1 files changed, 7 insertions, 1 deletions
diff --git a/flang/lib/Lower/ConvertExprToHLFIR.cpp b/flang/lib/Lower/ConvertExprToHLFIR.cpp
index 2298e836e4cb..22425cc441b9 100644
--- a/flang/lib/Lower/ConvertExprToHLFIR.cpp
+++ b/flang/lib/Lower/ConvertExprToHLFIR.cpp
@@ -1558,7 +1558,13 @@ private:
   hlfir::EntityWithAttributes
   gen(const Fortran::evaluate::ImpliedDoIndex &var) {
     mlir::Value value = symMap.lookupImpliedDo(toStringRef(var.name));
-    assert(value && "impled do was not mapped");
+    if (!value)
+      fir::emitFatalError(getLoc(), "ac-do-variable has no binding");
+    // The index value generated by the implied-do has Index type,
+    // while computations based on it inside the loop body are using
+    // the original data type. So we need to cast it appropriately.
+    mlir::Type varTy = getConverter().genType(toEvExpr(var));
+    value = getBuilder().createConvert(getLoc(), varTy, value);
     return hlfir::EntityWithAttributes{value};
   }