I do not have enough information to provide the exact number of hotel rooms within a specific building called "the Chengdu mall," as there is no single entity by that name. Chengdu features several massive multi-use complexes that integrate shopping malls with hotels. For instance, the InterContinental Chengdu Global Center is located within the New Century Global Center, one of the world's largest buildings, and offers 975 rooms. Another prominent example is the M Hotel Chengdu, which is situated near the Galleria shopping area and contains 176 rooms. Without a more specific name for the mall or development, it is impossible to determine an accurate room count.