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When a value of real floating type is converted to a real floating type, if the value being converted can be represented exactly in the new type, it is unchanged. If the value being converted is in the range of values that can be represented but cannot be represented exactly, the result is either the nearest higher or nearest lower representable value, chosen in an implementation-defined manner. If the value being converted is outside the range of values that can be represented, the behavior is undefined.
See also undefined behaviors 17 and 18 in Annex J of the C Standard.
Consequently, in implementations that do not allow for the representation of all numbers, conversions of values between zero and FLT_MIN may result in undefined behavior.
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