diff --git a/src/main.cpp b/src/main.cpp
index 83d7a56..078f229 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -32,6 +32,8 @@
 #include "mlir/Target/LLVMIR.h"
 #include "mlir/Transforms/Passes.h"
 
+void EmitLLVMBitCode(const mlir::OwningModuleRef &module);
+
 using namespace std;
 using namespace onnf;
 
@@ -57,13 +59,22 @@ void LoadMLIR(string inputFilename, mlir::MLIRContext &context,
   }
 }
 
+void EmitLLVMBitCode(const mlir::OwningModuleRef &module) {
+  error_code error;
+  llvm::raw_fd_ostream moduleBitcodeStream("model.bc", error,
+                                           llvm::sys::fs::F_None);
+  llvm::WriteBitcodeToFile(*mlir::translateModuleToLLVMIR(*module),
+                           moduleBitcodeStream);
+  moduleBitcodeStream.flush();
+}
+
 int main(int argc, char *argv[]) {
   mlir::registerDialect<mlir::ONNXOpsDialect>();
   mlir::registerDialect<mlir::KrnlOpsDialect>();
 
   llvm::cl::OptionCategory OnnfOptions("ONNF Options",
                                        "These are frontend options.");
-  llvm::cl::opt<string> InputFilename(
+  llvm::cl::opt<string> inputFilename(
       llvm::cl::Positional, llvm::cl::desc("<input file>"), llvm::cl::init("-"),
       llvm::cl::cat(OnnfOptions));
   llvm::cl::HideUnrelatedOptions(OnnfOptions);
@@ -75,17 +86,16 @@ int main(int argc, char *argv[]) {
 
   // Decide if the input file is an ONNX model or a model specified
   // in MLIR. The extension of the file is the decider.
-  string extension =
-      InputFilename.substr(InputFilename.find_last_of(".") + 1);
-  bool onnx_model_provided = (extension == "onnx");
-  bool mlir_model_provided = (extension == "mlir");
+  string extension = inputFilename.substr(inputFilename.find_last_of(".") + 1);
+  bool inputIsONNX = (extension == "onnx");
+  bool inputIsMLIR = (extension == "mlir");
 
-  if (onnx_model_provided) {
-    ImportFrontendModelFile(InputFilename, context, module);
-  } else if (mlir_model_provided) {
-    LoadMLIR(InputFilename, context, module);
+  assert(inputIsONNX != inputIsMLIR &&
+         "Either ONNX model or MLIR file needs to be provided.");
+  if (inputIsONNX) {
+    ImportFrontendModelFile(inputFilename, context, module);
   } else {
-    assert(false && "No ONNX or MLIR models provided!");
+    LoadMLIR(inputFilename, context, module);
   }
 
   mlir::PassManager pm(&context);
@@ -97,15 +107,11 @@ int main(int argc, char *argv[]) {
   pm.addPass(mlir::createLowerToCFGPass());
   pm.addPass(mlir::createKrnlLowerToLLVMPass());
   pm.addPass(mlir::createCanonicalizerPass());
-  pm.run(*module);
+
+  if (mlir::failed(pm.run(*module)))
+    return 4;
 
   // Write LLVM bitcode to disk.
-  std::error_code EC;
-  llvm::raw_fd_ostream moduleBitcodeStream("model.bc", EC,
-                                           llvm::sys::fs::F_None);
-  llvm::WriteBitcodeToFile(*mlir::translateModuleToLLVMIR(*module),
-                           moduleBitcodeStream);
-  moduleBitcodeStream.flush();
-
+  EmitLLVMBitCode(module);
   return 0;
 }