_bpf_cmp
#define bpf_cmp_unlikely(LHS, OP, RHS) _bpf_cmp(LHS, OP, RHS, true)
ret = _bpf_cmp(LHS, !=, RHS, false); \
ret = _bpf_cmp(LHS, ==, RHS, false); \
ret = _bpf_cmp(LHS, >, RHS, false); \
ret = _bpf_cmp(LHS, >=, RHS, false); \
ret = _bpf_cmp(LHS, <=, RHS, false); \
ret = _bpf_cmp(LHS, <, RHS, false); \