1199481Srdivacky//===- LazyValueInfo.h - Value constraint analysis --------------*- C++ -*-===// 2199481Srdivacky// 3199481Srdivacky// The LLVM Compiler Infrastructure 4199481Srdivacky// 5199481Srdivacky// This file is distributed under the University of Illinois Open Source 6199481Srdivacky// License. See LICENSE.TXT for details. 7199481Srdivacky// 8199481Srdivacky//===----------------------------------------------------------------------===// 9199481Srdivacky// 10199481Srdivacky// This file defines the interface for lazy computation of value constraint 11199481Srdivacky// information. 12199481Srdivacky// 13199481Srdivacky//===----------------------------------------------------------------------===// 14199481Srdivacky 15212904Sdim#ifndef LLVM_ANALYSIS_LAZYVALUEINFO_H 16212904Sdim#define LLVM_ANALYSIS_LAZYVALUEINFO_H 17199481Srdivacky 18199481Srdivacky#include "llvm/Pass.h" 19199481Srdivacky 20199481Srdivackynamespace llvm { 21199481Srdivacky class Constant; 22243830Sdim class DataLayout; 23234353Sdim class TargetLibraryInfo; 24199481Srdivacky class Value; 25199481Srdivacky 26199481Srdivacky/// LazyValueInfo - This pass computes, caches, and vends lazy value constraint 27199481Srdivacky/// information. 28199481Srdivackyclass LazyValueInfo : public FunctionPass { 29243830Sdim class DataLayout *TD; 30234353Sdim class TargetLibraryInfo *TLI; 31199481Srdivacky void *PImpl; 32243830Sdim LazyValueInfo(const LazyValueInfo&) LLVM_DELETED_FUNCTION; 33243830Sdim void operator=(const LazyValueInfo&) LLVM_DELETED_FUNCTION; 34199481Srdivackypublic: 35199481Srdivacky static char ID; 36218893Sdim LazyValueInfo() : FunctionPass(ID), PImpl(0) { 37218893Sdim initializeLazyValueInfoPass(*PassRegistry::getPassRegistry()); 38218893Sdim } 39199481Srdivacky ~LazyValueInfo() { assert(PImpl == 0 && "releaseMemory not called"); } 40199481Srdivacky 41199481Srdivacky /// Tristate - This is used to return true/false/dunno results. 42199481Srdivacky enum Tristate { 43199481Srdivacky Unknown = -1, False = 0, True = 1 44199481Srdivacky }; 45199481Srdivacky 46199481Srdivacky 47199481Srdivacky // Public query interface. 48199481Srdivacky 49199481Srdivacky /// getPredicateOnEdge - Determine whether the specified value comparison 50199481Srdivacky /// with a constant is known to be true or false on the specified CFG edge. 51199481Srdivacky /// Pred is a CmpInst predicate. 52199481Srdivacky Tristate getPredicateOnEdge(unsigned Pred, Value *V, Constant *C, 53199481Srdivacky BasicBlock *FromBB, BasicBlock *ToBB); 54199481Srdivacky 55199481Srdivacky 56199481Srdivacky /// getConstant - Determine whether the specified value is known to be a 57199481Srdivacky /// constant at the end of the specified block. Return null if not. 58199481Srdivacky Constant *getConstant(Value *V, BasicBlock *BB); 59199481Srdivacky 60199481Srdivacky /// getConstantOnEdge - Determine whether the specified value is known to be a 61199481Srdivacky /// constant on the specified edge. Return null if not. 62199481Srdivacky Constant *getConstantOnEdge(Value *V, BasicBlock *FromBB, BasicBlock *ToBB); 63199481Srdivacky 64212904Sdim /// threadEdge - Inform the analysis cache that we have threaded an edge from 65212904Sdim /// PredBB to OldSucc to be from PredBB to NewSucc instead. 66212904Sdim void threadEdge(BasicBlock *PredBB, BasicBlock *OldSucc, BasicBlock *NewSucc); 67199481Srdivacky 68212904Sdim /// eraseBlock - Inform the analysis cache that we have erased a block. 69212904Sdim void eraseBlock(BasicBlock *BB); 70212904Sdim 71199481Srdivacky // Implementation boilerplate. 72199481Srdivacky 73234353Sdim virtual void getAnalysisUsage(AnalysisUsage &AU) const; 74199481Srdivacky virtual void releaseMemory(); 75199481Srdivacky virtual bool runOnFunction(Function &F); 76199481Srdivacky}; 77199481Srdivacky 78199481Srdivacky} // end namespace llvm 79199481Srdivacky 80199481Srdivacky#endif 81199481Srdivacky 82