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Commit Graph

45434 Commits

Author SHA1 Message Date
Alberto Donizetti
bc0d7fd9b7 cmd/compile: delete log2, switch to log64
rewrite.go has two identical functions log2 and log64; the former has
been there for a while, while the latter was added together with
log{8,16,32} for use in typed rules.

This change deletes log2 and switches to using log64 everywhere.

Change-Id: I759b878814e4c115a5fa470274f22477738d69ef
Reviewed-on: https://go-review.googlesource.com/c/go/+/265457
Trust: Alberto Donizetti <alb.donizetti@gmail.com>
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
2020-10-28 19:19:04 +00:00
Joel Sing
4d6dfd64c1 runtime: add defs for openbsd/mips64
Update #40995

Change-Id: I6963ead1a7c4520092361cce80edb17010e7f436
Reviewed-on: https://go-review.googlesource.com/c/go/+/250579
Trust: Joel Sing <joel@sing.id.au>
Run-TryBot: Joel Sing <joel@sing.id.au>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
2020-10-28 18:54:46 +00:00
Joel Sing
76661d12e8 runtime: remove new g register (X27) from preempt save/restore
The g register is now in X27 (previously X4, which collided with TP usage). Remove
X27 from preempt save/restore.

Change-Id: I9dd38ec3a8222fa0710757463769dbfac8ae7d20
Reviewed-on: https://go-review.googlesource.com/c/go/+/265517
Trust: Joel Sing <joel@sing.id.au>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
2020-10-28 18:11:26 +00:00
Michael Pratt
fc116b69e2 runtime: try to elide timer stealing if P has no timers
Following golang.org/cl/259578, findrunnable still must touch every
other P in checkTimers in order to look for timers to steal. This scales
poorly with GOMAXPROCS and potentially performs poorly by pulling remote
Ps into cache.

Add timerpMask, a bitmask that tracks whether each P may have any timers
on its timer heap.

Ideally we would update this field on any timer add / remove to always
keep it up to date. Unfortunately, updating a shared global structure is
antithetical to sharding timers by P, and doing so approximately doubles
the cost of addtimer / deltimer in microbenchmarks.

Instead we only (potentially) clear the mask when the P goes idle. This
covers the best case of avoiding looking at a P _at all_ when it is idle
and has no timers. See the comment on updateTimerPMask for more details
on the trade-off. Future CLs may be able to expand cases we can avoid
looking at the timers.

Note that the addition of idlepMask to p.init is a no-op. The zero value
of the mask is the correct init value so it is not necessary, but it is
included for clarity.

Benchmark results from WakeupParallel/syscall/pair/race/1ms (see
golang.org/cl/228577). Note that these are on top of golang.org/cl/259578:

name                        old msec           new msec   delta
Perf-task-clock-8           244 ± 4%           246 ± 4%     ~     (p=0.841 n=5+5)
Perf-task-clock-16          247 ±11%           252 ± 4%     ~     (p=1.000 n=5+5)
Perf-task-clock-32          270 ± 1%           268 ± 2%     ~     (p=0.548 n=5+5)
Perf-task-clock-64          302 ± 3%           296 ± 1%     ~     (p=0.222 n=5+5)
Perf-task-clock-128         358 ± 3%           352 ± 2%     ~     (p=0.310 n=5+5)
Perf-task-clock-256         483 ± 3%           458 ± 1%   -5.16%  (p=0.008 n=5+5)
Perf-task-clock-512         663 ± 1%           612 ± 4%   -7.61%  (p=0.008 n=5+5)
Perf-task-clock-1024      1.06k ± 1%         0.95k ± 2%  -10.24%  (p=0.008 n=5+5)

Updates #28808
Updates #18237

Change-Id: I4239cd89f21ad16dfbbef58d81981da48acd0605
Reviewed-on: https://go-review.googlesource.com/c/go/+/264477
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Trust: Michael Pratt <mpratt@google.com>
2020-10-28 17:54:13 +00:00
Cuong Manh Le
642329fdd5 Revert "cmd/compile: split exported/non-exported methods for interface type"
This reverts commit 8f26b57f9a.

Reason for revert: break a bunch of code, include standard library.

Fixes #42123

Change-Id: Ife90ecbafd2cb395623d1db555fbfc9c1b0098e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/264026
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2020-10-28 17:10:08 +00:00
Antonio Huete Jimenez
e3c58bbeb8 os: do not use procfs for os.Executable in dragonfly
procfs(5) is not always mounted in DragonFly BSD, for example during
  the binary package build with synth. os.Executable() consumers
  will then fail, we've spotted this when trying to build tinygo:

    [...]

    copying source files
    ./build/tinygo build-builtins -target=armv6m-none-eabi [...]
    panic: could not get executable path: readlink /proc/curproc/file:
    no such file or directory

    [...]

  Use KERN_PROC_PATHNAME as FreeBSD does.

Change-Id: Ic65bea02cd0309fb24dec8ba8d2b151d1acde67b
GitHub-Last-Rev: 083120a43b
GitHub-Pull-Request: golang/go#36826
Reviewed-on: https://go-review.googlesource.com/c/go/+/216622
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Trust: Brad Fitzpatrick <bradfitz@golang.org>
2020-10-28 17:08:06 +00:00
Tzu-Chiao Yeh
d4c1ad8829 database/sql: fix tx stmt deadlock when rollback
Tx acquires tx.closemu W-lock and then acquires stmt.closemu.W-lock
to fully close the transaction and associated prepared statement.
Stmt query and execution run in reverse ways - acquires
stmt.closemu.R-lock and then acquires tx.closemu.R-lock to grab tx
connection, which may cause deadlock.

Prevent the lock is held around tx.closePrepared to ensure no
deadlock happens.

Fixes #40985

Change-Id: If53909822b87bce11861a6e3035ecb9476d2cd17
Reviewed-on: https://go-review.googlesource.com/c/go/+/250178
Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
2020-10-28 16:55:17 +00:00
Tobias Klauser
421d4e72de cmd/go/internal/modfetch: drop gopkg.in/russross/blackfriday.v2 from TestCodeRepoVersions
Follow-up for CL 265819.

Given the -pre tag added recently, a new stable version is likely
tagged soon. This would break TestCodeRepoVersions on the longtest
builders again. Since the other test cases in codeRepoVersionsTests
already provide enough coverage, drop gopkg.in/russross/blackfriday.v2
to avoid breaking TestCodeRepoVersions once the release happens.

Updates #28856

Change-Id: If86a637b5e47f59faf9048fc1cbbae6e8f1dcc53
Reviewed-on: https://go-review.googlesource.com/c/go/+/265917
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
2020-10-28 16:17:54 +00:00
Dan Scales
a69cda9a65 runtime: add edge lockRankSysmon -> lockRankRwmutexR
Sysmon can actually get the RW lock execLock while holding the sysmon
lock (if no M is available), so there is an edge from lockRankSysmon to
lockRankRwmutexR. The stack trace is sysmon() [gets sched.sysmonlock] ->
startm() -> newm() -> newm1() -> execLock.runlock() [gets
execLock.rLock]

Change-Id: I9658659ba3899afb5219114d66b989abd50540db
Reviewed-on: https://go-review.googlesource.com/c/go/+/265721
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2020-10-28 15:52:02 +00:00
Cherry Zhang
b85c2dd56c cmd/link: enable internal linking by default on darwin/arm64
With previous CLs, internal linking without cgo should work well.
Enable it by default. And stop always requiring cgo.

Enable tests that were previously disabled due to the lack of
internal linking.

Updates #38485.

Change-Id: I45125b9c263fd21d6847aa6b14ecaea3a2989b29
Reviewed-on: https://go-review.googlesource.com/c/go/+/265121
Trust: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
2020-10-28 14:25:56 +00:00
Cherry Zhang
7c8d82e92b runtime: always enable async preemption on darwin/arm64
Now that we have the G register saved, we can enable asynchronous
preemption for pure Go programs on darwin/arm64.

Updates #38485, #36365.

Change-Id: Ic654fa4dce369efe289b38d59cf1a184b358fe9e
Reviewed-on: https://go-review.googlesource.com/c/go/+/265120
Trust: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-10-28 14:00:36 +00:00
Cherry Zhang
a0a44397e9 runtime: save/restore g unconditionally on darwin/arm64
Now that we always have TLS set up, we can always save the G
register, regardless of whether cgo is used. This makes pure Go
programs signal-safe.

Updates #38485.

Change-Id: Icbc69acf0e2a5652fbcbbd074258a1a5efe87f1a
Reviewed-on: https://go-review.googlesource.com/c/go/+/265119
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Joel Sing <joel@sing.id.au>
2020-10-28 13:46:11 +00:00
Cherry Zhang
72dec90bfd runtime: set up TLS without cgo on darwin/arm64
Currently, on darwin/arm64 we set up TLS using cgo. TLS is not
set for pure Go programs. As we use libc for syscalls on darwin,
we need to save the G register before the libc call. Otherwise it
is not signal-safe, as a signal may land during the execution of
a libc function, where the G register may be clobbered.

This CL initializes TLS in Go, by calling the pthread functions
directly without cgo. This makes it possible to save the G
register to TLS in pure Go programs (done in a later CL).

Inspired by Elias's CL 209197. Write the logic in Go instead of
assembly.

Updates #38485, #35853.

Change-Id: I257ba2a411ad387b2f4d50d10129d37fec7a226e
Reviewed-on: https://go-review.googlesource.com/c/go/+/265118
Trust: Cherry Zhang <cherryyz@google.com>
Trust: Elias Naur <mail@eliasnaur.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-10-28 13:25:44 +00:00
Tobias Klauser
cf6cfba4d5 cmd/go/internal/modfetch: update expected tags for TestCodeRepoVersions
Updates #28856

Change-Id: I89c564cefd7c5777904bc00c74617dab693373bf
Reviewed-on: https://go-review.googlesource.com/c/go/+/265819
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Alberto Donizetti <alb.donizetti@gmail.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
2020-10-28 12:41:19 +00:00
Michał Derkacz
150d2448e5 cmd/compile,cmd/internal/obj/riscv,runtime: use Duff's devices on riscv64
Implement runtime.duffzero and runtime.duffcopy for riscv64.
Use obj.ADUFFZERO/obj.ADUFFCOPY for medium size, word aligned
zeroing/moving.

Change-Id: I42ec622055630c94cb77e286d8d33dbe7c9f846c
Reviewed-on: https://go-review.googlesource.com/c/go/+/237797
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-10-28 05:02:44 +00:00
Keith Randall
c95bd2e6a9 cmd/compile: optimize generated struct/array equality code
Use a standard "not-equal" label that we can jump to when we
detect that the arguments are not equal. This prevents the
recombination that was noticed in #39428.

Fixes #39428

Change-Id: Ib7c6b3539f4f6046043fd7148f940fcdcab70427
Reviewed-on: https://go-review.googlesource.com/c/go/+/255317
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2020-10-28 04:33:41 +00:00
Ian Lance Taylor
02335cf413 runtime: move TestNeedmDeadlock to crash_cgo_test.go
It requires cgo. Also, skip the test on windows and plan9.

For #42207

Change-Id: I8522773f93bc3f9826506a41a08b86a083262e31
Reviewed-on: https://go-review.googlesource.com/c/go/+/265778
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2020-10-28 04:20:39 +00:00
David Chase
2414e1f17b cmd/compile: make sure field offset is aligned for structure splitting
Always use the aligned form -- the old code sometimes could
at least nominally use a misaligned field in an SSA-able struct,
even if not actually.

Fixes #42181.

Change-Id: Ibdce0985f9349da70921a37423054b85ee4200d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/265277
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Trust: David Chase <drchase@google.com>
2020-10-28 01:22:47 +00:00
Meng Zhuo
7be9158ce5 cmd/link: remove all constants of elf
Use debug/elf instead.

Related:
CL 252478
CL 265317

Change-Id: If63b0458d9a6e825b40616bfb7a5a2c2e32402b4
Reviewed-on: https://go-review.googlesource.com/c/go/+/265318
Trust: Meng Zhuo <mzh@golangcn.org>
Run-TryBot: Meng Zhuo <mzh@golangcn.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Joel Sing <joel@sing.id.au>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-10-28 01:18:38 +00:00
Ian Lance Taylor
368c401164 runtime: block signals in needm before allocating M
Otherwise, if a signal occurs just after we allocated the M,
we can deadlock if the signal handler needs to allocate an M
itself.

Fixes #42207

Change-Id: I76f44547f419e8b1c14cbf49bf602c6e645d8c14
Reviewed-on: https://go-review.googlesource.com/c/go/+/265759
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2020-10-28 01:03:23 +00:00
Dave Pifke
94f3762462 cmd/go: add -include to cgo whitelist
Fixes #39988.

Change-Id: Ia6f5b73e6508f27e3badbcbd29dbeadffd55a932
Reviewed-on: https://go-review.googlesource.com/c/go/+/240739
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-10-28 00:49:40 +00:00
George Tsilias
49b017fe59 runtime: handle signal 34 for musl setgid
It has been observed that setgid hangs when using cgo with musl.
This fix ensures that signal 34 gets handled in an appropriate way,
like signal 33 when using glibc.

Fixes #39343

Change-Id: I89565663e2c361f62cbccfe80aaedf290bd58d57
Reviewed-on: https://go-review.googlesource.com/c/go/+/236518
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-10-28 00:48:22 +00:00
Cherry Zhang
40d1ec588f cmd/dist: use GOOS=ios for iOS simulator test
Updates #42100.

Change-Id: Ib59432bea99a9dd6e25fbd759b31e423dc250f42
Reviewed-on: https://go-review.googlesource.com/c/go/+/265197
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-10-28 00:25:05 +00:00
Christopher Hlubek
70e022e4a8 time: fix LoadLocationFromTZData with slim tzdata
The extend information of a time zone file with last transition < now
could result in a wrong cached zone because it used the zone of the
last transition.

This could lead to wrong zones in systems with slim zoneinfo.

Fixes #42216

Change-Id: I7c57c35b5cfa58482ac7925b5d86618c52f5444d
Reviewed-on: https://go-review.googlesource.com/c/go/+/264939
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-10-27 23:36:05 +00:00
Roland Shoemaker
5d3666e1a4 crypto/tls: document the ClientAuthType consts
Fixes #34023

Change-Id: Ib7552a8873a79a91e8d971f906c6d7283da7a80c
Reviewed-on: https://go-review.googlesource.com/c/go/+/264027
Trust: Roland Shoemaker <roland@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>
2020-10-27 23:12:41 +00:00
Ian Lance Taylor
b4b0144652 runtime: don't always adjust timers
Some programs have a lot of timers that they adjust both forward and
backward in time. This can cause a large number of timerModifiedEarlier
timers. In practice these timers are used for I/O deadlines and are
rarely reached. The effect is that the runtime spends a lot of time
in adjusttimers making sure that there are no timerModifiedEarlier
timers, but the effort is wasted because none of the adjusted timers
are near the top of the timer heap anyhow.

Avoid much of this extra work by keeping track of the earliest known
timerModifiedEarlier timer. This lets us skip adjusttimers if we know
that none of the timers will be ready to run anyhow. We will still
eventually run it, when we reach the deadline of the earliest known
timerModifiedEarlier, although in practice that timer has likely
been removed. When we do run adjusttimers, we will reset all of the
timerModifiedEarlier timers, and clear our notion of when we need
to run adjusttimers again.

This effect should be to significantly reduce the number of times we
walk through the timer list in adjusttimers.

Fixes #41699

Change-Id: I38eb2be611fb34e3017bb33d0a9ed40d75fb414f
Reviewed-on: https://go-review.googlesource.com/c/go/+/258303
Trust: Ian Lance Taylor <iant@golang.org>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2020-10-27 22:57:36 +00:00
Keith Randall
091257def9 cmd/compile: print pointers to go:notinheap types without converting to unsafe.Pointer
Pretty minor concern, but after auditing the compiler/runtime for
conversions from pointers to go:notinheap types to unsafe.Pointer,
this is the only remaining one I found.

Update #42076

Change-Id: I81d5b893c9ada2fc19a51c2559262f2e9ff71c35
Reviewed-on: https://go-review.googlesource.com/c/go/+/265757
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-10-27 22:13:30 +00:00
Keith Randall
009d714098 cmd/compile, runtime: store pointers to go:notinheap types indirectly
pointers to go:notinheap types should be treated as scalars. That
means they shouldn't be stored directly in interfaces, or directly
in reflect.Value.ptr.

Also be sure to use uintpr to compare such pointers in reflect.DeepEqual.

Fixes #42076

Change-Id: I53735f6d434e9c3108d4940bd1bae14c61ef2a74
Reviewed-on: https://go-review.googlesource.com/c/go/+/264480
Trust: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-10-27 21:29:13 +00:00
Keith Randall
933721b8c7 cmd/compile: fix storeType to handle pointers to go:notinheap types
storeType splits compound stores up into a scalar parts and a pointer parts.
The scalar part happens unconditionally, and the pointer part happens
under the guard of a write barrier check.

Types which are declared as pointers, but are represented as scalars because
they might have "bad" values, were not handled correctly here. They ended
up not getting stored in either set.

Fixes #42032

Change-Id: I46f6600075c0c370e640b807066247237f93c7ac
Reviewed-on: https://go-review.googlesource.com/c/go/+/264300
Trust: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-10-27 21:28:53 +00:00
Ian Lance Taylor
9fcb5e0c52 go/internal/gccgoimporter: support notinheap annotation
The gofrontend has started emitting a notinheap annotation for types
marked go:notinheap.

For #41761

Change-Id: Ic8f7ffc32dbfe98ec09b3d835957f1be8e6c1208
Reviewed-on: https://go-review.googlesource.com/c/go/+/265702
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2020-10-27 20:49:38 +00:00
Daniel Martí
9113d8c37f doc/go1.16: document BuildID in 'go list -export'
This corresponds to the feature in https://golang.org/cl/263542, since
this can be a noteworthy change to people writing tools to inspect Go
builds.

Also amend the wording to clarify that build IDs are for an entire
compiled package, not just their export data or object file.

Change-Id: I2eb295492807d5d2997a35e5e2371914cb3ad3a0
Reviewed-on: https://go-review.googlesource.com/c/go/+/264158
Trust: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2020-10-27 20:22:56 +00:00
Alberto Donizetti
de2d1c3fe2 cmd/compile: replace int32(b2i(x)) with b2i32(x) in rules
Change-Id: I7fbb0c1ead6e29a7445c8ab43f7050947597f3e8
Reviewed-on: https://go-review.googlesource.com/c/go/+/265497
Trust: Alberto Donizetti <alb.donizetti@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
2020-10-27 20:04:19 +00:00
Alberto Donizetti
5c1122b528 cmd/compile: delete isPowerOfTwo, switch to isPowerOfTwo64
rewrite.go has two identical functions isPowerOfTwo and
isPowerOfTwo64; the former has been there for a while, while the
latter was added together with isPowerOfTwo{8,16,32} for use in typed
rules.

This change deletes isPowerOfTwo and switch to using isPowerOfTwo64
everywhere.

Change-Id: If26c94565d2393fac6f0ba117ee7ee2fc915f7cd
Reviewed-on: https://go-review.googlesource.com/c/go/+/265417
Trust: Alberto Donizetti <alb.donizetti@gmail.com>
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-10-27 20:03:41 +00:00
Alberto Donizetti
d68c01fa1d cmd/compile: clean up ValAndOff funcs after untyped aux removal
Changes:
- makeValAndOff is deleted in favour of MakeValAndOff{32,64}
- canAdd is renamed to canAdd64 to uniform with existing canAdd32
- addOffset{32,64} is simplified by directly using MakeValAndOff{32,64}
- ValAndOff.Int64 is removed

Change-Id: Ic01db7fa31ddfe0aaaf1d1d77af823d48a7bee84
Reviewed-on: https://go-review.googlesource.com/c/go/+/265357
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Alberto Donizetti <alb.donizetti@gmail.com>
2020-10-27 20:03:25 +00:00
Alberto Donizetti
79a3482d9e cmd/compile: remove support for untyped ssa rules
This change removes support in rulegen for untyped -> ssa rules.

Change-Id: I202018e191fc74f027243351bc8cf96145f2482c
Reviewed-on: https://go-review.googlesource.com/c/go/+/264679
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Alberto Donizetti <alb.donizetti@gmail.com>
2020-10-27 20:03:12 +00:00
Heisenberg
c515852732 runtime: add 2-byte and 8-byte sub-benchmarks for memmove load/store
Change-Id: I6389d7efe90836b6ece44d2e75053d1ad9f35d08
Reviewed-on: https://go-review.googlesource.com/c/go/+/253417
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
Reviewed-by: Keith Randall <khr@golang.org>
2020-10-27 19:52:40 +00:00
Dan Peterson
f0c9ae5452 net/http: use exponential backoff for polling in Server.Shutdown
Instead of always polling 500ms, start with an interval of 1ms and
exponentially back off to at most 500ms. 10% jitter is added to each
interval.

This makes Shutdown more responsive when connections and listeners
close quickly.

Also removes the need for the polling interval to be changed in tests
since if tests' connections and listeners close quickly Shutdown will
also return quickly.

Fixes #42156

Change-Id: I5e59844a2980c09adebff57ae8b58817965e6db4
Reviewed-on: https://go-review.googlesource.com/c/go/+/264479
Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
Trust: Bryan C. Mills <bcmills@google.com>
2020-10-27 18:38:48 +00:00
Paul E. Murphy
c3c6fbf314 cmd/compile: combine more 32 bit shift and mask operations on ppc64
Combine (AND m (SRWconst x)) or (SRWconst (AND m x)) when mask m is
and the shift value produce constant which can be encoded into an
RLWINM instruction.

Combine (CLRLSLDI (SRWconst x)) if the combining of the underling rotate
masks produces a constant which can be encoded into RLWINM.

Likewise for (SLDconst (SRWconst x)) and (CLRLSDI (RLWINM x)).

Combine rotate word + and operations which can be encoded as a single
RLWINM/RLWNM instruction.

The most notable performance improvements arise from the crypto
benchmarks below (GOARCH=power8 on a ppc64le/linux):

pkg:golang.org/x/crypto/blowfish goos:linux goarch:ppc64le
ExpandKeyWithSalt                               52.2µs ± 0%    47.5µs ± 0%  -8.88%
ExpandKey                                       44.4µs ± 0%    40.3µs ± 0%  -9.15%

pkg:golang.org/x/crypto/ssh/internal/bcrypt_pbkdf goos:linux goarch:ppc64le
Key                                             57.6ms ± 0%    52.3ms ± 0%  -9.13%

pkg:golang.org/x/crypto/bcrypt goos:linux goarch:ppc64le
Equal                                           90.9ms ± 0%    82.6ms ± 0%  -9.13%
DefaultCost                                     91.0ms ± 0%    82.7ms ± 0%  -9.12%

Change-Id: I59a0ca29face38f4ab46e37124c32906f216c4ce
Reviewed-on: https://go-review.googlesource.com/c/go/+/260798
Run-TryBot: Carlos Eduardo Seo <carlos.seo@linaro.com>
TryBot-Result: Go Bot <gobot@golang.org>
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Reviewed-by: Carlos Eduardo Seo <carlos.seo@linaro.com>
Trust: Lynn Boger <laboger@linux.vnet.ibm.com>
2020-10-27 18:33:20 +00:00
Cuong Manh Le
e3bb53a768 cmd/compile: remove isLiteral
It has duplicated logic with "n.isGoConst".

Passes toolstash-check.

Change-Id: I5bf871ef81c7188ca09dae29c7ff55b3a254d972
Reviewed-on: https://go-review.googlesource.com/c/go/+/265437
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
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Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-10-27 18:23:46 +00:00
HowJMay
3f6b1a0d5e misc/cgo/test: test C.enum_*
Allocate a C enum object, and test if it can be assigned a value
successfully.

For #39537

Change-Id: I7b5482112486440b9d99f2ee4051328d87f45dca
GitHub-Last-Rev: 81890f40ac
GitHub-Pull-Request: golang/go#39977
Reviewed-on: https://go-review.googlesource.com/c/go/+/240697
Run-TryBot: Ian Lance Taylor <iant@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
2020-10-27 18:13:59 +00:00
Chris Hines
8fdc79e18a runtime: reduce timer latency
Change the scheduler to treat expired timers with the same approach it
uses to steal runnable G's.

Previously the scheduler ignored timers on P's not marked for
preemption. That had the downside that any G's waiting on those expired
timers starved until the G running on their P completed or was
preempted. That could take as long as 20ms if sysmon was in a 10ms
wake up cycle.

In addition, a spinning P that ignored an expired timer and found no
other work would stop despite there being available work, missing the
opportunity for greater parallelism.

With this change the scheduler no longer ignores timers on
non-preemptable P's or relies on sysmon as a backstop to start threads
when timers expire. Instead it wakes an idle P, if needed, when
creating a new timer because it cannot predict if the current P will
have a scheduling opportunity before the new timer expires. The P it
wakes will determine how long to sleep and block on the netpoller for
the required time, potentially stealing the new timer when it wakes.

This change also eliminates a race between a spinning P transitioning
to idle concurrently with timer creation using the same pattern used
for submission of new goroutines in the same window.

Benchmark analysis:

CL 232199, which was included in Go 1.15 improved timer latency over Go
1.14 by allowing P's to steal timers from P's not marked for preemption.
The benchmarks added in this CL measure that improvement in the
ParallelTimerLatency benchmark seen below. However, Go 1.15 still relies
on sysmon to notice expired timers in some situations and sysmon can
sleep for up to 10ms before waking to check timers. This CL fixes that
shortcoming with modest regression on other benchmarks.

name \ avg-late-ns                                        go14.time.bench  go15.time.bench  fix.time.bench
ParallelTimerLatency-8                                         17.3M ± 3%        7.9M ± 0%       0.2M ± 3%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=1-8        53.4k ±23%       50.7k ±31%     252.4k ± 9%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=2-8         204k ±14%         90k ±58%       188k ±12%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=3-8        1.17M ± 0%       0.11M ± 5%      0.11M ± 2%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=4-8        1.81M ±44%       0.10M ± 4%      0.10M ± 2%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=5-8        2.28M ±66%       0.09M ±13%      0.08M ±21%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=6-8        2.84M ±85%       0.07M ±15%      0.07M ±18%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=7-8        2.13M ±27%       0.06M ± 4%      0.06M ± 9%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=8-8        2.63M ± 6%       0.06M ±11%      0.06M ± 9%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=9-8        3.32M ±17%       0.06M ±16%      0.07M ±14%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=10-8       8.46M ±20%       4.37M ±21%      5.03M ±23%
StaggeredTickerLatency/work-dur=2ms/tickers-per-P=1-8          1.02M ± 1%       0.20M ± 2%      0.20M ± 2%

name \ max-late-ns                                        go14.time.bench  go15.time.bench  fix.time.bench
ParallelTimerLatency-8                                         18.3M ± 1%        8.2M ± 0%       0.5M ±12%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=1-8         141k ±19%        127k ±19%      1129k ± 3%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=2-8        2.78M ± 4%       1.23M ±15%      1.26M ± 5%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=3-8        6.05M ± 5%       0.67M ±56%      0.81M ±33%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=4-8        7.93M ±20%       0.71M ±46%      0.76M ±41%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=5-8        9.41M ±30%       0.92M ±23%      0.81M ±44%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=6-8        10.8M ±42%        0.8M ±41%       0.8M ±30%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=7-8        9.62M ±24%       0.77M ±38%      0.88M ±27%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=8-8        10.6M ±10%        0.8M ±32%       0.7M ±27%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=9-8        11.9M ±36%        0.6M ±46%       0.8M ±38%
StaggeredTickerLatency/work-dur=300µs/tickers-per-P=10-8       36.8M ±21%       24.7M ±21%      27.5M ±16%
StaggeredTickerLatency/work-dur=2ms/tickers-per-P=1-8          2.12M ± 2%       1.02M ±11%      1.03M ± 7%

Other time benchmarks:
name \ time/op          go14.time.bench  go15.time.bench  fix.time.bench
AfterFunc-8                  137µs ± 4%       123µs ± 4%      131µs ± 2%
After-8                      212µs ± 3%       195µs ± 4%      204µs ± 7%
Stop-8                       165µs ± 6%       156µs ± 2%      151µs ±12%
SimultaneousAfterFunc-8      260µs ± 3%       248µs ± 3%      284µs ± 2%
StartStop-8                 65.8µs ± 9%      64.4µs ± 7%     67.3µs ±15%
Reset-8                     13.6µs ± 2%       9.6µs ± 2%      9.1µs ± 4%
Sleep-8                      307µs ± 4%       306µs ± 3%      320µs ± 2%
Ticker-8                    53.0µs ± 5%      54.5µs ± 5%     57.0µs ±11%
TickerReset-8                                9.24µs ± 2%     9.51µs ± 3%
TickerResetNaive-8                            149µs ± 5%      145µs ± 5%

Fixes #38860
Updates #25471
Updates #27707

Change-Id: If52680509b0f3b66dbd1d0c13fa574bd2d0bbd57
Reviewed-on: https://go-review.googlesource.com/c/go/+/232298
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Trust: Ian Lance Taylor <iant@golang.org>
2020-10-27 17:24:42 +00:00
xd
b3f7f60129 cmd/dist: fix build failure of misc/cgo/test on arm64
misc/cgo/test fails in 'dist test' on arm64 if the C compiler is of GCC-9.4 or
above and its 'outline atomics' feature is enabled, since the internal linking
hasn't yet supported "__attribute__((constructor))" and also mis-handles hidden
visibility.

This change addresses the problem by skipping the internal linking cases of
misc/cgo/test on linux/arm64. It fixes 'dist test' failure only, user is expected to
pass a GCC option '-mno-outline-atomics' via CGO_CFLAGS if running into the same
problem when building cgo programs using internal linking.

Updates #39466

Change-Id: I57f9e85fca881e5fd2dae6c1b4446bce9e0c1975
Reviewed-on: https://go-review.googlesource.com/c/go/+/262357
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
2020-10-27 15:42:41 +00:00
Russ Cox
3c55aea67a cmd/go/internal/fsys: add Glob
Glob is needed for //go:embed processing.

Also change TestReadDir to be deterministic
and print more output about failures.

Change-Id: Ie22a9c5b32bda753579ff98cec1d28e3244c4e06
Reviewed-on: https://go-review.googlesource.com/c/go/+/264538
Trust: Russ Cox <rsc@golang.org>
Trust: Jay Conrod <jayconrod@google.com>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>
2020-10-27 15:34:01 +00:00
Andy Williams
ece7a33386 mime: look up mime types on Arch Linux
Some systems use "httpd" directory structure instead of "apache"

Change-Id: I77600baf356f0c0c3359b331505b0426112daebb
GitHub-Last-Rev: c64766f88c
GitHub-Pull-Request: golang/go#39416
Reviewed-on: https://go-review.googlesource.com/c/go/+/236677
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Trust: Brad Fitzpatrick <bradfitz@golang.org>
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Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2020-10-27 15:22:02 +00:00
Bryan C. Mills
d73d5d9fb0 cmd/go/internal/imports: make Tags and AnyTags safe for concurrent use
AnyTags turned up as a data race while running 'go test -race cmd/go'.
I'm not sure how long the race has been present.

==================
WARNING: DATA RACE
Read at 0x000001141ec0 by goroutine 8:
  cmd/go/internal/imports.AnyTags()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/imports/tags.go:45 +0x10e
  cmd/go/internal/modload.QueryPattern.func2()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/modload/query.go:539 +0x11d
  cmd/go/internal/modload.QueryPattern.func4.1()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/modload/query.go:607 +0x3db
  cmd/go/internal/modload.queryPrefixModules.func1()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/modload/query.go:677 +0xa7

Previous write at 0x000001141ec0 by goroutine 7:
  cmd/go/internal/imports.AnyTags()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/imports/tags.go:46 +0x26b
  cmd/go/internal/modload.QueryPattern.func2()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/modload/query.go:539 +0x11d
  cmd/go/internal/modload.QueryPattern.func4.1()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/modload/query.go:607 +0x3db
  cmd/go/internal/modload.queryPrefixModules.func1()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/modload/query.go:677 +0xa7

Goroutine 8 (running) created at:
  cmd/go/internal/modload.queryPrefixModules()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/modload/query.go:676 +0x284
  cmd/go/internal/modload.QueryPattern.func4()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/modload/query.go:624 +0x2e4
  cmd/go/internal/modfetch.TryProxies()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/modfetch/proxy.go:220 +0x107
  cmd/go/internal/modload.QueryPattern()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/modload/query.go:590 +0x69e
  cmd/go/internal/work.installOutsideModule()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/work/build.go:744 +0x4b0
  cmd/go/internal/work.runInstall()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/work/build.go:556 +0x217
  main.main()
      /usr/local/google/home/bcmills/go/src/cmd/go/main.go:194 +0xb94

Goroutine 7 (finished) created at:
  cmd/go/internal/modload.queryPrefixModules()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/modload/query.go:676 +0x284
  cmd/go/internal/modload.QueryPattern.func4()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/modload/query.go:624 +0x2e4
  cmd/go/internal/modfetch.TryProxies()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/modfetch/proxy.go:220 +0x107
  cmd/go/internal/modload.QueryPattern()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/modload/query.go:590 +0x69e
  cmd/go/internal/work.installOutsideModule()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/work/build.go:744 +0x4b0
  cmd/go/internal/work.runInstall()
      /usr/local/google/home/bcmills/go/src/cmd/go/internal/work/build.go:556 +0x217
  main.main()
      /usr/local/google/home/bcmills/go/src/cmd/go/main.go:194 +0xb94
==================

Change-Id: Id394978fd6ea0c30614caf8f90ee4f8e2d272843
Reviewed-on: https://go-review.googlesource.com/c/go/+/265278
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
2020-10-27 15:15:13 +00:00
Ayzat Sadykov
de477138d1 database/sql: fix comment on DB.stop()
Previously, 2 goroutines were created in OpenDB and a comment in the DB.close() field indicated that they were canceled. Later, session Resetter () was removed, but the comment remained the same. This commit just fixes this message

Change-Id: Ie81026f51d7770e9cf8004818154021f626fb2e8
GitHub-Last-Rev: 38b338a0d1
GitHub-Pull-Request: golang/go#42191
Reviewed-on: https://go-review.googlesource.com/c/go/+/264838
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Trust: Brad Fitzpatrick <bradfitz@golang.org>
2020-10-27 15:12:12 +00:00
Russ Cox
69496a2268 cmd/go: fix bug introduced in CL 264537
Shadowing bug noted after submit by Tom Thorogood.

Change-Id: I5f40cc3863dcd7dba5469f8530e9d0460e7c3e7e
Reviewed-on: https://go-review.googlesource.com/c/go/+/265537
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
2020-10-27 15:11:50 +00:00
Joel Sing
320cc79002 cmd/compile: eliminate unnecessary sign/zero extension for riscv64
Add additional rules to eliminate unnecessary sign/zero extension for riscv64.
Also where possible, replace an extension following a load with a different typed
load. This removes almost another 8,000 instructions from the go binary.

Of particular note, change Eq16/Eq8/Neq16/Neq8 to zero extend each value before
subtraction, rather than zero extending after subtraction. While this appears to
double the number of zero extensions, it often lets us completely eliminate them
as the load can already be performed in a properly typed manner.

As an example, prior to this change runtime.memequal16 was:

0000000000013028 <runtime.memequal16>:
   13028:       00813183                ld      gp,8(sp)
   1302c:       00019183                lh      gp,0(gp)
   13030:       01013283                ld      t0,16(sp)
   13034:       00029283                lh      t0,0(t0)
   13038:       405181b3                sub     gp,gp,t0
   1303c:       03019193                slli    gp,gp,0x30
   13040:       0301d193                srli    gp,gp,0x30
   13044:       0011b193                seqz    gp,gp
   13048:       00310c23                sb      gp,24(sp)
   1304c:       00008067                ret

Whereas it now becomes:

0000000000012fa8 <runtime.memequal16>:
   12fa8:       00813183                ld      gp,8(sp)
   12fac:       0001d183                lhu     gp,0(gp)
   12fb0:       01013283                ld      t0,16(sp)
   12fb4:       0002d283                lhu     t0,0(t0)
   12fb8:       405181b3                sub     gp,gp,t0
   12fbc:       0011b193                seqz    gp,gp
   12fc0:       00310c23                sb      gp,24(sp)
   12fc4:       00008067                ret

Change-Id: I16321feb18381241cab121c0097a126104c56c2c
Reviewed-on: https://go-review.googlesource.com/c/go/+/264659
Trust: Joel Sing <joel@sing.id.au>
Run-TryBot: Joel Sing <joel@sing.id.au>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-10-27 12:36:54 +00:00
Jason A. Donenfeld
333e90448a crypto/rand: generate random numbers using RtlGenRandom on Windows
CryptGenRandom appears to be unfavorable these days, whereas the classic
RtlGenRandom is still going strong.

This commit also moves the warnBlocked function into rand_unix, rather
than rand, because it's now only used on unix.

Fixes #33542

Change-Id: I5c02a5917572f54079d627972401efb6e1ce4057
Reviewed-on: https://go-review.googlesource.com/c/go/+/210057
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
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Reviewed-by: Filippo Valsorda <filippo@golang.org>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
2020-10-27 12:00:35 +00:00
Joel Sing
8a013233ac cmd/compile: use MOV pseudo-instructions for sign/zero extension
Rather than handling sign and zero extension via rules, defer to the assembler
and use MOV pseudo-instructions. The instruction can also be omitted where the
type and size is already correct. This change results in more than 6,000
instructions being removed from the go binary (in part due to omitted
instructions, in part due to MOVBU having a more efficient implementation in
the assembler than what is used in the current ZeroExt8to{16,32,64} rules).

This will also allow for further rewriting to remove redundant sign/zero
extension.

Change-Id: I05e42fd9f09f40a69948be7de772cce8946c8744
Reviewed-on: https://go-review.googlesource.com/c/go/+/264658
Trust: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-10-27 11:40:45 +00:00