Remove unnecessary Subtensors from broadcast_to

aesara/tensor/extra_ops.py

@@ -1590,7 +1590,6 @@ class BroadcastTo(Op):
 
     def make_node(self, a, *shape):
         a = at.as_tensor_variable(a)
-        shape = at.as_tensor_variable(shape, ndim=1)
 
         shape, bcast = at.infer_broadcastable(shape)
 
@@ -1658,7 +1657,6 @@ def broadcast_to(
 
     """
     x = at.as_tensor(x)
-    shape = at.as_tensor(shape, ndim=1, dtype="int64")
     shape_len = get_vector_length(shape)
 
     if x.ndim == 0 and shape_len == 0:

tests/tensor/test_extra_ops.py

@@ -1123,6 +1123,14 @@ class TestBroadcastTo(utt.InferShapeTester):
         y = broadcast_to(x, ())
         assert y is x
 
+    def test_avoid_useless_subtensors(self):
+        x = scalar()
+        y = broadcast_to(x, (1, 2))
+        # There shouldn't be any unnecessary `Subtensor` operations
+        # (e.g. from `at.as_tensor((1, 2))[0]`)
+        assert y.owner.inputs[1].owner is None
+        assert y.owner.inputs[2].owner is None
+
     @config.change_flags(compute_test_value="raise")
     def test_perform(self):
         a = scalar()