System and Method for Efficiently Passing Information Between Compiler and Post-Compile-Time Software

Abstract

System and method are described for register optimization during code translation utilizes a technique that removes the time overhead for analyzing register usage and eliminates fixed restraints on the compiler register usage. The present invention for register optimization utilizes a compiler to produce a register usage bit vector in a NOP instruction within each basic block (i.e., subroutine, function, and / or procedure). Each bit in the bit vector represents a particular caller-saved register. A bit is set if, at the location of NOP instruction, the compiler uses the corresponding register within that basic block containing the NOP instruction to hold information to be used at a later time. During the translation, the translator examines the register usage bit vector to very quickly determine which registers are free and therefore can be used during the register optimization without the need to save and restore the register values.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of copending U.S. utility application entitled, “SYSTEM AND METHOD FOR EFFICIENTLY PASSING INFORMATION BETWEEN [0002] COMPILER AND POST-COMPILE-TIME SOFTWARE,” having Ser. No. 09 / 422,539, filed Oct. 21, 1999, which is entirely incorporated herein by reference.BACKGROUND OF THE INVENTION [0003] 1. Field of the Invention [0004] The present invention is generally related to program optimization, and more particularly related to an apparatus and method for efficiently passing compiler information to post-compile-time software. [0005] 2. Description of Related Art [0006] As is known in the computer and software arts, when a software program is developed it will be optimized to run on a particular computer architecture. While it is possible that the software program developed for an original computer architecture will run on a computer system with a new or different architecture, the execution of the software...

AI Technical Summary

Benefits of technology

"The present invention is a system and method for efficiently passing compiler information to hardware or software at run time. It uses unused operand fields of instructions, such as NOPs, to remove time overhead for analyzing binaries or low-level programs and does not increase program code size. The system produces bit vectors for each basic block and places them in the unused portion of the NOP instruction encoding. These bit vectors indicate which registers may be live or dead at the location of the NOP instruction. By using the unused NOP operands as a communication channel, the dynamic optimizer can quickly inspect them and reduce analysis overhead, improving runtime performance. The compiler can also pass hints to profiler software of what kind of feedback information is desired through the use of the unused NOP operands."

Problems solved by technology

While it is possible that the software program developed for an original computer architecture will run on a computer system with a new or different architecture, the execution of the software program optimized for an old computer architecture will not generally run as quickly on a computer system with a new architecture, if at all.

When software tools such as dynamic optimizer or profiling tools work on the binaries produced by the compiler, they face the challenge of analyzing low-level programs.

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