Implement Object.is and Number.is[Finite,NaN] functions.

Implement Object.is and Number.is[Finite,NaN] functions.

R=rossberg@chromium.org
TEST=mjsunit/object-is,mjsunit/number-is

Committed: https://code.google.com/p/v8/source/detail?r=10965

[rossberg, 2012-03-08 12:42:26]

lgtm

https://chromiumcodereview.appspot.com/9630009/diff/1/src/v8natives.js
File src/v8natives.js (right):

https://chromiumcodereview.appspot.com/9630009/diff/1/src/v8natives.js#newcod...
src/v8natives.js:1264: return (obj1 !== 0) || ((1 / obj1) === (1 / obj2));
What's with all the redundant parentheses?

[Michael Starzinger, 2012-03-08 12:50:00]

Added new patch set. Landed.

https://chromiumcodereview.appspot.com/9630009/diff/1/src/v8natives.js
File src/v8natives.js (right):

https://chromiumcodereview.appspot.com/9630009/diff/1/src/v8natives.js#newcod...
src/v8natives.js:1264: return (obj1 !== 0) || ((1 / obj1) === (1 / obj2));
On 2012/03/08 12:42:26, rossberg wrote:
> What's with all the redundant parentheses?

Done.

[arv (Not doing code reviews), 2012-03-13 05:15:49]

https://chromiumcodereview.appspot.com/9630009/diff/4002/src/v8natives.js
File src/v8natives.js (right):

https://chromiumcodereview.appspot.com/9630009/diff/4002/src/v8natives.js#new...
src/v8natives.js:1263: if (obj1 === obj2) {
Why don't we use the SameValue function?

http://code.google.com/codesearch#OAMlx_jo-ck/src/v8/src/runtime.js&exact_pac...

[Michael Starzinger, 2012-03-13 09:02:08]

https://chromiumcodereview.appspot.com/9630009/diff/4002/src/v8natives.js
File src/v8natives.js (right):

https://chromiumcodereview.appspot.com/9630009/diff/4002/src/v8natives.js#new...
src/v8natives.js:1263: if (obj1 === obj2) {
On 2012/03/13 05:15:49, arv wrote:
> Why don't we use the SameValue function?
> 
>
http://code.google.com/codesearch#OAMlx_jo-ck/src/v8/src/runtime.js&exact_pac...

Yes we could use that function, but I didn't care much about making it perfect
because this is only an intermediate step. And frankly I didn't remember we had
SameValue(), I only remembered it's native counterpart JSObject::SameValue(). If
you are interested in the full story, here is how I want to proceed with the
egal operator implementation:

1) Have our backends generate optimized code for [[SameValue]] and expose it via
an %_SameValue() intrinsic.
2) Use the same generated code to implement the "is" keyword behind --harmony
flag.
3) Once the --harmony flag is gone, switch Object.is() to actually use the "is"
keyword.

[arv (Not doing code reviews), 2012-03-13 16:58:32]

On 2012/03/13 09:02:08, Michael Starzinger wrote:
> https://chromiumcodereview.appspot.com/9630009/diff/4002/src/v8natives.js
> File src/v8natives.js (right):
> 
>
https://chromiumcodereview.appspot.com/9630009/diff/4002/src/v8natives.js#new...
> src/v8natives.js:1263: if (obj1 === obj2) {
> On 2012/03/13 05:15:49, arv wrote:
> > Why don't we use the SameValue function?
> > 
> >
>
http://code.google.com/codesearch#OAMlx_jo-ck/src/v8/src/runtime.js&exact_pac...
> 
> Yes we could use that function, but I didn't care much about making it perfect
> because this is only an intermediate step. And frankly I didn't remember we
had
> SameValue(), I only remembered it's native counterpart JSObject::SameValue().
If
> you are interested in the full story, here is how I want to proceed with the
> egal operator implementation:
> 
> 1) Have our backends generate optimized code for [[SameValue]] and expose it
via
> an %_SameValue() intrinsic.
> 2) Use the same generated code to implement the "is" keyword behind --harmony
> flag.
> 3) Once the --harmony flag is gone, switch Object.is() to actually use the
"is"
> keyword.

Thanks. That makes sense to me.