(1) After a plea or verdict of guilty, or after a verdict against the defendant on a plea of former conviction or acquittal, in a case where discretion is conferred upon the court as to the extent of the punishment to be inflicted, the court, upon the suggestion of either party that there are circumstances which may be properly considered in aggravation or mitigation of the punishment, may, in its discretion, hear the same summarily at a specified time and upon such notice to the adverse party as it may direct.
(2) Notwithstanding any other provision of law, the consideration of aggravating and mitigating circumstances as to felonies committed on or after November 1, 1989, including the maximum sentence that may be imposed because of aggravating circumstances, shall be in accordance with rules of the Oregon Criminal Justice Commission.