On Fri, Dec 21, 2018 at 08:59:04PM +0200, Janne Blomqvist wrote:
> On Fri, Dec 21, 2018 at 7:59 PM Steve Kargl <
> >
> > D.3853 = *i;
> > __result_foo = scalbnq (c,
> > (integer(kind=4)) MAX_EXPR <MIN_EXPR <D.3853, 2147483647>,
> > -2147483647>);
> >
> > The range [-32443,32443] is a subset of [-huge(),huge(0)].
> >
>
> True. I guess the advantage of scalbln* would be to avoid the MAX/MIN_EXPR
> and casting for kind int64.
>
fdlibm-based libm has
#define NMAX 65536
#define NMIN -65536
double
scalbln(double x, long n)
{
return (scalbn(x, (n > NMAX) ? NMAX : (n < NMIN) ? NMIN : (int)n));
}
A search for glibc's libm locates https://tinyurl.com/ybcy8w4t
which is a bit-twiddling routine. Not sure it's worth the
effort. Joseph Myers might have an opinion.
--
Steve
