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Date: Fri, 15 Oct 2021 17:24:23 -0500
From: Segher Boessenkool <segher@kernel.crashing.org>
To: Jakub Jelinek <jakub@redhat.com>
Cc: Bill Schmidt <wschmidt@linux.ibm.com>, fortran@gcc.gnu.org,
 gcc@gcc.gnu.org, Tobias Burnus <tobias@codesourcery.com>,
 Michael Meissner <meissner@linux.ibm.com>, tkoenig@netcologne.de
Subject: Re: libgfortran.so SONAME and powerpc64le-linux ABI changes
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On Fri, Oct 15, 2021 at 04:20:49PM +0200, Jakub Jelinek wrote:
> If we do implement double-double support, I think KIND=15 would be better
> than KIND=17, it is true that double-double has for certain numbers much
> higher precision than IEEE quad, but the precision depends on the numbers
> and most of the time is smaller, the range is always smaller.  And
> the PRECISION/RANGE intrinsic numbers are also both smaller.

Yes.

We want KIND=16 to mean the IEEE QP format whenever we can, right?  And
another 16-byte format would more logically be kind=17 then, considering
we want to have two 2-byte kinds at least, one of them IEEE as well.

Other practical considerations might well supersede elegance of course.


Segher