[Bug middle-end/68664] [6/7 Regression] Speculative sqrt in c-ray main loop causes large slow down

[dje at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68664

--- Comment #16 from David Edelsohn <dje at gcc dot gnu.org> ---
> That isn't an argument for -fno-sched-spec, it is an argument for a cost model which better matches the cost of the transformation, using the information available, without bloating the automaton.

And that's what Segher proposed with the patch for the hook on the mailing
list.