I am reversing an ELF64 executable created on AMD X86-64. I encountered this line near the end of the file and am puzzled to its meaning:
nop WORD PTR cs:[rax+rax*1+0x0]
In this case
nop means 'do nothing', so I am puzzled as to why there are arguments included on the line. The code is loaded with
libc function calls so I am assuming the source code is C/C++ and not GAS.
This post has good content but perror's explanation is more apropos and contains more "why" than a mere recital of the Intel docs.