Question

Write in assembly code

(Exercise #2) Passing Control and Data using Stack (2 In this exercise, you will be writing a procedure called call_max2, which will pass two values by reference into a procedure you will write called max2. For this, you will need to put the two hardcoded values of 10 and 20 on the stack and then pass their addresses as arguments. In max2, compare and return the larger of the two values call max2.s max2.s long call max201 long max2(long *arg1, long *arg2) long arg1 10; // arg1-2 values hard coded |{ long arg2 20; long max = max2(&arg1, &arg2); return max; return larger value of the two .text .g lobal call max2 type call_max2, Cfunction call_max2: # YOUR CODE HERE # END YOUR CODE .size call max2, .-call max2 .text global max2 type max2, @function maxZL: # YOUR CODE HERE # END YOUR CODE size max2, .-max2

Answer 1

procedure call_max2

.txt
.globl call_max2
.type   call_max2, @function
call_max2:
.LFB1:
.cfi_startproc
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset 6, -16
movq %rsp, %rbp
.cfi_def_cfa_register 6
subq $32, %rsp
movq %fs:40, %rax
movq %rax, -8(%rbp)
xorl %eax, %eax
movq $10, -32(%rbp)
movq $20, -24(%rbp)
leaq -24(%rbp), %rdx
leaq -32(%rbp), %rax
movq %rdx, %rsi
movq %rax, %rdi
call _Z4max2PlS_
movq %rax, -16(%rbp)
movq -16(%rbp), %rax
movq -8(%rbp), %rcx
xorq %fs:40, %rcx
je .L6
call __stack_chk_fail@PLT
.L6:
leave
.cfi_def_cfa 7, 8
ret
.cfi_endproc
.LFE1:
.size call_max2, .-call_max2

----------------------------------------------------------------

procedure max2

.text
.globl max2
.type max2, @function
max2:
.LFB0:
.cfi_startproc
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset 6, -16
movq %rsp, %rbp
.cfi_def_cfa_register 6
movq %rdi, -8(%rbp)
movq %rsi, -16(%rbp)
movq -8(%rbp), %rax
movq (%rax), %rdx
movq -16(%rbp), %rax
movq (%rax), %rax
cmpq %rax, %rdx
jle .L2
movq -8(%rbp), %rax
movq (%rax), %rax
jmp .L3
.L2:
movq -16(%rbp), %rax
movq (%rax), %rax
.L3:
popq %rbp
.cfi_def_cfa 7, 8
ret
.cfi_endproc
.LFE0:
.size max2, .-max2