Revert "[SPIR-V] add support for extension KHR_fragment_shading_baryc…

…entric (SV_Barycentrics)" (microsoft#5384)

Reverts microsoft#4638
This PR causes multiples issues (microsoft#5326, microsoft#5342, microsoft#5270). Reverting, will
need more testing.

Fixed microsoft#5270

docs/SPIR-V.rst

@@ -297,10 +297,10 @@ Supported extensions
 * SPV_EXT_mesh_shader
 * SPV_EXT_shader_stencil_support
 * SPV_AMD_shader_early_and_late_fragment_tests
+* SPV_AMD_shader_explicit_vertex_parameter
 * SPV_GOOGLE_hlsl_functionality1
 * SPV_GOOGLE_user_type
 * SPV_NV_mesh_shader
-* SPV_KHR_fragment_shading_barycentric
 
 Vulkan specific attributes
 --------------------------
@@ -1550,7 +1550,7 @@ some system-value (SV) semantic strings will be translated into SPIR-V
 +---------------------------+-------------+----------------------------------------+-----------------------+-----------------------------+
 | SV_StencilRef             | PSOut       | ``FragStencilRefEXT``                  | N/A                   | ``StencilExportEXT``        |
 +---------------------------+-------------+----------------------------------------+-----------------------+-----------------------------+
-| SV_Barycentrics           | PSIn        | ``BaryCoord*KHR``                      | N/A                   | ``FragmentBarycentricKHR``  |
+| SV_Barycentrics           | PSIn        | ``BaryCoord*AMD``                      | N/A                   | ``Shader``                  |
 +---------------------------+-------------+----------------------------------------+-----------------------+-----------------------------+
 |                           | GSOut       | ``Layer``                              | N/A                   | ``Geometry``                |
 |                           +-------------+----------------------------------------+-----------------------+-----------------------------+

tools/clang/include/clang/SPIRV/FeatureManager.h

@@ -48,6 +48,7 @@ enum class Extension {
   EXT_shader_viewport_index_layer,
   AMD_gpu_shader_half_float,
   AMD_shader_early_and_late_fragment_tests,
+  AMD_shader_explicit_vertex_parameter,
   GOOGLE_hlsl_functionality1,
   GOOGLE_user_type,
   NV_ray_tracing,
@@ -56,7 +57,6 @@ enum class Extension {
   EXT_shader_image_int64,
   KHR_physical_storage_buffer,
   KHR_vulkan_memory_model,
-  KHR_fragment_shader_barycentric,
   Unknown,
 };
 

tools/clang/include/clang/SPIRV/SpirvBuilder.h

@@ -706,9 +706,6 @@ class SpirvBuilder {
   void decoratePerTaskNV(SpirvInstruction *target, uint32_t offset,
                          SourceLocation);
 
-  /// \brief Decorates the given target with PerVertexKHR
-  void decoratePerVertexKHR(SpirvInstruction *argInst, SourceLocation);
-
   /// \brief Decorates the given target with Coherent
   void decorateCoherent(SpirvInstruction *target, SourceLocation);
 

tools/clang/lib/SPIRV/CapabilityVisitor.cpp

@@ -247,11 +247,6 @@ bool CapabilityVisitor::visit(SpirvDecoration *decor) {
                  loc);
     break;
   }
-  case spv::Decoration::PerVertexKHR: {
-    addExtension(Extension::KHR_fragment_shader_barycentric, "PerVertexKHR", loc);
-    addCapability(spv::Capability::FragmentBarycentricKHR);
-    break;
-  }
   // Capabilities needed for built-ins
   case spv::Decoration::BuiltIn: {
     AddVulkanMemoryModelForVolatile(decor, loc);
@@ -365,14 +360,15 @@ bool CapabilityVisitor::visit(SpirvDecoration *decor) {
       addCapability(spv::Capability::CullDistance);
       break;
     }
-    case spv::BuiltIn::BaryCoordKHR:
-    case spv::BuiltIn::BaryCoordNoPerspKHR: {
-      // SV_Barycentrics will have only two builtins
-      // But it is still allowed to decorate those two builtins with
-      // interpolation qualifier like centroid or sample.
-      addExtension(Extension::KHR_fragment_shader_barycentric,
+    case spv::BuiltIn::BaryCoordNoPerspAMD:
+    case spv::BuiltIn::BaryCoordNoPerspCentroidAMD:
+    case spv::BuiltIn::BaryCoordNoPerspSampleAMD:
+    case spv::BuiltIn::BaryCoordSmoothAMD:
+    case spv::BuiltIn::BaryCoordSmoothCentroidAMD:
+    case spv::BuiltIn::BaryCoordSmoothSampleAMD:
+    case spv::BuiltIn::BaryCoordPullModelAMD: {
+      addExtension(Extension::AMD_shader_explicit_vertex_parameter,
                    "SV_Barycentrics", loc);
-      addCapability(spv::Capability::FragmentBarycentricKHR);
       break;
     }
     case spv::BuiltIn::ShadingRateKHR:

tools/clang/lib/SPIRV/DeclResultIdMapper.cpp

@@ -2643,7 +2643,7 @@ bool DeclResultIdMapper::createStageVars(
       evalType = astContext.BoolTy;
       break;
     case hlsl::Semantic::Kind::Barycentrics:
-      evalType = astContext.getExtVectorType(astContext.FloatTy, 3);
+      evalType = astContext.getExtVectorType(astContext.FloatTy, 2);
       break;
     case hlsl::Semantic::Kind::DispatchThreadID:
     case hlsl::Semantic::Kind::GroupThreadID:
@@ -2774,16 +2774,15 @@ bool DeclResultIdMapper::createStageVars(
 
     // Decorate with interpolation modes for pixel shader input variables
     // or vertex shader output variables.
-    if ((spvContext.isPS() && sigPoint->IsInput()) ||
-        (spvContext.isVS() && sigPoint->IsOutput()))
-      decorateInterpolationMode(decl, type, varInstr, *semanticToUse);
+    if (((spvContext.isPS() && sigPoint->IsInput()) ||
+         (spvContext.isVS() && sigPoint->IsOutput())) &&
+        // BaryCoord*AMD buitins already encode the interpolation mode.
+        semanticKind != hlsl::Semantic::Kind::Barycentrics)
+      decorateInterpolationMode(decl, type, varInstr);
 
     if (asInput) {
-      if (decl->getAttr<HLSLNoInterpolationAttr>()) {
-        spvBuilder.decoratePerVertexKHR(varInstr,
-                                        varInstr->getSourceLocation());
-      }
       *value = spvBuilder.createLoad(evalType, varInstr, loc);
+
       // Fix ups for corner cases
 
       // Special handling of SV_TessFactor DS patch constant input.
@@ -2858,8 +2857,8 @@ bool DeclResultIdMapper::createStageVars(
                                          constOne, constZero, thisSemantic.loc);
       }
       // Special handling of SV_Barycentrics, which is a float3, but the
-      // The 3 values are NOT guaranteed to add up to floating-point 1.0 exactly.
-      // Calculate the third element here.
+      // underlying stage input variable is a float2 (only provides the first
+      // two components). Calculate the third element.
       else if (semanticKind == hlsl::Semantic::Kind::Barycentrics) {
         const auto x = spvBuilder.createCompositeExtract(
             astContext.FloatTy, *value, {0}, thisSemantic.loc);
@@ -3350,52 +3349,11 @@ DeclResultIdMapper::invertWIfRequested(SpirvInstruction *position,
 
 void DeclResultIdMapper::decorateInterpolationMode(const NamedDecl *decl,
                                                    QualType type,
-                                                   SpirvVariable *varInstr,
-                                                   const SemanticInfo semanticInfo)
-{
+                                                   SpirvVariable *varInstr) {
   if (varInstr->getStorageClass() != spv::StorageClass::Input &&
       varInstr->getStorageClass() != spv::StorageClass::Output) {
     return;
   }
-  const bool isBaryCoord = (semanticInfo.getKind() == hlsl::Semantic::Kind::Barycentrics);
-  uint32_t semanticIndex = semanticInfo.index;
-
-  if (isBaryCoord) {
-    // BaryCentrics inputs cannot have attrib 'nointerpolation'.
-    if (decl->getAttr<HLSLNoInterpolationAttr>()) {
-      emitError("SV_BaryCentrics inputs cannot have attribute 'nointerpolation'.",
-          decl->getLocation());
-    }
-    // SV_BaryCentrics could only have two index and apply to different inputs.
-    // The index should be 0 or 1, each index should be mapped to different
-    // interpolation type.
-    if (semanticIndex > 1) {
-      emitError("The index SV_BaryCentrics semantics could only be 1 or 0.",
-          decl->getLocation());
-    }
-    else if (noPerspBaryCentricsIndex < 2 && perspBaryCentricsIndex < 2) {
-      emitError("Cannot have more than 2 inputs with SV_BaryCentrics semantics.",
-          decl->getLocation());
-    }
-    else if (decl->getAttr<HLSLNoPerspectiveAttr>()) {
-      if (noPerspBaryCentricsIndex == 2 && perspBaryCentricsIndex != semanticIndex) {
-        noPerspBaryCentricsIndex = semanticIndex;
-      }
-      else {
-        emitError("Cannot have more than 1 noperspective inputs with SV_BaryCentrics semantics.",
-          decl->getLocation());
-      }
-    }
-    else {
-      if (perspBaryCentricsIndex == 2 && noPerspBaryCentricsIndex != semanticIndex) {
-        perspBaryCentricsIndex = semanticIndex;
-      }
-      else{
-        emitError("Cannot have more than 1 perspective-correct inputs with SV_BaryCentrics semantics.",
-          decl->getLocation());
-      }
-    }
-  }
 
   const auto loc = decl->getLocation();
   if (isUintOrVecMatOfUintType(type) || isSintOrVecMatOfSintType(type) ||
@@ -3416,9 +3374,9 @@ void DeclResultIdMapper::decorateInterpolationMode(const NamedDecl *decl,
     // Attributes can be used together. So cannot use else if.
     if (decl->getAttr<HLSLCentroidAttr>())
       spvBuilder.decorateCentroid(varInstr, loc);
-    if (decl->getAttr<HLSLNoInterpolationAttr>() && !isBaryCoord)
+    if (decl->getAttr<HLSLNoInterpolationAttr>())
       spvBuilder.decorateFlat(varInstr, loc);
-    if (decl->getAttr<HLSLNoPerspectiveAttr>() && !isBaryCoord)
+    if (decl->getAttr<HLSLNoPerspectiveAttr>())
       spvBuilder.decorateNoPerspective(varInstr, loc);
     if (decl->getAttr<HLSLSampleAttr>()) {
       spvBuilder.decorateSample(varInstr, loc);
@@ -3514,6 +3472,7 @@ SpirvVariable *DeclResultIdMapper::createSpirvStageVar(
   const auto sigPointKind = sigPoint->GetKind();
   const auto type = stageVar->getAstType();
   const auto isPrecise = decl->hasAttr<HLSLPreciseAttr>();
+
   spv::StorageClass sc = getStorageClassForSigPoint(sigPoint);
   if (sc == spv::StorageClass::Max)
     return 0;
@@ -3787,9 +3746,21 @@ SpirvVariable *DeclResultIdMapper::createSpirvStageVar(
     // Selecting the correct builtin according to interpolation mode
     auto bi = BuiltIn::Max;
     if (decl->hasAttr<HLSLNoPerspectiveAttr>()) {
-      bi = BuiltIn::BaryCoordNoPerspKHR;
+      if (decl->hasAttr<HLSLCentroidAttr>()) {
+        bi = BuiltIn::BaryCoordNoPerspCentroidAMD;
+      } else if (decl->hasAttr<HLSLSampleAttr>()) {
+        bi = BuiltIn::BaryCoordNoPerspSampleAMD;
+      } else {
+        bi = BuiltIn::BaryCoordNoPerspAMD;
+      }
     } else {
-      bi = BuiltIn::BaryCoordKHR;
+      if (decl->hasAttr<HLSLCentroidAttr>()) {
+        bi = BuiltIn::BaryCoordSmoothCentroidAMD;
+      } else if (decl->hasAttr<HLSLSampleAttr>()) {
+        bi = BuiltIn::BaryCoordSmoothSampleAMD;
+      } else {
+        bi = BuiltIn::BaryCoordSmoothAMD;
+      }
     }
 
     return spvBuilder.addStageBuiltinVar(type, sc, bi, isPrecise, srcLoc);

tools/clang/lib/SPIRV/DeclResultIdMapper.h

@@ -714,7 +714,7 @@ class DeclResultIdMapper {
   /// Decorates varInstr of the given asType with proper interpolation modes
   /// considering the attributes on the given decl.
   void decorateInterpolationMode(const NamedDecl *decl, QualType asType,
-                                 SpirvVariable *varInstr, const SemanticInfo semanticInfo);
+                                 SpirvVariable *varInstr);
 
   /// Returns the proper SPIR-V storage class (Input or Output) for the given
   /// SigPoint.
@@ -893,8 +893,6 @@ class DeclResultIdMapper {
   /// an additional SPIR-V optimization pass to flatten such structures.
   bool needsFlatteningCompositeResources;
 
-  uint32_t perspBaryCentricsIndex, noPerspBaryCentricsIndex;
-
 public:
   /// The gl_PerVertex structs for both input and output
   GlPerVertex glPerVertex;
@@ -926,7 +924,6 @@ DeclResultIdMapper::DeclResultIdMapper(ASTContext &context,
       spirvOptions(options), astContext(context), spvContext(spirvContext),
       diags(context.getDiagnostics()), entryFunction(nullptr),
       needsLegalization(false), needsFlatteningCompositeResources(false),
-      perspBaryCentricsIndex(2), noPerspBaryCentricsIndex(2),
       glPerVertex(context, spirvContext, spirvBuilder) {}
 
 bool DeclResultIdMapper::decorateStageIOLocations() {

tools/clang/lib/SPIRV/FeatureManager.cpp

@@ -181,6 +181,8 @@ Extension FeatureManager::getExtensionSymbol(llvm::StringRef name) {
             Extension::AMD_gpu_shader_half_float)
       .Case("SPV_AMD_shader_early_and_late_fragment_tests",
             Extension::AMD_shader_early_and_late_fragment_tests)
+      .Case("SPV_AMD_shader_explicit_vertex_parameter",
+            Extension::AMD_shader_explicit_vertex_parameter)
       .Case("SPV_GOOGLE_hlsl_functionality1",
             Extension::GOOGLE_hlsl_functionality1)
       .Case("SPV_GOOGLE_user_type", Extension::GOOGLE_user_type)
@@ -195,7 +197,6 @@ Extension FeatureManager::getExtensionSymbol(llvm::StringRef name) {
       .Case("SPV_KHR_physical_storage_buffer",
             Extension::KHR_physical_storage_buffer)
       .Case("SPV_KHR_vulkan_memory_model", Extension::KHR_vulkan_memory_model)
-      .Case("SPV_KHR_fragment_shader_barycentric", Extension::KHR_fragment_shader_barycentric)
       .Default(Extension::Unknown);
 }
 
@@ -237,6 +238,8 @@ const char *FeatureManager::getExtensionName(Extension symbol) {
     return "SPV_AMD_gpu_shader_half_float";
   case Extension::AMD_shader_early_and_late_fragment_tests:
     return "SPV_AMD_shader_early_and_late_fragment_tests";
+  case Extension::AMD_shader_explicit_vertex_parameter:
+    return "SPV_AMD_shader_explicit_vertex_parameter";
   case Extension::GOOGLE_hlsl_functionality1:
     return "SPV_GOOGLE_hlsl_functionality1";
   case Extension::GOOGLE_user_type:
@@ -255,8 +258,6 @@ const char *FeatureManager::getExtensionName(Extension symbol) {
     return "SPV_KHR_physical_storage_buffer";
   case Extension::KHR_vulkan_memory_model:
     return "SPV_KHR_vulkan_memory_model";
-  case Extension::KHR_fragment_shader_barycentric:
-    return "SPV_KHR_fragment_shader_barycentric";
   default:
     break;
   }

tools/clang/lib/SPIRV/SpirvBuilder.cpp

@@ -1543,13 +1543,6 @@ void SpirvBuilder::decoratePerTaskNV(SpirvInstruction *target, uint32_t offset,
   mod->addDecoration(decor);
 }
 
-void SpirvBuilder::decoratePerVertexKHR(SpirvInstruction *target,
-                                          SourceLocation srcLoc) {
-  auto *decor = new (context)
-      SpirvDecoration(srcLoc, target, spv::Decoration::PerVertexKHR);
-  mod->addDecoration(decor);
-}
-
 void SpirvBuilder::decorateCoherent(SpirvInstruction *target,
                                     SourceLocation srcLoc) {
   auto *decor =