Error of loop_partition

Here is the code extracted from the tvm tutorial:

from __future__ import absolute_import, print_function

import tvm
import numpy as np

tgt_host="llvm"
tgt="c"

n = tvm.var("n")
A = tvm.placeholder((n,), name='A')
B = tvm.placeholder((n,), name='B')
C = tvm.compute(A.shape, lambda i: A[i] + B[i], name="C")

s = tvm.create_schedule(C.op)
bx, tx = s[C].split(C.op.axis[0], factor=64)

fadd = tvm.build(s, [A, B, C], tgt, target_host=tgt_host, name="myadd")

The error it returns is:

[05:19:30] /home/elliot_he/tvm/src/pass/loop_partition.cc:541: Cannot prove: ((((((n + 63)/64) - 1) - (((n - 64)/64) + 1)) + 1) >= 0), when generating the post doubt loop

Those are warnings, You can ignore in most cases.