v850.c

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

int
compute_register_save_size (long * p_reg_saved)
{
  int size = 0;
  int i;
  int interrupt_handler = v850_interrupt_function_p (current_function_decl);
  int call_p = regs_ever_live [LINK_POINTER_REGNUM];
  long reg_saved = 0;

  /* Count the return pointer if we need to save it.  */
  if (current_function_profile && !call_p)
    regs_ever_live [LINK_POINTER_REGNUM] = call_p = 1;
 
  /* Count space for the register saves.  */
  if (interrupt_handler)
    {
      for (i = 0; i <= 31; i++)
	switch (i)
	  {
	  default:
	    if (regs_ever_live[i] || call_p)
	      {
		size += 4;
		reg_saved |= 1L << i;
	      }
	    break;

	    /* We don't save/restore r0 or the stack pointer */
	  case 0:
	  case STACK_POINTER_REGNUM:
	    break;

	    /* For registers with fixed use, we save them, set them to the
	       appropriate value, and then restore them.
	       These registers are handled specially, so don't list them
	       on the list of registers to save in the prologue.  */
	  case 1:		/* temp used to hold ep */
	  case 4:		/* gp */
	  case 10:		/* temp used to call interrupt save/restore */
	  case EP_REGNUM:	/* ep */
	    size += 4;
	    break;
	  }
    }
  else
    {
      /* Find the first register that needs to be saved.  */
      for (i = 0; i <= 31; i++)
	if (regs_ever_live[i] && ((! call_used_regs[i])
				  || i == LINK_POINTER_REGNUM))
	  break;

      /* If it is possible that an out-of-line helper function might be
	 used to generate the prologue for the current function, then we
	 need to cover the possibility that such a helper function will
	 be used, despite the fact that there might be gaps in the list of
	 registers that need to be saved.  To detect this we note that the
	 helper functions always push at least register r29 (provided
	 that the function is not an interrupt handler).  */
	 
      if (TARGET_PROLOG_FUNCTION
          && (i == 2 || ((i >= 20) && (i < 30))))
	{
	  if (i == 2)
	    {
	      size += 4;
	      reg_saved |= 1L << i;

	      i = 20;
	    }

	  /* Helper functions save all registers between the starting
	     register and the last register, regardless of whether they
	     are actually used by the function or not.  */
	  for (; i <= 29; i++)
	    {
	      size += 4;
	      reg_saved |= 1L << i;
	    }

	  if (regs_ever_live [LINK_POINTER_REGNUM])
	    {
	      size += 4;
	      reg_saved |= 1L << LINK_POINTER_REGNUM;
	    }
	}
      else
	{
	  for (; i <= 31; i++)
	    if (regs_ever_live[i] && ((! call_used_regs[i])
				      || i == LINK_POINTER_REGNUM))
	      {
		size += 4;
		reg_saved |= 1L << i;
	      }
	}
    }
  
  if (p_reg_saved)
    *p_reg_saved = reg_saved;

  return size;
}

int
compute_frame_size (int size, long * p_reg_saved)
{
  return (size
	  + compute_register_save_size (p_reg_saved)
	  + current_function_outgoing_args_size);
}


void
expand_prologue (void)
{
  unsigned int i;
  int offset;
  unsigned int size = get_frame_size ();
  unsigned int actual_fsize;
  unsigned int init_stack_alloc = 0;
  rtx save_regs[32];
  rtx save_all;
  unsigned int num_save;
  unsigned int default_stack;
  int code;
  int interrupt_handler = v850_interrupt_function_p (current_function_decl);
  long reg_saved = 0;

  actual_fsize = compute_frame_size (size, &reg_saved);

  /* Save/setup global registers for interrupt functions right now.  */
  if (interrupt_handler)
    {
      if (TARGET_V850E && ! TARGET_DISABLE_CALLT)
	emit_insn (gen_callt_save_interrupt ());
      else
	emit_insn (gen_save_interrupt ());

      actual_fsize -= INTERRUPT_FIXED_SAVE_SIZE;
      
      if (((1L << LINK_POINTER_REGNUM) & reg_saved) != 0)
	actual_fsize -= INTERRUPT_ALL_SAVE_SIZE;
    }

  /* Save arg registers to the stack if necessary.  */
  else if (current_function_args_info.anonymous_args)
    {
      if (TARGET_PROLOG_FUNCTION && TARGET_V850E && !TARGET_DISABLE_CALLT)
	emit_insn (gen_save_r6_r9_v850e ());
      else if (TARGET_PROLOG_FUNCTION && ! TARGET_LONG_CALLS)
	emit_insn (gen_save_r6_r9 ());
      else
	{
	  offset = 0;
	  for (i = 6; i < 10; i++)
	    {
	      emit_move_insn (gen_rtx_MEM (SImode,
					   plus_constant (stack_pointer_rtx,
							  offset)),
			      gen_rtx_REG (SImode, i));
	      offset += 4;
	    }
	}
    }

  /* Identify all of the saved registers.  */
  num_save = 0;
  default_stack = 0;
  for (i = 1; i < 31; i++)
    {
      if (((1L << i) & reg_saved) != 0)
	save_regs[num_save++] = gen_rtx_REG (Pmode, i);
    }

  /* If the return pointer is saved, the helper functions also allocate
     16 bytes of stack for arguments to be saved in.  */
  if (((1L << LINK_POINTER_REGNUM) & reg_saved) != 0)
    {
      save_regs[num_save++] = gen_rtx_REG (Pmode, LINK_POINTER_REGNUM);
      default_stack = 16;
    }

  /* See if we have an insn that allocates stack space and saves the particular
     registers we want to.  */
  save_all = NULL_RTX;
  if (TARGET_PROLOG_FUNCTION && num_save > 0 && actual_fsize >= default_stack)
    {
      int alloc_stack = (4 * num_save) + default_stack;
      int unalloc_stack = actual_fsize - alloc_stack;
      int save_func_len = 4;
      int save_normal_len;

      if (unalloc_stack)
	save_func_len += CONST_OK_FOR_J (unalloc_stack) ? 2 : 4;

      /* see if we would have used ep to save the stack */
      if (TARGET_EP && num_save > 3 && (unsigned)actual_fsize < 255)
	save_normal_len = (3 * 2) + (2 * num_save);
      else
	save_normal_len = 4 * num_save;

      save_normal_len += CONST_OK_FOR_J (actual_fsize) ? 2 : 4;

      /* Don't bother checking if we don't actually save any space.
	 This happens for instance if one register is saved and additional
	 stack space is allocated.  */
      if (save_func_len < save_normal_len)
	{
	  save_all = gen_rtx_PARALLEL
	    (VOIDmode,
	     rtvec_alloc (num_save + 1
			  + (TARGET_V850 ? (TARGET_LONG_CALLS ? 2 : 1) : 0)));

	  XVECEXP (save_all, 0, 0)
	    = gen_rtx_SET (VOIDmode,
			   stack_pointer_rtx,
			   plus_constant (stack_pointer_rtx, -alloc_stack));

	  offset = - default_stack;
	  for (i = 0; i < num_save; i++)
	    {
	      XVECEXP (save_all, 0, i+1)
		= gen_rtx_SET (VOIDmode,
			       gen_rtx_MEM (Pmode,
					    plus_constant (stack_pointer_rtx,
							   offset)),
			       save_regs[i]);
	      offset -= 4;
	    }

	  if (TARGET_V850)
	    {
	      XVECEXP (save_all, 0, num_save + 1)
		= gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (Pmode, 10));

	      if (TARGET_LONG_CALLS)
		XVECEXP (save_all, 0, num_save + 2)
		  = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (Pmode, 11));
	    }

	  code = recog (save_all, NULL_RTX, NULL);
	  if (code >= 0)
	    {
	      rtx insn = emit_insn (save_all);
	      INSN_CODE (insn) = code;
	      actual_fsize -= alloc_stack;
	      
	      if (TARGET_DEBUG)
		fprintf (stderr, "\
Saved %d bytes via prologue function (%d vs. %d) for function %s\n",
			 save_normal_len - save_func_len,
			 save_normal_len, save_func_len,
			 IDENTIFIER_POINTER (DECL_NAME (current_function_decl)));
	    }
	  else
	    save_all = NULL_RTX;
	}
    }

  /* If no prolog save function is available, store the registers the old
     fashioned way (one by one).  */
  if (!save_all)
    {
      /* Special case interrupt functions that save all registers for a call.  */
      if (interrupt_handler && ((1L << LINK_POINTER_REGNUM) & reg_saved) != 0)
	{
	  if (TARGET_V850E && ! TARGET_DISABLE_CALLT)
	    emit_insn (gen_callt_save_all_interrupt ());
	  else
	    emit_insn (gen_save_all_interrupt ());
	}
      else
	{
	  /* If the stack is too big, allocate it in chunks so we can do the
	     register saves.  We use the register save size so we use the ep
	     register.  */
	  if (actual_fsize && !CONST_OK_FOR_K (-actual_fsize))
	    init_stack_alloc = compute_register_save_size (NULL);
	  else
	    init_stack_alloc = actual_fsize;
	      
	  /* Save registers at the beginning of the stack frame.  */
	  offset = init_stack_alloc - 4;
	  
	  if (init_stack_alloc)
	    emit_insn (gen_addsi3 (stack_pointer_rtx,
				   stack_pointer_rtx,
				   GEN_INT (-init_stack_alloc)));
	  
	  /* Save the return pointer first.  */
	  if (num_save > 0 && REGNO (save_regs[num_save-1]) == LINK_POINTER_REGNUM)
	    {
	      emit_move_insn (gen_rtx_MEM (SImode,
					   plus_constant (stack_pointer_rtx,
							  offset)),
			      save_regs[--num_save]);
	      offset -= 4;
	    }
	  
	  for (i = 0; i < num_save; i++)
	    {
	      emit_move_insn (gen_rtx_MEM (SImode,
					   plus_constant (stack_pointer_rtx,
							  offset)),
			      save_regs[i]);
	      offset -= 4;
	    }
	}
    }

  /* Allocate the rest of the stack that was not allocated above (either it is
     > 32K or we just called a function to save the registers and needed more
     stack.  */
  if (actual_fsize > init_stack_alloc)
    {
      int diff = actual_fsize - init_stack_alloc;
      if (CONST_OK_FOR_K (diff))
	emit_insn (gen_addsi3 (stack_pointer_rtx,
			       stack_pointer_rtx,
			       GEN_INT (-diff)));
      else
	{
	  rtx reg = gen_rtx_REG (Pmode, 12);
	  emit_move_insn (reg, GEN_INT (-diff));
	  emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx, reg));
	}
    }

  /* If we need a frame pointer, set it up now.  */
  if (frame_pointer_needed)
    emit_move_insn (hard_frame_pointer_rtx, stack_pointer_rtx);
}


void
expand_epilogue (void)
{
  unsigned int i;
  int offset;
  unsigned int size = get_frame_size ();
  long reg_saved = 0;
  unsigned int actual_fsize = compute_frame_size (size, &reg_saved);
  unsigned int init_stack_free = 0;
  rtx restore_regs[32];
  rtx restore_all;
  unsigned int num_restore;
  unsigned int default_stack;
  int code;
  int interrupt_handler = v850_interrupt_function_p (current_function_decl);

  /* Eliminate the initial stack stored by interrupt functions.  */
  if (interrupt_handler)
    {
      actual_fsize -= INTERRUPT_FIXED_SAVE_SIZE;
      if (((1L << LINK_POINTER_REGNUM) & reg_saved) != 0)
	actual_fsize -= INTERRUPT_ALL_SAVE_SIZE;
    }

  /* Cut off any dynamic stack created.  */
  if (frame_pointer_needed)
    emit_move_insn (stack_pointer_rtx, hard_frame_pointer_rtx);

  /* Identify all of the saved registers.  */
  num_restore = 0;
  default_stack = 0;
  for (i = 1; i < 31; i++)
    {
      if (((1L << i) & reg_saved) != 0)
	restore_regs[num_restore++] = gen_rtx_REG (Pmode, i);
    }

  /* If the return pointer is saved, the helper functions also allocate
     16 bytes of stack for arguments to be saved in.  */
  if (((1L << LINK_POINTER_REGNUM) & reg_saved) != 0)
    {
      restore_regs[num_restore++] = gen_rtx_REG (Pmode, LINK_POINTER_REGNUM);
      default_stack = 16;
    }

  /* See if we have an insn that restores the particular registers we
     want to.  */
  restore_all = NULL_RTX;
  
  if (TARGET_PROLOG_FUNCTION
      && num_restore > 0
      && actual_fsize >= default_stack
      && !interrupt_handler)
    {
      int alloc_stack = (4 * num_restore) + default_stack;
      int unalloc_stack = actual_fsize - alloc_stack;
      int restore_func_len = 4;
      int restore_normal_len;

      if (unalloc_stack)
	restore_func_len += CONST_OK_FOR_J (unalloc_stack) ? 2 : 4;

      /* See if we would have used ep to restore the registers.  */
      if (TARGET_EP && num_restore > 3 && (unsigned)actual_fsize < 255)
	restore_normal_len = (3 * 2) + (2 * num_restore);
      else
	restore_normal_len = 4 * num_restore;

      restore_normal_len += (CONST_OK_FOR_J (actual_fsize) ? 2 : 4) + 2;

      /* Don't bother checking if we don't actually save any space.  */
      if (restore_func_len < restore_normal_len)
	{
	  restore_all = gen_rtx_PARALLEL (VOIDmode,
					  rtvec_alloc (num_restore + 2));
	  XVECEXP (restore_all, 0, 0) = gen_rtx_RETURN (VOIDmode);
	  XVECEXP (restore_all, 0, 1)
	    = gen_rtx_SET (VOIDmode, stack_pointer_rtx,
			    gen_rtx_PLUS (Pmode,
					  stack_pointer_rtx,
					  GEN_INT (alloc_stack)));

	  offset = alloc_stack - 4;
	  for (i = 0; i < num_restore; i++)
	    {
	      XVECEXP (restore_all, 0, i+2)
		= gen_rtx_SET (VOIDmode,
			       restore_regs[i],
			       gen_rtx_MEM (Pmode,
					    plus_constant (stack_pointer_rtx,
							   offset)));
	      offset -= 4;
	    }

	  code = recog (restore_all, NULL_RTX, NULL);
	  
	  if (code >= 0)
	    {
	      rtx insn;

	      actual_fsize -= alloc_stack;
	      if (actual_fsize)
		{
		  if (CONST_OK_FOR_K (actual_fsize))
		    emit_insn (gen_addsi3 (stack_pointer_rtx,
					   stack_pointer_rtx,
					   GEN_INT (actual_fsize)));
		  else
		    {
		      rtx reg = gen_rtx_REG (Pmode, 12);
		      emit_move_insn (reg, GEN_INT (actual_fsize));
		      emit_insn (gen_addsi3 (stack_pointer_rtx,
					     stack_pointer_rtx,
					     reg));
		    }
		}

	      insn = emit_jump_insn (restore_all);
	      INSN_CODE (insn) = code;

	      if (TARGET_DEBUG)
		fprintf (stderr, "\
Saved %d bytes via epilogue function (%d vs. %d) in function %s\n",
			 restore_normal_len - restore_func_len,
			 restore_normal_len, restore_func_len,
			 IDENTIFIER_POINTER (DECL_NAME (current_function_decl)));
	    }
	  else
	    restore_all = NULL_RTX;
	}
    }

  /* If no epilog save function is available, restore the registers the
     old fashioned way (one by one).  */
  if (!restore_all)
    {
      /* If the stack is large, we need to cut it down in 2 pieces.  */
      if (actual_fsize && !CONST_OK_FOR_K (-actual_fsize))
	init_stack_free = 4 * num_restore;
      else
	init_stack_free = actual_fsize;

      /* Deallocate the rest of the stack if it is > 32K.  */
      if (actual_fsize > init_stack_free)
	{
	  int diff;

	  diff = actual_fsize - ((interrupt_handler) ? 0 : init_stack_free);

	  if (CONST_OK_FOR_K (diff))
	    emit_insn (gen_addsi3 (stack_pointer_rtx,
				   stack_pointer_rtx,
				   GEN_INT (diff)));
	  else
	    {
	      rtx reg = gen_rtx_REG (Pmode, 12);
	      emit_move_insn (reg, GEN_INT (diff));
	      emit_insn (gen_addsi3 (stack_pointer_rtx,
				     stack_pointer_rtx,
				     reg));
	    }
	}

      /* Special case interrupt functions that save all registers
	 for a call.  */
      if (interrupt_handler && ((1L << LINK_POINTER_REGNUM) & reg_saved) != 0)
	{
	  if (TARGET_V850E && ! TARGET_DISABLE_CALLT)
	    emit_insn (gen_callt_restore_all_interrupt ());
	  else
	    emit_insn (gen_restore_all_interrupt ());
	}
      else
	{
	  /* Restore registers from the beginning of the stack frame.  */
	  offset = init_stack_free - 4;

	  /* Restore the return pointer first.  */