Coverage Report

Created: 2019-02-20 07:29

/Users/buildslave/jenkins/workspace/clang-stage2-coverage-R/llvm/include/llvm/Analysis/LazyValueInfo.h
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//===- LazyValueInfo.h - Value constraint analysis --------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines the interface for lazy computation of value constraint
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// information.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_ANALYSIS_LAZYVALUEINFO_H
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#define LLVM_ANALYSIS_LAZYVALUEINFO_H
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#include "llvm/IR/PassManager.h"
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#include "llvm/Pass.h"
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namespace llvm {
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  class AssumptionCache;
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  class Constant;
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  class ConstantRange;
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  class DataLayout;
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  class DominatorTree;
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  class Instruction;
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  class TargetLibraryInfo;
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  class Value;
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/// This pass computes, caches, and vends lazy value constraint information.
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class LazyValueInfo {
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  friend class LazyValueInfoWrapperPass;
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  AssumptionCache *AC = nullptr;
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  const DataLayout *DL = nullptr;
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  class TargetLibraryInfo *TLI = nullptr;
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  DominatorTree *DT = nullptr;
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  void *PImpl = nullptr;
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  LazyValueInfo(const LazyValueInfo&) = delete;
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  void operator=(const LazyValueInfo&) = delete;
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public:
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  ~LazyValueInfo();
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  LazyValueInfo() {}
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  LazyValueInfo(AssumptionCache *AC_, const DataLayout *DL_, TargetLibraryInfo *TLI_,
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                DominatorTree *DT_)
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      : AC(AC_), DL(DL_), TLI(TLI_), DT(DT_) {}
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  LazyValueInfo(LazyValueInfo &&Arg)
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      : AC(Arg.AC), DL(Arg.DL), TLI(Arg.TLI), DT(Arg.DT), PImpl(Arg.PImpl) {
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    Arg.PImpl = nullptr;
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  }
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  LazyValueInfo &operator=(LazyValueInfo &&Arg) {
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    releaseMemory();
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    AC = Arg.AC;
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    DL = Arg.DL;
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    TLI = Arg.TLI;
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    DT = Arg.DT;
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    PImpl = Arg.PImpl;
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    Arg.PImpl = nullptr;
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    return *this;
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  }
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  /// This is used to return true/false/dunno results.
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  enum Tristate {
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    Unknown = -1, False = 0, True = 1
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  };
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  // Public query interface.
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  /// Determine whether the specified value comparison with a constant is known
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  /// to be true or false on the specified CFG edge.
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  /// Pred is a CmpInst predicate.
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  Tristate getPredicateOnEdge(unsigned Pred, Value *V, Constant *C,
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                              BasicBlock *FromBB, BasicBlock *ToBB,
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                              Instruction *CxtI = nullptr);
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  /// Determine whether the specified value comparison with a constant is known
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  /// to be true or false at the specified instruction
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  /// (from an assume intrinsic). Pred is a CmpInst predicate.
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  Tristate getPredicateAt(unsigned Pred, Value *V, Constant *C,
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                          Instruction *CxtI);
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  /// Determine whether the specified value is known to be a
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  /// constant at the end of the specified block.  Return null if not.
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  Constant *getConstant(Value *V, BasicBlock *BB, Instruction *CxtI = nullptr);
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  /// Return the ConstantRange constraint that is known to hold for the
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  /// specified value at the end of the specified block. This may only be called
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  /// on integer-typed Values.
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  ConstantRange getConstantRange(Value *V, BasicBlock *BB, Instruction *CxtI = nullptr);
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  /// Determine whether the specified value is known to be a
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  /// constant on the specified edge.  Return null if not.
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  Constant *getConstantOnEdge(Value *V, BasicBlock *FromBB, BasicBlock *ToBB,
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                              Instruction *CxtI = nullptr);
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  /// Return the ConstantRage constraint that is known to hold for the
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  /// specified value on the specified edge. This may be only be called
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  /// on integer-typed Values.
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  ConstantRange getConstantRangeOnEdge(Value *V, BasicBlock *FromBB,
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                                       BasicBlock *ToBB,
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                                       Instruction *CxtI = nullptr);
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  /// Inform the analysis cache that we have threaded an edge from
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  /// PredBB to OldSucc to be from PredBB to NewSucc instead.
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  void threadEdge(BasicBlock *PredBB, BasicBlock *OldSucc, BasicBlock *NewSucc);
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  /// Inform the analysis cache that we have erased a block.
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  void eraseBlock(BasicBlock *BB);
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  /// Print the \LazyValueInfo Analysis.
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  /// We pass in the DTree that is required for identifying which basic blocks
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  /// we can solve/print for, in the LVIPrinter. The DT is optional
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  /// in LVI, so we need to pass it here as an argument.
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  void printLVI(Function &F, DominatorTree &DTree, raw_ostream &OS);
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  /// Disables use of the DominatorTree within LVI.
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  void disableDT();
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  /// Enables use of the DominatorTree within LVI. Does nothing if the class
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  /// instance was initialized without a DT pointer.
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  void enableDT();
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  // For old PM pass. Delete once LazyValueInfoWrapperPass is gone.
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  void releaseMemory();
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  /// Handle invalidation events in the new pass manager.
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  bool invalidate(Function &F, const PreservedAnalyses &PA,
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                  FunctionAnalysisManager::Invalidator &Inv);
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};
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/// Analysis to compute lazy value information.
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class LazyValueAnalysis : public AnalysisInfoMixin<LazyValueAnalysis> {
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public:
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  typedef LazyValueInfo Result;
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  Result run(Function &F, FunctionAnalysisManager &FAM);
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private:
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  static AnalysisKey Key;
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  friend struct AnalysisInfoMixin<LazyValueAnalysis>;
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};
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/// Wrapper around LazyValueInfo.
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class LazyValueInfoWrapperPass : public FunctionPass {
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  LazyValueInfoWrapperPass(const LazyValueInfoWrapperPass&) = delete;
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  void operator=(const LazyValueInfoWrapperPass&) = delete;
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public:
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  static char ID;
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  LazyValueInfoWrapperPass() : FunctionPass(ID) {
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    initializeLazyValueInfoWrapperPassPass(*PassRegistry::getPassRegistry());
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  }
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  ~LazyValueInfoWrapperPass() override {
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    assert(!Info.PImpl && "releaseMemory not called");
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  }
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  LazyValueInfo &getLVI();
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  void getAnalysisUsage(AnalysisUsage &AU) const override;
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  void releaseMemory() override;
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  bool runOnFunction(Function &F) override;
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private:
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  LazyValueInfo Info;
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};
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}  // end namespace llvm
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#endif
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