[Bug tree-optimization/96674] New: Failure to optimize combination of comparisons to dec+compare

[gabravier at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96674

            Bug ID: 96674
           Summary: Failure to optimize combination of comparisons to
                    dec+compare
           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(unsigned a, unsigned b)
{
    return (b == 0) | (a < b);
}

This can be optimized to `return a <= (b - 1);`. This transformation is done by
LLVM, but not by GCC.