# When shall I use \`BLAS.axpy!\` and when \`muladd\`?

**URL:** <https://discourse.julialang.org/t/when-shall-i-use-blas-axpy-and-when-muladd/7466>\
**Category:** Numerics\
**Created:** [December 3, 2017, 1:46am UTC](https://discourse.julialang.org/t/when-shall-i-use-blas-axpy-and-when-muladd/7466 "2017-12-03T01:46:44Z")\
**Posts on this page:** 1\
**Showing post:** 7

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**Author:** ![antoine-levitt](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/antoine-levitt/32/4008_2.png) [@antoine-levitt](https://discourse.julialang.org/u/antoine-levitt)\
**Post date:** [December 3, 2017, 2:22pm UTC](https://discourse.julialang.org/t/when-shall-i-use-blas-axpy-and-when-muladd/7466/7 "2017-12-03T14:22:03Z")

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It does. It might or might not be useful, depending on the architecture/BLAS/weather : [Using axpy!](https://discourse.julialang.org/t/using-axpy/7072). It also might have an overhead for small sizes.

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