[llvm-commits] CVS: llvm/lib/Transforms/Utils/LoopSimplify.cpp
Nick Lewycky
nicholas at mxc.ca
Sat Apr 7 18:04:47 PDT 2007
Changes in directory llvm/lib/Transforms/Utils:
LoopSimplify.cpp updated: 1.83 -> 1.84
---
Log message:
Remove DominatorSet usage from LoopSimplify. Patch from Owen Anderson.
---
Diffs of the changes: (+54 -89)
LoopSimplify.cpp | 143 ++++++++++++++++++++-----------------------------------
1 files changed, 54 insertions(+), 89 deletions(-)
Index: llvm/lib/Transforms/Utils/LoopSimplify.cpp
diff -u llvm/lib/Transforms/Utils/LoopSimplify.cpp:1.83 llvm/lib/Transforms/Utils/LoopSimplify.cpp:1.84
--- llvm/lib/Transforms/Utils/LoopSimplify.cpp:1.83 Sat Apr 7 13:23:27 2007
+++ llvm/lib/Transforms/Utils/LoopSimplify.cpp Sat Apr 7 20:04:30 2007
@@ -64,12 +64,10 @@
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
// We need loop information to identify the loops...
AU.addRequired<LoopInfo>();
- AU.addRequired<DominatorSet>();
AU.addRequired<DominatorTree>();
AU.addRequired<ETForest>();
AU.addPreserved<LoopInfo>();
- AU.addPreserved<DominatorSet>();
AU.addPreserved<ImmediateDominators>();
AU.addPreserved<ETForest>();
AU.addPreserved<DominatorTree>();
@@ -313,8 +311,9 @@
// Can we eliminate this phi node now?
if (Value *V = PN->hasConstantValue(true)) {
- if (!isa<Instruction>(V) ||
- getAnalysis<DominatorSet>().dominates(cast<Instruction>(V), PN)) {
+ Instruction *I = dyn_cast<Instruction>(V);
+ if (!I || (I->getParent() != NewBB &&
+ getAnalysis<ETForest>().dominates(I, PN))) {
PN->replaceAllUsesWith(V);
if (AA) AA->deleteValue(PN);
BB->getInstList().erase(PN);
@@ -542,10 +541,9 @@
// Determine which blocks should stay in L and which should be moved out to
// the Outer loop now.
- DominatorSet &DS = getAnalysis<DominatorSet>();
std::set<BasicBlock*> BlocksInL;
for (pred_iterator PI = pred_begin(Header), E = pred_end(Header); PI!=E; ++PI)
- if (DS.dominates(Header, *PI))
+ if (EF->dominates(Header, *PI))
AddBlockAndPredsToSet(*PI, Header, BlocksInL);
@@ -674,8 +672,8 @@
}
/// UpdateDomInfoForRevectoredPreds - This method is used to update the four
-/// different kinds of dominator information (dominator sets, immediate
-/// dominators, dominator trees, and dominance frontiers) after a new block has
+/// different kinds of dominator information (immediate dominators,
+/// dominator trees, et-forest and dominance frontiers) after a new block has
/// been added to the CFG.
///
/// This only supports the case when an existing block (known as "NewBBSucc"),
@@ -693,33 +691,8 @@
++succ_begin(NewBB) == succ_end(NewBB) &&
"NewBB should have a single successor!");
BasicBlock *NewBBSucc = *succ_begin(NewBB);
- DominatorSet &DS = getAnalysis<DominatorSet>();
-
- // Update dominator information... The blocks that dominate NewBB are the
- // intersection of the dominators of predecessors, plus the block itself.
- //
- DominatorSet::DomSetType NewBBDomSet = DS.getDominators(PredBlocks[0]);
- {
- unsigned i, e = PredBlocks.size();
- // It is possible for some preds to not be reachable, and thus have empty
- // dominator sets (all blocks must dom themselves, so no domset would
- // otherwise be empty). If we see any of these, don't intersect with them,
- // as that would certainly leave the resultant set empty.
- for (i = 1; NewBBDomSet.empty(); ++i) {
- assert(i != e && "Didn't find reachable pred?");
- NewBBDomSet = DS.getDominators(PredBlocks[i]);
- }
-
- // Intersect the rest of the non-empty sets.
- for (; i != e; ++i) {
- const DominatorSet::DomSetType &PredDS = DS.getDominators(PredBlocks[i]);
- if (!PredDS.empty())
- set_intersect(NewBBDomSet, PredDS);
- }
- NewBBDomSet.insert(NewBB); // All blocks dominate themselves.
- DS.addBasicBlock(NewBB, NewBBDomSet);
- }
-
+ ETForest& ETF = getAnalysis<ETForest>();
+
// The newly inserted basic block will dominate existing basic blocks iff the
// PredBlocks dominate all of the non-pred blocks. If all predblocks dominate
// the non-pred blocks, then they all must be the same block!
@@ -727,14 +700,16 @@
bool NewBBDominatesNewBBSucc = true;
{
BasicBlock *OnePred = PredBlocks[0];
- unsigned i, e = PredBlocks.size();
- for (i = 1; !DS.isReachable(OnePred); ++i) {
+ unsigned i = 1, e = PredBlocks.size();
+ for (i = 1; !ETF.dominates(&OnePred->getParent()->getEntryBlock(), OnePred);
+ ++i) {
assert(i != e && "Didn't find reachable pred?");
OnePred = PredBlocks[i];
}
for (; i != e; ++i)
- if (PredBlocks[i] != OnePred && DS.isReachable(PredBlocks[i])) {
+ if (PredBlocks[i] != OnePred &&
+ ETF.dominates(&PredBlocks[i]->getParent()->getEntryBlock(), OnePred)){
NewBBDominatesNewBBSucc = false;
break;
}
@@ -742,7 +717,7 @@
if (NewBBDominatesNewBBSucc)
for (pred_iterator PI = pred_begin(NewBBSucc), E = pred_end(NewBBSucc);
PI != E; ++PI)
- if (*PI != NewBB && !DS.dominates(NewBBSucc, *PI)) {
+ if (*PI != NewBB && !ETF.dominates(NewBBSucc, *PI)) {
NewBBDominatesNewBBSucc = false;
break;
}
@@ -755,44 +730,31 @@
NewBBDominatesNewBBSucc = true;
for (pred_iterator PI = pred_begin(NewBBSucc), E = pred_end(NewBBSucc);
PI != E; ++PI)
- if (*PI != NewBB && !DS.dominates(NewBBSucc, *PI)) {
+ if (*PI != NewBB && !ETF.dominates(NewBBSucc, *PI)) {
NewBBDominatesNewBBSucc = false;
break;
}
}
- // If NewBB dominates some blocks, then it will dominate all blocks that
- // NewBBSucc does.
- if (NewBBDominatesNewBBSucc) {
- Function *F = NewBB->getParent();
- for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I)
- if (DS.dominates(NewBBSucc, I))
- DS.addDominator(I, NewBB);
- }
-
- // Update immediate dominator information if we have it.
BasicBlock *NewBBIDom = 0;
+
+ // Update immediate dominator information if we have it.
if (ImmediateDominators *ID = getAnalysisToUpdate<ImmediateDominators>()) {
- // To find the immediate dominator of the new exit node, we trace up the
- // immediate dominators of a predecessor until we find a basic block that
- // dominates the exit block.
- //
- BasicBlock *Dom = PredBlocks[0]; // Some random predecessor.
-
- // Find a reachable pred.
- for (unsigned i = 1; !DS.isReachable(Dom); ++i) {
- assert(i != PredBlocks.size() && "Didn't find reachable pred!");
- Dom = PredBlocks[i];
- }
-
- while (!NewBBDomSet.count(Dom)) { // Loop until we find a dominator.
- assert(Dom != 0 && "No shared dominator found???");
- Dom = ID->get(Dom);
+ unsigned i = 0;
+ for (i = 0; i < PredBlocks.size(); ++i)
+ if (ETF.dominates(&PredBlocks[i]->getParent()->getEntryBlock(), PredBlocks[i])) {
+ NewBBIDom = PredBlocks[i];
+ break;
+ }
+ assert(i != PredBlocks.size() && "No reachable preds?");
+ for (i = i + 1; i < PredBlocks.size(); ++i) {
+ if (ETF.dominates(&PredBlocks[i]->getParent()->getEntryBlock(), PredBlocks[i]))
+ NewBBIDom = ETF.nearestCommonDominator(NewBBIDom, PredBlocks[i]);
}
-
+ assert(NewBBIDom && "No immediate dominator found??");
+
// Set the immediate dominator now...
- ID->addNewBlock(NewBB, Dom);
- NewBBIDom = Dom; // Reuse this if calculating DominatorTree info...
+ ID->addNewBlock(NewBB, NewBBIDom);
// If NewBB strictly dominates other blocks, we need to update their idom's
// now. The only block that need adjustment is the NewBBSucc block, whose
@@ -805,24 +767,21 @@
if (DominatorTree *DT = getAnalysisToUpdate<DominatorTree>()) {
// If we don't have ImmediateDominator info around, calculate the idom as
// above.
- DominatorTree::Node *NewBBIDomNode;
- if (NewBBIDom) {
- NewBBIDomNode = DT->getNode(NewBBIDom);
- } else {
- // Scan all the pred blocks that were pulled out. Any individual one may
- // actually be unreachable, which would mean it doesn't have dom info.
- NewBBIDomNode = 0;
- for (unsigned i = 0; !NewBBIDomNode; ++i) {
- assert(i != PredBlocks.size() && "No reachable preds?");
- NewBBIDomNode = DT->getNode(PredBlocks[i]);
- }
-
- while (!NewBBDomSet.count(NewBBIDomNode->getBlock())) {
- NewBBIDomNode = NewBBIDomNode->getIDom();
- assert(NewBBIDomNode && "No shared dominator found??");
+ if (!NewBBIDom) {
+ unsigned i = 0;
+ for (i = 0; i < PredBlocks.size(); ++i)
+ if (ETF.dominates(&PredBlocks[i]->getParent()->getEntryBlock(), PredBlocks[i])) {
+ NewBBIDom = PredBlocks[i];
+ break;
+ }
+ assert(i != PredBlocks.size() && "No reachable preds?");
+ for (i = i + 1; i < PredBlocks.size(); ++i) {
+ if (ETF.dominates(&PredBlocks[i]->getParent()->getEntryBlock(), PredBlocks[i]))
+ NewBBIDom = ETF.nearestCommonDominator(NewBBIDom, PredBlocks[i]);
}
- NewBBIDom = NewBBIDomNode->getBlock();
+ assert(NewBBIDom && "No immediate dominator found??");
}
+ DominatorTree::Node *NewBBIDomNode = DT->getNode(NewBBIDom);
// Create the new dominator tree node... and set the idom of NewBB.
DominatorTree::Node *NewBBNode = DT->createNewNode(NewBB, NewBBIDomNode);
@@ -857,7 +816,7 @@
bool DominatesPred = false;
for (pred_iterator PI = pred_begin(*SetI), E = pred_end(*SetI);
PI != E; ++PI)
- if (DS.dominates(NewBB, *PI))
+ if (ETF.dominates(NewBB, *PI))
DominatesPred = true;
if (!DominatesPred)
Set.erase(SetI++);
@@ -885,8 +844,14 @@
for (unsigned i = 0, e = PredBlocks.size(); i != e; ++i) {
BasicBlock *Pred = PredBlocks[i];
// Get all of the dominators of the predecessor...
- const DominatorSet::DomSetType &PredDoms = DS.getDominators(Pred);
- for (DominatorSet::DomSetType::const_iterator PDI = PredDoms.begin(),
+ // FIXME: There's probably a better way to do this...
+ std::vector<BasicBlock*> PredDoms;
+ for (Function::iterator I = Pred->getParent()->begin(),
+ E = Pred->getParent()->end(); I != E; ++I)
+ if (ETF.dominates(&(*I), Pred))
+ PredDoms.push_back(I);
+
+ for (std::vector<BasicBlock*>::const_iterator PDI = PredDoms.begin(),
PDE = PredDoms.end(); PDI != PDE; ++PDI) {
BasicBlock *PredDom = *PDI;
@@ -900,12 +865,12 @@
// We remove it unless there is a predecessor of NewBBSucc that we
// dominate, but we don't strictly dominate NewBBSucc.
bool ShouldRemove = true;
- if (PredDom == NewBBSucc || !DS.dominates(PredDom, NewBBSucc)) {
+ if (PredDom == NewBBSucc || !ETF.dominates(PredDom, 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 (DS.dominates(PredDom, *PI)) {
+ if (ETF.dominates(PredDom, *PI)) {
ShouldRemove = false;
break;
}
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