The 32-bit register names start with an E and the 64-bit ones start with an R. What do the E and R stand for? Is there a reason for choosing these alphabets?
Also, in 64-bit registers, too, we can see in any low-level debugger such as Windbg that the right-most bits are still referred to by the same name as that of the 64-bit register except the name starts with an E. For e.g. the right-most 32 bits of the RAX register in a 64-bit system is referred to as EAX.
So, do the E and R stand for something? And also, why the suffix X for register?