[fpc-devel] format function

Jonas Maebe jonas.maebe at elis.ugent.be
Thu Oct 12 15:46:23 CEST 2006


On 12 okt 2006, at 15:41, Пётр Косаревский wrote:

> In the othe case, if the user is supposed to understand, that he  
> looks at some representation of binary representation of a real  
> number, "-0.000" obviously means "little negative number".

No, it means the value 0, but with a negative sign. The value "-0" is  
representable in an exact way on any IEEE standard-compliant fpu. The  
reason is that fpu's have a separate bit to store the sign. So even  
if the mantissa and exponent show that it's the value zero, the sign  
bit can still be one (meaning that it's a negative zero). And for  
some fpu calculations this even matters.


Jonas


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