Because NameOffsetExpr is always used with global variables, and SSA
backend only needs (*Name).Linksym() to generate value for them.
Passes toolstash -cmp.
Updates #43737
Change-Id: I17209e21383edb766070c0accd1fa4660659caef
Reviewed-on: https://go-review.googlesource.com/c/go/+/284119
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It is always used with global variables, so we can skip analyze it, the
same as what we are doing for ONAME/PEXTERN nodes.
While at it, add a Fatalf check to ensure NewNameOffsetExpr is only
called for global variables.
For #43737
Change-Id: Iac444ed8d583baba5042bea096531301843b1e8f
Reviewed-on: https://go-review.googlesource.com/c/go/+/284118
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This CL simplifies the previous one a little bit further, by combining
reordering stack-temporary initialization and getting rid of an
unneeded temporary variable. (Does not pass toolstash -cmp.)
Change-Id: I17799dfe368484f33a8ddd0ab4f68647d6262147
Reviewed-on: https://go-review.googlesource.com/c/go/+/284225
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This CL adds a few new helper functions for constructing and
initializing temporary variables during walk.
Passes toolstash -cmp.
Change-Id: I54965d992cd8dfef7cb7dc92a17c88372e52a0d6
Reviewed-on: https://go-review.googlesource.com/c/go/+/284224
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After CL 284220, we now only need to detect expressions that contain
function calls in the arguments list of further function calls. So we
can simplify Node.HasCall/fncall/etc a lot.
Instead of incrementally tracking whether an expression contains
function calls all throughout walk, simply check once at the point of
using an expression as a function call argument. Since any expression
checked here will itself become a function call argument, it won't be
checked again because we'll short circuit at the enclosing function
call.
Also, restructure the recursive walk code to use mayCall, and trim
down the list of acceptable expressions. It should be okay to be
stricter, since we'll now only see function call arguments and after
they've already been walked.
It's possible I was overly aggressive removing Ops here. But if so,
we'll get an ICE, and it'll be easy to re-add them. I think this is
better than the alternative of accidentally allowing expressions
through that risk silently clobbering the stack.
Passes toolstash -cmp.
Change-Id: I585ef35dcccd9f4018e4bf2c3f9ccb1514a826f3
Reviewed-on: https://go-review.googlesource.com/c/go/+/284223
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Currently, to ensure OAS2FUNC results are assigned in the correct
order, they're always assigned to temporary variables. However, these
temporary variables are typed based on the destination type, which may
require an interface conversion. This means walk may have to then
introduce a second set of temporaries to ensure result parameters are
all copied out of the results area, before it emits calls to runtime
conversion functions.
That's just silly. Instead, this CL changes order to allocate the
result temporaries with the same type as the function returns in the
first place, and then assign them one at a time to their destinations,
with conversions as needed.
While here, also fix an order-of-evaluation issue with has-ok
assignments that I almost added to multi-value function call
assignments, and add tests for each.
Change-Id: I9f4e962425fe3c5e3305adbbfeae2c7f253ec365
Reviewed-on: https://go-review.googlesource.com/c/go/+/284220
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Went in a semi-automated way through the clearest renames of functions,
and updated comments and error messages where it made sense.
Change-Id: Ied8e152b562b705da7f52f715991a77dab60da35
Reviewed-on: https://go-review.googlesource.com/c/go/+/284216
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After CL 283233, SSA can now handle new(typ) without the frontend to
generate the type address, so we can remove ONEWOBJ in favor of ONEW
only.
This is also not save for toolstash, the same reason with CL 284115.
Change-Id: Ie03ea36b3b6f95fc7ce080376c6f7afc402d51a3
Reviewed-on: https://go-review.googlesource.com/c/go/+/284117
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CL 283233 added reflectType method to ssagen.state, which we can use to
setup type address in the SSA backend in favor of the frontend. However,
this will change the order of symbols generation, so not safe for toolstash.
Change-Id: Ib6932ec42a9d28c3fd7a1c055596e75494c29843
Reviewed-on: https://go-review.googlesource.com/c/go/+/284115
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WriteType isn't safe for direct concurrent use, and users should
instead use TypeLinksym or another higher-level API provided by
reflectdata. After the previous CL, there are no remaining uses of
WriteType elsewhere in the compiler, so unexport it to keep it that
way.
For #43701.
[git-generate]
cd src/cmd/compile/internal/reflectdata
rf '
mv WriteType writeType
'
Change-Id: I294a78be570a47feb38a1ad4eaae7723653d5991
Reviewed-on: https://go-review.googlesource.com/c/go/+/284077
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The code for allocating linksyms and recording that we need runtime
type descriptors is now concurrent-safe, so move it to where those
symbols are actually needed to reduce complexity and risk of failing
to generate all needed symbols in advance.
For #43701.
Change-Id: I759d2508213ac9a4e0b504b51a75fa10dfa37a8d
Reviewed-on: https://go-review.googlesource.com/c/go/+/284076
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We decide during escape analysis whether to pass closure variables by
value or reference. One of the factors that's considered is whether a
variable has had its address taken.
However, this analysis is based only on the user-written source code,
whereas order+walk may introduce rewrites that take the address of a
variable (e.g., passing a uint16 key by reference to the size-generic
map runtime builtins).
Typically this would be harmless, albeit suboptimal. But in #43701 it
manifested as needing a stack object for a function where we didn't
realize we needed one up front when we generate symbols.
Probably we should just generate symbols on demand, now that those
routines are all concurrent-safe, but this is a first fix.
Thanks to Alberto Donizetti for reporting the issue, and Cuong Manh Le
for initial investigation.
Fixes#43701.
Change-Id: I16d87e9150723dcb16de7b43f2a8f3cd807a9437
Reviewed-on: https://go-review.googlesource.com/c/go/+/284075
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The feature being tested is insensitive to the OS anyway.
Change-Id: Ieac9bfaafc6a54c00017afcc0b87bd8bbe80af7b
Reviewed-on: https://go-review.googlesource.com/c/go/+/284032
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fmt.go:dumpNodeHeader uses reflection to call all "func() bool"-typed
methods on Nodes during printing, but the OnStack method that I added
in CL 283233 isn't meant to be called on non-variables.
dumpNodeHeader does already guard against panics, as happen in some
other accessors, but not against Fatalf, as I was using in OnStack. So
simply change OnStack to use panic too.
Thanks to drchase@ for the report.
Change-Id: I0cfac84a96292193401a32fc5e7fd3c48773e008
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This patch pulls in a few additional changes requested by code
reviewers for CL 270863 that were accidentally left out. Specifically,
guarding use of ORETJMP to insure it is not used when building dynlink
on ppc64le, and a tweaking the command line flags used to control
wrapper generation.
Change-Id: I4f96462e570180887eb8693e11badd83d142710a
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CL 283672 added a flag to prevent double walking, use that flag instead
of checking SwitchStmt.Compiled field.
Passes toolstash -cmp.
Change-Id: Idb8f9078412fb789f51ed4fc4206638011e38a93
Reviewed-on: https://go-review.googlesource.com/c/go/+/283733
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This CL moves almost all PAUTOHEAP handling code to SSA construction.
Instead of changing Names to PAUTOHEAP, escape analysis now only sets
n.Esc() to ir.EscHeap, and SSA handles creating the "&x"
pseudo-variables and associating them via Heapaddr.
This CL also gets rid of n.Stackcopy, which was used to distinguish
the heap copy of a parameter used within a function from the stack
copy used in the function calling convention. In practice, this is
always obvious from context: liveness and function prologue/epilogue
want to know about the stack copies, and everywhere else wants the
heap copy.
Hopefully moving all parameter/result handling into SSA helps with
making the register ABI stuff easier.
Also, the only remaining uses of PAUTOHEAP are now for closure
variables, so I intend to rename it to PCLOSUREVAR or get rid of those
altogether too. But this CL is already big and scary enough.
Change-Id: Ief5ef6205041b9d0ee445314310c0c5a98187e77
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Reduce 16 byte for CallExpr, from 184 to 168 on 64-bit archs.
Passes toolstash -cmp.
Change-Id: I59c7609ccd03e8b4a7df8d2c30de8022ae312cee
Reviewed-on: https://go-review.googlesource.com/c/go/+/283732
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Currently, there's an awkward issue with walk pass. When walking the AST
tree, the compiler generate code for runtime functions (using mkcall* variants),
add/modify the AST tree and walk new generated tree again. This causes the
double walking on some CallExpr, which is relying on checking Rargs to prevent
that. But checking Rargs has its own issue as well.
For functions that does not have arguments, this check is failed, and we
still double walk the CallExpr node.
This CL change the way that compiler detects double walking, by using
separated field instead of relying on Rargs. In perfect world, we should make
the compiler walks the AST tree just once, but it's not safe to do that at
this moment.
Passes toolstash -cmp.
Change-Id: Ifdd1e0f98940ddb1f574af2da2ac7f005b5fcadd
Reviewed-on: https://go-review.googlesource.com/c/go/+/283672
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CL 278914 introduced NameOffsetExpr to avoid copying ONAME nodes and
hacking up their offsets, but evidently staticinit subtly depended on
the prior behavior to allow dynamic initialization of blank variables.
This CL refactors the code somewhat to avoid using NameOffsetExpr with
blank variables, and to instead create dynamic assignments directly to
the global blank node. It also adds a check to NewNameOffsetExpr to
guard against misuse like this, since I suspect there could be other
cases still lurking within staticinit. (This code is overdue for an
makeover anyway.)
Thanks to thanm@ for bisect and test case minimization.
Fixes#43677.
Change-Id: Ic71cb5d6698382feb9548dc3bb9fd606b207a172
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I misread the FIXME comment in InitLSym the first time. It's referring
to how InitLSym is supposed to be called exactly once per
function (see function documentation), but this is evidently not
actually the case currently in GOEXPERIMENT=regabi mode.
So just move the NeedFuncSym call below the GOEXPERIMENT=regabi
workaround.
Also, to fix the linux-arm64-{aws,packet} builders, move the call to
reflectdata.WriteFuncSyms() to after the second batch of functions are
compiled. This is necessary to make sure we catch all the funcsyms
that can be added by late function compilation.
Change-Id: I6d6396d48e2ee29c1fb007fa2b99e065b36375db
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Needs to be visible to ssagen, and might as well start clean to avoid
creating a lot of accidental dependencies.
Added some methods for export.
Decided to use a pointer instead of value for ABIConfig uses.
Tests ended up separate from abiutil itself; otherwise there are import cycles.
Change-Id: I5570e1e6a463e303c5e2dc84e8dd4125e7c1adcc
Reviewed-on: https://go-review.googlesource.com/c/go/+/282614
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This only works for functions; if you try it with a method, it will
fail. It does work for both local package and imports. For now,
it tells you when it thinks it sees either a declaration or a call of
such a function (this will normally be silent since no existing
code uses this pragma).
Note: it appears to be really darn hard to figure out if this
pragma was set for a method, and the method's call site. Better
ir.Node wranglers than I might be able to make headway, but it
seemed unnecessary for this experiment.
Change-Id: I601c2ddd124457bf6d62f714d7ac871705743c0a
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This is a selected copy from the register ABI experiment CL, focused
on the files and data structures that handle spilling around morestack.
Unnecessary code from the experiment was removed, other code was adapted.
Would it make sense to leave comments in the experiment as pieces are
brought over?
Experiment CL (for comparison purposes)
https://go-review.googlesource.com/c/go/+/28832
Change-Id: I92136f070351d4fcca1407b52ecf9b80898fed95
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This is intended to make it easier to write/change a test
without referring to the source code to figure out what the
error messages actually mean, or how to correct them.
Change-Id: Ie79ff7cd9f2d1fa605257fe97eace68adc8a6716
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Current many architectures use a rule along the lines of
// Canonicalize the order of arguments to comparisons - helps with CSE.
((CMP|CMPW) x y) && x.ID > y.ID => (InvertFlags ((CMP|CMPW) y x))
to normalize comparisons as much as possible for CSE. Replace the
ID comparison with something less variable across compiler changes.
This helps avoid spurious failures in some of the codegen-comparison
tests (though the current choice of comparison is sensitive to Op
ordering).
Two tests changed to accommodate modified instruction choice.
Change-Id: Ib35f450bd2bae9d4f9f7838ceaf7ec682bcf1e1a
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The closure's type always matches the corresponding function's type,
so just use one instance rather than carrying around two. Simplifies
construction of closures, rewriting them during walk, and shrinks
memory usage.
Passes toolstash -cmp.
Change-Id: I83b8b8f435b02ab25a30fb7aa15d5ec7ad97189d
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We used to transform directly called closures in a separate pass
before walk, because we couldn't guarantee whether we'd see the
closure call or the closure itself first. As of the last CL, this
ordering is always guaranteed, so we can rewrite calls and the closure
at the same time.
Change-Id: Ia6f4d504c24795e41500108589b53395d301123b
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This CL reorders function compilation to ensure that functions are
always compiled before any enclosed function literals. The primary
goal of this is to reduce the risk of race conditions that arise due
to compilation of function literals needing to inspect data from their
closure variables. However, a pleasant side effect is that it allows
skipping the redundant, separate compilation of function literals that
were inlined into their enclosing function.
Change-Id: I03ee96212988cb578c2452162b7e99cc5e92918f
Reviewed-on: https://go-review.googlesource.com/c/go/+/282892
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No real code changes. Just splitting into a separate CL so the next
one is easier to review.
Change-Id: I428dc986b76370d8d3afc12cf19585f6384389d7
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The compiler currently has two modes for compilation: one where it
compiles each function as it sees them, and another where it enqueues
them all into a work queue. A subsequent CL is going to reorder
function compilation to ensure that functions are always compiled
before any non-trivial function literals they enclose, and this will
be easier if we always use the compile work queue.
Also, fewer compilation modes makes things simpler to reason about.
Change-Id: Ie090e81f7476c49486296f2b90911fa0a466a5dd
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InitLSym is where we're now generating ABI wrappers, so it seems as
good a place as any to make sure we're generating the degenerate
closure wrappers for declared functions and methods.
Change-Id: I097f34bbcee65dee87a97f9ed6f3f38e4cf2e2b5
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Just directly set Type.Vargen when declaring defined types within a
function.
Change-Id: Idcc0007084a660ce1c39da4a3697e158a1c615b5
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Historically, inline function bodies were exported as plain Go source
code, and symbol mangling was a convenient hack because it allowed
variables to be re-imported with largely the same names as they were
originally exported as.
However, nowadays we use a binary format that's more easily extended,
so we can simply serialize all of a function's declared objects up
front, and then refer to them by index later on. This also allows us
to easily report unmangled names all the time (e.g., error message
from issue7921.go).
Fixes#43633.
Change-Id: I46c88f5a47cb921f70ab140976ba9ddce38df216
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Creating closure vars is subtle and is also needed in both CL 281932
and CL 283112, so refactor out a common implementation that can be
used in all 3 places.
Passes toolstash -cmp.
Change-Id: Ib993eb90c895b52759bfbfbaad88921e391b0b4d
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Escape analysis needs to know the index of result parameters for
recording escape-flow information. It currently relies on Vargen for
this, but it can easily figure this out for itself. So just do that
instead, so that we can remove Vargen.
Passes toolstash -cmp.
For #43633.
Change-Id: I65dedc2d73bc25e85ff400f308e50b73dc503630
Reviewed-on: https://go-review.googlesource.com/c/go/+/283192
Trust: Matthew Dempsky <mdempsky@google.com>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
After the previous CLs, all closure reads are handled during SSA
construction.
Change-Id: Iad67b01fa2d3798f50ea647be7ccf8195f189c27
Reviewed-on: https://go-review.googlesource.com/c/go/+/281512
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Similar to with regular closures, we can change method value wrappers
to use ClosureVars and allow SSA construction to take care of wiring
it up appropriately.
Change-Id: I05c0b1bcec4e24305324755df35b7bc5b8a6ce7a
Reviewed-on: https://go-review.googlesource.com/c/go/+/281353
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
For function literals that aren't inlined or directly called, we need
to pass their arguments via a closure struct. This also means we need
to rewrite uses of closure variables to access from this closure
struct.
Currently we do this rewrite in a pass before walking begins. This CL
moves the code to SSA construction instead, alongside binding other
input parameters.
Change-Id: I13538ef3394e2d6f75d5b7b2d0adbb00db812dc2
Reviewed-on: https://go-review.googlesource.com/c/go/+/281352
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Currently, during walk we rewrite PAUTOHEAP uses into derefs of their
corresponding Heapaddr, but we can easily do this instead during SSA
construction. This does involve updating two test cases:
* nilptr3.go
This file had a test that we emit a "removed nil check" diagnostic for
the implicit dereference from accessing a PAUTOHEAP variable. This CL
removes this diagnostic, since it's not really useful to end users:
from the user's point of view, there's no pointer anyway, so they
needn't care about whether we check for nil or not. That's a purely
internal detail. And with the PAUTOHEAP dereference handled during SSA
construction, we can more robustly ensure this happens, rather than
relying on setting a flag in walk and hoping that SSA sees it.
* issue20780.go
Previously, when PAUTOHEAPs were dereferenced during walk, it had a
consequence that when they're passed as a function call argument, they
would first get copied to the stack before being copied to their
actual destination. Moving the dereferencing to SSA had a side-effect
of eliminating this unnecessary temporary, and copying directly to the
destination parameter.
The test is updated to instead call "g(h(), h())" where h() returns a
large value, as the first result will always need to be spilled
somewhere will calling the second function. Maybe eventually we're
smart enough to realize it can be spilled to the heap, but we don't do
that today.
Because I'm concerned that the direct copy-to-parameter optimization
could interfere with race-detector instrumentation (e.g., maybe the
copies were previously necessary to ensure they're not clobbered by
inserted raceread calls?), I've also added issue20780b.go to exercise
this in a few different ways.
Change-Id: I720598cb32b17518bc10a03e555620c0f25fd28d
Reviewed-on: https://go-review.googlesource.com/c/go/+/281293
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
With the recent compiler rewrites and cleanups to gc/fmt.go, the
"safety net" provided by fmt_test has become less important and
the test itself has become a burden (often breaks because of small
format changes elsewhere).
Eventually, the syntax and types2 packages will provide most error
and diagnostic compiler output at which point fmt.go can be further
simplified as well.
Change-Id: Ie93eefd3e1166f3548fed0199b732dbd6c81948a
Reviewed-on: https://go-review.googlesource.com/c/go/+/282560
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Now that CaptureVars is gone, we can remove the extra code in escape
analysis that only served to appease toolstash -cmp.
Change-Id: I8c811834f3d966e76702e2d362e3de414c94bea6
Reviewed-on: https://go-review.googlesource.com/c/go/+/281544
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Capture analysis is now part of escape analysis.
Passes toolstash -cmp.
Change-Id: Ifcd3ecc342074c590e0db1ff0646dfa1ea2ff57b
Reviewed-on: https://go-review.googlesource.com/c/go/+/281543
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Currently we rely on the type-checker to do some basic data-flow
analysis to help decide whether function literals should capture
variables by value or reference. However, this analysis isn't done by
go/types, and escape analysis already has a better framework for doing
this more precisely.
This CL extends escape analysis to recalculate the same "byval" as
CaptureVars and check that it matches. A future CL will remove
CaptureVars in favor of escape analysis's calculation.
Notably, escape analysis happens after deadcode removes obviously
unreachable code, so it sees the AST without any unreachable
assignments. (Also without unreachable addrtakens, but
ComputeAddrtaken already happens after deadcode too.) There are two
test cases where a variable is only reassigned on certain CPUs. This
CL changes them to reassign the variables unconditionally (as no-op
reassignments that avoid triggering cmd/vet's self-assignment check),
at least until we remove CaptureVars.
Passes toolstash -cmp.
Change-Id: I7162619739fedaf861b478fb8d506f96a6ac21f3
Reviewed-on: https://go-review.googlesource.com/c/go/+/281535
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
The gc implementation has had precise GC for a while now, so we can
enable these tests more broadly.
Confirmed that they still fail with gccgo 10.2.1.
Change-Id: Ic1c0394ab832024a99e34163c422941a3706e1a2
Reviewed-on: https://go-review.googlesource.com/c/go/+/281542
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
The backend doesn't synchronize compilation of functions with their
enclosed function literals, so it's not safe to double-check that
IsClosureVar isn't set on the underlying Name. Plenty of frontend
stuff would blow-up if this was wrong anyway, so it should be fine to
omit.
Change-Id: I3e97b64051fe56d97bf316c9b5dcce61f2082428
Reviewed-on: https://go-review.googlesource.com/c/go/+/281812
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
There's a bunch of code that wants to map closure variables back to
their original name, so add a single Name.Canonical method that they
can all use.
Also, move the Byval flag from being stored on individual closure
variables to being stored on the canonical variable.
Passes toolstash -cmp.
Change-Id: Ia3ef81af5a15783d09f04b4e274ce33df94518e6
Reviewed-on: https://go-review.googlesource.com/c/go/+/281541
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
