[Bug rtl-optimization/40761] IRA memory hog for insanely nested loops

[vmakarov at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40761

--- Comment #17 from Vladimir Makarov <vmakarov at redhat dot com> 2012-01-19 20:42:57 UTC ---
  The problem was in building CFG loops which took the most of time.   CFG
loops were built even if we don't use regional allocation as for -O0.

  I'll send a patch soon.  It is not small because IRA in any case uses one
region with CFG loop representing the whole function.