[Bug tree-optimization/102056] VEC_PERM_EXPR of different sizes are not combined

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102056

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Actually VEC_PERM_EXPR of the same size is not optimized either:

vector char g1(vector char a)
{
    vector char t= __builtin_shuffle(a,(vector
char){7,6,5,4,3,2,1,0,15,14,13,12,11,10,9,8,});
    vector long long t1 = (vector long long)t;
    return __builtin_shuffle(t, (vector
char){8,9,10,11,12,13,14,15,0,1,2,3,4,5,6,7});
    return (vector char)t1;
}