DEVICE AND METHOD FOR COMPILATION

摘要

PROBLEM TO BE SOLVED: To effectively optimize an object code in the range satisfying limitation caused by the number of physical registers of a processor. SOLUTION: This compiler device performs code generation from a program represented by a DAG(directed acyclic graph) while evaluating the number of used registers and the number of execution cycles and optimizes a code to be generated. That is, the compiler calculates the number of cycles with which each operation can be executed on the DAG and the number of the currently available registers, performs code generation while preceding an operator on an execution path that takes the most time in the DAG in a part where the number of registers is sufficient, and performs code generation while preceding such an operator as to reduce the number of used registers when the number of registers is not sufficient.