[Bug target/110484] Spec2017 541 after adding the '-flto-fomit-frame-pointer' optimization, after optimizing the rnreg, directly replaced other registers with the $r22 register, so that the value of the $r22 register was destroyed without being saved.

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110484

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by LuluCheng <chenglulu@gcc.gnu.org>:

https://gcc.gnu.org/g:1967f21d000e09d3d3190317af7923b578ce02b1

commit r14-3605-g1967f21d000e09d3d3190317af7923b578ce02b1
Author: Lulu Cheng <chenglulu@loongson.cn>
Date:   Thu Jun 29 19:30:59 2023 +0800

    LoongArch: Fix bug in loongarch_emit_stack_tie [PR110484].

    Which may result in implicit references to $fp when frame_pointer_needed is
false,
    causing regs_ever_live[$fp] to be true when $fp is not explicitly used,
    resulting in $fp being used as the target replacement register in the rnreg
pass.

    The bug originates from SPEC2017 541.leela_r(-flto).

    gcc/ChangeLog:

            PR target/110484
            * config/loongarch/loongarch.cc (loongarch_emit_stack_tie): Use the
            frame_pointer_needed to determine whether to use the $fp register.

    Co-authored-by: Guo Jie <guojie@loongson.cn>