Re: [PATCH v2 1/4] siphash: add cryptographically secure hashtable function

From: Hannes Frederic Sowa
Date: Thu Dec 15 2016 - 16:10:15 EST


On 15.12.2016 22:04, Peter Zijlstra wrote:
> On Thu, Dec 15, 2016 at 09:43:04PM +0100, Jason A. Donenfeld wrote:
>> On Thu, Dec 15, 2016 at 9:31 PM, Hannes Frederic Sowa
>> <hannes@xxxxxxxxxxxxxxxxxxx> wrote:
>>> ARM64 and x86-64 have memory operations that are not vector operations
>>> that operate on 128 bit memory.
>>
>> Fair enough. imull I guess.
>
> imull is into rdx:rax, not memory. I suspect he's talking about
> cmpxchg16b.

Exactly and I think I saw a ll/sc 128 bit on armv8 to atomically
manipulate linked lists.

Bye,
Hannes