https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83496
--- Comment #8 from Paul Hua <paul.hua.gm at gmail dot com> --- On GCC 8.x, the r248351 fixed this. commit fd891ec7f659e8785c3ed5757f6e60c95117b837 Author: segher <segher@138bc75d-0d04-0410-961f-82ee72b054a4> Date: Mon May 22 21:20:51 2017 +0000 cfgcleanup: Ignore clobbers in bb_is_just_return The function bb_is_just_return finds if the BB it is asked about does just a return and nothing else. It currently does not allow clobbers in the block either, which we of course can allow just fine. This patch changes that. * cfgcleanup.c (bb_is_just_return): Allow CLOBBERs. gcc/testsuite/ git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@248351 138bc75d-0d04-0410-961f-82ee72b054a4 Paul Hua