+doubleinfbytes (infnan.U):
+ This variable contains comma-separated list of hexadecimal bytes
+ for the double precision infinity.
+
+doublekind (longdblfio.U):
+ This variable, if defined, encodes the type of a double:
+ 1 = IEEE 754 32-bit little endian,
+ 2 = IEEE 754 32-bit big endian,
+ 3 = IEEE 754 64-bit little endian,
+ 4 = IEEE 754 64-bit big endian,
+ 5 = IEEE 754 128-bit little endian,
+ 6 = IEEE 754 128-bit big endian,
+ 7 = IEEE 754 64-bit mixed endian le-be,
+ 8 = IEEE 754 64-bit mixed endian be-le,
+ -1 = unknown format.
+
+doublemantbits (mantbits.U):
+ This symbol, if defined, tells how many mantissa bits
+ there are in double precision floating point format.
+ Note that this is usually DBL_MANT_DIG minus one, since
+ with the standard IEEE 754 formats DBL_MANT_DIG includes
+ the implicit bit which doesn't really exist.
+
+doublenanbytes (infnan.U):
+ This variable contains comma-separated list of hexadecimal bytes
+ for the double precision not-a-number.
+