Computed property names for object literals in TurboFan.

Computed property names for object literals in TurboFan.

R=dslomov@chromium.org
TEST=mjsunit/harmony/computed-property-names

Committed: https://crrev.com/bd7f546f11036974c9fec616b02bdb56ce86a114
Cr-Commit-Position: refs/heads/master@{#26174}

[Dmitry Lomov (no reviews), 2015-01-20 14:45:58]

lgtm

[Michael Starzinger, 2015-01-20 16:22:35]

The CQ bit was checked by mstarzinger@chromium.org

[commit-bot: I haz the power, 2015-01-20 16:23:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/860033002/20001

[commit-bot: I haz the power, 2015-01-20 16:52:57]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-01-20 16:53:10]

Patchset 2 (id:??) landed as
https://crrev.com/bd7f546f11036974c9fec616b02bdb56ce86a114
Cr-Commit-Position: refs/heads/master@{#26174}

[arv (Not doing code reviews), 2015-02-13 15:15:56]

arv@chromium.org changed reviewers:
+ arv@chromium.org

[arv (Not doing code reviews), 2015-02-13 15:15:57]

https://codereview.chromium.org/860033002/diff/20001/src/compiler/ast-graph-b...
File src/compiler/ast-graph-builder.cc (right):

https://codereview.chromium.org/860033002/diff/20001/src/compiler/ast-graph-b...
src/compiler/ast-graph-builder.cc:1131: // TODO(mstarzinger): For
ObjectLiteral::Property::PROTOTYPE the key should
In the case of the property being `__proto__: expr` then we know the property
key is not computed. We therefore do not need to execute it. However, in that
case, property->key() is a string literal so no harm is done, just unnecessary
computations.

[Michael Starzinger, 2015-02-16 10:39:15]

https://codereview.chromium.org/860033002/diff/20001/src/compiler/ast-graph-b...
File src/compiler/ast-graph-builder.cc (right):

https://codereview.chromium.org/860033002/diff/20001/src/compiler/ast-graph-b...
src/compiler/ast-graph-builder.cc:1131: // TODO(mstarzinger): For
ObjectLiteral::Property::PROTOTYPE the key should
On 2015/02/13 15:15:57, arv wrote:
> In the case of the property being `__proto__: expr` then we know the property
> key is not computed. We therefore do not need to execute it. However, in that
> case, property->key() is a string literal so no harm is done, just unnecessary
> computations.

The TODO is not about evaluating the "key" being observable. It is about a deopt
that could be potentially caused by evaluating the "value". In this case the
simulated operand stack in the environment needs to match up with full-codegen
exactly. If it doesn't then the deoptimizer will materialize a stack-frame on
which full-codegen will choke. AFAICT, this is the case here, so the TODO is
still accurate IMHO.