I22dcbfebf2f57735b2f479886bbeb623f95b132f
Reviewed-on: https://go-review.googlesource.com/c/go/+/231043
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-30 02:29:55 +00:00
Emmanuel T Odeke
4f7053c87f cmd/compile: omit file:pos for non-existent, permission errors
Omits printing the file:line:column when trying to open either
* non-existent files
* files without permission

Given:
    go tool compile x.go

For either of x.go not existing, or if no read permissions:

* Before:
    x.go:0: open x.go: no such file or directory
    x.go:0: open x.go: permission denied

* After:
    open x.go: no such file or directory
    open x.go: permission denied

While here, noticed an oddity with the Linux builders, that appear
to always be running under root, hence the test for permission errors
with 0222 -W-*-W-*-W- can't pass on linux-amd64 builders.
The filed bug is #38608.

Fixes #36437

Change-Id: I9645ef73177c286c99547e3a0f3719fa07b35cb5
Reviewed-on: https://go-review.googlesource.com/c/go/+/229357
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2020-04-30 01:17:47 +00:00
Austin Clements
4e00b4c366 runtime: move condition into wakep
All five calls to wakep are protected by the same check of nmidle and
nmspinning. Move this check into wakep.

Change-Id: I2094eec211ce551e462e87614578f37f1896ba38
Reviewed-on: https://go-review.googlesource.com/c/go/+/230757
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2020-04-30 00:42:35 +00:00
kakulisen
df2862cf54 math: Add a function example
When I browsed the source code, I saw that there is no corresponding example of this function. I am not sure if there is a need for an increase, this is my first time to submit CL.

Change-Id: Idbf4e1e1ed2995176a76959d561e152263a2fd26
Reviewed-on: https://go-review.googlesource.com/c/go/+/230741
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2020-04-30 00:33:38 +00:00
Matthew Dempsky
844b410922 net/http/cgi: replace constant map with switch statement
The switch statement can be statically optimized by the compiler,
whereas similarly optimizing the map index expression would require
additional compiler analysis to detect the map is never mutated.

Updates #10848.

Change-Id: I2fc70d4a34dc545677b99f218b51023c7891bbbd
Reviewed-on: https://go-review.googlesource.com/c/go/+/231041
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-30 00:13:38 +00:00
Keith Randall
a7e539619e cmd/compile: move last of the generic rules to typed aux
Change-Id: I1193fff570ff2917979e5cb610fb14c3b347aa92
Reviewed-on: https://go-review.googlesource.com/c/go/+/230938
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-29 22:40:20 +00:00
Austin Clements
9d812cfa5c cmd/compile,runtime: stack maps only at calls, remove register maps
Currently, we emit stack maps and register maps at almost every
instruction. This was originally intended to support non-cooperative
preemption, but was only ever used for debug call injection. Now debug
call injection also uses conservative frame scanning. As a result,
stack maps are only needed at call sites and register maps aren't
needed at all except that we happen to also encode unsafe-point
information in the register map PCDATA stream.

This CL reduces stack maps to only appear at calls, and replace full
register maps with just safe/unsafe-point information.

This is all protected by the go115ReduceLiveness feature flag, which
is defined in both runtime and cmd/compile.

This CL significantly reduces binary sizes and also speeds up compiles
and links:

name                      old exe-bytes     new exe-bytes     delta
BinGoSize                      15.0MB ± 0%       14.1MB ± 0%   -5.72%

name                      old pcln-bytes    new pcln-bytes    delta
BinGoSize                      3.14MB ± 0%       2.48MB ± 0%  -21.08%

name                      old time/op       new time/op       delta
Template                        178ms ± 7%        172ms ±14%  -3.59%  (p=0.005 n=19+19)
Unicode                        71.0ms ±12%       69.8ms ±10%    ~     (p=0.126 n=18+18)
GoTypes                         655ms ± 8%        615ms ± 8%  -6.11%  (p=0.000 n=19+19)
Compiler                        3.27s ± 6%        3.15s ± 7%  -3.69%  (p=0.001 n=20+20)
SSA                             7.10s ± 5%        6.85s ± 8%  -3.53%  (p=0.001 n=19+20)
Flate                           124ms ±15%        116ms ±22%  -6.57%  (p=0.024 n=18+19)
GoParser                        156ms ±26%        147ms ±34%    ~     (p=0.070 n=19+19)
Reflect                         406ms ± 9%        387ms ±21%  -4.69%  (p=0.028 n=19+20)
Tar                             163ms ±15%        162ms ±27%    ~     (p=0.370 n=19+19)
XML                             223ms ±13%        218ms ±14%    ~     (p=0.157 n=20+20)
LinkCompiler                    503ms ±21%        484ms ±23%    ~     (p=0.072 n=20+20)
ExternalLinkCompiler            1.27s ± 7%        1.22s ± 8%  -3.85%  (p=0.005 n=20+19)
LinkWithoutDebugCompiler        294ms ±17%        273ms ±11%  -7.16%  (p=0.001 n=19+18)

(https://perf.golang.org/search?q=upload:20200428.8)

The binary size improvement is even slightly better when you include
the CLs leading up to this. Relative to the parent of "cmd/compile:
mark PanicBounds/Extend as calls":

name                      old exe-bytes     new exe-bytes     delta
BinGoSize                      15.0MB ± 0%       14.1MB ± 0%   -6.18%

name                      old pcln-bytes    new pcln-bytes    delta
BinGoSize                      3.22MB ± 0%       2.48MB ± 0%  -22.92%

(https://perf.golang.org/search?q=upload:20200428.9)

For #36365.

Change-Id: I69448e714f2a44430067ca97f6b78e08c0abed27
Reviewed-on: https://go-review.googlesource.com/c/go/+/230544
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-29 21:29:21 +00:00
Austin Clements
ee7d9f1c37 cmd/compile: make LivenessMap sparse
We're about to switch to having significantly fewer maps in the
liveness map, so switch from a dense representation to a sparse
representation.

Passes toolstash-check.

For #36365.

Change-Id: Icb17bd6ace17667a280bc5fba4039cae3020a8d1
Reviewed-on: https://go-review.googlesource.com/c/go/+/230543
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2020-04-29 21:29:20 +00:00
Austin Clements
601bc41da2 cmd/compile: don't emit stack maps for write barrier calls
These are necessarily deeply non-preemptible, so there's no point in
emitting stack maps for them. We already mark them as unsafe points,
so this only affects the runtime, since user code does not emit stack
maps at unsafe points. SSAGenState.PrepareCall also excludes them when
it's sanity checking call stack maps.

Right now this only drops a handful of unnecessary stack maps from the
runtime, but we're about to start emitting stack maps only at calls
for user code, too. At that point, this will matter much more.

For #36365.

Change-Id: Ib3abfedfddc8e724d933a064fa4d573500627990
Reviewed-on: https://go-review.googlesource.com/c/go/+/230542
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-29 21:29:18 +00:00
Austin Clements
faafdf5115 cmd/compile: fix unsafe-points with stack maps
The compiler currently conflates whether a Value has a stack map with
whether it's an unsafe point. For the most part, unsafe-points don't
have stack maps, so this is mostly fine, but call instructions can be
both an unsafe-point *and* have a stack map. For example, none of the
instructions in a nosplit function should be preemptible, but calls
must still have stack maps in case the called function grows the stack
or get preempted.

Currently, the compiler can't distinguish this case, so calls in
nosplit functions are marked as safe-points just because they have
stack maps. This is particularly problematic if a nosplit function
calls another nosplit function, since this can introduce a preemption
point where there should be none.

We realized this was a problem for split-stack prologues a while back,
and CL 207349 changed the encoding of unsafe-points to use the
register map index instead of the stack map index so we could record
both a stack map and an unsafe-point at the same instruction. But this
was never extended into the compiler.

This CL fixes this problem in the compiler. We make LivenessIndex
slightly more abstract by separating unsafe-point marks from stack and
register map indexes. We map this to the PCDATA encoding later when
producing Progs. This isn't enough to fix the whole problem for
nosplit functions, because obj still adds prologues and marks those as
preemptible, but it's a step in the right direction.

I checked this CL by comparing maps before and after this change in
the runtime and net/http. In net/http, unsafe-points match exactly; at
anything that isn't an unsafe-point, both the stack and register maps
are unchanged by this CL. In the runtime, at every point that was a
safe-point before this change, the stack maps agree (and mostly the
runtime doesn't have register maps at all now). In both, all CALLs
(except write barrier calls) have stack maps.

For #36365.

Change-Id: I066628938b02e78be5c81a6614295bcf7cc566c2
Reviewed-on: https://go-review.googlesource.com/c/go/+/230541
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-29 21:29:17 +00:00
Austin Clements
a6deafaf9e cmd/compile: rename issafepoint -> hasStackMap
Currently, this function conflates two (easily conflated!) concepts:
whether a Value is a safe-point and whether it has a stack map. In
particular, call Values may not be a safe-point, but may need a stack
map anyway in case the called function grows the stack.

Hence, rename this function to "hasStackMap", since that's really what
it represents.

For #36365.

Change-Id: I89839de0be8db3be3f0d3a7fb5fcf0b0b6ebc98a
Reviewed-on: https://go-review.googlesource.com/c/go/+/230540
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-29 21:29:16 +00:00
Austin Clements
2bad2f7eba cmd/compile: mark PanicBounds/Extend as calls
PanicBounds and PanicExtend are lowered to runtime calls (with a
non-Go ABI), but are not currently marked as calls. Since liveness
analysis only emits stack maps at calls in the runtime, this means
these panic call sites in the runtime won't get a stack map. These
almost immediately turn into throws in the runtime, but there's still
a chance they'll try to grow the stack first, which would lead to a
different panic.

To fix this, mark these operations as calls.

Outside the runtime, we currently emit stack maps for everything that
isn't an unsafe-point, so these panic calls get stack maps by default.
However, we're about to move to emitting stack maps only at call
sites, at which point this will start to matter outside the runtime as
well.

I confirmed that this has no effect on anything but PCDATA/FUNCDATA in
runtime and net/http.

For #36365.

Change-Id: Ic5bb463fd152cc320c815dc04cf62005261ae169
Reviewed-on: https://go-review.googlesource.com/c/go/+/230539
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-29 21:29:14 +00:00
Austin Clements
57d751370c runtime: use conservative scanning for debug calls
A debugger can inject a call at almost any PC, which causes
significant complications with stack scanning and growth. Currently,
the runtime solves this using precise stack maps and register maps at
nearly all PCs, but these extra maps require roughly 5% of the binary.
These extra maps were originally considered worth this space because
they were intended to be used for non-cooperative preemption, but are
now used only for debug call injection.

This CL switches from using precise maps to instead using conservative
frame scanning, much like how non-cooperative preemption works. When a
call is injected, the runtime flushes all potential pointer registers
to the stack, and then treats that frame as well as the interrupted
frame conservatively.

The limitation of conservative frame scanning is that we cannot grow
the goroutine stack. That's doable because the previous CL switched to
performing debug calls on a new goroutine, where they are free to grow
the stack.

With this CL, there are no remaining uses of precise register maps
(though we still use the unsafe-point information that's encoded in
the register map PCDATA stream), and stack maps are only used at call
sites.

For #36365.

Change-Id: Ie217b6711f3741ccc437552d8ff88f961a73cee0
Reviewed-on: https://go-review.googlesource.com/c/go/+/229300
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-29 21:29:13 +00:00
Austin Clements
3633d2c545 runtime: perform debug call injection on a new goroutine
Currently, when a debugger injects a call, that call happens on the
goroutine where the debugger injected it. However, this requires
significant runtime complexity that we're about to remove.

To prepare for this, this CL switches to a different approach that
leaves the interrupted goroutine parked and runs the debug call on a
new goroutine. When the debug call returns, it resumes the original
goroutine.

This should be essentially transparent to debuggers. It follows the
exact same call injection protocol and ensures the whole protocol
executes indivisibly on a single OS thread. The only difference is
that the current G and stack now change part way through the protocol.

For #36365.

Change-Id: I68463bfd73cbee06cfc49999606410a59dd8f653
Reviewed-on: https://go-review.googlesource.com/c/go/+/229299
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-29 21:29:11 +00:00
Austin Clements
b3863fbbc2 runtime: make newproc1 not start the goroutine
Currently, newproc1 allocates, initializes, and schedules a new
goroutine. We're about to change debug call injection in a way that
will need to create a new goroutine without immediately scheduling it.
To prepare for that, make scheduling the responsibility of newproc1's
caller. Currently, there's exactly one caller (newproc), so this
simply shifts that responsibility.

For #36365.

Change-Id: Idacd06b63e738982e840fe995d891bfd377ce23b
Reviewed-on: https://go-review.googlesource.com/c/go/+/229298
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-29 21:29:08 +00:00
Austin Clements
197a2a3799 runtime/pprof: fix units of MaxRSS on Linux
Rusage.Maxrss is in bytes on Darwin but in KiB on Linux. Fix this
discrepancy so it's always in bytes.

Change-Id: Ic714abc3276566b8fe5e30565072092212610854
Reviewed-on: https://go-review.googlesource.com/c/go/+/230979
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-04-29 20:33:31 +00:00
Austin Clements
45cd312394 runtime: fix debuglog traceback printing off-by-one
The debuglog traceback printer wasn't adjusting for call/return PCs.

Change-Id: I98dda1c0f22cd78651d88124ea51dc166dc91c7a
Reviewed-on: https://go-review.googlesource.com/c/go/+/227646
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2020-04-29 20:33:30 +00:00
Alberto Donizetti
c8b42f9aa5 cmd/compile: convert CCop arm64 rules to typed aux
Passes

  GOARCH=arm64 gotip build -toolexec 'toolstash -cmp' -a std

Change-Id: Id88141dfc0dfb02c3e958e48ab4adfbac7ba1380
Reviewed-on: https://go-review.googlesource.com/c/go/+/230837
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-29 20:32:48 +00:00
Martin Möhrmann
f2163c4d45 bytes, strings: align requirements for functions passed to FieldFuncs
golang.org/cl/229763 removed the documentation of requirements of
the function passed to FieldsFunc. The current implementation does
not require functions to return consistent results but this had not
been the case for previous implementations.

Add the requirement for consistent results back to the documentation
to allow for future implementations to be more allocation efficient
for an output with more than 32 fields. This is possible with a two
pass algorithm first determining the number of fields used to allocate
the output slice and then splitting the input into fields.

While at it align the documentation of bytes.FieldsFunc with
strings.FieldFunc.

Fixes #38630

Change-Id: Iabbf9ca3dff0daa41f4ec930a21a3dd98e19f122
Reviewed-on: https://go-review.googlesource.com/c/go/+/230797
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2020-04-29 19:58:47 +00:00
Jay Conrod
35dce1d67c cmd/go: trim source paths when compiling C with -trimpath
When then go command is run with -trimpath, it will now use
-fdebug-prefix-map when invoking the C compiler (if supported) to
replace the source root directory with a dummy root directory.

This should prevent source directories from appearing either literally
or in compressed DWARF in linked binaries.

Updates #36072

Change-Id: Iedd08d5e886f81e981f11248a1be4ed4f58bdd29
Reviewed-on: https://go-review.googlesource.com/c/go/+/212101
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2020-04-29 19:03:10 +00:00
Russ Cox
5a550b6951 go/ast: drop //directive comments from doc.Text
This allows writing

	// F does a thing.
	//go:noinline
	func F()

without the //go:noinline or other directive (such as //line)
ending up looking like extra words in the doc comment.

Fixes #37974.

Change-Id: Ic738d72802cc2fa448f7633915e7126d2f76d8ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/224737
Reviewed-by: Robert Griesemer <gri@golang.org>
2020-04-29 19:02:32 +00:00
Richard Miller
b13ce66d1b cmd/go/internal/modload: use lockedfile to read path-replacement go.mod files
When parsing go.mod files found via file-path replacements, it's safer to
use lockedfile.Read instead of ioutil.ReadFile, in case of overwriting by
other concurrent go commands.

Change-Id: I7dcac3bb5ada84bee1eb634b39f813c461ef103a
Reviewed-on: https://go-review.googlesource.com/c/go/+/230838
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
2020-04-29 18:56:19 +00:00
Katie Hockman
202c43b2ad crypto/x509/pkix: improve docs and Name.String()
Previously, non-standard attributes in Name.Names were being
omitted when printed using Name.String(). Now, any non-standard
attributes that would not already be printed in Name.String()
are being added temporarily to Name.ExtraNames to be printed.

Fixes #33094
Fixes #23069

Change-Id: Id9829c20968e16db7194549f69c0eb5985044944
Reviewed-on: https://go-review.googlesource.com/c/go/+/229864
Run-TryBot: Katie Hockman <katie@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
2020-04-29 18:50:32 +00:00
Ruixin Bao
3dc4d37387 crypto/ed25519: drop the purego build tag
Per suggestion in CL 202578, this CL drops the purego build tag used
within this package.

Change-Id: I33626c73d6602e321528544ee601741f7e634c1b
Reviewed-on: https://go-review.googlesource.com/c/go/+/230677
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Michael Munday <mike.munday@ibm.com>
2020-04-29 18:33:42 +00:00
Lynn Boger
f512041eca cmd/asm: update ppc64enc.s testcase
Adds a few instructions to ppc64enc.s that were missing from the
previous update.

Change-Id: Ieafce39e905cdf4da3bfb00fdd5a39ab28089cb3
Reviewed-on: https://go-review.googlesource.com/c/go/+/230437
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-29 18:15:08 +00:00
Keith Randall
3d34c77829 cmd/compile: convert constant divide strength reduction rules to typed aux
Passes toolstash-check.

Change-Id: Ia5d11c099b8c6c0ed670960b2af808200e3b1ca1
Reviewed-on: https://go-review.googlesource.com/c/go/+/230739
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-29 16:45:32 +00:00