[v1.x] ONNX export support for broadcast_like

python/mxnet/contrib/onnx/mx2onnx/_op_translations.py

@@ -3348,3 +3348,45 @@ def convert_slice_like(node, **kwargs):
             ]
 
     return nodes
+
+
+@mx_op.register("broadcast_like")
+def convert_broadcast_like(node, **kwargs):
+    """Map MXNet's broadcast_like operator attributes to onnx's operator.
+    """
+    from onnx.helper import make_node
+    name, input_nodes, attrs = get_inputs(node, kwargs)
+
+    lhs = input_nodes[0]
+    rhs = input_nodes[1]
+    lhs_axes = convert_string_to_list(str(attrs.get('lhs_axes', 'None')))
+    rhs_axes = convert_string_to_list(str(attrs.get('rhs_axes', 'None')))
+
+    if lhs_axes[0] is None or rhs_axes[0] is None:
+        nodes = [
+            make_node('Shape', [rhs], [name+'_rhs_shape']),
+            make_node('Expand', [lhs, name+'_rhs_shape'], [name], name=name)
+        ]
+        return nodes
+
+    lhs_axes = [[i] for i in lhs_axes]
+    rhs_axes = [[i] for i in rhs_axes]
+
+    nodes = [
+        create_tensor([0], name+'_0', kwargs['initializer']),
+        create_tensor(lhs_axes, name+'_lhs_axes', kwargs['initializer']),
+        create_tensor(rhs_axes, name+'_rhs_axes', kwargs['initializer']),
+        make_node('Shape', [lhs], [name+'_lhs_shape']),
+        make_node('Shape', [rhs], [name+'_rhs_shape']),
+        make_node('Shape', [name+'_lhs_shape'], [name+'_lhs_dim']),
+        make_node('Less', [name+'_lhs_axes', name+'_0'], [name+'_less']),
+        make_node('Cast', [name+'_less'], [name+'_mask'], to=int(onnx.TensorProto.INT64)),
+        make_node('Mul', [name+'_mask', name+'_lhs_dim'], [name+'_mul']),
+        make_node('Add', [name+'_lhs_axes', name+'_mul'], [name+'_lhs_axes_positive']),
+        make_node('GatherND', [name+'_rhs_shape', name+'_rhs_axes'], [name+'_gather']),
+        make_node('ScatterND', [name+'_lhs_shape', name+'_lhs_axes_positive', name+'_gather'],
+                  [name+'_scatter']),
+        make_node('Expand', [lhs, name+'_scatter'], [name], name=name)
+    ]
+
+    return nodes

tests/python-pytest/onnx/test_operators.py

@@ -557,3 +557,14 @@ def test_onnx_export_slice_like(tmp_path, dtype, axes):
         op_export_test('slice_like_2', M, [x, y2], tmp_path)
         op_export_test('slice_like_3', M, [x, y3], tmp_path)
 
+
+@pytest.mark.parametrize('dtype', ['int32', 'int64', 'float16', 'float32', 'float64'])
+@pytest.mark.parametrize('lhs_axes', [[1, 3], [3, 1], [-2, -4], [-4, -2]])
+@pytest.mark.parametrize('rhs_axes', [[1, 3], [3, 1], [-2, -4], [-4, -2]])
+def test_onnx_export_broadcast_like(tmp_path, dtype, lhs_axes, rhs_axes):
+    x = mx.random.normal(0, 10, (2, 1, 1, 1, 6)).astype(dtype)
+    y = mx.random.normal(0, 10, (2, 3, 4, 5, 6)).astype(dtype)
+    M1 = def_model('broadcast_like')
+    op_export_test('broadcast_like1', M1, [x, y], tmp_path)
+    M2 = def_model('broadcast_like', lhs_axes=lhs_axes, rhs_axes=rhs_axes)
+    op_export_test('broadcast_like2', M2, [x, y], tmp_path)