F.2.7 Arithmetic Operations on Exceptional Values (Sun Studio 12: C User's Guide)

Sun Studio 12: C User's Guide

F.2.7 Arithmetic Operations on Exceptional Values

This section describes the results derived from applying the basic arithmetic operations to combinations of exceptional and ordinary floating-point values. The information that follows assumes that no traps or any other exception actions are taken.

The following table explains the abbreviations:

Table F–16 Abbreviation Usage


Abbreviation	Meaning
Num	Subnormal or normal number
Inf	Infinity (positive or negative)
NaN	Not a number
Uno	Unordered

The following tables describe the types of values that result from arithmetic operations performed with combinations of different types of operands.

Table F–17 Addition and Subtraction Results


	Right Operand: 0	Right Operand: Num	Right Operand: Inf	Right Operand: NaN
Left Operand: 0	0	Num	Inf	NaN
Left Operand: Num	Num	See [Num + Num could be Inf, rather than Num, when the result is too large (overflow). Inf + Inf = NaN when the infinities are of opposite `sign`.]	Inf	NaN
Left Operand: Inf	Inf	Inf	See	NaN
Left Operand: NaN	NaN	NaN	NaN	NaN

Table F–18 Multiplication Results


	Right Operand:0	Right Operand:Num	Right Operand:Inf	Right Operand:NaN
Left Operand:0	0	0	NaN	NaN
Left Operand: Num	0	Num	Inf	NaN
Left Operand: Inf	NaN	Inf	Inf	NaN
Left Operand: NaN	NaN	NaN	NaN	NaN

Table F–19 Division Results


	Right Operand:0	Right Operand:Num	Right Operand:Inf	Right Operand:NaN
Left Operand:0	NaN	0	0	NaN
Left Operand: Num	Inf	Num	0	NaN
Left Operand: Inf	Inf	Inf	NaN	NaN
Left Operand: NaN	NaN	NaN	NaN	NaN

Table F–20 Comparison Results


	Right Operand:0	Right Operand:+Num	Right Operand:+Inf	Right Operand:+NaN
Left Operand:0	=	<	<	Uno
Left Operand: +Num	>	The result of the comparison	<	Uno
Left Operand: +Inf	>	>	=	Uno
Left Operand: +NaN	Uno	Uno	Uno	Uno

Note –

NaN compared with NaN is unordered, and results in inequality. +0 compares equal to- 0.