https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87871
--- Comment #51 from Richard Earnshaw <rearnsha at gcc dot gnu.org> ---
(In reply to Segher Boessenkool from comment #50)
> The insn is
>
> (insn 7 3 8 2 (parallel [
> (set (reg:CC 100 cc)
> (compare:CC (reg:SI 0 r0 [116])
> (const_int 0 [0])))
> (set (reg/v:SI 4 r4 [orig:112 a ] [112])
> (reg:SI 0 r0 [116]))
> ]) "ira-shrinkwrap-prep-1.c":17:6 188 {*movsi_compare0}
> (nil))
>
> and that isn't split, and then prepare_shrink_wrap gives up on it.
In the more general case splitting this would produce worse code, not better,
since then we'd end up with two instructions rather than one.
