Proposal for improving performance of TreeMap and others

[Rémi Forax]

Clemens Eisserer a écrit :
> Hi cowwoc,
>
>   
>> I guess you're right. It is probably as likely that the JIT will optimize
>> away the null check as it is that it will optimize away the
>> NullPointerException check. One exception, though, is when production
>> systems run using -Xverify:none. In such a case, wouldn't my approach run
>> faster?
>>     
> I don't think it will optimize the null-check away, 
Hotspot  removes nullcheck and install a signal handler since its v2
(around 2000/01 If my memory serves me well).

> however it is so
> cheap that it most likely will not weight at all, compared to all the
> other operations happening there. Its maybe 5 instructions compared to
> thousands or even more.
> -Xverify:none only disables bytecode verification at class-loading
> time and has no influence (as far as I know) on the performance of the
> generated code.
>   
yes, and there is an option to remove nullcheck that is only available 
on debug VM.
...
>
> lg Clemens
>   
Rémi