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Re: Line number notes revamp?


> Richard Henderson wrote:-
> 
> > > You need column number as well.
> > 
> > No I don't.  We don't have one now.  Further, I thought Niel was
> > talking about hashing file+line+column together into a single number.
> 
> No, I've put file + line into a single number, but since we wanted to
> be able to support really large files, column numbers will be a
> separate 16-bit quantity to line numbers.  I have no intention of
> doing much else in this area; I don't think much can be done.

I was thinking about reserving separate field in instruction overnight too.
I believe it should be done in a way that the field points to LINFO RTX,
that has needed information - that way we can add column or whatever
we want later w/o renumbering fields in the INSN rtx itself.

Also I see one problem with GCOV.  For that pass our current behaviour
is far supperrior to the notes on instructions.  Be I see that:
1) in longer term, profiling should be very first optimization pass, so we can
   kill line notes afterwards
2) it may make sense to give up gcov on the optimized code in short term, as it
   don't work currently perfectly anyway.

Otherwise if the plan sounds resonable, I will probably invest my time into
it, once I am finished with the CFG cleanups I am working on currently.

Concerning the new inssn - I agree that for spilling code we don't want
to attach line number.  Case where we want to is instruction splitting and
combinning, so we definitly need to be able do both.

Concerning multiple statements per single instruction - I am also not quite
sure it makes sense. Is there some debug format able to do that?

Honza
> Neil.


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