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//===- GlobalARCSequenceDataflow.h - ARC Sequence Flow Analysis -*- C++ -*-===//
// This source file is part of the open source project
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
// See for license information
// See for the list of Swift project authors
#include "RefCountState.h"
#include "swift/SILOptimizer/Analysis/PostOrderAnalysis.h"
#include "swift/SILOptimizer/Analysis/ProgramTerminationAnalysis.h"
#include "swift/Basic/BlotMapVector.h"
#include "swift/Basic/NullablePtr.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/Optional.h"
namespace swift {
class SILFunction;
class AliasAnalysis;
} // end swift namespace
namespace swift {
/// A class that implements the ARC sequence data flow.
class ARCSequenceDataflowEvaluator {
// Forward declaration of private classes that are opaque in this header.
class ARCBBStateInfoHandle;
class ARCBBStateInfo;
class ARCBBState;
/// The SILFunction that we are applying the dataflow to.
SILFunction &F;
/// The alias analysis that we are using for alias queries.
AliasAnalysis *AA;
/// The post order analysis we are using for computing post orders, reverse
/// post orders.
PostOrderAnalysis *POA;
/// An analysis which computes the identity root of a SILValue(), i.e. the
/// dominating origin SILValue of the reference count that by retaining or
/// releasing this value one is affecting.
RCIdentityFunctionInfo *RCIA;
/// An analysis to get the epilogue ARC instructions.
EpilogueARCFunctionInfo *EAFI;
/// The map from dataflow terminating decrements -> increment dataflow state.
BlotMapVector<SILInstruction *, TopDownRefCountState> &DecToIncStateMap;
/// The map from dataflow terminating increment -> decrement dataflow state.
BlotMapVector<SILInstruction *, BottomUpRefCountState> &IncToDecStateMap;
llvm::BumpPtrAllocator Allocator;
ImmutablePointerSetFactory<SILInstruction> SetFactory;
/// Stashed BB information.
std::unique_ptr<ARCBBStateInfo> BBStateInfo;
SILFunction &F, AliasAnalysis *AA, PostOrderAnalysis *POA,
RCIdentityFunctionInfo *RCIA, EpilogueARCFunctionInfo *EAFI,
ProgramTerminationFunctionInfo *PTFI,
BlotMapVector<SILInstruction *, TopDownRefCountState> &DecToIncStateMap,
BlotMapVector<SILInstruction *, BottomUpRefCountState> &IncToDecStateMap);
/// Run the dataflow evaluator.
bool run(bool FreezePostDomReleases);
/// Clear all of the states we are tracking for the various basic blocks.
void clear();
SILFunction *getFunction() const { return &F; }
/// Perform the bottom up data flow.
bool processBottomUp(bool freezePostDomReleases);
/// Perform the top down dataflow.
bool processTopDown();
/// Merge in the BottomUp state of any successors of DataHandle.getBB() into
/// DataHandle.getState().
void mergeSuccessors(ARCBBStateInfoHandle &DataHandle);
/// Merge in the TopDown state of any predecessors of DataHandle.getBB() into
/// DataHandle.getState().
void mergePredecessors(ARCBBStateInfoHandle &DataHandle);
bool processBBBottomUp(ARCBBState &BBState,
bool FreezeOwnedArgEpilogueReleases);
bool processBBTopDown(ARCBBState &BBState);
void computePostDominatingConsumedArgMap();
llvm::Optional<ARCBBStateInfoHandle> getBottomUpBBState(SILBasicBlock *BB);
llvm::Optional<ARCBBStateInfoHandle> getTopDownBBState(SILBasicBlock *BB);
void dumpDataflowResults();
} // end swift namespace