[clang] [llvm] Add cross builtins and cross HLSL function to DirectX and SPIR-V backend (PR #109180)

[Joshua Batista via llvm-commits]

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@@ -1828,6 +1828,41 @@ bool SemaHLSL::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
       return true;
     break;
   }
+  case Builtin::BI__builtin_hlsl_cross: {
+    if (SemaRef.checkArgCount(TheCall, 2))
+      return true;
+    if (CheckVectorElementCallArgs(&SemaRef, TheCall))
+      return true;
+    if (CheckFloatOrHalfRepresentations(&SemaRef, TheCall))
+      return true;
+    // ensure both args have 3 elements
+    int NumElementsArg1 =
+        TheCall->getArg(0)->getType()->getAs<VectorType>()->getNumElements();
+    int NumElementsArg2 =
+        TheCall->getArg(1)->getType()->getAs<VectorType>()->getNumElements();
+
+    if (NumElementsArg1 != 3) {
+      int LessOrMore = NumElementsArg1 > 3 ? 1 : 0;
+      SemaRef.Diag(TheCall->getBeginLoc(),
+                   diag::err_vector_incorrect_num_initializers)
+          << LessOrMore << 3 << NumElementsArg1 << 1;
+      return true;
+    }
+    if (NumElementsArg2 != 3) {
+      int LessOrMore = NumElementsArg1 > 3 ? 1 : 0;
----------------
bob80905 wrote:

Good catch!

https://github.com/llvm/llvm-project/pull/109180