I probably made too general statement in this topic. However for the PRE case, I believe the choice of not using UNKNOWN location is still better.
thanks, David On Thu, Nov 15, 2012 at 9:23 AM, Eric Botcazou <ebotca...@adacore.com> wrote: >> The randomness here means that if we set UNKNOWN_LOCATION to insn, it >> can get source location anywhere. Even with some small code layout >> changes, the location for that insn could change. I would hope that in >> the future, we add an assertion when emitting instruction to enforce >> that INSN_LOCATION is never UNKNOWN_LOCATION. So when generate new >> instructions/stmts, if we can surely know where it is coming from, it >> is fine. Otherwise, instead of using UNKNOWN_LOCATION, we will set its >> location to where it is inserted. How does that sound? > > Still the same problem: you cannot make that a general rule, since you don't > know the coverage status of the instruction just above the insertion point. > If a later optimization moves the new statements around, you may well end up > with wrong coverage info. > > -- > Eric Botcazou
