[gfortran] patch for pr12839 / F2003 format of Inf and NaN

[Zack Weinberg]

Steve Kargl <sgk@troutmask.apl.washington.edu> writes:

> On Sun, Jun 13, 2004 at 06:20:18PM +0200, Andreas Schwab wrote:
>> Steve Kargl <sgk@troutmask.apl.washington.edu> writes:
>> 
>> > I've sent an email to the FreeBSD-standards mailing list to
>> > determine if isinf() conforms to the C99 standard.  I only
>> > have Harbison and Steele, which suggests isinf() should return
>> > the sign.
>> 
>> The C99 standard says: "The isinf macro returns a nonzero value if and
>> only if its argument has an infinite value."
>> 
>
> H&S have the same statement except the parenthetical clause
> "(with any sign)" prior to the period.  This must fall under
> the infamous implementation defined bahavior.

This is more accurately described as unspecified behavior - the
implementation is obliged to return some nonzero value iff ..., but is
not obliged to document *which* nonzero value.

zw