Improve creating external array buffer in d8.

Improve creating external array buffer in d8.


BUG=
TEST=

[Yang, 2012-06-29 09:54:50]

PTAL.

[rossberg, 2012-06-29 09:56:36]

I'm confused. Are you sure that this doesn't break instanceof and .constructor?

[Yang, 2012-06-29 10:49:02]

On 2012/06/29 09:56:36, rossberg wrote:
> I'm confused. Are you sure that this doesn't break instanceof and
.constructor?

Not sure what you mean.

var a = new Array(3);
var b = new Float32Array(a);
print(b instanceof ArrayBuffer);
print(b instanceof Float32Array);
print(b.constructor)

returns the same result with and without the patch:

false
true
function Float32Array() { [native code] }

[rossberg, 2012-06-29 11:03:29]

On 2012/06/29 10:49:02, Yang wrote:
> On 2012/06/29 09:56:36, rossberg wrote:
> > I'm confused. Are you sure that this doesn't break instanceof and
> .constructor?
> 
> Not sure what you mean.
> 
> var a = new Array(3);
> var b = new Float32Array(a);
> print(b instanceof ArrayBuffer);
> print(b instanceof Float32Array);
> print(b.constructor)
> 
> returns the same result with and without the patch:
> 
> false
> true
> function Float32Array() { [native code] }

Try:

var a = new Int32Array(10)
var b = a.buffer
print(b instanceof ArrayBuffer)
print(b.constructor)

I'm sure that e.g. the first print will not give "true". (Hm, I thought I had
written tests for that.)

[rossberg, 2012-06-29 11:07:15]

On 2012/06/29 11:03:29, rossberg wrote:
> (Hm, I thought I had written tests for that.)

I just checked, and it indeed seems like I forgot to cover that case. Can you
please add respective tests to mjsunit/external-array.js?

[Yang, 2012-06-29 11:17:38]

On 2012/06/29 11:07:15, rossberg wrote:
> On 2012/06/29 11:03:29, rossberg wrote:
> > (Hm, I thought I had written tests for that.)
> 
> I just checked, and it indeed seems like I forgot to cover that case. Can you
> please add respective tests to mjsunit/external-array.js?

I see. Never mind then.