sejourne_kevin wrote:

> Do you want to say that one small logical operation (' and ' or '
> shift') after the evaluation of an expression ' float ' will be slower
> than the management of it box?

Shifting floats wouldn't make much sense, but you could just clear/set 
the tag bit (it would be the least significant bit of the mantissa). 
However, this would be insufficient if you wanted control over rounding 
(you could only have round-toward-zero).

Of course someone content with losing a bit of precision from the 
mantissa probably wouldn't care too much about rounding.