Hewlett-packard Company

Michelle A Ruscetta

William B Buzbee

Arun Kwangil Iyengar

Carol Linda Thompson

Donald L Curreri

Russell A Biesele

A method and system for relating profile data generated by monitoring the execution of an optimized machine-code computer program back to the source-language description of the computer program. Logical line numbers are associated with the basic blocks of the intermediate-code representation of the computer program and actual line numbers are associated with each instruction of the intermediate-code representation of the computer program. During optimization of the intermediate code, the logical line numbers remain fixed to basic blocks, while actual line numbers remain fixed to intermediate-code instructions. A branch instruction and the target of the branch instruction in the optimized machine-code computer program or in an optimized assembly-language computer program can be related back to source-language statements by using the actual line number associated with the branch instruction and the logical line number associated with the basic block that contains the target of the branch instruction.

Method and system for correlating profile data dynamically generated from an optimized executable program with source code statements

A software development system with improved facilities for debugging optimized code. Certain parts of the operations specified by source statements are categorized as 'data change points'. A compiler 102 identifies the correspondence between the machine instructions that perform data change point operations and the source statements from which these machine instructions were derived and stores this mapping data 110 for use by a debugger program 104. This source code/machine instruction mapping data is used by the debugger to permit users to specify machine instruction locations (such as for setting breakpoints) by identifying a source statement and specifying that the debugger use the data change point of that statement; as another example, the step command includes an option that permits a user to continue execution until the next data change point instruction is reached. The debugger's source code display (FIGS. 5A and 5B) is also adapted to take advantage of the data change point mapping data: a user can request that the debugger highlight source statements for which the data change point instruction has executed; in marking the source display to indicate the location of the current execution point, the debugger can also show whether the next instruction to execute will be a data change point instruction.

Debugging optimized code using data change points

Source code is compiled into intermediate code which includes object code instructions. Logical line markers are inserted within the intermediate code. Each logical line marker identifies a source code line from which originated object code instructions immediately adjacent to the logical line marker. Each logical line marker is associated with a specific basic block. Also, actual line markers are inserted so that an actual line marker is associated with every object code instruction. The actual line marker identifies a source code line from which originated the object code instruction associated with the actual line marker. The intermediate code is optimized to produce the optimized object code. During optimization, object code instructions are freely moved relative to the logical line markers; however, the logical line markers are not moved relative to each other. When an object code instruction is moved, the actual line marker associated with the moved object code instruction is also moved.

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San Jose, CA, United States of America

Michelle A Ruscetta