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Simplify the code to check for existing PHIs, now that it is only used in 

one place.  This removes the template function added in svn 94690.

llvm-svn: 100130
This commit is contained in:
Bob Wilson 2010-04-01 19:53:48 +00:00
parent d603b54c55
commit 043c0406f7
1 changed files with 12 additions and 30 deletions
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42
llvm/lib/Transforms/Utils/SSAUpdater.cpp
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@ -135,32 +135,6 @@ static bool IsEquivalentPHI(PHINode *PHI,
return true; return true;
} }
/// GetExistingPHI - Check if BB already contains a phi node that is equivalent
/// to the specified mapping from predecessor blocks to incoming values.
static Value *GetExistingPHI(BasicBlock *BB,
DenseMap<BasicBlock*, Value*> &ValueMapping) {
PHINode *SomePHI;
for (BasicBlock::iterator It = BB->begin();
(SomePHI = dyn_cast<PHINode>(It)); ++It) {
if (IsEquivalentPHI(SomePHI, ValueMapping))
return SomePHI;
}
return 0;
}
/// GetExistingPHI - Check if BB already contains an equivalent phi node.
/// The InputIt type must be an iterator over std::pair<BasicBlock*, Value*>
/// objects that specify the mapping from predecessor blocks to incoming values.
template<typename InputIt>
static Value *GetExistingPHI(BasicBlock *BB, const InputIt &I,
const InputIt &E) {
// Avoid create the mapping if BB has no phi nodes at all.
if (!isa<PHINode>(BB->begin()))
return 0;
DenseMap<BasicBlock*, Value*> ValueMapping(I, E);
return GetExistingPHI(BB, ValueMapping);
}
/// GetValueAtEndOfBlock - Construct SSA form, materializing a value that is /// GetValueAtEndOfBlock - Construct SSA form, materializing a value that is
/// live at the end of the specified block. /// live at the end of the specified block.
Value *SSAUpdater::GetValueAtEndOfBlock(BasicBlock *BB) { Value *SSAUpdater::GetValueAtEndOfBlock(BasicBlock *BB) {
@ -239,10 +213,18 @@ Value *SSAUpdater::GetValueInMiddleOfBlock(BasicBlock *BB) {
if (SingularValue != 0) if (SingularValue != 0)
return SingularValue; return SingularValue;
// Otherwise, we do need a PHI. // Otherwise, we do need a PHI: check to see if we already have one available
if (Value *ExistingPHI = GetExistingPHI(BB, PredValues.begin(), // in this block that produces the right value.
PredValues.end())) if (isa<PHINode>(BB->begin())) {
return ExistingPHI; DenseMap<BasicBlock*, Value*> ValueMapping(PredValues.begin(),
PredValues.end());
PHINode *SomePHI;
for (BasicBlock::iterator It = BB->begin();
(SomePHI = dyn_cast<PHINode>(It)); ++It) {
if (IsEquivalentPHI(SomePHI, ValueMapping))
return SomePHI;
}
}
// Ok, we have no way out, insert a new one now. // Ok, we have no way out, insert a new one now.
PHINode *InsertedPHI = PHINode::Create(PrototypeValue->getType(), PHINode *InsertedPHI = PHINode::Create(PrototypeValue->getType(),