[llvm-commits] [llvm] r40858 - /llvm/trunk/lib/VMCore/Dominators.cpp
Chris Lattner
sabre at nondot.org
Sun Aug 5 23:19:47 PDT 2007
Author: lattner
Date: Mon Aug 6 01:19:47 2007
New Revision: 40858
URL: http://llvm.org/viewvc/llvm-project?rev=40858&view=rev
Log:
1. Random tidiness cleanups
2. Make domtree printing print dfin/dfout #'s
3. Fix the Transforms/LoopSimplify/2004-04-13-LoopSimplifyUpdateDomFrontier.ll failure from last night (in DominanceFrontier::splitBlock).
w.r.t. #3, my patches last night happened to expose the bug, but this
has been broken since Owen's r35839 patch to LoopSimplify. The code
was subsequently moved over from LoopSimplify into Dominators, carrying
the latent bug. Fun stuff.
Modified:
llvm/trunk/lib/VMCore/Dominators.cpp
Modified: llvm/trunk/lib/VMCore/Dominators.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/Dominators.cpp?rev=40858&r1=40857&r2=40858&view=diff
==============================================================================
--- llvm/trunk/lib/VMCore/Dominators.cpp (original)
+++ llvm/trunk/lib/VMCore/Dominators.cpp Mon Aug 6 01:19:47 2007
@@ -66,7 +66,6 @@
// NewBB is split and now it has one successor. Update dominator tree to
// reflect this change.
void DominatorTree::splitBlock(BasicBlock *NewBB) {
-
assert(NewBB->getTerminator()->getNumSuccessors() == 1
&& "NewBB should have a single successor!");
BasicBlock *NewBBSucc = NewBB->getTerminator()->getSuccessor(0);
@@ -92,7 +91,7 @@
}
for (; i != e; ++i)
- if (PredBlocks[i] != OnePred && isReachableFromEntry(OnePred)){
+ if (PredBlocks[i] != OnePred && isReachableFromEntry(OnePred)) {
NewBBDominatesNewBBSucc = false;
break;
}
@@ -119,7 +118,6 @@
}
}
-
// Find NewBB's immediate dominator and create new dominator tree node for
// NewBB.
BasicBlock *NewBBIDom = 0;
@@ -390,9 +388,7 @@
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;
- DomTreeNode *BBNode = getNode(BB);
- if (BBNode) {
+ if (DomTreeNode *BBNode = getNode(*I)) {
if (!BBNode->getIDom())
BBNode->assignDFSNumber(dfsnum);
}
@@ -462,11 +458,11 @@
return &Entry;
// If B dominates A then B is nearest common dominator.
- if (dominates(B,A))
+ if (dominates(B, A))
return B;
// If A dominates B then A is nearest common dominator.
- if (dominates(A,B))
+ if (dominates(A, B))
return A;
DomTreeNode *NodeA = getNode(A);
@@ -476,7 +472,7 @@
SmallPtrSet<DomTreeNode*, 16> NodeADoms;
NodeADoms.insert(NodeA);
DomTreeNode *IDomA = NodeA->getIDom();
- while(IDomA) {
+ while (IDomA) {
NodeADoms.insert(IDomA);
IDomA = IDomA->getIDom();
}
@@ -542,8 +538,8 @@
}
DomTreeNode *DominatorTree::getNodeForBlock(BasicBlock *BB) {
- DomTreeNode *&BBNode = DomTreeNodes[BB];
- if (BBNode) return BBNode;
+ if (DomTreeNode *BBNode = DomTreeNodes[BB])
+ return BBNode;
// Haven't calculated this node yet? Get or calculate the node for the
// immediate dominator.
@@ -556,12 +552,14 @@
return DomTreeNodes[BB] = IDomNode->addChild(C);
}
-static std::ostream &operator<<(std::ostream &o,
- const DomTreeNode *Node) {
+static std::ostream &operator<<(std::ostream &o, const DomTreeNode *Node) {
if (Node->getBlock())
WriteAsOperand(o, Node->getBlock(), false);
else
o << " <<exit node>>";
+
+ o << " {" << Node->getDFSNumIn() << "," << Node->getDFSNumOut() << "}";
+
return o << "\n";
}
@@ -574,13 +572,17 @@
}
void DominatorTreeBase::print(std::ostream &o, const Module* ) const {
- o << "=============================--------------------------------\n"
- << "Inorder Dominator Tree:\n";
+ o << "=============================--------------------------------\n";
+ o << "Inorder Dominator Tree: ";
+ if (DFSInfoValid)
+ o << "DFSNumbers invalid: " << SlowQueries << " slow queries.";
+ o << "\n";
+
PrintDomTree(getRootNode(), o, 1);
}
void DominatorTreeBase::dump() {
- print (llvm::cerr);
+ print(llvm::cerr);
}
bool DominatorTree::runOnFunction(Function &F) {
@@ -601,7 +603,6 @@
// NewBB is split and now it has one successor. Update dominace frontier to
// reflect this change.
void DominanceFrontier::splitBlock(BasicBlock *NewBB) {
-
assert(NewBB->getTerminator()->getNumSuccessors() == 1
&& "NewBB should have a single successor!");
BasicBlock *NewBBSucc = NewBB->getTerminator()->getSuccessor(0);
@@ -617,12 +618,7 @@
// other blocks.
return;
- DominatorTree &DT = getAnalysis<DominatorTree>();
- bool NewBBDominatesNewBBSucc = true;
- if (!DT.dominates(NewBB, NewBBSucc))
- NewBBDominatesNewBBSucc = false;
-
- // NewBBSucc inherites original NewBB frontier.
+ // NewBBSucc inherits original NewBB frontier.
DominanceFrontier::iterator NewBBI = find(NewBB);
if (NewBBI != end()) {
DominanceFrontier::DomSetType NewBBSet = NewBBI->second;
@@ -634,7 +630,8 @@
// If NewBB dominates NewBBSucc, then DF(NewBB) is now going to be the
// DF(PredBlocks[0]) without the stuff that the new block does not dominate
// a predecessor of.
- if (NewBBDominatesNewBBSucc) {
+ DominatorTree &DT = getAnalysis<DominatorTree>();
+ if (DT.dominates(NewBB, NewBBSucc)) {
DominanceFrontier::iterator DFI = find(PredBlocks[0]);
if (DFI != end()) {
DominanceFrontier::DomSetType Set = DFI->second;
@@ -678,9 +675,11 @@
DominanceFrontier::iterator DFI = find(FI);
if (DFI == end()) continue; // unreachable block.
- // Only consider dominators of NewBBSucc
+ // Only consider nodes that have NewBBSucc in their dominator frontier.
if (!DFI->second.count(NewBBSucc)) continue;
+ // Verify whether this block dominates a block in predblocks. If not, do
+ // not update it.
bool BlockDominatesAny = false;
for (std::vector<BasicBlock*>::const_iterator BI = PredBlocks.begin(),
BE = PredBlocks.end(); BI != BE; ++BI) {
@@ -690,29 +689,27 @@
}
}
- if (BlockDominatesAny) {
- // If NewBBSucc should not stay in our dominator frontier, remove it.
- // We remove it unless there is a predecessor of NewBBSucc that we
- // dominate, but we don't strictly dominate NewBBSucc.
- bool ShouldRemove = true;
- if ((BasicBlock*)FI == NewBBSucc
- || !DT.dominates(FI, NewBBSucc)) {
- // Okay, we know that PredDom does not strictly dominate NewBBSucc.
- // Check to see if it dominates any predecessors of NewBBSucc.
- for (pred_iterator PI = pred_begin(NewBBSucc),
- E = pred_end(NewBBSucc); PI != E; ++PI)
- if (DT.dominates(FI, *PI)) {
- ShouldRemove = false;
- break;
- }
-
- if (ShouldRemove)
- removeFromFrontier(DFI, NewBBSucc);
- addToFrontier(DFI, NewBB);
-
- break;
- }
+ if (!BlockDominatesAny)
+ continue;
+
+ // If NewBBSucc should not stay in our dominator frontier, remove it.
+ // We remove it unless there is a predecessor of NewBBSucc that we
+ // dominate, but we don't strictly dominate NewBBSucc.
+ bool ShouldRemove = true;
+ if ((BasicBlock*)FI == NewBBSucc || !DT.dominates(FI, NewBBSucc)) {
+ // Okay, we know that PredDom does not strictly dominate NewBBSucc.
+ // Check to see if it dominates any predecessors of NewBBSucc.
+ for (pred_iterator PI = pred_begin(NewBBSucc),
+ E = pred_end(NewBBSucc); PI != E; ++PI)
+ if (DT.dominates(FI, *PI)) {
+ ShouldRemove = false;
+ break;
+ }
}
+
+ if (ShouldRemove)
+ removeFromFrontier(DFI, NewBBSucc);
+ addToFrontier(DFI, NewBB);
}
}
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