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4795 Commits

Author SHA1 Message Date
Matthew Dempsky
a7de684e1b cmd/compile/internal/noder: stop creating TUNION types
In the types1 universe under the unified frontend, we never need to
worry about type parameter constraints, so we only see pure
interfaces. However, we might still see interfaces that contain union
types, because of interfaces like "interface{ any | int }" (equivalent
to just "any").

We can handle these without needing to actually represent type unions
within types1 by simply mapping any union to "any".

Updates #57410.

Change-Id: I5e4efcf0339edbb01f4035c54fb6fb1f9ddc0c65
Reviewed-on: https://go-review.googlesource.com/c/go/+/458619
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2023-01-26 21:43:08 +00:00
Matthew Dempsky
4f467f1082 cmd: remove GOEXPERIMENT=nounified knob
This CL removes the GOEXPERIMENT=nounified knob, and any conditional
statements that depend on that knob. Further CLs to remove unreachable
code follow this one.

Updates #57410.

Change-Id: I39c147e1a83601c73f8316a001705778fee64a91
Reviewed-on: https://go-review.googlesource.com/c/go/+/458615
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2023-01-25 21:16:32 +00:00
Paul E. Murphy
a37672bb7b test/codegen: accept ppc64x as alias for ppc64le and ppc64 arches
This helps simplify the noise when adding ppc codegen tests. ppc64x
is used in other places to indicate something which runs on either
endian.

This helps cleanup existing codegen tests which are mostly
identical between endian variants.

condmove tests are converted as an example.

Change-Id: I2b2d98a9a1859015f62db38d62d9d5d7593435b4
Reviewed-on: https://go-review.googlesource.com/c/go/+/462895
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Paul Murphy <murp@ibm.com>
2023-01-24 22:55:18 +00:00
Matthew Dempsky
ffbd194f5c test: remove TODO in issue20250.go
This has been investigated and explained on the issue tracker.

Fixes #54402.

Change-Id: I4d8b971faa810591983ad028b7db16411f3b3b4a
Reviewed-on: https://go-review.googlesource.com/c/go/+/461456
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
2023-01-24 19:47:54 +00:00
Keith Randall
a6ddb15f8f Revert "cmd/compile: teach prove about bitwise OR operation"
This reverts commit 3680b5e9c4.

Reason for revert: causes long compile times on certain functions. See issue #57959

Change-Id: Ie9e881ca8abbc79a46de2bfeaed0b9d6c416ed42
Reviewed-on: https://go-review.googlesource.com/c/go/+/463295
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2023-01-24 17:58:12 +00:00
Than McIntosh
733ba92187 cmd/compile: flag 'large' functions when -m=2+ in effect
When -m=N (where N > 1) is in effect, include a note in the trace
output if a given function is considered "big" during inlining
analysis, since this causes the inliner to be less aggressive. If a
small change to a large function happens to nudge it over the large
function threshold, it can be confusing for developers, thus it's
probably worth including this info in the remark output.

Change-Id: Id31a1b76371ab1ef9265ba28a377f97b0247d0a7
Reviewed-on: https://go-review.googlesource.com/c/go/+/460317
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: Keith Randall <khr@google.com>
2023-01-24 13:28:54 +00:00
Jorropo
35755d772f cmd/compile: teach prove about unsigned division, modulus and rsh
Fixes: #57077
Change-Id: Icffcac42e28622eadecdba26e3cd7ceca6c4aacc
Reviewed-on: https://go-review.googlesource.com/c/go/+/455095
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2023-01-23 18:35:41 +00:00
Jakub Ciolek
bb5ff5342d cmd/compile: make loopbce handle 8, 16 and 32 bit induction variables
Compute limits and increment values for all integer widths.
Resolves 2 TODO's in loopbce.go

compilecmp linux/amd64:

compress/flate
compress/flate.(*huffmanEncoder).bitCounts 1235 -> 1207  (-2.27%)

cmd/internal/obj/wasm
cmd/internal/obj/wasm.assemble 7443 -> 7303  (-1.88%)
cmd/internal/obj/wasm.assemble.func1 165 -> 138  (-16.36%)

cmd/link/internal/ld
cmd/link/internal/ld.(*Link).findfunctab.func1 1646 -> 1627  (-1.15%)

Change-Id: I2d79b7376eb67d6bcc8fdaf0c197c11e631562d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/435258
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
2023-01-23 18:10:40 +00:00
David Chase
e22bd2348c internal/abi,runtime: refactor map constants into one place
Previously TryBot-tested with bucket bits = 4.
Also tested locally with bucket bits = 5.
This makes it much easier to change the size of map
buckets, and hopefully provides pointers to all the
code that in some way depends on details of map layout.

Change-Id: I9f6669d1eadd02f182d0bc3f959dc5f385fa1683
Reviewed-on: https://go-review.googlesource.com/c/go/+/462115
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Austin Clements <austin@google.com>
2023-01-23 15:51:32 +00:00
Keith Randall
ba91377454 test: test that we schedule OpArgIntReg early
If OpArgIntReg is incorrectly scheduled, that causes it to be spilled
incorrectly, which causes the argument to not be considered live
at the start of the function.

This is the test for CL 462858

Add a brief mention of why CL 462858 is needed in the scheduling code.

Change-Id: Id199456f88d9ee5ca46d7b0353a3c2049709880e
Reviewed-on: https://go-review.googlesource.com/c/go/+/462899
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
2023-01-21 21:08:30 +00:00
Keith Randall
4ff074945a cmd/compile: sort liveness variable reports
Sort variables before display so that when there are multiple variables
to report, they are in a consistent order.

Otherwise they are ordered in the order they appear in the fn.Dcl list,
which can vary. Particularly, they vary depending on regabi.

Change-Id: I0db380f7cbe6911e87177503a4c3b39851ff1b5a
Reviewed-on: https://go-review.googlesource.com/c/go/+/462898
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2023-01-21 21:08:00 +00:00
Jorropo
5c67ebbb31 cmd/compile: AMD64v3 remove unnecessary TEST comparision in isPowerOfTwo
With GOAMD64=V3 the canonical isPowerOfTwo function:
  func isPowerOfTwo(x uintptr) bool {
    return x&(x-1) == 0
  }

Used to compile to:
  temp := BLSR(x) // x&(x-1)
  flags = TEST(temp, temp)
  return flags.zf

However the blsr instruction already set ZF according to the result.
So we can remove the TEST instruction if we are just checking ZF.
Such as in multiple pieces of code around memory allocations.

This make the code smaller and faster.

Change-Id: Ia12d5a73aa3cb49188c0b647b1eff7b56c5a7b58
Reviewed-on: https://go-review.googlesource.com/c/go/+/448255
Run-TryBot: Jakub Ciolek <jakub@ciolek.dev>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2023-01-20 04:58:59 +00:00
Jorropo
fc814056aa cmd/compile: rewrite empty makeslice to zerobase pointer
make\(\[\][a-zA-Z0-9]+, 0\) is seen 52 times in the go source.
And at least 391 times on internet:
https://grep.app/search?q=make%5C%28%5C%5B%5C%5D%5Ba-zA-Z0-9%5D%2B%2C%200%5C%29&regexp=true
This used to compile to calling runtime.makeslice.
However we can copy what we do for []T{}, just use a zerobase pointer.

On my machine this is 10x faster (from 3ns to 0.3ns).
Note that an empty loop also runs in 0.3ns,
so this really is free when you count superscallar execution.

Change-Id: I1cfe7e69f5a7a4dabbc71912ce6a4f8a2d4a7f3c
Reviewed-on: https://go-review.googlesource.com/c/go/+/454036
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Jakub Ciolek <jakub@ciolek.dev>
2023-01-20 04:57:35 +00:00
Keith Randall
12befc3ce3 cmd/compile: improve scheduling pass
Convert the scheduling pass from scheduling backwards to scheduling forwards.

Forward scheduling makes it easier to prioritize scheduling values as
soon as they are ready, which is important for things like nil checks,
select ops, etc.

Forward scheduling is also quite a bit clearer. It was originally
backwards because computing uses is tricky, but I found a way to do it
simply and with n lg n complexity. The new scheme also makes it easy
to add new scheduling edges if needed.

Fixes #42673
Update #56568

Change-Id: Ibbb38c52d191f50ce7a94f8c1cbd3cd9b614ea8b
Reviewed-on: https://go-review.googlesource.com/c/go/+/270940
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2023-01-20 04:54:01 +00:00
Keith Randall
f959fb3872 cmd/compile: add anchored version of SP
The SPanchored opcode is identical to SP, except that it takes a memory
argument so that it (and more importantly, anything that uses it)
must be scheduled at or after that memory argument.

This opcode ensures that a LEAQ of a variable gets scheduled after the
corresponding VARDEF for that variable.

This may lead to less CSE of LEAQ operations. The effect is very small.
The go binary is only 80 bytes bigger after this CL. Usually LEAQs get
folded into load/store operations, so the effect is only for pointerful
types, large enough to need a duffzero, and have their address passed
somewhere. Even then, usually the CSEd LEAQs will be un-CSEd because
the two uses are on different sides of a function call and the LEAQ
ends up being rematerialized at the second use anyway.

Change-Id: Ib893562cd05369b91dd563b48fb83f5250950293
Reviewed-on: https://go-review.googlesource.com/c/go/+/452916
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Reviewed-by: Martin Möhrmann <martin@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
2023-01-19 22:43:12 +00:00
Russ Cox
aa51c40b1c runtime: replace panic(nil) with panic(new(runtime.PanicNilError))
Long ago we decided that panic(nil) was too unlikely to bother
making a special case for purposes of recover. Unfortunately,
it has turned out not to be a special case. There are many examples
of code in the Go ecosystem where an author has written panic(nil)
because they want to panic and don't care about the panic value.

Using panic(nil) in this case has the unfortunate behavior of
making recover behave as though the goroutine isn't panicking.
As a result, code like:

	func f() {
		defer func() {
			if err := recover(); err != nil {
				log.Fatalf("panicked! %v", err)
			}
		}()
		call1()
		call2()
	}

looks like it guarantees that call2 has been run any time f returns,
but that turns out not to be strictly true. If call1 does panic(nil),
then f returns "successfully", having recovered the panic, but
without calling call2.

Instead you have to write something like:

	func f() {
		done := false
		defer func() {
			if err := recover(); !done {
				log.Fatalf("panicked! %v", err)
			}
		}()
		call1()
		call2()
		done = true
	}

which defeats nearly the whole point of recover. No one does this,
with the result that almost all uses of recover are subtly broken.

One specific broken use along these lines is in net/http, which
recovers from panics in handlers and sends back an HTTP error.
Users discovered in the early days of Go that panic(nil) was a
convenient way to jump out of a handler up to the serving loop
without sending back an HTTP error. This was a bug, not a feature.
Go 1.8 added panic(http.ErrAbortHandler) as a better way to access the feature.
Any lingering code that uses panic(nil) to abort an HTTP handler
without a failure message should be changed to use http.ErrAbortHandler.

Programs that need the old, unintended behavior from net/http
or other packages can set GODEBUG=panicnil=1 to stop the run-time error.

Uses of recover that want to detect panic(nil) in new programs
can check for recover returning a value of type *runtime.PanicNilError.

Because the new GODEBUG is used inside the runtime, we can't
import internal/godebug, so there is some new machinery to
cross-connect those in this CL, to allow a mutable GODEBUG setting.
That won't be necessary if we add any other mutable GODEBUG settings
in the future. The CL also corrects the handling of defaulted GODEBUG
values in the runtime, for #56986.

Fixes #25448.

Change-Id: I2b39c7e83e4f7aa308777dabf2edae54773e03f5
Reviewed-on: https://go-review.googlesource.com/c/go/+/461956
Reviewed-by: Robert Griesemer <gri@google.com>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Russ Cox <rsc@golang.org>
2023-01-19 22:21:50 +00:00
Cuong Manh Le
198074abd7 cmd/compile: fix unsafe.{SliceData,StringData} escape analysis memory corruption
Fixes #57823

Change-Id: I54654d3ecb20b75afa9052c5c9db2072a86188d4
Reviewed-on: https://go-review.googlesource.com/c/go/+/461759
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2023-01-18 01:27:21 +00:00
Matthew Dempsky
f773bef9ab cmd/compile: fix static init inlining for hidden node fields
Unified IR added several new IR fields for holding *runtime._type
expressions. To avoid throwing off any frontend semantics
(particularly inlining cost heuristics), they were marked as
`mknode:"-"` so that code wouldn't visit them.

Unfortunately, this has a bad interaction with the static init
inlining optimization, because the latter relies on ir.EditChildren to
substitute all parameters. This potentially includes dictionary
parameters, which can appear within the new RType fields.

This CL adds a new ir.EditChildrenWithHidden function that also edits
these fields, and switches staticinit to use it. Longer term, we
should unhide the RType fields so that ir.EditChildren visits them
normally, but that's scarier so late in the release cycle.

Fixes #57778.

Change-Id: I98c1e8cf366156dc0c81a0cb79029cc5e59c476f
Reviewed-on: https://go-review.googlesource.com/c/go/+/461686
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
2023-01-17 22:13:42 +00:00
Keith Randall
9088c691da cmd/compile: ensure temp register mask isn't empty
We need to avoid nospill registers at this point in regalloc.
Make sure that we don't restrict our register set to avoid registers
desired by other instructions, if the resulting set includes only
nospill registers.

Fixes #57846

Change-Id: I05478e4513c484755dc2e8621d73dac868e45a27
Reviewed-on: https://go-review.googlesource.com/c/go/+/461685
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2023-01-17 18:21:06 +00:00
Robert Findley
245e95dfab go/types, types2: don't look up fields or methods when expecting a type
As we have seen many times, the type checker must be careful to avoid
accessing named type information before the type is fully set up. We
need a more systematic solution to this problem, but for now avoid one
case that causes a crash: checking a selector expression on an
incomplete type when a type expression is expected.

For golang/go#57522

Change-Id: I7ed31b859cca263276e3a0647d1f1b49670023a9
Reviewed-on: https://go-review.googlesource.com/c/go/+/461577
Run-TryBot: Robert Findley <rfindley@google.com>
Auto-Submit: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@google.com>
2023-01-11 22:29:34 +00:00
Marcel Meyer
841c3eb166 all: fix typos in go file comments
These typos were found by executing grep, aspell, sort, and uniq in
a pipe and searching the resulting list manually for possible typos.

    grep -r --include '*.go' -E '^// .*$' . | aspell list | sort | uniq

Change-Id: I56281eda3b178968fbf104de1f71316c1feac64f
GitHub-Last-Rev: e91c7cee34
GitHub-Pull-Request: golang/go#57669
Reviewed-on: https://go-review.googlesource.com/c/go/+/460767
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
2023-01-09 15:34:31 +00:00
Robert Griesemer
46e3d9d12a cmd/compile: use "satisfies" (not "implements") for constraint errors
Per the latest spec, we distinguish between interface implementation
and constraint satisfaction. Use the verb "satisfy" when reporting
an error about failing constraint satisfaction.

This CL only changes error messages. It has no impact on correct code.

Fixes #57564.

Change-Id: I6dfb3b2093c2e04fe5566628315fb5f6bd709f17
Reviewed-on: https://go-review.googlesource.com/c/go/+/460396
Reviewed-by: Robert Griesemer <gri@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Robert Griesemer <gri@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
2023-01-04 19:07:27 +00:00
Matthew Dempsky
4f8bc6224b cmd/compile: desugar OCALLMETH->OCALLFUNC within devirtualization
Devirtualization can turn OCALLINTER into OCALLMETH, but then we want
to actually desugar into OCALLFUNC instead for later phases. Just
needs a missing call to typecheck.FixMethodCall.

Fixes #57309.

Change-Id: I331fbd40804e1a370134ef17fa6dd501c0920ed3
Reviewed-on: https://go-review.googlesource.com/c/go/+/457715
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-12-14 20:37:17 +00:00
Keith Randall
e8f78cb60c cmd/compile: fix conditional select rule
ARM64 maintains booleans in the low byte of registers. Upper parts
of that register are junk.
This rule is using all 32 bits of a boolean-containing register, which
is wrong. Change the rule to only look at the low bit.

Fixes #57184

Change-Id: Ibbef86b2be859df3d06d993db00e1231c481c428
Reviewed-on: https://go-review.googlesource.com/c/go/+/456556
Auto-Submit: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
2022-12-09 21:38:33 +00:00
Keith Randall
1eb0465fa5 cmd/compile: turn off jump tables when spectre retpolines are on
Fixes #57097

Change-Id: I6ab659abbca1ae0ac8710674d39aec116fab0baa
Reviewed-on: https://go-review.googlesource.com/c/go/+/455336
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
2022-12-06 05:12:12 +00:00
cui fliter
3a7a528c2d all: fix some comments for method
Change-Id: I4cff6b2a1fed6acdf754539c3c53a61eaa3b3f84
Reviewed-on: https://go-review.googlesource.com/c/go/+/450176
Auto-Submit: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-12-03 17:08:51 +00:00
Cuong Manh Le
c85848a4a6 cmd/compile: fix inline static init with derived types
CL 450136 added handling for simple calls in staticinit. If there's any
derived types conversion in the body of generic function called, that
conversion will require runtime dictionary, thus the optimization could
not happen.

Fixes #56923

Change-Id: I498cee9f8ab4397812ef79a6c2ab6c55e0ee4aef
Reviewed-on: https://go-review.googlesource.com/c/go/+/453315
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Gabriel Morency (Amgc63spaming) <morencyvincent8@gmail.com>
2022-11-30 23:25:43 +00:00
Keith Randall
c8057d8569 cmd/compile: disallow CMOV optimization with ptr arithmetic as an arg
if q != nil {
        p = &q.f
    }

Which gets rewritten to a conditional move:

    tmp := &q.f
    p = Select q!=nil, tmp, p

Unfortunately, we can't compute &q.f before we've checked if q is nil,
because if it is nil, &q.f is an invalid pointer (if f's offset is
nonzero but small).

Normally this is not a problem because the tmp variable above
immediately dies, and is thus not live across any safepoint. However,
if later there is another &q.f computation, those two computations are
CSEd, causing tmp to be used at both use points. That will extend
tmp's lifetime, possibly across a call.

Fixes #56990

Change-Id: I3ea31be93feae04fbe3304cb11323194c5df3879
Reviewed-on: https://go-review.googlesource.com/c/go/+/454155
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
2022-11-30 17:46:51 +00:00
Russ Cox
f89b39c0af cmd/compile: reenable inlstaticinit
This was disabled in CL 452676 out of an abundance of caution,
but further analysis has shown that the failures were not being
caused by this optimization. Instead the sequence of commits was:

CL 450136 cmd/compile: handle simple inlined calls in staticinit
...
CL 449937 archive/tar, archive/zip: return ErrInsecurePath for unsafe paths
...
CL 451555 cmd/compile: fix static init for inlined calls

The failures in question became compile failures in the first CL
and started building again after the last CL.
But in the interim the code had been broken by the middle CL.
CL 451555 was just the first time that the tests could run and fail.

For #30820.

Change-Id: I65064032355b56fdb43d9731be2f9f32ef6ee600
Reviewed-on: https://go-review.googlesource.com/c/go/+/452817
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Russ Cox <rsc@golang.org>
Auto-Submit: Russ Cox <rsc@golang.org>
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2022-11-23 21:54:55 +00:00
Matthew Dempsky
152119990f cmd/compile: add -d=inlstaticinit debug flag
This CL adds -d=inlstaticinit to control whether static initialization
of inlined function calls (added in CL 450136) is allowed.

We've needed to fix it once already (CL 451555) and Google-internal
testing is hitting additional failure cases, so putting this
optimization behind a feature flag seems appropriate regardless.

Also, while we diagnose and fix the remaining cases, this CL also
disables the optimization to avoid miscompilations.

Updates #56894.

Change-Id: If52a358ad1e9d6aad1c74fac5a81ff9cfa5a3793
Reviewed-on: https://go-review.googlesource.com/c/go/+/452676
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
2022-11-22 01:42:49 +00:00
Matthew Dempsky
840b346c5d cmd/compile: reject anonymous interface cycles
This CL changes cmd/compile to reject anonymous interface cycles like:

	type I interface { m() interface { I } }

We don't anticipate any users to be affected by this change in
practice. Nonetheless, this CL also adds a `-d=interfacecycles`
compiler flag to suppress the error. And assuming no issue reports
from users, we'll move the check into go/types and types2 instead.

Updates #56103.

Change-Id: I1f1dce2d7aa19fb388312cc020e99cc354afddcb
Reviewed-on: https://go-review.googlesource.com/c/go/+/445598
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
2022-11-21 20:15:23 +00:00
Wayne Zuo
8893da7c72 cmd/compile: fix wrong optimization for eliding Not in Phi
The previous rule may move the phi value into a wrong block.
This CL make it only rewrite the phi value not the If block,
so that the phi value will stay in old block.

Fixes #56777

Change-Id: I9479a5c7f28529786968413d35b82a16181bb1f1
Reviewed-on: https://go-review.googlesource.com/c/go/+/451496
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Wayne Zuo <wdvxdr@golangcn.org>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: David Chase <drchase@google.com>
2022-11-18 13:26:33 +00:00
Cuong Manh Le
81c9b1d65f cmd/compile: fix broken IR for iface -> eface
For implementing interface to empty interface conversion, the compiler
generate code like:

	var res *uint8
	res = itab
	if res != nil {
		res = res.type
	}

However, itab has type *uintptr, so the assignment is broken. The
problem is not shown up, until CL 450215, which call typecheck on this
broken assignment.

To fix this, just cast itab to *uint8 when doing the conversion.

Fixes #56768

Change-Id: Id42792d18e7f382578b40854d46eecd49673792c
Reviewed-on: https://go-review.googlesource.com/c/go/+/451256
Reviewed-by: Keith Randall <khr@google.com>
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Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2022-11-17 19:55:28 +00:00
Cuong Manh Le
249e51e5d9 cmd/compile: fix static init for inlined calls
CL 450136 made the compiler to be able to handle simple inlined calls in
staticinit. However, it's missed a condition when checking substituting
arg for param. If there's any non-trivial closures, it has captured one
of the param, so the substitution could not happen.

Fixes #56778

Change-Id: I427c9134e333e2f9af136c1a124da4d37d326f10
Reviewed-on: https://go-review.googlesource.com/c/go/+/451555
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: David Chase <drchase@google.com>
2022-11-17 18:31:28 +00:00
Cuong Manh Le
1daa8e2d52 test: remove optimizationOff
Cl 426334 removed its only usage, and now we have gcflags_noopt.

Change-Id: I3b33a8c868669deea00bf6dfcf8d81981504e293
Reviewed-on: https://go-review.googlesource.com/c/go/+/451255
Reviewed-by: Joedian Reid <joedian@golang.org>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
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2022-11-17 16:06:03 +00:00
Russ Cox
bed970b3ff cmd/compile: handle integer conversions in static init inliner
Given code like

	func itou(i int) uint { return uint(i) }
	var x = itou(-1)

the static inliner from CL 450136 was rewriting the code to

	var x = uint(-1)

which is not valid Go code. Fix this by converting the
constants appropriately during inlining.

Fixes golang.org/x/image/vector test.

Change-Id: I13448df8504c6a70525b1cdc36e2c947e22cdd33
Reviewed-on: https://go-review.googlesource.com/c/go/+/451376
Auto-Submit: Russ Cox <rsc@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
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Reviewed-by: Keith Randall <khr@golang.org>
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2022-11-17 13:46:05 +00:00
Russ Cox
5947a07d72 test: fix noinit on noopt builder
Fix noopt build break from CL 450136 by not running test.

I can't reproduce the failure locally, but it's entirely reasonable
for this test to fail when optimizations are disabled, so just don't
run it when optimizations are disabled.

Change-Id: I882760fc7373ba0449379f81d295312a6be49be1
Reviewed-on: https://go-review.googlesource.com/c/go/+/450740
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Michael Stapelberg <stapelberg@google.com>
Auto-Submit: Russ Cox <rsc@golang.org>
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2022-11-16 13:26:16 +00:00
Russ Cox
b1678e508b cmd/compile: handle simple inlined calls in staticinit
Global variable initializers like

	var myErr error = &myError{"msg"}

have been converted to statically initialized data
from the earliest days of Go: there is no init-time
execution or allocation for that line of code.

But if the expression is moved into an inlinable function,
the static initialization no longer happens.
That is, this code has always executed and allocated
at init time, even after we added inlining to the compiler,
which should in theory make this code equivalent to
the original:

	func NewError(s string) error { return &myError{s} }
	var myErr2 = NewError("msg")

This CL makes the static initialization rewriter understand
inlined functions consisting of a single return statement,
like in this example, so that myErr2 can be implemented as
statically initialized data too, just like myErr, with no init-time
execution or allocation.

A real example of code that benefits from this rewrite is
all globally declared errors created with errors.New, like

	package io
	var EOF = errors.New("EOF")

Package io no longer has to allocate and initialize EOF each
time a program starts.

Another example of code that benefits is any globally declared
godebug setting (using the API from CL 449504), like

	package http
	var http2server = godebug.New("http2server")

These are no longer allocated and initialized at program startup either.

The list of functions that are inlined into static initializers when
compiling std and cmd (along with how many times each occurs) is:

	cmd/compile/internal/ssa.StringToAux (3)
	cmd/compile/internal/walk.mkmapnames (4)
	errors.New (360)
	go/ast.NewIdent (1)
	go/constant.MakeBool (4)
	go/constant.MakeInt64 (3)
	image.NewUniform (4)
	image/color.ModelFunc (11)
	internal/godebug.New (12)
	vendor/golang.org/x/text/unicode/bidi.newBidiTrie (1)
	vendor/golang.org/x/text/unicode/norm.newNfcTrie (1)
	vendor/golang.org/x/text/unicode/norm.newNfkcTrie (1)

For the cmd/go binary, this CL cuts the number of init-time
allocations from about 1920 to about 1620 (a 15% reduction).

The total executable code footprint of init functions is reduced
by 24kB, from 137kB to 113kB (an 18% reduction).
The overall binary size is reduced by 45kB,
from 15.335MB to 15.290MB (a 0.3% reduction).
(The binary size savings is larger than the executable code savings
because every byte of executable code also requires corresponding
runtime tables for unwinding, source-line mapping, and so on.)

Also merge test/sinit_run.go, which had stopped testing anything
at all as of CL 161337 (Feb 2019) and initempty.go into a new test
noinit.go.

Fixes #30820.

Change-Id: I52f7275b1ac2a0a32e22c29f9095071c7b1fac20
Reviewed-on: https://go-review.googlesource.com/c/go/+/450136
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Joedian Reid <joedian@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Auto-Submit: Russ Cox <rsc@golang.org>
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2022-11-16 04:04:52 +00:00
Cuong Manh Le
03a1810473 cmd/compile: fix missing typecheck for static initialization slice
CL 440455 fixed missing walk pass for static initialization slice.
However, slicelit may produce un-typechecked node, thus we need to do
typecheck for sinit before calling walkStmtList.

Fixes #56727

Change-Id: I40730cebcd09f2be4389d71c5a90eb9a060e4ab7
Reviewed-on: https://go-review.googlesource.com/c/go/+/450215
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
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Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2022-11-15 17:35:03 +00:00
Paul E. Murphy
dc6b7c86df cmd/compile: merge zero constant ISEL in PPC64 lateLower pass
Add a new SSA opcode ISELZ, similar to ISELB to represent a select
of value or 0. Then, merge candidate ISEL opcodes inside the late
lower pass.

This avoids complicating rules within the the lower pass.

Change-Id: I3b14c94b763863aadc834b0e910a85870c131313
Reviewed-on: https://go-review.googlesource.com/c/go/+/442596
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Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Paul Murphy <murp@ibm.com>
Reviewed-by: Joedian Reid <joedian@golang.org>
2022-11-14 19:44:47 +00:00
Cuong Manh Le
73f987c88b test: add regression test for issue 53439
Fixes #53439

Change-Id: I425af0f78153511034e4a4648f32ef8c9378a325
Reviewed-on: https://go-review.googlesource.com/c/go/+/449756
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
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Reviewed-by: Keith Randall <khr@google.com>
2022-11-11 14:48:29 +00:00
Wayne Zuo
268f4629df cmd/compile: enable brachelim pass on loong64
Change-Id: I4fd1c307901c265ab9865bf8a74460ddc15e5d14
Reviewed-on: https://go-review.googlesource.com/c/go/+/416735
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: xiaodong liu <teaofmoli@gmail.com>
Auto-Submit: Wayne Zuo <wdvxdr@golangcn.org>
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Reviewed-by: David Chase <drchase@google.com>
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2022-11-09 06:10:55 +00:00
Matthew Dempsky
9944ba757b cmd/compile: fix transitive inlining of generic functions
If an imported, non-generic function F transitively calls a generic
function G[T], we may need to call CanInline on G[T].

While here, we can also take advantage of the fact that we know G[T]
was already seen and compiled in an imported package, so we don't need
to call InlineCalls or add it to typecheck.Target.Decls. This saves us
from wasting compile time re-creating DUPOK symbols that we know
already exist in the imported package's link objects.

Fixes #56280.

Change-Id: I3336786bee01616ee9f2b18908738e4ca41c8102
Reviewed-on: https://go-review.googlesource.com/c/go/+/443535
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2022-11-08 21:26:09 +00:00
Paul E. Murphy
390abbbbf1 codegen: check for PPC64 ISEL in condmove tests
ISEL is roughly equivalent to CMOV on PPC64. Verify ISEL generation
in all reasonable cases.

Note "ISEL test x y z" is the same as "ISEL !test y x z". test is
always one of LT (0), GT (1), EQ (2), SO (3). Sometimes x and y are
swapped if GE/LE/NE is desired.

Change-Id: Ie1bf029224064e004d855099731fe5e8d05aa990
Reviewed-on: https://go-review.googlesource.com/c/go/+/445215
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
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Reviewed-by: Than McIntosh <thanm@google.com>
2022-11-07 15:19:20 +00:00
Matthew Dempsky
aa6240a445 cmd/compile: allow ineffectual //go:linkname in -lang=go1.17 and older
Prior to Go 1.18, ineffectual //go:linkname directives (i.e.,
directives referring to an undeclared name, or to a declared type or
constant) were treated as noops. In Go 1.18, we changed this into a
compiler error to mitigate accidental misuse.

However, the x/sys repo contained ineffectual //go:linkname directives
up until go.dev/cl/274573, which has caused a lot of user confusion.

It seems a bit late to worry about now, but to at least prevent
further user pain, this CL changes the error message to only apply to
modules using "go 1.18" or newer. (The x/sys repo declared "go 1.12"
at the time go.dev/cl/274573 was submitted.)

Fixes #55889.

Change-Id: Id762fff96fd13ba0f1e696929a9e276dfcba2620
Reviewed-on: https://go-review.googlesource.com/c/go/+/447755
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2022-11-03 20:35:31 +00:00
Paul E. Murphy
d031e9e07a cmd/compile/internal/ssa: re-adjust CarryChainTail scheduling priority
This needs to be as low as possible while not breaking priority
assumptions of other scores to correctly schedule carry chains.

Prior to the arm64 changes, it was set below ReadTuple. At the time,
this prevented the MulHiLo implementation on PPC64 from occluding
the scheduling of a full carry chain.

Memory scores can also prevent better scheduling, as can be observed
with crypto/internal/edwards25519/field.feMulGeneric.

Fixes #56497

Change-Id: Ia4b54e6dffcce584faf46b1b8d7cea18a3913887
Reviewed-on: https://go-review.googlesource.com/c/go/+/447435
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2022-11-03 19:59:19 +00:00
Austin Clements
6a44a3aa9f test/bench/go1: eliminate start-up time
The go1 benchmark suite does a lot of work at package init time, which
makes it take quite a while to run even if you're not running any of
the benchmarks, or if you're only running a subset of them. This leads
to an awkward workaround in dist test to compile but not run the
package, unlike roughly all other packages. It also reduces isolation
between benchmarks by affecting the starting heap size of all
benchmarks.

Fix this by initializing all data required by a benchmark when that
benchmark runs, and keeping it local so it gets freed by the GC and
doesn't leak between benchmarks. Now, none of the benchmarks depend on
global state.

Re-initializing the data on each benchmark run does add overhead to an
actual benchmark run, as each benchmark function is called several
times with different values of b.N. A full run of all benchmarks at
the default -benchtime=1s now takes ~10% longer; higher -benchtimes
would be less. It would be quite difficult to cache this data between
invocations of the same benchmark function without leaking between
different benchmarks and affecting GC overheads, as the testing
package doesn't provide any mechanism for this.

This reduces the time to run the binary with no benchmarks from 1.5
seconds to 10 ms, and also reduces the memory required to do this from
342 MiB to 17 MiB.

To make sure data was not leaking between different benchmarks, I ran
the benchmarks with -shuffle=on. The variance remained low: mostly
under 3%. A few benchmarks had higher variance, but in all cases it
was similar to the variance between this change.

This CL naturally changes the measured performance of several of the
benchmarks because it dramatically changes the heap size and hence GC
overheads. However, going forward the benchmarks should be much better
isolated.

For #37486.

Change-Id: I252ebea703a9560706cc1990dc5ad22d1927c7a0
Reviewed-on: https://go-review.googlesource.com/c/go/+/443336
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2022-11-01 17:07:14 +00:00
Keith Randall
9ce27feaeb cmd/compile: add rule for post-decomposed growslice optimization
The recently added rule only works before decomposing slices.
Add a rule that works after decomposing slices.

The reason we need the latter is because although the length may
be a constant, it can be hidden inside a slice that is not constant
(its pointer or capacity might be changing). By applying this
optimization after decomposing slices, we can find more cases
where it applies.

Fixes #56440

Change-Id: I0094e59eee3065ab4d210defdda8227a6e897420
Reviewed-on: https://go-review.googlesource.com/c/go/+/446277
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2022-10-31 21:40:49 +00:00
Keith Randall
0156b797e6 cmd/compile: recognize when the result of append has a constant length
Fixes a performance regression due to CL 418554.

Fixes #56440

Change-Id: I6ff152e9b83084756363f49ee6b0844a7a284880
Reviewed-on: https://go-review.googlesource.com/c/go/+/445875
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2022-10-27 17:09:50 +00:00
Keith Randall
8415ec8c98 cmd/compile: in compiler errors, print more digits for floats close to an int
Error messages currently print floats with %.6g, which means that if
you tried to convert something close to, but not quite, an integer, to
an integer, the error you get looks like "cannot convert 1 to type
int", when really you want "cannot convert 0.9999999 to type int".

Add more digits to floats when printing them, to make it clear that they
aren't quite integers. This helps for errors which are the result of not
being an integer. For other errors, it won't hurt much.

Fixes #56220

Change-Id: I7f5873af5993114a61460ef399d15316925a15a5
Reviewed-on: https://go-review.googlesource.com/c/go/+/442935
Reviewed-by: Rob Pike <r@golang.org>
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2022-10-20 21:52:09 +00:00