Architecture support for custom instructions with memory operations.

ABSTRACTCustomized instructions (CIs) implemented using custom functional units (CFUs) have been proposed as a way of improving performance and energy efficiency of software while minimizing cost of designing and verifying accelerators from scratch. However, previous work allows CIs to only communicate with the processor through registers or with limited memory operations. In this work we propose an architecture that allows CIs to seamlessly execute memory operations without any special synchronization operations to guarantee program order of instructions. Our results show that our architecture can provide 24\% energy savings with 14% performance improvement for 2-issue and 4-issue superscalar processor cores.