The current wasm write barrier implementation incorrectly implements
the "deletion" part of the barrier. It correctly greys the new value
of the pointer, but rather than also greying the old value of the
pointer, it greys the object containing the slot (which, since the old
value was just overwritten, is not going to contain the old value).
This can lead to unmarked, reachable objects.
Often, this is masked by other marking activity, but one specific
sequence that can lead to an unmarked object because of this bug is:
1. Initially, GC is off, object A is reachable from just one pointer
in the heap.
2. GC starts and scans the stack of goroutine G.
3. G copies the pointer to A on to its stack and overwrites the
pointer to A in the heap. (Now A is reachable only from G's stack.)
4. GC finishes while A is still reachable from G's stack.
With a functioning deletion barrier, step 3 causes A to be greyed.
Without a functioning deletion barrier, nothing causes A to be greyed,
so A will be freed even though it's still reachable from G's stack.
This CL fixes the wasm write barrier.
Fixes#30871.
Change-Id: I8a74ee517facd3aa9ad606e5424bcf8f0d78e754
Reviewed-on: https://go-review.googlesource.com/c/go/+/167743
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Enhance the type decoder to do a better job handling unknown type
tags. DWARF has a number of type DIEs that this package doesn't handle
(things like "pointer to member" types in C++); avoid crashing for
such types, but instead return a placeholder "UnsupportedType" object
(this idea suggested by Austin). This provides a compromise between
implementing the entire kitchen sink and simply returning an error
outright on any unknown type DIE.
Fixes#29601.
Change-Id: I2eeffa094c86ef3a2c358ee42e8e629d74cec2ed
Reviewed-on: https://go-review.googlesource.com/c/go/+/158797
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Modify the |x| == |y| case to return -0 when x < 0.
Fixes#30814.
Change-Id: Ic4cd48001e0e894a12b5b813c6a1ddc3a055610b
Reviewed-on: https://go-review.googlesource.com/c/go/+/167479
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
This commit fixes trampoline generation on aix/ppc64 which must use TOC
symbols.
It also adds a size to runtime.text.X symbols to prevent ld from moving
them, like runtime.text.
Change-Id: Ida033ec20ad8d7b7fb3faeb0ec4fa7bc4ce86b7e
Reviewed-on: https://go-review.googlesource.com/c/go/+/164009
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The general code for setting a timespec value sometimes used set_nsec
and sometimes used a combination of set_sec and set_nsec. Standardize
on a setNsec function that takes a number of nanoseconds and splits
them up to set the tv_sec and tv_nsec fields. Consistently mark
setNsec as go:nosplit, since it has to be that way on some systems
including Darwin and GNU/Linux. Consistently use timediv on 32-bit
systems to help stay within split-stack limits on processors that
don't have a 64-bit division instruction.
Change-Id: I6396bb7ddbef171a96876bdeaf7a1c585a6d725b
Reviewed-on: https://go-review.googlesource.com/c/go/+/167389
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This logic is used by the current escape analysis pass, but otherwise
logically independent. Move (unchanged) into a separate file to make
that clearer, and to make it easier to replace esc.go later.
Updates #23109.
Change-Id: Iec8c0c47ea04c0008165791731c11d9104d5a474
Reviewed-on: https://go-review.googlesource.com/c/go/+/167715
Reviewed-by: Robert Griesemer <gri@golang.org>
This is a re-attempt at CL 153841, which caused two regressions:
1. crypto/ecdsa failed to build with -gcflags=-l=4. This was because
when "t1, t2, ... := g(); f(t1, t2, ...)" was exported, we were losing
the first assignment from the call's Ninit field.
2. net/http/pprof failed to run with -gcflags=-N. This is due to a
conflict with CL 159717: as of that CL, package-scope initialization
statements are executed within the "init.ializer" function, rather
than the "init" function, and the generated temp variables need to be
moved accordingly too.
[Rest of description is as before.]
This CL moves order.go's copyRet logic for rewriting f(g()) into t1,
t2, ... := g(); f(t1, t2, ...) earlier into typecheck. This allows the
rest of the compiler to stop worrying about multi-value functions
appearing outside of OAS2FUNC nodes.
This changes compiler behavior in a few observable ways:
1. Typechecking error messages for builtin functions now use general
case error messages rather than unnecessarily differing ones.
2. Because f(g()) is rewritten before inlining, saved inline bodies
now see the rewritten form too. This could be addressed, but doesn't
seem worthwhile.
3. Most notably, this simplifies escape analysis and fixes a memory
corruption issue in esc.go. See #29197 for details.
Fixes#15992.
Fixes#29197.
Change-Id: I930b10f7e27af68a0944d6c9bfc8707c3fab27a4
Reviewed-on: https://go-review.googlesource.com/c/go/+/166983
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
The return values are integers, as opposed to floats, since the fractionals can be derived from multiplying t.Seconds().
Fixes#28564
Change-Id: I3796227e1f64ead39ff0aacfbdce912d952f2994
GitHub-Last-Rev: b843ab740b
GitHub-Pull-Request: golang/go#30819
Reviewed-on: https://go-review.googlesource.com/c/go/+/167387
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
CL 163760 was submitted with this file generated from an old version
of the code generator.
Change-Id: I9a3b9a48f794f74567f82ef58637cb1820befd11
Reviewed-on: https://go-review.googlesource.com/c/go/+/167677
Reviewed-by: Richard Musiol <neelance@gmail.com>
TryBot is sometimes running into deadlocks on js/wasm. We haven't been
able to reproduce them yet. This workaround is an experiment to resolve
these deadlocks by retrying a missed timeout event.
A timeout event is scheduled by Go to be woken by JavaScript after a
certain amount of time. The checkTimeouts function then checks which
notes to wake by comparing their deadline to nanotime. If this
check fails erroneously then the note may stay asleep forever, causing
a deadlock. This may or may not be the reason of the observed
deadlocks.
Updates #28975.
Change-Id: I46b9d4069307142914f0e7b3acd4e65578319f0b
Reviewed-on: https://go-review.googlesource.com/c/go/+/167119
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Checks that specs exist before attempting to access the first element in genDecl printer.
Change-Id: I3619bcabf6fec64c88b7a10cdb7be355e9e40559
GitHub-Last-Rev: 54cf699c96
GitHub-Pull-Request: golang/go#30823
Reviewed-on: https://go-review.googlesource.com/c/go/+/167390
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This reverts CL 166985, restoring CL 162698.
The bootstrap failure from CL 162698 was fixed in
CL 167077 and CL 167078.
Fixes#30228
Change-Id: I5a4e3081018c51b74b67185e64f20a9c824a564e
Reviewed-on: https://go-review.googlesource.com/c/go/+/167087
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
A bug in the encoding of XX1-Form is flipping bit 31 of such instructions.
This may result in register clobering when using VSX instructions.
This was not exposed before because we currently don't generate these
instructions in SSA, and the asm files in which they are present aren't
affected by register clobbering.
This change fixes the bug and adds a testcase for the problem.
Fixes#30112
Change-Id: I77b606159ae1efea33d2ba3e1c74b7fae8d5d2e7
Reviewed-on: https://go-review.googlesource.com/c/go/+/163759
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This applies only for cases where %w is not used.
The purpose of this change is to reduce test failures where tests
depend on these two being the same type, as they previously were.
Change-Id: I2dd28b93fe1d59f3cfbb4eb0875d1fb8ee699746
Reviewed-on: https://go-review.googlesource.com/c/go/+/167402
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
See Issue #29382 and Issue #30468.
Improvements in this CL:
name old time/op new time/op delta
New-8 352ns ± 2% 225ns ± 5% -36.04% (p=0.008 n=5+5)
Improvements together with moving to 1 uintptr:
name old time/op new time/op delta
New-8 475ns ± 3% 225ns ± 5% -52.59% (p=0.008 n=5+5)
Change-Id: I9d69a14e5e10a6498767defb7d5f26ceedcf9ba5
Reviewed-on: https://go-review.googlesource.com/c/go/+/167401
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
This is a refinement of CL 164557.
Make it explicit in tests that using a non-string verb with
fmtError does not result in falling back to using fmt.Formatter.
Change-Id: I6d090f31818eb7cc7668d7565b1449c91cd03a23
Reviewed-on: https://go-review.googlesource.com/c/go/+/164701
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
Standard output is reserved for actual program output.
Debug print should be limited in general (here they are
enabled by an environment variable) and always go to
standard error.
Came across by accident.
Change-Id: I1490be71473520f049719572b3acaa0ea9f9e5c1
Reviewed-on: https://go-review.googlesource.com/c/go/+/167502
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
As of CL 163747, we can write arbitrary length strings
in assembly DATA instructions.
Make use of it here to improve readability.
Change-Id: I556279ca893f527874e3b26112c43573834ccd9c
Reviewed-on: https://go-review.googlesource.com/c/go/+/167386
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
CL 165619 removed these names when it removed
the use of the plain 'return'. But the names help for
documentation purposes even without being mentioned
directly in the function, so removing them makes the
code less readable. Put them back. I renamed found
to zeroFound to make the meaning clearer.
Change-Id: I1010931f08290af0b0ede7d21b1404c2eea196a0
Reviewed-on: https://go-review.googlesource.com/c/go/+/165899
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This rewrite rule triggers only once, in math/big.quotToFloat64,
as part of converting a uint64 to a float64.
Nevertheless, it is cheap; let's add it.
Change-Id: I3ed4a197a559110fec1bc04b3a8abb4c7fcc2c89
Reviewed-on: https://go-review.googlesource.com/c/go/+/167500
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
We know that a & 31 is non-negative for all a, signed or not.
We can avoid checking that and needing to write out an
unreachable call to panicshift.
Change-Id: I32f32fb2c950d2b2b35ac5c0e99b7b2dbd47f917
Reviewed-on: https://go-review.googlesource.com/c/go/+/167499
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
Based on suggestion from gri@ on golang.org/cl/166980.
Passes toolstash-check.
Change-Id: I79b66bb09b5635f3a9daecaa5d605b661a0ab108
Reviewed-on: https://go-review.googlesource.com/c/go/+/167501
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The len godoc uses a blockquote to list the rules for its semantics.
The item that describes channels is a bit long, so it's split in two
lines. However, the first line ends with a semicolon, and the second
line can be read as a sentence of its own, so it's easy to misinterpret
that the two lines are separate.
Making that easy mistake would lead to an incorrect understanding of
len:
if v is nil, len(v) is zero.
This could lead us to think that len(nil) is valid and should return
zero. When in fact, that statement only applies to nil channels.
To make this less ambiguous, add a bit of indentation to the follow-up
line, to align with the channel body. If lists are added to godoc in the
future via #7873, perhaps this text can be simplified.
Fixes#30349.
Change-Id: I84226edc812d429493137bcc65c332e92d4e6c87
Reviewed-on: https://go-review.googlesource.com/c/go/+/167403
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
`go build` has chosen the last element of the package import path
as the default output name when -o option is given. That caused
the output of a package build when the module root is the major
version component such as 'v2'.
A similar issue involving `go install` was fixed in
https://golang.org/cl/128900. This CL refactors the logic added
with the change and makes it available as
internal/load.DefaultExecName.
This CL makes 'go test' to choose the right default test binary
name when the tested package is in the module root. (E.g.,
instead of v2.test, choose pkg.test for the test of 'path/pkg/v2')
Fixes#27283.
Change-Id: I6905754f0906db46e3ce069552715f45356913ae
Reviewed-on: https://go-review.googlesource.com/c/go/+/140863
Reviewed-by: Bryan C. Mills <bcmills@google.com>
The only ways to construct an OLITERAL node are (1) a basic literal
from the source package, (2) constant folding within evconst (which
only folds Go language constants), (3) the universal "nil" constant,
and (4) implicit conversions of nil to some concrete type.
Passes toolstash-check.
Change-Id: I30fc6b07ebede7adbdfa4ed562436cbb7078a2ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/166981
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
All setconst calls now happen within evconst. While here, get rid of
callrecv, which (incompletely) duplicates the logic of hascallchan.
Passes toolstash-check.
Change-Id: Ic67b9dd2a1b397d4bc25e8c8b6f81daf4f6cfb75
Reviewed-on: https://go-review.googlesource.com/c/go/+/166980
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
We already have a pure go code sequence that is compiled into single load.
Just use it everywhere, instead of pointer hackery.
Passes toolstash-check.
Change-Id: I0c42b5532fa9a5665da3385913609c6d42aaff27
Reviewed-on: https://go-review.googlesource.com/c/go/+/118568
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This reduces the number of extra bounds check hints we need to
insert. For example, rather than producing:
_ = v.Args[2]
x := v.Args[0]
y := v.Args[1]
z := v.Args[2]
We now produce:
z := v.Args[2]
x := v.Args[0]
y := v.Args[1]
This gets rid of about 7000 lines of code from the rewrite rules.
Change-Id: I1291cf0f82e8d035a6d65bce7dee6cedee04cbcd
Reviewed-on: https://go-review.googlesource.com/c/go/+/167397
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
ppc64{,le} processor level selection allows the compiler to generate instructions
targeting newer processors and processor-specific optimizations without breaking
compatibility with our current baseline. This feature introduces a new environment
variable, GOPPC64.
GOPPC64 is a GOARCH=ppc64{,le} specific option, for a choice between different
processor levels (i.e. Instruction Set Architecture versions) for which the
compiler will target. The default is 'power8'.
Change-Id: Ic152e283ae1c47084ece4346fa002a3eabb3bb9e
Reviewed-on: https://go-review.googlesource.com/c/go/+/163758
Run-TryBot: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
When a jump at the end of a block is about to be marked as
a statement, if the first real instruction in the target
block is also a statement for the same line, remove the
mark from the jump.
This is a first effort at a minimal-harm heuristic.
A better heuristic might skip over any "not-statement"
values preceding a definitely marked value.
Fixes#29443.
Change-Id: Ibd52783713b4936e0c2dfda8d708bf186f33b00a
Reviewed-on: https://go-review.googlesource.com/c/go/+/159977
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
