Open Bug 2042395 Opened 1 month ago Updated 1 month ago

Attached CacheIR stub for uncachable DOM proxies always fails

Categories

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

Product:
Core
Component:
JavaScript Engine: JIT
Type:
defect

Tracking

()

Status:
ASSIGNED

People

(Reporter: jandem, Assigned: jandem)

References

(Blocks 3 open bugs)

Details

This is a (minor but real) performance bug that affects certain DOM proxies:

  1. GetProxyStubType returns ProxyStubType::Generic for proxies that have IsCacheableDOMProxy false. This includes DOM proxies with a dynamic proto.
  2. The callers will then call tryAttachGenericProxy with handleDOMProxies = false.
  3. This will generate an IC stub that fails for DOM proxies, even though we want to handle DOM proxies in this case.

I see this show up for lookups on Location objects in the browser.

The simplest option may be to remove the handleDOMProxies argument for tryAttachGenericProxy. I'll see if that has any effect on sp3.

Blocks: sm-jits, sm-js-perf, sm-perf-next
Severity: -- → S4
Priority: -- → P2
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