i370.c

linux下的gcc编译器

      mvs_page_code = code;
      mvs_page_lit = lit;
      return 1;
    }
  mvs_page_code += code;
  mvs_page_lit += lit;
  return 0;
}
#endif /* TARGET_HLASM */


#ifdef TARGET_ELF_ABI
int
mvs_check_page (file, code, lit)
     FILE *file;
     int code, lit;
{
  if (file)
    assembler_source = file;

  if (mvs_page_code + code + mvs_page_lit + lit > MAX_MVS_PAGE_LENGTH)
    {
      /* hop past the literal pool */
      fprintf (assembler_source, "\tB\t.LPGE%d\n", mvs_page_num);

      /* dump the literal pool. The .baligns are optional, since 
       * ltorg will align to the size of the largest literal 
       * (which is possibly 8 bytes) */
      fprintf (assembler_source, "\t.balign\t4\n");
      fprintf (assembler_source, "\t.LTORG\n");
      fprintf (assembler_source, "\t.balign\t4\n");

      /* we continue execution here ...  */
      fprintf (assembler_source, ".LPGE%d:\n", mvs_page_num);
      fprintf (assembler_source, "\t.DROP\t%d\n", BASE_REGISTER);
      mvs_page_num++;

      /* BASR puts the contents of the PSW into r3
       * that is, r3 will be loaded with the address of "." */
      fprintf (assembler_source, "\tBASR\tr%d,0\n", BASE_REGISTER);
      fprintf (assembler_source, ".LPG%d:\n", mvs_page_num);
      fprintf (assembler_source, "\t.USING\t.,r%d\n", BASE_REGISTER);
      mvs_page_code = code;
      mvs_page_lit = lit;
      return 1;
    }
  mvs_page_code += code;
  mvs_page_lit += lit;
  return 0;
}
#endif /* TARGET_ELF_ABI */

/* ===================================================== */
/* defines and functions specific to the HLASM assembler */
#ifdef TARGET_HLASM

/* Check for C/370 runtime function, they don't use standard calling
   conventions.  True is returned if the function is in the table.
   NAME is the name of the current function.  */

int
mvs_function_check (name)
     const char *name;
{
  int lower, middle, upper;
  int i;

  lower = 0;
  upper = MVS_FUNCTION_TABLE_LENGTH - 1;
  while (lower <= upper)
    {
      middle = (lower + upper) / 2;
      i = strcmp (name, mvs_function_table[middle]);
      if (i == 0)
	return 1;
      if (i < 0)
	upper = middle - 1;
      else
	lower = middle + 1;
    }
  return 0;
}

/* Generate a hash for a given key.  */

#ifdef LONGEXTERNAL
static int
mvs_hash_alias (key)
     const char *key;
{
  int h;
  int i;
  int l = strlen (key);

  h = key[0];
  for (i = 1; i < l; i++)
    h = ((h * MVS_SET_SIZE) + key[i]) % MVS_HASH_PRIME;
  return (h);
}
#endif

/* Add the alias to the current alias list.  */

void
mvs_add_alias (realname, aliasname, emitted)
     const char *realname;
     const char *aliasname;
     int   emitted;
{
  alias_node_t *ap;

  ap = (alias_node_t *) xmalloc (sizeof (alias_node_t));
  if (strlen (realname) > MAX_LONG_LABEL_SIZE)
    {
      warning ("real name is too long - alias ignored");
      return;
    }
  if (strlen (aliasname) > MAX_MVS_LABEL_SIZE)
    {
      warning ("alias name is too long - alias ignored");
      return;
    }
      
  strcpy (ap->real_name, realname);
  strcpy (ap->alias_name, aliasname);
  ap->alias_emitted = emitted;
  ap->alias_next = alias_anchor;
  alias_anchor = ap;
}

/* Check to see if the name needs aliasing. ie. the name is either:
     1. Longer than 8 characters
     2. Contains an underscore
     3. Is mixed case */

int
mvs_need_alias (realname)
      const char *realname;
{
   int i, j = strlen (realname);

   if (mvs_function_check (realname))
     return 0;
#if 0
   if (!strcmp (realname, "gccmain"))
     return 0;
   if (!strcmp (realname, "main"))
     return 0;
#endif
   if (j > MAX_MVS_LABEL_SIZE)
     return 1;
   if (strchr (realname, '_') != 0)
     return 1;
   if (ISUPPER (realname[0]))
     {
       for (i = 1; i < j; i++)
	 {
	   if (ISLOWER (realname[i]))
	     return 1;
	 }
     }
   else
     {
       for (i = 1; i < j; i++)
         {
	   if (ISUPPER (realname[i]))
	     return 1;
	 }
     }

   return 0;
}

/* Get the alias from the list. 
   If 1 is returned then it's in the alias list, 0 if it was not */

int
mvs_get_alias (realname, aliasname)
     const char *realname;
     char *aliasname;
{
#ifdef LONGEXTERNAL
  alias_node_t *ap;

  for (ap = alias_anchor; ap; ap = ap->alias_next)
    {
      if (!strcmp (ap->real_name, realname))
	{
	  strcpy (aliasname, ap->alias_name);
	  return 1;
	}
    }
  if (mvs_need_alias (realname))
    {
      char c1, c2;

      c1 = realname[0];
      c2 = realname[1];
      if (ISLOWER (c1)) c1 = TOUPPER (c1);
      else if (c1 == '_') c1 = 'A';
      if (ISLOWER (c2)) c2 = TOUPPER (c2);
      else if (c2 == '_' || c2 == '\0') c2 = '#';

      sprintf (aliasname, "%c%c%06d", c1, c2, mvs_hash_alias (realname));
      mvs_add_alias (realname, aliasname, 0);
      return 1;
    }
#else
  if (strlen (realname) > MAX_MVS_LABEL_SIZE)
    {
      strncpy (aliasname, realname, MAX_MVS_LABEL_SIZE);
      aliasname[MAX_MVS_LABEL_SIZE] = '\0';
      return 1;
    }
#endif
  return 0;
}

/* Check to see if the alias is in the list. 
   If 1 is returned then it's in the alias list, 2 it was emitted  */

int
mvs_check_alias (realname, aliasname)
     const char *realname;
     char *aliasname;
{
#ifdef LONGEXTERNAL
  alias_node_t *ap;

  for (ap = alias_anchor; ap; ap = ap->alias_next)
    {
      if (!strcmp (ap->real_name, realname))
	{
	  int rc = (ap->alias_emitted == 1) ? 1 : 2; 
	  strcpy (aliasname, ap->alias_name);
	  ap->alias_emitted = 1; 
	  return rc;
	}
    }
  if (mvs_need_alias (realname))
    {
      char c1, c2;

      c1 = realname[0];
      c2 = realname[1];
      if (ISLOWER (c1)) c1 = TOUPPER (c1);
      else if (c1 == '_') c1 = 'A';
      if (ISLOWER (c2)) c2 = TOUPPER (c2);
      else if (c2 == '_' || c2 == '\0') c2 = '#';

      sprintf (aliasname, "%c%c%06d", c1, c2, mvs_hash_alias (realname));
      mvs_add_alias (realname, aliasname, 0);
      alias_anchor->alias_emitted = 1;
      return 2;
    }
#else
  if (strlen (realname) > MAX_MVS_LABEL_SIZE)
    {
      strncpy (aliasname, realname, MAX_MVS_LABEL_SIZE);
      aliasname[MAX_MVS_LABEL_SIZE] = '\0';
      return 1;
    }
#endif
  return 0;
}

/* defines and functions specific to the HLASM assembler */
#endif /* TARGET_HLASM */
/* ===================================================== */
/* ===================================================== */
/* defines and functions specific to the gas assembler */
#ifdef TARGET_ELF_ABI

/* Check for C/370 runtime function, they don't use standard calling
   conventions.  True is returned if the function is in the table.
   NAME is the name of the current function.  */
/* no special calling conventions (yet ??) */

int
mvs_function_check (name)
     const char *name ATTRIBUTE_UNUSED;
{
   return 0;
}

#endif /* TARGET_ELF_ABI */
/* ===================================================== */


/* Return 1 if OP is a valid S operand for an RS, SI or SS type instruction.
   OP is the current operation.
   MODE is the current operation mode.  */

int
s_operand (op, mode)
     register rtx op;
     enum machine_mode mode;
{
  extern int volatile_ok;
  register enum rtx_code code = GET_CODE (op);

  if (CONSTANT_ADDRESS_P (op))
    return 1;
  if (mode == VOIDmode || GET_MODE (op) != mode)
    return 0;
  if (code == MEM)
    {
      register rtx x = XEXP (op, 0);

      if (!volatile_ok && op->volatil)
	return 0;
      if (REG_P (x) && REG_OK_FOR_BASE_P (x))
	return 1;
      if (GET_CODE (x) == PLUS
	  && REG_P (XEXP (x, 0)) && REG_OK_FOR_BASE_P (XEXP (x, 0))
	  && GET_CODE (XEXP (x, 1)) == CONST_INT
	  && (unsigned) INTVAL (XEXP (x, 1)) < 4096)
	return 1;
    }
  return 0;
}


/* Return 1 if OP is a valid R or S operand for an RS, SI or SS type
   instruction.
   OP is the current operation.
   MODE is the current operation mode.  */

int
r_or_s_operand (op, mode)
     register rtx op;
     enum machine_mode mode;
{
  extern int volatile_ok;
  register enum rtx_code code = GET_CODE (op);

  if (CONSTANT_ADDRESS_P (op))
    return 1;
  if (mode == VOIDmode || GET_MODE (op) != mode)
    return 0;
  if (code == REG)
    return 1;
  else if (code == MEM)
    {
      register rtx x = XEXP (op, 0);

      if (!volatile_ok && op->volatil)
	return 0;
      if (REG_P (x) && REG_OK_FOR_BASE_P (x))
	return 1;
      if (GET_CODE (x) == PLUS
	  && REG_P (XEXP (x, 0)) && REG_OK_FOR_BASE_P (XEXP (x, 0))
	  && GET_CODE (XEXP (x, 1)) == CONST_INT
	  && (unsigned) INTVAL (XEXP (x, 1)) < 4096)
	return 1;
    }
  return 0;
}


/* Some remarks about unsigned_jump_follows_p():
   gcc is built around the assumption that branches are signed
   or unsigned, whereas the 370 doesn't care; its the compares that
   are signed or unsigned.  Thus, we need to somehow know if we
   need to do a signed or an unsigned compare, and we do this by 
   looking ahead in the instruction sequence until we find a jump.
   We then note whether this jump is signed or unsigned, and do the 
   compare appropriately.  Note that we have to scan ahead indefinitley,
   as the gcc optimizer may insert any number of instructions between 
   the compare and the jump.
  
   Note that using conditional branch expanders seems to be be a more 
   elegant/correct way of doing this.   See, for instance, the Alpha 
   cmpdi and bgt patterns.  Note also that for the i370, various
   arithmetic insn's set the condition code as well.

   The unsigned_jump_follows_p() routine  returns a 1 if the next jump 
   is unsigned.  INSN is the current instruction.  */

int
unsigned_jump_follows_p (insn)
     register rtx insn;
{
  rtx orig_insn = insn;
  while (1) 
    {
      register rtx tmp_insn;
      enum rtx_code coda;
  
      insn = NEXT_INSN (insn);
      if (!insn) fatal_insn ("internal error--no jump follows compare:", orig_insn);
  
      if (GET_CODE (insn) != JUMP_INSN) continue;
    
      tmp_insn = XEXP (insn, 3);
      if (GET_CODE (tmp_insn) != SET) continue;
    
      if (GET_CODE (XEXP (tmp_insn, 0)) != PC) continue;
    
      tmp_insn = XEXP (tmp_insn, 1);