Always false float comparisons

[Johan Engelen via Digitalmars-d]

On Thursday, 19 May 2016 at 18:22:48 UTC, Timon Gehr wrote:
> 
> dmd -run kahanDemo.d
> 1000000000000000.000000
> 1000000100000000.000000
> 1000000000000000.000000
>
> dmd -m32 -O -run kahanDemo.d
> 1000000000000000.000000
> 1000000000000000.000000
> 1000000000000000.000000
>
> Better?

Ignore if you think it's not relevant.
I am a bit lost in this thread. I thought this was about floating 
point CTFE, but I think what you are seeing here (in the 2nd 
case) is the DMD optimizer allowing reassociation of fp 
expressions? LDC does not allow that (per default) and produces 
the 1000000100000000.000000 result also with optimization on.

-Johan