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

[Carsten Schlote]

On Tuesday, 13 August 2024 at 07:56:34 UTC, Abdulhaq wrote:
> One little piece of anecdata, when working with python I saw 
> differing results in the 17th d.p. when running the exact same 
> calculation in the same python session. The reason turned out 
> to be which registers were being used each time, which could 
> vary. This is not considered to be a bug.

I would consider it a bug.

Running the same piece of code multiple times with exactly the 
same parameters should result into the exactly same results.

But once I also expected that CTFE and real execution of some 
code should always yield the same results. This assumption is 
wrong as I learned recently. But using 'real' as type usually 
leads to the same result.

All the other issues with floats of any size are some separate 
topic.