Revert "Implementation of global.get/set for reftypes in LLVM IR"

This reverts commit 31859f8.

Causing SVE and RISCV-V test failures on bots.

Author: DavidSpickett

clang/lib/Basic/Targets/WebAssembly.cpp

@@ -214,8 +214,6 @@ bool WebAssemblyTargetInfo::handleTargetFeatures(
       continue;
     }
     if (Feature == "+reference-types") {
-      // FIXME: Ensure address spaces 10 and 20 are marked as non-integral in
-      // the datalayout string.
       HasReferenceTypes = true;
       continue;
     }

llvm/include/llvm/CodeGen/TargetLowering.h

@@ -350,7 +350,7 @@ class TargetLoweringBase {
   /// Return the in-memory pointer type for the given address space, defaults to
   /// the pointer type from the data layout.  FIXME: The default needs to be
   /// removed once all the code is updated.
-  virtual MVT getPointerMemTy(const DataLayout &DL, uint32_t AS = 0) const {
+  MVT getPointerMemTy(const DataLayout &DL, uint32_t AS = 0) const {
     return MVT::getIntegerVT(DL.getPointerSizeInBits(AS));
   }
 

llvm/include/llvm/CodeGen/ValueTypes.h

@@ -120,9 +120,6 @@ namespace llvm {
       return changeExtendedTypeToInteger();
     }
 
-    /// Test if the given EVT has zero size
-    bool isZeroSized() const { return getSizeInBits() == 0; }
-
     /// Test if the given EVT is simple (as opposed to being extended).
     bool isSimple() const {
       return V.SimpleTy != MVT::INVALID_SIMPLE_VALUE_TYPE;
@@ -210,9 +207,7 @@ namespace llvm {
     }
 
     /// Return true if the bit size is a multiple of 8.
-    bool isByteSized() const {
-      return !isZeroSized() && getSizeInBits().isKnownMultipleOf(8);
-    }
+    bool isByteSized() const { return getSizeInBits().isKnownMultipleOf(8); }
 
     /// Return true if the size is a power-of-two number of bytes.
     bool isRound() const {

llvm/include/llvm/Support/MachineValueType.h

@@ -1026,11 +1026,6 @@ namespace llvm {
       }
     }
 
-    /// Test if the given MVT has zero size
-    bool isZeroSized() const {
-      return !getSizeInBits().isScalable() && getFixedSizeInBits() == 0;
-    }
-
     /// Return the size of the specified fixed width value type in bits. The
     /// function will assert if the type is scalable.
     uint64_t getFixedSizeInBits() const {

llvm/lib/CodeGen/CodeGenPrepare.cpp

@@ -6451,10 +6451,6 @@ bool CodeGenPrepare::optimizeLoadExt(LoadInst *Load) {
 
   EVT LoadResultVT = TLI->getValueType(*DL, Load->getType());
   unsigned BitWidth = LoadResultVT.getSizeInBits();
-  // If the BitWidth is 0, do not try to optimize the type
-  if (BitWidth == 0)
-    return false;
-
   APInt DemandBits(BitWidth, 0);
   APInt WidestAndBits(BitWidth, 0);
 

llvm/lib/CodeGen/MachineOperand.cpp

@@ -1163,8 +1163,8 @@ void MachineMemOperand::print(raw_ostream &OS, ModuleSlotTracker &MST,
        << "unknown-address";
   }
   MachineOperand::printOperandOffset(OS, getOffset());
-  if (getSize() > 0 && getAlign() != getSize())
-      OS << ", align " << getAlign().value();
+  if (getAlign() != getSize())
+    OS << ", align " << getAlign().value();
   if (getAlign() != getBaseAlign())
     OS << ", basealign " << getBaseAlign().value();
   auto AAInfo = getAAInfo();

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

@@ -23090,10 +23090,6 @@ bool DAGCombiner::parallelizeChainedStores(StoreSDNode *St) {
   if (BasePtr.getBase().isUndef())
     return false;
 
-  // Do not handle stores to opaque types
-  if (St->getMemoryVT().isZeroSized())
-    return false;
-
   // BaseIndexOffset assumes that offsets are fixed-size, which
   // is not valid for scalable vectors where the offsets are
   // scaled by `vscale`, so bail out early.

llvm/lib/CodeGen/TargetLoweringBase.cpp

@@ -1706,7 +1706,7 @@ bool TargetLoweringBase::allowsMemoryAccessForAlignment(
   // For example, the ABI alignment may change based on software platform while
   // this function should only be affected by hardware implementation.
   Type *Ty = VT.getTypeForEVT(Context);
-  if (VT.isZeroSized() || Alignment >= DL.getABITypeAlign(Ty)) {
+  if (Alignment >= DL.getABITypeAlign(Ty)) {
     // Assume that an access that meets the ABI-specified alignment is fast.
     if (Fast != nullptr)
       *Fast = true;

llvm/lib/CodeGen/ValueTypes.cpp

@@ -198,10 +198,6 @@ Type *EVT::getTypeForEVT(LLVMContext &Context) const {
   case MVT::ppcf128: return Type::getPPC_FP128Ty(Context);
   case MVT::x86mmx:  return Type::getX86_MMXTy(Context);
   case MVT::x86amx:  return Type::getX86_AMXTy(Context);
-  case MVT::externref:
-    return PointerType::get(StructType::create(Context), 10);
-  case MVT::funcref:
-    return PointerType::get(StructType::create(Context), 20);
   case MVT::v1i1:
     return FixedVectorType::get(Type::getInt1Ty(Context), 1);
   case MVT::v2i1:

llvm/lib/Target/WebAssembly/Utils/WebAssemblyUtilities.cpp

@@ -116,31 +116,6 @@ MCSymbolWasm *WebAssembly::getOrCreateFunctionTableSymbol(
   return Sym;
 }
 
-MCSymbolWasm *WebAssembly::getOrCreateFuncrefCallTableSymbol(
-    MCContext &Ctx, const WebAssemblySubtarget *Subtarget) {
-  StringRef Name = "__funcref_call_table";
-  MCSymbolWasm *Sym = cast_or_null<MCSymbolWasm>(Ctx.lookupSymbol(Name));
-  if (Sym) {
-    if (!Sym->isFunctionTable())
-      Ctx.reportError(SMLoc(), "symbol is not a wasm funcref table");
-  } else {
-    Sym = cast<MCSymbolWasm>(Ctx.getOrCreateSymbol(Name));
-
-    // Setting Weak ensure only one table is left after linking when multiple
-    // modules define the table.
-    Sym->setWeak(true);
-
-    wasm::WasmLimits Limits = {0, 1, 1};
-    wasm::WasmTableType TableType = {wasm::WASM_TYPE_FUNCREF, Limits};
-    Sym->setType(wasm::WASM_SYMBOL_TYPE_TABLE);
-    Sym->setTableType(TableType);
-  }
-  // MVP object files can't have symtab entries for tables.
-  if (!(Subtarget && Subtarget->hasReferenceTypes()))
-    Sym->setOmitFromLinkingSection();
-  return Sym;
-}
-
 // Find a catch instruction from an EH pad.
 MachineInstr *WebAssembly::findCatch(MachineBasicBlock *EHPad) {
   assert(EHPad->isEHPad());

llvm/lib/Target/WebAssembly/Utils/WebAssemblyUtilities.h

@@ -68,12 +68,6 @@ MCSymbolWasm *
 getOrCreateFunctionTableSymbol(MCContext &Ctx,
                                const WebAssemblySubtarget *Subtarget);
 
-/// Returns the __funcref_call_table, for use in funcref calls when lowered to
-/// table.set + call_indirect.
-MCSymbolWasm *
-getOrCreateFuncrefCallTableSymbol(MCContext &Ctx,
-                                  const WebAssemblySubtarget *Subtarget);
-
 /// Find a catch instruction from an EH pad. Returns null if no catch
 /// instruction found or the catch is in an invalid location.
 MachineInstr *findCatch(MachineBasicBlock *EHPad);

llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp

@@ -130,12 +130,9 @@ class WebAssemblyFastISel final : public FastISel {
     case MVT::i64:
     case MVT::f32:
     case MVT::f64:
-      return VT;
     case MVT::funcref:
     case MVT::externref:
-      if (Subtarget->hasReferenceTypes())
-        return VT;
-      break;
+      return VT;
     case MVT::f16:
       return MVT::f32;
     case MVT::v16i8:

llvm/lib/Target/WebAssembly/WebAssemblyISD.def

@@ -48,4 +48,3 @@ HANDLE_NODETYPE(MEMORY_FILL)
 HANDLE_MEM_NODETYPE(LOAD_SPLAT)
 HANDLE_MEM_NODETYPE(GLOBAL_GET)
 HANDLE_MEM_NODETYPE(GLOBAL_SET)
-HANDLE_MEM_NODETYPE(TABLE_SET)

llvm/lib/Target/WebAssembly/WebAssemblyISelDAGToDAG.cpp

@@ -63,7 +63,6 @@ class WebAssemblyDAGToDAGISel final : public SelectionDAGISel {
 
   bool SelectInlineAsmMemoryOperand(const SDValue &Op, unsigned ConstraintID,
                                     std::vector<SDValue> &OutOps) override;
-  bool SelectExternRefAddr(const SDValue &Addr, const SDValue &Base);
 
 // Include the pieces autogenerated from the target description.
 #include "WebAssemblyGenDAGISel.inc"

llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp

@@ -13,7 +13,6 @@
 
 #include "WebAssemblyISelLowering.h"
 #include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
-#include "Utils/WebAssemblyTypeUtilities.h"
 #include "Utils/WebAssemblyUtilities.h"
 #include "WebAssemblyMachineFunctionInfo.h"
 #include "WebAssemblySubtarget.h"
@@ -67,10 +66,6 @@ WebAssemblyTargetLowering::WebAssemblyTargetLowering(
     addRegisterClass(MVT::v2i64, &WebAssembly::V128RegClass);
     addRegisterClass(MVT::v2f64, &WebAssembly::V128RegClass);
   }
-  if (Subtarget->hasReferenceTypes()) {
-    addRegisterClass(MVT::externref, &WebAssembly::EXTERNREFRegClass);
-    addRegisterClass(MVT::funcref, &WebAssembly::FUNCREFRegClass);
-  }
   // Compute derived properties from the register classes.
   computeRegisterProperties(Subtarget->getRegisterInfo());
 
@@ -87,12 +82,6 @@ WebAssemblyTargetLowering::WebAssemblyTargetLowering(
       setOperationAction(ISD::STORE, T, Custom);
     }
   }
-  if (Subtarget->hasReferenceTypes()) {
-    for (auto T : {MVT::externref, MVT::funcref}) {
-      setOperationAction(ISD::LOAD, T, Custom);
-      setOperationAction(ISD::STORE, T, Custom);
-    }
-  }
 
   setOperationAction(ISD::GlobalAddress, MVTPtr, Custom);
   setOperationAction(ISD::GlobalTLSAddress, MVTPtr, Custom);
@@ -479,16 +468,6 @@ LowerCallResults(MachineInstr &CallResults, DebugLoc DL, MachineBasicBlock *BB,
   bool IsIndirect = CallParams.getOperand(0).isReg();
   bool IsRetCall = CallResults.getOpcode() == WebAssembly::RET_CALL_RESULTS;
 
-  bool IsFuncrefCall = false;
-  if (IsIndirect) {
-    Register Reg = CallParams.getOperand(0).getReg();
-    const MachineFunction *MF = BB->getParent();
-    const MachineRegisterInfo &MRI = MF->getRegInfo();
-    const TargetRegisterClass *TRC = MRI.getRegClass(Reg);
-    IsFuncrefCall = (TRC == &WebAssembly::FUNCREFRegClass);
-    assert(!IsFuncrefCall || Subtarget->hasReferenceTypes());
-  }
-
   unsigned CallOp;
   if (IsIndirect && IsRetCall) {
     CallOp = WebAssembly::RET_CALL_INDIRECT;
@@ -532,11 +511,8 @@ LowerCallResults(MachineInstr &CallResults, DebugLoc DL, MachineBasicBlock *BB,
     // Placeholder for the type index.
     MIB.addImm(0);
     // The table into which this call_indirect indexes.
-    MCSymbolWasm *Table = IsFuncrefCall
-                              ? WebAssembly::getOrCreateFuncrefCallTableSymbol(
-                                    MF.getContext(), Subtarget)
-                              : WebAssembly::getOrCreateFunctionTableSymbol(
-                                    MF.getContext(), Subtarget);
+    MCSymbolWasm *Table =
+        WebAssembly::getOrCreateFunctionTableSymbol(MF.getContext(), Subtarget);
     if (Subtarget->hasReferenceTypes()) {
       MIB.addSym(Table);
     } else {
@@ -555,39 +531,6 @@ LowerCallResults(MachineInstr &CallResults, DebugLoc DL, MachineBasicBlock *BB,
   CallParams.eraseFromParent();
   CallResults.eraseFromParent();
 
-  // If this is a funcref call, to avoid hidden GC roots, we need to clear the
-  // table slot with ref.null upon call_indirect return.
-  //
-  // This generates the following code, which comes right after a call_indirect
-  // of a funcref:
-  //
-  //    i32.const 0
-  //    ref.null func
-  //    table.set __funcref_call_table
-  if (IsIndirect && IsFuncrefCall) {
-    MCSymbolWasm *Table = WebAssembly::getOrCreateFuncrefCallTableSymbol(
-        MF.getContext(), Subtarget);
-    Register RegZero =
-        MF.getRegInfo().createVirtualRegister(&WebAssembly::I32RegClass);
-    MachineInstr *Const0 =
-        BuildMI(MF, DL, TII.get(WebAssembly::CONST_I32), RegZero).addImm(0);
-    BB->insertAfter(MIB.getInstr()->getIterator(), Const0);
-
-    Register RegFuncref =
-        MF.getRegInfo().createVirtualRegister(&WebAssembly::FUNCREFRegClass);
-    MachineInstr *RefNull =
-        BuildMI(MF, DL, TII.get(WebAssembly::REF_NULL_FUNCREF), RegFuncref)
-            .addImm(static_cast<int32_t>(WebAssembly::HeapType::Funcref));
-    BB->insertAfter(Const0->getIterator(), RefNull);
-
-    MachineInstr *TableSet =
-        BuildMI(MF, DL, TII.get(WebAssembly::TABLE_SET_FUNCREF))
-            .addSym(Table)
-            .addReg(RegZero)
-            .addReg(RegFuncref);
-    BB->insertAfter(RefNull->getIterator(), TableSet);
-  }
-
   return BB;
 }
 
@@ -1111,33 +1054,6 @@ WebAssemblyTargetLowering::LowerCall(CallLoweringInfo &CLI,
     InTys.push_back(In.VT);
   }
 
-  // Lastly, if this is a call to a funcref we need to add an instruction
-  // table.set to the chain and transform the call.
-  if (CLI.CB && isFuncref(CLI.CB->getCalledOperand())) {
-    // In the absence of function references proposal where a funcref call is
-    // lowered to call_ref, using reference types we generate a table.set to set
-    // the funcref to a special table used solely for this purpose, followed by
-    // a call_indirect. Here we just generate the table set, and return the
-    // SDValue of the table.set so that LowerCall can finalize the lowering by
-    // generating the call_indirect.
-    SDValue Chain = Ops[0];
-
-    MCSymbolWasm *Table = WebAssembly::getOrCreateFuncrefCallTableSymbol(
-        MF.getContext(), Subtarget);
-    SDValue Sym = DAG.getMCSymbol(Table, PtrVT);
-    SDValue TableSlot = DAG.getConstant(0, DL, MVT::i32);
-    SDValue TableSetOps[] = {Chain, Sym, TableSlot, Callee};
-    SDValue TableSet = DAG.getMemIntrinsicNode(
-        WebAssemblyISD::TABLE_SET, DL, DAG.getVTList(MVT::Other), TableSetOps,
-        MVT::funcref,
-        // Machine Mem Operand args
-        MachinePointerInfo(WasmAddressSpace::FUNCREF),
-        CLI.CB->getCalledOperand()->getPointerAlignment(DAG.getDataLayout()),
-        MachineMemOperand::MOStore);
-
-    Ops[0] = TableSet; // The new chain is the TableSet itself
-  }
-
   if (CLI.IsTailCall) {
     // ret_calls do not return values to the current frame
     SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
@@ -1369,13 +1285,6 @@ static Optional<unsigned> IsWebAssemblyLocal(SDValue Op, SelectionDAG &DAG) {
   return WebAssemblyFrameLowering::getLocalForStackObject(MF, FI->getIndex());
 }
 
-bool WebAssemblyTargetLowering::isFuncref(const Value *Op) const {
-  const Type *Ty = Op->getType();
-
-  return isa<PointerType>(Ty) &&
-         Ty->getPointerAddressSpace() == WasmAddressSpace::FUNCREF;
-}
-
 SDValue WebAssemblyTargetLowering::LowerStore(SDValue Op,
                                               SelectionDAG &DAG) const {
   SDLoc DL(Op);

llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.h

@@ -45,33 +45,6 @@ class WebAssemblyTargetLowering final : public TargetLowering {
   WebAssemblyTargetLowering(const TargetMachine &TM,
                             const WebAssemblySubtarget &STI);
 
-  enum WasmAddressSpace : unsigned {
-    // WebAssembly uses the following address spaces:
-    // AS 0 : is the default address space for values in linear memory
-    DEFAULT = 0,
-    // AS 1 : is a non-integral address space for global variables
-    GLOBAL = 1,
-    // AS 10 : is a non-integral address space for externref values
-    EXTERNREF = 10,
-    // AS 20 : is a non-integral address space for funcref values
-    FUNCREF = 20,
-  };
-
-  MVT getPointerTy(const DataLayout &DL, uint32_t AS = 0) const override {
-    if (AS == WasmAddressSpace::EXTERNREF)
-      return MVT::externref;
-    else if (AS == WasmAddressSpace::FUNCREF)
-      return MVT::funcref;
-    return TargetLowering::getPointerTy(DL, AS);
-  }
-  MVT getPointerMemTy(const DataLayout &DL, uint32_t AS = 0) const override {
-    if (AS == WasmAddressSpace::EXTERNREF)
-      return MVT::externref;
-    else if (AS == WasmAddressSpace::FUNCREF)
-      return MVT::funcref;
-    return TargetLowering::getPointerMemTy(DL, AS);
-  }
-
 private:
   /// Keep a pointer to the WebAssemblySubtarget around so that we can make the
   /// right decision when generating code for different targets.
@@ -93,7 +66,6 @@ class WebAssemblyTargetLowering final : public TargetLowering {
   bool isLegalAddressingMode(const DataLayout &DL, const AddrMode &AM, Type *Ty,
                              unsigned AS,
                              Instruction *I = nullptr) const override;
-  bool isFuncref(const Value *Op) const;
   bool allowsMisalignedMemoryAccesses(EVT, unsigned AddrSpace, Align Alignment,
                                       MachineMemOperand::Flags Flags,
                                       bool *Fast) const override;