[DirectX] Infrastructure to collect shader flags for each function

llvm/lib/Target/DirectX/DXContainerGlobals.cpp

@@ -78,13 +78,13 @@ bool DXContainerGlobals::runOnModule(Module &M) {
 }
 
 GlobalVariable *DXContainerGlobals::getFeatureFlags(Module &M) {
-  const uint64_t FeatureFlags =
-      static_cast<uint64_t>(getAnalysis<ShaderFlagsAnalysisWrapper>()
-                                .getShaderFlags()
-                                .getFeatureFlags());
+  uint64_t CombinedFeatureFlags = getAnalysis<ShaderFlagsAnalysisWrapper>()
+                                      .getShaderFlags()
+                                      .getCombinedFlags()
+                                      .getFeatureFlags();
 
   Constant *FeatureFlagsConstant =
-      ConstantInt::get(M.getContext(), APInt(64, FeatureFlags));
+      ConstantInt::get(M.getContext(), APInt(64, CombinedFeatureFlags));
   return buildContainerGlobal(M, FeatureFlagsConstant, "dx.sfi0", "SFI0");
 }
 

llvm/lib/Target/DirectX/DXILShaderFlags.cpp

@@ -13,36 +13,54 @@
 
 #include "DXILShaderFlags.h"
 #include "DirectX.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
 using namespace llvm::dxil;
 
-static void updateFlags(ComputedShaderFlags &Flags, const Instruction &I) {
-  Type *Ty = I.getType();
-  if (Ty->isDoubleTy()) {
-    Flags.Doubles = true;
+static void updateFunctionFlags(ComputedShaderFlags &CSF,
+                                const Instruction &I) {
+  if (!CSF.Doubles)
+    CSF.Doubles = I.getType()->isDoubleTy();
+
+  if (!CSF.Doubles) {
+    for (Value *Op : I.operands())
+      CSF.Doubles |= Op->getType()->isDoubleTy();
+  }
+  if (CSF.Doubles) {
     switch (I.getOpcode()) {
     case Instruction::FDiv:
     case Instruction::UIToFP:
     case Instruction::SIToFP:
     case Instruction::FPToUI:
     case Instruction::FPToSI:
-      Flags.DX11_1_DoubleExtensions = true;
+      // TODO: To be set if I is a call to DXIL intrinsic DXIL::Opcode::Fma
+      // https://github.com/llvm/llvm-project/issues/114554
+      CSF.DX11_1_DoubleExtensions = true;
       break;
     }
   }
 }
 
-ComputedShaderFlags ComputedShaderFlags::computeFlags(Module &M) {
-  ComputedShaderFlags Flags;
-  for (const auto &F : M)
+void ModuleShaderFlags::initialize(const Module &M) {
+  // Collect shader flags for each of the functions
+  for (const auto &F : M.getFunctionList()) {
+    if (F.isDeclaration())
+      continue;
+    ComputedShaderFlags CSF;
     for (const auto &BB : F)
       for (const auto &I : BB)
-        updateFlags(Flags, I);
-  return Flags;
+        updateFunctionFlags(CSF, I);
+    // Insert shader flag mask for function F
+    FunctionFlags.push_back({&F, CSF});
+    // Update combined shader flags mask
+    CombinedSFMask.merge(CSF);
+  }
+  llvm::sort(FunctionFlags);
 }
 
 void ComputedShaderFlags::print(raw_ostream &OS) const {
@@ -63,20 +81,58 @@ void ComputedShaderFlags::print(raw_ostream &OS) const {
   OS << ";\n";
 }
 
+/// Return the shader flags mask of the specified function Func.
+const ComputedShaderFlags &
+ModuleShaderFlags::getFunctionFlags(const Function *Func) const {
+  const auto Iter = llvm::lower_bound(
+      FunctionFlags, Func,
+      [](const std::pair<const Function *, ComputedShaderFlags> FSM,
+         const Function *FindFunc) { return (FSM.first < FindFunc); });
+  assert((Iter != FunctionFlags.end() && Iter->first == Func) &&
+         "No Shader Flags Mask exists for function");
+  return Iter->second;
+}
+
+//===----------------------------------------------------------------------===//
+// ShaderFlagsAnalysis and ShaderFlagsAnalysisPrinterPass
+
+// Provide an explicit template instantiation for the static ID.
 AnalysisKey ShaderFlagsAnalysis::Key;
 
-ComputedShaderFlags ShaderFlagsAnalysis::run(Module &M,
-                                             ModuleAnalysisManager &AM) {
-  return ComputedShaderFlags::computeFlags(M);
+ModuleShaderFlags ShaderFlagsAnalysis::run(Module &M,
+                                           ModuleAnalysisManager &AM) {
+  ModuleShaderFlags MSFI;
+  MSFI.initialize(M);
+  return MSFI;
 }
 
 PreservedAnalyses ShaderFlagsAnalysisPrinter::run(Module &M,
                                                   ModuleAnalysisManager &AM) {
-  ComputedShaderFlags Flags = AM.getResult<ShaderFlagsAnalysis>(M);
-  Flags.print(OS);
+  const ModuleShaderFlags &FlagsInfo = AM.getResult<ShaderFlagsAnalysis>(M);
+  // Print description of combined shader flags for all module functions
+  OS << "; Combined Shader Flags for Module\n";
+  FlagsInfo.getCombinedFlags().print(OS);
+  // Print shader flags mask for each of the module functions
+  OS << "; Shader Flags for Module Functions\n";
+  for (const auto &F : M.getFunctionList()) {
+    if (F.isDeclaration())
+      continue;
+    auto SFMask = FlagsInfo.getFunctionFlags(&F);
+    OS << formatv("; Function {0} : {1:x8}\n;\n", F.getName(),
+                  (uint64_t)(SFMask));
+  }
+
   return PreservedAnalyses::all();
 }
 
+//===----------------------------------------------------------------------===//
+// ShaderFlagsAnalysis and ShaderFlagsAnalysisPrinterPass
+
+bool ShaderFlagsAnalysisWrapper::runOnModule(Module &M) {
+  MSFI.initialize(M);
+  return false;
+}
+
 char ShaderFlagsAnalysisWrapper::ID = 0;
 
 INITIALIZE_PASS(ShaderFlagsAnalysisWrapper, "dx-shader-flag-analysis",

llvm/lib/Target/DirectX/DXILShaderFlags.h

@@ -14,12 +14,14 @@
 #ifndef LLVM_TARGET_DIRECTX_DXILSHADERFLAGS_H
 #define LLVM_TARGET_DIRECTX_DXILSHADERFLAGS_H
 
+#include "llvm/IR/Function.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cstdint>
+#include <memory>
 
 namespace llvm {
 class Module;
@@ -43,15 +45,23 @@ struct ComputedShaderFlags {
   constexpr uint64_t getMask(int Bit) const {
     return Bit != -1 ? 1ull << Bit : 0;
   }
+
+  uint64_t getModuleFlags() const {
+    uint64_t ModuleFlags = 0;
+#define DXIL_MODULE_FLAG(DxilModuleBit, FlagName, Str)                         \
+  ModuleFlags |= FlagName ? getMask(DxilModuleBit) : 0ull;
+#include "llvm/BinaryFormat/DXContainerConstants.def"
+    return ModuleFlags;
+  }
+
   operator uint64_t() const {
-    uint64_t FlagValue = 0;
+    uint64_t FlagValue = getModuleFlags();
 #define SHADER_FEATURE_FLAG(FeatureBit, DxilModuleBit, FlagName, Str)          \
   FlagValue |= FlagName ? getMask(DxilModuleBit) : 0ull;
-#define DXIL_MODULE_FLAG(DxilModuleBit, FlagName, Str)                         \
-  FlagValue |= FlagName ? getMask(DxilModuleBit) : 0ull;
 #include "llvm/BinaryFormat/DXContainerConstants.def"
     return FlagValue;
   }
+
   uint64_t getFeatureFlags() const {
     uint64_t FeatureFlags = 0;
 #define SHADER_FEATURE_FLAG(FeatureBit, DxilModuleBit, FlagName, Str)          \
@@ -60,21 +70,43 @@ struct ComputedShaderFlags {
     return FeatureFlags;
   }
 
-  static ComputedShaderFlags computeFlags(Module &M);
+  void merge(const uint64_t IVal) {
+#define SHADER_FEATURE_FLAG(FeatureBit, DxilModuleBit, FlagName, Str)          \
+  FlagName |= (IVal & getMask(DxilModuleBit));
+#define DXIL_MODULE_FLAG(DxilModuleBit, FlagName, Str)                         \
+  FlagName |= (IVal & getMask(DxilModuleBit));
+#include "llvm/BinaryFormat/DXContainerConstants.def"
+    return;
+  }
+
   void print(raw_ostream &OS = dbgs()) const;
   LLVM_DUMP_METHOD void dump() const { print(); }
 };
 
+struct ModuleShaderFlags {
+  void initialize(const Module &);
+  const ComputedShaderFlags &getFunctionFlags(const Function *) const;
+  const ComputedShaderFlags &getCombinedFlags() const { return CombinedSFMask; }
+
+private:
+  /// Vector of sorted Function-Shader Flag mask pairs representing properties
+  /// of each of the functions in the module. Shader Flags of each function
+  /// represent both module-level and function-level flags
+  SmallVector<std::pair<Function const *, ComputedShaderFlags>> FunctionFlags;
+  /// Combined Shader Flag Mask of all functions of the module
+  ComputedShaderFlags CombinedSFMask{};
+};
+
 class ShaderFlagsAnalysis : public AnalysisInfoMixin<ShaderFlagsAnalysis> {
   friend AnalysisInfoMixin<ShaderFlagsAnalysis>;
   static AnalysisKey Key;
 
 public:
   ShaderFlagsAnalysis() = default;
 
-  using Result = ComputedShaderFlags;
+  using Result = ModuleShaderFlags;
 
-  ComputedShaderFlags run(Module &M, ModuleAnalysisManager &AM);
+  ModuleShaderFlags run(Module &M, ModuleAnalysisManager &AM);
 };
 
 /// Printer pass for ShaderFlagsAnalysis results.
@@ -92,19 +124,16 @@ class ShaderFlagsAnalysisPrinter
 /// This is required because the passes that will depend on this are codegen
 /// passes which run through the legacy pass manager.
 class ShaderFlagsAnalysisWrapper : public ModulePass {
-  ComputedShaderFlags Flags;
+  ModuleShaderFlags MSFI;
 
 public:
   static char ID;
 
   ShaderFlagsAnalysisWrapper() : ModulePass(ID) {}
 
-  const ComputedShaderFlags &getShaderFlags() { return Flags; }
+  const ModuleShaderFlags &getShaderFlags() { return MSFI; }
 
-  bool runOnModule(Module &M) override {
-    Flags = ComputedShaderFlags::computeFlags(M);
-    return false;
-  }
+  bool runOnModule(Module &M) override;
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.setPreservesAll();

llvm/lib/Target/DirectX/DXILTranslateMetadata.cpp

@@ -25,6 +25,7 @@
 #include "llvm/IR/Module.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/Pass.h"
+#include "llvm/Support/Error.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/VersionTuple.h"
 #include "llvm/TargetParser/Triple.h"
@@ -286,11 +287,6 @@ static MDTuple *emitTopLevelLibraryNode(Module &M, MDNode *RMD,
   MDTuple *Properties = nullptr;
   if (ShaderFlags != 0) {
     SmallVector<Metadata *> MDVals;
-    // FIXME: ShaderFlagsAnalysis pass needs to collect and provide
-    // ShaderFlags for each entry function. Currently, ShaderFlags value
-    // provided by ShaderFlagsAnalysis pass is created by walking *all* the
-    // function instructions of the module. Is it is correct to use this value
-    // for metadata of the empty library entry?
     MDVals.append(
         getTagValueAsMetadata(EntryPropsTag::ShaderFlags, ShaderFlags, Ctx));
     Properties = MDNode::get(Ctx, MDVals);
@@ -302,7 +298,7 @@ static MDTuple *emitTopLevelLibraryNode(Module &M, MDNode *RMD,
 
 static void translateMetadata(Module &M, const DXILResourceMap &DRM,
                               const Resources &MDResources,
-                              const ComputedShaderFlags &ShaderFlags,
+                              const ModuleShaderFlags &ShaderFlags,
                               const ModuleMetadataInfo &MMDI) {
   LLVMContext &Ctx = M.getContext();
   IRBuilder<> IRB(Ctx);
@@ -318,23 +314,27 @@ static void translateMetadata(Module &M, const DXILResourceMap &DRM,
   // See https://github.com/llvm/llvm-project/issues/57928
   MDTuple *Signatures = nullptr;
 
-  if (MMDI.ShaderProfile == Triple::EnvironmentType::Library)
+  if (MMDI.ShaderProfile == Triple::EnvironmentType::Library) {
+    // Get the combined shader flag mask of all functions in the library to be
+    // used as shader flags mask value associated with top-level library entry
+    // metadata.
+    uint64_t CombinedMask = ShaderFlags.getCombinedFlags();
     EntryFnMDNodes.emplace_back(
-        emitTopLevelLibraryNode(M, ResourceMD, ShaderFlags));
-  else if (MMDI.EntryPropertyVec.size() > 1) {
+        emitTopLevelLibraryNode(M, ResourceMD, CombinedMask));
+  } else if (MMDI.EntryPropertyVec.size() > 1) {
     M.getContext().diagnose(DiagnosticInfoTranslateMD(
         M, "Non-library shader: One and only one entry expected"));
   }
 
   for (const EntryProperties &EntryProp : MMDI.EntryPropertyVec) {
-    // FIXME: ShaderFlagsAnalysis pass needs to collect and provide
-    // ShaderFlags for each entry function. For now, assume shader flags value
-    // of entry functions being compiled for lib_* shader profile viz.,
-    // EntryPro.Entry is 0.
-    uint64_t EntryShaderFlags =
-        (MMDI.ShaderProfile == Triple::EnvironmentType::Library) ? 0
-                                                                 : ShaderFlags;
+    const ComputedShaderFlags &EntrySFMask =
+        ShaderFlags.getFunctionFlags(EntryProp.Entry);
+
+    // If ShaderProfile is Library, mask is already consolidated in the
+    // top-level library node. Hence it is not emitted.
+    uint64_t EntryShaderFlags = 0;
     if (MMDI.ShaderProfile != Triple::EnvironmentType::Library) {
+      EntryShaderFlags = EntrySFMask;
       if (EntryProp.ShaderStage != MMDI.ShaderProfile) {
         M.getContext().diagnose(DiagnosticInfoTranslateMD(
             M,
@@ -361,8 +361,7 @@ PreservedAnalyses DXILTranslateMetadata::run(Module &M,
                                              ModuleAnalysisManager &MAM) {
   const DXILResourceMap &DRM = MAM.getResult<DXILResourceAnalysis>(M);
   const dxil::Resources &MDResources = MAM.getResult<DXILResourceMDAnalysis>(M);
-  const ComputedShaderFlags &ShaderFlags =
-      MAM.getResult<ShaderFlagsAnalysis>(M);
+  const ModuleShaderFlags &ShaderFlags = MAM.getResult<ShaderFlagsAnalysis>(M);
   const dxil::ModuleMetadataInfo MMDI = MAM.getResult<DXILMetadataAnalysis>(M);
 
   translateMetadata(M, DRM, MDResources, ShaderFlags, MMDI);
@@ -393,7 +392,7 @@ class DXILTranslateMetadataLegacy : public ModulePass {
         getAnalysis<DXILResourceWrapperPass>().getResourceMap();
     const dxil::Resources &MDResources =
         getAnalysis<DXILResourceMDWrapper>().getDXILResource();
-    const ComputedShaderFlags &ShaderFlags =
+    const ModuleShaderFlags &ShaderFlags =
         getAnalysis<ShaderFlagsAnalysisWrapper>().getShaderFlags();
     dxil::ModuleMetadataInfo MMDI =
         getAnalysis<DXILMetadataAnalysisWrapperPass>().getModuleMetadata();

llvm/test/CodeGen/DirectX/ShaderFlags/double-extensions-obj-test.ll

@@ -0,0 +1,17 @@
+; RUN: llc %s --filetype=obj -o - | obj2yaml | FileCheck %s
+
+target triple = "dxil-pc-shadermodel6.7-library"
+define double @div(double %a, double %b) #0 {
+  %res = fdiv double %a, %b
+  ret double %res
+}
+
+attributes #0 = { convergent norecurse nounwind "hlsl.export"}
+
+; CHECK: - Name:            SFI0
+; CHECK-NEXT:     Size:            8
+; CHECK-NEXT:     Flags:
+; CHECK-NEXT:       Doubles:         true
+; CHECK-NOT:   {{[A-Za-z]+: +true}}
+; CHECK:            DX11_1_DoubleExtensions:         true
+