[Bug middle-end/35204] [4.3 Regression] crash by too deep recursion in DFS tree-ssa-sccvn.c:1898

[steven at gcc dot gnu dot org]

------- Comment #6 from steven at gcc dot gnu dot org  2008-02-14 23:25 -------
Should be P1.

This bug is shows an intrinsic scalability problem with SCC-VN as it is
implemented right now (and presented in the literature).

The key issue is, SCC-VN should use a non-recursive SCC finding algorithm, but
one that still pops the SCCs in topological order.  I tried once to write
SCC-VN's DFS in a non-recursive way, but I never succeeded.  I also tried to
find a substitute for Tarjan's algorithm that possesses the properties required
for SCC-VN, but also failed there.

CCing Danny on this one for advice.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35204