fix(mge/tensor): fix const target shape in reshape

GitOrigin-RevId: 7c04a9efbabc7c7e75d87c67a611a08a7371fe49

imperative/python/megengine/core/tensor/tensor_wrapper.py

@@ -74,9 +74,7 @@ def _reshape(x, shape):
                 raise ValueError("multiple -1 in shape: {} & {}".format(unspec_axis, i))
             unspec_axis = i
 
-    if not isinstance(shape, (TensorBase, TensorWrapperBase)):
-        # TODO: device should be None (cpu)
-        (shape,) = Const(shape, dtype=np.int32, device=x.device)(x)
+    shape = utils.astensor1d(shape, x, dtype="int32", device=x.device)
 
     if unspec_axis is None:
         op = builtin.Reshape()

imperative/python/test/unit/test_tracing.py

@@ -266,3 +266,20 @@ def test_trace_cvt_bool():
 
     for i in range(3):
         np.testing.assert_equal(f(x).numpy()[0], False)
+
+
+def test_trace_reshape():
+    for symbolic in [False, True]:
+        set_tensor_shape(True)
+        x1 = tensor(np.random.randn(2, 10, 10))
+        x2 = tensor(np.random.randn(4, 10, 10))
+        x3 = tensor(np.random.randn(8, 10, 10))
+
+        @trace(symbolic=symbolic, capture_as_const=True)
+        def f(x):
+            y = x.reshape(x.shape[0], 100)
+            return y
+
+        f(x1)
+        f(x2)
+        f(x3)