Kevin Burke [Wed, 31 Jan 2018 03:25:37 +0000 (19:25 -0800)]
database/sql: add more examples
This aims to expand the coverage of examples showing how the sql
package works, as well as to address a number of issues I've observed
while explaining how the database package works:
- The best way to issue UPDATE or INSERT queries, that don't need
to scan anything in return. (Previously, we had no examples for any
Execute statement).
- How to use prepared statements and transactions.
- How to aggregate arguments from a Query/QueryContext query into
a slice.
Furthermore just having examples in more places should help, as users
click on e.g. the "Rows" return parameter and are treated with the
lack of any example about how Rows is used.
Switch package examples to use QueryContext/QueryRowContext; I think
it is a good practice to prepare users to issue queries with a timeout
attached, even if they are not using it immediately.
Change-Id: I4e63af91c7e4fff88b25f820906104ecefde4cc3
Reviewed-on: https://go-review.googlesource.com/91015 Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Daniel Martí [Sat, 24 Mar 2018 15:49:43 +0000 (15:49 +0000)]
all: remove some unused return parameters
As found by unparam. Picked the low-hanging fruit, consisting only of
errors that were always nil and results that were never used. Left out
those that were useful for consistency with other func signatures.
Giovanni Bajo [Mon, 12 Mar 2018 23:25:06 +0000 (00:25 +0100)]
cmd/compile: in prove, shortcircuit self-facts
Sometimes, we can end up calling update with a self-relation
about a variable (x REL x). In this case, there is no need
to record anything: the relation is unsatisfiable if and only
if it doesn't contain eq.
This also helps avoiding infinite loop in next CL that will
introduce transitive closure of relations.
Matthew Dempsky [Thu, 22 Mar 2018 20:51:13 +0000 (13:51 -0700)]
cmd/compile: always write pack files
By always writing out pack files, the object file format can be
simplified somewhat. In particular, the export data format will no
longer require escaping, because the pack file provides appropriate
framing.
This CL does not affect build systems that use -pack, which includes
all major Go build systems (cmd/go, gb, bazel).
Also, existing package import logic already distinguishes pack/object
files based on file contents rather than file extension.
The only exception is cmd/pack, which specially handled object files
created by cmd/compile when used with the 'c' mode. This mode is
extended to now recognize the pack files produced by cmd/compile and
handle them as before.
Passes toolstash-check.
Updates #21705.
Updates #24512.
Change-Id: Idf131013bfebd73a5cde7e087eb19964503a9422
Reviewed-on: https://go-review.googlesource.com/102236
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Matthew Dempsky [Fri, 23 Mar 2018 17:28:39 +0000 (10:28 -0700)]
cmd/link: skip __.PKGDEF in archives
The __.PKGDEF file is a compiler object file only intended for other
compilers. Also, for build systems that use -linkobj, all of the
information it contains is present within the linker object files
already, so look for it there instead.
This requires a little bit of code reorganization. Significantly,
previously when loading an archive file, the __.PKGDEF file was
authoritative on whether the package was "main" and/or "safe". Now
that we're using the Go object files instead, there's the issue that
there can be multiple Go object files in an archive (because when
using assembly, each assembly file becomes its own additional object
file).
The solution taken here is to check if any object file within the
package declares itself as "main" and/or "safe".
Updates #24512.
Change-Id: I70243a293bdf34b8555c0bf1833f8933b2809449
Reviewed-on: https://go-review.googlesource.com/102281
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Yuval Pavel Zholkover [Fri, 23 Mar 2018 14:53:26 +0000 (17:53 +0300)]
runtime: fix AT_HWCAP auxv parsing on freebsd
AT_HWCAP is not available on FreeBSD-11.1-RELEASE or earlier and the wrong const was used.
Use the correct value, and initialize hwcap with ^uint32(0) inorder not to fail the VFP tests.
The compiler can't currently figure out that it can eliminate both c.s
loads (using store to load forwarding) in the second line of the
following code:
The compiler eliminates the second load of c.s[j] (using the original
value of c.s[i]), however the load of c.s[i] remains because the compiler
doesn't know that c.s[i] and c.s[j] either overlap completely or not at
all.
Introducing temporaries to make this explicit improves the performance
of the generic code slightly, the goal being to remove the assembly in
this package in the future. This change also hoists a bounds check out
of the main loop which gives a slight performance boost and also makes
the behaviour identical to the assembly implementation when len(dst) <
len(src).
Change-Id: I66abff0dd14ec6e1f8d8d982ccfb0438633b639d
Reviewed-on: https://go-review.googlesource.com/102316 Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Adam Langley [Fri, 13 Oct 2017 21:46:06 +0000 (14:46 -0700)]
crypto/x509: follow OpenSSL and emit Extension structures directly in CSRs.
I don't know if I got lost in the old PKCS documents, or whether this is
a case where reality diverges from the spec, but OpenSSL clearly stuffs
PKIX Extension objects in CSR attributues directly[1].
In either case, doing what OpenSSL does seems valid here and allows the
critical flag in extensions to be serialised.
Daniel Martí [Wed, 14 Mar 2018 10:50:49 +0000 (10:50 +0000)]
cmd/compile: use more range fors in gc
Slightly simplifies the code. Made sure to exclude the cases that would
change behavior, such as when the iterated value is a string, when the
index is modified within the body, or when the slice is modified.
Also checked that all the elements are of pointer type, to avoid the
corner case where non-pointer types could be copied by mistake.
Change-Id: Iea64feb2a9a6a4c94ada9ff3ace40ee173505849
Reviewed-on: https://go-review.googlesource.com/100557
Run-TryBot: Daniel Martí <mvdan@mvdan.cc> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This experiment has gone stale. It causes a type-checking failure
because the condition of the OIF produced by range loop lowering has
type "untyped bool". Fix this by typechecking the whole OIF statement,
not just its condition.
This doesn't quite fix the whole experiment, but it gets further.
Something about preemption point insertion is causing failures like
"internal compiler error: likeliness prediction 1 for block b10 with 1
successors" in cmd/compile/internal/gc.
Travis Bischel [Wed, 14 Mar 2018 03:19:52 +0000 (20:19 -0700)]
cmd/compile: specialize Move up to 79B on amd64
Move currently uses mov instructions directly up to 31 bytes and then
switches to duffcopy. Moving 31 bytes is 4 instructions corresponding to
two loads and two stores, (or 6 if !useSSE) depending on the usage,
duffcopy is five (one or two mov, two or three lea, one call).
This adds direct mov instructions for Move's of size 32, 48, and 64 with
sse and for only size 32 without.
With useSSE:
- 32 is 4 instructions (byte +/- comparison below)
- 33 thru 48 is 6
- 49 thru 64 is 8
Without:
- 32 is 8
Note that the only platform with useSSE set to false is plan 9. I have
built three projects based off tip and tip with this patch and the
project's byte size is equal to or less than they were prior.
The basis of this change is that copying data with instructions directly
is nearly free, whereas calling into duffcopy adds a bit of overhead.
This is most noticeable in range statements where elements are 32+
bytes. For code with the following pattern:
func Benchmark32Range(b *testing.B) {
var f s32
for _, count := range []int{10, 100, 1000, 10000} {
name := strconv.Itoa(count)
b.Run(name, func(b *testing.B) {
base := make([]s32, count)
for i := 0; i < b.N; i++ {
for _, v := range base {
f = v
}
}
})
}
_ = f
}
Function calls are not benefitted as much due how they are compiled, but
other benchmarks I ran show that calling function with 64 byte elements
is marginally improved.
The main downside with this change is that it may increase binary sizes
depending on the size of the copy, but this change also decreases
binaries for moves of 48 bytes or less.
For the following code:
package main
type size [32]byte
//go:noinline
func use(t size) {
}
//go:noinline
func get() size {
var z size
return z
}
func main() {
var a size
use(a)
}
Changing size around gives the following assembly leading up to the call
(the initialization and actual call are removed):
So, at best we save 9B, at worst we gain 17. I do not think that copying
around 65+B sized types is common enough to bloat program sizes. Using
bincmp on the go binary itself shows a zero byte difference; there are
gains and losses all over. One of the largest gains in binary size comes
from cmd/go/internal/cache.(*Cache).Get, which passes around a 64 byte
sized type -- this is one of the cases I would expect to be benefitted
by this change.
I think that this marginal improvement in struct copying for 64 byte
structs is worth it: most data structs / work items I use in my programs
are small, but few are smaller than 32 bytes: with one slice, the budget
is up. The 32 rule alone would allow another 16 bytes, the 48 and 64
rules allow another 32 and 48.
Giovanni Bajo [Tue, 13 Feb 2018 01:51:23 +0000 (02:51 +0100)]
doc: first version of new contribute guide
I've reorganized the guide and rewritten large sections.
The structure is now more clear and logical, and can
be understood and navigated using the summary displayed at
the top of the page (before, the summary was confusing because
the guide contained H1s that were being ignored by the summary).
Both the initial onboarding process and the Gerrit
change submission process have been reworked to
include a concise checklist of steps that can be
read and understood in a few seconds, for people
that don't want or need to bother with details.
More in-depth descriptions have been moved into
separate sections, one per each checklist step.
This is by far the biggest improvement, as the previous
approach of having to read several pages just to understand
the requires steps was very scaring for beginners, in
addition of being harder to navigate.
GitHub pull requests have been integrated as a different
way to submit a change, suggested for first time contributors.
The review process has been described in more details,
documenting the workflow and the used conventions.
Most miscellanea have been moved into an "advanced
topics" chapter.
Paragraphs describing how to use git have been removed
to simplify reading. This guide should focus on Go contribution,
and not help users getting familiar with git, for which many
guides are available.
Change-Id: I6f4b76583c9878b230ba1d0225745a1708fad2e8
Reviewed-on: https://go-review.googlesource.com/93495 Reviewed-by: Rob Pike <r@golang.org>
Ilya Tocar [Wed, 21 Mar 2018 21:42:02 +0000 (16:42 -0500)]
compress/bzip2: remove bit-tricks
Since compiler is now able to generate conditional moves, we can replace
bit-tricks with simple if/else. This even results in slightly better performance:
Tim Wright [Wed, 14 Feb 2018 03:00:17 +0000 (19:00 -0800)]
all: enable c-shared/c-archive support for freebsd/amd64
Fixes #14327
Much of the code is based on the linux/amd64 code that implements these
build modes, and code is shared where possible.
Change-Id: Ia510f2023768c0edbc863aebc585929ec593b332
Reviewed-on: https://go-review.googlesource.com/93875
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
isharipo [Mon, 19 Mar 2018 20:07:18 +0000 (23:07 +0300)]
runtime,sync/atomic: replace asm BYTEs with insts for x86
For each replacement, test case is added to new 386enc.s file
with exception of EMMS, SYSENTER, MFENCE and LFENCE as they
are already covered in amd64enc.s (same on amd64 and 386).
The replacement became less obvious after go vet suggested changes
Before:
BYTE $0x0f; BYTE $0x7f; BYTE $0x44; BYTE $0x24; BYTE $0x08
Changed to MOVQ (this form is being tested):
MOVQ M0, 8(SP)
Refactored to FP-relative access (go vet advice):
MOVQ M0, val+4(FP)
Tobias Klauser [Fri, 9 Mar 2018 10:44:59 +0000 (11:44 +0100)]
runtime: parse auxv on freebsd
Decode AT_PAGESZ to determine physPageSize on freebsd/{386,amd64,arm}
and AT_HWCAP for hwcap and hardDiv on freebsd/arm. Also use hwcap to
perform the FP checks in checkgoarm akin to the linux/arm
implementation.
Change-Id: I532810a1581efe66277e4305cb234acdc79ee91e
Reviewed-on: https://go-review.googlesource.com/99780
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Hiroshi Ioka [Mon, 11 Dec 2017 23:59:01 +0000 (08:59 +0900)]
go/internal/srcimporter: simplify and fix package file lookup
The old code was a blend of (copied) code that existed before go/build,
and incorrect adjustments made when go/build was introduced. This change
leaves package path determination entirely to go/build and in the process
fixes issues with relative import paths.
Fixes #23092
Fixes #24392
Change-Id: I9e900538b365398751bace56964495c5440ac4ae
Reviewed-on: https://go-review.googlesource.com/83415
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
Adam Langley [Thu, 22 Feb 2018 22:40:03 +0000 (14:40 -0800)]
crypto/x509: support the PSS certificates that OpenSSL 1.1.0 generates.
It serialises optional parameters as empty rather than NULL. It's
probably technically correct, although ASN.1 has a long history of doing
this different ways.
But OpenSSL is likely common enough that we want to support this
encoding.
Ilya Tocar [Thu, 14 Dec 2017 19:27:11 +0000 (13:27 -0600)]
cmd/compile/internal/ssa: update regalloc in loops
Currently we don't lift spill out of loop if loop contains call.
However often we have code like this:
for .. {
if hard_case {
call()
}
// simple case, without call
}
So instead of checking for any call, check for unavoidable call.
For #22698 cases I see:
mime/quotedprintable/Writer-6 10.9µs ± 4% 9.2µs ± 3% -15.02% (p=0.000 n=8+8)
And:
compress/flate/Encode/Twain/Huffman/1e4-6 99.4µs ± 6% 90.9µs ± 0% -8.57% (p=0.000 n=8+8)
compress/flate/Encode/Twain/Huffman/1e5-6 760µs ± 1% 725µs ± 1% -4.56% (p=0.000 n=8+8)
compress/flate/Encode/Twain/Huffman/1e6-6 7.55ms ± 0% 7.24ms ± 0% -4.07% (p=0.000 n=8+7)
There are no significant changes on go1 benchmarks.
But for cases with runtime arch checks, where we call generic version on old hardware,
there are respectable performance gains:
math/RoundToEven-6 1.43ns ± 0% 1.25ns ± 0% -12.59% (p=0.001 n=7+7)
math/bits/OnesCount64-6 1.60ns ± 1% 1.42ns ± 1% -11.32% (p=0.000 n=8+8)
Also on some runtime benchmarks loops have less loads and higher performance:
runtime/RuneIterate/range1/ASCII-6 15.6ns ± 1% 13.9ns ± 1% -10.74% (p=0.000 n=7+8)
runtime/ArrayEqual-6 3.22ns ± 0% 2.86ns ± 2% -11.06% (p=0.000 n=7+8)
Than McIntosh [Tue, 20 Mar 2018 16:36:37 +0000 (12:36 -0400)]
cmd/compile: fix regression in DWARF inlined routine variable tracking
Fix a bug in the code that generates the pre-inlined variable
declaration table used as raw material for emitting DWARF inline
routine records. The fix for issue 23704 altered the recipe for
assigning file/line/col to variables in one part of the compiler, but
didn't update a similar recipe in the code for variable tracking.
Added a new test that should catch problems of a similar nature.
Fangming.Fang [Mon, 19 Mar 2018 06:52:28 +0000 (06:52 +0000)]
cmd/asm: fix bug about VMOV instruction (move register to vector element) on ARM64
This change fixes index error when encoding VMOV instruction which pattern is
VMOV Rn, V.<T>[index]. For example VMOV R1, V1.S[1] is assembled as VMOV R1, V1.S[0]
However, this is suboptimal, as we could instead produce just:
tmp := mapassign(m, k)
*tmp := append(*tmp, ...)
Optimization is possible only if during Order it may tell that m[k] is
exactly the same at left and right part of assignment. It doesn't work:
1) m[f(k)] = append(m[f(k)], ...)
2) sink, m[k] = sink, append(m[k]...)
3) m[k] = append(..., m[k],...)
fanzha02 [Fri, 26 Jan 2018 09:18:31 +0000 (09:18 +0000)]
bytes: add optimized Compare for arm64
Use LDP instructions to load 16 bytes per loop when the source length is long. Specially
process the 8 bytes length, 4 bytes length and 2 bytes length to get a better performance.
Alberto Donizetti [Mon, 15 Jan 2018 11:06:27 +0000 (12:06 +0100)]
math/big: add 0 shift fastpath to shl and shr
One could expect calls like
z.mant.shl(z.mant, shiftAmount)
(or higher-level-functions calls that use lhs/rhs) to be almost free
when shiftAmount = 0; and expect calls like
z.mant.shl(x.mant, 0)
to have the same cost of a x.mant -> z.mant copy. Neither of this
things are currently true.
For an 800 words nat, the first kind of calls cost ~800ns for rigth
shifts and ~3.5µs for left shift; while the second kind of calls are
doing more work than necessary by calling shlVU/shrVU.
This change makes the first kind of calls ({Shl,Shr}Same) almost free,
and the second kind of calls ({Shl,Shr}) about 30% faster.
David Chase [Fri, 16 Mar 2018 19:15:50 +0000 (15:15 -0400)]
cmd/compile: enable scopes unconditionally
This revives Alessandro Arzilli's CL to enable scopes
whenever any dwarf is emitted (with optimization or not),
adds a test that detects this changes and shows that it
creates more truthful debugging output.
Reverted change to ssa/debug_test tests made when
scopes were disabled during dwarflocationlist development.
Also included are updates to the Delve test output (it
had fallen out of sync; creating test output for one
updates it for all) and minor naming changes in
ssa/debug_test.
Compile-time/space changes (relative to tip including dwarflocationlists):
Matthew Dempsky [Thu, 15 Mar 2018 20:40:57 +0000 (13:40 -0700)]
reflect: sort exported methods first
By moving exported methods to the front of method lists, filtering
down to only the exported methods just needs a count of how many
exported methods exist, which the compiler can statically
provide. This allows getting rid of the exported method cache.
For #22075.
Change-Id: I8eeb274563a2940e1347c34d673f843ae2569064
Reviewed-on: https://go-review.googlesource.com/100846 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Matthew Dempsky [Thu, 15 Mar 2018 20:14:41 +0000 (13:14 -0700)]
cmd/compile: sort method sets earlier
By sorting method sets earlier, we can change the interface
satisfaction problem from taking O(NM) time to O(N+M). This is the
same algorithm already used by runtime and reflect for dynamic
interface satisfaction testing.
For #22075.
Change-Id: I3d889f0227f37704535739bbde11f5107b4eea17
Reviewed-on: https://go-review.googlesource.com/100845
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
David Chase [Wed, 14 Mar 2018 20:54:33 +0000 (16:54 -0400)]
cmd/compile: turn on DWARF locations lists for ssa vars
This changes the default setting for -dwarflocationlists
from false to true, removes the flag from ssa/debug_test.go,
and updates runtime/runtime-gdb_test.go to match a change
in debugging output for composite variables.
Hana Kim [Thu, 15 Mar 2018 01:27:25 +0000 (21:27 -0400)]
internal/trace: fix GC time computation of short goroutines
Goroutine analysis reports the sum of all overlapping GC intervals as
the GCTime of a goroutine. The computation is done by adding the length
of a completed GC interval to 'active' goroutines when processing the
corresponding EvGCDone event. This change fixes the two corner cases
the current implementation ignores:
1) Goroutine that ends during GC. Previously, this goroutine was ignored
and GC time was undercounted. We handle this case by setting the
gcStartTime only when GC is active and handling non-zero gcStartTime
when processing EvGoStop and EvGoStart.
2) Goroutine that starts during GC. Previously, the entire GC interval
length was added to the Goroutine's GCTime which resulted in overcount
of GC time. We handle this case by computing the length of overlapped
period precisely.
Robert Griesemer [Tue, 13 Mar 2018 00:00:55 +0000 (17:00 -0700)]
go/scanner: report errors for incorrect line directives
Based on decision for #24183. This makes the go/scanner behavior
match cmd/compile behavior. Adjusted a go/printer test that assumed
silent behavior for invalid line directive, and added more scanner
tests verifying the correct error position and message for invalid
line directives.
The filenames in line directives now remain untouched by the scanner;
there is no cleanup or conversion of relative into absolute paths
anymore, in sync with what the compiler's scanner/parser are doing.
Any kind of filename transformation has to be done by a client. This
makes the scanner code simpler and also more predictable.
For #24183.
Change-Id: Ia091548e1d3d89dfdf6e7d82dab50bea05742ce3
Reviewed-on: https://go-review.googlesource.com/100235
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Keith Randall [Wed, 14 Mar 2018 22:21:37 +0000 (15:21 -0700)]
runtime: identify special functions by flag instead of address
When there are plugins, there may not be a unique copy of runtime
functions like goexit, mcall, etc. So identifying them by entry
address is problematic. Instead, keep track of each special function
using a field in the symbol table. That way, multiple copies of
the same runtime function will be treated identically.
Fixes #24351
Fixes #23133
Change-Id: Iea3232df8a6af68509769d9ca618f530cc0f84fd
Reviewed-on: https://go-review.googlesource.com/100739
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Daniel Martí [Mon, 5 Mar 2018 10:46:44 +0000 (10:46 +0000)]
cmd/compile: cache sparse maps across ssa passes
This is done for sparse sets already, but it was missing for sparse
maps. Only affects deadstore and regalloc, as they're the only ones that
use sparse maps.
James Cowgill [Wed, 28 Feb 2018 16:10:14 +0000 (16:10 +0000)]
cmd/internal/obj/mips: load/store even float registers first
There is a bug in Octeon III processors where storing an odd floating
point register after it has recently been written to by a double
floating point operation will store the old value from before the double
operation (there are some extra details - the operation and store
must be a certain number of cycles apart). However, this bug does not
occur if the even register is stored first. Currently the bug only
happens on big endian because go always loads the even register first on
little endian.
Workaround the bug by always loading / storing the even floating point
register first. Since this is just an instruction reordering, it should
have no performance penalty. This follows other compilers like GCC which
will always store the even register first (although you do have to set
the ISA level to MIPS I to prevent it from using SDC1).
Change-Id: I5e73daa4d724ca1df7bf5228aab19f53f26a4976
Reviewed-on: https://go-review.googlesource.com/97735 Reviewed-by: Keith Randall <khr@golang.org>
There are some opportunities to improve this change further by adding
patterns to match the "extended register" versions of ADD/SUB/CMP, but I
think that should be evaluated on its own. The regressions in Template
and TimeFormat would likely be recovered by this, as they seem to be due
to generating:
Tobias Klauser [Thu, 15 Mar 2018 09:45:51 +0000 (10:45 +0100)]
syscall: use Android O friendly fstatat syscall to implement Stat on linux/amd64
The Android O seccomp policy disallows the stat syscall on amd64, see
https://android.googlesource.com/platform/bionic/+/android-4.2.2_r1.2/libc/SYSCALLS.TXT
Use the fstatat syscall with AT_FDCWD and zero flags instead to achieve
the same behavior.
Tobias Klauser [Thu, 15 Mar 2018 09:21:57 +0000 (10:21 +0100)]
runtime: use Android O friendly faccessat syscall on linux/amd64
The Android O seccomp policy disallows the access syscall on amd64, see
https://android.googlesource.com/platform/bionic/+/android-4.2.2_r1.2/libc/SYSCALLS.TXT
Use the faccessat syscall with AT_FDCWD instead to achieve the same
behavior.
Diogo Pinela [Tue, 13 Mar 2018 23:36:45 +0000 (23:36 +0000)]
sync: make WaitGroup more space-efficient
The struct stores its 64-bit state field in a 12-byte array to
ensure that it can be 64-bit-aligned. This leaves 4 spare bytes,
which we can reuse to store the sema field.
(32-bit alignment is still guaranteed because the array type was
changed to [3]uint32.)
Matthew Dempsky [Tue, 13 Mar 2018 22:07:12 +0000 (15:07 -0700)]
cmd/compile: fix duplicate code generation in swt.go
When combining adjacent type switch cases with the same type hash, we
failed to actually remove the combined cases, so we would generate
code for them twice.
We use MD5 for type hashes, so collisions are rare, but they do
currently appear in test/fixedbugs/bug248.dir/bug2.go, which is how I
noticed this failure.
Matthew Dempsky [Thu, 8 Mar 2018 14:25:04 +0000 (06:25 -0800)]
cmd/compile: cleanup closure.go
The main thing is we now eagerly create the ODCLFUNC node for
closures, immediately cross-link them, and assign fields (e.g., Nbody,
Dcl, Parents, Marks) directly on the ODCLFUNC (previously they were
assigned on the OCLOSURE and later moved to the ODCLFUNC).
This allows us to set Curfn to the ODCLFUNC instead of the OCLOSURE,
which makes things more consistent with normal function declarations.
(Notably, this means Cvars now hang off the ODCLFUNC instead of the
OCLOSURE.)
Assignment of xfunc symbol names also now happens before typechecking
their body, which means debugging output now provides a more helpful
name than "<S>".
In golang.org/cl/66810, we changed "x := y" statements to avoid
creating false closure variables for x, but we still create them for
struct literals like "s{f: x}". Update comment in capturevars
accordingly.
More opportunity for cleanups still, but this makes some substantial
progress, IMO.
Passes toolstash-check.
Change-Id: I65a4efc91886e3dcd1000561348af88297775cd7
Reviewed-on: https://go-review.googlesource.com/100197
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
Heschi Kreinick [Tue, 13 Mar 2018 20:14:52 +0000 (16:14 -0400)]
cmd/compile/internal/ssa: track stack-only vars
User variables that cannot be SSA'd, either because their addresses are
taken or because they are too large for the decomposition heuristic, do
not explicitly appear as operands of SSA values. Instead they are written
to directly via the stack pointer.
This hid them from the location list generation, which is only
interested in the named value table. Fortunately, the lifetime of
stack-only variables is delineated by VarDef/VarKill ops, and it's easy
enough to turn those into location list bounds.
One wrinkle: stack frame information is not explicitly available in the
SSA phases, because it's owned by the frontend in AllocFrame. It would
be easier if the set of live LocalSlots were returned by that, but this
is the minimal change to fix missing variables. Or VarDef/VarKills
could appear in NamedValues, which would make this change even easier.
Change-Id: Ice6654dad6f9babb0286e95c7ec28594561dc91f
Reviewed-on: https://go-review.googlesource.com/100458 Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Lynn Boger [Wed, 14 Mar 2018 15:25:02 +0000 (11:25 -0400)]
cmd/compile: improve PPC64.rules to reduce size of rewritePPC64.go
Some rules in PPC64.rules cause an extremely large rewritePPC64.go
file to be generated, due to rules with commutative operations and
many operands. This happens with the existing
rules for combining byte loads in little endian order, and
also happens with the pending change to do the same for bytes
in big endian order.
The change improves the existing rules and reduces the size of
the rewrite file by more than 60%. Once this change is merged,
then the pending change for big endian ordered rules will be
updated to use rules that avoid generating an excessively large
rewrite file.
This also includes a fix to a performance regression for
littleEndian.PutUint16 on ppc64le.
Robert Griesemer [Wed, 14 Mar 2018 18:19:42 +0000 (11:19 -0700)]
math/big: add comment about internal assumptions on nat values
Change-Id: I7ed40507a019c0bf521ba748fc22c03d74bb17b7
Reviewed-on: https://go-review.googlesource.com/100719 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Robert Griesemer [Tue, 13 Mar 2018 23:08:16 +0000 (16:08 -0700)]
cmd/compile: document new line directives
Fixes #24183.
Change-Id: I5ef31c4a3aad7e05568b7de1227745d686d4aff8
Reviewed-on: https://go-review.googlesource.com/100462 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Tobias Klauser [Wed, 14 Mar 2018 15:35:22 +0000 (15:35 +0000)]
runtime, syscall: add RawSyscall6 on Solaris and make it panic
The syscall package currently declares RawSyscall6 for every GOOS, but
does not define it on Solaris. This leads to code using said function
to compile but it will not link. Fix it by adding RawSyscall6 and make
it panic.
Also remove the obsolete comment above runtime.syscall_syscall as
pointed out by Aram.
Alberto Donizetti [Wed, 14 Mar 2018 10:07:06 +0000 (11:07 +0100)]
test/codegen: port all small memmove tests to codegen
This change ports all the remaining tests checking that small memmoves
are replaced with MOVs to the new codegen test harness, and deletes
them from the asm_test file.
Change-Id: I01c94b441e27a5d61518035af62d62779dafeb56
Reviewed-on: https://go-review.googlesource.com/100476
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
David du Colombier [Wed, 14 Mar 2018 12:36:31 +0000 (13:36 +0100)]
runtime: don't use floating point in findnull on Plan 9
In CL 98015, findnull was rewritten so it uses bytes.IndexByte.
This broke the build on plan9/amd64 because the implementation
of bytes.IndexByte on AMD64 relies on SSE instructions while
floating point instructions are not allowed in the note handler.
This change fixes findnull by using the former implementation
on Plan 9, so it doesn't use bytes.IndexByte.
Fixes #24387.
Change-Id: I084d1a44d38d9f77a6c1ad492773f0a98226be16
Reviewed-on: https://go-review.googlesource.com/100577
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Rob Pike <r@golang.org>