1763103 - Don't require extended functions when methods don't use [[HomeObject]]

Status: RESOLVED FIXED

(Core :: JavaScript Engine, enhancement, P1)

Description

[André Bargull [:anba]]

Currently all methods are allocated as extended functions, even when they don't use METHOD_HOMEOBJECT_SLOT. Thanks to Stencil, we no longer allocate functions in the parser, which enables us to only require extended functions when the home object is actually needed.

Comment 1

[André Bargull [:anba]]

Attachment: Bug 1763103 - Part 1: Update a comment to no longer mention object groups. r=arai!

Object groups have been removed.

Comment 2

[André Bargull [:anba]]

Attachment: Bug 1763103 - Part 2: Stop passing redundant FunctionFlags when initialising a FunctionBox. r=arai!

The FunctionBox is created with the exact same FunctionFlags, so we don't have
to pass the flags as a separate parameter, but instead can read them from the
FunctionBox::flags_ member.

Depends on D142929

Comment 3

[André Bargull [:anba]]

Attachment: Bug 1763103 - Part 3: Clean-up emitPrivateMethodInitializer. r=arai!

Change emitPrivateMethodInitializer() to accept a ClassMethod* instead of
receiving the separate child parse nodes of ClassMethod.

Drive-by change:

• Use less casts.
• Remove unreachable PrivateNameKind::Method case from switch.

Depends on D142930

Comment 4

[André Bargull [:anba]]

Attachment: Bug 1763103 - Part 4: Only initialise home object for private instance accessors when neeeded. r=arai!

Private instance accessors were always initialising the home object, even when
needsHomeObject() was false.

Depends on D142931

Comment 5

[André Bargull [:anba]]

Attachment: Bug 1763103 - Part 5: Don't require extended functions when |super| isn't used. r=arai!

Methods only need to be created as extended functions when they need to store
their home-object. So any method which doesn't use super can actually be
created as a normal, non-extended function.

Depends on D142932

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/9a662b26eb81
Part 1: Update a comment to no longer mention object groups. r=arai
https://hg.mozilla.org/integration/autoland/rev/fddaa6af17d6
Part 2: Stop passing redundant FunctionFlags when initialising a FunctionBox. r=arai
https://hg.mozilla.org/integration/autoland/rev/d3a0f6499f71
Part 3: Clean-up emitPrivateMethodInitializer. r=arai
https://hg.mozilla.org/integration/autoland/rev/dc55792f6bcc
Part 4: Only initialise home object for private instance accessors when neeeded. r=arai
https://hg.mozilla.org/integration/autoland/rev/4e0f719f9498
Part 5: Don't require extended functions when |super| isn't used. r=arai

Comment 7

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/9a662b26eb81
https://hg.mozilla.org/mozilla-central/rev/fddaa6af17d6
https://hg.mozilla.org/mozilla-central/rev/d3a0f6499f71
https://hg.mozilla.org/mozilla-central/rev/dc55792f6bcc
https://hg.mozilla.org/mozilla-central/rev/4e0f719f9498

Comment 8

[Andrej (:aglavic)]

== Change summary for alert #33809 (as of Tue, 12 Apr 2022 18:42:06 GMT) ==

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
1%	Base Content JS	windows10-64-2004-shippable-qr		1,813,717.33 -> 1,801,448.00
1%	Base Content JS	linux1804-64-shippable-qr		1,811,600.00 -> 1,799,633.33
0.44%	Base Content JS	macosx1015-64-shippable-qr		1,841,482.67 -> 1,833,458.67

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=33809