[PATCH] gfortran -- Map REAL128 to REAL kind type with widest precision

[Jerry DeLisle]

On 02/09/2017 12:40 PM, Janne Blomqvist wrote:
> On Thu, Feb 9, 2017 at 8:33 PM, Steve Kargl
> <sgk@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

Same result as before the patch.

Jerry