[FFmpeg-devel] [PATCH]v6 Opus Pyramid Vector Quantization Search in x86 SIMD asm

Ivan Kalvachev ikalvachev at gmail.com
Sat Aug 5 13:21:15 EEST 2017


On 8/5/17, Rostislav Pehlivanov <atomnuker at gmail.com> wrote:
> On 4 August 2017 at 23:58, Ivan Kalvachev <ikalvachev at gmail.com> wrote:
>
>>
>> >> I had it mixed before, but I changed it to be consistent.
>> >> Some new avx instruction are not overloaded or
>> >> available without their "v-" prefix.
>> >> e.g. x86util uses vpbroadcastw in SPLATW.
>> >
>> > Every instruction that has both a legacy encoding and a VEX-encoding
>> > will be automatically converted to VEX in AVX functions when written
>> > without the v-prefix. There is no legacy encoding for newer
>> > instructions so there's no reason for x86inc to overload those.
>>
>> That's great, but it doesn't address the original problem.
>> Do you insist on removing the "v-" prefix from AVX only instructions?
>>
>>
> I insist.

If you insist, then you should have a good technical reason for it.
Something that is not based on looks, cosmetics or "it has always been
like this".

For example, slow compilation because of unnecessary macro expansion is
a technical reason to keep the "v-" prefix.

;)


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