[Bug tree-optimization/67328] New: range test rather than single bit test for code testing enum values

[amodra at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67328

            Bug ID: 67328
           Summary: range test rather than single bit test for code
                    testing enum values
           Product: gcc
           Version: 5.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: amodra at gmail dot com
  Target Milestone: ---

The attached file generates ideal code, a test of a single bit, for the
condition in test_pic or test_exe depending on -DALT.  gcc ought to be able to
optimise to a single bit test for both functions whether or not -DALT.  It
looks like gcc incorrectly prefers a range test.