int zerotail = 0; /* how many extra zeros to append */
int exponent = 0; /* exponent of the floating point input */
+ /* XXX: denormals, NaN, Inf.
+ *
+ * For example with denormals, (assuming the vanilla
+ * 64-bit double): the exponent is zero. 1xp-1074 is
+ * the smallest denormal and the smallest double, it
+ * should be output as 0x0.0000000000001p-1022 to
+ * match its internal structure. */
+
vend = S_hextract(aTHX_ nv, &exponent, vhex, NULL);
S_hextract(aTHX_ nv, &exponent, vhex, vend);