# ReinterpretedArray Performance (even worse on 1.8)

**URL:** <https://discourse.julialang.org/t/reinterpretedarray-performance-even-worse-on-1-8/80102>\
**Category:** Performance\
**Tags:** performance\
**Created:** [April 27, 2022, 3:31am UTC](https://discourse.julialang.org/t/reinterpretedarray-performance-even-worse-on-1-8/80102 "2022-04-27T03:31:02Z")\
**Posts on this page:** 1\
**Showing post:** 27

<div class="post-metadata">

**Author:** ![jishnub](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jishnub/32/33620_2.png) [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Post date:** [April 28, 2022, 6:16am UTC](https://discourse.julialang.org/t/reinterpretedarray-performance-even-worse-on-1-8/80102/27 "2022-04-28T06:16:45Z")

</div>

Note that this will improve considerably with [https://github.com/JuliaLang/julia/pull/44186](https://github.com/JuliaLang/julia/pull/44186)

nightly:

```julia
julia> print(" Array: "); @btime cheb!($A, $x)
           Array: 225.605 ns (0 allocations: 0 bytes)

julia> print("ReinterpretArray: "); @btime cheb!($B, $x)
ReinterpretArray: 2.839 μs (0 allocations: 0 bytes)

julia> VERSION
v"1.9.0-DEV.411"

```

This PR:

```julia
julia> print(" Array: "); @btime cheb!($A, $x)
           Array: 226.522 ns (0 allocations: 0 bytes)

julia> print("ReinterpretArray: "); @btime cheb!($B, $x)
ReinterpretArray: 458.822 ns (0 allocations: 0 bytes)

julia> VERSION
v"1.8.0-DEV.1561"

```

Wish this PR would get reviewed

---

_[View the full topic](https://discourse.julialang.org/t/reinterpretedarray-performance-even-worse-on-1-8/80102)._