m32r.c

Mac OS X 10.4.9 for x86 Source Code gcc 实现源代码

      /* If the last insn was a BARRIER, we don't have to write any code
	 because a jump (aka return) was put there.  */
      if (GET_CODE (insn) == NOTE)
	insn = prev_nonnote_insn (insn);
      if (insn && GET_CODE (insn) == BARRIER)
	noepilogue = TRUE;
    }

  if (!noepilogue)
    {
      unsigned int var_size = current_frame_info.var_size;
      unsigned int args_size = current_frame_info.args_size;
      unsigned int gmask = current_frame_info.gmask;
      int can_trust_sp_p = !current_function_calls_alloca;
      const char * sp_str = reg_names[STACK_POINTER_REGNUM];
      const char * fp_str = reg_names[FRAME_POINTER_REGNUM];

      /* The first thing to do is point the sp at the bottom of the register
	 save area.  */
      if (can_trust_sp_p)
	{
	  unsigned int reg_offset = var_size + args_size;
	  if (reg_offset == 0)
	    ; /* Nothing to do.  */
	  else if (reg_offset < 128)
	    fprintf (file, "\taddi %s,%s%d\n",
		     sp_str, IMMEDIATE_PREFIX, reg_offset);
	  else if (reg_offset < 32768)
	    fprintf (file, "\tadd3 %s,%s,%s%d\n",
		     sp_str, sp_str, IMMEDIATE_PREFIX, reg_offset);
	  else
	    fprintf (file, "\tld24 %s,%s%d\n\tadd %s,%s\n",
		     reg_names[PROLOGUE_TMP_REGNUM],
		     IMMEDIATE_PREFIX, reg_offset,
		     sp_str, reg_names[PROLOGUE_TMP_REGNUM]);
	}
      else if (frame_pointer_needed)
	{
	  unsigned int reg_offset = var_size + args_size;

	  if (reg_offset == 0)
	    fprintf (file, "\tmv %s,%s\n", sp_str, fp_str);
	  else if (reg_offset < 32768)
	    fprintf (file, "\tadd3 %s,%s,%s%d\n",
		     sp_str, fp_str, IMMEDIATE_PREFIX, reg_offset);
	  else
	    fprintf (file, "\tld24 %s,%s%d\n\tadd %s,%s\n",
		     reg_names[PROLOGUE_TMP_REGNUM],
		     IMMEDIATE_PREFIX, reg_offset,
		     sp_str, reg_names[PROLOGUE_TMP_REGNUM]);
	}
      else
	abort ();

      if (current_frame_info.save_lr)
	fprintf (file, "\tpop %s\n", reg_names[RETURN_ADDR_REGNUM]);

      /* Restore any saved registers, in reverse order of course.  */
      gmask &= ~(FRAME_POINTER_MASK | RETURN_ADDR_MASK);
      for (regno = M32R_MAX_INT_REGS - 1; regno >= 0; --regno)
	{
	  if ((gmask & (1L << regno)) != 0)
	    fprintf (file, "\tpop %s\n", reg_names[regno]);
	}

      if (current_frame_info.save_fp)
	fprintf (file, "\tpop %s\n", fp_str);

      /* Remove varargs area if present.  */
      if (current_frame_info.pretend_size != 0)
	fprintf (file, "\taddi %s,%s%d\n",
		 sp_str, IMMEDIATE_PREFIX, current_frame_info.pretend_size);
	
      /* Emit the return instruction.  */
      if (M32R_INTERRUPT_P (fn_type))
	fprintf (file, "\trte\n");
      else
	fprintf (file, "\tjmp %s\n", reg_names[RETURN_ADDR_REGNUM]);
    }

  /* Reset state info for each function.  */
  current_frame_info = zero_frame_info;
  m32r_compute_function_type (NULL_TREE);
}

/* Return nonzero if this function is known to have a null or 1 instruction
   epilogue.  */

int
direct_return (void)
{
  if (!reload_completed)
    return FALSE;

  if (! current_frame_info.initialized)
    m32r_compute_frame_size (get_frame_size ());

   return current_frame_info.total_size == 0;
}


/* PIC.  */

int
m32r_legitimate_pic_operand_p (rtx x)
{
  if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
    return 0;
                                                                                
  if (GET_CODE (x) == CONST
      && GET_CODE (XEXP (x, 0)) == PLUS
      && (GET_CODE (XEXP (XEXP (x, 0), 0)) == SYMBOL_REF
          || GET_CODE (XEXP (XEXP (x, 0), 0)) == LABEL_REF)
      && (GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
    return 0;
                                                                                
  return 1;
}

rtx
m32r_legitimize_pic_address (rtx orig, rtx reg)
{
#ifdef DEBUG_PIC
  printf("m32r_legitimize_pic_address()\n");
#endif

  if (GET_CODE (orig) == SYMBOL_REF || GET_CODE (orig) == LABEL_REF)
    {
      rtx pic_ref, address;
      rtx insn;
      int subregs = 0;

      if (reg == 0)
        {
          if (reload_in_progress || reload_completed)
            abort ();
          else
            reg = gen_reg_rtx (Pmode);

          subregs = 1;
        }

      if (subregs)
        address = gen_reg_rtx (Pmode);
      else
        address = reg;

      current_function_uses_pic_offset_table = 1;

      if (GET_CODE (orig) == LABEL_REF
          || (GET_CODE (orig) == SYMBOL_REF && SYMBOL_REF_LOCAL_P (orig)))
        {
          emit_insn (gen_gotoff_load_addr (reg, orig));
          emit_insn (gen_addsi3 (reg, reg, pic_offset_table_rtx));
          return reg;
        }

      emit_insn (gen_pic_load_addr (address, orig));

      emit_insn (gen_addsi3 (address, address, pic_offset_table_rtx));
      pic_ref = gen_const_mem (Pmode, address);
      insn = emit_move_insn (reg, pic_ref);
#if 0
      /* Put a REG_EQUAL note on this insn, so that it can be optimized
         by loop.  */
      REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUAL, orig,
                  REG_NOTES (insn));
#endif
      return reg;
    }
  else if (GET_CODE (orig) == CONST)
    {
      rtx base, offset;

      if (GET_CODE (XEXP (orig, 0)) == PLUS
          && XEXP (XEXP (orig, 0), 1) == pic_offset_table_rtx)
        return orig;

      if (reg == 0)
        {
          if (reload_in_progress || reload_completed)
            abort ();
          else
            reg = gen_reg_rtx (Pmode);
        }

      if (GET_CODE (XEXP (orig, 0)) == PLUS)
        {
          base = m32r_legitimize_pic_address (XEXP (XEXP (orig, 0), 0), reg);
          if (base == reg)
            offset = m32r_legitimize_pic_address (XEXP (XEXP (orig, 0), 1), NULL_RTX);
          else
            offset = m32r_legitimize_pic_address (XEXP (XEXP (orig, 0), 1), reg);
        }
      else
        return orig;

      if (GET_CODE (offset) == CONST_INT)
        {
          if (INT16_P (INTVAL (offset)))
            return plus_constant (base, INTVAL (offset));
          else if (! reload_in_progress && ! reload_completed)
            offset = force_reg (Pmode, offset);
          else
            /* If we reach here, then something is seriously wrong.  */
            abort ();
        }

      return gen_rtx_PLUS (Pmode, base, offset);
    }

  return orig;
}

/* Emit special PIC prologues and epilogues.  */

void
m32r_finalize_pic (void)
{
  current_function_uses_pic_offset_table |= current_function_profile;
}

/* Nested function support.  */

/* Emit RTL insns to initialize the variable parts of a trampoline.
   FNADDR is an RTX for the address of the function's pure code.
   CXT is an RTX for the static chain value for the function.  */

void
m32r_initialize_trampoline (rtx tramp ATTRIBUTE_UNUSED,
			    rtx fnaddr ATTRIBUTE_UNUSED,
			    rtx cxt ATTRIBUTE_UNUSED)
{
}

static void
m32r_file_start (void)
{
  default_file_start ();

  if (flag_verbose_asm)
    fprintf (asm_out_file,
	     "%s M32R/D special options: -G " HOST_WIDE_INT_PRINT_UNSIGNED "\n",
	     ASM_COMMENT_START, g_switch_value);

  if (TARGET_LITTLE_ENDIAN)
    fprintf (asm_out_file, "\t.little\n");
}

/* Print operand X (an rtx) in assembler syntax to file FILE.
   CODE is a letter or dot (`z' in `%z0') or 0 if no letter was specified.
   For `%' followed by punctuation, CODE is the punctuation and X is null.  */

void
m32r_print_operand (FILE * file, rtx x, int code)
{
  rtx addr;

  switch (code)
    {
      /* The 's' and 'p' codes are used by output_block_move() to
	 indicate post-increment 's'tores and 'p're-increment loads.  */
    case 's':
      if (GET_CODE (x) == REG)
	fprintf (file, "@+%s", reg_names [REGNO (x)]);
      else
	output_operand_lossage ("invalid operand to %%s code");
      return;
      
    case 'p':
      if (GET_CODE (x) == REG)
	fprintf (file, "@%s+", reg_names [REGNO (x)]);
      else
	output_operand_lossage ("invalid operand to %%p code");
      return;

    case 'R' :
      /* Write second word of DImode or DFmode reference,
	 register or memory.  */
      if (GET_CODE (x) == REG)
	fputs (reg_names[REGNO (x)+1], file);
      else if (GET_CODE (x) == MEM)
	{
	  fprintf (file, "@(");
	  /* Handle possible auto-increment.  Since it is pre-increment and
	     we have already done it, we can just use an offset of four.  */
	  /* ??? This is taken from rs6000.c I think.  I don't think it is
	     currently necessary, but keep it around.  */
	  if (GET_CODE (XEXP (x, 0)) == PRE_INC
	      || GET_CODE (XEXP (x, 0)) == PRE_DEC)
	    output_address (plus_constant (XEXP (XEXP (x, 0), 0), 4));
	  else
	    output_address (plus_constant (XEXP (x, 0), 4));
	  fputc (')', file);
	}
      else
	output_operand_lossage ("invalid operand to %%R code");
      return;

    case 'H' : /* High word.  */
    case 'L' : /* Low word.  */
      if (GET_CODE (x) == REG)
	{
	  /* L = least significant word, H = most significant word.  */
	  if ((WORDS_BIG_ENDIAN != 0) ^ (code == 'L'))
	    fputs (reg_names[REGNO (x)], file);
	  else
	    fputs (reg_names[REGNO (x)+1], file);
	}
      else if (GET_CODE (x) == CONST_INT
	       || GET_CODE (x) == CONST_DOUBLE)
	{
	  rtx first, second;

	  split_double (x, &first, &second);
	  fprintf (file, HOST_WIDE_INT_PRINT_HEX,
		   code == 'L' ? INTVAL (first) : INTVAL (second));
	}
      else
	output_operand_lossage ("invalid operand to %%H/%%L code");
      return;

    case 'A' :
      {
	char str[30];

	if (GET_CODE (x) != CONST_DOUBLE
	    || GET_MODE_CLASS (GET_MODE (x)) != MODE_FLOAT)
	  fatal_insn ("bad insn for 'A'", x);

	real_to_decimal (str, CONST_DOUBLE_REAL_VALUE (x), sizeof (str), 0, 1);
	fprintf (file, "%s", str);
	return;
      }

    case 'B' : /* Bottom half.  */
    case 'T' : /* Top half.  */
      /* Output the argument to a `seth' insn (sets the Top half-word).
	 For constants output arguments to a seth/or3 pair to set Top and
	 Bottom halves.  For symbols output arguments to a seth/add3 pair to
	 set Top and Bottom halves.  The difference exists because for
	 constants seth/or3 is more readable but for symbols we need to use
	 the same scheme as `ld' and `st' insns (16 bit addend is signed).  */
      switch (GET_CODE (x))
	{
	case CONST_INT :
	case CONST_DOUBLE :
	  {
	    rtx first, second;

	    split_double (x, &first, &second);
	    x = WORDS_BIG_ENDIAN ? second : first;
	    fprintf (file, HOST_WIDE_INT_PRINT_HEX,
		     (code == 'B'
		      ? INTVAL (x) & 0xffff
		      : (INTVAL (x) >> 16) & 0xffff));
	  }
	  return;
	case CONST :
	case SYMBOL_REF :
	  if (code == 'B'
	      && small_data_operand (x, VOIDmode))
	    {
	      fputs ("sda(", file);
	      output_addr_const (file, x);
	      fputc (')', file);
	      return;
	    }
	  /* fall through */
	case LABEL_REF :
	  fputs (code == 'T' ? "shigh(" : "low(", file);
	  output_addr_const (file, x);
	  fputc (')', file);
	  return;
	default :
	  output_operand_lossage ("invalid operand to %%T/%%B code");
	  return;
	}
      break;

    case 'U' :
      /* ??? wip */
      /* Output a load/store with update indicator if appropriate.  */
      if (GET_CODE (x) == MEM)
	{
	  if (GET_CODE (XEXP (x, 0)) == PRE_INC
	      || GET_CODE (XEXP (x, 0)) == PRE_DEC)
	    fputs (".a", file);
	}
      else
	output_operand_lossage ("invalid operand to %%U code");
      return;

    case 'N' :
      /* Print a constant value negated.  */
      if (GET_CODE (x) == CONST_INT)
	output_addr_const (file, GEN_INT (- INTVAL (x)));
      else
	output_operand_lossage ("invalid operand to %%N code");
      return;

    case 'X' :
      /* Print a const_int in hex.  Used in comments.  */
      if (GET_CODE (x) == CONST_INT)
	fprintf (file, HOST_WIDE_INT_PRINT_HEX, INTVAL (x));
      return;

    case '#' :
      fputs (IMMEDIATE_PREFIX, file);
      return;

    case 0 :
      /* Do nothing special.  */
      break;

    default :
      /* Unknown flag.  */
      output_operand_lossage ("invalid operand output code");
    }

  switch (GET_CODE (x))
    {
    case REG :
      fputs (reg_names[REGNO (x)], file);
      break;

    case MEM :
      addr = XEXP (x, 0);
      if (GET_CODE (addr) == PRE_INC)
	{
	  if (GET_CODE (XEXP (addr, 0)) != REG)
	    fatal_insn ("pre-increment address is not a register", x);

	  fprintf (file, "@+%s", reg_names[REGNO (XEXP (addr, 0))]);
	}
      else if (GET_CODE (addr) == PRE_DEC)
	{
	  if (GET_CODE (XEXP (addr, 0)) != REG)
	    fatal_insn ("pre-decrement address is not a register", x);

	  fprintf (file, "@-%s", reg_names[REGNO (XEXP (addr, 0))]);
	}
      else if (GET_CODE (addr) == POST_INC)
	{
	  if (GET_CODE (XEXP (addr, 0)) != REG)
	    fatal_insn ("post-increment address is not a register", x);

	  fprintf (file, "@%s+", reg_names[REGNO (XEXP (addr, 0))]);
	}
      else
	{
	  fputs ("@(", file);
	  output_address (XEXP (x, 0));
	  fputc (')', file);
	}
      break;

    case CONST_DOUBLE :
      /* We handle