i370.c

linux下的gcc编译器

      if (GET_CODE (tmp_insn) != IF_THEN_ELSE) continue;
    
      /* if we got to here, this instruction is a jump.  Is it signed? */
      tmp_insn = XEXP (tmp_insn, 0);
      coda = GET_CODE (tmp_insn);
  
      return coda != GE && coda != GT && coda != LE && coda != LT;
    }
}

#ifdef TARGET_HLASM

/* Target hook for assembling integer objects.  This version handles all
   objects when TARGET_HLASM is defined.  */

static bool
i370_hlasm_assemble_integer (x, size, aligned_p)
     rtx x;
     unsigned int size;
     int aligned_p;
{
  const char *int_format = NULL;

  if (aligned_p)
    switch (size)
      {
      case 1:
	int_format = "\tDC\tX'%02X'\n";
	break;

      case 2:
	int_format = "\tDC\tX'%04X'\n";
	break;

      case 4:
	if (GET_CODE (x) == CONST_INT)
	  {
	    fputs ("\tDC\tF'", asm_out_file);
	    output_addr_const (asm_out_file, x);
	    fputs ("'\n", asm_out_file);
	  }
	else
	  {
	    fputs ("\tDC\tA(", asm_out_file);
	    output_addr_const (asm_out_file, x);
	    fputs (")\n", asm_out_file);
	  }
	return true;
      }

  if (int_format && GET_CODE (x) == CONST_INT)
    {
      fprintf (asm_out_file, int_format, INTVAL (x));
      return true;
    }
  return default_assemble_integer (x, size, aligned_p);
}

/* Generate the assembly code for function entry.  FILE is a stdio
   stream to output the code to.  SIZE is an int: how many units of
   temporary storage to allocate.

   Refer to the array `regs_ever_live' to determine which registers to
   save; `regs_ever_live[I]' is nonzero if register number I is ever
   used in the function.  This function is responsible for knowing
   which registers should not be saved even if used.  */

static void
i370_output_function_prologue (f, l)
     FILE *f;
     HOST_WIDE_INT l;
{
#if MACROPROLOGUE == 1
  fprintf (f, "* Function %s prologue\n", mvs_function_name);
  fprintf (f, "\tEDCPRLG USRDSAL=%d,BASEREG=%d\n",
	   STACK_POINTER_OFFSET + l - 120 +
	   current_function_outgoing_args_size, BASE_REGISTER);
#else /* MACROPROLOGUE != 1 */
  static int function_label_index = 1;
  static int function_first = 0;
  static int function_year, function_month, function_day;
  static int function_hour, function_minute, function_second;
#if defined(LE370)
  if (!function_first)
    {
      struct tm *function_time;
      time_t lcltime;
      time (&lcltime);
      function_time = localtime (&lcltime);
      function_year = function_time->tm_year + 1900;
      function_month = function_time->tm_mon + 1;
      function_day = function_time->tm_mday;
      function_hour = function_time->tm_hour;
      function_minute = function_time->tm_min;
      function_second = function_time->tm_sec;
    }
  fprintf (f, "* Function %s prologue\n", mvs_function_name);
  fprintf (f, "FDSE%03d\tDSECT\n", function_label_index);
  fprintf (f, "\tDS\tD\n");
  fprintf (f, "\tDS\tCL(%d)\n", STACK_POINTER_OFFSET + l
			+ current_function_outgoing_args_size);
  fprintf (f, "\tORG\tFDSE%03d\n", function_label_index);
  fprintf (f, "\tDS\tCL(120+8)\n");
  fprintf (f, "\tORG\n");
  fprintf (f, "\tDS\t0D\n");
  fprintf (f, "FDSL%03d\tEQU\t*-FDSE%03d-8\n", function_label_index,
	   function_label_index);
  fprintf (f, "\tDS\t0H\n");
  assemble_name (f, mvs_function_name);
  fprintf (f, "\tCSECT\n");
  fprintf (f, "\tUSING\t*,15\n");
  fprintf (f, "\tB\tFENT%03d\n", function_label_index);
  fprintf (f, "\tDC\tAL1(FNAM%03d+4-*)\n", function_label_index);
  fprintf (f, "\tDC\tX'CE',X'A0',AL1(16)\n");
  fprintf (f, "\tDC\tAL4(FPPA%03d)\n", function_label_index);
  fprintf (f, "\tDC\tAL4(0)\n");
  fprintf (f, "\tDC\tAL4(FDSL%03d)\n", function_label_index);
  fprintf (f, "FNAM%03d\tEQU\t*\n", function_label_index);
  fprintf (f, "\tDC\tAL2(%d),C'%s'\n", strlen (mvs_function_name),
	mvs_function_name);
  fprintf (f, "FPPA%03d\tDS\t0F\n", function_label_index);
  fprintf (f, "\tDC\tX'03',X'00',X'33',X'00'\n");
  fprintf (f, "\tDC\tV(CEESTART)\n");
  fprintf (f, "\tDC\tAL4(0)\n");
  fprintf (f, "\tDC\tAL4(FTIM%03d)\n", function_label_index);
  fprintf (f, "FTIM%03d\tDS\t0F\n", function_label_index);
  fprintf (f, "\tDC\tCL4'%d',CL4'%02d%02d',CL6'%02d%02d00'\n",
  		 function_year, function_month, function_day,
    		 function_hour, function_minute);
  fprintf (f, "\tDC\tCL2'01',CL4'0100'\n");
  fprintf (f, "FENT%03d\tDS\t0H\n", function_label_index);
  fprintf (f, "\tSTM\t14,12,12(13)\n");
  fprintf (f, "\tL\t2,76(,13)\n");
  fprintf (f, "\tL\t0,16(,15)\n");
  fprintf (f, "\tALR\t0,2\n");
  fprintf (f, "\tCL\t0,12(,12)\n");
  fprintf (f, "\tBNH\t*+10\n");
  fprintf (f, "\tL\t15,116(,12)\n");
  fprintf (f, "\tBALR\t14,15\n");
  fprintf (f, "\tL\t15,72(,13)\n");
  fprintf (f, "\tSTM\t15,0,72(2)\n");
  fprintf (f, "\tMVI\t0(2),X'10'\n");
  fprintf (f, "\tST\t2,8(,13)\n ");
  fprintf (f, "\tST\t13,4(,2)\n ");
  fprintf (f, "\tLR\t13,2\n");
  fprintf (f, "\tDROP\t15\n");
  fprintf (f, "\tBALR\t%d,0\n", BASE_REGISTER);
  fprintf (f, "\tUSING\t*,%d\n", BASE_REGISTER);
  function_first = 1;
  function_label_index ++;
#else /* !LE370 */
  if (!function_first)
    {
      struct tm *function_time;
      time_t lcltime;
      time (&lcltime);
      function_time = localtime (&lcltime);
      function_year = function_time->tm_year + 1900;
      function_month = function_time->tm_mon + 1;
      function_day = function_time->tm_mday;
      function_hour = function_time->tm_hour;
      function_minute = function_time->tm_min;
      function_second = function_time->tm_sec;
      fprintf (f, "PPA2\tDS\t0F\n");
      fprintf (f, "\tDC\tX'03',X'00',X'33',X'00'\n");
      fprintf (f, "\tDC\tV(CEESTART),A(0)\n");
      fprintf (f, "\tDC\tA(CEETIMES)\n");
      fprintf (f, "CEETIMES\tDS\t0F\n");
      fprintf (f, "\tDC\tCL4'%d',CL4'%02d%02d',CL6'%02d%02d00'\n",
    		 function_year, function_month, function_day,
    		 function_hour, function_minute, function_second);
      fprintf (f, "\tDC\tCL2'01',CL4'0100'\n");
    }
  fprintf (f, "* Function %s prologue\n", mvs_function_name);
  fprintf (f, "FDSD%03d\tDSECT\n", function_label_index);
  fprintf (f, "\tDS\tD\n");
  fprintf (f, "\tDS\tCL(%d)\n", STACK_POINTER_OFFSET + l
			+ current_function_outgoing_args_size);
  fprintf (f, "\tORG\tFDSD%03d\n", function_label_index);
  fprintf (f, "\tDS\tCL(120+8)\n");
  fprintf (f, "\tORG\n");
  fprintf (f, "\tDS\t0D\n");
  fprintf (f, "FDSL%03d\tEQU\t*-FDSD%03d-8\n", function_label_index,
	   function_label_index);
  fprintf (f, "\tDS\t0H\n");
  assemble_name (f, mvs_function_name);
  fprintf (f, "\tCSECT\n");
  fprintf (f, "\tUSING\t*,15\n");
  fprintf (f, "\tB\tFPL%03d\n", function_label_index);
  fprintf (f, "\tDC\tAL1(FPL%03d+4-*)\n", function_label_index + 1);
  fprintf (f, "\tDC\tX'CE',X'A0',AL1(16)\n");
  fprintf (f, "\tDC\tAL4(PPA2)\n");
  fprintf (f, "\tDC\tAL4(0)\n");
  fprintf (f, "\tDC\tAL4(FDSL%03d)\n", function_label_index);
  fprintf (f, "FPL%03d\tEQU\t*\n", function_label_index + 1);
  fprintf (f, "\tDC\tAL2(%d),C'%s'\n", strlen (mvs_function_name),
	mvs_function_name);
  fprintf (f, "FPL%03d\tDS\t0H\n", function_label_index);
  fprintf (f, "\tSTM\t14,12,12(13)\n");
  fprintf (f, "\tL\t2,76(,13)\n");
  fprintf (f, "\tL\t0,16(,15)\n");
  fprintf (f, "\tALR\t0,2\n");
  fprintf (f, "\tCL\t0,12(,12)\n");
  fprintf (f, "\tBNH\t*+10\n");
  fprintf (f, "\tL\t15,116(,12)\n");
  fprintf (f, "\tBALR\t14,15\n");
  fprintf (f, "\tL\t15,72(,13)\n");
  fprintf (f, "\tSTM\t15,0,72(2)\n");
  fprintf (f, "\tMVI\t0(2),X'10'\n");
  fprintf (f, "\tST\t2,8(,13)\n ");
  fprintf (f, "\tST\t13,4(,2)\n ");
  fprintf (f, "\tLR\t13,2\n");
  fprintf (f, "\tDROP\t15\n");
  fprintf (f, "\tBALR\t%d,0\n", BASE_REGISTER);
  fprintf (f, "\tUSING\t*,%d\n", BASE_REGISTER);
  function_first = 1;
  function_label_index += 2;
#endif /* !LE370 */
#endif /* MACROPROLOGUE */
  fprintf (f, "PG%d\tEQU\t*\n", mvs_page_num );
  fprintf (f, "\tLR\t11,1\n"); 
  fprintf (f, "\tL\t%d,=A(PGT%d)\n", PAGE_REGISTER, mvs_page_num);
  fprintf (f, "* Function %s code\n", mvs_function_name);

  mvs_free_label_list ();
  mvs_page_code = 6;
  mvs_page_lit = 4;
  mvs_check_page (f, 0, 0);
  function_base_page = mvs_page_num;

  /* find all labels in this routine */
  i370_label_scan ();
}

static void
i370_globalize_label (stream, name)
     FILE *stream;
     const char *name;
{
  char temp[MAX_MVS_LABEL_SIZE + 1];
  if (mvs_check_alias (name, temp) == 2)
    fprintf (stream, "%s\tALIAS\tC'%s'\n", temp, name);
  fputs ("\tENTRY\t", stream);
  assemble_name (stream, name);
  putc ('\n', stream);
}
#endif /* TARGET_HLASM */


#ifdef TARGET_ELF_ABI
/*
   The 370_function_prolog() routine generates the current ELF ABI ES/390 prolog.
   It implements a stack that grows downward. 
   It performs the following steps:
   -- saves the callers non-volatile registers on the callers stack.
   -- subtracts stackframe size from the stack pointer.
   -- stores backpointer to old caller stack.
  
   XXX hack alert -- if the global var int leaf_function is nonzero, 
   then this is a leaf, and it might be possible to optimize the prologue
   into doing even less, e.g. not grabbing a new stackframe or maybe just a
   partial stack frame.
  
   XXX hack alert -- the current stack frame is bloated into twice the 
   needed size by unused entries. These entries make it marginally 
   compatible with MVS/OE/USS C environment, but really they're not used
   and could probably chopped out. Modifications to i370.md would be needed
   also, to quite using addresses 136, 140, etc.
 */

static void
i370_output_function_prologue (f, frame_size)
     FILE *f;
     HOST_WIDE_INT frame_size;
{
  static int function_label_index = 1;
  static int function_first = 0;
  int stackframe_size, aligned_size;

  fprintf (f, "# Function prologue\n");
  /* define the stack, put it into its own data segment
     FDSE == Function Stack Entry
     FDSL == Function Stack Length */
  stackframe_size = 
     STACK_POINTER_OFFSET + current_function_outgoing_args_size + frame_size;
  aligned_size = (stackframe_size + 7) >> 3;
  aligned_size <<= 3;
  
  fprintf (f, "# arg_size=0x%x frame_size=0x%x aligned size=0x%x\n", 
     current_function_outgoing_args_size, frame_size, aligned_size);

  fprintf (f, "\t.using\t.,r15\n");

  /* Branch to exectuable part of prologue.  */
  fprintf (f, "\tB\t.LFENT%03d\n", function_label_index);

  /* write the length of the stackframe */
  fprintf (f, "\t.long\t%d\n", aligned_size);

  /* FENT == function prologue entry */
  fprintf (f, "\t.balign 2\n.LFENT%03d:\n",
              function_label_index);

  /* store multiple registers 14,15,0,...12 at 12 bytes from sp */
  fprintf (f, "\tSTM\tr14,r12,12(sp)\n");

  /* r3 == saved callee stack pointer */
  fprintf (f, "\tLR\tr3,sp\n");

  /* 4(r15) == stackframe size */
  fprintf (f, "\tSL\tsp,4(,r15)\n");

  /* r11 points to arg list in callers stackframe; was passed in r2 */
  fprintf (f, "\tLR\tr11,r2\n");

  /* store callee stack pointer at 8(sp) */
  /* fprintf (f, "\tST\tsp,8(,r3)\n ");  wasted cycles, no one uses this ...  */

  /* backchain -- store caller sp at 4(callee_sp)  */
  fprintf (f, "\tST\tr3,4(,sp)\n ");

  fprintf (f, "\t.drop\tr15\n");
  /* Place contents of the PSW into r3
     that is, place the address of "." into r3 */
  fprintf (f, "\tBASR\tr%d,0\n", BASE_REGISTER);
  fprintf (f, "\t.using\t.,r%d\n", BASE_REGISTER);
  function_first = 1;
  function_label_index ++;

  fprintf (f, ".LPG%d:\n", mvs_page_num  );
  fprintf (f, "\tL\tr%d,=A(.LPGT%d)\n", PAGE_REGISTER, mvs_page_num);
  fprintf (f, "# Function code\n");

  mvs_free_label_list ();
  mvs_page_code = 6;
  mvs_page_lit = 4;
  mvs_check_page (f, 0, 0);
  function_base_page = mvs_page_num;

  /* find all labels in this routine */
  i370_label_scan ();
}
#endif /* TARGET_ELF_ABI */

/* This function generates the assembly code for function exit.
   Args are as for output_function_prologue ().

   The function epilogue should not depend on the current stack
   pointer!  It should use the frame pointer only.  This is mandatory
   because of alloca; we also take advantage of it to omit stack
   adjustments before returning.  */

static void
i370_output_function_epilogue (file, l)
     FILE *file;
     HOST_WIDE_INT l ATTRIBUTE_UNUSED;
{
  int i;

  check_label_emit ();
  mvs_check_page (file, 14, 0);
  fprintf (file, "* Function %s epilogue\n", mvs_function_name);
  mvs_page_num++;

#if MACROEPILOGUE == 1
  fprintf (file, "\tEDCEPIL\n");
#else /* MACROEPILOGUE != 1 */
  fprintf (file, "\tL\t13,4(,13)\n");
  fprintf (file, "\tL\t14,12(,13)\n");
  fprintf (file, "\tLM\t2,12,28(13)\n");
  fprintf (file, "\tBALR\t1,14\n");
  fprintf (file, "\tDC\tA(");
  assemble_name (file, mvs_function_name);
  fprintf (file, ")\n" );
#endif /* MACROEPILOGUE */

  fprintf (file, "* Function %s literal pool\n", mvs_function_name);
  fprintf (file, "\tDS\t0F\n" );
  fprintf (file, "\tLTORG\n");
  fprintf (file, "* Function %s page table\n", mvs_function_name);
  fprintf (file, "\tDS\t0F\n");
  fprintf (file, "PGT%d\tEQU\t*\n", function_base_page);

  mvs_free_label_list();
  for (i = function_base_page; i < mvs_page_num; i++)
    fprintf (file, "\tDC\tA(PG%d)\n", i);
}

/* Mark external references.  */

static void
i370_encode_section_info (decl, first)
     tree decl;
     int first ATTRIBUTE_UNUSED;
{
  if (DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
    SYMBOL_REF_FLAG (XEXP (DECL_RTL (decl), 0)) = 1;
}