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llvm/lib/VMCore/Dominators.cpp
Reid Spencer 4f1bd9e996 For PR780: 
1. Fix the macros in IncludeFile.h to put everything in the llvm namespace
2. Replace the previous explicit mechanism in all the .h and .cpp files
   with the macros in IncludeFile.h
This gets us a consistent mechanism throughout LLVM for ensuring linkage.
Next step is to make sure its used in enough places.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28715 91177308-0d34-0410-b5e6-96231b3b80d8
2006-06-07 22:00:26 +00:00

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//===- Dominators.cpp - Dominator Calculation -----------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements simple dominator construction algorithms for finding
// forward dominators. Postdominators are available in libanalysis, but are not
// included in libvmcore, because it's not needed. Forward dominators are
// needed to support the Verifier pass.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/Dominators.h"
#include "llvm/Support/CFG.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/SetOperations.h"
#include <algorithm>
#include <iostream>
using namespace llvm;
//===----------------------------------------------------------------------===//
// ImmediateDominators Implementation
//===----------------------------------------------------------------------===//
//
// Immediate Dominators construction - This pass constructs immediate dominator
// information for a flow-graph based on the algorithm described in this
// document:
//
// A Fast Algorithm for Finding Dominators in a Flowgraph
// T. Lengauer & R. Tarjan, ACM TOPLAS July 1979, pgs 121-141.
//
// This implements both the O(n*ack(n)) and the O(n*log(n)) versions of EVAL and
// LINK, but it turns out that the theoretically slower O(n*log(n))
// implementation is actually faster than the "efficient" algorithm (even for
// large CFGs) because the constant overheads are substantially smaller. The
// lower-complexity version can be enabled with the following #define:
//
#define BALANCE_IDOM_TREE 0
//
//===----------------------------------------------------------------------===//
static RegisterAnalysis<ImmediateDominators>
C("idom", "Immediate Dominators Construction", true);
unsigned ImmediateDominators::DFSPass(BasicBlock *V, InfoRec &VInfo,
unsigned N) {
VInfo.Semi = ++N;
VInfo.Label = V;
Vertex.push_back(V); // Vertex[n] = V;
//Info[V].Ancestor = 0; // Ancestor[n] = 0
//Child[V] = 0; // Child[v] = 0
VInfo.Size = 1; // Size[v] = 1
for (succ_iterator SI = succ_begin(V), E = succ_end(V); SI != E; ++SI) {
InfoRec &SuccVInfo = Info[*SI];
if (SuccVInfo.Semi == 0) {
SuccVInfo.Parent = V;
N = DFSPass(*SI, SuccVInfo, N);
}
}
return N;
}
void ImmediateDominators::Compress(BasicBlock *V, InfoRec &VInfo) {
BasicBlock *VAncestor = VInfo.Ancestor;
InfoRec &VAInfo = Info[VAncestor];
if (VAInfo.Ancestor == 0)
return;
Compress(VAncestor, VAInfo);
BasicBlock *VAncestorLabel = VAInfo.Label;
BasicBlock *VLabel = VInfo.Label;
if (Info[VAncestorLabel].Semi < Info[VLabel].Semi)
VInfo.Label = VAncestorLabel;
VInfo.Ancestor = VAInfo.Ancestor;
}
BasicBlock *ImmediateDominators::Eval(BasicBlock *V) {
InfoRec &VInfo = Info[V];
#if !BALANCE_IDOM_TREE
// Higher-complexity but faster implementation
if (VInfo.Ancestor == 0)
return V;
Compress(V, VInfo);
return VInfo.Label;
#else
// Lower-complexity but slower implementation
if (VInfo.Ancestor == 0)
return VInfo.Label;
Compress(V, VInfo);
BasicBlock *VLabel = VInfo.Label;
BasicBlock *VAncestorLabel = Info[VInfo.Ancestor].Label;
if (Info[VAncestorLabel].Semi >= Info[VLabel].Semi)
return VLabel;
else
return VAncestorLabel;
#endif
}
void ImmediateDominators::Link(BasicBlock *V, BasicBlock *W, InfoRec &WInfo){
#if !BALANCE_IDOM_TREE
// Higher-complexity but faster implementation
WInfo.Ancestor = V;
#else
// Lower-complexity but slower implementation
BasicBlock *WLabel = WInfo.Label;
unsigned WLabelSemi = Info[WLabel].Semi;
BasicBlock *S = W;
InfoRec *SInfo = &Info[S];
BasicBlock *SChild = SInfo->Child;
InfoRec *SChildInfo = &Info[SChild];
while (WLabelSemi < Info[SChildInfo->Label].Semi) {
BasicBlock *SChildChild = SChildInfo->Child;
if (SInfo->Size+Info[SChildChild].Size >= 2*SChildInfo->Size) {
SChildInfo->Ancestor = S;
SInfo->Child = SChild = SChildChild;
SChildInfo = &Info[SChild];
} else {
SChildInfo->Size = SInfo->Size;
S = SInfo->Ancestor = SChild;
SInfo = SChildInfo;
SChild = SChildChild;
SChildInfo = &Info[SChild];
}
}
InfoRec &VInfo = Info[V];
SInfo->Label = WLabel;
assert(V != W && "The optimization here will not work in this case!");
unsigned WSize = WInfo.Size;
unsigned VSize = (VInfo.Size += WSize);
if (VSize < 2*WSize)
std::swap(S, VInfo.Child);
while (S) {
SInfo = &Info[S];
SInfo->Ancestor = V;
S = SInfo->Child;
}
#endif
}
bool ImmediateDominators::runOnFunction(Function &F) {
IDoms.clear(); // Reset from the last time we were run...
BasicBlock *Root = &F.getEntryBlock();
Roots.clear();
Roots.push_back(Root);
Vertex.push_back(0);
// Step #1: Number blocks in depth-first order and initialize variables used
// in later stages of the algorithm.
unsigned N = 0;
for (unsigned i = 0, e = Roots.size(); i != e; ++i)
N = DFSPass(Roots[i], Info[Roots[i]], 0);
for (unsigned i = N; i >= 2; --i) {
BasicBlock *W = Vertex[i];
InfoRec &WInfo = Info[W];
// Step #2: Calculate the semidominators of all vertices
for (pred_iterator PI = pred_begin(W), E = pred_end(W); PI != E; ++PI)
if (Info.count(*PI)) { // Only if this predecessor is reachable!
unsigned SemiU = Info[Eval(*PI)].Semi;
if (SemiU < WInfo.Semi)
WInfo.Semi = SemiU;
}
Info[Vertex[WInfo.Semi]].Bucket.push_back(W);
BasicBlock *WParent = WInfo.Parent;
Link(WParent, W, WInfo);
// Step #3: Implicitly define the immediate dominator of vertices
std::vector<BasicBlock*> &WParentBucket = Info[WParent].Bucket;
while (!WParentBucket.empty()) {
BasicBlock *V = WParentBucket.back();
WParentBucket.pop_back();
BasicBlock *U = Eval(V);
IDoms[V] = Info[U].Semi < Info[V].Semi ? U : WParent;
}
}
// Step #4: Explicitly define the immediate dominator of each vertex
for (unsigned i = 2; i <= N; ++i) {
BasicBlock *W = Vertex[i];
BasicBlock *&WIDom = IDoms[W];
if (WIDom != Vertex[Info[W].Semi])
WIDom = IDoms[WIDom];
}
// Free temporary memory used to construct idom's
Info.clear();
std::vector<BasicBlock*>().swap(Vertex);
return false;
}
void ImmediateDominatorsBase::print(std::ostream &o, const Module* ) const {
Function *F = getRoots()[0]->getParent();
for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
o << " Immediate Dominator For Basic Block:";
WriteAsOperand(o, I, false);
o << " is:";
if (BasicBlock *ID = get(I))
WriteAsOperand(o, ID, false);
else
o << " <<exit node>>";
o << "\n";
}
o << "\n";
}
//===----------------------------------------------------------------------===//
// DominatorSet Implementation
//===----------------------------------------------------------------------===//
static RegisterAnalysis<DominatorSet>
B("domset", "Dominator Set Construction", true);
// dominates - Return true if A dominates B. This performs the special checks
// necessary if A and B are in the same basic block.
//
bool DominatorSetBase::dominates(Instruction *A, Instruction *B) const {
BasicBlock *BBA = A->getParent(), *BBB = B->getParent();
if (BBA != BBB) return dominates(BBA, BBB);
// Loop through the basic block until we find A or B.
BasicBlock::iterator I = BBA->begin();
for (; &*I != A && &*I != B; ++I) /*empty*/;
if(!IsPostDominators) {
// A dominates B if it is found first in the basic block.
return &*I == A;
} else {
// A post-dominates B if B is found first in the basic block.
return &*I == B;
}
}
// runOnFunction - This method calculates the forward dominator sets for the
// specified function.
//
bool DominatorSet::runOnFunction(Function &F) {
BasicBlock *Root = &F.getEntryBlock();
Roots.clear();
Roots.push_back(Root);
assert(pred_begin(Root) == pred_end(Root) &&
"Root node has predecessors in function!");
ImmediateDominators &ID = getAnalysis<ImmediateDominators>();
Doms.clear();
if (Roots.empty()) return false;
// Root nodes only dominate themselves.
for (unsigned i = 0, e = Roots.size(); i != e; ++i)
Doms[Roots[i]].insert(Roots[i]);
// Loop over all of the blocks in the function, calculating dominator sets for
// each function.
for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
if (BasicBlock *IDom = ID[I]) { // Get idom if block is reachable
DomSetType &DS = Doms[I];
assert(DS.empty() && "Domset already filled in for this block?");
DS.insert(I); // Blocks always dominate themselves
// Insert all dominators into the set...
while (IDom) {
// If we have already computed the dominator sets for our immediate
// dominator, just use it instead of walking all the way up to the root.
DomSetType &IDS = Doms[IDom];
if (!IDS.empty()) {
DS.insert(IDS.begin(), IDS.end());
break;
} else {
DS.insert(IDom);
IDom = ID[IDom];
}
}
} else {
// Ensure that every basic block has at least an empty set of nodes. This
// is important for the case when there is unreachable blocks.
Doms[I];
}
return false;
}
namespace llvm {
static std::ostream &operator<<(std::ostream &o,
const std::set<BasicBlock*> &BBs) {
for (std::set<BasicBlock*>::const_iterator I = BBs.begin(), E = BBs.end();
I != E; ++I)
if (*I)
WriteAsOperand(o, *I, false);
else
o << " <<exit node>>";
return o;
}
}
void DominatorSetBase::print(std::ostream &o, const Module* ) const {
for (const_iterator I = begin(), E = end(); I != E; ++I) {
o << " DomSet For BB: ";
if (I->first)
WriteAsOperand(o, I->first, false);
else
o << " <<exit node>>";
o << " is:\t" << I->second << "\n";
}
}
//===----------------------------------------------------------------------===//
// DominatorTree Implementation
//===----------------------------------------------------------------------===//
static RegisterAnalysis<DominatorTree>
E("domtree", "Dominator Tree Construction", true);
// DominatorTreeBase::reset - Free all of the tree node memory.
//
void DominatorTreeBase::reset() {
for (NodeMapType::iterator I = Nodes.begin(), E = Nodes.end(); I != E; ++I)
delete I->second;
Nodes.clear();
RootNode = 0;
}
void DominatorTreeBase::Node::setIDom(Node *NewIDom) {
assert(IDom && "No immediate dominator?");
if (IDom != NewIDom) {
std::vector<Node*>::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);
}
}
DominatorTreeBase::Node *DominatorTree::getNodeForBlock(BasicBlock *BB) {
Node *&BBNode = Nodes[BB];
if (BBNode) return BBNode;
// Haven't calculated this node yet? Get or calculate the node for the
// immediate dominator.
BasicBlock *IDom = getAnalysis<ImmediateDominators>()[BB];
Node *IDomNode = getNodeForBlock(IDom);
// Add a new tree node for this BasicBlock, and link it as a child of
// IDomNode
return BBNode = IDomNode->addChild(new Node(BB, IDomNode));
}
void DominatorTree::calculate(const ImmediateDominators &ID) {
assert(Roots.size() == 1 && "DominatorTree should have 1 root block!");
BasicBlock *Root = Roots[0];
Nodes[Root] = RootNode = new Node(Root, 0); // Add a node for the root...
Function *F = Root->getParent();
// Loop over all of the reachable blocks in the function...
for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I)
if (BasicBlock *ImmDom = ID.get(I)) { // Reachable block.
Node *&BBNode = Nodes[I];
if (!BBNode) { // Haven't calculated this node yet?
// Get or calculate the node for the immediate dominator
Node *IDomNode = getNodeForBlock(ImmDom);
// Add a new tree node for this BasicBlock, and link it as a child of
// IDomNode
BBNode = IDomNode->addChild(new Node(I, IDomNode));
}
}
}
static std::ostream &operator<<(std::ostream &o,
const DominatorTreeBase::Node *Node) {
if (Node->getBlock())
WriteAsOperand(o, Node->getBlock(), false);
else
o << " <<exit node>>";
return o << "\n";
}
static void PrintDomTree(const DominatorTreeBase::Node *N, std::ostream &o,
unsigned Lev) {
o << std::string(2*Lev, ' ') << "[" << Lev << "] " << N;
for (DominatorTreeBase::Node::const_iterator I = N->begin(), E = N->end();
I != E; ++I)
PrintDomTree(*I, o, Lev+1);
}
void DominatorTreeBase::print(std::ostream &o, const Module* ) const {
o << "=============================--------------------------------\n"
<< "Inorder Dominator Tree:\n";
PrintDomTree(getRootNode(), o, 1);
}
//===----------------------------------------------------------------------===//
// DominanceFrontier Implementation
//===----------------------------------------------------------------------===//
static RegisterAnalysis<DominanceFrontier>
G("domfrontier", "Dominance Frontier Construction", true);
const DominanceFrontier::DomSetType &
DominanceFrontier::calculate(const DominatorTree &DT,
const DominatorTree::Node *Node) {
// Loop over CFG successors to calculate DFlocal[Node]
BasicBlock *BB = Node->getBlock();
DomSetType &S = Frontiers[BB]; // The new set to fill in...
for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB);
SI != SE; ++SI) {
// Does Node immediately dominate this successor?
if (DT[*SI]->getIDom() != Node)
S.insert(*SI);
}
// At this point, S is DFlocal. Now we union in DFup's of our children...
// Loop through and visit the nodes that Node immediately dominates (Node's
// children in the IDomTree)
//
for (DominatorTree::Node::const_iterator NI = Node->begin(), NE = Node->end();
NI != NE; ++NI) {
DominatorTree::Node *IDominee = *NI;
const DomSetType &ChildDF = calculate(DT, IDominee);
DomSetType::const_iterator CDFI = ChildDF.begin(), CDFE = ChildDF.end();
for (; CDFI != CDFE; ++CDFI) {
if (!Node->properlyDominates(DT[*CDFI]))
S.insert(*CDFI);
}
}
return S;
}
void DominanceFrontierBase::print(std::ostream &o, const Module* ) const {
for (const_iterator I = begin(), E = end(); I != E; ++I) {
o << " DomFrontier for BB";
if (I->first)
WriteAsOperand(o, I->first, false);
else
o << " <<exit node>>";
o << " is:\t" << I->second << "\n";
}
}
//===----------------------------------------------------------------------===//
// ETOccurrence Implementation
//===----------------------------------------------------------------------===//
void ETOccurrence::Splay() {
ETOccurrence *father;
ETOccurrence *grandfather;
int occdepth;
int fatherdepth;
while (Parent) {
occdepth = Depth;
father = Parent;
fatherdepth = Parent->Depth;
grandfather = father->Parent;
// If we have no grandparent, a single zig or zag will do.
if (!grandfather) {
setDepthAdd(fatherdepth);
MinOccurrence = father->MinOccurrence;
Min = father->Min;
// See what we have to rotate
if (father->Left == this) {
// Zig
father->setLeft(Right);
setRight(father);
if (father->Left)
father->Left->setDepthAdd(occdepth);
} else {
// Zag
father->setRight(Left);
setLeft(father);
if (father->Right)
father->Right->setDepthAdd(occdepth);
}
father->setDepth(-occdepth);
Parent = NULL;
father->recomputeMin();
return;
}
// If we have a grandfather, we need to do some
// combination of zig and zag.
int grandfatherdepth = grandfather->Depth;
setDepthAdd(fatherdepth + grandfatherdepth);
MinOccurrence = grandfather->MinOccurrence;
Min = grandfather->Min;
ETOccurrence *greatgrandfather = grandfather->Parent;
if (grandfather->Left == father) {
if (father->Left == this) {
// Zig zig
grandfather->setLeft(father->Right);
father->setLeft(Right);
setRight(father);
father->setRight(grandfather);
father->setDepth(-occdepth);
if (father->Left)
father->Left->setDepthAdd(occdepth);
grandfather->setDepth(-fatherdepth);
if (grandfather->Left)
grandfather->Left->setDepthAdd(fatherdepth);
} else {
// Zag zig
grandfather->setLeft(Right);
father->setRight(Left);
setLeft(father);
setRight(grandfather);
father->setDepth(-occdepth);
if (father->Right)
father->Right->setDepthAdd(occdepth);
grandfather->setDepth(-occdepth - fatherdepth);
if (grandfather->Left)
grandfather->Left->setDepthAdd(occdepth + fatherdepth);
}
} else {
if (father->Left == this) {
// Zig zag
grandfather->setRight(Left);
father->setLeft(Right);
setLeft(grandfather);
setRight(father);
father->setDepth(-occdepth);
if (father->Left)
father->Left->setDepthAdd(occdepth);
grandfather->setDepth(-occdepth - fatherdepth);
if (grandfather->Right)
grandfather->Right->setDepthAdd(occdepth + fatherdepth);
} else { // Zag Zag
grandfather->setRight(father->Left);
father->setRight(Left);
setLeft(father);
father->setLeft(grandfather);
father->setDepth(-occdepth);
if (father->Right)
father->Right->setDepthAdd(occdepth);
grandfather->setDepth(-fatherdepth);
if (grandfather->Right)
grandfather->Right->setDepthAdd(fatherdepth);
}
}
// Might need one more rotate depending on greatgrandfather.
setParent(greatgrandfather);
if (greatgrandfather) {
if (greatgrandfather->Left == grandfather)
greatgrandfather->Left = this;
else
greatgrandfather->Right = this;
}
grandfather->recomputeMin();
father->recomputeMin();
}
}
//===----------------------------------------------------------------------===//
// ETNode implementation
//===----------------------------------------------------------------------===//
void ETNode::Split() {
ETOccurrence *right, *left;
ETOccurrence *rightmost = RightmostOcc;
ETOccurrence *parent;
// Update the occurrence tree first.
RightmostOcc->Splay();
// Find the leftmost occurrence in the rightmost subtree, then splay
// around it.
for (right = rightmost->Right; right->Left; right = right->Left);
right->Splay();
// Start splitting
right->Left->Parent = NULL;
parent = ParentOcc;
parent->Splay();
ParentOcc = NULL;
left = parent->Left;
parent->Right->Parent = NULL;
right->setLeft(left);
right->recomputeMin();
rightmost->Splay();
rightmost->Depth = 0;
rightmost->Min = 0;
delete parent;
// Now update *our* tree
if (Father->Son == this)
Father->Son = Right;
if (Father->Son == this)
Father->Son = NULL;
else {
Left->Right = Right;
Right->Left = Left;
}
Left = Right = NULL;
Father = NULL;
}
void ETNode::setFather(ETNode *NewFather) {
ETOccurrence *rightmost;
ETOccurrence *leftpart;
ETOccurrence *NewFatherOcc;
ETOccurrence *temp;
// First update the path in the splay tree
NewFatherOcc = new ETOccurrence(NewFather);
rightmost = NewFather->RightmostOcc;
rightmost->Splay();
leftpart = rightmost->Left;
temp = RightmostOcc;
temp->Splay();
NewFatherOcc->setLeft(leftpart);
NewFatherOcc->setRight(temp);
temp->Depth++;
temp->Min++;
NewFatherOcc->recomputeMin();
rightmost->setLeft(NewFatherOcc);
if (NewFatherOcc->Min + rightmost->Depth < rightmost->Min) {
rightmost->Min = NewFatherOcc->Min + rightmost->Depth;
rightmost->MinOccurrence = NewFatherOcc->MinOccurrence;
}
delete ParentOcc;
ParentOcc = NewFatherOcc;
// Update *our* tree
ETNode *left;
ETNode *right;
Father = NewFather;
right = Father->Son;
if (right)
left = right->Left;
else
left = right = this;
left->Right = this;
right->Left = this;
Left = left;
Right = right;
Father->Son = this;
}
bool ETNode::Below(ETNode *other) {
ETOccurrence *up = other->RightmostOcc;
ETOccurrence *down = RightmostOcc;
if (this == other)
return true;
up->Splay();
ETOccurrence *left, *right;
left = up->Left;
right = up->Right;
if (!left)
return false;
left->Parent = NULL;
if (right)
right->Parent = NULL;
down->Splay();
if (left == down || left->Parent != NULL) {
if (right)
right->Parent = up;
up->setLeft(down);
} else {
left->Parent = up;
// If the two occurrences are in different trees, put things
// back the way they were.
if (right && right->Parent != NULL)
up->setRight(down);
else
up->setRight(right);
return false;
}
if (down->Depth <= 0)
return false;
return !down->Right || down->Right->Min + down->Depth >= 0;
}
ETNode *ETNode::NCA(ETNode *other) {
ETOccurrence *occ1 = RightmostOcc;
ETOccurrence *occ2 = other->RightmostOcc;
ETOccurrence *left, *right, *ret;
ETOccurrence *occmin;
int mindepth;
if (this == other)
return this;
occ1->Splay();
left = occ1->Left;
right = occ1->Right;
if (left)
left->Parent = NULL;
if (right)
right->Parent = NULL;
occ2->Splay();
if (left == occ2 || (left && left->Parent != NULL)) {
ret = occ2->Right;
occ1->setLeft(occ2);
if (right)
right->Parent = occ1;
} else {
ret = occ2->Left;
occ1->setRight(occ2);
if (left)
left->Parent = occ1;
}
if (occ2->Depth > 0) {
occmin = occ1;
mindepth = occ1->Depth;
} else {
occmin = occ2;
mindepth = occ2->Depth + occ1->Depth;
}
if (ret && ret->Min + occ1->Depth + occ2->Depth < mindepth)
return ret->MinOccurrence->OccFor;
else
return occmin->OccFor;
}
//===----------------------------------------------------------------------===//
// ETForest implementation
//===----------------------------------------------------------------------===//
static RegisterAnalysis<ETForest>
D("etforest", "ET Forest Construction", true);
void ETForestBase::reset() {
for (ETMapType::iterator I = Nodes.begin(), E = Nodes.end(); I != E; ++I)
delete I->second;
Nodes.clear();
}
void ETForestBase::updateDFSNumbers()
{
int dfsnum = 0;
// Iterate over all nodes in depth first order.
for (unsigned i = 0, e = Roots.size(); i != e; ++i)
for (df_iterator<BasicBlock*> I = df_begin(Roots[i]),
E = df_end(Roots[i]); I != E; ++I) {
BasicBlock *BB = *I;
if (!getNode(BB)->hasFather())
getNode(BB)->assignDFSNumber(dfsnum);
}
SlowQueries = 0;
DFSInfoValid = true;
}
ETNode *ETForest::getNodeForBlock(BasicBlock *BB) {
ETNode *&BBNode = Nodes[BB];
if (BBNode) return BBNode;
// Haven't calculated this node yet? Get or calculate the node for the
// immediate dominator.
BasicBlock *IDom = getAnalysis<ImmediateDominators>()[BB];
// If we are unreachable, we may not have an immediate dominator.
if (!IDom)
return BBNode = new ETNode(BB);
else {
ETNode *IDomNode = getNodeForBlock(IDom);
// Add a new tree node for this BasicBlock, and link it as a child of
// IDomNode
BBNode = new ETNode(BB);
BBNode->setFather(IDomNode);
return BBNode;
}
}
void ETForest::calculate(const ImmediateDominators &ID) {
assert(Roots.size() == 1 && "ETForest should have 1 root block!");
BasicBlock *Root = Roots[0];
Nodes[Root] = new ETNode(Root); // Add a node for the root
Function *F = Root->getParent();
// Loop over all of the reachable blocks in the function...
for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I)
if (BasicBlock *ImmDom = ID.get(I)) { // Reachable block.
ETNode *&BBNode = Nodes[I];
if (!BBNode) { // Haven't calculated this node yet?
// Get or calculate the node for the immediate dominator
ETNode *IDomNode = getNodeForBlock(ImmDom);
// Add a new ETNode for this BasicBlock, and set it's parent
// to it's immediate dominator.
BBNode = new ETNode(I);
BBNode->setFather(IDomNode);
}
}
// Make sure we've got nodes around for every block
for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
ETNode *&BBNode = Nodes[I];
if (!BBNode)
BBNode = new ETNode(I);
}
updateDFSNumbers ();
}
//===----------------------------------------------------------------------===//
// ETForestBase Implementation
//===----------------------------------------------------------------------===//
void ETForestBase::addNewBlock(BasicBlock *BB, BasicBlock *IDom) {
ETNode *&BBNode = Nodes[BB];
assert(!BBNode && "BasicBlock already in ET-Forest");
BBNode = new ETNode(BB);
BBNode->setFather(getNode(IDom));
DFSInfoValid = false;
}
void ETForestBase::setImmediateDominator(BasicBlock *BB, BasicBlock *newIDom) {
assert(getNode(BB) && "BasicBlock not in ET-Forest");
assert(getNode(newIDom) && "IDom not in ET-Forest");
ETNode *Node = getNode(BB);
if (Node->hasFather()) {
if (Node->getFather()->getData<BasicBlock>() == newIDom)
return;
Node->Split();
}
Node->setFather(getNode(newIDom));
DFSInfoValid= false;
}
void ETForestBase::print(std::ostream &o, const Module *) const {
o << "=============================--------------------------------\n";
o << "ET Forest:\n";
o << "DFS Info ";
if (DFSInfoValid)
o << "is";
else
o << "is not";
o << " up to date\n";
Function *F = getRoots()[0]->getParent();
for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
o << " DFS Numbers For Basic Block:";
WriteAsOperand(o, I, false);
o << " are:";
if (ETNode *EN = getNode(I)) {
o << "In: " << EN->getDFSNumIn();
o << " Out: " << EN->getDFSNumOut() << "\n";
} else {
o << "No associated ETNode";
}
o << "\n";
}
o << "\n";
}
DEFINING_FILE_FOR(DominatorSet)
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