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

[Iain Buclaw via Digitalmars-d]

On 6 August 2016 at 11:48, Ilya Yaroshenko via Digitalmars-d
<digitalmars-d at puremagic.com> wrote:
> On Saturday, 6 August 2016 at 09:35:32 UTC, Walter Bright wrote:
>>
>> On 8/6/2016 1:21 AM, Ilya Yaroshenko wrote:
>>>
>>> We need 2 new pragmas with the same syntax as `pragma(inline, xxx)`:
>>>
>>> 1. `pragma(fusedMath)` allows fused mul-add, mul-sub, div-add, div-sub
>>> operations.
>>> 2. `pragma(fastMath)` equivalents to [1]. This pragma can be used to
>>> allow
>>> extended precision.
>>
>>
>>
>> The LDC fastmath bothers me a lot. It throws away proper NaN and infinity
>> handling, and throws away precision by allowing reciprocal and algebraic
>> transformations. As I've said before, correctness should be first, not
>> speed, and fastmath has nothing to do with this thread.
>
>
> OK, then we need a third pragma,`pragma(ieeeRound)`. But `pragma(fusedMath)`
> and `pragma(fastMath)` should be presented too.
>
>> 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.

No pragmas tied to a specific architecture should be allowed in the
language spec, please.