[llvm] [InstCombine][X86] Only demand the active index bits for VPERMV/VPERMV3 mask values (PR #106750)

[via llvm-commits]

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@@ -3004,6 +3020,8 @@ X86TTIImpl::instCombineIntrinsic(InstCombiner &IC, IntrinsicInst &II) const {
     if (Value *V = simplifyX86vpermv(II, IC.Builder)) {
       return IC.replaceInstUsesWith(II, V);
     }
+    if (simplifyX86VPERMMask(&II, false, IC))
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goldsteinn wrote:

nit: `/*IsBinary=*/false`, likewise below for `true`.

https://github.com/llvm/llvm-project/pull/106750