https://icyveins7.github.io/tags/msvc/Recent content in Msvc on icyveins7's blogHugoen-usThis work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.Sat, 24 Feb 2024 20:00:00 +0800https://icyveins7.github.io/posts/2024/02/msvcs-terrible-auto-vectoriser-for-avx/Sat, 24 Feb 2024 20:00:00 +0800https://icyveins7.github.io/posts/2024/02/msvcs-terrible-auto-vectoriser-for-avx/<blockquote> <p>MSVC has extremely lackluster auto-vectorisation, so I handrolled intrinsic calls by backtranslating GCC&rsquo;s output.</p> </blockquote> <h1 id="the-motivation">The Motivation</h1> <p>I recently decided I wanted to spend some time understanding intrinsics and SIMD at a deeper level.</p> <p>In developing code for my project <a href="https://github.com/icyveins7/ffs"><code>ffs</code></a>, I wanted to make sure that the code was running with at least AVX instructions (because that&rsquo;s my target architecture, and honestly very few computers don&rsquo;t have AVX these days..).</p> <p>This led me down a path of discovery; first I discovered the amazing-ness that is <a href="https://godbolt.org">godbolt.org</a>, then I joined their discord, where I then asked for some help with understanding basic .asm compiler output.</p>