[Bug rtl-optimization/85455] [8 Regression] ICE in verify_loop_structure, at cfgloop.c:1708 (error: basic block 3 should be marked irreducible)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85455

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Thu Apr 19 13:53:06 2018
New Revision: 259494

URL: https://gcc.gnu.org/viewcvs?rev=259494&root=gcc&view=rev
Log:
2018-04-19  Richard Biener  <rguent...@suse.de>

        PR middle-end/85455
        * cfg.c (clear_bb_flags): When loop state says we have
        marked irreducible regions also preserve BB_IRREDUCIBLE_LOOP.

        * gcc.dg/pr85455.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/pr85455.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/cfg.c
    trunk/gcc/testsuite/ChangeLog