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Commit Graph

43712 Commits

Author SHA1 Message Date
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
Lynn Boger
56933fb838 cmd/compile,cmd/internal/obj/ppc64: use mod instructions on power9
This updates the PPC64.rules file to use the MOD instructions
that are available in power9. Prior to power9 this is done
using a longer sequence with multiply and divide.

Included in this change is removal of the REM* opcode variations
that set the CC or OV bits since their settings are based
on the DIV and are not appropriate for the REM.

Change-Id: Iceed9ce33e128e1911c15592ee674276ce8ba3fa
Reviewed-on: https://go-review.googlesource.com/c/go/+/229761
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-29 14:45:56 +00:00
Nigel Tao
07d9ea64ab image: guard against NewXxx integer overflow
Prior to this commit, NewXxx could panic when passed an image.Rectangle
with one of width or height being negative. But it might not panic if
both were negative, because (bpp * w * h) could still be positive. After
this commit, it will panic if both are negative.

With overflow, NewXxx might not have panicked if (bpp * w * h), the
length passed to "make([]uint8, length)", was still non-negative (after
truncation), but even if w and h were valid (non-negative), the overall
byte slice wasn't long enough. Iterating over the pixels would possibly
panic later with index out of bounds. This change moves the panic
earlier, closer to where the mistake is.

Change-Id: I011feb2d53515fc3f0fe72bb6c23b3953772c577
Reviewed-on: https://go-review.googlesource.com/c/go/+/230220
Reviewed-by: Rob Pike <r@golang.org>
2020-04-29 11:57:50 +00:00
Nigel Tao
7250dd2540 image/jpeg: accept "\xff\x00" before a RST marker
Fixes #28717

Change-Id: I0a1e4ef1583fff89b6f46ef647fb6e4499bdf999
Reviewed-on: https://go-review.googlesource.com/c/go/+/230122
Run-TryBot: Nigel Tao <nigeltao@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
2020-04-29 11:48:24 +00:00
Nigel Tao
03efd42631 image: add a NewUniform doc comment
Fixes #38739

Change-Id: I42b9b601e63ab8df69a0e5ce9bcabf75bb98d83e
Reviewed-on: https://go-review.googlesource.com/c/go/+/230777
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-29 11:47:27 +00:00
Ruixin Bao
e1a96b82df cmd/compile: adopt strong aux typing for some s390x rules
Convert some optimizations rules to strongly-typed versions. Similar to
CL 230338, this CL only converts rules that need no additional changes
(i.e: only need to change '->' to '=>').

This CL covers the rules from line 800 - 1219.

Passes toolstash-check

Change-Id: I94181a809fa38918b78301f1c0c680b7a8ab552f
Reviewed-on: https://go-review.googlesource.com/c/go/+/230738
Reviewed-by: Michael Munday <mike.munday@ibm.com>
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-29 08:57:33 +00:00
Meng Zhuo
67d40873ad cmd/compile: adjust MIPS64x rewrite rules to use typed aux fields
Pass toolstash-check

Change-Id: I673c9a24bf69c09573be5aeddbd6072ef35d2d83
Reviewed-on: https://go-review.googlesource.com/c/go/+/228937
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-29 04:16:08 +00:00
Ian Gudger
b1b67841d1 net: add (*Resolver).LookupIP
Previously, looking up only IPv4 or IPv6 addresses was only possible
with DefaultResolver via ResolveIPAddr. Add this functionality to the
Resolver type with a new method, LookupIP. This largely brings Resolver
functionally to parity with the global functions. The name LookupIP is
used over ResolveIPAddr to be consistent with the other Resolver
methods.

There are two main benefits to (*Resolver).LookupIP over
(*Resolver).LookupHost. First is an ergonomic benefit. Wanting a
specific family of address is common enough to justify a method, evident
by the existence of ResolveIPAddr. Second, this opens the possibility of
not performing unnecessary DNS requests when only a specific family of
addresses are needed. This optimization is left to follow up work.

Updates #30452

Change-Id: I241f61019588022a39738f8920b0ddba900cecdd
Reviewed-on: https://go-review.googlesource.com/c/go/+/228641
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-28 21:46:16 +00:00
Martin Möhrmann
17d5cef257 reflect: reduce allocations for Select with up to 4 cases
Allocate the runcases slice on the stack if the number
of select cases is small (up to 4).

Found while looking at production profiles of common
proto based RPC server framework code in Google which do
not have a large number of cases.

name      old time/op    new time/op    delta
Select/1     147ns ± 2%     120ns ± 6%  -18.32%  (p=0.000 n=7+10)
Select/4     316ns ± 5%     249ns ± 2%  -21.23%  (p=0.000 n=10+10)
Select/8     516ns ± 3%     515ns ± 3%     ~     (p=0.858 n=10+9)

name      old alloc/op   new alloc/op   delta
Select/1     96.0B ± 0%     64.0B ± 0%  -33.33%  (p=0.000 n=10+10)
Select/4      336B ± 0%      208B ± 0%  -38.10%  (p=0.000 n=10+10)
Select/8      672B ± 0%      672B ± 0%     ~     (all equal)

name      old allocs/op  new allocs/op  delta
Select/1      4.00 ± 0%      3.00 ± 0%  -25.00%  (p=0.000 n=10+10)
Select/4      7.00 ± 0%      6.00 ± 0%  -14.29%  (p=0.000 n=10+10)
Select/8      11.0 ± 0%      11.0 ± 0%     ~     (all equal)

Change-Id: I1687e74fc8e86606a27f03fa8a561bcfb68775d6
Reviewed-on: https://go-review.googlesource.com/c/go/+/230657
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-28 21:08:32 +00:00
Daniel Theophanes
ca854f3cda database/sql: document Connect and Close may need a timeout
Opening a connection with Connect should still create a derived
context with a timeout because some clients will not use a timeout
and the connection pool may open a connection asynchronously.

Likewise, if a connection close makes a network operation it should
provide some type of sane timeout for the operation.

Fixes #38185

Change-Id: I9b7ce2996c81c486170dcc84b12672a99610fa27
Reviewed-on: https://go-review.googlesource.com/c/go/+/230438
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
2020-04-28 20:42:02 +00:00
Robert Griesemer
e193725184 strings: simpler and slightly faster implementation of FieldsFunc
Removed the need for maintaining an extra variable in one of the inner loops,
leading to a slight speed-up for short strings.

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          147ns ± 0%     144ns ± 1%  -2.04%  (p=0.000 n=4+5)
FieldsFunc/ASCII/256-4        1.63µs ± 0%    1.59µs ± 1%  -2.50%  (p=0.008 n=5+5)
FieldsFunc/ASCII/4096-4       30.0µs ± 0%    29.3µs ± 2%    ~     (p=0.190 n=4+5)
FieldsFunc/ASCII/65536-4       491µs ± 5%     473µs ± 2%    ~     (p=0.095 n=5+5)
FieldsFunc/ASCII/1048576-4    8.02ms ± 7%    7.85ms ± 4%    ~     (p=0.548 n=5+5)
FieldsFunc/Mixed/16-4          182ns ± 1%     181ns ± 4%    ~     (p=0.357 n=5+5)
FieldsFunc/Mixed/256-4        1.74µs ± 1%    1.74µs ± 1%    ~     (p=0.881 n=5+5)
FieldsFunc/Mixed/4096-4       34.9µs ± 2%    34.7µs ± 0%    ~     (p=0.310 n=5+5)
FieldsFunc/Mixed/65536-4       595µs ± 1%     589µs ± 2%    ~     (p=0.095 n=5+5)
FieldsFunc/Mixed/1048576-4    10.1ms ± 3%     9.8ms ± 2%    ~     (p=0.095 n=5+5)

name                        old speed      new speed      delta
FieldsFunc/ASCII/16-4        109MB/s ± 1%   111MB/s ± 1%  +2.33%  (p=0.008 n=5+5)
FieldsFunc/ASCII/256-4       157MB/s ± 0%   161MB/s ± 1%  +2.57%  (p=0.008 n=5+5)
FieldsFunc/ASCII/4096-4      137MB/s ± 0%   140MB/s ± 2%    ~     (p=0.190 n=4+5)
FieldsFunc/ASCII/65536-4     134MB/s ± 4%   139MB/s ± 2%    ~     (p=0.095 n=5+5)
FieldsFunc/ASCII/1048576-4   131MB/s ± 6%   134MB/s ± 4%    ~     (p=0.548 n=5+5)
FieldsFunc/Mixed/16-4       87.8MB/s ± 1%  88.3MB/s ± 4%    ~     (p=0.421 n=5+5)
FieldsFunc/Mixed/256-4       147MB/s ± 1%   147MB/s ± 1%    ~     (p=0.841 n=5+5)
FieldsFunc/Mixed/4096-4      117MB/s ± 2%   118MB/s ± 0%    ~     (p=0.310 n=5+5)
FieldsFunc/Mixed/65536-4     110MB/s ± 1%   111MB/s ± 2%    ~     (p=0.095 n=5+5)
FieldsFunc/Mixed/1048576-4   104MB/s ± 3%   107MB/s ± 2%    ~     (p=0.095 n=5+5)

name                        old alloc/op   new alloc/op   delta
FieldsFunc/ASCII/16-4          32.0B ± 0%     32.0B ± 0%    ~     (all equal)
FieldsFunc/ASCII/256-4          352B ± 0%      352B ± 0%    ~     (all equal)
FieldsFunc/ASCII/4096-4       21.9kB ± 0%    21.9kB ± 0%    ~     (all equal)
FieldsFunc/ASCII/65536-4       448kB ± 0%     448kB ± 0%    ~     (all equal)
FieldsFunc/ASCII/1048576-4    8.85MB ± 0%    8.85MB ± 0%    ~     (p=0.738 n=5+5)
FieldsFunc/Mixed/16-4          48.0B ± 0%     48.0B ± 0%    ~     (all equal)
FieldsFunc/Mixed/256-4          416B ± 0%      416B ± 0%    ~     (all equal)
FieldsFunc/Mixed/4096-4       21.5kB ± 0%    21.5kB ± 0%    ~     (all equal)
FieldsFunc/Mixed/65536-4       448kB ± 0%     448kB ± 0%    ~     (all equal)
FieldsFunc/Mixed/1048576-4    8.85MB ± 0%    8.85MB ± 0%    ~     (p=0.690 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: I06828d798ca1a624a26edd7f7b68c3bf2fc28f84
Reviewed-on: https://go-review.googlesource.com/c/go/+/229765
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
2020-04-28 20:18:12 +00:00
Josh Bleecher Snyder
71e0cd815d cmd/compile: simplify readonly sym checks in writebarrier pass
CL 220499 started marking readonly syms as SRODATA earlier,
so we can use that in the writebarrier pass now.

Passes toolstash-check.

Change-Id: Ic4d49714b8bffbe03c8e9a75ca96df4475bae732
Reviewed-on: https://go-review.googlesource.com/c/go/+/230559
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-04-28 19:49:53 +00:00
Michael Anthony Knyszek
39380e8e01 runtime: fix block leak due to race in span set
The span set data structure may leak blocks due to a race in the logic
to check whether it's safe to free a block. The simplest example of this
race is between two poppers:

1. Popper A claims slot spanSetEntries-2.
2. Popper B claims slot spanSetEntries-1.
3. Popper A gets descheduled before it subtracts from block.used.
4. Popper B subtracts from block.used, sees that claimed
   spanSetEntries-1, but also that block.used != 0, so it returns.
5. Popper A comes back and subtracts from block.used, but it didn't
   claim spanSetEntries-1 so it also returns.

The spine is left with a stale block pointer and the block later gets
overwritten by pushes, never to be re-used again.

The problem here is that we designate the claimer of slot
spanSetEntries-1 to be the one who frees the block, but that may not be
the thread that actually does the last subtraction from block.used.

Fixing this problem is tricky, and the fundamental problem there is that
block.used is not stable: it may be observed to be zero, but that
doesn't necessarily mean you're the last popper!

Do something simpler: keep a counter of how many pops have happened to a
given block instead of block.used. This counter monotonically increases
when a pop is _completely done_.  Because this counter is monotonically
increasing, and only increases when a popper is done, then we know for
sure whichever popper is the last to increase it (i.e. its value is
spanSetBlockEntries) is also the last popper in the block. Because the
race described above still exists, the last popper may not be the one
which claimed the last slot in the block, but we know for certain nobody
else is popping from that block anymore so we can safely free it.
Finally, because pops serialize with pushes to the same slot, we need
not worry about concurrent pushers at all.

Updates #37487.

Change-Id: I6697219372774c8ca7d8ee6895eaa230a64ce9e1
Reviewed-on: https://go-review.googlesource.com/c/go/+/230497
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-28 18:41:07 +00:00
Michael Anthony Knyszek
0ddde4ada2 runtime: flush mcaches to mcentral before reading memstats
Currently mcaches are flushed to mcentral after a bunch of memstats have
already been read. This is not safe (in the sense that it doesn't ensure
consisent memstats) since memstats may in general change when mcentral
data structures are manipulated.

Note that prior to the new mcentral implementation this was not a
problem because mcentral operations happened to never modify certain
memstats. As of the new mcentral implementation, we might for example
persistentalloc when uncaching a span, which would change memstats. This
can cause a skew between the value of sys (which currently is calculated
before mcaches are flushed) and the value of gc_sys and other_sys.

Fix this by moving mcache flushing to the very top of updatememstats.
Also leave a comment explaining that this must be done first, in
general, because mcentrals make no guarantee that they will not
influence memstats (and doing so would be unnecessarily restrictive).

Fixes #38712.

Change-Id: I15bacb313c54a46e380a945a71bb75db67169c1b
Reviewed-on: https://go-review.googlesource.com/c/go/+/230498
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
2020-04-28 17:42:24 +00:00
Alberto Donizetti
bd01a1b756 cmd/compile: port first part of arm64 opt rules to typed aux
Fairly minimal changes.

Passes

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

Change-Id: I14b2e3ad4933ef14b1b6993f427bf84fe85b1818
Reviewed-on: https://go-review.googlesource.com/c/go/+/229939
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-28 17:39:36 +00:00
Jay Conrod
495a287f0b doc/go1.15: add notes for GOMODCACHE, modcacheunzipinplace
For #36568
For #34527

Change-Id: Ieea4b4a7644e9c957f48d08d2e172e39b571502f
Reviewed-on: https://go-review.googlesource.com/c/go/+/230537
Reviewed-by: Michael Matloob <matloob@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2020-04-28 17:17:53 +00:00
Bryan C. Mills
863424beb2 internal/goversion: update to 1.15
This is a second attempt at CL 230024, with
cmd/go/testdata/script/mod_retention.txt updated to perform a
version-independent comparison on the 'go' version added to a go.mod
file that lacks one.

Fixes #38708

Change-Id: I15dcd83b51ed5ec57946b419bcbaec41e85a46f9
Reviewed-on: https://go-review.googlesource.com/c/go/+/230382
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
2020-04-28 15:02:35 +00:00
Vivian Liang
7b0c518032 database/sql: fix incorrect function name in example_test
fixes incorrect function name prefix in `example_test.go`

Change-Id: I0cce8afc89f6ee6dab3e5152246d28deb597fe53
GitHub-Last-Rev: 4e9a6067c8
GitHub-Pull-Request: golang/go#38715
Reviewed-on: https://go-review.googlesource.com/c/go/+/230381
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
2020-04-28 14:05:09 +00:00
Ruixin Bao
f639a81cd5 cmd/compile: adopt strong aux typing for some s390x rules
Convert some optimizations rules to strongly-typed versions. So far, I
have only converted the rules that need no additional changes (i.e: only
need to change '->' to "=>").

This CL covers the rules from line 478 - line 800 in S390X.rules file.
Some compare and branch rules also fall in this range, but they were
already done previously in another CL.

Passes toolstash-check.
Change-Id: I9167c5f1a32f4fd6c29bacc13fff95e83b0533e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/230338
Reviewed-by: Michael Munday <mike.munday@ibm.com>
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-28 07:36:20 +00:00
fanzha02
ac211c037d cmd/compile: rewrite some arm64 rules to use typed aux fields
Passes toolstash-check -all.

Change-Id: Ibf8c2532b0de65901bf0dd9ef0d198dc54d56470
Reviewed-on: https://go-review.googlesource.com/c/go/+/229738
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-28 02:36:39 +00:00
Rebecca Stambler
5c22c01d45 go/types: improve errors for method calls with pointer receivers
The compiler has better error messages for methods called without a
pointer receiver when one is expected. This change is similar to
CL 229801, but for method calls.

Also, added better error messages for functions called with the wrong
capitalization. I left the third TODO in this switch statement almost
as-is because I'm not sure that the extra complexity is worth it -
I adjusted the error to look like the one the compiler reports.

Fixes golang/go#38658

Change-Id: Ie0ca2503e12f3659f112f0135cc27db1b027fdcb
Reviewed-on: https://go-review.googlesource.com/c/go/+/230380
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2020-04-28 01:38:32 +00:00
Andrei Tudor Călin
7be3f09deb os, internal/poll, internal/syscall/unix: use copy_file_range on Linux
Linux 4.5 introduced (and Linux 5.3 refined) the copy_file_range
system call, which allows file systems the opportunity to implement
copy acceleration techniques. This commit adds support for
copy_file_range(2) to the os package.

Introduce a new ReadFrom method on *os.File, which makes *os.File
implement the io.ReaderFrom interface. If dst and src are both files,
this enables io.Copy(dst, src) to call dst.ReadFrom(src), which, in
turn, will call copy_file_range(2) if possible. If copy_file_range(2)
is not supported by the host kernel, or if either of dst or src
refers to a non-regular file, ReadFrom falls back to the regular
io.Copy code path.

Add internal/poll.CopyFileRange, which acquires locks on the
appropriate poll.FDs and performs the actual work, as well as
internal/syscall/unix.CopyFileRange, which wraps the copy_file_range
system call itself at the lowest level.

Rework file layout in internal/syscall/unix to accomodate the
additional system call numbers needed for copy_file_range.
Merge these definitions with the ones used by getrandom(2) into
sysnum_linux_$GOARCH.go files.

A note on additional optimizations: if dst and src both refer to pipes
in the invocation dst.ReadFrom(src), we could, in theory, use the
existing splice(2) code in package internal/poll to splice directly
from src to dst. Attempting this runs into trouble with the poller,
however. If we call splice(src, dst) and see EAGAIN, we cannot know
if it came from src not being ready for reading or dst not being
ready for writing. The write end of src and the read end of dst are
not under our control, so we cannot reliably use the poller to wait
for readiness. Therefore, it seems infeasible to use the new ReadFrom
method to splice between pipes directly. In conclusion, for now, the
only optimization enabled by the new ReadFrom method on *os.File is
the copy_file_range optimization.

Fixes #36817.

Change-Id: I696372639fa0cdf704e3f65414f7321fc7d30adb
Reviewed-on: https://go-review.googlesource.com/c/go/+/229101
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-04-28 00:59:36 +00:00
Alex Gaynor
c2e0f01598 bufio: optimize bufio.Reader.ReadString to avoid an allocation and copy
name                old time/op    new time/op    delta
ReaderReadString-4     226ns ±12%     161ns ±11%  -28.76%  (p=0.008 n=5+5)

name                old alloc/op   new alloc/op   delta
ReaderReadString-4      288B ± 0%      144B ± 0%  -50.00%  (p=0.008 n=5+5)

name                old allocs/op  new allocs/op  delta
ReaderReadString-4      2.00 ± 0%      1.00 ± 0%  -50.00%  (p=0.008 n=5+5)

Change-Id: I77f330b8340c2bfbfff1f6f1000170b65953a200
GitHub-Last-Rev: 65d65302a7
GitHub-Pull-Request: golang/go#34706
Reviewed-on: https://go-review.googlesource.com/c/go/+/199257
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-04-28 00:53:32 +00:00
Nigel Tao
42c48998aa image/draw: optimize paletted dst + uniform src
name            old time/op  new time/op  delta
PalettedFill-4  5.74ms ± 1%  0.01ms ± 1%  -99.78%  (p=0.008 n=5+5)
PalettedRGBA-4  3.34ms ± 3%  3.33ms ± 0%     ~     (p=0.690 n=5+5)

Fixes #35938

Thanks to pjbgtnj for the suggestion.

Change-Id: I07b494482cce918f556e196c5a4b481b4c16de3a
Reviewed-on: https://go-review.googlesource.com/c/go/+/230118
Run-TryBot: Nigel Tao <nigeltao@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
2020-04-27 23:05:16 +00:00
smasher164
0a364330a2 strconv: remove redundant conversions to int
IntSize is an untyped constant that does not need explicit conversion.
Annotating IntSize as an int and running github.com/mdempsky/unconvert
reveals these two cases.

Fixes #38682.

Change-Id: I014646b7457ddcde32474810153229dcf0c269c6
Reviewed-on: https://go-review.googlesource.com/c/go/+/230306
Run-TryBot: Akhil Indurti <aindurti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2020-04-27 21:46:18 +00:00
Michael Anthony Knyszek
287d1ec96c runtime: ensure allocToCache updates searchAddr in a valid way
Currently allocToCache assumes it can move the search address past the
block it allocated the cache from, which violates the property that
searchAddr should always point to mapped memory (i.e. memory represented
by pageAlloc.inUse).

This bug was already fixed once for pageAlloc.alloc in the Go 1.14
release via CL 216697, but that changed failed to take into account
allocToCache.

Fixes #38605.

Change-Id: Id08180aa10d19dc0f9f551a1d9e327a295560dff
Reviewed-on: https://go-review.googlesource.com/c/go/+/229577
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2020-04-27 21:37:31 +00:00
Ruixin(Peter) Bao
9a3f22be7a hash/crc32: simplify hasVX checking on s390x
Originally, we use an assembly function that returns a boolean result to
tell whether the machine has vector facility or not. It is now no longer
needed when we can directly use cpu.S390X.HasVX variable. This CL
also removes the last occurence of hasVectorFacility function on s390x.

Change-Id: Id20cb746c21eacac5e13344b362e2d87adfe4317
Reviewed-on: https://go-review.googlesource.com/c/go/+/230337
Reviewed-by: Michael Munday <mike.munday@ibm.com>
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-27 21:18:58 +00:00
Ruixin(Peter) Bao
a7e9e84716 math/big: simplify hasVX checking on s390x
Originally, we use an assembly function that returns a boolean result to
tell whether the machine has vector facility or not. It is now no longer
needed when we can directly use cpu.S390X.HasVX variable.

Change-Id: Ic1dae851982532bcfd9a9453416c112347f21d87
Reviewed-on: https://go-review.googlesource.com/c/go/+/230318
Reviewed-by: Michael Munday <mike.munday@ibm.com>
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-27 20:20:53 +00:00
Ruixin Bao
d2f5e4e38c math: simplify hasVX checking on s390x
Originally, we use an assembly function that returns a boolean result to
tell whether the machine has vector facility or not. It is now no longer
needed when we can directly use cpu.S390X.HasVX variable.

Change-Id: Ic3ffeb9e63238ef41406d97cdc42502145ddb454
Reviewed-on: https://go-review.googlesource.com/c/go/+/230319
Reviewed-by: Michael Munday <mike.munday@ibm.com>
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-27 20:06:57 +00:00
Ruixin Bao
a637ee1970 crypto/ecdsa: implement ecdsa on s390x for P256/P384/P521 using KDSA instruction
This CL revives CL 174437(also IBM CLA) and adds benchmarks and some simplifications.

The original commit message is as follows:

Utilize KDSA when available. This guarantees constant time operation on all three curves mentioned,
and is faster than conventional assembly.

Benchmarks:
name             old time/op    new time/op    delta
SignP256-8         15.2µs ±14%    14.1µs ±18%     ~     (p=0.356 n=9+10)
SignP384-8         4.28ms ±26%    0.02ms ±30%  -99.43%  (p=0.000 n=10+10)
VerifyP256-8       33.6µs ±13%    13.3µs ±38%  -60.32%  (p=0.000 n=9+10)

name             old alloc/op   new alloc/op   delta
SignP256-8         2.16kB ± 0%    1.60kB ± 0%  -25.63%  (p=0.000 n=9+10)
SignP384-8         1.75MB ± 0%    0.00MB ± 0%  -99.90%  (p=0.000 n=9+10)
VerifyP256-8       1.08kB ± 0%    0.18kB ± 0%  -83.70%  (p=0.000 n=9+10)

name             old allocs/op  new allocs/op  delta
SignP256-8           29.0 ± 0%      22.0 ± 0%  -24.14%  (p=0.000 n=10+10)
SignP384-8          14.4k ± 0%      0.0k ± 0%  -99.85%  (p=0.000 n=9+10)
VerifyP256-8         23.0 ± 0%       7.0 ± 0%  -69.57%  (p=0.000 n=10+10)

Change-Id: Ifa1fc5917fa7592dd592affa7549147dbc9b4169
Reviewed-on: https://go-review.googlesource.com/c/go/+/228580
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <mike.munday@ibm.com>
2020-04-27 19:49:49 +00:00
Ruixin(Peter) Bao
d646c035f9 crypto/ed25519: implement ed25519 on s390x using KDSA instruction
This CL allows the usage of KDSA instruction when it is available.  The
instruction is designed to be resistant to side channel attacks and
offers performance improvement for ed25519.

Benchmarks:
name              old time/op    new time/op    delta
Signing-8            120µs ±20%      62µs ±12%   -48.40%  (p=0.000 n=10+10)
Verification-8       325µs ±17%      69µs ±10%   -78.80%  (p=0.000 n=10+10)

name              old alloc/op   new alloc/op   delta
Signing-8             448B ± 0%        0B       -100.00%  (p=0.000 n=10+10)
Verification-8        288B ± 0%        0B       -100.00%  (p=0.000 n=10+10)

name              old allocs/op  new allocs/op  delta
Signing-8             5.00 ± 0%      0.00       -100.00%  (p=0.000 n=10+10)
Verification-8        2.00 ± 0%      0.00       -100.00%  (p=0.000 n=10+10)

Change-Id: I0330ce83d807370b419ce638bc2cae4cb3c250dc
Reviewed-on: https://go-review.googlesource.com/c/go/+/202578
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <mike.munday@ibm.com>
2020-04-27 19:49:42 +00:00
Andrew Bonventre
6a4441d6fe Revert "go/types: add UsesCgo config to support _cgo_gotypes.go"
This reverts CL 33677.

Reason for revert: NetBSD is broken

Updates #38649

Change-Id: Id60e3c97d3cb4fb0053dea03b95dbbb0b850c883
Reviewed-on: https://go-review.googlesource.com/c/go/+/230038
Run-TryBot: Andrew Bonventre <andybons@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-04-27 19:35:01 +00:00