On Mon, Jun 23, 2014 at 7:32 AM, Chung-Lin Tang <clt...@codesourcery.com> wrote: > Hi Richard, > > In this change: > https://gcc.gnu.org/ml/gcc-patches/2014-06/msg01278.html > > where substitute_and_fold() was changed to use a dom walker, the calls > to purge dead EH edges during the walk can alter the dom-tree, and have > chaotic results; the testcase in PR 61554 has some blocks traversed > twice during the walk, causing the segfault during CCP. > > The patch records the to-be-purged-for-dead-EH blocks in a similar > manner like stmts_to_remove, and processes it after the walk. (another > possible method would be using a bitmap to record the BBs + calling > gimple_purge_all_dead_eh_edges...)
Oops. > Bootstrapped and tested on x86_64-linux, is this okay for trunk? Can you please use a bitmap and use gimple_purge_all_dead_eh_edges like tree-ssa-pre.c does? Also please add the reduced testcase from the PR to the g++.dg/torture Ok with that changes. Thanks, Richard. > Thanks, > Chung-Lin > > 2014-06-23 Chung-Lin Tang <clt...@codesourcery.com> > > PR tree-optimization/61554 > * tree-ssa-propagate.c (substitute_and_fold_dom_walker): > Add 'vec<basic_block> bbs_to_purge_dead_eh_edges' member, > properly update constructor/destructor. > (substitute_and_fold_dom_walker::before_dom_children): > Remove call to gimple_purge_dead_eh_edges, add bb to > bbs_to_purge_dead_eh_edges instead. > (substitute_and_fold): Call gimple_purge_dead_eh_edges for > bbs recorded in bbs_to_purge_dead_eh_edges.
