1. (16 pts) Fill in the missing expressions in the C code. int main() { int x, y; } else { } } Suppose a compiler generates the following X.86 assembly code: (assume x at %rbx, y at %rcx) movq %rbx, %rsi subq %rcx, %rsi jle .L1 .L2: halt movq $3, %rdx addq %rdx, %rbx .L2 jmp .L1: movq $0, %rbx movq $2, %rdx addq %rdx, %rcx ){