https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117805
--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
Note with a patch like in comment#4 you'd get different answers for
complex * { a, -0.} and complex * { a, b } with b being -0., that
might be undesirable. The question is how the Frontend presents
us with a complex times real multiplication (I think GENERIC requires
two complex operands), and thus whether the desired optimization would
have to take place in the frontend to avoid the above consistency issue.
