1551796 - Merge TypeScript and ICScript into JitScript

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, task, P1)

Description

[Jan de Mooij [:jandem]]

The plan is to do the following:

1. Rename TypeScript to JitScript.
2. Move it from vm/TypeInference.* to jit/JitScript.{h,cpp}
3. Merge ICScript into JitScript. TypeScript and ICScript have the same lifetime already so this should be straight-forward. It will eliminate a malloc/free + extra dereferences + we can do a single bytecode walk instead of two when allocating JitScript.
4. Move JIT-related fields currently in JSScript (baseline/ion/etc) to JitScript. This is nice because sizeof(JSScript) matters and it will move some JIT-related code out of vm/

Comment 1

[Jan de Mooij [:jandem]]

Attachment: Bug 1551796 part 1 - Rename TypeScript to JitScript. r?tcampbell!

Also JSScript::makeTypes => JSScript::createJitScript for consistency with code
elsewhere.

Comment 2

[Jan de Mooij [:jandem]]

Attachment: Bug 1551796 part 2 - Move JitScript from vm/TypeInference.* to jit/JitScript.*. r?tcampbell!

Some of the TypeInference-related static methods were kept in TypeInference-inl.h and
TypeInference.cpp because of various dependencies. Also, methods like JitScript::MonitorAssign
probably don't belong on JitScript anyway, but for now this seems reasonable.

Depends on D31755

Comment 3

[Jan de Mooij [:jandem]]

Attachment: Bug 1551796 part 3 - Merge ICScript into JitScript. r?tcampbell!

ICScript and JitScript had the same lifetime already, but this eliminates
a malloc/free and some extra dereferences (especially for accessing ICEntries
from Baseline Interpreter code).

This is just the minimal set of changes to make it easier to review. Follow-up
changes should:

• Move (now) JitScript methods to JitScript.cpp

• Merge FillBytecodeTypeMap with JitScript::initICEntries so we do just a single
  bytecode walk.

• Move JitScript from the js namespace to js::jit.

Depends on D31982

Comment 4

[Jan de Mooij [:jandem]]

Attachment: Bug 1551796 part 4 - Remove unnecessary hasJitScript() checks in BaselineInspector. r?tcampbell!

These have been unnecessary since the ICScript introduction: when performing the
arguments analysis we have a JitScript but not a BaselineScript.

Depends on D32103

Comment 5

[Jan de Mooij [:jandem]]

Attachment: Bug 1551796 part 5 - Make JitScript::destroy static. r?tcampbell!

The destroy() call in JSScript::finalize was moved into DestroyJitScripts for
consistency with BaselineScript and IonScript.

Comment 6

[Jan de Mooij [:jandem]]

Attachment: Bug 1551796 part 6 - Use DefaultInitializeElements to initialize JitScript's StackTypeSet array. r?tcampbell!

Depends on D32290

Comment 7

[Jan de Mooij [:jandem]]

Attachment: Bug 1551796 part 7 - Improve the JitScript comment a bit. r?tcampbell!

Depends on D32292

Comment 8

[Jan de Mooij [:jandem]]

Attachment: Bug 1551796 part 8 - Rename ShouldReleaseTypes to ShouldDiscardJitScripts. r?tcampbell!

"Discard" instead of "Release" for consistency with ShouldDiscardBaselineCode.

Depends on D32293

Comment 9

[Jan de Mooij [:jandem]]

Attachment: Bug 1551796 part 9 - Merge FillBytecodeTypeMap into JitScript::initICEntries. r?tcampbell!

We now do a single pass over the bytecode instead of two.

Register pressure of the combined code might be a bit worse but it also
eliminates some duplication so I think it's worth it.

Comment 10

[Jan de Mooij [:jandem]]

Attachment: Bug 1551796 part 10 - Move JitScript to js::jit namespace. r?tcampbell!

Depends on D32298

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2ac16f08196a
part 1 - Rename TypeScript to JitScript. r=tcampbell
https://hg.mozilla.org/integration/autoland/rev/330f42984cf4
part 2 - Move JitScript from vm/TypeInference.* to jit/JitScript.*. r=tcampbell

Comment 13

[Jan de Mooij [:jandem]]

Attachment: Bug 1551796 part 11 - Move more JitScript code into JitScript.cpp. r?tcampbell!

JitScript::initICEntriesAndBytecodeTypeMap is still in BaselineIC.cpp because
it depends on things defined there (like FallbackStubAllocator) and I think it's
not unreasonable to keep it there.

Depends on D32299

Comment 14

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e81b72b58694
part 3 - Merge ICScript into JitScript. r=tcampbell
https://hg.mozilla.org/integration/autoland/rev/71c4f7fd04f0
part 4 - Remove unnecessary hasJitScript() checks in BaselineInspector. r=tcampbell

Comment 15

[Andrei Ciure[:aciure]]

https://hg.mozilla.org/mozilla-central/rev/2ac16f08196a
https://hg.mozilla.org/mozilla-central/rev/330f42984cf4
https://hg.mozilla.org/mozilla-central/rev/e81b72b58694
https://hg.mozilla.org/mozilla-central/rev/71c4f7fd04f0

Comment 16

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c0f95fe29f8a
part 5 - Make JitScript::destroy static. r=tcampbell
https://hg.mozilla.org/integration/autoland/rev/547d1940a27f
part 6 - Use DefaultInitializeElements to initialize JitScript's StackTypeSet array. r=tcampbell
https://hg.mozilla.org/integration/autoland/rev/56f1c5f12b84
part 7 - Improve the JitScript comment a bit. r=tcampbell
https://hg.mozilla.org/integration/autoland/rev/5ee66c20f298
part 8 - Rename ShouldReleaseTypes to ShouldDiscardJitScripts. r=tcampbell

Comment 17

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/05c094ef90ca
part 9 - Merge FillBytecodeTypeMap into JitScript::initICEntries. r=tcampbell
https://hg.mozilla.org/integration/autoland/rev/87aaa29b2fff
part 10 - Move JitScript to js::jit namespace. r=tcampbell
https://hg.mozilla.org/integration/autoland/rev/ec5f175f4f2c
part 11 - Move more JitScript code into JitScript.cpp. r=tcampbell

Comment 18

[Cristian Brindusan [:cbrindusan]]

https://hg.mozilla.org/mozilla-central/rev/c0f95fe29f8a
https://hg.mozilla.org/mozilla-central/rev/547d1940a27f
https://hg.mozilla.org/mozilla-central/rev/56f1c5f12b84
https://hg.mozilla.org/mozilla-central/rev/5ee66c20f298
https://hg.mozilla.org/mozilla-central/rev/05c094ef90ca
https://hg.mozilla.org/mozilla-central/rev/87aaa29b2fff
https://hg.mozilla.org/mozilla-central/rev/ec5f175f4f2c