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swift-mirror/lib/SILOptimizer/Transforms/GenericSpecializer.cpp
practicalswift 1339b5403b Consistent use of header comment format.
Correct format:
//===--- Name of file - Description ----------------------------*- Lang -*-===//
2016-01-04 13:26:31 +01:00

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//===--- GenericSpecializer.cpp - Specialization of generic functions -----===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// Specialize calls to generic functions by substituting static type
// information.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "sil-generic-specializer"
#include "swift/SIL/SILFunction.h"
#include "swift/SIL/SILInstruction.h"
#include "swift/SILOptimizer/Utils/Generics.h"
#include "swift/SILOptimizer/Utils/Local.h"
#include "swift/SILOptimizer/PassManager/Transforms.h"
#include "llvm/ADT/SmallVector.h"
using namespace swift;
namespace {
class GenericSpecializer : public SILFunctionTransform {
bool specializeAppliesInFunction(SILFunction &F);
/// The entry point to the transformation.
void run() override {
SILFunction &F = *getFunction();
DEBUG(llvm::dbgs() << "***** GenericSpecializer on function:" << F.getName()
<< " *****\n");
if (specializeAppliesInFunction(F))
invalidateAnalysis(SILAnalysis::InvalidationKind::Everything);
}
StringRef getName() override { return "Generic Specializer"; }
};
} // end anonymous namespace
bool GenericSpecializer::specializeAppliesInFunction(SILFunction &F) {
bool Changed = false;
llvm::SmallVector<SILInstruction *, 8> DeadApplies;
for (auto &BB : F) {
for (auto It = BB.begin(), End = BB.end(); It != End;) {
auto &I = *It++;
// Skip non-apply instructions, apply instructions with no
// substitutions, apply instructions where we do not statically
// know the called function, and apply instructions where we do
// not have the body of the called function.
ApplySite Apply = ApplySite::isa(&I);
if (!Apply || !Apply.hasSubstitutions())
continue;
auto *Callee = Apply.getCalleeFunction();
if (!Callee || !Callee->isDefinition())
continue;
// We have a call that can potentially be specialized, so
// attempt to do so.
// The specializer helper function currently expects a collector
// argument, but we aren't going to make use of the results so
// we'll have our filter always return false;
auto Filter = [](SILInstruction *I) -> bool { return false; };
CloneCollector Collector(Filter);
SILFunction *SpecializedFunction;
auto Specialized =
trySpecializeApplyOfGeneric(Apply, SpecializedFunction, Collector);
if (Specialized) {
Changed = true;
// If calling the specialization utility resulted in a new
// function (as opposed to returning a previous
// specialization), we need to notify the pass manager so that
// the new function gets optimized.
if (SpecializedFunction)
notifyPassManagerOfFunction(SpecializedFunction);
auto *AI = Apply.getInstruction();
if (!isa<TryApplyInst>(AI))
AI->replaceAllUsesWith(Specialized.getInstruction());
DeadApplies.push_back(AI);
}
}
}
// Remove all the now-dead applies.
while (!DeadApplies.empty()) {
auto *AI = DeadApplies.pop_back_val();
recursivelyDeleteTriviallyDeadInstructions(AI, true);
}
return Changed;
}
SILTransform *swift::createGenericSpecializer() {
return new GenericSpecializer();
}