diff --git a/src/Compiler/CompilerOptions.cpp b/src/Compiler/CompilerOptions.cpp
index 8a5bd9d657..139cbd1847 100644
--- a/src/Compiler/CompilerOptions.cpp
+++ b/src/Compiler/CompilerOptions.cpp
@@ -407,13 +407,19 @@ static llvm::cl::opt<bool, true> VerboseOutputOpt("v",
     llvm::cl::init(false), llvm::cl::cat(OnnxMlirOptions));
 
 static llvm::cl::list<std::string, std::vector<std::string>> XoptOpt("Xopt",
-    llvm::cl::desc("Arguments to forward to LLVM's 'opt' option processing"),
+    llvm::cl::desc(
+        "Arguments to forward to LLVM's 'opt' option processing"
+        "Multiple arguments to 'opt' need to be pass with seperate 'Xopt'"
+        "For example, '-Xopt opt1 -Xopt opt2 ...'"),
     llvm::cl::value_desc("A valid LLVM's 'opt' option"),
     llvm::cl::location(Xopt), llvm::cl::cat(OnnxMlirOptions), llvm::cl::Hidden,
     llvm::cl::ValueRequired, llvm::cl::ZeroOrMore, llvm::cl::CommaSeparated);
 
 static llvm::cl::list<std::string, std::vector<std::string>> XllcOpt("Xllc",
-    llvm::cl::desc("Arguments to forward to LLVM's 'llc' option processing"),
+    llvm::cl::desc(
+        "Arguments to forward to LLVM's 'llc' option processing"
+        "Multiple arguments to 'llc' need to be pass with seperate 'Xllc'"
+        "For example, '-Xllc opt1 -Xllc opt2 ...'"),
     llvm::cl::value_desc("A valid LLVM's 'llc' option"),
     llvm::cl::location(Xllc), llvm::cl::cat(OnnxMlirOptions), llvm::cl::Hidden,
     llvm::cl::ValueRequired, llvm::cl::ZeroOrMore, llvm::cl::CommaSeparated);
@@ -914,6 +920,21 @@ void setLLVMOption(const std::string &flag) { mllvm = flag; }
 void clearLLVMOption() { mllvm.clear(); }
 std::string getLLVMOption() { return (mllvm != "") ? mllvm : std::string(); }
 
+static std::vector<std::string> split(std::string &input) {
+  std::stringstream ss(input);
+  std::istream_iterator<std::string> begin(ss);
+  std::istream_iterator<std::string> end;
+  std::vector<std::string> vstrings(begin, end);
+  return vstrings;
+}
+
+std::vector<std::string> getLLVMOptions() {
+  if (mllvm == "")
+    return std::vector<std::string>();
+
+  return split(mllvm);
+}
+
 // Support for model tag
 void setModelTag(const std::string &str) { modelTag = str; }
 void clearModelTag() { modelTag = ""; }
diff --git a/src/Compiler/CompilerOptions.hpp b/src/Compiler/CompilerOptions.hpp
index 3e0940d70b..449202198a 100644
--- a/src/Compiler/CompilerOptions.hpp
+++ b/src/Compiler/CompilerOptions.hpp
@@ -183,6 +183,10 @@ std::vector<std::string> getXllcOption();
 void setLLVMOption(const std::string &flag);
 void clearLLVMOption();
 std::string getLLVMOption();
+// Break down the result of getLLVMOption into substrings
+std::vector<std::string> getLLVMOptions();
+std::vector<std::string> getLLVMOPTOptions();
+std::vector<std::string> getLLVMLLCOptions();
 
 // Options support for OMCompilerOptions.
 using CompilerOptionList =
diff --git a/src/Compiler/CompilerUtils.cpp b/src/Compiler/CompilerUtils.cpp
index f4ec2d6d45..260e56a534 100644
--- a/src/Compiler/CompilerUtils.cpp
+++ b/src/Compiler/CompilerUtils.cpp
@@ -72,6 +72,26 @@ enum class KeepFilesOfType { All, MLIR, LLVMIR, Bitcode, Object, None };
 // flags.
 static constexpr KeepFilesOfType overridePreserveFiles = KeepFilesOfType::None;
 
+// Get optimization level from onnx-mlir only when it is not specified
+std::string getOptimizationLevelUniqueOption(
+    std::vector<std::vector<std::string>> specialOptionsList) {
+  if (std::any_of(specialOptionsList.begin(), specialOptionsList.end(),
+          [](std::vector<std::string> specialOptions) {
+            if (std::any_of(specialOptions.begin(), specialOptions.end(),
+                    [](std::string str) {
+                      std::regex optimization("^-O[0-9]");
+                      std::smatch m;
+                      return std::regex_match(str, m, optimization);
+                    })) // End of one options
+              return true;
+            else
+              return false;
+          }))
+    return std::string();
+  else
+    return getOptimizationLevelOption();
+}
+
 static bool keepFiles(KeepFilesOfType preserve) {
   // When wanting to preserve all files, do it regardless of isBitcode.
   if (overridePreserveFiles == KeepFilesOfType::All)
@@ -437,12 +457,14 @@ static int genLLVMBitcode(const mlir::OwningOpRef<ModuleOp> &module,
   std::string optPath = getToolPath("opt");
   Command optBitcode(/*exePath=*/optPath);
   setXoptOption({"--code-model", modelSizeStr[modelSize]});
-  int rc = optBitcode.appendStr(getOptimizationLevelOption())
+  int rc = optBitcode
+               .appendStr(getOptimizationLevelUniqueOption(
+                   {getLLVMOptions(), getXoptOption()}))
                .appendStr(getTargetTripleOption())
                .appendStr(getTargetArchOption())
                .appendStr(getTargetCPUOption())
                .appendList(getXoptOption())
-               .appendStr(getLLVMOption())
+               .appendList(getLLVMOptions())
                .appendList({"-o", optimizedBitcodeNameWithExt})
                .appendStr(unoptimizedBitcodeNameWithExt)
                .exec();
@@ -459,12 +481,14 @@ static int genModelObject(
   std::string llcPath = getToolPath("llc");
   Command llvmToObj(/*exePath=*/llcPath);
   setXllcOption({"--code-model", modelSizeStr[modelSize]});
-  int rc = llvmToObj.appendStr(getOptimizationLevelOption())
+  int rc = llvmToObj
+               .appendStr(getOptimizationLevelUniqueOption(
+                   {getLLVMOptions(), getXllcOption()}))
                .appendStr(getTargetTripleOption())
                .appendStr(getTargetArchOption())
                .appendStr(getTargetCPUOption())
                .appendList(getXllcOption())
-               .appendStr(getLLVMOption())
+               .appendList(getLLVMOptions())
                .appendStr("-filetype=obj")
                .appendStr("-relocation-model=pic")
                .appendList({"-o", modelObjNameWithExt})