[llvm-branch-commits] [DXIL][Analysis] Implement enough of DXILResourceAnalysis for buffers (PR #100699)

[Justin Bogner via llvm-branch-commits]

================
@@ -331,6 +336,249 @@ std::pair<uint32_t, uint32_t> ResourceInfo::getAnnotateProps() const {
   return {Word0, Word1};
 }
 
+void ResourceInfo::print(raw_ostream &OS) const {
+  OS << "  Symbol: ";
+  Symbol->printAsOperand(OS);
+  OS << "\n";
+
+  OS << "  Name: \"" << Name << "\"\n"
+     << "  Binding:\n"
+     << "    Unique ID: " << Binding.UniqueID << "\n"
+     << "    Space: " << Binding.Space << "\n"
+     << "    Lower Bound: " << Binding.LowerBound << "\n"
+     << "    Size: " << Binding.Size << "\n"
+     << "  Class: " << static_cast<unsigned>(RC) << "\n"
+     << "  Kind: " << static_cast<unsigned>(Kind) << "\n";
+
+  if (isCBuffer()) {
+    OS << "  CBuffer size: " << CBufferSize << "\n";
+  } else if (isSampler()) {
+    OS << "  Sampler Type: " << static_cast<unsigned>(SamplerTy) << "\n";
+  } else {
+    if (isUAV()) {
+      OS << "  Globally Coherent: " << UAVFlags.GloballyCoherent << "\n"
+         << "  HasCounter: " << UAVFlags.HasCounter << "\n"
+         << "  IsROV: " << UAVFlags.IsROV << "\n";
+    }
+    if (isMultiSample())
+      OS << "  Sample Count: " << MultiSample.Count << "\n";
+
+    if (isStruct()) {
+      OS << "  Buffer Stride: " << Struct.Stride << "\n";
+      uint32_t AlignLog2 = Struct.Alignment ? Log2(*Struct.Alignment) : 0;
+      OS << "  Alignment: " << AlignLog2 << "\n";
+    } else if (isTyped()) {
+      OS << "  Element Type: " << static_cast<unsigned>(Typed.ElementTy) << "\n"
+         << "  Element Count: " << static_cast<unsigned>(Typed.ElementCount)
+         << "\n";
+    } else if (isFeedback())
+      OS << "  Feedback Type: " << static_cast<unsigned>(Feedback.Type) << "\n";
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// ResourceMapper
+
+static dxil::ElementType toDXILElementType(Type *Ty, bool IsSigned) {
+  // TODO: Handle unorm, snorm, and packed.
+  Ty = Ty->getScalarType();
+
+  if (Ty->isIntegerTy()) {
+    switch (Ty->getIntegerBitWidth()) {
+    case 16:
+      return IsSigned ? ElementType::I16 : ElementType::U16;
+    case 32:
+      return IsSigned ? ElementType::I32 : ElementType::U32;
+    case 64:
+      return IsSigned ? ElementType::I64 : ElementType::U64;
+    case 1:
+    default:
+      return ElementType::Invalid;
+    }
+  } else if (Ty->isFloatTy()) {
+    return ElementType::F32;
+  } else if (Ty->isDoubleTy()) {
+    return ElementType::F64;
+  } else if (Ty->isHalfTy()) {
+    return ElementType::F16;
+  }
+
+  return ElementType::Invalid;
+}
+
+namespace {
+
+class ResourceMapper {
+  Module &M;
+  LLVMContext &Context;
+  DXILResourceMap &Resources;
+
+  // Unique ID is per resource type to match DXC.
+  uint32_t NextUAV = 0;
+  uint32_t NextSRV = 0;
+  uint32_t NextCBuf = 0;
+  uint32_t NextSmp = 0;
+
+public:
+  ResourceMapper(Module &M,
+                 MapVector<CallInst *, dxil::ResourceInfo> &Resources)
+      : M(M), Context(M.getContext()), Resources(Resources) {}
+
+  void diagnoseHandle(CallInst *CI, const Twine &Msg,
+                      DiagnosticSeverity Severity = DS_Error) {
+    std::string S;
+    raw_string_ostream SS(S);
+    CI->printAsOperand(SS);
+    DiagnosticInfoUnsupported Diag(*CI->getFunction(), Msg + ": " + SS.str(),
+                                   CI->getDebugLoc(), Severity);
+    Context.diagnose(Diag);
+  }
+
+  ResourceInfo *mapBufferType(CallInst *CI, TargetExtType *HandleTy,
+                              bool IsTyped) {
+    if (HandleTy->getNumTypeParameters() != 1 ||
+        HandleTy->getNumIntParameters() != (IsTyped ? 3 : 2)) {
+      diagnoseHandle(CI, Twine("Invalid buffer target type"));
+      return nullptr;
+    }
+
+    Type *ElTy = HandleTy->getTypeParameter(0);
+    unsigned IsWriteable = HandleTy->getIntParameter(0);
+    unsigned IsROV = HandleTy->getIntParameter(1);
+    bool IsSigned = IsTyped && HandleTy->getIntParameter(2);
+
+    ResourceClass RC = IsWriteable ? ResourceClass::UAV : ResourceClass::SRV;
+    ResourceKind Kind;
+    if (IsTyped)
+      Kind = ResourceKind::TypedBuffer;
+    else if (ElTy->isIntegerTy(8))
+      Kind = ResourceKind::RawBuffer;
+    else
+      Kind = ResourceKind::StructuredBuffer;
+
+    // TODO: We need to lower to a typed pointer, can we smuggle the type
+    // through?
+    Value *Symbol = UndefValue::get(PointerType::getUnqual(Context));
+    // TODO: We don't actually keep track of the name right now...
+    StringRef Name = "";
+
+    auto [It, Success] = Resources.try_emplace(CI, RC, Kind, Symbol, Name);
+    assert(Success && "Mapping the same CallInst again?");
+    (void)Success;
+    // We grab a pointer into the map's storage, which isn't generally safe.
+    // Since we're just using this to fill in the info the map won't mutate and
+    // the pointer stays valid for as long as we need it to.
+    ResourceInfo *RI = &(It->second);
+
+    if (RI->isUAV())
+      // TODO: We need analysis for GloballyCoherent and HasCounter
+      RI->setUAV(false, false, IsROV);
+
+    if (RI->isTyped()) {
+      dxil::ElementType ET = toDXILElementType(ElTy, IsSigned);
+      uint32_t Count = 1;
+      if (auto *VTy = dyn_cast<FixedVectorType>(ElTy))
+        Count = VTy->getNumElements();
+      RI->setTyped(ET, Count);
+    } else if (RI->isStruct()) {
+      const DataLayout &DL = M.getDataLayout();
+
+      // This mimics what DXC does. Notably, we only ever set the alignment if
+      // the type is actually a struct type.
+      uint32_t Stride = DL.getTypeAllocSize(ElTy);
+      MaybeAlign Alignment;
+      if (auto *STy = dyn_cast<StructType>(ElTy))
+        Alignment = DL.getStructLayout(STy)->getAlignment();
+      RI->setStruct(Stride, Alignment);
+    }
+
+    return RI;
+  }
+
+  ResourceInfo *mapHandleIntrin(CallInst *CI) {
+    FunctionType *FTy = CI->getFunctionType();
+    Type *RetTy = FTy->getReturnType();
+    auto *HandleTy = dyn_cast<TargetExtType>(RetTy);
+    if (!HandleTy) {
+      diagnoseHandle(CI, "dx.handle.fromBinding requires target type");
+      return nullptr;
+    }
+
+    StringRef TypeName = HandleTy->getName();
+    if (TypeName == "dx.TypedBuffer") {
+      return mapBufferType(CI, HandleTy, /*IsTyped=*/true);
+    } else if (TypeName == "dx.RawBuffer") {
+      return mapBufferType(CI, HandleTy, /*IsTyped=*/false);
+    } else if (TypeName == "dx.CBuffer") {
+      // TODO: implement
+      diagnoseHandle(CI, "dx.CBuffer handles are not implemented yet");
----------------
bogner wrote:

We could potentially use that approach for RawBuffer, but that's something we'd need to design and it seems awkward to have a separate code path for RawBuffer vs the other buffer and texture types. I'm not sure if it would be worth it or not.

CBuffer probably shouldn't be done like that - it's much more akin to TypedBuffer in that it can only be accessed by 16 byte loads and it has all of the special layout stuff to deal with.

https://github.com/llvm/llvm-project/pull/100699