[compiler-rt] [llvm] [MSAN] support vpermilvar AVX instructions (PR #143053)

[Florian Mayer via llvm-commits]

fmayer wrote:

> use insertShadowCheck(I.getArgOperand(1)), which will report it as uninitialized memory; similar to extractLowerShadow, where "intuitively it feels like a partly uninitialized mask is unintended, and we should warn the user immediately."

Done

https://github.com/llvm/llvm-project/pull/143053