v850.c

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	max_offset = (1 << 4);
      else
	max_offset = (1 << 7);
      break;

    case HImode:
      if (TARGET_SMALL_SLD)
	max_offset = (1 << 5);
      else if (TARGET_V850E
	       && (   (  unsignedp && ! TARGET_US_BIT_SET)
		   || (! unsignedp &&   TARGET_US_BIT_SET)))
	max_offset = (1 << 5);
      else
	max_offset = (1 << 8);
      break;

    case SImode:
    case SFmode:
      max_offset = (1 << 8);
      break;
      
    default:
      break;
    }

  return max_offset;
}

/* Return true if OP is a valid short EP memory reference */

int
ep_memory_operand (rtx op, enum machine_mode mode, int unsigned_load)
{
  rtx addr, op0, op1;
  int max_offset;
  int mask;

  /* If we are not using the EP register on a per-function basis
     then do not allow this optimisation at all.  This is to
     prevent the use of the SLD/SST instructions which cannot be
     guaranteed to work properly due to a hardware bug.  */
  if (!TARGET_EP)
    return FALSE;

  if (GET_CODE (op) != MEM)
    return FALSE;

  max_offset = ep_memory_offset (mode, unsigned_load);

  mask = GET_MODE_SIZE (mode) - 1;

  addr = XEXP (op, 0);
  if (GET_CODE (addr) == CONST)
    addr = XEXP (addr, 0);

  switch (GET_CODE (addr))
    {
    default:
      break;

    case SYMBOL_REF:
      return SYMBOL_REF_TDA_P (addr);

    case REG:
      return REGNO (addr) == EP_REGNUM;

    case PLUS:
      op0 = XEXP (addr, 0);
      op1 = XEXP (addr, 1);
      if (GET_CODE (op1) == CONST_INT
	  && INTVAL (op1) < max_offset
	  && INTVAL (op1) >= 0
	  && (INTVAL (op1) & mask) == 0)
	{
	  if (GET_CODE (op0) == REG && REGNO (op0) == EP_REGNUM)
	    return TRUE;

	  if (GET_CODE (op0) == SYMBOL_REF && SYMBOL_REF_TDA_P (op0))
	    return TRUE;
	}
      break;
    }

  return FALSE;
}

/* Substitute memory references involving a pointer, to use the ep pointer,
   taking care to save and preserve the ep.  */

static void
substitute_ep_register (rtx first_insn,
                        rtx last_insn,
                        int uses,
                        int regno,
                        rtx * p_r1,
                        rtx * p_ep)
{
  rtx reg = gen_rtx_REG (Pmode, regno);
  rtx insn;

  if (!*p_r1)
    {
      regs_ever_live[1] = 1;
      *p_r1 = gen_rtx_REG (Pmode, 1);
      *p_ep = gen_rtx_REG (Pmode, 30);
    }

  if (TARGET_DEBUG)
    fprintf (stderr, "\
Saved %d bytes (%d uses of register %s) in function %s, starting as insn %d, ending at %d\n",
	     2 * (uses - 3), uses, reg_names[regno],
	     IDENTIFIER_POINTER (DECL_NAME (current_function_decl)),
	     INSN_UID (first_insn), INSN_UID (last_insn));

  if (GET_CODE (first_insn) == NOTE)
    first_insn = next_nonnote_insn (first_insn);

  last_insn = next_nonnote_insn (last_insn);
  for (insn = first_insn; insn && insn != last_insn; insn = NEXT_INSN (insn))
    {
      if (GET_CODE (insn) == INSN)
	{
	  rtx pattern = single_set (insn);

	  /* Replace the memory references.  */
	  if (pattern)
	    {
	      rtx *p_mem;
	      /* Memory operands are signed by default.  */
	      int unsignedp = FALSE;

	      if (GET_CODE (SET_DEST (pattern)) == MEM
		  && GET_CODE (SET_SRC (pattern)) == MEM)
		p_mem = (rtx *)0;

	      else if (GET_CODE (SET_DEST (pattern)) == MEM)
		p_mem = &SET_DEST (pattern);

	      else if (GET_CODE (SET_SRC (pattern)) == MEM)
		p_mem = &SET_SRC (pattern);

	      else if (GET_CODE (SET_SRC (pattern)) == SIGN_EXTEND
		       && GET_CODE (XEXP (SET_SRC (pattern), 0)) == MEM)
		p_mem = &XEXP (SET_SRC (pattern), 0);

	      else if (GET_CODE (SET_SRC (pattern)) == ZERO_EXTEND
		       && GET_CODE (XEXP (SET_SRC (pattern), 0)) == MEM)
		{
		  p_mem = &XEXP (SET_SRC (pattern), 0);
		  unsignedp = TRUE;
		}
	      else
		p_mem = (rtx *)0;

	      if (p_mem)
		{
		  rtx addr = XEXP (*p_mem, 0);

		  if (GET_CODE (addr) == REG && REGNO (addr) == (unsigned) regno)
		    *p_mem = change_address (*p_mem, VOIDmode, *p_ep);

		  else if (GET_CODE (addr) == PLUS
			   && GET_CODE (XEXP (addr, 0)) == REG
			   && REGNO (XEXP (addr, 0)) == (unsigned) regno
			   && GET_CODE (XEXP (addr, 1)) == CONST_INT
			   && ((INTVAL (XEXP (addr, 1)))
			       < ep_memory_offset (GET_MODE (*p_mem),
						   unsignedp))
			   && ((INTVAL (XEXP (addr, 1))) >= 0))
		    *p_mem = change_address (*p_mem, VOIDmode,
					     gen_rtx_PLUS (Pmode,
							   *p_ep,
							   XEXP (addr, 1)));
		}
	    }
	}
    }

  /* Optimize back to back cases of ep <- r1 & r1 <- ep.  */
  insn = prev_nonnote_insn (first_insn);
  if (insn && GET_CODE (insn) == INSN
      && GET_CODE (PATTERN (insn)) == SET
      && SET_DEST (PATTERN (insn)) == *p_ep
      && SET_SRC (PATTERN (insn)) == *p_r1)
    delete_insn (insn);
  else
    emit_insn_before (gen_rtx_SET (Pmode, *p_r1, *p_ep), first_insn);

  emit_insn_before (gen_rtx_SET (Pmode, *p_ep, reg), first_insn);
  emit_insn_before (gen_rtx_SET (Pmode, *p_ep, *p_r1), last_insn);
}


/* TARGET_MACHINE_DEPENDENT_REORG.  On the 850, we use it to implement
   the -mep mode to copy heavily used pointers to ep to use the implicit
   addressing.  */

static void
v850_reorg (void)
{
  struct
  {
    int uses;
    rtx first_insn;
    rtx last_insn;
  }
  regs[FIRST_PSEUDO_REGISTER];

  int i;
  int use_ep = FALSE;
  rtx r1 = NULL_RTX;
  rtx ep = NULL_RTX;
  rtx insn;
  rtx pattern;

  /* If not ep mode, just return now.  */
  if (!TARGET_EP)
    return;

  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
    {
      regs[i].uses = 0;
      regs[i].first_insn = NULL_RTX;
      regs[i].last_insn = NULL_RTX;
    }

  for (insn = get_insns (); insn != NULL_RTX; insn = NEXT_INSN (insn))
    {
      switch (GET_CODE (insn))
	{
	  /* End of basic block */
	default:
	  if (!use_ep)
	    {
	      int max_uses = -1;
	      int max_regno = -1;

	      for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
		{
		  if (max_uses < regs[i].uses)
		    {
		      max_uses = regs[i].uses;
		      max_regno = i;
		    }
		}

	      if (max_uses > 3)
		substitute_ep_register (regs[max_regno].first_insn,
					regs[max_regno].last_insn,
					max_uses, max_regno, &r1, &ep);
	    }

	  use_ep = FALSE;
	  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
	    {
	      regs[i].uses = 0;
	      regs[i].first_insn = NULL_RTX;
	      regs[i].last_insn = NULL_RTX;
	    }
	  break;

	case NOTE:
	  break;

	case INSN:
	  pattern = single_set (insn);

	  /* See if there are any memory references we can shorten */
	  if (pattern)
	    {
	      rtx src = SET_SRC (pattern);
	      rtx dest = SET_DEST (pattern);
	      rtx mem;
	      /* Memory operands are signed by default.  */
	      int unsignedp = FALSE;

	      /* We might have (SUBREG (MEM)) here, so just get rid of the
		 subregs to make this code simpler.  */
	      if (GET_CODE (dest) == SUBREG
		  && (GET_CODE (SUBREG_REG (dest)) == MEM
		      || GET_CODE (SUBREG_REG (dest)) == REG))
		alter_subreg (&dest);
	      if (GET_CODE (src) == SUBREG
		  && (GET_CODE (SUBREG_REG (src)) == MEM
		      || GET_CODE (SUBREG_REG (src)) == REG))
		alter_subreg (&src);

	      if (GET_CODE (dest) == MEM && GET_CODE (src) == MEM)
		mem = NULL_RTX;

	      else if (GET_CODE (dest) == MEM)
		mem = dest;

	      else if (GET_CODE (src) == MEM)
		mem = src;

	      else if (GET_CODE (src) == SIGN_EXTEND
		       && GET_CODE (XEXP (src, 0)) == MEM)
		mem = XEXP (src, 0);

	      else if (GET_CODE (src) == ZERO_EXTEND
		       && GET_CODE (XEXP (src, 0)) == MEM)
		{
		  mem = XEXP (src, 0);
		  unsignedp = TRUE;
		}
	      else
		mem = NULL_RTX;

	      if (mem && ep_memory_operand (mem, GET_MODE (mem), unsignedp))
		use_ep = TRUE;

	      else if (!use_ep && mem
		       && GET_MODE_SIZE (GET_MODE (mem)) <= UNITS_PER_WORD)
		{
		  rtx addr = XEXP (mem, 0);
		  int regno = -1;
		  int short_p;

		  if (GET_CODE (addr) == REG)
		    {
		      short_p = TRUE;
		      regno = REGNO (addr);
		    }

		  else if (GET_CODE (addr) == PLUS
			   && GET_CODE (XEXP (addr, 0)) == REG
			   && GET_CODE (XEXP (addr, 1)) == CONST_INT
			   && ((INTVAL (XEXP (addr, 1)))
			       < ep_memory_offset (GET_MODE (mem), unsignedp))
			   && ((INTVAL (XEXP (addr, 1))) >= 0))
		    {
		      short_p = TRUE;
		      regno = REGNO (XEXP (addr, 0));
		    }

		  else
		    short_p = FALSE;

		  if (short_p)
		    {
		      regs[regno].uses++;
		      regs[regno].last_insn = insn;
		      if (!regs[regno].first_insn)
			regs[regno].first_insn = insn;
		    }
		}

	      /* Loading up a register in the basic block zaps any savings
		 for the register */
	      if (GET_CODE (dest) == REG)
		{
		  enum machine_mode mode = GET_MODE (dest);
		  int regno;
		  int endregno;

		  regno = REGNO (dest);
		  endregno = regno + HARD_REGNO_NREGS (regno, mode);

		  if (!use_ep)
		    {
		      /* See if we can use the pointer before this
			 modification.  */
		      int max_uses = -1;
		      int max_regno = -1;

		      for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
			{
			  if (max_uses < regs[i].uses)
			    {
			      max_uses = regs[i].uses;
			      max_regno = i;
			    }
			}

		      if (max_uses > 3
			  && max_regno >= regno
			  && max_regno < endregno)
			{
			  substitute_ep_register (regs[max_regno].first_insn,
						  regs[max_regno].last_insn,
						  max_uses, max_regno, &r1,
						  &ep);

			  /* Since we made a substitution, zap all remembered
			     registers.  */
			  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
			    {
			      regs[i].uses = 0;
			      regs[i].first_insn = NULL_RTX;
			      regs[i].last_insn = NULL_RTX;
			    }
			}
		    }

		  for (i = regno; i < endregno; i++)
		    {
		      regs[i].uses = 0;
		      regs[i].first_insn = NULL_RTX;
		      regs[i].last_insn = NULL_RTX;
		    }
		}
	    }
	}
    }
}


/* # of registers saved by the interrupt handler.  */
#define INTERRUPT_FIXED_NUM 4

/* # of bytes for registers saved by the interrupt handler.  */
#define INTERRUPT_FIXED_SAVE_SIZE (4 * INTERRUPT_FIXED_NUM)

/* # of registers saved in register parameter area.  */
#define INTERRUPT_REGPARM_NUM 4
/* # of words saved for other registers.  */
#define INTERRUPT_ALL_SAVE_NUM \
  (30 - INTERRUPT_FIXED_NUM + INTERRUPT_REGPARM_NUM)

#define INTERRUPT_ALL_SAVE_SIZE (4 * INTERRUPT_ALL_SAVE_NUM)

int
compute_register_save_size (long * p_reg_saved)
{
  int size = 0;
  int i;
  int interrupt_handler = v850_interrupt_function_p (current_function_decl);
  int call_p = regs_ever_live [LINK_POINTER_REGNUM];
  long reg_saved = 0;

  /* Count the return pointer if we need to save it.  */
  if (current_function_profile && !call_p)
    regs_ever_live [LINK_POINTER_REGNUM] = call_p = 1;
 
  /* Count space for the register saves.  */
  if (interrupt_handler)
    {
      for (i = 0; i <= 31; i++)
	switch (i)
	  {
	  default:
	    if (regs_ever_live[i] || call_p)
	      {
		size += 4;
		reg_saved |= 1L << i;
	      }
	    break;

	    /* We don't save/restore r0 or the stack pointer */
	  case 0:
	  case STACK_POINTER_REGNUM:
	    break;

	    /* For registers with fixed use, we save them, set them to the
	       appropriate value, and then restore them.
	       These registers are handled specially, so don't list them
	       on the list of registers to save in the prologue.  */
	  case 1:		/* temp used to hold ep */
	  case 4:		/* gp */
	  case 10:		/* temp used to call interrupt save/restore */
	  case EP_REGNUM:	/* ep */
	    size += 4;
	    break;
	  }
    }
  else
    {
      /* Find the first register that needs to be saved.  */
      for (i = 0; i <= 31; i++)
	if (regs_ever_live[i] && ((! call_used_regs[i])
				  || i == LINK_POINTER_REGNUM))
	  break;

      /* If it is possible that an out-of-line helper function might be
	 used to generate the prologue for the current function, then we
	 need to cover the possibility that such a helper function will
	 be used, despite the fact that there might be gaps in the list of
	 registers that need to be saved.  To detect this we note that the
	 helper functions always push at least register r29 (provided
	 that the function is not an interrupt handler).  */
	 
      if (TARGET_PROLOG_FUNCTION
          && (i == 2 || ((i >= 20) && (i < 30))))
	{
	  if (i == 2)
	    {
	      size += 4;
	      reg_saved |= 1L << i;

	      i = 20;
	    }

	  /* Helper functions save all registers between the starting
	     register and the last register, regardless of whether they
	     are actually used by the function or not.  */
	  for (; i <= 29; i++)
	    {
	      size += 4;
	      reg_saved |= 1L << i;
	    }

	  if (regs_ever_live [LINK_POINTER_REGNUM])
	    {
	      size += 4;
	      reg_saved |= 1L << LINK_POINTER_REGNUM;
	    }
	}
      else
	{
	  for (; i <= 31; i++)