WIP: Addressed PR feedback

Author: sumitsays

clang/lib/CodeGen/CGHLSLBuiltins.cpp

@@ -380,6 +380,18 @@ Value *CodeGenFunction::EmitHLSLBuiltinExpr(unsigned BuiltinID,
         getDotProductIntrinsic(CGM.getHLSLRuntime(), VecTy0->getElementType()),
         ArrayRef<Value *>{Op0, Op1}, nullptr, "hlsl.dot");
   }
+  case Builtin::BI__builtin_hlsl_dot2add: {
+    llvm::Triple::ArchType Arch = CGM.getTarget().getTriple().getArch();
+    assert(Arch == llvm::Triple::dxil && "Intrinsic dot2add is only allowed for dxil architecture");
+    Value *A = EmitScalarExpr(E->getArg(0));
+    Value *B = EmitScalarExpr(E->getArg(1));
+    Value *C = EmitScalarExpr(E->getArg(2));
+
+    Intrinsic::ID ID = llvm ::Intrinsic::dx_dot2add;
+    return Builder.CreateIntrinsic(
+        /*ReturnType=*/C->getType(), ID, ArrayRef<Value *>{A, B, C}, nullptr,
+        "dx.dot2add");
+  }
   case Builtin::BI__builtin_hlsl_dot4add_i8packed: {
     Value *A = EmitScalarExpr(E->getArg(0));
     Value *B = EmitScalarExpr(E->getArg(1));

clang/test/CodeGenHLSL/builtins/dot2add.hlsl

@@ -8,7 +8,7 @@
 // Test basic lowering to runtime function call.
 
 // CHECK-LABEL: define {{.*}}test
-float test(half2 p1, half2 p2, float p3) {
+float test_default_parameter(half2 p1, half2 p2, float p3) {
   // CHECK-SPIRV:  %[[RES:.*]] = call {{.*}} float @_ZN4hlsl7dot2addEDv2_DhS0_f(<2 x half> {{.*}} %1, <2 x half> {{.*}} %2, float {{.*}} %3) #3 {{.*}}
   // CHECK-DXIL:  %[[RES:.*]] = call {{.*}} float @_ZN4hlsl7dot2addEDv2_DhS0_f(<2 x half> {{.*}} %0, <2 x half> {{.*}} %1, float {{.*}} %2) #2
   // CHECK:  ret float %[[RES]]