Note that this architecture goes under many different names, including
"AMD64" and "Intel 64". (But "IA-64" refers to a different architecture altogether,
the Intel Itanium.)
Warning: There are two assembler syntaxes in common use for the x86.
So-called AT&T syntax, used by the GNU assembler, uses the format
"opcode src,dst" whereas so-called Intel syntax, used by Microsoft's MASM
assmebler, uses the format "opcode dst,src". When trying to decode documentation,
make sure you know which format is being used!