[Bug target/128184] wrong code with __sync_fetch_and_nand on _BitInt on riscv64

[law at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128184

Jeffrey A. Law <law at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Blocks|120763                      |
     Ever confirmed|0                           |1
                 CC|                            |jakub at redhat dot com
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2026-11-02

--- Comment #1 from Jeffrey A. Law <law at gcc dot gnu.org> ---
Looks like it goes wrong pretty early.  Hard to see how it's a target issue.

>From the .gimple dump:

    _1 = __atomic_load_8 (&g, 0);
    _2 = VIEW_CONVERT_EXPR<_BitInt(63)>(_1);
    D.2459 = _2;
    <D.2461>:
    _3 = D.2459;
    _4 = ~_3;
    _5 = _4 & 5;


Jakub, thoughts here?


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120763
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