http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58920
--- Comment #1 from Jason Merrill <jason at gcc dot gnu.org> --- Created attachment 31109 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31109&action=edit Simplified testcase Here's a simplified version of one of the ext_pointer testcases. Compiling it with -O -fstrict-aliasing (and the attached front end patch) produces the bug.