On Wed, Jul 30, 2014 at 4:31 AM, Katelyn Gadd <[email protected]> wrote:
> History has shown that native code developers concerned with > performance (game devs, graphics devs, etc) will happily use > approximations of these special functions when performance is > important, and will pick approximations with suitable accuracy. > > The inverse we have here, where the builtins have unpredictable > precision, requires developers to test on various os/browser > combinations to figure out whether they have precision issues, and if > they do, try to find an accurate high-precision sw implementation of > these builtins and use that. I think this will lead to a lot of > unreliable software out there on the web, and worse, lead to existing > apps breaking when new browser releases reduce precision/accuracy. > > If there's a strong desire for high-performance builtin sin, cos, etc > it could be reasonable to add Math.fastCos etc but I feel like most > developers would feel safer with approximations that have known > characteristics, so you should encourage that instead. > I think Math.fastCos would be difficult to specify. Only the developer really knows what the appropriate tradeoff between accuracy and speed should be. Math.fastCos probably won't satisfy that. > > On Tue, Jul 29, 2014 at 10:45 PM, Raymond Toy <[email protected]> > wrote: > > > > On Jul 29, 2014 5:47 AM, "alawatthe" <[email protected]> wrote: > >> > >> Clear rules would also help in discussions like this one: > >> https://code.google.com/p/v8/issues/detail?id=3006 > >> > >> Background: > >> V8 implemented a new version of sin and cos, which is faster, but does > not > >> have the precision many user want. > >> One of the comments (#8) said about precision: > >> > >> - The ECMA script specification clearly states that Math.sin/cos are > >> implementation-dependent approximations. There is no guarantees required > >> regarding precision. > >> > >> I think, this feels a little bit odd, because where do we draw the line > >> between performance and precision? > >> So, again clear rules (even if they are not as strict as in Java), would > >> help a lot. > > > > Yes. There are no requirements, but the spirit of the spec is clearly to > be > > accurate or at least no worse than fdlibm. > > > > Carried to the extreme, this lack of requirements allows implementations > to > > be conforming even if all functions returned 0 everywhere. Fortunately, > no > > one does that. > > > >> > >> All the best > >> alex aka alawatthe > >> > >> > >> _______________________________________________ > >> es-discuss mailing list > >> [email protected] > >> https://mail.mozilla.org/listinfo/es-discuss > >> > > > > > > _______________________________________________ > > es-discuss mailing list > > [email protected] > > https://mail.mozilla.org/listinfo/es-discuss > > >
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