2 files changed, 11 insertions, 0 deletions
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index 81610ed..548ca67 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -1425,6 +1425,9 @@ static bool parseFloatingPointArgs(CompilerInvocation &invoc,
     opts.setFPContractMode(Fortran::common::LangOptions::FPM_Fast);
   }
 
+  if (args.hasArg(clang::driver::options::OPT_fno_fast_real_mod))
+    opts.NoFastRealMod = true;
+
   return true;
 }
 
diff --git a/flang/lib/Frontend/FrontendActions.cpp b/flang/lib/Frontend/FrontendActions.cpp
index d5e0325..0c630d2 100644
--- a/flang/lib/Frontend/FrontendActions.cpp
+++ b/flang/lib/Frontend/FrontendActions.cpp
@@ -277,6 +277,14 @@ bool CodeGenAction::beginSourceFileAction() {
                               ci.getInvocation().getLangOpts().OpenMPVersion);
   }
 
+  if (ci.getInvocation().getLangOpts().NoFastRealMod) {
+    mlir::ModuleOp mod = lb.getModule();
+    mod.getOperation()->setAttr(
+        mlir::StringAttr::get(mod.getContext(),
+                              llvm::Twine{"fir.no_fast_real_mod"}),
+        mlir::BoolAttr::get(mod.getContext(), true));
+  }
+
   // Create a parse tree and lower it to FIR
   parseAndLowerTree(ci, lb);