assembly function flow

Question

I am reading a \"programming from the ground up\", if you don\'t know what this book is, you still can help me.

In this book(chapter 4) there are 2 things that I don\'t

Answer 1

I believe that this:

 movl 8(%ebp), %ebx #put first argument in %eax  

was a typo, and it should really be:

 movl 8(%ebp), %ebx #put first argument in %ebx  

and if you noticed, later the code is correct:

 movl %ebx, -4(%ebp) #store current result

In the end, the author could have used %eax for this operation as well (instead of %ebx), there's no reason why he shouldn't since it wouldn't change the program at all.

But the comment could be a lot clearer and I believe that this is a typo as well. At this point, it would be better if it said: #storing 1st argument on the local stack frame.

label power_loop_start uses that variable and temporarily stores it in %eax for quick operations and then place it back on the same location on the stack for the next loop:

 movl %eax, -4(%ebp)   #store the current result
 decl %ecx             #decrease the power
 jmp  power_loop_start #run for the next power