On Wed, Mar 6, 2019 at 11:05 AM Richard Biener <richard.guent...@gmail.com> wrote: > > 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?
I have now applied this variant. Richard. > 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.