[gfortran] PR15206 RRSPACING wrong for zero

[Tobias Schlüter]

Paul Brook wrote:
> 
> I'd forgotten about that. Looks like I don't understand this bit of code 
> either :)
> Go ahead and check in your original patch.

Done.

> On a related issue, the existing rrspacing code to handle denormals is broken. 
> This occurs when x < TINY(x), ie. expn == 0, frac != 0
> I suspect the right shift should be a logical (unsigned) shift, not an 
> arithmetic (signed) one. 

Should I close the old bug and add a new one where we keep track of this 
or should I change the summary line and add this information?

> Paul
>