Checking for exception by floating point instruction reordered across branch by comparing current status in FP status register against last status copied in shadow register

摘要

A process which automatically inserts commands that test for and raise exceptions indicating floating point status exceptions into a sequence of instructions to be executed, re-ordering a pipelined instructions by moving a floating point instruction from after a branch instruction to before the branch instruction, and responds to exceptions in execution of the sequence of instructions by returning execution to a point in the sequence of instructions at which correct state is known and then executing each instruction in the sequence singly to completion so that exceptions in pipelined floating point instructions can be automatically-detected and handled precisely.