On Tue, Mar 5, 2019 at 10:36 PM Jeff Law <l...@redhat.com> wrote: > > On 3/5/19 7:44 AM, Richard Biener wrote: > > > So fixing it properly with also re-optimize_stmt those stmts so we'd CSE > > the MAX_EXPR introduced by folding makes it somewhat ugly. > > > > Bootstrapped on x86_64-unknown-linux-gnu, testing in progress. > > > > Any ideas how to make it less so? I can split out making optimize_stmt > > take a gsi * btw, in case that's a more obvious change and it makes the > > patch a little smaller. > > > > Richard. > > > > 2019-03-05 Richard Biener <rguent...@suse.de> > > > > PR tree-optimization/89595 > > * tree-ssa-dom.c (dom_opt_dom_walker::optimize_stmt): Take > > stmt iterator as reference, take boolean output parameter to > > indicate whether the stmt was removed and thus the iterator > > already advanced. > > (dom_opt_dom_walker::before_dom_children): Re-iterate over > > stmts created by folding. > > > > * gcc.dg/torture/pr89595.c: New testcase. > > > > Well, all the real logic changs are in the before_dom_children method. > The bits in optimize_stmt are trivial enough to effectively ignore. > > I don't see a better way to discover and process statements that are > created in the bowels of fold_stmt.
I'm not entirely happy so I created the following alternative which is a bit larger and slower due to the pre-pass clearing the visited flag but is IMHO easier to follow. I guess there's plenty of TLC opportunity here but then I also hope to retire the VN parts of DOM in favor of the non-iterating RPO-VN code... So - I'd lean to this variant even though it has the extra loop over stmts, would you agree? Bootstrap / regtest running on x86_64-unknown-linux-gnu. Richard. 2019-03-06 Richard Biener <rguent...@suse.de> PR tree-optimization/89595 * tree-ssa-dom.c (dom_opt_dom_walker::optimize_stmt): Take stmt iterator as reference, take boolean output parameter to indicate whether the stmt was removed and thus the iterator already advanced. (dom_opt_dom_walker::before_dom_children): Re-iterate over stmts created by folding. * gcc.dg/torture/pr89595.c: New testcase.
fix-pr89595-2
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