1 //===- LazyValueInfo.h - Value constraint analysis --------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file defines the interface for lazy computation of value constraint 11 // information. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_ANALYSIS_LAZYVALUEINFO_H 16 #define LLVM_ANALYSIS_LAZYVALUEINFO_H 17 18 #include "llvm/Pass.h" 19 20 namespace llvm { 21 class Constant; 22 class DataLayout; 23 class TargetLibraryInfo; 24 class Value; 25 26 /// LazyValueInfo - This pass computes, caches, and vends lazy value constraint 27 /// information. 28 class LazyValueInfo : public FunctionPass { 29 class DataLayout *TD; 30 class TargetLibraryInfo *TLI; 31 void *PImpl; 32 LazyValueInfo(const LazyValueInfo&) LLVM_DELETED_FUNCTION; 33 void operator=(const LazyValueInfo&) LLVM_DELETED_FUNCTION; 34 public: 35 static char ID; 36 LazyValueInfo() : FunctionPass(ID), PImpl(0) { 37 initializeLazyValueInfoPass(*PassRegistry::getPassRegistry()); 38 } 39 ~LazyValueInfo() { assert(PImpl == 0 && "releaseMemory not called"); } 40 41 /// Tristate - This is used to return true/false/dunno results. 42 enum Tristate { 43 Unknown = -1, False = 0, True = 1 44 }; 45 46 47 // Public query interface. 48 49 /// getPredicateOnEdge - Determine whether the specified value comparison 50 /// with a constant is known to be true or false on the specified CFG edge. 51 /// Pred is a CmpInst predicate. 52 Tristate getPredicateOnEdge(unsigned Pred, Value *V, Constant *C, 53 BasicBlock *FromBB, BasicBlock *ToBB); 54 55 56 /// getConstant - Determine whether the specified value is known to be a 57 /// constant at the end of the specified block. Return null if not. 58 Constant *getConstant(Value *V, BasicBlock *BB); 59 60 /// getConstantOnEdge - Determine whether the specified value is known to be a 61 /// constant on the specified edge. Return null if not. 62 Constant *getConstantOnEdge(Value *V, BasicBlock *FromBB, BasicBlock *ToBB); 63 64 /// threadEdge - Inform the analysis cache that we have threaded an edge from 65 /// PredBB to OldSucc to be from PredBB to NewSucc instead. 66 void threadEdge(BasicBlock *PredBB, BasicBlock *OldSucc, BasicBlock *NewSucc); 67 68 /// eraseBlock - Inform the analysis cache that we have erased a block. 69 void eraseBlock(BasicBlock *BB); 70 71 // Implementation boilerplate. 72 73 virtual void getAnalysisUsage(AnalysisUsage &AU) const; 74 virtual void releaseMemory(); 75 virtual bool runOnFunction(Function &F); 76 }; 77 78 } // end namespace llvm 79 80 #endif 81 82
