The liveness computation of parameters generally was never
correct, but forcing all parameters to be live throughout the
function covered up that problem. The new SSA back end is
too clever: even though it currently keeps the parameter values live
throughout the function, it may find optimizations that mean
the current values are not written back to the original parameter
stack slots immediately or ever (for example if a parameter is set
to nil, SSA constant propagation may replace all later uses of the
parameter with a constant nil, eliminating the need to write the nil
value back to the stack slot), so the liveness code must now
track the actual operations on the stack slots, exposing these
problems.
One small problem in the handling of arguments is that nodarg
can return ONAME PPARAM nodes with adjusted offsets, so that
there are actually multiple *Node pointers for the same parameter
in the instruction stream. This might be possible to correct, but
not in this CL. For now, we fix this by using n.Orig instead of n
when considering PPARAM and PPARAMOUT nodes.
The major problem in the handling of arguments is general
confusion in the liveness code about the meaning of PPARAM|PHEAP
and PPARAMOUT|PHEAP nodes, especially as contrasted with PAUTO|PHEAP.
The difference between these two is that when a local variable "moves"
to the heap, it's really just allocated there to start with; in contrast,
when an argument moves to the heap, the actual data has to be copied
there from the stack at the beginning of the function, and when a
result "moves" to the heap the value in the heap has to be copied
back to the stack when the function returns
This general confusion is also present in the SSA back end.
The PHEAP bit worked decently when I first introduced it 7 years ago (!)
in 391425ae. The back end did nothing sophisticated, and in particular
there was no analysis at all: no escape analysis, no liveness analysis,
and certainly no SSA back end. But the complications caused in the
various downstream consumers suggest that this should be a detail
kept mainly in the front end.
This CL therefore eliminates both the PHEAP bit and even the idea of
"heap variables" from the back ends.
First, it replaces the PPARAM|PHEAP, PPARAMOUT|PHEAP, and PAUTO|PHEAP
variable classes with the single PAUTOHEAP, a pseudo-class indicating
a variable maintained on the heap and available by indirecting a
local variable kept on the stack (a plain PAUTO).
Second, walkexpr replaces all references to PAUTOHEAP variables
with indirections of the corresponding PAUTO variable.
The back ends and the liveness code now just see plain indirected
variables. This may actually produce better code, but the real goal
here is to eliminate these little-used and somewhat suspect code
paths in the back end analyses.
The OPARAM node type goes away too.
A followup CL will do the same to PPARAMREF. I'm not sure that
the back ends (SSA in particular) are handling those right either,
and with the framework established in this CL that change is trivial
and the result clearly more correct.
Fixes#15747.
Change-Id: I2770b1ce3cbc93981bfc7166be66a9da12013d74
Reviewed-on: https://go-review.googlesource.com/23393
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Instead of using TARRAY for both arrays and slices, create a new
TSLICE kind to handle slices.
Also, get rid of the "DDDArray" distinction. While kinda ugly, it
seems likely we'll need to defer evaluating the constant bounds
expressions for golang.org/issue/13890.
Passes toolstash/buildall.
Change-Id: I8e45d4900e7df3a04cce59428ec8b38035d3cc3a
Reviewed-on: https://go-review.googlesource.com/22329
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Many of Type's fields are etype-specific.
This CL organizes them into their own auxiliary types,
duplicating a few fields as necessary,
and adds an Extra field to hold them.
It also sorts the remaining fields for better struct packing.
It also improves documentation for most fields.
This reduces the size of Type at the cost of some extra allocations.
There's no CPU impact; memory impact below.
It also makes the natural structure of Type clearer.
Passes toolstash -cmp on all architectures.
Ideas for future work in this vein:
(1) Width and Align probably only need to be
stored for Struct and Array types.
The refactoring to accomplish this would hopefully
also eliminate TFUNCARGS and TCHANARGS entirely.
(2) Maplineno is sparsely used and could probably better be
stored in a separate map[*Type]int32, with mapqueue updated
to store both a Node and a line number.
(3) The Printed field may be removable once the old (non-binary)
importer/exported has been removed.
(4) StructType's fields field could be changed from *[]*Field to []*Field,
which would remove a common allocation.
(5) I believe that Type.Nod can be moved to ForwardType. Separate CL.
name old alloc/op new alloc/op delta
Template 57.9MB ± 0% 55.9MB ± 0% -3.43% (p=0.000 n=50+50)
Unicode 38.3MB ± 0% 37.8MB ± 0% -1.39% (p=0.000 n=50+50)
GoTypes 185MB ± 0% 180MB ± 0% -2.56% (p=0.000 n=50+50)
Compiler 824MB ± 0% 806MB ± 0% -2.19% (p=0.000 n=50+50)
name old allocs/op new allocs/op delta
Template 486k ± 0% 497k ± 0% +2.25% (p=0.000 n=50+50)
Unicode 377k ± 0% 379k ± 0% +0.55% (p=0.000 n=50+50)
GoTypes 1.39M ± 0% 1.42M ± 0% +1.63% (p=0.000 n=50+50)
Compiler 5.52M ± 0% 5.57M ± 0% +0.84% (p=0.000 n=47+50)
Change-Id: I828488eeb74902b013d5ae4cf844de0b6c0dfc87
Reviewed-on: https://go-review.googlesource.com/21611
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Changes generated with eg and then manually
checked and in some cases simplified.
Passes toolstash -cmp.
Change-Id: I2119f37f003368ce1884d2863b406d6ffbfe38c7
Reviewed-on: https://go-review.googlesource.com/21563
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Add a constant for the magic -1 for slice bounds.
Use it.
Enforce more aggressively that bounds must be
slice, ddd, or non-negative.
Remove ad hoc check in plive.go.
Check bounds before constructing an array type
when typechecking.
All changes are manual.
Passes toolstash -cmp.
Change-Id: I9fd9cc789d7d4b4eea3b30b24037a254d3788add
Reviewed-on: https://go-review.googlesource.com/21348
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This removes almost all direct access to
Type’s heavily overloaded Type field.
Mostly generated by eg, manually checked.
Significant manual changes:
* reflect.go's typPkg used Type indiscriminately.
Use it only for specific etypes.
* gen.go's visitComponents contained a usage of Type
with structs. Using Type for structs no longer
occurs, and the Fatal contained therein has not triggered,
so it has been axed.
* Scary code in cgen.go's cgen_slice is now explicitly scary.
Passes toolstash -cmp.
Change-Id: I2dbfb3c959da7ae239f964d83898c204affcabc6
Reviewed-on: https://go-review.googlesource.com/21331
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Changes generated by eg and manually checked.
Isfixedarray, Isslice, and many other
Type-related functions in subr.go should
either be deleted or moved to type.go.
Later, though; the game now is cleanup via encapsulation.
Passes toolstash -cmp.
Change-Id: I83dd8816f6263b74367d23c2719a08c362e330f9
Reviewed-on: https://go-review.googlesource.com/21303
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This mostly a mechanical change.
However, the change in assignop (subr.go) is a bug fix.
The code didn’t match the comment,
and the comment was correct.
Nevertheless, this CL passes toolstash -cmp.
The last direct reference to dddBound outside
type.go (in typecheck.go) will go away
in a future CL.
Change-Id: Ifb1691e0a07f906712c18c4a4cd23060807a5da5
Reviewed-on: https://go-review.googlesource.com/21235
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This is an automated rewrite of all the calls of the form:
for f, it := IterFields(t); f != nil; f = it.Next() { ... }
Followup CLs will work on cleaning up the remaining cases.
Change-Id: Ic1005ad45ae0b50c63e815e34e507e2d2644ba1a
Reviewed-on: https://go-review.googlesource.com/20794
Reviewed-by: David Crawshaw <crawshaw@golang.org>
The obj.Fmt* values are only used by gc/fmt.go, so just move them
there. Also, add comments documenting the correspondance between
FmtFoo names and their flag characters to make understanding the
existing documentation slightly less confusing.
While here, add a new FmtFlag named type to represent these values.
Change-Id: I9631214b892557d094823f1ac575d0c43a84007b
Reviewed-on: https://go-review.googlesource.com/20717
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Move lexinit, typeinit, lexinit1, and lexfini into new universe.go
file, and give them a more idiomatic and descriptive API. No code
changes.
Change-Id: I0e9b25dcc86ad10f4b990dc02bd33477b488cc85
Reviewed-on: https://go-review.googlesource.com/20604
Reviewed-by: Robert Griesemer <gri@golang.org>
Allows safely eliminating more direct uses of Type's Type and Down
fields.
Passes toolstash -cmp.
Change-Id: I5c17fe541a0473c3cd2978d8314c4ab759079a61
Reviewed-on: https://go-review.googlesource.com/20541
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This CL was mostly produced by a one-off automated rewrite tool
looking for statements like "for X := T.Type; X != nil; X = X.Down"
and a few minor variations.
Passes toolstash -cmp.
Change-Id: Ib22705e37d078ef97841ee2e08f60bdbcabb94ad
Reviewed-on: https://go-review.googlesource.com/20520
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: Ice3aa807169f4fec85745a3991b1084a9f85c1b5
Reviewed-on: https://go-review.googlesource.com/20499
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
It's only used once, so just make the caller responsible for iterating
both the receiver and input params.
Change-Id: Icb34f3f0cf96e80fbe27f3f49d12eddc26599b92
Reviewed-on: https://go-review.googlesource.com/20454
Reviewed-by: Dave Cheney <dave@cheney.net>
More idiomatic naming (in particular, matches the naming used for
go/types.Signature).
Also, convert more code to use these methods and/or IterFields.
(Still more to go; only made a quick pass for low hanging fruit.)
Passes toolstash -cmp.
Change-Id: I61831bfb1ec2cd50d4c7efc6062bca4e0dcf267b
Reviewed-on: https://go-review.googlesource.com/20451
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Good riddance to another one-off linked list type.
Change-Id: Idf9926a701ab4da8a022be1d61f1257020d58fc5
Reviewed-on: https://go-review.googlesource.com/20212
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Arch backends already provide us Widthint and Widthptr, which is ample
information to figure out how to define the universal "int", "uint",
and "uintptr" types. No need for providing a generic typedef
mechanism beyond that.
Change-Id: I35c0c17a67c80605a9208b93d77d6960b2cbb17d
Reviewed-on: https://go-review.googlesource.com/20153
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The tree's pretty inconsistent about single space vs double space
after a period in documentation. Make it consistently a single space,
per earlier decisions. This means contributors won't be confused by
misleading precedence.
This CL doesn't use go/doc to parse. It only addresses // comments.
It was generated with:
$ perl -i -npe 's,^(\s*// .+[a-z]\.) +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.) +([A-Z])')
$ go test go/doc -update
Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7
Reviewed-on: https://go-review.googlesource.com/20022
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dave Day <djd@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Type Op is enfored now.
Type EType will need further CLs.
Added TODOs where Node.EType is used as a union type.
The TODOs have the format `TODO(marvin): Fix Node.EType union type.`.
Furthermore:
-The flag of Econv function in fmt.go is removed, since unused.
-Some cleaning along the way, e.g. declare vars first when getting initialized.
Passes go build -toolexec 'toolstash -cmp' -a std.
Fixes#11846
Change-Id: I908b955d5a78a195604970983fb9194bd9e9260b
Reviewed-on: https://go-review.googlesource.com/14956
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Marvin Stenger <marvin.stenger94@gmail.com>
Update old c-style comments to look like Go comments. Also replace some
lingering references to old .c files that don't exist anymore.
Change-Id: I72b2407a40fc76c23e9048643e0622fd70b4cf90
Reviewed-on: https://go-review.googlesource.com/16190
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Convert some fields of struct Type in go.go from uint8 to bool.
This change passes go build -toolexec 'toolstash -cmp' -a std.
Change-Id: I0a6c53f8ee686839b5234010ee2de7ae3940d499
Reviewed-on: https://go-review.googlesource.com/14370
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Convert Type.Broke from a uint8 to a boolean
This change passes go build -toolexec 'toolstash -cmp' -a std.
Change-Id: I44e7548c71b00467e36576bdf62933c42555a21a
Reviewed-on: https://go-review.googlesource.com/14307
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Håvard Haugen <havard.haugen@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This helps vet see a real issue:
cmd/internal/gc$ go vet
gen.go:1223: unreachable code
Fixes#12106.
Change-Id: I720868b07ae6b6d5a4dc6b238baa8c9c889da6d8
Reviewed-on: https://go-review.googlesource.com/14083
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
In walkdiv, an OMUL node was created and passed to typecheck,
before the op was changed back to OHMUL. In some instances,
the node that came back was an evaluated literal constant that
occurred with a full multiply. The end result was a literal node
with a non-shifted value and an OHMUL op. This change causes code
to be generated for the OHMUL.
Fixes#11358Fixes#11369
Change-Id: If42a98c6830d07fe065d5ca57717704fb8cfbd33
Reviewed-on: https://go-review.googlesource.com/11400
Reviewed-by: Russ Cox <rsc@golang.org>
This is an automated follow-up to CL 10210.
It was generated with a combination of eg and gofmt -r.
No functional changes. Passes toolstash -cmp.
Change-Id: I35f5897948a270b472d8cf80612071b4b29e9a2b
Reviewed-on: https://go-review.googlesource.com/10253
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Trivial merging of 5g, 6g, ... into go tool compile,
and similarlly 5l, 6l, ... into go tool link.
The files compile/main.go and link/main.go are new.
Everything else in those directories is a move followed by
change of imports and package name.
This CL breaks the build. Manual fixups are in the next CL.
See golang-dev thread titled "go tool compile, etc" for background.
Change-Id: Id35ff5a5859ad9037c61275d637b1bd51df6828b
Reviewed-on: https://go-review.googlesource.com/10287
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Rob Pike <r@golang.org>
2015-05-21 17:31:51 +00:00
Renamed from src/cmd/internal/gc/align.go (Browse further)