1. Assuming AT&T Syntax, which of the following x86 instructions is both correctly written and will compute %rax = %rdi * 5 ?

A: mov (%rdi), %rax B: mov %rdi * 5, %rax

C: lea (, %rdi, 5), %rax D: lea (%rdi, %rdi, 4), %rax

2. Which of the following would you highlight as an example of a CISC processor instruction?

A: Adding two numbers B: Finding length of a C string

C: Jumping to an address D: 64-bit XOR Operation

3. Of the following, what x86 register might you expect a compiler to use when utilizing a variable declared as ashort when SHORT_UMAX is defined as ?

A: %rax B: %eax

C: %ax D: %al

4. Consider the x86-64 Linux C ABI mentioned in our slides. How many items (not byte size) are written to the stack as part of this (otherwise nonsense) functions activation frame to account for arguments and variables? (Ignore the return address and any potential preserved registers, such as %rbp.)

int main(char x, char y, int i, int j, const char* s, char* d, size_t length) {

char* tmp = s;

while(*d++ != '\0') {

*d = x;

}

int num = 0;

while(*s++ != '\0' && num < length) {

*d++ = *(s - 1);

num++;

}

tmp[0] = y;

return num;

}

5. Consider the following x86 assembly. What is the value is %rax at the end of its execution? (An int, here, is 32-bits, you can specify your answer in base 10.)

.data

arr: .int 1, -2, 6, -4, 11

.text

_start:

lea (arr), %rbx

mov $4, %rdi

lea (%rbx, %rdi, 4), %rax

movl (%rax), %eax