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generalize the fix for PR977 to also fix 

Transforms/LCSSA/2006-10-31-UnreachableBlock-2.ll

llvm-svn: 31317
This commit is contained in:
Chris Lattner 2006-10-31 18:56:48 +00:00
parent d739064b20
commit 984d6e1669
1 changed files with 26 additions and 28 deletions
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54
llvm/lib/Transforms/Utils/LCSSA.cpp
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@ -71,8 +71,8 @@ namespace {
private:
SetVector<Instruction*> getLoopValuesUsedOutsideLoop(Loop *L);
PHINode *GetValueForBlock(DominatorTree::Node *BB, Instruction *OrigInst,
std::map<DominatorTree::Node*, PHINode*> &Phis);
Value *GetValueForBlock(DominatorTree::Node *BB, Instruction *OrigInst,
std::map<DominatorTree::Node*, Value*> &Phis);
/// inLoop - returns true if the given block is within the current loop
const bool inLoop(BasicBlock* B) {
@ -140,7 +140,7 @@ void LCSSA::ProcessInstruction(Instruction *Instr,
++NumLCSSA; // We are applying the transformation
// Keep track of the blocks that have the value available already.
std::map<DominatorTree::Node*, PHINode*> Phis;
std::map<DominatorTree::Node*, Value*> Phis;
DominatorTree::Node *InstrNode = DT->getNode(Instr->getParent());
@ -150,18 +150,18 @@ void LCSSA::ProcessInstruction(Instruction *Instr,
BBE = exitBlocks.end(); BBI != BBE; ++BBI) {
BasicBlock *BB = *BBI;
DominatorTree::Node *ExitBBNode = DT->getNode(BB);
PHINode *&Phi = Phis[ExitBBNode];
Value *&Phi = Phis[ExitBBNode];
if (!Phi && InstrNode->dominates(ExitBBNode)) {
Phi = new PHINode(Instr->getType(), Instr->getName()+".lcssa",
BB->begin());
Phi->reserveOperandSpace(std::distance(pred_begin(BB), pred_end(BB)));
PHINode *PN = new PHINode(Instr->getType(), Instr->getName()+".lcssa",
BB->begin());
PN->reserveOperandSpace(std::distance(pred_begin(BB), pred_end(BB)));
// Remember that this phi makes the value alive in this block.
Phi = PN;
// Add inputs from inside the loop for this PHI.
for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
Phi->addIncoming(Instr, *PI);
// Remember that this phi makes the value alive in this block.
Phis[ExitBBNode] = Phi;
PN->addIncoming(Instr, *PI);
}
}
@ -184,14 +184,7 @@ void LCSSA::ProcessInstruction(Instruction *Instr,
// Otherwise, patch up uses of the value with the appropriate LCSSA Phi,
// inserting PHI nodes into join points where needed.
DominatorTree::Node *UserBBNode = DT->getNode(UserBB);
// If the block has no dominator info, it is unreachable.
Value *Val;
if (UserBBNode)
Val = GetValueForBlock(UserBBNode, Instr, Phis);
else
Val = UndefValue::get(Instr->getType());
Value *Val = GetValueForBlock(DT->getNode(UserBB), Instr, Phis);
// Preincrement the iterator to avoid invalidating it when we change the
// value.
@ -233,10 +226,14 @@ SetVector<Instruction*> LCSSA::getLoopValuesUsedOutsideLoop(Loop *L) {
/// GetValueForBlock - Get the value to use within the specified basic block.
/// available values are in Phis.
PHINode *LCSSA::GetValueForBlock(DominatorTree::Node *BB, Instruction *OrigInst,
std::map<DominatorTree::Node*, PHINode*> &Phis) {
Value *LCSSA::GetValueForBlock(DominatorTree::Node *BB, Instruction *OrigInst,
std::map<DominatorTree::Node*, Value*> &Phis) {
// If there is no dominator info for this BB, it is unreachable.
if (BB == 0)
return UndefValue::get(OrigInst->getType());
// If we have already computed this value, return the previously computed val.
PHINode *&V = Phis[BB];
Value *&V = Phis[BB];
if (V) return V;
DominatorTree::Node *IDom = BB->getIDom();
@ -262,13 +259,14 @@ PHINode *LCSSA::GetValueForBlock(DominatorTree::Node *BB, Instruction *OrigInst,
// Otherwise, the idom is the loop, so we need to insert a PHI node. Do so
// now, then get values to fill in the incoming values for the PHI.
V = new PHINode(OrigInst->getType(), OrigInst->getName()+".lcssa",
BBN->begin());
V->reserveOperandSpace(std::distance(pred_begin(BBN), pred_end(BBN)));
PHINode *PN = new PHINode(OrigInst->getType(), OrigInst->getName()+".lcssa",
BBN->begin());
PN->reserveOperandSpace(std::distance(pred_begin(BBN), pred_end(BBN)));
V = PN;
// Fill in the incoming values for the block.
for (pred_iterator PI = pred_begin(BBN), E = pred_end(BBN); PI != E; ++PI)
V->addIncoming(GetValueForBlock(DT->getNode(*PI), OrigInst, Phis), *PI);
return V;
PN->addIncoming(GetValueForBlock(DT->getNode(*PI), OrigInst, Phis), *PI);
return PN;
}