[llvm] [DirectX][DXIL] Distinguish return type for overload type resolution. (PR #85646)

[Justin Bogner via llvm-commits]

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@@ -44,7 +44,12 @@ static void lowerIntrinsic(dxil::OpCode DXILOp, Function &F, Module &M) {
     Args.emplace_back(DXILOpArg);
     Args.append(CI->arg_begin(), CI->arg_end());
     B.SetInsertPoint(CI);
-    CallInst *DXILCI = DXILB.createDXILOpCall(DXILOp, OverloadTy, CI->args());
+    // Return type of F may be different from that of its arguments.
+    // It may not correspond to any overload type (if one exists) of the
+    // parameters. Pass the return type and overload type separately to handle
+    // such situations.
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bogner wrote:

I'm not convinced this comment really adds anything here - it describes why the API is the way it is, but why describe that at some random caller? *If* this is worth keeping it's probably better as API doc on the `createDXILOpCall` method, but I personally think it's pretty clear why it's there and this is just commentary that belongs in the commit message.

https://github.com/llvm/llvm-project/pull/85646