[PATCH, rs6000, testsuite] Skip gfortran.dg/round_4.f90 for PowerPC Linux

[Tim Prince]

On 6/30/2014 5:57 AM, Tobias Burnus wrote:
> Hi Bill,
>
> Bill Schmidt wrote:
>> The test in gfortran.dg/round_4.f90, introduced in GCC 4.9, checks for
>> correct behavior of different rounding modes.  However, for
>> quad-precision floating-point, it requires that the number
>> 0.10000000000000000000000000000000000481 be exactly represented.  Since
>> the PowerPC long double implementation (double-double) only guarantees
>> 31 bits of precision, the test fails for the real(qp) portions of the
>> test.  Thus this patch marks the test invalid for PowerPC Linux for now.
>> (We may want to also do this for other subtargets; let me know if so.)
>>
>> At such time as IEEE 128-bit floating-point is supported by the PowerPC
>> port, we should revisit this.
>>
>> Is this ok for trunk and 4.9?
> Looks good to me. Thanks for digging into test-suite failures!
>
> However, it probably wouldn't harm either to add a test case for
> powerpc*-*-* (which might also work with hppa-*-*-hpux) for the rounding.
> I worry less about the quad-precision (qp) rounding, but I think it would
> be useful to test that the single and double precision rounding work. But
> as it requires an extra file, one could also check for the 31bit QP as
> well. Thus, if you have some spare cycles and agree on the usefulness ...
>
The test doesn't get that far on newlib implementations, including 
cygwin, as the build fails due to newlib not providing nextafterl().  It 
seems misleading to me to have the test marked as unexpected fail for 
all data widths when just that one is unsupported.

-- 
Tim Prince