Please give an example for: Switch the integer values stored in two registers without using any additional memory?

Question

Requirements:

1.No input should be processed, and the output should be in the form of 2 3 5 7 11 13 ... etc.
2. No reserved words in the language are used at all
3.The language should at least allow structured programming, and have reserved words (otherwise point 2 would be moot).

Answer 1

To swap the values, you can carry out the following instructions:

Reg_1 = Reg_1 + Reg_2;
Reg_2 = Reg_1 - Reg_2;
Reg_1 = Reg_1 - Reg_2;