Fix dispatch of Elemwised ScalarLoop in Numba backend

pytensor/link/numba/dispatch/elemwise.py

@@ -30,20 +30,19 @@
     OR,
     XOR,
     Add,
-    Composite,
     IntDiv,
     Mul,
     ScalarMaximum,
     ScalarMinimum,
     Sub,
     TrueDiv,
+    get_scalar_type,
     scalar_maximum,
 )
 from pytensor.scalar.basic import add as add_as
 from pytensor.tensor.elemwise import CAReduce, DimShuffle, Elemwise
 from pytensor.tensor.math import Argmax, MulWithoutZeros, Sum
 from pytensor.tensor.special import LogSoftmax, Softmax, SoftmaxGrad
-from pytensor.tensor.type import scalar
 
 
 @singledispatch
@@ -348,13 +347,8 @@ def axis_apply_fn(x):
 
 @numba_funcify.register(Elemwise)
 def numba_funcify_Elemwise(op, node, **kwargs):
-    # Creating a new scalar node is more involved and unnecessary
-    # if the scalar_op is composite, as the fgraph already contains
-    # all the necessary information.
-    scalar_node = None
-    if not isinstance(op.scalar_op, Composite):
-        scalar_inputs = [scalar(dtype=input.dtype) for input in node.inputs]
-        scalar_node = op.scalar_op.make_node(*scalar_inputs)
+    scalar_inputs = [get_scalar_type(dtype=input.dtype)() for input in node.inputs]
+    scalar_node = op.scalar_op.make_node(*scalar_inputs)
 
     scalar_op_fn = numba_funcify(
         op.scalar_op,

tests/link/numba/test_basic.py

@@ -267,11 +267,11 @@ def assert_fn(x, y):
                 x, y
             )
 
-    if isinstance(fgraph, tuple):
-        fn_inputs, fn_outputs = fgraph
-    else:
+    if isinstance(fgraph, FunctionGraph):
         fn_inputs = fgraph.inputs
         fn_outputs = fgraph.outputs
+    else:
+        fn_inputs, fn_outputs = fgraph
 
     fn_inputs = [i for i in fn_inputs if not isinstance(i, SharedVariable)]
 

tests/link/numba/test_elemwise.py

@@ -15,7 +15,8 @@
 from pytensor.gradient import grad
 from pytensor.graph.basic import Constant
 from pytensor.graph.fg import FunctionGraph
-from pytensor.tensor.elemwise import CAReduce, DimShuffle
+from pytensor.scalar import float64
+from pytensor.tensor.elemwise import CAReduce, DimShuffle, Elemwise
 from pytensor.tensor.math import All, Any, Max, Min, Prod, ProdWithoutZeros, Sum
 from pytensor.tensor.special import LogSoftmax, Softmax, SoftmaxGrad
 from tests.link.numba.test_basic import (
@@ -691,3 +692,17 @@ def test_numba_careduce_benchmark(axis, c_contiguous, benchmark):
     return careduce_benchmark_tester(
         axis, c_contiguous, mode="NUMBA", benchmark=benchmark
     )
+
+
+def test_scalar_loop():
+    a = float64("a")
+    scalar_loop = pytensor.scalar.ScalarLoop([a], [a + a])
+
+    x = pt.tensor("x", shape=(3,))
+    elemwise_loop = Elemwise(scalar_loop)(3, x)
+
+    with pytest.warns(UserWarning, match="object mode"):
+        compare_numba_and_py(
+            ([x], [elemwise_loop]),
+            (np.array([1, 2, 3], dtype="float64"),),
+        )