https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83301
Bug ID: 83301 Summary: [6 Regression] cgraph.c segfault Product: gcc Version: 6.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: henning.schild at siemens dot com Target Milestone: --- Trying to build an application fails on 6.3/6.4 but works on 5 and 7. I ran into that over two different call stacks: -- 0xa898af crash_signal ../.././gcc/toplev.c:333 0xbe3f2c find_func_aliases ../.././gcc/tree-ssa-structalias.c:4804 0xbeb1be compute_points_to_sets ../.././gcc/tree-ssa-structalias.c:7101 0xbeb1be compute_may_aliases() ../.././gcc/tree-ssa-structalias.c:7465 0x9d8dec execute_function_todo ../.././gcc/passes.c:1930 0x9d988b execute_todo ../.././gcc/passes.c:2010 -- 0xa898af crash_signal ../.././gcc/toplev.c:333 0xac0de4 is_complex_reg ../.././gcc/tree-complex.c:177 0xac0de4 init_dont_simulate_again ../.././gcc/tree-complex.c:231 0xac0de4 tree_lower_complex ../.././gcc/tree-complex.c:1646 0xac0de4 execute ../.././gcc/tree-complex.c:1772 -- Both happen with -O3 but not -O1. Bisecting why 7 works lead me to #78692 and backporting that fix to 6.4 solved the problem for both cases. Unfortunately i do not have a small piece of test-code to reproduce it. And the big piece i have can not easily be published. Maybe the reports contains enough information so we can go without that code.