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Use IRBuilder while folding two entry PHINode. 

llvm-svn: 131548
This commit is contained in:
Devang Patel 2011-05-18 18:16:44 +00:00
parent 2fd66441c6
commit 5c810ce4a3
1 changed files with 8 additions and 6 deletions
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14
llvm/lib/Transforms/Utils/SimplifyCFG.cpp
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@ -1228,7 +1228,8 @@ static bool FoldCondBranchOnPHI(BranchInst *BI, const TargetData *TD) {
/// FoldTwoEntryPHINode - Given a BB that starts with the specified two-entry
/// PHI node, see if we can eliminate it.
static bool FoldTwoEntryPHINode(PHINode *PN, const TargetData *TD) {
static bool FoldTwoEntryPHINode(PHINode *PN, const TargetData *TD,
IRBuilder<> &Builder) {
// Ok, this is a two entry PHI node. Check to see if this is a simple "if
// statement", which has a very simple dominance structure. Basically, we
// are trying to find the condition that is being branched on, which
@ -1327,6 +1328,7 @@ static bool FoldTwoEntryPHINode(PHINode *PN, const TargetData *TD) {
// If we can still promote the PHI nodes after this gauntlet of tests,
// do all of the PHI's now.
Instruction *InsertPt = DomBlock->getTerminator();
Builder.SetInsertPoint(InsertPt);
// Move all 'aggressive' instructions, which are defined in the
// conditional parts of the if's up to the dominating block.
@ -1344,8 +1346,8 @@ static bool FoldTwoEntryPHINode(PHINode *PN, const TargetData *TD) {
Value *TrueVal = PN->getIncomingValue(PN->getIncomingBlock(0) == IfFalse);
Value *FalseVal = PN->getIncomingValue(PN->getIncomingBlock(0) == IfTrue);
SelectInst *NV = SelectInst::Create(IfCond, TrueVal, FalseVal, "", InsertPt);
NV->setDebugLoc(InsertPt->getDebugLoc());
SelectInst *NV =
cast<SelectInst>(Builder.CreateSelect(IfCond, TrueVal, FalseVal, ""));
PN->replaceAllUsesWith(NV);
NV->takeName(PN);
PN->eraseFromParent();
@ -1355,8 +1357,8 @@ static bool FoldTwoEntryPHINode(PHINode *PN, const TargetData *TD) {
// has been flattened. Change DomBlock to jump directly to our new block to
// avoid other simplifycfg's kicking in on the diamond.
TerminatorInst *OldTI = DomBlock->getTerminator();
BranchInst *NewBI = BranchInst::Create(BB, OldTI);
NewBI->setDebugLoc(OldTI->getDebugLoc());
Builder.SetInsertPoint(OldTI);
Builder.CreateBr(BB);
OldTI->eraseFromParent();
return true;
}
@ -2645,7 +2647,7 @@ bool SimplifyCFGOpt::run(BasicBlock *BB) {
// eliminate it, do so now.
if (PHINode *PN = dyn_cast<PHINode>(BB->begin()))
if (PN->getNumIncomingValues() == 2)
Changed |= FoldTwoEntryPHINode(PN, TD);
Changed |= FoldTwoEntryPHINode(PN, TD, Builder);
if (BranchInst *BI = dyn_cast<BranchInst>(BB->getTerminator())) {
if (BI->isUnconditional()) {