RFR: 8186838: Generalize Atomic::inc/dec with templates

[David Holmes]

On 7/09/2017 7:34 PM, Erik Österlund wrote:
> Hi David,
> 
> On 2017-09-07 04:10, David Holmes wrote:
>> <trimming>
>>
>> On 5/09/2017 10:09 PM, Erik Österlund wrote:
>>> Okay, great. So far it sounds like as for Atomic::inc/dec, there are 
>>> no loud voices against the idea of removing the Atomic::inc/dec 
>>> specializations. So I propose this new webrev that does exactly that.
>>>
>>> Full webrev:
>>> http://cr.openjdk.java.net/~eosterlund/8186838/webrev.01/
>>>
>>> Incremental over last webrev:
>>> http://cr.openjdk.java.net/~eosterlund/8186838/webrev.00_01/
>>>
>>> I hope this looks simpler.
>>
>> Yes this is much simpler.
> 
> Glad to hear it!
> 
>> I am still totally dismayed by the complexity that was needed to 
>> retain the inc/dec specializations. To me it just screams that there 
>> is something fundamentally wrong with what was being done. :(
> 
> Okay.
> 
>> I'm also somewhat perplexed. I can't read inline assembly fluently, 
>> but looking at the existing inc_ptr implementations, eg for x86, I'm 
>> not seeing code that adds 1*sizeof(*dest). ??
> 
> Neither can I.

Okay so ... something not right here. :)

It seems to me that the uses of inc_ptr are actually just bumping a 
counter by 1, where the counter is defined to be the same size as a ptr 
ie 32-bit on 32-bit and 64-bit on 64-bit.

Cheers,
David

> Thanks,
> /Erik
> 
>> Thanks,
>> David
>>
>>> Thanks,
>>> /Erik
>