[LLVMdev] Proposal for a new LLVM concurrency memory model

[Jeffrey Yasskin]

On Mon, Apr 26, 2010 at 3:14 AM, Renato Golin <rengolin at systemcall.org> wrote:
> On 26 April 2010 10:49, Chandler Carruth <chandlerc at google.com> wrote:
>> Certainly for languages such as Java, they will make up a surprisingly large
>> chunk of the loads and stores, and instructions have much mor flexibility in
>> terms of syntax. On the flip side, it's a lot of plumbing IIRC, and we'd
>> really need to stick to the very minimal set of operations, supporting more
>> obscure ones by pattern matching or intrinsics.
>
> If you add it to the instructions, their syntax will be more complex
> than they are today, and reading them could prove a challenge.

To be clear, Chandler wasn't suggesting any change to the existing
load and store instructions. Instead, we were wondering if people like
the idea of _new_ atomic_load, atomic_store, atomic_cmpxchg, and maybe
atomic_exchange and atomic_add instructions.

> IMHO, we should keep it simple. I agree that multi-task is ubiquitous
> nowadays but the detailed implementation might vary considerably from
> language to language and making it explicit only helps, at least in
> the beginning.
>
> cheers,
> --renato