Different versions of fib in Erlang

adjacent.erl

-module( adjacent ).
-export( [ fib/1 ] ).

fibP( 0 ) ->
	{ 0, 1 };
fibP( N ) ->
	{ P, C } = fibP( N - 1 ),
	{ C, P + C }.

fib( N ) ->
	{ P, _ } = fibP( N ),
	P.

adjacent.S

{function, fibP, 1, 2}.
  {label,1}.
    {line,[{location,"adjacent.erl",4}]}.
    {func_info,{atom,adjacent},{atom,fibP},1}.
  {label,2}.
    {test,is_eq_exact,{f,3},[{x,0},{integer,0}]}.
    {move,{literal,{0,1}},{x,0}}.
    return.
  {label,3}.
    {allocate,0,1}.
    {line,[{location,"adjacent.erl",7}]}.
    {gc_bif,'-',{f,0},1,[{x,0},{integer,1}],{x,0}}.
    {line,[{location,"adjacent.erl",7}]}.
    {call,1,{f,2}}.
    {test,is_tuple,{f,4},[{x,0}]}.
    {test,test_arity,{f,4},[{x,0},2]}.
    {get_tuple_element,{x,0},0,{x,1}}.
    {get_tuple_element,{x,0},1,{x,2}}.
    {line,[{location,"adjacent.erl",8}]}.
    {gc_bif,'+',{f,0},3,[{x,1},{x,2}],{x,0}}.
    {test_heap,3,3}.
    {put_tuple,2,{x,1}}.
    {put,{x,2}}.
    {put,{x,0}}.
    {move,{x,1},{x,0}}.
    {deallocate,0}.
    return.
  {label,4}.
    {line,[{location,"adjacent.erl",7}]}.
    {badmatch,{x,0}}.


{function, fib, 1, 6}.
  {label,5}.
    {line,[{location,"adjacent.erl",10}]}.
    {func_info,{atom,adjacent},{atom,fib},1}.
  {label,6}.
    {allocate,0,1}.
    {line,[{location,"adjacent.erl",11}]}.
    {call,1,{f,2}}.
    {test,is_tuple,{f,7},[{x,0}]}.
    {test,test_arity,{f,7},[{x,0},2]}.
    {get_tuple_element,{x,0},0,{x,0}}.
    {deallocate,0}.
    return.
  {label,7}.
    {line,[{location,"adjacent.erl",11}]}.
    {badmatch,{x,0}}.

direct.erl

-module( direct ).
-export( [ fib/1 ] ).

fib( 0 ) ->
	0;
fib( 1 ) ->
	1;
fib( N ) ->
	fib( N - 1 ) + fib( N - 2 ).

direct.S

{function, fib, 1, 2}.
  {label,1}.
    {line,[{location,"direct.erl",4}]}.
    {func_info,{atom,direct},{atom,fib},1}.
  {label,2}.
    {test,is_integer,{f,4},[{x,0}]}.
    {select_val,{x,0},{f,4},{list,[{integer,1},{f,3},{integer,0},{f,3}]}}.
  {label,3}.
    return.
  {label,4}.
    {allocate_zero,1,1}.
    {line,[{location,"direct.erl",9}]}.
    {gc_bif,'-',{f,0},1,[{x,0},{integer,1}],{x,1}}.
    {move,{x,0},{y,0}}.
    {move,{x,1},{x,0}}.
    {line,[{location,"direct.erl",9}]}.
    {call,1,{f,2}}.
    {line,[{location,"direct.erl",9}]}.
    {gc_bif,'-',{f,0},1,[{y,0},{integer,2}],{x,1}}.
    {move,{x,0},{y,0}}.
    {move,{x,1},{x,0}}.
    {line,[{location,"direct.erl",9}]}.
    {call,1,{f,2}}.
    {line,[{location,"direct.erl",9}]}.
    {gc_bif,'+',{f,0},1,[{y,0},{x,0}],{x,0}}.
    {deallocate,1}.
    return.

tail.erl

-module( tail ).
-export( [ fib/1 ] ).

fib( 0, P, _C ) ->
	P;
fib( N, P, C ) ->
	fib( N - 1, C, P + C ).

fib( N ) ->
	fib( N, 0, 1 ).

tail.S

{function, fib, 3, 2}.
  {label,1}.
    {line,[{location,"tail.erl",4}]}.
    {func_info,{atom,tail},{atom,fib},3}.
  {label,2}.
    {test,is_eq_exact,{f,3},[{x,0},{integer,0}]}.
    {move,{x,1},{x,0}}.
    return.
  {label,3}.
    {line,[{location,"tail.erl",7}]}.
    {gc_bif,'-',{f,0},3,[{x,0},{integer,1}],{x,0}}.
    {line,[{location,"tail.erl",7}]}.
    {gc_bif,'+',{f,0},3,[{x,1},{x,2}],{x,1}}.
    {move,{x,2},{x,3}}.
    {move,{x,1},{x,2}}.
    {move,{x,3},{x,1}}.
    {call_only,3,{f,2}}.


{function, fib, 1, 5}.
  {label,4}.
    {line,[{location,"tail.erl",9}]}.
    {func_info,{atom,tail},{atom,fib},1}.
  {label,5}.
    {move,{integer,1},{x,2}}.
    {move,{integer,0},{x,1}}.