/* SUBREG of a hard register => just change the register number
and/or mode. If the hard register is not valid in that mode,
- suppress this combination. */
+ suppress this combination. If the hard register is the stack,
+ frame, or argument pointer, leave this as a SUBREG. */
if (GET_CODE (SUBREG_REG (x)) == REG
- && REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
+ && REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER
+ && REGNO (SUBREG_REG (x)) != FRAME_POINTER_REGNUM
+#if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
+ && REGNO (SUBREG_REG (x)) != ARG_POINTER_REGNUM
+#endif
+ && REGNO (SUBREG_REG (x)) != STACK_POINTER_REGNUM)
{
if (HARD_REGNO_MODE_OK (REGNO (SUBREG_REG (x)) + SUBREG_WORD (x),
mode))