FACTOR_SET
reg = FACTOR_SET(config->nshift, config->nwidth, reg, req.n);
reg = FACTOR_SET(config->kshift, config->kwidth, reg, req.k);
reg = FACTOR_SET(config->mshift, config->mwidth, reg, req.m);
reg = FACTOR_SET(config->pshift, config->pwidth, reg, req.p);