llvm · nikic · Mar 20, 2025 · Mar 19, 2025
diff --git a/llvm/include/llvm/IR/Intrinsics.h b/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.

diff --git a/llvm/lib/CodeGen/ExpandVectorPredication.cpp b/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;

diff --git a/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp b/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);
 }
 

diff --git a/llvm/lib/CodeGen/MachineVerifier.cpp b/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);

diff --git a/llvm/lib/IR/Intrinsics.cpp b/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,

diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/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;

diff --git a/llvm/lib/Transforms/Vectorize/VPlan.h b/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;

diff --git a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp b/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);

diff --git a/llvm/test/TableGen/intrinsic-attrs.td b/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)}

diff --git a/llvm/utils/TableGen/Basic/IntrinsicEmitter.cpp b/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();