Re: [PATCH] Preserve ::is{inf,nan}{f,l} prototypes even for C++11 and later

[Jakub Jelinek <jakub at redhat dot com>]

On Tue, Feb 23, 2016 at 04:23:42PM +0100, Andreas Schwab wrote:
> > +static int
> > +do_test (void)
> > +{
> > +  /* Verify that isinff, isinfl, isnanf, and isnanlf are defined
> > +     in the header under C++11 and can be called.  Without the
> > +     header fix this test will not compile.  */
> > +  if (isinff (1.0f)
> > +      || !isinff (INFINITY)
> > +      || isinfl (1.0L)
> > +      || !isinfl (INFINITY)
> > +      || isnanf (2.0f)
> > +      || !isnanf (NAN)
> > +      || isnanl (2.0L)
> > +      || !isnanl (NAN))
> 
> That doesn't compile on platforms where long == long double, since they
> do not declare any *l functions (arm, hppa, mips/o32).
> 
> test-math-isinff.cc: In function 'int do_test()':
> test-math-isinff.cc:33:22: error: 'isinfl' was not declared in this scope
>        || isinfl (1.0L)
>                       ^
> test-math-isinff.cc:37:22: error: 'isnanl' was not declared in this scope
>        || isnanl (2.0L)
>                       ^

Thus the *l stuff needs to be guarded with
#ifndef __NO_LONG_DOUBLE_MATH

	Jakub