[WebAssembly] Use 64-bit table when targeting wasm64

See WebAssembly/memory64#51

Author: sbc100

lld/test/wasm/shared64.s

@@ -154,6 +154,7 @@ get_local_func_address:
 # CHECK-NEXT:           Index:           0
 # CHECK-NEXT:           ElemType:        FUNCREF
 # CHECK-NEXT:           Limits:
+# CHECK-NEXT:             Flags:         [ IS_64 ]
 # CHECK-NEXT:             Minimum:         0x2
 # CHECK-NEXT:       - Module:          env
 # CHECK-NEXT:         Field:           __stack_pointer

lld/wasm/SyntheticSections.cpp

@@ -584,12 +584,10 @@ void ElemSection::writeBody() {
   initExpr.Extended = false;
   if (ctx.isPic) {
     initExpr.Inst.Opcode = WASM_OPCODE_GLOBAL_GET;
-    initExpr.Inst.Value.Global =
-        (config->is64.value_or(false) ? WasmSym::tableBase32
-                                      : WasmSym::tableBase)
-            ->getGlobalIndex();
+    initExpr.Inst.Value.Global = WasmSym::tableBase->getGlobalIndex();
   } else {
-    initExpr.Inst.Opcode = WASM_OPCODE_I32_CONST;
+    bool is64 = config->is64.value_or(false);
+    initExpr.Inst.Opcode = is64 ? WASM_OPCODE_I64_CONST : WASM_OPCODE_I32_CONST;
     initExpr.Inst.Value.Int32 = config->tableBase;
   }
   writeInitExpr(os, initExpr);

lld/wasm/Writer.cpp

@@ -939,6 +939,8 @@ static void finalizeIndirectFunctionTable() {
     limits.Flags |= WASM_LIMITS_FLAG_HAS_MAX;
     limits.Maximum = limits.Minimum;
   }
+  if (config->is64.value_or(false))
+    limits.Flags |= WASM_LIMITS_FLAG_IS_64;
   WasmSym::indirectFunctionTable->setLimits(limits);
 }
 

llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp

@@ -885,18 +885,6 @@ bool WebAssemblyFastISel::selectCall(const Instruction *I) {
       Table->setNoStrip();
       MIB.addImm(0);
     }
-    // See if we must truncate the function pointer.
-    // CALL_INDIRECT takes an i32, but in wasm64 we represent function pointers
-    // as 64-bit for uniformity with other pointer types.
-    // See also: WebAssemblyISelLowering.cpp: LowerCallResults
-    if (Subtarget->hasAddr64()) {
-      auto Wrap = BuildMI(*FuncInfo.MBB, std::prev(FuncInfo.InsertPt), MIMD,
-                          TII.get(WebAssembly::I32_WRAP_I64));
-      Register Reg32 = createResultReg(&WebAssembly::I32RegClass);
-      Wrap.addReg(Reg32, RegState::Define);
-      Wrap.addReg(CalleeReg);
-      CalleeReg = Reg32;
-    }
   }
 
   for (unsigned ArgReg : Args)

llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp

@@ -576,20 +576,6 @@ LowerCallResults(MachineInstr &CallResults, DebugLoc DL, MachineBasicBlock *BB,
   const MCInstrDesc &MCID = TII.get(CallOp);
   MachineInstrBuilder MIB(MF, MF.CreateMachineInstr(MCID, DL));
 
-  // See if we must truncate the function pointer.
-  // CALL_INDIRECT takes an i32, but in wasm64 we represent function pointers
-  // as 64-bit for uniformity with other pointer types.
-  // See also: WebAssemblyFastISel::selectCall
-  if (IsIndirect && MF.getSubtarget<WebAssemblySubtarget>().hasAddr64()) {
-    Register Reg32 =
-        MF.getRegInfo().createVirtualRegister(&WebAssembly::I32RegClass);
-    auto &FnPtr = CallParams.getOperand(0);
-    BuildMI(*BB, CallResults.getIterator(), DL,
-            TII.get(WebAssembly::I32_WRAP_I64), Reg32)
-        .addReg(FnPtr.getReg());
-    FnPtr.setReg(Reg32);
-  }
-
   // Move the function pointer to the end of the arguments for indirect calls
   if (IsIndirect) {
     auto FnPtr = CallParams.getOperand(0);