[Bug target/112855] [14] RISC-V vector: vsetivli clobbers variable value

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112855

--- Comment #2 from GCC 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:c9d5b46a25547035e381b0246de5cb553ca8b02d

commit r14-6222-gc9d5b46a25547035e381b0246de5cb553ca8b02d
Author: Juzhe-Zhong <juzhe.zh...@rivai.ai>
Date:   Wed Dec 6 22:26:46 2023 +0800

    RISC-V: Fix VSETVL PASS bug

    As PR112855 mentioned, the VSETVL PASS insert vsetvli in unexpected
location.

    Due to 2 reasons:
    1. incorrect transparant computation LCM data. We need to check VL operand
defs and uses.
    2. incorrect fusion of unrelated edge which is the edge never reach the
vsetvl expression.

            PR target/112855

    gcc/ChangeLog:

            * config/riscv/riscv-vsetvl.cc
            (pre_vsetvl::compute_lcm_local_properties): Fix transparant LCM
data.
            (pre_vsetvl::earliest_fuse_vsetvl_info): Disable earliest fusion
for unrelated edge.

    gcc/testsuite/ChangeLog:

            * gcc.target/riscv/rvv/autovec/pr112855.c: New test.