#ifndef LLVM_CODEGEN_MACHINEBASICBLOCK_H
#define LLVM_CODEGEN_MACHINEBASICBLOCK_H
-#include "llvm/CodeGen/MachineInstr.h"
#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>
namespace llvm {
+class Pass;
class BasicBlock;
class MachineFunction;
-class MCContext;
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> {
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:
+ // XXX-update: A flag that checks whether we can eliminate this machine basic
+ // block.
+ bool canEliminateMachineBB;
+
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;
- /// LiveIns - Keep track of the physical registers that are livein of
- /// the basicblock.
- std::vector<unsigned> LiveIns;
+ /// 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;
- /// Alignment - Alignment of the basic block. Zero if the basic block does
- /// not need to be aligned.
- unsigned Alignment;
-
- /// IsLandingPad - Indicate that this basic block is entered via an
- /// exception handler.
- bool IsLandingPad;
+ /// Keep track of the physical registers that are livein of the basicblock.
+ typedef std::vector<RegisterMaskPair> LiveInVector;
+ LiveInVector LiveIns;
- /// AddressTaken - Indicate that this basic block is potentially the
- /// target of an indirect branch.
- bool AddressTaken;
+ /// 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;
+
+ /// Indicate that this basic block is entered via an exception handler.
+ bool IsEHPad = false;
+
+ /// Indicate that this basic block is potentially the target of an indirect
+ /// branch.
+ bool AddressTaken = false;
+
+ /// Indicate that this basic block is the entry block of an EH funclet.
+ bool IsEHFuncletEntry = false;
+
+ /// 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 = nullptr;
// Intrusive list support
MachineBasicBlock() {}
- explicit MachineBasicBlock(MachineFunction &mf, const BasicBlock *bb);
+ explicit MachineBasicBlock(MachineFunction &MF, const BasicBlock *BB);
~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.
- ///
+ // XXX-update:
+ void disableCanEliminateMachineBB() {
+ canEliminateMachineBB = false;
+ }
+
+ bool getCanEliminateMachineBB() {
+ return canEliminateMachineBB;
+ }
+
+ /// 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;
- /// hasAddressTaken - Test whether this block is potentially the target
- /// of an indirect branch.
+ /// Return a formatted string to identify this block and its parent function.
+ std::string getFullName() const;
+
+ /// 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; }
- typedef Instructions::iterator iterator;
- typedef Instructions::const_iterator const_iterator;
- typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
- typedef std::reverse_iterator<iterator> reverse_iterator;
+ /// 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 MI) : MII(MI) {}
+
+ 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()) &&
+ "It's not legal to initialize bundle_iterator with a bundled MI");
+ }
+ // Template allows conversion from const to nonconst.
+ template<class OtherTy, class OtherIterTy>
+ bundle_iterator(const bundle_iterator<OtherTy, OtherIterTy> &I)
+ : MII(I.getInstrIterator()) {}
+ bundle_iterator() : MII(nullptr) {}
+
+ Ty &operator*() const { return *MII; }
+ Ty *operator->() const { return &operator*(); }
+
+ 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 !operator==(X);
+ }
+
+ // Increment and decrement operators...
+ bundle_iterator &operator--() { // predecrement - Back up
+ do --MII;
+ while (MII->isBundledWithPred());
+ return *this;
+ }
+ bundle_iterator &operator++() { // preincrement - Advance
+ while (MII->isBundledWithSucc())
+ ++MII;
+ ++MII;
+ return *this;
+ }
+ bundle_iterator operator--(int) { // postdecrement operators...
+ bundle_iterator tmp = *this;
+ --*this;
+ return tmp;
+ }
+ bundle_iterator operator++(int) { // postincrement operators...
+ bundle_iterator tmp = *this;
+ ++*this;
+ return tmp;
+ }
+
+ IterTy getInstrIterator() const {
+ return MII;
+ }
+ };
+
+ typedef Instructions::iterator instr_iterator;
+ typedef Instructions::const_iterator const_instr_iterator;
+ typedef std::reverse_iterator<instr_iterator> reverse_instr_iterator;
+ typedef
+ std::reverse_iterator<const_instr_iterator> const_reverse_instr_iterator;
+
+ typedef
+ bundle_iterator<MachineInstr,instr_iterator> iterator;
+ typedef
+ bundle_iterator<const MachineInstr,const_instr_iterator> const_iterator;
+ typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
+ typedef std::reverse_iterator<iterator> reverse_iterator;
+
unsigned size() const { return (unsigned)Insts.size(); }
bool empty() const { return Insts.empty(); }
- MachineInstr& front() { return Insts.front(); }
- MachineInstr& back() { return Insts.back(); }
- const MachineInstr& front() const { return Insts.front(); }
- const MachineInstr& back() const { return Insts.back(); }
+ MachineInstr &instr_front() { return Insts.front(); }
+ MachineInstr &instr_back() { return Insts.back(); }
+ const MachineInstr &instr_front() const { return Insts.front(); }
+ const MachineInstr &instr_back() const { return Insts.back(); }
+
+ MachineInstr &front() { return Insts.front(); }
+ MachineInstr &back() { return *--end(); }
+ const MachineInstr &front() const { return Insts.front(); }
+ const MachineInstr &back() const { return *--end(); }
+
+ instr_iterator instr_begin() { return Insts.begin(); }
+ const_instr_iterator instr_begin() const { return Insts.begin(); }
+ instr_iterator instr_end() { return Insts.end(); }
+ const_instr_iterator instr_end() const { return Insts.end(); }
+ reverse_instr_iterator instr_rbegin() { return Insts.rbegin(); }
+ const_reverse_instr_iterator instr_rbegin() const { return Insts.rbegin(); }
+ reverse_instr_iterator instr_rend () { return Insts.rend(); }
+ const_reverse_instr_iterator instr_rend () const { return Insts.rend(); }
+
+ iterator begin() { return instr_begin(); }
+ const_iterator begin() const { return instr_begin(); }
+ iterator end () { return instr_end(); }
+ const_iterator end () const { return instr_end(); }
+ reverse_iterator rbegin() { return instr_rbegin(); }
+ const_reverse_iterator rbegin() const { return instr_rbegin(); }
+ 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;
+ }
- iterator begin() { return Insts.begin(); }
- const_iterator begin() const { return Insts.begin(); }
- iterator end() { return Insts.end(); }
- const_iterator end() const { return Insts.end(); }
- reverse_iterator rbegin() { return Insts.rbegin(); }
- const_reverse_iterator rbegin() const { return Insts.rbegin(); }
- reverse_iterator rend () { return Insts.rend(); }
- const_reverse_iterator rend () const { return Insts.rend(); }
+ inline iterator_range<iterator> terminators() {
+ return make_range(getFirstTerminator(), end());
+ }
+ inline iterator_range<const_iterator> terminators() const {
+ return make_range(getFirstTerminator(), end());
+ }
// Machine-CFG iterators
typedef std::vector<MachineBasicBlock *>::iterator pred_iterator;
succ_reverse_iterator;
typedef std::vector<MachineBasicBlock *>::const_reverse_iterator
const_succ_reverse_iterator;
-
pred_iterator pred_begin() { return Predecessors.begin(); }
const_pred_iterator pred_begin() const { return Predecessors.begin(); }
pred_iterator pred_end() { return Predecessors.end(); }
}
bool succ_empty() const { return Successors.empty(); }
+ inline iterator_range<pred_iterator> predecessors() {
+ return make_range(pred_begin(), pred_end());
+ }
+ inline iterator_range<const_pred_iterator> predecessors() const {
+ return make_range(pred_begin(), pred_end());
+ }
+ inline iterator_range<succ_iterator> successors() {
+ return make_range(succ_begin(), succ_end());
+ }
+ inline iterator_range<const_succ_iterator> successors() const {
+ return make_range(succ_begin(), succ_end());
+ }
+
// LiveIn management methods.
- /// addLiveIn - Add 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.
- void addLiveIn(unsigned Reg) { LiveIns.push_back(Reg); }
+ /// 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(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();
- /// removeLiveIn - Remove the specified register from the live in set.
- ///
- void removeLiveIn(unsigned Reg);
+ /// 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(MCPhysReg PhysReg, const TargetRegisterClass *RC);
- /// isLiveIn - Return true if the specified register is in the live in set.
- ///
- bool isLiveIn(unsigned Reg) const;
+ /// Remove the specified register from the live in set.
+ void removeLiveIn(MCPhysReg Reg, LaneBitmask LaneMask = ~0u);
+
+ /// 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>::iterator livein_iterator;
- typedef std::vector<unsigned>::const_iterator const_livein_iterator;
- livein_iterator livein_begin() { return LiveIns.begin(); }
- const_livein_iterator livein_begin() const { return LiveIns.begin(); }
- livein_iterator livein_end() { return LiveIns.end(); }
- const_livein_iterator livein_end() const { return LiveIns.end(); }
+ 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.
- ///
+ /// 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.
- ///
+ /// 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; }
+
+ /// 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; }
+
+ /// If this block has a successor that is a landing pad, return it. Otherwise
+ /// return NULL.
+ const MachineBasicBlock *getLandingPadSuccessor() const;
+
+ bool hasEHPadSuccessor() const;
- /// setIsLandingPad - Indicates the block is a landing pad. That is
- /// this basic block is entered via an exception handler.
- void setIsLandingPad() { IsLandingPad = true; }
+ /// 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.
- ///
- void addSuccessor(MachineBasicBlock *succ);
- /// removeSuccessor - Remove successor from the successors list of this
- /// MachineBasicBlock. The Predecessors list of succ is automatically updated.
+ /// 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.
///
- void removeSuccessor(MachineBasicBlock *succ);
+ /// Note that duplicate Machine CFG edges are not allowed.
+ 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());
+ }
- /// 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);
-
- /// 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);
-
- /// isSuccessor - Return true if the specified MBB is a successor of this
- /// block.
+ /// 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);
+
+ /// 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(); }
+
+ /// Return true if the specified MBB is a predecessor of this block.
+ bool isPredecessor(const MachineBasicBlock *MBB) const;
+
+ /// 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();
- /// getFirstTerminator - returns an iterator to the first terminator
- /// instruction of this basic block. If a terminator does not exist,
- /// it returns end()
+ /// Returns a pointer to the first instruction in this block that is not a
+ /// PHINode instruction. When adding instructions 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 end() is there's no non-PHI instruction.
+ iterator getFirstNonPHI();
+
+ /// 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);
+
+ /// 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();
+ }
+
+ /// Same getFirstTerminator but it ignores bundles and return an
+ /// instr_iterator instead.
+ instr_iterator getFirstInstrTerminator();
+
+ /// 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();
+ }
+
+ /// 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();
+ }
+
+ /// 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.
+ MachineBasicBlock *SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P);
void pop_front() { Insts.pop_front(); }
void pop_back() { Insts.pop_back(); }
void push_back(MachineInstr *MI) { Insts.push_back(MI); }
+
+ /// Insert MI into the instruction list before I, possibly inside a bundle.
+ ///
+ /// If the insertion point is inside a bundle, MI will be added to the bundle,
+ /// otherwise MI will not be added to any bundle. That means this function
+ /// alone can't be used to prepend or append instructions to bundles. See
+ /// MIBundleBuilder::insert() for a more reliable way of doing that.
+ instr_iterator insert(instr_iterator I, MachineInstr *M);
+
+ /// Insert a range of instructions into the instruction list before I.
template<typename IT>
- void insert(iterator I, IT S, IT E) { Insts.insert(I, S, E); }
- iterator insert(iterator I, MachineInstr *M) { return Insts.insert(I, M); }
+ void insert(iterator I, IT S, IT E) {
+ assert((I == end() || I->getParent() == this) &&
+ "iterator points outside of basic block");
+ Insts.insert(I.getInstrIterator(), S, E);
+ }
+
+ /// Insert MI into the instruction list before I.
+ iterator insert(iterator I, MachineInstr *MI) {
+ assert((I == end() || I->getParent() == this) &&
+ "iterator points outside of basic block");
+ assert(!MI->isBundledWithPred() && !MI->isBundledWithSucc() &&
+ "Cannot insert instruction with bundle flags");
+ return Insts.insert(I.getInstrIterator(), MI);
+ }
+
+ /// Insert MI into the instruction list after I.
+ iterator insertAfter(iterator I, MachineInstr *MI) {
+ assert((I == end() || I->getParent() == this) &&
+ "iterator points outside of basic block");
+ assert(!MI->isBundledWithPred() && !MI->isBundledWithSucc() &&
+ "Cannot insert instruction with bundle flags");
+ return Insts.insertAfter(I.getInstrIterator(), MI);
+ }
+
+ /// Remove an instruction from the instruction list and delete it.
+ ///
+ /// If the instruction is part of a bundle, the other instructions in the
+ /// bundle will still be bundled after removing the single instruction.
+ instr_iterator erase(instr_iterator I);
+
+ /// Remove an instruction from the instruction list and delete it.
+ ///
+ /// If the instruction is part of a bundle, the other instructions in the
+ /// bundle will still be bundled after removing the single instruction.
+ instr_iterator erase_instr(MachineInstr *I) {
+ return erase(instr_iterator(I));
+ }
+
+ /// Remove a range of instructions from the instruction list and delete them.
+ iterator erase(iterator I, iterator E) {
+ return Insts.erase(I.getInstrIterator(), E.getInstrIterator());
+ }
+
+ /// Remove an instruction or bundle from the instruction list and delete it.
+ ///
+ /// If I points to a bundle of instructions, they are all erased.
+ iterator erase(iterator I) {
+ return erase(I, std::next(I));
+ }
+
+ /// Remove an instruction from the instruction list and delete it.
+ ///
+ /// If I is the head of a bundle of instructions, the whole bundle will be
+ /// erased.
+ iterator erase(MachineInstr *I) {
+ return erase(iterator(I));
+ }
+
+ /// Remove the unbundled instruction from the instruction list without
+ /// deleting it.
+ ///
+ /// This function can not be used to remove bundled instructions, use
+ /// remove_instr to remove individual instructions from a bundle.
+ MachineInstr *remove(MachineInstr *I) {
+ assert(!I->isBundled() && "Cannot remove bundled instructions");
+ return Insts.remove(instr_iterator(I));
+ }
+
+ /// Remove the possibly bundled instruction from the instruction list
+ /// without deleting it.
+ ///
+ /// If the instruction is part of a bundle, the other instructions in the
+ /// bundle will still be bundled after removing the single instruction.
+ MachineInstr *remove_instr(MachineInstr *I);
- // erase - Remove the specified element or range from the instruction list.
- // These functions delete any instructions removed.
- //
- iterator erase(iterator I) { return Insts.erase(I); }
- iterator erase(iterator I, iterator E) { return Insts.erase(I, E); }
- MachineInstr *remove(MachineInstr *I) { return Insts.remove(I); }
- void clear() { Insts.clear(); }
+ void clear() {
+ Insts.clear();
+ }
- /// splice - Take an instruction from MBB 'Other' at the position From,
- /// and insert it into this MBB right before 'where'.
- void splice(iterator where, MachineBasicBlock *Other, iterator From) {
- Insts.splice(where, Other->Insts, From);
+ /// Take an instruction from MBB 'Other' at the position From, and insert it
+ /// into this MBB right before 'Where'.
+ ///
+ /// If From points to a bundle of instructions, the whole bundle is moved.
+ void splice(iterator Where, MachineBasicBlock *Other, iterator From) {
+ // The range splice() doesn't allow noop moves, but this one does.
+ if (Where != From)
+ splice(Where, Other, From, std::next(From));
}
- /// splice - Take a block of instructions from MBB 'Other' in the range [From,
- /// To), and insert them into this MBB right before 'where'.
- void splice(iterator where, MachineBasicBlock *Other, iterator From,
- iterator To) {
- Insts.splice(where, Other->Insts, From, To);
+ /// Take a block of instructions from MBB 'Other' in the range [From, To),
+ /// and insert them into this MBB right before 'Where'.
+ ///
+ /// The instruction at 'Where' must not be included in the range of
+ /// instructions to move.
+ void splice(iterator Where, MachineBasicBlock *Other,
+ iterator From, iterator To) {
+ Insts.splice(Where.getInstrIterator(), Other->Insts,
+ 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);
+
+ /// 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());
+ }
+
+ /// Possible outcome of a register liveness query to computeRegisterLiveness()
+ enum LivenessQueryResult {
+ 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.
+ };
- /// findDebugLoc - find the next valid DebugLoc starting at MBBI, skipping
- /// any DBG_VALUE instructions. Return UnknownLoc if there is none.
- DebugLoc findDebugLoc(MachineBasicBlock::iterator &MBBI);
+ /// Return whether (physical) register \p Reg has been <def>ined and not
+ /// <kill>ed as of just before \p Before.
+ ///
+ /// Search is localised to a neighborhood of \p Neighborhood instructions
+ /// before (searching for defs or kills) and \p Neighborhood instructions
+ /// after (searching just for defs) \p Before.
+ ///
+ /// \p Reg must be a physical register.
+ LivenessQueryResult computeRegisterLiveness(const TargetRegisterInfo *TRI,
+ unsigned Reg,
+ const_iterator Before,
+ unsigned Neighborhood=10) const;
// Debugging methods.
void dump() const;
- void print(raw_ostream &OS) const;
+ void print(raw_ostream &OS, SlotIndexes* = nullptr) const;
+ void print(raw_ostream &OS, ModuleSlotTracker &MST,
+ SlotIndexes * = nullptr) 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.
- ///
+ // Printing method used by LoopInfo.
+ void printAsOperand(raw_ostream &OS, bool PrintType = true) const;
+
+ /// 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.
- ///
- MCSymbol *getSymbol(MCContext &Ctx) const;
-
-private: // Methods used to maintain doubly linked list of blocks...
+ /// Return the MCSymbol for this basic block.
+ MCSymbol *getSymbol() const;
+
+
+private:
+ /// 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;
+
+ /// 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);
-void WriteAsOperand(raw_ostream &, const MachineBasicBlock*, bool t);
+// This is useful when building IndexedMaps keyed on basic block pointers.
+struct MBB2NumberFunctor :
+ public std::unary_function<const MachineBasicBlock*, unsigned> {
+ unsigned operator()(const MachineBasicBlock *MBB) const {
+ return MBB->getNumber();
+ }
+};
//===--------------------------------------------------------------------===//
// GraphTraits specializations for machine basic block graphs (machine-CFGs)
//===--------------------------------------------------------------------===//
// 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 *> {
};
// 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.
}
};
+
+
+/// MachineInstrSpan provides an interface to get an iteration range
+/// containing the instruction it was initialized with, along with all
+/// those instructions inserted prior to or following that instruction
+/// at some point after the MachineInstrSpan is constructed.
+class MachineInstrSpan {
+ MachineBasicBlock &MBB;
+ MachineBasicBlock::iterator I, B, E;
+public:
+ MachineInstrSpan(MachineBasicBlock::iterator I)
+ : MBB(*I->getParent()),
+ I(I),
+ B(I == MBB.begin() ? MBB.end() : std::prev(I)),
+ E(std::next(I)) {}
+
+ MachineBasicBlock::iterator begin() {
+ return B == MBB.end() ? MBB.begin() : std::next(B);
+ }
+ MachineBasicBlock::iterator end() { return E; }
+ bool empty() { return begin() == end(); }
+
+ MachineBasicBlock::iterator getInitial() { return I; }
+};
+
} // End llvm namespace
#endif