fix(mge/functional): fix trace topk

GitOrigin-RevId: c88ca8219b0dc25e2f1a4d26c3fea86220c86962

imperative/python/megengine/functional/math.py

@@ -14,8 +14,9 @@ from typing import Optional, Sequence, Tuple, Union
 
 from ..core.ops import builtin
 from ..core.ops._internal import param_defs as P
+from ..core.ops.special import Const
 from ..core.tensor import utils
-from ..core.tensor.core import apply
+from ..core.tensor.core import TensorBase, TensorWrapperBase, apply
 from ..tensor import Tensor
 from .elemwise import clamp, exp, log, log1p
 from .tensor import add_axis, remove_axis, reshape
@@ -665,15 +666,18 @@ def topk(
         mode = Mode.VALUE_IDX_SORTED
     op = builtin.TopK(mode=mode)
 
+    if not isinstance(k, (TensorBase, TensorWrapperBase)):
+        (k,) = Const(k, dtype="int32", device=inp.device)(inp)
+
     if len(inp.shape) == 1:
         inp = inp.reshape(1, -1)
-        res = apply(op, inp, Tensor(k, dtype="int32"))
+        res = apply(op, inp, k)
         if kth_only:
             tns = res[0]
         else:
             tns, ind = res[0][0], res[1][0]
     else:
-        res = apply(op, inp, Tensor(k, dtype="int32"))
+        res = apply(op, inp, k)
         if kth_only:
             tns = res
         else: