In OpenGL 1.5 Spec. 2.1.1 Floating-Point Computation section, 2^32 was refered as the maximum representable magnitude of floating point numbers.

“…The maximum representable magnitude of a floating-point number

used to represent positional or normal coordinates must be at least 2^32; the maximum

representable magnitude for colors or texture coordinates must be at least 2^10.

The maximum representable magnitude for all other floating-point values must be

at least 2^32. x·0 = 0 ·x = 0 for any non-infinite and non-NaN x. 1 ·x = x·1 = x.

x+0 = 0+x = x. 00 = 1…”

Even there are 64 bit types, 2^64 accuracy was not mentioned. Can we simply say that none of the gl functions return floating point values in double (64 bit) precision?