NOREBA: a compiler-informed non-speculative out-of-order commit processor
Ali Hajiabadi, Andreas Diavastos, Trevor E. Carlson · 2021
Modern superscalar processors execute instructions out-of-order, but commit them in program order to provide precise exception handling and safe instruction retirement. However, in-order instruction commit is highly conservative and holds on to critical resources far longer than necessary, severely limiting the reach of general-purpose processors, ultimately reducing performance. Solutions that allow for efficient, early reclamation of these critical resources could seize the opportunity to improve performance. One such solution is out-of-order commit, which has traditionally been challenging due to inefficient, complex hardware used to guarantee safe instruction retirement and provide precise exception handling.