recursion - concept beind this version of fibonacci code in assembly -

This is an alternative version of the Fibonacci code in the assembly used by my professor in this class, instead it is used as a new formula is.

  f (n-2) / 2 + f (n-1) * 2 then the sequence 1, 2, 4, 9, 20, 44, 98, 218  

I just have a few things that confuse me.

1. What does JB and J mean?

2. Is one and two two local variables? Do they take a different part of the equation?

3. [ebp-4] and [ebp-8], are they the registry?

Please help me, I have really lost the concept behind this code!

This code is

this code is

  TITLE Mobonacci.586 Model FLAT, c. Mobonacci PROC; Will take N to EX; EBP Move EBP Push, ESP Mov EX, [EBP +8]; See that the eX is less than or equal to 1; CAPX, 2 JB one JJ JL1; Mobonacci calls; L1: Sub Special, 8; MOBO (N-1) * 2; Sub eX, 1 app call app call mobonachi; Mov Ebux, EX PopEx; 2 times ebx; SHL EBX, 1 Mop [EPP-4], EBX; Mobo (n-2) / 2; SubEx, 1AP Call App Call, Mobonkey MB EBX, EX POPEX; Divide the ebay from 2; Shr ebx, 1 mov [ebp-8], ebx; The sum of two numbers; Mov eax, add 0X, [EBP-4] add eX, [EPP-8]; neat pile; Mov esp, ebp jmp finished; Return 1; A: mov eax, closing 1 jmp; Return 2; Two: mov eax, 2 jmp finished; Return value in EX; End: Pop EBP ART MOBOONICIENDP End  
 post-text itemprop = "text"> 
 
 1) What is the  JB  and  J  mean? 
 
 
 They jump into the x86 instruction set. Go to  jb , and  j  jumps if they are equal, determine whether "down" or "equals" is correct, based on recent operation which is x86 The flag affects the register. Or, in other ways, for example you compared  cmp eax, ebx  ( eax  and  ebx  registers), then  Jb foo  value  down   ebx  value  and  je foo  label  foo  Would jump for if the values ​​were the same. Google "x86 Jump Directions" for more information 
 
 
 2) What is the  one  and  two  two local variables? What part of the equation do they take in the input? 
 
 
 No variables are labeled, which indicate the location that can jump from other places in the code. If you combine this information with the question # 1, then with the code  eax  with  2  ( cmp eax, 2 ) and < Code> JB jumps to a  label  one  if less than  eax   2  (its price is probably 1), and If the value of  jE  eax  is equal to  2 , two  jumps to  two  label. Lastly, jumps to  jl1  label  L1  if the value of  eax  is  above  the value is 2. Note that the next instruction label is  L1 , it has no functional effect. 
 
 
 3)  [ebp-4]  and  [Ebp-8] , are they the registry? Why are they elected? 
 
 
 In the x86 architecture the  code  is the base pointer register. It usually has an address in the context of  [ebp-4]  and  [ebp-8]  view the values ​​that are in the place  ebp-4  And in the  ebp-8  memory (the value of that address decreased from 4 to 8 and decreased to 8) why such a thing is done in this way, Google "x86 stack frame" .