This modifies issafepoint in liveness analysis to report almost every
operation as a safe point. There are four things we don't mark as
safe-points:
1. Runtime code (other than at calls).
2. go:nosplit functions (other than at calls).
3. Instructions between the load of the write barrier-enabled flag and
the write.
4. Instructions leading up to a uintptr -> unsafe.Pointer conversion.
We'll optimize this in later CLs:
name old time/op new time/op delta
Template 185ms ± 2% 190ms ± 2% +2.95% (p=0.000 n=10+10)
Unicode 96.3ms ± 3% 96.4ms ± 1% ~ (p=0.905 n=10+9)
GoTypes 658ms ± 0% 669ms ± 1% +1.72% (p=0.000 n=10+9)
Compiler 3.14s ± 1% 3.18s ± 1% +1.56% (p=0.000 n=9+10)
SSA 7.41s ± 2% 7.59s ± 1% +2.48% (p=0.000 n=9+10)
Flate 126ms ± 1% 128ms ± 1% +2.08% (p=0.000 n=10+10)
GoParser 153ms ± 1% 157ms ± 2% +2.38% (p=0.000 n=10+10)
Reflect 437ms ± 1% 442ms ± 1% +0.98% (p=0.001 n=10+10)
Tar 178ms ± 1% 179ms ± 1% +0.67% (p=0.035 n=10+9)
XML 223ms ± 1% 229ms ± 1% +2.58% (p=0.000 n=10+10)
[Geo mean] 394ms 401ms +1.75%
No effect on binary size because we're not yet emitting these extra
safe points.
For #24543.
Change-Id: I16a1eebb9183cad7cef9d53c0fd21a973cad6859
Reviewed-on: https://go-review.googlesource.com/109348
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Currently liveness only produces a stack map index at each safe point,
so the information is summarized in a map[*ssa.Value]int. We're about
to have both a stack map index and a register map index, so replace
the int with a LivenessIndex type we can extend, and replace the map
with a LivenessMap that we can also change more easily in the future.
This also gives us an easy hook for defining the value that means "not
a safe point".
Passes toolstash -cmp.
For #24543.
Change-Id: Ic4c069839635efed4fd0f603899b80f8be3b56ec
Reviewed-on: https://go-review.googlesource.com/109347
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The explanation about VARDEF/VARKILL is from when liveness analysis
was performed on Progs. Now that it's performed on SSA, it should
reference their corresponding SSA ops (OpVarDef/OpVarKill) instead.
Change-Id: Icc4385b52768f6987cda162824b75340aee0b223
Reviewed-on: https://go-review.googlesource.com/76313
Reviewed-by: Robert Griesemer <gri@golang.org>
Currently Liveness.compact rewrites the Liveness.livevars slice in
place. However, we're about to add register maps, which we'll want to
track in livevars, but compact independently from the stack maps.
Hence, this CL modifies Liveness.compact to consume Liveness.livevars
and produce a new slice of deduplicated stack maps. This is somewhat
clearer anyway because it avoids potential confusion over how
Liveness.livevars is indexed.
Passes toolstash -cmp.
For #24543.
Change-Id: I7093fbc71143f8a29e677aa30c96e501f953ca2b
Reviewed-on: https://go-review.googlesource.com/108498
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
These refer to old function names.
Change-Id: Ic4507ff836b442e953a21c8a2d09def54e1e43a7
Reviewed-on: https://go-review.googlesource.com/108495
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Remove a couple of unnecessary var declarations, an unused sort.Sort
type, and simplify a range by using the two-name variant.
Change-Id: Ia251f634db0bfbe8b1d553b8659272ddbd13b2c3
Reviewed-on: https://go-review.googlesource.com/102336
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Slightly simplifies the code. Made sure to exclude the cases that would
change behavior, such as when the iterated value is a string, when the
index is modified within the body, or when the slice is modified.
Also checked that all the elements are of pointer type, to avoid the
corner case where non-pointer types could be copied by mistake.
Change-Id: Iea64feb2a9a6a4c94ada9ff3ace40ee173505849
Reviewed-on: https://go-review.googlesource.com/100557
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
The first word of an interface is a pointer, but for the purposes
of GC we don't need to treat it as such.
1. If it is a non-empty interface, the pointer points to an itab
which is always in persistentalloc space.
2. If it is an empty interface, the pointer points to a _type.
a. If it is a compile-time-allocated type, it points into
the read-only data section.
b. If it is a reflect-allocated type, it points into the Go heap.
Reflect is responsible for keeping a reference to
the underlying type so it won't be GCd.
If we ever have a moving GC, we need to change this for 2b (as
well as scan itabs to update their itab._type fields).
Write barriers on the first word of interfaces have already been removed.
Change-Id: I643e91d7ac4de980ac2717436eff94097c65d959
Reviewed-on: https://go-review.googlesource.com/97518
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
The liveness analysis no longer directly emits PCDATA. Fix stale
comments that say so.
Change-Id: Id26b112ddf4c13a12ebf766f64bf57c68fbfe3ef
Reviewed-on: https://go-review.googlesource.com/67691
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
strings.IndexByte was introduced in go1.2 and it can be used
effectively wherever the second argument to strings.Index is
exactly one byte long.
This avoids generating unnecessary string symbols and saves
a few calls to strings.Index.
Change-Id: I1ab5edb7c4ee9058084cfa57cbcc267c2597e793
Reviewed-on: https://go-review.googlesource.com/65930
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
onebitwalktype1 no longer appears to be a bottleneck for the mentioned
test case. In fact, we appear to compile it significantly faster now
than Go 1.4 did (~1.8s vs ~3s).
Fixes#21951.
Change-Id: I315313e906092a7d6ff4ff60a918d80a4cff7a7f
Reviewed-on: https://go-review.googlesource.com/65110
Reviewed-by: Keith Randall <khr@golang.org>
No functional change; just making the code slightly more idiomatic.
Passes toolstash-check.
Change-Id: I66d14a8410bbecf260d0ea5683564aa413ce5747
Reviewed-on: https://go-review.googlesource.com/65070
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The existing logic tried to advance the offset for each variable's
width, but then tried to undo this logic with the array and struct
handling code. It can all be much simpler by only worrying about
computing offsets within the array and struct code.
While here, include a short-circuit for zero-width arrays to fix a
pedantic compiler failure case.
Passes toolstash-check.
Fixes#20739.
Change-Id: I98af9bb512a33e3efe82b8bf1803199edb480640
Reviewed-on: https://go-review.googlesource.com/64471
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
We used to have {Arg,Auto,Extern}Symbol structs with which we wrapped
a *gc.Node or *obj.LSym before storing them in the Aux field
of an ssa.Value. This let the SSA part of the compiler distinguish
between autos and args, for example. We no longer need the wrappers
as we can query the underlying objects directly.
There was also some sloppy usage, where VarDef had a *gc.Node
directly in its Aux field, whereas the use of that variable had
that *gc.Node wrapped in an AutoSymbol. Thus the Aux fields didn't
match (using ==) when they probably should.
This sloppy usage cleanup is the only thing in the CL that changes the
generated code - we can get rid of some more unused auto variables if
the matching happens reliably.
Removing this wrapper also lets us get rid of the varsyms cache
(which was used to prevent wrapping the same *gc.Node twice).
Change-Id: I0dedf8f82f84bfee413d310342b777316bd1d478
Reviewed-on: https://go-review.googlesource.com/64452
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This is a crude compiler pass to eliminate stores to auto variables
that are only ever written to.
Eliminates an unnecessary store to x from the following code:
func f() int {
var x := 1
return *(&x)
}
Fixes#19765.
Change-Id: If2c63a8ae67b8c590b6e0cc98a9610939a3eeffa
Reviewed-on: https://go-review.googlesource.com/38746
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
When package ssa was created, Type was in package gc.
To avoid circular dependencies, we used an interface (ssa.Type)
to represent type information in SSA.
In the Go 1.9 cycle, gri extricated the Type type from package gc.
As a result, we can now use it in package ssa.
Now, instead of package types depending on package ssa,
it is the other way.
This is a more sensible dependency tree,
and helps compiler performance a bit.
Though this is a big CL, most of the changes are
mechanical and uninteresting.
Interesting bits:
* Add new singleton globals to package types for the special
SSA types Memory, Void, Invalid, Flags, and Int128.
* Add two new Types, TSSA for the special types,
and TTUPLE, for SSA tuple types.
ssa.MakeTuple is now types.NewTuple.
* Move type comparison result constants CMPlt, CMPeq, and CMPgt
to package types.
* We had picked the name "types" in our rules for the handy
list of types provided by ssa.Config. That conflicted with
the types package name, so change it to "typ".
* Update the type comparison routine to handle tuples and special
types inline.
* Teach gc/fmt.go how to print special types.
* We can now eliminate ElemTypes in favor of just Elem,
and probably also some other duplicated Type methods
designed to return ssa.Type instead of *types.Type.
* The ssa tests were using their own dummy types,
and they were not particularly careful about types in general.
Of necessity, this CL switches them to use *types.Type;
it does not make them more type-accurate.
Unfortunately, using types.Type means initializing a bit
of the types universe.
This is prime for refactoring and improvement.
This shrinks ssa.Value; it now fits in a smaller size class
on 64 bit systems. This doesn't have a giant impact,
though, since most Values are preallocated in a chunk.
name old alloc/op new alloc/op delta
Template 37.9MB ± 0% 37.7MB ± 0% -0.57% (p=0.000 n=10+8)
Unicode 28.9MB ± 0% 28.7MB ± 0% -0.52% (p=0.000 n=10+10)
GoTypes 110MB ± 0% 109MB ± 0% -0.88% (p=0.000 n=10+10)
Flate 24.7MB ± 0% 24.6MB ± 0% -0.66% (p=0.000 n=10+10)
GoParser 31.1MB ± 0% 30.9MB ± 0% -0.61% (p=0.000 n=10+9)
Reflect 73.9MB ± 0% 73.4MB ± 0% -0.62% (p=0.000 n=10+8)
Tar 25.8MB ± 0% 25.6MB ± 0% -0.77% (p=0.000 n=9+10)
XML 41.2MB ± 0% 40.9MB ± 0% -0.80% (p=0.000 n=10+10)
[Geo mean] 40.5MB 40.3MB -0.68%
name old allocs/op new allocs/op delta
Template 385k ± 0% 386k ± 0% ~ (p=0.356 n=10+9)
Unicode 343k ± 1% 344k ± 0% ~ (p=0.481 n=10+10)
GoTypes 1.16M ± 0% 1.16M ± 0% -0.16% (p=0.004 n=10+10)
Flate 238k ± 1% 238k ± 1% ~ (p=0.853 n=10+10)
GoParser 320k ± 0% 320k ± 0% ~ (p=0.720 n=10+9)
Reflect 957k ± 0% 957k ± 0% ~ (p=0.460 n=10+8)
Tar 252k ± 0% 252k ± 0% ~ (p=0.133 n=9+10)
XML 400k ± 0% 400k ± 0% ~ (p=0.796 n=10+10)
[Geo mean] 428k 428k -0.01%
Removing all the interface calls helps non-trivially with CPU, though.
name old time/op new time/op delta
Template 178ms ± 4% 173ms ± 3% -2.90% (p=0.000 n=94+96)
Unicode 85.0ms ± 4% 83.9ms ± 4% -1.23% (p=0.000 n=96+96)
GoTypes 543ms ± 3% 528ms ± 3% -2.73% (p=0.000 n=98+96)
Flate 116ms ± 3% 113ms ± 4% -2.34% (p=0.000 n=96+99)
GoParser 144ms ± 3% 140ms ± 4% -2.80% (p=0.000 n=99+97)
Reflect 344ms ± 3% 334ms ± 4% -3.02% (p=0.000 n=100+99)
Tar 106ms ± 5% 103ms ± 4% -3.30% (p=0.000 n=98+94)
XML 198ms ± 5% 192ms ± 4% -2.88% (p=0.000 n=92+95)
[Geo mean] 178ms 173ms -2.65%
name old user-time/op new user-time/op delta
Template 229ms ± 5% 224ms ± 5% -2.36% (p=0.000 n=95+99)
Unicode 107ms ± 6% 106ms ± 5% -1.13% (p=0.001 n=93+95)
GoTypes 696ms ± 4% 679ms ± 4% -2.45% (p=0.000 n=97+99)
Flate 137ms ± 4% 134ms ± 5% -2.66% (p=0.000 n=99+96)
GoParser 176ms ± 5% 172ms ± 8% -2.27% (p=0.000 n=98+100)
Reflect 430ms ± 6% 411ms ± 5% -4.46% (p=0.000 n=100+92)
Tar 128ms ±13% 123ms ±13% -4.21% (p=0.000 n=100+100)
XML 239ms ± 6% 233ms ± 6% -2.50% (p=0.000 n=95+97)
[Geo mean] 220ms 213ms -2.76%
Change-Id: I15c7d6268347f8358e75066dfdbd77db24e8d0c1
Reviewed-on: https://go-review.googlesource.com/42145
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Node.Used was written to from the backend
concurrently with reads of Node.Class
for the same ONAME Nodes.
I do not know why it was not failing consistently
under the race detector, but it is a race.
This is likely also a problem with Node.HasVal and Node.HasOpt.
They will be handled in a separate CL.
Fix Used by moving it to gc.Name and making it a separate bool.
There was one non-Name use of Used, marking OLABELs as used.
That is no longer needed, now that goto and label checking
happens early in the front end.
Leave the getters and setters in place,
to ease changing the representation in the future
(or changing to an interface!).
Updates #20144
Change-Id: I9bec7c6d33dcb129a4cfa9d338462ea33087f9f7
Reviewed-on: https://go-review.googlesource.com/42015
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Type.Size and Type.Alignment are for the front end:
They calculate size and alignment if needed.
Type.MustSize and Type.MustAlignment are for the back end:
They call Fatal if size and alignment are not already calculated.
Most uses are of MustSize and MustAlignment,
but that's because the back end is newer,
and this API was added to support it.
This CL was mostly generated with sed and selective reversion.
The only mildly interesting bit is the change of the ssa.Type interface
and the supporting ssa dummy types.
Follow-up to review feedback on CL 41970.
Passes toolstash-check.
Change-Id: I0d9b9505e57453dae8fb6a236a07a7a02abd459e
Reviewed-on: https://go-review.googlesource.com/42016
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
ARM's udiv function is nosplit and it shouldn't be preemptied
(passing args in registers). It is in some sense like DUFFCOPY,
which we don't mark as safepoint.
Change-Id: I49f7c4e69e787ac364d0b0def0661e79a0ea9e69
Reviewed-on: https://go-review.googlesource.com/41370
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
The experiment "clobberdead" clobbers all pointer fields that the
compiler thinks are dead, just before and after every safepoint.
Useful for debugging the generation of live pointer bitmaps.
Helped find the following issues:
Update #15936
Update #16026
Update #16095
Update #18860
Change-Id: Id1d12f86845e3d93bae903d968b1eac61fc461f9
Reviewed-on: https://go-review.googlesource.com/23924
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
At VARKILLs, zero a variable if it is ambiguously live.
After the VARKILL anything this variable references
might be collected. If it were to become live again later,
the GC will see references to already-collected objects.
We don't know a variable is ambiguously live until very
late in compilation (after lowering, register allocation, ...),
so it is hard to generate the code in an arch-independent way.
We also have to be careful not to clobber any registers.
Fortunately, this almost never happens so performance is ~irrelevant.
There are only 2 instances where this triggers in the stdlib.
Fixes#20029
Change-Id: Ia9585a91d7b823fad4a9d141d954464cc7af31f4
Reviewed-on: https://go-review.googlesource.com/41076
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Automated refactoring using github.com/mdempsky/unbed (to rewrite
s.Foo to s.FuncInfo.Foo) and then gorename (to rename the FuncInfo
field to just Func).
Passes toolstash-check -all.
Change-Id: I802c07a1239e0efea058a91a87c5efe12170083a
Reviewed-on: https://go-review.googlesource.com/40670
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
A prior CL eliminated the last reference to Ctxt.Hash
from the compiler.
Change-Id: Ic97ff84ed1a14e0c93fb0e8ec0b2617c3397c0e8
Reviewed-on: https://go-review.googlesource.com/40699
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
It was a bit weird to have it at the top of pgen.go.
This does half of the TODO at the top of the comment.
Change-Id: I65140fa05673b2dbb6feddb8c1877f6d624a7844
Reviewed-on: https://go-review.googlesource.com/40698
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
The compiler handled gcargs and gclocals LSyms unusually.
It generated placeholder symbols (makefuncdatasym),
filled them in, and then renamed them for content-addressability.
This is an important binary size optimization;
the same locals information occurs over and over.
This CL continues to treat these LSyms unusually,
but in a slightly more explicit way,
and importantly for concurrent compilation,
in a way that does not require concurrent
modification of Ctxt.Hash.
Instead of creating gcargs and gclocals in the usual way,
by creating a types.Sym and then an obj.LSym,
we add them directly to obj.FuncInfo,
initialize them in obj.InitTextSym,
and deduplicate and add them to ctxt.Data at the end.
Then the backend's job is simply to fill them in
and rename them appropriately.
Updates #15756
name old alloc/op new alloc/op delta
Template 38.8MB ± 0% 38.7MB ± 0% -0.22% (p=0.016 n=5+5)
Unicode 29.8MB ± 0% 29.8MB ± 0% ~ (p=0.690 n=5+5)
GoTypes 113MB ± 0% 113MB ± 0% -0.24% (p=0.008 n=5+5)
SSA 1.25GB ± 0% 1.24GB ± 0% -0.39% (p=0.008 n=5+5)
Flate 25.3MB ± 0% 25.2MB ± 0% -0.43% (p=0.008 n=5+5)
GoParser 31.7MB ± 0% 31.7MB ± 0% -0.22% (p=0.008 n=5+5)
Reflect 78.2MB ± 0% 77.6MB ± 0% -0.80% (p=0.008 n=5+5)
Tar 26.6MB ± 0% 26.3MB ± 0% -0.85% (p=0.008 n=5+5)
XML 42.4MB ± 0% 41.9MB ± 0% -1.04% (p=0.008 n=5+5)
name old allocs/op new allocs/op delta
Template 378k ± 0% 377k ± 1% ~ (p=0.151 n=5+5)
Unicode 321k ± 1% 321k ± 0% ~ (p=0.841 n=5+5)
GoTypes 1.14M ± 0% 1.14M ± 0% -0.47% (p=0.016 n=5+5)
SSA 9.71M ± 0% 9.67M ± 0% -0.33% (p=0.008 n=5+5)
Flate 233k ± 1% 232k ± 1% ~ (p=0.151 n=5+5)
GoParser 316k ± 0% 315k ± 0% -0.49% (p=0.016 n=5+5)
Reflect 979k ± 0% 972k ± 0% -0.75% (p=0.008 n=5+5)
Tar 250k ± 0% 247k ± 1% -0.92% (p=0.008 n=5+5)
XML 392k ± 1% 389k ± 0% -0.67% (p=0.008 n=5+5)
Change-Id: Idc36186ca9d2f8214b5f7720bbc27b6bb22fdc48
Reviewed-on: https://go-review.googlesource.com/40697
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
- created new package cmd/compile/internal/types
- moved Pkg, Sym, Type to new package
- to break cycles, for now we need the (ugly) types/utils.go
file which contains a handful of functions that must be installed
early by the gc frontend
- to break cycles, for now we need two functions to convert between
*gc.Node and *types.Node (the latter is a dummy type)
- adjusted the gc's code to use the new package and the conversion
functions as needed
- made several Pkg, Sym, and Type methods functions as needed
- renamed constructors typ, typPtr, typArray, etc. to types.New,
types.NewPtr, types.NewArray, etc.
Passes toolstash-check -all.
Change-Id: I8adfa5e85c731645d0a7fd2030375ed6ebf54b72
Reviewed-on: https://go-review.googlesource.com/39855
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
In livenessepilogue, if we save liveness information for instructions
before updating liveout, we can avoid an extra bitvector temporary and
some extra copying around.
Passes toolstash-check -all.
Change-Id: I10d5803167ef3eba2e9e95094adc7e3d33929cc7
Reviewed-on: https://go-review.googlesource.com/38408
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Must have been lost when rebasing the SSA liveness CLs.
Change-Id: Iaac33158cc7c92ea44a023c242eb914a7d6979c6
Reviewed-on: https://go-review.googlesource.com/38427
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
I think this got lost in a rebase somewhere.
Updates #15756
Change-Id: Ia3e7c60d1b9254f2877217073732b46c91059ade
Reviewed-on: https://go-review.googlesource.com/38425
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
During AllocFrame, we drop unused variables from Curfn.Func.Dcl, but
there might still be OpVarFoo instructions that reference those
variables. This wasn't a problem though because gvardefx used to emit
ANOP for unused variables instead of AVARFOO.
As an easy fix, if we see OpVarFoo (or OpKeepAlive) referencing an
unused variable, we can ignore it.
Fixes#19632.
Change-Id: I4e9ffabdb4058f7cdcc4663b540f5a5a692daf8b
Reviewed-on: https://go-review.googlesource.com/38400
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
This CL changes the order that liveness analysis visits CFG blocks to
PC order, rather than RPO. This doesn't meaningfully change anything
except that the PCDATA_StackMapIndex values will be assigned in PC
order too.
However, this does have the benefit that the subsequent CL to port
liveness analysis to the SSA CFG (which has blocks in PC order) will
now pass toolstash-check.
Change-Id: I1de5a2eecb8027723a6e422d46186d0c63d48c8d
Reviewed-on: https://go-review.googlesource.com/38086
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
While we're here, also eliminate a few more Curfn uses.
Passes toolstash -cmp. No compiler performance impact.
Updates #15756
Change-Id: Ib8db9e23467bbaf16cc44bf62d604910f733d6b8
Reviewed-on: https://go-review.googlesource.com/38331
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
In the SSA CFG, TEXT, RET, and JMP instructions correspond to Blocks,
not Values. Rework liveness analysis so that progeffects only cares
about Progs that result from Values, and handle Blocks separately.
Passes toolstash-check -all.
Change-Id: Ic23719c75b0421fdb51382a08dac18c3ba042b32
Reviewed-on: https://go-review.googlesource.com/38085
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
There were a surprising number of places
in the tree that used yyerror for failed internal
consistency checks. Switch them to Fatalf.
Updates #15756
Updates #19250
Change-Id: Ie4278148185795a28ff3c27dacffc211cda5bbdd
Reviewed-on: https://go-review.googlesource.com/38153
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Move the zeroing of results earlier. In particular, they need to
come before any move-to-heap operations, as those require allocation.
Those allocations are points at which the GC can see the uninitialized
result slots.
For the function:
func f() (x, y, z *int) {
defer(){}()
escape(&y)
return
}
We used to generate code like this:
x = nil
y = nil
&y = new(int)
z = nil
Now we will generate:
x = nil
y = nil
z = nil
&y = new(int)
Since the fix for #18860, the return slots are always live if there
is a defer, so the former ordering allowed the GC to see junk
in the z slot.
Fixes#19078
Change-Id: I71554ae437549725bb79e13b2c100b2911d47ed4
Reviewed-on: https://go-review.googlesource.com/38133
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
