6 files changed, 11 insertions, 4 deletions

diff --git a/lib/Transforms/Utils/BasicBlockUtils.cpp b/lib/Transforms/Utils/BasicBlockUtils.cpp
index acaea195e7..fb217bfa98 100644
--- a/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -448,6 +448,7 @@ BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB,
       // Create the new PHI node, insert it into NewBB at the end of the block
       PHINode *NewPHI =
         PHINode::Create(PN->getType(), PN->getName()+".ph", BI);
+      NewPHI->reserveOperandSpace(NumPreds);
       if (AA) AA->copyValue(PN, NewPHI);
       
       // Move all of the PHI values for 'Preds' to the new PHI.
diff --git a/lib/Transforms/Utils/BreakCriticalEdges.cpp b/lib/Transforms/Utils/BreakCriticalEdges.cpp
index 616b066b5a..3384cb6b5e 100644
--- a/lib/Transforms/Utils/BreakCriticalEdges.cpp
+++ b/lib/Transforms/Utils/BreakCriticalEdges.cpp
@@ -142,6 +142,7 @@ static void CreatePHIsForSplitLoopExit(SmallVectorImpl<BasicBlock *> &Preds,
     // Otherwise a new PHI is needed. Create one and populate it.
     PHINode *NewPN = PHINode::Create(PN->getType(), "split",
                                      SplitBB->getTerminator());
+    NewPN->reserveOperandSpace(Preds.size());
     for (unsigned i = 0, e = Preds.size(); i != e; ++i)
       NewPN->addIncoming(V, Preds[i]);
     // Update the original PHI.
diff --git a/lib/Transforms/Utils/CodeExtractor.cpp b/lib/Transforms/Utils/CodeExtractor.cpp
index e6337722c8..7576717077 100644
--- a/lib/Transforms/Utils/CodeExtractor.cpp
+++ b/lib/Transforms/Utils/CodeExtractor.cpp
@@ -104,7 +104,7 @@ namespace {
 /// region, we need to split the entry block of the region so that the PHI node
 /// is easier to deal with.
 void CodeExtractor::severSplitPHINodes(BasicBlock *&Header) {
-  bool HasPredsFromRegion = false;
+  unsigned NumPredsFromRegion = 0;
   unsigned NumPredsOutsideRegion = 0;
 
   if (Header != &Header->getParent()->getEntryBlock()) {
@@ -116,7 +116,7 @@ void CodeExtractor::severSplitPHINodes(BasicBlock *&Header) {
     // header block into two.
     for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
       if (BlocksToExtract.count(PN->getIncomingBlock(i)))
-        HasPredsFromRegion = true;
+        ++NumPredsFromRegion;
       else
         ++NumPredsOutsideRegion;
 
@@ -147,7 +147,7 @@ void CodeExtractor::severSplitPHINodes(BasicBlock *&Header) {
 
   // Okay, now we need to adjust the PHI nodes and any branches from within the
   // region to go to the new header block instead of the old header block.
-  if (HasPredsFromRegion) {
+  if (NumPredsFromRegion) {
     PHINode *PN = cast<PHINode>(OldPred->begin());
     // Loop over all of the predecessors of OldPred that are in the region,
     // changing them to branch to NewBB instead.
@@ -165,6 +165,7 @@ void CodeExtractor::severSplitPHINodes(BasicBlock *&Header) {
       // from OldPred of PN.
       PHINode *NewPN = PHINode::Create(PN->getType(), PN->getName()+".ce",
                                        NewBB->begin());
+      NewPN->reserveOperandSpace(1+NumPredsFromRegion);
       NewPN->addIncoming(PN, OldPred);
 
       // Loop over all of the incoming value in PN, moving them to NewPN if they
diff --git a/lib/Transforms/Utils/InlineFunction.cpp b/lib/Transforms/Utils/InlineFunction.cpp
index c1faf24113..80d6770131 100644
--- a/lib/Transforms/Utils/InlineFunction.cpp
+++ b/lib/Transforms/Utils/InlineFunction.cpp
@@ -626,6 +626,7 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI) {
     if (!TheCall->use_empty()) {
       PHI = PHINode::Create(RTy, TheCall->getName(),
                             AfterCallBB->begin());
+      PHI->reserveOperandSpace(Returns.size());
       // Anything that used the result of the function call should now use the
       // PHI node as their operand.
       TheCall->replaceAllUsesWith(PHI);
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp
index f924eebb0d..8b81555bc5 100644
--- a/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -1598,13 +1598,15 @@ static bool SimplifyCondBranchToCondBranch(BranchInst *PBI, BranchInst *BI) {
     // in the constant and simplify the block result.  Subsequent passes of
     // simplifycfg will thread the block.
     if (BlockIsSimpleEnoughToThreadThrough(BB)) {
+      pred_iterator PB = pred_begin(BB), PE = pred_end(BB);
       PHINode *NewPN = PHINode::Create(Type::getInt1Ty(BB->getContext()),
                                        BI->getCondition()->getName() + ".pr",
                                        BB->begin());
+      NewPN->reserveOperandSpace(std::distance(PB, PE));
       // Okay, we're going to insert the PHI node.  Since PBI is not the only
       // predecessor, compute the PHI'd conditional value for all of the preds.
       // Any predecessor where the condition is not computable we keep symbolic.
-      for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) {
+      for (pred_iterator PI = PB; PI != PE; ++PI) {
         BasicBlock *P = *PI;
         if ((PBI = dyn_cast<BranchInst>(P->getTerminator())) &&
             PBI != BI && PBI->isConditional() &&
diff --git a/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp b/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
index ccb8287d79..24d20d0e84 100644
--- a/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
+++ b/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
@@ -117,6 +117,7 @@ bool UnifyFunctionExitNodes::runOnFunction(Function &F) {
   } else {
     // If the function doesn't return void... add a PHI node to the block...
     PN = PHINode::Create(F.getReturnType(), "UnifiedRetVal");
+    PN->reserveOperandSpace(ReturningBlocks.size());
     NewRetBlock->getInstList().push_back(PN);
     ReturnInst::Create(F.getContext(), PN, NewRetBlock);
   }