[PATCH] D88396: [X86] Replace movaps with movups when avx is enabled.

Craig Topper via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Mon Sep 28 12:26:41 PDT 2020


craig.topper added a comment.

Ignoring the motivating code here for a second. Using aligned load/store instructions with AVX is a little weird. If we fold the load into an arithmetic op, with AVX it doesn't have to be aligned so using the folded instruction suppresses the fault check. This is different than SSE where we can only fold aligned loads except on AMD CPUs. So AVX provides an inconsistent faulting experience. But if we were going to change that I'd hunt down all the places we check the alignment and remove them and take the code size reduction in the compiler instead of adding a new pass.


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https://reviews.llvm.org/D88396



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