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Avoid extra DenseMap lookups in StackColoring::calculateLocalLiveness. 

llvm-svn: 175487
This commit is contained in:
Craig Topper 2013-02-19 04:47:31 +00:00
parent 3e457f505e
commit 9a4b318491
1 changed files with 32 additions and 18 deletions
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50
llvm/lib/CodeGen/StackColoring.cpp
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@ -316,30 +316,44 @@ void StackColoring::calculateLocalLiveness() {
MachineBasicBlock *BB = *PI;
if (!BBSet.count(BB)) continue;
// Use an iterator to avoid repeated lookups.
DenseMap<MachineBasicBlock*, BlockLifetimeInfo>::iterator BI =
BlockLiveness.find(BB);
assert(BI != BlockLiveness.end() && "Block not found");
BlockLifetimeInfo &BlockInfo = BI->second;
BitVector LocalLiveIn;
BitVector LocalLiveOut;
// Forward propagation from begins to ends.
for (MachineBasicBlock::pred_iterator PI = BB->pred_begin(),
PE = BB->pred_end(); PI != PE; ++PI)
LocalLiveIn |= BlockLiveness[*PI].LiveOut;
LocalLiveIn |= BlockLiveness[BB].End;
LocalLiveIn.reset(BlockLiveness[BB].Begin);
for (MachineBasicBlock::const_pred_iterator PI = BB->pred_begin(),
PE = BB->pred_end(); PI != PE; ++PI) {
DenseMap<MachineBasicBlock*, BlockLifetimeInfo>::const_iterator I =
BlockLiveness.find(*PI);
assert(I != BlockLiveness.end() && "Predecessor not found");
LocalLiveIn |= I->second.LiveOut;
}
LocalLiveIn |= BlockInfo.End;
LocalLiveIn.reset(BlockInfo.Begin);
// Reverse propagation from ends to begins.
for (MachineBasicBlock::succ_iterator SI = BB->succ_begin(),
SE = BB->succ_end(); SI != SE; ++SI)
LocalLiveOut |= BlockLiveness[*SI].LiveIn;
LocalLiveOut |= BlockLiveness[BB].Begin;
LocalLiveOut.reset(BlockLiveness[BB].End);
for (MachineBasicBlock::const_succ_iterator SI = BB->succ_begin(),
SE = BB->succ_end(); SI != SE; ++SI) {
DenseMap<MachineBasicBlock*, BlockLifetimeInfo>::const_iterator I =
BlockLiveness.find(*SI);
assert(I != BlockLiveness.end() && "Successor not found");
LocalLiveOut |= I->second.LiveIn;
}
LocalLiveOut |= BlockInfo.Begin;
LocalLiveOut.reset(BlockInfo.End);
LocalLiveIn |= LocalLiveOut;
LocalLiveOut |= LocalLiveIn;
// After adopting the live bits, we need to turn-off the bits which
// are de-activated in this block.
LocalLiveOut.reset(BlockLiveness[BB].End);
LocalLiveIn.reset(BlockLiveness[BB].Begin);
LocalLiveOut.reset(BlockInfo.End);
LocalLiveIn.reset(BlockInfo.Begin);
// If we have both BEGIN and END markers in the same basic block then
// we know that the BEGIN marker comes after the END, because we already
@ -348,23 +362,23 @@ void StackColoring::calculateLocalLiveness() {
// Want to enable the LIVE_IN and LIVE_OUT of slots that have both
// BEGIN and END because it means that the value lives before and after
// this basic block.
BitVector LocalEndBegin = BlockLiveness[BB].End;
LocalEndBegin &= BlockLiveness[BB].Begin;
BitVector LocalEndBegin = BlockInfo.End;
LocalEndBegin &= BlockInfo.Begin;
LocalLiveIn |= LocalEndBegin;
LocalLiveOut |= LocalEndBegin;
if (LocalLiveIn.test(BlockLiveness[BB].LiveIn)) {
if (LocalLiveIn.test(BlockInfo.LiveIn)) {
changed = true;
BlockLiveness[BB].LiveIn |= LocalLiveIn;
BlockInfo.LiveIn |= LocalLiveIn;
for (MachineBasicBlock::pred_iterator PI = BB->pred_begin(),
PE = BB->pred_end(); PI != PE; ++PI)
NextBBSet.insert(*PI);
}
if (LocalLiveOut.test(BlockLiveness[BB].LiveOut)) {
if (LocalLiveOut.test(BlockInfo.LiveOut)) {
changed = true;
BlockLiveness[BB].LiveOut |= LocalLiveOut;
BlockInfo.LiveOut |= LocalLiveOut;
for (MachineBasicBlock::succ_iterator SI = BB->succ_begin(),
SE = BB->succ_end(); SI != SE; ++SI)