Patent ID: 7278138

Claim:
A computer program product, comprising a computer usable medium having computer program logic recorded thereon for enabling a processor in a computer system to convert an execution program, the computer program logic comprising: analyzing means for enabling the processor to analyze sign extension instructions to be issued in order to perform the sign extension of a value defined in said execution program; a removal order determination unit to determine the order in which sign extension instructions are to be removed by determining (i) the frequencies of execution of the sign extension instructions during execution of the program, and (ii), considering the sign extension instructions in the order of said frequencies of execution, whether each of the sign extension instructions is redundant, including for each of the sign extension instructions in the order of said frequencies of execution, identifying all places in said execution program where a value output from the sign extension instruction is used, determining if said value is needed at each of said all places, and if said value is not needed at each one of said all places, determining said each of the sign extension instructions to be redundant; and removal means, responsive to analysis results and the removal order determination unit, for enabling the processor to remove a redundant sign extension instruction determined to be redundant from those included in said execution program.