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51831 Commits

Author SHA1 Message Date
Cuong Manh Le
9743e9b6d8 cmd/compile: fix re-export closure
For hidden closure built during stenciling to implement a function
instantiation, the function may come from other package, not local
package, which causes the ICE for code that re-export the hidden closure
after inlining.

To fix it, use the closure package for export writer when writing out
the closure itself.

Fixes #51423

Change-Id: I23b067ba14e2d602a0fc3b2e99bd9317afbe53ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/391574
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-11 00:42:08 +00:00
Steven Johnstone
5003ed884a internal/fuzz: minimization should not reduce coverage
Minimization should result in a fuzz input which
includes the same coverage bits as the original
input.

Updates #48326

Change-Id: I6c5f30058b57ccd1a096ad0e9452a4dfbb7d9aab
Reviewed-on: https://go-review.googlesource.com/c/go/+/391454
Trust: Bryan Mills <bcmills@google.com>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Run-TryBot: Roland Shoemaker <roland@golang.org>
Auto-Submit: Roland Shoemaker <roland@golang.org>
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2022-03-10 23:06:14 +00:00
Roland Shoemaker
bd71dee2b4 internal/fuzz: don't use dirty coverage maps during minimization
When minimizing a value, if the value cannot be minimized (i.e. it is
the final value is the same value as was sent for minimization) return
the initial coverage map, rather than the coverageSnapshot, which is
actually the coverage map for the final minimization step and may not
accurately reflect whether the input actually expands the coverage set
or not.

Updates #48326

Change-Id: I01f0eebe5841e808b6799647d2e5fe3aa45cd2e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/391614
Reviewed-by: Bryan Mills <bcmills@google.com>
Trust: Roland Shoemaker <roland@golang.org>
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Auto-Submit: Roland Shoemaker <roland@golang.org>
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2022-03-10 22:50:18 +00:00
Robert Griesemer
914195c132 go/types, types2: remove incorrect assertion (don't crash)
The removed assertion was never incorrect, as signatures may
be from methods in interfaces, and (some) interfaces set the
receivers of their methods (so we have a position for error
reporting).

This CL changes the issue below from a release blocker to an
issue for Go 1.19.

For #51593.

Change-Id: I0c5f2913b397b9ab557ed74a80cc7a715e840412
Reviewed-on: https://go-review.googlesource.com/c/go/+/391615
Trust: Robert Griesemer <gri@golang.org>
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Reviewed-by: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-10 21:10:30 +00:00
Keith Randall
2e46a0a997 cmd/compile: fix expression switches using type parameters
Both the thing we're switching on, as well as the cases we're switching for.
Convert anything containing a type parameter to interface{} before the
comparison happens.

Fixes #51522

Change-Id: I97ba9429ed332cb7d4240cb60f46d42226dcfa5f
Reviewed-on: https://go-review.googlesource.com/c/go/+/391594
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2022-03-10 19:30:33 +00:00
Keith Randall
8cf11694ab cmd/compile: fix transform of OEQ/ONE when one arg is a type param
At this point in stenciling, we have shape types, not raw type parameters.
The code was correct in the other part of this function.

Update #51522

Change-Id: Ife495160a2be5f6af5400363c3efb68dda518b5f
Reviewed-on: https://go-review.googlesource.com/c/go/+/391475
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-10 18:50:50 +00:00
Joe Tsai
91daaabd56 flag: add TextVar function
The TextVar function makes it easier to integrate the flag package
with any Go type that implements encoding.Text{Marshaler,Unmarshaler}.

Fixes #45754

Change-Id: Id23c37d59cf8c9699a7943a22ce27a45eb685c0f
Reviewed-on: https://go-review.googlesource.com/c/go/+/313329
Trust: Joseph Tsai <joetsai@digital-static.net>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
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2022-03-10 16:56:17 +00:00
Joe Tsai
2d026a4ea5 bytes: rely on runtime.growslice for growing
Rather than naively making a slice of capacity 2*c+n,
rely on the append(..., make(...)) pattern to allocate a
slice that aligns up to the closest size class.

Performance:
	name                          old time/op    new time/op    delta
	BufferWriteBlock/N4096       3.03µs ± 6%    2.04µs ± 6%  -32.60%  (p=0.000 n=10+10)
	BufferWriteBlock/N65536      47.8µs ± 6%    28.1µs ± 2%  -41.32%  (p=0.000 n=9+8)
	BufferWriteBlock/N1048576     844µs ± 7%     510µs ± 5%  -39.59%  (p=0.000 n=8+9)

	name                          old alloc/op   new alloc/op   delta
	BufferWriteBlock/N4096       12.3kB ± 0%     7.2kB ± 0%  -41.67%  (p=0.000 n=10+10)
	BufferWriteBlock/N65536       258kB ± 0%     130kB ± 0%  -49.60%  (p=0.000 n=10+10)
	BufferWriteBlock/N1048576    4.19MB ± 0%    2.10MB ± 0%  -49.98%  (p=0.000 n=10+8)

	name                          old allocs/op  new allocs/op  delta
	BufferWriteBlock/N4096         3.00 ± 0%      3.00 ± 0%     ~     (all equal)
	BufferWriteBlock/N65536        7.00 ± 0%      7.00 ± 0%     ~     (all equal)
	BufferWriteBlock/N1048576      11.0 ± 0%      11.0 ± 0%     ~     (all equal)

The performance is faster since the growth rate is capped at 2x,
while previously it could grow by amounts potentially much greater than 2x,
leading to significant amounts of memory waste and extra copying.

Credit goes to Martin Möhrmann for suggesting the
append(b, make([]T, n)...) pattern.

Fixes #42984
Updates #51462

Change-Id: I7b23f75dddbf53f8b8b93485bb1a1fff9649b96b
Reviewed-on: https://go-review.googlesource.com/c/go/+/349994
Trust: Joseph Tsai <joetsai@digital-static.net>
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2022-03-10 16:24:16 +00:00
Michael Pratt
1cf67709be runtime: fix SegvInCgo skip check
CL 390034 changed this throw message to add the goid, breaking the
match.

For #50979.

Change-Id: I52d97695484938701e5b7c269e2caf0c87d44d7a
Reviewed-on: https://go-review.googlesource.com/c/go/+/391139
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
2022-03-10 16:06:29 +00:00
Daniel Martí
5a040c5a36 go/token: allocate fewer times at init time
go/token has had a global "keywords" map filled at init time for years.
Overall, the package's init time cost is small, as per GODEBUG=inittrace=1:

	init go/token @0.51 ms, 0.004 ms clock, 1776 bytes, 5 allocs
	init go/token @0.44 ms, 0.003 ms clock, 1776 bytes, 5 allocs
	init go/token @0.45 ms, 0.003 ms clock, 1568 bytes, 4 allocs

However, adding the map size hint does help with the allocations:

	init go/token @0.45 ms, 0.002 ms clock, 944 bytes, 2 allocs
	init go/token @0.46 ms, 0.002 ms clock, 944 bytes, 2 allocs
	init go/token @0.55 ms, 0.003 ms clock, 1152 bytes, 3 allocs

Three samples are rather unscientific, and the clock time is basically
unchanged, but we might as well reduce the allocs.

Change-Id: I48121a4cea4113d991882e32f274d7b7736800dc
Reviewed-on: https://go-review.googlesource.com/c/go/+/391094
Trust: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
2022-03-10 09:12:04 +00:00
Meng Zhuo
29b968e766 runtime,cmd/compile: change reg duff{zero,copy} for regabi riscv64
As CL 356519 require, X8-X23 will be argument register, however X10, X11
is used by duff device.

This CL changes X10, X11 into X24, X25 to meet the prerequisite.

Update #40724

Change-Id: Ie9b899afbba7e9a51bb7dacd89e49ca1c1fc33ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/357976
Trust: mzh <mzh@golangcn.org>
Run-TryBot: mzh <mzh@golangcn.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Joel Sing <joel@sing.id.au>
2022-03-10 06:26:28 +00:00
Robert Griesemer
00535b8398 spec: remove note re: field accesses on type literals
For #51576.

Change-Id: I43f72c3fb618e724d46360a70ab9f8abc3d63273
Reviewed-on: https://go-review.googlesource.com/c/go/+/391137
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-10 01:57:27 +00:00
Robert Griesemer
6fb07317e5 spec: more adjustments/corrections
- Change section title from "Type parameters lists" to
  "Type parameter declarations" as the enclosing section
  is about declarations.

- Correct section on parsing ambiguity in type parameter
  lists.

- Rephrase paragraphs on type parameters for method receivers
  and adjust examples.

- Remove duplicate prose in section on function argument type
  inference.

- Clarified "after substitution" column in Instantiations section.

Change-Id: Id76be9804ad96a3f1221e5c4942552dde015dfcb
Reviewed-on: https://go-review.googlesource.com/c/go/+/390994
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-10 01:57:22 +00:00
Robert Griesemer
46f352de2d spec: remove notion of specific types
Specific types were introduced to explain rules for operands of
type parameter type. Specific types are really an implementation
mechanism to represent (possibly infinite) type sets in the machine;
they are not needed in the specification.

A specific type is either standing for a single named or unnamed
type, or it is the underlying (unnamed) type of an infinite set of
types. Each rule that applies to a type T of the set of specific
types must also apply to all types T' in the type set for which T
is a representative of. Thus, in the spec we can simply refer to
the type set directly, infinite or not.

Rather then excluding operands with empty type sets in each instance,
leave unspecified what happens when such an operand is used. Instead
give an implementation some leeway with an implementation restriction.

(The implementation restriction also needs to be formulated for types,
such as in conversions, which technically are not "operands". Left for
another CL.)

Minor: Remove the two uses of the word "concrete" to refer to non-
interface types; instead just say "non-interface type" for clarity.

Change-Id: I67ac89a640c995369c9d421a03820a0c0435835a
Reviewed-on: https://go-review.googlesource.com/c/go/+/390694
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-10 01:57:17 +00:00
Carl Johnson
604140d931 net/url: add JoinPath, URL.JoinPath
Builds on CL 332209.

Fixes #47005

Change-Id: I82708dede05d79a196ca63f5a4e7cb5ac9a041ea
GitHub-Last-Rev: 51b735066e
GitHub-Pull-Request: golang/go#50383
Reviewed-on: https://go-review.googlesource.com/c/go/+/374654
Reviewed-by: Russ Cox <rsc@golang.org>
Auto-Submit: Russ Cox <rsc@golang.org>
Trust: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-10 01:34:17 +00:00
Meng Zhuo
9faef5a654 cmd/compile,bytealg: change context register on riscv64
The register ABI will use X8-X23 (CL 356519),
this CL changes context register from X20(S4) to X26(S10) to meet the
prerequisite.

Update #40724

Change-Id: I93d51d22fe7b3ea5ceffe96dff93e3af60fbe7f6
Reviewed-on: https://go-review.googlesource.com/c/go/+/357974
Trust: mzh <mzh@golangcn.org>
Run-TryBot: mzh <mzh@golangcn.org>
Reviewed-by: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-10 01:28:37 +00:00
Robert Griesemer
3a5e3d8173 go/types, types2: pointer base types cannot be type constraints
Pointer types may appear in expressions *P and we don't know if
we have an indirection (P is a pointer value) or a pointer type
(P is a type) until we type-check P. Don't forget to check that
a type P must be an ordinary (not a constraint) type in this
special case.

Fixes #51578.

Change-Id: If782cc6dd2a602a498574c78c99e40c3b72274a5
Reviewed-on: https://go-review.googlesource.com/c/go/+/391275
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-09 23:21:06 +00:00
Robert Findley
e189b5e06d go/types, types2: clarify documentation with respect to generic types
Address several areas where documentation was inaccurate or unclear
regarding generic types. Also prefer the use of the word 'generic' over
'parameterized', and add additional documentation for the use of
SetConstraint.

For #49593

Change-Id: Iccac60d1b3e2c45a57a3d03b3c10984293af57dd
Reviewed-on: https://go-review.googlesource.com/c/go/+/391154
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
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2022-03-09 22:51:34 +00:00
Russ Cox
a987aaf5f7 cmd/compile: require -p flag
The -p flag specifies the import path of the package being compiled.
This CL makes it required when invoking the compiler and
adjusts tests that invoke the compiler directly to conform to this
new requirement. The go command already passes the flag, so it
is unmodified in this CL. It is expected that any other Go build systems
also already pass -p, or else they will need to arrange to do so before
updating to Go 1.19. Of particular note, Bazel already does for rules
with an importpath= attribute, which includes all Gazelle-generated rules.

There is more cleanup possible now in cmd/compile, cmd/link,
and other consumers of Go object files, but that is left to future CLs.

Additional historical background follows but can be ignored.

Long ago, before the go command, or modules, or any kind of
versioning, symbols in Go archive files were named using just the
package name, so that for example func F in math/rand and func F in
crypto/rand would both be the object file symbol 'rand.F'. This led to
collisions even in small source trees, which made certain packages
unusable in the presence of other packages and generally was a problem
for Go's goal of scaling to very large source trees.

Fixing this problem required changing from package names to import
paths in symbol names, which was mostly straightforward. One wrinkle,
though, is that the compiler did not know the import path of the
package being compiled; it only knew the package name. At the time,
there was no go command, just Makefiles that people had invoking 6g
(now “go tool compile”) and then copying the resulting object file to
an importable location. That is, everyone had a custom build setup for
Go, because there was no standard one. So it was not particularly
attractive to change how the compiler was invoked, since that would
break approximately every Go user at the time. Instead, we arranged
for the compiler to emit, and other tools reading object files to
recognize, a special import path (the empty string, it turned out)
denoting “the import path of this object file”. This worked well
enough at the time and maintained complete command-line compatibility
with existing Go usage.

The changes implementing this transition can be found by searching
the Git history for “package global name space”, which is what they
eliminated. In particular, CL 190076 (a6736fa4), CL 186263 (758f2bc5),
CL 193080 (1cecac81), CL 194053 (19126320), and CL 194071 (531e6b77)
did the bulk of this transformation in January 2010.

Later, in September 2011, we added the -p flag to the compiler for
diagnostic purposes. The problem was that it was easy to create import
cycles, especially in tests, and these could not be diagnosed until
link time. You'd really want the compiler to diagnose these, for
example if the compilation of package sort noticed it was importing a
package that itself imported "sort". But the compilation of package
sort didn't know its own import path, and so it could not tell whether
it had found itself as a transitive dependency. Adding the -p flag
solved this problem, and its use was optional, since the linker would
still diagnose the import cycle in builds that had not updated to
start passing -p. This was CL 4972057 (1e480cd1).

There was still no go command at this point, but when we introduced
the go command we made it pass -p, which it has for many years at this
point.

Over time, parts of the compiler began to depend on the presence of
the -p flag for various reasonable purposes. For example:

In CL 6497074 (041fc8bf; Oct 2012), the race detector used -p to
detect packages that should not have race annotations, such as
runtime/race and sync/atomic.

In CL 13367052 (7276c02b; Sep 2013), a bug fix used -p to detect the
compilation of package reflect.

In CL 30539 (8aadcc55; Oct 2016), the compiler started using -p to
identify package math, to be able to intrinsify calls to Sqrt inside
that package.

In CL 61019 (9daee931; Sep 2017), CL 71430 (2c1d2e06; Oct 2017), and
later related CLs, the compiler started using the -p value when
creating various DWARF debugging information.

In CL 174657 (cc5eaf93; May 2019), the compiler started writing
symbols without the magic empty string whenever -p was used, to reduce
the amount of work required in the linker.

In CL 179861 (dde7c770; Jun 2019), the compiler made the second
argument to //go:linkname optional when -p is used, because in that
case the compiler can derive an appropriate default.

There are more examples. Today it is impossible to compile the Go
standard library without using -p, and DWARF debug information is
incomplete without using -p.

All known Go build systems pass -p. In particular, the go command
does, which is what nearly all Go developers invoke to build Go code.
And Bazel does, for go_library rules that set the importpath
attribute, which is all rules generated by Gazelle.

Gccgo has an equivalent of -p and has required its use in order to
disambiguate packages with the same name but different import paths
since 2010.

On top of all this, various parts of code generation for generics
are made more complicated by needing to cope with the case where -p
is not specified, even though it's essentially always specified.

In summary, the current state is:

 - Use of the -p flag with cmd/compile is required for building
   the standard library, and for complete DWARF information,
   and to enable certain linker speedups.

 - The go command and Bazel, which we expect account for just
   about 100% of Go builds, both invoke cmd/compile with -p.

 - The code in cmd/compile to support builds without -p is
   complex and has become more complex with generics, but it is
   almost always dead code and therefore not worth maintaining.

 - Gccgo already requires its equivalent of -p in any build
   where two packages have the same name.

All this supports the change in this CL, which makes -p required
and adjusts tests that invoke cmd/compile to add -p appropriately.

Future CLs will be able to remove all the code dealing with the
possibility of -p not having been specified.

Change-Id: I6b95b9d4cffe59c7bac82eb273ef6c4a67bb0e43
Reviewed-on: https://go-review.googlesource.com/c/go/+/391014
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2022-03-09 21:31:58 +00:00
Robert Griesemer
b8248fab89 go/types, types2: disable field accesses through type parameters
This is a feature that is not understood well enough and may have
subtle repercussions impacting future changes. Disable for Go 1.18.

The actual change is trivial: disable a branch through a flag.
The remaining changes are adjustments to tests.

Fixes #51576.

Change-Id: Ib77b038b846711a808315a8889b3904e72367bce
Reviewed-on: https://go-review.googlesource.com/c/go/+/391135
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-09 21:26:42 +00:00
Mark Pulford
7026eeb8cf cmd/go: fix buildvcs when using older git versions
Git versions before v2.10.0 do not support --no-show-signature.
Using "-c" allows Git to ignore the configuration option if it does not
exist.

Fixes #51253

Change-Id: I2b1adaca0eb18ae31f2e1119e354ce515b00cfc2
Reviewed-on: https://go-review.googlesource.com/c/go/+/388194
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
2022-03-09 17:16:12 +00:00
Rhys Hiltner
0d33a99675 runtime/pprof: fix pcDeck's frame indexing
When building the inlining deck, correctly identify which is the last
frame in the deck. Otherwise, when some forms of inlining cause a PC to
expand to multiple frames, the length of the deck's two slices will
diverge.

Fixes #51567

Change-Id: I24e7ba32cb16b167f4307178b3f03c29e5362c4b
Reviewed-on: https://go-review.googlesource.com/c/go/+/391134
Reviewed-by: Michael Pratt <mpratt@google.com>
Trust: Than McIntosh <thanm@google.com>
2022-03-09 17:07:49 +00:00
Matthew Dempsky
7160e32529 cmd/compile: mark instantiated generic functions as DUPOK
Unified IR wasn't marking instantiated generic functions as DUPOK,
even though they can appear in multiple compilation units, which
evidently interfered with cmd/link's dead code elimination logic.

Manually confirmed to fix the issue, but non-trivial to test within
$GOROOT/test currently, because it's only reproducible when
cmd/compile is invoked with -p. @rsc is currently investigating
updating test/run.go appropriately, after which I'll revisit writing a
test case.

Fixes #51519.

Change-Id: I74a79ed0ca15b25b826e419714af5ceb6e567012
Reviewed-on: https://go-review.googlesource.com/c/go/+/390956
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-03-09 16:08:24 +00:00
eric fang
c6d9b38dd8 cmd/internal/obj/arm64: optimize function prologue/epilogue with STP/LDP
In function prologue and epilogue, we save and restore FP and LR
registers, and adjust RSP. The current instruction sequence is as
follow.

For frame size <= 240B,
  prologue:
    MOVD.W	R30, -offset(RSP)
    MOVD	R29, -8(RSP)
  epilogue:
    MOVD	-8(RSP), R29
    MOVD.P	offset(RSP), R30

For frame size > 240B,
  prologue:
    SUB		$offset, RSP, R27
    MOVD	R30, (R27)
    MOVD	R27, RSP
    MOVD	R29, -8(RSP)
  epilogue:
    MOVD	-8(RSP), R29
    MOVD	(RSP), R30
    ADD		$offset, RSP

Each sequence uses two load or store instructions, actually we can load
or store two registers with one LDP or STP instruction. This CL changes
the sequences as follow.

For frame size <= 496B,
  prologue:
    STP		(R29, R30), -(offset+8)(RSP)
    SUB		$offset, RSP, RSP
  epilogue:
    LDP		-8(RSP), (R29, R30)
    ADD		$offset, RSP, RSP

For frame size > 496B,
  prologue:
    SUB		$offset, RSP, R20
    STP		(R29, R30), -8(R20)
    MOVD	R20, RSP
  epilogue:
    LDP		-8(RSP), (R29, R30)
    ADD		$offset, RSP, RSP

Change-Id: Ia58af85fc81cce9b7c393dc38df43bffb203baad
Reviewed-on: https://go-review.googlesource.com/c/go/+/379075
Reviewed-by: Cherry Mui <cherryyz@google.com>
Trust: Eric Fang <eric.fang@arm.com>
Run-TryBot: Eric Fang <eric.fang@arm.com>
2022-03-09 06:51:37 +00:00
Meng Zhuo
1045faa38c cmd/compile/internal: add ABI register information for riscv64
This CL adds the defines for ABI registers on riscv64.

Updates #40724

Change-Id: I53a89d88b6feb1a88cf7008b8484d444791e8a55
Reviewed-on: https://go-review.googlesource.com/c/go/+/356519
Trust: mzh <mzh@golangcn.org>
Run-TryBot: mzh <mzh@golangcn.org>
Reviewed-by: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-09 05:28:28 +00:00
Ian Lance Taylor
20d333b6f4 cmd/go: for gccgo expect one fewer file in TestScript/list_swigcxx
One of the files in CompileGoFiles is actually _cgo_import.go, but
that file is only generated for gc, not for gccgo.

Change-Id: I87bb55552e1409cc57da8f35a32b37ce4a3df60c
Reviewed-on: https://go-review.googlesource.com/c/go/+/390895
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
2022-03-08 23:18:30 +00:00
Robert Findley
0add0647d8 go/printer: don't print unnecesary commas for func type param lists
Type parameter lists are not ambiguous for function declarations in the
way that they are ambiguous for type declarations. Avoid printing an
extra comma to disambiguate.

Fixes #51548

Change-Id: I8ca2b21e271982013653b9e220f92ee74f577ba2
Reviewed-on: https://go-review.googlesource.com/c/go/+/390914
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-08 22:23:42 +00:00
Bryan C. Mills
4469557974 net/http/pprof: skip TestDeltaProfile on all arm and arm64 architectures
Given that we have seen failures with the same failure mode on both
openbsd/arm and android/arm64, it seems likely that the underlying bug
affects at least all ARM-based architectures.

It appears that either these architectures are not able to sample at
the frequency expected by the test, or the samples are for some reason
being dropped.

For #50218

Change-Id: I42a6c8ecda57448f8068e8facb42a4a2cecbbb37
Reviewed-on: https://go-review.googlesource.com/c/go/+/383997
Trust: Bryan Mills <bcmills@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-03-08 22:10:32 +00:00
Michael Pratt
dbbe4cca5d cmd/dist: log OS version when testing
As a follow-up to https://golang.org/cl/371474, add the OS version to
the metadata printed for each test.

This is a redo of CL 371475. This version updates go.mod and conforms to
the changes made in the parent commit.

Fixes #50146.

Change-Id: Iba5541cc8dd2c85c1fa3a215e30c8c3f9b6aaaab
Reviewed-on: https://go-review.googlesource.com/c/go/+/378590
Reviewed-by: Austin Clements <austin@google.com>
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-08 21:35:38 +00:00
Michael Pratt
67f1a436b9 cmd/dist: log CPU model when testing
Knowing whether test failures are correlated with specific CPU models on
has proven useful on several issues. Log it for prior to testing so it
is always available.

internal/sysinfo provides the CPU model, but it is not available in the
bootstrap toolchain, so we can't access this in cmd/dist. Instead use a
separate binary which cmd/dist will only build once testing begins.

The addition of new data to the beginning of cmd/dist output will break
x/build/cmd/coordinator's banner parsing, leaving extra lines in the log
output, though information will not be lost.
https://golang.org/cl/372538 fixes up the coordinator and should be
submitted and deployed before this CL is submitted.

This is a redo of CL 371474. It switches back to the original approach
of using a separate binary, as the bootstap toolchain won't allow
cmd/dist to import internal packages.

For #46272.
For #49209.
For #50146.

Change-Id: I906bbda987902a2120c5183290a4e89a2440de58
Reviewed-on: https://go-review.googlesource.com/c/go/+/378589
Reviewed-by: Austin Clements <austin@google.com>
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-08 21:35:32 +00:00
Rhys Hiltner
bd77d6e240 runtime/pprof: check if PC is reused for inlining
When describing call stacks that include inlined function calls, the
runtime uses "fake" PCs to represent the frames that inlining removed.
Those PCs correspond to real NOP instructions that the compiler inserts
for this purpose.

Describing the call stack in a protobuf-formatted profile requires the
runtime/pprof package to collapse any sequences of fake call sites back
into single PCs, removing the NOPs but retaining their line info.

But because the NOP instructions are part of the function, they can
appear as leaf nodes in a CPU profile. That results in an address that
should sometimes be ignored (when it appears as a call site) and that
sometimes should be present in the profile (when it is observed
consuming CPU time).

When processing a PC address, consider it first as a fake PC to add to
the current inlining deck, and then as a previously-seen (real) PC.

Fixes #50996

Change-Id: I80802369978bd7ac9969839ecfc9995ea4f84ab4
Reviewed-on: https://go-review.googlesource.com/c/go/+/384239
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
2022-03-08 21:23:02 +00:00
Tobias Klauser
c3c74777bc runtime, syscall: implement syscall.Pipe using syscall.Pipe2 on solaris
All other platforms providing the pipe2 syscall already implement it
that way. Do so as well on solaris, which allows to drop
runtime.syscall_pipe and its dependencies as well.

Change-Id: Icf04777f21d1804da74325d173fefdc87caa42eb
Reviewed-on: https://go-review.googlesource.com/c/go/+/390716
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Trust: Matt Layher <mdlayher@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-08 21:16:53 +00:00
Tobias Klauser
085ef537c4 os, internal/syscall/unix: consolidate Pipe implementations
All platforms with the pipe2 syscall now provide syscall.Pipe2.  Use it
to implement os.Pipe.

This also allows to drop the illumos-specific wrapper in
internal/sys/unix.

Change-Id: Ieb712a1498e86a389bad261e4e97c61c11d4bdd0
Reviewed-on: https://go-review.googlesource.com/c/go/+/390715
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Trust: Matt Layher <mdlayher@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-08 21:16:44 +00:00
Tobias Klauser
de8ddd97ac syscall: add Pipe2 on solaris and use it for forkExecPipe
Other platforms already define Pipe2, so add it for solaris as well.

Change-Id: If0d2dfc9a3613479fb4611a673a20a4aa0af0b2b
Reviewed-on: https://go-review.googlesource.com/c/go/+/390714
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Trust: Matt Layher <mdlayher@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-08 21:16:30 +00:00
Bryan C. Mills
e030833880 cmd/compile/internal/syntax: don't try to parse files in GOROOT/.git
This test was failing locally in my clone of the go repo due to a Git
branch ending in ".go", which the test found and was attempting to
parse as a file. It's fragile to try to parse .go files in
GOROOT/.git, and wasteful to scan GOROOT/pkg and other non-source
directories; instead, let's only parse the directories we actually
expect to contain source files.

(I was running the test for #51461.)

Change-Id: I5d4e31ec2bcd9b4b6840ec32ad9b12bf44f349a5
Reviewed-on: https://go-review.googlesource.com/c/go/+/390023
Trust: Bryan Mills <bcmills@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2022-03-08 21:00:10 +00:00
Bryan C. Mills
7419bb3ebb internal/fuzz: fix encoding for out-of-range ints and runes
Also switch float64 NaN encoding to use hexadecimal, and accept
hexadecimal encoding for all other integer types too. (That gives us
the flexibility to change the encodings in either direction in the
future without breaking earlier Go versions.)

Out-of-range runes encoded using "%q" were previously replaced with
the Unicode replacement charecter, losing their values.

Out-of-range ints and uints on 32-bit platforms were previously
rejected. Now they are wrapped instead: an “interesting” case with a
large int or uint found on a 64-bit platform likely remains
interesting on a 32-bit platform, even if the specific values differ.

To verify the above changes, I have made TestMarshalUnmarshal accept
(and check for) arbitrary differences between input and output, and
added tests cases that include values in valid but non-canonical
encodings.

I have also added round-trip fuzz tests in the opposite direction for
most of the types affected by this change, verifying that a marshaled
value unmarshals to the same bitwise value.

Updates #51258
Updates #51526
Fixes #51528

Change-Id: I7727a9d0582d81be0d954529545678a4374e88ed
Reviewed-on: https://go-review.googlesource.com/c/go/+/390424
Trust: Bryan Mills <bcmills@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
Reviewed-by: Roland Shoemaker <roland@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-08 18:07:39 +00:00
thepudds
d3070a767b cmd/compile/internal/types2: more consistently print "check go.mod" if language version < 1.18
If you attempt to instantiate a generic type or func and run 'go build'
with a language version < 1.18 in the 'go' directive inside the go.mod
file, cmd/compile emits a friendly message that includes the suggestion
to 'check go.mod':

    type instantiation requires go1.18 or later (-lang was set to go1.17; check go.mod)

However, if the code instead only declares a generic type or func
without instantiating, cmd/compile currently emits a less friendly
message:

    type parameters require go1.18 or later

With this CL, the error in that situation becomes:

    type parameter requires go1.18 or later (-lang was set to go1.17; check go.mod)

Within cmd/compile/internal/types2, it already calls check.versionErrorf
in a dozen or so places, including three existing calls to
check.versionErrorf within typeset.go (e.g., for embedding a constraint
interface).

This CL adds two more calls to check.versionErrorf, replacing calls to
check.softErrorf. Both check.versionErrorf and check.softErrorf call
check.err(at, <string>, true) after massaging the string message.

Fixes #51531

Change-Id: If54e179f5952b97701d1dfde4abb08101de07811
GitHub-Last-Rev: b0b7c1346f
GitHub-Pull-Request: golang/go#51536
Reviewed-on: https://go-review.googlesource.com/c/go/+/390578
Reviewed-by: Robert Griesemer <gri@golang.org>
Trust: Robert Findley <rfindley@google.com>
2022-03-08 16:50:57 +00:00
Joel Sing
291bda80e5 internal/bytealg: optimise compare on riscv64
Implement compare using loops that process 32 bytes, 16 bytes, 4 bytes
or 1 byte depending on size and alignment. For comparisons that are less
than 32 bytes the overhead of checking and adjusting alignment usually
exceeds the overhead of reading and processing 4 bytes at a time.

Updates #50615

name                           old time/op    new time/op     delta
BytesCompare/1-4                 68.4ns _ 1%     61.0ns _ 0%   -10.78%  (p=0.001 n=3+3)
BytesCompare/2-4                 82.9ns _ 0%     71.0ns _ 1%   -14.31%  (p=0.000 n=3+3)
BytesCompare/4-4                  107ns _ 0%       70ns _ 0%   -34.96%  (p=0.000 n=3+3)
BytesCompare/8-4                  156ns _ 0%       90ns _ 0%   -42.36%  (p=0.000 n=3+3)
BytesCompare/16-4                 267ns _11%      130ns _ 0%   -51.10%  (p=0.011 n=3+3)
BytesCompare/32-4                 446ns _ 0%       74ns _ 0%   -83.31%  (p=0.000 n=3+3)
BytesCompare/64-4                 840ns _ 2%       91ns _ 0%   -89.17%  (p=0.000 n=3+3)
BytesCompare/128-4               1.60_s _ 0%     0.13_s _ 0%   -92.18%  (p=0.000 n=3+3)
BytesCompare/256-4               3.15_s _ 0%     0.19_s _ 0%   -93.91%  (p=0.000 n=3+3)
BytesCompare/512-4               6.25_s _ 0%     0.33_s _ 0%   -94.80%  (p=0.000 n=3+3)
BytesCompare/1024-4              12.5_s _ 0%      0.6_s _ 0%   -95.23%  (p=0.000 n=3+3)
BytesCompare/2048-4              24.8_s _ 0%      1.1_s _ 0%   -95.46%  (p=0.000 n=3+3)
CompareBytesEqual-4               225ns _ 0%      131ns _ 0%   -41.69%  (p=0.000 n=3+3)
CompareBytesToNil-4              45.3ns _ 7%     46.7ns _ 0%      ~     (p=0.452 n=3+3)
CompareBytesEmpty-4              41.0ns _ 1%     40.6ns _ 0%      ~     (p=0.071 n=3+3)
CompareBytesIdentical-4          48.9ns _ 0%     41.3ns _ 1%   -15.58%  (p=0.000 n=3+3)
CompareBytesSameLength-4          127ns _ 0%       77ns _ 0%   -39.48%  (p=0.000 n=3+3)
CompareBytesDifferentLength-4     136ns _12%       78ns _ 0%   -42.65%  (p=0.018 n=3+3)
CompareBytesBigUnaligned-4       14.9ms _ 1%      7.3ms _ 1%   -50.95%  (p=0.000 n=3+3)
CompareBytesBig-4                14.9ms _ 1%      2.7ms _ 8%   -82.10%  (p=0.000 n=3+3)
CompareBytesBigIdentical-4       52.5ns _ 0%     44.9ns _ 0%   -14.53%  (p=0.000 n=3+3)

name                           old speed      new speed       delta
CompareBytesBigUnaligned-4     70.5MB/s _ 1%  143.8MB/s _ 1%  +103.87%  (p=0.000 n=3+3)
CompareBytesBig-4              70.3MB/s _ 1%  393.8MB/s _ 8%  +460.43%  (p=0.003 n=3+3)
CompareBytesBigIdentical-4     20.0TB/s _ 0%   23.4TB/s _ 0%   +17.00%  (p=0.000 n=3+3)

Change-Id: Ie18712a9009d425c75e1ab49d5a673d84e73a1eb
Reviewed-on: https://go-review.googlesource.com/c/go/+/380076
Trust: Joel Sing <joel@sing.id.au>
Trust: mzh <mzh@golangcn.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-03-08 15:42:25 +00:00
Joel Sing
3c42ebf3e2 internal/bytealg: optimise memequal on riscv64
Implement memequal using loops that process 32 bytes, 16 bytes, 4 bytes
or 1 byte depending on size and alignment. For comparisons that are less
than 32 bytes the overhead of checking and adjusting alignment usually
exceeds the overhead of reading and processing 4 bytes at a time.

Updates #50615

name                 old time/op    new time/op     delta
Equal/0-4              38.3ns _ 0%     43.1ns _ 0%    +12.54%  (p=0.000 n=3+3)
Equal/1-4              77.7ns _ 0%     90.3ns _ 0%    +16.27%  (p=0.000 n=3+3)
Equal/6-4               116ns _ 0%      121ns _ 0%     +3.85%  (p=0.002 n=3+3)
Equal/9-4               137ns _ 0%      126ns _ 0%     -7.98%  (p=0.000 n=3+3)
Equal/15-4              179ns _ 0%      170ns _ 0%     -4.77%  (p=0.001 n=3+3)
Equal/16-4              186ns _ 0%      159ns _ 0%    -14.65%  (p=0.000 n=3+3)
Equal/20-4              215ns _ 0%      178ns _ 0%    -17.18%  (p=0.000 n=3+3)
Equal/32-4              298ns _ 0%      101ns _ 0%    -66.22%  (p=0.000 n=3+3)
Equal/4K-4             28.9_s _ 0%      2.2_s _ 0%    -92.56%  (p=0.000 n=3+3)
Equal/4M-4             29.6ms _ 0%      2.2ms _ 0%    -92.72%  (p=0.000 n=3+3)
Equal/64M-4             758ms _75%       35ms _ 0%       ~     (p=0.127 n=3+3)
CompareBytesEqual-4     226ns _ 0%      131ns _ 0%    -41.76%  (p=0.000 n=3+3)

name                 old speed      new speed       delta
Equal/1-4            12.9MB/s _ 0%   11.1MB/s _ 0%    -13.98%  (p=0.000 n=3+3)
Equal/6-4            51.7MB/s _ 0%   49.8MB/s _ 0%     -3.72%  (p=0.002 n=3+3)
Equal/9-4            65.7MB/s _ 0%   71.4MB/s _ 0%     +8.67%  (p=0.000 n=3+3)
Equal/15-4           83.8MB/s _ 0%   88.0MB/s _ 0%     +5.02%  (p=0.001 n=3+3)
Equal/16-4           85.9MB/s _ 0%  100.6MB/s _ 0%    +17.19%  (p=0.000 n=3+3)
Equal/20-4           93.2MB/s _ 0%  112.6MB/s _ 0%    +20.74%  (p=0.000 n=3+3)
Equal/32-4            107MB/s _ 0%    317MB/s _ 0%   +195.97%  (p=0.000 n=3+3)
Equal/4K-4            142MB/s _ 0%   1902MB/s _ 0%  +1243.76%  (p=0.000 n=3+3)
Equal/4M-4            142MB/s _ 0%   1946MB/s _ 0%  +1274.22%  (p=0.000 n=3+3)
Equal/64M-4           111MB/s _55%   1941MB/s _ 0%  +1641.21%  (p=0.000 n=3+3)

Change-Id: I9af7e82de3c4c5af8813772ed139230900c03b92
Reviewed-on: https://go-review.googlesource.com/c/go/+/380075
Trust: Joel Sing <joel@sing.id.au>
Trust: mzh <mzh@golangcn.org>
Reviewed-by: mzh <mzh@golangcn.org>
Run-TryBot: Joel Sing <joel@sing.id.au>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-03-08 15:39:49 +00:00
Russ Cox
7fd9564fcd cmd/compile: allow fieldtrack of unexported fields
The fieldtrack support is experimental and used mainly inside Google,
where we have included this change for years. No reason not to make
it in the public copy.

Change-Id: I5233e4e775ccce60a17098c007aed8c82a0425d7
Reviewed-on: https://go-review.googlesource.com/c/go/+/387355
Trust: Russ Cox <rsc@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-08 15:18:31 +00:00
Russ Cox
0b76afc75c crypto/rand: simplify Prime to use only rejection sampling
The old code picks a random number n and then tests n, n+2, n+4, up to
n+(1<<20) for primality before giving up and picking a new n.
(The chance of finishing the loop and picking a new n is infinitesimally
small.) This approach, called “incremental search” in the Handbook of
Applied Cryptography, section 4.51, demands fewer bits from the random
source and amortizes some of the cost of the small-prime division
checks across the incremented values.

This commit deletes the n+2, n+4, ... checks, instead picking a series
of random n and stopping at the first one that is probably prime.
This approach is called “rejection sampling.”

Reasons to make this change, in decreasing order of importance:

1. Rejection sampling is simpler, and simpler is more clearly correct.

2. The main benefit of incremental search was performance, and that is
   less important than before. Incremental search required fewer random
   bits and was able to amortize the checks for small primes across the
   entire sequence. However, both random bit generation and primality
   checks have gotten faster much quicker than typical primes have
   gotten longer, so the benefits are not as important today.
   Also, random prime generation is not typically on the critical path.

   Negating any lingering concerns about performance, rejection sampling
   no slower in practice than the incremental search, perhaps because
   the incremental search was using a somewhat inefficient test to
   eliminate multiples of small primes; ProbablyPrime does it better.

   name              old time/op  new time/op  delta
   Prime/MathRand    69.3ms ±23%  68.0ms ±37%   ~     (p=0.531 n=20+19)
   Prime/CryptoRand  69.2ms ±27%  63.8ms ±36%   ~     (p=0.076 n=20+20)

   (Here, Prime/MathRand is the current Prime benchmark,
   and Prime/CryptoRand is an adaptation to use crypto/rand.Reader
   instead of math/rand's non-cryptographic randomness source,
   just in case the quality of the bits affects the outcome.
   If anything, rejection sampling is even better with cryptographically
   random bits, but really the two are statistically indistinguishable
   over 20 runs.)

3. Incremental search has a clear bias when generating small primes:
   a prime is more likely to be returned the larger the gap between
   it and the next smaller prime. Although the bias is negligible in
   practice for cryptographically large primes, people can measure the
   bias for smaller prime sizes, and we have received such reports
   extrapolating the bias to larger sizes and claiming a security bug
   (which, to be clear, does not exist).

   However, given that rejection sampling is simpler, more clearly
   correct and at least no slower than incremental search, the bias
   is indefensible.

4. Incremental search has a timing leak. If you can tell the incremental
   search ran 10 times, then you know that p is such that there are no
   primes in the range [p-20, p). To be clear, there are other timing
   leaks in our current primality testing, so there's no definitive
   benefit to eliminating this one, but there's also no reason to keep
   it around.

   (See https://bugs.chromium.org/p/boringssl/issues/detail?id=238 for
   all the work that would be needed to make RSA key generation
   constant-time, which is definitely not something we have planned for
   Go crypto.)

5. Rejection sampling moves from matching OpenSSL to matching BoringSSL.
   As a general rule BoringSSL is the better role model.
   (Everyone started out using incremental search; BoringSSL switched
   to rejection sampling in 2019, as part of the constant-time work
   linked above.)

Change-Id: Ie67e572a967c12d8728c752045c7e38f21804f8e
Reviewed-on: https://go-review.googlesource.com/c/go/+/387554
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Peter Weinberger <pjw@google.com>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
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Auto-Submit: Russ Cox <rsc@golang.org>
2022-03-08 15:18:16 +00:00
Robert Griesemer
6e63be7b69 spec: document that type inference doesn't apply to generic types
Type inference for types was always a "nice to have" feature.
Given the under-appreciated complexity of making it work in all
cases, and the fact that we don't have a good understanding of
how it might affect readability of generic code, require explicit
type arguments for generic types.

This matches the current implementation.

Change-Id: Ie7ff6293d3fbea92ddc54c46285a4cabece7fe01
Reviewed-on: https://go-review.googlesource.com/c/go/+/390577
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2022-03-08 02:22:37 +00:00
eric fang
31be6285a8 cmd/internal/obj/arm64: optimize stacksplit prologue for small stack
When framesize <= objabi.StackSmall, 128B, the stacksplit prologue is:
  MOVD	16(g), R16
  MOVD	SP, R17
  CMP	R16, R17
  BLS	morestack_label

The second instruction is not necessary, we can compare R16 with SP
directly, so the sequence becomes:
  MOVD	16(g), R16
  CMP	R16, SP
  BLS	morestack_label

This CL removes this instruction.

Change-Id: I0567ac52e9be124880957271951e1186da203612
Reviewed-on: https://go-review.googlesource.com/c/go/+/379076
Trust: Eric Fang <eric.fang@arm.com>
Run-TryBot: Eric Fang <eric.fang@arm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Eric Fang <eric.fang@arm.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-03-08 02:01:53 +00:00
Dmitri Shuralyov
0043c1efbb fmt: use tabs for indentation
Replace 24 spaces added in CL 389434 with 3 tabs,
so the new line is indented like other lines around it.

Updates #51419.

Change-Id: Ic3e50023a01f233c52dda53c36de2c461222d95c
Reviewed-on: https://go-review.googlesource.com/c/go/+/390674
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
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Reviewed-by: Adam Shannon <adamkshannon@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-08 00:44:45 +00:00
Paul E. Murphy
d9d55724bd internal/cpu: set PPC64.IsPOWER8
This should always be true, but use the HWCAP2 bit anyways.

Change-Id: Ib164cf05b4c9f0c509f41b7eb339ef32fb63e384
Reviewed-on: https://go-review.googlesource.com/c/go/+/389894
Trust: Paul Murphy <murp@ibm.com>
Run-TryBot: Paul Murphy <murp@ibm.com>
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Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-03-07 23:46:55 +00:00
Jorropo
079a027d27 io: add WriterTo to MultiReader
This patch allows to zerocopy using MultiReader.
This is done by MultiReader implementing WriterTo.

Each sub reader is copied using usual io copy helper and thus use
WriterTo or ReadFrom with reflection.

There is a special case for when a subreader is a MultiReader.
Instead of using copyBuffer which would call multiReader.WriteTo,
multiReader.writeToWithBuffer is used instead, the difference
is that the temporary copy buffer is passed along, saving
allocations for nested MultiReaders.

The workflow looks like this:
- multiReader.WriteTo (allocates 32k buffer)
  - multiReader.writeToWithBuffer
    - for each subReader:
      - is instance of multiReader ?
        - yes, call multiReader.writeToWithBuffer
        - no, call copyBuffer(writer, currentReader, buffer)
          - does currentReader implements WriterTo ?
           - yes, use use currentReader.WriteTo
           - no, does writer implement ReadFrom ?
             - yes, use writer.ReadFrom
             - no, copy using Read / Write with buffer

This can be improved by lazy allocating the 32k buffer.
For example a MultiReader of such types:
  MultiReader(
    bytes.Reader, // WriterTo-able
    bytes.Reader, // WriterTo-able
    bytes.Reader, // WriterTo-able
  )

Doesn't need any allocation, all copy can be done using bytes.Reader's
internal data slice. However currently we still allocate a 32k buffer
for nothing.

This optimisation has been omitted for a future patch because of high
complexity costs for a non obvious performance cost (it needs a benchmark).
This patch at least is on par with the previous MultiReader.Read
workflow allocation wise.

Fixes #50842

Change-Id: Ib070c8f36337d9dd86090df8a703c5df97a773ae
GitHub-Last-Rev: 8ebe60ceac
GitHub-Pull-Request: golang/go#51502
Reviewed-on: https://go-review.googlesource.com/c/go/+/390215
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Trust: Daniel Martí <mvdan@mvdan.cc>
2022-03-07 23:22:26 +00:00
Robert Griesemer
3bb90a278a spec: clarifications based on feedback
This change includes several smaller changes based on feedback
received so far.

These changes were reviewed at CL 385536. The only additional
change here is to the current date in the subtitle.

Change-Id: I653eb4a143e3b86c5357a2fd3b19168419c9f432
Reviewed-on: https://go-review.googlesource.com/c/go/+/390634
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-07 22:45:58 +00:00
Daniel Martí
38174b3a35 go/build: use static maps rather than an init func
go/build is one of the packages that contributes the most towards
cmd/go's init cost, which adds up to any call to the tool.

One piece of low-hanging fruit is knownOS and knownArch,
maps which are filled via an init func from a space-separated list.
Using GODEBUG=inittrace=1, we can get three samples:

	init go/build @0.36 ms, 0.024 ms clock, 6568 bytes, 74 allocs
	init go/build @0.33 ms, 0.025 ms clock, 6888 bytes, 76 allocs
	init go/build @0.36 ms, 0.025 ms clock, 6728 bytes, 75 allocs

After using a static map instead, we see an improvement:

	init go/build @0.33 ms, 0.018 ms clock, 5096 bytes, 69 allocs
	init go/build @0.36 ms, 0.021 ms clock, 5096 bytes, 69 allocs
	init go/build @0.33 ms, 0.019 ms clock, 5096 bytes, 69 allocs

The speedup isn't huge, but it helps, and also reduces allocs.
One can also imagine that the compiler may get better with static,
read-only maps in the future, whereas the init func will likely always
have a linear cost and extra allocations.

Change-Id: I430212bad03d25358d2cc7b1eab4536ad88d05a8
Reviewed-on: https://go-review.googlesource.com/c/go/+/390274
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Trust: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-07 21:31:03 +00:00
Robert Findley
28fab5ef21 go/types, types2: disable inference for type instances
Inference for type instances has dependencies on type-checking order
that can lead to subtle bugs. As explained in #51527, disable it for
1.18.

Fixes #51527

Change-Id: I42795bad30ce53abecfc5a4914599ae5a2041a9e
Reviewed-on: https://go-review.googlesource.com/c/go/+/387934
Trust: Robert Findley <rfindley@google.com>
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Reviewed-by: Robert Griesemer <gri@golang.org>
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2022-03-07 21:18:15 +00:00
Robert Findley
20dd9a42fb go/types: document that predicates are undefined on generic types
Fixes #50887

Change-Id: I451d66b067badcfb7cf2e2756ea2b062366ac9d4
Reviewed-on: https://go-review.googlesource.com/c/go/+/390039
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
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2022-03-07 20:22:24 +00:00