Bug 150983 – We should treat structures that vary solely in their prototype as a single polymorphic type.

• Status: RESOLVED
• Resolution: DUPLICATE
• Component: JavaScriptCore

[Keith Miller]

Consider the following code:

function foo()
    function Bar(x) {
        this.x = x;
    }

    return new Bar(1);
}

Every time foo() is called the returned value will have a different prototype. At some point, probably the second time we construct a new Bar() we should convert the structure into a new one that instead indicates we should get the prototype off the object itself rather than off the structure. This would prevent inline caches from becoming megamorphic.

[Keith Miller]

*** This bug has been marked as a duplicate of bug 176391 ***