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Make various i256 methods const #3026
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const fn split_array(vals: [u8; 32]) -> ([u8; 16], [u8; 16]) { | ||
let mut a = [0; 16]; | ||
let mut b = [0; 16]; | ||
let mut i = 0; | ||
while i != 16 { | ||
a[i] = vals[i]; | ||
b[i] = vals[i + 16]; | ||
i += 1; | ||
} | ||
(a, b) | ||
} |
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Doesn't this have new memory allocation?
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Arrays are stack allocated, and in practice the compiler will optimise all of this away
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In fact it does a better job optimising it than the old TryInto based approach - https://rust.godbolt.org/z/f6jj3PM9c
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I see. That's good point.
Benchmark runs are scheduled for baseline = e2c4199 and contender = 53b7f64. 53b7f64 is a master commit associated with this PR. Results will be available as each benchmark for each run completes. |
Which issue does this PR close?
Closes #.
Rationale for this change
Help with #3025 among others
What changes are included in this PR?
Tweaks various methods to make the const
This makes use of const support for loops added stabilised in 1.46 - https://blog.rust-lang.org/2020/08/27/Rust-1.46.0.html#const-fn-improvements, which is well under our MSRV which appears to be 1.62!
Are there any user-facing changes?
No