[stubs]: Support 1->2 byte copies in CopyStringCharacters

[stubs]: Support 1->2 byte copies in CopyStringCharacters

In the process, add a more general mechanism for passing around
and amending list of CodeStubAssembler Variables. That change
makes it possible to more easily add Variables to loops that are
generated by utility functions, e.g. BuildFastLoop.

LOG=N

Committed: https://crrev.com/9e2fd36c3b3b77b0ade7e753a1997a9130c5d75a
Cr-Commit-Position: refs/heads/master@{#40700}

[danno, 2016-10-31 12:07:41]

Description was changed from

==========
[stubs]: Support 1->2 byte copies in CopyStringCharacters

LOG=N
==========

to

==========
[stubs]: Support 1->2 byte copies in CopyStringCharacters

In the process, add a more general mechanism for passing around
and amending list of CodeStubAssembler Variables. That change 
makes it possible to more easily add Variables to loops that are
generated by utility functions, e.g. BuildFastLoop.

LOG=N
==========

[danno, 2016-10-31 14:12:14]

danno@chromium.org changed reviewers:
+ ishell@chromium.org, jgruber@chromium.org

[danno, 2016-10-31 14:12:15]

PTAL

[danno, 2016-10-31 14:12:57]

danno@chromium.org changed reviewers:
+ mstarzinger@chromium.org

[danno, 2016-10-31 14:12:58]

Adding Michi for compiler/ changes.

[Michael Starzinger, 2016-10-31 14:26:45]

LGTM on "compiler" with comments. Didn't look at the rest.

https://codereview.chromium.org/2461363002/diff/40001/src/compiler/code-assem...
File src/compiler/code-assembler.h (right):

https://codereview.chromium.org/2461363002/diff/40001/src/compiler/code-assem...
src/compiler/code-assembler.h:215: struct VariableList {
Please make this a class, make the fields private and add the
{ConcatVariableList} as {static VariableList::Concat} if possible. I am fine
with making CodeAssembler::Label a friend of the VariableList class if that
makes things easier.

[Igor Sheludko, 2016-10-31 18:35:57]

First round of comments.

https://codereview.chromium.org/2461363002/diff/40001/src/code-stub-assembler.cc
File src/code-stub-assembler.cc (right):

https://codereview.chromium.org/2461363002/diff/40001/src/code-stub-assembler...
src/code-stub-assembler.cc:2090: DCHECK_EQ(SeqOneByteString::kHeaderSize,
SeqTwoByteString::kHeaderSize);
STATIC_ASSERT

https://codereview.chromium.org/2461363002/diff/40001/src/code-stub-assembler...
src/code-stub-assembler.cc:6989: CodeStubAssembler::VariableList vars,
MachineRepresentation index_rep,
const CodeStubAssembler::VariableList& vars

https://codereview.chromium.org/2461363002/diff/40001/src/compiler/code-assem...
File src/compiler/code-assembler.cc (right):

https://codereview.chromium.org/2461363002/diff/40001/src/compiler/code-assem...
src/compiler/code-assembler.cc:1069: CodeAssembler::Label::Label(CodeAssembler*
assembler, VariableList vars,
const VariableList& vars

https://codereview.chromium.org/2461363002/diff/40001/src/compiler/code-assem...
File src/compiler/code-assembler.h (right):

https://codereview.chromium.org/2461363002/diff/40001/src/compiler/code-assem...
src/compiler/code-assembler.h:215: struct VariableList {
I think 
  typedef ZoneVector<Variable*> VariableList;
would be a better choice here.
And if we add an initializer-list constructor to ZoneVector we will be able to
write
   VariableList vars({&var_1, &var_2}, zone());

https://codereview.chromium.org/2461363002/diff/40001/src/compiler/code-assem...
src/compiler/code-assembler.h:228: VariableList ConcatVariableList(VariableList
first, VariableList second) {
(const VariableList& first, const VariableList& second)

https://codereview.chromium.org/2461363002/diff/40001/src/compiler/code-assem...
src/compiler/code-assembler.h:237: VariableList ConcatVariableList(VariableList
first, Variable* second) {
Same here.

https://codereview.chromium.org/2461363002/diff/40001/src/compiler/code-assem...
src/compiler/code-assembler.h:524: Label(CodeAssembler* assembler, VariableList
merged_variables,
const VariableList& merged_variables

[danno, 2016-11-01 16:30:22]

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

[commit-bot: I haz the power, 2016-11-01 16:30:25]

Dry run: 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, 2016-11-01 16:33:17]

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

[commit-bot: I haz the power, 2016-11-01 16:33:18]

Dry run: Try jobs failed on following builders:
  v8_linux64_avx2_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_avx2_rel_ng/buil...)
  v8_linux64_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_rel_ng/builds/15475)
  v8_linux_arm64_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_arm64_rel_ng/build...)

[danno, 2016-11-01 16:38:40]

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

[commit-bot: I haz the power, 2016-11-01 16:38:48]

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

[danno, 2016-11-01 16:40:33]

Feedback addressed. Please take another look.

[commit-bot: I haz the power, 2016-11-01 17:22:38]

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

[commit-bot: I haz the power, 2016-11-01 17:22:38]

Dry run: This issue passed the CQ dry run.

[jgruber, 2016-11-02 09:14:22]

LGTM, nice!

https://codereview.chromium.org/2461363002/diff/80001/src/code-stub-assembler.h
File src/code-stub-assembler.h (right):

https://codereview.chromium.org/2461363002/diff/80001/src/code-stub-assembler...
src/code-stub-assembler.h:521: // must be either both one-byte strings or both
two-byte strings.
Comment still needs to be updated.

[Igor Sheludko, 2016-11-02 11:15:38]

https://codereview.chromium.org/2461363002/diff/80001/src/compiler/code-assem...
File src/compiler/code-assembler.cc (right):

https://codereview.chromium.org/2461363002/diff/80001/src/compiler/code-assem...
src/compiler/code-assembler.cc:1069: CodeAssembler::Label::Label(CodeAssembler*
assembler, size_t size,
size -> vars_count?

[Igor Sheludko, 2016-11-02 11:15:45]

lgtm

[danno, 2016-11-02 12:48:52]

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

[commit-bot: I haz the power, 2016-11-02 12:48:57]

Dry run: 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, 2016-11-02 13:15:26]

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

[commit-bot: I haz the power, 2016-11-02 13:15:27]

Dry run: This issue passed the CQ dry run.

[danno, 2016-11-02 13:16:40]

The CQ bit was checked by danno@chromium.org

[danno, 2016-11-02 13:16:41]

The patchset sent to the CQ was uploaded after l-g-t-m from
mstarzinger@chromium.org, ishell@chromium.org, jgruber@chromium.org
Link to the patchset: https://codereview.chromium.org/2461363002/#ps100001
(title: "Review feedback")

[commit-bot: I haz the power, 2016-11-02 13:16:46]

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, 2016-11-02 13:18:55]

Description was changed from

==========
[stubs]: Support 1->2 byte copies in CopyStringCharacters

In the process, add a more general mechanism for passing around
and amending list of CodeStubAssembler Variables. That change 
makes it possible to more easily add Variables to loops that are
generated by utility functions, e.g. BuildFastLoop.

LOG=N
==========

to

==========
[stubs]: Support 1->2 byte copies in CopyStringCharacters

In the process, add a more general mechanism for passing around
and amending list of CodeStubAssembler Variables. That change 
makes it possible to more easily add Variables to loops that are
generated by utility functions, e.g. BuildFastLoop.

LOG=N
==========

[commit-bot: I haz the power, 2016-11-02 13:18:56]

Committed patchset #6 (id:100001)

[commit-bot: I haz the power, 2016-11-17 22:19:22]

Description was changed from

==========
[stubs]: Support 1->2 byte copies in CopyStringCharacters

In the process, add a more general mechanism for passing around
and amending list of CodeStubAssembler Variables. That change 
makes it possible to more easily add Variables to loops that are
generated by utility functions, e.g. BuildFastLoop.

LOG=N
==========

to

==========
[stubs]: Support 1->2 byte copies in CopyStringCharacters

In the process, add a more general mechanism for passing around
and amending list of CodeStubAssembler Variables. That change
makes it possible to more easily add Variables to loops that are
generated by utility functions, e.g. BuildFastLoop.

LOG=N

Committed: https://crrev.com/9e2fd36c3b3b77b0ade7e753a1997a9130c5d75a
Cr-Commit-Position: refs/heads/master@{#40700}
==========

[commit-bot: I haz the power, 2016-11-17 22:19:23]

Patchset 6 (id:??) landed as
https://crrev.com/9e2fd36c3b3b77b0ade7e753a1997a9130c5d75a
Cr-Commit-Position: refs/heads/master@{#40700}