[Bug rtl-optimization/56181] [4.8 Regression] ICE in verify_loop_structure, at cfgloop.c:1581 with -ftracer

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56181



--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> 2013-02-05 
15:58:32 UTC ---

(In reply to comment #4)

> Or maybe tracer shouldn't duplicate BB between headers, i.e. BB whose 
> successor

> and predecessor is a header.  Testing a patch for that...



Not sure what's so special about such block ... apart from making the

2nd loop not have a simple preheader.