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Two small cleanups/speedups:

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* Do not insert a new entry into NewPhiNodes during the rename pass if there are no PHIs in a block.
 * Do not compute WriteSets in parallel


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8858 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2003-10-05 02:37:36 +00:00
parent 0fa157127f
commit 9157f041ab
1 changed files with 31 additions and 29 deletions
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60
lib/Transforms/Utils/PromoteMemoryToRegister.cpp
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@ -93,26 +93,24 @@ void PromoteMem2Reg::run() {
AllocaLookup[Allocas[i]] = i; AllocaLookup[Allocas[i]] = i;
} }
// Calculate the set of write-locations for each alloca. This is analogous to PhiNodes.resize(Allocas.size());
// counting the number of 'redefinitions' of each variable.
std::vector<std::vector<BasicBlock*> > WriteSets;// Idx corresponds to Allocas
WriteSets.resize(Allocas.size());
for (unsigned i = 0; i != Allocas.size(); ++i) { for (unsigned i = 0; i != Allocas.size(); ++i) {
AllocaInst *AI = Allocas[i]; AllocaInst *AI = Allocas[i];
// Calculate the set of write-locations for each alloca. This is analogous
// to counting the number of 'redefinitions' of each variable.
std::vector<BasicBlock*> WriteSets;
for (Value::use_iterator U =AI->use_begin(), E = AI->use_end(); U != E; ++U) for (Value::use_iterator U =AI->use_begin(), E = AI->use_end(); U != E; ++U)
if (StoreInst *SI = dyn_cast<StoreInst>(*U)) if (StoreInst *SI = dyn_cast<StoreInst>(*U))
// jot down the basic-block it came from // jot down the basic-block it came from
WriteSets[i].push_back(SI->getParent()); WriteSets.push_back(SI->getParent());
}
// Compute the locations where PhiNodes need to be inserted. Look at the
// Compute the locations where PhiNodes need to be inserted. Look at the // dominance frontier of EACH basic-block we have a write in.
// dominance frontier of EACH basic-block we have a write in //
// for (unsigned j = 0; j != WriteSets.size(); j++) {
PhiNodes.resize(Allocas.size());
for (unsigned i = 0; i != Allocas.size(); ++i) {
for (unsigned j = 0; j != WriteSets[i].size(); j++) {
// Look up the DF for this write, add it to PhiNodes // Look up the DF for this write, add it to PhiNodes
DominanceFrontier::const_iterator it = DF.find(WriteSets[i][j]); DominanceFrontier::const_iterator it = DF.find(WriteSets[j]);
if (it != DF.end()) { if (it != DF.end()) {
const DominanceFrontier::DomSetType &S = it->second; const DominanceFrontier::DomSetType &S = it->second;
for (DominanceFrontier::DomSetType::iterator P = S.begin(),PE = S.end(); for (DominanceFrontier::DomSetType::iterator P = S.begin(),PE = S.end();
@ -200,22 +198,26 @@ bool PromoteMem2Reg::QueuePhiNode(BasicBlock *BB, unsigned AllocaNo) {
void PromoteMem2Reg::RenamePass(BasicBlock *BB, BasicBlock *Pred, void PromoteMem2Reg::RenamePass(BasicBlock *BB, BasicBlock *Pred,
std::vector<Value*> &IncomingVals) { std::vector<Value*> &IncomingVals) {
// If this is a BB needing a phi node, lookup/create the phinode for each // If this BB needs a PHI node, update the PHI node for each variable we need
// variable we need phinodes for. // PHI nodes for.
std::vector<PHINode *> &BBPNs = NewPhiNodes[BB]; std::map<BasicBlock*, std::vector<PHINode *> >::iterator
for (unsigned k = 0; k != BBPNs.size(); ++k) BBPNI = NewPhiNodes.find(BB);
if (PHINode *PN = BBPNs[k]) { if (BBPNI != NewPhiNodes.end()) {
// The PHI node may have multiple entries for this predecessor. We must std::vector<PHINode *> &BBPNs = BBPNI->second;
// make sure we update all of them. for (unsigned k = 0; k != BBPNs.size(); ++k)
for (unsigned i = 0, e = PN->getNumOperands(); i != e; i += 2) { if (PHINode *PN = BBPNs[k]) {
if (PN->getOperand(i+1) == Pred) // The PHI node may have multiple entries for this predecessor. We must
// At this point we can assume that the array has phi nodes.. let's // make sure we update all of them.
// update the incoming data. for (unsigned i = 0, e = PN->getNumOperands(); i != e; i += 2) {
PN->setOperand(i, IncomingVals[k]); if (PN->getOperand(i+1) == Pred)
// At this point we can assume that the array has phi nodes.. let's
// update the incoming data.
PN->setOperand(i, IncomingVals[k]);
}
// also note that the active variable IS designated by the phi node
IncomingVals[k] = PN;
} }
// also note that the active variable IS designated by the phi node }
IncomingVals[k] = PN;
}
// don't revisit nodes // don't revisit nodes
if (Visited.count(BB)) return; if (Visited.count(BB)) return;