International audienceThis article presents a new tool for automatic design of application-specific reconfigurable processor extensions based on UPaK (Abstract Unified Patterns Based Synthesis Kernel for Hardware and Software Systems). We introduce a complete design flow that identifies new instructions, selects specific instructions and schedules a considered application on the newly created reconfigurable ar- chitecture. The identified extensions are implemented as specialized sequential or parallel instruc- tions. These instructions are executed on a reconfigurable unit implementing all merged patterns. Our method uses specially developed algorithms for subgraph isomorphism that are implemented as graph matching constraints. These constraints tog...