cis-lclient05:~/2012/system>more max.s
# Data section begins
# Declaration of memory variables
# .byte, .int, .long, .ascii, .asciz, and .string
.section .data
   var1:
      .int 40
   var2:
      .int 20
   var3:
      .int 30

.section .text
   .globl _start
   _start:
# find max of three variables
      movl  var1, %ecx
      cmpl  var2, %ecx
      jg    check_third_var
      movl  var2, %ecx
   check_third_var:
      cmpl  var3, %ecx
      jg    _exit
      movl  var3, %ecx
   
   _exit:
      movl  $1, %eax
      movl  %ecx, %ebx
      int   $0x80
cis-lclient05:~/2012/system>as -o max.o max.s
cis-lclient05:~/2012/system>ld -o max max.o
cis-lclient05:~/2012/system>max
cis-lclient05:~/2012/system>echo $?
40
cis-lclient05:~/2012/system>