Ian Davis [Mon, 10 Sep 2018 08:27:47 +0000 (09:27 +0100)]
image/png: minor cleanup of a few tests
Removes a redundant err check and replaces some returns in a testing
loop with continue to prevent skipping unrelated test cases when
a failure is encountered.
Change-Id: Ic1a560751b95bb0ef8dfa957e057e0fa0c2b281d
Reviewed-on: https://go-review.googlesource.com/134236
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Clarify the behavior of splice on older kernels, merge comments so
control flow becomes more obvious, as discussed in CL 133575.
Change-Id: I95855991bd0b1fa1c78a900b39c4382f65d83468
Reviewed-on: https://go-review.googlesource.com/135436 Reviewed-by: Ian Lance Taylor <iant@golang.org>
The cmd/compile/internal/ld/go.go file not exist, actually cmd/link/internal/ld/go.go.
Also, write line number is not good because it changes every commit of the file.
Change-Id: Id2b9f2c9904390adb011dab357716ee8e2fe84fc
Reviewed-on: https://go-review.googlesource.com/135516 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Ben Burkert [Wed, 5 Sep 2018 17:20:26 +0000 (10:20 -0700)]
internal/poll: fall back on unsupported splice from unix socket
Gracefully fallback to a userspace copy when the kernel does not support
splice(2) on a unix domain socket. EINVAL is returned by the splice
syscall if it does not support unix domain sockets. Keeping the handled
return value as false when the first splice call fails with EINVAL will
cause the caller to fall back to a userspace copy.
Dmitri Shuralyov [Wed, 12 Sep 2018 17:58:18 +0000 (13:58 -0400)]
doc/go1.11, cmd/go: elaborate on new GOFLAGS environment variable
In Go 1.11, cmd/go gained support for the GOFLAGS environment variable.
It was added and described in detail in CL 126656.
Mention it in the Go 1.11 release notes, link to the cmd/go documentation,
and add more details there.
Fixes #27282.
Change-Id: Ifc35bfe3e0886a145478d36dde8e80aedd8ec68e
Reviewed-on: https://go-review.googlesource.com/135035 Reviewed-by: Bryan C. Mills <bcmills@google.com> Reviewed-by: Rob Pike <r@golang.org>
Agniva De Sarker [Sat, 30 Jun 2018 20:05:38 +0000 (01:35 +0530)]
time: improve error message for LoadLocation
Currently, when a tz file was being checked inside a zoneInfo dir,
a syscall.ENOENT error was being returned, which caused it to look
in the zoneinfo.zip file and return an error for that case.
We return a syscall.ENOENT error for the zip file case too, so that
it falls through to the end of the loop and returns an uniform error
for both cases.
Fixes #20969
Change-Id: If1de068022ac7693caabb5cffd1c929878460140
Reviewed-on: https://go-review.googlesource.com/121877
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Michael Munday [Thu, 13 Sep 2018 12:16:46 +0000 (13:16 +0100)]
cmd/compile: skip float32 constant folding test on 387 builder
The 387 unit always quietens float64 and float32 signaling NaNs,
even when just loading and storing them. This makes it difficult
to propagate such values in the compiler. This is a hard problem
to fix and it is also very obscure.
Roberto Selbach [Mon, 27 Aug 2018 15:57:32 +0000 (15:57 +0000)]
cmd/go/internal/modfetch: stop cutting the last character of versions
When a zip archive for a module contains an unexpected file, the error
message removes the last character in the version number, e.g. an invalid
archive for "somemod@v1.2.3" would generate the following error:
"zip for somemod@1.2. has unexpected file..."
Lynn Boger [Wed, 15 Aug 2018 21:34:06 +0000 (17:34 -0400)]
cmd/compile: improve rules for PPC64.rules
This adds some improvements to the rules for PPC64 to eliminate
unnecessary zero or sign extends, and fix some rule for truncates
which were not always using the correct sign instruction.
This reduces of size of many functions by 1 or 2 instructions and
can improve performance in cases where the execution time depends
on small loops where at least 1 instruction was removed and where that
loop contributes a significant amount of the total execution time.
Included is a testcase for codegen to verify the sign/zero extend
instructions are omitted.
Robert Griesemer [Wed, 12 Sep 2018 23:45:10 +0000 (16:45 -0700)]
go/types: fix scope printing (debugging support)
Printing of scopes was horribly wrong: If a scope contained
no object declarations, it would abort printing even if the
scope had children scopes. Also, the line breaks were not
inserted consistently. The actual test case (ExampleScope)
was incorrect as well.
Fixed and simplified printing, and adjusted example which
tests the printing output.
Change-Id: If21c1d4ad71b15a517d4a54da16de5e6228eb4b5
Reviewed-on: https://go-review.googlesource.com/135115
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Alan Donovan <adonovan@google.com>
13:10:32 --- FAIL: TestGcSys (0.06s)
13:10:32 gc_test.go:30: expected "OK\n", but got "using too much memory: 71401472 bytes\n"
13:10:32 FAIL
Updates #27636
Change-Id: Ifd4cfce167d8054dc6f037bd34368d63c7f68ed4
Reviewed-on: https://go-review.googlesource.com/135155
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Ian Lance Taylor [Fri, 29 Jun 2018 17:39:44 +0000 (10:39 -0700)]
path/filepath: rewrite walkSymlinks
Rather than try to work around Clean and Join on intermediate steps,
which can remove ".." components unexpectedly, just do everything in
walkSymlinks. Use a single loop over path components.
Fixes #23444
Change-Id: I4f15e50d0df32349cc4fd55e3d224ec9ab064379
Reviewed-on: https://go-review.googlesource.com/121676
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Alan Donovan [Thu, 13 Sep 2018 15:15:30 +0000 (11:15 -0400)]
regexp: fix incorrect name in Match doc comment
Change-Id: I628aad9a3abe9cc0c3233f476960e53bd291eca9
Reviewed-on: https://go-review.googlesource.com/135235 Reviewed-by: Ralph Corderoy <ralph@inputplus.co.uk> Reviewed-by: Ian Lance Taylor <iant@golang.org>
This change compares the first two characters instead of the first one,
and if they match, the entire string is compared. Comparing the first two
characters helps to filter out the case where the first character matches
but the subsequent characters do not match, thereby improving the substring
search speed in this case.
Benchmarks with no effect or minimal impact (less than 5%) is not listed,
the following are improved benchmarks:
On arm64:
strings:
IndexPeriodic/IndexPeriodic16-8 172890.00ns +- 2% 124156.20ns +- 0% -28.19% (p=0.008 n=5+5)
IndexPeriodic/IndexPeriodic32-8 78092.80ns +- 0% 65138.60ns +- 0% -16.59% (p=0.008 n=5+5)
IndexPeriodic/IndexPeriodic64-8 42322.20ns +- 0% 34661.60ns +- 0% -18.10% (p=0.008 n=5+5)
bytes:
IndexPeriodic/IndexPeriodic16-8 183468.20ns +- 6% 123759.00ns +- 0% -32.54% (p=0.008 n=5+5)
IndexPeriodic/IndexPeriodic32-8 84776.40ns +- 0% 63907.80ns +- 0% -24.62% (p=0.008 n=5+5)
IndexPeriodic/IndexPeriodic64-8 45835.60ns +- 0% 34194.20ns +- 0% -25.40% (p=0.008 n=5+5)
Change-Id: I2d9e7e138d29e960d20a203eb74dc2ec976a9d71
Reviewed-on: https://go-review.googlesource.com/131177
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Robert Griesemer [Thu, 13 Sep 2018 01:07:51 +0000 (18:07 -0700)]
cmd/vet: avoid internal error for implicitly declared type switch vars
For type switches using a short variable declaration of the form
switch t := x.(type) {
case T1:
...
go/types doesn't declare the symbolic variable (t in this example)
with the switch; thus such variables are not found in types.Info.Defs.
Instead they are implicitly declared with each type switch case,
and can be found in types.Info.Implicits.
Adjust the shadowing code accordingly.
Added a test case to verify that the issue is fixed, and a test
case verifying that the shadowing code now considers implicitly
declared variables introduces in type switch cases.
While at it, also fixed the (internal) error reporting to provide
more accurate information.
Fixe #26725.
Change-Id: If408ed9e692bf47c640f81de8f46bf5eb43415b0
Reviewed-on: https://go-review.googlesource.com/135117
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Daniel Martí <mvdan@mvdan.cc> Reviewed-by: Alan Donovan <adonovan@google.com>
erifan01 [Tue, 22 May 2018 06:58:32 +0000 (06:58 +0000)]
cmd/compile: intrinsify math.RoundToEven and math.Abs on arm64
math.RoundToEven can be done by one arm64 instruction FRINTND, intrinsify it to improve performance.
The current pure Go implementation of the function Abs is translated into five instructions on arm64:
str, ldr, and, str, ldr. The intrinsic implementation requires only one instruction, so in terms of
performance, intrinsify it is worthwhile.
Benchmarks:
name old time/op new time/op delta
Abs-8 3.50ns ± 0% 1.50ns ± 0% -57.14% (p=0.000 n=10+10)
RoundToEven-8 9.26ns ± 0% 1.50ns ± 0% -83.80% (p=0.000 n=10+10)
runtime: regression test for semasleep indefinite hang
A regression test in which: for a program that invokes semasleep,
we send non-terminal signals such as SIGIO.
Since the signal wakes up pthread_cond_timedwait_relative_np,
after CL 133655, we should only re-spin for the amount of
time left, instead of re-spinning with the original duration
which would cause an indefinite spin.
erifan01 [Mon, 7 May 2018 08:08:30 +0000 (08:08 +0000)]
internal/bytealg: optimize Equal on arm64
Currently the 16-byte loop chunk16_loop is implemented with NEON instructions LD1, VMOV and VCMEQ.
Using scalar instructions LDP and CMP to achieve this loop can reduce the number of clock cycles.
For cases where the length of strings are between 4 to 15 bytes, loading the last 8 or 4 bytes at
a time to reduce the number of comparisons.
cmd/go: avoid type names in __debug__modinfo__ variable injected in package main
If we use the name 'string' to refer to the built-in type, that name
can be shadowed by a local declaration. Use a string constant instead,
but keep the init function to populate it so that //go:linkname will
still work properly.
Fixes #27584.
Change-Id: I850cad6663e566f70fd123107d2e4e742c93b450
Reviewed-on: https://go-review.googlesource.com/134915 Reviewed-by: Ian Lance Taylor <iant@golang.org>
The implementations of the functions in mem_darwin.go is identical to
the ones defined in mem_bsd.go for all other BSD-like GOOSes. Also use
them on Darwin.
cmd/dist: make raceDetectorSupported an exact copy of cmd/internal/sys.RaceDetectorSupported
The comment states that cmd/internal/sys.RaceDetectorSupported is a copy,
so make the two identical. No functional difference, since ppce64le is
only supported on linux anyway.
Change-Id: Id3e4d445fb700b9b3bb53bf15ea05b8911b4f95e
Reviewed-on: https://go-review.googlesource.com/134595
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
runtime: convert initial timediv quotient increments to bitsets
At the very beginning of timediv, inside a for loop,
we reduce the base value by at most (1<<31)-1, while
incrementing the quotient result by 1<<uint(bit).
However, since the quotient value was 0 to begin with,
we are essentially just doing bitsets.
This change is in the hot path of various concurrency and
scheduling operations that require sleeping, waiting
on mutexes and futexes etc. On the following OSes:
* Dragonfly
* FreeBSD
* Linux
* NetBSD
* OpenBSD
* Plan9
* Windows
and paired with architectures that provide the BTS instruction, this
change shaves off a couple of nanoseconds per invocation of timediv.
Lynn Boger [Mon, 27 Aug 2018 20:34:53 +0000 (16:34 -0400)]
internal/bytealg: implement bytes.Count in asm for ppc64x
This adds an asm implementation for the Count function in ppc64x.
The Go code that manipulates a byte at a time is especially
inefficient on ppc64x, so an asm implementation is a significant
improvement.
test: fix the wrong test of math.Copysign(c, -1) for arm64
The CL 132915 added the wrong codegen test for math.Copysign(c, -1),
it should test that AND is not emitted. This CL fixes this error.
Change-Id: Ida1d3d54ebfc7f238abccbc1f70f914e1b5bfd91
Reviewed-on: https://go-review.googlesource.com/134815 Reviewed-by: Giovanni Bajo <rasky@develer.com> Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Daniel Martí [Wed, 12 Sep 2018 07:26:31 +0000 (09:26 +0200)]
encoding/json: use panics for phase errors
Having these panic-like errors used to be ok, since they were used in
the internal decoder state instead of passed around via return
parameters.
Recently, the decoder was rewritten to use explicit error returns
instead. This error is a terrible fit for error returns; a handful of
functions must return an error because of it, and their callers must
check for an error that should never happen.
This is precisely what panics are for, so use them. The test coverage of
the package goes up from 91.3% to 91.6%, and performance is unaffected.
We can also get rid of some unnecessary verbosity in the code.
name old time/op new time/op delta
CodeDecoder-4 27.5ms ± 1% 27.5ms ± 1% ~ (p=0.937 n=6+6)
Change-Id: I01033b3f5b7c0cf0985082fa272754f96bf6353c
Reviewed-on: https://go-review.googlesource.com/134835
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Ian Lance Taylor [Fri, 7 Sep 2018 19:53:52 +0000 (12:53 -0700)]
cmd/link: don't pass all linker args when testing flag
Some linker flags can actually be input files, which can cause
misleading errors when doing the trial link, which can cause the
linker to incorrectly decide that the flag is not supported, which can
cause the link to fail.
Fixes #27510
Updates #27110
Updates #27293
Change-Id: I70c1e913cee3c813e7b267bf779bcff26d4d194a
Reviewed-on: https://go-review.googlesource.com/134057
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com> Reviewed-by: Damien Neil <dneil@google.com>
cmd/link,compress/zip,image/png: use binary.{Big,Little}Endian methods
Use the binary.{Big,Little}Endian integer encoding methods rather than
variations found in local implementations. The functions in
the binary package have been tested to ensure they inline correctly and
don't add unnecessary bounds checking.
Ian Davis [Mon, 10 Sep 2018 11:13:09 +0000 (12:13 +0100)]
net/url: remove an allocation for short strings in escape
Use a 64 byte array to avoid an allocation on the assumption that
most url escaping is performed on short strings. Also adds a fast
path for escaping strings whose only replacements are spaces which
is common in query components.
Adds benchmarks for QueryEscape, PathEscape, QueryUnescape and
PathUnescape but no optimizations are include for the unescape functions
so I don't include those benchmark results here.
Reduces allocations by 10% in the existing String benchmark with a
modest performance increase.
Alan Donovan [Fri, 7 Sep 2018 13:54:38 +0000 (09:54 -0400)]
go/token: add (*File).LineStart, which returns Pos for a given line
LineStart returns the position of the start of a given line.
Like MergeLine, it panics if the 1-based line number is invalid.
This function is especially useful in programs that occasionally
handle non-Go files such as assembly but wish to use the token.Pos
mechanism to identify file positions.
Change-Id: I5f774c0690074059553cdb38c0f681f5aafc8da1
Reviewed-on: https://go-review.googlesource.com/134075 Reviewed-by: Robert Griesemer <gri@golang.org>
Kevin Burke [Sat, 8 Sep 2018 19:35:03 +0000 (12:35 -0700)]
os/user: retrieve Current username from /etc/passwd, not $USER
Per golang/go#27524 there are situations where the username for the
uid does not match the value in the $USER environment variable and it
seems sensible to choose the value in /etc/passwd when they disagree.
This may make the Current() call slightly more expensive, since we
read /etc/passwd with cgo disabled instead of just checking the
environment. However, we cache the result of Current() calls, so we
only invoke this cost once in the lifetime of the process.
Fixes #14626.
Fixes #27524.
Updates #24884.
Change-Id: I0dcd224cf7f61dd5292f3fcc363aa2e9656a2cb1
Reviewed-on: https://go-review.googlesource.com/134218 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Alex Brainman [Sun, 9 Sep 2018 04:21:25 +0000 (14:21 +1000)]
internal/poll: handle zero-byte write in FD.WriteTo
Zero-byte write was fixed by CL 132781, that was submitted 3 days ago.
But I just submitted CL 129137, and the CL broken zero-byte write
functionality without me noticing. CL 129137 was based on old commit
(older than 3 days ago), and try-bots did not discover the breakage.
Fix zero-byte write again.
Fixes windows build.
Change-Id: Ib403b25fd25cb881963f25706eecca92b924aaa1
Reviewed-on: https://go-review.googlesource.com/134275
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Alex Brainman [Sun, 12 Aug 2018 01:16:26 +0000 (11:16 +1000)]
internal/poll: cap reads and writes to 1GB on windows
Fixes #26923
Change-Id: I62fec814220ccdf7acd8d79a133d1add3f24cf98
Reviewed-on: https://go-review.googlesource.com/129137 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Ian Davis [Fri, 7 Sep 2018 23:57:31 +0000 (00:57 +0100)]
doc: make golang-nuts discussion list more prominent
The discussion list was buried beneath the developer mailing list.
This change puts the discussion list first and gives it a more
prominent heading.
Change-Id: I8dcb4af98e454ae3a0140f9758a5656909126983
Reviewed-on: https://go-review.googlesource.com/134136 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Michael Pratt [Fri, 7 Sep 2018 00:21:59 +0000 (17:21 -0700)]
runtime: use tgkill for raise
raise uses tkill to send a signal to the current thread. For this use,
tgkill is functionally equivalent to tkill expect that it also takes the
pid as the first argument.
Using tgkill makes it simpler to run a Go program in a strict sandbox.
With kill and tgkill, the sandbox policy (e.g., seccomp) can prevent the
program from sending signals to other processes by checking that the
first argument == getpid().
With tkill, the policy must whitelist all tids in the process, which is
effectively impossible given Go's dynamic thread creation.
Fixes #27548
Change-Id: I8ed282ef1f7215b02ef46de144493e36454029ea
Reviewed-on: https://go-review.googlesource.com/133975
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
At least one popular service puts a hostname which contains a ":"
in the Common Name field. On the other hand, I don't know of any name
constrained certificates that only work if we ignore such CNs.
Keith Randall [Wed, 5 Sep 2018 21:36:20 +0000 (14:36 -0700)]
runtime: in semasleep, subtract time spent so far from timeout
When pthread_cond_timedwait_relative_np gets a spurious wakeup
(due to a signal, typically), we used to retry with the same
relative timeout. That's incorrect, we should lower the timeout
by the time we've spent in this function so far.
In the worst case, signals come in and cause spurious wakeups
faster than the timeout, causing semasleep to never time out.
Also fix nacl and netbsd while we're here. They have similar issues.
Fixes #27520
Change-Id: I6601e120e44a4b8ef436eef75a1e7c8cf1d39e39
Reviewed-on: https://go-review.googlesource.com/133655
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
erifan01 [Sat, 30 Jun 2018 06:48:51 +0000 (06:48 +0000)]
cmd/compile: implement non-constant rotates using ROR on arm64
Add some rules to match the Go code like:
y &= 63
x << y | x >> (64-y)
or
y &= 63
x >> y | x << (64-y)
as a ROR instruction. Make math/bits.RotateLeft faster on arm64.
Change-Id: I9ce6541a95b5ecd13f3932558427de1f597df07a
Reviewed-on: https://go-review.googlesource.com/134036
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: I2fa63b0d1981a419626072d985e6f3326f6013ff
Reviewed-on: https://go-review.googlesource.com/134035
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: I0ceb672a9fcd7bbf491be1577d7f135ef35b2561
Reviewed-on: https://go-review.googlesource.com/133455
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Marko Kevac [Tue, 5 Jun 2018 19:41:18 +0000 (22:41 +0300)]
runtime/pprof: remove "deleted" suffix while parsing maps file
If binary file of a running program was deleted or moved, maps
file (/proc/pid/maps) will contain lines that have this binary
filename suffixed with "(deleted)" string. This suffix stayed
as a part of the filename and made remote profiling slightly more
difficult by requiring from a user to rename binary file to
include this suffix.
This change cleans up the filename and removes this suffix and
thus simplify debugging.
Fixes #25740
Change-Id: Ib3c8c3b9ef536c2ac037fcc14e8037fa5c960036
Reviewed-on: https://go-review.googlesource.com/116395
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Ben Shi [Thu, 6 Sep 2018 01:13:14 +0000 (01:13 +0000)]
cmd/compile: optimize 386's comparison
Optimization of "(CMPconst [0] (ANDL x y)) -> (TESTL x y)" only
get benefits if there is no further use of the result of x&y. A
condition of uses==1 will have slight improvements.
1. The code size of pkg/linux_386 decreases about 300 bytes, excluding
cmd/compile/.
2. The go1 benchmark shows no regression, and even a slight improvement
in test case FmtFprintfEmpty-4, excluding noise.
fanzha02 [Fri, 15 Jun 2018 10:20:00 +0000 (10:20 +0000)]
cmd/internal/obj/arm64: add CONSTRAINED UNPREDICTABLE behavior check for some load/store
According to ARM64 manual, it is "constrained unpredictable behavior"
if the src and dst registers of some load/store instructions are same.
In order to completely prevent such unpredictable behavior, adding the
check for load/store instructions that are supported by the assembler
in the assembler.
Rationale: small buffer optimization does not work and it has
made things slower since 2014. Until we can make it work,
we should prefer simpler code that also turns out to be more
efficient.
With this change, it's possible to use
NewBuffer(make([]byte, 0, bootstrapSize)) to get the desired
stack-allocated initial buffer since escape analysis can
prove the created slice to be non-escaping.
New implementation key points:
- Zero value bytes.Buffer performs better than before
- You can have a truly stack-allocated buffer, and it's not even limited to 64 bytes
- The unsafe.Sizeof(bytes.Buffer{}) is reduced significantly
- Empty writes don't cause allocations
Jake B [Wed, 5 Sep 2018 08:52:43 +0000 (08:52 +0000)]
net: ensure WriteTo on Windows sends even zero-byte payloads
This builds on:
https://github.com/golang/go/pull/27445
"...And then send change to fix windows internal/poll.FD.WriteTo - together with making TestUDPZeroBytePayload run again."
- alexbrainman - https://github.com/golang/go/issues/26668#issuecomment-408657503
Fixes #26668
Change-Id: Icd9ecb07458f13e580b3e7163a5946ccec342509
GitHub-Last-Rev: 3bf2b8b46bb8cf79903930631433a1f2ce50ec42
GitHub-Pull-Request: golang/go#27446
Reviewed-on: https://go-review.googlesource.com/132781
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Daniel Martí [Thu, 30 Aug 2018 17:02:41 +0000 (11:02 -0600)]
text/template: simplify line tracking in the lexer
First, move the strings.Count logic out of emit, since only itemText
requires that. Use it in those call sites. itemLeftDelim and
itemRightDelim cannot contain newlines, as they're the "{{" and "}}"
tokens.
Secondly, introduce a startLine lexer field so that we don't have to
keep track of it elsewhere. That's also a requirement to move the
strings.Count out of emit, as emit modifies the start position field.
Change-Id: I69175f403487607a8e5b561b3f1916ee9dc3c0c6
Reviewed-on: https://go-review.googlesource.com/132275
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Rob Pike <r@golang.org>
Robert Griesemer [Wed, 5 Sep 2018 00:18:22 +0000 (17:18 -0700)]
go/types: fix internal comments and add additional test case
https://go-review.googlesource.com/c/go/+/132355 addressed
a crash and inadvertently fixed #27346; however the comment
added to the type-checker was incorrect and misleading.
This CL fixes the comment, and adds a test case for #27346.
Michael Munday [Mon, 3 Sep 2018 11:14:31 +0000 (12:14 +0100)]
cmd/compile: fix store-to-load forwarding of 32-bit sNaNs
Signalling NaNs were being converted to quiet NaNs during constant
propagation through integer <-> float store-to-load forwarding.
This occurs because we store float32 constants as float64
values and CPU hardware 'quietens' NaNs during conversion between
the two.
Eventually we want to move to using float32 values to store float32
constants, however this will be a big change since both the compiler
and the assembler expect float64 values. So for now this is a small
change that will fix the immediate issue.
Fixes #27193.
Change-Id: Iac54bd8c13abe26f9396712bc71f9b396f842724
Reviewed-on: https://go-review.googlesource.com/132956
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
Ben Shi [Thu, 30 Aug 2018 01:19:58 +0000 (01:19 +0000)]
cmd/compile: optimize ARM's comparision
Optimize (CMPconst [0] (ADD x y)) to (CMN x y) will only get benefits
when the result of the addition is no longer used, otherwise there
might be even performance drop. And this CL fixes that issue for
CMP/CMN/TST/TEQ.
There is little regression in the go1 benchmark (excluding noise),
and the test case JSONDecode-4 even gets improvement.
cmd/internal/obj/arm64: encode float constants into FMOVS/FMOVD instructions
Current assembler rewrites float constants to values stored in memory
except 0.0, which is not performant. This patch uses the FMOVS/FMOVD
instructions to move some available floating-point immediate constants
into SIMD&FP destination registers. These available constants can be
encoded into FMOVS/FMOVD instructions, checked by the chipfloat7() function.
cmd/compile/internal/gc: fix mayAffectMemory in esc.go
For OINDEX and other Left+Right nodes, we want the whole
node to be considered as "may affect memory" if either
of Left or Right affect memory. Initial implementation
only considered node as such if both Left and Right were non-safe.
syscall: correct argument order for SyncFileRange syscall on linux/ppc64{,le}
On linux/ppc64{,le} the SYS_SYNC_FILE_RANGE2 syscall is used to
implement SyncFileRange. This syscall has a different argument order
than SYS_SYNC_FILE_RANGE. Apart from that the implementations of both
syscalls are the same, so use a simple wrapper to invoke the syscall
with the correct argument order.
Ben Burkert [Mon, 21 May 2018 19:56:02 +0000 (12:56 -0700)]
net: use splice(2) on Linux when reading from UnixConn, rework splice tests
Rework the splice tests and benchmarks. Move the reading and writing of
the spliced connections to child processes so that the I/O is not part
of benchmarks or profiles.
Enable the use of splice(2) when reading from a unix connection and
writing to a TCP connection. The updated benchmarks show a performance
gain when using splice(2) to copy large chunks of data that the original
benchmark did not capture.
cmd/link: move dwarf part of DWARF generation before type name mangling
Splits part of dwarfgeneratedebugsyms into a new function,
dwarfGenerateDebugInfo which is called between deadcode elimination
and type name mangling.
This function takes care of collecting and processing the DIEs for
all functions and package-level variables and also generates DIEs
for all types used in the program.
The indirectType function comment uses the phrase 'layed out'. In the
context of that phrase, where something is being placed or sprawled,
the word should be 'laid'. 'Layed' is a misspelling of 'laid'.
Change-Id: I05ecb97637276e2252c47e92a0bd678130714889
GitHub-Last-Rev: 6ee67371b42c12ceaf4c6c245319748008ac7e7b
GitHub-Pull-Request: golang/go#27444
Reviewed-on: https://go-review.googlesource.com/132779 Reviewed-by: Ian Lance Taylor <iant@golang.org>