Differences in results when using the same function in CTFE and Runtime

[IchorDev]

On Friday, 9 August 2024 at 00:46:12 UTC, Nicholas Wilson wrote:
> On Thursday, 8 August 2024 at 10:31:32 UTC, Carsten Schlote 
> wrote:
>> Hi
>> - Can CTFE be used under all circumstances when float numbers 
>> of any precision are involved?
>> - Or is this some kind of expected behaviour whenever floats 
>> are involved?
>> - Is the D CTFE documentation completely covering such 
>> possible issues?
>>
>> I can imagine that bugs causes by such subtil differences 
>> might be very difficult to fix.
>>
>>
>> Any experiences or thought on this?
>>
>
> there are `toPrec`[1] intrinsics to solve exactly this issue of 
> lack of truncation of precision.
>
>
> [1]: 
> https://github.com/dlang/dmd/blob/958ba9cbe3583830efe39505238939daa0dbd64c/druntime/src/core/math.d#L198-L214
>
>> Greetz
>> Carsten

Can anyone remind me whether there’s a way to force calculations 
to be performed with a certain degree of precision (e.g. single 
or double) instead of rounding down from the largest floats 
available? Would be really useful for cross-platform consistency. 
:’|