On Mar 25, 2013, at 6:00 PM, Brendan Eich wrote: > Right, thanks for the reminder. It all comes back now, including the "how to > write correct ending-independent typed array code" bit.
Ok, so looping back to my earlier observation. It sounds like endian-ness can be observed by writing into an Float64Array element and then reading back from a Uint8Array that is backed by the same buffer. If there is agreement that this doesn't represent a significant interoperability hazard can we also agree that not doing NaN cannonicalization on writes to FloatXArray is an even less significant hazard and need not be mandated? Allen > > /be > > On Mar 25, 2013, at 4:33 PM, Kenneth Russell <[email protected]> wrote: > >> On Mon, Mar 25, 2013 at 4:23 PM, Brendan Eich <[email protected]> wrote: >>> Allen Wirfs-Brock wrote: >>>> >>>> On Mar 25, 2013, at 4:05 PM, Brendan Eich wrote: >>>> >>>>> Allen Wirfs-Brock wrote: >>>>>> >>>>>> BTW, isn't cannonicalization of endian-ness for both integers and floats >>>>>> a bigger interop issue than NaN cannonicalization? I know this was >>>>>> discussed in the past, but it doesn't seem to be covered in the latest >>>>>> Khronos spec. Was there ever a resolution as to whether or not >>>>>> TypedArray >>>>>> [[Set]] operations need to use a cannonical endian-ness? >>>>> >>>>> Search for "byte order" at >>>>> https://www.khronos.org/registry/typedarray/specs/latest/. >>>> >>>> >>>> I had already search for "endian" with similar results. It says that the >>>> default for DataViews gets/sets that do not specify a byte order is >>>> big-endean. It doesn't say anything (that I can find) about such accesses >>>> on >>>> TypedArray gets/sets. >>> >>> >>> Oh, odd -- I recall that it used to say little-endian. Typed arrays are LE >>> to match dominant architectures, while DataViews are BE to match packed >>> serialization use-cases. >>> >>> Ken, did something get edited out? >> >> No. The typed array views (everything except DataView) have used the >> host machine's endianness from day one by design -- although the typed >> array spec does not state this explicitly. If desired, text can be >> added to the specification to this effect. Any change in this behavior >> will destroy the performance of APIs like WebGL and Web Audio on >> big-endian architectures. >> >> Correctly written code works identically on big-endian and >> little-endian architectures. See >> http://www.html5rocks.com/en/tutorials/webgl/typed_arrays/ for a >> detailed description of the usage of the APIs. >> >> DataView, which is designed for input/output, operates on data with a >> specified endianness. >> >> -Ken >> _______________________________________________ >> 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 > _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
