[clang] [llvm] Implements isnan() HLSL intrinsic for DXIL and SPIR-V targets. (PR #157733)

[Dan Brown via cfe-commits]

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@@ -1024,6 +1025,9 @@ static bool expandIntrinsic(Function &F, CallInst *Orig) {
   case Intrinsic::dx_isinf:
     Result = expand16BitIsInf(Orig);
     break;
+  case Intrinsic::dx_isnan:
+    Result = expand16BitIsInf(Orig);
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danbrown-amd wrote:

Fixed.copy/paste error and other bugs and added the requested test.

https://github.com/llvm/llvm-project/pull/157733