[PATCH v2][PR libgfortran/78314] Fix ieee_support_halting

[Szabolcs Nagy]

On 16/11/16 16:53, Szabolcs Nagy wrote:
> ieee_support_halting only checked the availability of status
> flags, not trapping support.  On some targets the later can
> only be checked at runtime: feenableexcept reports if
> enabling traps failed.
> 
> So check trapping support by enabling/disabling it.
> 
> Updated the test that enabled trapping to check if it is
> supported.
> 
> Tested on aarch64-linux-gnu and x86_64-linux-gnu.
> 
> gcc/testsuite/
> 2016-11-16  Szabolcs Nagy  <szabolcs.nagy@arm.com>
> 
> 	PR libgfortran/78314
> 	* gfortran.dg/ieee/ieee_6.f90: Use ieee_support_halting.
> 
> libgfortran/
> 2016-11-16  Szabolcs Nagy  <szabolcs.nagy@arm.com>
> 
> 	PR libgfortran/78314
> 	* config/fpu-glibc.h (support_fpu_trap): Use feenableexcept.
> 

it seems this broke ieee_8.f90 which tests compile time
vs runtime value of ieee_support_halting

if fortran needs this, then support_halting should be
always false on arm and aarch64.

but i'm not familiar enough with fortran to tell if
there is some better workaround.