[Bug sanitizer/69656] New: -fsanitize=undefined compile time hog

["trippels at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69656

            Bug ID: 69656
           Summary: -fsanitize=undefined compile time hog
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: sanitizer
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trippels at gcc dot gnu.org
                CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
                    jakub at gcc dot gnu.org, kcc at gcc dot gnu.org
  Target Milestone: ---

Created attachment 37573
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37573&action=edit
testcase

The compile time for the attached testcase increases from 
~4o sec (-O2) to 3:32 minutes (-O2 -fsanitize=undefined).

(clang: from 1 minute to 1:30 minutes)