[Bug tree-optimization/71264] [4.9/5/6/7 Regression] ICE in convert_move

["rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71264

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
So the issue is that the code is alread "vectorized" but the footype vector
type
has SImode and thus get_vectype_for_scalar_type happily returns V4SI as vector
type.  But the rest of the vectorizer isn't really prepared to handle vector
types in the to-be-vectorized IL.

I have a patch that ends up producing

test:
.LFB0:
        .cfi_startproc
        movd    (%rsi), %xmm1
        movdqu  (%rdi), %xmm2
        pshufd  $0, %xmm1, %xmm0
        pxor    %xmm2, %xmm0
        movups  %xmm0, (%rdi)
        ret