Adding ElementsAccessor::Shift

Adding ElementsAccessor::Shift
- Use the new ElementsAccessor methods
- improve test coverage

BUG=

Committed: https://crrev.com/a369ab1838180284f4bbb668dfe18e2497567867
Cr-Commit-Position: refs/heads/master@{#30546}

[Camillo Bruni, 2015-09-01 17:38:26]

cbruni@chromium.org changed reviewers:
+ ishell@chromium.org

[Camillo Bruni, 2015-09-02 09:52:28]

PTAL

[Igor Sheludko, 2015-09-02 12:35:21]

https://codereview.chromium.org/1317053006/diff/40001/src/elements.cc
File src/elements.cc (right):

https://codereview.chromium.org/1317053006/diff/40001/src/elements.cc#newcode...
src/elements.cc:1317: if (len == 0) {
ArrayPop already handles this case. Maybe this should be a DCHECK instead?

https://codereview.chromium.org/1317053006/diff/40001/src/elements.cc#newcode...
src/elements.cc:1337: if (len == 0) {
Same here.

https://codereview.chromium.org/1317053006/diff/40001/test/mjsunit/array-nati...
File test/mjsunit/array-natives-elements.js (right):

https://codereview.chromium.org/1317053006/diff/40001/test/mjsunit/array-nati...
test/mjsunit/array-natives-elements.js:257:
//assertTrue(%HasFastSmiElements(a4));
Why is this assert commented?

[Camillo Bruni, 2015-09-02 13:04:55]

Moved explicit range checks to bultins.cc and only leave DCHECKs in elements.cc

https://codereview.chromium.org/1317053006/diff/40001/src/elements.cc
File src/elements.cc (right):

https://codereview.chromium.org/1317053006/diff/40001/src/elements.cc#newcode...
src/elements.cc:1317: if (len == 0) {
On 2015/09/02 at 12:35:20, Igor Sheludko wrote:
> ArrayPop already handles this case. Maybe this should be a DCHECK instead?

Right.

https://codereview.chromium.org/1317053006/diff/40001/src/elements.cc#newcode...
src/elements.cc:1337: if (len == 0) {
On 2015/09/02 at 12:35:20, Igor Sheludko wrote:
> Same here.

ditto.

https://codereview.chromium.org/1317053006/diff/40001/test/mjsunit/array-nati...
File test/mjsunit/array-natives-elements.js (right):

https://codereview.chromium.org/1317053006/diff/40001/test/mjsunit/array-nati...
test/mjsunit/array-natives-elements.js:257:
//assertTrue(%HasFastSmiElements(a4));
On 2015/09/02 at 12:35:21, Igor Sheludko wrote:
> Why is this assert commented?

I got weird side-effects from this point on when optimized. All of a sudden the
backing stores do no longer have the same type:
https://code.google.com/p/chromium/issues/detail?id=523972

[Igor Sheludko, 2015-09-02 14:37:44]

lgtm

[Camillo Bruni, 2015-09-02 14:44:56]

The CQ bit was checked by cbruni@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-09-02 14:45:01]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1317053006/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1317053006/60001

[commit-bot: I haz the power, 2015-09-02 15:11:44]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-09-02 15:11:45]

Dry run: This issue passed the CQ dry run.

[Camillo Bruni, 2015-09-02 15:27:57]

The CQ bit was checked by cbruni@chromium.org

[commit-bot: I haz the power, 2015-09-02 15:28:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1317053006/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1317053006/60001

[commit-bot: I haz the power, 2015-09-02 15:29:26]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-09-02 15:29:51]

Patchset 4 (id:??) landed as
https://crrev.com/a369ab1838180284f4bbb668dfe18e2497567867
Cr-Commit-Position: refs/heads/master@{#30546}