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Re: [fortran,patch] Complete front-end support for __float128

On 08/26/2010 05:00 PM, FX wrote:
Why do you need a flag at all? Simply support real(kind=16).
Some people have codes, in standard Fortran, that autodetect the floating-point mode with the largest precision and use that. If we introduce soft-float modes, they might be annoyed as everything slows down immensely... and they have no way to detect "the most precise hardware-supported floating-point type".
On the other hand, I suppose that most people actually hardcode kind numbers rather than use carefully crafted selected_real_kind calls, so it may not be such a big deal.

My impression is that 99% of the codes use REAL, REAL(4), REAL(8), DOUBLE PRECISION, sp=kind(0.0), dp=kind(0.0d0) - thus for those, it does not matter. If one uses REAL(16) unconditionally, one would currently get an error (invalid kind); with the patch one would get a linkage error. If one uses selected_real_kind with numbers allowing for kind=10, it also returns them instead of kind=16 - thus those programs still should work.

Thus, I am fine with enabling them without a flag - but a flag is also fine with me.


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