[Bug rtl-optimization/56921] [4.9 Regression] ICE in rtx_cost called by doloop_optimize_loops for PPC

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56921

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.9.0

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> 2013-04-12 07:46:01 UTC ---
niter_desc is not marked GTY(()) but is cached from struct loop aux field.
niter_desc uses heap memory but points to GC memory.  Thus, caching of this
across passes is not safe.

I suppose passes are missing free_simple_loop_desc, loop-doloop.c calls
get_simple_loop_desc but never free_simple_loop_desc for example (which
then at least leaks the niter_desc memory).