[llvm-branch-commits] [llvm] InstCombine: Rudimentary support of shufflevector in SimplifyDemandedFPClass (PR #174101)

[Simon Pilgrim via llvm-branch-commits]

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@@ -2314,6 +2314,17 @@ Value *InstCombinerImpl::SimplifyDemandedUseFPClass(Value *V,
     Known = KnownVec | KnownInserted;
     break;
   }
+  case Instruction::ShuffleVector: {
+    KnownFPClass KnownLHS, KnownRHS;
+    if (SimplifyDemandedFPClass(I, 1, DemandedMask, KnownRHS, Depth + 1) ||
+        SimplifyDemandedFPClass(I, 0, DemandedMask, KnownLHS, Depth + 1))
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RKSimon wrote:

DemandedMask can't be passed directly to shufflevector operands, it needs to be resorted by the mask

https://github.com/llvm/llvm-project/pull/174101