Minor optimization to v8::internal::Factory::InternalizeOneByteString.

Minor optimization to v8::internal::Factory::InternalizeOneByteString.

This makes StringTable lookup up to the hashtable (which is already in object-inl.h)
inline (which allows a redundant check to optimize away).

Also, a specialized key which checks for the case where the string table contains
an internalized SeqOneByteString, which is the common case when looking up a
string from raw one-byte data, before falling back to more general logic.

BUG=chromium:685748

[jbroman, 2017-03-21 19:23:22]

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

[commit-bot: I haz the power, 2017-03-21 19:23:26]

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, 2017-03-21 19:51:32]

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

[commit-bot: I haz the power, 2017-03-21 19:51:33]

Dry run: This issue passed the CQ dry run.

[jbroman, 2017-03-21 21:25:01]

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

[commit-bot: I haz the power, 2017-03-21 21:25:09]

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, 2017-03-21 21:51:29]

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

[commit-bot: I haz the power, 2017-03-21 21:51:29]

Dry run: This issue passed the CQ dry run.

[jbroman, 2017-03-21 22:05:16]

Description was changed from

==========
WIP: Minor optimization to v8::internal::Factory::InternalizeOneByteString.

Make GetHashField inline, as it matters and at least one compare/branch can
easily optimize away.

When internalizing one-byte strings, pray that the existing one is one-byte
sequential already.

Profiling may be misleading about the total effect of this.

BUG=
==========

to

==========
WIP: Minor optimization to v8::internal::Factory::InternalizeOneByteString.

This makes StringTable lookup up to the hashtable (which is already in
object-inl.h)
inline (which allows a redundant check to optimize away).

Make GetHashField inline, as it matters and at least one compare/branch can
easily optimize away.

When internalizing one-byte strings, pray that the existing one is one-byte
sequential already.

Profiling may be misleading about the total effect of this.

BUG=
==========

[jbroman, 2017-03-21 22:06:25]

Description was changed from

==========
WIP: Minor optimization to v8::internal::Factory::InternalizeOneByteString.

This makes StringTable lookup up to the hashtable (which is already in
object-inl.h)
inline (which allows a redundant check to optimize away).

Make GetHashField inline, as it matters and at least one compare/branch can
easily optimize away.

When internalizing one-byte strings, pray that the existing one is one-byte
sequential already.

Profiling may be misleading about the total effect of this.

BUG=
==========

to

==========
Minor optimization to v8::internal::Factory::InternalizeOneByteString.

This makes StringTable lookup up to the hashtable (which is already in
object-inl.h)
inline (which allows a redundant check to optimize away).

Also, a specialized key which checks for the case where the string table
contains
an internalized SeqOneByteString, which is the common case when looking up a
string from raw one-byte data, before falling back to more general logic.

BUG=
==========

[jbroman, 2017-03-21 22:06:37]

Description was changed from

==========
Minor optimization to v8::internal::Factory::InternalizeOneByteString.

This makes StringTable lookup up to the hashtable (which is already in
object-inl.h)
inline (which allows a redundant check to optimize away).

Also, a specialized key which checks for the case where the string table
contains
an internalized SeqOneByteString, which is the common case when looking up a
string from raw one-byte data, before falling back to more general logic.

BUG=
==========

to

==========
Minor optimization to v8::internal::Factory::InternalizeOneByteString.

This makes StringTable lookup up to the hashtable (which is already in
object-inl.h)
inline (which allows a redundant check to optimize away).

Also, a specialized key which checks for the case where the string table
contains
an internalized SeqOneByteString, which is the common case when looking up a
string from raw one-byte data, before falling back to more general logic.

BUG=chromium:685748
==========