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replace a slow and verbose version of Instruction::isUsedOutsideOfBlock with 

a call to Instruction::isUsedOutsideOfBlock.

llvm-svn: 50005
This commit is contained in:
Chris Lattner 2008-04-20 22:18:22 +00:00
parent 8ec6e8af60
commit 567166c0a8
1 changed files with 4 additions and 34 deletions
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38
llvm/lib/Transforms/Scalar/TailDuplication.cpp
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@ -264,40 +264,10 @@ void TailDup::eliminateUnconditionalBranch(BranchInst *Branch) {
// this reason, we spill all values that are used outside of the tail to the
// stack.
for (BasicBlock::iterator I = DestBlock->begin(); I != DestBlock->end(); ++I)
for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E;
++UI) {
bool ShouldDemote = false;
if (cast<Instruction>(*UI)->getParent() != DestBlock) {
// We must allow our successors to use tail values in their PHI nodes
// (if the incoming value corresponds to the tail block).
if (PHINode *PN = dyn_cast<PHINode>(*UI)) {
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
if (PN->getIncomingValue(i) == I &&
PN->getIncomingBlock(i) != DestBlock) {
ShouldDemote = true;
break;
}
} else {
ShouldDemote = true;
}
} else if (PHINode *PN = dyn_cast<PHINode>(cast<Instruction>(*UI))) {
// If the user of this instruction is a PHI node in the current block,
// which has an entry from another block using the value, spill it.
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
if (PN->getIncomingValue(i) == I &&
PN->getIncomingBlock(i) != DestBlock) {
ShouldDemote = true;
break;
}
}
if (ShouldDemote) {
// We found a use outside of the tail. Create a new stack slot to
// break this inter-block usage pattern.
DemoteRegToStack(*I);
break;
}
if (I->isUsedOutsideOfBlock(DestBlock)) {
// We found a use outside of the tail. Create a new stack slot to
// break this inter-block usage pattern.
DemoteRegToStack(*I);
}
// We are going to have to map operands from the original block B to the new