The loop-A-encloses-loop-C code did not properly handle the
case where really C was already known to be enclosed by B,
and A was nearest-outer to B, not C.
Fixes#19217.
Change-Id: I755dd768e823cb707abdc5302fed39c11cdb34d4
Reviewed-on: https://go-review.googlesource.com/37340
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Avoid printing a second error message when a field of an undefined
variable is accessed.
Fixes#8440.
Change-Id: I3fe0b11fa3423cec3871cb01b5951efa8ea7451a
Reviewed-on: https://go-review.googlesource.com/36751
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The existing CPU profiling buffer is a slice of uintptr, but we want to
start including profiling label data in the profiles, and those labels need
to be pointers in order to let them describe rich information.
This CL implements a new profBuf type that holds both a slice of uint64
for data and a slice of unsafe.Pointer for profiling labels (aka tags).
Making the runtime use these buffers will happen in followup CLs.
Change-Id: I9ff16b532d8edaf4ce0cbba1098229a561834efc
Reviewed-on: https://go-review.googlesource.com/36713
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
xdg-open's man page says:
> xdg-open is for use inside a desktop session only.
Use the DISPLAY environment variable to detect this.
Updates #19131.
Change-Id: I3926b3e1042393939b2ec6aacd9b63ac8192df3b
Reviewed-on: https://go-review.googlesource.com/37390
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
When running on the host platform,
the standard library has almost certainly already been built.
However, all other platforms will probably need building.
Use the new -dolinkobj=false flag to cmd/compile
to only build the export data instead of doing a full compile.
Having partial object files could be confusing for people
doing subsequent cross-compiles, depending on what happens with #18369.
However, cmd/vet/all will mainly be run by builders
and core developers, who are probably fairly well-placed
to handle any such confusion.
This reduces the time on my machine for a cold run of
'go run main.go -all' by almost half:
benchmark old ns/op new ns/op delta
BenchmarkVetAll 240670814551 130784517074 -45.66%
Change-Id: Ieb866ffb2cb714b361b0a6104077652f8eacd166
Reviewed-on: https://go-review.googlesource.com/37385
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When set to false, the -dolinkobj flag instructs the compiler
not to generate or emit linker information.
This is handy when you need the compiler's export data,
e.g. for use with go/importer,
but you want to avoid the cost of full compilation.
This must be used with care, since the resulting
files are unusable for linking.
This CL interacts with #18369,
where adding gcflags and ldflags to buildid has been mooted.
On the one hand, adding gcflags would make safe use of this
flag easier, since if the full object files were needed,
a simple 'go install' would fix it.
On the other hand, this would mean that
'go install -gcflags=-dolinkobj=false' would rebuild the object files,
although any existing object files would probably suffice.
Change-Id: I8dc75ab5a40095c785c1a4d2260aeb63c4d10f73
Reviewed-on: https://go-review.googlesource.com/37384
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Replaces pairs of shifts with sign/zero extension where possible.
For example:
(uint64(x) << 32) >> 32 -> uint64(uint32(x))
Reduces the execution time of the following code by ~4.5% on s390x:
for i := 0; i < N; i++ {
x += (uint64(i)<<32)>>32
}
Change-Id: Idb2d56f27e80a2e1366bc995922ad3fd958c51a7
Reviewed-on: https://go-review.googlesource.com/37292
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
ExampleSliceStable echoes the sort.Slice example, to demonstrate sorting
on two fields together preserving order between sorts.
Change-Id: I8afc20c0203991bfd57260431eda73913c165355
Reviewed-on: https://go-review.googlesource.com/37196
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Fix the encoding of the SH field for rldimi.
The SH field of rldimi is 6-bit wide and it is not contiguous in the instruction.
Bits 0-4 are placed in bit fields 16-20 in the instruction, while bit 5 is
placed in bit field 30. The current implementation does not consider this and,
therefore, any SH field between 32 and 63 are encoded wrongly in the instruciton.
Change-Id: I4d25a0a70f4219569be0e18160dea5505bd7fff0
Reviewed-on: https://go-review.googlesource.com/37350
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Describe the difference from String encoding when len(ip) is zero.
Change-Id: Ia9b36b405d4fec3fee9a77498a839b6d90c2ec0d
Reviewed-on: https://go-review.googlesource.com/37379
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Removes init function from the math package.
Allows stripping of arrays with pre-computed values
used for Pow10 from binaries if Pow10 is not used.
cmd/go shrinks by 128 bytes.
Fixed small values like 10**-323 being 0 instead of 1e-323.
Overall precision is increased but still not as good as
predefined constants for some inputs.
Samples:
Pow10(208)
before: 1.0000000000000006662e+208
after: 1.0000000000000000959e+208
Pow10(202)
before 1.0000000000000009895e+202
after 1.0000000000000001193e+202
Pow10(60)
before 1.0000000000000001278e+60
after 0.9999999999999999494e+60
Pow10(-100)
before 0.99999999999999938551e-100
after 0.99999999999999989309e-100
Pow10(-200)
before 0.9999999999999988218e-200
after 1.0000000000000001271e-200
name old time/op new time/op delta
Pow10Pos-4 44.6ns ± 2% 1.2ns ± 1% -97.39% (p=0.000 n=19+17)
Pow10Neg-4 50.8ns ± 1% 4.1ns ± 2% -92.02% (p=0.000 n=17+19)
Change-Id: If094034286b8ac64be3a95fd9e8ffa3d4ad39b31
Reviewed-on: https://go-review.googlesource.com/36331
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
std and race bench tests fail to check against t.runRxWant, so what
should be negative filters act as positive filters.
Fixes#19239
Change-Id: Icf02b2192bcd806a162fca9fb0af68a27ccfc936
Reviewed-on: https://go-review.googlesource.com/37336
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Fixes#19012.
Fallback to return signatures without detailed types.
These error message will be of the form of issue:
* https://golang.org/issues/4215
* https://golang.org/issues/6750
So:
func f(x int, y uint) {
return x > y
}
f(10, "a" < 3)
will give errors:
too many errors to return
too many arguments in call to f
instead of:
too many errors to return
have (<T>)
want ()
too many arguments in call to f
have (number, <T>)
want (number, number)
Change-Id: I680abc7cdd8444400e234caddf3ff49c2d69f53d
Reviewed-on: https://go-review.googlesource.com/36806
Reviewed-by: Robert Griesemer <gri@golang.org>
Test finite negative x with Y0(-1), Y1(-1), Yn(2,-1), Yn(-3,-1).
Also test the special case Yn(0,0).
Fixes#19130.
Change-Id: I95f05a72e1c455ed8ddf202c56f4266f03f370fd
Reviewed-on: https://go-review.googlesource.com/37310
Reviewed-by: Robert Griesemer <gri@golang.org>
It could have been defined the other way, but since the behavior has
been unspecified, this is the conservative approach for people writing
different implementations of the Context interface.
Change-Id: I7334a4c674bc2330cca6874f7cac1eb0eaea3cff
Reviewed-on: https://go-review.googlesource.com/37375
Reviewed-by: Matt Layher <mdlayher@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Sameer Ajmani <sameer@golang.org>
Run-TryBot: Sameer Ajmani <sameer@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This updates the testcase to display the timestamps for the
runtime.a, it dependent packages atomic.a and sys.a, and
source files.
Change-Id: Id2901b4e8aa8eb9775c4f404ac01cc07b394ba91
Reviewed-on: https://go-review.googlesource.com/37332
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Keith pointed out that these rules should zero extend during the review
of CL 36845. In practice the generic rules are responsible for eliminating
most load-hit-stores and they do not have this problem. When the s390x
rules are triggered any cast following the elided load-hit-store is
kept because of the sequence the rules are applied in (i.e. the load is
removed before the zero extension gets a chance to be merged into the load).
It is therefore not clear that this issue results in any functional bugs.
This CL includes a test, but it only tests the generic rules currently.
Change-Id: Idbc43c782097a3fb159be293ec3138c5b36858ad
Reviewed-on: https://go-review.googlesource.com/37154
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Added a flag to generic and various architectures' atomic
operations that are judged to have observable side effects
and thus cannot be dead-code-eliminated.
Test requires GOMAXPROCS > 1 without preemption in loop.
Fixes#19182.
Change-Id: Id2230031abd2cca0bbb32fd68fc8a58fb912070f
Reviewed-on: https://go-review.googlesource.com/37333
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
The gcdata field only records ptrdata entries, not size entries.
Also fix an obsolete comment: the enforced limit on pointer maps is
now 2048 bytes, not 16 bytes.
I wasn't able to contruct a test case for this. It would require
building a type whose size is greater than 64 bytes but less than 128
bytes, with at least one pointer in first 64 bytes but no pointers
after the first 64 bytes, such that the linker arranges for the one
byte gcbits value to be immediately followed by a non-zero byte.
Change-Id: I9118d3e4ec6f07fd18b72f621c1e5f4fdfe5f80b
Reviewed-on: https://go-review.googlesource.com/37142
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
The definition of writeBarrier in the runtime was changed in CL 22855
to include padding. Update the definition built in to the compiler to match.
This doesn't affect the generated code, as the compiler sets the type
to use anyhow, but having them be different seems clearly wrong.
Change-Id: I8eac05bf70a424a0b2338ba5e9e41af231316de0
Reviewed-on: https://go-review.googlesource.com/37377
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
For compatibility with math/bits uint operations.
When math/big was written originally, the Go compiler used 32bit
int/uint values even on a 64bit machine. uintptr was the type that
represented the machine register size. Now, the int/uint types are
sized to the native machine register size, so they are the natural
machine Word type.
On most machines, the size of int/uint correspond to the size of
uintptr. On platforms where uint and uintptr have different sizes,
this change may lead to performance differences (e.g., amd64p32).
Change-Id: Ief249c160b707b6441848f20041e32e9e9d8d8ca
Reviewed-on: https://go-review.googlesource.com/37372
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The type of the OffPtr should be consistent with the type of the
following load. Before this CL it was typed as a pointer to the
struct.
Fixes#19164.
Change-Id: Ibcdec4411c6f719702f76f8dba3cce8691bfbe0c
Reviewed-on: https://go-review.googlesource.com/37254
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
doEncryptKeyAsm is tail-called from other assembly routines.
Give it a proper prototype so that vet can check it.
Adjust one assembly FP reference accordingly.
Change-Id: I263fcb0191529214b16e6bd67330fadee492eef4
Reviewed-on: https://go-review.googlesource.com/37305
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
A last-minute rollback of a change left some
unreachable code that we don't want to remove.
Change-Id: Ida0af5b18ed1a2e13ef66c303694afcc49d7bff4
Reviewed-on: https://go-review.googlesource.com/37304
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
cmd/vet has a known deficiency in its handling of fmt.Formatters.
This causes a spurious printf error only for non-host platforms.
Since cmd/vet/all may get run on any given platform,
whitelists cannot help here.
Work around the issue by skipping printf tests entirely
for non-host platforms.
Work around the one known acceptable false positive from vet
by whitelisting the file that contains it.
Change-Id: Id74b3d4db0519cf9a670a065683715f856266e45
Reviewed-on: https://go-review.googlesource.com/36936
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Stop reporting errors from cmd.Process.Kill; they don't matter for
purposes of this test, and they can occur if the process exits quickly.
Fixes#19211.
Fixes#19213.
Change-Id: I1a0bb9170220ca69199abb8e8811b1dde43e1897
Reviewed-on: https://go-review.googlesource.com/37309
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
storeOrder visits values in DFS order. It should "break" after
pushing one argument to stack, instead of "continue".
Fixes#19179.
Change-Id: I561afb44213df40ebf8bf7d28e0fd00f22a81ac0
Reviewed-on: https://go-review.googlesource.com/37250
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>
No functional changes.
For #10776.
Change-Id: If9a5ef832af116c5802b06a38e0c050d7363f2d5
Reviewed-on: https://go-review.googlesource.com/36981
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
dwarf writing code assumes that dwarf sections follow
.data and .bss, not .ctors. Make pe section writing code
match that assumption.
For #10776.
Change-Id: I128c3ad125f7d0db19e922f165704a054b2af7ba
Reviewed-on: https://go-review.googlesource.com/36980
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The symbols get in a way when using external linker. They are
not associated with a section. And linker fails when
generating relocations for them.
__image_base__ and _image_base__ have been added long time ago.
I do not think they are needed anymore. If I delete them, all
tests still PASS. I tried going back to the commit that added
them to see if I can reproduce original error, but I cannot
build it. I don't have hg version of go repo, and my gcc is
complaining about cc source code.
I wasted too much time with this, so I decided to leave them only
for internal linker. That is what they were originally added for.
For #10776.
Change-Id: Ibb72b04f3864947c782f964a7badc69f4b074e25
Reviewed-on: https://go-review.googlesource.com/36979
Reviewed-by: Ian Lance Taylor <iant@golang.org>
dwarf relocations refer to dwarf section symbols, so dwarf
section symbols must be present in pe symbol table before we
write dwarf relocations.
.ctors pe section already refer to .text symbol.
Write all pe section name symbols into symbol table, so we
can use them whenever we need them.
This CL also simplified some code.
For #10776.
Change-Id: I9b8c680ea75904af90c797a06bbb1f4df19e34b6
Reviewed-on: https://go-review.googlesource.com/36978
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Introduce a slice that keeps long pe section names as we add them.
It will be used later to output pe symbol table and dwarf relocations.
For #10776.
Change-Id: I02f808a456393659db2354031baf1d4f9e0b2d61
Reviewed-on: https://go-review.googlesource.com/36977
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This is what gcc does when it generates object files.
And pecoff.doc says: "for simplicity, compilers should
set this to zero". It is easier to count everything,
when it starts from 0. Make go linker do the same.
For #10776.
Change-Id: Iffa4b3ad86160624ed34adf1c6ba13feba34c658
Reviewed-on: https://go-review.googlesource.com/36976
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Change list https://golang.org/cl/37015/ moved the optimization
of division by constants to the generic ssa backend.
This removes the old now unused code that was used
for this optimization outside of the ssa backend.
Change-Id: I86223e56742e48dbb372ba8d779681e66448c513
Reviewed-on: https://go-review.googlesource.com/37198
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
Change list https://golang.org/cl/20686/ removed the last use
of the variable byteType.
Change-Id: I4ea79095136a49a9d22767b37f48f3404da05056
Reviewed-on: https://go-review.googlesource.com/37197
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
XCHG needs to allow the stack pointer as an argument because we have a
rewrite that incorporates the address of a local variable into the
instruction.
Fixes#19184
Change-Id: Ic438e6e1946332cdce3864d15abecd41b911b2a9
Reviewed-on: https://go-review.googlesource.com/37253
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Before the change, `go env` reports PKG_CONFIG in between the
CGO env group:
GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/jbd"
GORACE=""
GOROOT="/Users/jbd/go"
GOTOOLDIR="/Users/jbd/go/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/lq/qcn67khn4_1b41_g48x3zchh005d21/T/go-build184491598=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"
PKG_CONFIG="pkg-config"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
The change makes PKG_CONFIG to be reported as the final item,
and not breaking the CGO_* group apart.
Change-Id: I1e7ed6bdec83009ff118f85c9f0f7b78a67fdd76
Reviewed-on: https://go-review.googlesource.com/37228
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Added an alternate form of printing floats and complex values
by specifying the sharp flag.
Output formatted using the the verbs v, e, E, f, F, g and G in
combination with the sharp flag will always include a decimal point.
The alternate form specified by the sharp flag for %g and %G verbs
will not truncate trailing zeros and assume a default precision of 6.
Fixes#18857.
Change-Id: I4d776239e06d7a6a90f2d8556240a359888cb7c3
Reviewed-on: https://go-review.googlesource.com/37051
Reviewed-by: Rob Pike <r@golang.org>
Add exported global variables and store the results of benchmarked
functions in them. This prevents the current compiler optimizations
from removing the instructions that are needed to compute the return
values of the benchmarked functions.
Change-Id: If8b08424e85f3796bb6dd73e761c653abbabcc5e
Reviewed-on: https://go-review.googlesource.com/37195
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The below range loop will not stop when encountering
the first '.' character in a Darwin version string like "15.6.0".
for i = range osver {
if osver[i] != '.' {
continue
}
}
}
Therefore, the condition i > 2 was always satisfied and
supportsCloseOnExec was always set to true.
Since the minimum supported version of OSX for go is currently 10.8
and O_CLOEXEC is implemented from OSX 10.7 on the detection code
can be removed and support for O_CLOEXEC is always assumed to exist.
Change-Id: Idd10094d8385dd4adebc8d7a6d9e9a8f29455867
Reviewed-on: https://go-review.googlesource.com/37193
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The emphasize function used a complex regexp to find URLs, which
truncated some types of URL and did not match others.
This has been simplified and adjusted to allow valid punctuation
like :: or ! in the path part and :[] in the host part.
Comments were added to clarify what this regexp allows.
The path part matches query and fragment also so document this.
Removed news, telnet, wais, and prospero protocols.
Tests were added for:
IPV6 URLs
URLs surrounded by brackets
URLs containing ::
URLs containing :;!- in the path
In order to allow punctuation and yet preserve current behaviour,
URLs are not permitted to end in .,:;?! to allow the use of
normal punctuation surrounding URLs in comments.
Fixes#18139
Change-Id: I38b2d7a85fe0d171e4bf4aac420f8c2d3ced8a2f
Reviewed-on: https://go-review.googlesource.com/37192
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
On AMD64 Most operation can have one operand in memory.
Combine load and dependand operation into one new operation,
where possible. I've seen no significant performance changes on go1,
but this allows to remove ~1.8kb code from go tool. And in math package
I see e. g.:
Remainder-6 70.0ns ± 0% 64.6ns ± 0% -7.76% (p=0.000 n=9+1
Change-Id: I88b8602b1d55da8ba548a34eb7da4b25d59a297e
Reviewed-on: https://go-review.googlesource.com/36793
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The type of an intermediate multiply was wrong. When that
intermediate multiply was spilled, the top 32 bits were lost.
Fixes#19153
Change-Id: Ib29350a4351efa405935b7f7ee3c112668e64108
Reviewed-on: https://go-review.googlesource.com/37212
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
- moved from: x&m>>k | x&^m<<k to: x&m>>k | x<<k&m
This permits use of the same constant m twice (*) which may be
better for machines that can't use large immediate constants
directly with an AND instruction and have to load them explicitly.
*) CPUs don't usually have a &^ instruction, so x&^m becomes x&(^m)
- simplified returns
This improves the generated code because the compiler recognizes
x>>k | x<<k as ROT when k is the bitsize of x.
The 8-bit versions of these instructions can be significantly faster
still if they are replaced with table lookups, as long as the table
is in cache. If the table is not in cache, table-lookup is probably
slower, hence the choice of an explicit register-only implementation
for now.
BenchmarkReverse-8 8.50 6.86 -19.29%
BenchmarkReverse8-8 2.17 1.74 -19.82%
BenchmarkReverse16-8 2.89 2.34 -19.03%
BenchmarkReverse32-8 3.55 2.95 -16.90%
BenchmarkReverse64-8 6.81 5.57 -18.21%
BenchmarkReverseBytes-8 3.49 2.48 -28.94%
BenchmarkReverseBytes16-8 0.93 0.62 -33.33%
BenchmarkReverseBytes32-8 1.55 1.13 -27.10%
BenchmarkReverseBytes64-8 2.47 2.47 +0.00%
Reverse-8 8.50ns ± 0% 6.86ns ± 0% ~ (p=1.000 n=1+1)
Reverse8-8 2.17ns ± 0% 1.74ns ± 0% ~ (p=1.000 n=1+1)
Reverse16-8 2.89ns ± 0% 2.34ns ± 0% ~ (p=1.000 n=1+1)
Reverse32-8 3.55ns ± 0% 2.95ns ± 0% ~ (p=1.000 n=1+1)
Reverse64-8 6.81ns ± 0% 5.57ns ± 0% ~ (p=1.000 n=1+1)
ReverseBytes-8 3.49ns ± 0% 2.48ns ± 0% ~ (p=1.000 n=1+1)
ReverseBytes16-8 0.93ns ± 0% 0.62ns ± 0% ~ (p=1.000 n=1+1)
ReverseBytes32-8 1.55ns ± 0% 1.13ns ± 0% ~ (p=1.000 n=1+1)
ReverseBytes64-8 2.47ns ± 0% 2.47ns ± 0% ~ (all samples are equal)
Change-Id: I0064de8c7e0e568ca7885d6f7064344bef91a06d
Reviewed-on: https://go-review.googlesource.com/37215
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
We can immediately emit static assignment data rather than queueing
them up to be processed during SSA building.
Passes toolstash -cmp.
Change-Id: I8bcea4b72eafb0cc0b849cd93e9cde9d84f30d5e
Reviewed-on: https://go-review.googlesource.com/37024
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
The rules for folding addresses into load/stores checks sym1 is
not on stack (because the stack offset is not known at that point).
But sym1 could be nil, which invalidates the check. Check merged
sym instead.
Fixes#19137.
Change-Id: I8574da22ced1216bb5850403d8f08ec60a8d1005
Reviewed-on: https://go-review.googlesource.com/37145
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
These seem not to really matter, but good to be correct.
Change-Id: I02edb9797c3d6739725cfbe4723c75f151acd05e
Reviewed-on: https://go-review.googlesource.com/36837
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
SSA's writebarrier pass requires WB store ops are always at the
end of a block. If we move write barrier insertion into SSA and
emits normal Store ops when building SSA, this requirement becomes
impractical -- it will create too many blocks for all the Store
ops.
Redo SSA's writebarrier pass, explicitly order values in store
order, so it no longer needs this requirement.
Updates #17583.
Fixes#19067.
Change-Id: I66e817e526affb7e13517d4245905300a90b7170
Reviewed-on: https://go-review.googlesource.com/36834
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Nil check removal in the same block is disabled due to issue 18725:
because the values are not ordered, a nilcheck may influence a
value that is logically before it. This CL re-enables same-block
nilcheck removal by ordering values in store order first.
Updates #18725.
Change-Id: I287a38525230c14c5412cbcdbc422547dabd54f6
Reviewed-on: https://go-review.googlesource.com/35496
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
If the caller set ups a Credential in os/exec.Command,
os/exec.Command.Start will end up calling setgroups(2), even if no
supplementary groups were given.
Only root can call setgroups(2) on BSD kernels, which causes Start to
fail for non-root users when they try to set uid and gid for the new
process.
We fix by introducing a new field to syscall.Credential named
NoSetGroups, and setgroups(2) is only called if it is false.
We make this field with inverted logic to preserve backward
compatibility.
RELNOTES=yes
Change-Id: I3cff1f21c117a1430834f640ef21fd4e87e06804
Reviewed-on: https://go-review.googlesource.com/36697
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Currently the conversion from constant divides to multiplies is mostly
done during the walk pass. This is suboptimal because SSA can
determine that the value being divided by is constant more often
(e.g. after inlining).
Change-Id: If1a9b993edd71be37396b9167f77da271966f85f
Reviewed-on: https://go-review.googlesource.com/37015
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Currently, whether we need a write barrier is simply a property of the
pointer slot being written to.
The only optimization we currently apply using the value being written
is that pointers to stack variables can omit write barriers because
they're only written to stack slots... but we already omit write
barriers for all writes to the stack anyway.
Passes toolstash -cmp.
Change-Id: I7f16b71ff473899ed96706232d371d5b2b7ae789
Reviewed-on: https://go-review.googlesource.com/37109
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Suggested by Dmitry in CL 36792 review.
Clearly safe since there are many different semaRoots
that could all have profiled sudogs calling mutexevent.
Change-Id: I45eed47a5be3e513b2dad63b60afcd94800e16d1
Reviewed-on: https://go-review.googlesource.com/37104
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Also runs 100X faster on average, because it takes so many
fewer attempts to trigger the failure.
Fixes#11443.
Change-Id: I8c39ee48bb3ff6c36fa63083e04076771b65a80d
Reviewed-on: https://go-review.googlesource.com/36841
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
For #10776.
Change-Id: Id64a7e35c7cdcd9be16cbe3358402fa379090e36
Reviewed-on: https://go-review.googlesource.com/36975
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This is what gcc does when it generates object files.
And it is easier to count everything, when it starts from 0.
Make go linker do the same.
gcc also does not output IMAGE_OPTIONAL_HEADER or
PE64_IMAGE_OPTIONAL_HEADER for object files.
Perhaps we should do the same, but not in this CL.
For #10776.
Change-Id: I9789c337648623b6cfaa7d18d1ac9cef32e180dc
Reviewed-on: https://go-review.googlesource.com/36974
Reviewed-by: Ian Lance Taylor <iant@golang.org>
For #10776.
Change-Id: I7931558257c1f6b895e4d44b46d320a54de0d677
Reviewed-on: https://go-review.googlesource.com/36973
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Fixes#19114.
Change-Id: I352add53d6ee8bf78792564225099f8537ac6b46
Reviewed-on: https://go-review.googlesource.com/37106
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David du Colombier <0intro@gmail.com>
I don't know why it is not working. Filed issue 19111 for this.
Fixes build.
Update #19111.
Change-Id: I76f8d6aafba5951da2f3ad7d10960419cca7dd1f
Reviewed-on: https://go-review.googlesource.com/37092
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
It can't work since Plan 9 does not support the runtime poller.
Fixes build.
Change-Id: I9ec33eb66019d9364c6ff6519b61b32e59498559
Reviewed-on: https://go-review.googlesource.com/37091
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
We have seen one instance of a production job suddenly spinning to
100% CPU and becoming unresponsive. In that one instance, a SIGQUIT
was sent after 328 minutes of spinning, and the stacks showed a single
goroutine in "IO wait (scan)" state.
Looking for things that might get stuck if a goroutine got stuck in
scanning a stack, we found that injectglist does:
lock(&sched.lock)
var n int
for n = 0; glist != nil; n++ {
gp := glist
glist = gp.schedlink.ptr()
casgstatus(gp, _Gwaiting, _Grunnable)
globrunqput(gp)
}
unlock(&sched.lock)
and that casgstatus spins on gp.atomicstatus until the _Gscan bit goes
away. Essentially, this code locks sched.lock and then while holding
sched.lock, waits to lock gp.atomicstatus.
The code that is doing the scan is:
if castogscanstatus(gp, s, s|_Gscan) {
if !gp.gcscandone {
scanstack(gp, gcw)
gp.gcscandone = true
}
restartg(gp)
break loop
}
More analysis showed that scanstack can, in a rare case, end up
calling back into code that acquires sched.lock. For example:
runtime.scanstack at proc.go:866
calls runtime.gentraceback at mgcmark.go:842
calls runtime.scanstack$1 at traceback.go:378
calls runtime.scanframeworker at mgcmark.go:819
calls runtime.scanblock at mgcmark.go:904
calls runtime.greyobject at mgcmark.go:1221
calls (*runtime.gcWork).put at mgcmark.go:1412
calls (*runtime.gcControllerState).enlistWorker at mgcwork.go:127
calls runtime.wakep at mgc.go:632
calls runtime.startm at proc.go:1779
acquires runtime.sched.lock at proc.go:1675
This path was found with an automated deadlock-detecting tool.
There are many such paths but they all go through enlistWorker -> wakep.
The evidence strongly suggests that one of these paths is what caused
the deadlock we observed. We're running those jobs with
GOTRACEBACK=crash now to try to get more information if it happens
again.
Further refinement and analysis shows that if we drop the wakep call
from enlistWorker, the remaining few deadlock cycles found by the tool
are all false positives caused by not understanding the effect of calls
to func variables.
The enlistWorker -> wakep call was intended only as a performance
optimization, it rarely executes, and if it does execute at just the
wrong time it can (and plausibly did) cause the deadlock we saw.
Comment it out, to avoid the potential deadlock.
Fixes#19112.
Unfixes #14179.
Change-Id: I6f7e10b890b991c11e79fab7aeefaf70b5d5a07b
Reviewed-on: https://go-review.googlesource.com/37093
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This adds more information to the pkg stale reason for debugging
purposes.
Change-Id: I7b626db4520baa1127195ae859f4da9b49304636
Reviewed-on: https://go-review.googlesource.com/36944
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This changes the os package to use the runtime poller for file I/O
where possible. When a system call blocks on a pollable descriptor,
the goroutine will be blocked on the poller but the thread will be
released to run other goroutines. When using a non-pollable
descriptor, the os package will continue to use thread-blocking system
calls as before.
For example, on GNU/Linux, the runtime poller uses epoll. epoll does
not support ordinary disk files, so they will continue to use blocking
I/O as before. The poller will be used for pipes.
Since this means that the poller is used for many more programs, this
modifies the runtime to only block waiting for the poller if there is
some goroutine that is waiting on the poller. Otherwise, there is no
point, as the poller will never make any goroutine ready. This
preserves the runtime's current simple deadlock detection.
This seems to crash FreeBSD systems, so it is disabled on FreeBSD.
This is issue 19093.
Using the poller on Windows requires opening the file with
FILE_FLAG_OVERLAPPED. We should only do that if we can remove that
flag if the program calls the Fd method. This is issue 19098.
Update #6817.
Update #7903.
Update #15021.
Update #18507.
Update #19093.
Update #19098.
Change-Id: Ia5197dcefa7c6fbcca97d19a6f8621b2abcbb1fe
Reviewed-on: https://go-review.googlesource.com/36800
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
We did not create it. We should not delete it.
Change-Id: If98454ab233ce25367e11a7c68d31b49074537dd
Reviewed-on: https://go-review.googlesource.com/37030
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Until now, the parser set the position for each Node to the position of
the first token belonging to that node. For compatibility with the now
defunct gc parser, in many places that position information was modified
when the gcCompat flag was set (which it was, by default). Furthermore,
in some places, position information was not set at all.
This change removes the gcCompat flag and all associated code, and sets
position information for all nodes in a more principled way, as proposed
by mdempsky (see #16943 for details). Specifically, the position of a
node may not be at the very beginning of the respective production. For
instance for an Operation `a + b`, the position associated with the node
is the position of the `+`. Thus, for `a + b + c` we now get different
positions for the two additions.
This change does not pass toolstash -cmp because position information
recorded in export data and pcline tables is different. There are no
other functional changes.
Added test suite testing the position of all nodes.
Fixes#16943.
Change-Id: I3fc02bf096bc3b3d7d2fa655dfd4714a1a0eb90c
Reviewed-on: https://go-review.googlesource.com/37017
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
