X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FBasicBlock.h;h=5a1c5a45b2b57df82fe33a8788cc569a042bf928;hb=fc82fabe00b0b820e3c0d7fc9e289bace0295f11;hp=fc41a1215631973107ecf1ff062ad8761cbd704d;hpb=2cb0722c00707c04be1bee9f9f6094bdf1069cbf;p=oota-llvm.git diff --git a/include/llvm/BasicBlock.h b/include/llvm/BasicBlock.h index fc41a121563..5a1c5a45b2b 100644 --- a/include/llvm/BasicBlock.h +++ b/include/llvm/BasicBlock.h @@ -1,143 +1,228 @@ -//===-- llvm/BasicBlock.h - Represent a basic block in the VM ----*- C++ -*--=// +//===-- llvm/BasicBlock.h - Represent a basic block in the VM ---*- C++ -*-===// // -// This file contains the declaration of the BasicBlock class, which represents -// a single basic block in the VM. +// The LLVM Compiler Infrastructure // -// Note that basic blocks themselves are Def's, because they are referenced -// by instructions like branches and can go in switch tables and stuff... -// -// This may see wierd at first, but it's really pretty cool. :) +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // -// Note that well formed basic blocks are formed of a list of instructions -// followed by a single TerminatorInst instruction. TerminatorInst's may not -// occur in the middle of basic blocks, and must terminate the blocks. -// -// This code allows malformed basic blocks to occur, because it may be useful -// in the intermediate stage of analysis or modification of a program. // +// This file contains the declaration of the BasicBlock class. //===----------------------------------------------------------------------===// #ifndef LLVM_BASICBLOCK_H #define LLVM_BASICBLOCK_H -#include "llvm/Value.h" // Get the definition of Value -#include "llvm/ValueHolder.h" -#include "llvm/CFGdecls.h" +#include "llvm/Instruction.h" +#include "llvm/SymbolTableListTraits.h" +#include "llvm/ADT/ilist" +#include "llvm/Support/DataTypes.h" + +namespace llvm { -class Instruction; -class Method; class TerminatorInst; -class MachineCodeForBasicBlock; +template class SuccIterator; // Successor Iterator +template class PredIterator; + +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); + static ValueSymbolTable *getSymTab(BasicBlock *ItemParent); + static int getListOffset(); +}; -class BasicBlock : public Value { // Basic blocks are data objects also +/// This represents a single basic block in LLVM. A basic block is simply a +/// container of instructions that execute sequentially. Basic blocks are Values +/// because they are referenced by instructions such as branches and switch +/// 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 +/// 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 User { // Basic blocks are data objects also public: - typedef ValueHolder InstListType; + typedef iplist InstListType; private : InstListType InstList; - MachineCodeForBasicBlock* machineInstrVec; + BasicBlock *Prev, *Next; // Next and Prev links for our intrusive linked list + Function *Parent; + Use unwindDest; - friend class ValueHolder; - void setParent(Method *parent); + void setParent(Function *parent); + void setNext(BasicBlock *N) { Next = N; } + void setPrev(BasicBlock *N) { Prev = N; } + friend class SymbolTableListTraits; + + BasicBlock(const BasicBlock &); // Do not implement + void operator=(const BasicBlock &); // Do not implement public: - // Instruction iterators... - typedef InstListType::iterator iterator; - typedef InstListType::const_iterator const_iterator; - typedef reverse_iterator const_reverse_iterator; - typedef reverse_iterator reverse_iterator; - - typedef cfg::succ_iterator succ_iterator; // Include CFG.h to use these - typedef cfg::pred_iterator pred_iterator; - typedef cfg::succ_const_iterator succ_const_iterator; - typedef cfg::pred_const_iterator pred_const_iterator; - - BasicBlock(const string &Name = "", Method *Parent = 0); + /// 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. + /// + explicit BasicBlock(const std::string &Name = "", Function *Parent = 0, + BasicBlock *InsertBefore = 0, BasicBlock *unwindDest = 0); ~BasicBlock(); - // Specialize setName to take care of symbol table majik - virtual void setName(const string &name, SymbolTable *ST = 0); - - const Method *getParent() const { return InstList.getParent(); } - Method *getParent() { return InstList.getParent(); } - - // 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. - // + /// getUnwindDest - Returns the BasicBlock that flow will enter if an unwind + /// instruction occurs in this block. May be null, in which case unwinding + /// is undefined in this block. + const BasicBlock *getUnwindDest() const; + BasicBlock *getUnwindDest(); + + /// setUnwindDest - Set which BasicBlock flow will enter if an unwind is + /// executed within this block. It may be set to null if unwinding is not + /// permitted in this block. + void setUnwindDest(BasicBlock *unwindDest); + + /// getParent - Return the enclosing method, or null if none + /// + const Function *getParent() const { return Parent; } + Function *getParent() { return Parent; } + + /// use_back - Specialize the methods defined in Value, as we know that an + /// BasicBlock can only be used by Instructions (specifically PHI and terms). + Instruction *use_back() { return cast(*use_begin());} + const Instruction *use_back() const { return cast(*use_begin());} + + /// 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; - // Machine code accessor... - inline MachineCodeForBasicBlock& getMachineInstrVec() const { - return *machineInstrVec; - } + /// 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(); + + /// removeFromParent - This method unlinks 'this' from the containing + /// function, but does not delete it. + /// + void removeFromParent(); + + /// eraseFromParent - This method unlinks 'this' from the containing function + /// and deletes it. + /// + void eraseFromParent(); + + /// 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(); + const BasicBlock *getSinglePredecessor() const { + return const_cast(this)->getSinglePredecessor(); + } + //===--------------------------------------------------------------------===// - // Instruction iterator methods + /// Instruction iterator methods + /// inline iterator begin() { return InstList.begin(); } inline const_iterator begin() const { return InstList.begin(); } inline iterator end () { return InstList.end(); } inline const_iterator end () const { return InstList.end(); } - inline reverse_iterator rbegin() { return InstList.rbegin(); } - inline const_reverse_iterator rbegin() const { return InstList.rbegin(); } - inline reverse_iterator rend () { return InstList.rend(); } - inline const_reverse_iterator rend () const { return InstList.rend(); } - - inline unsigned size() const { return InstList.size(); } + inline size_t size() const { return InstList.size(); } inline bool empty() const { return InstList.empty(); } - inline const Instruction *front() const { return InstList.front(); } - inline Instruction *front() { return InstList.front(); } - inline const Instruction *back() const { return InstList.back(); } - inline Instruction *back() { return InstList.back(); } - - // getInstList() - Return the underlying instruction list container. You need - // to access it directly if you want to modify it currently. - // + inline const Instruction &front() const { return InstList.front(); } + inline Instruction &front() { return InstList.front(); } + inline const Instruction &back() const { return InstList.back(); } + inline Instruction &back() { return InstList.back(); } + + /// getInstList() - Return the underlying instruction list container. You + /// need to access it directly if you want to modify it currently. + /// const InstListType &getInstList() const { return InstList; } InstListType &getInstList() { return InstList; } - // hasConstantPoolReferences() - This predicate is true if there is a - // reference to this basic block in the constant pool for this method. For - // example, if a block is reached through a switch table, that table resides - // in the constant pool, and the basic block is reference from it. - // - bool hasConstantPoolReferences() const; - - // dropAllReferences() - This function causes all the subinstructions to "let - // go" of all references that they are maintaining. This allows one to - // 'delete' a whole class at a time, even though there may be circular - // references... first all references are dropped, and all use counts go to - // zero. Then everything is delete'd for real. Note that no operations are - // valid on an object that has "dropped all references", except operator - // delete. - // + virtual void print(std::ostream &OS) const { print(OS, 0); } + void print(std::ostream *OS) const { if (OS) print(*OS); } + void print(std::ostream &OS, AssemblyAnnotationWriter *AAW) const; + + /// 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->getValueID() == Value::BasicBlockVal; + } + + /// dropAllReferences() - This function causes all the subinstructions to "let + /// go" of all references that they are maintaining. This allows one to + /// 'delete' a whole class at a time, even though there may be circular + /// references... first all references are dropped, and all use counts go to + /// zero. Then everything is delete'd for real. Note that no operations are + /// valid on an object that has "dropped all references", except operator + /// delete. + /// void dropAllReferences(); - // removePredecessor - This method is used to notify a BasicBlock that the - // specified Predecessor of the block is no longer able to reach it. This is - // actually not used to update the Predecessor list, but is actually used to - // update the PHI nodes that reside in the block. Note that this should be - // called while the predecessor still refers to this block. - // - void removePredecessor(BasicBlock *Pred); - - // splitBasicBlock - This splits a basic block into two at the specified - // instruction. Note that all instructions BEFORE the specified iterator stay - // as part of the original basic block, an unconditional branch is added to - // the new BB, and the rest of the instructions in the BB are moved to the new - // BB, including the old terminator. The newly formed BasicBlock is returned. - // This function invalidates the specified iterator. - // - // Note that this only works on well formed basic blocks (must have a - // terminator), and 'I' must not be the end of instruction list (which would - // cause a degenerate basic block to be formed, having a terminator inside of - // the basic block). - // - BasicBlock *splitBasicBlock(iterator I); + /// removePredecessor - This method is used to notify a BasicBlock that the + /// specified Predecessor of the block is no longer able to reach it. This is + /// actually not used to update the Predecessor list, but is actually used to + /// update the PHI nodes that reside in the block. Note that this should be + /// called while the predecessor still refers to this block. + /// + void removePredecessor(BasicBlock *Pred, bool DontDeleteUselessPHIs = false); + + /// splitBasicBlock - This splits a basic block into two at the specified + /// instruction. Note that all instructions BEFORE the specified iterator + /// stay as part of the original basic block, an unconditional branch is added + /// to the original BB, and the rest of the instructions in the BB are moved + /// to the new BB, including the old terminator. The newly formed BasicBlock + /// is returned. This function invalidates the specified iterator. + /// + /// Note that this only works on well formed basic blocks (must have a + /// terminator), and 'I' must not be the end of instruction list (which would + /// cause a degenerate basic block to be formed, having a terminator inside of + /// the basic block). + /// + BasicBlock *splitBasicBlock(iterator I, const std::string &BBName = ""); + + + static unsigned getInstListOffset() { + BasicBlock *Obj = 0; + return unsigned(reinterpret_cast(&Obj->InstList)); + } + +private: + // getNext/Prev - Return the next or previous basic block in the list. Access + // these with Function::iterator. + BasicBlock *getNext() { return Next; } + const BasicBlock *getNext() const { return Next; } + BasicBlock *getPrev() { return Prev; } + const BasicBlock *getPrev() const { return Prev; } }; +inline int +ilist_traits::getListOffset() { + return BasicBlock::getInstListOffset(); +} + +} // End llvm namespace + #endif