See how they're using #ifdefs? Those work much better with initial operators. Consider: ... == NO_REGS)) #ifdef CANNOT_CHANGE_MODE_CLASS || (REG_

See how they're using #ifdefs? Those work much better with initial operators. Consider: ... == NO_REGS)) #ifdef CANNOT_CHANGE_MODE_CLASS || (REG_P (SUBREG_REG (in)) && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER && REG_CANNOT_CHANGE_MODE_P (REGNO (SUBREG_REG (in)), GET_MODE (SUBREG_REG (in)), inmode)) #endif )) That || needs to be inside the #ifdef, so it can't follow on the same line as the "== NO_REGS))". And once you're doing that, might as well use them for the whole file.