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Bias
is chosen as follows
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Let
e be the number of bits in the exponent
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bias =
2(e-1)-1
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Gives
exponents in range -bias +1 to bias
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e=8
=> bias is 127
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=> min exponent
= -126 = 00000001
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=> max exponent = 127
= 11111110
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What
about 11111111?
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Used
to represent NaN - Not a Number
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Could
be caused by overflow or underflow
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What
about 00000000?
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If
mantissa is zero => the number 0
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Note
this is special, since a leading one is usually implicit
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If
mantissa is non-zero => denormalized numbers
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Numbers
where leading bit is not 1
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Depending
on implementation, may cause an
underflow
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Too
small a number
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