Let's Get a Loop

Notes

• This is Jorgensen 7.5
• add dest, src
  • dest = src + dest
  • must be same size
  • dest can't be imm
  • both can not be memory
  • If the operation does not involve a register, you might have to qualify memory size
  • add byte [incrementValue], 3
  • The immediate can not be a quadword
• We do ++i so often that inc dest exists
• There are other add instructions, but I would like to get on with it.
• sub dest, src
• dec dest
• The result of the operation can be tested
• But for the momemt we will be inefficent and use cmp
  • Jorgensen 7.7.3
  • cmp op, op
  • Sets bits in the flags register
• Then we can take an action based on this
  • je label, jne label
  • jl label, jle label
  • jg label, jge label
  • These are for signed numbers
  • also j label