diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index 5511f4f1af1ad..98775c2d18bd4 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -4095,6 +4095,12 @@ static void sortMapIndices(llvm::SmallVectorImpl<size_t> &indices,
   llvm::SmallVector<size_t> occludedChildren;
   llvm::sort(
       indices.begin(), indices.end(), [&](const size_t a, const size_t b) {
+        // Bail early if we are asked to look at the same index. If we do not
+        // bail early, we can end up mistakenly adding indices to
+        // occludedChildren. This can occur with some types of libc++ hardening.
+        if (a == b)
+          return false;
+
         auto memberIndicesA = cast<ArrayAttr>(indexAttr[a]);
         auto memberIndicesB = cast<ArrayAttr>(indexAttr[b]);