X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FBasicBlock.h;h=ba8406e3974ce77865be800312a7e4c9e3100fb7;hb=cd7ee1ced017d7a957113df9d6cf855ecbc3797e;hp=7fcf8847bd52597c35a4861488d3096a94335ba4;hpb=bddcb9427cb36ac6609fef233eaac3c9b5e5a8f4;p=oota-llvm.git diff --git a/include/llvm/BasicBlock.h b/include/llvm/BasicBlock.h index 7fcf8847bd5..ba8406e3974 100644 --- a/include/llvm/BasicBlock.h +++ b/include/llvm/BasicBlock.h @@ -2,34 +2,55 @@ // // The LLVM Compiler Infrastructure // -// This file was developed by the LLVM research group and is distributed under -// the University of Illinois Open Source License. See LICENSE.TXT for details. +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // -// // This file contains the declaration of the BasicBlock class. +// //===----------------------------------------------------------------------===// #ifndef LLVM_BASICBLOCK_H #define LLVM_BASICBLOCK_H +#include "llvm/ADT/Twine.h" +#include "llvm/ADT/ilist.h" #include "llvm/Instruction.h" +#include "llvm/Support/DataTypes.h" #include "llvm/SymbolTableListTraits.h" -#include "llvm/ADT/ilist" namespace llvm { +class LandingPadInst; class TerminatorInst; -template class SuccIterator; // Successor Iterator -template class PredIterator; +class LLVMContext; +class BlockAddress; template<> struct ilist_traits - : public SymbolTableListTraits { - // createSentinel is used to create a node that marks the end of the list... - static Instruction *createSentinel(); - static void destroySentinel(Instruction *I) { delete I; } - static iplist &getList(BasicBlock *BB); + : public SymbolTableListTraits { + // createSentinel is used to get hold of a node that marks the end of + // the list... + // The sentinel is relative to this instance, so we use a non-static + // method. + Instruction *createSentinel() const { + // since i(p)lists always publicly derive from the corresponding + // traits, placing a data member in this class will augment i(p)list. + // But since the NodeTy is expected to publicly derive from + // ilist_node, there is a legal viable downcast from it + // to NodeTy. We use this trick to superpose i(p)list with a "ghostly" + // NodeTy, which becomes the sentinel. Dereferencing the sentinel is + // forbidden (save the ilist_node) so no one will ever notice + // the superposition. + return static_cast(&Sentinel); + } + static void destroySentinel(Instruction*) {} + + Instruction *provideInitialHead() const { return createSentinel(); } + Instruction *ensureHead(Instruction*) const { return createSentinel(); } + static void noteHead(Instruction*, Instruction*) {} +private: + mutable ilist_half_node Sentinel; }; /// This represents a single basic block in LLVM. A basic block is simply a @@ -38,59 +59,93 @@ template<> struct ilist_traits /// tables. The type of a BasicBlock is "Type::LabelTy" because the basic block /// represents a label to which a branch can jump. /// -/// A well formed basic block is formed of a list of non-terminating -/// instructions followed by a single TerminatorInst instruction. -/// TerminatorInst's may not occur in the middle of basic blocks, and must +/// A well formed basic block is formed of a list of non-terminating +/// instructions followed by a single TerminatorInst instruction. +/// TerminatorInst's may not occur in the middle of basic blocks, and must /// terminate the blocks. The BasicBlock class allows malformed basic blocks to /// occur because it may be useful in the intermediate stage of constructing or /// modifying a program. However, the verifier will ensure that basic blocks /// are "well formed". /// @brief LLVM Basic Block Representation -class BasicBlock : public Value { // Basic blocks are data objects also +class BasicBlock : public Value, // Basic blocks are data objects also + public ilist_node { + friend class BlockAddress; public: typedef iplist InstListType; -private : +private: InstListType InstList; - BasicBlock *Prev, *Next; // Next and Prev links for our intrusive linked list + Function *Parent; void setParent(Function *parent); - void setNext(BasicBlock *N) { Next = N; } - void setPrev(BasicBlock *N) { Prev = N; } - friend class SymbolTableListTraits; + friend class SymbolTableListTraits; - BasicBlock(const BasicBlock &); // Do not implement - void operator=(const BasicBlock &); // Do not implement + BasicBlock(const BasicBlock &) LLVM_DELETED_FUNCTION; + void operator=(const BasicBlock &) LLVM_DELETED_FUNCTION; + /// BasicBlock ctor - If the function parameter is specified, the basic block + /// is automatically inserted at either the end of the function (if + /// InsertBefore is null), or before the specified basic block. + /// + explicit BasicBlock(LLVMContext &C, const Twine &Name = "", + Function *Parent = 0, BasicBlock *InsertBefore = 0); public: + /// getContext - Get the context in which this basic block lives. + LLVMContext &getContext() const; + /// Instruction iterators... typedef InstListType::iterator iterator; typedef InstListType::const_iterator const_iterator; - /// BasicBlock ctor - If the function parameter is specified, the basic block - /// is automatically inserted at either the end of the function (if - /// InsertBefore is null), or before the specified basic block. - /// - BasicBlock(const std::string &Name = "", Function *Parent = 0, - BasicBlock *InsertBefore = 0); + /// Create - Creates a new BasicBlock. If the Parent parameter is specified, + /// the basic block is automatically inserted at either the end of the + /// function (if InsertBefore is 0), or before the specified basic block. + static BasicBlock *Create(LLVMContext &Context, const Twine &Name = "", + Function *Parent = 0,BasicBlock *InsertBefore = 0) { + return new BasicBlock(Context, Name, Parent, InsertBefore); + } ~BasicBlock(); /// getParent - Return the enclosing method, or null if none /// - const Function *getParent() const { return InstList.getParent(); } - Function *getParent() { return InstList.getParent(); } - - // getNext/Prev - Return the next or previous basic block in the list. - BasicBlock *getNext() { return Next; } - const BasicBlock *getNext() const { return Next; } - BasicBlock *getPrev() { return Prev; } - const BasicBlock *getPrev() const { return Prev; } + const Function *getParent() const { return Parent; } + Function *getParent() { return Parent; } /// getTerminator() - If this is a well formed basic block, then this returns /// a pointer to the terminator instruction. If it is not, then you get a /// null pointer back. /// TerminatorInst *getTerminator(); - const TerminatorInst *const getTerminator() const; + const TerminatorInst *getTerminator() const; + + /// Returns a pointer to the first instructon in this block that is not a + /// PHINode instruction. When adding instruction to the beginning of the + /// basic block, they should be added before the returned value, not before + /// the first instruction, which might be PHI. + /// Returns 0 is there's no non-PHI instruction. + Instruction* getFirstNonPHI(); + const Instruction* getFirstNonPHI() const { + return const_cast(this)->getFirstNonPHI(); + } + + // Same as above, but also skip debug intrinsics. + Instruction* getFirstNonPHIOrDbg(); + const Instruction* getFirstNonPHIOrDbg() const { + return const_cast(this)->getFirstNonPHIOrDbg(); + } + + // Same as above, but also skip lifetime intrinsics. + Instruction* getFirstNonPHIOrDbgOrLifetime(); + const Instruction* getFirstNonPHIOrDbgOrLifetime() const { + return const_cast(this)->getFirstNonPHIOrDbgOrLifetime(); + } + + /// getFirstInsertionPt - Returns an iterator to the first instruction in this + /// block that is suitable for inserting a non-PHI instruction. In particular, + /// it skips all PHIs and LandingPad instructions. + iterator getFirstInsertionPt(); + const_iterator getFirstInsertionPt() const { + return const_cast(this)->getFirstInsertionPt(); + } /// removeFromParent - This method unlinks 'this' from the containing /// function, but does not delete it. @@ -101,12 +156,16 @@ public: /// and deletes it. /// void eraseFromParent(); - - /// moveBefore - Unlink this instruction from its current function and - /// insert it into the function that MovePos lives in, right before - /// MovePos. + + /// moveBefore - Unlink this basic block from its current function and + /// insert it into the function that MovePos lives in, right before MovePos. void moveBefore(BasicBlock *MovePos); + /// moveAfter - Unlink this basic block from its current function and + /// insert it into the function that MovePos lives in, right after MovePos. + void moveAfter(BasicBlock *MovePos); + + /// getSinglePredecessor - If this basic block has a single predecessor block, /// return the block, otherwise return a null pointer. BasicBlock *getSinglePredecessor(); @@ -114,6 +173,16 @@ public: return const_cast(this)->getSinglePredecessor(); } + /// getUniquePredecessor - If this basic block has a unique predecessor block, + /// return the block, otherwise return a null pointer. + /// Note that unique predecessor doesn't mean single edge, there can be + /// multiple edges from the unique predecessor to this block (for example + /// a switch statement with multiple cases having the same destination). + BasicBlock *getUniquePredecessor(); + const BasicBlock *getUniquePredecessor() const { + return const_cast(this)->getUniquePredecessor(); + } + //===--------------------------------------------------------------------===// /// Instruction iterator methods /// @@ -135,13 +204,17 @@ public: const InstListType &getInstList() const { return InstList; } InstListType &getInstList() { return InstList; } - virtual void print(std::ostream &OS) const { print(OS, 0); } - void print(std::ostream &OS, AssemblyAnnotationWriter *AAW) const; + /// getSublistAccess() - returns pointer to member of instruction list + static iplist BasicBlock::*getSublistAccess(Instruction*) { + return &BasicBlock::InstList; + } + + /// getValueSymbolTable() - returns pointer to symbol table (if any) + ValueSymbolTable *getValueSymbolTable(); /// Methods for support type inquiry through isa, cast, and dyn_cast: - static inline bool classof(const BasicBlock *) { return true; } static inline bool classof(const Value *V) { - return V->getValueType() == Value::BasicBlockVal; + return V->getValueID() == Value::BasicBlockVal; } /// dropAllReferences() - This function causes all the subinstructions to "let @@ -174,7 +247,42 @@ public: /// cause a degenerate basic block to be formed, having a terminator inside of /// the basic block). /// - BasicBlock *splitBasicBlock(iterator I, const std::string &BBName = ""); + /// Also note that this doesn't preserve any passes. To split blocks while + /// keeping loop information consistent, use the SplitBlock utility function. + /// + BasicBlock *splitBasicBlock(iterator I, const Twine &BBName = ""); + + /// hasAddressTaken - returns true if there are any uses of this basic block + /// other than direct branches, switches, etc. to it. + bool hasAddressTaken() const { return getSubclassDataFromValue() != 0; } + + /// replaceSuccessorsPhiUsesWith - Update all phi nodes in all our successors + /// to refer to basic block New instead of to us. + void replaceSuccessorsPhiUsesWith(BasicBlock *New); + + /// isLandingPad - Return true if this basic block is a landing pad. I.e., + /// it's the destination of the 'unwind' edge of an invoke instruction. + bool isLandingPad() const; + + /// getLandingPadInst() - Return the landingpad instruction associated with + /// the landing pad. + LandingPadInst *getLandingPadInst(); + const LandingPadInst *getLandingPadInst() const; + +private: + /// AdjustBlockAddressRefCount - BasicBlock stores the number of BlockAddress + /// objects using it. This is almost always 0, sometimes one, possibly but + /// almost never 2, and inconceivably 3 or more. + void AdjustBlockAddressRefCount(int Amt) { + setValueSubclassData(getSubclassDataFromValue()+Amt); + assert((int)(signed char)getSubclassDataFromValue() >= 0 && + "Refcount wrap-around"); + } + // Shadow Value::setValueSubclassData with a private forwarding method so that + // any future subclasses cannot accidentally use it. + void setValueSubclassData(unsigned short D) { + Value::setValueSubclassData(D); + } }; } // End llvm namespace