diff --git a/mlir/lib/Transforms/CSE.cpp b/mlir/lib/Transforms/CSE.cpp
--- a/mlir/lib/Transforms/CSE.cpp
+++ b/mlir/lib/Transforms/CSE.cpp
@@ -50,7 +50,9 @@
 
     // If op has no regions, operation equivalence w.r.t operands alone is
     // enough.
-    if (lhs->getNumRegions() == 0 && rhs->getNumRegions() == 0) {
+    if ((lhs->getNumRegions() == 0 && rhs->getNumRegions() == 0) ||
+        ((lhs->getNumRegions() == 1 && lhs->getRegion(0).empty()) &&
+         (rhs->getNumRegions() == 1 && rhs->getRegion(0).empty()))) {
       return OperationEquivalence::isEquivalentTo(
           const_cast<Operation *>(lhsC), const_cast<Operation *>(rhsC),
           OperationEquivalence::exactValueMatch,
@@ -264,7 +266,8 @@
   // equality comparisons correctly among other things. It is also unclear
   // whether we would want to CSE such operations.
   if (op->getNumRegions() != 0 &&
-      (op->getNumRegions() != 1 || !llvm::hasSingleElement(op->getRegion(0))))
+      (op->getNumRegions() != 1 ||
+       !(llvm::hasSingleElement(op->getRegion(0)) || op->getRegion(0).empty())))
     return failure();
 
   // Some simple use case of operation with memory side-effect are dealt with