Revert r259662, which caused regressions on polly tests.

llvm-svn: 259675

1 files changed, 4 insertions, 16 deletions

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 58e3e8470d3..e3905d78063 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -2718,10 +2718,6 @@ void InnerLoopVectorizer::emitMinimumIterationCountCheck(Loop *L,
   
   BasicBlock *NewBB = BB->splitBasicBlock(BB->getTerminator(),
                                           "min.iters.checked");
-  // Update dominator tree immediately if the generated block is a
-  // LoopBypassBlock because SCEV expansions to generate loop bypass
-  // checks may query it before the current function is finished.
-  DT->addNewBlock(NewBB, BB);
   if (L->getParentLoop())
     L->getParentLoop()->addBasicBlockToLoop(NewBB, *LI);
   ReplaceInstWithInst(BB->getTerminator(),
@@ -2744,10 +2740,6 @@ void InnerLoopVectorizer::emitVectorLoopEnteredCheck(Loop *L,
   // adding one to the backedge-taken count will not overflow.
   BasicBlock *NewBB = BB->splitBasicBlock(BB->getTerminator(),
                                           "vector.ph");
-  // Update dominator tree immediately if the generated block is a
-  // LoopBypassBlock because SCEV expansions to generate loop bypass
-  // checks may query it before the current function is finished.
-  DT->addNewBlock(NewBB, BB);
   if (L->getParentLoop())
     L->getParentLoop()->addBasicBlockToLoop(NewBB, *LI);
   ReplaceInstWithInst(BB->getTerminator(),
@@ -2773,10 +2765,6 @@ void InnerLoopVectorizer::emitSCEVChecks(Loop *L, BasicBlock *Bypass) {
   // Create a new block containing the stride check.
   BB->setName("vector.scevcheck");
   auto *NewBB = BB->splitBasicBlock(BB->getTerminator(), "vector.ph");
-  // Update dominator tree immediately if the generated block is a
-  // LoopBypassBlock because SCEV expansions to generate loop bypass
-  // checks may query it before the current function is finished.
-  DT->addNewBlock(NewBB, BB);
   if (L->getParentLoop())
     L->getParentLoop()->addBasicBlockToLoop(NewBB, *LI);
   ReplaceInstWithInst(BB->getTerminator(),
@@ -2802,10 +2790,6 @@ void InnerLoopVectorizer::emitMemRuntimeChecks(Loop *L,
   // Create a new block containing the memory check.
   BB->setName("vector.memcheck");
   auto *NewBB = BB->splitBasicBlock(BB->getTerminator(), "vector.ph");
-  // Update dominator tree immediately if the generated block is a
-  // LoopBypassBlock because SCEV expansions to generate loop bypass
-  // checks may query it before the current function is finished.
-  DT->addNewBlock(NewBB, BB);
   if (L->getParentLoop())
     L->getParentLoop()->addBasicBlockToLoop(NewBB, *LI);
   ReplaceInstWithInst(BB->getTerminator(),
@@ -3973,6 +3957,10 @@ void InnerLoopVectorizer::updateAnalysis() {
   assert(DT->properlyDominates(LoopBypassBlocks.front(), LoopExitBlock) &&
          "Entry does not dominate exit.");
 
+  for (unsigned I = 1, E = LoopBypassBlocks.size(); I != E; ++I)
+    DT->addNewBlock(LoopBypassBlocks[I], LoopBypassBlocks[I-1]);
+  DT->addNewBlock(LoopVectorPreHeader, LoopBypassBlocks.back());
+
   // We don't predicate stores by this point, so the vector body should be a
   // single loop.
   assert(LoopVectorBody.size() == 1 && "Expected single block loop!");