cl::desc("Disable memory promotion in LICM pass"));
struct VISIBILITY_HIDDEN LICM : public LoopPass {
+ static char ID; // Pass identification, replacement for typeid
+ LICM() : LoopPass((intptr_t)&ID) {}
+
virtual bool runOnLoop(Loop *L, LPPassManager &LPM);
/// This transformation requires natural loop information & requires that
AU.setPreservesCFG();
AU.addRequiredID(LoopSimplifyID);
AU.addRequired<LoopInfo>();
+ AU.addRequired<DominatorTree>();
AU.addRequired<ETForest>();
AU.addRequired<DominanceFrontier>(); // For scalar promotion (mem2reg)
AU.addRequired<AliasAnalysis>();
// Various analyses that we use...
AliasAnalysis *AA; // Current AliasAnalysis information
LoopInfo *LI; // Current LoopInfo
- ETForest *ET; // ETForest for the current Loop...
+ ETForest *ET; // ETForest for the current loop..
+ DominatorTree *DT; // Dominator Tree for the current Loop...
DominanceFrontier *DF; // Current Dominance Frontier
// State that is updated as we process loops
/// SinkRegion - Walk the specified region of the CFG (defined by all blocks
/// dominated by the specified block, and that are in the current loop) in
- /// reverse depth first order w.r.t the ETForest. This allows us to
+ /// reverse depth first order w.r.t the DominatorTree. This allows us to
/// visit uses before definitions, allowing us to sink a loop body in one
/// pass without iteration.
///
- void SinkRegion(BasicBlock *BB);
+ void SinkRegion(DominatorTree::Node *N);
/// HoistRegion - Walk the specified region of the CFG (defined by all
/// blocks dominated by the specified block, and that are in the current
- /// loop) in depth first order w.r.t the ETForest. This allows us to
+ /// loop) in depth first order w.r.t the DominatorTree. This allows us to
/// visit definitions before uses, allowing us to hoist a loop body in one
/// pass without iteration.
///
- void HoistRegion(BasicBlock *BB);
+ void HoistRegion(DominatorTree::Node *N);
/// inSubLoop - Little predicate that returns true if the specified basic
/// block is in a subloop of the current one, not the current one itself.
if (BlockInLoop == LoopHeader)
return true;
- BasicBlock *IDom = ExitBlock;
+ DominatorTree::Node *BlockInLoopNode = DT->getNode(BlockInLoop);
+ DominatorTree::Node *IDom = DT->getNode(ExitBlock);
// Because the exit block is not in the loop, we know we have to get _at
// least_ its immediate dominator.
do {
// Get next Immediate Dominator.
- IDom = ET->getIDom(IDom);
+ IDom = IDom->getIDom();
// If we have got to the header of the loop, then the instructions block
// did not dominate the exit node, so we can't hoist it.
- if (IDom == LoopHeader)
+ if (IDom->getBlock() == LoopHeader)
return false;
- } while (IDom != BlockInLoop);
+ } while (IDom != BlockInLoopNode);
return true;
}
std::map<Value*, AllocaInst*> &Val2AlMap);
};
+ char LICM::ID = 0;
RegisterPass<LICM> X("licm", "Loop Invariant Code Motion");
}
LI = &getAnalysis<LoopInfo>();
AA = &getAnalysis<AliasAnalysis>();
DF = &getAnalysis<DominanceFrontier>();
+ DT = &getAnalysis<DominatorTree>();
ET = &getAnalysis<ETForest>();
CurAST = new AliasSetTracker(*AA);
- // Collect Alias info frmo subloops
+ // Collect Alias info from subloops
for (Loop::iterator LoopItr = L->begin(), LoopItrE = L->end();
LoopItr != LoopItrE; ++LoopItr) {
Loop *InnerL = *LoopItr;
// us to sink instructions in one pass, without iteration. AFter sinking
// instructions, we perform another pass to hoist them out of the loop.
//
- SinkRegion(L->getHeader());
- HoistRegion(L->getHeader());
+ SinkRegion(DT->getNode(L->getHeader()));
+ HoistRegion(DT->getNode(L->getHeader()));
// Now that all loop invariants have been removed from the loop, promote any
// memory references to scalars that we can...
/// SinkRegion - Walk the specified region of the CFG (defined by all blocks
/// dominated by the specified block, and that are in the current loop) in
-/// reverse depth first order w.r.t the ETForest. This allows us to visit
+/// reverse depth first order w.r.t the DominatorTree. This allows us to visit
/// uses before definitions, allowing us to sink a loop body in one pass without
/// iteration.
///
-void LICM::SinkRegion(BasicBlock *BB) {
- assert(BB != 0 && "Null sink block?");
+void LICM::SinkRegion(DominatorTree::Node *N) {
+ assert(N != 0 && "Null dominator tree node?");
+ BasicBlock *BB = N->getBlock();
// If this subregion is not in the top level loop at all, exit.
if (!CurLoop->contains(BB)) return;
// We are processing blocks in reverse dfo, so process children first...
- std::vector<BasicBlock*> Children;
- ET->getChildren(BB, Children);
+ const std::vector<DominatorTree::Node*> &Children = N->getChildren();
for (unsigned i = 0, e = Children.size(); i != e; ++i)
SinkRegion(Children[i]);
/// HoistRegion - Walk the specified region of the CFG (defined by all blocks
/// dominated by the specified block, and that are in the current loop) in depth
-/// first order w.r.t the ETForest. This allows us to visit definitions
+/// first order w.r.t the DominatorTree. This allows us to visit definitions
/// before uses, allowing us to hoist a loop body in one pass without iteration.
///
-void LICM::HoistRegion(BasicBlock *BB) {
- assert(BB != 0 && "Null hoist block?");
+void LICM::HoistRegion(DominatorTree::Node *N) {
+ assert(N != 0 && "Null dominator tree node?");
+ BasicBlock *BB = N->getBlock();
// If this subregion is not in the top level loop at all, exit.
if (!CurLoop->contains(BB)) return;
hoist(I);
}
- std::vector<BasicBlock*> Children;
- ET->getChildren(BB, Children);
+ const std::vector<DominatorTree::Node*> &Children = N->getChildren();
for (unsigned i = 0, e = Children.size(); i != e; ++i)
HoistRegion(Children[i]);
}
// Firstly, we create a stack object to hold the value...
AllocaInst *AI = 0;
- if (I.getType() != Type::VoidTy)
+ if (I.getType() != Type::VoidTy) {
AI = new AllocaInst(I.getType(), 0, I.getName(),
I.getParent()->getParent()->getEntryBlock().begin());
+ CurAST->add(AI);
+ }
// Secondly, insert load instructions for each use of the instruction
// outside of the loop.
// Insert a new load instruction right before the terminator in
// the predecessor block.
PredVal = new LoadInst(AI, "", Pred->getTerminator());
+ CurAST->add(cast<LoadInst>(PredVal));
}
UPN->setIncomingValue(i, PredVal);
} else {
LoadInst *L = new LoadInst(AI, "", U);
U->replaceUsesOfWith(&I, L);
+ CurAST->add(L);
}
}
if (AI) {
std::vector<AllocaInst*> Allocas;
Allocas.push_back(AI);
- PromoteMemToReg(Allocas, *ET, *DF, AA->getTargetData(), CurAST);
+ PromoteMemToReg(Allocas, *ET, *DF, CurAST);
}
}
}
std::vector<BasicBlock*> ExitBlocks;
CurLoop->getExitBlocks(ExitBlocks);
- // For each exit block, walk up the ET until the
+ // For each exit block, get the DT node and walk up the DT until the
// instruction's basic block is found or we exit the loop.
for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i)
if (!isExitBlockDominatedByBlockInLoop(ExitBlocks[i], Inst.getParent()))
PromotedAllocas.reserve(PromotedValues.size());
for (unsigned i = 0, e = PromotedValues.size(); i != e; ++i)
PromotedAllocas.push_back(PromotedValues[i].first);
- PromoteMemToReg(PromotedAllocas, *ET, *DF, AA->getTargetData(), CurAST);
+ PromoteMemToReg(PromotedAllocas, *ET, *DF, CurAST);
}
/// FindPromotableValuesInLoop - Check the current loop for stores to definite
projects / oota-llvm.git / blobdiff