https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122843
--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> --- Created attachment 62901 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=62901&action=edit debugging patch A bit of debugging, dump when we re-simplify. Applying pattern match.pd:2085, gimple-match-8.cc:1893 resimplify nop_expr_614 resimplify nop_expr_353 Applying pattern match.pd:5661, gimple-match-7.cc:7671 Applying pattern match.pd:5778, gimple-match-7.cc:7729 Applying pattern match.pd:2302, gimple-match-4.cc:2120 resimplify nop_expr_353 Applying pattern match.pd:2302, gimple-match-4.cc:2120 Applying pattern match.pd:2085, gimple-match-8.cc:1893 resimplify nop_expr_575 resimplify nop_expr_353 Applying pattern match.pd:5661, gimple-match-7.cc:7671 Applying pattern match.pd:5778, gimple-match-7.cc:7729 I'll note the testcase is a bit big, but likely a GIMPLE testcase from before forwprop4 could cut it down for easier analysis.
