crx.c

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	    }

	case REG:
	  if (REGNO (x) + 1 >= FIRST_PSEUDO_REGISTER) abort ();
	  fprintf (file, "%s", reg_names[REGNO (x) + 1]);
	  return;

	case MEM:
	  /* Adjust memory address to high part.  */
	    {
	      rtx adj_mem = x;
	      adj_mem = adjust_address (adj_mem, GET_MODE (adj_mem), 4);

	      output_memory_reference_mode = GET_MODE (adj_mem);
	      output_address (XEXP (adj_mem, 0));
	      return;
	    }

	default:
	  abort ();
	}

    case 'L':
      /* Print low part of a double precision value. */
      switch (GET_CODE (x))
	{
	case CONST_DOUBLE:
	  if (GET_MODE (x) == SFmode) abort ();
	  if (GET_MODE (x) == DFmode)
	    {
	      /* High part of a DF const. */
	      REAL_VALUE_TYPE r;
	      long l[2];

	      REAL_VALUE_FROM_CONST_DOUBLE (r, x);
	      REAL_VALUE_TO_TARGET_DOUBLE (r, l);

	      fprintf (file, "$0x%lx", l[0]);
	      return;
	    }

	  /* -- Fallthrough to handle DI consts -- */

	case CONST_INT:
	    {
	      rtx high, low;
	      split_double (x, &low, &high);
	      putc ('$', file);
	      output_addr_const (file, low);
	      return;
	    }

	case REG:
	  fprintf (file, "%s", reg_names[REGNO (x)]);
	  return;

	case MEM:
	  output_memory_reference_mode = GET_MODE (x);
	  output_address (XEXP (x, 0));
	  return;

	default:
	  abort ();
	}

    case 0 : /* default */
      switch (GET_CODE (x))
	{
	case REG:
	  fprintf (file, "%s", reg_names[REGNO (x)]);
	  return;

	case MEM:
	  output_memory_reference_mode = GET_MODE (x);
	  output_address (XEXP (x, 0));
	  return;

	case CONST_DOUBLE:
	    {
	      REAL_VALUE_TYPE r;
	      long l;

	      /* Always use H and L for double precision - see above */
	      gcc_assert (GET_MODE (x) == SFmode);

	      REAL_VALUE_FROM_CONST_DOUBLE (r, x);
	      REAL_VALUE_TO_TARGET_SINGLE (r, l);

	      fprintf (file, "$0x%lx", l);
	      return;
	    }

	default:
	  putc ('$', file);
	  output_addr_const (file, x);
	  return;
	}

    default:
      output_operand_lossage ("invalid %%xn code");
    }

  abort ();
}

/* Implements the macro PRINT_OPERAND_ADDRESS defined in crx.h.  */

void
crx_print_operand_address (FILE * file, rtx addr)
{
  enum crx_addrtype addrtype;
  struct crx_address address;

  int offset;
  
  addrtype = crx_decompose_address (addr, &address);
  
  if (address.disp)
    offset = INTVAL (address.disp);
  else
    offset = 0;

  switch (addrtype)
    {
    case CRX_REG_REL:
      fprintf (file, "%d(%s)", offset, reg_names[REGNO (address.base)]);
      return;
      
    case CRX_POST_INC:
      switch (GET_CODE (address.side_effect))
	{
	case PLUS:
	  break;
	case MINUS:
	  offset = -offset;
	  break;
	case POST_INC:
	  offset = GET_MODE_SIZE (output_memory_reference_mode);
	  break;
	case POST_DEC:
	  offset = -GET_MODE_SIZE (output_memory_reference_mode);
	  break;
	default:
	  abort ();
	}
	fprintf (file, "%d(%s)+", offset, reg_names[REGNO (address.base)]);
      return;
      
    case CRX_SCALED_INDX:
      fprintf (file, "%d(%s, %s, %d)", offset, reg_names[REGNO (address.base)],
	       reg_names[REGNO (address.index)], address.scale);
      return;
      
    case CRX_ABSOLUTE:
      output_addr_const (file, address.disp);
      return;
      
    default:
      abort ();
    }
}


/*****************************************************************************/
/* MACHINE DESCRIPTION HELPER-FUNCTIONS					     */
/*****************************************************************************/

void crx_expand_movmem_single (rtx src, rtx srcbase, rtx dst, rtx dstbase,
			       rtx tmp_reg, unsigned HOST_WIDE_INT *offset_p)
{
  rtx addr, mem;
  unsigned HOST_WIDE_INT offset = *offset_p;

  /* Load */
  addr = plus_constant (src, offset);
  mem = adjust_automodify_address (srcbase, SImode, addr, offset);
  emit_move_insn (tmp_reg, mem);

  /* Store */
  addr = plus_constant (dst, offset);
  mem = adjust_automodify_address (dstbase, SImode, addr, offset);
  emit_move_insn (mem, tmp_reg);

  *offset_p = offset + 4;
}

int
crx_expand_movmem (rtx dstbase, rtx srcbase, rtx count_exp, rtx align_exp)
{
  unsigned HOST_WIDE_INT count = 0, offset, si_moves, i;
  HOST_WIDE_INT align = 0;

  rtx src, dst;
  rtx tmp_reg;

  if (GET_CODE (align_exp) == CONST_INT)
    { /* Only if aligned */
      align = INTVAL (align_exp);
      if (align & 3)
	return 0;
    }

  if (GET_CODE (count_exp) == CONST_INT)
    { /* No more than 16 SImode moves */
      count = INTVAL (count_exp);
      if (count > 64)
	return 0;
    }

  tmp_reg = gen_reg_rtx (SImode);

  /* Create psrs for the src and dest pointers */
  dst = copy_to_mode_reg (Pmode, XEXP (dstbase, 0));
  if (dst != XEXP (dstbase, 0))
    dstbase = replace_equiv_address_nv (dstbase, dst);
  src = copy_to_mode_reg (Pmode, XEXP (srcbase, 0));
  if (src != XEXP (srcbase, 0))
    srcbase = replace_equiv_address_nv (srcbase, src);

  offset = 0;

  /* Emit SImode moves */
  si_moves = count >> 2;
  for (i = 0; i < si_moves; i++)
    crx_expand_movmem_single (src, srcbase, dst, dstbase, tmp_reg, &offset);

  /* Special cases */
  if (count & 3)
    {
      offset = count - 4;
      crx_expand_movmem_single (src, srcbase, dst, dstbase, tmp_reg, &offset);
    }

  gcc_assert (offset == count);

  return 1;
}

rtx
crx_expand_compare (enum rtx_code code, enum machine_mode mode)
{
  rtx op0, op1, cc_reg, ret;

  op0 = crx_compare_op0;
  op1 = crx_compare_op1;

  /* Emit the compare that writes into CC_REGNUM) */
  cc_reg = gen_rtx_REG (CCmode, CC_REGNUM);
  ret = gen_rtx_COMPARE (CCmode, op0, op1);
  emit_insn (gen_rtx_SET (VOIDmode, cc_reg, ret));
  /* debug_rtx (get_last_insn ()); */

  /* Return the rtx for using the result in CC_REGNUM */
  return gen_rtx_fmt_ee (code, mode, cc_reg, const0_rtx);
}

void
crx_expand_branch (enum rtx_code code, rtx label)
{
  rtx tmp = crx_expand_compare (code, VOIDmode);
  tmp = gen_rtx_IF_THEN_ELSE (VOIDmode, tmp,
			      gen_rtx_LABEL_REF (VOIDmode, label),
			      pc_rtx);
  emit_jump_insn (gen_rtx_SET (VOIDmode, pc_rtx, tmp));
  /* debug_rtx (get_last_insn ()); */
}

void
crx_expand_scond (enum rtx_code code, rtx dest)
{
  rtx tmp = crx_expand_compare (code, GET_MODE (dest));
  emit_move_insn (dest, tmp);
  /* debug_rtx (get_last_insn ()); */
}

static void
mpushpop_str (char *stringbuffer, const char *mnemonic, char *mask)
{
  if (strlen (mask) > 2 || crx_interrupt_function_p ()) /* needs 2-word instr. */
    sprintf (stringbuffer, "\n\t%s\tsp, {%s}", mnemonic, mask);
  else /* single word instruction */
    sprintf (stringbuffer, "\n\t%s\t%s", mnemonic, mask);
}

/* Called from crx.md. The return value depends on the parameter push_or_pop:
 * When push_or_pop is zero -> string for push instructions of prologue.
 * When push_or_pop is nonzero -> string for pop/popret/retx in epilogue.
 * Relies on the assumptions:
 * 1. RA is the last register to be saved.
 * 2. The maximal value of the counter is MAX_COUNT. */

char *
crx_prepare_push_pop_string (int push_or_pop)
{
  /* j is the number of registers being saved, takes care that there won't be
   * more than 8 in one push/pop instruction */

  /* For the register mask string */
  static char mask_str[50];

  /* i is the index of save_regs[], going from 0 until last_reg_to_save */
  int i = 0;

  int ra_in_bitmask = 0;

  char *return_str;

  /* For reversing on the push instructions if there are more than one. */
  char *temp_str;

  return_str = (char *) xmalloc (120);
  temp_str = (char *) xmalloc (120);

  /* Initialize */
  memset (return_str, 0, 3);

  while (i <= last_reg_to_save)
    {
      /* Prepare mask for one instruction. */
      mask_str[0] = 0;

      if (i <= SP_REGNUM)
	{ /* Add regs unit full or SP register reached */
	  int j = 0;
	  while (j < MAX_COUNT && i <= SP_REGNUM)
	    {
	      if (save_regs[i])
		{
		  /* TODO to use ra_in_bitmask for detecting last pop is not
		   * smart it prevents things like:  popret r5 */
		  if (i == RETURN_ADDRESS_REGNUM) ra_in_bitmask = 1;
		  if (j > 0) strcat (mask_str, ", ");
		  strcat (mask_str, reg_names[i]);
		  ++j;
		}
	      ++i;
	    }
	}
      else
	{
	  /* Handle hi/lo savings */
	  while (i <= last_reg_to_save)
	    {
	      if (save_regs[i])
		{
		  strcat (mask_str, "lo, hi");
		  i = last_reg_to_save + 1;
		  break;
		}
	      ++i;
	    }
	}

      if (strlen (mask_str) == 0) continue;
       	
      if (push_or_pop == 1)
	{
	  if (crx_interrupt_function_p ())
	    mpushpop_str (temp_str, "popx", mask_str);
	  else
	    {
	      if (ra_in_bitmask)
		{
		  mpushpop_str (temp_str, "popret", mask_str);
		  ra_in_bitmask = 0;
		}
	      else mpushpop_str (temp_str, "pop", mask_str);
	    }

	  strcat (return_str, temp_str);
	}
      else
	{
	  /* push - We need to reverse the order of the instructions if there
	   * are more than one. (since the pop will not be reversed in the
	   * epilogue */
      	  if (crx_interrupt_function_p ())
	    mpushpop_str (temp_str, "pushx", mask_str);
	  else
	    mpushpop_str (temp_str, "push", mask_str);
	  strcat (temp_str, return_str);
	  strcpy (strcat (return_str, "\t"), temp_str);
	}

    }

  if (push_or_pop == 1)
    {
      /* pop */
      if (crx_interrupt_function_p ())
	strcat (return_str, "\n\tretx\n");

      else if (!FUNC_IS_NORETURN_P (current_function_decl)
	       && !save_regs[RETURN_ADDRESS_REGNUM])
	strcat (return_str, "\n\tjump\tra\n");
    }

  /* Skip the newline and the tab in the start of return_str. */
  return_str += 2;
  return return_str;
}

/*  CompactRISC CRX Architecture stack layout:

     0 +---------------------
	|
	.
	.
	|
	+==================== Sp(x)=Ap(x+1)
      A | Args for functions
      | | called by X and      Dynamically
      | | Dynamic allocations  allocated and
      | | (alloca, variable    deallocated
  Stack | length arrays).
  grows +-------------------- Fp(x)
  down| | Local variables of X
  ward| +--------------------
      | | Regs saved for X-1
      | +==================== Sp(x-1)=Ap(x)
	| Args for func X
	| pushed by X-1
	+-------------------- Fp(x-1)
	|
	|
	V

*/

void
crx_expand_prologue (void)
{
  crx_compute_frame ();
  crx_compute_save_regs ();

  /* If there is no need in push and adjustment to sp, return. */
  if (size_for_adjusting_sp + sum_regs == 0)
    return;

  if (last_reg_to_save != -1)
    /* If there are registers to push.  */
    emit_insn (gen_push_for_prologue (GEN_INT (sum_regs)));

  if (size_for_adjusting_sp > 0)
    emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx,
			   GEN_INT (-size_for_adjusting_sp)));

  if (frame_pointer_needed)
    /* Initialize the frame pointer with the value of the stack pointer
     * pointing now to the locals. */
    emit_move_insn (frame_pointer_rtx, stack_pointer_rtx);
}

/* Generate insn that updates the stack for local variables and padding for
 * registers we save. - Generate the appropriate return insn. */

void
crx_expand_epilogue (void)
{
  rtx return_reg;

  /* Nonzero if we need to return and pop only RA. This will generate a
   * different insn. This differentiate is for the peepholes for call as last
   * statement in function. */
  int only_popret_RA = (save_regs[RETURN_ADDRESS_REGNUM]
			&& (sum_regs == UNITS_PER_WORD));

  /* Return register.  */
  return_reg = gen_rtx_REG (Pmode, RETURN_ADDRESS_REGNUM);

  if (frame_pointer_needed)
    /* Restore the stack pointer with the frame pointers value */
    emit_move_insn (stack_pointer_rtx, frame_pointer_rtx);

  if (size_for_adjusting_sp > 0)
    emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx,
			   GEN_INT (size_for_adjusting_sp)));

  if (crx_interrupt_function_p ())
    emit_jump_insn (gen_interrupt_return ());
  else if (last_reg_to_save == -1)
    /* Nothing to pop */
    /* Don't output jump for interrupt routine, only retx.  */
    emit_jump_insn (gen_indirect_jump_return ());
  else if (only_popret_RA)
    emit_jump_insn (gen_popret_RA_return ());
  else
    emit_jump_insn (gen_pop_and_popret_return (GEN_INT (sum_regs)));
}