Always deserialize scope infos for parsing

Always deserialize scope infos for parsing

When looking up variables in the ScopeInfo, we did a linear scan of the
ScopeInfo. Since that's unacceptably slow, a context slot cache was added
that would speed up repeated lookups of the same variable.

Instead, just always fully convert the ScopeInfo into scopes, so they can
lookup variables without scanning the ScopeInfo.

This also allows for removing the now unused ContextSlotCache.

R=adamk@chromium.org,verwaest@chromium.org,marja@chromium.org
BUG=v8:5315
Committed: https://crrev.com/81f824cad18e4dc873a8838943217eb9c9f0c1f0
Cr-Commit-Position: refs/heads/master@{#38953}

[jochen (gone - plz use gerrit), 2016-08-26 11:20:40]

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

[commit-bot: I haz the power, 2016-08-26 11:20:46]

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, 2016-08-26 11:45:04]

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

[commit-bot: I haz the power, 2016-08-26 11:45:06]

Dry run: This issue passed the CQ dry run.

[Toon Verwaest, 2016-08-26 12:00:17]

lgtm if performance is ok

[Toon Verwaest, 2016-08-26 12:00:17]

lgtm if performance is ok

[Toon Verwaest, 2016-08-26 12:01:14]

Shouldn't you update LookupLocal to not check the scopeinfo anymore?

[Toon Verwaest, 2016-08-26 12:01:15]

Shouldn't you update LookupLocal to not check the scopeinfo anymore?

[jochen (gone - plz use gerrit), 2016-08-26 14:16:49]

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

[commit-bot: I haz the power, 2016-08-26 14:16:51]

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

[jochen (gone - plz use gerrit), 2016-08-26 14:17:02]

delete moar code... ptal

[commit-bot: I haz the power, 2016-08-26 14:41:16]

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

[commit-bot: I haz the power, 2016-08-26 14:41:17]

Dry run: This issue passed the CQ dry run.

[Toon Verwaest, 2016-08-26 14:41:36]

lgtm

[jochen (gone - plz use gerrit), 2016-08-26 14:58:31]

The CQ bit was checked by jochen@chromium.org

[adamk, 2016-08-26 17:12:29]

Description was changed from

==========
Always deserialize scope infos for parsing

That allows for ripping on the context slot cache

R=adamk@chromium.org,verwaest@chromium.org,marja@chromium.org
BUG=
==========

to

==========
Always deserialize scope infos for parsing

That allows for ripping out the context slot cache

R=adamk@chromium.org,verwaest@chromium.org,marja@chromium.org
BUG=
==========

[adamk, 2016-08-26 17:14:27]

Can you add some more background to the CL description (and/or a tracking bug)?
I'm missing context on what the ContextSlotCache was doing and why it's OK to
delete.

[jochen (gone - plz use gerrit), 2016-08-26 17:19:06]

Description was changed from

==========
Always deserialize scope infos for parsing

That allows for ripping out the context slot cache

R=adamk@chromium.org,verwaest@chromium.org,marja@chromium.org
BUG=
==========

to

==========
Always deserialize scope infos for parsing

When looking up variables in the ScopeInfo, we did a linear scan of the
ScopeInfo. Since that's unacceptably slow, a context slot cache was added
that would speed up repeated lookups of the same variable.

Instead, just always fully convert the ScopeInfo into scopes, so they can
lookup variables without scanning the ScopeInfo.

This also allows for removing the now unused ContextSlotCache.

R=adamk@chromium.org,verwaest@chromium.org,marja@chromium.org
BUG=
==========

[jochen (gone - plz use gerrit), 2016-08-26 17:19:26]

ptal

[adamk, 2016-08-26 17:32:34]

Code lgtm, but I want to make sure we keep our ears open for perf regressions
due to this.

I'm imagining a module system like:

(function module() {
// thousands of declarations, many of them closed over by other functions
// ...
function foo() {
  return 42;
}
})()

[jochen (gone - plz use gerrit), 2016-08-26 17:37:06]

Description was changed from

==========
Always deserialize scope infos for parsing

When looking up variables in the ScopeInfo, we did a linear scan of the
ScopeInfo. Since that's unacceptably slow, a context slot cache was added
that would speed up repeated lookups of the same variable.

Instead, just always fully convert the ScopeInfo into scopes, so they can
lookup variables without scanning the ScopeInfo.

This also allows for removing the now unused ContextSlotCache.

R=adamk@chromium.org,verwaest@chromium.org,marja@chromium.org
BUG=
==========

to

==========
Always deserialize scope infos for parsing

When looking up variables in the ScopeInfo, we did a linear scan of the
ScopeInfo. Since that's unacceptably slow, a context slot cache was added
that would speed up repeated lookups of the same variable.

Instead, just always fully convert the ScopeInfo into scopes, so they can
lookup variables without scanning the ScopeInfo.

This also allows for removing the now unused ContextSlotCache.

R=adamk@chromium.org,verwaest@chromium.org,marja@chromium.org
BUG=v8:5315
==========

[jochen (gone - plz use gerrit), 2016-08-26 17:37:26]

filed a tracking bug to make it easier to handle regressions should there be any

[jochen (gone - plz use gerrit), 2016-08-26 17:37:33]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2016-08-26 17:37:51]

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, 2016-08-26 17:39:31]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-08-26 17:39:59]

Description was changed from

==========
Always deserialize scope infos for parsing

When looking up variables in the ScopeInfo, we did a linear scan of the
ScopeInfo. Since that's unacceptably slow, a context slot cache was added
that would speed up repeated lookups of the same variable.

Instead, just always fully convert the ScopeInfo into scopes, so they can
lookup variables without scanning the ScopeInfo.

This also allows for removing the now unused ContextSlotCache.

R=adamk@chromium.org,verwaest@chromium.org,marja@chromium.org
BUG=v8:5315
==========

to

==========
Always deserialize scope infos for parsing

When looking up variables in the ScopeInfo, we did a linear scan of the
ScopeInfo. Since that's unacceptably slow, a context slot cache was added
that would speed up repeated lookups of the same variable.

Instead, just always fully convert the ScopeInfo into scopes, so they can
lookup variables without scanning the ScopeInfo.

This also allows for removing the now unused ContextSlotCache.

R=adamk@chromium.org,verwaest@chromium.org,marja@chromium.org
BUG=v8:5315

Committed: https://crrev.com/81f824cad18e4dc873a8838943217eb9c9f0c1f0
Cr-Commit-Position: refs/heads/master@{#38953}
==========

[commit-bot: I haz the power, 2016-08-26 17:40:01]

Patchset 3 (id:??) landed as
https://crrev.com/81f824cad18e4dc873a8838943217eb9c9f0c1f0
Cr-Commit-Position: refs/heads/master@{#38953}

[Toon Verwaest, 2016-08-26 20:36:39]

This tanks codeload by 7%, RuntimeCallStats-compile by 7% and parse by ~50%. I
guess we should revert.

[Toon Verwaest, 2016-08-27 07:08:10]

A revert of this CL (patchset #3 id:40001) has been created in
https://codereview.chromium.org/2287783003/ by verwaest@chromium.org.

The reason for reverting is: Significantly tanks parsing. We probably should
just keep on doing what we're doing: partially deserialize while resolving
variables. If we do scope-info backed resolution after regular resolution based
on remaining free variables, we can probably reduce the time-frame of that part.
We soon after anyway need to sync with the main thread..