MicroTESK

struct mod_STR (
  r: card(3),
  e: card(3),
  m: card(2)
)

var mod[mod_STR]

op mov_1(r: R4, r2: R4)
  init = {
...
    mod = 0;
    mod.m = 0b00;
...
  }
  image  = format("%8s", mod)

op mov_2(r: R4, r2: R4)
  init = {
...
    mod = 0;
    mod.m = 0b11;
...
  }
  image  = format("%8s", mod)

Result:

Warning: Group MovOp contains two items mov_1 and mov_2 with the same opcode 00000000

But:
mov_1 -> mod.m = 0b00;
mov_2 -> mod.m = 0b11;