very long double

Question

I know that for very long ints there is int64. Is there something similar for very long doubles? I want to save a number with a very big precision.

There is a _float128 type in newer gcc which is software floating point with <= 128 bit precision — osgx, Feb 03 '12 at 13:24

score 5 · Accepted Answer · answered Mar 17 '11 at 14:56

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long double is the largest standard type. If this isn't enough, you'll need a bignum library (e.g. GMP)

answered Mar 17 '11 at 14:56

Erik

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score 3 · Answer 2 · edited May 23 '17 at 10:33

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Have a look at:

What is the precision of long double in C++?

It depends upon the implementation.

I got a feeling there might be something in the new standard c++0x about long double, but I forget, will check shortly.

Edit: checked it, my bad, there is no change: long double is at least as good as double.

edited May 23 '17 at 10:33

Community

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answered Mar 17 '11 at 14:56

Tom

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score 3 · Answer 3 · answered Mar 17 '11 at 14:57

Try this out http://gmplib.org/

GMP is a free library for arbitrary precision arithmetic, operating on signed integers, rational numbers, and floating point numbers. There is no practical limit to the precision except the ones implied by the available memory in the machine GMP runs on. GMP has a rich set of functions, and the functions have a regular interface.

very long double

3 Answers3