[shmolyneaux]

The floating point error problem has not been solved. This patent describes a floating-point representation that includes fields for storing error information. The standard IEEE floating-point representation has three fields: a sign field, an exponent field, and a mantissa (or significand). This patent proposes reducing the size of other fields and adding additional fields to store error information. The error information would be updated by hardware during regular operations. The patent proposed adding a configurable amount of precision to the numbers. If an operation exceeds this limit, an insufficient significant bits signal "sNaN(isb)" would be raised.

Not only does this method not reduce floating point error, it reduces the precision that you have for any given number of bits.

Unfortunately I can't find any of the figures referenced in the patent to help me understand the novelty of this patent.

[kbenson]

It depends on how you interpret "floating point error". If by that you mean the error the error inherent in the representation, it actually increases that through loss of precision, as you note. If you interpret it as "problems caused by lack of precision in floating point" (i.e. the patriot missile problem references in the article is a "floating point error"), then the tracking of precision will allow you to easily know when you've hit an error threshold that is unacceptable, allowing you to avoid those problems.

[enervate]

how is this better than checking if its within some value by some epsilon manually?

[jovial_cavalier]

> If an operation exceeds this limit, an insufficient significant bits signal "sNaN(isb)" would be raised.

What about for binary repeating decimals like 0.3? Wouldn't it always raise that signal?

[oh_sigh]

Presumably if you specify that you want more units of precision than are available, then yes. But if you say you only want 1 significant digit, then it can store it.

[_bxg1]

Yeah. It seems like just a clever mitigation technique, which could prove useful in the fields he mentioned (military, industrial, etc.), but it's far from the wholesale solution he claims.