[Fix][ONNX] No precision widening for numpy binary operations

Author: cbalint13

python/tvm/relax/frontend/onnx/onnx_frontend.py

@@ -336,15 +336,17 @@ def base_impl(cls, bb, inputs, attr, params):
         """Base implementation for binary operations."""
         if cls.numpy_op is None or cls.relax_op is None:
             raise ValueError("Numpy and Relax operators must be defined for BinaryBase.")
-        if all([isinstance(inp, relax.Constant) for inp in inputs]):
-            output = cls.numpy_op(  # pylint: disable=not-callable
-                inputs[0].data.numpy(), inputs[1].data.numpy()
-            )
-            return relax.const(output, inputs[0].struct_info.dtype)
-        if any([isinstance(inp, relax.PrimValue) for inp in inputs]):
+        if all([not isinstance(inp, (relax.expr.Call, relax.Var)) for inp in inputs]):
             x = _to_numpy(inputs[0])
             y = _to_numpy(inputs[1])
-            return relax.PrimValue(cls.numpy_op(x, y))  # pylint: disable=not-callable
+            output = cls.numpy_op(x, y)  # pylint: disable=not-callable
+            if x.dtype == y.dtype:
+                # no numpy precision widening
+                output = output.astype(x.dtype)
+            if all([isinstance(inp, relax.Constant) for inp in inputs]):
+                return relax.const(output, output.dtype)  # pylint: disable=not-callable
+            if any([isinstance(inp, relax.PrimValue) for inp in inputs]):
+                return relax.PrimValue(output.item())  # pylint: disable=not-callable
 
         return cls.relax_op(inputs[0], inputs[1])  # pylint: disable=not-callable
 

tests/python/relax/test_frontend_onnx.py

@@ -27,7 +27,7 @@
 import onnx
 import onnxruntime
 import pytest
-from onnx import ModelProto, TensorProto, helper, mapping
+from onnx import ModelProto, TensorProto, helper
 
 import tvm
 import tvm.testing
@@ -62,7 +62,7 @@ def generate_random_inputs(
 def generate_random_value(shape, elem_type) -> np.ndarray:
     # Extract datatype for the input.
     if elem_type:
-        dtype = str(onnx.mapping.TENSOR_TYPE_TO_NP_TYPE[elem_type])
+        dtype = str(helper.tensor_dtype_to_np_dtype(elem_type))
     else:
         dtype = "float32"
 
@@ -87,6 +87,7 @@ def check_correctness(
     opset: int = 14,
     rtol: float = 1e-7,
     atol: float = 1e-5,
+    check_dtypes = False
 ) -> None:
     """Run an onnx model in both onnxruntime and TVM through our importer
        confirm that the results match. Otherwise, an exception will be raised.
@@ -104,6 +105,8 @@ def check_correctness(
     atol: float
         Set the tolerance of correctness checking. Some ops may be show more
         arithmetic variance than others.
+    check_dtypes: bool
+        Check if data types are the same.
     """
     # Configure model format.
     if ir_version is not None:
@@ -158,11 +161,15 @@ def _check_output(tvm_out, ort_out):
             for tvm_out_i, ort_out_i in zip(tvm_out, ort_out):
                 _check_output(tvm_out_i, ort_out_i)
         elif isinstance(tvm_out, tvm.nd.NDArray) and isinstance(ort_out, np.ndarray):
+            if check_dtypes:
+                assert _get_numpy_subdtype(tvm_out.numpy()) == _get_numpy_subdtype(ort_out)
             tvm.testing.assert_allclose(tvm_out.numpy(), ort_out, rtol=rtol, atol=atol)
         elif isinstance(tvm_out, tvm.runtime.ShapeTuple) and isinstance(ort_out, np.ndarray):
             shape_out = tvm.nd.array([int(i) for i in tvm_out])
             tvm.testing.assert_allclose(shape_out.numpy(), ort_out, rtol=rtol, atol=atol)
         elif isinstance(tvm_out, (int, float, bool)) and isinstance(ort_out, np.ndarray):
+            if check_dtypes:
+                assert _get_numpy_subdtype(np.array(tvm_out)) == _get_numpy_subdtype(ort_out)
             tvm.testing.assert_allclose(np.array(tvm_out), ort_out, rtol=rtol, atol=atol)
         else:
             raise ValueError(f"Unsupported types: {type(tvm_out)}, {type(ort_out)}")
@@ -267,7 +274,7 @@ def verify_binary(
     )
 
     model = helper.make_model(graph, producer_name="binary_test")
-    check_correctness(model, opset=opset)
+    check_correctness(model, opset=opset, check_dtypes=True)
 
 
 def verify_binary_scalar(op_name, attrs={}, domain=None, dtype=TensorProto.INT32, opset=14):
@@ -282,7 +289,7 @@ def verify_binary_scalar(op_name, attrs={}, domain=None, dtype=TensorProto.INT32
     )
 
     model = helper.make_model(graph, producer_name="binary_test")
-    check_correctness(model, opset=opset)
+    check_correctness(model, opset=opset, check_dtypes=True)
 
 
 def verify_compare(op_name, shape, attrs={}, domain=None):
@@ -1897,7 +1904,7 @@ def verify_constantofshape(input_dim, value, dtype):
             ["input"],
             ["output"],
             value=helper.make_tensor(
-                "value", mapping.NP_TYPE_TO_TENSOR_TYPE[np.dtype(dtype)], (1,), (value,)
+                "value", helper.np_dtype_to_tensor_dtype(np.dtype(dtype)), (1,), (value,)
             ),
         )
 
@@ -1917,7 +1924,7 @@ def verify_constantofshape(input_dim, value, dtype):
             ],
             outputs=[
                 helper.make_tensor_value_info(
-                    "output", mapping.NP_TYPE_TO_TENSOR_TYPE[np.dtype(dtype)], input_dim
+                    "output", helper.np_dtype_to_tensor_dtype(np.dtype(dtype)), input_dim
                 )
             ],
         )
@@ -2299,7 +2306,7 @@ def verify_split(indata_shape, outdata_shapes, split, axis=0, pass_split=True, o
 
         inputs = [
             helper.make_tensor_value_info(
-                "input", mapping.NP_TYPE_TO_TENSOR_TYPE[indata.dtype], indata_shape
+                "input", helper.np_dtype_to_tensor_dtype(indata.dtype), indata_shape
             )
         ]
 
@@ -2333,7 +2340,7 @@ def verify_split(indata_shape, outdata_shapes, split, axis=0, pass_split=True, o
             outputs=[
                 helper.make_tensor_value_info(
                     f"output_{i}",
-                    mapping.NP_TYPE_TO_TENSOR_TYPE[indata.dtype],
+                    helper.np_dtype_to_tensor_dtype(indata.dtype),
                     list(outdata_shapes[i]),
                 )
                 for i in range(len(split_index))