On Unsafe.defineAnonymousClass-intensive benchmarks, you can see this branch in profiler:

  5.794 (12%) InstanceKlass::link_class(Thread*)
    1.141 (2%) Verifier::verify(instanceKlassHandle,Verifier::Mode,bool,Thread*)
      0.841 (2%) Klass::external_name()const

Anonymous classes are not verified, but we do useless work before checking for that with is_eligible_for_verification:

 101 Symbol* exception_name = NULL;
 102 const size_t message_buffer_len = klass->name()->utf8_length() + 1024;
 103 char* message_buffer = NEW_RESOURCE_ARRAY(char, message_buffer_len);
 104 char* exception_message = message_buffer;
 105
 106 const char* klassName = klass->external_name();
 107 bool can_failover = FailOverToOldVerifier &&
 108 klass->major_version() < NOFAILOVER_MAJOR_VERSION;
 109
 110 // If the class should be verified, first see if we can use the split
 111 // verifier. If not, or if verification fails and FailOverToOldVerifier
 112 // is set, then call the inference verifier.
 113 if (is_eligible_for_verification(klass, should_verify_class)) {