float? double?

[Dave Thompson]

I think the name "double" probably comes from Fortran, where "DOUBLE
PRECISION" is exactly twice the size of "FLOAT". (I'm not much of a
Fortran person, so I could easily be mistaken.)

<OT> In Fortran -- which at the time C was created was still uppercase
FORTRAN -- the type names are REAL and DOUBLE PRECISION. (Combination
mnemonic and flamebait: God is real, unless declared integer. <G>)

Double is indeed required to occupy twice as much space in storage as
single, and single float to occupy the same space as INTEGER (of which
standard FORTRAN had only one width, although INTEGER*2 INTEGER*4 etc.
were a fairly common extension). However both/all of these can have
unused bits, so double doesn't necessarily have twice the precision of
single, although it must be at least one bit more. And similarly it
needn't have a larger exponent range, although often it does.

- David.Thompson1 at worldnet.att.net