[ONNX] only broadcast matmul if the shape has changed (#10321)

* [ONNX] only broadcast matmul if the shape has changed * fix copy-pasta mistake
apache · Feb 22, 2022 · 5956125 · 5956125
1 parent 33082e0
commit 5956125
Showing 1 changed file with 22 additions and 14 deletions.
diff --git a/python/tvm/relay/frontend/onnx.py b/python/tvm/relay/frontend/onnx.py
@@ -264,23 +264,31 @@ def flatten_to_nd(x, x_shape, nd=3):
             b = _op.transpose(inputs[1])
             output = _op.nn.dense(a, b, out_dtype=out_dtype)
         else:
+            a = inputs[0]
+            b = inputs[1]
             # broadcast a and b
-            a_broadcasted_shape = _op.concatenate(
-                [
-                    out_batch,
-                    _op.strided_slice(a_shape, [a_rank - 2], [a_rank]),
-                ],
-                0,
+            a_broadcasted_shape = fold_constant(
+                _op.concatenate(
+                    [
+                        out_batch,
+                        _op.strided_slice(a_shape, [a_rank - 2], [a_rank]),
+                    ],
+                    0,
+                )
             )
-            b_broadcasted_shape = _op.concatenate(
-                [
-                    out_batch,
-                    _op.strided_slice(b_shape, [b_rank - 2], [b_rank]),
-                ],
-                0,
+            b_broadcasted_shape = fold_constant(
+                _op.concatenate(
+                    [
+                        out_batch,
+                        _op.strided_slice(b_shape, [b_rank - 2], [b_rank]),
+                    ],
+                    0,
+                )
             )
-            a = _op.transform.broadcast_to(inputs[0], fold_constant(a_broadcasted_shape))
-            b = _op.transform.broadcast_to(inputs[1], fold_constant(b_broadcasted_shape))
+            if not tvm.ir.structural_equal(a_shape, a_broadcasted_shape):
+                a = _op.transform.broadcast_to(a, a_broadcasted_shape)
+            if not tvm.ir.structural_equal(b_shape, b_broadcasted_shape):
+                b = _op.transform.broadcast_to(b, b_broadcasted_shape)
             # Convert a and b into 3 dimensional tensors.
             a = flatten_to_nd(a, shape_of(a), 3)
             b = flatten_to_nd(b, shape_of(b), 3)