Towards a viable out-of-order soft core: Copy-Free, checkpointed register renaming

As a step torward a viable, single-issue out-of-order soft core, this work presents copy-free checkpointing (CFC), an FPGA-friendly register renaming design. CFC supports speculative execution by implementing checkpoint recovery. Compared against the best conventional register renaming implementation CFC requires 7.5x to 6.4x fewer LUTs and is at least 10% faster.