Questions about NCEG

[Paul Eggert]

Doug Gwyn writes:

	The C standard supports use of IEEE floating-point.  However, it
	doesn't require that access be granted to all features of it, just the
	consistent subset chosen for the C implementation.

The question is whether an implementation can conform to both ANSI C and IEEE
754.  For example, IEEE 754 requires that -0.0 and 0.0 be distinguishable.
Suppose ANSI C somehow required that -0.0 and 0.0 be identical: then, because
the standards would be inconsistent, an implementation couldn't conform to both
standards.  O'Keefe's contention that IEEE 754 requires run-time
decimal<->binary conversion made me worry about this issue, because it would
make implementations impractical, but more careful reading of IEEE 754 seems to
have found a loophole in O'Keefe's argument.