Registers

Description / Use	64 bit	32	16	8
Data/Argument Registers
Syscall Number/Return value	rax	eax	ax	al
Callee saved	rbx	ebx	bx	bl
1st arg -Dest operand	rdi	edi	di	dil
2nd arg - Src operand	rsi	esi	si	sil
3rd arg	rdx	edx	dx	dl
4th arg	rcx	ecx	cx	cl
5th arg	r8	r8d	r8w	r8b
6th arg	r9	r9d	r9w	r9b
Pointer registers
Base Stack	rbp	ebp	bp	bpl
Top Stack pointer	rsp	esp	sp	spl
Instruction Pointer	rip	eip	ip	ipl