| //===- LazyValueInfo.h - Value constraint analysis --------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines the interface for lazy computation of value constraint |
| // information. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_ANALYSIS_LAZYVALUEINFO_H |
| #define LLVM_ANALYSIS_LAZYVALUEINFO_H |
| |
| #include "llvm/Pass.h" |
| |
| namespace llvm { |
| class AssumptionCache; |
| class Constant; |
| class DataLayout; |
| class DominatorTree; |
| class Instruction; |
| class TargetLibraryInfo; |
| class Value; |
| |
| /// This pass computes, caches, and vends lazy value constraint information. |
| class LazyValueInfo : public FunctionPass { |
| AssumptionCache *AC; |
| const DataLayout *DL; |
| class TargetLibraryInfo *TLI; |
| DominatorTree *DT; |
| void *PImpl; |
| LazyValueInfo(const LazyValueInfo&) LLVM_DELETED_FUNCTION; |
| void operator=(const LazyValueInfo&) LLVM_DELETED_FUNCTION; |
| public: |
| static char ID; |
| LazyValueInfo() : FunctionPass(ID), PImpl(nullptr) { |
| initializeLazyValueInfoPass(*PassRegistry::getPassRegistry()); |
| } |
| ~LazyValueInfo() { assert(!PImpl && "releaseMemory not called"); } |
| |
| /// This is used to return true/false/dunno results. |
| enum Tristate { |
| Unknown = -1, False = 0, True = 1 |
| }; |
| |
| |
| // Public query interface. |
| |
| /// Determine whether the specified value comparison with a constant is known |
| /// to be true or false on the specified CFG edge. |
| /// Pred is a CmpInst predicate. |
| Tristate getPredicateOnEdge(unsigned Pred, Value *V, Constant *C, |
| BasicBlock *FromBB, BasicBlock *ToBB, |
| Instruction *CxtI = nullptr); |
| |
| /// Determine whether the specified value comparison with a constant is known |
| /// to be true or false at the specified instruction |
| /// (from an assume intrinsic). Pred is a CmpInst predicate. |
| Tristate getPredicateAt(unsigned Pred, Value *V, Constant *C, |
| Instruction *CxtI); |
| |
| /// Determine whether the specified value is known to be a |
| /// constant at the end of the specified block. Return null if not. |
| Constant *getConstant(Value *V, BasicBlock *BB, Instruction *CxtI = nullptr); |
| |
| /// Determine whether the specified value is known to be a |
| /// constant on the specified edge. Return null if not. |
| Constant *getConstantOnEdge(Value *V, BasicBlock *FromBB, BasicBlock *ToBB, |
| Instruction *CxtI = nullptr); |
| |
| /// Inform the analysis cache that we have threaded an edge from |
| /// PredBB to OldSucc to be from PredBB to NewSucc instead. |
| void threadEdge(BasicBlock *PredBB, BasicBlock *OldSucc, BasicBlock *NewSucc); |
| |
| /// Inform the analysis cache that we have erased a block. |
| void eraseBlock(BasicBlock *BB); |
| |
| // Implementation boilerplate. |
| |
| void getAnalysisUsage(AnalysisUsage &AU) const override; |
| void releaseMemory() override; |
| bool runOnFunction(Function &F) override; |
| }; |
| |
| } // end namespace llvm |
| |
| #endif |
| |