RFR(XXS): 8189244: x86: eliminate frame::adjust_unextended_sp() overhead

[dean.long at oracle.com]

Thanks Vladimir.

dl


On 10/12/17 2:13 PM, Vladimir Kozlov wrote:
> Nice find.
>
> Thanks,
> Vladimir
>
> On 10/12/17 12:46 PM, dean.long at oracle.com wrote:
>> https://bugs.openjdk.java.net/browse/JDK-8189244
>>
>> http://cr.openjdk.java.net/~dlong/8189244/webrev
>>
>> The work that frame::adjust_unextended_sp() does is DEBUG_ONLY, but 
>> the compiler cannot completely eliminate the code because of the 
>> virtual call to is_compiled() that could have side-effects. We can 
>> fix the problem by wrapping the whole thing in #ifdef ASSERT.
>>
>> This change reduces the size of libjvm.so by almost 2K, and the size 
>> of frame::sender() by 8%.
>>
>> dl