general information

• registers

  see [[Registers]]
  

• some jump instructions

  Instruction	Mnemonic	C Example	Flags
  j (jmp)	Jump	break;	(Unconditional)
  je (jz)	Jump if equal (zero)	if (x == y)	ZF
  jne (jnz)	Jump if not equal (nonzero)	if (x != y)	!ZF
  jg (jnle)	Jump if greater	if (x > y), signed	!ZF && !(SF ^ OF)
  jge (jnl)	Jump if greater or equal	if (x >= y), signed	!(SF ^ OF)
  jl (jnge)	Jump if less	if (x < y), signed	SF ^ OF
  jle (jng)	Jump if less or equal	if (x <= y), signed	(SF ^ OF) or JF
  ja (jnbe)	Jump if above	if (x > y), unsigned	!CF && !ZF
  jae (jnb)	Jump if above or equal	if (x >= y), unsigned	!CF
  jb (jnae)	Jump if below	if (x < y), unsigned	CF
  jbe (jna)	Jump if below or equal	if (x <= y), unsigned	CF or ZF
  js	Jump if sign bit	if (x < 0), signed	SF
  jns	Jump if not sign bit	if (x >= 0), signed	!SF
  jc	Jump if carry bit	N/A	CF
  jnc	Jump if not carry bit	N/A	!CF
  jo	Jump if overflow bit	N/A	OF
  jno	Jump if not overflow bit	N/A	!OF

  
• Figure 2 shows the stack layout, both before and after a function call. If the function has more than 6 arguments, then arguments 0 . . . 5 get passed in reg- isters rdi, rsi, rdx, rcx, r8, and r9, and arguments 6 . . . n − 1 get passed on the stack. If the function has at most 6 arguments, all arguments get passed in registers. Just before the caller executes the call in- struction, the stack layout is as shown in Figure 2(a), with register rsp (the stack pointer) pointing to the lowest argument on the stack
  #assembly #programming