[Bug target/111927] RISC-V: internal compiler error: in merge, at config/riscv/riscv-vsetvl.cc:1997

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111927

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

https://gcc.gnu.org/g:0c4bd1321a6def5eb44c530e83b01a415633b660

commit r14-4856-g0c4bd1321a6def5eb44c530e83b01a415633b660
Author: Juzhe-Zhong <juzhe.zh...@rivai.ai>
Date:   Mon Oct 23 17:40:34 2023 +0800

    RISC-V: Fix ICE for the fusion case from vsetvl to scalar move[PR111927]

    ICE:

    during RTL pass: vsetvl
    <source>: In function 'riscv_lms_f32':
    <source>:240:1: internal compiler error: in merge, at
config/riscv/riscv-vsetvl.cc:1997
      240 | }

    In general compatible_p (avl_equal_p) has:

        if (next.has_vl () && next.vl_used_by_non_rvv_insn_p ())
          return false;

    Don't fuse AVL of vsetvl if the VL operand is used by non-RVV instructions.

    It is reasonable to add it into 'can_use_next_avl_p' since we don't want to
    fuse AVL of vsetvl into a scalar move instruction which doesn't demand AVL.
    And after the fusion, we will alway use compatible_p to check whether the
demand
    is correct or not.

            PR target/111927

    gcc/ChangeLog:

            * config/riscv/riscv-vsetvl.cc: Fix bug.

    gcc/testsuite/ChangeLog:

            * gcc.target/riscv/rvv/vsetvl/pr111927.c: New test.