Daniel Martí [Wed, 26 Apr 2017 11:04:08 +0000 (12:04 +0100)]
cmd/compile: make duplicate expr cases readable
Instead of just printing the value, print the original node to make the
error more human-friendly. Also print the value if its string form is
different than the original node, to make sure it's obvious what value
was duplicated.
This means that "case '@', '@':", which used to print:
duplicate case 64 in switch
Will now print:
duplicate case '@' (value 64) in switch
Factor this logic out into its own function to reuse it in range cases
and any other place where we might want to print a node and its value in
the future.
Also needed to split the errorcheck files because expression switch case
duplicates are now detected earlier, so they stop the compiler before it
gets to generating the AST and detecting the type switch case
duplicates.
Fixes #20112.
Change-Id: I9009b50dec0d0e705e5de9c9ccb08f1dce8a5a99
Reviewed-on: https://go-review.googlesource.com/41852
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Austin Clements [Thu, 18 May 2017 20:56:48 +0000 (16:56 -0400)]
runtime: use pselect6 for usleep on linux/amd64 and linux/arm
Android O black-lists the select system call because its libc, Bionic,
does not use this system call. Replace our use of select with pselect6
(which is allowed) on the platforms that support targeting Android.
linux/arm64 already uses pselect6 because there is no select on arm64,
so only linux/amd64 and linux/arm need changing. pselect6 has been
available since Linux 2.6.16, which is before Go's minimum
requirement.
Mikio Hara [Mon, 13 Feb 2017 21:38:10 +0000 (06:38 +0900)]
net: make {TCP,UDP,IP,Unix}Conn compliant of syscall.Conn interface
This change makes {TCP,UDP,IP,Unix}Conn types compliant of
syscall.Conn interface and adds type rawConn as an implementation of
syscall.RawConn interface.
By this change, the long-standing issues regarding unsupported socket
options and system calls can be solved partly and the broken x/net
packages due to https://go-review.googlesource.com/36799 can be
repaired.
Mikio Hara [Mon, 13 Feb 2017 20:55:41 +0000 (05:55 +0900)]
internal/poll: add RawControl, RawRead and RawWrite methods to FD
This change adds RawControl, RawRead and RawWrite methods to type FD
to make the runtime-integrated network poller work together with a
user-defined function. The methods are used via the net package from
external packages and type FD is considered as an implementation of
syscall.Conn and syscall.RawConn interfaces.
Updates #19435.
Change-Id: I4ad04b10ffddb2b54fa8d70587440960d73c0a2d
Reviewed-on: https://go-review.googlesource.com/37038
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Mikio Hara [Tue, 7 Mar 2017 20:52:07 +0000 (05:52 +0900)]
syscall: add Conn and RawConn interfaces
This change adds Conn and RawConn interfaces which can be used to
manipulate raw network connection end points typically represented as
socket descriptors.
Alex Brainman [Tue, 9 May 2017 06:50:41 +0000 (16:50 +1000)]
os: make windows Stat as fast as Lstat for files and directories
Recent CL 41834 made windows Stat work for all symlinks.
But CL 41834 also made Stat slow.
John Starks sugested
(see https://github.com/golang/go/issues/19922#issuecomment-300031421)
to use GetFileAttributesEx for files and directories instead.
This makes Stat as fast as at go1.9.
David du Colombier [Fri, 19 May 2017 00:13:50 +0000 (02:13 +0200)]
cmd/compile: skip TestScopeRanges on Plan 9
TestScopeRanges has been added in CL 40095. This
test is failing on Plan 9 because executables don't
have a DWARF symbol table.
Fixes #20418.
Change-Id: I6dd3baa636998134ccd042203c8b5c3199a4d6e1
Reviewed-on: https://go-review.googlesource.com/43670
Run-TryBot: David du Colombier <0intro@gmail.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Alessandro Arzilli [Tue, 2 May 2017 14:46:01 +0000 (16:46 +0200)]
cmd/compile: output DWARF lexical blocks for local variables
Change compiler and linker to emit DWARF lexical blocks in .debug_info
section when compiling with -N -l.
Version of debug_info is updated from DWARF v2 to DWARF v3 since
version 2 does not allow lexical blocks with discontinuous PC ranges.
Remaining open problems:
- scope information is removed from inlined functions
- variables records do not have DW_AT_start_scope attributes so a
variable will shadow other variables with the same name as soon as its
containing scope begins, even before its declaration.
A number of issues in decoder.Read and newlineFilteringReader.Read were
preventing errors from the reader supplying the encoded data from being
propagated to the caller. Fixing these issues revealed some additional
problems in which valid decoded data was not always returned to the user
when errors were actually propagated.
This commit fixes both the error propagation and the lost decoded data
problems. It also adds some new unit tests to ensure errors are handled
correctly by decoder.Read. The new unit tests increase the test coverage
of this package from 96.2% to 97.9%.
Daniel Theophanes [Thu, 23 Mar 2017 20:17:59 +0000 (13:17 -0700)]
database/sql: allow drivers to support custom arg types
Previously all arguments were passed through driver.IsValid.
This checked arguments against a few fundamental go types and
prevented others from being passed in as arguments.
The new interface driver.NamedValueChecker may be implemented
by both driver.Stmt and driver.Conn. This allows
this new interface to completely supersede the
driver.ColumnConverter interface as it can be used for
checking arguments known to a prepared statement and
arbitrary query arguments. The NamedValueChecker may be
skipped with driver.ErrSkip after all special cases are
exhausted to use the default argument converter.
In addition if driver.ErrRemoveArgument is returned
the argument will not be passed to the query at all,
useful for passing in driver specific per-query options.
Add a canonical Out argument wrapper to be passed
to OUTPUT parameters. This will unify checks that need to
be written in the NameValueChecker.
The statement number check is also moved to the argument
converter so the NamedValueChecker may remove arguments
passed to the query.
cmd/compile: search for remaining WB ops from end to beginning
The writebarrier pass processes WB ops from beginning to end,
replacing them by other values.
But it also checks whether there are more ops to process
by walking from beginning to end.
This is quadratic, so walk from end to beginning instead.
This speeds up compiling the code in issue 13554:
name old time/op new time/op delta
Pkg 11.9s ± 2% 8.3s ± 3% -29.88% (p=0.000 n=18+17)
cmd/compile: don't break up contiguous blocks in looprotate
looprotate finds loop headers and arranges for them to be placed
after the body of the loop. This eliminates a jump from the body.
However, if the loop header is a series of contiguously laid out blocks,
the rotation introduces a new jump in that series.
This CL expands the "loop header" to move to be the entire
run of contiguously laid out blocks in the same loop.
This shrinks object files a little, and actually speeds up
the compiler noticeably. Numbers below.
Fannkuch performance seems to vary a lot by machine. On my laptop:
name old time/op new time/op delta
Fannkuch11-8 2.89s ± 2% 2.85s ± 3% -1.22% (p=0.000 n=50+50)
This has a significant affect on the append benchmarks in #14758:
name old time/op new time/op delta
Foo-8 312ns ± 3% 276ns ± 2% -11.37% (p=0.000 n=30+29)
Bar-8 565ns ± 2% 456ns ± 2% -19.27% (p=0.000 n=27+28)
Alex Brainman [Tue, 2 May 2017 06:03:45 +0000 (16:03 +1000)]
cmd/link: make sure that runtime.epclntab lives in .text section
Second attempt to fix #14710.
CL 35272 already tried to fix this issue. But CL 35272 assumed
that runtime.epclntab type is STEXT, while it is actually SRODATA.
This CL uses Symbol.Sect.Seg to determine if symbol is part
of Segtext or Segdata.
Fixes #14710
Change-Id: Ic6b6f657555c87a64d2bc36cc4c07ab0591d00c4
Reviewed-on: https://go-review.googlesource.com/42390
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Austin Clements [Wed, 17 May 2017 18:27:28 +0000 (14:27 -0400)]
runtime/pprof: don't produce 0 location in count profiles
profileBuilder.locForPC returns 0 to mean "no location" because 0 is
an invalid location index. However, the code to build count profiles
doesn't check the result of locForPC, so this 0 location index ends up
in the profile's location list. This, in turn, causes problems later
when we decode the profile because it puts a nil *Location in the
sample's location slice, which can later lead to a nil pointer panic.
Fix this by making printCountProfile correctly discard the result of
locForPC if it returns 0. This makes this call match the other two
calls of locForPC.
Carl Henrik Lunde [Wed, 17 May 2017 17:37:33 +0000 (19:37 +0200)]
runtime/pprof: deflake TestGoroutineCounts
TestGoroutineCounts was flaky when running on a system under load.
This happened on three builds the last couple of days.
Fix this by running this test with a single operating system thread, so
we do not depend on the operating system scheduler. 50 000 tests ran
without failure with the new version, the old version failed 0.5% of the
time.
fuseBlockPlain was accidentally quadratic.
If you had plain blocks b1 -> b2 -> b3 -> b4,
each containing single values v1, v2, v3, and v4 respectively,
fuseBlockPlain would move v1 from b1 to b2 to b3 to b4,
then v2 from b2 to b3 to b4, etc.
There are two obvious fixes.
* Look for runs of blocks in fuseBlockPlain
and handle them in a single go.
* Fuse from end to beginning; any given value in a run
of blocks to fuse then moves only once.
The latter is much simpler, so that's what this CL does.
Somewhat surprisingly, this change does not pass toolstash-check.
The resulting set of blocks is the same,
and the values in them are the same,
but the order of values in them differ,
and that order of values (while arbitrary)
is enough to change the compiler's output.
This may be due to #20178; deadstore is the next pass after fuse.
Adding basic sorting to the beginning of deadstore
is enough to make this CL pass toolstash-check:
for _, b := range f.Blocks {
obj.SortSlice(b.Values, func(i, j int) bool { return b.Values[i].ID < b.Values[j].ID })
}
Happily, this CL appears to result in better code on average,
if only by accident. It cuts 4k off of cmd/go; go1 benchmarks
are noisy as always but don't regress (numbers below).
No impact on the standard compilebench benchmarks.
For the code in #13554, this speeds up compilation dramatically:
name old time/op new time/op delta
Pkg 53.1s ± 2% 12.8s ± 3% -75.92% (p=0.008 n=5+5)
name old user-time/op new user-time/op delta
Pkg 55.0s ± 2% 14.9s ± 3% -73.00% (p=0.008 n=5+5)
name old alloc/op new alloc/op delta
Pkg 2.04GB ± 0% 2.04GB ± 0% +0.18% (p=0.008 n=5+5)
name old allocs/op new allocs/op delta
Pkg 6.21M ± 0% 6.21M ± 0% ~ (p=0.222 n=5+5)
name old object-bytes new object-bytes delta
Pkg 28.4M ± 0% 28.4M ± 0% +0.00% (p=0.008 n=5+5)
name old export-bytes new export-bytes delta
Pkg 208 ± 0% 208 ± 0% ~ (all equal)
cmd/compile: seed rand with time when race enabled
When the race detector is enabled,
the compiler randomizes the order in which functions are compiled,
in an attempt to shake out bugs.
But we never re-seed the rand source, so every execution is identical.
Fix that to get more coverage.
Hiroshi Ioka [Tue, 16 May 2017 12:52:41 +0000 (21:52 +0900)]
cmd/cgo: support large unsigned macros
Currently, cgo converts integer macros into int64 if it's possible.
As a result, some macros which satisfy
math.MaxInt64 < x <= math.MaxUint64
will lose their original values.
This CL introduces the new probe to check signs,
so we can handle signed ints and unsigned ints separately.
Fixes #20369
Change-Id: I002ba452a82514b3a87440960473676f842cc9ee
Reviewed-on: https://go-review.googlesource.com/43476 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Ian Lance Taylor [Wed, 17 May 2017 01:02:56 +0000 (18:02 -0700)]
cmd/go: don't fail on missing runtime/internal/sys/zversion.go
The generated file runtime/internal/sys/zversion.go is deleted by
`go tool cmd dist clean` as part of running clean.bash. Don't treat
a missing file as a reason to stop running the go tool; just treat
is as meaning that runtime/internal/sys is stale.
No test because I don't particularly want to clobber $GOROOT.
Fixes #20385.
Change-Id: I5251a99542cc93c33f627f133d7118df56e18af1
Reviewed-on: https://go-review.googlesource.com/43559
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Ian Lance Taylor [Wed, 17 May 2017 00:41:42 +0000 (17:41 -0700)]
os: fix handling of ErrShortWrite in (*File).Write
Restore the handling of io.ErrShortWrite in (*File).Write:
if we write less than the requested amount, and there is no error from
the syscall, then return io.ErrShortWrite.
I can't figure out how to write a test for this. It would require a
non-pollable file (not a pipe) on a device that is almost but not
quite entirely full. The original code (https://golang.org/cl/36800043,
committed as part of https://golang.org/cl/36930044) does not have a test.
Fixes #20386.
Change-Id: Ied7b411e621e1eaf49f864f8db90069f276256f5
Reviewed-on: https://go-review.googlesource.com/43558
Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Sean Chittenden [Sun, 14 May 2017 16:42:35 +0000 (09:42 -0700)]
runtime: mmap(2) on Solaris & Illumos can return EAGAIN.
In low memory situations mmap(2) on Illumos[2] can return EAGAIN when it
is unable to reserve the necessary space for the requested mapping. Go
was not previously handling this correctly for Illumos and would fail to
recognize it was in a low-memory situation, the result being the program
would terminate with a panic instead of running the GC.
Robert Griesemer [Mon, 15 May 2017 18:46:05 +0000 (11:46 -0700)]
go/types: fewer spurious "declared but not used" follow-on errors
Mark variables as used even when they appear within an expression
context which we can't type-check; e.g., because the expression is
erroneous, or comes from an import "C" declaration.
Fixes #20358.
Change-Id: Ib28cc78d3867c597c7a1ace54de09ada02f5b33a
Reviewed-on: https://go-review.googlesource.com/43500 Reviewed-by: Alan Donovan <adonovan@google.com>
David Chase [Mon, 15 May 2017 17:49:30 +0000 (13:49 -0400)]
cmd/compile: don't attach lines to SB, SP, similar constants
Attaching positions to SB, SP, initial mem can result in
less-good line-numbering when compiled for debugging.
This "fix" also removes source position from a zero-valued
struct (but not from its fields) and from a zero-length
array constant.
This may be a general problem for constants in entry blocks.
Fixes #20367.
Change-Id: I7e9df3341be2e2f60f127d35bb31e43cdcfce9a1
Reviewed-on: https://go-review.googlesource.com/43531
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
Dmitri Shuralyov [Mon, 1 May 2017 21:28:33 +0000 (17:28 -0400)]
go/build: return partial information on Import error, for local import paths
Documentation of build.Import says:
// If the path is a local import path naming a package that can be imported
// using a standard import path, the returned package will set p.ImportPath
// to that path.
// ...
// If an error occurs, Import returns a non-nil error and a non-nil
// *Package containing partial information.
That behavior was previously untested, and broken by change in CL 33158.
Fix that by avoiding returning early on error for local import paths.
First, gather partial information, and only then check that the p.Dir
directory exists.
Add tests for this behavior.
Fixes #19769.
Fixes #20175 (duplicate of #19769).
Updates #17863.
runtime/pprof: expand inlined frames in symbolized proto profiles
Currently proto symbolization uses runtime.FuncForPC and assumes each
PC maps to a single frame. This isn't true in the presence of inlining
(even with leaf-only inlining this can get incorrect results).
Change PC symbolization to use runtime.CallersFrames to expand each PC
to all of the frames at that PC.
Austin Clements [Tue, 9 May 2017 02:31:41 +0000 (22:31 -0400)]
runtime/pprof: clean up call/return PCs in memory profiles
Proto profile conversion is inconsistent about call vs return PCs in
profile locations. The proto defines locations to be call PCs. This is
what we do when proto-izing CPU profiles, but we fail to convert the
return PCs in memory and count profile stacks to call PCs when
converting them to proto locations.
Fix this in the heap and count profile conversion functions.
TestConvertMemProfile also hard-codes this failure to convert from
return PCs to call PCs, so fix up the addresses in the synthesized
profile to be return PCs while checking that we get call PCs out of
the conversion.
Alex Brainman [Thu, 11 May 2017 01:55:59 +0000 (11:55 +1000)]
cmd/link: actually generate .debug_gdb_scripts section on windows
Adjust finddebugruntimepath to look for runtime/debug.go file
instead of runtime/runtime.go. This actually finds runtime.GOMAXPROCS
in every Go executable (including windows).
I also included "-Wl,-T,fix_debug_gdb_scripts.ld" parameter to gcc
invocation on windows to work around gcc bug (see #20183 for details).
This CL only fixes windows -buildmode=exe, buildmode=c-archive
is still broken.
Thanks to Egon Elbre and Nick Clifton for investigation.
Fixes #20183
Fixes #20218
Change-Id: I5369a4db3913226aef3d9bd6317446856b0a1c34
Reviewed-on: https://go-review.googlesource.com/43331 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Make yellow the last highlight color rather than the first.
Yellow is also the color that Chrome uses to highlight
search results, which can be confusing.
Also, when Night Shift is on on macOS,
yellow highlighting is completely invisible.
I suppose should be sleeping instead.
cmd/compile: don't update outer variables after capturevars is complete
When compiling concurrently, we walk all functions before compiling
any of them. Walking functions can cause variables to switch from
being non-addrtaken to addrtaken, e.g. to prepare for a runtime call.
Typechecking propagates addrtaken-ness of closure variables to
their outer variables, so that capturevars can decide whether to
pass the variable's value or a pointer to it.
When all functions are compiled immediately, as long as the containing
function is compiled prior to the closure, this propagation has no effect.
When compilation is deferred, though, in rare cases, this results in
a change in the addrtaken-ness of a variable in the outer function,
which in turn changes the compiler's output.
(This is rare because in a great many cases, a temporary has been
introduced, insulating the outer variable from modification.)
But concurrent compilation must generate identical results.
To fix this, track whether capturevars has run.
If it has, there is no need to update outer variables
when closure variables change.
Capturevars always runs before any functions are walked or compiled.
The remainder of the changes in this CL are to support the test.
In particular, -d=compilelater forces the compiler to walk all
functions before compiling any of them, despite being non-concurrent.
This is useful because -live is fundamentally incompatible with
concurrent compilation, but we want -c=1 to have no behavior changes.
Lars Jeppesen [Sat, 29 Apr 2017 21:25:34 +0000 (23:25 +0200)]
archive/tar: remove file type bits from mode field
When writing tar files by using the FileInfoHeader
the type bits was set in the mode field of the header
This is not correct according to the standard (GNU/Posix) and
other implementations.
Fixed #20150
Change-Id: I3be7d946a1923ad5827cf45c696546a5e287ebba
Reviewed-on: https://go-review.googlesource.com/42093 Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Matt Harden [Mon, 20 Feb 2017 13:58:55 +0000 (05:58 -0800)]
net: allow Resolver to use a custom dialer
In some cases it is desirable to customize the way the DNS server is
contacted, for instance to use a specific LocalAddr. While most
operating-system level resolvers do not allow this, we have the
opportunity to do so with the Go resolver. Most of the code was
already in place to allow tests to override the dialer. This exposes
that functionality, and as a side effect eliminates the need for a
testing hook.
Austin Clements [Thu, 11 May 2017 19:28:39 +0000 (15:28 -0400)]
runtime: doubly fix "double wakeup" panic
runtime.gchelper depends on the non-atomic load of work.ndone
happening strictly before the atomic add of work.nwait. Until very
recently (commit 978af9c2db, fixing #20334), the compiler reordered
these operations. This created a race since work.ndone can change as
soon as work.nwait is equal to work.ndone. If that happened, more than
one gchelper could attempt to wake up the work.alldone note, causing a
"double wakeup" panic.
This was fixed in the compiler, but to make this code less subtle,
make the load of work.ndone atomic. This clearly forces the order of
these operations, ensuring the race doesn't happen.
Hiroshi Ioka [Fri, 12 May 2017 00:04:55 +0000 (09:04 +0900)]
cmd/go: fix TestCgoContainsSpace
TestCgoContainsSpace builds a small program which mimics $CC.
Usually, $CC attempts to compile a trivial code to detect its own
supported flags (i.e. "-no-pie", which must be passed on some systems),
however the mimic didn't consider these cases.
This CL solve the issue.
Also, use the same name as $CC, it may solve other potential problems.
Fixes #20324
Change-Id: I7a00ac016a5fd0667540f2a715371f8152edc395
Reviewed-on: https://go-review.googlesource.com/43330 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Keith Randall [Thu, 11 May 2017 21:46:49 +0000 (14:46 -0700)]
cmd/compile: fix store chain in schedule pass
Tuple ops are weird. They are essentially a pair of ops,
one which consumes a mem and one which generates a mem (the Select1).
The schedule pass didn't handle these quite right.
Fix the scheduler to include both parts of the paired op in
the store chain. That makes sure that loads are correctly ordered
with respect to the first of the pair.
Add a check for the ssacheck builder, that there is only one
live store at a time. I thought we already had such a check, but
apparently not...
This was discovered in the context for the Fannkuch benchmark.
It shrinks the number of panicindex calls in that function
from 13 back to 9, their 1.8.1 level.
It shrinks the function text a bit, from 829 to 801 bytes.
It slows down execution a little, presumably due to alignment (?).
name old time/op new time/op delta
Fannkuch11-8 2.68s ± 2% 2.74s ± 1% +2.09% (p=0.000 n=19+20)
After this CL, 1.8.1 and tip are identical:
name old time/op new time/op delta
Fannkuch11-8 2.74s ± 2% 2.74s ± 1% ~ (p=0.301 n=20+20)
cmd/compile: don't use statictmps for SSA-able composite literals
The writebarrier test has to change.
Now that T23 composite literals are passed to the backend,
they get SSA'd, so writes to their fields are treated separately,
so the relevant part of the first write to t23 is now a dead store.
Preserve the intent of the test by splitting it up into two functions.
Ben Shi [Tue, 2 May 2017 09:29:03 +0000 (09:29 +0000)]
cmd/internal/obj: continue to optimize ARM's constant pool
Both Keith's https://go-review.googlesource.com/c/41612/ and
and Ben's https://go-review.googlesource.com/c/41679/ optimized ARM's
constant pool. But neither was complete.
First, BIC was forgotten.
1. "BIC $0xff00ff00, Reg" can be optimized to
"BIC $0xff000000, Reg
BIC $0x0000ff00, Reg"
2. "BIC $0xffff00ff, Reg" can be optimized to
"AND $0x0000ff00, Reg"
3. "AND $0xffff00ff, Reg" can be optimized to
"BIC $0x0000ff00, Reg"
Second, break a non-ARMImmRot to the subtraction of two ARMImmRots was
left as TODO.
1. "ADD $0x00fffff0, Reg" can be optimized to
"ADD $0x01000000, Reg
SUB $0x00000010, Reg"
2. "SUB $0x00fffff0, Reg" can be optimized to
"SUB $0x01000000, Reg
ADD $0x00000010, Reg"
David Chase [Thu, 2 Feb 2017 19:51:15 +0000 (14:51 -0500)]
cmd/compile: reduce debugger-worsening line number churn
Reuse block head or preceding instruction's line number for
register allocator's spill, fill, copy, rematerialization
instructionsl; and also for phi, and for no-src-pos
instructions. Assembler creates same line number tables
for copy-predecessor-line and for no-src-pos,
but copy-predecessor produces better-looking assembly
language output with -S and with GOSSAFUNC, and does not
require changes to tests of existing assembly language.
Split "copyInto" into two cases, one for register allocation,
one for otherwise. This caused the test score line change
count to increase by one, which may reflect legitimately
useful information preserved. Without any special treatment
for copyInto, the change count increases by 21 more, from
51 to 72 (i.e., quite a lot).
There is a test; using two naive "scores" for line number
churn, the old numbering is 2x or 4x worse.
Fixes #18902.
Change-Id: I0a0a69659d30ee4e5d10116a0dd2b8c5df8457b1
Reviewed-on: https://go-review.googlesource.com/36207
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
Hiroshi Ioka [Wed, 10 May 2017 06:35:33 +0000 (15:35 +0900)]
go/build: accept spaces in cgo directives
Fixes #7906
Change-Id: Ibcf9cd670593241921ab3c426ff7357f799ebc3e
Reviewed-on: https://go-review.googlesource.com/43072 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Michael Munday [Wed, 29 Mar 2017 20:37:12 +0000 (16:37 -0400)]
cmd/compile: add generic rules to eliminate some unnecessary stores
Eliminates stores of values that have just been loaded from the same
location. Handles the common case where there are up to 3 intermediate
stores to non-overlapping struct fields.
For example the loads and stores of x.a, x.b and x.d in the following
function are now removed:
Michael Munday [Wed, 10 May 2017 15:00:03 +0000 (11:00 -0400)]
cmd/compile/internal/ssa: fix generation of ppc64x rules
The files PPC64.rules and rewritePPC64.go were out of sync due to
conflicts between CL 41630 and CL 42145 (i.e. running 'go run *.go'
in the gen directory resulted in unexpected changes).
Change-Id: I1d409656b66afeab6cb9c6df9b3dcab7859caa75
Reviewed-on: https://go-review.googlesource.com/43091
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com> Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Daniel Martí [Wed, 10 May 2017 11:53:39 +0000 (13:53 +0200)]
reflect: don't panic in ArrayOf if elem size is 0
We do a division by the elem type size to check if the array size would
be too large for the virtual address space. This is a silly check if the
size is 0, but the problem is that it means a division by zero and a
panic.
Since arrays of empty structs are valid in a regular program, make them
also work in reflect.
Use a separate, explicit test with struct{}{} to make sure the test for
a zero-sized type is not confused with the rest.
Daniel Martí [Wed, 10 May 2017 11:10:46 +0000 (13:10 +0200)]
reflect: fix String of new array types
When constructing a new type for an array type in ArrayOf, we don't
reset tflag to 0. All the other methods in the package, such as SliceOf,
do this already. This results in the new array type having weird issues
when being printed, such as having tflagExtraStar set when it shouldn't.
That flag removes the first char to get rid of '*', but when used
incorrectly in this case it eats the '[' character leading to broken
strings like "3]int".
This was fixed in 56752eb2 for issue #16722, but ArrayOf was missed.
Also make the XM test struct have a non-zero size as that leads to a
division by zero panic in ArrayOf.
Fixes #20311.
Change-Id: I18f1027fdbe9f71767201e7424269c3ceeb23eb5
Reviewed-on: https://go-review.googlesource.com/43130
Run-TryBot: Daniel Martí <mvdan@mvdan.cc> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
cmd/compile: allow OpVarXXX calls to be duplicated in writebarrier blocks
OpVarXXX Values don't generate instructions,
so there's no reason not to duplicate them,
and duplicating them generates better code
(fewer branches).
This requires changing the start/end accounting
to correctly handle the case in which we have run
of Values beginning with an OpVarXXX, e.g.
OpVarDef, OpZeroWB, OpMoveWB.
In that case, the sequence of values should begin
at the OpZeroWB, not the OpVarDef.
This also lays the groundwork for experimenting
with allowing duplication of some scalar stores.
Ian Lance Taylor [Tue, 9 May 2017 21:34:16 +0000 (14:34 -0700)]
cmd/internal/obj, cmd/link: fix st_other field on PPC64
In PPC64 ELF files, the st_other field indicates the number of
prologue instructions between the global and local entry points.
We add the instructions in the compiler and assembler if -shared is used.
We were assuming that the instructions were present when building a
c-archive or PIE or doing dynamic linking, on the assumption that those
are the cases where the go tool would be building with -shared.
That assumption fails when using some other tool, such as Bazel,
that does not necessarily use -shared in exactly the same way.
This CL records in the object file whether a symbol was compiled
with -shared (this will be the same for all symbols in a given compilation)
and uses that information when setting the st_other field.
Fixes #20290.
Change-Id: Ib2b77e16aef38824871102e3c244fcf04a86c6ea
Reviewed-on: https://go-review.googlesource.com/43051
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
When package ssa was created, Type was in package gc.
To avoid circular dependencies, we used an interface (ssa.Type)
to represent type information in SSA.
In the Go 1.9 cycle, gri extricated the Type type from package gc.
As a result, we can now use it in package ssa.
Now, instead of package types depending on package ssa,
it is the other way.
This is a more sensible dependency tree,
and helps compiler performance a bit.
Though this is a big CL, most of the changes are
mechanical and uninteresting.
Interesting bits:
* Add new singleton globals to package types for the special
SSA types Memory, Void, Invalid, Flags, and Int128.
* Add two new Types, TSSA for the special types,
and TTUPLE, for SSA tuple types.
ssa.MakeTuple is now types.NewTuple.
* Move type comparison result constants CMPlt, CMPeq, and CMPgt
to package types.
* We had picked the name "types" in our rules for the handy
list of types provided by ssa.Config. That conflicted with
the types package name, so change it to "typ".
* Update the type comparison routine to handle tuples and special
types inline.
* Teach gc/fmt.go how to print special types.
* We can now eliminate ElemTypes in favor of just Elem,
and probably also some other duplicated Type methods
designed to return ssa.Type instead of *types.Type.
* The ssa tests were using their own dummy types,
and they were not particularly careful about types in general.
Of necessity, this CL switches them to use *types.Type;
it does not make them more type-accurate.
Unfortunately, using types.Type means initializing a bit
of the types universe.
This is prime for refactoring and improvement.
This shrinks ssa.Value; it now fits in a smaller size class
on 64 bit systems. This doesn't have a giant impact,
though, since most Values are preallocated in a chunk.
cmd/compile: make builds reproducible in presence of **byte and **int8
CL 39915 introduced sorting of signats by ShortString
for reproducible builds. But ShortString treats types
byte and uint8 identically; same for rune and uint32.
CL 39915 attempted to compensate for this by only
adding the underlying type (uint8) to signats in addsignat.
This only works for byte and uint8. For e.g. *byte and *uint,
both get added, and their sort order is random,
leading to non-reproducible builds.
One fix would be to add yet another type printing mode
that doesn't eliminate byte and rune, and use it
for sorting signats. But the formatting routines
are complicated enough as it is.
Instead, just sort first by ShortString and then by String.
We can't just use String, because ShortString makes distinctions
that String doesn't. ShortString is really preferred here;
String is serving only as a backstop for handling of bytes and runes.
The long series of types in the test helps increase the odds of
failure, allowing a smaller number of iterations in the test.
On my machine, a full test takes 700ms.
cmd/internal/obj/arm64, cmd/compile: improve offset folding on ARM64
ARM64 assembler backend only accepts loads and stores with small
or aligned offset. The compiler therefore can only fold small or
aligned offsets into loads and stores. For locals and args, their
offsets to SP are not known until very late, and the compiler
makes conservative decision not folding some of them. However,
in most cases, the offset is indeed small or aligned, and can
be folded into load and store (but actually not).
This CL adds support of loads and stores with large and unaligned
offsets. When the offset doesn't fit into the instruction, it
uses two instructions and (for very large offset) the constant
pool. This way, the compiler doesn't need to be conservative,
and can simply fold the offset.
To make it work, the assembler's optab matching rules need to be
changed. Before, MOVD accepts C_UAUTO32K which matches multiple
of 8 between 0 and 32K, and also C_UAUTO16K, which may not be
multiple of 8 and does not fit into MOVD instruction. The
assembler errors in the latter case. This change makes it only
matches multiple of 8 (or offsets within ±256, which also fits
in instruction), and uses the large-or-unaligned-offset rule
for things doesn't fit (without error). Other sized move rules
are changed similarly.
Class C_UAUTO64K and C_UOREG64K are removed, as they are never
used.
In shared library, load/store of global is rewritten to using
GOT and temp register, which conflicts with the use of temp
register for assembling large offset. So the folding is disabled
for globals in shared library mode.
cmd/go: add support for concurrent backend compilation
It is disabled by default.
It can be enabled by setting the environment variable
GO19CONCURRENTCOMPILATION=1.
Benchmarking results are presented in a grid.
Columns are different values of c (compiler backend concurrency);
rows are different values of p (process concurrency).
Austin Clements [Tue, 9 May 2017 13:42:16 +0000 (09:42 -0400)]
runtime/pprof: deflake TestGoroutineCounts
TestGoroutineCounts currently depends on timing to get 100 goroutines
to a known blocking point before taking a profile. This fails
frequently, with different goroutines captured at different stacks.
The test is disabled on openbsd because it was too flaky, but in fact
it flakes on all platforms.
Fix this by using Gosched instead of timing. This is both much more
reliable and makes the test run faster.
Ian Lance Taylor [Tue, 9 May 2017 13:40:04 +0000 (06:40 -0700)]
cmd/go: put user flags after code generation flag
This permits the user to override the code generation flag when they
know better. This is always a good policy for all flags automatically
inserted by the build system.
Doing this now so that I can write a test for #20290.
Update #20290
Change-Id: I5c6708a277238d571b8d037993a5a59e2a442e98
Reviewed-on: https://go-review.googlesource.com/42952
Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>