Digital Equipment Corporation

Amitabh Srivastava

Robert A Eustace

A computer system is directed to convert a program written as a plurality of high level source code modules into corresponding machine executable code. The source code modules are compiled into an object code module, and the object code modules are translated into a single linked code module in the form of a register translation language and logical symbol table compatible with a plurality of computer system hardware architectures. The source code program structures are recovered from the linked code module, and the linked code module is partitioned into a plurality of procedure, and instructions of each of the procedures grouped into basic blocks. A procedure flow graph is constructed for each of the procedures, and a program call graph is constructed for the linked code module. The linked code module is modified by eliminating dead code and moving loop-invariant code from loops. The modified linked code is converted into machine executable code compatible with a target one of said plurality of computer system hardware architectures.

Link time optimization via dead code elimination, code motion, code

Link time optimization with translation to intermediate program and

A program for monitoring computer system performance includes a collection of source code modules in the form of a high level language. Each of the source code modules is compiled into a corresponding object code module. The object code modules are assembled into machine dependent code. The machine code is translated into a program module in the form of a machine independent register translation language. The program module is partitioned into basic program components. The basic program components include procedures, basic blocks within procedures, and instructions within basic blocks. Fundamental instrumentation routines identify, locate, and modify specific program components to be monitored. The modified basic program components are converted to an instrumented machine executable code to be executed in the computer system so that performance data can be collected while the program is executing in the computer.

System for monitoring computer system performance

A program for monitoring computer system performance includes a collection of source code modules in the form of a high level language. Each of the source code modules is compiled into a corresponding object code module. The object code modules are assembled into machine dependent code. The machine code is translated into a program module in the form of a machine independent register translation language. The program module is partitioned into basic program components. The basic program components include procedures, basic blocks within procedures, and instructions within basic blocks. Fundamental instrumentation routines identify, locate, and modify specific program components to be monitored. The modified basic program components are converted to an instrumented machine executable code to be executed in the computer system so that performance dam can be collected while the program is executing in the computer.

System for monitoring compute system performance

A program for monitoring computer system performance includes a collection of source code modules in the form of a high level language. Each of the source code modules is compiled into a corresponding object code module. The object code modules are translated into a single linked code module in the form of a machine independent register transfer language. The linked code module is partitioned into basic program components. The basic program components include procedures, basic blocks within procedures, and instructions within basic blocks. Fundamental instrumentation routines identify, locate, and modify specific program components to be monitored. The modified linked code module is converted to machine executable code to be executed in the computer system so that performance data can be collected while the program is executing in the computer.

In a method for optimizing loops of a program, the program is partitioned into a plurality of procedures, each procedure including instructions related for execution. A program call graph is constructed for the program, the call graph indicating the flow of execution among the several procedures. A specific one of the procedures is identified as a dominating procedure if the specific procedure is executed more than once. Procedures called from the dominating procedure are identified as descendant procedures. The descendent and dominating procedures are designated as a loop region. Any of the descendant procedure which are called by any of procedures of the program other than the dominating procedure and the descendant procedure are identified as step procedures. Step procedures are removed from the loop region. Instructions of the loop region that do not change the execution state of the computer are removed from the loop region in a sequence as determined by the frequency of execution of such instructions.

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Menlo Park, CA, United States of America

Amitabh Srivastava