[llvm] [ConstantTime][LLVM] Add llvm.ct.select intrinsic with generic SelectionDAG lowering (PR #166702)

[Yingwei Zheng via llvm-commits]

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@@ -6106,6 +6106,17 @@ void Verifier::visitIntrinsicCall(Intrinsic::ID ID, CallBase &Call) {
     }
     break;
   }
+  case Intrinsic::ct_select: {
+    // The value type is only constrained to first-class by tablegen's
+    // llvm_any_ty; SelectionDAG lowering only supports single-value types.
+    Type *ValTy = Call.getType();
+    Check(ValTy->isIntOrIntVectorTy() || ValTy->isFPOrFPVectorTy() ||
+              ValTy->isPtrOrPtrVectorTy(),
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dtcxzyw wrote:

`|| ValTy->isByteOrByteVectorTy()`

https://github.com/llvm/llvm-project/pull/166702