stackFetch
len += stackFetch(vm->pStack, i * 2).i + 1;
CELL stackFetch (FICL_STACK *pStack, int n);
#define FETCH(n) stackFetch(pVM->pStack,n)
stackPush(pStack, stackFetch(pStack, n));
FICL_INT limit = stackFetch(pVM->rStack, 1).i;
limit = stackFetch(pVM->rStack, 1).i;
CELL index = stackFetch(pVM->rStack, 3);
CELL index = stackFetch(pVM->rStack, 6);
stackPush(pVM->pStack, stackFetch(pVM->rStack, 1));
stackPush(pVM->pStack, stackFetch(pVM->rStack, 0));