DYNAMIC OBJECT-LEVEL CODE TRANSLATION FOR IMPROVED PERFORMANCE OF A COMPUTER PROCESSOR

• US 20080320286A1
• Filed: 08/25/2008
• Published: 12/25/2008
• Est. Priority Date: 12/02/1999
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ventrone, Sebastian T., Campbell, John E., Devine, William T.
• Granted Patent: US 8,200,987 B2
• Time in Patent Office: Days
• US Class Current: 712/226
• CPC Class Codes: G06F 9/3017 Runtime instruction translation, e.g. macros
• CPC Class Codes: G06F 9/30174 for non-native instruction set, e.g. Javabyte, legacy code
• CPC Class Codes: G06F 9/30181 Instruction operation extension or modification

Abstract

A system and method for improving the efficiency of an object-level instruction stream in a computer processor. Translation logic for generating translated instructions from an object-level instruction stream in a RISC-architected computer processor, and an execution unit which executes the translated instructions, are integrated into the processor. The translation logic combines the functions of a plurality of the object-level instructions into a single translated instruction which can be dispatched to a single execution unit as compared with the untranslated instructions, which would otherwise be serially dispatched to separate execution units. Processor throughput is thereby increased since the number of instructions which can be dispatched per cycle is extended.

Claims

1. A method for protecting a computer program executed by a processor from unauthorized use, comprising the steps of:

determining a translation table constituting a security code, said security code defining operations on instructions in said program at the object level; and

using said security code to encode said instructions, such that said program will be unusable for its intended purpose if executed without said encoded instructions being decoded;

wherein said encoded instructions are decoded by;

providing said translation table to said processor;

translating said encoded instructions using said translation table to generate translated instructions having a decoded format; and

replacing said encoded instructions with said translated instructions.

2. The method of claim 1, wherein said translating step comprises:

including in said translation table conditions to be met by said encoded instructions for replacement by said translated instructions;

detecting instructions meeting said conditions;

constructing said translated instructions from instructions detected in said detecting step; and

replacing said detected instructions with said translated instructions.

3. The method of claim 2, wherein said translation table further comprises selected instruction fields and substitute instruction fields;

said conditions require the presence of said selected instruction fields in said encoded instructions; and

said control logic constructs translated instructions having said decoded format by replacing said selected instruction fields with said substitute instruction fields.