-#define ST(s) stack_base[sp + s]
+#define ST(off) stack_base[ax + (off)]
+
+#ifdef CAN_PROTOTYPE
+#define XS(name) void name(CV* cv)
+#else
+#define XS(name) void name(cv) CV* cv;
+#endif
+
+#define dXSARGS \
+ dSP; dMARK; \
+ I32 ax = mark - stack_base + 1; \
+ I32 items = sp - mark
+
+#define XSANY CvXSUBANY(cv)
+
+#define dXSI32 I32 ix = XSANY.any_i32
+
+#define XSRETURN(off) stack_sp = stack_base + ax + ((off) - 1); return
+
+/* Simple macros to put new mortal values onto the stack. */
+/* Typically used to return values from XS functions. */
+#define XST_mIV(i,v) (ST(i) = sv_2mortal(newSViv(v)) )
+#define XST_mNV(i,v) (ST(i) = sv_2mortal(newSVnv(v)) )
+#define XST_mPV(i,v) (ST(i) = sv_2mortal(newSVpv(v,0)))
+#define XST_mNO(i) (ST(i) = &sv_no )
+#define XST_mYES(i) (ST(i) = &sv_yes )
+#define XST_mUNDEF(i) (ST(i) = &sv_undef)
+
+#define XSRETURN_IV(v) do { XST_mIV(0,v); XSRETURN(1); } while (0)
+#define XSRETURN_NV(v) do { XST_mNV(0,v); XSRETURN(1); } while (0)
+#define XSRETURN_PV(v) do { XST_mPV(0,v); XSRETURN(1); } while (0)
+#define XSRETURN_NO do { XST_mNO(0); XSRETURN(1); } while (0)
+#define XSRETURN_YES do { XST_mYES(0); XSRETURN(1); } while (0)
+#define XSRETURN_UNDEF do { XST_mUNDEF(0); XSRETURN(1); } while (0)
+#define XSRETURN_EMPTY do { XSRETURN(0); } while (0)
+
+#define newXSproto(a,b,c,d) sv_setpv((SV*)newXS(a,b,c), d)