diff options
Diffstat (limited to 'include/llvm/CodeGen/MachineBasicBlock.h')
| -rw-r--r-- | include/llvm/CodeGen/MachineBasicBlock.h | 468 |
1 files changed, 266 insertions, 202 deletions
diff --git a/include/llvm/CodeGen/MachineBasicBlock.h b/include/llvm/CodeGen/MachineBasicBlock.h index 5e5f45cae8fb..3d58c499823e 100644 --- a/include/llvm/CodeGen/MachineBasicBlock.h +++ b/include/llvm/CodeGen/MachineBasicBlock.h @@ -16,6 +16,8 @@ #include "llvm/ADT/GraphTraits.h" #include "llvm/CodeGen/MachineInstr.h" +#include "llvm/Support/BranchProbability.h" +#include "llvm/MC/MCRegisterInfo.h" #include "llvm/Support/DataTypes.h" #include <functional> @@ -25,11 +27,15 @@ class Pass; class BasicBlock; class MachineFunction; class MCSymbol; +class MIPrinter; class SlotIndexes; class StringRef; class raw_ostream; class MachineBranchProbabilityInfo; +// Forward declaration to avoid circular include problem with TargetRegisterInfo +typedef unsigned LaneBitmask; + template <> struct ilist_traits<MachineInstr> : public ilist_default_traits<MachineInstr> { private: @@ -52,57 +58,76 @@ public: void addNodeToList(MachineInstr* N); void removeNodeFromList(MachineInstr* N); void transferNodesFromList(ilist_traits &SrcTraits, - ilist_iterator<MachineInstr> first, - ilist_iterator<MachineInstr> last); + ilist_iterator<MachineInstr> First, + ilist_iterator<MachineInstr> Last); void deleteNode(MachineInstr *N); private: void createNode(const MachineInstr &); }; -class MachineBasicBlock : public ilist_node<MachineBasicBlock> { +class MachineBasicBlock + : public ilist_node_with_parent<MachineBasicBlock, MachineFunction> { +public: + /// Pair of physical register and lane mask. + /// This is not simply a std::pair typedef because the members should be named + /// clearly as they both have an integer type. + struct RegisterMaskPair { + public: + MCPhysReg PhysReg; + LaneBitmask LaneMask; + + RegisterMaskPair(MCPhysReg PhysReg, LaneBitmask LaneMask) + : PhysReg(PhysReg), LaneMask(LaneMask) {} + }; + +private: typedef ilist<MachineInstr> Instructions; Instructions Insts; const BasicBlock *BB; int Number; MachineFunction *xParent; - /// Predecessors/Successors - Keep track of the predecessor / successor - /// basicblocks. + /// Keep track of the predecessor / successor basic blocks. std::vector<MachineBasicBlock *> Predecessors; std::vector<MachineBasicBlock *> Successors; - /// Weights - Keep track of the weights to the successors. This vector - /// has the same order as Successors, or it is empty if we don't use it - /// (disable optimization). - std::vector<uint32_t> Weights; - typedef std::vector<uint32_t>::iterator weight_iterator; - typedef std::vector<uint32_t>::const_iterator const_weight_iterator; + /// Keep track of the probabilities to the successors. This vector has the + /// same order as Successors, or it is empty if we don't use it (disable + /// optimization). + std::vector<BranchProbability> Probs; + typedef std::vector<BranchProbability>::iterator probability_iterator; + typedef std::vector<BranchProbability>::const_iterator + const_probability_iterator; + + /// Keep track of the physical registers that are livein of the basicblock. + typedef std::vector<RegisterMaskPair> LiveInVector; + LiveInVector LiveIns; + + /// Alignment of the basic block. Zero if the basic block does not need to be + /// aligned. The alignment is specified as log2(bytes). + unsigned Alignment = 0; - /// LiveIns - Keep track of the physical registers that are livein of - /// the basicblock. - std::vector<unsigned> LiveIns; + /// Indicate that this basic block is entered via an exception handler. + bool IsEHPad = false; - /// Alignment - Alignment of the basic block. Zero if the basic block does - /// not need to be aligned. - /// The alignment is specified as log2(bytes). - unsigned Alignment; + /// Indicate that this basic block is potentially the target of an indirect + /// branch. + bool AddressTaken = false; - /// IsLandingPad - Indicate that this basic block is entered via an - /// exception handler. - bool IsLandingPad; + /// Indicate that this basic block is the entry block of an EH funclet. + bool IsEHFuncletEntry = false; - /// AddressTaken - Indicate that this basic block is potentially the - /// target of an indirect branch. - bool AddressTaken; + /// Indicate that this basic block is the entry block of a cleanup funclet. + bool IsCleanupFuncletEntry = false; /// \brief since getSymbol is a relatively heavy-weight operation, the symbol /// is only computed once and is cached. - mutable MCSymbol *CachedMCSymbol; + mutable MCSymbol *CachedMCSymbol = nullptr; // Intrusive list support MachineBasicBlock() {} - explicit MachineBasicBlock(MachineFunction &mf, const BasicBlock *bb); + explicit MachineBasicBlock(MachineFunction &MF, const BasicBlock *BB); ~MachineBasicBlock(); @@ -110,50 +135,44 @@ class MachineBasicBlock : public ilist_node<MachineBasicBlock> { friend class MachineFunction; public: - /// getBasicBlock - Return the LLVM basic block that this instance - /// corresponded to originally. Note that this may be NULL if this instance - /// does not correspond directly to an LLVM basic block. - /// + /// Return the LLVM basic block that this instance corresponded to originally. + /// Note that this may be NULL if this instance does not correspond directly + /// to an LLVM basic block. const BasicBlock *getBasicBlock() const { return BB; } - /// getName - Return the name of the corresponding LLVM basic block, or - /// "(null)". + /// Return the name of the corresponding LLVM basic block, or "(null)". StringRef getName() const; - /// getFullName - Return a formatted string to identify this block and its - /// parent function. + /// Return a formatted string to identify this block and its parent function. std::string getFullName() const; - /// hasAddressTaken - Test whether this block is potentially the target - /// of an indirect branch. + /// Test whether this block is potentially the target of an indirect branch. bool hasAddressTaken() const { return AddressTaken; } - /// setHasAddressTaken - Set this block to reflect that it potentially - /// is the target of an indirect branch. + /// Set this block to reflect that it potentially is the target of an indirect + /// branch. void setHasAddressTaken() { AddressTaken = true; } - /// getParent - Return the MachineFunction containing this basic block. - /// + /// Return the MachineFunction containing this basic block. const MachineFunction *getParent() const { return xParent; } MachineFunction *getParent() { return xParent; } - - /// bundle_iterator - MachineBasicBlock iterator that automatically skips over - /// MIs that are inside bundles (i.e. walk top level MIs only). + /// MachineBasicBlock iterator that automatically skips over MIs that are + /// inside bundles (i.e. walk top level MIs only). template<typename Ty, typename IterTy> class bundle_iterator : public std::iterator<std::bidirectional_iterator_tag, Ty, ptrdiff_t> { IterTy MII; public: - bundle_iterator(IterTy mii) : MII(mii) {} + bundle_iterator(IterTy MI) : MII(MI) {} - bundle_iterator(Ty &mi) : MII(mi) { - assert(!mi.isBundledWithPred() && + bundle_iterator(Ty &MI) : MII(MI) { + assert(!MI.isBundledWithPred() && "It's not legal to initialize bundle_iterator with a bundled MI"); } - bundle_iterator(Ty *mi) : MII(mi) { - assert((!mi || !mi->isBundledWithPred()) && + bundle_iterator(Ty *MI) : MII(MI) { + assert((!MI || !MI->isBundledWithPred()) && "It's not legal to initialize bundle_iterator with a bundled MI"); } // Template allows conversion from const to nonconst. @@ -165,13 +184,13 @@ public: Ty &operator*() const { return *MII; } Ty *operator->() const { return &operator*(); } - operator Ty*() const { return MII; } + operator Ty *() const { return MII.getNodePtrUnchecked(); } - bool operator==(const bundle_iterator &x) const { - return MII == x.MII; + bool operator==(const bundle_iterator &X) const { + return MII == X.MII; } - bool operator!=(const bundle_iterator &x) const { - return !operator==(x); + bool operator!=(const bundle_iterator &X) const { + return !operator==(X); } // Increment and decrement operators... @@ -247,11 +266,16 @@ public: reverse_iterator rend () { return instr_rend(); } const_reverse_iterator rend () const { return instr_rend(); } + /// Support for MachineInstr::getNextNode(). + static Instructions MachineBasicBlock::*getSublistAccess(MachineInstr *) { + return &MachineBasicBlock::Insts; + } + inline iterator_range<iterator> terminators() { - return iterator_range<iterator>(getFirstTerminator(), end()); + return make_range(getFirstTerminator(), end()); } inline iterator_range<const_iterator> terminators() const { - return iterator_range<const_iterator>(getFirstTerminator(), end()); + return make_range(getFirstTerminator(), end()); } // Machine-CFG iterators @@ -301,16 +325,16 @@ public: bool succ_empty() const { return Successors.empty(); } inline iterator_range<pred_iterator> predecessors() { - return iterator_range<pred_iterator>(pred_begin(), pred_end()); + return make_range(pred_begin(), pred_end()); } inline iterator_range<const_pred_iterator> predecessors() const { - return iterator_range<const_pred_iterator>(pred_begin(), pred_end()); + return make_range(pred_begin(), pred_end()); } inline iterator_range<succ_iterator> successors() { - return iterator_range<succ_iterator>(succ_begin(), succ_end()); + return make_range(succ_begin(), succ_end()); } inline iterator_range<const_succ_iterator> successors() const { - return iterator_range<const_succ_iterator>(succ_begin(), succ_end()); + return make_range(succ_begin(), succ_end()); } // LiveIn management methods. @@ -318,131 +342,177 @@ public: /// Adds the specified register as a live in. Note that it is an error to add /// the same register to the same set more than once unless the intention is /// to call sortUniqueLiveIns after all registers are added. - void addLiveIn(unsigned Reg) { LiveIns.push_back(Reg); } + void addLiveIn(MCPhysReg PhysReg, LaneBitmask LaneMask = ~0u) { + LiveIns.push_back(RegisterMaskPair(PhysReg, LaneMask)); + } + void addLiveIn(const RegisterMaskPair &RegMaskPair) { + LiveIns.push_back(RegMaskPair); + } /// Sorts and uniques the LiveIns vector. It can be significantly faster to do /// this than repeatedly calling isLiveIn before calling addLiveIn for every /// LiveIn insertion. - void sortUniqueLiveIns() { - std::sort(LiveIns.begin(), LiveIns.end()); - LiveIns.erase(std::unique(LiveIns.begin(), LiveIns.end()), LiveIns.end()); - } + void sortUniqueLiveIns(); /// Add PhysReg as live in to this block, and ensure that there is a copy of /// PhysReg to a virtual register of class RC. Return the virtual register /// that is a copy of the live in PhysReg. - unsigned addLiveIn(unsigned PhysReg, const TargetRegisterClass *RC); + unsigned addLiveIn(MCPhysReg PhysReg, const TargetRegisterClass *RC); - /// removeLiveIn - Remove the specified register from the live in set. - /// - void removeLiveIn(unsigned Reg); + /// Remove the specified register from the live in set. + void removeLiveIn(MCPhysReg Reg, LaneBitmask LaneMask = ~0u); - /// isLiveIn - Return true if the specified register is in the live in set. - /// - bool isLiveIn(unsigned Reg) const; + /// Return true if the specified register is in the live in set. + bool isLiveIn(MCPhysReg Reg, LaneBitmask LaneMask = ~0u) const; // Iteration support for live in sets. These sets are kept in sorted // order by their register number. - typedef std::vector<unsigned>::const_iterator livein_iterator; + typedef LiveInVector::const_iterator livein_iterator; livein_iterator livein_begin() const { return LiveIns.begin(); } livein_iterator livein_end() const { return LiveIns.end(); } bool livein_empty() const { return LiveIns.empty(); } + iterator_range<livein_iterator> liveins() const { + return make_range(livein_begin(), livein_end()); + } - /// getAlignment - Return alignment of the basic block. - /// The alignment is specified as log2(bytes). - /// + /// Get the clobber mask for the start of this basic block. Funclets use this + /// to prevent register allocation across funclet transitions. + const uint32_t *getBeginClobberMask(const TargetRegisterInfo *TRI) const; + + /// Get the clobber mask for the end of the basic block. + /// \see getBeginClobberMask() + const uint32_t *getEndClobberMask(const TargetRegisterInfo *TRI) const; + + /// Return alignment of the basic block. The alignment is specified as + /// log2(bytes). unsigned getAlignment() const { return Alignment; } - /// setAlignment - Set alignment of the basic block. - /// The alignment is specified as log2(bytes). - /// + /// Set alignment of the basic block. The alignment is specified as + /// log2(bytes). void setAlignment(unsigned Align) { Alignment = Align; } - /// isLandingPad - Returns true if the block is a landing pad. That is - /// this basic block is entered via an exception handler. - bool isLandingPad() const { return IsLandingPad; } + /// Returns true if the block is a landing pad. That is this basic block is + /// entered via an exception handler. + bool isEHPad() const { return IsEHPad; } - /// setIsLandingPad - Indicates the block is a landing pad. That is - /// this basic block is entered via an exception handler. - void setIsLandingPad(bool V = true) { IsLandingPad = V; } + /// Indicates the block is a landing pad. That is this basic block is entered + /// via an exception handler. + void setIsEHPad(bool V = true) { IsEHPad = V; } - /// getLandingPadSuccessor - If this block has a successor that is a landing - /// pad, return it. Otherwise return NULL. + /// If this block has a successor that is a landing pad, return it. Otherwise + /// return NULL. const MachineBasicBlock *getLandingPadSuccessor() const; + bool hasEHPadSuccessor() const; + + /// Returns true if this is the entry block of an EH funclet. + bool isEHFuncletEntry() const { return IsEHFuncletEntry; } + + /// Indicates if this is the entry block of an EH funclet. + void setIsEHFuncletEntry(bool V = true) { IsEHFuncletEntry = V; } + + /// Returns true if this is the entry block of a cleanup funclet. + bool isCleanupFuncletEntry() const { return IsCleanupFuncletEntry; } + + /// Indicates if this is the entry block of a cleanup funclet. + void setIsCleanupFuncletEntry(bool V = true) { IsCleanupFuncletEntry = V; } + // Code Layout methods. - /// moveBefore/moveAfter - move 'this' block before or after the specified - /// block. This only moves the block, it does not modify the CFG or adjust - /// potential fall-throughs at the end of the block. + /// Move 'this' block before or after the specified block. This only moves + /// the block, it does not modify the CFG or adjust potential fall-throughs at + /// the end of the block. void moveBefore(MachineBasicBlock *NewAfter); void moveAfter(MachineBasicBlock *NewBefore); - /// updateTerminator - Update the terminator instructions in block to account - /// for changes to the layout. If the block previously used a fallthrough, - /// it may now need a branch, and if it previously used branching it may now - /// be able to use a fallthrough. + /// Update the terminator instructions in block to account for changes to the + /// layout. If the block previously used a fallthrough, it may now need a + /// branch, and if it previously used branching it may now be able to use a + /// fallthrough. void updateTerminator(); // Machine-CFG mutators - /// addSuccessor - Add succ as a successor of this MachineBasicBlock. - /// The Predecessors list of succ is automatically updated. WEIGHT - /// parameter is stored in Weights list and it may be used by - /// MachineBranchProbabilityInfo analysis to calculate branch probability. + /// Add Succ as a successor of this MachineBasicBlock. The Predecessors list + /// of Succ is automatically updated. PROB parameter is stored in + /// Probabilities list. The default probability is set as unknown. Mixing + /// known and unknown probabilities in successor list is not allowed. When all + /// successors have unknown probabilities, 1 / N is returned as the + /// probability for each successor, where N is the number of successors. /// /// Note that duplicate Machine CFG edges are not allowed. - /// - void addSuccessor(MachineBasicBlock *succ, uint32_t weight = 0); - - /// Set successor weight of a given iterator. - void setSuccWeight(succ_iterator I, uint32_t weight); - - /// removeSuccessor - Remove successor from the successors list of this - /// MachineBasicBlock. The Predecessors list of succ is automatically updated. - /// - void removeSuccessor(MachineBasicBlock *succ); - - /// removeSuccessor - Remove specified successor from the successors list of - /// this MachineBasicBlock. The Predecessors list of succ is automatically - /// updated. Return the iterator to the element after the one removed. - /// - succ_iterator removeSuccessor(succ_iterator I); - - /// replaceSuccessor - Replace successor OLD with NEW and update weight info. - /// + void addSuccessor(MachineBasicBlock *Succ, + BranchProbability Prob = BranchProbability::getUnknown()); + + /// Add Succ as a successor of this MachineBasicBlock. The Predecessors list + /// of Succ is automatically updated. The probability is not provided because + /// BPI is not available (e.g. -O0 is used), in which case edge probabilities + /// won't be used. Using this interface can save some space. + void addSuccessorWithoutProb(MachineBasicBlock *Succ); + + /// Set successor probability of a given iterator. + void setSuccProbability(succ_iterator I, BranchProbability Prob); + + /// Normalize probabilities of all successors so that the sum of them becomes + /// one. This is usually done when the current update on this MBB is done, and + /// the sum of its successors' probabilities is not guaranteed to be one. The + /// user is responsible for the correct use of this function. + /// MBB::removeSuccessor() has an option to do this automatically. + void normalizeSuccProbs() { + BranchProbability::normalizeProbabilities(Probs.begin(), Probs.end()); + } + + /// Validate successors' probabilities and check if the sum of them is + /// approximate one. This only works in DEBUG mode. + void validateSuccProbs() const; + + /// Remove successor from the successors list of this MachineBasicBlock. The + /// Predecessors list of Succ is automatically updated. + /// If NormalizeSuccProbs is true, then normalize successors' probabilities + /// after the successor is removed. + void removeSuccessor(MachineBasicBlock *Succ, + bool NormalizeSuccProbs = false); + + /// Remove specified successor from the successors list of this + /// MachineBasicBlock. The Predecessors list of Succ is automatically updated. + /// If NormalizeSuccProbs is true, then normalize successors' probabilities + /// after the successor is removed. + /// Return the iterator to the element after the one removed. + succ_iterator removeSuccessor(succ_iterator I, + bool NormalizeSuccProbs = false); + + /// Replace successor OLD with NEW and update probability info. void replaceSuccessor(MachineBasicBlock *Old, MachineBasicBlock *New); + /// Transfers all the successors from MBB to this machine basic block (i.e., + /// copies all the successors FromMBB and remove all the successors from + /// FromMBB). + void transferSuccessors(MachineBasicBlock *FromMBB); - /// transferSuccessors - Transfers all the successors from MBB to this - /// machine basic block (i.e., copies all the successors fromMBB and - /// remove all the successors from fromMBB). - void transferSuccessors(MachineBasicBlock *fromMBB); + /// Transfers all the successors, as in transferSuccessors, and update PHI + /// operands in the successor blocks which refer to FromMBB to refer to this. + void transferSuccessorsAndUpdatePHIs(MachineBasicBlock *FromMBB); - /// transferSuccessorsAndUpdatePHIs - Transfers all the successors, as - /// in transferSuccessors, and update PHI operands in the successor blocks - /// which refer to fromMBB to refer to this. - void transferSuccessorsAndUpdatePHIs(MachineBasicBlock *fromMBB); + /// Return true if any of the successors have probabilities attached to them. + bool hasSuccessorProbabilities() const { return !Probs.empty(); } - /// isPredecessor - Return true if the specified MBB is a predecessor of this - /// block. + /// Return true if the specified MBB is a predecessor of this block. bool isPredecessor(const MachineBasicBlock *MBB) const; - /// isSuccessor - Return true if the specified MBB is a successor of this - /// block. + /// Return true if the specified MBB is a successor of this block. bool isSuccessor(const MachineBasicBlock *MBB) const; - /// isLayoutSuccessor - Return true if the specified MBB will be emitted - /// immediately after this block, such that if this block exits by - /// falling through, control will transfer to the specified MBB. Note - /// that MBB need not be a successor at all, for example if this block - /// ends with an unconditional branch to some other block. + /// Return true if the specified MBB will be emitted immediately after this + /// block, such that if this block exits by falling through, control will + /// transfer to the specified MBB. Note that MBB need not be a successor at + /// all, for example if this block ends with an unconditional branch to some + /// other block. bool isLayoutSuccessor(const MachineBasicBlock *MBB) const; - /// canFallThrough - Return true if the block can implicitly transfer - /// control to the block after it by falling off the end of it. This should - /// return false if it can reach the block after it, but it uses an explicit - /// branch to do so (e.g., a table jump). True is a conservative answer. + /// Return true if the block can implicitly transfer control to the block + /// after it by falling off the end of it. This should return false if it can + /// reach the block after it, but it uses an explicit branch to do so (e.g., a + /// table jump). True is a conservative answer. bool canFallThrough(); /// Returns a pointer to the first instruction in this block that is not a @@ -452,40 +522,44 @@ public: /// Returns end() is there's no non-PHI instruction. iterator getFirstNonPHI(); - /// SkipPHIsAndLabels - Return the first instruction in MBB after I that is - /// not a PHI or a label. This is the correct point to insert copies at the - /// beginning of a basic block. + /// Return the first instruction in MBB after I that is not a PHI or a label. + /// This is the correct point to insert copies at the beginning of a basic + /// block. iterator SkipPHIsAndLabels(iterator I); - /// getFirstTerminator - returns an iterator to the first terminator - /// instruction of this basic block. If a terminator does not exist, - /// it returns end() + /// Returns an iterator to the first terminator instruction of this basic + /// block. If a terminator does not exist, it returns end(). iterator getFirstTerminator(); const_iterator getFirstTerminator() const { return const_cast<MachineBasicBlock *>(this)->getFirstTerminator(); } - /// getFirstInstrTerminator - Same getFirstTerminator but it ignores bundles - /// and return an instr_iterator instead. + /// Same getFirstTerminator but it ignores bundles and return an + /// instr_iterator instead. instr_iterator getFirstInstrTerminator(); - /// getFirstNonDebugInstr - returns an iterator to the first non-debug - /// instruction in the basic block, or end() + /// Returns an iterator to the first non-debug instruction in the basic block, + /// or end(). iterator getFirstNonDebugInstr(); const_iterator getFirstNonDebugInstr() const { return const_cast<MachineBasicBlock *>(this)->getFirstNonDebugInstr(); } - /// getLastNonDebugInstr - returns an iterator to the last non-debug - /// instruction in the basic block, or end() + /// Returns an iterator to the last non-debug instruction in the basic block, + /// or end(). iterator getLastNonDebugInstr(); const_iterator getLastNonDebugInstr() const { return const_cast<MachineBasicBlock *>(this)->getLastNonDebugInstr(); } - /// SplitCriticalEdge - Split the critical edge from this block to the - /// given successor block, and return the newly created block, or null - /// if splitting is not possible. + /// Convenience function that returns true if the block ends in a return + /// instruction. + bool isReturnBlock() const { + return !empty() && back().isReturn(); + } + + /// Split the critical edge from this block to the given successor block, and + /// return the newly created block, or null if splitting is not possible. /// /// This function updates LiveVariables, MachineDominatorTree, and /// MachineLoopInfo, as applicable. @@ -570,7 +644,7 @@ public: /// remove_instr to remove individual instructions from a bundle. MachineInstr *remove(MachineInstr *I) { assert(!I->isBundled() && "Cannot remove bundled instructions"); - return Insts.remove(I); + return Insts.remove(instr_iterator(I)); } /// Remove the possibly bundled instruction from the instruction list @@ -605,30 +679,29 @@ public: From.getInstrIterator(), To.getInstrIterator()); } - /// removeFromParent - This method unlinks 'this' from the containing - /// function, and returns it, but does not delete it. + /// This method unlinks 'this' from the containing function, and returns it, + /// but does not delete it. MachineBasicBlock *removeFromParent(); - /// eraseFromParent - This method unlinks 'this' from the containing - /// function and deletes it. + /// This method unlinks 'this' from the containing function and deletes it. void eraseFromParent(); - /// ReplaceUsesOfBlockWith - Given a machine basic block that branched to - /// 'Old', change the code and CFG so that it branches to 'New' instead. + /// Given a machine basic block that branched to 'Old', change the code and + /// CFG so that it branches to 'New' instead. void ReplaceUsesOfBlockWith(MachineBasicBlock *Old, MachineBasicBlock *New); - /// CorrectExtraCFGEdges - Various pieces of code can cause excess edges in - /// the CFG to be inserted. If we have proven that MBB can only branch to - /// DestA and DestB, remove any other MBB successors from the CFG. DestA and - /// DestB can be null. Besides DestA and DestB, retain other edges leading - /// to LandingPads (currently there can be only one; we don't check or require - /// that here). Note it is possible that DestA and/or DestB are LandingPads. + /// Various pieces of code can cause excess edges in the CFG to be inserted. + /// If we have proven that MBB can only branch to DestA and DestB, remove any + /// other MBB successors from the CFG. DestA and DestB can be null. Besides + /// DestA and DestB, retain other edges leading to LandingPads (currently + /// there can be only one; we don't check or require that here). Note it is + /// possible that DestA and/or DestB are LandingPads. bool CorrectExtraCFGEdges(MachineBasicBlock *DestA, MachineBasicBlock *DestB, - bool isCond); + bool IsCond); - /// findDebugLoc - find the next valid DebugLoc starting at MBBI, skipping - /// any DBG_VALUE instructions. Return UnknownLoc if there is none. + /// Find the next valid DebugLoc starting at MBBI, skipping any DBG_VALUE + /// instructions. Return UnknownLoc if there is none. DebugLoc findDebugLoc(instr_iterator MBBI); DebugLoc findDebugLoc(iterator MBBI) { return findDebugLoc(MBBI.getInstrIterator()); @@ -636,12 +709,9 @@ public: /// Possible outcome of a register liveness query to computeRegisterLiveness() enum LivenessQueryResult { - LQR_Live, ///< Register is known to be live. - LQR_OverlappingLive, ///< Register itself is not live, but some overlapping - ///< register is. - LQR_Dead, ///< Register is known to be dead. - LQR_Unknown ///< Register liveness not decidable from local - ///< neighborhood. + LQR_Live, ///< Register is known to be (at least partially) live. + LQR_Dead, ///< Register is known to be fully dead. + LQR_Unknown ///< Register liveness not decidable from local neighborhood. }; /// Return whether (physical) register \p Reg has been <def>ined and not @@ -666,49 +736,43 @@ public: // Printing method used by LoopInfo. void printAsOperand(raw_ostream &OS, bool PrintType = true) const; - /// getNumber - MachineBasicBlocks are uniquely numbered at the function - /// level, unless they're not in a MachineFunction yet, in which case this - /// will return -1. - /// + /// MachineBasicBlocks are uniquely numbered at the function level, unless + /// they're not in a MachineFunction yet, in which case this will return -1. int getNumber() const { return Number; } void setNumber(int N) { Number = N; } - /// getSymbol - Return the MCSymbol for this basic block. - /// + /// Return the MCSymbol for this basic block. MCSymbol *getSymbol() const; private: - /// getWeightIterator - Return weight iterator corresponding to the I - /// successor iterator. - weight_iterator getWeightIterator(succ_iterator I); - const_weight_iterator getWeightIterator(const_succ_iterator I) const; + /// Return probability iterator corresponding to the I successor iterator. + probability_iterator getProbabilityIterator(succ_iterator I); + const_probability_iterator + getProbabilityIterator(const_succ_iterator I) const; friend class MachineBranchProbabilityInfo; + friend class MIPrinter; - /// getSuccWeight - Return weight of the edge from this block to MBB. This - /// method should NOT be called directly, but by using getEdgeWeight method - /// from MachineBranchProbabilityInfo class. - uint32_t getSuccWeight(const_succ_iterator Succ) const; - + /// Return probability of the edge from this block to MBB. This method should + /// NOT be called directly, but by using getEdgeProbability method from + /// MachineBranchProbabilityInfo class. + BranchProbability getSuccProbability(const_succ_iterator Succ) const; // Methods used to maintain doubly linked list of blocks... friend struct ilist_traits<MachineBasicBlock>; // Machine-CFG mutators - /// addPredecessor - Remove pred as a predecessor of this MachineBasicBlock. - /// Don't do this unless you know what you're doing, because it doesn't - /// update pred's successors list. Use pred->addSuccessor instead. - /// - void addPredecessor(MachineBasicBlock *pred); + /// Remove Pred as a predecessor of this MachineBasicBlock. Don't do this + /// unless you know what you're doing, because it doesn't update Pred's + /// successors list. Use Pred->addSuccessor instead. + void addPredecessor(MachineBasicBlock *Pred); - /// removePredecessor - Remove pred as a predecessor of this - /// MachineBasicBlock. Don't do this unless you know what you're - /// doing, because it doesn't update pred's successors list. Use - /// pred->removeSuccessor instead. - /// - void removePredecessor(MachineBasicBlock *pred); + /// Remove Pred as a predecessor of this MachineBasicBlock. Don't do this + /// unless you know what you're doing, because it doesn't update Pred's + /// successors list. Use Pred->removeSuccessor instead. + void removePredecessor(MachineBasicBlock *Pred); }; raw_ostream& operator<<(raw_ostream &OS, const MachineBasicBlock &MBB); @@ -726,7 +790,7 @@ struct MBB2NumberFunctor : //===--------------------------------------------------------------------===// // Provide specializations of GraphTraits to be able to treat a -// MachineFunction as a graph of MachineBasicBlocks... +// MachineFunction as a graph of MachineBasicBlocks. // template <> struct GraphTraits<MachineBasicBlock *> { @@ -756,7 +820,7 @@ template <> struct GraphTraits<const MachineBasicBlock *> { }; // Provide specializations of GraphTraits to be able to treat a -// MachineFunction as a graph of MachineBasicBlocks... and to walk it +// MachineFunction as a graph of MachineBasicBlocks and to walk it // in inverse order. Inverse order for a function is considered // to be when traversing the predecessor edges of a MBB // instead of the successor edges. |