On Thu, Feb 09, 2017 at 07:35:11PM -0800, Jerry DeLisle wrote: > On 02/09/2017 12:40 PM, Janne Blomqvist wrote: > > On Thu, Feb 9, 2017 at 8:33 PM, Steve Kargl > > <s...@troutmask.apl.washington.edu> wrote: > >> On Thu, Feb 09, 2017 at 12:10:02PM +0200, Janne Blomqvist wrote: > >>> > >>> That being said, I think even with Steve's patch, it's not guaranteed > >>> to give you IEEE 754-2008 binary128. E.g. on IBM POWER targets, > >>> depending on the ABI you may get an IBM extended double (double-double > >>> or __ibm128) format. Although if IEEE binary128 is also available, > >>> with Steve's patch you should get that one has it has more precision > >>> that __ibm128. > >> > >> I do not have to a IBM POWER system, so cannot easily check the > >> effect of my patch. > > On IBM Power > > program foo > use iso_fortran_env > REAL(REAL128) x > print '(3(I0,1X))', kind(x), digits(x), precision(x) > end program foo > > $ gfc -static foo.f90 > $ ./a.out > 16 106 31 >
That is the double-double format. The gcc manual says that powerpc takes a -mfloat128 option (among others). This will probably give you 16 113 33. -- Steve 20161221 https://www.youtube.com/watch?v=IbCHE-hONow
