Implement broadcast routines

cunumeric/_ufunc/ufunc.py

@@ -18,7 +18,7 @@
 
 import numpy as np
 
-from ..array import convert_to_cunumeric_ndarray, ndarray
+from ..array import check_writeable, convert_to_cunumeric_ndarray, ndarray
 from ..config import BinaryOpCode, UnaryOpCode, UnaryRedCode
 from ..types import NdShape
 
@@ -327,6 +327,7 @@ def _prepare_operands(
                     f"{out.shape} doesn't match the broadcast shape "
                     f"{out_shape}"
                 )
+            check_writeable(out)
 
         if not isinstance(where, bool) or not where:
             raise NotImplementedError(
@@ -648,6 +649,7 @@ def __call__(
         arrs, (out,), out_shape, where = self._prepare_operands(
             *args, out=out, where=where
         )
+
         orig_args = args[: self.nin]
 
         # If no dtype is given to prescribe the accuracy, we use the dtype