Fix tests and fix scalar numba return types

pytensor/link/numba/dispatch/basic.py

@@ -204,7 +204,7 @@ enable_slice_boxing()
 
 
 def to_scalar(x):
-    raise NotImplementedError()
+    return np.asarray(x).item()
 
 
 @numba.extending.overload(to_scalar)
@@ -543,7 +543,7 @@ def {fn_name}({", ".join(input_names)}):
     {index_prologue}
     {indices_creation_src}
     {index_body}
-    return z
+    return np.asarray(z)
     """
 
     return subtensor_def_src
@@ -665,7 +665,7 @@ def numba_funcify_Shape_i(op, **kwargs):
 
     @numba_njit
     def shape_i(x):
-        return np.shape(x)[i]
+        return np.asarray(np.shape(x)[i])
 
     return shape_i
 

pytensor/link/numba/dispatch/elemwise.py

@@ -9,6 +9,7 @@ import numba
 import numpy as np
 from numba import TypingError, types
 from numba.core import cgutils
+from numba.core.extending import overload
 from numba.np import arrayobj
 from numpy.core.numeric import normalize_axis_index, normalize_axis_tuple
 
@@ -174,6 +175,7 @@ def create_axis_reducer(
     ndim: int,
     dtype: numba.types.Type,
     keepdims: bool = False,
+    return_scalar=False,
 ) -> numba.core.dispatcher.Dispatcher:
     r"""Create Python function that performs a NumPy-like reduction on a given axis.
 
@@ -284,6 +286,8 @@ def {reduce_elemwise_fn_name}(x):
         inplace_update_statement = indent(inplace_update_statement, " " * 4 * 2)
 
         return_expr = "res" if keepdims else "res.item()"
+        if not return_scalar:
+            return_expr = f"np.asarray({return_expr})"
         reduce_elemwise_def_src = f"""
 def {reduce_elemwise_fn_name}(x):
 
@@ -305,7 +309,13 @@ def {reduce_elemwise_fn_name}(x):
 
 
 def create_multiaxis_reducer(
-    scalar_op, identity, axes, ndim, dtype, input_name="input"
+    scalar_op,
+    identity,
+    axes,
+    ndim,
+    dtype,
+    input_name="input",
+    return_scalar=False,
 ):
     r"""Construct a function that reduces multiple axes.
 
@@ -336,6 +346,8 @@ def create_multiaxis_reducer(
         The number of dimensions of the result.
     dtype:
         The data type of the result.
+    return_scalar:
+        If True, return a scalar, otherwise an array.
 
     Returns
     =======
@@ -370,10 +382,17 @@ def create_multiaxis_reducer(
         )
 
     careduce_assign_lines = indent("\n".join(careduce_lines_src), " " * 4)
+    if not return_scalar:
+        pre_result = "np.asarray"
+        post_result = ""
+    else:
+        pre_result = "np.asarray"
+        post_result = ".item()"
+
     careduce_def_src = f"""
 def {careduce_fn_name}({input_name}):
 {careduce_assign_lines}
-    return np.asarray({var_name})
+    return {pre_result}({var_name}){post_result}
     """
 
     careduce_fn = compile_function_src(
@@ -383,7 +402,7 @@ def {careduce_fn_name}({input_name}):
     return careduce_fn
 
 
-def jit_compile_reducer(node, fn, **kwds):
+def jit_compile_reducer(node, fn, *, reduce_to_scalar=False, **kwds):
     """Compile Python source for reduction loops using additional optimizations.
 
     Parameters
@@ -400,7 +419,7 @@ def jit_compile_reducer(node, fn, **kwds):
     A :func:`numba.njit`-compiled function.
 
     """
-    signature = create_numba_signature(node, reduce_to_scalar=True)
+    signature = create_numba_signature(node, reduce_to_scalar=reduce_to_scalar)
 
     # Eagerly compile the function using increased optimizations.  This should
     # help improve nested loop reductions.
@@ -618,24 +637,59 @@ def numba_funcify_Elemwise(op, node, **kwargs):
     inplace_pattern = tuple(op.inplace_pattern.items())
 
     # numba doesn't support nested literals right now...
-    input_bc_patterns = base64.encodebytes(pickle.dumps(input_bc_patterns)).decode()
-    output_bc_patterns = base64.encodebytes(pickle.dumps(output_bc_patterns)).decode()
-    output_dtypes = base64.encodebytes(pickle.dumps(output_dtypes)).decode()
-    inplace_pattern = base64.encodebytes(pickle.dumps(inplace_pattern)).decode()
+    input_bc_patterns_enc = base64.encodebytes(pickle.dumps(input_bc_patterns)).decode()
+    output_bc_patterns_enc = base64.encodebytes(
+        pickle.dumps(output_bc_patterns)
+    ).decode()
+    output_dtypes_enc = base64.encodebytes(pickle.dumps(output_dtypes)).decode()
+    inplace_pattern_enc = base64.encodebytes(pickle.dumps(inplace_pattern)).decode()
 
-    @numba_njit
     def elemwise_wrapper(*inputs):
         return _vectorized(
             scalar_op_fn,
-            input_bc_patterns,
-            output_bc_patterns,
-            output_dtypes,
-            inplace_pattern,
+            input_bc_patterns_enc,
+            output_bc_patterns_enc,
+            output_dtypes_enc,
+            inplace_pattern_enc,
             inputs,
         )
 
+    # Pure python implementation, that will be used in tests
+    def elemwise(*inputs):
+        inputs = [np.asarray(input) for input in inputs]
+        inputs_bc = np.broadcast_arrays(*inputs)
+        shape = inputs[0].shape
+        for input, bc in zip(inputs, input_bc_patterns):
+            for length, allow_bc, iter_length in zip(input.shape, bc, shape):
+                if length == 1 and shape and iter_length != 1 and not allow_bc:
+                    raise ValueError("Broadcast not allowed.")
+
+        outputs = []
+        for dtype in output_dtypes:
+            outputs.append(np.empty(shape, dtype=dtype))
+
+        for idx in np.ndindex(shape):
+            vals = [input[idx] for input in inputs_bc]
+            outs = scalar_op_fn(*vals)
+            if not isinstance(outs, tuple):
+                outs = (outs,)
+            for out, out_val in zip(outputs, outs):
+                out[idx] = out_val
+
+        outputs_summed = []
+        for output, bc in zip(outputs, output_bc_patterns):
+            axes = tuple(np.nonzero(bc)[0])
+            outputs_summed.append(output.sum(axes, keepdims=True))
+        if len(outputs_summed) != 1:
+            return tuple(outputs_summed)
+        return outputs_summed[0]
+
+    @overload(elemwise)
+    def ov_elemwise(*inputs):
         return elemwise_wrapper
 
+    return elemwise
+
 
 @numba_funcify.register(Sum)
 def numba_funcify_Sum(op, node, **kwargs):
@@ -643,7 +697,7 @@ def numba_funcify_Sum(op, node, **kwargs):
     if axes is None:
         axes = list(range(node.inputs[0].ndim))
 
-    axes = list(axes)
+    axes = tuple(axes)
 
     ndim_input = node.inputs[0].ndim
 
@@ -658,15 +712,16 @@ def numba_funcify_Sum(op, node, **kwargs):
 
         @numba_njit(fastmath=True)
         def impl_sum(array):
-            # TODO The accumulation itself should happen in acc_dtype...
-            return np.asarray(array.sum()).astype(np_acc_dtype)
+            return np.asarray(array.sum(), dtype=np_acc_dtype)
 
-    else:
+    elif len(axes) == 0:
 
         @numba_njit(fastmath=True)
         def impl_sum(array):
-            # TODO The accumulation itself should happen in acc_dtype...
-            return array.sum(axes).astype(np_acc_dtype)
+            return array
+
+    else:
+        impl_sum = numba_funcify_CAReduce(op, node, **kwargs)
 
     return impl_sum
 
@@ -705,7 +760,7 @@ def numba_funcify_CAReduce(op, node, **kwargs):
         input_name=input_name,
     )
 
-    careduce_fn = jit_compile_reducer(node, careduce_py_fn)
+    careduce_fn = jit_compile_reducer(node, careduce_py_fn, reduce_to_scalar=False)
     return careduce_fn
 
 
@@ -888,7 +943,12 @@ def numba_funcify_LogSoftmax(op, node, **kwargs):
     if axis is not None:
         axis = normalize_axis_index(axis, x_at.ndim)
         reduce_max_py = create_axis_reducer(
-            scalar_maximum, -np.inf, axis, x_at.ndim, x_dtype, keepdims=True
+            scalar_maximum,
+            -np.inf,
+            axis,
+            x_at.ndim,
+            x_dtype,
+            keepdims=True,
         )
         reduce_sum_py = create_axis_reducer(
             add_as, 0.0, axis, x_at.ndim, x_dtype, keepdims=True
@@ -935,10 +995,17 @@ def numba_funcify_MaxAndArgmax(op, node, **kwargs):
         keep_axes = tuple(i for i in range(x_ndim) if i not in axes)
 
         reduce_max_py_fn = create_multiaxis_reducer(
-            scalar_maximum, -np.inf, axes, x_ndim, x_dtype
+            scalar_maximum,
+            -np.inf,
+            axes,
+            x_ndim,
+            x_dtype,
+            return_scalar=False,
         )
         reduce_max = jit_compile_reducer(
-            Apply(node.op, node.inputs, [node.outputs[0].clone()]), reduce_max_py_fn
+            Apply(node.op, node.inputs, [node.outputs[0].clone()]),
+            reduce_max_py_fn,
+            reduce_to_scalar=False,
         )
 
         reduced_x_ndim = x_ndim - len(axes) + 1

pytensor/link/numba/dispatch/elemwise_codegen.py

@@ -117,19 +117,6 @@ def make_loop_call(
 
     # context.printf(builder, "iter shape: " + ', '.join(["%i"] * len(iter_shape)) + "\n", *iter_shape)
 
-    # Lower the code of the scalar function so that we can use it in the inner loop
-    # Caching is set to false to avoid a numba bug TODO ref?
-    inner_func = context.compile_subroutine(
-        builder,
-        # I don't quite understand why we need to access `dispatcher` here.
-        # The object does seem to be a dispatcher already? But it is missing
-        # attributes...
-        scalar_func.dispatcher,
-        scalar_signature,
-        caching=False,
-    )
-    inner = inner_func.fndesc
-
     # Extract shape and stride information from the array.
     # For later use in the loop body to do the indexing
     def extract_array(aryty, obj):
@@ -191,14 +178,15 @@ def make_loop_call(
         # val.set_metadata("noalias", output_scope_set)
         input_vals.append(val)
 
-    # Call scalar function
-    output_values = context.call_internal(
-        builder,
-        inner,
-        scalar_signature,
-        input_vals,
-    )
-    if isinstance(scalar_signature.return_type, types.Tuple):
+    inner_codegen = context.get_function(scalar_func, scalar_signature)
+
+    if isinstance(
+        scalar_signature.args[0], (types.StarArgTuple, types.StarArgUniTuple)
+    ):
+        input_vals = [context.make_tuple(builder, scalar_signature.args[0], input_vals)]
+    output_values = inner_codegen(builder, input_vals)
+
+    if isinstance(scalar_signature.return_type, (types.Tuple, types.UniTuple)):
         output_values = cgutils.unpack_tuple(builder, output_values)
     else:
         output_values = [output_values]

pytensor/link/numba/dispatch/extra_ops.py

@@ -364,6 +364,7 @@ def numba_funcify_BroadcastTo(op, node, **kwargs):
         lambda _: 0, len(node.inputs) - 1
     )
 
+    # TODO broadcastable checks
     @numba_basic.numba_njit
     def broadcast_to(x, *shape):
         scalars_shape = create_zeros_tuple()

pytensor/link/numba/dispatch/scalar.py

@@ -38,6 +38,9 @@ def numba_funcify_ScalarOp(op, node, **kwargs):
     # TODO: Do we need to cache these functions so that we don't end up
     # compiling the same Numba function over and over again?
 
+    if not hasattr(op, "nfunc_spec"):
+        return generate_fallback_impl(op, node, **kwargs)
+
     scalar_func_path = op.nfunc_spec[0]
     scalar_func_numba = None
 

pytensor/link/numba/dispatch/scan.py

@@ -17,7 +17,11 @@ from pytensor.tensor.type import TensorType
 
 
 def idx_to_str(
-    array_name: str, offset: int, size: Optional[str] = None, idx_symbol: str = "i"
+    array_name: str,
+    offset: int,
+    size: Optional[str] = None,
+    idx_symbol: str = "i",
+    allow_scalar=False,
 ) -> str:
     if offset < 0:
         indices = f"{idx_symbol} + {array_name}.shape[0] - {offset}"
@@ -32,7 +36,10 @@ def idx_to_str(
         # compensate for this poor `Op`/rewrite design and implementation.
         indices = f"({indices}) % {size}"
 
+    if allow_scalar:
         return f"{array_name}[{indices}]"
+    else:
+        return f"np.asarray({array_name}[{indices}])"
 
 
 @overload(range)
@@ -115,7 +122,9 @@ def numba_funcify_Scan(op, node, **kwargs):
         indexed_inner_in_str = (
             storage_name
             if tap_offset is None
-            else idx_to_str(storage_name, tap_offset, size=storage_size_var)
+            else idx_to_str(
+                storage_name, tap_offset, size=storage_size_var, allow_scalar=False
+            )
         )
         inner_in_exprs.append(indexed_inner_in_str)
 
@@ -232,7 +241,12 @@ def numba_funcify_Scan(op, node, **kwargs):
                 )
                 for out_tap in output_taps:
                     inner_out_to_outer_in_stmts.append(
-                        idx_to_str(storage_name, out_tap, size=storage_size_name)
+                        idx_to_str(
+                            storage_name,
+                            out_tap,
+                            size=storage_size_name,
+                            allow_scalar=True,
+                        )
                     )
 
                 add_output_storage_post_proc_stmt(
@@ -269,7 +283,7 @@ def numba_funcify_Scan(op, node, **kwargs):
             storage_size_name = f"{outer_in_name}_len"
 
             inner_out_to_outer_in_stmts.append(
-                idx_to_str(storage_name, 0, size=storage_size_name)
+                idx_to_str(storage_name, 0, size=storage_size_name, allow_scalar=True)
             )
             add_output_storage_post_proc_stmt(storage_name, (0,), storage_size_name)
 

pytensor/link/numba/linker.py

@@ -27,9 +27,9 @@ class NumbaLinker(JITLinker):
         return numba_funcify(fgraph, **kwargs)
 
     def jit_compile(self, fn):
-        import numba
+        from pytensor.link.numba.dispatch.basic import numba_njit
 
-        jitted_fn = numba.njit(fn)
+        jitted_fn = numba_njit(fn)
         return jitted_fn
 
     def create_thunk_inputs(self, storage_map):

tests/link/numba/test_basic.py

@@ -27,6 +27,7 @@ from pytensor.link.numba.dispatch import basic as numba_basic
 from pytensor.link.numba.dispatch import numba_typify
 from pytensor.link.numba.linker import NumbaLinker
 from pytensor.raise_op import assert_op
+from pytensor.scalar.basic import ScalarOp, as_scalar
 from pytensor.tensor import blas
 from pytensor.tensor import subtensor as at_subtensor
 from pytensor.tensor.elemwise import Elemwise
@@ -63,6 +64,33 @@ class MySingleOut(Op):
         outputs[0][0] = res
 
 
+class ScalarMyMultiOut(ScalarOp):
+    nin = 2
+    nout = 2
+
+    @staticmethod
+    def impl(a, b):
+        res1 = 2 * a
+        res2 = 2 * b
+        return [res1, res2]
+
+    def make_node(self, a, b):
+        a = as_scalar(a)
+        b = as_scalar(b)
+        return Apply(self, [a, b], [a.type(), b.type()])
+
+    def perform(self, node, inputs, outputs):
+        res1, res2 = self.impl(inputs[0], inputs[1])
+        outputs[0][0] = res1
+        outputs[1][0] = res2
+
+
+scalar_my_multi_out = Elemwise(ScalarMyMultiOut())
+scalar_my_multi_out.ufunc = ScalarMyMultiOut.impl
+scalar_my_multi_out.ufunc.nin = 2
+scalar_my_multi_out.ufunc.nout = 2
+
+
 class MyMultiOut(Op):
     nin = 2
     nout = 2
@@ -86,7 +114,6 @@ my_multi_out = Elemwise(MyMultiOut())
 my_multi_out.ufunc = MyMultiOut.impl
 my_multi_out.ufunc.nin = 2
 my_multi_out.ufunc.nout = 2
-
 opts = RewriteDatabaseQuery(include=[None], exclude=["cxx_only", "BlasOpt"])
 numba_mode = Mode(NumbaLinker(), opts)
 py_mode = Mode("py", opts)
@@ -988,8 +1015,8 @@ def test_config_options_parallel():
     x = at.dvector()
 
     with config.change_flags(numba__vectorize_target="parallel"):
-        pytensor_numba_fn = function([x], x * 2, mode=numba_mode)
-        numba_mul_fn = pytensor_numba_fn.vm.jit_fn.py_func.__globals__["mul"]
+        pytensor_numba_fn = function([x], at.sum(x), mode=numba_mode)
+        numba_mul_fn = pytensor_numba_fn.vm.jit_fn.py_func.__globals__["impl_sum"]
         assert numba_mul_fn.targetoptions["parallel"] is True
 
 
@@ -997,8 +1024,9 @@ def test_config_options_fastmath():
     x = at.dvector()
 
     with config.change_flags(numba__fastmath=True):
-        pytensor_numba_fn = function([x], x * 2, mode=numba_mode)
-        numba_mul_fn = pytensor_numba_fn.vm.jit_fn.py_func.__globals__["mul"]
+        pytensor_numba_fn = function([x], at.sum(x), mode=numba_mode)
+        print(list(pytensor_numba_fn.vm.jit_fn.py_func.__globals__.keys()))
+        numba_mul_fn = pytensor_numba_fn.vm.jit_fn.py_func.__globals__["impl_sum"]
         assert numba_mul_fn.targetoptions["fastmath"] is True
 
 
@@ -1006,16 +1034,14 @@ def test_config_options_cached():
     x = at.dvector()
 
     with config.change_flags(numba__cache=True):
-        pytensor_numba_fn = function([x], x * 2, mode=numba_mode)
-        numba_mul_fn = pytensor_numba_fn.vm.jit_fn.py_func.__globals__["mul"]
-        assert not isinstance(
-            numba_mul_fn._dispatcher.cache, numba.core.caching.NullCache
-        )
+        pytensor_numba_fn = function([x], at.sum(x), mode=numba_mode)
+        numba_mul_fn = pytensor_numba_fn.vm.jit_fn.py_func.__globals__["impl_sum"]
+        assert not isinstance(numba_mul_fn._cache, numba.core.caching.NullCache)
 
     with config.change_flags(numba__cache=False):
-        pytensor_numba_fn = function([x], x * 2, mode=numba_mode)
-        numba_mul_fn = pytensor_numba_fn.vm.jit_fn.py_func.__globals__["mul"]
-        assert isinstance(numba_mul_fn._dispatcher.cache, numba.core.caching.NullCache)
+        pytensor_numba_fn = function([x], at.sum(x), mode=numba_mode)
+        numba_mul_fn = pytensor_numba_fn.vm.jit_fn.py_func.__globals__["impl_sum"]
+        assert isinstance(numba_mul_fn._cache, numba.core.caching.NullCache)
 
 
 def test_scalar_return_value_conversion():

tests/link/numba/test_elemwise.py

@@ -16,7 +16,7 @@ from pytensor.tensor.math import All, Any, Max, Mean, Min, Prod, ProdWithoutZero
 from pytensor.tensor.special import LogSoftmax, Softmax, SoftmaxGrad
 from tests.link.numba.test_basic import (
     compare_numba_and_py,
-    my_multi_out,
+    scalar_my_multi_out,
     set_test_value,
 )
 
@@ -99,8 +99,8 @@ rng = np.random.default_rng(42849)
                 rng.standard_normal(100).astype(config.floatX),
                 rng.standard_normal(100).astype(config.floatX),
             ],
-            lambda x, y: my_multi_out(x, y),
-            NotImplementedError,
+            lambda x, y: scalar_my_multi_out(x, y),
+            None,
         ),
     ],
 )

tests/link/numba/test_extra_ops.py

@@ -32,6 +32,7 @@ def test_Bartlett(val):
             for i in g_fg.inputs
             if not isinstance(i, (SharedVariable, Constant))
         ],
+        assert_fn=lambda x, y: np.testing.assert_allclose(x, y, atol=1e-15),
     )