-#define HvKEYS(hv) ((XPVHV*) SvANY(hv))->xhv_keys
-#define HvRITER(hv) ((XPVHV*) SvANY(hv))->xhv_riter
-#define HvEITER(hv) ((XPVHV*) SvANY(hv))->xhv_eiter
-#define HvPMROOT(hv) ((XPVHV*) SvANY(hv))->xhv_pmroot
-#define HvNAME(hv) ((XPVHV*) SvANY(hv))->xhv_name
+/* This quite intentionally does no flag checking first. That's your
+ responsibility. */
+#define HvAUX(hv) ((struct xpvhv_aux*)&(HvARRAY(hv)[HvMAX(hv)+1]))
+#define HvRITER(hv) (*Perl_hv_riter_p(aTHX_ (HV*)(hv)))
+#define HvEITER(hv) (*Perl_hv_eiter_p(aTHX_ (HV*)(hv)))
+#define HvRITER_set(hv,r) Perl_hv_riter_set(aTHX_ (HV*)(hv), r)
+#define HvEITER_set(hv,e) Perl_hv_eiter_set(aTHX_ (HV*)(hv), e)
+#define HvRITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_riter : -1)
+#define HvEITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_eiter : 0)
+#define HvNAME(hv) HvNAME_get(hv)
+/* FIXME - all of these should use a UTF8 aware API, which should also involve
+ getting the length. */
+/* This macro may go away without notice. */
+#define HvNAME_HEK(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_name : 0)
+#define HvNAME_get(hv) ((SvOOK(hv) && (HvAUX(hv)->xhv_name)) \
+ ? HEK_KEY(HvAUX(hv)->xhv_name) : 0)
+#define HvNAMELEN_get(hv) ((SvOOK(hv) && (HvAUX(hv)->xhv_name)) \
+ ? HEK_LEN(HvAUX(hv)->xhv_name) : 0)
+
+/* the number of keys (including any placeholers) */
+#define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys)
+
+/*
+ * HvKEYS gets the number of keys that actually exist(), and is provided
+ * for backwards compatibility with old XS code. The core uses HvUSEDKEYS
+ * (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders)
+ */
+#define HvKEYS(hv) HvUSEDKEYS(hv)
+#define HvUSEDKEYS(hv) (HvTOTALKEYS(hv) - HvPLACEHOLDERS_get(hv))
+#define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv))
+#define HvPLACEHOLDERS(hv) (*Perl_hv_placeholders_p(aTHX_ (HV*)hv))
+#define HvPLACEHOLDERS_get(hv) (SvMAGIC(hv) ? Perl_hv_placeholders_get(aTHX_ (HV*)hv) : 0)
+#define HvPLACEHOLDERS_set(hv,p) Perl_hv_placeholders_set(aTHX_ (HV*)hv, p)