template<class N, class M> class LoopBase;
//===----------------------------------------------------------------------===//
-/// LoopBase class - Instances of this class are used to represent loops that
-/// are detected in the flow graph
+/// Instances of this class are used to represent loops that are detected in the
+/// flow graph.
///
template<class BlockT, class LoopT>
class LoopBase {
LoopT *ParentLoop;
- // SubLoops - Loops contained entirely within this one.
+ // Loops contained entirely within this one.
std::vector<LoopT *> SubLoops;
- // Blocks - The list of blocks in this loop. First entry is the header node.
+ // The list of blocks in this loop. First entry is the header node.
std::vector<BlockT*> Blocks;
SmallPtrSet<const BlockT*, 8> DenseBlockSet;
const LoopBase<BlockT, LoopT>&
operator=(const LoopBase<BlockT, LoopT> &) = delete;
public:
- /// Loop ctor - This creates an empty loop.
+ /// This creates an empty loop.
LoopBase() : ParentLoop(nullptr) {}
~LoopBase() {
for (size_t i = 0, e = SubLoops.size(); i != e; ++i)
delete SubLoops[i];
}
- /// getLoopDepth - Return the nesting level of this loop. An outer-most
- /// loop has depth 1, for consistency with loop depth values used for basic
- /// blocks, where depth 0 is used for blocks not inside any loops.
+ /// Return the nesting level of this loop. An outer-most loop has depth 1,
+ /// for consistency with loop depth values used for basic blocks, where depth
+ /// 0 is used for blocks not inside any loops.
unsigned getLoopDepth() const {
unsigned D = 1;
for (const LoopT *CurLoop = ParentLoop; CurLoop;
BlockT *getHeader() const { return Blocks.front(); }
LoopT *getParentLoop() const { return ParentLoop; }
- /// setParentLoop is a raw interface for bypassing addChildLoop.
+ /// This is a raw interface for bypassing addChildLoop.
void setParentLoop(LoopT *L) { ParentLoop = L; }
- /// contains - Return true if the specified loop is contained within in
- /// this loop.
- ///
+ /// Return true if the specified loop is contained within in this loop.
bool contains(const LoopT *L) const {
if (L == this) return true;
if (!L) return false;
return contains(L->getParentLoop());
}
- /// contains - Return true if the specified basic block is in this loop.
- ///
+ /// Return true if the specified basic block is in this loop.
bool contains(const BlockT *BB) const {
return DenseBlockSet.count(BB);
}
- /// contains - Return true if the specified instruction is in this loop.
- ///
+ /// Return true if the specified instruction is in this loop.
template<class InstT>
bool contains(const InstT *Inst) const {
return contains(Inst->getParent());
}
- /// iterator/begin/end - Return the loops contained entirely within this loop.
- ///
+ /// Return the loops contained entirely within this loop.
const std::vector<LoopT *> &getSubLoops() const { return SubLoops; }
std::vector<LoopT *> &getSubLoopsVector() { return SubLoops; }
typedef typename std::vector<LoopT *>::const_iterator iterator;
reverse_iterator rend() const { return SubLoops.rend(); }
bool empty() const { return SubLoops.empty(); }
- /// getBlocks - Get a list of the basic blocks which make up this loop.
- ///
+ /// Get a list of the basic blocks which make up this loop.
const std::vector<BlockT*> &getBlocks() const { return Blocks; }
typedef typename std::vector<BlockT*>::const_iterator block_iterator;
block_iterator block_begin() const { return Blocks.begin(); }
return make_range(block_begin(), block_end());
}
- /// getNumBlocks - Get the number of blocks in this loop in constant time.
+ /// Get the number of blocks in this loop in constant time.
unsigned getNumBlocks() const {
return Blocks.size();
}
/// Return true if this loop is no longer valid.
bool isInvalid() { return IsInvalid; }
- /// isLoopExiting - True if terminator in the block can branch to another
- /// block that is outside of the current loop.
- ///
+ /// True if terminator in the block can branch to another block that is
+ /// outside of the current loop.
bool isLoopExiting(const BlockT *BB) const {
typedef GraphTraits<const BlockT*> BlockTraits;
for (typename BlockTraits::ChildIteratorType SI =
return false;
}
- /// getNumBackEdges - Calculate the number of back edges to the loop header
- ///
+ /// Calculate the number of back edges to the loop header.
unsigned getNumBackEdges() const {
unsigned NumBackEdges = 0;
BlockT *H = getHeader();
// induction variable canonicalization pass should be used to normalize loops
// for easy analysis. These methods assume canonical loops.
- /// getExitingBlocks - Return all blocks inside the loop that have successors
- /// outside of the loop. These are the blocks _inside of the current loop_
- /// which branch out. The returned list is always unique.
- ///
+ /// Return all blocks inside the loop that have successors outside of the
+ /// loop. These are the blocks _inside of the current loop_ which branch out.
+ /// The returned list is always unique.
void getExitingBlocks(SmallVectorImpl<BlockT *> &ExitingBlocks) const;
- /// getExitingBlock - If getExitingBlocks would return exactly one block,
- /// return that block. Otherwise return null.
+ /// If getExitingBlocks would return exactly one block, return that block.
+ /// Otherwise return null.
BlockT *getExitingBlock() const;
- /// getExitBlocks - Return all of the successor blocks of this loop. These
- /// are the blocks _outside of the current loop_ which are branched to.
- ///
+ /// Return all of the successor blocks of this loop. These are the blocks
+ /// _outside of the current loop_ which are branched to.
void getExitBlocks(SmallVectorImpl<BlockT*> &ExitBlocks) const;
- /// getExitBlock - If getExitBlocks would return exactly one block,
- /// return that block. Otherwise return null.
+ /// If getExitBlocks would return exactly one block, return that block.
+ /// Otherwise return null.
BlockT *getExitBlock() const;
/// Edge type.
typedef std::pair<const BlockT*, const BlockT*> Edge;
- /// getExitEdges - Return all pairs of (_inside_block_,_outside_block_).
+ /// Return all pairs of (_inside_block_,_outside_block_).
void getExitEdges(SmallVectorImpl<Edge> &ExitEdges) const;
- /// getLoopPreheader - If there is a preheader for this loop, return it. A
- /// loop has a preheader if there is only one edge to the header of the loop
- /// from outside of the loop. If this is the case, the block branching to the
- /// header of the loop is the preheader node.
+ /// If there is a preheader for this loop, return it. A loop has a preheader
+ /// if there is only one edge to the header of the loop from outside of the
+ /// loop. If this is the case, the block branching to the header of the loop
+ /// is the preheader node.
///
/// This method returns null if there is no preheader for the loop.
- ///
BlockT *getLoopPreheader() const;
- /// getLoopPredecessor - If the given loop's header has exactly one unique
- /// predecessor outside the loop, return it. Otherwise return null.
- /// This is less strict that the loop "preheader" concept, which requires
+ /// If the given loop's header has exactly one unique predecessor outside the
+ /// loop, return it. Otherwise return null.
+ /// This is less strict that the loop "preheader" concept, which requires
/// the predecessor to have exactly one successor.
- ///
BlockT *getLoopPredecessor() const;
- /// getLoopLatch - If there is a single latch block for this loop, return it.
+ /// If there is a single latch block for this loop, return it.
/// A latch block is a block that contains a branch back to the header.
BlockT *getLoopLatch() const;
- /// getLoopLatches - Return all loop latch blocks of this loop. A latch block
- /// is a block that contains a branch back to the header.
+ /// Return all loop latch blocks of this loop. A latch block is a block that
+ /// contains a branch back to the header.
void getLoopLatches(SmallVectorImpl<BlockT *> &LoopLatches) const {
BlockT *H = getHeader();
typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits;
// APIs for updating loop information after changing the CFG
//
- /// addBasicBlockToLoop - This method is used by other analyses to update loop
- /// information. NewBB is set to be a new member of the current loop.
+ /// This method is used by other analyses to update loop information.
+ /// NewBB is set to be a new member of the current loop.
/// Because of this, it is added as a member of all parent loops, and is added
/// to the specified LoopInfo object as being in the current basic block. It
/// is not valid to replace the loop header with this method.
- ///
void addBasicBlockToLoop(BlockT *NewBB, LoopInfoBase<BlockT, LoopT> &LI);
- /// replaceChildLoopWith - This is used when splitting loops up. It replaces
- /// the OldChild entry in our children list with NewChild, and updates the
- /// parent pointer of OldChild to be null and the NewChild to be this loop.
+ /// This is used when splitting loops up. It replaces the OldChild entry in
+ /// our children list with NewChild, and updates the parent pointer of
+ /// OldChild to be null and the NewChild to be this loop.
/// This updates the loop depth of the new child.
void replaceChildLoopWith(LoopT *OldChild, LoopT *NewChild);
- /// addChildLoop - Add the specified loop to be a child of this loop. This
- /// updates the loop depth of the new child.
- ///
+ /// Add the specified loop to be a child of this loop.
+ /// This updates the loop depth of the new child.
void addChildLoop(LoopT *NewChild) {
assert(!NewChild->ParentLoop && "NewChild already has a parent!");
NewChild->ParentLoop = static_cast<LoopT *>(this);
SubLoops.push_back(NewChild);
}
- /// removeChildLoop - This removes the specified child from being a subloop of
- /// this loop. The loop is not deleted, as it will presumably be inserted
- /// into another loop.
+ /// This removes the specified child from being a subloop of this loop. The
+ /// loop is not deleted, as it will presumably be inserted into another loop.
LoopT *removeChildLoop(iterator I) {
assert(I != SubLoops.end() && "Cannot remove end iterator!");
LoopT *Child = *I;
return Child;
}
- /// addBlockEntry - This adds a basic block directly to the basic block list.
+ /// This adds a basic block directly to the basic block list.
/// This should only be used by transformations that create new loops. Other
/// transformations should use addBasicBlockToLoop.
void addBlockEntry(BlockT *BB) {
DenseBlockSet.insert(BB);
}
- /// reverseBlocks - interface to reverse Blocks[from, end of loop] in this loop
+ /// interface to reverse Blocks[from, end of loop] in this loop
void reverseBlock(unsigned from) {
std::reverse(Blocks.begin() + from, Blocks.end());
}
- /// reserveBlocks- interface to do reserve() for Blocks
+ /// interface to do reserve() for Blocks
void reserveBlocks(unsigned size) {
Blocks.reserve(size);
}
- /// moveToHeader - This method is used to move BB (which must be part of this
- /// loop) to be the loop header of the loop (the block that dominates all
- /// others).
+ /// This method is used to move BB (which must be part of this loop) to be the
+ /// loop header of the loop (the block that dominates all others).
void moveToHeader(BlockT *BB) {
if (Blocks[0] == BB) return;
for (unsigned i = 0; ; ++i) {
}
}
- /// removeBlockFromLoop - This removes the specified basic block from the
- /// current loop, updating the Blocks as appropriate. This does not update
- /// the mapping in the LoopInfo class.
+ /// This removes the specified basic block from the current loop, updating the
+ /// Blocks as appropriate. This does not update the mapping in the LoopInfo
+ /// class.
void removeBlockFromLoop(BlockT *BB) {
auto I = std::find(Blocks.begin(), Blocks.end(), BB);
assert(I != Blocks.end() && "N is not in this list!");
DenseBlockSet.erase(BB);
}
- /// verifyLoop - Verify loop structure
+ /// Verify loop structure
void verifyLoop() const;
- /// verifyLoop - Verify loop structure of this loop and all nested loops.
+ /// Verify loop structure of this loop and all nested loops.
void verifyLoopNest(DenseSet<const LoopT*> *Loops) const;
void print(raw_ostream &OS, unsigned Depth = 0) const;
public:
Loop() {}
- /// isLoopInvariant - Return true if the specified value is loop invariant
- ///
+ /// Return true if the specified value is loop invariant.
bool isLoopInvariant(const Value *V) const;
- /// hasLoopInvariantOperands - Return true if all the operands of the
- /// specified instruction are loop invariant.
+ /// Return true if all the operands of the specified instruction are loop
+ /// invariant.
bool hasLoopInvariantOperands(const Instruction *I) const;
- /// makeLoopInvariant - If the given value is an instruction inside of the
- /// loop and it can be hoisted, do so to make it trivially loop-invariant.
+ /// If the given value is an instruction inside of the loop and it can be
+ /// hoisted, do so to make it trivially loop-invariant.
/// Return true if the value after any hoisting is loop invariant. This
/// function can be used as a slightly more aggressive replacement for
/// isLoopInvariant.
///
/// If InsertPt is specified, it is the point to hoist instructions to.
/// If null, the terminator of the loop preheader is used.
- ///
bool makeLoopInvariant(Value *V, bool &Changed,
Instruction *InsertPt = nullptr) const;
- /// makeLoopInvariant - If the given instruction is inside of the
- /// loop and it can be hoisted, do so to make it trivially loop-invariant.
+ /// If the given instruction is inside of the loop and it can be hoisted, do
+ /// so to make it trivially loop-invariant.
/// Return true if the instruction after any hoisting is loop invariant. This
/// function can be used as a slightly more aggressive replacement for
/// isLoopInvariant.
bool makeLoopInvariant(Instruction *I, bool &Changed,
Instruction *InsertPt = nullptr) const;
- /// getCanonicalInductionVariable - Check to see if the loop has a canonical
- /// induction variable: an integer recurrence that starts at 0 and increments
- /// by one each time through the loop. If so, return the phi node that
- /// corresponds to it.
+ /// Check to see if the loop has a canonical induction variable: an integer
+ /// recurrence that starts at 0 and increments by one each time through the
+ /// loop. If so, return the phi node that corresponds to it.
///
/// The IndVarSimplify pass transforms loops to have a canonical induction
/// variable.
///
PHINode *getCanonicalInductionVariable() const;
- /// isLCSSAForm - Return true if the Loop is in LCSSA form
+ /// Return true if the Loop is in LCSSA form.
bool isLCSSAForm(DominatorTree &DT) const;
- /// \brief Return true if this Loop and all inner subloops are in LCSSA form.
+ /// Return true if this Loop and all inner subloops are in LCSSA form.
bool isRecursivelyLCSSAForm(DominatorTree &DT) const;
- /// isLoopSimplifyForm - Return true if the Loop is in the form that
- /// the LoopSimplify form transforms loops to, which is sometimes called
- /// normal form.
+ /// Return true if the Loop is in the form that the LoopSimplify form
+ /// transforms loops to, which is sometimes called normal form.
bool isLoopSimplifyForm() const;
- /// isSafeToClone - Return true if the loop body is safe to clone in practice.
+ /// Return true if the loop body is safe to clone in practice.
bool isSafeToClone() const;
/// Returns true if the loop is annotated parallel.
/// operand should should be the node itself.
void setLoopID(MDNode *LoopID) const;
- /// hasDedicatedExits - Return true if no exit block for the loop
- /// has a predecessor that is outside the loop.
+ /// Return true if no exit block for the loop has a predecessor that is
+ /// outside the loop.
bool hasDedicatedExits() const;
- /// getUniqueExitBlocks - Return all unique successor blocks of this loop.
+ /// Return all unique successor blocks of this loop.
/// These are the blocks _outside of the current loop_ which are branched to.
/// This assumes that loop exits are in canonical form.
- ///
void getUniqueExitBlocks(SmallVectorImpl<BasicBlock *> &ExitBlocks) const;
- /// getUniqueExitBlock - If getUniqueExitBlocks would return exactly one
- /// block, return that block. Otherwise return null.
+ /// If getUniqueExitBlocks would return exactly one block, return that block.
+ /// Otherwise return null.
BasicBlock *getUniqueExitBlock() const;
void dump() const;
- /// \brief Return the debug location of the start of this loop.
+ /// Return the debug location of the start of this loop.
/// This looks for a BB terminating instruction with a known debug
/// location by looking at the preheader and header blocks. If it
/// cannot find a terminating instruction with location information,
};
//===----------------------------------------------------------------------===//
-/// LoopInfo - This class builds and contains all of the top level loop
+/// This class builds and contains all of the top-level loop
/// structures in the specified function.
///
reverse_iterator rend() const { return TopLevelLoops.rend(); }
bool empty() const { return TopLevelLoops.empty(); }
- /// getLoopFor - Return the inner most loop that BB lives in. If a basic
- /// block is in no loop (for example the entry node), null is returned.
- ///
+ /// Return the inner most loop that BB lives in. If a basic block is in no
+ /// loop (for example the entry node), null is returned.
LoopT *getLoopFor(const BlockT *BB) const { return BBMap.lookup(BB); }
- /// operator[] - same as getLoopFor...
- ///
+ /// Same as getLoopFor.
const LoopT *operator[](const BlockT *BB) const {
return getLoopFor(BB);
}
- /// getLoopDepth - Return the loop nesting level of the specified block. A
- /// depth of 0 means the block is not inside any loop.
- ///
+ /// Return the loop nesting level of the specified block. A depth of 0 means
+ /// the block is not inside any loop.
unsigned getLoopDepth(const BlockT *BB) const {
const LoopT *L = getLoopFor(BB);
return L ? L->getLoopDepth() : 0;
}
- // isLoopHeader - True if the block is a loop header node
+ // True if the block is a loop header node
bool isLoopHeader(const BlockT *BB) const {
const LoopT *L = getLoopFor(BB);
return L && L->getHeader() == BB;
}
- /// removeLoop - This removes the specified top-level loop from this loop info
- /// object. The loop is not deleted, as it will presumably be inserted into
+ /// This removes the specified top-level loop from this loop info object.
+ /// The loop is not deleted, as it will presumably be inserted into
/// another loop.
LoopT *removeLoop(iterator I) {
assert(I != end() && "Cannot remove end iterator!");
return L;
}
- /// changeLoopFor - Change the top-level loop that contains BB to the
- /// specified loop. This should be used by transformations that restructure
- /// the loop hierarchy tree.
+ /// Change the top-level loop that contains BB to the specified loop.
+ /// This should be used by transformations that restructure the loop hierarchy
+ /// tree.
void changeLoopFor(BlockT *BB, LoopT *L) {
if (!L) {
BBMap.erase(BB);
BBMap[BB] = L;
}
- /// changeTopLevelLoop - Replace the specified loop in the top-level loops
- /// list with the indicated loop.
+ /// Replace the specified loop in the top-level loops list with the indicated
+ /// loop.
void changeTopLevelLoop(LoopT *OldLoop,
LoopT *NewLoop) {
auto I = std::find(TopLevelLoops.begin(), TopLevelLoops.end(), OldLoop);
"Loops already embedded into a subloop!");
}
- /// addTopLevelLoop - This adds the specified loop to the collection of
- /// top-level loops.
+ /// This adds the specified loop to the collection of top-level loops.
void addTopLevelLoop(LoopT *New) {
assert(!New->getParentLoop() && "Loop already in subloop!");
TopLevelLoops.push_back(New);
}
- /// removeBlock - This method completely removes BB from all data structures,
+ /// This method completely removes BB from all data structures,
/// including all of the Loop objects it is nested in and our mapping from
/// BasicBlocks to loops.
void removeBlock(BlockT *BB) {
/// will remain valid until this LoopInfo's memory is released.
void markAsRemoved(Loop *L);
- /// replacementPreservesLCSSAForm - Returns true if replacing From with To
- /// everywhere is guaranteed to preserve LCSSA form.
+ /// Returns true if replacing From with To everywhere is guaranteed to
+ /// preserve LCSSA form.
bool replacementPreservesLCSSAForm(Instruction *From, Value *To) {
// Preserving LCSSA form is only problematic if the replacing value is an
// instruction.
return ToLoop->contains(getLoopFor(From->getParent()));
}
- /// \brief Checks if moving a specific instruction can break LCSSA in any
- /// loop.
+ /// Checks if moving a specific instruction can break LCSSA in any loop.
///
/// Return true if moving \p Inst to before \p NewLoc will break LCSSA,
/// assuming that the function containing \p Inst and \p NewLoc is currently
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