v850.c

gcc-2.95.3 Linux下最常用的C编译器

	{
	  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 + (TARGET_V850 ? 2 : 1)));
	  XVECEXP (save_all, 0, 0) = gen_rtx (SET, VOIDmode,
					      stack_pointer_rtx,
					      gen_rtx (PLUS, Pmode,
						       stack_pointer_rtx,
						       GEN_INT (-alloc_stack)));

	  if (TARGET_V850)
	    {
	      XVECEXP (save_all, 0, num_save + 1)
		= gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, Pmode, 10));
	    }

	  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;
	    }

	  code = recog (save_all, NULL_RTX, NULL_PTR);
	  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)
	{
	  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 ()
{
  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_PTR);
	  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)
	{
	  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.  */
	  if (num_restore > 0
	      && REGNO (restore_regs [num_restore - 1]) == LINK_POINTER_REGNUM)
	    {
	      emit_move_insn (restore_regs[--num_restore],
			      gen_rtx (MEM, SImode,
				       plus_constant (stack_pointer_rtx,
						      offset)));
	      offset -= 4;
	    }

	  for (i = 0; i < num_restore; i++)
	    {
	      emit_move_insn (restore_regs[i],
			      gen_rtx (MEM, SImode,
				       plus_constant (stack_pointer_rtx,
						      offset)));

	      offset -= 4;
	    }

	  /* Cut back the remainder of the stack.  */
	  if (init_stack_free)
	    emit_insn (gen_addsi3 (stack_pointer_rtx,
				   stack_pointer_rtx,
				   GEN_INT (init_stack_free)));
	}

      /* And return or use reti for interrupt handlers.  */
      if (interrupt_handler)
	emit_jump_insn (gen_restore_interrupt ());
      else if (actual_fsize)
	emit_jump_insn (gen_return_internal ());
      else
	emit_jump_insn (gen_return ());
    }

  current_function_anonymous_args = 0;
  v850_interrupt_cache_p = FALSE;
  v850_interrupt_p = FALSE;
}


/* Update the condition code from the insn.  */

void
notice_update_cc (body, insn)
     rtx body;
     rtx insn;
{
  switch (get_attr_cc (insn))
    {
    case CC_NONE:
      /* Insn does not affect CC at all.  */
      break;

    case CC_NONE_0HIT:
      /* Insn does not change CC, but the 0'th operand has been changed.  */
      if (cc_status.value1 != 0
	  && reg_overlap_mentioned_p (recog_operand[0], cc_status.value1))
	cc_status.value1 = 0;
      break;

    case CC_SET_ZN:
      /* Insn sets the Z,N flags of CC to recog_operand[0].
	 V,C is in an unusable state.  */
      CC_STATUS_INIT;
      cc_status.flags |= CC_OVERFLOW_UNUSABLE | CC_NO_CARRY;
      cc_status.value1 = recog_operand[0];
      break;

    case CC_SET_ZNV:
      /* Insn sets the Z,N,V flags of CC to recog_operand[0].
	 C is in an unusable state.  */
      CC_STATUS_INIT;
      cc_status.flags |= CC_NO_CARRY;
      cc_status.value1 = recog_operand[0];
      break;

    case CC_COMPARE:
      /* The insn is a compare instruction.  */
      CC_STATUS_INIT;
      cc_status.value1 = SET_SRC (body);
      break;

    case CC_CLOBBER:
      /* Insn doesn't leave CC in a usable state.  */
      CC_STATUS_INIT;
      break;
    }
}

/* Retrieve the data area that has been chosen for the given decl.  */

v850_data_area
v850_get_data_area (decl)
     tree decl;
{
  if (lookup_attribute ("sda", DECL_MACHINE_ATTRIBUTES (decl)) != NULL_TREE)
    return DATA_AREA_SDA;
  
  if (lookup_attribute ("tda", DECL_MACHINE_ATTRIBUTES (decl)) != NULL_TREE)
    return DATA_AREA_TDA;
  
  if (lookup_attribute ("zda", DECL_MACHINE_ATTRIBUTES (decl)) != NULL_TREE)
    return DATA_AREA_ZDA;

  return DATA_AREA_NORMAL;
}

/* Store the indicated data area in the decl's attributes.  */

static void
v850_set_data_area (decl, data_area)
     tree decl;
     v850_data_area data_area;
{
  tree name;
  
  switch (data_area)
    {
    case DATA_AREA_SDA: name = get_identifier ("sda"); break;
    case DATA_AREA_TDA: name = get_identifier ("tda"); break;
    case DATA_AREA_ZDA: name = get_identifier ("zda"); break;
    default:
      return;
    }

  DECL_MACHINE_ATTRIBUTES (decl) = tree_cons
    (name, NULL, DECL_MACHINE_ATTRIBUTES (decl));
}

/* Return nonzero if ATTR is a valid attribute for DECL.
   ARGS are the arguments supplied with ATTR.  */

int
v850_valid_machine_decl_attribute (decl, attr, args)
     tree decl;
     tree attr;
     tree args;
{
  v850_data_area data_area;
  v850_data_area area;
  
  if (args != NULL_TREE)
    return 0;

  if (is_attribute_p ("interrupt_handler", attr)
      || is_attribute_p ("interrupt", attr))
    return TREE_CODE (decl) == FUNCTION_DECL;

  /* Implement data area attribute.  */
  if (is_attribute_p ("sda", attr))
    data_area = DATA_AREA_SDA;
  else if (is_attribute_p ("tda", attr))
    data_area = DATA_AREA_TDA;
  else if (is_attribute_p ("zda", attr))
    data_area = DATA_AREA_ZDA;
  else
    return 0;
  
  switch (TREE_CODE (decl))
    {
    case VAR_DECL:
      if (current_function_decl != NULL_TREE)
	error_with_decl (decl, "\
a data area attribute cannot be specified for local variables");
      
      /* Drop through.  */