mov      rdx,rax
shr      rdx,0x1
xor      rax,rdx

mov      rdx,rax
shr      rdx,0x2
xor      rax,rdx

mov      rdx,rax
shr      rdx,0x4
xor      rax,rdx

mov      rdx,rax
shr      rdx,0x8
xor      rax,rdx

mov      rdx,rax
shr      rdx,0x10
xor      rax,rdx

mov      rdx,rax
shr      rdx,0x20
xor      rax,rdx