[DXIL] Define DXILAttribute

- switch to using DXILAttribute to only denote function attributes

- attribute enums can't be or'd together as is currently implemented, so
  we switch to using a list of attributes in DXILOpBuilder.cpp and
  DXILEmitter.cpp

Author: inbelic

llvm/lib/Target/DirectX/DXIL.td

@@ -266,18 +266,18 @@ def miss : DXILShaderStage;
 def all_stages : DXILShaderStage;
 // Denote support for DXIL Op to have been removed
 def removed : DXILShaderStage;
+
 // DXIL Op attributes
 
+// A function attribute denotes that there is a corresponding LLVM function
+// attribute that will be set when building the DXIL op. The mapping for
+// non-trivial cases is defined by setDXILAttribute in DXILOpBuilder.cpp
 class DXILAttribute;
 
-def ReadOnly : DXILAttribute;
 def ReadNone : DXILAttribute;
-def IsDerivative : DXILAttribute;
-def IsGradient : DXILAttribute;
-def IsFeedback : DXILAttribute;
-def IsWave : DXILAttribute;
-def NeedsUniformInputs : DXILAttribute;
-def IsBarrier : DXILAttribute;
+def ReadOnly : DXILAttribute;
+def NoDuplicate : DXILAttribute;
+def NoReturn : DXILAttribute;
 
 class Overloads<Version ver, list<DXILOpParamType> ols> {
   Version dxil_version = ver;
@@ -291,7 +291,7 @@ class Stages<Version ver, list<DXILShaderStage> st> {
 
 class Attributes<Version ver = DXIL1_0, list<DXILAttribute> attrs> {
   Version dxil_version = ver;
-  list<DXILAttribute> op_attrs = attrs;
+  list<DXILAttribute> fn_attrs = attrs;
 }
 
 defvar BarrierMode_DeviceMemoryBarrier              = 2;

llvm/lib/Target/DirectX/DXILConstants.h

@@ -30,6 +30,11 @@ enum class OpParamType : unsigned {
 #include "DXILOperation.inc"
 };
 
+enum class Attribute : unsigned {
+#define DXIL_ATTRIBUTE(Name) Name,
+#include "DXILOperation.inc"
+};
+
 } // namespace dxil
 } // namespace llvm
 

llvm/lib/Target/DirectX/DXILOpBuilder.cpp

@@ -54,7 +54,7 @@ struct OpStage {
 
 struct OpAttribute {
   Version DXILVersion;
-  uint32_t ValidAttrs;
+  llvm::SmallVector<dxil::Attribute> ValidAttrs;
 };
 
 static const char *getOverloadTypeName(OverloadKind Kind) {
@@ -367,6 +367,20 @@ static std::optional<size_t> getPropIndex(ArrayRef<T> PropList,
   return std::nullopt;
 }
 
+static void setDXILAttribute(CallInst *CI, dxil::Attribute Attr) {
+  switch (Attr) {
+  case dxil::Attribute::ReadNone:
+    return CI->setDoesNotAccessMemory();
+  case dxil::Attribute::ReadOnly:
+    return CI->setOnlyReadsMemory();
+  case dxil::Attribute::NoReturn:
+    return CI->setDoesNotReturn();
+  case dxil::Attribute::NoDuplicate:
+    return CI->setCannotDuplicate();
+  }
+  llvm_unreachable("Invalid function attribute specified for DXIL operation");
+}
+
 namespace llvm {
 namespace dxil {
 
@@ -461,7 +475,17 @@ Expected<CallInst *> DXILOpBuilder::tryCreateOp(dxil::OpCode OpCode,
   OpArgs.push_back(IRB.getInt32(llvm::to_underlying(OpCode)));
   OpArgs.append(Args.begin(), Args.end());
 
-  return IRB.CreateCall(DXILFn, OpArgs, Name);
+  // Create the function call instruction
+  CallInst *CI = IRB.CreateCall(DXILFn, OpArgs, Name);
+
+  // We then need to attach available function attributes
+  for (auto OpAttr : Prop->Attributes)
+    if (VersionTuple(OpAttr.DXILVersion.Major, OpAttr.DXILVersion.Minor) <=
+        DXILVersion)
+      for (auto Attr : OpAttr.ValidAttrs)
+        setDXILAttribute(CI, Attr);
+
+  return CI;
 }
 
 CallInst *DXILOpBuilder::createOp(dxil::OpCode OpCode, ArrayRef<Value *> Args,

llvm/utils/TableGen/DXILEmitter.cpp

@@ -315,41 +315,37 @@ static std::string getStageMaskString(ArrayRef<const Record *> Recs) {
 // by input records
 //
 /// \param Recs A vector of records of TableGen Attribute records
-/// \return std::string string representation of stages mask string
+/// \return std::string string representation of attributes list string
 ///         predicated by DXIL Version. E.g.,
-//          {{{1, 0}, Mask1}, {{1, 2}, Mask2}, ...}
-static std::string getAttributeMaskString(ArrayRef<const Record *> Recs) {
-  std::string MaskString = "";
+//          {{{1, 0}, {Attr1, ...}}, {{1, 2}, {Attr2, ...}}, ...}
+static std::string getAttributeListString(ArrayRef<const Record *> Recs) {
+  std::string ListString = "";
   std::string Prefix = "";
-  MaskString.append("{");
+  ListString.append("{");
 
   for (const auto *Rec : Recs) {
     unsigned Major = Rec->getValueAsDef("dxil_version")->getValueAsInt("Major");
     unsigned Minor = Rec->getValueAsDef("dxil_version")->getValueAsInt("Minor");
-    MaskString.append(Prefix)
+    ListString.append(Prefix)
         .append("{{")
         .append(std::to_string(Major))
         .append(", ")
-        .append(std::to_string(Minor).append("}, "));
-
-    std::string PipePrefix = "";
-    auto Attrs = Rec->getValueAsListOfDefs("op_attrs");
-    if (Attrs.empty()) {
-      MaskString.append("Attribute::None");
-    } else {
-      for (const auto *Attr : Attrs) {
-        MaskString.append(PipePrefix)
-            .append("Attribute::")
-            .append(Attr->getName());
-        PipePrefix = " | ";
-      }
+        .append(std::to_string(Minor).append("}, {"));
+
+    std::string CommaPrefix = "";
+    auto Attrs = Rec->getValueAsListOfDefs("fn_attrs");
+    for (const auto *Attr : Attrs) {
+      ListString.append(CommaPrefix)
+          .append("dxil::Attribute::")
+          .append(Attr->getName());
+      CommaPrefix = ", ";
     }
-
-    MaskString.append("}");
+    ListString.append("}"); // End of Attrs
+    ListString.append("}"); // End of Rec
     Prefix = ", ";
   }
-  MaskString.append("}");
-  return MaskString;
+  ListString.append("}"); // End of List
+  return ListString;
 }
 
 /// Emit a mapping of DXIL opcode to opname
@@ -381,6 +377,15 @@ static void emitDXILOpParamTypes(const RecordKeeper &Records, raw_ostream &OS) {
   OS << "#endif\n\n";
 }
 
+/// Emit a list of DXIL op function attributes
+static void emitDXILAttributes(const RecordKeeper &Records, raw_ostream &OS) {
+  OS << "#ifdef DXIL_ATTRIBUTE\n";
+  for (const Record *Attr : Records.getAllDerivedDefinitions("DXILAttribute"))
+    OS << "DXIL_ATTRIBUTE(" << Attr->getName() << ")\n";
+  OS << "#undef DXIL_ATTRIBUTE\n";
+  OS << "#endif\n\n";
+}
+
 /// Emit a list of DXIL op function types
 static void emitDXILOpFunctionTypes(ArrayRef<DXILOperationDesc> Ops,
                                     raw_ostream &OS) {
@@ -477,7 +482,7 @@ static void emitDXILOperationTable(ArrayRef<DXILOperationDesc> Ops,
        << OpClassStrings.get(Op.OpClass.data()) << ", "
        << getOverloadMaskString(Op.OverloadRecs) << ", "
        << getStageMaskString(Op.StageRecs) << ", "
-       << getAttributeMaskString(Op.AttrRecs) << ", " << Op.OverloadParamIndex
+       << getAttributeListString(Op.AttrRecs) << ", " << Op.OverloadParamIndex
        << " }";
     Prefix = ",\n";
   }
@@ -582,6 +587,7 @@ static void emitDxilOperation(const RecordKeeper &Records, raw_ostream &OS) {
   emitDXILOpCodes(DXILOps, OS);
   emitDXILOpClasses(Records, OS);
   emitDXILOpParamTypes(Records, OS);
+  emitDXILAttributes(Records, OS);
   emitDXILOpFunctionTypes(DXILOps, OS);
   emitDXILIntrinsicArgSelectTypes(Records, OS);
   emitDXILIntrinsicMap(DXILOps, OS);