I'm porting for microcontroller C166. I've defined some peepholes in machine description file C166.md. When I configured and made cc1 file, everything seemed to be OK. But when I tried to compile some C program into assembly code, I've realized that the peepholes I had defined didn't run. I've tried some options -O1, -O2 but it still didn't run. I don't know if I have to define some special options so that my peepholes can run. If you know why, would you please explain me. Thank you for your help.