[Bug tree-optimization/112694] RISC-V: zve64d testing expose many ICE on C/C++ testing

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112694

--- Comment #5 from CVS 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:aea337cf740ec33022f3cabfa7dd4333d5ba78ee

commit r14-5825-gaea337cf740ec33022f3cabfa7dd4333d5ba78ee
Author: Juzhe-Zhong <juzhe.zhong@rivai.ai>
Date:   Fri Nov 24 16:34:28 2023 +0800

    RISC-V: Fix inconsistency among all vectorization hooks

    This patches 200+ ICEs exposed by testing with rv64gc_zve64d.
    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112694

    The rootcause is we disallow poly (1,1) size vectorization in
preferred_simd_mode.
    with this following code:
    -      if (TARGET_MIN_VLEN < 128 && TARGET_MAX_LMUL < RVV_M2)
    -       return word_mode;

    However, we allow poly (1,1) size in hook:
    TARGET_VECTORIZE_RELATED_MODE
    TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES

    And also enables it in all vectorization patterns.

    I was adding this into preferred_simd_mode because poly (1,1) size mode
will cause
    ICE in can_duplicate_and_interleave_p.

    So, the alternative approach we need to block poly (1,1) size in both
TARGET_VECTORIZE_RELATED_MODE
    and TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES hooks and all vectorization
patterns.
    which is ugly approach and too much codes change.

    Now, after investivation, I find it's nice that loop vectorizer can
automatically block poly (1,1)
    size vector in interleave vectorization with this commit:
   
https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=730909fa858bd691095bc23655077aa13b7941a9

    So, we don't need to worry about ICE in interleave vectorization and allow
poly (1,1) size vector
    in vectorization which fixes 200+ ICEs in zve64d march.

            PR target/112694

    gcc/ChangeLog:

            * config/riscv/riscv-v.cc (preferred_simd_mode): Allow poly_int
(1,1) vectors.

    gcc/testsuite/ChangeLog:

            * gcc.target/riscv/rvv/autovec/pr112694-1.c: New test.