goto start // effectively: tailcall stmt(g, s.Stmt, label)

	case *ast.ReturnStmt:
		b.add(s)
		b.current = b.newBlock(KindUnreachable, s)

	case *ast.BranchStmt:
		b.branchStmt(s)

	case *ast.BlockStmt:
		b.stmtList(s.List)

	case *ast.IfStmt:
		if s.Init != nil {
			b.stmt(s.Init)
		}
		then := b.newBlock(KindIfThen, s)
		done := b.newBlock(KindIfDone, s)
		_else := done
		if s.Else != nil {

		return false
	}
	if len(call.Body) != 2 || call.Body[0].Op() != ir.OBLOCK || call.Body[1].Op() != ir.OLABEL {
		return false
	}
	label := call.Body[1].(*ir.LabelStmt).Label
	block := call.Body[0].(*ir.BlockStmt)
	list := block.List
	var dcl *ir.Decl
	if len(list) == 3 && list[0].Op() == ir.ODCL {
		dcl = list[0].(*ir.Decl)
		list = list[1:]
	}
	if len(list) != 2 ||
		list[0].Op() != ir.OAS2 ||

	case ir.OAS2:
		tcAssignList(n.(*ir.AssignListStmt))
		return n

	case ir.OBREAK,
		ir.OCONTINUE,
		ir.ODCL,
		ir.OGOTO,
		ir.OFALL:
		return n

	case ir.OBLOCK:
		n := n.(*ir.BlockStmt)
		Stmts(n.List)
		return n

	case ir.OLABEL:
		if n.Sym().IsBlank() {
			// Empty identifier is valid but useless.
			// Eliminate now to simplify life later.
			// See issues 7538, 11589, 11593.

		default:
			base.Fatalf("order.stmt: %v", r.Op())
		}

		o.as2ok(n)
		o.popTemp(t)

	// Special: does not save n onto out.
	case ir.OBLOCK:
		n := n.(*ir.BlockStmt)
		o.stmtList(n.List)

	// Special: n->left is not an expression; save as is.
	case ir.OBREAK,
		ir.OCONTINUE,
		ir.ODCL,
		ir.OFALL,
		ir.OGOTO,
		ir.OLABEL,
		ir.OTAILCALL: