# ANN: ILog2.jl

**URL:** <https://discourse.julialang.org/t/ann-ilog2-jl/17997>\
**Category:** Specific Domains\
**Tags:** package\
**Created:** [November 26, 2018, 2:28am UTC](https://discourse.julialang.org/t/ann-ilog2-jl/17997 "2018-11-26T02:28:46Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![jlapeyre](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jlapeyre/32/4514_2.png) [@jlapeyre](https://discourse.julialang.org/u/jlapeyre)\
**Post date:** [November 26, 2018, 2:28am UTC](https://discourse.julialang.org/t/ann-ilog2-jl/17997/1 "2018-11-26T02:28:46Z")

</div>

Efficient integer valued base 2 logarithm.  
`ilog2(n::Real)`

Compute the largest `m` such that `2^m <= n`.

[https://github.com/jlapeyre/ILog2.jl](https://github.com/jlapeyre/ILog2.jl)