Improve performance of String.fromCharCodes by implementing it in Dart. Add tow internal natives to…

Improve performance of String.fromCharCodes by implementing it in Dart. Add tow internal natives to Dart in order to be able to allocate and fill a String. Next step is to implement String.concatAll in Dart as well and to inline String._setAt operation (currently intrinsified).

R=asiva@google.com

Committed: https://code.google.com/p/dart/source/detail?r=22399

[siva, 2013-05-03 23:05:01]

LGTM with couple of comments.

https://codereview.chromium.org/14862006/diff/1/runtime/vm/intrinsifier_x64.cc
File runtime/vm/intrinsifier_x64.cc (right):

https://codereview.chromium.org/14862006/diff/1/runtime/vm/intrinsifier_x64.c...
runtime/vm/intrinsifier_x64.cc:1498: __ movl(RDI, length_reg);
movq

https://codereview.chromium.org/14862006/diff/9001/runtime/lib/string.cc
File runtime/lib/string.cc (right):

https://codereview.chromium.org/14862006/diff/9001/runtime/lib/string.cc#newc...
runtime/lib/string.cc:131: const String& receiver =
String::CheckedHandle(arguments->NativeArgAt(0));
May be do a GET_NON_NULL_NATIVE_ARGUMENT(...)

https://codereview.chromium.org/14862006/diff/9001/runtime/vm/intrinsifier_x6...
File runtime/vm/intrinsifier_x64.cc (right):

https://codereview.chromium.org/14862006/diff/9001/runtime/vm/intrinsifier_x6...
runtime/vm/intrinsifier_x64.cc:1498: __ movl(RDI, length_reg);
movq instead of movl.

[srdjan, 2013-05-03 23:36:37]

https://codereview.chromium.org/14862006/diff/1/runtime/vm/intrinsifier_x64.cc
File runtime/vm/intrinsifier_x64.cc (right):

https://codereview.chromium.org/14862006/diff/1/runtime/vm/intrinsifier_x64.c...
runtime/vm/intrinsifier_x64.cc:1498: __ movl(RDI, length_reg);
On 2013/05/03 23:05:01, siva wrote:
> movq

Done.

https://codereview.chromium.org/14862006/diff/9001/runtime/lib/string.cc
File runtime/lib/string.cc (right):

https://codereview.chromium.org/14862006/diff/9001/runtime/lib/string.cc#newc...
runtime/lib/string.cc:131: const String& receiver =
String::CheckedHandle(arguments->NativeArgAt(0));
On 2013/05/03 23:05:01, siva wrote:
> May be do a GET_NON_NULL_NATIVE_ARGUMENT(...)

Done.

https://codereview.chromium.org/14862006/diff/9001/runtime/vm/intrinsifier_x6...
File runtime/vm/intrinsifier_x64.cc (right):

https://codereview.chromium.org/14862006/diff/9001/runtime/vm/intrinsifier_x6...
runtime/vm/intrinsifier_x64.cc:1498: __ movl(RDI, length_reg);
On 2013/05/03 23:05:01, siva wrote:
> movq instead of movl.

Done.

[srdjan, 2013-05-03 23:48:16]

Committed patchset #4 manually as r22399 (presubmit successful).