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

Hendrik Leppkes h.leppkes at gmail.com
Sat Aug 5 14:54:22 EEST 2017

On Sat, Aug 5, 2017 at 12:21 PM, Ivan Kalvachev <ikalvachev at gmail.com> wrote:
> 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.

Consistency with the typical style of our codebase is also a reason.

- Hendrik

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