Lab9_x861

long fun_a(unsigned long x){ long val = 0; while ( ){ } return val; } The gcc C compiler generates the x86-64 assembly code on the right. Reverse engineer this assembly code and fill in the missing parts of the fun_a definition so the C code does the same thing. 2. The gcc C compiler generates the assembly code blow to the right. Reverse engineer the operation of this code and fill in the missing parts of the C code to the left so that it does the same thing. long loop(long x, long n){ long result = ; long mask; for (mask = ; ; mask = ){ result |= ; } return result; } # x in %rdi fun_a: movl $0, %eax jmp .L5 .L6: xorq %rdi, %rax shrq %rdi # shift right 1 .L5: testq %rdi, %rdi jne .L6 andl $1, %eax ret # x in %rdi, n in %esi Loop: movl %esi, %ecx movl $1, %edx movl $0, %eax jmp .L2 .L3: movq %rdi, %r8 andq %rdx, %r8 orq %r8, %rax salq %cl, %rdx .L2: testq %rdx, %rdx jne .L3 ret