Fix dartbug.com/17261

Fix dartbug.com/17261
- Make sure to preserve type arguments when morphing a growable
  array to a fixed sized array.
- Small performance optimization for getting the number of type
  parameters in a class.

R=asiva@google.com, regis@google.com

Committed: https://code.google.com/p/dart/source/detail?r=33286

[regis, 2014-03-04 17:41:40]

LGTM

https://codereview.chromium.org/186673003/diff/1/runtime/vm/object.cc
File runtime/vm/object.cc (right):

https://codereview.chromium.org/186673003/diff/1/runtime/vm/object.cc#newcode...
runtime/vm/object.cc:12840: const intptr_t num_type_params =
cls.NumTypeParameters(isolate);
Passing the isolate looks really strange to me. Why only here and not everywhere
else? Did it show on the profile?

[srdjan, 2014-03-04 17:57:06]

DBC

https://codereview.chromium.org/186673003/diff/1/runtime/vm/object.cc
File runtime/vm/object.cc (right):

https://codereview.chromium.org/186673003/diff/1/runtime/vm/object.cc#newcode...
runtime/vm/object.cc:12838: Isolate* isolate = Isolate::Current();
Why not move this up and use it for all handles?

[siva, 2014-03-04 18:02:09]

lgtm

https://codereview.chromium.org/186673003/diff/1/runtime/vm/object.cc
File runtime/vm/object.cc (right):

https://codereview.chromium.org/186673003/diff/1/runtime/vm/object.cc#newcode...
runtime/vm/object.cc:12838: Isolate* isolate = Isolate::Current();
I would not move it up as there seem to be number of escapes from the function
in the code above which do not need an Isolate and by moving this up we would
unnecessarily get the isolate in those cases.


On 2014/03/04 17:57:07, srdjan wrote:
> Why not move this up and use it for all handles?

[Ivan Posva, 2014-03-04 18:08:59]

https://codereview.chromium.org/186673003/diff/1/runtime/vm/object.cc
File runtime/vm/object.cc (right):

https://codereview.chromium.org/186673003/diff/1/runtime/vm/object.cc#newcode...
runtime/vm/object.cc:12838: Isolate* isolate = Isolate::Current();
On 2014/03/04 18:02:10, siva wrote:
> I would not move it up as there seem to be number of escapes from the function
> in the code above which do not need an Isolate and by moving this up we would
> unnecessarily get the isolate in those cases.
> 
> 
> On 2014/03/04 17:57:07, srdjan wrote:
> > Why not move this up and use it for all handles?

As Siva says, but added it to the handle allocations below.

https://codereview.chromium.org/186673003/diff/1/runtime/vm/object.cc#newcode...
runtime/vm/object.cc:12840: const intptr_t num_type_params =
cls.NumTypeParameters(isolate);
On 2014/03/04 17:41:41, regis wrote:
> Passing the isolate looks really strange to me. Why only here and not
everywhere
> else? Did it show on the profile?
Yes.

[Ivan Posva, 2014-03-04 18:20:06]

Committed patchset #1 manually as r33286 (presubmit successful).