mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-26 07:29:55 +00:00
can be used by both the new pass manager and the old. This removes it from any of the virtual mess of the pass interfaces and lets it derive cleanly from the DominatorTreeBase<> template. In turn, tons of boilerplate interface can be nuked and it turns into a very straightforward extension of the base DominatorTree interface. The old analysis pass is now a simple wrapper. The names and style of this split should match the split between CallGraph and CallGraphWrapperPass. All of the users of DominatorTree have been updated to match using many of the same tricks as with CallGraph. The goal is that the common type remains the resulting DominatorTree rather than the pass. This will make subsequent work toward the new pass manager significantly easier. Also in numerous places things became cleaner because I switched from re-running the pass (!!! mid way through some other passes run!!!) to directly recomputing the domtree. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199104 91177308-0d34-0410-b5e6-96231b3b80d8
719 lines
24 KiB
C++
719 lines
24 KiB
C++
//===- GenericDomTree.h - Generic dominator trees for graphs ----*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
/// \file
|
|
///
|
|
/// This file defines a set of templates that efficiently compute a dominator
|
|
/// tree over a generic graph. This is used typically in LLVM for fast
|
|
/// dominance queries on the CFG, but is fully generic w.r.t. the underlying
|
|
/// graph types.
|
|
///
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_SUPPORT_GENERIC_DOM_TREE_H
|
|
#define LLVM_SUPPORT_GENERIC_DOM_TREE_H
|
|
|
|
#include "llvm/ADT/DenseMap.h"
|
|
#include "llvm/ADT/DepthFirstIterator.h"
|
|
#include "llvm/ADT/GraphTraits.h"
|
|
#include "llvm/ADT/SmallPtrSet.h"
|
|
#include "llvm/ADT/SmallVector.h"
|
|
#include "llvm/Support/CFG.h"
|
|
#include "llvm/Support/Compiler.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
#include <algorithm>
|
|
|
|
namespace llvm {
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
/// DominatorBase - Base class that other, more interesting dominator analyses
|
|
/// inherit from.
|
|
///
|
|
template <class NodeT>
|
|
class DominatorBase {
|
|
protected:
|
|
std::vector<NodeT*> Roots;
|
|
const bool IsPostDominators;
|
|
inline explicit DominatorBase(bool isPostDom) :
|
|
Roots(), IsPostDominators(isPostDom) {}
|
|
public:
|
|
|
|
/// getRoots - Return the root blocks of the current CFG. This may include
|
|
/// multiple blocks if we are computing post dominators. For forward
|
|
/// dominators, this will always be a single block (the entry node).
|
|
///
|
|
inline const std::vector<NodeT*> &getRoots() const { return Roots; }
|
|
|
|
/// isPostDominator - Returns true if analysis based of postdoms
|
|
///
|
|
bool isPostDominator() const { return IsPostDominators; }
|
|
};
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// DomTreeNodeBase - Dominator Tree Node
|
|
template<class NodeT> class DominatorTreeBase;
|
|
struct PostDominatorTree;
|
|
|
|
template <class NodeT>
|
|
class DomTreeNodeBase {
|
|
NodeT *TheBB;
|
|
DomTreeNodeBase<NodeT> *IDom;
|
|
std::vector<DomTreeNodeBase<NodeT> *> Children;
|
|
mutable int DFSNumIn, DFSNumOut;
|
|
|
|
template<class N> friend class DominatorTreeBase;
|
|
friend struct PostDominatorTree;
|
|
public:
|
|
typedef typename std::vector<DomTreeNodeBase<NodeT> *>::iterator iterator;
|
|
typedef typename std::vector<DomTreeNodeBase<NodeT> *>::const_iterator
|
|
const_iterator;
|
|
|
|
iterator begin() { return Children.begin(); }
|
|
iterator end() { return Children.end(); }
|
|
const_iterator begin() const { return Children.begin(); }
|
|
const_iterator end() const { return Children.end(); }
|
|
|
|
NodeT *getBlock() const { return TheBB; }
|
|
DomTreeNodeBase<NodeT> *getIDom() const { return IDom; }
|
|
const std::vector<DomTreeNodeBase<NodeT>*> &getChildren() const {
|
|
return Children;
|
|
}
|
|
|
|
DomTreeNodeBase(NodeT *BB, DomTreeNodeBase<NodeT> *iDom)
|
|
: TheBB(BB), IDom(iDom), DFSNumIn(-1), DFSNumOut(-1) { }
|
|
|
|
DomTreeNodeBase<NodeT> *addChild(DomTreeNodeBase<NodeT> *C) {
|
|
Children.push_back(C);
|
|
return C;
|
|
}
|
|
|
|
size_t getNumChildren() const {
|
|
return Children.size();
|
|
}
|
|
|
|
void clearAllChildren() {
|
|
Children.clear();
|
|
}
|
|
|
|
bool compare(const DomTreeNodeBase<NodeT> *Other) const {
|
|
if (getNumChildren() != Other->getNumChildren())
|
|
return true;
|
|
|
|
SmallPtrSet<const NodeT *, 4> OtherChildren;
|
|
for (const_iterator I = Other->begin(), E = Other->end(); I != E; ++I) {
|
|
const NodeT *Nd = (*I)->getBlock();
|
|
OtherChildren.insert(Nd);
|
|
}
|
|
|
|
for (const_iterator I = begin(), E = end(); I != E; ++I) {
|
|
const NodeT *N = (*I)->getBlock();
|
|
if (OtherChildren.count(N) == 0)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
void setIDom(DomTreeNodeBase<NodeT> *NewIDom) {
|
|
assert(IDom && "No immediate dominator?");
|
|
if (IDom != NewIDom) {
|
|
typename std::vector<DomTreeNodeBase<NodeT>*>::iterator I =
|
|
std::find(IDom->Children.begin(), IDom->Children.end(), this);
|
|
assert(I != IDom->Children.end() &&
|
|
"Not in immediate dominator children set!");
|
|
// I am no longer your child...
|
|
IDom->Children.erase(I);
|
|
|
|
// Switch to new dominator
|
|
IDom = NewIDom;
|
|
IDom->Children.push_back(this);
|
|
}
|
|
}
|
|
|
|
/// getDFSNumIn/getDFSNumOut - These are an internal implementation detail, do
|
|
/// not call them.
|
|
unsigned getDFSNumIn() const { return DFSNumIn; }
|
|
unsigned getDFSNumOut() const { return DFSNumOut; }
|
|
private:
|
|
// Return true if this node is dominated by other. Use this only if DFS info
|
|
// is valid.
|
|
bool DominatedBy(const DomTreeNodeBase<NodeT> *other) const {
|
|
return this->DFSNumIn >= other->DFSNumIn &&
|
|
this->DFSNumOut <= other->DFSNumOut;
|
|
}
|
|
};
|
|
|
|
template<class NodeT>
|
|
inline raw_ostream &operator<<(raw_ostream &o,
|
|
const DomTreeNodeBase<NodeT> *Node) {
|
|
if (Node->getBlock())
|
|
Node->getBlock()->printAsOperand(o, false);
|
|
else
|
|
o << " <<exit node>>";
|
|
|
|
o << " {" << Node->getDFSNumIn() << "," << Node->getDFSNumOut() << "}";
|
|
|
|
return o << "\n";
|
|
}
|
|
|
|
template<class NodeT>
|
|
inline void PrintDomTree(const DomTreeNodeBase<NodeT> *N, raw_ostream &o,
|
|
unsigned Lev) {
|
|
o.indent(2*Lev) << "[" << Lev << "] " << N;
|
|
for (typename DomTreeNodeBase<NodeT>::const_iterator I = N->begin(),
|
|
E = N->end(); I != E; ++I)
|
|
PrintDomTree<NodeT>(*I, o, Lev+1);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
/// DominatorTree - Calculate the immediate dominator tree for a function.
|
|
///
|
|
|
|
template<class FuncT, class N>
|
|
void Calculate(DominatorTreeBase<typename GraphTraits<N>::NodeType>& DT,
|
|
FuncT& F);
|
|
|
|
template<class NodeT>
|
|
class DominatorTreeBase : public DominatorBase<NodeT> {
|
|
bool dominatedBySlowTreeWalk(const DomTreeNodeBase<NodeT> *A,
|
|
const DomTreeNodeBase<NodeT> *B) const {
|
|
assert(A != B);
|
|
assert(isReachableFromEntry(B));
|
|
assert(isReachableFromEntry(A));
|
|
|
|
const DomTreeNodeBase<NodeT> *IDom;
|
|
while ((IDom = B->getIDom()) != 0 && IDom != A && IDom != B)
|
|
B = IDom; // Walk up the tree
|
|
return IDom != 0;
|
|
}
|
|
|
|
protected:
|
|
typedef DenseMap<NodeT*, DomTreeNodeBase<NodeT>*> DomTreeNodeMapType;
|
|
DomTreeNodeMapType DomTreeNodes;
|
|
DomTreeNodeBase<NodeT> *RootNode;
|
|
|
|
mutable bool DFSInfoValid;
|
|
mutable unsigned int SlowQueries;
|
|
// Information record used during immediate dominators computation.
|
|
struct InfoRec {
|
|
unsigned DFSNum;
|
|
unsigned Parent;
|
|
unsigned Semi;
|
|
NodeT *Label;
|
|
|
|
InfoRec() : DFSNum(0), Parent(0), Semi(0), Label(0) {}
|
|
};
|
|
|
|
DenseMap<NodeT*, NodeT*> IDoms;
|
|
|
|
// Vertex - Map the DFS number to the NodeT*
|
|
std::vector<NodeT*> Vertex;
|
|
|
|
// Info - Collection of information used during the computation of idoms.
|
|
DenseMap<NodeT*, InfoRec> Info;
|
|
|
|
void reset() {
|
|
for (typename DomTreeNodeMapType::iterator I = this->DomTreeNodes.begin(),
|
|
E = DomTreeNodes.end(); I != E; ++I)
|
|
delete I->second;
|
|
DomTreeNodes.clear();
|
|
IDoms.clear();
|
|
this->Roots.clear();
|
|
Vertex.clear();
|
|
RootNode = 0;
|
|
}
|
|
|
|
// NewBB is split and now it has one successor. Update dominator tree to
|
|
// reflect this change.
|
|
template<class N, class GraphT>
|
|
void Split(DominatorTreeBase<typename GraphT::NodeType>& DT,
|
|
typename GraphT::NodeType* NewBB) {
|
|
assert(std::distance(GraphT::child_begin(NewBB),
|
|
GraphT::child_end(NewBB)) == 1 &&
|
|
"NewBB should have a single successor!");
|
|
typename GraphT::NodeType* NewBBSucc = *GraphT::child_begin(NewBB);
|
|
|
|
std::vector<typename GraphT::NodeType*> PredBlocks;
|
|
typedef GraphTraits<Inverse<N> > InvTraits;
|
|
for (typename InvTraits::ChildIteratorType PI =
|
|
InvTraits::child_begin(NewBB),
|
|
PE = InvTraits::child_end(NewBB); PI != PE; ++PI)
|
|
PredBlocks.push_back(*PI);
|
|
|
|
assert(!PredBlocks.empty() && "No predblocks?");
|
|
|
|
bool NewBBDominatesNewBBSucc = true;
|
|
for (typename InvTraits::ChildIteratorType PI =
|
|
InvTraits::child_begin(NewBBSucc),
|
|
E = InvTraits::child_end(NewBBSucc); PI != E; ++PI) {
|
|
typename InvTraits::NodeType *ND = *PI;
|
|
if (ND != NewBB && !DT.dominates(NewBBSucc, ND) &&
|
|
DT.isReachableFromEntry(ND)) {
|
|
NewBBDominatesNewBBSucc = false;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Find NewBB's immediate dominator and create new dominator tree node for
|
|
// NewBB.
|
|
NodeT *NewBBIDom = 0;
|
|
unsigned i = 0;
|
|
for (i = 0; i < PredBlocks.size(); ++i)
|
|
if (DT.isReachableFromEntry(PredBlocks[i])) {
|
|
NewBBIDom = PredBlocks[i];
|
|
break;
|
|
}
|
|
|
|
// It's possible that none of the predecessors of NewBB are reachable;
|
|
// in that case, NewBB itself is unreachable, so nothing needs to be
|
|
// changed.
|
|
if (!NewBBIDom)
|
|
return;
|
|
|
|
for (i = i + 1; i < PredBlocks.size(); ++i) {
|
|
if (DT.isReachableFromEntry(PredBlocks[i]))
|
|
NewBBIDom = DT.findNearestCommonDominator(NewBBIDom, PredBlocks[i]);
|
|
}
|
|
|
|
// Create the new dominator tree node... and set the idom of NewBB.
|
|
DomTreeNodeBase<NodeT> *NewBBNode = DT.addNewBlock(NewBB, NewBBIDom);
|
|
|
|
// If NewBB strictly dominates other blocks, then it is now the immediate
|
|
// dominator of NewBBSucc. Update the dominator tree as appropriate.
|
|
if (NewBBDominatesNewBBSucc) {
|
|
DomTreeNodeBase<NodeT> *NewBBSuccNode = DT.getNode(NewBBSucc);
|
|
DT.changeImmediateDominator(NewBBSuccNode, NewBBNode);
|
|
}
|
|
}
|
|
|
|
public:
|
|
explicit DominatorTreeBase(bool isPostDom)
|
|
: DominatorBase<NodeT>(isPostDom), DFSInfoValid(false), SlowQueries(0) {}
|
|
virtual ~DominatorTreeBase() { reset(); }
|
|
|
|
/// compare - Return false if the other dominator tree base matches this
|
|
/// dominator tree base. Otherwise return true.
|
|
bool compare(const DominatorTreeBase &Other) const {
|
|
|
|
const DomTreeNodeMapType &OtherDomTreeNodes = Other.DomTreeNodes;
|
|
if (DomTreeNodes.size() != OtherDomTreeNodes.size())
|
|
return true;
|
|
|
|
for (typename DomTreeNodeMapType::const_iterator
|
|
I = this->DomTreeNodes.begin(),
|
|
E = this->DomTreeNodes.end(); I != E; ++I) {
|
|
NodeT *BB = I->first;
|
|
typename DomTreeNodeMapType::const_iterator OI = OtherDomTreeNodes.find(BB);
|
|
if (OI == OtherDomTreeNodes.end())
|
|
return true;
|
|
|
|
DomTreeNodeBase<NodeT>* MyNd = I->second;
|
|
DomTreeNodeBase<NodeT>* OtherNd = OI->second;
|
|
|
|
if (MyNd->compare(OtherNd))
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
virtual void releaseMemory() { reset(); }
|
|
|
|
/// getNode - return the (Post)DominatorTree node for the specified basic
|
|
/// block. This is the same as using operator[] on this class.
|
|
///
|
|
inline DomTreeNodeBase<NodeT> *getNode(NodeT *BB) const {
|
|
return DomTreeNodes.lookup(BB);
|
|
}
|
|
|
|
/// getRootNode - This returns the entry node for the CFG of the function. If
|
|
/// this tree represents the post-dominance relations for a function, however,
|
|
/// this root may be a node with the block == NULL. This is the case when
|
|
/// there are multiple exit nodes from a particular function. Consumers of
|
|
/// post-dominance information must be capable of dealing with this
|
|
/// possibility.
|
|
///
|
|
DomTreeNodeBase<NodeT> *getRootNode() { return RootNode; }
|
|
const DomTreeNodeBase<NodeT> *getRootNode() const { return RootNode; }
|
|
|
|
/// Get all nodes dominated by R, including R itself.
|
|
void getDescendants(NodeT *R, SmallVectorImpl<NodeT *> &Result) const {
|
|
Result.clear();
|
|
const DomTreeNodeBase<NodeT> *RN = getNode(R);
|
|
if (RN == NULL)
|
|
return; // If R is unreachable, it will not be present in the DOM tree.
|
|
SmallVector<const DomTreeNodeBase<NodeT> *, 8> WL;
|
|
WL.push_back(RN);
|
|
|
|
while (!WL.empty()) {
|
|
const DomTreeNodeBase<NodeT> *N = WL.pop_back_val();
|
|
Result.push_back(N->getBlock());
|
|
WL.append(N->begin(), N->end());
|
|
}
|
|
}
|
|
|
|
/// properlyDominates - Returns true iff A dominates B and A != B.
|
|
/// Note that this is not a constant time operation!
|
|
///
|
|
bool properlyDominates(const DomTreeNodeBase<NodeT> *A,
|
|
const DomTreeNodeBase<NodeT> *B) const {
|
|
if (A == 0 || B == 0)
|
|
return false;
|
|
if (A == B)
|
|
return false;
|
|
return dominates(A, B);
|
|
}
|
|
|
|
bool properlyDominates(const NodeT *A, const NodeT *B) const;
|
|
|
|
/// isReachableFromEntry - Return true if A is dominated by the entry
|
|
/// block of the function containing it.
|
|
bool isReachableFromEntry(const NodeT* A) const {
|
|
assert(!this->isPostDominator() &&
|
|
"This is not implemented for post dominators");
|
|
return isReachableFromEntry(getNode(const_cast<NodeT *>(A)));
|
|
}
|
|
|
|
inline bool isReachableFromEntry(const DomTreeNodeBase<NodeT> *A) const {
|
|
return A;
|
|
}
|
|
|
|
/// dominates - Returns true iff A dominates B. Note that this is not a
|
|
/// constant time operation!
|
|
///
|
|
inline bool dominates(const DomTreeNodeBase<NodeT> *A,
|
|
const DomTreeNodeBase<NodeT> *B) const {
|
|
// A node trivially dominates itself.
|
|
if (B == A)
|
|
return true;
|
|
|
|
// An unreachable node is dominated by anything.
|
|
if (!isReachableFromEntry(B))
|
|
return true;
|
|
|
|
// And dominates nothing.
|
|
if (!isReachableFromEntry(A))
|
|
return false;
|
|
|
|
// Compare the result of the tree walk and the dfs numbers, if expensive
|
|
// checks are enabled.
|
|
#ifdef XDEBUG
|
|
assert((!DFSInfoValid ||
|
|
(dominatedBySlowTreeWalk(A, B) == B->DominatedBy(A))) &&
|
|
"Tree walk disagrees with dfs numbers!");
|
|
#endif
|
|
|
|
if (DFSInfoValid)
|
|
return B->DominatedBy(A);
|
|
|
|
// If we end up with too many slow queries, just update the
|
|
// DFS numbers on the theory that we are going to keep querying.
|
|
SlowQueries++;
|
|
if (SlowQueries > 32) {
|
|
updateDFSNumbers();
|
|
return B->DominatedBy(A);
|
|
}
|
|
|
|
return dominatedBySlowTreeWalk(A, B);
|
|
}
|
|
|
|
bool dominates(const NodeT *A, const NodeT *B) const;
|
|
|
|
NodeT *getRoot() const {
|
|
assert(this->Roots.size() == 1 && "Should always have entry node!");
|
|
return this->Roots[0];
|
|
}
|
|
|
|
/// findNearestCommonDominator - Find nearest common dominator basic block
|
|
/// for basic block A and B. If there is no such block then return NULL.
|
|
NodeT *findNearestCommonDominator(NodeT *A, NodeT *B) {
|
|
assert(A->getParent() == B->getParent() &&
|
|
"Two blocks are not in same function");
|
|
|
|
// If either A or B is a entry block then it is nearest common dominator
|
|
// (for forward-dominators).
|
|
if (!this->isPostDominator()) {
|
|
NodeT &Entry = A->getParent()->front();
|
|
if (A == &Entry || B == &Entry)
|
|
return &Entry;
|
|
}
|
|
|
|
// If B dominates A then B is nearest common dominator.
|
|
if (dominates(B, A))
|
|
return B;
|
|
|
|
// If A dominates B then A is nearest common dominator.
|
|
if (dominates(A, B))
|
|
return A;
|
|
|
|
DomTreeNodeBase<NodeT> *NodeA = getNode(A);
|
|
DomTreeNodeBase<NodeT> *NodeB = getNode(B);
|
|
|
|
// Collect NodeA dominators set.
|
|
SmallPtrSet<DomTreeNodeBase<NodeT>*, 16> NodeADoms;
|
|
NodeADoms.insert(NodeA);
|
|
DomTreeNodeBase<NodeT> *IDomA = NodeA->getIDom();
|
|
while (IDomA) {
|
|
NodeADoms.insert(IDomA);
|
|
IDomA = IDomA->getIDom();
|
|
}
|
|
|
|
// Walk NodeB immediate dominators chain and find common dominator node.
|
|
DomTreeNodeBase<NodeT> *IDomB = NodeB->getIDom();
|
|
while (IDomB) {
|
|
if (NodeADoms.count(IDomB) != 0)
|
|
return IDomB->getBlock();
|
|
|
|
IDomB = IDomB->getIDom();
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
const NodeT *findNearestCommonDominator(const NodeT *A, const NodeT *B) {
|
|
// Cast away the const qualifiers here. This is ok since
|
|
// const is re-introduced on the return type.
|
|
return findNearestCommonDominator(const_cast<NodeT *>(A),
|
|
const_cast<NodeT *>(B));
|
|
}
|
|
|
|
//===--------------------------------------------------------------------===//
|
|
// API to update (Post)DominatorTree information based on modifications to
|
|
// the CFG...
|
|
|
|
/// addNewBlock - Add a new node to the dominator tree information. This
|
|
/// creates a new node as a child of DomBB dominator node,linking it into
|
|
/// the children list of the immediate dominator.
|
|
DomTreeNodeBase<NodeT> *addNewBlock(NodeT *BB, NodeT *DomBB) {
|
|
assert(getNode(BB) == 0 && "Block already in dominator tree!");
|
|
DomTreeNodeBase<NodeT> *IDomNode = getNode(DomBB);
|
|
assert(IDomNode && "Not immediate dominator specified for block!");
|
|
DFSInfoValid = false;
|
|
return DomTreeNodes[BB] =
|
|
IDomNode->addChild(new DomTreeNodeBase<NodeT>(BB, IDomNode));
|
|
}
|
|
|
|
/// changeImmediateDominator - This method is used to update the dominator
|
|
/// tree information when a node's immediate dominator changes.
|
|
///
|
|
void changeImmediateDominator(DomTreeNodeBase<NodeT> *N,
|
|
DomTreeNodeBase<NodeT> *NewIDom) {
|
|
assert(N && NewIDom && "Cannot change null node pointers!");
|
|
DFSInfoValid = false;
|
|
N->setIDom(NewIDom);
|
|
}
|
|
|
|
void changeImmediateDominator(NodeT *BB, NodeT *NewBB) {
|
|
changeImmediateDominator(getNode(BB), getNode(NewBB));
|
|
}
|
|
|
|
/// eraseNode - Removes a node from the dominator tree. Block must not
|
|
/// dominate any other blocks. Removes node from its immediate dominator's
|
|
/// children list. Deletes dominator node associated with basic block BB.
|
|
void eraseNode(NodeT *BB) {
|
|
DomTreeNodeBase<NodeT> *Node = getNode(BB);
|
|
assert(Node && "Removing node that isn't in dominator tree.");
|
|
assert(Node->getChildren().empty() && "Node is not a leaf node.");
|
|
|
|
// Remove node from immediate dominator's children list.
|
|
DomTreeNodeBase<NodeT> *IDom = Node->getIDom();
|
|
if (IDom) {
|
|
typename std::vector<DomTreeNodeBase<NodeT>*>::iterator I =
|
|
std::find(IDom->Children.begin(), IDom->Children.end(), Node);
|
|
assert(I != IDom->Children.end() &&
|
|
"Not in immediate dominator children set!");
|
|
// I am no longer your child...
|
|
IDom->Children.erase(I);
|
|
}
|
|
|
|
DomTreeNodes.erase(BB);
|
|
delete Node;
|
|
}
|
|
|
|
/// removeNode - Removes a node from the dominator tree. Block must not
|
|
/// dominate any other blocks. Invalidates any node pointing to removed
|
|
/// block.
|
|
void removeNode(NodeT *BB) {
|
|
assert(getNode(BB) && "Removing node that isn't in dominator tree.");
|
|
DomTreeNodes.erase(BB);
|
|
}
|
|
|
|
/// splitBlock - BB is split and now it has one successor. Update dominator
|
|
/// tree to reflect this change.
|
|
void splitBlock(NodeT* NewBB) {
|
|
if (this->IsPostDominators)
|
|
this->Split<Inverse<NodeT*>, GraphTraits<Inverse<NodeT*> > >(*this, NewBB);
|
|
else
|
|
this->Split<NodeT*, GraphTraits<NodeT*> >(*this, NewBB);
|
|
}
|
|
|
|
/// print - Convert to human readable form
|
|
///
|
|
void print(raw_ostream &o) const {
|
|
o << "=============================--------------------------------\n";
|
|
if (this->isPostDominator())
|
|
o << "Inorder PostDominator Tree: ";
|
|
else
|
|
o << "Inorder Dominator Tree: ";
|
|
if (!this->DFSInfoValid)
|
|
o << "DFSNumbers invalid: " << SlowQueries << " slow queries.";
|
|
o << "\n";
|
|
|
|
// The postdom tree can have a null root if there are no returns.
|
|
if (getRootNode())
|
|
PrintDomTree<NodeT>(getRootNode(), o, 1);
|
|
}
|
|
|
|
protected:
|
|
template<class GraphT>
|
|
friend typename GraphT::NodeType* Eval(
|
|
DominatorTreeBase<typename GraphT::NodeType>& DT,
|
|
typename GraphT::NodeType* V,
|
|
unsigned LastLinked);
|
|
|
|
template<class GraphT>
|
|
friend unsigned DFSPass(DominatorTreeBase<typename GraphT::NodeType>& DT,
|
|
typename GraphT::NodeType* V,
|
|
unsigned N);
|
|
|
|
template<class FuncT, class N>
|
|
friend void Calculate(DominatorTreeBase<typename GraphTraits<N>::NodeType>& DT,
|
|
FuncT& F);
|
|
|
|
/// updateDFSNumbers - Assign In and Out numbers to the nodes while walking
|
|
/// dominator tree in dfs order.
|
|
void updateDFSNumbers() const {
|
|
unsigned DFSNum = 0;
|
|
|
|
SmallVector<std::pair<const DomTreeNodeBase<NodeT>*,
|
|
typename DomTreeNodeBase<NodeT>::const_iterator>, 32> WorkStack;
|
|
|
|
const DomTreeNodeBase<NodeT> *ThisRoot = getRootNode();
|
|
|
|
if (!ThisRoot)
|
|
return;
|
|
|
|
// Even in the case of multiple exits that form the post dominator root
|
|
// nodes, do not iterate over all exits, but start from the virtual root
|
|
// node. Otherwise bbs, that are not post dominated by any exit but by the
|
|
// virtual root node, will never be assigned a DFS number.
|
|
WorkStack.push_back(std::make_pair(ThisRoot, ThisRoot->begin()));
|
|
ThisRoot->DFSNumIn = DFSNum++;
|
|
|
|
while (!WorkStack.empty()) {
|
|
const DomTreeNodeBase<NodeT> *Node = WorkStack.back().first;
|
|
typename DomTreeNodeBase<NodeT>::const_iterator ChildIt =
|
|
WorkStack.back().second;
|
|
|
|
// If we visited all of the children of this node, "recurse" back up the
|
|
// stack setting the DFOutNum.
|
|
if (ChildIt == Node->end()) {
|
|
Node->DFSNumOut = DFSNum++;
|
|
WorkStack.pop_back();
|
|
} else {
|
|
// Otherwise, recursively visit this child.
|
|
const DomTreeNodeBase<NodeT> *Child = *ChildIt;
|
|
++WorkStack.back().second;
|
|
|
|
WorkStack.push_back(std::make_pair(Child, Child->begin()));
|
|
Child->DFSNumIn = DFSNum++;
|
|
}
|
|
}
|
|
|
|
SlowQueries = 0;
|
|
DFSInfoValid = true;
|
|
}
|
|
|
|
DomTreeNodeBase<NodeT> *getNodeForBlock(NodeT *BB) {
|
|
if (DomTreeNodeBase<NodeT> *Node = getNode(BB))
|
|
return Node;
|
|
|
|
// Haven't calculated this node yet? Get or calculate the node for the
|
|
// immediate dominator.
|
|
NodeT *IDom = getIDom(BB);
|
|
|
|
assert(IDom || this->DomTreeNodes[NULL]);
|
|
DomTreeNodeBase<NodeT> *IDomNode = getNodeForBlock(IDom);
|
|
|
|
// Add a new tree node for this NodeT, and link it as a child of
|
|
// IDomNode
|
|
DomTreeNodeBase<NodeT> *C = new DomTreeNodeBase<NodeT>(BB, IDomNode);
|
|
return this->DomTreeNodes[BB] = IDomNode->addChild(C);
|
|
}
|
|
|
|
inline NodeT *getIDom(NodeT *BB) const {
|
|
return IDoms.lookup(BB);
|
|
}
|
|
|
|
inline void addRoot(NodeT* BB) {
|
|
this->Roots.push_back(BB);
|
|
}
|
|
|
|
public:
|
|
/// recalculate - compute a dominator tree for the given function
|
|
template<class FT>
|
|
void recalculate(FT& F) {
|
|
typedef GraphTraits<FT*> TraitsTy;
|
|
reset();
|
|
this->Vertex.push_back(0);
|
|
|
|
if (!this->IsPostDominators) {
|
|
// Initialize root
|
|
NodeT *entry = TraitsTy::getEntryNode(&F);
|
|
this->Roots.push_back(entry);
|
|
this->IDoms[entry] = 0;
|
|
this->DomTreeNodes[entry] = 0;
|
|
|
|
Calculate<FT, NodeT*>(*this, F);
|
|
} else {
|
|
// Initialize the roots list
|
|
for (typename TraitsTy::nodes_iterator I = TraitsTy::nodes_begin(&F),
|
|
E = TraitsTy::nodes_end(&F); I != E; ++I) {
|
|
if (TraitsTy::child_begin(I) == TraitsTy::child_end(I))
|
|
addRoot(I);
|
|
|
|
// Prepopulate maps so that we don't get iterator invalidation issues later.
|
|
this->IDoms[I] = 0;
|
|
this->DomTreeNodes[I] = 0;
|
|
}
|
|
|
|
Calculate<FT, Inverse<NodeT*> >(*this, F);
|
|
}
|
|
}
|
|
};
|
|
|
|
// These two functions are declared out of line as a workaround for building
|
|
// with old (< r147295) versions of clang because of pr11642.
|
|
template<class NodeT>
|
|
bool DominatorTreeBase<NodeT>::dominates(const NodeT *A, const NodeT *B) const {
|
|
if (A == B)
|
|
return true;
|
|
|
|
// Cast away the const qualifiers here. This is ok since
|
|
// this function doesn't actually return the values returned
|
|
// from getNode.
|
|
return dominates(getNode(const_cast<NodeT *>(A)),
|
|
getNode(const_cast<NodeT *>(B)));
|
|
}
|
|
template<class NodeT>
|
|
bool
|
|
DominatorTreeBase<NodeT>::properlyDominates(const NodeT *A, const NodeT *B) const {
|
|
if (A == B)
|
|
return false;
|
|
|
|
// Cast away the const qualifiers here. This is ok since
|
|
// this function doesn't actually return the values returned
|
|
// from getNode.
|
|
return dominates(getNode(const_cast<NodeT *>(A)),
|
|
getNode(const_cast<NodeT *>(B)));
|
|
}
|
|
|
|
}
|
|
|
|
#endif
|