Inside Macintosh: PowerPC Numerics / Part 3 - Appendixes

Appendix F - PowerPC Assembly-Language Numerics Reference

Floating-Point Data Formats

Figure F-1 Floating-point data formats

Table F-1 Interpreting floating-point values

If biased exponent e is:	And fraction f is:	Then value v is:	And class of v is:
	(any)	$v\; =\; (-1)s\times 2(e+-bias)\times (1.f)$	Normalized number
$e\; =\; 0$	$f$ 0	$v\; =\; (-1)s\times 2minexp\times (0.f)$ [78]	Denormalized number
$e\; =\; 0$	$f\; =\; 0$	$v\; =\; (-1)s\times 0$	Zero
$e\; =\; max$	$f\; =\; 0$	$v\; =\; (-1)s\times$	Infinity
$e\; =\; max$	$f$ 0	$v\; =\; NaN$	NaN

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[77] max = 255 for single format, 2047 for double format.

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[78] minexp = -126 for single format, -1022 for double format.