Unified sequential optimization directives in openmp

Brandon Neth, Thomas R.W. Scogland, Michelle Mills Strout, Bronis R. de Supinski

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Scopus citations


OpenMP began as a mechanism to support portability of shared-memory, loop-level parallelization via directives. OpenMP has become widely popular due to the high value that users place on portability. Its original motivation has justified additions to its specification to support SIMD parallelism and, as has been adopted for OpenMP 5.1, directives for common loop optimizations such as tiling and unrolling. In this paper, we explore another opportunity for OpenMP to provide portability to common compiler directives – ones that support sequential optimizations such as inlining or providing information about aliasing. We survey the current support in production compilers for these features. We find that the situation is similar to the one that originally motivated OpenMP’s creation. Different compilers have different syntax and sometimes different semantics for the same directives, thus requiring complicated pragma configuration for an application to support the use of multiple compilers. We also find that interaction of these directives with OpenMP further complicates their use. Our performance study demonstrates that these directives can substantially improve the performance of common programming usage by as much as 406%. Overall, we argue that inclusion of similar directives in OpenMP would substantially benefit users and compiler implementers.

Original languageEnglish (US)
Title of host publicationOpenMP
Subtitle of host publicationPortable Multi-Level Parallelism on Modern Systems - 16th International Workshop on OpenMP, IWOMP 2020, Proceedings
EditorsKent Milfeld, Lars Koesterke, Bronis R. de Supinski, Jannis Klinkenberg
PublisherSpringer Science and Business Media Deutschland GmbH
Number of pages13
ISBN (Print)9783030581435
StatePublished - 2020
Event16th International Workshop on OpenMP, IWOMP 2020 - Austin, United States
Duration: Sep 22 2020Sep 24 2020

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume12295 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference16th International Workshop on OpenMP, IWOMP 2020
Country/TerritoryUnited States

ASJC Scopus subject areas

  • Theoretical Computer Science
  • General Computer Science


Dive into the research topics of 'Unified sequential optimization directives in openmp'. Together they form a unique fingerprint.

Cite this