Fix proto bytes extension for windows.

PiperOrigin-RevId: 563892946

tensorflow/python/framework/tensor_util.py

@@ -73,14 +73,11 @@ def FastAppendBFloat16ArrayToTensorProto(tensor_proto, proto_values):
           proto_values, dtype=dtypes.bfloat16.as_numpy_dtype).view(np.uint16))
 
 
-def ExtractBitsFromFloat8e5m2(x):
-  return np.asarray(
-      x, dtype=dtypes.float8_e5m2.as_numpy_dtype).view(np.uint8).item()
-
-
 def SlowAppendFloat8e5m2ArrayToTensorProto(tensor_proto, proto_values):
-  tensor_proto.float8_val.extend(
-      [ExtractBitsFromFloat8e5m2(x) for x in proto_values]
+  tensor_proto.float8_val += (
+      np.asarray(proto_values, dtype=dtypes.float8_e5m2.as_numpy_dtype)
+      .view(np.uint8)
+      .tobytes()
   )
 
 
@@ -91,14 +88,11 @@ def FastAppendFloat8e5m2ArrayToTensorProto(tensor_proto, proto_values):
                  dtype=dtypes.float8_e5m2.as_numpy_dtype).view(np.uint8))
 
 
-def ExtractBitsFromFloat8e4m3fn(x):
-  return np.asarray(
-      x, dtype=dtypes.float8_e4m3fn.as_numpy_dtype).view(np.uint8).item()
-
-
 def SlowAppendFloat8e4m3fnArrayToTensorProto(tensor_proto, proto_values):
-  tensor_proto.float8_val.extend(
-      [ExtractBitsFromFloat8e4m3fn(x) for x in proto_values]
+  tensor_proto.float8_val += (
+      np.asarray(proto_values, dtype=dtypes.float8_e4m3fn.as_numpy_dtype)
+      .view(np.uint8)
+      .tobytes()
   )