Re: [v8-users] Profiling: what is "LoadIC: A load IC from the snapshot"?

[Andrew Wilcox]

>
> Depending on usage patterns, you might see a further speed boost if you 
> split your objects into two parts, where one has the same shape for all 
> objects and the other is type dependent
>

Oh interesting idea!  Thanks!

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Re: [v8-users] Profiling: what is "LoadIC: A load IC from the snapshot"?

[Jakob Kummerow]

Depending on usage patterns, you might see a further speed boost if you
split your objects into two parts, where one has the same shape for all
objects and the other is type dependent, roughly:

class Thing {
  constructor(type, specific, ...) {
this.type = type;
this.other_common_field = ...;

// If type === 100, this is a Foo; if type === 101, it's a Bar; etc.
this.type_specific_stuff = specific;
  }
}

var x = new Thing(100, new Foo(...), ...);  // Maybe wrap in a factory?

if (x.type === 100) {
  var data = x.type_specific_stuff.foo_field;  // Both loads are
monomorphic, yay!
}



On Thu, Mar 1, 2018 at 12:31 PM Andrew Wilcox 
wrote:

> can anyone tell me what LoadIC is?
>>
>>
>
>> The thing that handles property loads (like foo.bar;).
>
>
> Thank you Jacob!
>
>
> Seeing it take 22% is rare. Is your app heavy on polymorphic property
>> loads?
>
>
> Yes, I'm writing an interpreter and it was doing a *lot* of instanceof
> checks.  Since I don't have undefined or null values in my interpreter,
> rather than use x instanceof Foo I can instead give Foo instances a
> "type" property of e.g. 100 and use x.type === 100, which is faster.  So
> indeed yes, now it's doing a lot of polymorphic property loads! :-)  Makes
> perfect sense, thanks!
>
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Re: [v8-users] Profiling: what is "LoadIC: A load IC from the snapshot"?

[Andrew Wilcox]

>
> can anyone tell me what LoadIC is?
>
>  

> The thing that handles property loads (like foo.bar;).


Thank you Jacob!
 

Seeing it take 22% is rare. Is your app heavy on polymorphic property loads?

 
Yes, I'm writing an interpreter and it was doing a *lot* of instanceof 
checks.  Since I don't have undefined or null values in my interpreter, 
rather than use x instanceof Foo I can instead give Foo instances a "type" 
property of e.g. 100 and use x.type === 100, which is faster.  So indeed 
yes, now it's doing a lot of polymorphic property loads! :-)  Makes perfect 
sense, thanks!

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Re: [v8-users] Profiling: what is "LoadIC: A load IC from the snapshot"?

[Jakob Kummerow]

The thing that handles property loads (like foo.bar;).

Seeing it take 22% is rare. Is your app heavy on polymorphic property loads?


On Thu, Mar 1, 2018 at 9:44 AM Andrew Wilcox 
wrote:

> My prof output starts off with
>
>  [JavaScript]:
>ticks  total  nonlib   name
>   12065   22.7%   22.7%  LoadIC: A load IC from the snapshot
>27325.1%5.1%  Builtin: StrictEqual
>
> and I was wondering, can anyone tell me what LoadIC is?
>
> Thanks!
>
> Andrew
>
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