[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 #8 from Richard Biener <rguenth at gcc dot gnu.org> 2013-02-06 14:20:30 UTC ---
Created attachment 29368
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29368
patch to make flow_loops_find work in-place

One idea is, as in the attached patch, to unify flow_loops_find and
fix_loop_structure.  Basically re-discover loops, but in-place.

Doesn't work as-is - loop size is off for some reason.

This way fix_loop_structure would also discover new loops (and eventually
we'd simply run it at loop_optimizer_init time - which of course will hide
pass bugs).