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46 lines
1.6 KiB
C++
46 lines
1.6 KiB
C++
//===--- RedundantMoveValueElimination.cpp - Delete spurious move_values --===//
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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 - 2023 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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// A move_value ends an owned lifetime and begins an owned lifetime.
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//
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// The new lifetime may have the same characteristics as the original lifetime
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// with regards to
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// - lexicality
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// - escaping
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//
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// If it has the same characteristics, there is no reason to have two separate
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// lifetimes--they are redundant. This optimization deletes such redundant
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// move_values.
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//===----------------------------------------------------------------------===//
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#include "SemanticARC/SemanticARCOpts.h"
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#include "SemanticARCOptVisitor.h"
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#include "swift/SIL/LinearLifetimeChecker.h"
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using namespace swift;
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using namespace semanticarc;
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//===----------------------------------------------------------------------===//
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// Top Level Entrypoint
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//===----------------------------------------------------------------------===//
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bool SemanticARCOptVisitor::visitMoveValueInst(MoveValueInst *mvi) {
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if (!ctx.shouldPerform(ARCTransformKind::RedundantMoveValueElim))
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return false;
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if (!isRedundantMoveValue(mvi))
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return false;
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// Both characteristics match.
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eraseAndRAUWSingleValueInstruction(mvi, mvi->getOperand());
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return true;
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}
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