[Bug target/80820] _mm_set_epi64x shouldn't store/reload for -mtune=haswell, Zen should avoid store/reload, and generic should think about it.

[peter at cordes dot ca]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80820

--- Comment #2 from Peter Cordes <peter at cordes dot ca> ---
See also https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80833.

gcc -m32 does an even worse job of getting int64_t into an xmm reg, e.g. as
part of a 64-bit atomic store.

We get a store-forwarding failure from code like this, even with -march=haswell

        movl    %eax, (%esp)
        movl    %edx, 4(%esp)
        movq    (%esp), %xmm0