Work around runtime engine deficiencies.

Work around runtime engine deficiencies.

This CL changes length access of typed arrays to a call to a runtime helper. That helper is an optimized version for V8, or a regular length access for other engines.

R=ahe@google.com, bak@google.com

Committed: https://code.google.com/p/dart/source/detail?r=26905

[bakster, 2013-08-30 07:56:27]

Great speedup despite the hack.
LGTM after comments have been addressed,
  Lars

https://codereview.chromium.org/23766002/diff/3001/sdk/lib/_internal/compiler...
File sdk/lib/_internal/compiler/implementation/ssa/codegen.dart (right):

https://codereview.chromium.org/23766002/diff/3001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/ssa/codegen.dart:1669: // TODO(...):
Remove this custom code for typed arrays once V8
Please replace ... with your name.

https://codereview.chromium.org/23766002/diff/3001/sdk/lib/typed_data/dart2js...
File sdk/lib/typed_data/dart2js/typed_data_dart2js.dart (right):

https://codereview.chromium.org/23766002/diff/3001/sdk/lib/typed_data/dart2js...
sdk/lib/typed_data/dart2js/typed_data_dart2js.dart:75: // TODO(...): Remove this
method once V8 optimizes length access of
Please add an Issues for these todos.

It might be appropriate to rename this method from
  _setHackLength
to
  _setCachedLength

[ahe, 2013-08-30 08:08:46]

Please add more documentation, if so LGTM

https://codereview.chromium.org/23766002/diff/3001/sdk/lib/typed_data/dart2js...
File sdk/lib/typed_data/dart2js/typed_data_dart2js.dart (right):

https://codereview.chromium.org/23766002/diff/3001/sdk/lib/typed_data/dart2js...
sdk/lib/typed_data/dart2js/typed_data_dart2js.dart:78: JS('void', r'#.HACK =
#.length', this, this);
Rename "HACK" to $dartCachedLength or something.

[ngeoffray, 2013-08-30 08:51:33]

Thanks Lars and Peter.

https://codereview.chromium.org/23766002/diff/3001/sdk/lib/_internal/compiler...
File sdk/lib/_internal/compiler/implementation/ssa/codegen.dart (right):

https://codereview.chromium.org/23766002/diff/3001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/ssa/codegen.dart:1669: // TODO(...):
Remove this custom code for typed arrays once V8
On 2013/08/30 07:56:27, bakster wrote:
> Please replace ... with your name.

Done.

https://codereview.chromium.org/23766002/diff/3001/sdk/lib/typed_data/dart2js...
File sdk/lib/typed_data/dart2js/typed_data_dart2js.dart (right):

https://codereview.chromium.org/23766002/diff/3001/sdk/lib/typed_data/dart2js...
sdk/lib/typed_data/dart2js/typed_data_dart2js.dart:75: // TODO(...): Remove this
method once V8 optimizes length access of
On 2013/08/30 07:56:27, bakster wrote:
> Please add an Issues for these todos.
> 
> It might be appropriate to rename this method from
>   _setHackLength
> to
>   _setCachedLength

Done.

https://codereview.chromium.org/23766002/diff/3001/sdk/lib/typed_data/dart2js...
sdk/lib/typed_data/dart2js/typed_data_dart2js.dart:78: JS('void', r'#.HACK =
#.length', this, this);
On 2013/08/30 08:08:47, ahe wrote:
> Rename "HACK" to $dartCachedLength or something.

Done.

[ngeoffray, 2013-08-30 09:17:12]

Committed patchset #3 manually as r26905 (presubmit successful).