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# [RESOLVIDO][assembly] Dúvida em código.

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Boas.

Estou a ler o livro "Programming from the Ground Up" e tenho uma dúvida em relação a um dos exemplos.

```#PURPOSE - Given a number, this program computes the
#          factorial. For example, the factorial of
#          3 is 3 * 2 * 1, or 6. The factorial of
#          4 is 4 * 3 * 2 * 1, or 24, and so on.
#
#This program shows how to call a function recursively.
.section .data
#This program has no global data
.section .text
.globl _start
.globl factorial #this is unneeded unless we want to share
#this function among other programs
_start:
pushl \$4         #The factorial takes one argument - the
#number we want a factorial of. So, it
#gets pushed
call factorial #run the factorial function
addl \$4, %esp    #Scrubs the parameter that was pushed on
#the stack
movl %eax, %ebx #factorial returns the answer in %eax, but
#we want it in %ebx to send it as our exit
#status
movl  \$1, %eax   #call the kernel’s exit function
int   \$0x80
#This is the actual function definition
.type factorial,@function
factorial:
pushl %ebp       #standard function stuff - we have to
#restore %ebp to its prior state before
#returning, so we have to push it
movl %esp, %ebp #This is because we don’t want to modify
#the stack pointer, so we use %ebp.
movl  8(%ebp), %eax #This moves the first argument to %eax
#4(%ebp) holds the return address, and
#8(%ebp) holds the first parameter
cmpl \$1, %eax       #If the number is 1, that is our base
#case, and we simply return (1 is
#already in %eax as the return value)
je end_factorial
decl %eax           #otherwise, decrease the value
pushl %eax          #push it for our call to factorial
call factorial      #call factorial
movl 8(%ebp), %ebx #%eax has the return value, so we
imull %ebx, %eax    #multiply that by the result of the
#last call to factorial (in %eax)
#the answer is stored in %eax, which
#is good since that’s where return
#values go.
end_factorial:
movl %ebp, %esp #standard function return stuff - we
popl %ebp       #have to restore %ebp and %esp to where
#they were before the function started
#return value, too)
```

Não estou a perceber as duas linhas a seguir ao segundo "call factorial" :

```movl 8(%ebp), %ebx
imull %ebx, %eax
```

Estas são alguma vez executadas ?

Está uma condição antes que se for verdadeira vai para "end_factorial", se for falsa um pouco à frente é feita a "call factorial". Não estou a perceber como estas duas linhas são executadas.

Se a vida te voltar as costas aproveita e apalpa-lhe o cu.

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Esqueçam, tinha analisado mal o código.

Se a vida te voltar as costas aproveita e apalpa-lhe o cu.

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