Ejemplo n.º 1
0
static void
write_value (bfd *abfd, bfd_byte *buf, bfd_vma value, int width)
{
  switch (width)
    {
    case 2: bfd_put_16 (abfd, value, buf); break;
    case 4: bfd_put_32 (abfd, value, buf); break;
    case 8: bfd_put_64 (abfd, value, buf); break;
    default: BFD_FAIL ();
    }
}
Ejemplo n.º 2
0
static void
build_link_order (lang_statement_union_type *statement)
{
  switch (statement->header.type)
    {
    case lang_data_statement_enum:
      {
	asection *output_section;
	struct bfd_link_order *link_order;
	bfd_vma value;
	bfd_boolean big_endian = FALSE;

	output_section = statement->data_statement.output_section;
	ASSERT (output_section->owner == link_info.output_bfd);

	if (!((output_section->flags & SEC_HAS_CONTENTS) != 0
	      || ((output_section->flags & SEC_LOAD) != 0
		  && (output_section->flags & SEC_THREAD_LOCAL))))
	  break;

	link_order = bfd_new_link_order (link_info.output_bfd, output_section);
	if (link_order == NULL)
	  einfo (_("%F%P: bfd_new_link_order failed\n"));

	link_order->type = bfd_data_link_order;
	link_order->offset = statement->data_statement.output_offset;
	link_order->u.data.contents = (bfd_byte *) xmalloc (QUAD_SIZE);

	value = statement->data_statement.value;

	/* If the endianness of the output BFD is not known, then we
	   base the endianness of the data on the first input file.
	   By convention, the bfd_put routines for an unknown
	   endianness are big endian, so we must swap here if the
	   input file is little endian.  */
	if (bfd_big_endian (link_info.output_bfd))
	  big_endian = TRUE;
	else if (bfd_little_endian (link_info.output_bfd))
	  big_endian = FALSE;
	else
	  {
	    bfd_boolean swap;

	    swap = FALSE;
	    if (command_line.endian == ENDIAN_BIG)
	      big_endian = TRUE;
	    else if (command_line.endian == ENDIAN_LITTLE)
	      {
		big_endian = FALSE;
		swap = TRUE;
	      }
	    else if (command_line.endian == ENDIAN_UNSET)
	      {
		big_endian = TRUE;
		{
		  LANG_FOR_EACH_INPUT_STATEMENT (s)
		  {
		    if (s->the_bfd != NULL)
		      {
			if (bfd_little_endian (s->the_bfd))
			  {
			    big_endian = FALSE;
			    swap = TRUE;
			  }
			break;
		      }
		  }
		}
	      }

	    if (swap)
	      {
		bfd_byte buffer[8];

		switch (statement->data_statement.type)
		  {
		  case QUAD:
		  case SQUAD:
		    if (sizeof (bfd_vma) >= QUAD_SIZE)
		      {
			bfd_putl64 (value, buffer);
			value = bfd_getb64 (buffer);
			break;
		      }
		    /* Fall through.  */
		  case LONG:
		    bfd_putl32 (value, buffer);
		    value = bfd_getb32 (buffer);
		    break;
		  case SHORT:
		    bfd_putl16 (value, buffer);
		    value = bfd_getb16 (buffer);
		    break;
		  case BYTE:
		    break;
		  default:
		    abort ();
		  }
	      }
	  }

	ASSERT (output_section->owner == link_info.output_bfd);
	switch (statement->data_statement.type)
	  {
	  case QUAD:
	  case SQUAD:
	    if (sizeof (bfd_vma) >= QUAD_SIZE)
	      bfd_put_64 (link_info.output_bfd, value,
			  link_order->u.data.contents);
	    else
	      {
		bfd_vma high;

		if (statement->data_statement.type == QUAD)
		  high = 0;
		else if ((value & 0x80000000) == 0)
		  high = 0;
		else
		  high = (bfd_vma) -1;
		bfd_put_32 (link_info.output_bfd, high,
			    (link_order->u.data.contents
			     + (big_endian ? 0 : 4)));
		bfd_put_32 (link_info.output_bfd, value,
			    (link_order->u.data.contents
			     + (big_endian ? 4 : 0)));
	      }
	    link_order->size = QUAD_SIZE;
	    break;
	  case LONG:
	    bfd_put_32 (link_info.output_bfd, value,
			link_order->u.data.contents);
	    link_order->size = LONG_SIZE;
	    break;
	  case SHORT:
	    bfd_put_16 (link_info.output_bfd, value,
			link_order->u.data.contents);
	    link_order->size = SHORT_SIZE;
	    break;
	  case BYTE:
	    bfd_put_8 (link_info.output_bfd, value,
		       link_order->u.data.contents);
	    link_order->size = BYTE_SIZE;
	    break;
	  default:
	    abort ();
	  }
	link_order->u.data.size = link_order->size;
      }
      break;

    case lang_reloc_statement_enum:
      {
	lang_reloc_statement_type *rs;
	asection *output_section;
	struct bfd_link_order *link_order;

	rs = &statement->reloc_statement;

	output_section = rs->output_section;
	ASSERT (output_section->owner == link_info.output_bfd);

	if (!((output_section->flags & SEC_HAS_CONTENTS) != 0
	      || ((output_section->flags & SEC_LOAD) != 0
		  && (output_section->flags & SEC_THREAD_LOCAL))))
	  break;

	link_order = bfd_new_link_order (link_info.output_bfd, output_section);
	if (link_order == NULL)
	  einfo (_("%F%P: bfd_new_link_order failed\n"));

	link_order->offset = rs->output_offset;
	link_order->size = bfd_get_reloc_size (rs->howto);

	link_order->u.reloc.p = (struct bfd_link_order_reloc *)
	  xmalloc (sizeof (struct bfd_link_order_reloc));

	link_order->u.reloc.p->reloc = rs->reloc;
	link_order->u.reloc.p->addend = rs->addend_value;

	if (rs->name == NULL)
	  {
	    link_order->type = bfd_section_reloc_link_order;
	    if (rs->section->owner == link_info.output_bfd)
	      link_order->u.reloc.p->u.section = rs->section;
	    else
	      {
		link_order->u.reloc.p->u.section = rs->section->output_section;
		link_order->u.reloc.p->addend += rs->section->output_offset;
	      }
	  }
	else
	  {
	    link_order->type = bfd_symbol_reloc_link_order;
	    link_order->u.reloc.p->u.name = rs->name;
	  }
      }
      break;

    case lang_input_section_enum:
      {
	/* Create a new link_order in the output section with this
	   attached */
	asection *i = statement->input_section.section;

	if (i->sec_info_type != SEC_INFO_TYPE_JUST_SYMS
	    && (i->flags & SEC_EXCLUDE) == 0)
	  {
	    asection *output_section = i->output_section;
	    struct bfd_link_order *link_order;

	    ASSERT (output_section->owner == link_info.output_bfd);

	    if (!((output_section->flags & SEC_HAS_CONTENTS) != 0
		  || ((output_section->flags & SEC_LOAD) != 0
		      && (output_section->flags & SEC_THREAD_LOCAL))))
	      break;

	    link_order = bfd_new_link_order (link_info.output_bfd,
					     output_section);
	    if (link_order == NULL)
	      einfo (_("%F%P: bfd_new_link_order failed\n"));

	    if ((i->flags & SEC_NEVER_LOAD) != 0
		&& (i->flags & SEC_DEBUGGING) == 0)
	      {
		/* We've got a never load section inside one which is
		   going to be output, we'll change it into a fill.  */
		link_order->type = bfd_data_link_order;
		link_order->u.data.contents = (unsigned char *) "";
		link_order->u.data.size = 1;
	      }
	    else
	      {
		link_order->type = bfd_indirect_link_order;
		link_order->u.indirect.section = i;
		ASSERT (i->output_section == output_section);
	      }
	    link_order->size = i->size;
	    link_order->offset = i->output_offset;
	  }
      }
      break;

    case lang_padding_statement_enum:
      /* Make a new link_order with the right filler */
      {
	asection *output_section;
	struct bfd_link_order *link_order;

	output_section = statement->padding_statement.output_section;
	ASSERT (statement->padding_statement.output_section->owner
		== link_info.output_bfd);

	if (!((output_section->flags & SEC_HAS_CONTENTS) != 0
	      || ((output_section->flags & SEC_LOAD) != 0
		  && (output_section->flags & SEC_THREAD_LOCAL))))
	  break;

	link_order = bfd_new_link_order (link_info.output_bfd,
					 output_section);
	if (link_order == NULL)
	  einfo (_("%F%P: bfd_new_link_order failed\n"));
	link_order->type = bfd_data_link_order;
	link_order->size = statement->padding_statement.size;
	link_order->offset = statement->padding_statement.output_offset;
	link_order->u.data.contents = statement->padding_statement.fill->data;
	link_order->u.data.size = statement->padding_statement.fill->size;
      }
      break;

    default:
      /* All the other ones fall through */
      break;
    }
Ejemplo n.º 3
0
/* Insert the addend/value into the instruction or data object being
   relocated.  */
bfd_reloc_status_type
_bfd_aarch64_elf_put_addend (bfd *abfd,
			     bfd_byte *address, bfd_reloc_code_real_type r_type,
			     reloc_howto_type *howto, bfd_signed_vma addend)
{
  bfd_reloc_status_type status = bfd_reloc_ok;
  bfd_signed_vma old_addend = addend;
  bfd_vma contents;
  int size;

  size = bfd_get_reloc_size (howto);
  switch (size)
    {
    case 2:
      contents = bfd_get_16 (abfd, address);
      break;
    case 4:
      if (howto->src_mask != 0xffffffff)
	/* Must be 32-bit instruction, always little-endian.  */
	contents = bfd_getl32 (address);
      else
	/* Must be 32-bit data (endianness dependent).  */
	contents = bfd_get_32 (abfd, address);
      break;
    case 8:
      contents = bfd_get_64 (abfd, address);
      break;
    default:
      abort ();
    }

  switch (howto->complain_on_overflow)
    {
    case complain_overflow_dont:
      break;
    case complain_overflow_signed:
      status = aarch64_signed_overflow (addend,
					howto->bitsize + howto->rightshift);
      break;
    case complain_overflow_unsigned:
      status = aarch64_unsigned_overflow (addend,
					  howto->bitsize + howto->rightshift);
      break;
    case complain_overflow_bitfield:
    default:
      abort ();
    }

  addend >>= howto->rightshift;

  switch (r_type)
    {
    case BFD_RELOC_AARCH64_JUMP26:
    case BFD_RELOC_AARCH64_CALL26:
      contents = reencode_branch_ofs_26 (contents, addend);
      break;

    case BFD_RELOC_AARCH64_BRANCH19:
      contents = reencode_cond_branch_ofs_19 (contents, addend);
      break;

    case BFD_RELOC_AARCH64_TSTBR14:
      contents = reencode_tst_branch_ofs_14 (contents, addend);
      break;

    case BFD_RELOC_AARCH64_LD_LO19_PCREL:
    case BFD_RELOC_AARCH64_GOT_LD_PREL19:
      if (old_addend & ((1 << howto->rightshift) - 1))
	return bfd_reloc_overflow;
      contents = reencode_ld_lit_ofs_19 (contents, addend);
      break;

    case BFD_RELOC_AARCH64_TLSDESC_CALL:
      break;

    case BFD_RELOC_AARCH64_TLSGD_ADR_PAGE21:
    case BFD_RELOC_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
    case BFD_RELOC_AARCH64_TLSDESC_ADR_PAGE21:
    case BFD_RELOC_AARCH64_ADR_GOT_PAGE:
    case BFD_RELOC_AARCH64_ADR_LO21_PCREL:
    case BFD_RELOC_AARCH64_ADR_HI21_PCREL:
    case BFD_RELOC_AARCH64_ADR_HI21_NC_PCREL:
      contents = reencode_adr_imm (contents, addend);
      break;

    case BFD_RELOC_AARCH64_TLSGD_ADD_LO12_NC:
    case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_LO12:
    case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_HI12:
    case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_LO12_NC:
    case BFD_RELOC_AARCH64_TLSDESC_ADD_LO12_NC:
    case BFD_RELOC_AARCH64_ADD_LO12:
      /* Corresponds to: add rd, rn, #uimm12 to provide the low order
         12 bits of the page offset following
         BFD_RELOC_AARCH64_ADR_HI21_PCREL which computes the
         (pc-relative) page base.  */
      contents = reencode_add_imm (contents, addend);
      break;

    case BFD_RELOC_AARCH64_LDST8_LO12:
    case BFD_RELOC_AARCH64_LDST16_LO12:
    case BFD_RELOC_AARCH64_LDST32_LO12:
    case BFD_RELOC_AARCH64_LDST64_LO12:
    case BFD_RELOC_AARCH64_LDST128_LO12:
    case BFD_RELOC_AARCH64_TLSDESC_LD64_LO12_NC:
    case BFD_RELOC_AARCH64_TLSDESC_LD32_LO12_NC:
    case BFD_RELOC_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
    case BFD_RELOC_AARCH64_TLSIE_LD32_GOTTPREL_LO12_NC:
    case BFD_RELOC_AARCH64_LD64_GOT_LO12_NC:
    case BFD_RELOC_AARCH64_LD32_GOT_LO12_NC:
      if (old_addend & ((1 << howto->rightshift) - 1))
	return bfd_reloc_overflow;
      /* Used for ldr*|str* rt, [rn, #uimm12] to provide the low order
         12 bits of the page offset following BFD_RELOC_AARCH64_ADR_HI21_PCREL
         which computes the (pc-relative) page base.  */
      contents = reencode_ldst_pos_imm (contents, addend);
      break;

      /* Group relocations to create high bits of a 16, 32, 48 or 64
         bit signed data or abs address inline. Will change
         instruction to MOVN or MOVZ depending on sign of calculated
         value.  */

    case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G2:
    case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G1:
    case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G1_NC:
    case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G0:
    case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G0_NC:
    case BFD_RELOC_AARCH64_MOVW_G0_S:
    case BFD_RELOC_AARCH64_MOVW_G1_S:
    case BFD_RELOC_AARCH64_MOVW_G2_S:
      /* NOTE: We can only come here with movz or movn.  */
      if (addend < 0)
	{
	  /* Force use of MOVN.  */
	  addend = ~addend;
	  contents = reencode_movzn_to_movn (contents);
	}
      else
	{
	  /* Force use of MOVZ.  */
	  contents = reencode_movzn_to_movz (contents);
	}
      /* fall through */

      /* Group relocations to create a 16, 32, 48 or 64 bit unsigned
         data or abs address inline.  */

    case BFD_RELOC_AARCH64_MOVW_G0:
    case BFD_RELOC_AARCH64_MOVW_G0_NC:
    case BFD_RELOC_AARCH64_MOVW_G1:
    case BFD_RELOC_AARCH64_MOVW_G1_NC:
    case BFD_RELOC_AARCH64_MOVW_G2:
    case BFD_RELOC_AARCH64_MOVW_G2_NC:
    case BFD_RELOC_AARCH64_MOVW_G3:
      contents = reencode_movw_imm (contents, addend);
      break;

    default:
      /* Repack simple data */
      if (howto->dst_mask & (howto->dst_mask + 1))
	return bfd_reloc_notsupported;

      contents = ((contents & ~howto->dst_mask) | (addend & howto->dst_mask));
      break;
    }

  switch (size)
    {
    case 2:
      bfd_put_16 (abfd, contents, address);
      break;
    case 4:
      if (howto->dst_mask != 0xffffffff)
	/* must be 32-bit instruction, always little-endian */
	bfd_putl32 (contents, address);
      else
	/* must be 32-bit data (endianness dependent) */
	bfd_put_32 (abfd, contents, address);
      break;
    case 8:
      bfd_put_64 (abfd, contents, address);
      break;
    default:
      abort ();
    }

  return status;
}
Ejemplo n.º 4
0
bfd_boolean
_bfd_write_section_stabs (bfd *output_bfd,
			  struct stab_info *sinfo,
			  asection *stabsec,
			  void * *psecinfo,
			  bfd_byte *contents)
{
  struct stab_section_info *secinfo;
  struct stab_excl_list *e;
  bfd_byte *sym, *tosym, *symend;
  bfd_size_type *pstridx;

  secinfo = (struct stab_section_info *) *psecinfo;

  if (secinfo == NULL)
    return bfd_set_section_contents (output_bfd, stabsec->output_section,
				     contents, stabsec->output_offset,
				     stabsec->size);

  /* Handle each N_BINCL entry.  */
  for (e = secinfo->excls; e != NULL; e = e->next)
    {
      bfd_byte *excl_sym;

      BFD_ASSERT (e->offset < stabsec->rawsize);
      excl_sym = contents + e->offset;
      bfd_put_32 (output_bfd, e->val, excl_sym + VALOFF);
      excl_sym[TYPEOFF] = e->type;
    }

  /* Copy over all the stabs symbols, omitting the ones we don't want,
     and correcting the string indices for those we do want.  */
  tosym = contents;
  symend = contents + stabsec->rawsize;
  for (sym = contents, pstridx = secinfo->stridxs;
       sym < symend;
       sym += STABSIZE, ++pstridx)
    {
      if (*pstridx != (bfd_size_type) -1)
	{
	  if (tosym != sym)
	    memcpy (tosym, sym, STABSIZE);
	  bfd_put_32 (output_bfd, *pstridx, tosym + STRDXOFF);

	  if (sym[TYPEOFF] == 0)
	    {
	      /* This is the header symbol for the stabs section.  We
		 don't really need one, since we have merged all the
		 input stabs sections into one, but we generate one
		 for the benefit of readers which expect to see one.  */
	      BFD_ASSERT (sym == contents);
	      bfd_put_32 (output_bfd, _bfd_stringtab_size (sinfo->strings),
			  tosym + VALOFF);
	      bfd_put_16 (output_bfd,
			  stabsec->output_section->size / STABSIZE - 1,
			  tosym + DESCOFF);
	    }

	  tosym += STABSIZE;
	}
    }

  BFD_ASSERT ((bfd_size_type) (tosym - contents) == stabsec->size);

  return bfd_set_section_contents (output_bfd, stabsec->output_section,
				   contents, (file_ptr) stabsec->output_offset,
				   stabsec->size);
}
Ejemplo n.º 5
0
static void
extra_case (bfd *in_abfd,
            struct bfd_link_info *link_info,
            struct bfd_link_order *link_order,
            arelent *reloc,
            bfd_byte *data,
            unsigned int *src_ptr,
            unsigned int *dst_ptr)
{
  asection * input_section = link_order->u.indirect.section;

  switch (reloc->howto->type)
    {
    case R_IMM8:
      bfd_put_8 (in_abfd,
		 bfd_coff_reloc16_get_value (reloc, link_info, input_section),
		 data + *dst_ptr);
      (*dst_ptr) += 1;
      (*src_ptr) += 1;
      break;

    case R_IMM32:
      /* If no flags are set, assume immediate value.  */
      if (! (*reloc->sym_ptr_ptr)->section->flags)
	{
	  bfd_put_32 (in_abfd,
		      bfd_coff_reloc16_get_value (reloc, link_info,
						  input_section),
		      data + *dst_ptr);
	}
      else
	{
	  bfd_vma dst = bfd_coff_reloc16_get_value (reloc, link_info,
						    input_section);
	  /* Addresses are 23 bit, and the layout of those in a 32-bit
	     value is as follows:
	       1AAAAAAA xxxxxxxx AAAAAAAA AAAAAAAA
	     (A - address bits,  x - ignore).  */
	  dst = (dst & 0xffff) | ((dst & 0xff0000) << 8) | 0x80000000;
	  bfd_put_32 (in_abfd, dst, data + *dst_ptr);
	}
      (*dst_ptr) += 4;
      (*src_ptr) += 4;
      break;

    case R_IMM4L:
      bfd_put_8 (in_abfd,
		 ((bfd_get_8 (in_abfd, data + *dst_ptr) & 0xf0)
		  | (0x0f
		     & bfd_coff_reloc16_get_value (reloc, link_info,
						   input_section))),
		 data + *dst_ptr);
      (*dst_ptr) += 1;
      (*src_ptr) += 1;
      break;

    case R_IMM16:
      bfd_put_16 (in_abfd,
		  bfd_coff_reloc16_get_value (reloc, link_info, input_section),
		  data + *dst_ptr);
      (*dst_ptr) += 2;
      (*src_ptr) += 2;
      break;

    case R_JR:
      {
	bfd_vma dst = bfd_coff_reloc16_get_value (reloc, link_info,
						  input_section);
	bfd_vma dot = (link_order->offset
		       + *dst_ptr
		       + input_section->output_section->vma);
	/* -1L, since we are in the odd byte of the word, and the pc has been
	 * incremented: */
	ptrdiff_t gap = ((ptrdiff_t)(dst - dot) - 1L); 

	if (gap & 1L)
	  abort();
	gap /= 2L;
	if ((gap > 128L) || (gap < -128L))
	  {
	    if (!((*link_info->callbacks->reloc_overflow)
		  (link_info, NULL,
		   bfd_asymbol_name(*reloc->sym_ptr_ptr),
		   reloc->howto->name, reloc->addend, input_section->owner,
		   input_section, reloc->address)))
	      abort();
	  }
	bfd_put_8(in_abfd, gap, (data + *dst_ptr));
	(*dst_ptr)++;
	(*src_ptr)++;
	break;
      }

    case R_DISP7:
      {
	bfd_vma dst = bfd_coff_reloc16_get_value (reloc, link_info,
						  input_section);
	bfd_vma dot = (link_order->offset
		       + *dst_ptr
		       + input_section->output_section->vma);
	/* -1L, since we are in the odd byte of the word, and the pc has been
	 * incremented: */
	ptrdiff_t gap = ((ptrdiff_t)(dst - dot) - 1L);

	if (gap & 1L)
	  abort();
	gap /= 2L;

	if ((gap > 0L) || (gap < -127L))
	  {
	    if (!((*link_info->callbacks->reloc_overflow)
		  (link_info, NULL,
		   bfd_asymbol_name(*reloc->sym_ptr_ptr),
		   reloc->howto->name, reloc->addend, input_section->owner,
		   input_section, reloc->address)))
	      abort();
	  }
	bfd_put_8(in_abfd,
                  (bfd_get_8(in_abfd, data + *dst_ptr) & 0x80) + (-gap & 0x7f),
                  (data + *dst_ptr));
	(*dst_ptr)++;
	(*src_ptr)++;
	break;
      }

    case R_CALLR:
      {
	bfd_vma dst = bfd_coff_reloc16_get_value (reloc, link_info,
						  input_section);
	bfd_vma dot = (link_order->offset
		       + *dst_ptr
		       + input_section->output_section->vma);
	ptrdiff_t gap = ((ptrdiff_t)(dst - dot) - 2L);

	if (gap & 1L)
	  abort();
	if ((gap > 4096L) || (gap < -4095L))
	  {
	    if (!((*link_info->callbacks->reloc_overflow)
		  (link_info, NULL,
		   bfd_asymbol_name(*reloc->sym_ptr_ptr),
		   reloc->howto->name, reloc->addend, input_section->owner,
		   input_section, reloc->address)))
	      abort();
	  }
	gap /= 2L;
	bfd_put_16(in_abfd,
                   ((bfd_get_16(in_abfd, (data + *dst_ptr)) & 0xf000)
		    | (-gap & 0x0fff)),
                   (data + *dst_ptr));
	(*dst_ptr) += 2;
	(*src_ptr) += 2;
	break;
      }

    case R_REL16:
      {
	bfd_vma dst = bfd_coff_reloc16_get_value (reloc, link_info,
						  input_section);
	bfd_vma dot = (link_order->offset
		       + *dst_ptr
		       + input_section->output_section->vma);
	ptrdiff_t gap = ((ptrdiff_t)(dst - dot) - 2L);

	if ((gap > 32767L) || (gap < -32768L))
	  {
	    if (!((*link_info->callbacks->reloc_overflow)
		  (link_info, NULL,
		   bfd_asymbol_name(*reloc->sym_ptr_ptr),
		   reloc->howto->name, reloc->addend, input_section->owner,
		   input_section, reloc->address)))
	      abort();
	  }
	bfd_put_16(in_abfd, (bfd_vma)gap, (data + *dst_ptr));
	(*dst_ptr) += 2;
	(*src_ptr) += 2;
	break;
      }

    default:
      abort();
    }
}