+2005-01-22 Roger Sayle <roger@eyesopen.com>
+
+ PR middle-end/19378
+ * config/avr/avr.c (avr_hard_regno_mode_ok): Rewrite.
+
2005-01-22 Richard Henderson <rth@redhat.com>
PR target/19506
int
avr_hard_regno_mode_ok (int regno, enum machine_mode mode)
{
- /* Bug workaround: recog.c (peep2_find_free_register) and probably
- a few other places assume that the frame pointer is a single hard
- register, so r29 may be allocated and overwrite the high byte of
- the frame pointer. Do not allow any value to start in r29. */
- if (regno == REG_Y + 1)
- return 0;
+ /* The only thing that can go into registers r28:r29 is a Pmode. */
+ if (regno == REG_Y && mode == Pmode)
+ return 1;
- /* Reload can use r28:r29 for reload register and for frame pointer
- in one insn. It's wrong. We must disable it. */
- if (mode != Pmode && reload_in_progress && frame_pointer_required_p ()
- && regno <= REG_Y && (regno + GET_MODE_SIZE (mode)) >= (REG_Y + 1))
+ /* Otherwise disallow all regno/mode combinations that span r28:r29. */
+ if (regno <= (REG_Y + 1) && (regno + GET_MODE_SIZE (mode)) >= (REG_Y + 1))
return 0;
if (mode == QImode)
return 1;
- /* if (regno < 24 && !AVR_ENHANCED)
- return 1;*/
+
+ /* Modes larger than QImode occupy consecutive registers. */
+ if (regno + GET_MODE_SIZE (mode) > FIRST_PSEUDO_REGISTER)
+ return 0;
+
+ /* All modes larger than QImode should start in an even register. */
return !(regno & 1);
}