[interpreter] Remove redundant code in ForInPrepare

[interpreter] Remove redundant code in ForInPrepare

ForInPrepare checked whether the receiver object was null, undefined or
converted to a JSObject. This is already done by the generated bytecode.

BUG=v8:4820
LOG=n

Committed: https://crrev.com/4732c219b0d263bde01f624e325e0865aba65834
Cr-Commit-Position: refs/heads/master@{#38394}

[klaasb, 2016-08-03 16:32:07]

The CQ bit was checked by klaasb@google.com to run a CQ dry run

[commit-bot: I haz the power, 2016-08-03 16:32:18]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[klaasb, 2016-08-03 16:32:20]

klaasb@google.com changed reviewers:
+ rmcilroy@chromium.org

[commit-bot: I haz the power, 2016-08-03 16:50:47]

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

[commit-bot: I haz the power, 2016-08-03 16:50:48]

Dry run: This issue passed the CQ dry run.

[rmcilroy, 2016-08-04 14:06:35]

https://codereview.chromium.org/2208043002/diff/1/src/interpreter/interpreter.cc
File src/interpreter/interpreter.cc (left):

https://codereview.chromium.org/2208043002/diff/1/src/interpreter/interpreter...
src/interpreter/interpreter.cc:1947: &nothing_to_iterate, &convert_to_receiver);
I think we still need the null and undefined checks don't we? Or are they dealt
with by the CheckEnumCache? Either way, could you check the behaviour when null
/ undefined is past to this and make sure it still does the right thing.

[klaasb, 2016-08-04 15:20:54]

https://codereview.chromium.org/2208043002/diff/1/src/interpreter/interpreter.cc
File src/interpreter/interpreter.cc (left):

https://codereview.chromium.org/2208043002/diff/1/src/interpreter/interpreter...
src/interpreter/interpreter.cc:1947: &nothing_to_iterate, &convert_to_receiver);
On 2016/08/04 14:06:35, rmcilroy wrote:
> I think we still need the null and undefined checks don't we? Or are they
dealt
> with by the CheckEnumCache? Either way, could you check the behaviour when
null
> / undefined is past to this and make sure it still does the right thing.

Null/undefined are also handled in bytecode already, so here we just expect a
non-null/undefined, converted receiver. CheckEnumCache would fail for
null/undefined as far as I can see.
There are test cases for null/undefined in the cctest
test-interpreter/InterpreterForIn that still hold.

[rmcilroy, 2016-08-04 15:41:46]

LGTM with nits, thanks.

https://codereview.chromium.org/2208043002/diff/1/src/interpreter/interpreter.cc
File src/interpreter/interpreter.cc (right):

https://codereview.chromium.org/2208043002/diff/1/src/interpreter/interpreter...
src/interpreter/interpreter.cc:1913: // ForInPrepare <cache_info_triple>
I know you didn't change this, but could you update this comment to add
<reciever> operand and mention that it needs to be a JSReceiver object.

https://codereview.chromium.org/2208043002/diff/1/src/interpreter/interpreter...
src/interpreter/interpreter.cc:1924: 
Could you add some debug code (with "if (FLAG_debug_code) { ... }") which checks
that the code is a JS_RECEIVER and Aborts with the Abort(...) instruction with a
appropriate bailout (added one if needed).

[klaasb, 2016-08-05 16:08:34]

https://codereview.chromium.org/2208043002/diff/1/src/interpreter/interpreter.cc
File src/interpreter/interpreter.cc (right):

https://codereview.chromium.org/2208043002/diff/1/src/interpreter/interpreter...
src/interpreter/interpreter.cc:1913: // ForInPrepare <cache_info_triple>
On 2016/08/04 15:41:45, rmcilroy wrote:
> I know you didn't change this, but could you update this comment to add
> <reciever> operand and mention that it needs to be a JSReceiver object.

Oops, I actually did that change, just in an earlier CL. Done.

https://codereview.chromium.org/2208043002/diff/1/src/interpreter/interpreter...
src/interpreter/interpreter.cc:1924: 
On 2016/08/04 15:41:45, rmcilroy wrote:
> Could you add some debug code (with "if (FLAG_debug_code) { ... }") which
checks
> that the code is a JS_RECEIVER and Aborts with the Abort(...) instruction with
a
> appropriate bailout (added one if needed).

Done.

[klaasb, 2016-08-05 16:39:18]

The CQ bit was checked by klaasb@google.com

[klaasb, 2016-08-05 16:39:19]

The patchset sent to the CQ was uploaded after l-g-t-m from
rmcilroy@chromium.org
Link to the patchset: https://codereview.chromium.org/2208043002/#ps20001
(title: "add debug abort and comments")

[commit-bot: I haz the power, 2016-08-05 16:39:25]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-05 16:52:54]

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

[commit-bot: I haz the power, 2016-08-05 16:52:55]

Try jobs failed on following builders:
  v8_linux64_gyp_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_gyp_rel_ng/build...)
  v8_linux64_gyp_rel_ng_triggered on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_gyp_rel_ng_trigg...)

[klaasb, 2016-08-05 17:11:39]

The CQ bit was checked by klaasb@google.com

[klaasb, 2016-08-05 17:11:40]

The patchset sent to the CQ was uploaded after l-g-t-m from
rmcilroy@chromium.org
Link to the patchset: https://codereview.chromium.org/2208043002/#ps40001
(title: "fix golden file")

[commit-bot: I haz the power, 2016-08-05 17:11:50]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-05 17:33:54]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-08-05 17:36:12]

Description was changed from

==========
[interpreter] Remove redundant code in ForInPrepare

ForInPrepare checked whether the receiver object was null, undefined or
converted to a JSObject. This is already done by the generated bytecode.

BUG=v8:4820
LOG=n
==========

to

==========
[interpreter] Remove redundant code in ForInPrepare

ForInPrepare checked whether the receiver object was null, undefined or
converted to a JSObject. This is already done by the generated bytecode.

BUG=v8:4820
LOG=n

Committed: https://crrev.com/4732c219b0d263bde01f624e325e0865aba65834
Cr-Commit-Position: refs/heads/master@{#38394}
==========

[commit-bot: I haz the power, 2016-08-05 17:36:13]

Patchset 3 (id:??) landed as
https://crrev.com/4732c219b0d263bde01f624e325e0865aba65834
Cr-Commit-Position: refs/heads/master@{#38394}