810373 - BaselineCompiler: Add WeakMap-per-runtime of baseline stubCode and enable their sharing between different ICs.

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Comment 1

[Kannan Vijayan [:djvj]]

Attachment: Add weakmap to IonCompartment to share baseline IC stub codes.

Needed to add a new type WeakValueMap that doesn't try to treat its keys as gcthings, since we're using int32 keys.

Comment 2

[Jan de Mooij [:jandem]]

Comment on attachment 680329 [details] [diff] [review]
Add weakmap to IonCompartment to share baseline IC stub codes.

Review of attachment 680329 [details] [diff] [review]:
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Nice.

::: js/src/jsweakcache.h
@@ +86,5 @@
> +    explicit WeakValueCache(JSContext *cx) : Base(cx) { }
> +
> +  public:
> +    // Sweep all entries which have unmarked key or value.
> +    void sweep(FreeOp *fop) {

We should call this method in IonCompartment::sweep.

For now we can mark all values in the table in IonCompartment::mark, but if we want it to behave like a real WeakMap we have to iterate over all stubs, find out which IonCode belongs to it and mark that. Do we have to store an IonCode pointer in the stub for that?

@@ +91,5 @@
> +        // Remove all entries whose values remain unmarked.
> +        for (Enum e(*this); !e.empty(); e.popFront()) {
> +            if (!gc::IsMarked(e.front().value)) {
> +                e.removeFront();
> +            }

Nit: no braces

@@ +99,5 @@
> +        // Once we've swept, all remaining edges should stay within the
> +        // known-live part of the graph.
> +        for (Range r = Base::all(); !r.empty(); r.popFront()) {
> +            JS_ASSERT(gc::IsMarked(r.front().value));
> +        }

Same here.

Comment 3

[Kannan Vijayan [:djvj]]

https://hg.mozilla.org/projects/ionmonkey/rev/ba510446fef6