Compiling method and memory storing the program code

Abstract

A compiling method, for compiling a source program into an object program for a CPU having multiple functional units that allow for concurrent operations and supporting predicated execution, for generating the object program that can be executed on the CPU at high speed by analyzing the source program and generating intermediate codes, making an analysis of the intermediate codes, generating, based on the analysis, an execution mode set instruction to set an execution mode managed within the CPU, allocating, based on the analysis, instructions such that whether they are to be executed or not to be executed depends on the execution mode set by the execution mode set instruction from the intermediate codes, wherein one or more instructions in which values in their respective specific fields are identical make an block together for every value in the specific field, finding, for each block, an ending part of the block in which its last instruction is allocated, and generating, when the ending part of a certain block is to be earlier in the object program than the ending part of another block, an unconditional branch instruction identical in specific field value to the instructions in the certain block, and allocating it either to be executed in the ending part of the certain block or to be executed as immediately as possible after the ending part of the block.