[clang] [llvm] [HLSL] Implement the `smoothstep` intrinsic (PR #132288)

[Kaitlin Peng via llvm-commits]

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@@ -101,6 +101,52 @@ bool SemaSPIRV::CheckSPIRVBuiltinFunctionCall(unsigned BuiltinID,
     TheCall->setType(RetTy);
     break;
   }
+  case SPIRV::BI__builtin_spirv_smoothstep: {
+    if (SemaRef.checkArgCount(TheCall, 3))
+      return true;
+
+    // check if the all arguments have floating representation
+    ExprResult A = TheCall->getArg(0);
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kmpeng wrote:

I'm already checking `hasFloatingRepresentation` for all of the args and emitting the corresponding diag. Do you want me to move the individual checks into a for loop?

https://github.com/llvm/llvm-project/pull/132288