For a function with prototype

long decode2(long x; long y; long z);

GCC generates the following assembly code:

1 decode2:

2 subq %rdx, %rsi

3 imulp %rsi, %rdi

4 movq %rsi, %rax

5 salq $63, %rax

6 sarq $63,%rax

7 xorq %rdi,%rax

8 ret

Parameters x,y and z are passed in registers %rdi, %rsi, and %rds. The code stores the return value in register %rax. Write C code for decode2 that will have an effect equivalent to the assembly code shown