[Intrinsics] Add Intrinsic::getFnAttributes() (NFC) (#132029)

Most places that call Intrinsic::getAttributes() are only interested in
the function attributes, so add a separate function for that.

The motivation for this is that I'd like to add the ability to specify
range attributes on intrinsics, which requires knowing the function
type. This avoids needing to know the type for most attribute queries.

Author: nikic

llvm/include/llvm/IR/Intrinsics.h

@@ -28,6 +28,7 @@ class Function;
 class LLVMContext;
 class Module;
 class AttributeList;
+class AttributeSet;
 
 /// This namespace contains an enum with a value for every intrinsic/builtin
 /// function known by LLVM. The enum values are returned by
@@ -87,6 +88,9 @@ namespace Intrinsic {
   /// Return the attributes for an intrinsic.
   AttributeList getAttributes(LLVMContext &C, ID id);
 
+  /// Return the function attributes for an intrinsic.
+  AttributeSet getFnAttributes(LLVMContext &C, ID id);
+
   /// Look up the Function declaration of the intrinsic \p id in the Module
   /// \p M. If it does not exist, add a declaration and return it. Otherwise,
   /// return the existing declaration.

llvm/lib/CodeGen/ExpandVectorPredication.cpp

@@ -121,8 +121,8 @@ static bool maySpeculateLanes(VPIntrinsic &VPI) {
     return false;
   // Fallback to whether the intrinsic is speculatable.
   if (auto IntrID = VPI.getFunctionalIntrinsicID())
-    return Intrinsic::getAttributes(VPI.getContext(), *IntrID)
-        .hasFnAttr(Attribute::AttrKind::Speculatable);
+    return Intrinsic::getFnAttributes(VPI.getContext(), *IntrID)
+        .hasAttribute(Attribute::AttrKind::Speculatable);
   if (auto Opc = VPI.getFunctionalOpcode())
     return isSafeToSpeculativelyExecuteWithOpcode(*Opc, &VPI);
   return false;

llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp

@@ -880,9 +880,9 @@ MachineIRBuilder::buildIntrinsic(Intrinsic::ID ID,
 MachineInstrBuilder
 MachineIRBuilder::buildIntrinsic(Intrinsic::ID ID,
                                  ArrayRef<Register> ResultRegs) {
-  auto Attrs = Intrinsic::getAttributes(getContext(), ID);
+  AttributeSet Attrs = Intrinsic::getFnAttributes(getContext(), ID);
   bool HasSideEffects = !Attrs.getMemoryEffects().doesNotAccessMemory();
-  bool isConvergent = Attrs.hasFnAttr(Attribute::Convergent);
+  bool isConvergent = Attrs.hasAttribute(Attribute::Convergent);
   return buildIntrinsic(ID, ResultRegs, HasSideEffects, isConvergent);
 }
 
@@ -899,9 +899,9 @@ MachineInstrBuilder MachineIRBuilder::buildIntrinsic(Intrinsic::ID ID,
 
 MachineInstrBuilder MachineIRBuilder::buildIntrinsic(Intrinsic::ID ID,
                                                      ArrayRef<DstOp> Results) {
-  auto Attrs = Intrinsic::getAttributes(getContext(), ID);
+  AttributeSet Attrs = Intrinsic::getFnAttributes(getContext(), ID);
   bool HasSideEffects = !Attrs.getMemoryEffects().doesNotAccessMemory();
-  bool isConvergent = Attrs.hasFnAttr(Attribute::Convergent);
+  bool isConvergent = Attrs.hasAttribute(Attribute::Convergent);
   return buildIntrinsic(ID, Results, HasSideEffects, isConvergent);
 }
 

llvm/lib/CodeGen/MachineVerifier.cpp

@@ -1070,7 +1070,7 @@ bool MachineVerifier::verifyGIntrinsicSideEffects(const MachineInstr *MI) {
                        Opcode == TargetOpcode::G_INTRINSIC_CONVERGENT;
   unsigned IntrID = cast<GIntrinsic>(MI)->getIntrinsicID();
   if (IntrID != 0 && IntrID < Intrinsic::num_intrinsics) {
-    AttributeList Attrs = Intrinsic::getAttributes(
+    AttributeSet Attrs = Intrinsic::getFnAttributes(
         MF->getFunction().getContext(), static_cast<Intrinsic::ID>(IntrID));
     bool DeclHasSideEffects = !Attrs.getMemoryEffects().doesNotAccessMemory();
     if (NoSideEffects && DeclHasSideEffects) {
@@ -1094,9 +1094,9 @@ bool MachineVerifier::verifyGIntrinsicConvergence(const MachineInstr *MI) {
                        Opcode == TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS;
   unsigned IntrID = cast<GIntrinsic>(MI)->getIntrinsicID();
   if (IntrID != 0 && IntrID < Intrinsic::num_intrinsics) {
-    AttributeList Attrs = Intrinsic::getAttributes(
+    AttributeSet Attrs = Intrinsic::getFnAttributes(
         MF->getFunction().getContext(), static_cast<Intrinsic::ID>(IntrID));
-    bool DeclIsConvergent = Attrs.hasFnAttr(Attribute::Convergent);
+    bool DeclIsConvergent = Attrs.hasAttribute(Attribute::Convergent);
     if (NotConvergent && DeclIsConvergent) {
       report(Twine(TII->getName(Opcode), " used with a convergent intrinsic"),
              MI);

llvm/lib/IR/Intrinsics.cpp

@@ -753,6 +753,14 @@ Intrinsic::ID Intrinsic::lookupIntrinsicID(StringRef Name) {
 #include "llvm/IR/IntrinsicImpl.inc"
 #undef GET_INTRINSIC_ATTRIBUTES
 
+AttributeSet Intrinsic::getFnAttributes(LLVMContext &C, ID id) {
+  if (id == 0)
+    return AttributeSet();
+  uint16_t PackedID = IntrinsicsToAttributesMap[id - 1];
+  uint8_t FnAttrID = PackedID >> 8;
+  return getIntrinsicFnAttributeSet(C, FnAttrID);
+}
+
 Function *Intrinsic::getOrInsertDeclaration(Module *M, ID id,
                                             ArrayRef<Type *> Tys) {
   // There can never be multiple globals with the same name of different types,

llvm/lib/Target/AMDGPU/SIISelLowering.cpp

@@ -1222,8 +1222,8 @@ bool SITargetLowering::getTgtMemIntrinsic(IntrinsicInfo &Info,
 
   if (const AMDGPU::RsrcIntrinsic *RsrcIntr =
           AMDGPU::lookupRsrcIntrinsic(IntrID)) {
-    AttributeList Attr =
-        Intrinsic::getAttributes(CI.getContext(), (Intrinsic::ID)IntrID);
+    AttributeSet Attr =
+        Intrinsic::getFnAttributes(CI.getContext(), (Intrinsic::ID)IntrID);
     MemoryEffects ME = Attr.getMemoryEffects();
     if (ME.doesNotAccessMemory())
       return false;

llvm/lib/Transforms/Vectorize/VPlan.h

@@ -1263,13 +1263,13 @@ class VPWidenIntrinsicRecipe : public VPRecipeWithIRFlags {
       : VPRecipeWithIRFlags(VPDef::VPWidenIntrinsicSC, CallArguments, DL),
         VectorIntrinsicID(VectorIntrinsicID), ResultTy(Ty) {
     LLVMContext &Ctx = Ty->getContext();
-    AttributeList Attrs = Intrinsic::getAttributes(Ctx, VectorIntrinsicID);
+    AttributeSet Attrs = Intrinsic::getFnAttributes(Ctx, VectorIntrinsicID);
     MemoryEffects ME = Attrs.getMemoryEffects();
     MayReadFromMemory = ME.onlyWritesMemory();
     MayWriteToMemory = ME.onlyReadsMemory();
     MayHaveSideEffects = MayWriteToMemory ||
-                         !Attrs.hasFnAttr(Attribute::NoUnwind) ||
-                         !Attrs.hasFnAttr(Attribute::WillReturn);
+                         !Attrs.hasAttribute(Attribute::NoUnwind) ||
+                         !Attrs.hasAttribute(Attribute::WillReturn);
   }
 
   ~VPWidenIntrinsicRecipe() override = default;

llvm/lib/Transforms/Vectorize/VectorCombine.cpp

@@ -995,8 +995,8 @@ bool VectorCombine::scalarizeVPIntrinsic(Instruction &I) {
   // scalarizing it.
   bool SafeToSpeculate;
   if (ScalarIntrID)
-    SafeToSpeculate = Intrinsic::getAttributes(I.getContext(), *ScalarIntrID)
-                          .hasFnAttr(Attribute::AttrKind::Speculatable);
+    SafeToSpeculate = Intrinsic::getFnAttributes(I.getContext(), *ScalarIntrID)
+                          .hasAttribute(Attribute::AttrKind::Speculatable);
   else
     SafeToSpeculate = isSafeToSpeculativelyExecuteWithOpcode(
         *FunctionalOpcode, &VPI, nullptr, &AC, &DT);

llvm/test/TableGen/intrinsic-attrs.td

@@ -22,11 +22,11 @@ def int_deref_ptr_ret : Intrinsic<[llvm_ptr_ty], [], [Dereferenceable<RetIndex,
 // CHECK-NEXT: Attribute::get(C, Attribute::NoUnwind),
 // CHECK-NEXT: });
 
-
-// CHECK: getAttributes(LLVMContext &C, ID id)
+// CHECK: static constexpr uint16_t IntrinsicsToAttributesMap[] = {
 // CHECK: 0 << 8 | 0, // llvm.deref.ptr.ret
 // CHECK: 1 << 8 | 1, // llvm.random.gen
 
+// CHECK: getAttributes(LLVMContext &C, ID id)
 // CHECK: case 1:
 // CHECK-NEXT: return AttributeList::get(C, {
 // CHECK-NEXT:   {AttributeList::FunctionIndex, getIntrinsicFnAttributeSet(C, FnAttrID)}

llvm/utils/TableGen/Basic/IntrinsicEmitter.cpp

@@ -555,8 +555,6 @@ static AttributeSet getIntrinsicFnAttributeSet(LLVMContext &C, unsigned ID) {
     default: llvm_unreachable("Invalid attribute set number");)";
 
   for (const CodeGenIntrinsic &Int : Ints) {
-    if (!hasFnAttributes(Int))
-      continue;
     unsigned ID = UniqFnAttributes.size();
     if (!UniqFnAttributes.try_emplace(&Int, ID).second)
       continue;
@@ -606,8 +604,7 @@ static AttributeSet getIntrinsicFnAttributeSet(LLVMContext &C, unsigned ID) {
   }
 } // getIntrinsicFnAttributeSet
 
-AttributeList Intrinsic::getAttributes(LLVMContext &C, ID id) {
-)";
+static constexpr uint16_t IntrinsicsToAttributesMap[] = {)";
 
   // Compute the maximum number of attribute arguments and the map. For function
   // attributes, we only consider whether the intrinsics has any function
@@ -619,6 +616,14 @@ AttributeList Intrinsic::getAttributes(LLVMContext &C, ID id) {
     UniqAttributes.try_emplace(&Int, ID);
   }
 
+  // Emit an array of AttributeList.  Most intrinsics will have at least one
+  // entry, for the function itself (index ~1), which is usually nounwind.
+  for (const CodeGenIntrinsic &Int : Ints) {
+    uint16_t FnAttrIndex = UniqFnAttributes[&Int];
+    OS << formatv("\n    {} << 8 | {}, // {}", FnAttrIndex,
+                  UniqAttributes[&Int], Int.Name);
+  }
+
   // Assign a 16-bit packed ID for each intrinsic. The lower 8-bits will be its
   // "argument attribute ID" (index in UniqAttributes) and upper 8 bits will be
   // its "function attribute ID" (index in UniqFnAttributes).
@@ -627,17 +632,12 @@ AttributeList Intrinsic::getAttributes(LLVMContext &C, ID id) {
   if (UniqFnAttributes.size() > 256)
     PrintFatalError("Too many unique function attributes for table!");
 
-  // Emit an array of AttributeList.  Most intrinsics will have at least one
-  // entry, for the function itself (index ~1), which is usually nounwind.
-  OS << "  static constexpr uint16_t IntrinsicsToAttributesMap[] = {";
-  for (const CodeGenIntrinsic &Int : Ints) {
-    uint16_t FnAttrIndex = hasFnAttributes(Int) ? UniqFnAttributes[&Int] : 0;
-    OS << formatv("\n    {} << 8 | {}, // {}", FnAttrIndex,
-                  UniqAttributes[&Int], Int.Name);
-  }
+  OS << R"(
+};
+
+AttributeList Intrinsic::getAttributes(LLVMContext &C, ID id) {)";
 
   OS << formatv(R"(
-  };
   if (id == 0)
     return AttributeList();