dsp16xx.c

gcc-you can use this code to learn something about gcc, and inquire further into linux,

	      cc_status.value2 = SET_DEST (exp);
	      break;
	      
	    default:
	      CC_STATUS_INIT;
	    }
	else
	{
	    CC_STATUS_INIT;
	}
    }
    else if (GET_CODE (exp) == PARALLEL
	     && GET_CODE (XVECEXP (exp, 0, 0)) == SET)
    {
	if (SET_DEST (XVECEXP (exp, 0, 0)) == pc_rtx)
	    return;

	if (SET_DEST (XVECEXP (exp, 0, 0)) == cc0_rtx)
	{
	    CC_STATUS_INIT;
	    cc_status.value1 = SET_SRC (XVECEXP (exp, 0, 0));
	    return;
	}

	CC_STATUS_INIT;
    }
    else
    {
	CC_STATUS_INIT;
    }
}

int
dsp16xx_makes_calls ()
{
  rtx insn;

  for (insn = get_insns (); insn; insn = next_insn (insn))
    if (GET_CODE (insn) == CALL_INSN)
      return (1);

  return 0;
}

long
compute_frame_size (size)
     int size;
{
  long total_size;
  long var_size;
  long args_size;
  long extra_size;
  long reg_size;

  /* This value is needed to compute reg_size.  */
  current_frame_info.function_makes_calls = !leaf_function_p ();

  reg_size = 0;
  extra_size = 0;
  var_size = size;
  args_size = current_function_outgoing_args_size;
  reg_size = reg_save_size ();  

  total_size = var_size + args_size + extra_size + reg_size;


  /* Save other computed information.  */
  current_frame_info.total_size  = total_size;
  current_frame_info.var_size    = var_size;
  current_frame_info.args_size   = args_size;
  current_frame_info.extra_size  = extra_size;
  current_frame_info.reg_size    = reg_size;
  current_frame_info.initialized = reload_completed;
  current_frame_info.reg_size	 = reg_size / UNITS_PER_WORD;

  if (reg_size)
    {
      unsigned long offset = args_size + var_size + reg_size;
      current_frame_info.sp_save_offset = offset;
      current_frame_info.fp_save_offset = offset - total_size;
    }

  return total_size;
}

int
dsp16xx_call_saved_register (regno)
     int regno;
{
#if 0
  if (regno == REG_PR && current_frame_info.function_makes_calls)
    return 1;
#endif
  return (regs_ever_live[regno] && !call_used_regs[regno] &&
	  !IS_YBASE_REGISTER_WINDOW(regno));
}

int
ybase_regs_ever_used ()
{
  int regno;
  int live = 0;

  for (regno = REG_YBASE0; regno <= REG_YBASE31; regno++)
    if (regs_ever_live[regno])
      {
	live = 1;
	break;
      }

  return live;
}

static void 
dsp16xx_output_function_prologue (file, size)
     FILE *file;
     HOST_WIDE_INT size;
{
  int regno;
  long total_size;
  fp = reg_names[FRAME_POINTER_REGNUM];
  sp = reg_names[STACK_POINTER_REGNUM];
  rr = reg_names[RETURN_ADDRESS_REGNUM];   /* return address register */
  a1h = reg_names[REG_A1];
  
  total_size = compute_frame_size (size);
  
  fprintf (file, "\t/* FUNCTION PROLOGUE: */\n");
  fprintf (file, "\t/* total=%ld, vars= %ld, regs= %d, args=%d, extra= %ld */\n",
	   current_frame_info.total_size,
	   current_frame_info.var_size,
	   current_frame_info.reg_size,
	   current_function_outgoing_args_size,
	   current_frame_info.extra_size);
  
  fprintf (file, "\t/* fp save offset= %ld, sp save_offset= %ld */\n\n",
	   current_frame_info.fp_save_offset,
	   current_frame_info.sp_save_offset);
  /* Set up the 'ybase' register window.  */
  
  if (ybase_regs_ever_used())
    {
      fprintf (file, "\t%s=%s\n", a1h, reg_names[REG_YBASE]);
      if (TARGET_YBASE_HIGH)
	fprintf (file, "\t%s=%sh-32\n", reg_names[REG_A1], a1h);
      else
	fprintf (file, "\t%s=%sh+32\n", reg_names[REG_A1], a1h);
      fprintf (file, "\t%s=%s\n", reg_names[REG_YBASE], a1h);
    }
  
  if (current_frame_info.var_size)
    {
      if (current_frame_info.var_size == 1)
	fprintf (file, "\t*%s++\n", sp);
      else
        {
	  if (SMALL_INTVAL(current_frame_info.var_size) && ((current_frame_info.var_size & 0x8000) == 0))
	    fprintf (file, "\t%s=%ld\n\t*%s++%s\n", reg_names[REG_J], current_frame_info.var_size, sp, reg_names[REG_J]);
	  else
	    fatal_error ("stack size > 32k");
	}
    }
  
  /* Save any registers this function uses, unless they are
     used in a call, in which case we don't need to.  */
  
  for(regno = 0; regno < FIRST_PSEUDO_REGISTER; ++ regno)
    if (dsp16xx_call_saved_register (regno)) 
      {
	fprintf (file, "\tpush(*%s)=%s\n", sp, reg_names[regno]);
      }

  /* For debugging purposes, we want the return address to be at a predictable
     location.  */
  if (current_frame_info.function_makes_calls)
    fprintf (file, "\tpush(*%s)=%s\n", sp, reg_names[RETURN_ADDRESS_REGNUM]);

  if (current_frame_info.args_size)
    {
      if (current_frame_info.args_size == 1)
	fprintf (file, "\t*%s++\n", sp);
      else
	error ("stack size > 32k");
    }
   
  if (frame_pointer_needed)
    {
      fprintf (file, "\t%s=%s\n", a1h, sp);
      fprintf (file, "\t%s=%s\n", fp, a1h);  /* Establish new base frame */
      fprintf (file, "\t%s=%ld\n", reg_names[REG_J], -total_size);
      fprintf (file, "\t*%s++%s\n", fp, reg_names[REG_J]);
    }
  
  fprintf (file, "\t/* END FUNCTION PROLOGUE: */\n\n");
}

void
init_emulation_routines ()
{
 dsp16xx_addhf3_libcall = (rtx) 0;
 dsp16xx_subhf3_libcall = (rtx) 0;
 dsp16xx_mulhf3_libcall = (rtx) 0;
 dsp16xx_divhf3_libcall = (rtx) 0;
 dsp16xx_cmphf3_libcall = (rtx) 0;
 dsp16xx_fixhfhi2_libcall = (rtx) 0;
 dsp16xx_floathihf2_libcall = (rtx) 0;
 dsp16xx_neghf2_libcall = (rtx) 0;

 dsp16xx_mulhi3_libcall = (rtx) 0;
 dsp16xx_udivqi3_libcall = (rtx) 0;
 dsp16xx_udivhi3_libcall = (rtx) 0;
 dsp16xx_divqi3_libcall = (rtx) 0;
 dsp16xx_divhi3_libcall = (rtx) 0;
 dsp16xx_modqi3_libcall = (rtx) 0;
 dsp16xx_modhi3_libcall = (rtx) 0;
 dsp16xx_umodqi3_libcall = (rtx) 0;
 dsp16xx_umodhi3_libcall = (rtx) 0;
 dsp16xx_ashrhi3_libcall = (rtx) 0;
 dsp16xx_ashlhi3_libcall = (rtx) 0;
 dsp16xx_ucmphi2_libcall = (rtx) 0;
 dsp16xx_lshrhi3_libcall = (rtx) 0;

}
static void
dsp16xx_output_function_epilogue (file, size)
     FILE *file;
     HOST_WIDE_INT size ATTRIBUTE_UNUSED;
{
  int regno;
  
  fp = reg_names[FRAME_POINTER_REGNUM];
  sp = reg_names[STACK_POINTER_REGNUM];
  rr = reg_names[RETURN_ADDRESS_REGNUM];   /* return address register */
  a1h = reg_names[REG_A1];
  
  fprintf (file, "\n\t/* FUNCTION EPILOGUE: */\n");
  
  if (current_frame_info.args_size)
    {
      if (current_frame_info.args_size == 1)
	fprintf (file, "\t*%s--\n", sp);
      else
	{
	  fprintf (file, "\t%s=%ld\n\t*%s++%s\n", 
		   reg_names[REG_J], -current_frame_info.args_size, sp, reg_names[REG_J]);
	}
    }
  
  if (ybase_regs_ever_used())
    {
      fprintf (file, "\t%s=%s\n", a1h, reg_names[REG_YBASE]);
      if (TARGET_YBASE_HIGH)
	fprintf (file, "\t%s=%sh+32\n", reg_names[REG_A1], a1h);
      else
	fprintf (file, "\t%s=%sh-32\n", reg_names[REG_A1], a1h);
      fprintf (file, "\t%s=%s\n", reg_names[REG_YBASE], a1h);
    }

  if (current_frame_info.function_makes_calls)
    fprintf (file, "\t%s=pop(*%s)\n", reg_names[RETURN_ADDRESS_REGNUM], sp);
  
  for (regno = FIRST_PSEUDO_REGISTER - 1; regno >= 0; --regno)
    if (dsp16xx_call_saved_register(regno))
      {
	fprintf (file, "\t%s=pop(*%s)\n", reg_names[regno], sp);
      }
  
  if (current_frame_info.var_size)
    {
      if (current_frame_info.var_size == 1)
	fprintf (file, "\t*%s--\n", sp);
      else
	{
	  fprintf (file, "\t%s=%ld\n\t*%s++%s\n", 
		   reg_names[REG_J], -current_frame_info.var_size, sp, reg_names[REG_J]);
	}
    }
  
  fprintf (file, "\treturn\n");
  /* Reset the frame info for the next function.  */
  current_frame_info = zero_frame_info;
  init_emulation_routines ();
}

/* Emit insns to move operands[1] into operands[0].

   Return 1 if we have written out everything that needs to be done to
   do the move.  Otherwise, return 0 and the caller will emit the move
   normally.  */

int
emit_move_sequence (operands, mode)
     rtx *operands;
     enum machine_mode mode;
{
  register rtx operand0 = operands[0];
  register rtx operand1 = operands[1];

  /* We can only store registers to memory.  */

  if (GET_CODE (operand0) == MEM && GET_CODE (operand1) != REG)
    operands[1] = force_reg (mode, operand1);

  return 0;
}

void
double_reg_from_memory (operands)
     rtx operands[];
{
    rtx xoperands[4];

    if (GET_CODE(XEXP(operands[1],0)) == POST_INC)
    {
	output_asm_insn ("%u0=%1", operands);
	output_asm_insn ("%w0=%1", operands);
    }
    else if (GET_CODE(XEXP(operands[1],0)) == POST_DEC)
    {
	xoperands[1] = XEXP (XEXP (operands[1], 0), 0);
	xoperands[0] = operands[0];
	
	/* We can't use j anymore since the compiler can allocate it.  */
/*	output_asm_insn ("j=-3\n\t%u0=*%1++\n\t%w0=*%1++j", xoperands); */
	output_asm_insn ("%u0=*%1++\n\t%w0=*%1--\n\t*%1--\n\t*%1--", xoperands);
    }
    else if (GET_CODE(XEXP(operands[1],0)) == PLUS)
    {
      rtx addr;
      int offset = 0;

      output_asm_insn ("%u0=%1", operands);


      /* In order to print out the least significant word we must
	 use 'offset + 1'.  */
      addr = XEXP (operands[1], 0);
      if (GET_CODE (XEXP(addr,0)) == CONST_INT)
	offset = INTVAL(XEXP(addr,0)) + 1;
      else if (GET_CODE (XEXP(addr,1)) == CONST_INT)
	offset = INTVAL(XEXP(addr,1)) + 1;

      fprintf (asm_out_file, "\t%s=*(%d)\n", reg_names[REGNO(operands[0]) + 1], offset + 31);
    }
    else
    {
	xoperands[1] = XEXP(operands[1],0);
	xoperands[0] = operands[0];

	output_asm_insn ("%u0=*%1++\n\t%w0=*%1--", xoperands);
    }
}


void
double_reg_to_memory (operands)
     rtx operands[];
{
    rtx xoperands[4];

    if (GET_CODE(XEXP(operands[0],0)) == POST_INC)
    {
	output_asm_insn ("%0=%u1", operands);
	output_asm_insn ("%0=%w1", operands);
    }
    else if (GET_CODE(XEXP(operands[0],0)) == POST_DEC)
    {
	xoperands[0] = XEXP (XEXP (operands[0], 0), 0);
	xoperands[1] = operands[1];
	
	/* We can't use j anymore since the compiler can allocate it.  */

/*	output_asm_insn ("j=-3\n\t*%0++=%u1\n\t*%0++j=%w1", xoperands); */
	output_asm_insn ("*%0++=%u1\n\t*%0--=%w1\n\t*%0--\n\t*%0--", xoperands);

    }
    else if (GET_CODE(XEXP(operands[0],0)) == PLUS)
    {
      rtx addr;
      int offset = 0;

      output_asm_insn ("%0=%u1", operands);

      /* In order to print out the least significant word we must
	 use 'offset + 1'.  */
      addr = XEXP (operands[0], 0);
      if (GET_CODE (XEXP(addr,0)) == CONST_INT)
	offset = INTVAL(XEXP(addr,0)) + 1;
      else if (GET_CODE (XEXP(addr,1)) == CONST_INT)
	offset = INTVAL(XEXP(addr,1)) + 1;
      else
	fatal_error ("invalid addressing mode");

      fprintf (asm_out_file, "\t*(%d)=%s\n", offset + 31, reg_names[REGNO(operands[1]) + 1]);
    }
    else
    {
	xoperands[0] = XEXP(operands[0],0);
	xoperands[1] = operands[1];

	output_asm_insn ("*%0++=%u1\n\t*%0--=%w1", xoperands);
    }
}

void
override_options ()
{
  if (chip_name == (char *) 0)
    chip_name = DEFAULT_CHIP_NAME;

  if (text_seg_name == (char *) 0)
    text_seg_name = DEFAULT_TEXT_SEG_NAME;
  
  if (data_seg_name == (char *) 0)
    data_seg_name = DEFAULT_DATA_SEG_NAME;
  
  if (bss_seg_name == (char *) 0)
    bss_seg_name = DEFAULT_BSS_SEG_NAME;
  
  if (const_seg_name == (char *) 0)
    const_seg_name = DEFAULT_CONST_SEG_NAME;
  
  save_chip_name = xstrdup (chip_name);

  rsect_text = concat (".rsect \"", text_seg_name, "\"", NULL);
  rsect_data = concat (".rsect \"", data_seg_name, "\"", NULL);
  rsect_bss = concat (".rsect \"", bss_seg_name, "\"", NULL);
  rsect_const = concat (".rsect \"", const_seg_name, "\"", NULL);
}

int
next_cc_user_unsigned (insn)
     rtx insn;
{
  switch (next_cc_user_code (insn))
    {
    case GTU:
    case GEU:
    case LTU:
    case LEU:
      return 1;
    default:
      return 0;
    }
}

enum rtx_code
next_cc_user_code (insn)
     rtx insn;
{
  /* If no insn could be found we assume that the jump has been
     deleted and the compare will be deleted later.  */

  if (!(insn = next_cc0_user (insn)))
    return (enum rtx_code) 0;
  else if (GET_CODE (insn) == JUMP_INSN
	   && GET_CODE (PATTERN (insn)) == SET
	   && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
    return GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 0));
  else if (GET_CODE (insn) == INSN
	   && GET_CODE (PATTERN (insn)) == SET
	   && comparison_operator (SET_SRC (PATTERN (insn)), VOIDmode))
    return GET_CODE (SET_SRC (PATTERN (insn)));
  else
    abort ();
}

void
print_operand(file, op, letter)
     FILE *file;
     rtx op;
     int letter;
{
    enum rtx_code code;

    code = GET_CODE(op);

    switch (letter)
    {
       case 'I':
	  code = reverse_condition (code);
	  /* Fallthrough */

       case 'C':
          if (code == EQ) 
          { 
	      fputs ("eq", file); 
	      return; 
	  }
          else if (code == NE)  
	  { 
	      fputs ("ne", file); 
	      return; 
	  }
          else if (code == GT || code == GTU)  
	  { 
	      fputs ("gt", file); 
	      return; 
	  }
          else if (code == LT || code == LTU)  
	  { 
	      fputs ("mi", file); 
	      return; 
	  }
          else if (code == GE || code == GEU)  
	  {
	      fputs ("pl", file); 
	      return; 
	  }
          else if (code == LE || code == LEU)  
	  { 
	      fputs ("le", file); 
	      return; 
	  }
          else 
	      abort ();
	  break;

       default:
          break;  
    }

    if (code == REG)
    {
	/* Print the low half of a 32-bit register pair.  */
        if (letter == 'w')
           fprintf (file, "%s", reg_names[REGNO (op) + 1]);
        else if (letter == 'u' || !letter)
           fprintf (file, "%s", reg_names[REGNO (op)]);
	else if (letter == 'b')
	    fprintf (file, "%sh", reg_names[REGNO (op)]);
	else if (letter == 'm')
	  fprintf (file, "%s", himode_reg_name[REGNO (op)]);
        else
	  output_operand_lossage ("bad register extension code");
    }
    else if (code == MEM)
      output_address (XEXP(op,0));
    else if (code == CONST_INT)
      { 
	HOST_WIDE_INT val = INTVAL (op);

        if (letter == 'H')
	  fprintf (file, HOST_WIDE_INT_PRINT_HEX, val & 0xffff);
	else if (letter == 'h')
	  fprintf (file, HOST_WIDE_INT_PRINT_DEC, val);
        else if (letter == 'U')
	  fprintf (file, HOST_WIDE_INT_PRINT_HEX, (val >> 16) & 0xffff);
        else
           output_addr_const(file, op);
      }
    else if (code == CONST_DOUBLE && GET_MODE(op) != DImode)
      {
	long l;
	REAL_VALUE_TYPE r;
	REAL_VALUE_FROM_CONST_DOUBLE (r, op);
	REAL_VALUE_TO_TARGET_SINGLE (r, l);
	fprintf (file, "0x%lx", l);
      }
    else if (code == CONST)
      {
	rtx addr = XEXP (op, 0);
	
	if (GET_CODE (addr) != PLUS)
	  {
	    output_addr_const(file, op);
	    return;
	  }
	
	if ((GET_CODE (XEXP (addr, 0)) == SYMBOL_REF
	     || GET_CODE (XEXP (addr, 0)) == LABEL_REF)
	    && (GET_CODE (XEXP (addr, 1)) == CONST_INT))
	  {
	    int n = INTVAL (XEXP(addr, 1));
	    output_addr_const (file, XEXP (addr, 0));
	    
	    if (n >= 0)
	      fprintf (file, "+");
	    
	    n = (int) (short) n;
	    fprintf (file, "%d", n);
	  }
	else if ((GET_CODE (XEXP (addr, 1)) == SYMBOL_REF
		  || GET_CODE (XEXP (addr, 1)) == LABEL_REF)
		 && (GET_CODE (XEXP (addr, 0)) == CONST_INT))
	  {
	    int n = INTVAL (XEXP(addr, 0));
	    output_addr_const (file, XEXP (addr, 1));
	    
	    if (n >= 0)
	      fprintf (file, "+");
	    
	    n = (int) (short) n;
	    fprintf (file, "%d", n);
	  }
	else
	  output_addr_const(file, op);
      }
    else
      output_addr_const (file, op);
}


void
print_operand_address(file, addr)
     FILE *file;
     rtx addr;
{
  rtx base;
  int offset = 0;;
  
  switch (GET_CODE (addr))
    {
    case REG:
      fprintf (file, "*%s", reg_names[REGNO (addr)]);
      break;
    case POST_DEC:
      fprintf (file, "*%s--", reg_names[REGNO (XEXP (addr, 0))]);
      break;
    case POST_INC:
      fprintf (file, "*%s++", reg_names[REGNO (XEXP (addr, 0))]);
      break;
    case PLUS:
      if (GET_CODE (XEXP(addr,0)) == CONST_INT)
	offset = INTVAL(XEXP(addr,0)), base = XEXP(addr,1);
      else if (GET_CODE (XEXP(addr,1)) == CONST_INT)
	offset = INTVAL(XEXP(addr,1)), base = XEXP(addr,0);
      else
	abort();
      if (GET_CODE (base) == REG && REGNO(base) == STACK_POINTER_REGNUM)
	{
	  if (offset >= -31 && offset <= 0)
	    offset = 31 + offset;
	  else
	    fatal_error ("invalid offset in ybase addressing");
	}
      else
	fatal_error ("invalid register in ybase addressing");
      
      fprintf (file, "*(%d)", offset);
      break;
      
    default: