1710075 - Allocate fallback stubs as ICScript array

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, task, P2)

Description

[Jan de Mooij [:jandem]]

After Jon's changes removing the NewObject and NewArray templates, we can get rid of the Rest IC template object and then allocate fallback stubs as a fixed-size array in ICScript instead of using the LifoAlloc.

Comment 1

[Jan de Mooij [:jandem]]

Attachment: Bug 1710075 part 1 - Add CanUseFixedElementsForArray helper function. r?jonco!

Comment 2

[Jan de Mooij [:jandem]]

Attachment: Bug 1710075 part 2 - Treat MNewArrayObject as non-effectful. r?jonco!

This matches MNewArray and is what we need for the Rest code.

Depends on D114603

Comment 3

[Jan de Mooij [:jandem]]

Attachment: Bug 1710075 part 3 - Cache array shape in a global object slot. r?jonco!

This will be used by a later patch in the stack, but can likely be used in more
places in the future.

Depends on D114604

Comment 4

[Jan de Mooij [:jandem]]

Attachment: Bug 1710075 part 4 - Allocate Rest array in Warp using the array shape instead of a template object. r?jonco!

Depends on D114605

Comment 5

[Jan de Mooij [:jandem]]

Attachment: Bug 1710075 part 5 - Remove template object from Rest fallback stub. r?jonco!

Depends on D114606

Comment 6

[Jan de Mooij [:jandem]]

Attachment: Bug 1710075 part 6 - Clean up fallback stub tracing a bit now that they never contain a GC pointer. r?jonco!

Depends on D114607

Comment 7

[Jan de Mooij [:jandem]]

Attachment: Bug 1710075 part 7 - Remove IsInlinableFallback assertion. r?iain!

The next patch wants to remove the derived classes (and kinds) for fallback stubs.

This assertion seems redundant with getStubReturnAddress so it should be fine
to remove it.

Depends on D114608

Comment 8

[Jan de Mooij [:jandem]]

Attachment: Bug 1710075 part 8 - Remove classes and kinds for fallback stubs. r?iain!

Each fallback stub is now allocated as just ICFallbackStub.

Also replaces the switch-statement in initICEntries with a faster table lookup
to map from JSOp to fallback kind (to get the trampoline code for the fallback stub).

Depends on D114609

Comment 9

[Jan de Mooij [:jandem]]

Attachment: Bug 1710075 part 9 - Allocate fallback stubs as an array in ICScript. r?iain!

This is more efficient than using the LifoAlloc and lets us make more code infallible.

Depends on D114610

Comment 10

[Jan de Mooij [:jandem]]

Attachment: Bug 1710075 part 10 - Rename FallbackICStubSpace to JitScriptICStubSpace. r?iain!

FallbackICStubSpace is no longer a good name because it isn't used for fallback
stubs anymore.

Depends on D114611

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d333a377131f
part 1 - Add CanUseFixedElementsForArray helper function. r=jonco
https://hg.mozilla.org/integration/autoland/rev/43c37724bf56
part 2 - Treat MNewArrayObject as non-effectful. r=jonco
https://hg.mozilla.org/integration/autoland/rev/f6f61139baf1
part 3 - Cache array shape in a global object slot. r=jonco
https://hg.mozilla.org/integration/autoland/rev/2ee0591c2226
part 4 - Allocate Rest array in Warp using the array shape instead of a template object. r=jonco
https://hg.mozilla.org/integration/autoland/rev/608bfdfe6fd0
part 5 - Remove template object from Rest fallback stub. r=jonco

Comment 12

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/d333a377131f
https://hg.mozilla.org/mozilla-central/rev/43c37724bf56
https://hg.mozilla.org/mozilla-central/rev/f6f61139baf1
https://hg.mozilla.org/mozilla-central/rev/2ee0591c2226
https://hg.mozilla.org/mozilla-central/rev/608bfdfe6fd0

Comment 13

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a4369f6d34be
part 6 - Clean up fallback stub tracing a bit now that they never contain a GC pointer. r=jonco
https://hg.mozilla.org/integration/autoland/rev/94bc946d5498
part 7 - Remove IsInlinableFallback assertion. r=iain
https://hg.mozilla.org/integration/autoland/rev/731b32928128
part 8 - Remove classes and kinds for fallback stubs. r=iain
https://hg.mozilla.org/integration/autoland/rev/d7ca3338e716
part 9 - Allocate fallback stubs as an array in ICScript. r=iain
https://hg.mozilla.org/integration/autoland/rev/ab1fc35f9ba6
part 10 - Rename FallbackICStubSpace to JitScriptICStubSpace. r=iain

Comment 14

[Cristian Brindusan [:cbrindusan]]

https://hg.mozilla.org/mozilla-central/rev/a4369f6d34be
https://hg.mozilla.org/mozilla-central/rev/94bc946d5498
https://hg.mozilla.org/mozilla-central/rev/731b32928128
https://hg.mozilla.org/mozilla-central/rev/d7ca3338e716
https://hg.mozilla.org/mozilla-central/rev/ab1fc35f9ba6