[Bug rtl-optimization/113495] RISC-V: Time and memory awful consumption of SPEC2017 wrf benchmark

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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113495

--- Comment #33 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Pan Li <panli@gcc.gnu.org>:

https://gcc.gnu.org/g:9dd10de15b183f7b662905e1383fdc3a08755f2e

commit r14-8639-g9dd10de15b183f7b662905e1383fdc3a08755f2e
Author: Juzhe-Zhong <juzhe.zhong@rivai.ai>
Date:   Mon Jan 29 19:32:02 2024 +0800

    RISC-V: Fix VSETLV PASS compile-time issue

    The compile time issue was discovered in SPEC 2017 wrf:

    Use time and -ftime-report to analyze the profile data of SPEC 2017 wrf
compilation .

    Before this patch (Lazy vsetvl):

    scheduling                         : 121.89 ( 15%)   0.53 ( 11%) 122.72 (
15%)    13M (  1%)
    machine dep reorg                  : 424.61 ( 53%)   1.84 ( 37%) 427.44 (
53%)  5290k (  0%)
    real    13m27.074s
    user    13m19.539s
    sys     0m5.180s

    Simple vsetvl:

    machine dep reorg                  :   0.10 (  0%)   0.00 (  0%)   0.11 ( 
0%)  4138k (  0%)
    real    6m5.780s
    user    6m2.396s
    sys     0m2.373s

    The machine dep reorg is the compile time of VSETVL PASS (424 seconds)
which counts 53% of
    the compilation time, spends much more time than scheduling.

    After investigation, the critical patch of VSETVL pass is
compute_lcm_local_properties which
    is called every iteration of phase 2 (earliest fusion) and phase 3 (global
lcm).

    This patch optimized the codes of compute_lcm_local_properties to reduce
the compilation time.

    After this patch:

    scheduling                         : 117.51 ( 27%)   0.21 (  6%) 118.04 (
27%)    13M (  1%)
    machine dep reorg                  :  80.13 ( 18%)   0.91 ( 26%)  81.26 (
18%)  5290k (  0%)
    real    7m25.374s
    user    7m20.116s
    sys     0m3.795s

    The optimization of this patch is very obvious, lazy VSETVL PASS: 424s
(53%) -> 80s (18%) which
    spend less time than scheduling.

    Tested on both RV32 and RV64 no regression.  Ok for trunk ?

            PR target/113495

    gcc/ChangeLog:

            * config/riscv/riscv-vsetvl.cc (extract_single_source): Remove.
            (pre_vsetvl::compute_vsetvl_def_data): Fix compile time issue.
            (pre_vsetvl::compute_transparent): New function.
            (pre_vsetvl::compute_lcm_local_properties): Fix compile time time
issue.