#pragma once #ifdef __GNUC__ #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wunused-parameter" #endif //===- PHITransAddr.h - PHI Translation for Addresses -----------*- C++ -*-===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // // This file declares the PHITransAddr class. // //===----------------------------------------------------------------------===// #ifndef LLVM_ANALYSIS_PHITRANSADDR_H #define LLVM_ANALYSIS_PHITRANSADDR_H #include "llvm/ADT/SmallVector.h" #include "llvm/IR/Instruction.h" namespace llvm { class AssumptionCache; class DominatorTree; class DataLayout; class TargetLibraryInfo; /// PHITransAddr - An address value which tracks and handles phi translation. /// As we walk "up" the CFG through predecessors, we need to ensure that the /// address we're tracking is kept up to date. For example, if we're analyzing /// an address of "&A[i]" and walk through the definition of 'i' which is a PHI /// node, we *must* phi translate i to get "&A[j]" or else we will analyze an /// incorrect pointer in the predecessor block. /// /// This is designed to be a relatively small object that lives on the stack and /// is copyable. /// class PHITransAddr { /// Addr - The actual address we're analyzing. Value *Addr; /// The DataLayout we are playing with. const DataLayout &DL; /// TLI - The target library info if known, otherwise null. const TargetLibraryInfo *TLI = nullptr; /// A cache of \@llvm.assume calls used by SimplifyInstruction. AssumptionCache *AC; /// InstInputs - The inputs for our symbolic address. SmallVector InstInputs; public: PHITransAddr(Value *addr, const DataLayout &DL, AssumptionCache *AC) : Addr(addr), DL(DL), AC(AC) { // If the address is an instruction, the whole thing is considered an input. if (Instruction *I = dyn_cast(Addr)) InstInputs.push_back(I); } Value *getAddr() const { return Addr; } /// NeedsPHITranslationFromBlock - Return true if moving from the specified /// BasicBlock to its predecessors requires PHI translation. bool NeedsPHITranslationFromBlock(BasicBlock *BB) const { // We do need translation if one of our input instructions is defined in // this block. for (unsigned i = 0, e = InstInputs.size(); i != e; ++i) if (InstInputs[i]->getParent() == BB) return true; return false; } /// IsPotentiallyPHITranslatable - If this needs PHI translation, return true /// if we have some hope of doing it. This should be used as a filter to /// avoid calling PHITranslateValue in hopeless situations. bool IsPotentiallyPHITranslatable() const; /// PHITranslateValue - PHI translate the current address up the CFG from /// CurBB to Pred, updating our state to reflect any needed changes. If /// 'MustDominate' is true, the translated value must dominate /// PredBB. This returns true on failure and sets Addr to null. bool PHITranslateValue(BasicBlock *CurBB, BasicBlock *PredBB, const DominatorTree *DT, bool MustDominate); /// PHITranslateWithInsertion - PHI translate this value into the specified /// predecessor block, inserting a computation of the value if it is /// unavailable. /// /// All newly created instructions are added to the NewInsts list. This /// returns null on failure. /// Value *PHITranslateWithInsertion(BasicBlock *CurBB, BasicBlock *PredBB, const DominatorTree &DT, SmallVectorImpl &NewInsts); void dump() const; /// Verify - Check internal consistency of this data structure. If the /// structure is valid, it returns true. If invalid, it prints errors and /// returns false. bool Verify() const; private: Value *PHITranslateSubExpr(Value *V, BasicBlock *CurBB, BasicBlock *PredBB, const DominatorTree *DT); /// InsertPHITranslatedSubExpr - Insert a computation of the PHI translated /// version of 'V' for the edge PredBB->CurBB into the end of the PredBB /// block. All newly created instructions are added to the NewInsts list. /// This returns null on failure. /// Value *InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB, BasicBlock *PredBB, const DominatorTree &DT, SmallVectorImpl &NewInsts); /// AddAsInput - If the specified value is an instruction, add it as an input. Value *AddAsInput(Value *V) { // If V is an instruction, it is now an input. if (Instruction *VI = dyn_cast(V)) InstInputs.push_back(VI); return V; } }; } // end namespace llvm #endif #ifdef __GNUC__ #pragma GCC diagnostic pop #endif