64-bit float

[sargx]

Can anyone explain to me how a floating point number is handled on a 64 bit architecture?

in this form:


|_|_________|_______________|
a b c



where
a is the sign bit
b is the exponent
and c is the mantissa


I'm just curious how exactly the assign the spacing whether it's 1, 31,32, or what.

[avenger_jcc]

*plays the jeopardy theme* I havent a CLUE. WTF is a mantissa??
*shrug* sorry, this is WAY above me

[xmaddness]

Here it is in laymans terms for others reading.

In programming there are two types of ways to declare a number as a variable.

• int - for integers that don't have a decimal. ie... 1, 2, 3, 4, 5, etc..
  
• float - for numbers with decimals. ie... 2.3487, 234.22, 2.564, etc..

An int variable stores its number in a 32 bit binary value. the first bit is a sign bit: 0 is + number, and 1 is a - number.

Floats are a bit different. A 64-bit float uses:

|___|__________|____________________________|
1bit (sign) 11bit (exponent) 52bit (mantissa)


hope that helps