Early compression tag lookup for memory accesses

摘要

Systems and methods for determining a compression tag state prior to memory client arbitration may reduce the latency for memory accesses. A compression tag is associated with each portion of a surface stored in memory and indicates whether or not the data stored in each portion is compressed or not. A client uses the compression tags to construct memory access requests and the size of each request is based on whether or not the portion of the surface to be accessed is compressed or not. When multiple clients access the same surface the compression tag reads are interlocked with the pending memory access requests to ensure that the compression tags provided to each client are accurate. This mechanism allows for memory bandwidth optimizations including reordering memory access requests for efficient access.