[WebAssembly] Initial implementation of PIC code generation

This change implements lowering of references global symbols in PIC
mode.

This change implements lowering of global references in PIC mode using a
new @GOT reference type. @GOT references can be used with function or
data symbol names combined with the get_global instruction. In this case
the linker will insert the wasm global that stores the address of the
symbol (either in memory for data symbols or in the wasm table for
function symbols).

For now I'm continuing to use the R_WASM_GLOBAL_INDEX_LEB relocation
type for this type of reference which means that this relocation type
can refer to either a global or a function or data symbol. We could
choose to introduce specific relocation types for GOT entries in the
future.  See the current dynamic linking proposal:

https://github.com/WebAssembly/tool-conventions/blob/master/DynamicLinking.md

Differential Revision: https://reviews.llvm.org/D54647

llvm-svn: 357022

9 files changed, 126 insertions, 49 deletions

diff --git a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.h b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.h
index 5db72910315..303fd3ed265 100644
--- a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.h
+++ b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.h
@@ -94,7 +94,12 @@ enum TOF {
   MO_SYMBOL_GLOBAL = 0x2,
   MO_SYMBOL_EVENT = 0x4,
   MO_SYMBOL_MASK = 0x7,
+
+  // Address of data symbol via a wasm global.  This adds a level of indirection
+  // similar to the GOT on native platforms.
+  MO_GOT = 0x8,
 };
+
 } // end namespace WebAssemblyII
 
 } // end namespace llvm
diff --git a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyWasmObjectWriter.cpp b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyWasmObjectWriter.cpp
index 3b800858063..1a9c714ed0f 100644
--- a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyWasmObjectWriter.cpp
+++ b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyWasmObjectWriter.cpp
@@ -46,6 +46,10 @@ static bool isFunctionSignatureRef(const MCSymbolRefExpr *Ref) {
   return Ref->getKind() == MCSymbolRefExpr::VK_WebAssembly_TYPEINDEX;
 }
 
+static bool isGOTRef(const MCSymbolRefExpr *Ref) {
+  return Ref->getKind() == MCSymbolRefExpr::VK_GOT;
+}
+
 static const MCSection *getFixupSection(const MCExpr *Expr) {
   if (auto SyExp = dyn_cast<MCSymbolRefExpr>(Expr)) {
     if (SyExp->getSymbol().isInSection())
@@ -79,14 +83,14 @@ unsigned WebAssemblyWasmObjectWriter::getRelocType(const MCValue &Target,
   case WebAssembly::fixup_code_sleb128_i64:
     llvm_unreachable("fixup_sleb128_i64 not implemented yet");
   case WebAssembly::fixup_code_uleb128_i32:
+    if (SymA.isGlobal() || isGOTRef(RefA))
+      return wasm::R_WASM_GLOBAL_INDEX_LEB;
     if (SymA.isFunction()) {
       if (isFunctionSignatureRef(RefA))
         return wasm::R_WASM_TYPE_INDEX_LEB;
       else
         return wasm::R_WASM_FUNCTION_INDEX_LEB;
     }
-    if (SymA.isGlobal())
-      return wasm::R_WASM_GLOBAL_INDEX_LEB;
     if (SymA.isEvent())
       return wasm::R_WASM_EVENT_INDEX_LEB;
     return wasm::R_WASM_MEMORY_ADDR_LEB;
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
index 15df3d4ba06..17057486737 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
@@ -151,7 +151,7 @@ private:
     return MVT::INVALID_SIMPLE_VALUE_TYPE;
   }
   bool computeAddress(const Value *Obj, Address &Addr);
-  void materializeLoadStoreOperands(Address &Addr);
+  bool materializeLoadStoreOperands(Address &Addr);
   void addLoadStoreOperands(const Address &Addr, const MachineInstrBuilder &MIB,
                             MachineMemOperand *MMO);
   unsigned maskI1Value(unsigned Reg, const Value *V);
@@ -374,10 +374,13 @@ bool WebAssemblyFastISel::computeAddress(const Value *Obj, Address &Addr) {
   return Addr.getReg() != 0;
 }
 
-void WebAssemblyFastISel::materializeLoadStoreOperands(Address &Addr) {
+bool WebAssemblyFastISel::materializeLoadStoreOperands(Address &Addr) {
   if (Addr.isRegBase()) {
     unsigned Reg = Addr.getReg();
     if (Reg == 0) {
+      const GlobalValue *GV = Addr.getGlobalValue();
+      if (GV && TLI.isPositionIndependent())
+        return false;
       Reg = createResultReg(Subtarget->hasAddr64() ? &WebAssembly::I64RegClass
                                                    : &WebAssembly::I32RegClass);
       unsigned Opc = Subtarget->hasAddr64() ? WebAssembly::CONST_I64
@@ -387,6 +390,7 @@ void WebAssemblyFastISel::materializeLoadStoreOperands(Address &Addr) {
       Addr.setReg(Reg);
     }
   }
+  return true;
 }
 
 void WebAssemblyFastISel::addLoadStoreOperands(const Address &Addr,
@@ -604,7 +608,9 @@ unsigned WebAssemblyFastISel::fastMaterializeAlloca(const AllocaInst *AI) {
 }
 
 unsigned WebAssemblyFastISel::fastMaterializeConstant(const Constant *C) {
-  if (const auto *GV = dyn_cast<GlobalValue>(C)) {
+  if (const GlobalValue *GV = dyn_cast<GlobalValue>(C)) {
+    if (TLI.isPositionIndependent())
+      return 0;
     unsigned ResultReg =
         createResultReg(Subtarget->hasAddr64() ? &WebAssembly::I64RegClass
                                                : &WebAssembly::I32RegClass);
@@ -1181,7 +1187,8 @@ bool WebAssemblyFastISel::selectLoad(const Instruction *I) {
     return false;
   }
 
-  materializeLoadStoreOperands(Addr);
+  if (!materializeLoadStoreOperands(Addr))
+    return false;
 
   unsigned ResultReg = createResultReg(RC);
   auto MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc),
@@ -1233,7 +1240,8 @@ bool WebAssemblyFastISel::selectStore(const Instruction *I) {
     return false;
   }
 
-  materializeLoadStoreOperands(Addr);
+  if (!materializeLoadStoreOperands(Addr))
+    return false;
 
   unsigned ValueReg = getRegForValue(Store->getValueOperand());
   if (ValueReg == 0)
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISD.def b/llvm/lib/Target/WebAssembly/WebAssemblyISD.def
index 36b146498c3..af5fcd8c09c 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISD.def
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISD.def
@@ -17,7 +17,11 @@ HANDLE_NODETYPE(CALL1)
 HANDLE_NODETYPE(CALL0)
 HANDLE_NODETYPE(RETURN)
 HANDLE_NODETYPE(ARGUMENT)
+// A wrapper node for TargetExternalSymbol, TargetGlobalAddress, and MCSymbol
 HANDLE_NODETYPE(Wrapper)
+// A special wapper used in PIC code for __memory_base/__table_base relcative
+// access.
+HANDLE_NODETYPE(WrapperPIC)
 HANDLE_NODETYPE(BR_IF)
 HANDLE_NODETYPE(BR_TABLE)
 HANDLE_NODETYPE(SHUFFLE)
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
index aa7bba8b17d..dc9afb73a93 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -729,6 +729,18 @@ WebAssemblyTargetLowering::LowerCall(CallLoweringInfo &CLI,
     FINode = DAG.getIntPtrConstant(0, DL);
   }
 
+  if (Callee->getOpcode() == ISD::GlobalAddress) {
+    // If the callee is a GlobalAddress node (quite common, every direct call
+    // is) turn it into a TargetGlobalAddress node so that LowerGlobalAddress
+    // doesn't at MO_GOT which is not needed for direct calls.
+    GlobalAddressSDNode* GA = cast<GlobalAddressSDNode>(Callee);
+    Callee = DAG.getTargetGlobalAddress(GA->getGlobal(), DL,
+                                        getPointerTy(DAG.getDataLayout()),
+                                        GA->getOffset());
+    Callee = DAG.getNode(WebAssemblyISD::Wrapper, DL,
+                         getPointerTy(DAG.getDataLayout()), Callee);
+  }
+
   // Compute the operands for the CALLn node.
   SmallVector<SDValue, 16> Ops;
   Ops.push_back(Chain);
@@ -983,9 +995,35 @@ SDValue WebAssemblyTargetLowering::LowerGlobalAddress(SDValue Op,
          "Unexpected target flags on generic GlobalAddressSDNode");
   if (GA->getAddressSpace() != 0)
     fail(DL, DAG, "WebAssembly only expects the 0 address space");
-  return DAG.getNode(
-      WebAssemblyISD::Wrapper, DL, VT,
-      DAG.getTargetGlobalAddress(GA->getGlobal(), DL, VT, GA->getOffset()));
+
+  unsigned Flags = 0;
+  if (isPositionIndependent()) {
+    const GlobalValue *GV = GA->getGlobal();
+    if (getTargetMachine().shouldAssumeDSOLocal(*GV->getParent(), GV)) {
+      MachineFunction &MF = DAG.getMachineFunction();
+      MVT PtrVT = getPointerTy(MF.getDataLayout());
+      const char *BaseName;
+      if (GV->getValueType()->isFunctionTy())
+        BaseName = MF.createExternalSymbolName("__table_base");
+      else
+        BaseName = MF.createExternalSymbolName("__memory_base");
+      SDValue BaseAddr =
+          DAG.getNode(WebAssemblyISD::Wrapper, DL, PtrVT,
+                      DAG.getTargetExternalSymbol(BaseName, PtrVT));
+
+      SDValue SymAddr = DAG.getNode(
+          WebAssemblyISD::WrapperPIC, DL, VT,
+          DAG.getTargetGlobalAddress(GA->getGlobal(), DL, VT, GA->getOffset()));
+
+      return DAG.getNode(ISD::ADD, DL, VT, BaseAddr, SymAddr);
+    } else {
+      Flags |= WebAssemblyII::MO_GOT;
+    }
+  }
+
+  return DAG.getNode(WebAssemblyISD::Wrapper, DL, VT,
+                     DAG.getTargetGlobalAddress(GA->getGlobal(), DL, VT,
+                                                GA->getOffset(), Flags));
 }
 
 SDValue
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td
index 4a2bf2a9914..40a8f6089c2 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td
@@ -15,6 +15,9 @@
 // WebAssembly Instruction Predicate Definitions.
 //===----------------------------------------------------------------------===//
 
+def IsPIC     : Predicate<"TM.isPositionIndependent()">;
+def IsNotPIC  : Predicate<"!TM.isPositionIndependent()">;
+
 def HasAddr32 : Predicate<"!Subtarget->hasAddr64()">;
 
 def HasAddr64 : Predicate<"Subtarget->hasAddr64()">;
@@ -67,14 +70,16 @@ def SDT_WebAssemblyCallSeqStart : SDCallSeqStart<[SDTCisVT<0, iPTR>,
                                                   SDTCisVT<1, iPTR>]>;
 def SDT_WebAssemblyCallSeqEnd :
     SDCallSeqEnd<[SDTCisVT<0, iPTR>, SDTCisVT<1, iPTR>]>;
-def SDT_WebAssemblyCall0    : SDTypeProfile<0, -1, [SDTCisPtrTy<0>]>;
-def SDT_WebAssemblyCall1    : SDTypeProfile<1, -1, [SDTCisPtrTy<1>]>;
-def SDT_WebAssemblyBrTable  : SDTypeProfile<0, -1, [SDTCisPtrTy<0>]>;
-def SDT_WebAssemblyArgument : SDTypeProfile<1, 1, [SDTCisVT<1, i32>]>;
-def SDT_WebAssemblyReturn   : SDTypeProfile<0, -1, []>;
-def SDT_WebAssemblyWrapper  : SDTypeProfile<1, 1, [SDTCisSameAs<0, 1>,
-                                                   SDTCisPtrTy<0>]>;
-def SDT_WebAssemblyThrow    : SDTypeProfile<0, -1, [SDTCisPtrTy<0>]>;
+def SDT_WebAssemblyCall0      : SDTypeProfile<0, -1, [SDTCisPtrTy<0>]>;
+def SDT_WebAssemblyCall1      : SDTypeProfile<1, -1, [SDTCisPtrTy<1>]>;
+def SDT_WebAssemblyBrTable    : SDTypeProfile<0, -1, [SDTCisPtrTy<0>]>;
+def SDT_WebAssemblyArgument   : SDTypeProfile<1, 1, [SDTCisVT<1, i32>]>;
+def SDT_WebAssemblyReturn     : SDTypeProfile<0, -1, []>;
+def SDT_WebAssemblyWrapper    : SDTypeProfile<1, 1, [SDTCisSameAs<0, 1>,
+                                                     SDTCisPtrTy<0>]>;
+def SDT_WebAssemblyWrapperPIC : SDTypeProfile<1, 1, [SDTCisSameAs<0, 1>,
+                                                     SDTCisPtrTy<0>]>;
+def SDT_WebAssemblyThrow      : SDTypeProfile<0, -1, [SDTCisPtrTy<0>]>;
 
 //===----------------------------------------------------------------------===//
 // WebAssembly-specific DAG Nodes.
@@ -101,6 +106,8 @@ def WebAssemblyreturn   : SDNode<"WebAssemblyISD::RETURN",
                                  SDT_WebAssemblyReturn, [SDNPHasChain]>;
 def WebAssemblywrapper  : SDNode<"WebAssemblyISD::Wrapper",
                                  SDT_WebAssemblyWrapper>;
+def WebAssemblywrapperPIC  : SDNode<"WebAssemblyISD::WrapperPIC",
+                                     SDT_WebAssemblyWrapperPIC>;
 def WebAssemblythrow : SDNode<"WebAssemblyISD::THROW", SDT_WebAssemblyThrow,
                               [SDNPHasChain, SDNPVariadic]>;
 
@@ -295,9 +302,20 @@ defm CONST_F64 : I<(outs F64:$res), (ins f64imm_op:$imm),
 } // isMoveImm = 1, isAsCheapAsAMove = 1, isReMaterializable = 1
 
 def : Pat<(i32 (WebAssemblywrapper tglobaladdr:$addr)),
-          (CONST_I32 tglobaladdr:$addr)>;
+          (CONST_I32 tglobaladdr:$addr)>, Requires<[IsNotPIC]>;
+
+def : Pat<(i32 (WebAssemblywrapper tglobaladdr:$addr)),
+          (GLOBAL_GET_I32 tglobaladdr:$addr)>, Requires<[IsPIC]>;
+
+def : Pat<(i32 (WebAssemblywrapperPIC tglobaladdr:$addr)),
+          (CONST_I32 tglobaladdr:$addr)>, Requires<[IsPIC]>;
+
+def : Pat<(i32 (WebAssemblywrapper texternalsym:$addr)),
+          (GLOBAL_GET_I32 texternalsym:$addr)>, Requires<[IsPIC]>;
+
 def : Pat<(i32 (WebAssemblywrapper texternalsym:$addr)),
-          (CONST_I32 texternalsym:$addr)>;
+          (CONST_I32 texternalsym:$addr)>, Requires<[IsNotPIC]>;
+
 def : Pat<(i32 (WebAssemblywrapper mcsym:$sym)), (CONST_I32 mcsym:$sym)>;
 def : Pat<(i64 (WebAssemblywrapper mcsym:$sym)), (CONST_I64 mcsym:$sym)>;
 
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrMemory.td b/llvm/lib/Target/WebAssembly/WebAssemblyInstrMemory.td
index 46a87f97cc7..6916b165f97 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrMemory.td
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrMemory.td
@@ -95,7 +95,7 @@ def : LoadPatImmOff<f64, load, or_is_add, LOAD_F64>;
 
 class LoadPatGlobalAddr<ValueType ty, PatFrag kind, NI inst> :
   Pat<(ty (kind (regPlusGA I32:$addr, (WebAssemblywrapper tglobaladdr:$off)))),
-      (inst 0, tglobaladdr:$off, I32:$addr)>;
+      (inst 0, tglobaladdr:$off, I32:$addr)>, Requires<[IsNotPIC]>;
 
 def : LoadPatGlobalAddr<i32, load, LOAD_I32>;
 def : LoadPatGlobalAddr<i64, load, LOAD_I64>;
@@ -113,7 +113,7 @@ def : LoadPatOffsetOnly<f64, load, LOAD_F64>;
 
 class LoadPatGlobalAddrOffOnly<ValueType ty, PatFrag kind, NI inst> :
   Pat<(ty (kind (WebAssemblywrapper tglobaladdr:$off))),
-      (inst 0, tglobaladdr:$off, (CONST_I32 0))>;
+      (inst 0, tglobaladdr:$off, (CONST_I32 0))>, Requires<[IsNotPIC]>;
 
 def : LoadPatGlobalAddrOffOnly<i32, load, LOAD_I32>;
 def : LoadPatGlobalAddrOffOnly<i64, load, LOAD_I64>;
@@ -285,7 +285,7 @@ def : StorePatImmOff<f64, store, or_is_add, STORE_F64>;
 class StorePatGlobalAddr<ValueType ty, PatFrag kind, NI inst> :
   Pat<(kind ty:$val,
             (regPlusGA I32:$addr, (WebAssemblywrapper tglobaladdr:$off))),
-      (inst 0, tglobaladdr:$off, I32:$addr, ty:$val)>;
+      (inst 0, tglobaladdr:$off, I32:$addr, ty:$val)>, Requires<[IsNotPIC]>;
 def : StorePatGlobalAddr<i32, store, STORE_I32>;
 def : StorePatGlobalAddr<i64, store, STORE_I64>;
 def : StorePatGlobalAddr<f32, store, STORE_F32>;
@@ -301,7 +301,7 @@ def : StorePatOffsetOnly<f64, store, STORE_F64>;
 
 class StorePatGlobalAddrOffOnly<ValueType ty, PatFrag kind, NI inst> :
   Pat<(kind ty:$val, (WebAssemblywrapper tglobaladdr:$off)),
-      (inst 0, tglobaladdr:$off, (CONST_I32 0), ty:$val)>;
+      (inst 0, tglobaladdr:$off, (CONST_I32 0), ty:$val)>, Requires<[IsNotPIC]>;
 def : StorePatGlobalAddrOffOnly<i32, store, STORE_I32>;
 def : StorePatGlobalAddrOffOnly<i64, store, STORE_I64>;
 def : StorePatGlobalAddrOffOnly<f32, store, STORE_F32>;
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
index e357842b3e9..9ca97796ac3 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
@@ -73,16 +73,18 @@ MCSymbol *WebAssemblyMCInstLower::GetExternalSymbolSymbol(
   auto *WasmSym = cast<MCSymbolWasm>(Printer.GetExternalSymbolSymbol(Name));
   const WebAssemblySubtarget &Subtarget = Printer.getSubtarget();
 
-  // Except for the two exceptions (__stack_pointer and __cpp_exception), all
-  // other external symbols used by CodeGen are functions. It's OK to hardcode
-  // knowledge of specific symbols here; this method is precisely there for
-  // fetching the signatures of known Clang-provided symbols.
-  if (strcmp(Name, "__stack_pointer") == 0) {
+  // Except for certain known symbols, all symbols used by CodeGen are
+  // functions. It's OK to hardcode knowledge of specific symbols here; this
+  // method is precisely there for fetching the signatures of known
+  // Clang-provided symbols.
+  if (strcmp(Name, "__stack_pointer") == 0 ||
+      strcmp(Name, "__memory_base") == 0 || strcmp(Name, "__table_base") == 0) {
+    bool Mutable = strcmp(Name, "__stack_pointer") == 0;
     WasmSym->setType(wasm::WASM_SYMBOL_TYPE_GLOBAL);
     WasmSym->setGlobalType(wasm::WasmGlobalType{
         uint8_t(Subtarget.hasAddr64() ? wasm::WASM_TYPE_I64
                                       : wasm::WASM_TYPE_I32),
-        true});
+        Mutable});
     return WasmSym;
   }
 
@@ -118,19 +120,23 @@ MCSymbol *WebAssemblyMCInstLower::GetExternalSymbolSymbol(
   return WasmSym;
 }
 
-MCOperand WebAssemblyMCInstLower::lowerSymbolOperand(MCSymbol *Sym,
-                                                     int64_t Offset,
-                                                     bool IsFunc, bool IsGlob,
-                                                     bool IsEvent) const {
-  const MCExpr *Expr =
-      MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_None, Ctx);
+MCOperand WebAssemblyMCInstLower::lowerSymbolOperand(
+    MCSymbol *Sym, int64_t Offset, bool IsFunc, unsigned TargetFlags) const {
+  MCSymbolRefExpr::VariantKind Kind = MCSymbolRefExpr::VK_None;
+  if (TargetFlags & WebAssemblyII::MO_GOT)
+    Kind = MCSymbolRefExpr::VK_GOT;
+  const MCExpr *Expr = MCSymbolRefExpr::create(Sym, Kind, Ctx);
 
   if (Offset != 0) {
-    if (IsFunc)
+    if (TargetFlags & WebAssemblyII::MO_GOT)
+      report_fatal_error("GOT symbol references do not support offsets");
+    unsigned Type = TargetFlags & WebAssemblyII::MO_SYMBOL_MASK;
+    assert((Type == WebAssemblyII::MO_SYMBOL_FUNCTION) == IsFunc);
+    if (Type == WebAssemblyII::MO_SYMBOL_FUNCTION || IsFunc)
       report_fatal_error("Function addresses with offsets not supported");
-    if (IsGlob)
+    if (Type == WebAssemblyII::MO_SYMBOL_GLOBAL)
       report_fatal_error("Global indexes with offsets not supported");
-    if (IsEvent)
+    if (Type == WebAssemblyII::MO_SYMBOL_EVENT)
       report_fatal_error("Event indexes with offsets not supported");
     Expr =
         MCBinaryExpr::createAdd(Expr, MCConstantExpr::create(Offset, Ctx), Ctx);
@@ -230,11 +236,9 @@ void WebAssemblyMCInstLower::lower(const MachineInstr *MI,
       break;
     }
     case MachineOperand::MO_GlobalAddress:
-      assert(MO.getTargetFlags() == WebAssemblyII::MO_NO_FLAG &&
-             "WebAssembly does not use target flags on GlobalAddresses");
       MCOp = lowerSymbolOperand(GetGlobalAddressSymbol(MO), MO.getOffset(),
                                 MO.getGlobal()->getValueType()->isFunctionTy(),
-                                false, false);
+                                MO.getTargetFlags());
       break;
     case MachineOperand::MO_ExternalSymbol:
       // The target flag indicates whether this is a symbol for a
@@ -242,18 +246,14 @@ void WebAssemblyMCInstLower::lower(const MachineInstr *MI,
       assert((MO.getTargetFlags() & ~WebAssemblyII::MO_SYMBOL_MASK) == 0 &&
              "WebAssembly uses only symbol flags on ExternalSymbols");
       MCOp = lowerSymbolOperand(
-          GetExternalSymbolSymbol(MO), /*Offset=*/0,
-          (MO.getTargetFlags() & WebAssemblyII::MO_SYMBOL_FUNCTION) != 0,
-          (MO.getTargetFlags() & WebAssemblyII::MO_SYMBOL_GLOBAL) != 0,
-          (MO.getTargetFlags() & WebAssemblyII::MO_SYMBOL_EVENT) != 0);
+          GetExternalSymbolSymbol(MO), /*Offset=*/0, false, MO.getTargetFlags());
       break;
     case MachineOperand::MO_MCSymbol:
       // This is currently used only for LSDA symbols (GCC_except_table),
       // because global addresses or other external symbols are handled above.
       assert(MO.getTargetFlags() == 0 &&
              "WebAssembly does not use target flags on MCSymbol");
-      MCOp = lowerSymbolOperand(MO.getMCSymbol(), /*Offset=*/0, false, false,
-                                false);
+      MCOp = lowerSymbolOperand(MO.getMCSymbol(), /*Offset=*/0, false, MO.getTargetFlags());
       break;
     }
 
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.h b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.h
index 5753fb760a1..125ba1dcfa5 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.h
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.h
@@ -33,7 +33,7 @@ class LLVM_LIBRARY_VISIBILITY WebAssemblyMCInstLower {
   MCSymbol *GetGlobalAddressSymbol(const MachineOperand &MO) const;
   MCSymbol *GetExternalSymbolSymbol(const MachineOperand &MO) const;
   MCOperand lowerSymbolOperand(MCSymbol *Sym, int64_t Offset, bool IsFunc,
-                               bool IsGlob, bool IsEvent) const;
+                               unsigned flags) const;
 
 public:
   WebAssemblyMCInstLower(MCContext &ctx, WebAssemblyAsmPrinter &printer)