Why don't we switch to C like floating pointed arithmetic instead of automatic expansion to reals?

[Ilya Yaroshenko via Digitalmars-d]

On Saturday, 6 August 2016 at 19:51:11 UTC, Walter Bright wrote:
> On 8/6/2016 2:48 AM, Ilya Yaroshenko wrote:
>>> I don't know what the point of fusedMath is.
>> It allows a compiler to replace two arithmetic operations with 
>> single composed
>> one, see AVX2 (FMA3 for intel and FMA4 for AMD) instruction 
>> set.
>
> I understand that, I just don't understand why that wouldn't be 
> done anyway.

Some applications requires exactly the same results for different 
architectures (probably because business requirement). So this 
optimization is turned off by default in LDC for example.