[Bug tree-optimization/119181] Missed vectorization due to imperfect SLP discovery for 2 grouped load with same base pointer (taken as 1 interleaved load)

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119181

--- Comment #11 from Hongtao Liu <liuhongt at gcc dot gnu.org> ---
More common case is 

typedef int v8si __attribute__((vector_size(32)));

v8si
foo1 (v8si a, v8si b)
{
    v8si c = __builtin_shufflevector (a, b, 0, 1, 2, 11, 4, 5, 6, 15);
    v8si d = __builtin_shufflevector (b, a, 0, 1, 2, 11, 4, 5, 6, 15);
    return c * d;
}

Redudant vector permutation is not optimized off.