Leo Famulari <leo@famulari.name> writes:

> On Sun, Nov 27, 2016 at 10:02:35PM +0100, Tobias Geerinckx-Rice wrote:
>> Leo,
>> 
>> On 27/11/16 21:56, Leo Famulari wrote:
>> > Will this work on nachines that don't support SSE? My understanding is
>> > that we don't wish to require it.
>> 
>> Why wouldn't it?
>> 
>> I don't often use Icecat, but when I do... I don't see why it would
>> require SSE by default. ;-) And it's not like we ever patched it to use
>> IJG's libjpeg to begin with.
>
> I'm not sure, but the comment seems to indicate that we don't want to
> use it:
>
> ;; According to
> ;; http://sourceforge.net/projects/libjpeg-turbo/ ,
> ;; "libjpeg-turbo is a derivative of libjpeg that
> ;; uses MMX, SSE, SSE2, and NEON SIMD instructions
> ;; to accelerate baseline JPEG compression/
> ;; decompression", so we had better not use it

SSE is pentium III, and SSE2 was introduced in Pentium IV. MMX is even
older. Are we really committed to supporting 15+ year old hardware?

The NEON SIMD instruction seems to be ARM-specific and is available at
least on Cortex A8, which is an ARMv7 design.