Method and apparatus for implementing precise interrupts in a pipelined data processing system

An apparatus for producing in a superscalar pipelined system out-of-order execution and in-order completion of a set of macroinstructions, wherein the set of macroinstructions are translated into a set of microinstructions and the microinstructions are executed by the pipelined system and wherein at least some of said macroinstructions translate into more than one microinstruction, the apparatus including a result completion register having a plurality of entry fields each of which is used to indicate a completion state of a different corresponding microinstruction among the set of microinstructions; an interrupt condition register having a plurality of entry fields each of which is used to specify an occurrence of an interrupt condition during fetching, decoding, and executing a corresponding microinstruction among the set of microinstructions; an instruction size register having a plurality of entry fields which are used to identify locations of boundaries between macroinstructions among the set of microinstructions; a priority encoder which receives input from the result completion register and the instruction size register and which during operation generates an output indicating when all of the microinstructions of a next-in-line macroinstruction have been executed; and a retirement controller which receives the output from the priority encoder and which during operation in response to the output of the priority encoder retires the next-in-line macroinstruction when said output indicates that all of the microinstructions of the next-in-line macroinstruction have been executed.