} while (node->IsIdentity());
        const Node* switch_input;
        bool is_loop_invariant = node->IsSwitch() &&
                                 node->input_node(0, &switch_input).ok() &&
                                 switch_input == n;
        if (is_loop_invariant) {
          shape_inference::InferenceContext* context =
              shape_refiner->GetContext(n);

}

Status DeadnessAnalysisImpl::HandleNode(Node* n,
                                        std::vector<bool>* should_revisit,
                                        bool use_optimistic_mode) {
  if (n->IsSwitch()) {
    TF_RETURN_IF_ERROR(HandleSwitch(n, should_revisit));
  } else if (n->IsMerge()) {
    TF_RETURN_IF_ERROR(HandleMerge(n, should_revisit, use_optimistic_mode));
  } else if (n->IsControlTrigger()) {

  }

  // Check if the Identity is driven by a Switch on its true path.
  auto it = absl::c_find_if(node->in_edges(), [](const Edge* e) {
    return e->src()->IsSwitch() && e->src_output() == 1;
  });
  if (it == node->in_edges().end()) {
    return false;
  }
  const Node* switch_node = (*it)->src();

  // Check if the Switch is driven by LoopCond.
  const Node* maybe_loop_cond;

	}
}

// NeedSwitch reports whether Switch would attempt to switch toolchains.
func (s *Switcher) NeedSwitch() bool {
	return s.TooNew != nil && (HasAuto() || HasPath())
}

// Switch decides whether to switch to a newer toolchain
// to resolve any of the saved errors.
// It switches if toolchain switches are permitted and there is at least one TooNewError.
//

// expression switch.
func walkSwitchExpr(sw *ir.SwitchStmt) {
	lno := ir.SetPos(sw)

	cond := sw.Tag
	sw.Tag = nil

	// convert switch {...} to switch true {...}
	if cond == nil {
		cond = ir.NewBool(base.Pos, true)
		cond = typecheck.Expr(cond)
		cond = typecheck.DefaultLit(cond, nil)
	}

	// Given "switch string(byteslice)",
	// with all cases being side-effect free,

  operands.append(control_operands.begin(), control_operands.end());

  auto loc = result.location;
  // Dispatch based on the name and create the appropriate operation.
  if (node.IsSwitch()) {
    // Switch and _SwitchN both are in switch class, differentiate based on
    // op name.
    if (node.op_def().name() == "_SwitchN") {
      return builder_.create<mlir::tf_executor::SwitchNOp>(loc, types, operands,

			return hostLookupCgo, nil
		}

		// If something is unrecognized, use cgo.
		fallbackOrder = hostLookupCgo
		canUseCgo = true
	}

	// On systems that don't use /etc/resolv.conf or /etc/nsswitch.conf, we are done.
	switch c.goos {
	case "windows", "plan9", "android", "ios":
		return fallbackOrder, nil
	}

	// Try to figure out the order to use for searches.
	// If we don't recognize something, use fallbackOrder.

		}
		return p.simpleStmt(lhs, 0)
	}

	switch p.tok {
	case _Var:
		return p.declStmt(p.varDecl)

	case _Const:
		return p.declStmt(p.constDecl)

	case _Type:
		return p.declStmt(p.typeDecl)
	}

	p.clearPragma()

	switch p.tok {
	case _Lbrace:
		return p.blockStmt("")

	case _Operator, _Star:
		switch p.op {
		case Add, Sub, Mul, And, Xor, Not:

	original := file.AsStringOrFail(t, "/etc/nsswitch.conf")
	var sandboxed string

	originalNetNS, err := netns.Get()
	assert.NoError(t, err)
	var sandboxedNetNS netns.NsHandle

	// Due to unshare-go imports above, this can run
	assert.NoError(t, runInSandbox("", func() error {
		// We should have overwritten this file with /dev/null
		sandboxed = file.AsStringOrFail(t, "/etc/nsswitch.conf")
		sandboxedNetNS, err = netns.Get()

	}

	switch extractBits(isar0, 16, 19) {
	case 1:
		ARM64.HasCRC32 = true
	}

	switch extractBits(isar0, 20, 23) {
	case 2:
		ARM64.HasATOMICS = true
	}

	switch extractBits(isar0, 28, 31) {
	case 1:
		ARM64.HasASIMDRDM = true
	}

	switch extractBits(isar0, 32, 35) {
	case 1:
		ARM64.HasSHA3 = true
	}

	switch extractBits(isar0, 36, 39) {
	case 1: