Re: Did clang 14 lose some intrinsics support?

Reply: Warner Losh : "Re: Did clang 14 lose some intrinsics support?"
In reply to: Dimitry Andric : "Re: Did clang 14 lose some intrinsics support?"
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From: Lev Serebryakov <lev_at_FreeBSD.org>
Date: Mon, 26 Sep 2022 13:54:04 UTC

On 26.09.2022 13:03, Dimitry Andric wrote:

> Sure, but if you are compiling without -mavx, why would you want the AVX
> intrinsics? You cannot use AVX intrinsics anyway, if AVX is not enabled.
   Because autovectorization (generation of SSE or AVX instructions by compiler itself, without intrinsics) can pessimize code.

   Sometimes it is valuable to know exactly where AVX is used. I don't have examples on hands, but I've seen situations, when autovectorized code was much slower than scalar code.

-- 
// Lev Serebryakov