Bit1 is not defined so this line is evaluated by the processor: #define SET(Reg,Bit) Bit=1; Then line 10 gets expanded to SMOD=1;; which isn't valid because SMOD expands to a constant value. Edit: I just noticed how old this question is. Hopefully it'll help anyone else with a similar problem!
Bit1 is not defined so this line is evaluated by the processor: #define SET(Reg,Bit) Bit=1; Then line 10 gets expanded to SMOD=1;; which isn't valid because SMOD expands to a constant value.
MOS6502 peephole rules bugs