Optimizing a bigint fibonacci

[codephantom]

On Wednesday, 6 December 2017 at 09:59:12 UTC, codephantom wrote:
> On Wednesday, 6 December 2017 at 09:12:08 UTC, helxi wrote:
>> This is question not directly related to language concepts, 
>> it's got more to do with the application. I would appreciate 
>> if anyone would point to me how I could optimize this bit of 
>> code
>
> Compile it with ldc ;-)

also, fyi....in my test, when compiling with dmd and using -m32 
(instead of -m64) it timed *twice as fast* compared to the timing 
of the 64bit run; whereas compiling with ldc, both the 32bit and 
64bit run timed at about the same speed.

lesson? don't 'just' look at how to optimise your 'code' ;-)