+static MAGIC *
+S_get_aux_mg(pTHX_ AV *av) {
+ dVAR;
+ MAGIC *mg;
+
+ PERL_ARGS_ASSERT_GET_AUX_MG;
+ assert(SvTYPE(av) == SVt_PVAV);
+
+ mg = mg_find((const SV *)av, PERL_MAGIC_arylen_p);
+
+ if (!mg) {
+ mg = sv_magicext(MUTABLE_SV(av), 0, PERL_MAGIC_arylen_p,
+ &PL_vtbl_arylen_p, 0, 0);
+ assert(mg);
+ /* sv_magicext won't set this for us because we pass in a NULL obj */
+ mg->mg_flags |= MGf_REFCOUNTED;
+ }
+ return mg;
+}
+
+SV **
+Perl_av_arylen_p(pTHX_ AV *av) {
+ MAGIC *const mg = get_aux_mg(av);
+
+ PERL_ARGS_ASSERT_AV_ARYLEN_P;
+ assert(SvTYPE(av) == SVt_PVAV);
+
+ return &(mg->mg_obj);
+}
+
+IV *
+Perl_av_iter_p(pTHX_ AV *av) {
+ MAGIC *const mg = get_aux_mg(av);
+
+ PERL_ARGS_ASSERT_AV_ITER_P;
+ assert(SvTYPE(av) == SVt_PVAV);
+
+#if IVSIZE == I32SIZE
+ return (IV *)&(mg->mg_len);
+#else
+ if (!mg->mg_ptr) {
+ IV *temp;
+ mg->mg_len = IVSIZE;
+ Newxz(temp, 1, IV);
+ mg->mg_ptr = (char *) temp;
+ }
+ return (IV *)mg->mg_ptr;
+#endif
+}
+