text: # Licensed to the Apache Software Foundation (ASF) under one
  # or more contributor license agreements.  See the NOTICE file
  # distributed with this work for additional information
  # regarding copyright ownership.  The ASF licenses this file
  # to you under the Apache License, Version 2.0 (the
  # "License"); you may not use this file except in compliance
  # with the License.  You may obtain a copy of the License at
  #
  #   http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing,
  # software distributed under the License is distributed on an
  # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  # KIND, either express or implied.  See the License for the
  # specific language governing permissions and limitations
  # under the License.
  import tvm
  
  def nop():
      return tvm.stmt.Evaluate(0)
  
  def test_remove_no_op():
      i = tvm.var('i')
      j = tvm.var('j')
      k = tvm.var('k')
      m = tvm.var('m')
      n = tvm.var('n')
      dtype = 'int64'
      Ab = tvm.decl_buffer((n, ), dtype)
      stmt = tvm.make.For(
          i, 0, 4, 0, 0,
          tvm.make.For(
              j, 0, n, 0, 0,
              tvm.make.For(
                  k, 0, m, 0, 0,
                  tvm.make.IfThenElse(
                      (i*m+j+k < n), tvm.make.Evaluate(m), tvm.make.Evaluate(n)))))
      ret = tvm.ir_pass.RemoveNoOp(stmt)
      assert(isinstance(ret, tvm.stmt.Evaluate))
      store = tvm.make.Store(Ab.data,
                             tvm.make.Load(dtype, Ab.data, i) + 1,
                             i + 1)
      stmt2 = tvm.stmt.SeqStmt([nop(), tvm.stmt.SeqStmt([store, nop()])])
      assert(tvm.ir_pass.RemoveNoOp(stmt2) == store)
      # remove zero extent loop
      stmt3 = tvm.make.For(i, 0, 0, 0, 0, store)
      ret = tvm.ir_pass.RemoveNoOp(stmt3)
      assert(isinstance(ret, tvm.stmt.Evaluate))
  
  
  if __name__ == "__main__":
      test_remove_no_op()
  