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Numbers in the single and double formats are composed of the following
three fields:
- 1.
- 1-bit sign s
- 2.
- Biased exponent e = E + bias
- 3.
- Fraction
![$f= \bullet b_{1} b_{2} \cdots b_{p-1}$](img40.gif)
The range of the unbiased exponent E shall include every integer
between two values Emin and Emax, inclusive, and
also two other reserved values Emin-1 to encode
±0 and
denormalized numbers, and Emax+1 to encode
and
NaNs. The foregoing parameters are given in Table H.1.
Each nonzero numerical value has just one encoding. The fields are
interpreted as follows:
Table H.1:
Summary of Format Parameters
|
Format
|
Parameter |
Single |
Single Extended |
Double |
Double Extended |
p |
24 |
![$\geq 32$](img42.gif) |
53 |
![$\geq 64$](img43.gif) |
Emax |
+127 |
![$\geq +1023$](img44.gif) |
+1023 |
![$\geq +16383$](img45.gif) |
Emin |
-126 |
![$\leq -1022$](img46.gif) |
-1022 |
![$\leq -16382$](img47.gif) |
Exponent bias |
+127 |
unspecified |
+1023 |
unspecified |
Exponent width in bits |
8 |
![$\geq 11$](img48.gif) |
11 |
![$\geq 15$](img49.gif) |
Format width in bits |
32 |
![$\geq 43$](img50.gif) |
64 |
![$\geq 79$](img51.gif) |
Next: H.1.1 Single
Up: H IEEE Floating Point
Previous: H IEEE Floating Point
5/13/1999