floating point inconsistency

Vincent Lefevre vincent+gcc@vinc17.org
Wed Feb 17 14:35:00 GMT 2010

On 2010-02-16 09:14:58 +0100, Christoph Groth wrote:
> I am aware of the limited precision of floating point calculations.
> However, I assumed that on the processors in question these calculations
> are done according to IEEE standards, i.e. the results of are defined
> unambiguously.

Note that the old IEEE 754-1985 standard didn't consider elementary
functions such as sin and cos (only +, -, *, / and square root).
The current IEEE 754-2008 standard recommends that (some) elementary
functions be correctly rounded, but that's only a recommendation.

Vincent Lefèvre <vincent@vinc17.net> - Web: <http://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / Arénaire project (LIP, ENS-Lyon)

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