On Wed, Apr 21, 2021 at 10:10:07AM +0200, Tobias Burnus wrote: > On 20.04.21 08:58, Richard Biener via Fortran wrote: > >On Mon, Apr 19, 2021 at 9:40 PM Michael Meissner via Fortran > ><fortran@gcc.gnu.org> wrote: > Is there any reason to not only send the email to fortran@ _and_ > gcc-patches@ but sending it to 13 Fortran maintainers explicitly? (Now > removed)
Sorry about that. With PowerPC backend changes, I generally do explicitly add the maintainers so things don't get lost. > >>Fix Fortran rounding issues, PR fortran/96983. > >> > >>Can I check this change into the GCC trunk? > >The patch looks fine technically and is definitely an improvement since the > >intermediate conversion looks odd. But it might be that the standard > >requires such dance though the preceeding cases handled don't seem to > >care. I'm thinking of a FP format where round(1.6) == 3 because of lack > >of precision but using an intermediate FP format with higher precision > >would "correctly" compute 2. > > The patched build_round_expr is only called by ANINT / NINT; > NINT is real → integer; ANINT is real → real > [And the modified code is only called for NINT, reason: see comment far > below.] > > NINT (A[, KIND]) is described (F2018) as "Nearest integer": > * Result Characteristics. Integer. If KIND is present, the kind type parameter > is that specified by the value of KIND; > otherwise, the kind type parameter is that of default integer type. > * The result is the integer nearest A, or if there are two > integers equally near A, the result is whichever such integer has the > greater > magnitude. > * Example. NINT (2.783) has the value 3. > > ANINT (A[, KIND]) as "Nearest whole number": > * The result is of type real. If KIND is present, the kind type parameter is > that > specified by the value of KIND; otherwise, the kind type parameter is that > of A. > * The result is the integer nearest A, or if there are two integers equally > near A, > the result is whichever such integer has the greater magnitude. > * Examples. ANINT (2.783) has the value 3.0. ANINT (−2.783) has the value > −3.0. > > >Of course the current code doesn't handle this correctly for the > >case if llroundf either. > >>I've not contributed to the Fortran front end before. If the maintainers > >>like > >>the patch, can somebody point out if I need to do additional things to > >>commit > >>the patch? > Nothing special: a testcase already exists, committing is done as usual > and a PR to update you have as well. Given GCC 11 has branched, is it ok to backport the patch to the GCC 11 branch as well? I assume it is, since it fixes a regression in the compiler. -- Michael Meissner, IBM IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA email: meiss...@linux.ibm.com, phone: +1 (978) 899-4797
