[clang] [HLSL] Implement support for HLSL intrinsic - select (PR #107129)

[Damyan Pepper via cfe-commits]

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@@ -1544,6 +1604,30 @@ bool SemaHLSL::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
       return true;
     break;
   }
+  case Builtin::BI__builtin_hlsl_select: {
+    if (SemaRef.checkArgCount(TheCall, 3))
+      return true;
+    QualType ArgTy = TheCall->getArg(0)->getType();
+    if (ArgTy->isBooleanType()) {
+      if (CheckBoolSelect(&SemaRef, TheCall))
+	return true;
+    } else if (ArgTy->isVectorType() &&
+	       ArgTy->getAs<VectorType>()->getElementType()->isBooleanType()) {
+      if (CheckVectorSelect(&SemaRef, TheCall))
+	return true;
+    } else { // first operand is not a bool or a vector of bools.
+      SemaRef.Diag(TheCall->getArg(0)->getBeginLoc(),
+		   diag::err_typecheck_convert_incompatible)
+	<< TheCall->getArg(0)->getType() << getASTContext().BoolTy
+	<< 1 << 0 << 0;
+      SemaRef.Diag(TheCall->getArg(0)->getBeginLoc(),
+		   diag::err_builtin_non_vector_type)
+	<< "First" << "__builtin_hlsl_select" << TheCall->getArg(0)->getType()
+	<< TheCall->getArg(0)->getSourceRange();
+      return true;
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damyanp wrote:

Wondering why this case doesn't also use a helper function and instead inlines the detection and diagnostic code here.

https://github.com/llvm/llvm-project/pull/107129