901100 - Generate set ICs for non-shadowing DOM proxies

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Boris Zbarsky [:bzbarsky]]

This comes up for "style.whatever = something" calls.  We should just call the setter from the proto chain, instead of going through the proxy code, since the prop is on the proto chain and the proxy is non-shadowing.

There's a bit of microbenchmark in attachment 383408 [details].

Comment 1

[Eric Faust [:efaust]]

Attachment: Implement SetPropertyIC stubs for unshadowed DOM proxies

As discussed with bz, this entails calling a setter if found on the prototype chain, else falling back to Proxy::set after the appropriate guards.

This includes a factor out of the setter code as well.

Comment 2

[Kannan Vijayan [:djvj]]

Comment on attachment 795846 [details] [diff] [review]
Implement SetPropertyIC stubs for unshadowed DOM proxies

Review of attachment 795846 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/jit/IonCaches.cpp
@@ +2441,5 @@
> +            break;
> +        }
> +
> +        isSetter = true;
> +    } while(0);

The logic in this do-while loop is more appropriate in a separate checker procedure (e.g. IsCacheableSetDOMProxyUnshadowed).  When we call
|attachDOMProxyUnshadowed|, we should already know that it's an appropriate stub to be attached.

Comment 3

[Eric Faust [:efaust]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/3cd1d0ccb812

Comment 4

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/3cd1d0ccb812