.text
.global isspace
isspace:
  oldBP = 0
  retAddr = oldBP + 4
  ch = retAddr + 4

  pushl  %ebp
  movl   %esp,%ebp

  movw   $1, %ax # initialize return code to 1

  cmpb   $' ',ch(%ebp)
  jz     end_of_func
  cmpb   $'\n',ch(%ebp)
  jz     end_of_func
  cmpb   $12,ch(%ebp)
  jz     end_of_func
  cmpb   $'\t',ch(%ebp)
  jz     end_of_func

  movw   $0,%ax

end_of_func:
  movl   %ebp,%esp
  popl   %ebp
  ret