1629721 - Cleanup run-once-lambda/singleton handling in BCE

Status: RESOLVED FIXED

(Core :: JavaScript Engine, task, P1)

Description

[Ted Campbell [:tcampbell]]

The TreatAsRunOnce flag is a source of the BytecodeEmitter reading and writing from live BaseScript instances which we would like to avoid for Project Stencil. These patches also try to unify more of the lazy and non-lazy paths in the BCE.

Comment 1

[Ted Campbell [:tcampbell]]

Attachment: Bug 1629721 - Use the TreatAsRunOnce flag on SharedContext. r?mgaudet

Depends on D70726

Comment 2

[Ted Campbell [:tcampbell]]

Attachment: Bug 1629721 - Unified runOnceLambda definition for lazy/non-lazy. r?mgaudet

Use the same conditions for qualifying an inner function as a run-once-lambda
between the lazy and non-lazy code paths. Use the FunctionBox::immutableFlags
so that this works well with delazification too.

Depends on D70778

Comment 3

[Ted Campbell [:tcampbell]]

Attachment: Bug 1629721 - Remove BytecodeEmitter::runOnceLambda helper. r?mgaudet

Instead rely on consistent definitions of the TreatAsRunOnce flag on the
SharedContext. Also simplify the BCE::check{RunOnce,Singleton}Context
accessors. Note that the TreatAsRunOnce flag indicates the script is expected
to run-once, but the BCE also checks for isInLoop to decide if current
bytecode location within the script should still be considered run-once.

Depends on D70779

Comment 4

[Ted Campbell [:tcampbell]]

Attachment: Bug 1629721 - Remove FunctionEmitter::interpretedCommon. r?mgaudet

Move the TI heuristic into BCE::emitFunction where the other special mutation
of inner-functions is happening.

Depends on D70780

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f7cd6b6c2334
Use the TreatAsRunOnce flag on SharedContext. r=mgaudet
https://hg.mozilla.org/integration/autoland/rev/19a37953cb0d
Unified runOnceLambda definition for lazy/non-lazy. r=mgaudet
https://hg.mozilla.org/integration/autoland/rev/2c04486aa1e7
Remove BytecodeEmitter::runOnceLambda helper. r=mgaudet
https://hg.mozilla.org/integration/autoland/rev/90bc2f89ea84
Remove FunctionEmitter::interpretedCommon. r=mgaudet

Comment 6

[Cristian Brindusan [:cbrindusan]]

https://hg.mozilla.org/mozilla-central/rev/f7cd6b6c2334
https://hg.mozilla.org/mozilla-central/rev/19a37953cb0d
https://hg.mozilla.org/mozilla-central/rev/2c04486aa1e7
https://hg.mozilla.org/mozilla-central/rev/90bc2f89ea84