[Bug tree-optimization/126138] `fp0 == fp1 || fp0 CMP fp1` can be combined always even with trapping

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126138

--- Comment #8 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Andrea Pinski <[email protected]>:

https://gcc.gnu.org/g:7d781db9c3d5159386b1f645355955da5f844ec4

commit r17-2707-g7d781db9c3d5159386b1f645355955da5f844ec4
Author: Andrea Pinski <[email protected]>
Date:   Sat Jul 11 22:56:40 2026 -0700

    fold: Allow combining eq/ne with a trapping to get a trapping [PR126138]

    For `(i == j) || (i < j)` this can be combined to just `i <= j` without
    worrying about removal of a trap as a NaN would cause the the equal to be
    false which will cause not to short circuit and the trapping instruction
    will always be executed.

    `(i != j) && (i < j)` has the same reasoning.

    Bootstrapped and tested on x86_64-linux-gnu.

            PR tree-optimization/126138

    gcc/ChangeLog:

            * fold-const.cc (combine_comparisons): Allow eq to combine
            with || and ne combine with && if the original rcode was trapping
            and the new code is trapping.

    gcc/testsuite/ChangeLog:

            * gcc.dg/tree-ssa/fp-trapping-cmp-1.c: New test.

    Signed-off-by: Andrea Pinski <[email protected]>