https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84342
--- Comment #8 from Alexandre Oliva <aoliva at gcc dot gnu.org> --- That's the hook, yes. But if you return 1, then the view-computing logic will behave just as if it noticed a nonzero length for the insn. If the branch is eliminated and no code it generated for that insn, you should instead return -1.
