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

[Walter Bright via Digitalmars-d]

On 8/5/2016 2:40 AM, Ilya Yaroshenko wrote:
> No. For example std.math.log requires it! But you don't care about other
> compilers which not use yl2x and about making it template (real version slows
> down code for double and float).

I'm interested in correct to the last bit results first, and performance second. 
std.math changes that hew to that are welcome.