diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -5052,6 +5052,11 @@
 def fno_automatic : Flag<["-"], "fno-automatic">, Group<f_Group>,
   HelpText<"Implies the SAVE attribute for non-automatic local objects in subprograms unless RECURSIVE">;
 
+def floop_versioning : Flag<["-"], "floop-versioning">, Group<f_Group>,
+  HelpText<"Attempt to version loops">;
+def fno_loop_versioning : Flag<["-"], "fno-loop-versioning">, Group<f_Group>,
+  HelpText<"Do not version loops (default)">;
+
 } // let Flags = [FC1Option, FlangOption, FlangOnlyOption]
 
 def J : JoinedOrSeparate<["-"], "J">,
diff --git a/clang/lib/Driver/ToolChains/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp
--- a/clang/lib/Driver/ToolChains/Flang.cpp
+++ b/clang/lib/Driver/ToolChains/Flang.cpp
@@ -57,6 +57,12 @@
                    options::OPT_fintrinsic_modules_path, options::OPT_pedantic,
                    options::OPT_std_EQ, options::OPT_W_Joined,
                    options::OPT_fconvert_EQ, options::OPT_fpass_plugin_EQ});
+  Arg *loopVersioning =
+      Args.getLastArg(options::OPT_Ofast, options::OPT_floop_versioning,
+                      options::OPT_fno_loop_versioning);
+  if (loopVersioning &&
+      !loopVersioning->getOption().matches(options::OPT_fno_loop_versioning))
+    CmdArgs.push_back("-floop-versioning");
 }
 
 void Flang::addPicOptions(const ArgList &Args, ArgStringList &CmdArgs) const {
diff --git a/flang/include/flang/Frontend/CodeGenOptions.def b/flang/include/flang/Frontend/CodeGenOptions.def
--- a/flang/include/flang/Frontend/CodeGenOptions.def
+++ b/flang/include/flang/Frontend/CodeGenOptions.def
@@ -24,6 +24,7 @@
 CODEGENOPT(DebugPassManager, 1, 0) ///< Prints debug information for the new
                                    ///< pass manager.
 
+CODEGENOPT(LoopVersioning, 1, 0) ///< PIC level of the LLVM module.
 CODEGENOPT(PICLevel, 2, 0) ///< PIC level of the LLVM module.
 CODEGENOPT(IsPIE, 1, 0) ///< PIE level is the same as PIC Level.
 
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -126,6 +126,11 @@
                    clang::driver::options::OPT_fno_debug_pass_manager, false))
     opts.DebugPassManager = 1;
 
+  if (args.hasFlag(clang::driver::options::OPT_floop_versioning,
+                   clang::driver::options::OPT_fno_loop_versioning, false)) {
+    opts.LoopVersioning = 1;
+  }
+
   for (auto *a : args.filtered(clang::driver::options::OPT_fpass_plugin_EQ))
     opts.LLVMPassPlugins.push_back(a->getValue());
 
diff --git a/flang/lib/Frontend/FrontendActions.cpp b/flang/lib/Frontend/FrontendActions.cpp
--- a/flang/lib/Frontend/FrontendActions.cpp
+++ b/flang/lib/Frontend/FrontendActions.cpp
@@ -541,7 +541,7 @@
   pm.enableVerifier(/*verifyPasses=*/true);
 
   // Create the pass pipeline
-  fir::createMLIRToLLVMPassPipeline(pm, level);
+  fir::createMLIRToLLVMPassPipeline(pm, opts.LoopVersioning, level);
   mlir::applyPassManagerCLOptions(pm);
 
   // run the pass manager
diff --git a/flang/tools/bbc/bbc.cpp b/flang/tools/bbc/bbc.cpp
--- a/flang/tools/bbc/bbc.cpp
+++ b/flang/tools/bbc/bbc.cpp
@@ -273,7 +273,8 @@
     pm.addPass(std::make_unique<Fortran::lower::VerifierPass>());
 
     // Add O2 optimizer pass pipeline.
-    fir::createDefaultFIROptimizerPassPipeline(pm, llvm::OptimizationLevel::O2);
+    fir::createDefaultFIROptimizerPassPipeline(pm, false,
+                                               llvm::OptimizationLevel::O2);
   }
 
   if (mlir::succeeded(pm.run(mlirModule))) {
diff --git a/flang/tools/tco/tco.cpp b/flang/tools/tco/tco.cpp
--- a/flang/tools/tco/tco.cpp
+++ b/flang/tools/tco/tco.cpp
@@ -122,7 +122,7 @@
       fir::createDefaultFIRCodeGenPassPipeline(pm);
     } else {
       // Run tco with O2 by default.
-      fir::createMLIRToLLVMPassPipeline(pm, llvm::OptimizationLevel::O2);
+      fir::createMLIRToLLVMPassPipeline(pm, false, llvm::OptimizationLevel::O2);
     }
     fir::addLLVMDialectToLLVMPass(pm, out.os());
   }