X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FBasicBlock.h;h=4f4da1ca2fb65929ceb8f1054a49e9dd4dadbec1;hb=47128fe2969b90880c5ffdbeb8c699a06bbaa9f9;hp=7fcf8847bd52597c35a4861488d3096a94335ba4;hpb=bddcb9427cb36ac6609fef233eaac3c9b5e5a8f4;p=oota-llvm.git diff --git a/include/llvm/BasicBlock.h b/include/llvm/BasicBlock.h index 7fcf8847bd5..4f4da1ca2fb 100644 --- a/include/llvm/BasicBlock.h +++ b/include/llvm/BasicBlock.h @@ -2,13 +2,13 @@ // // 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 @@ -16,20 +16,38 @@ #include "llvm/Instruction.h" #include "llvm/SymbolTableListTraits.h" -#include "llvm/ADT/ilist" +#include "llvm/ADT/ilist.h" +#include "llvm/Support/DataTypes.h" namespace llvm { class TerminatorInst; -template class SuccIterator; // Successor Iterator -template class PredIterator; +class LLVMContext; 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_node Sentinel; }; /// This represents a single basic block in LLVM. A basic block is simply a @@ -46,52 +64,73 @@ template<> struct ilist_traits /// 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 { + 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 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); public: + /// getContext - Get the context in which this basic block lives, + /// or null if it is not currently attached to a function. + 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(const std::string &Name = "", Function *Parent = 0, + BasicBlock *InsertBefore = 0) { + return new BasicBlock(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; } + + /// use_back - Specialize the methods defined in Value, as we know that an + /// BasicBlock can only be used by Instructions (specifically PHI nodes and + /// terminators). + 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; + + /// 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(); + } + /// removeFromParent - This method unlinks 'this' from the containing /// function, but does not delete it. /// @@ -102,10 +141,14 @@ public: /// 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. @@ -114,6 +157,16 @@ 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 +188,18 @@ 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