[Bug tree-optimization/96669] New: Failure to optimize left shift+and to test for 0

[gabravier at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96669

            Bug ID: 96669
           Summary: Failure to optimize left shift+and to test for 0
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gabravier at gmail dot com
  Target Milestone: ---

int f(int x)
{
    return (1 << x) & 1;
}

This can be converted to `return x == 0;`. This transformation is done by LLVM,
but not by GCC.