1. A parallelizing compile method comprising: dividing a sequential program for an embedded system for an onboard apparatus into a plurality of macro tasks according to a predetermined method, the sequential program being executed by a single processor system; specifying, based on a control dependency between the macro tasks, (i) a starting end task of the macro tasks as a starting point, wherein the starting end task has a processing branched into different ones of the macro tasks, and (ii) a termination end task of the macro tasks, wherein the termination end task is either one of the macro tasks commonly executed among a plurality of series of processings, which are sequentially executed from the starting end task; fusing (i) the starting end task specified by the specifying, (ii) the termination end task executed from the starting end task in the processings, and (iii) a group of the macro tasks executed after execution of the starting end task and before execution of the termination end task into a new macro task; extracting a group of new macro tasks, which are parallelly executable by a plurality of processor units included in a multiprocessor system mounted to the onboard apparatus, from the new macro tasks fused in the fusing, based on a data dependency; performing a static scheduling assigning the new macro tasks to the processor units, so that the group of new macro tasks is parallelly executable by the processor units; and generating a parallelizing program executed by the multiprocessor system, based on a result of the static scheduling.