Home | History | Annotate | Line # | Download | only in bfd
cpu-ns32k.c revision 1.1.1.1
      1 /* BFD support for the ns32k architecture.
      2    Copyright 1990, 1991, 1994, 1995, 1998, 1999, 2000, 2001, 2002, 2003,
      3    2004, 2005, 2007 Free Software Foundation, Inc.
      4    Almost totally rewritten by Ian Dall from initial work
      5    by Andrew Cagney.
      6 
      7    This file is part of BFD, the Binary File Descriptor library.
      8 
      9    This program is free software; you can redistribute it and/or modify
     10    it under the terms of the GNU General Public License as published by
     11    the Free Software Foundation; either version 3 of the License, or
     12    (at your option) any later version.
     13 
     14    This program is distributed in the hope that it will be useful,
     15    but WITHOUT ANY WARRANTY; without even the implied warranty of
     16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     17    GNU General Public License for more details.
     18 
     19    You should have received a copy of the GNU General Public License
     20    along with this program; if not, write to the Free Software
     21    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
     22    MA 02110-1301, USA.  */
     23 
     24 #include "sysdep.h"
     25 #include "bfd.h"
     26 #include "libbfd.h"
     27 #include "ns32k.h"
     28 
     29 #define N(machine, printable, d, next)  \
     30 {  32, 32, 8, bfd_arch_ns32k, machine, "ns32k",printable,3,d,bfd_default_compatible,bfd_default_scan, next, }
     31 
     32 static const bfd_arch_info_type arch_info_struct[] =
     33 {
     34   N(32532,"ns32k:32532",TRUE, 0), /* The word ns32k will match this too.  */
     35 };
     36 
     37 const bfd_arch_info_type bfd_ns32k_arch =
     38   N(32032,"ns32k:32032",FALSE, &arch_info_struct[0]);
     39 
     40 static bfd_reloc_status_type do_ns32k_reloc
     41   PARAMS ((bfd *, arelent *, struct bfd_symbol *, PTR, asection *,
     42 	   bfd *, char **,
     43 	   bfd_vma (*) (bfd_byte *, int),
     44 	   void (*) (bfd_vma, bfd_byte *, int)));
     45 
     46 bfd_vma
     47 _bfd_ns32k_get_displacement (buffer, size)
     48      bfd_byte *buffer;
     49      int size;
     50 {
     51   bfd_signed_vma value;
     52 
     53   switch (size)
     54     {
     55     case 1:
     56       value = ((*buffer & 0x7f) ^ 0x40) - 0x40;
     57       break;
     58 
     59     case 2:
     60       value = ((*buffer++ & 0x3f) ^ 0x20) - 0x20;
     61       value = (value << 8) | (0xff & *buffer);
     62       break;
     63 
     64     case 4:
     65       value = ((*buffer++ & 0x3f) ^ 0x20) - 0x20;
     66       value = (value << 8) | (0xff & *buffer++);
     67       value = (value << 8) | (0xff & *buffer++);
     68       value = (value << 8) | (0xff & *buffer);
     69       break;
     70 
     71     default:
     72       abort ();
     73       return 0;
     74     }
     75 
     76   return value;
     77 }
     78 
     79 void
     80 _bfd_ns32k_put_displacement (value, buffer, size)
     81      bfd_vma value;
     82      bfd_byte *buffer;
     83      int size;
     84 {
     85   switch (size)
     86     {
     87     case 1:
     88       value &= 0x7f;
     89       *buffer++ = value;
     90       break;
     91 
     92     case 2:
     93       value &= 0x3fff;
     94       value |= 0x8000;
     95       *buffer++ = (value >> 8);
     96       *buffer++ = value;
     97       break;
     98 
     99     case 4:
    100       value |= (bfd_vma) 0xc0000000;
    101       *buffer++ = (value >> 24);
    102       *buffer++ = (value >> 16);
    103       *buffer++ = (value >> 8);
    104       *buffer++ = value;
    105       break;
    106   }
    107   return;
    108 }
    109 
    110 bfd_vma
    111 _bfd_ns32k_get_immediate (buffer, size)
    112      bfd_byte *buffer;
    113      int size;
    114 {
    115   bfd_vma value = 0;
    116 
    117   switch (size)
    118     {
    119     case 4:
    120       value = (value << 8) | (*buffer++ & 0xff);
    121       value = (value << 8) | (*buffer++ & 0xff);
    122     case 2:
    123       value = (value << 8) | (*buffer++ & 0xff);
    124     case 1:
    125       value = (value << 8) | (*buffer++ & 0xff);
    126       break;
    127     default:
    128       abort ();
    129     }
    130   return value;
    131 }
    132 
    133 void
    134 _bfd_ns32k_put_immediate (value, buffer, size)
    135      bfd_vma value;
    136      bfd_byte *buffer;
    137      int size;
    138 {
    139   buffer += size - 1;
    140   switch (size)
    141     {
    142     case 4:
    143       *buffer-- = (value & 0xff); value >>= 8;
    144       *buffer-- = (value & 0xff); value >>= 8;
    145     case 2:
    146       *buffer-- = (value & 0xff); value >>= 8;
    147     case 1:
    148       *buffer-- = (value & 0xff); value >>= 8;
    149     }
    150 }
    151 
    152 /* This is just like the standard perform_relocation except we
    153    use get_data and put_data which know about the ns32k storage
    154    methods.  This is probably a lot more complicated than it
    155    needs to be!  */
    156 
    157 static bfd_reloc_status_type
    158 do_ns32k_reloc (abfd, reloc_entry, symbol, data, input_section, output_bfd,
    159 		error_message, get_data, put_data)
    160      bfd *abfd;
    161      arelent *reloc_entry;
    162      struct bfd_symbol *symbol;
    163      PTR data;
    164      asection *input_section;
    165      bfd *output_bfd;
    166      char **error_message ATTRIBUTE_UNUSED;
    167      bfd_vma (*get_data) PARAMS ((bfd_byte *, int));
    168      void (*put_data) PARAMS ((bfd_vma, bfd_byte *, int));
    169 {
    170   int overflow = 0;
    171   bfd_vma relocation;
    172   bfd_reloc_status_type flag = bfd_reloc_ok;
    173   bfd_size_type addr = reloc_entry->address;
    174   bfd_vma output_base = 0;
    175   reloc_howto_type *howto = reloc_entry->howto;
    176   asection *reloc_target_output_section;
    177   bfd_byte *location;
    178 
    179   if ((symbol->section == &bfd_abs_section)
    180       && output_bfd != (bfd *) NULL)
    181     {
    182       reloc_entry->address += input_section->output_offset;
    183       return bfd_reloc_ok;
    184     }
    185 
    186   /* If we are not producing relocatable output, return an error if
    187      the symbol is not defined.  An undefined weak symbol is
    188      considered to have a value of zero (SVR4 ABI, p. 4-27).  */
    189   if (symbol->section == &bfd_und_section
    190       && (symbol->flags & BSF_WEAK) == 0
    191       && output_bfd == (bfd *) NULL)
    192     flag = bfd_reloc_undefined;
    193 
    194   /* Is the address of the relocation really within the section?  */
    195   if (reloc_entry->address > bfd_get_section_limit (abfd, input_section))
    196     return bfd_reloc_outofrange;
    197 
    198   /* Work out which section the relocation is targeted at and the
    199      initial relocation command value.  */
    200 
    201   /* Get symbol value.  (Common symbols are special.)  */
    202   if (bfd_is_com_section (symbol->section))
    203     relocation = 0;
    204   else
    205     relocation = symbol->value;
    206 
    207   reloc_target_output_section = symbol->section->output_section;
    208 
    209   /* Convert input-section-relative symbol value to absolute.  */
    210   if (output_bfd != NULL && ! howto->partial_inplace)
    211     output_base = 0;
    212   else
    213     output_base = reloc_target_output_section->vma;
    214 
    215   relocation += output_base + symbol->section->output_offset;
    216 
    217   /* Add in supplied addend.  */
    218   relocation += reloc_entry->addend;
    219 
    220   /* Here the variable relocation holds the final address of the
    221      symbol we are relocating against, plus any addend.  */
    222 
    223   if (howto->pc_relative)
    224     {
    225       /* This is a PC relative relocation.  We want to set RELOCATION
    226 	 to the distance between the address of the symbol and the
    227 	 location.  RELOCATION is already the address of the symbol.
    228 
    229 	 We start by subtracting the address of the section containing
    230 	 the location.
    231 
    232 	 If pcrel_offset is set, we must further subtract the position
    233 	 of the location within the section.  Some targets arrange for
    234 	 the addend to be the negative of the position of the location
    235 	 within the section; for example, i386-aout does this.  For
    236 	 i386-aout, pcrel_offset is FALSE.  Some other targets do not
    237 	 include the position of the location; for example, m88kbcs,
    238 	 or ELF.  For those targets, pcrel_offset is TRUE.
    239 
    240 	 If we are producing relocatable output, then we must ensure
    241 	 that this reloc will be correctly computed when the final
    242 	 relocation is done.  If pcrel_offset is FALSE we want to wind
    243 	 up with the negative of the location within the section,
    244 	 which means we must adjust the existing addend by the change
    245 	 in the location within the section.  If pcrel_offset is TRUE
    246 	 we do not want to adjust the existing addend at all.
    247 
    248 	 FIXME: This seems logical to me, but for the case of
    249 	 producing relocatable output it is not what the code
    250 	 actually does.  I don't want to change it, because it seems
    251 	 far too likely that something will break.  */
    252       relocation -=
    253 	input_section->output_section->vma + input_section->output_offset;
    254 
    255       if (howto->pcrel_offset)
    256 	relocation -= reloc_entry->address;
    257     }
    258 
    259   if (output_bfd != (bfd *) NULL)
    260     {
    261       if (! howto->partial_inplace)
    262 	{
    263 	  /* This is a partial relocation, and we want to apply the relocation
    264 	     to the reloc entry rather than the raw data. Modify the reloc
    265 	     inplace to reflect what we now know.  */
    266 	  reloc_entry->addend = relocation;
    267 	  reloc_entry->address += input_section->output_offset;
    268 	  return flag;
    269 	}
    270       else
    271 	{
    272 	  /* This is a partial relocation, but inplace, so modify the
    273 	     reloc record a bit.
    274 
    275 	     If we've relocated with a symbol with a section, change
    276 	     into a ref to the section belonging to the symbol.  */
    277 
    278 	  reloc_entry->address += input_section->output_offset;
    279 
    280 	  /* WTF?? */
    281 	  if (abfd->xvec->flavour == bfd_target_coff_flavour)
    282 	    {
    283 	      /* For m68k-coff, the addend was being subtracted twice during
    284 		 relocation with -r.  Removing the line below this comment
    285 		 fixes that problem; see PR 2953.
    286 
    287 		 However, Ian wrote the following, regarding removing the line
    288 		 below, which explains why it is still enabled:  --djm
    289 
    290 		 If you put a patch like that into BFD you need to check all
    291 		 the COFF linkers.  I am fairly certain that patch will break
    292 		 coff-i386 (e.g., SCO); see coff_i386_reloc in coff-i386.c
    293 		 where I worked around the problem in a different way.  There
    294 		 may very well be a reason that the code works as it does.
    295 
    296 		 Hmmm.  The first obvious point is that bfd_perform_relocation
    297 		 should not have any tests that depend upon the flavour.  It's
    298 		 seem like entirely the wrong place for such a thing.  The
    299 		 second obvious point is that the current code ignores the
    300 		 reloc addend when producing relocatable output for COFF.
    301 		 That's peculiar.  In fact, I really have no idea what the
    302 		 point of the line you want to remove is.
    303 
    304 		 A typical COFF reloc subtracts the old value of the symbol
    305 		 and adds in the new value to the location in the object file
    306 		 (if it's a pc relative reloc it adds the difference between
    307 		 the symbol value and the location).  When relocating we need
    308 		 to preserve that property.
    309 
    310 		 BFD handles this by setting the addend to the negative of the
    311 		 old value of the symbol.  Unfortunately it handles common
    312 		 symbols in a non-standard way (it doesn't subtract the old
    313 		 value) but that's a different story (we can't change it
    314 		 without losing backward compatibility with old object files)
    315 		 (coff-i386 does subtract the old value, to be compatible with
    316 		 existing coff-i386 targets, like SCO).
    317 
    318 		 So everything works fine when not producing relocatable
    319 		 output.  When we are producing relocatable output, logically
    320 		 we should do exactly what we do when not producing
    321 		 relocatable output.  Therefore, your patch is correct.  In
    322 		 fact, it should probably always just set reloc_entry->addend
    323 		 to 0 for all cases, since it is, in fact, going to add the
    324 		 value into the object file.  This won't hurt the COFF code,
    325 		 which doesn't use the addend; I'm not sure what it will do
    326 		 to other formats (the thing to check for would be whether
    327 		 any formats both use the addend and set partial_inplace).
    328 
    329 		 When I wanted to make coff-i386 produce relocatable output,
    330 		 I ran into the problem that you are running into: I wanted
    331 		 to remove that line.  Rather than risk it, I made the
    332 		 coff-i386 relocs use a special function; it's coff_i386_reloc
    333 		 in coff-i386.c.  The function specifically adds the addend
    334 		 field into the object file, knowing that bfd_perform_relocation
    335 		 is not going to.  If you remove that line, then coff-i386.c
    336 		 will wind up adding the addend field in twice.  It's trivial
    337 		 to fix; it just needs to be done.
    338 
    339 		 The problem with removing the line is just that it may break
    340 		 some working code.  With BFD it's hard to be sure of anything.
    341 		 The right way to deal with this is simply to build and test at
    342 		 least all the supported COFF targets.  It should be
    343 		 straightforward if time and disk space consuming.  For each
    344 		 target:
    345 		   1) build the linker
    346 		   2) generate some executable, and link it using -r (I would
    347 		      probably use paranoia.o and link against newlib/libc.a,
    348 		      which for all the supported targets would be available in
    349 		      /usr/cygnus/progressive/H-host/target/lib/libc.a).
    350 		   3) make the change to reloc.c
    351 		   4) rebuild the linker
    352 		   5) repeat step 2
    353 		   6) if the resulting object files are the same, you have at
    354 		      least made it no worse
    355 		   7) if they are different you have to figure out which
    356 		      version is right.  */
    357 	      relocation -= reloc_entry->addend;
    358 	      reloc_entry->addend = 0;
    359 	    }
    360 	  else
    361 	    {
    362 	      reloc_entry->addend = relocation;
    363 	    }
    364 	}
    365     }
    366   else
    367     {
    368       reloc_entry->addend = 0;
    369     }
    370 
    371   /* FIXME: This overflow checking is incomplete, because the value
    372      might have overflowed before we get here.  For a correct check we
    373      need to compute the value in a size larger than bitsize, but we
    374      can't reasonably do that for a reloc the same size as a host
    375      machine word.
    376      FIXME: We should also do overflow checking on the result after
    377      adding in the value contained in the object file.  */
    378   if (howto->complain_on_overflow != complain_overflow_dont)
    379     {
    380       bfd_vma check;
    381 
    382       /* Get the value that will be used for the relocation, but
    383 	 starting at bit position zero.  */
    384       if (howto->rightshift > howto->bitpos)
    385 	check = relocation >> (howto->rightshift - howto->bitpos);
    386       else
    387 	check = relocation << (howto->bitpos - howto->rightshift);
    388       switch (howto->complain_on_overflow)
    389 	{
    390 	case complain_overflow_signed:
    391 	  {
    392 	    /* Assumes two's complement.  */
    393 	    bfd_signed_vma reloc_signed_max = (1 << (howto->bitsize - 1)) - 1;
    394 	    bfd_signed_vma reloc_signed_min = ~reloc_signed_max;
    395 
    396 	    /* The above right shift is incorrect for a signed value.
    397 	       Fix it up by forcing on the upper bits.  */
    398 	    if (howto->rightshift > howto->bitpos
    399 		&& (bfd_signed_vma) relocation < 0)
    400 	      check |= ((bfd_vma) - 1
    401 			& ~((bfd_vma) - 1
    402 			    >> (howto->rightshift - howto->bitpos)));
    403 	    if ((bfd_signed_vma) check > reloc_signed_max
    404 		|| (bfd_signed_vma) check < reloc_signed_min)
    405 	      flag = bfd_reloc_overflow;
    406 	  }
    407 	  break;
    408 	case complain_overflow_unsigned:
    409 	  {
    410 	    /* Assumes two's complement.  This expression avoids
    411 	       overflow if howto->bitsize is the number of bits in
    412 	       bfd_vma.  */
    413 	    bfd_vma reloc_unsigned_max =
    414 	    (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
    415 
    416 	    if ((bfd_vma) check > reloc_unsigned_max)
    417 	      flag = bfd_reloc_overflow;
    418 	  }
    419 	  break;
    420 	case complain_overflow_bitfield:
    421 	  {
    422 	    /* Assumes two's complement.  This expression avoids
    423 	       overflow if howto->bitsize is the number of bits in
    424 	       bfd_vma.  */
    425 	    bfd_vma reloc_bits = (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
    426 
    427 	    if (((bfd_vma) check & ~reloc_bits) != 0
    428 		&& (((bfd_vma) check & ~reloc_bits)
    429 		    != (-(bfd_vma) 1 & ~reloc_bits)))
    430 	      {
    431 		/* The above right shift is incorrect for a signed
    432 		   value.  See if turning on the upper bits fixes the
    433 		   overflow.  */
    434 		if (howto->rightshift > howto->bitpos
    435 		    && (bfd_signed_vma) relocation < 0)
    436 		  {
    437 		    check |= ((bfd_vma) - 1
    438 			      & ~((bfd_vma) - 1
    439 				  >> (howto->rightshift - howto->bitpos)));
    440 		    if (((bfd_vma) check & ~reloc_bits)
    441 			!= (-(bfd_vma) 1 & ~reloc_bits))
    442 		      flag = bfd_reloc_overflow;
    443 		  }
    444 		else
    445 		  flag = bfd_reloc_overflow;
    446 	      }
    447 	  }
    448 	  break;
    449 	default:
    450 	  abort ();
    451 	}
    452     }
    453 
    454   /* Either we are relocating all the way, or we don't want to apply
    455      the relocation to the reloc entry (probably because there isn't
    456      any room in the output format to describe addends to relocs).  */
    457 
    458   /* The cast to bfd_vma avoids a bug in the Alpha OSF/1 C compiler
    459      (OSF version 1.3, compiler version 3.11).  It miscompiles the
    460      following program:
    461 
    462      struct str
    463      {
    464        unsigned int i0;
    465      } s = { 0 };
    466 
    467      int
    468      main ()
    469      {
    470        unsigned long x;
    471 
    472        x = 0x100000000;
    473        x <<= (unsigned long) s.i0;
    474        if (x == 0)
    475 	 printf ("failed\n");
    476        else
    477 	 printf ("succeeded (%lx)\n", x);
    478      }
    479      */
    480 
    481   relocation >>= (bfd_vma) howto->rightshift;
    482 
    483   /* Shift everything up to where it's going to be used.  */
    484   relocation <<= (bfd_vma) howto->bitpos;
    485 
    486   /* Wait for the day when all have the mask in them.  */
    487 
    488   /* What we do:
    489      i instruction to be left alone
    490      o offset within instruction
    491      r relocation offset to apply
    492      S src mask
    493      D dst mask
    494      N ~dst mask
    495      A part 1
    496      B part 2
    497      R result
    498 
    499      Do this:
    500      i i i i i o o o o o        from bfd_get<size>
    501      and           S S S S S    to get the size offset we want
    502      +   r r r r r r r r r r  to get the final value to place
    503      and           D D D D D  to chop to right size
    504      -----------------------
    505      A A A A A
    506      And this:
    507      ...   i i i i i o o o o o  from bfd_get<size>
    508      and   N N N N N            get instruction
    509      -----------------------
    510      ...   B B B B B
    511 
    512      And then:
    513      B B B B B
    514      or              A A A A A
    515      -----------------------
    516      R R R R R R R R R R        put into bfd_put<size>.  */
    517 
    518 #define DOIT(x) \
    519   x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) +  relocation) & howto->dst_mask))
    520 
    521   location = (bfd_byte *) data + addr;
    522   switch (howto->size)
    523     {
    524     case 0:
    525       {
    526 	bfd_vma x = get_data (location, 1);
    527 	DOIT (x);
    528 	put_data ((bfd_vma) x, location, 1);
    529       }
    530       break;
    531 
    532     case 1:
    533       if (relocation)
    534 	{
    535 	  bfd_vma x = get_data (location, 2);
    536 	  DOIT (x);
    537 	  put_data ((bfd_vma) x, location, 2);
    538 	}
    539       break;
    540     case 2:
    541       if (relocation)
    542 	{
    543 	  bfd_vma x = get_data (location, 4);
    544 	  DOIT (x);
    545 	  put_data ((bfd_vma) x, location, 4);
    546 	}
    547       break;
    548     case -2:
    549       {
    550 	bfd_vma x = get_data (location, 4);
    551 	relocation = -relocation;
    552 	DOIT(x);
    553 	put_data ((bfd_vma) x, location, 4);
    554       }
    555       break;
    556 
    557     case 3:
    558       /* Do nothing.  */
    559       break;
    560 
    561     case 4:
    562 #ifdef BFD64
    563       if (relocation)
    564 	{
    565 	  bfd_vma x = get_data (location, 8);
    566 	  DOIT (x);
    567 	  put_data (x, location, 8);
    568 	}
    569 #else
    570       abort ();
    571 #endif
    572       break;
    573     default:
    574       return bfd_reloc_other;
    575     }
    576   if ((howto->complain_on_overflow != complain_overflow_dont) && overflow)
    577     return bfd_reloc_overflow;
    578 
    579   return flag;
    580 }
    581 
    582 /* Relocate a given location using a given value and howto.  */
    583 
    584 bfd_reloc_status_type
    585 _bfd_do_ns32k_reloc_contents (howto, input_bfd, relocation, location,
    586 			      get_data, put_data)
    587      reloc_howto_type *howto;
    588      bfd *input_bfd ATTRIBUTE_UNUSED;
    589      bfd_vma relocation;
    590      bfd_byte *location;
    591      bfd_vma (*get_data) PARAMS ((bfd_byte *, int));
    592      void (*put_data) PARAMS ((bfd_vma, bfd_byte *, int));
    593 {
    594   int size;
    595   bfd_vma x;
    596   bfd_boolean overflow;
    597 
    598   /* If the size is negative, negate RELOCATION.  This isn't very
    599      general.  */
    600   if (howto->size < 0)
    601     relocation = -relocation;
    602 
    603   /* Get the value we are going to relocate.  */
    604   size = bfd_get_reloc_size (howto);
    605   switch (size)
    606     {
    607     default:
    608     case 0:
    609       abort ();
    610     case 1:
    611     case 2:
    612     case 4:
    613 #ifdef BFD64
    614     case 8:
    615 #endif
    616       x = get_data (location, size);
    617       break;
    618     }
    619 
    620   /* Check for overflow.  FIXME: We may drop bits during the addition
    621      which we don't check for.  We must either check at every single
    622      operation, which would be tedious, or we must do the computations
    623      in a type larger than bfd_vma, which would be inefficient.  */
    624   overflow = FALSE;
    625   if (howto->complain_on_overflow != complain_overflow_dont)
    626     {
    627       bfd_vma check;
    628       bfd_signed_vma signed_check;
    629       bfd_vma add;
    630       bfd_signed_vma signed_add;
    631 
    632       if (howto->rightshift == 0)
    633 	{
    634 	  check = relocation;
    635 	  signed_check = (bfd_signed_vma) relocation;
    636 	}
    637       else
    638 	{
    639 	  /* Drop unwanted bits from the value we are relocating to.  */
    640 	  check = relocation >> howto->rightshift;
    641 
    642 	  /* If this is a signed value, the rightshift just dropped
    643 	     leading 1 bits (assuming twos complement).  */
    644 	  if ((bfd_signed_vma) relocation >= 0)
    645 	    signed_check = check;
    646 	  else
    647 	    signed_check = (check
    648 			    | ((bfd_vma) - 1
    649 			       & ~((bfd_vma) - 1 >> howto->rightshift)));
    650 	}
    651 
    652       /* Get the value from the object file.  */
    653       add = x & howto->src_mask;
    654 
    655       /* Get the value from the object file with an appropriate sign.
    656 	 The expression involving howto->src_mask isolates the upper
    657 	 bit of src_mask.  If that bit is set in the value we are
    658 	 adding, it is negative, and we subtract out that number times
    659 	 two.  If src_mask includes the highest possible bit, then we
    660 	 can not get the upper bit, but that does not matter since
    661 	 signed_add needs no adjustment to become negative in that
    662 	 case.  */
    663       signed_add = add;
    664       if ((add & (((~howto->src_mask) >> 1) & howto->src_mask)) != 0)
    665 	signed_add -= (((~howto->src_mask) >> 1) & howto->src_mask) << 1;
    666 
    667       /* Add the value from the object file, shifted so that it is a
    668 	 straight number.  */
    669       if (howto->bitpos == 0)
    670 	{
    671 	  check += add;
    672 	  signed_check += signed_add;
    673 	}
    674       else
    675 	{
    676 	  check += add >> howto->bitpos;
    677 
    678 	  /* For the signed case we use ADD, rather than SIGNED_ADD,
    679 	     to avoid warnings from SVR4 cc.  This is OK since we
    680 	     explicitly handle the sign bits.  */
    681 	  if (signed_add >= 0)
    682 	    signed_check += add >> howto->bitpos;
    683 	  else
    684 	    signed_check += ((add >> howto->bitpos)
    685 			     | ((bfd_vma) - 1
    686 				& ~((bfd_vma) - 1 >> howto->bitpos)));
    687 	}
    688 
    689       switch (howto->complain_on_overflow)
    690 	{
    691 	case complain_overflow_signed:
    692 	  {
    693 	    /* Assumes two's complement.  */
    694 	    bfd_signed_vma reloc_signed_max = (1 << (howto->bitsize - 1)) - 1;
    695 	    bfd_signed_vma reloc_signed_min = ~reloc_signed_max;
    696 
    697 	    if (signed_check > reloc_signed_max
    698 		|| signed_check < reloc_signed_min)
    699 	      overflow = TRUE;
    700 	  }
    701 	  break;
    702 	case complain_overflow_unsigned:
    703 	  {
    704 	    /* Assumes two's complement.  This expression avoids
    705 	       overflow if howto->bitsize is the number of bits in
    706 	       bfd_vma.  */
    707 	    bfd_vma reloc_unsigned_max =
    708 	    (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
    709 
    710 	    if (check > reloc_unsigned_max)
    711 	      overflow = TRUE;
    712 	  }
    713 	  break;
    714 	case complain_overflow_bitfield:
    715 	  {
    716 	    /* Assumes two's complement.  This expression avoids
    717 	       overflow if howto->bitsize is the number of bits in
    718 	       bfd_vma.  */
    719 	    bfd_vma reloc_bits = (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
    720 
    721 	    if ((check & ~reloc_bits) != 0
    722 		&& (((bfd_vma) signed_check & ~reloc_bits)
    723 		    != (-(bfd_vma) 1 & ~reloc_bits)))
    724 	      overflow = TRUE;
    725 	  }
    726 	  break;
    727 	default:
    728 	  abort ();
    729 	}
    730     }
    731 
    732   /* Put RELOCATION in the right bits.  */
    733   relocation >>= (bfd_vma) howto->rightshift;
    734   relocation <<= (bfd_vma) howto->bitpos;
    735 
    736   /* Add RELOCATION to the right bits of X.  */
    737   x = ((x & ~howto->dst_mask)
    738        | (((x & howto->src_mask) + relocation) & howto->dst_mask));
    739 
    740   /* Put the relocated value back in the object file.  */
    741   switch (size)
    742     {
    743     default:
    744     case 0:
    745       abort ();
    746     case 1:
    747     case 2:
    748     case 4:
    749 #ifdef BFD64
    750     case 8:
    751 #endif
    752       put_data (x, location, size);
    753       break;
    754     }
    755 
    756   return overflow ? bfd_reloc_overflow : bfd_reloc_ok;
    757 }
    758 
    759 bfd_reloc_status_type
    760 _bfd_ns32k_reloc_disp (abfd, reloc_entry, symbol, data, input_section,
    761 		       output_bfd, error_message)
    762      bfd *abfd;
    763      arelent *reloc_entry;
    764      struct bfd_symbol *symbol;
    765      PTR data;
    766      asection *input_section;
    767      bfd *output_bfd;
    768      char **error_message;
    769 {
    770   return do_ns32k_reloc (abfd, reloc_entry, symbol, data, input_section,
    771 			 output_bfd, error_message,
    772 			 _bfd_ns32k_get_displacement,
    773 			 _bfd_ns32k_put_displacement);
    774 }
    775 
    776 bfd_reloc_status_type
    777 _bfd_ns32k_reloc_imm (abfd, reloc_entry, symbol, data, input_section,
    778 		      output_bfd, error_message)
    779      bfd *abfd;
    780      arelent *reloc_entry;
    781      struct bfd_symbol *symbol;
    782      PTR data;
    783      asection *input_section;
    784      bfd *output_bfd;
    785      char **error_message;
    786 {
    787   return do_ns32k_reloc (abfd, reloc_entry, symbol, data, input_section,
    788 			 output_bfd, error_message, _bfd_ns32k_get_immediate,
    789 			 _bfd_ns32k_put_immediate);
    790 }
    791 
    792 bfd_reloc_status_type
    793 _bfd_ns32k_final_link_relocate (howto, input_bfd, input_section, contents,
    794 				address, value, addend)
    795      reloc_howto_type *howto;
    796      bfd *input_bfd;
    797      asection *input_section;
    798      bfd_byte *contents;
    799      bfd_vma address;
    800      bfd_vma value;
    801      bfd_vma addend;
    802 {
    803   bfd_vma relocation;
    804 
    805   /* Sanity check the address.  */
    806   if (address > bfd_get_section_limit (input_bfd, input_section))
    807     return bfd_reloc_outofrange;
    808 
    809   /* This function assumes that we are dealing with a basic relocation
    810      against a symbol.  We want to compute the value of the symbol to
    811      relocate to.  This is just VALUE, the value of the symbol, plus
    812      ADDEND, any addend associated with the reloc.  */
    813   relocation = value + addend;
    814 
    815   /* If the relocation is PC relative, we want to set RELOCATION to
    816      the distance between the symbol (currently in RELOCATION) and the
    817      location we are relocating.  Some targets (e.g., i386-aout)
    818      arrange for the contents of the section to be the negative of the
    819      offset of the location within the section; for such targets
    820      pcrel_offset is FALSE.  Other targets (e.g., m88kbcs or ELF)
    821      simply leave the contents of the section as zero; for such
    822      targets pcrel_offset is TRUE.  If pcrel_offset is FALSE we do not
    823      need to subtract out the offset of the location within the
    824      section (which is just ADDRESS).  */
    825   if (howto->pc_relative)
    826     {
    827       relocation -= (input_section->output_section->vma
    828 		     + input_section->output_offset);
    829       if (howto->pcrel_offset)
    830 	relocation -= address;
    831     }
    832 
    833   return _bfd_ns32k_relocate_contents (howto, input_bfd, relocation,
    834 				       contents + address);
    835 }
    836