fp32 as default data type because fp16 not fully supported (#2597)

Summary:

fp32 as default data type because fp16 not fully supported

Reviewed By: JacobSzwejbka

Differential Revision: D55258223

Author: Michael Gschwind

examples/models/llama2/export_llama_lib.py

@@ -290,9 +290,9 @@ def build_args_parser() -> argparse.ArgumentParser:
     ckpt_dir = f"{Path(__file__).absolute().parent.as_posix()}"
     parser = argparse.ArgumentParser()
     parser.add_argument("-o", "--output-dir", default=".", help="output directory")
-    parser.add_argument(
-        "-q", "--quantized_ckpt", default=None, help="quantized checkpoint file"
-    )
+    # parser.add_argument(
+    #     "-q", "--quantized_ckpt", default=None, help="quantized checkpoint file"
+    # )
     parser.add_argument(
         "-E",
         "--embedding-quantize",
@@ -396,8 +396,10 @@ def build_args_parser() -> argparse.ArgumentParser:
     parser.add_argument(
         "-d",
         "--dtype-override",
-        default=None,
-        help="Override the dtype of the model (default is the checkpoint dtype). Options: fp16, fp32",
+        default="fp32",
+        type=str,
+        choices=["fp32"],
+        help="Override the dtype of the model (default is the checkpoint dtype). Options: fp32",
     )
 
     parser.add_argument(
@@ -495,7 +497,7 @@ def _prepare_for_llama_export(modelname: str, args) -> LlamaEdgeManager:
 
     # source transforms
     transforms = []
-    if args.quantized_ckpt or args.quantization_mode:
+    if args.quantization_mode:
         modelname = f"{modelname}_q"
         transforms.append(
             partial(