1 files changed, 11 insertions, 21 deletions

diff --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp
index 340c81fed0f..2b84150a000 100644
--- a/llvm/lib/Transforms/Scalar/LICM.cpp
+++ b/llvm/lib/Transforms/Scalar/LICM.cpp
@@ -478,27 +478,17 @@ bool llvm::hoistRegion(DomTreeNode *N, AliasAnalysis *AA, LoopInfo *LI,
 ///
 void llvm::computeLoopSafetyInfo(LoopSafetyInfo *SafetyInfo, Loop *CurLoop) {
   assert(CurLoop != nullptr && "CurLoop cant be null");
-  BasicBlock *Header = CurLoop->getHeader();
-  // Setting default safety values.
-  SafetyInfo->MayThrow = false;
-  SafetyInfo->HeaderMayThrow = false;
-  // Iterate over header and compute safety info.
-  for (BasicBlock::iterator I = Header->begin(), E = Header->end();
-       (I != E) && !SafetyInfo->HeaderMayThrow; ++I)
-    SafetyInfo->HeaderMayThrow |=
-        !isGuaranteedToTransferExecutionToSuccessor(&*I);
-
-  SafetyInfo->MayThrow = SafetyInfo->HeaderMayThrow;
-  // Iterate over loop instructions and compute safety info.
-  // Skip header as it has been computed and stored in HeaderMayThrow.
-  // The first block in loopinfo.Blocks is guaranteed to be the header.
-  assert(Header == *CurLoop->getBlocks().begin() && "First block must be header");
-  for (Loop::block_iterator BB = std::next(CurLoop->block_begin()),
+  // Iterate over loop instructions and compute early exit points.
+  for (Loop::block_iterator BB = CurLoop->block_begin(),
                             BBE = CurLoop->block_end();
-       (BB != BBE) && !SafetyInfo->MayThrow; ++BB)
-    for (BasicBlock::iterator I = (*BB)->begin(), E = (*BB)->end();
-         (I != E) && !SafetyInfo->MayThrow; ++I)
-      SafetyInfo->MayThrow |= !isGuaranteedToTransferExecutionToSuccessor(&*I);
+       BB != BBE; ++BB) {
+    for (BasicBlock::iterator I = (*BB)->begin(), E = (*BB)->end(); I != E;
+         ++I) {
+      if (isGuaranteedToTransferExecutionToSuccessor(&*I))
+        continue;
+      SafetyInfo->EarlyExits.push_back(&*I);
+    }
+  }
 
   // Compute funclet colors if we might sink/hoist in a function with a funclet
   // personality routine.
@@ -1094,7 +1084,7 @@ bool llvm::promoteLoopAccessesToScalars(
 
   // Do we know this object does not escape ?
   bool IsKnownNonEscapingObject = false;
-  if (SafetyInfo->MayThrow) {
+  if (!SafetyInfo->EarlyExits.empty()) {
     // If a loop can throw, we have to insert a store along each unwind edge.
     // That said, we can't actually make the unwind edge explicit. Therefore,
     // we have to prove that the store is dead along the unwind edge.