Addressed PR feedback

Author: sumitsays

clang/include/clang/Basic/Builtins.td

@@ -4894,7 +4894,7 @@ def HLSLDotProduct : LangBuiltin<"HLSL_LANG"> {
 def HLSLDot2Add : LangBuiltin<"HLSL_LANG"> {
   let Spellings = ["__builtin_hlsl_dot2add"];
   let Attributes = [NoThrow, Const, CustomTypeChecking];
-  let Prototype = "void(...)";
+  let Prototype = "float(_ExtVector<2, _Float16>,_ExtVector<2, _Float16>, float)";
 }
 
 def HLSLDot4AddI8Packed : LangBuiltin<"HLSL_LANG"> {

clang/lib/Headers/hlsl/hlsl_intrinsics.h

@@ -179,12 +179,15 @@ const inline float distance(__detail::HLSL_FIXED_VECTOR<float, N> X,
 // dot2add builtins
 //===----------------------------------------------------------------------===//
 
-/// \fn float dot2add(half2 a, half2 b, float c)
+/// \fn float dot2add(half2 A, half2 B, float C)
 /// \brief Dot product of 2 vector of type half and add a float scalar value.
+/// \param A The first input value to dot product. 
+/// \param B The second input value to dot product.
+/// \param C The input value added to the dot product.
 
 _HLSL_AVAILABILITY(shadermodel, 6.4)
-const inline float dot2add(half2 a, half2 b, float c) {
-  return __detail::dot2add_impl(a, b, c);
+const inline float dot2add(half2 A, half2 B, float C) {
+  return __detail::dot2add_impl(A, B, C);
 }
 
 //===----------------------------------------------------------------------===//

clang/lib/Sema/SemaHLSL.cpp

@@ -2476,11 +2476,9 @@ bool SemaHLSL::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
     break;
   }
   case Builtin::BI__builtin_hlsl_dot2add: {
-    // Check number of arguments should be 3
     if (SemaRef.checkArgCount(TheCall, 3))
       return true;
 
-    // Check first two arguments are vector of length 2 with half data type
     auto checkHalfVectorOfSize2 = [](clang::QualType PassedType) -> bool {
       if (const auto *VecTy = PassedType->getAs<VectorType>())
         return !(VecTy->getNumElements() == 2 &&
@@ -2496,10 +2494,9 @@ bool SemaHLSL::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
                              checkHalfVectorOfSize2))
       return true;
 
-    // Check third argument is a float
     if (CheckArgTypeMatches(&SemaRef, TheCall->getArg(2), SemaRef.getASTContext().FloatTy))
       return true;
-    TheCall->setType(TheCall->getArg(2)->getType());
+    TheCall->setType(SemaRef.getASTContext().FloatTy);
     break;
   }
   case Builtin::BI__builtin_hlsl_elementwise_firstbithigh:

clang/test/CodeGenHLSL/builtins/dot2add.hlsl

@@ -1,17 +1,18 @@
-// RUN: %clang_cc1 -finclude-default-header -triple \
+// RUN: %clang_cc1 -finclude-default-header -fnative-half-type -triple \
 // RUN:   dxil-pc-shadermodel6.3-compute %s -emit-llvm -disable-llvm-passes -o - | \
 // RUN:   FileCheck %s --check-prefixes=CHECK,CHECK-DXIL
-// RUN: %clang_cc1 -finclude-default-header -triple \
+// RUN: %clang_cc1 -finclude-default-header -fnative-half-type -triple \
 // RUN:   spirv-pc-vulkan-compute %s -emit-llvm -disable-llvm-passes -o - | \
 // RUN:   FileCheck %s --check-prefixes=CHECK,CHECK-SPIRV
 
 // Test basic lowering to runtime function call.
 
 float test(half2 p1, half2 p2, float p3) {
-  // CHECK-SPIRV:  %[[MUL:.*]] = call {{.*}} float @llvm.spv.fdot.v2f32(<2 x float> %1, <2 x float> %2)
+  // CHECK-SPIRV:  %[[MUL:.*]] = call {{.*}} half @llvm.spv.fdot.v2f16(<2 x half> %1, <2 x half> %2)
+  // CHECK-SPIRV:  %[[CONVERT:.*]] = fpext {{.*}} half %[[MUL:.*]] to float
   // CHECK-SPIRV:  %[[C:.*]] = load float, ptr %c.addr, align 4
-  // CHECK-SPIRV:  %[[RES:.*]] = fadd {{.*}} float %[[MUL]], %[[C]]
-  // CHECK-DXIL:  %[[RES:.*]] = call {{.*}} float @llvm.dx.dot2add.v2f32(<2 x float> %0, <2 x float> %1, float %2)
+  // CHECK-SPIRV:  %[[RES:.*]] = fadd {{.*}} float %[[CONVERT:.*]], %[[C:.*]]
+  // CHECK-DXIL:  %[[RES:.*]] = call {{.*}} float @llvm.dx.dot2add.v2f16(<2 x half> %0, <2 x half> %1, float %2)
   // CHECK:  ret float %[[RES]]
   return dot2add(p1, p2, p3);
-}
+}

clang/test/SemaHLSL/BuiltIns/Dot2Add-errors.hlsl

@@ -1,11 +1,36 @@
-// RUN: %clang_cc1 -finclude-default-header -triple dxil-pc-shadermodel6.6-library %s -emit-llvm-only -disable-llvm-passes -verify
+// RUN: %clang_cc1 -finclude-default-header -triple dxil-pc-shadermodel6.6-library %s -fnative-half-type -emit-llvm-only -disable-llvm-passes -verify
 
-bool test_too_few_arg() {
+float test_too_few_arg() {
   return __builtin_hlsl_dot2add();
   // expected-error@-1 {{too few arguments to function call, expected 3, have 0}}
 }
 
-bool test_too_many_arg(half2 p1, half2 p2, float p3) {
+float test_too_many_arg(half2 p1, half2 p2, float p3) {
   return __builtin_hlsl_dot2add(p1, p2, p3, p1);
   // expected-error@-1 {{too many arguments to function call, expected 3, have 4}}
 }
+
+float test_float_arg2_type(half2 p1, float2 p2, float p3) {
+  return __builtin_hlsl_dot2add(p1, p2, p3);
+  // expected-error@-1 {{passing 'float2' (aka 'vector<float, 2>') to parameter of incompatible type '__attribute__((__vector_size__(2 * sizeof(half)))) half' (vector of 2 'half' values)}}
+}
+
+float test_float_arg1_type(float2 p1, half2 p2, float p3) {
+  return __builtin_hlsl_dot2add(p1, p2, p3);
+  // expected-error@-1 {{passing 'float2' (aka 'vector<float, 2>') to parameter of incompatible type '__attribute__((__vector_size__(2 * sizeof(half)))) half' (vector of 2 'half' values)}}
+}
+
+float test_double_arg3_type(half2 p1, half2 p2, double p3) {
+  return __builtin_hlsl_dot2add(p1, p2, p3);
+  // expected-error@-1 {{passing 'double' to parameter of incompatible type 'float'}}
+}
+
+float test_float_arg1_arg2_type(float2 p1, float2 p2, float p3) {
+  return __builtin_hlsl_dot2add(p1, p2, p3);
+  // expected-error@-1 {{passing 'float2' (aka 'vector<float, 2>') to parameter of incompatible type '__attribute__((__vector_size__(2 * sizeof(half)))) half' (vector of 2 'half' values)}}
+}
+
+float test_int16_arg1_arg2_type(int16_t2 p1, int16_t2 p2, float p3) {
+  return __builtin_hlsl_dot2add(p1, p2, p3);
+  // expected-error@-1 {{passing 'int16_t2' (aka 'vector<int16_t, 2>') to parameter of incompatible type '__attribute__((__vector_size__(2 * sizeof(half)))) half' (vector of 2 'half' values)}}
+}

llvm/test/CodeGen/DirectX/dot2add.ll

@@ -5,4 +5,4 @@ entry:
 ; CHECK: call float @dx.op.dot2AddHalf(i32 162, float %c, half %0, half %1, half %2, half %3)
   %ret = call float @llvm.dx.dot2add(<2 x half> %a, <2 x half> %b, float %c)
   ret float %ret
-}
+}