[Bug rtl-optimization/122170] [15/16 Regression] gcc 15.2.0 (and gcc 15.1.0 as well) - ICE upon try to build CMSIS_DSP Library with and Optimization on

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122170

--- Comment #14 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Andrew Pinski <pinskia@gcc.gnu.org>:

https://gcc.gnu.org/g:40f6ae016571ce6ea5951f406c4be7ff84914fbc

commit r16-7166-g40f6ae016571ce6ea5951f406c4be7ff84914fbc
Author: Andrew Pinski <andrew.pinski@oss.qualcomm.com>
Date:   Wed Jan 28 12:32:12 2026 -0800

    ifcvt: Improve noce_can_force_operand in ifcvt [PR122170]

    Currently if the rtl is either an arithmetic or an unary
    rtl, noce_can_force_operand checks to see if there is an
    optab for that rtl code. This works for more things except
    on some targets they have a ss_minus instruction but don't
    implement the optab for it. In the case of arm you can
    generate a ss_minus with a builtin and then when it comes
    to trying to do ifcvt, force_operand fails over.
    In this case the optab, sssub was only supported for
    fixed-point modes before and it was working as code_to_optab
    would return there was not optabs. But after r15-1030-gabe6d39365476e,
    the optab will be return. What the backend is doing is correct and will
    most likely happen with other rtl codes/optabs later on.

    To fix this instead of just returning true if the optab exists, we need
    to check if the optab entry for the mode exists.

            PR rtl-optimization/122170

    gcc/ChangeLog:

            * ifcvt.cc (noce_can_force_operand): Don't only check if
            there is an optab for the code check the entry for the
            mode is non-null. Handle non integral div by checking
            optab like force_operand does.

    Signed-off-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>