Method defaultFor

deps/v8/test/mjsunit/wasm/wasm-module-builder.js:1581–1604

(type)

  nextTypeIndex() { return this.types.length; }

  static defaultFor(type) {
    switch (type) {
      case kWasmI32:
        return wasmI32Const(0);
      case kWasmI64:
        return wasmI64Const(0);
      case kWasmF32:
        return wasmF32Const(0.0);
      case kWasmF64:
        return wasmF64Const(0.0);
      case kWasmS128:
        return [kSimdPrefix, kExprS128Const, ...(new Array(16).fill(0))];
      case kWasmStringViewIter:
      case kWasmStringViewWtf8:
      case kWasmStringViewWtf16:
        throw new Error("String views are non-defaultable");
      default:
        if ((typeof type) != 'number' && type.opcode != kWasmRefNull) {
          throw new Error("Non-defaultable type");
        }
        let heap_type = (typeof type) == 'number' ? type : type.heap_type;
        return [kExprRefNull, ...wasmSignedLeb(heap_type, kMaxVarInt32Size)];
    }
  }

  addGlobal(type, mutable, shared, init) {
    if (init === undefined) init = WasmModuleBuilder.defaultFor(type);