Date: Mon, 26 Sep 2022 16:54:04 +0300 From: Lev Serebryakov <lev@FreeBSD.org> To: freebsd-current@freebsd.org Subject: Re: Did clang 14 lose some intrinsics support? Message-ID: <8cd08b95-396a-b8a3-e33a-b0482a7f23e5@FreeBSD.org> In-Reply-To: <430A830E-3473-4EF4-9605-039F8254999C@FreeBSD.org> References: <YzCL/%2BUEhLy7kHaL@lorvorc.mips.inka.de> <zgen-6zwv-wny@FreeBSD.org> <1A903FD8-D904-4B91-ABC4-2F704F0E2CF4@FreeBSD.org> <YzDKQsfciGd%2BJBQ5@lorvorc.mips.inka.de> <430A830E-3473-4EF4-9605-039F8254999C@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?8cd08b95-396a-b8a3-e33a-b0482a7f23e5>