clean up

Author: inbelic

clang/lib/CodeGen/CGHLSLRuntime.cpp

@@ -471,10 +471,9 @@ void CGHLSLRuntime::emitEntryFunction(const FunctionDecl *FD,
 
   // Add and identify root signature to function, if applicable
   const AttrVec &Attrs = FD->getAttrs();
-  for (const Attr *Attr : Attrs) {
+  for (const Attr *Attr : Attrs)
     if (const auto *RSAttr = dyn_cast<HLSLRootSignatureAttr>(Attr))
       addRootSignature(RSAttr->getElements(), EntryFn, M);
-  }
 }
 
 void CGHLSLRuntime::setHLSLFunctionAttributes(const FunctionDecl *FD,

clang/test/CodeGenHLSL/RootSignature.hlsl

@@ -19,7 +19,7 @@ void FirstEntry() {}
 [numthreads(1,1,1)]
 void SecondEntry() {}
 
-// Sanity test to ensure to root is added for this function
+// Sanity test to ensure no root is added for this function
 [shader("compute")]
 [numthreads(1,1,1)]
 void ThirdEntry() {}

llvm/include/llvm/Frontend/HLSL/HLSLRootSignature.h

@@ -133,7 +133,10 @@ class MetadataBuilder {
   MetadataBuilder(llvm::LLVMContext &Ctx, ArrayRef<RootElement> Elements)
    : Ctx(Ctx), Elements(Elements) {}
 
-  // Iterates through the elements and builds the respective nodes
+  // Iterates through the elements and dispatches onto the correct Build method
+  //
+  // Accumulates the root signature and returns the Metadata node that is just
+  // a list of all the elements
   MDNode *BuildRootSignature();
 
  private:

llvm/lib/Frontend/HLSL/HLSLRootSignature.cpp

@@ -19,6 +19,8 @@ namespace llvm {
 namespace hlsl {
 namespace root_signature {
 
+// Static helper functions
+
 static MDString *ClauseTypeToName(LLVMContext &Ctx, ClauseType Type) {
   StringRef Name;
   switch (Type) {
@@ -66,11 +68,17 @@ MDNode *MetadataBuilder::BuildRootSignature() {
 MDNode *MetadataBuilder::BuildDescriptorTable(const DescriptorTable &Table) {
   IRBuilder<> B(Ctx);
   SmallVector<Metadata *> TableOperands;
+  // Set the mandatory arguments
   TableOperands.push_back(MDString::get(Ctx, "DescriptorTable"));
   TableOperands.push_back(ConstantAsMetadata::get(B.getInt32(llvm::to_underlying(Table.Visibility))));
 
+  // Remaining operands are references to the table's clauses. The in-memory
+  // representation of the Root Elements created from parsing will ensure that
+  // the previous N elements are the clauses for this table.
   assert(Table.NumClauses <= GeneratedMetadata.size() && "Table expected all owned clauses to be generated already");
+  // So, add a refence to each clause to our operands
   TableOperands.append(GeneratedMetadata.end() - Table.NumClauses, GeneratedMetadata.end());
+  // Then, remove those clauses from the general list of Root Elements
   GeneratedMetadata.pop_back_n(Table.NumClauses);
 
   return MDNode::get(Ctx, TableOperands);