[Bug tree-optimization/80549] [7/8 Regression] wrong code at -O2 and -O3 in both 32-bit and 64-bit modes on x86_64-linux-gnu (executable does not terminate)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80549

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue May  2 11:24:52 2017
New Revision: 247486

URL: https://gcc.gnu.org/viewcvs?rev=247486&root=gcc&view=rev
Log:
2017-05-02  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/80549
        * tree-cfgcleanup.c (mfb_keep_latches): New helper.
        (cleanup_tree_cfg_noloop): Create forwarders to known loop
        headers if they do not have a preheader.

        * gcc.dg/torture/pr80549.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr80549.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-cfgcleanup.c