[HLSL][RootSignature] Implement serialized dump of Descriptor Tables (#138326)

- defines the `dump` method for in-memory descriptor table data structs
in `Frontend/HLSLRootSignature`
- creates unit test infrastructure to support unit tests of the dump
methods

Resolves https://github.com/llvm/llvm-project/issues/138189

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

@@ -15,6 +15,7 @@
 #define LLVM_FRONTEND_HLSL_HLSLROOTSIGNATURE_H
 
 #include "llvm/Support/DXILABI.h"
+#include "llvm/Support/raw_ostream.h"
 #include <variant>
 
 namespace llvm {
@@ -83,6 +84,8 @@ struct RootConstants {
 struct DescriptorTable {
   ShaderVisibility Visibility = ShaderVisibility::All;
   uint32_t NumClauses = 0; // The number of clauses in the table
+
+  void dump(raw_ostream &OS) const;
 };
 
 static const uint32_t NumDescriptorsUnbounded = 0xffffffff;
@@ -111,6 +114,8 @@ struct DescriptorTableClause {
       break;
     }
   }
+
+  void dump(raw_ostream &OS) const;
 };
 
 // Models RootElement : RootConstants | DescriptorTable | DescriptorTableClause

llvm/lib/Frontend/HLSL/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_llvm_component_library(LLVMFrontendHLSL
   CBuffer.cpp
   HLSLResource.cpp
+  HLSLRootSignature.cpp
 
   ADDITIONAL_HEADER_DIRS
   ${LLVM_MAIN_INCLUDE_DIR}/llvm/Frontend

llvm/lib/Frontend/HLSL/HLSLRootSignature.cpp

@@ -0,0 +1,149 @@
+//===- 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.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file This file contains helpers for working with HLSL Root Signatures.
+///
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Frontend/HLSL/HLSLRootSignature.h"
+#include "llvm/ADT/bit.h"
+
+namespace llvm {
+namespace hlsl {
+namespace rootsig {
+
+static raw_ostream &operator<<(raw_ostream &OS, const Register &Reg) {
+  switch (Reg.ViewType) {
+  case RegisterType::BReg:
+    OS << "b";
+    break;
+  case RegisterType::TReg:
+    OS << "t";
+    break;
+  case RegisterType::UReg:
+    OS << "u";
+    break;
+  case RegisterType::SReg:
+    OS << "s";
+    break;
+  }
+  OS << Reg.Number;
+  return OS;
+}
+
+static raw_ostream &operator<<(raw_ostream &OS,
+                               const ShaderVisibility &Visibility) {
+  switch (Visibility) {
+  case ShaderVisibility::All:
+    OS << "All";
+    break;
+  case ShaderVisibility::Vertex:
+    OS << "Vertex";
+    break;
+  case ShaderVisibility::Hull:
+    OS << "Hull";
+    break;
+  case ShaderVisibility::Domain:
+    OS << "Domain";
+    break;
+  case ShaderVisibility::Geometry:
+    OS << "Geometry";
+    break;
+  case ShaderVisibility::Pixel:
+    OS << "Pixel";
+    break;
+  case ShaderVisibility::Amplification:
+    OS << "Amplification";
+    break;
+  case ShaderVisibility::Mesh:
+    OS << "Mesh";
+    break;
+  }
+
+  return OS;
+}
+
+void DescriptorTable::dump(raw_ostream &OS) const {
+  OS << "DescriptorTable(numClauses = " << NumClauses
+     << ", visibility = " << Visibility << ")";
+}
+
+static raw_ostream &operator<<(raw_ostream &OS, const ClauseType &Type) {
+  switch (Type) {
+  case ClauseType::CBuffer:
+    OS << "CBV";
+    break;
+  case ClauseType::SRV:
+    OS << "SRV";
+    break;
+  case ClauseType::UAV:
+    OS << "UAV";
+    break;
+  case ClauseType::Sampler:
+    OS << "Sampler";
+    break;
+  }
+
+  return OS;
+}
+
+static raw_ostream &operator<<(raw_ostream &OS,
+                               const DescriptorRangeFlags &Flags) {
+  bool FlagSet = false;
+  unsigned Remaining = llvm::to_underlying(Flags);
+  while (Remaining) {
+    unsigned Bit = 1u << llvm::countr_zero(Remaining);
+    if (Remaining & Bit) {
+      if (FlagSet)
+        OS << " | ";
+
+      switch (static_cast<DescriptorRangeFlags>(Bit)) {
+      case DescriptorRangeFlags::DescriptorsVolatile:
+        OS << "DescriptorsVolatile";
+        break;
+      case DescriptorRangeFlags::DataVolatile:
+        OS << "DataVolatile";
+        break;
+      case DescriptorRangeFlags::DataStaticWhileSetAtExecute:
+        OS << "DataStaticWhileSetAtExecute";
+        break;
+      case DescriptorRangeFlags::DataStatic:
+        OS << "DataStatic";
+        break;
+      case DescriptorRangeFlags::DescriptorsStaticKeepingBufferBoundsChecks:
+        OS << "DescriptorsStaticKeepingBufferBoundsChecks";
+        break;
+      default:
+        OS << "invalid: " << Bit;
+        break;
+      }
+
+      FlagSet = true;
+    }
+    Remaining &= ~Bit;
+  }
+
+  if (!FlagSet)
+    OS << "None";
+
+  return OS;
+}
+
+void DescriptorTableClause::dump(raw_ostream &OS) const {
+  OS << Type << "(" << Reg << ", numDescriptors = " << NumDescriptors
+     << ", space = " << Space << ", offset = ";
+  if (Offset == DescriptorTableOffsetAppend)
+    OS << "DescriptorTableOffsetAppend";
+  else
+    OS << Offset;
+  OS << ", flags = " << Flags << ")";
+}
+
+} // namespace rootsig
+} // namespace hlsl
+} // namespace llvm

llvm/unittests/Frontend/CMakeLists.txt

@@ -1,6 +1,7 @@
 set(LLVM_LINK_COMPONENTS
   Analysis
   Core
+  FrontendHLSL
   FrontendOpenACC
   FrontendOpenMP
   Passes
@@ -10,6 +11,7 @@ set(LLVM_LINK_COMPONENTS
   )
 
 add_llvm_unittest(LLVMFrontendTests
+  HLSLRootSignatureDumpTest.cpp
   OpenACCTest.cpp
   OpenMPContextTest.cpp
   OpenMPIRBuilderTest.cpp

llvm/unittests/Frontend/HLSLRootSignatureDumpTest.cpp

@@ -0,0 +1,111 @@
+//===-------- HLSLRootSignatureDumpTest.cpp - RootSignature dump tests ----===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Frontend/HLSL/HLSLRootSignature.h"
+#include "gtest/gtest.h"
+
+using namespace llvm::hlsl::rootsig;
+
+namespace {
+
+TEST(HLSLRootSignatureTest, DescriptorCBVClauseDump) {
+  DescriptorTableClause Clause;
+  Clause.Type = ClauseType::CBuffer;
+  Clause.Reg = {RegisterType::BReg, 0};
+  Clause.setDefaultFlags();
+
+  std::string Out;
+  llvm::raw_string_ostream OS(Out);
+  Clause.dump(OS);
+  OS.flush();
+
+  std::string Expected = "CBV(b0, numDescriptors = 1, space = 0, "
+                         "offset = DescriptorTableOffsetAppend, "
+                         "flags = DataStaticWhileSetAtExecute)";
+  EXPECT_EQ(Out, Expected);
+}
+
+TEST(HLSLRootSignatureTest, DescriptorSRVClauseDump) {
+  DescriptorTableClause Clause;
+  Clause.Type = ClauseType::SRV;
+  Clause.Reg = {RegisterType::TReg, 0};
+  Clause.NumDescriptors = 2;
+  Clause.Space = 42;
+  Clause.Offset = 3;
+  Clause.Flags = DescriptorRangeFlags::None;
+
+  std::string Out;
+  llvm::raw_string_ostream OS(Out);
+  Clause.dump(OS);
+  OS.flush();
+
+  std::string Expected =
+      "SRV(t0, numDescriptors = 2, space = 42, offset = 3, flags = None)";
+  EXPECT_EQ(Out, Expected);
+}
+
+TEST(HLSLRootSignatureTest, DescriptorUAVClauseDump) {
+  DescriptorTableClause Clause;
+  Clause.Type = ClauseType::UAV;
+  Clause.Reg = {RegisterType::UReg, 92374};
+  Clause.NumDescriptors = 3298;
+  Clause.Space = 932847;
+  Clause.Offset = 1;
+  Clause.Flags = DescriptorRangeFlags::ValidFlags;
+
+  std::string Out;
+  llvm::raw_string_ostream OS(Out);
+  Clause.dump(OS);
+  OS.flush();
+
+  std::string Expected =
+      "UAV(u92374, numDescriptors = 3298, space = 932847, offset = 1, flags = "
+      "DescriptorsVolatile | "
+      "DataVolatile | "
+      "DataStaticWhileSetAtExecute | "
+      "DataStatic | "
+      "DescriptorsStaticKeepingBufferBoundsChecks)";
+  EXPECT_EQ(Out, Expected);
+}
+
+TEST(HLSLRootSignatureTest, DescriptorSamplerClauseDump) {
+  DescriptorTableClause Clause;
+  Clause.Type = ClauseType::Sampler;
+  Clause.Reg = {RegisterType::SReg, 0};
+  Clause.NumDescriptors = 2;
+  Clause.Space = 42;
+  Clause.Offset = DescriptorTableOffsetAppend;
+  Clause.Flags = DescriptorRangeFlags::ValidSamplerFlags;
+
+  std::string Out;
+  llvm::raw_string_ostream OS(Out);
+  Clause.dump(OS);
+  OS.flush();
+
+  std::string Expected = "Sampler(s0, numDescriptors = 2, space = 42, offset = "
+                         "DescriptorTableOffsetAppend, "
+                         "flags = DescriptorsVolatile)";
+  EXPECT_EQ(Out, Expected);
+}
+
+TEST(HLSLRootSignatureTest, DescriptorTableDump) {
+  DescriptorTable Table;
+  Table.NumClauses = 4;
+  Table.Visibility = ShaderVisibility::Geometry;
+
+  std::string Out;
+  llvm::raw_string_ostream OS(Out);
+  Table.dump(OS);
+  OS.flush();
+
+  std::string Expected =
+      "DescriptorTable(numClauses = 4, visibility = Geometry)";
+  EXPECT_EQ(Out, Expected);
+}
+
+} // namespace