roundTiesToEven

Jonathan Watt jwatt at jwatt.org
Sun Nov 11 05:23:00 PST 2007


liorean wrote:
> On 11/11/2007, Jonathan Watt <jwatt at jwatt.org> wrote:
>> I've noticed that rounding in the reference implementation is implemented using
>> IEEE roundTiesToEven, but in browsers .5 values appear to round towards zero.
>> Although roundTiesToEven is desirable from a computational point of view,
>> there's likely a significant risk that changing to this method could break some
>> existing ECMAScript.
> 
> That's really serious breakage

Well, it's likely only a small bug in the reference implementation rather than a
requirement of the specification, so not too big a deal I'd think.

> - books, tutorials, references and real
> world code all take for granted that halves alway round up.

Err, right. Round up, not round to zero. Thanks for the correction.




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