On May 19, 2014 6:57:52 PM CEST, Jeff Law <l...@redhat.com> wrote: >On 05/19/14 06:54, Richard Biener wrote: >> >> In this PR we run into the issue that releasing SSA names from >> FRE/PRE elimination corrupts the VN lattice and thus the VN lookup >> we perform for removing redudnant stores ICEs. The patch works >> around the particular case by making unreachable code detection >> in SCCVN more optimistic by ignoring backedges during reachability >> computation and by not doing any elimination on unreachable blocks. >> >> I still have to think about a "proper" fix to the underlying issue >> (propagate_value_into_stmt updating stmts on our back). >> >> Bootstrap and regtest running on x86_64-unknown-linux-gnu. >> >> Richard. >> >> 2014-05-19 Richard Biener <rguent...@suse.de> >> >> PR tree-optimization/61221 >> * tree-ssa-pre.c (eliminate_dom_walker::before_dom_children): >> Do nothing for unreachable blocks. >> * tree-ssa-sccvn.c (cond_dom_walker::before_dom_children): >> Improve unreachability detection. >> >> * gcc.dg/torture/pr61221.c: New testcase. >Is this another case where having two lists rather than just one in the > >SSA_NAME manager would help? It's something I really need to sit down >and just do.
No, it's unfortunately not that easy. Richard. > >Jeff
