ns32k.c

linux下的gcc编译器

/* Subroutines for assembler code output on the NS32000.
   Copyright (C) 1988, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001
   Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include "config.h"
#include "system.h"
#include "rtl.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "real.h"
#include "insn-config.h"
#include "conditions.h"
#include "output.h"
#include "insn-attr.h"
#include "tree.h"
#include "function.h"
#include "expr.h"
#include "flags.h"
#include "recog.h"
#include "tm_p.h"
#include "target.h"
#include "target-def.h"
#include "toplev.h"

#ifdef OSF_OS
int ns32k_num_files = 0;
#endif

/* This duplicates reg_class_contents in reg_class.c, but maybe that isn't
   initialized in time. Also this is more convenient as an array of ints.
   We know that HARD_REG_SET fits in an unsigned int */

const unsigned int ns32k_reg_class_contents[N_REG_CLASSES][1] = REG_CLASS_CONTENTS;

const enum reg_class regclass_map[FIRST_PSEUDO_REGISTER] =
{
  GENERAL_REGS, GENERAL_REGS, GENERAL_REGS, GENERAL_REGS,
  GENERAL_REGS, GENERAL_REGS, GENERAL_REGS, GENERAL_REGS,
  FLOAT_REG0, LONG_FLOAT_REG0, FLOAT_REGS, FLOAT_REGS,
  FLOAT_REGS, FLOAT_REGS, FLOAT_REGS, FLOAT_REGS,
  FP_REGS, FP_REGS, FP_REGS, FP_REGS,
  FP_REGS, FP_REGS, FP_REGS, FP_REGS,
  FRAME_POINTER_REG, STACK_POINTER_REG
};

static const char *const ns32k_out_reg_names[] = OUTPUT_REGISTER_NAMES;

static rtx gen_indexed_expr PARAMS ((rtx, rtx, rtx));
static const char *singlemove_string PARAMS ((rtx *));
static void move_tail PARAMS ((rtx[], int, int));
static tree ns32k_handle_fntype_attribute PARAMS ((tree *, tree, tree, int, bool *));
const struct attribute_spec ns32k_attribute_table[];
static void ns32k_output_function_prologue PARAMS ((FILE *, HOST_WIDE_INT));
static void ns32k_output_function_epilogue PARAMS ((FILE *, HOST_WIDE_INT));
static void ns32k_encode_section_info PARAMS ((tree, int));

/* Initialize the GCC target structure.  */
#undef TARGET_ATTRIBUTE_TABLE
#define TARGET_ATTRIBUTE_TABLE ns32k_attribute_table

#undef TARGET_ASM_ALIGNED_HI_OP
#define TARGET_ASM_ALIGNED_HI_OP "\t.word\t"

#ifdef ENCORE_ASM
#undef TARGET_ASM_ALIGNED_SI_OP
#define TARGET_ASM_ALIGNED_SI_OP "\t.double\t"
#endif

#undef TARGET_ASM_FUNCTION_PROLOGUE
#define TARGET_ASM_FUNCTION_PROLOGUE ns32k_output_function_prologue
#undef TARGET_ASM_FUNCTION_EPILOGUE
#define TARGET_ASM_FUNCTION_EPILOGUE ns32k_output_function_epilogue
#undef TARGET_ENCODE_SECTION_INFO
#define TARGET_ENCODE_SECTION_INFO ns32k_encode_section_info

struct gcc_target targetm = TARGET_INITIALIZER;

/* 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.  */

/*
 * The function prologue for the ns32k is fairly simple.
 * If a frame pointer is needed (decided in reload.c ?) then
 * we need assembler of the form
 *
 *  # Save the oldframe pointer, set the new frame pointer, make space
 *  # on the stack and save any general purpose registers necessary
 *
 *  enter [<general purpose regs to save>], <local stack space>
 *
 *  movf  fn, tos    # Save any floating point registers necessary
 *  .
 *  .
 *
 * If a frame pointer is not needed we need assembler of the form
 *
 *  # Make space on the stack
 *
 *  adjspd <local stack space + 4>
 *
 *  # Save any general purpose registers necessary
 *
 *  save [<general purpose regs to save>]
 *
 *  movf  fn, tos    # Save any floating point registers necessary
 *  .
 *  .
 */

#if !defined (MERLIN_TARGET) && !defined (UTEK_ASM)

#if defined(IMMEDIATE_PREFIX) && IMMEDIATE_PREFIX
#define ADJSP(FILE, N) \
        fprintf (FILE, "\tadjspd %c%d\n", IMMEDIATE_PREFIX, (N))
#else
#define ADJSP(FILE, N) \
        fprintf (FILE, "\tadjspd %d\n", (N))
#endif

static void
ns32k_output_function_prologue (file, size)
     FILE *file;
     HOST_WIDE_INT size;
{
  register int regno, g_regs_used = 0;
  int used_regs_buf[8], *bufp = used_regs_buf;
  int used_fregs_buf[17], *fbufp = used_fregs_buf;

  for (regno = R0_REGNUM; regno < F0_REGNUM; regno++)
    if (regs_ever_live[regno]
	&& ! call_used_regs[regno])
      {
        *bufp++ = regno; g_regs_used++;
      }
  *bufp = -1;

  for (; regno < FRAME_POINTER_REGNUM; regno++)
    if (regs_ever_live[regno] && !call_used_regs[regno])
      {
        *fbufp++ = regno;
      }
  *fbufp = -1;

  bufp = used_regs_buf;
  if (frame_pointer_needed)
    fprintf (file, "\tenter [");
  else
    {
      if (size)
        ADJSP (file, size + 4);
      if (g_regs_used && g_regs_used > 4)
        fprintf (file, "\tsave [");
      else
	{
	  while (*bufp >= 0)
            fprintf (file, "\tmovd r%d,tos\n", *bufp++);
	  g_regs_used = 0;
	}
    }

  while (*bufp >= 0)
    {
      fprintf (file, "r%d", *bufp++);
      if (*bufp >= 0)
	fputc (',', file);
    }

  if (frame_pointer_needed)
    fprintf (file, "],%d\n", size);
  else if (g_regs_used)
    fprintf (file, "]\n");

  fbufp = used_fregs_buf;
  while (*fbufp >= 0)
    {
      if ((*fbufp & 1) || (fbufp[0] != fbufp[1] - 1))
	fprintf (file, "\tmovf %s,tos\n", ns32k_out_reg_names[*fbufp++]);
      else
	{
	  fprintf (file, "\tmovl %s,tos\n",
		   ns32k_out_reg_names[fbufp[0]]);
	  fbufp += 2;
	}
    }

  if (flag_pic && current_function_uses_pic_offset_table)
    {
      fprintf (file, "\tsprd sb,tos\n");
      if (TARGET_REGPARM)
	{
	  fprintf (file, "\taddr __GLOBAL_OFFSET_TABLE_(pc),tos\n");
	  fprintf (file, "\tlprd sb,tos\n");
	}
      else
	{
	  fprintf (file, "\taddr __GLOBAL_OFFSET_TABLE_(pc),r0\n");
	  fprintf (file, "\tlprd sb,r0\n");
	}
    }
}

#else /* MERLIN_TARGET || UTEK_ASM  */

/* This differs from the standard one above in printing a bitmask
   rather than a register list in the enter or save instruction.  */

static void
ns32k_output_function_prologue (file, size)
     FILE *file;
     HOST_WIDE_INT size;
{
  register int regno, g_regs_used = 0;
  int used_regs_buf[8], *bufp = used_regs_buf;
  int used_fregs_buf[8], *fbufp = used_fregs_buf;

  for (regno = 0; regno < 8; regno++)
    if (regs_ever_live[regno]
	&& ! call_used_regs[regno])
      {
	*bufp++ = regno; g_regs_used++;
      }
  *bufp = -1;

  for (; regno < 16; regno++)
    if (regs_ever_live[regno] && !call_used_regs[regno]) {
      *fbufp++ = regno;
    }
  *fbufp = -1;

  bufp = used_regs_buf;
  if (frame_pointer_needed)
    fprintf (file, "\tenter ");
  else if (g_regs_used)
    fprintf (file, "\tsave ");

  if (frame_pointer_needed || g_regs_used)
    {
      char mask = 0;
      while (*bufp >= 0)
	mask |= 1 << *bufp++;
      fprintf (file, "$0x%x", (int) mask & 0xff);
    }

  if (frame_pointer_needed)
#ifdef UTEK_ASM
    fprintf (file, ",$%d\n", size);
#else
    fprintf (file, ",%d\n", size);
#endif
  else if (g_regs_used)
    fprintf (file, "\n");

  fbufp = used_fregs_buf;
  while (*fbufp >= 0)
    {
      if ((*fbufp & 1) || (fbufp[0] != fbufp[1] - 1))
	fprintf (file, "\tmovf f%d,tos\n", *fbufp++ - 8);
      else
	{
	  fprintf (file, "\tmovl f%d,tos\n", fbufp[0] - 8);
	  fbufp += 2;
	}
    }
}

#endif /* MERLIN_TARGET || UTEK_ASM  */

/* This function generates the assembly code for function exit,
   on machines that need it.

   The function epilogue should not depend on the current stack pointer,
   if EXIT_IGNORE_STACK is nonzero.  That doesn't apply here.

   If a frame pointer is needed (decided in reload.c ?) then
   we need assembler of the form

    movf  tos, fn	# Restore any saved floating point registers
    .
    .

    # Restore any saved general purpose registers, restore the stack
    # pointer from the frame pointer, restore the old frame pointer.
    exit [<general purpose regs to save>]

   If a frame pointer is not needed we need assembler of the form
    # Restore any general purpose registers saved

    movf  tos, fn	# Restore any saved floating point registers
    .
    .
    .
    restore [<general purpose regs to save>]

    # reclaim space allocated on stack

    adjspd <-(local stack space + 4)> */

#if !defined (MERLIN_TARGET) && !defined (UTEK_ASM)

static void
ns32k_output_function_epilogue (file, size)
     FILE *file;
     HOST_WIDE_INT size;
{
  register int regno, g_regs_used = 0, f_regs_used = 0;
  int used_regs_buf[8], *bufp = used_regs_buf;
  int used_fregs_buf[17], *fbufp = used_fregs_buf;

  if (flag_pic && current_function_uses_pic_offset_table)
    fprintf (file, "\tlprd sb,tos\n");

  *fbufp++ = -2;
  for (regno = F0_REGNUM; regno < FRAME_POINTER_REGNUM; regno++)
    if (regs_ever_live[regno] && !call_used_regs[regno])
      {
	*fbufp++ = regno; f_regs_used++;
      }
  fbufp--;

  for (regno = 0; regno < F0_REGNUM; regno++)
    if (regs_ever_live[regno]
	&& ! call_used_regs[regno])
      {
        *bufp++ = regno; g_regs_used++;
      }

  while (fbufp > used_fregs_buf)
    {
      if ((*fbufp & 1) && fbufp[0] == fbufp[-1] + 1)
	{
	  fprintf (file, "\tmovl tos,%s\n",
		   ns32k_out_reg_names[fbufp[-1]]);
	  fbufp -= 2;
	}
      else fprintf (file, "\tmovf tos,%s\n", ns32k_out_reg_names[*fbufp--]);
    }

  if (frame_pointer_needed)
    fprintf (file, "\texit [");
  else
    {
      if (g_regs_used && g_regs_used > 4)
        fprintf (file, "\trestore [");
      else
        {
	  while (bufp > used_regs_buf)
            fprintf (file, "\tmovd tos,r%d\n", *--bufp);
	  g_regs_used = 0;
        }
    }

  while (bufp > used_regs_buf)
    {
      fprintf (file, "r%d", *--bufp);
      if (bufp > used_regs_buf)
	fputc (',', file);
    }

  if (g_regs_used || frame_pointer_needed)
    fprintf (file, "]\n");

  if (size && !frame_pointer_needed)
    ADJSP (file, -(size + 4));

  if (current_function_pops_args)
    fprintf (file, "\tret %d\n", current_function_pops_args);
  else
    fprintf (file, "\tret 0\n");
}

#else /* MERLIN_TARGET || UTEK_ASM  */

/* This differs from the standard one above in printing a bitmask
   rather than a register list in the exit or restore instruction.  */

static void
ns32k_output_function_epilogue (file, size)
     FILE *file;
     HOST_WIDE_INT size ATTRIBUTE_UNUSED;
{
  register int regno, g_regs_used = 0, f_regs_used = 0;
  int used_regs_buf[8], *bufp = used_regs_buf;
  int used_fregs_buf[8], *fbufp = used_fregs_buf;

  *fbufp++ = -2;
  for (regno = 8; regno < 16; regno++)
    if (regs_ever_live[regno] && !call_used_regs[regno]) {
      *fbufp++ = regno; f_regs_used++;
    }
  fbufp--;

  for (regno = 0; regno < 8; regno++)
    if (regs_ever_live[regno]
	&& ! call_used_regs[regno])
      {
	*bufp++ = regno; g_regs_used++;
      }

  while (fbufp > used_fregs_buf)
    {
      if ((*fbufp & 1) && fbufp[0] == fbufp[-1] + 1)
	{
	  fprintf (file, "\tmovl tos,f%d\n", fbufp[-1] - 8);
	  fbufp -= 2;
	}
      else fprintf (file, "\tmovf tos,f%d\n", *fbufp-- - 8);
    }

  if (frame_pointer_needed)
    fprintf (file, "\texit ");
  else if (g_regs_used)
    fprintf (file, "\trestore ");

  if (g_regs_used || frame_pointer_needed)
    {
      char mask = 0;

      while (bufp > used_regs_buf)
	{
	  /* Utek assembler takes care of reversing this */
	  mask |= 1 << *--bufp;
	}
      fprintf (file, "$0x%x\n", (int) mask & 0xff);
    }

#ifdef UTEK_ASM
  if (current_function_pops_args)
    fprintf (file, "\tret $%d\n", current_function_pops_args);
  else
    fprintf (file, "\tret $0\n");
#else
  if (current_function_pops_args)
    fprintf (file, "\tret %d\n", current_function_pops_args);
  else
    fprintf (file, "\tret 0\n");
#endif
}

#endif /* MERLIN_TARGET || UTEK_ASM  */

/* Value is 1 if hard register REGNO can hold a value of machine-mode MODE. */ 
int
hard_regno_mode_ok (regno, mode)
     int regno;
     enum machine_mode mode;
{
  int size = GET_MODE_UNIT_SIZE (mode);

  if (FLOAT_MODE_P (mode))
    {
      if (size == UNITS_PER_WORD && regno < L1_REGNUM)
	return 1;
      if (size == UNITS_PER_WORD * 2
	  && (((regno & 1) == 0 && regno < FRAME_POINTER_REGNUM)))
	return 1;
      return 0;
    }
  if (size == UNITS_PER_WORD * 2
      && (regno & 1) == 0 && regno < F0_REGNUM)
    return 1;
  if (size <= UNITS_PER_WORD
      && (regno < F0_REGNUM || regno == FRAME_POINTER_REGNUM
	  || regno == STACK_POINTER_REGNUM))
    return 1;
  return 0;
}

int register_move_cost (CLASS1, CLASS2)
     enum reg_class CLASS1;
     enum reg_class CLASS2;
{
  if (CLASS1 == NO_REGS || CLASS2 == NO_REGS)
    return 2;
  if ((SUBSET_P (CLASS1, FP_REGS) && !SUBSET_P (CLASS2, FP_REGS))
   || (!SUBSET_P (CLASS1, FP_REGS) && SUBSET_P (CLASS2, FP_REGS)))
    return 8;
  if (((CLASS1) == STACK_POINTER_REG && !SUBSET_P (CLASS2,GENERAL_REGS))
      || ((CLASS2) == STACK_POINTER_REG && !SUBSET_P (CLASS1,GENERAL_REGS)))
    return 6;
  if (((CLASS1) == FRAME_POINTER_REG && !SUBSET_P (CLASS2,GENERAL_REGS))
      || ((CLASS2) == FRAME_POINTER_REG && !SUBSET_P (CLASS1,GENERAL_REGS)))
    return 6;
  return 2;
}

#if 0
/* We made the insn definitions copy from floating point to general
  registers via the stack. */
int secondary_memory_needed (CLASS1, CLASS2, M)
     enum reg_class CLASS1;
     enum reg_class CLASS2;
     enum machine_mode M;
{
  int ret = ((SUBSET_P (CLASS1, FP_REGS) && !SUBSET_P (CLASS2, FP_REGS))
   || (!SUBSET_P (CLASS1, FP_REGS) && SUBSET_P (CLASS2, FP_REGS)));
  return ret;
}
#endif
    

/* ADDRESS_COST calls this.  This function is not optimal
   for the 32032 & 32332, but it probably is better than
   the default. */