WaitForSigusr1 registers a callback to be called on SIGUSR1 directly
from the runtime signal handler. Currently, this callback has a write
barrier in it, which can crash with a nil P if the GC is active and
the signal arrives on an M that doesn't have a P.
Fix this by recording the ID of the M that receives the signal instead
of the M itself, since that's all we needed anyway. To make sure there
are no other problems, this also lifts the callback into a package
function and marks it "go:nowritebarrierrec".
Fixes#35248.
Updates #35276, since in principle a write barrier at exactly the
wrong time while entering the scheduler could cause issues, though I
suspect that bug is unrelated.
Change-Id: I47b4bc73782efbb613785a93e381d8aaf6850826
Reviewed-on: https://go-review.googlesource.com/c/go/+/204620
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
token.IsExported expects to be passed a token, and does not check for
non-token arguments such as "C:\workdir\go\src\text".
While we're at it, clean up a few other parts of the code that
are assuming a package path where a directory may be passed instead.
There are probably others lurking around here, but I believe this
change is sufficient to get past the test failures on the
windows-amd64-longtest builder.
Fixes#35236
Change-Id: Ic79fa035531ca0777f64b1446c2f9237397b1bdf
Reviewed-on: https://go-review.googlesource.com/c/go/+/204442
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
With buildmode=c-archive, "runtime.types" type isn't STYPE but
STYPERELRO.
On AIX, this symbol is present in the symbol table and not under
typerel.* outersymbol. Therefore, the size of typerel.* must be adapted.
Fixes#35342
Change-Id: Ib982c6557d9b41bc3d8775e4825650897f9e0ee6
Reviewed-on: https://go-review.googlesource.com/c/go/+/205338
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
We seem to lack any tests for some corner cases of itab.init
(multiple methods with the same name, breaking itab.init doesn't
seem to fail any tests). We also lack tests that fix text of panics.
Add more tests for itab.init.
Change-Id: Id6b536179ba6b0d45c3cb9dc1c66b9311d0ab85e
Reviewed-on: https://go-review.googlesource.com/c/go/+/202451
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The check is not relevant anymore.
The comment claims that go run does not rebuild packages,
but this is not true. And we use go build anyway.
We may have added the check because without caching
rebuilding everything starting from runtime for each test
takes a while. But now we have caching.
So from every side this check just adds code and pain.
Change-Id: Ifbbb643724100622e5f9db884339b67cde4ba729
Reviewed-on: https://go-review.googlesource.com/c/go/+/202450
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The hash is used in type switches. However, compiler statically generates itab's
for all interface/type pairs used in switches (which are added to itabTable
in itabsinit). The dynamically-generated itab's never participate in type switches,
and thus the hash is irrelevant.
Change-Id: I4f6e37be31b8f5605cca7a1806cb04708e948cea
Reviewed-on: https://go-review.googlesource.com/c/go/+/202448
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Previously we would always “upgrade” to the semantically-highest
version, even if a newer compatible version exists.
That made certain classes of mistakes irreversible: in general we
expect users to address bad releases by releasing a new (higher)
version, but if the bad release was an unintended +incompatible
version, then no release that includes a go.mod file can ever have a
higher version, and the bad release will be treated as “latest”
forever.
Instead, when considering a +incompatible version we now consult the
latest compatible (v0 or v1) release first. If the compatible release
contains a go.mod file, we ignore the +incompatible releases unless
they are expicitly requested (by version, commit ID, or branch name).
Fixes#34165
Updates #34189
Change-Id: I7301eb963bbb91b21d3b96a577644221ed988ab7
Reviewed-on: https://go-review.googlesource.com/c/go/+/204440
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Also revert an incidental 'gofmt' of a vendored file from CL 205240.
Updates #34822
Change-Id: I82a015d865db4d865b4776a8013312f25dbb9181
Reviewed-on: https://go-review.googlesource.com/c/go/+/205539
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
codeRepo.Versions previously checked every possible +incompatible
version for a 'go.mod' file. That is wasteful and counterproductive.
It is wasteful because typically, a project will adopt modules at some
major version, after which they will (be required to) use semantic
import paths for future major versions.
It is counterproductive because it causes an accidental
'+incompatible' tag to exist, and no compatible tag can have higher
semantic precedence.
This change prunes out some of the +incompatible versions in
codeRepo.Versions, eliminating the “wasteful” part but not all of the
“counterproductive” part: the extraneous versions can still be fetched
explicitly, and proxies may include them in the @v/list endpoint.
Updates #34165
Updates #34189
Updates #34533
Change-Id: Ifc52c725aa396f7fde2afc727d0d5950acd06946
Reviewed-on: https://go-review.googlesource.com/c/go/+/204439
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
We had some issues with reports being marked as spam, so I added a
filter to never mark as spam something that mentions the word
"vulnerability". We get too much spam at that address to disable the
filter entirely, so instead meantion the bypass in the docs.
Change-Id: Idb4dabcf51a9dd8234a2d571cd020c970b0a582c
Reviewed-on: https://go-review.googlesource.com/c/go/+/205538
Reviewed-by: Katie Hockman <katie@golang.org>
dsa.Verify might currently use a nil s inverse in a
multiplication if the public key contains a non-prime Q,
causing a panic. Change this to check that the mod
inverse exists before using it.
Fixes CVE-2019-17596
Fixes#34960
Change-Id: I94d5f3cc38f1b5d52d38dcb1d253c71b7fd1cae7
Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/572809
Reviewed-by: Filippo Valsorda <valsorda@google.com>
Reviewed-on: https://go-review.googlesource.com/c/go/+/205441
Run-TryBot: Katie Hockman <katie@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
In the dev.link branch we implemented the new object file format
and (part of) the linker improvements described in
https://golang.org/s/better-linker
The new object file is index-based and provides random access.
The linker maps the object files into read-only memory, and
access symbols on-demand using indices, as opposed to reading
all object files sequentially into the heap with the old format.
The linker carries symbol informations using indices (as opposed
to Symbol data structure). Symbols are created after the
reachability analysis, and only created for reachable symbols.
This reduces the linker's memory usage.
Linking cmd/compile, it creates ~25% fewer Symbols, and reduces
memory usage (inuse_space) by ~15%. (More results from Than.)
Currently, both the old and new object file formats are supported.
The old format is used by default. The new format can be turned
on by using the compiler/assembler/linker's -newobj flag. Note
that the flag needs to be specified consistently to all
compilations, i.e.
go build -gcflags=all=-newobj -asmflags=all=-newobj -ldflags=-newobj
Change-Id: Ia0e35306b5b9b5b19fdc7fa7c602d4ce36fa6abd
Flip back to the old object files for Go 1.14.
Change-Id: I4ad499460fb7156b63fc63e9c6ea4f7099e20af2
Reviewed-on: https://go-review.googlesource.com/c/go/+/204098
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When using cgo, we save G to TLS, and when a signal happens, we
load G from TLS in sigtramp. This should give us a valid G. Don't
try to fetch from the signal stack. In particular, C code may
change the signal stack or call our signal handler directly (e.g.
TSAN), so we are not necessarily running on the original gsignal
stack where we saved G.
Also skip saving G on the signal stack when using cgo.
Updates #35249.
Change-Id: I40749ce6682709bd4ebfdfd9f23bd0f317fc197d
Reviewed-on: https://go-review.googlesource.com/c/go/+/204519
Reviewed-by: Ian Lance Taylor <iant@golang.org>
In the normal case, sigFetchG just returns the G register. But in
the case that sigFetchG fetches the G from somewhere else, the G
register still holding an invalid value. Setg here to make sure
they match.
This is particularly useful because setGsignalStack, called by
adjustSignalStack from sigtrampgo before setg to gsignal,
accesses the G register.
Should fix#35249.
Change-Id: I64c85143cb05cdb2ecca7f9936dbd8bfec186c2d
Reviewed-on: https://go-review.googlesource.com/c/go/+/204441
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Before this CL adjustTimers left timers being moved in an inconsistent
state: status timerWaiting but not on a P. Simplify the code by
leaving the timers in timerMoving status until they are actually moved.
Other functions (deltimer, modtimer) will wait until the move is complete
before changing anything on the timer. This does leave timers in timerMoving
state for longer, but still not all that long.
Fixes#35367
Change-Id: I31851002fb4053bd6914139125b4c82a68bf6fb2
Reviewed-on: https://go-review.googlesource.com/c/go/+/205418
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
TestFormats adds ~3s of running time to the test, which may be
slightly annoying in an edit/compile/test cycle but is negligible in a
TryBot run.
The test keeps regressing in the longtest builders, requiring a manual
fix. Instead, run it even in short mode on the builders, so that
TryBot runs will detect regressions ahead of time.
Updates #34907
Updates #33915
Updates #28621
Change-Id: I6f9bf0f2ca929a743438310b86d85d8673c720bf
Reviewed-on: https://go-review.googlesource.com/c/go/+/205440
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Once defined, a stack slot holding an open-coded defer arg should always be marked
live, since it may be used at any time if there is a panic. These stack slots are
typically kept live naturally by the open-defer code inlined at each return/exit point.
However, we need to do extra work to make sure that they are kept live if a
function has an infinite loop or a panic exit.
For this fix, only in the case of a function that is using open-coded defers, we
compute the set of blocks (most often empty) that cannot reach a return or a
BlockExit (panic) because of an infinite loop. Then, for each block b which
cannot reach a return or BlockExit or is a BlockExit block, we mark each defer arg
slot as live, as long as the definition of the defer arg slot dominates block b.
For this change, had to export (*Func).sdom (-> Sdom) and SparseTree.isAncestorEq
(-> IsAncestorEq)
Updates #35277
Change-Id: I7b53c9bd38ba384a3794386dd0eb94e4cbde4eb1
Reviewed-on: https://go-review.googlesource.com/c/go/+/204802
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
TestExecutableGOROOT, unlike most other tests in go_test.go, was
running subcommands in a process with an environment derived directly
from os.Environ(), rather than using tg.env on its testgoData object.
Since tg.env is what sets GO111MODULE=off for GOPATH-mode tests, that
caused TestExecutableGOROOT to unexpectedly run in module mode instead
of GOPATH mode. If the user's environment included 'GOFLAGS=-mod=mod',
that would cause the test to spuriously fail due to the inability to
download modules to $HOME (which in this test binary is hard-coded to
"/test-go-home-does-not-exist").
Updates #33848
Change-Id: I2f343008dd9e38cd76b9919eafd5a3181d0cbd6f
Reviewed-on: https://go-review.googlesource.com/c/go/+/205064
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The test for gopkg.in/yaml.v2@v2 assumes that there are
no future upstream releases. That assumption empirically
does not hold. Backporting fixes to this test is annoying,
and other gopkg.in cases are already reasonably covered,
so remove the problematic test.
Updates #28856
Change-Id: I6455baa1816ac69e02d1ad5d03b82a93e1481a17
Reviewed-on: https://go-review.googlesource.com/c/go/+/205437
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Recent Xcode versions started to complain about the current min
version:
ld: warning: OS version (6.0.0) too small, changing to 7.0.0
Change-Id: Ieb525dd3e57429fe226b9d30d584b073c5e4768c
Reviewed-on: https://go-review.googlesource.com/c/go/+/204663
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This does not include an upgrade of golang.org/x/net.
This is optional and best done as a separate CL.
Change-Id: Ifecc3fb6e3b7fe026b4ddefbe637186a3445b0bc
Reviewed-on: https://go-review.googlesource.com/c/go/+/204658
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
CL 196959 uses %v to print *EscLocation values. This happens at least at
Fatalf("path inconsistency: %v != %v", edge.src, src)
in (*Escape).explainPath.
Change-Id: I1c761406af6a1025403dfefa5ec40aee75e72944
Reviewed-on: https://go-review.googlesource.com/c/go/+/205377
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Pick up a dropped error in TestSendMailWithAuth() and simplify goroutine
to use an error channel instead of a sync.WaitGroup and an empty struct
doneCh.
Change-Id: Ie70d0f7c4c85835eb682e81d086ce4d9900269e6
Reviewed-on: https://go-review.googlesource.com/c/go/+/205247
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The flag field will be used for marking unsafe points. This CL
just adds the field, not doing anything with it. The next CL will
make use of it. This is for making the diff simpler.
Change-Id: I6ff5406ba2e53ae8a882184733d88482a2ca8e2a
Reviewed-on: https://go-review.googlesource.com/c/go/+/203938
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Frameless function is an interesting case for call injection
espcially for LR architectures. Extend the test for this case.
Change-Id: I074090d09eeaf642e71e3f44fea216f66d39b817
Reviewed-on: https://go-review.googlesource.com/c/go/+/202339
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Introduce a mechanism for marking architecture-specific Ops
unsafe. And mark ones that use REGTMP on ARM64, as for async
preemption we will be using REGTMP as a temporary register in the
injected call.
Change-Id: I8ff22e87d8f9cb10d02a2f0af7c12ad6d7d58f54
Reviewed-on: https://go-review.googlesource.com/c/go/+/203459
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Austin Clements <austin@google.com>
For async preemption, we will be using REGTMP as a temporary
register in injected call on ARM64, which will clobber it. So any
code that uses REGTMP is not safe for async preemption.
For ZeroRange, which is inserted at the function entry where
there is no register live, we could just use a different register
and avoid REGTMP.
Change-Id: I3db763828df6846908c9843a9912597efb9efcdf
Reviewed-on: https://go-review.googlesource.com/c/go/+/203458
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This CL adds support of call injection and async preemption on
ARM.
Injected call, like sigpanic, has special frame layout. Teach
traceback to handle it.
Change-Id: I887e90134fbf8a676b73c26321c50b3c4762dba4
Reviewed-on: https://go-review.googlesource.com/c/go/+/202338
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Austin Clements <austin@google.com>
Actual fix will be submitted to x/tools and vendored.
This is just an end-to-end test for vet after that is done.
Update #35264
Change-Id: I1a63f607e7cfa7aafee23c2c081086c276d3c38c
Reviewed-on: https://go-review.googlesource.com/c/go/+/204538
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
The logic for keeping arguments alive for calls to //go:uintptrescapes
functions was only applying to direct function calls. This CL changes
it to also apply to direct method calls, which should address most
uses of Proc.Call and LazyProc.Call.
It's still an open question (#34684) whether other call forms (e.g.,
method expressions, or indirect calls via function values, method
values, or interfaces).
Fixes#34474.
Change-Id: I874f97145972b0e237a4c9e8926156298f4d6ce0
Reviewed-on: https://go-review.googlesource.com/c/go/+/198043
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Programs should always check the error return of Close for a file opened
for writing. Update the example code in the comment to mention this.
Change-Id: I2ff6866ff1fe23b47c54268ac8e182210cc876c5
Reviewed-on: https://go-review.googlesource.com/c/go/+/202137
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
As a side-effect ensure that netpollinited only reports true when
netpoll initialization is complete.
Fixes#35282
Updates #35353
Change-Id: I21f08a04fcf229e0de5e6b5ad89c990426ae9b89
Reviewed-on: https://go-review.googlesource.com/c/go/+/204937
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This CL extends cmd/compile's experimental libFuzzer support with
calls to __sanitizer_cov_trace_{,const_}cmp{1,2,4,8}. This allows much
more efficient fuzzing of comparisons.
Only supports amd64 and arm64 for now.
Updates #14565.
Change-Id: Ibf82a8d9658f2bc50d955bdb1ae26723a3f0584d
Reviewed-on: https://go-review.googlesource.com/c/go/+/203887
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This CL adds experimental coverage instrumentation similar to what
github.com/dvyukov/go-fuzz produces in its -libfuzzer mode. The
coverage can be enabled by compiling with -d=libfuzzer. It's intended
to be used in conjunction with -buildmode=c-archive to produce an ELF
archive (.a) file that can be linked with libFuzzer. See #14565 for
example usage.
The coverage generates a unique 8-bit counter for each basic block in
the original source code, and emits an increment operation. These
counters are then collected into the __libfuzzer_extra_counters ELF
section for use by libFuzzer.
Updates #14565.
Change-Id: I239758cc0ceb9ca1220f2d9d3d23b9e761db9bf1
Reviewed-on: https://go-review.googlesource.com/c/go/+/202117
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This change renames the "round" function to the more appropriately named
"alignUp" which rounds an integer up to the next multiple of a power of
two.
This change also adds the alignDown function, which is almost like
alignUp but rounds down to the previous multiple of a power of two.
With these two functions, we also go and replace manual rounding code
with it where we can.
Change-Id: Ie1487366280484dcb2662972b01b4f7135f72fec
Reviewed-on: https://go-review.googlesource.com/c/go/+/190618
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
This change makes it so that the GC pacer's trigger ratio can never fall
below 0.6. Upcoming changes to the allocator make it significantly more
scalable and thus much faster in certain cases, creating a large gap
between the performance of allocation and scanning. The consequence of
this is that the trigger ratio can drop very low (0.07 was observed) in
order to drop GC utilization. A low trigger ratio like this results in a
high amount of black allocations, which causes the live heap to appear
larger, and thus the heap, and RSS, grows to a much higher stable point.
This change alleviates the problem by placing a lower bound on the
trigger ratio. The expected (and confirmed) effect of this is that
utilization in certain scenarios will no longer converge to the expected
25%, and may go higher. As a result of this artificially high trigger
ratio, more time will also be spent doing GC assists compared to
dedicated mark workers, since the GC will be on for an artifically short
fraction of time (artificial with respect to the pacer). The biggest
concern of this change is that allocation latency will suffer as a
result, since there will now be more assists. But, upcoming changes to
the allocator reduce the latency enough to outweigh the expected
increase in latency from this change, without the blowup in RSS observed
from the changes to the allocator.
Updates #35112.
Change-Id: Idd7c94fa974d0de673304c4397e716e89bfbf09b
Reviewed-on: https://go-review.googlesource.com/c/go/+/200439
Reviewed-by: Austin Clements <austin@google.com>
The js.Value struct now contains a pointer, so a finalizer can
determine if the value is not referenced by Go any more.
Unfortunately this breaks Go's == operator with js.Value. This change
adds a new Equal method to check for the equality of two Values.
This is a breaking change. The == operator is now disallowed to
not silently break code.
Additionally the helper methods IsUndefined, IsNull and IsNaN got added.
Fixes#35111
Change-Id: I58a50ca18f477bf51a259c668a8ba15bfa76c955
Reviewed-on: https://go-review.googlesource.com/c/go/+/203600
Run-TryBot: Richard Musiol <neelance@gmail.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This is a rough attempt at restoring -m=2 escape analysis diagnostics
on par with those that were available with esc.go. It's meant to be
simple and non-invasive.
For example, given this random example from bytes/reader.go:
138 func (r *Reader) WriteTo(w io.Writer) (n int64, err error) {
...
143 b := r.s[r.i:]
144 m, err := w.Write(b)
esc.go used to report:
bytes/reader.go:138:7: leaking param content: r
bytes/reader.go:138:7: from r.s (dot of pointer) at bytes/reader.go:143:8
bytes/reader.go:138:7: from b (assigned) at bytes/reader.go:143:4
bytes/reader.go:138:7: from w.Write(b) (parameter to indirect call) at bytes/reader.go:144:19
With this CL, escape.go now reports:
bytes/reader.go:138:7: parameter r leaks to {heap} with derefs=1:
bytes/reader.go:138:7: flow: b = *r:
bytes/reader.go:138:7: from r.s (dot of pointer) at bytes/reader.go:143:8
bytes/reader.go:138:7: from r.s[r.i:] (slice) at bytes/reader.go:143:10
bytes/reader.go:138:7: from b := r.s[r.i:] (assign) at bytes/reader.go:143:4
bytes/reader.go:138:7: flow: {heap} = b:
bytes/reader.go:138:7: from w.Write(b) (call parameter) at bytes/reader.go:144:19
Updates #31489.
Change-Id: I0c2b943a0f9ce6345bfff61e1c635172a9290cbb
Reviewed-on: https://go-review.googlesource.com/c/go/+/196959
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: David Chase <drchase@google.com>
Add a 'single lane' SIMD implemementation of the single byte count
function for use on machines that support the vector facility. This
allows up to 16 bytes to be counted per loop iteration.
We can probably improve performance further by adding more 'lanes'
(i.e. counting more bytes in parallel) however this will increase
the complexity of the function so I'm not sure it is worth doing
yet.
name old speed new speed delta
pkg:strings goos:linux goarch:s390x
CountByte/10 789MB/s ± 0% 1131MB/s ± 0% +43.44% (p=0.000 n=9+9)
CountByte/32 936MB/s ± 0% 3236MB/s ± 0% +245.87% (p=0.000 n=8+9)
CountByte/4096 1.06GB/s ± 0% 21.26GB/s ± 0% +1907.07% (p=0.000 n=10+10)
CountByte/4194304 1.06GB/s ± 0% 20.54GB/s ± 0% +1838.50% (p=0.000 n=10+10)
CountByte/67108864 1.06GB/s ± 0% 18.31GB/s ± 0% +1629.51% (p=0.000 n=10+10)
pkg:bytes goos:linux goarch:s390x
CountSingle/10 800MB/s ± 0% 986MB/s ± 0% +23.21% (p=0.000 n=9+10)
CountSingle/32 925MB/s ± 0% 2744MB/s ± 0% +196.55% (p=0.000 n=9+10)
CountSingle/4K 1.26GB/s ± 0% 19.44GB/s ± 0% +1445.59% (p=0.000 n=10+10)
CountSingle/4M 1.26GB/s ± 0% 20.28GB/s ± 0% +1510.26% (p=0.000 n=8+10)
CountSingle/64M 1.23GB/s ± 0% 17.78GB/s ± 0% +1350.67% (p=0.000 n=9+10)
Change-Id: I230d57905db92a8fdfc50b1d5be338941ae3a7a1
Reviewed-on: https://go-review.googlesource.com/c/go/+/199979
Run-TryBot: Michael Munday <mike.munday@ibm.com>
Reviewed-by: Keith Randall <khr@golang.org>
