vendor/llvm/llvm-trunk-r301441

1 files changed, 17 insertions, 26 deletions

diff --git a/lib/Transforms/Utils/CodeExtractor.cpp b/lib/Transforms/Utils/CodeExtractor.cpp
index 82552684b832..ed72099ec3ed 100644
--- a/lib/Transforms/Utils/CodeExtractor.cpp
+++ b/lib/Transforms/Utils/CodeExtractor.cpp
@@ -73,24 +73,26 @@ bool CodeExtractor::isBlockValidForExtraction(const BasicBlock &BB) {
 }
 
 /// \brief Build a set of blocks to extract if the input blocks are viable.
-template <typename IteratorT>
-static SetVector<BasicBlock *> buildExtractionBlockSet(IteratorT BBBegin,
-                                                       IteratorT BBEnd) {
+static SetVector<BasicBlock *>
+buildExtractionBlockSet(ArrayRef<BasicBlock *> BBs, DominatorTree *DT) {
+  assert(!BBs.empty() && "The set of blocks to extract must be non-empty");
   SetVector<BasicBlock *> Result;
 
-  assert(BBBegin != BBEnd);
-
   // Loop over the blocks, adding them to our set-vector, and aborting with an
   // empty set if we encounter invalid blocks.
-  do {
-    if (!Result.insert(*BBBegin))
-      llvm_unreachable("Repeated basic blocks in extraction input");
+  for (BasicBlock *BB : BBs) {
 
-    if (!CodeExtractor::isBlockValidForExtraction(**BBBegin)) {
+    // If this block is dead, don't process it.
+    if (DT && !DT->isReachableFromEntry(BB))
+      continue;
+
+    if (!Result.insert(BB))
+      llvm_unreachable("Repeated basic blocks in extraction input");
+    if (!CodeExtractor::isBlockValidForExtraction(*BB)) {
       Result.clear();
       return Result;
     }
-  } while (++BBBegin != BBEnd);
+  }
 
 #ifndef NDEBUG
   for (SetVector<BasicBlock *>::iterator I = std::next(Result.begin()),
@@ -106,23 +108,17 @@ static SetVector<BasicBlock *> buildExtractionBlockSet(IteratorT BBBegin,
   return Result;
 }
 
-/// \brief Helper to call buildExtractionBlockSet with an ArrayRef.
-static SetVector<BasicBlock *>
-buildExtractionBlockSet(ArrayRef<BasicBlock *> BBs) {
-  return buildExtractionBlockSet(BBs.begin(), BBs.end());
-}
-
 CodeExtractor::CodeExtractor(ArrayRef<BasicBlock *> BBs, DominatorTree *DT,
                              bool AggregateArgs, BlockFrequencyInfo *BFI,
                              BranchProbabilityInfo *BPI)
     : DT(DT), AggregateArgs(AggregateArgs || AggregateArgsOpt), BFI(BFI),
-      BPI(BPI), Blocks(buildExtractionBlockSet(BBs)), NumExitBlocks(~0U) {}
+      BPI(BPI), Blocks(buildExtractionBlockSet(BBs, DT)), NumExitBlocks(~0U) {}
 
 CodeExtractor::CodeExtractor(DominatorTree &DT, Loop &L, bool AggregateArgs,
                              BlockFrequencyInfo *BFI,
                              BranchProbabilityInfo *BPI)
     : DT(&DT), AggregateArgs(AggregateArgs || AggregateArgsOpt), BFI(BFI),
-      BPI(BPI), Blocks(buildExtractionBlockSet(L.getBlocks())),
+      BPI(BPI), Blocks(buildExtractionBlockSet(L.getBlocks(), &DT)),
       NumExitBlocks(~0U) {}
 
 /// definedInRegion - Return true if the specified value is defined in the
@@ -194,9 +190,7 @@ void CodeExtractor::severSplitPHINodes(BasicBlock *&Header) {
   // containing PHI nodes merging values from outside of the region, and a
   // second that contains all of the code for the block and merges back any
   // incoming values from inside of the region.
-  BasicBlock::iterator AfterPHIs = Header->getFirstNonPHI()->getIterator();
-  BasicBlock *NewBB = Header->splitBasicBlock(AfterPHIs,
-                                              Header->getName()+".ce");
+  BasicBlock *NewBB = llvm::SplitBlock(Header, Header->getFirstNonPHI(), DT);
 
   // We only want to code extract the second block now, and it becomes the new
   // header of the region.
@@ -205,11 +199,6 @@ void CodeExtractor::severSplitPHINodes(BasicBlock *&Header) {
   Blocks.insert(NewBB);
   Header = NewBB;
 
-  // Okay, update dominator sets. The blocks that dominate the new one are the
-  // blocks that dominate TIBB plus the new block itself.
-  if (DT)
-    DT->splitBlock(NewBB);
-
   // 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 (NumPredsFromRegion) {
@@ -224,12 +213,14 @@ void CodeExtractor::severSplitPHINodes(BasicBlock *&Header) {
 
     // Okay, everything within the region is now branching to the right block, we
     // just have to update the PHI nodes now, inserting PHI nodes into NewBB.
+    BasicBlock::iterator AfterPHIs;
     for (AfterPHIs = OldPred->begin(); isa<PHINode>(AfterPHIs); ++AfterPHIs) {
       PHINode *PN = cast<PHINode>(AfterPHIs);
       // Create a new PHI node in the new region, which has an incoming value
       // from OldPred of PN.
       PHINode *NewPN = PHINode::Create(PN->getType(), 1 + NumPredsFromRegion,
                                        PN->getName() + ".ce", &NewBB->front());
+      PN->replaceAllUsesWith(NewPN);
       NewPN->addIncoming(PN, OldPred);
 
       // Loop over all of the incoming value in PN, moving them to NewPN if they