[Bug rtl-optimization/126686] [16/17 Regression] ICE in require, at machmode.h:323 since r16-26 with -favoid-store-forwarding

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126686

--- Comment #5 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Philipp Tomsich <[email protected]>:

https://gcc.gnu.org/g:b01cd452a6c7ba2a2f95a77f62f0727cbbe9d6a5

commit r17-3498-gb01cd452a6c7ba2a2f95a77f62f0727cbbe9d6a5
Author: Konstantinos Eleftheriou <[email protected]>
Date:   Thu Aug 20 03:57:02 2026 -0700

    avoid-store-forwarding: Reject BLKmode memory operands [PR126686]

    Memory operands were only rejected when their size is unknown or
    non-constant, so a BLKmode store with a known size could become a
    forwarding candidate. Building the bit insert sequence for it asserts
    in store_bit_field, as BLKmode has no corresponding integer mode.
    Reject such memory when collecting candidates.

            PR rtl-optimization/126686

    gcc/ChangeLog:

            * avoid-store-forwarding.cc
            (store_forwarding_analyzer::avoid_store_forwarding): Reject
            BLKmode stores and loads as forwarding candidates.

    gcc/testsuite/ChangeLog:

            * gcc.dg/torture/pr126686.c: New test.