The purpose of this assignment is for you to become better at comprehending x86-64 assembly language. We will not write assembly language programs. Instead, in this assignment you are given 5 functions in x86-64 assembly language. Your task is to reverse engineer these 5 functions by writing them in C. Each correct answer is worth 1 point. Your C code does not have to compile into exactly the same .s code that I have given you. Rather, you will be graded on whether or not your C functions properly emulate the assembly language; that is, they both should return the same value provided they are passed the same values as parameters.

p5:

.LFB18:

.cfi_startproc

subl $1, %esi

testl %esi, %esi

jle .L21

movslq %esi, %rax

xorl %edx, %edx

leaq (%rdi,%rax,4), %rax

.p2align 4,,10

.p2align 3

.L24:

movl (%rdi), %ecx

movl (%rax), %r8d

addl $1, %edx

subl $1, %esi

addq $4, %rdi

subq $4, %rax

movl %r8d, -4(%rdi)

movl %ecx, 4(%rax)

cmpl %esi, %edx

jl .L24

.L21:

rep ret

.cfi_endproc