iOS WG (1.0.3) - ARM64 SIMD ChaCha20

[Lonnie Abelbeck]

> On Feb 20, 2019, at 3:01 PM, Sebastian Gottschall <s.gottschall at newmedia-net.de> wrote:
> 
> 
> Am 20.02.2019 um 16:03 schrieb Lonnie Abelbeck:
>> Thanks to Jason and the team, a new iOS WG 1.0.3 appeared as an update:
>> 
>> 1.0.3 / Feb 19, 2019
>> --
>> Performance should be higher and battery usage lower, thanks to a new ARM64 SIMD implementation of ChaCha20
>> --
>> For reference, the upstream golang crypto commit is here [1] with performance numbers.
>> 
>> So, the question come to mind, do my iOS devices have ARM64 SIMD support, quick answer is if the device is less than 6 years old it should have ARM64 SIMD support.  Added in the A5/A6 CPU's from what I can tell.
> 
> A5 and A6 is 32 bit. A7 was the first 64 bit cpu (introduced with Iphone 5s)
> 
> Sebastian

Thanks Sebastian for the info,

It appears if the device can run iOS 12 (required by iOS WG) then it also has ARM64 SIMD support.

Lonnie



>> Apple-designed processors
>> https://en.wikipedia.org/wiki/Apple-designed_processors
>> 
>> [1] chacha20: add SIMD implementation on arm64
>> https://go.googlesource.com/crypto/+/74369b46fc6756741c016591724fd1cb8e26845f