directly change pic->sp via PUSH/POP macros
directly change pic->sp via PUSH/POP macros

koba-e964/picrin,dcurrie/picrin,ktakashi/picrin,leavesbnw/picrin,leavesbnw/picrin,omasanori/picrin,ktakashi/picrin,koba-e964/picrin,ktakashi/picrin,picrin-scheme/picrin,leavesbnw/picrin,omasanori/picrin,koba-e964/picrin,dcurrie/picrin,picrin-scheme/picrin