Function call in the assembly language before linking-CodePudding

I was going through the assembly code generated by the compiler. I am using the C programming language and GCC compiler.

I wrote a function in C which adds two numbers by calling another function and stores the result in the variable pointed to by the pointer passed as an argument to the function.

void add_two_num(int x, int y, int * dest)
{
  int val;

  val = dummy(x, y);
  *dest = val;
}

I compiled the source code to object code (linking not done) and then disassembled the code using objdump -d

What is the meaning of the number 0x9 in the line call d <add_two_num 0x9>?
Is that useful at the stage of linking when that line will be replaced by the actual function call?

file format elf64-x86-64

0000000000000004 <add_two_num>:
   4:   53                      push   %rbx
   5:   48 89 d3                mov    %rdx,%rbx
   8:   e8 00 00 00 00          call   d <add_two_num 0x9>
   d:   89 03                   mov