Providing memory bandwidth compression using compression indicator (ci) hint directories in a central processing unit (cpu)-based system

A method for providing memory bandwidth compression, comprising:

• receiving, by a compressed memory controller, a memory write request comprising write data and a physical address of a memory line in a system memory;
• determining a compression pattern for the write data;
• generating a compression indicator (CI) for the write data based on the compression pattern;
• writing the write data to the memory line in the system memory;
• writing the generated CI into one or more error correcting code (ECC) bits of the memory line of the system memory;
• and
• in parallel with writing the write data to the memory line in the system memory:
• determining whether the physical address corresponds to a CI hint directory entry of a plurality of CI hint directory entries of a CI hint directory of the compressed memory controller;
• and
• responsive to determining that the physical address corresponds to a CI hint directory entry of the plurality of CI hint directory entries of the CI hint directory, updating a CI hint of a plurality of CI hints of the CI hint directory entry corresponding to the memory line based on the generated CI.

A compressed memory controller, comprising:

• a means for receiving a memory write request comprising write data and a physical address of a memory line in a system memory;
• a means for determining a compression pattern for the write data;
• a means for generating a compression indicator (CI) for the write data based on the compression pattern;
• a means for writing the write data to the memory line in the system memory;
• a means for writing the generated CI into one or more error correcting code (ECC) bits of the memory line of the system memory;
• a means for determining whether the physical address corresponds to a CI hint directory entry of a plurality of CI hint directory entries of a CI hint directory of the compressed memory controller, in parallel with writing the write data to the memory line in the system memory;
• and
• a means for updating a CI hint of a plurality of CI hints of the CI hint directory entry corresponding to the memory line based on the generated CI.