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Ryū revisited: printf floating point conversion

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Ulf AdamsAuthors Info & Claims

Proceedings of the ACM on Programming Languages, Volume 3, Issue OOPSLA

Article No.: 169, Pages 1 - 23

https://doi.org/10.1145/3360595

Published: 10 October 2019 Publication History

Abstract

Ryū Printf is a new algorithm to convert floating-point numbers to decimal strings according to the printf %f, %e, and %g formats: %f generates ‘full’ output (integer part of the input, dot, configurable number of digits), %e generates scientific output (one leading digit, dot, configurable number of digits, exponent), and %g generates the shorter of the two. Ryū Printf is based on the Ryū algorithm, which converts binary floating-point numbers to the shortest equivalent decimal floating-point representation. We provide quantitative evidence that Ryū Printf is between 3.8 and 55 times faster than existing printf implementations.

Furthermore, we show that both Ryū and Ryū Printf generalize to arbitrary number bases. This finding implies the existence of a fast algorithm to convert from base-10 to base-2, as long as the maximum precision of the input is known a priori.

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References

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Cited By

Izzard RHendriks DNemergut D(2023)libcdict: fast dictionaries in CJournal of Open Source Software10.21105/joss.047568:92(4756)Online publication date: Dec-2023
https://doi.org/10.21105/joss.04756
Mushtak NLemire D(2023)Fast number parsing without fallbackSoftware: Practice and Experience10.1002/spe.319853:7(1467-1471)Online publication date: 4-Mar-2023
https://doi.org/10.1002/spe.3198
Lemire D(2021)Number parsing at a gigabyte per secondSoftware: Practice and Experience10.1002/spe.298451:8(1700-1727)Online publication date: 11-May-2021
https://doi.org/10.1002/spe.2984

Index Terms

Ryū revisited: printf floating point conversion
1. Computing methodologies
  1. Symbolic and algebraic manipulation
    1. Representation of mathematical objects

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Published In

cover image Proceedings of the ACM on Programming Languages

Proceedings of the ACM on Programming Languages Volume 3, Issue OOPSLA

October 2019

2077 pages

EISSN:2475-1421

DOI:10.1145/3366395

Issue’s Table of Contents

Copyright © 2019 Owner/Author.

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs International 4.0 License.

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Association for Computing Machinery

New York, NY, United States

Publication History

Published: 10 October 2019

Published in PACMPL Volume 3, Issue OOPSLA

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Cited By

Izzard RHendriks DNemergut D(2023)libcdict: fast dictionaries in CJournal of Open Source Software10.21105/joss.047568:92(4756)Online publication date: Dec-2023
https://doi.org/10.21105/joss.04756
Mushtak NLemire D(2023)Fast number parsing without fallbackSoftware: Practice and Experience10.1002/spe.319853:7(1467-1471)Online publication date: 4-Mar-2023
https://doi.org/10.1002/spe.3198
Lemire D(2021)Number parsing at a gigabyte per secondSoftware: Practice and Experience10.1002/spe.298451:8(1700-1727)Online publication date: 11-May-2021
https://doi.org/10.1002/spe.2984

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