[Bug tree-optimization/96921] New: Failure to optimize combined boolean not patterns

[gabravier at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96921

            Bug ID: 96921
           Summary: Failure to optimize combined boolean not patterns
           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: ---

_Bool f(_Bool a, _Bool b)
{
    return 1 - ((1 - a) & (1 - b));
}

This can be optimized to `return a | b;`. This transformation is done by LLVM,
but not by GCC.