Fibonachi sequence in LLVM IR

fib.ll

@resultmsg = internal constant [14 x i8] c"fib(%u) = %u\0A\00"
declare i32 @printf(i8 *, ...)
declare i32 @atoi(i8 *)

define fastcc i32 @fib (i32 %n) {
  entry:
    %leone = icmp sle i32 %n, 1
    br i1 %leone, label %exitzero, label %checkiftwo

  checkiftwo:
    %letwo = icmp sle i32 %n, 2
    br i1 %letwo, label %exitone, label %continue

  exitzero:
    ret i32 0

  exitone:
    ret i32 1

  continue:
    %n.1 = sub i32 %n, 1
    %n.2 = sub i32 %n.1, 1
    %next1 = call fastcc i32 @fib(i32 %n.1)
    %next2 = call fastcc i32 @fib(i32 %n.2)
    %result = add i32 %next1, %next2
    ret i32 %result
}

define fastcc i32 @main (i32 %argc, i8** %argv) {
    %rmsg = getelementptr [14 x i8]* @resultmsg, i64 0, i64 0
    %n.1 = getelementptr i8** %argv, i64 1
    %n.2 = load i8** %n.1
    %n.3 = call i32 @atoi(i8* %n.2)
    %fibres = call fastcc i32 @fib(i32 %n.3)
    call i32 (i8 *, ...)* @printf(i8* %rmsg, i32 %n.3, i32 %fibres)
    ret i32 0 
}