A Proposal for Loop-Transformation Pragmas

TL;DR

This paper proposes new loop transformation pragmas to simplify and enhance loop optimization, aiming to standardize and extend compiler capabilities beyond current implementations.

Contribution

It introduces additional pragmas for loop transformations, advocating for their inclusion in the OpenMP standard to improve compiler support and reduce manual source code modifications.

Findings

Proposes new pragmas for advanced loop transformations

Aims to standardize loop optimization pragmas in OpenMP

Seeks to reduce manual source rewriting for loop optimization

Abstract

Pragmas for loop transformations, such as unrolling, are implemented in most mainstream compilers. They are used by application programmers because of their ease of use compared to directly modifying the source code of the relevant loops. We propose additional pragmas for common loop transformations that go far beyond the transformations today's compilers provide and should make most source rewriting for the sake of loop optimization unnecessary. To encourage compilers to implement these pragmas, and to avoid a diversity of incompatible syntaxes, we would like to spark a discussion about an inclusion to the OpenMP standard.