self-review: misc clean up

Author: inbelic

clang/lib/CodeGen/CGHLSLRuntime.cpp

@@ -126,8 +126,8 @@ void addRootSignature(
 
   llvm::hlsl::root_signature::MetadataBuilder Builder(Ctx, Elements);
   MDNode *RootSignature = Builder.BuildRootSignature();
-  MDNode *FnPairing = MDNode::get(Ctx, {ValueAsMetadata::get(Fn),
-                                        RootSignature});
+  MDNode *FnPairing =
+      MDNode::get(Ctx, {ValueAsMetadata::get(Fn), RootSignature});
 
   StringRef RootSignatureValKey = "dx.rootsignatures";
   auto *RootSignatureValMD = M.getOrInsertNamedMetadata(RootSignatureValKey);
@@ -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

@@ -129,15 +129,18 @@ using ParamType = std::variant<uint32_t *, DescriptorRangeOffset *,
                                DescriptorRangeFlags *, ShaderVisibility *>;
 
 class MetadataBuilder {
- public:
+public:
   MetadataBuilder(llvm::LLVMContext &Ctx, ArrayRef<RootElement> Elements)
-   : Ctx(Ctx), Elements(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:
-  // Define the various builders for the different metadata types
+private:
+  /// Define the various builders for the different metadata types
   MDNode *BuildDescriptorTable(const DescriptorTable &Table);
   MDNode *BuildDescriptorTableClause(const DescriptorTableClause &Clause);
 

llvm/lib/Frontend/HLSL/HLSLRootSignature.cpp

@@ -1,4 +1,5 @@
-//===- HLSLRootSignature.cpp - HLSL Root Signature helper objects ----------===//
+//===- HLSLRootSignature.cpp - HLSL Root Signature helper objects
+//----------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -17,7 +18,9 @@
 
 namespace llvm {
 namespace hlsl {
-namespace root_signature {
+namespace rootsig {
+
+// Static helper functions
 
 static MDString *ClauseTypeToName(LLVMContext &Ctx, ClauseType Type) {
   StringRef Name;
@@ -47,16 +50,15 @@ template <class... Ts> OverloadBuilds(Ts...) -> OverloadBuilds<Ts...>;
 MDNode *MetadataBuilder::BuildRootSignature() {
   for (const RootElement &Element : Elements) {
     MDNode *ElementMD =
-      std::visit(
-        OverloadBuilds{
-            [&](DescriptorTable Table) -> MDNode * {
-              return BuildDescriptorTable(Table);
-            },
-            [&](DescriptorTableClause Clause) -> MDNode * {
-              return BuildDescriptorTableClause(Clause);
-            },
-        },
-        Element);
+        std::visit(OverloadBuilds{
+                       [&](DescriptorTable Table) -> MDNode * {
+                         return BuildDescriptorTable(Table);
+                       },
+                       [&](DescriptorTableClause Clause) -> MDNode * {
+                         return BuildDescriptorTableClause(Clause);
+                       },
+                   },
+                   Element);
     GeneratedMetadata.push_back(ElementMD);
   }
 
@@ -66,29 +68,41 @@ 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))));
+  TableOperands.push_back(ConstantAsMetadata::get(
+      B.getInt32(llvm::to_underlying(Table.Visibility))));
 
-  assert(Table.NumClauses <= GeneratedMetadata.size() && "Table expected all owned clauses to be generated already");
-  TableOperands.append(GeneratedMetadata.end() - Table.NumClauses, GeneratedMetadata.end());
+  // 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);
 }
 
-MDNode *MetadataBuilder::BuildDescriptorTableClause(const DescriptorTableClause &Clause) {
+MDNode *MetadataBuilder::BuildDescriptorTableClause(
+    const DescriptorTableClause &Clause) {
   IRBuilder<> B(Ctx);
-  return MDNode::get(Ctx, {
-    ClauseTypeToName(Ctx, Clause.Type),
-    ConstantAsMetadata::get(B.getInt32(Clause.NumDescriptors)),
-    ConstantAsMetadata::get(B.getInt32(Clause.Register.Number)),
-    ConstantAsMetadata::get(B.getInt32(Clause.Space)),
-    ConstantAsMetadata::get(B.getInt32(llvm::to_underlying(Clause.Offset))),
-    ConstantAsMetadata::get(B.getInt32(llvm::to_underlying(Clause.Flags))),
-  });
+  return MDNode::get(
+      Ctx, {
+               ClauseTypeToName(Ctx, Clause.Type),
+               ConstantAsMetadata::get(B.getInt32(Clause.NumDescriptors)),
+               ConstantAsMetadata::get(B.getInt32(Clause.Register.Number)),
+               ConstantAsMetadata::get(B.getInt32(Clause.Space)),
+               ConstantAsMetadata::get(
+                   B.getInt32(llvm::to_underlying(Clause.Offset))),
+               ConstantAsMetadata::get(
+                   B.getInt32(llvm::to_underlying(Clause.Flags))),
+           });
 }
 
-} // namespace root_signature
+} // namespace rootsig
 } // namespace hlsl
 } // namespace llvm
-