Currently, we handle "x op= y" by rewriting as "x = x op y", while
ensuring that any calls or receive operations in 'x' are only
evaluated once. Notably, pointer indirection, indexing operations,
etc. are left alone as it's typically safe to re-evaluate those.
However, those operations were interleaved with evaluating 'y', which
could include function calls that might cause re-evaluation to yield
different memory addresses.
As a fix, simply ensure that we order side-effecting operations in 'y'
before either evaluation of 'x'.
Fixes#21687.
Change-Id: Ib14e77760fda9c828e394e8e362dc9e5319a84b2
Reviewed-on: https://go-review.googlesource.com/60091
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Do the similar thing to CL 55143 to reduce IMUL.
Change-Id: I1bd38f618058e3cd74fac181f003610ea13f2294
Reviewed-on: https://go-review.googlesource.com/56252
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This function avoids subtle faults found in many ad-hoc implementations,
and is simple enough to be inlined by the compiler.
Fixes#20100
Change-Id: Ib320254e9b1f1f798c6ef906b116f63bc29e8d08
Reviewed-on: https://go-review.googlesource.com/43652
Reviewed-by: Robert Griesemer <gri@golang.org>
overLoadFactor wasn't really doing what it says it does.
It was reporting overOrEqualToLoadFactor. That's actually what we
want when adding an entry to a map, but it isn't what we want when
constructing a map in the first place.
The impetus for this change is that if you make a map with a hint
of exactly 8 (which happens, for example, with the unitMap in
time/format.go), we allocate 2 buckets for it instead of 1.
Instead, make overLoadFactor really report when it is > the max
allowed load factor, not >=. Adjust the callers who want to ensure
that the map is no more than the max load factor after an insertion
by adding a +1 to the current (pre-addition) size.
Change-Id: Ie8d85344800a9a870036b637b1031ddd9e4b93f9
Reviewed-on: https://go-review.googlesource.com/61053
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Currently we only use 1 and 4 as a scale for indexed 4-byte load.
In code generated in #20711 we can use indexed load with scale=8,
to improve performance:
name old time/op new time/op delta
GM-6 108µs ± 0% 95µs ± 0% -12.06% (p=0.000 n=10+10)
So add new ops and combine loadidx1(shift 3..).. into loadidx8,
same for stores.
Change-Id: I5ed1c250ac40960e20606580cf9de221e75b72f1
Reviewed-on: https://go-review.googlesource.com/46134
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
When compiling a plugin, package main gets a new name so as not to
conflict with the main package in the host binary, or any other
plugins. It is already defined by cmd/go, and used by cmd/link when
filling out the "" package placeholder in symbols.
With this CL, the plugin-specific name for main is also passed to
cmd/compile's -p flag. This is used to fill out the pkgpath field
of types, and ensures that two types defined in two different plugin
mains with the same name will not be mistaken for one another at
runtime.
Fixes#21386
Change-Id: I8a646d8d7451caff533fe0007343ea8b8e1704ed
Reviewed-on: https://go-review.googlesource.com/60910
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The spec is not conclusive about whether a non-constant shift of
certain untyped constant left operands is valid when the shift
expression appears as an index in an index or slice expression,
or as a size in a `make` function call.
Despite identical spec rules in all these cases, cmd/compile accepts
make([]byte, 1.0 << s)
but pronounces an error for
a[1.0 << s]
(go/types accepts both).
This change clarifies the spec by explicitly stating that an
untyped constant left operand in a non-constant shift (1.0 in
the above examples) will be given type `int` in these contexts.
A separate issue #21693 addresses the cmd/compile bug.
Fixes#14844.
Change-Id: I4b52125e487a607fae377fcbed55463cdce9836c
Reviewed-on: https://go-review.googlesource.com/60230
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Extract device major/minor number on Darwin and set Devmajor and
Devminor in FileInfoHeader. Code based on the Major/Minor functions for
Darwin in golang.org/x/sys/unix.
Change-Id: I51b65f607bfa2e6b177b8b66e2b246b771367b84
Reviewed-on: https://go-review.googlesource.com/60850
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Packages of dot imports don't appear in the Info.Implicits map
since they are already taken care of by the Info.Defs map. Fix
documentation.
Implicitly dot-imported objects of a package shouldn't appear
in the Info.Implicits map because the documentation never said
so and there's no way to map multiple objects to the same
*ast.ImportSpec with the current data structure.
Added missing test for Info.Implicits.
The fix is a trivial one-line deletion, the rest is documentation
and test.
Fixes#21591.
Change-Id: I12a37dab85c531911c9363ec3d58daa095c7eb24
Reviewed-on: https://go-review.googlesource.com/60672
Reviewed-by: Alan Donovan <adonovan@google.com>
The "build flags" mentioned in the documentation are only those
that apply to analyzing packages and executing the tool.
Fixes#21711.
Change-Id: Ie7b2a354f1e30c928b40888c51fc68e599a5444a
Reviewed-on: https://go-review.googlesource.com/60830
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The approach of https://golang.org/cl/43476 turned out incorrect.
The problem is that the sniff introduced by the CL only work for simple
expression. And when it fails it fallback to uint64, not int64, which
breaks backward compatibility.
In this CL, we use DWARF for guessing kind instead. That should be more
reliable than previous approach. And importanly, it fallbacks to int64 even
if it fails to guess kind.
Fixes#21708
Change-Id: I39a18cb2efbe4faa9becdcf53d5ac68dba180d46
Reviewed-on: https://go-review.googlesource.com/60510
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
On OpenBSD -current, clang is available/installed as 'cc'. This means that
the existing clang check fails and the clang related flags are not enabled.
Fix this by enabling the clang flags if the compiler claims to support them.
Change-Id: I84d124d2409a10f87002c6cbfdb69b4c9a55981a
Reviewed-on: https://go-review.googlesource.com/60750
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Change-Id: Iebb5b67c8defec22edd482d587edaf399a7ba82a
Reviewed-on: https://go-review.googlesource.com/37418
Reviewed-by: Adam Langley <agl@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Appease the vet builder until we figure out the ideal solution.
Updates #21716.
Change-Id: I64ecdf9b6efb0933c5c79e11c860966ff1980305
Reviewed-on: https://go-review.googlesource.com/60776
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Simplify the DWARF representation of structs by emitting field offsets
as constants rather than location descriptions.
This was not explicitly mentioned as an option in DWARF2. It is
mentioned in DWARF4, but isn't listed in the changes, so it's not clear
if this was always intended to work or is an undocumented change. Either
way, it should be valid DWARF4.
Change-Id: Idf7fdd397a21c8f8745673ecc77ef65afa3ffe1c
Reviewed-on: https://go-review.googlesource.com/51611
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David Chase <drchase@google.com>
When we added a Stat call to determine the initial buffer size in
https://golang.org/cl/163069, we included an arbitrary 1e9-byte limit
"just in case". That interacts badly with power-of-2 resizing in
*bytes.Buffer: it causes buffers reading from very large files to
consume up to twice the necessary space.
The documentation for (os.FileInfo).Size says that it reports "length
in bytes for regular files; system-dependent for others", but the
"system dependent" cases overwhelmingly return either a small number
(e.g., the length of the target path for a symlink) or a non-positive
number (e.g., for a file in /proc under Linux). It should be
appropriate to use the number reported by Size as an approximate lower
bound, even if it is large.
fixes#21455
Change-Id: I609c72519b7b87428c24d0b22db46eede30e0e54
Reviewed-on: https://go-review.googlesource.com/55870
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Since these are type aliases in Go 1.9 make rewriting
golang.org/x/net/context imports to context the default.
Change-Id: Ib7ee58b59ea5463b92e1590c8b8f5c0ef87d310b
Reviewed-on: https://go-review.googlesource.com/58590
Reviewed-by: Sameer Ajmani <sameer@golang.org>
Run-TryBot: Sam Whited <sam@samwhited.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Fixes#20933
Change-Id: I827c8d265674a7448c51c1da991e9b3b4501ba11
Reviewed-on: https://go-review.googlesource.com/59850
Run-TryBot: Tom Bergan <tombergan@google.com>
Reviewed-by: Tom Bergan <tombergan@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This makes sure that the go/types package still builds even if
the hilbert test generated its test file in the go/types package
(when run as: go test -run Hilbert -out=h.go).
Change-Id: I60ecbaaa1537de14cfa95e2e6fc8ebedff651baf
Reviewed-on: https://go-review.googlesource.com/60531
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
Some constants were added to flate that seem to be an experimental
attempt at increasing the window size. However, according to RFC1951,
the largest window size is 32KiB, so these constants are non-standard.
Delete them.
Fixes#18458
Change-Id: Ia94989637ca031a56bce2548624fa48044caa7b9
Reviewed-on: https://go-review.googlesource.com/60490
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This change added support "end of central directory record comemnt" to the Writer.
There is a new exported field Writer.Comment in this change.
If invalid size of comment was set, Close returns error without closing resources.
Fixes#21634
Change-Id: Ifb62bc6c7f81b9257ac83eb570ad9915de727f8c
Reviewed-on: https://go-review.googlesource.com/59310
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Normal shift rules plus constant folding are enough to generate
efficient shift-by-constant instructions.
Add test to make sure we don't generate comparisons for constant
shifts.
TODO: there are still constant shift rules on PPC64. If they
are removed, the constant folding rules are not enough to remove
all the test and mask stuff for constant shifts. Leave them in
for now.
Fixes#20663.
Change-Id: I724cc324aa8607762d0c8aacf9bfa641bda5c2a1
Reviewed-on: https://go-review.googlesource.com/60330
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Matches other architectures by using names for syscalls instead of
numbers directly.
Fixes#20499.
Change-Id: I63d606b0b1fe6fb517fd994a7542a3f38d80dd54
Reviewed-on: https://go-review.googlesource.com/44213
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Between go1.7 and go1.8, a performance regression was introduced in some of the
BenchmarkCompareBytes benchmarks.
Go1.7 vs Go1.8:
BenchmarkCompareBytesToNil-8 7.44 8.44 +13.44%
BenchmarkCompareBytesIdentical-8 6.96 11.5 +65.23%
BenchmarkCompareBytesBigIdentical-8 6.65 47112 +708351.13%
This change fixes the problem by optimizing the case where the byte slices being
compared are equal:
Go1.9 vs current:
BenchmarkCompareBytesToNil-8 7.35 7.00 -4.76%
BenchmarkCompareBytesIdentical-8 11.4 6.81 -40.26%
BenchmarkCompareBytesBigIdentical-8 48396 9.26 -99.98%
runtime.cmpstring can benefit from the same approach and is also changed.
Change-Id: I3cb25f59d8b940a83a2cf687eea764cfeff90688
Reviewed-on: https://go-review.googlesource.com/59650
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Currently, cgo supports only macros which can be reduced to constants
or variables. The CL addresses remaining parts, macros which can be
represented as niladic functions.
The basic idea is simple:
1. make a thin wrapper function per macros.
2. replace macro expansions with function calls.
Fixes#10715Fixes#18720
Change-Id: I150b4fb48e9dc4cc34466ef6417c04ac93d4bc1a
Reviewed-on: https://go-review.googlesource.com/43970
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Use "file" consistently instead of "entry".
Change-Id: Ia81c9665d0d956adb78f7fa49de40cdb87fba000
Reviewed-on: https://go-review.googlesource.com/60150
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Nearly every Header obtained from FileInfoHeader via the FS has
timestamps with sub-second resolution and the AccessTime
and ChangeTime fields populated. This forces the PAX format
to almost always be used, which has the following problems:
* PAX is still not as widely supported compared to USTAR
* The PAX headers will occupy at minimum 1KiB for every entry
The old behavior of tar Writer had no support for sub-second resolution
nor any support for AccessTime or ChangeTime, so had neither problem.
Instead the Writer would just truncate sub-second information and
ignore the AccessTime and ChangeTime fields.
In this CL, we preserve the behavior such that the *default* behavior
would output a USTAR header for most cases by truncating sub-second
time measurements and ignoring AccessTime and ChangeTime.
To use either of the features, users will need to explicitly specify
that the format is PAX or GNU.
The exact policy chosen is this:
* USTAR and GNU may still be chosen even if sub-second measurements
are present; they simply truncate the timestamp to the nearest second.
As before, PAX uses sub-second resolutions.
* If the Format is unspecified, then WriteHeader ignores AccessTime
and ChangeTime when using the USTAR format.
This ensures that USTAR may still be chosen for a vast majority of
file entries obtained through FileInfoHeader.
Updates #11171
Updates #17876
Change-Id: Icc5274d4245922924498fd79b8d3ae94d5717271
Reviewed-on: https://go-review.googlesource.com/59230
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This change implements the convention for generated code header agreed upon in https://golang.org/s/generatedcode.
Additionally run go generate.
Also update some comments.
Updates #13560
Change-Id: If45f91b93aaa0d43280c2c4630823bc4d2dc7d3a
Reviewed-on: https://go-review.googlesource.com/60250
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Previously, the suggested code would result in the following golint warning:
“should drop = 0 from declaration of var errorsOnlyKey; it is the zero value”
Change-Id: I1a302c1e40ca89acbc76897e39097ecd04865460
Reviewed-on: https://go-review.googlesource.com/60290
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Some instructions operating on <= 32 bits also zero out upper 32bits.
Remove zeroextensions of such values. Triggers a few times during
all.bash. Also removes ugly code like:
MOVL CX,CX
Change-Id: I66a46c190dd6929b7e3c52f3fe6b967768d00638
Reviewed-on: https://go-review.googlesource.com/58090
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The last sentence in the section on slice expressions could be read
as if it might apply to strings. Changed the sentence a bit to
emphasize its applicability to slices only. See also the issue for
more background.
Fixes#19220.
Change-Id: I8551f34230e4ed93f951e7b871cc81f54a5874a9
Reviewed-on: https://go-review.googlesource.com/59890
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This makes the name of the function to construct the map bucket type
consistent with runtimes naming and the existing hmap function.
Change-Id: If4d8b4a54c92ab914d4adcb96022b48d8b5db631
Reviewed-on: https://go-review.googlesource.com/59915
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Padding needed for map buckets is dependent on the types used to
construct the map bucket. In case of indirect keys or values pointers
are used in the map bucket to the keys or values.
Change the map bucket padding calculation to take the alignment of
the key and value types used to construct the map bucket into account
instead of the original key and value type.
Since pointers are always 32bit aligned on amd64p32 this prevents
adding unneeded padding in case the key or value would have needed
64bit alignment without indirect referencing.
Change-Id: I7943448e882d269b5cff7e921a2a6f3430c50878
Reviewed-on: https://go-review.googlesource.com/60030
Reviewed-by: Keith Randall <khr@golang.org>
Check map invariants, type size and alignments during compile time.
Keep runtime checks for reflect by adding them to reflect_makemap.
Change-Id: Ia28610626591bf7fafb7d5a1ca318da272e54879
Reviewed-on: https://go-review.googlesource.com/59914
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
* rename to emitPcln because I'd like to skip not only container types,
but also something like "go.buildid" in the future.
* return bool instead of int.
Change-Id: I029adb81292f7dd2fe98e69f3877c5c27f32ec30
Reviewed-on: https://go-review.googlesource.com/59415
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
