Address PR review comments.

 - Improve comments.
 - Add fields to DXILType to distinguish types being represented.
   This allows for cleaner identification of the type.

Author: bharadwajy

llvm/lib/Target/DirectX/DXIL.td

@@ -222,13 +222,17 @@ defset list<DXILOpClass> OpClasses = {
 
 class DXILType : LLVMType<OtherVT> {
   let isAny = 1;
+  int isI16OrI32 = 0;
+  int isHalfOrFloat = 0;
 }
 
 // Concrete records for various overload types supported specifically by
 // DXIL Operations.
+let isI16OrI32 = 1 in
+  def llvm_i16ori32_ty : DXILType;
 
-def llvm_i16ori32_ty : DXILType;
-def llvm_halforfloat_ty : DXILType;
+let isHalfOrFloat = 1 in
+  def llvm_halforfloat_ty : DXILType;
 
 // Abstraction DXIL Operation to LLVM intrinsic
 class DXILOpMappingBase {

llvm/lib/Target/DirectX/DXILOpBuilder.cpp

@@ -257,7 +257,7 @@ static FunctionCallee getOrCreateDXILOpFunction(dxil::OpCode DXILOp,
   // FIXME: find the issue and report error in clang instead of check it in
   // backend.
   if ((Prop->OverloadTys & (uint16_t)Kind) == 0) {
-    report_fatal_error("Invalid Overload Type", false);
+    report_fatal_error("Invalid Overload Type", /* gen_crash_diag=*/false);
   }
 
   std::string FnName = constructOverloadName(Kind, OverloadTy, *Prop);

llvm/test/CodeGen/DirectX/frac_error.ll

@@ -1,6 +1,6 @@
 ; RUN: not opt -S -dxil-op-lower %s 2>&1 | FileCheck %s
 
-; This test is expected to fail with the following error
+; DXIL operation frac does not support double overload type
 ; CHECK: LLVM ERROR: Invalid Overload Type
 
 ; Function Attrs: noinline nounwind optnone

llvm/test/CodeGen/DirectX/sin_error.ll

@@ -1,6 +1,6 @@
 ; RUN: not opt -S -dxil-op-lower %s 2>&1 | FileCheck %s
 
-; This test is expected to fail with the following error
+; DXIL operation sin does not support double overload type
 ; CHECK: LLVM ERROR: Invalid Overload
 
 define noundef double @sin_double(double noundef %a) #0 {

llvm/utils/TableGen/DXILEmitter.cpp

@@ -272,14 +272,10 @@ static std::string getOverloadKindStr(const Record *R) {
   case MVT::Other:
     // Handle DXIL-specific overload types
     {
-      auto RetStr =
-          StringSwitch<std::string>(R->getNameInitAsString())
-              .Case("llvm_i16ori32_ty", "OverloadKind::I16 | OverloadKind::I32")
-              .Case("llvm_halforfloat_ty",
-                    "OverloadKind::HALF | OverloadKind::FLOAT")
-              .Default("");
-      if (RetStr != "") {
-        return RetStr;
+      if (R->getValueAsInt("isHalfOrFloat")) {
+        return "OverloadKind::HALF | OverloadKind::FLOAT";
+      } else if (R->getValueAsInt("isI16OrI32")) {
+        return "OverloadKind::I16 | OverloadKind::I32";
       }
     }
     LLVM_FALLTHROUGH;