Load global object and builtins from activation.

Load global object and builtins from activation.

BUG=
R=titzer@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=23205

[titzer, 2014-08-18 10:20:29]

I like the direction of this.

As with context specialization, this closure specialization should probably be
configurable. Consider adding a flag to turn it on/off.

https://codereview.chromium.org/474633003/diff/20001/src/compiler/ast-graph-b...
File src/compiler/ast-graph-builder.cc (right):

https://codereview.chromium.org/474633003/diff/20001/src/compiler/ast-graph-b...
src/compiler/ast-graph-builder.cc:1942: Node* field_load =
NewNode(machine.Load(kRepTagged), object,
I think you want kAnyTagged here, that's both a type and a representation.

[sigurds, 2014-08-18 14:48:12]

On 2014/08/18 10:20:29, titzer wrote:
> I like the direction of this.
> 
> As with context specialization, this closure specialization should probably be
> configurable. Consider adding a flag to turn it on/off.
> 
>
https://codereview.chromium.org/474633003/diff/20001/src/compiler/ast-graph-b...
> File src/compiler/ast-graph-builder.cc (right):
> 
>
https://codereview.chromium.org/474633003/diff/20001/src/compiler/ast-graph-b...
> src/compiler/ast-graph-builder.cc:1942: Node* field_load =
> NewNode(machine.Load(kRepTagged), object,
> I think you want kAnyTagged here, that's both a type and a representation.

I addressed the comments. As discussed, context specialization will specialize
the cases this patch generalizes, except for some field loads. I'd like to
submit an optimization that folds the field loads in a separate patch.

[sigurds, 2014-08-19 11:39:17]

I suggest landing this as-is. I'll provide a separate cl which uses
JSContextSpecializer to build context accesses (in particular for generic
lowering).

https://codereview.chromium.org/474633003/diff/20001/src/compiler/ast-graph-b...
File src/compiler/ast-graph-builder.cc (right):

https://codereview.chromium.org/474633003/diff/20001/src/compiler/ast-graph-b...
src/compiler/ast-graph-builder.cc:1942: Node* field_load =
NewNode(machine.Load(kRepTagged), object,
On 2014/08/18 10:20:29, titzer wrote:
> I think you want kAnyTagged here, that's both a type and a representation.

Done.

[titzer, 2014-08-19 12:05:02]

lgtm

[sigurds, 2014-08-19 15:16:31]

Committed patchset #3 manually as 23205 (presubmit successful).