[Bug tree-optimization/22630] [4.1 Regression] vrp produces wrong code

[ja2morri at csclub dot uwaterloo dot ca]

------- Additional Comments From ja2morri at csclub dot uwaterloo dot ca  2005-07-27 16:34 -------
Subject: Re:  [4.1 Regression] vrp produces
 wrong code


Jeffrey A Law <law@redhat.com> writes:

> The underlying problem here is the code to meet a VR_ANTI_RANGE and
> a VR_RANGE does not intersect the equivalence sets.  This in turn
> causes the VRP code to incorrectly evaluate a conditional.  It's
> all downhill after that.
>
> While investigating this problem I also noticed that the vrp_meet
> code does not properly handle intersecting the equivalence sets
> when vr0 has a set, but vr1 does not (their intersection is the
> null set of course).  This patch fixes that oversight as well.
>
> Bootstrapped and regression tested on i686-pc-linux-gnu.
>
> jeff

 You added 3 bitmap_clear calls here, do you have any testcases that
exercise this code?



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22630