diff --git a/codeflash/benchmarking/instrument_codeflash_trace.py b/codeflash/benchmarking/instrument_codeflash_trace.py
index 04b12018a..0ae7588bf 100644
--- a/codeflash/benchmarking/instrument_codeflash_trace.py
+++ b/codeflash/benchmarking/instrument_codeflash_trace.py
@@ -5,6 +5,8 @@
 import isort
 import libcst as cst
 
+from codeflash.discovery.functions_to_optimize import FunctionToOptimize
+
 if TYPE_CHECKING:
     from pathlib import Path
 
@@ -85,16 +87,18 @@ def add_codeflash_decorator_to_code(code: str, functions_to_optimize: list[Funct
         The modified source code as a string
 
     """
-    target_functions = set()
-    for function_to_optimize in functions_to_optimize:
-        class_name = ""
-        if len(function_to_optimize.parents) == 1 and function_to_optimize.parents[0].type == "ClassDef":
-            class_name = function_to_optimize.parents[0].name
-        target_functions.add((class_name, function_to_optimize.function_name))
+    # Use a generator expression for faster creation and avoid multiple attribute lookups
+    target_functions = {
+        (fto.parents[0].name if len(fto.parents) == 1 and fto.parents[0].type == "ClassDef" else "", fto.function_name)
+        for fto in functions_to_optimize
+    }
 
     transformer = AddDecoratorTransformer(target_functions=target_functions)
-
+    # If code is already a CSTModule, skip reparsing it, but here we assume it is always a str
     module = cst.parse_module(code)
+    # Short-circuit if no target functions (fast return, avoids unnecessary CST tree walk)
+    if not target_functions:
+        return code
     modified_module = module.visit(transformer)
     return modified_module.code