X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FBasicBlock.h;h=bf5874f6824a1bb725b6eeb117be2abaf6d0c90a;hb=cdfad36b401be6fc709ea4051f9de58e1a30bcc9;hp=ee5ceb3683a9b2d16852835aaba31e4a0da39d85;hpb=87f1e7796d02ea991bdbf084f312879988732a26;p=oota-llvm.git diff --git a/include/llvm/BasicBlock.h b/include/llvm/BasicBlock.h index ee5ceb3683a..bf5874f6824 100644 --- a/include/llvm/BasicBlock.h +++ b/include/llvm/BasicBlock.h @@ -17,20 +17,39 @@ #include "llvm/Instruction.h" #include "llvm/SymbolTableListTraits.h" #include "llvm/ADT/ilist.h" -#include "llvm/Support/DataTypes.h" +#include "llvm/ADT/Twine.h" +#include "llvm/System/DataTypes.h" namespace llvm { class TerminatorInst; +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); - static ValueSymbolTable *getSymTab(BasicBlock *ItemParent); - static int getListOffset(); + // 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 @@ -49,9 +68,10 @@ template<> struct ilist_traits /// @brief LLVM Basic Block Representation class BasicBlock : public Value, // Basic blocks are data objects also public ilist_node { + friend class BlockAddress; public: typedef iplist InstListType; -private : +private: InstListType InstList; Function *Parent; @@ -65,9 +85,12 @@ private : /// 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); + 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; @@ -75,9 +98,9 @@ public: /// 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); + static BasicBlock *Create(LLVMContext &Context, const Twine &Name = "", + Function *Parent = 0,BasicBlock *InsertBefore = 0) { + return new BasicBlock(Context, Name, Parent, InsertBefore); } ~BasicBlock(); @@ -87,9 +110,10 @@ public: 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());} + /// BasicBlock can only be used by Users (specifically PHI nodes, terminators, + /// and BlockAddress's). + User *use_back() { return cast(*use_begin());} + const User *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 @@ -107,6 +131,12 @@ public: 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(); + } /// removeFromParent - This method unlinks 'this' from the containing /// function, but does not delete it. @@ -137,8 +167,8 @@ public: /// 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 in - /// case of a switch statement with multiple cases having same destination). + /// 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(); @@ -165,6 +195,14 @@ public: const InstListType &getInstList() const { return InstList; } InstListType &getInstList() { return InstList; } + /// 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) { @@ -201,20 +239,31 @@ 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 = ""); - - - static unsigned getInstListOffset() { - BasicBlock *Obj = 0; - return unsigned(reinterpret_cast(&Obj->InstList)); + /// 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; } + +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); } }; -inline int -ilist_traits::getListOffset() { - return BasicBlock::getInstListOffset(); -} - } // End llvm namespace #endif