gprof's annotated source listing duplicates the source code of the program, labelling each line of code with the number of times it was executed. In this example, we see a function that was called twice, using each branch of an if/else statement once, and including a loop that ran 26,312 times.
ulg updcrc(s, n) uch *s; unsigned n; 2 ->{ register ulg c; static ulg crc = (ulg)0xffffffffL; 2 -> if (s == NULL) { 1 -> c = 0xffffffffL; 1 -> } else { 1 -> c = crc; 1 -> if (n) do { 26312 -> c = crc_32_tab[...]; 26312,1,26311 -> } while (--n); } 2 -> crc = c; 2 -> return c ^ 0xffffffffL; 2 ->}