663455 - IonMonkey: add functionality useful for dataflow analyses

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Ryan Pearl [:rpearl]]

For computing available expression sets, we must perform set intersection, and see if the intersection changed anything (that is, we haven't reached a fixed point in the analysis yet).

We can trivially do so in one pass, rather than doing a subset check and then performing intersection.

Comment 1

[Ryan Pearl [:rpearl]]

Attachment: implements intersection + fixedpoint test

Comment 2

[David Anderson [:dvander] - inactive, e-mail if emergency]

Comment on attachment 538551 [details] [diff] [review]
implements intersection + fixedpoint test

Review of attachment 538551 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/ion/BitSet.cpp
@@ +122,5 @@
>  }
> +
> +// returns true if the intersection caused the contents of the set to change.
> +bool BitSet::fixedPointIntersect(const BitSet *other)
> +{

Drive-by style nit, the type gets its own line:

bool
BitSet::fixedPointIntersect(const BitSet *other)

Comment 3

[Andrew Drake [:adrake]]

Comment on attachment 538551 [details] [diff] [review]
implements intersection + fixedpoint test

Review of attachment 538551 [details] [diff] [review]:
-----------------------------------------------------------------

Looks good! r+ with dvander's nits addressed.

Comment 4

[Andrew Drake [:adrake]]

Comment on attachment 538551 [details] [diff] [review]
implements intersection + fixedpoint test

Review of attachment 538551 [details] [diff] [review]:
-----------------------------------------------------------------

Looks good! r+ with dvander's nits addressed.

Comment 5

[Ryan Pearl [:rpearl]]

Attachment: new patch (added functionality)

This fixes the nit--I ask for a new review because I've added complement, also needed by my analysis phase.

Comment 6

[Andrew Drake [:adrake]]

Comment on attachment 538601 [details] [diff] [review]
new patch (added functionality)

Review of attachment 538601 [details] [diff] [review]:
-----------------------------------------------------------------

Looks good with that comment added.

::: js/src/ion/BitSet.h
@@ +103,5 @@
> +    // O(max): Intersect this set with the given set; return whether the
> +    // intersection caused the set to change.
> +    bool fixedPointIntersect(const BitSet *other);
> +
> +    void complement();

Could we get a comment like the ones on the other functions on this?

Comment 7

[Ryan Pearl [:rpearl]]

http://hg.mozilla.org/users/danderson_mozilla.com/ionmonkey/rev/fd48b9858f74