Application-specific instruction-set processors (ASIPs) with extended instructions (EIs) can effectively improve performance and meet time-to-market requirements.However

there are three problems to be solved when customizing EIs for embedded systems.First

design space increases exponentially as applications become more complex.Second

limited on-chip resources restrict the number and complexity of EIs.Third

current instruction-set extension (ISE) algorithms can hardly run on embedded systems due to their high complexity.We propose a fast automatic method called GISEES to address these problems.GISEES can effectively prune design space by enumerating EIs around typical operations of applications

and reduce resources overhead and the number of inserted multiplexers through sharing resources based on finding the maximal common equivalent substring (MCES).Experiment results show that

GISEES features linear complexity and can generate EIs with higher efficiency

which means it is more suitable for customizing power efficient instruction-set extension.