Language features like erasing concrete metatype
values are also left for the future. Still, baby steps.
The singleton ordinary metatype for existential types
is still potentially useful; we allow it to be written
as P.Protocol.
I've been somewhat cavalier in making code accept
AnyMetatypeType instead of a more specific type, and
it's likely that a number of these places can and
should be more restrictive.
When T is an existential type, parse T.Type as an
ExistentialMetatypeType instead of a MetatypeType.
An existential metatype is the formal type
\exists t:P . (t.Type)
whereas the ordinary metatype is the formal type
(\exists t:P . t).Type
which is singleton. Our inability to express that
difference was leading to an ever-increasing cascade
of hacks where information is shadily passed behind
the scenes in order to make various operations with
static members of protocols work correctly.
This patch takes the first step towards fixing that
by splitting out existential metatypes and giving
them a pointer representation. Eventually, we will
need them to be able to carry protocol witness tables
Swift SVN r15716
alloc_ref_dynamic allocates an instance of a class type based on the
value in its metatype operand. Start emitting these instructions for
the allocating constructor of a complete object initializer (not yet
tested) and for the allocating constructor synthesized for an imported
Objective-C init method.
Still missing:
- IRGen still does the same thing as alloc_ref right now. That
change will follow.
- There are devirtualization opportunities when we know the value of
the metatype that would turn an alloc_ref_dynamic into an alloc_ref;
I'm not planning to do this optimization.
Swift SVN r14560
Riding off of project_existential[_ref] was convenient, but the
resuls are used quite differently. Note that open_existential[_ref]
still don't print/parse reasonably yet.
Swift SVN r13878
Including Self in AllArchetypes introduced substitutions for Self's associated types as a side effect, which caused devirtualized witness calls to hold on to stale substitutions that were quietly ignored.
Swift SVN r13713
specialize on polymorphic arguments.
This can be enabled with: -sil-devirt-threshold 500.
It currently improves RC4 (when enabled) by 20%, but will be much more
important after Michael's load elimination with alias analysis lands.
This implementation is suitable for experimentation. Superficial code
reviews are also welcome. Although be warned that the design is overly
complex and I plan to rewrite it. I initially abandoned the idea of
incrementally specializing one function at a time, thinking that we
need to analyze full chains. However, I since realized after talking
to Nadav that the incremental approach can be made to work. A lot of
book-keeping will go away with that change.
TODO:
- Resolve protocol argument types. Currently we assume they can be
reinitialized at applies, but I don't think they can unless they are
@inouts. This is an issue with the existing local devirtualizer
that prevents it working across calls.
- Properly mangle the specialized methods. Find existing
specializations by demangling rather than maintaining a map.
- Rewrite the logic for specializing chains for simplicity.
- Enable by default.
Swift SVN r13642
Now the pass does not need to know about the pass manager. We also don't have
runOnFunction or runOnModule anymore because the trnasformation knows
which module it is processing. The Pass itself knows how to invalidate the
analysis, based on the injected pass manager that is internal to the
transformation.
Now our DCE transformation looks like this:
class DCE : public SILModuleTransform {
void run() {
performSILDeadCodeElimination(getModule());
invalidateAnalysis(SILAnalysis::InvalidationKind::All);
}
};
Swift SVN r13598
- purge @inout from comments in the compiler except for places talking about
the SIL argument convention.
- change diagnostics to not refer to @inout
- Change the astprinter to print InoutType without the @, so it doesn't show
up in diagnostics or in closure argument types in code completion.
- Implement type parsing support for the new inout syntax (before we just
handled patterns).
- Switch the last couple of uses in the stdlib (in types) to inout.
- Various testcase updates (more to come).
Swift SVN r13564
The old devirtualization procedure did not take into account the substitution list in the apply inst.
The new optimization works on the apply instruction that uses the archetype_method instruction.
We do not handle polymorphic types because we don't modify the protocol conformance yet.
Swift SVN r12826
For example, if ABC is not a generic type we can replace this instruction
with a function_ref instruction to a specific function:
archetype_method $ABC, #pingable.ping!1
Swift SVN r12571
In many cases these calls are constructors that were too big to be inlined.
We now devirtualize this code:
class ABC {
init() { /* Don't inline */ }
func member() { }
}
func foo() {
var x = ABC()
x.member()
}
Swift SVN r12223
