--- Comment #4 from amker at gcc dot gnu.org ---
(In reply to amker from comment #3)
> For function sign_lt and uns_lt, the change causes worse code generation
> unfortunately. Take uns_lt as example, the difference in optimized dump is
> So powerpc has to compute ">=" with "> || =="? Apart from this, the change
> itself only introduces additional canonicalization during tree-ifcvt,
> transforming "<" to "<=". If the former form is more efficient on powerpc,
> shall we take this into consideration when canonicalization?
In powerpc backend, function rs6000_emit_vector_cond_expr only inverts
unordered comparisons. If I understand correctly, it could be improved to
handle more cases like this one. So this is a backend issue?