On heap segregation, GC optimization and @nogc relaxing

[ponce via Digitalmars-d]

On Wednesday, 12 November 2014 at 09:56:57 UTC, Paulo  Pinto 
wrote:
> On Wednesday, 12 November 2014 at 08:55:30 UTC, deadalnix wrote:
>> On Wednesday, 12 November 2014 at 08:38:14 UTC, Ola Fosheim
>>In addition, the whole
>> CPU industry is backpedaling on the transactional memory 
>> concept. That is awesome on the paper, but it didn't worked.
>
> Given the support on Haskell, Clojure and C++ I am not sure if 
> they are really backpedaling on it.
>
> The Haskell bugs are supposed to have been fixed in the next 
> generation.
>
> And there is PowerPC A2 as well.
>
> Not that I have any use for it, though.
>
> --
> Paulo

I actually tested Haswell HLE and was underwhelmed (not the full 
STM, was just trying to get more out of some locks).
The trouble with STM is that to be applicable, you need to have 
huge contention (else it wouldn't be a bottleneck) and a small 
task to do.
And this use case is already well served with spinlock-guarded 
locks which already allows to stay in user space most of the time.
That, added with the usual restrictions and gotchas for lockfree, 
makes it something not very life-changing at least in my limited 
experience.