977181 - Don't push/assume IonContext when executing JIT code

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, defect)

Description

[Luke Wagner [:luke]]

Attachment: rm-ion-context-push

IonContext is used during JIT compilation (much less after the performance work to stop using GetIonContext), but it shouldn't be necessary while running JIT code since we already maintain PerThreadData::ionJSContext when pushing JitActivations.

This patch adds a GetJSContextFromJitCode() that returns TlsPerThreadData.get()->ionJSContext and uses this in the few places that use GetIonContext()->cx when called from JIT code.  The patch also pushes an IonContext in a few places that perform IC compilation.  (Hopefully later we'll be able to remove the remaining IonContext uses from compilation and just use explicit alloc/cx-passing.)

Comment 1

[Luke Wagner [:luke]]

Attachment: rename-ion-to-jit

While I'm here, I might as well rename ionJSContext to jitJSContext and ionStackLimit to jitStackLimit.

Comment 2

[Jan de Mooij [:jandem]]

Comment on attachment 8382328 [details] [diff] [review]
rm-ion-context-push

Review of attachment 8382328 [details] [diff] [review]:
-----------------------------------------------------------------

Nice! I think you can also remove FastInvokeGuard::ictx_ (in vm/Interpreter-inl.h) now, r=me with that.

Comment 3

[Jan de Mooij [:jandem]]

Comment on attachment 8382339 [details] [diff] [review]
rename-ion-to-jit

Review of attachment 8382339 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/vm/Stack.cpp
@@ +1340,5 @@
>  jit::JitActivation::~JitActivation()
>  {
>      if (active_) {
>          cx_->mainThread().ionTop = prevIonTop_;
> +        cx_->mainThread().jitJSContext = prevIonJSContext_;

Nit: we can rename prevIonJSContext_ too.

Comment 4

[Luke Wagner [:luke]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/1cec924f3734
https://hg.mozilla.org/integration/mozilla-inbound/rev/2fb5b3b138d7

Comment 5

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/2fb5b3b138d7
https://hg.mozilla.org/mozilla-central/rev/1cec924f3734