1 files changed, 12 insertions, 0 deletions
diff --git a/polly/lib/Analysis/ScopDetection.cpp b/polly/lib/Analysis/ScopDetection.cpp
index bd68ef5c817..4c5c95af6e6 100644
--- a/polly/lib/Analysis/ScopDetection.cpp
+++ b/polly/lib/Analysis/ScopDetection.cpp
@@ -1297,6 +1297,18 @@ bool ScopDetection::isValidLoop(Loop *L, DetectionContext &Context) const {
   if (!hasExitingBlocks(L))
     return invalid<ReportLoopHasNoExit>(Context, /*Assert=*/true, L);
 
+  // The algorithm for domain construction assumes that loops has only a single
+  // exit block (and hence corresponds to a subregion). Note that we cannot use
+  // L->getExitBlock() because it does not check whether all exiting edges point
+  // to the same BB.
+  SmallVector<BasicBlock *, 4> ExitBlocks;
+  L->getExitBlocks(ExitBlocks);
+  BasicBlock *TheExitBlock = ExitBlocks[0];
+  for (BasicBlock *ExitBB : ExitBlocks) {
+    if (TheExitBlock != ExitBB)
+      return invalid<ReportLoopHasMultipleExits>(Context, /*Assert=*/true, L);
+  }
+
   if (canUseISLTripCount(L, Context))
     return true;