https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111294
--- Comment #11 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Biener <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:9ea74d235c7e7816b996a17c61288f02ef767985 commit r14-3982-g9ea74d235c7e7816b996a17c61288f02ef767985 Author: Richard Biener <rguent...@suse.de> Date: Thu Sep 14 09:31:23 2023 +0200 tree-optimization/111294 - better DCE after forwprop The following adds more aggressive DCE to forwprop to clean up dead stmts when folding a stmt leaves some operands unused. The patch uses simple_dce_from_worklist for this purpose, queueing original operands before substitution and folding, but only if we folded the stmt. This removes one dead stmt biasing threading costs in a later pass but it doesn't resolve the optimization issue in the PR yet. PR tree-optimization/111294 * tree-ssa-forwprop.cc (pass_forwprop::execute): Track operands that eventually become dead and use simple_dce_from_worklist to remove their definitions if they did so. * gcc.dg/tree-ssa/evrp10.c: Adjust. * gcc.dg/tree-ssa/evrp6.c: Likewise. * gcc.dg/tree-ssa/forwprop-31.c: Likewise. * gcc.dg/tree-ssa/neg-cast-3.c: Likewise.
