add parsing of comparisonfunc

Author: inbelic

clang/include/clang/Parse/ParseHLSLRootSignature.h

@@ -117,6 +117,7 @@ class RootSignatureParser {
     std::optional<llvm::hlsl::rootsig::TextureAddressMode> AddressW;
     std::optional<float> MipLODBias;
     std::optional<uint32_t> MaxAnisotropy;
+    std::optional<llvm::hlsl::rootsig::ComparisonFunc> ComparisonFunc;
     std::optional<float> MinLOD;
     std::optional<float> MaxLOD;
   };
@@ -132,6 +133,7 @@ class RootSignatureParser {
   std::optional<llvm::hlsl::rootsig::Filter> parseFilter();
   std::optional<llvm::hlsl::rootsig::TextureAddressMode>
   parseTextureAddressMode();
+  std::optional<llvm::hlsl::rootsig::ComparisonFunc> parseComparisonFunc();
   std::optional<llvm::hlsl::rootsig::RootDescriptorFlags>
   parseRootDescriptorFlags();
   std::optional<llvm::hlsl::rootsig::DescriptorRangeFlags>

clang/lib/Parse/ParseHLSLRootSignature.cpp

@@ -399,6 +399,9 @@ std::optional<StaticSampler> RootSignatureParser::parseStaticSampler() {
   if (Params->MaxAnisotropy.has_value())
     Sampler.MaxAnisotropy = Params->MaxAnisotropy.value();
 
+  if (Params->ComparisonFunc.has_value())
+    Sampler.ComparisonFunc= Params->ComparisonFunc.value();
+
   if (Params->MinLOD.has_value())
     Sampler.MinLOD = Params->MinLOD.value();
 
@@ -793,6 +796,24 @@ RootSignatureParser::parseStaticSamplerParams() {
       Params.MaxAnisotropy = MaxAnisotropy;
     }
 
+
+    // `comparisonFunc` `=` COMPARISON_FUNC
+    if (tryConsumeExpectedToken(TokenKind::kw_comparisonFunc)) {
+      if (Params.ComparisonFunc.has_value()) {
+        getDiags().Report(CurToken.TokLoc, diag::err_hlsl_rootsig_repeat_param)
+            << CurToken.TokKind;
+        return std::nullopt;
+      }
+
+      if (consumeExpectedToken(TokenKind::pu_equal))
+        return std::nullopt;
+
+      auto ComparisonFunc = parseComparisonFunc();
+      if (!ComparisonFunc.has_value())
+        return std::nullopt;
+      Params.ComparisonFunc = ComparisonFunc;
+    }
+
     // `minLOD` `=` NUMBER
     if (tryConsumeExpectedToken(TokenKind::kw_minLOD)) {
       if (Params.MinLOD.has_value()) {
@@ -980,6 +1001,32 @@ RootSignatureParser::parseTextureAddressMode() {
   return std::nullopt;
 }
 
+std::optional<llvm::hlsl::rootsig::ComparisonFunc>
+RootSignatureParser::parseComparisonFunc() {
+  assert(CurToken.TokKind == TokenKind::pu_equal &&
+         "Expects to only be invoked starting at given keyword");
+
+  TokenKind Expected[] = {
+#define COMPARISON_FUNC_ENUM(NAME, LIT) TokenKind::en_##NAME,
+#include "clang/Lex/HLSLRootSignatureTokenKinds.def"
+  };
+
+  if (!tryConsumeExpectedToken(Expected))
+    return std::nullopt;
+
+  switch (CurToken.TokKind) {
+#define COMPARISON_FUNC_ENUM(NAME, LIT)                                      \
+  case TokenKind::en_##NAME:                                                   \
+    return ComparisonFunc::NAME;                                             \
+    break;
+#include "clang/Lex/HLSLRootSignatureTokenKinds.def"
+  default:
+    llvm_unreachable("Switch for consumed enum token was not provided");
+  }
+
+  return std::nullopt;
+}
+
 std::optional<llvm::hlsl::rootsig::RootDescriptorFlags>
 RootSignatureParser::parseRootDescriptorFlags() {
   assert(CurToken.TokKind == TokenKind::pu_equal &&

clang/unittests/Parse/ParseHLSLRootSignatureTest.cpp

@@ -231,7 +231,8 @@ TEST_F(ParseHLSLRootSignatureTest, ValidParseStaticSamplerTest) {
       addressW = TEXTURE_ADDRESS_CLAMP,
       addressV = TEXTURE_ADDRESS_BORDER,
       filter = FILTER_MAXIMUM_MIN_POINT_MAG_LINEAR_MIP_POINT,
-      maxLOD = 9000, addressU = TEXTURE_ADDRESS_MIRROR
+      maxLOD = 9000, addressU = TEXTURE_ADDRESS_MIRROR,
+      comparisonFunc = COMPARISON_NOT_EQUAL
     )
   )cc";
 
@@ -261,6 +262,7 @@ TEST_F(ParseHLSLRootSignatureTest, ValidParseStaticSamplerTest) {
   ASSERT_EQ(std::get<StaticSampler>(Elem).AddressW, TextureAddressMode::Wrap);
   ASSERT_EQ(std::get<StaticSampler>(Elem).MipLODBias, 0.f);
   ASSERT_EQ(std::get<StaticSampler>(Elem).MaxAnisotropy, 16u);
+  ASSERT_EQ(std::get<StaticSampler>(Elem).ComparisonFunc, ComparisonFunc::LessEqual);
   ASSERT_EQ(std::get<StaticSampler>(Elem).MinLOD, 0.f);
   ASSERT_EQ(std::get<StaticSampler>(Elem).MaxLOD, 3.402823466e+38f);
 
@@ -276,6 +278,8 @@ TEST_F(ParseHLSLRootSignatureTest, ValidParseStaticSamplerTest) {
   ASSERT_EQ(std::get<StaticSampler>(Elem).AddressW, TextureAddressMode::Clamp);
   ASSERT_EQ(std::get<StaticSampler>(Elem).MipLODBias, 230.f);
   ASSERT_EQ(std::get<StaticSampler>(Elem).MaxAnisotropy, 3u);
+  ASSERT_EQ(std::get<StaticSampler>(Elem).ComparisonFunc,
+            ComparisonFunc::NotEqual);
   ASSERT_EQ(std::get<StaticSampler>(Elem).MinLOD, 4.2f);
   ASSERT_EQ(std::get<StaticSampler>(Elem).MaxLOD, 9000.f);
 

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

@@ -123,6 +123,17 @@ enum class TextureAddressMode {
   MirrorOnce = 5
 };
 
+enum class ComparisonFunc : unsigned {
+  Never = 1,
+  Less = 2,
+  Equal = 3,
+  LessEqual = 4,
+  Greater = 5,
+  NotEqual = 6,
+  GreaterEqual = 7,
+  Always = 8
+};
+
 // Definitions of the in-memory data layout structures
 
 // Models the different registers: bReg | tReg | uReg | sReg
@@ -213,6 +224,7 @@ struct StaticSampler {
   TextureAddressMode AddressW = TextureAddressMode::Wrap;
   float MipLODBias = 0.f;
   uint32_t MaxAnisotropy = 16;
+  ComparisonFunc ComparisonFunc = ComparisonFunc::LessEqual;
   float MinLOD = 0.f;
   float MaxLOD = 3.402823466e+38f; // FLT_MAX
 };