fix recipe merge logic

Signed-off-by: shanjiaz <[email protected]>

Author: shanjiaz

src/llmcompressor/recipe/recipe.py

@@ -11,6 +11,7 @@
     _load_json_or_yaml_string,
     _parse_recipe_from_md,
     get_yaml_serializable_dict,
+    deep_merge_dicts,
 )
 
 __all__ = [
@@ -265,30 +266,49 @@ def dict(self, *args, **kwargs) -> Dict[str, Any]:
 
         return get_yaml_serializable_dict(modifiers=self.modifiers, stage=self.stage)
 
-    def yaml(self, file_path: Optional[str] = None) -> str:
+    def yaml(
+        self,
+        file_path: Optional[str] = None,
+        existing_recipe_path: Optional[str] = None,
+    ) -> str:
         """
-        Return a yaml string representation of the recipe.
+        Return a YAML string representation of the recipe, optionally merging with another YAML file.
 
-        :param file_path: optional file path to save yaml to
-        :return: The yaml string representation of the recipe
+        :param file_path: Optional path to save YAML
+        :param existing_recipe_path: Optional path to another recipe.yaml file
+        :return: Combined YAML string
         """
+        # Load the other recipe from file, if given
+        other_dict = {}
+        if existing_recipe_path:
+            with open(existing_recipe_path, "r") as f:
+                existing_recipe_str = f.read()
+            other_dict = _load_json_or_yaml_string(existing_recipe_str)
+
+        # Serialize current recipe
+        self_dict = get_yaml_serializable_dict(
+            modifiers=self.modifiers,
+            stage=self.stage,
+        )
+
+        # Deep merge — keep both recipe contents
+        merged_dict = deep_merge_dicts(other_dict, self_dict)
 
+        # Dump YAML
         file_stream = None if file_path is None else open(file_path, "w")
-        yaml_dict = get_yaml_serializable_dict(
-            modifiers=self.modifiers, stage=self.stage
-        )
-        ret = yaml.dump(
-            yaml_dict,
+        yaml_str = yaml.dump(
+            merged_dict,
             stream=file_stream,
             allow_unicode=True,
             sort_keys=False,
             default_flow_style=None,
             width=88,
         )
-
-        if file_stream is not None:
+        
+        if file_stream:
             file_stream.close()
-        return ret
+
+        return yaml_str
 
 
 RecipeInput = Union[str, List[str], Recipe, List[Recipe], Modifier, List[Modifier]]

src/llmcompressor/recipe/utils.py

@@ -96,3 +96,15 @@ def get_yaml_serializable_dict(modifiers: List[Modifier], stage: str) -> Dict[st
         stage_dict[stage_name][group_name][modifier_type] = args
 
     return stage_dict
+
+def deep_merge_dicts(d1: dict, d2: dict) -> dict:
+    """
+    Recursively merge d2 into d1.
+    """
+    result = dict(d1)  # copy base
+    for key, val in d2.items():
+        if key in result and isinstance(result[key], dict) and isinstance(val, dict):
+            result[key] = deep_merge_dicts(result[key], val)
+        else:
+            result[key] = val
+    return result

src/llmcompressor/transformers/sparsification/compressed_tensors_utils.py

@@ -293,12 +293,10 @@ def update_and_save_recipe(model_stub: str, save_directory: str):
         existing recipe
     :param save_directory: path to save combined existing recipe and current recipe
     """
-    recipe_file_name = RECIPE_FILE_NAME
+ 
     existing_recipe = infer_recipe_from_model_path(model_stub)
-    if existing_recipe is not None:
-        recipe_file_name = "new_recipe.yaml"
 
     recipe = active_session().lifecycle.recipe
-    if len(recipe.modifiers) > 0:
-        recipe_path = os.path.join(save_directory, recipe_file_name)
-        recipe.yaml(recipe_path)
+    
+    recipe_path = os.path.join(save_directory, RECIPE_FILE_NAME)
+    recipe.yaml(file_path=recipe_path, existing_recipe_path=existing_recipe)