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arXiv · 2212.06644

Fast Number Parsing Without Fallback

Noble Mushtak·Daniel Lemire
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Abstract

In recent work, Lemire (2021) presented a fast algorithm to convert number strings into binary floating-point numbers. The algorithm has been adopted by several important systems: e.g., it is part of the runtime libraries of GCC 12, Rust 1.55, and Go 1.16. The algorithm parses any number string with a significand containing no more than 19 digits into an IEEE floating-point number. However, there is a check leading to a fallback function to ensure correctness. This fallback function is never called in practice. We prove that the fallback is unnecessary. Thus we can slightly simplify the algorithm and its implementation.

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Noble Mushtak, Daniel Lemire. 2022-12-13. Fast Number Parsing Without Fallback. https://doi.org/10.1002/spe.3198

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