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Erik Eckstein
4a1950d292
Computing dominance relation between instructions in the same block was done with linear search, e.g. when checking if a value-use is before its lifetime ending instruction. This resulted in quadratic complexity and very long compile times for very large basic blocks. Now we do the dominance check with pre-computed instruction indices, which is O(0) instead of O(n). https://github.com/swiftlang/swift/issues/86663 rdar://168511262
65 lines
2.7 KiB
C++
65 lines
2.7 KiB
C++
//===--- GuaranteedPhiVerifier.cpp ----------------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "sil-guaranteed-phi-verifier"
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#include "GuaranteedPhiVerifierPrivate.h"
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using namespace swift;
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bool GuaranteedPhiVerifier::verifyDependentPhiLifetime(SILPhiArgument *phi,
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SILValue baseValue) {
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// If the (phi, baseValue) pair was visited before, return.
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auto it = dependentPhiToBaseValueMap.find(phi);
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if (it != dependentPhiToBaseValueMap.end() &&
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it->second.find(baseValue) != it->second.end()) {
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return false;
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}
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// Insert (phi, baseValue) into the map.
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dependentPhiToBaseValueMap[phi].insert(baseValue);
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// Now, verify whether phi's lifetime is within baseValue's lifetime
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SmallVector<Operand *, 4> baseValConsumingUses(lookThroughBorrowedFromUser(baseValue)->getConsumingUses());
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// If the baseValue has no consuming uses, there is nothing more to verify
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if (baseValConsumingUses.empty())
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return false;
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SmallVector<Operand *, 4> phiUses(lookThroughBorrowedFromUser(phi)->getUses());
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LinearLifetimeChecker checker(deadEndBlocks, instIndices);
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// newErrorBuilder is consumed at the end of the checkValue function.
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// Copy initial state from errorBuilder everytime
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LinearLifetimeChecker::ErrorBuilder newErrorBuilder = errorBuilder;
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// Verify whether the guaranteed phi lies within the lifetime of the base
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// value.
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auto linearLifetimeResult = checker.checkValue(
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baseValue, baseValConsumingUses, phiUses, newErrorBuilder);
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return linearLifetimeResult.getFoundError();
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}
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void GuaranteedPhiVerifier::verifyReborrows(BeginBorrowInst *borrow) {
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auto visitReborrowPhiBaseValuePair = [&](SILPhiArgument *phi,
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SILValue baseValue) {
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verifyDependentPhiLifetime(phi, baseValue);
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};
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visitExtendedReborrowPhiBaseValuePairs(borrow, visitReborrowPhiBaseValuePair);
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}
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void GuaranteedPhiVerifier::verifyGuaranteedForwardingPhis(
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BorrowedValue borrow) {
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auto visitGuaranteedPhiBaseValuePair = [&](SILPhiArgument *phi,
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SILValue baseValue) {
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verifyDependentPhiLifetime(phi, baseValue);
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};
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visitExtendedGuaranteedForwardingPhiBaseValuePairs(
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borrow, visitGuaranteedPhiBaseValuePair);
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}
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