# Compaq KAP Fortran/OpenMP
for Tru64 UNIX
User Guide

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# Chapter 1
What Is KAP?

Compaq KAP Fortran/OpenMP is a Fortran source-to-source preprocessor that restructures Fortran 90 code for improved performance and better utilization of the memory hierarchy of Tru64 UNIX systems. Additionally, KAP performs parallel decomposition to take advantage of shared memory and symmetric multiprocessors. By eliminating inefficiencies and bottlenecks, KAP enables Tru64 UNIX users to get their answers faster, without time-consuming hand-recoding of their applications programs.

The KAP conversion process is designed to operate effectively without user intervention. KAP provides a large set of command-line switches, directives, and assertions that the advanced user can use for even better results. The KAP generated listing includes messages and questions that point out parts of the program that might be further improved.

KAP optimizations include:

- Memory management for data locality
- Subprogram inlining
- Loop reordering
- Induction variable recognition
- Global forward substitution
- Variable lifetime analysis
- Invariant IF restructuring
- Loop peeling
- Scalar optimizations

KAP is especially useful for programs characterized by:

- Intensive CPU usage
- Large number of loops and/or loops having large loop bounds
- Action on large data sets
- Significant reuse of data
- Large number of procedure calls
- Large number of floating-point operations

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