[Bug tree-optimization/90271] [missed-optimization] failure to keep variables in registers during "faux" memcpy

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90271

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
One thing is that store-merging doesn't optimize this, I think we have an open
enhancement request for that that should be able to cure that case.

Another one is that perhaps we should consider such MEM_REFs as not necessarily
forcing the variable into memory, and if that is the only thing to keep it
addressable, we could in tree-ssa-live.c rewrite it using BIT_INSERT_EXPR.