# Why is 2^63 negative?

**URL:** <https://discourse.julialang.org/t/why-is-2-63-negative/48513>\
**Category:** New to Julia\
**Tags:** integer-overflow\
**Created:** [October 16, 2020, 7:18pm UTC](https://discourse.julialang.org/t/why-is-2-63-negative/48513 "2020-10-16T19:18:34Z")\
**Posts on this page:** 1\
**Showing post:** 9

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**Author:** ![Oscar\_Smith](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/oscar_smith/32/25343_2.png) [@Oscar\_Smith](https://discourse.julialang.org/u/Oscar_Smith)\
**Post date:** [October 16, 2020, 8:52pm UTC](https://discourse.julialang.org/t/why-is-2-63-negative/48513/9 "2020-10-16T20:52:52Z")

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For the how much does this cost question, the answer is anywhere from 10% to 20x. A typical cost is usually in the 2x case, but the added complication can easily prevent massive optimizations.

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