[Bug fortran/93948] Surprising option processing of -fdec and -fdec-math in combination with -std

[sgk at troutmask dot apl.washington.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93948

--- Comment #3 from Steve Kargl <sgk at troutmask dot apl.washington.edu> ---
On Thu, Feb 27, 2020 at 09:15:53AM +0000, thenlich at gcc dot gnu.org wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93948
> 
> --- Comment #2 from Thomas Henlich <thenlich at gcc dot gnu.org> ---
> -fall-intrinsics is a nice workaround, but it also enables more than I want.
> 

It's not a workaround given the wording of the Fortran stanard.
A processor is allowed to provide additional intrinsic subprograms
not specified in the standard.  However, if a program uses the
nonstandard subprograms that program is nonconforming.  With a
-std= option, one is requested conformance to the Fortran standard,
which leads to a catch 22.  When I introduced -fall-intrinsics, it
was suggested that we have -fintrinsics=cotan,sind to allow only
cotan and sind to be added to the set in Fortran standard.  I did not
and still do not see how to do this given the number of nonstandard
intrinsics.

> 
> Requiring one of -fdec or -fall-intrinsics, if -std is specified. Is redundant
> in the first case.

As I stated earlier, I think -fdec-math should go away and
these routines would be handled just like, for example,
etime().