[Bug debug/31412] [4.3] inf loop/long compile time, time spent in var-tracking.c

[zadeck at naturalbridge dot com]

------- Comment #14 from zadeck at naturalbridge dot com  2007-04-03 16:47 -------
Subject: Re:  [4.3] inf loop/long compile time, time spent
 in var-tracking.c

steven at gcc dot gnu dot org wrote:
> ------- Comment #13 from steven at gcc dot gnu dot org  2007-04-03 16:40 -------
> So this may be a non-monotonous dataflow problem...?
>
> Do we have the dataflow equations of the var-tracking problem somewhere?  It'd
> be interesting to check them against the actual implementation.
>
>
>   
this is a pretty complex problem.  I gave it a cursory once over and it
looks like the problem may not terminate if the location (stack offset)
of a variable is not the same on all paths into a block.  (the code may
be different than the comments and i did just scan this) I assume that
this case has a "bug" where a variable appears to be at a different
location coming across an exception edge. 


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31412