1552154 - Stop storing native code offset for each bytecode pc in BaselineScript

Status: RESOLVED FIXED

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

Description

[Jan de Mooij [:jandem]]

BaselineScript::nativeCodeForPC has the following consumers:

1. Ion bailouts
2. DebugModeOSR
3. Exception handling
4. OSR
5. Profiler (also BaselineScript::approximatePcForNativeAddress)

I'm hoping we can change 1-3 to resume in the interpreter instead, once it's enabled by default (we would switch to Baseline JIT code at the next loop edge or call).

For 4 we only care about JSOP_LOOPENTRY ops. When the profiler is enabled we could choose to record more offsets but we wouldn't have to do this for every op - it would be more of a heuristic.

This should speed up BaselineCompiler a bit, use less memory, and simplify the code a bit (no need to handle and worry about unsynced stack values for example).

Comment 1

[Jan de Mooij [:jandem]]

Attachment: Bug 1552154 part 1 - Use mozilla::Span<> in BaselineScript, clean up RetAddrEntry code a bit. r?tcampbell!

Comment 2

[Jan de Mooij [:jandem]]

Attachment: Bug 1552154 part 2 - Stop using pc-to-native map for OSR into Baseline JIT. r?tcampbell!

Depends on D40944

Comment 3

[Jan de Mooij [:jandem]]

Attachment: Bug 1552154 part 3 - Stop using pc-to-native map for BaselineScript::computeResumeNativeOffsets. r?tcampbell!

Depends on D40945

Comment 4

[Jan de Mooij [:jandem]]

Attachment: Bug 1552154 part 4 - Stop using pc-to-native map for BaselineScript::approximatePcForNativeAddress. r?tcampbell!

Depends on D40946

Comment 5

[Jan de Mooij [:jandem]]

Attachment: Bug 1552154 part 5 - Stop using pc-to-native map for BaselineScript::toggleDebugTraps. r?tcampbell!

Because DebugTrapEntries are only present if the script has debugger instrumentation
it should be fine to store this as a simple list of entries.

Depends on D40947

Comment 6

[Jan de Mooij [:jandem]]

Attachment: Bug 1552154 part 6 - Remove BaselineScript's pc-to-native map. r?tcampbell!

Depends on D40948

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/235c854c3233
part 1 - Use mozilla::Span<> in BaselineScript, clean up RetAddrEntry code a bit. r=tcampbell
https://hg.mozilla.org/integration/autoland/rev/77497544ca03
part 2 - Stop using pc-to-native map for OSR into Baseline JIT. r=tcampbell
https://hg.mozilla.org/integration/autoland/rev/941b29575f6a
part 3 - Stop using pc-to-native map for BaselineScript::computeResumeNativeOffsets. r=tcampbell
https://hg.mozilla.org/integration/autoland/rev/703a39b468df
part 4 - Stop using pc-to-native map for BaselineScript::approximatePcForNativeAddress. r=tcampbell
https://hg.mozilla.org/integration/autoland/rev/e481b4ed7784
part 5 - Stop using pc-to-native map for BaselineScript::toggleDebugTraps. r=tcampbell
https://hg.mozilla.org/integration/autoland/rev/937e9c6da43c
part 6 - Remove BaselineScript's pc-to-native map. r=tcampbell

Comment 8

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/235c854c3233
https://hg.mozilla.org/mozilla-central/rev/77497544ca03
https://hg.mozilla.org/mozilla-central/rev/941b29575f6a
https://hg.mozilla.org/mozilla-central/rev/703a39b468df
https://hg.mozilla.org/mozilla-central/rev/e481b4ed7784
https://hg.mozilla.org/mozilla-central/rev/937e9c6da43c