"x is Foo" will become getInterceptor(x).$isFoo
Testing against a type with type arguments is still a giveup().
This test always works, but is not very fast. For instance, testing
against an int should be "typeof x === 'number' && Math.floor(x) === x".
Following an offline discussion with Karl, the plan is to rewrite
'is'-checks to more fine-grained tests in a CPS optimization pass,
probably the type propagator.
Concretely, we plan to introduce IR nodes like TypeOfTest, FloorTest,
InstanceofTest, etc, which optimization phases can introduce under the
right circumstances. That way, the code generation phase remains simple.
BUG=
R=karlklose@google.com
Review URL: https://codereview.chromium.org//1144163004
Asger Feldthaus
f42a0ef25c