Пример #1
0
CORE_ADDR
ppc64_sysv_abi_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
				struct regcache *regcache, CORE_ADDR bp_addr,
				int nargs, struct value **args, CORE_ADDR sp,
				int struct_return, CORE_ADDR struct_addr)
{
  CORE_ADDR func_addr = find_function_addr (function, NULL);
  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
  /* By this stage in the proceedings, SP has been decremented by "red
     zone size" + "struct return size".  Fetch the stack-pointer from
     before this and use that as the BACK_CHAIN.  */
  const CORE_ADDR back_chain = read_sp ();
  /* See for-loop comment below.  */
  int write_pass;
  /* Size of the Altivec's vector parameter region, the final value is
     computed in the for-loop below.  */
  LONGEST vparam_size = 0;
  /* Size of the general parameter region, the final value is computed
     in the for-loop below.  */
  LONGEST gparam_size = 0;
  /* Kevin writes ... I don't mind seeing tdep->wordsize used in the
     calls to align_up(), align_down(), etc.  because this makes it
     easier to reuse this code (in a copy/paste sense) in the future,
     but it is a 64-bit ABI and asserting that the wordsize is 8 bytes
     at some point makes it easier to verify that this function is
     correct without having to do a non-local analysis to figure out
     the possible values of tdep->wordsize.  */
  gdb_assert (tdep->wordsize == 8);

  /* Go through the argument list twice.

     Pass 1: Compute the function call's stack space and register
     requirements.

     Pass 2: Replay the same computation but this time also write the
     values out to the target.  */

  for (write_pass = 0; write_pass < 2; write_pass++)
    {
      int argno;
      /* Next available floating point register for float and double
         arguments.  */
      int freg = 1;
      /* Next available general register for non-vector (but possibly
         float) arguments.  */
      int greg = 3;
      /* Next available vector register for vector arguments.  */
      int vreg = 2;
      /* The address, at which the next general purpose parameter
         (integer, struct, float, ...) should be saved.  */
      CORE_ADDR gparam;
      /* Address, at which the next Altivec vector parameter should be
         saved.  */
      CORE_ADDR vparam;

      if (!write_pass)
	{
	  /* During the first pass, GPARAM and VPARAM are more like
	     offsets (start address zero) than addresses.  That way
	     the accumulate the total stack space each region
	     requires.  */
	  gparam = 0;
	  vparam = 0;
	}
      else
	{
	  /* Decrement the stack pointer making space for the Altivec
	     and general on-stack parameters.  Set vparam and gparam
	     to their corresponding regions.  */
	  vparam = align_down (sp - vparam_size, 16);
	  gparam = align_down (vparam - gparam_size, 16);
	  /* Add in space for the TOC, link editor double word,
	     compiler double word, LR save area, CR save area.  */
	  sp = align_down (gparam - 48, 16);
	}

      /* If the function is returning a `struct', then there is an
         extra hidden parameter (which will be passed in r3)
         containing the address of that struct..  In that case we
         should advance one word and start from r4 register to copy
         parameters.  This also consumes one on-stack parameter slot.  */
      if (struct_return)
	{
	  if (write_pass)
	    regcache_cooked_write_signed (regcache,
					  tdep->ppc_gp0_regnum + greg,
					  struct_addr);
	  greg++;
	  gparam = align_up (gparam + tdep->wordsize, tdep->wordsize);
	}

      for (argno = 0; argno < nargs; argno++)
	{
	  struct value *arg = args[argno];
	  struct type *type = check_typedef (value_type (arg));
	  const bfd_byte *val = value_contents (arg);
	  if (TYPE_CODE (type) == TYPE_CODE_FLT && TYPE_LENGTH (type) <= 8)
	    {
	      /* Floats and Doubles go in f1 .. f13.  They also
	         consume a left aligned GREG,, and can end up in
	         memory.  */
	      if (write_pass)
		{
		  if (ppc_floating_point_unit_p (current_gdbarch)
		      && freg <= 13)
		    {
		      gdb_byte regval[MAX_REGISTER_SIZE];
		      struct type *regtype
                        = register_type (gdbarch, tdep->ppc_fp0_regnum);
		      convert_typed_floating (val, type, regval, regtype);
		      regcache_cooked_write (regcache,
                                             tdep->ppc_fp0_regnum + freg,
					     regval);
		    }
		  if (greg <= 10)
		    {
		      /* The ABI states "Single precision floating
		         point values are mapped to the first word in
		         a single doubleword" and "... floating point
		         values mapped to the first eight doublewords
		         of the parameter save area are also passed in
		         general registers").

		         This code interprets that to mean: store it,
		         left aligned, in the general register.  */
		      gdb_byte regval[MAX_REGISTER_SIZE];
		      memset (regval, 0, sizeof regval);
		      memcpy (regval, val, TYPE_LENGTH (type));
		      regcache_cooked_write (regcache,
					     tdep->ppc_gp0_regnum + greg,
					     regval);
		    }
		  write_memory (gparam, val, TYPE_LENGTH (type));
		}
	      /* Always consume parameter stack space.  */
	      freg++;
	      greg++;
	      gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
	    }
	  else if (TYPE_LENGTH (type) == 16 && TYPE_VECTOR (type)
		   && TYPE_CODE (type) == TYPE_CODE_ARRAY
		   && tdep->ppc_vr0_regnum >= 0)
	    {
	      /* In the Altivec ABI, vectors go in the vector
	         registers v2 .. v13, or when that runs out, a vector
	         annex which goes above all the normal parameters.
	         NOTE: cagney/2003-09-21: This is a guess based on the
	         PowerOpen Altivec ABI.  */
	      if (vreg <= 13)
		{
		  if (write_pass)
		    regcache_cooked_write (regcache,
					   tdep->ppc_vr0_regnum + vreg, val);
		  vreg++;
		}
	      else
		{
		  if (write_pass)
		    write_memory (vparam, val, TYPE_LENGTH (type));
		  vparam = align_up (vparam + TYPE_LENGTH (type), 16);
		}
	    }
	  else if ((TYPE_CODE (type) == TYPE_CODE_INT
		    || TYPE_CODE (type) == TYPE_CODE_ENUM
		    || TYPE_CODE (type) == TYPE_CODE_PTR)
		   && TYPE_LENGTH (type) <= 8)
	    {
	      /* Scalars and Pointers get sign[un]extended and go in
	         gpr3 .. gpr10.  They can also end up in memory.  */
	      if (write_pass)
		{
		  /* Sign extend the value, then store it unsigned.  */
		  ULONGEST word = unpack_long (type, val);
		  /* Convert any function code addresses into
		     descriptors.  */
		  if (TYPE_CODE (type) == TYPE_CODE_PTR
		      && TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_FUNC)
		    {
		      CORE_ADDR desc = word;
		      convert_code_addr_to_desc_addr (word, &desc);
		      word = desc;
		    }
		  if (greg <= 10)
		    regcache_cooked_write_unsigned (regcache,
						    tdep->ppc_gp0_regnum +
						    greg, word);
		  write_memory_unsigned_integer (gparam, tdep->wordsize,
						 word);
		}
	      greg++;
	      gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
	    }
	  else
	    {
	      int byte;
	      for (byte = 0; byte < TYPE_LENGTH (type);
		   byte += tdep->wordsize)
		{
		  if (write_pass && greg <= 10)
		    {
		      gdb_byte regval[MAX_REGISTER_SIZE];
		      int len = TYPE_LENGTH (type) - byte;
		      if (len > tdep->wordsize)
			len = tdep->wordsize;
		      memset (regval, 0, sizeof regval);
		      /* WARNING: cagney/2003-09-21: As best I can
		         tell, the ABI specifies that the value should
		         be left aligned.  Unfortunately, GCC doesn't
		         do this - it instead right aligns even sized
		         values and puts odd sized values on the
		         stack.  Work around that by putting both a
		         left and right aligned value into the
		         register (hopefully no one notices :-^).
		         Arrrgh!  */
		      /* Left aligned (8 byte values such as pointers
		         fill the buffer).  */
		      memcpy (regval, val + byte, len);
		      /* Right aligned (but only if even).  */
		      if (len == 1 || len == 2 || len == 4)
			memcpy (regval + tdep->wordsize - len,
				val + byte, len);
		      regcache_cooked_write (regcache, greg, regval);
		    }
		  greg++;
		}
	      if (write_pass)
		/* WARNING: cagney/2003-09-21: Strictly speaking, this
		   isn't necessary, unfortunately, GCC appears to get
		   "struct convention" parameter passing wrong putting
		   odd sized structures in memory instead of in a
		   register.  Work around this by always writing the
		   value to memory.  Fortunately, doing this
		   simplifies the code.  */
		write_memory (gparam, val, TYPE_LENGTH (type));
	      if (write_pass)
		/* WARNING: cagney/2004-06-20: It appears that GCC
		   likes to put structures containing a single
		   floating-point member in an FP register instead of
		   general general purpose.  */
	      /* Always consume parameter stack space.  */
	      gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
	    }
	}

      if (!write_pass)
	{
	  /* Save the true region sizes ready for the second pass.  */
	  vparam_size = vparam;
	  /* Make certain that the general parameter save area is at
	     least the minimum 8 registers (or doublewords) in size.  */
	  if (greg < 8)
	    gparam_size = 8 * tdep->wordsize;
	  else
	    gparam_size = gparam;
	}
    }

  /* Update %sp.   */
  regcache_cooked_write_signed (regcache, SP_REGNUM, sp);

  /* Write the backchain (it occupies WORDSIZED bytes).  */
  write_memory_signed_integer (sp, tdep->wordsize, back_chain);

  /* Point the inferior function call's return address at the dummy's
     breakpoint.  */
  regcache_cooked_write_signed (regcache, tdep->ppc_lr_regnum, bp_addr);

  /* Use the func_addr to find the descriptor, and use that to find
     the TOC.  */
  {
    CORE_ADDR desc_addr;
    if (convert_code_addr_to_desc_addr (func_addr, &desc_addr))
      {
	/* The TOC is the second double word in the descriptor.  */
	CORE_ADDR toc =
	  read_memory_unsigned_integer (desc_addr + tdep->wordsize,
					tdep->wordsize);
	regcache_cooked_write_unsigned (regcache,
					tdep->ppc_gp0_regnum + 2, toc);
      }
  }

  return sp;
}
Пример #2
0
static CORE_ADDR
rs6000_lynx178_push_dummy_call (struct gdbarch *gdbarch,
				struct value *function,
				struct regcache *regcache, CORE_ADDR bp_addr,
				int nargs, struct value **args, CORE_ADDR sp,
				int struct_return, CORE_ADDR struct_addr)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  int ii;
  int len = 0;
  int argno;			/* current argument number */
  int argbytes;			/* current argument byte */
  gdb_byte tmp_buffer[50];
  int f_argno = 0;		/* current floating point argno */
  int wordsize = gdbarch_tdep (gdbarch)->wordsize;
  CORE_ADDR func_addr = find_function_addr (function, NULL);

  struct value *arg = 0;
  struct type *type;

  ULONGEST saved_sp;

  /* The calling convention this function implements assumes the
     processor has floating-point registers.  We shouldn't be using it
     on PPC variants that lack them.  */
  gdb_assert (ppc_floating_point_unit_p (gdbarch));

  /* The first eight words of ther arguments are passed in registers.
     Copy them appropriately.  */
  ii = 0;

  /* If the function is returning a `struct', then the first word
     (which will be passed in r3) is used for struct return address.
     In that case we should advance one word and start from r4
     register to copy parameters.  */
  if (struct_return)
    {
      regcache_raw_write_unsigned (regcache, tdep->ppc_gp0_regnum + 3,
				   struct_addr);
      ii++;
    }

  /* Effectively indirect call... gcc does...

     return_val example( float, int);

     eabi:
     float in fp0, int in r3
     offset of stack on overflow 8/16
     for varargs, must go by type.
     power open:
     float in r3&r4, int in r5
     offset of stack on overflow different
     both:
     return in r3 or f0.  If no float, must study how gcc emulates floats;
     pay attention to arg promotion.
     User may have to cast\args to handle promotion correctly
     since gdb won't know if prototype supplied or not.  */

  for (argno = 0, argbytes = 0; argno < nargs && ii < 8; ++ii)
    {
      int reg_size = register_size (gdbarch, ii + 3);

      arg = args[argno];
      type = check_typedef (value_type (arg));
      len = TYPE_LENGTH (type);

      if (TYPE_CODE (type) == TYPE_CODE_FLT)
	{

	  /* Floating point arguments are passed in fpr's, as well as gpr's.
	     There are 13 fpr's reserved for passing parameters.  At this point
	     there is no way we would run out of them.

	     Always store the floating point value using the register's
	     floating-point format.  */
	  const int fp_regnum = tdep->ppc_fp0_regnum + 1 + f_argno;
	  gdb_byte reg_val[MAX_REGISTER_SIZE];
	  struct type *reg_type = register_type (gdbarch, fp_regnum);

	  gdb_assert (len <= 8);

	  convert_typed_floating (value_contents (arg), type,
				  reg_val, reg_type);
	  regcache_cooked_write (regcache, fp_regnum, reg_val);
	  ++f_argno;
	}

      if (len > reg_size)
	{

	  /* Argument takes more than one register.  */
	  while (argbytes < len)
	    {
	      gdb_byte word[MAX_REGISTER_SIZE];
	      memset (word, 0, reg_size);
	      memcpy (word,
		      ((char *) value_contents (arg)) + argbytes,
		      (len - argbytes) > reg_size
		        ? reg_size : len - argbytes);
	      regcache_cooked_write (regcache,
	                            tdep->ppc_gp0_regnum + 3 + ii,
				    word);
	      ++ii, argbytes += reg_size;

	      if (ii >= 8)
		goto ran_out_of_registers_for_arguments;
	    }
	  argbytes = 0;
	  --ii;
	}
      else
	{
	  /* Argument can fit in one register.  No problem.  */
	  int adj = gdbarch_byte_order (gdbarch)
		    == BFD_ENDIAN_BIG ? reg_size - len : 0;
	  gdb_byte word[MAX_REGISTER_SIZE];

	  memset (word, 0, reg_size);
	  memcpy (word, value_contents (arg), len);
	  regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 3 +ii, word);
	}
      ++argno;
    }

ran_out_of_registers_for_arguments:

  regcache_cooked_read_unsigned (regcache,
				 gdbarch_sp_regnum (gdbarch),
				 &saved_sp);

  /* Location for 8 parameters are always reserved.  */
  sp -= wordsize * 8;

  /* Another six words for back chain, TOC register, link register, etc.  */
  sp -= wordsize * 6;

  /* Stack pointer must be quadword aligned.  */
  sp = align_down (sp, 16);

  /* If there are more arguments, allocate space for them in
     the stack, then push them starting from the ninth one.  */

  if ((argno < nargs) || argbytes)
    {
      int space = 0, jj;

      if (argbytes)
	{
	  space += align_up (len - argbytes, 4);
	  jj = argno + 1;
	}
      else
	jj = argno;

      for (; jj < nargs; ++jj)
	{
	  struct value *val = args[jj];

	  space += align_up (TYPE_LENGTH (value_type (val)), 4);
	}

      /* Add location required for the rest of the parameters.  */
      space = align_up (space, 16);
      sp -= space;

      /* This is another instance we need to be concerned about
         securing our stack space.  If we write anything underneath %sp
         (r1), we might conflict with the kernel who thinks he is free
         to use this area.  So, update %sp first before doing anything
         else.  */

      regcache_raw_write_signed (regcache,
				 gdbarch_sp_regnum (gdbarch), sp);

      /* If the last argument copied into the registers didn't fit there
         completely, push the rest of it into stack.  */

      if (argbytes)
	{
	  write_memory (sp + 24 + (ii * 4),
			value_contents (arg) + argbytes,
			len - argbytes);
	  ++argno;
	  ii += align_up (len - argbytes, 4) / 4;
	}

      /* Push the rest of the arguments into stack.  */
      for (; argno < nargs; ++argno)
	{

	  arg = args[argno];
	  type = check_typedef (value_type (arg));
	  len = TYPE_LENGTH (type);


	  /* Float types should be passed in fpr's, as well as in the
             stack.  */
	  if (TYPE_CODE (type) == TYPE_CODE_FLT && f_argno < 13)
	    {

	      gdb_assert (len <= 8);

	      regcache_cooked_write (regcache,
				     tdep->ppc_fp0_regnum + 1 + f_argno,
				     value_contents (arg));
	      ++f_argno;
	    }

	  write_memory (sp + 24 + (ii * 4), value_contents (arg), len);
	  ii += align_up (len, 4) / 4;
	}
    }

  /* Set the stack pointer.  According to the ABI, the SP is meant to
     be set _before_ the corresponding stack space is used.  On AIX,
     this even applies when the target has been completely stopped!
     Not doing this can lead to conflicts with the kernel which thinks
     that it still has control over this not-yet-allocated stack
     region.  */
  regcache_raw_write_signed (regcache, gdbarch_sp_regnum (gdbarch), sp);

  /* Set back chain properly.  */
  store_unsigned_integer (tmp_buffer, wordsize, byte_order, saved_sp);
  write_memory (sp, tmp_buffer, wordsize);

  /* Point the inferior function call's return address at the dummy's
     breakpoint.  */
  regcache_raw_write_signed (regcache, tdep->ppc_lr_regnum, bp_addr);

  target_store_registers (regcache, -1);
  return sp;
}
CORE_ADDR
ppc64_sysv_abi_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
				struct regcache *regcache, CORE_ADDR bp_addr,
				int nargs, struct value **args, CORE_ADDR sp,
				int struct_return, CORE_ADDR struct_addr)
{
  CORE_ADDR func_addr = find_function_addr (function, NULL);
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  ULONGEST back_chain;
  /* See for-loop comment below.  */
  int write_pass;
  /* Size of the Altivec's vector parameter region, the final value is
     computed in the for-loop below.  */
  LONGEST vparam_size = 0;
  /* Size of the general parameter region, the final value is computed
     in the for-loop below.  */
  LONGEST gparam_size = 0;
  /* Kevin writes ... I don't mind seeing tdep->wordsize used in the
     calls to align_up(), align_down(), etc.  because this makes it
     easier to reuse this code (in a copy/paste sense) in the future,
     but it is a 64-bit ABI and asserting that the wordsize is 8 bytes
     at some point makes it easier to verify that this function is
     correct without having to do a non-local analysis to figure out
     the possible values of tdep->wordsize.  */
  gdb_assert (tdep->wordsize == 8);

  /* This function exists to support a calling convention that
     requires floating-point registers.  It shouldn't be used on
     processors that lack them.  */
  gdb_assert (ppc_floating_point_unit_p (gdbarch));

  /* By this stage in the proceedings, SP has been decremented by "red
     zone size" + "struct return size".  Fetch the stack-pointer from
     before this and use that as the BACK_CHAIN.  */
  regcache_cooked_read_unsigned (regcache, gdbarch_sp_regnum (gdbarch),
				 &back_chain);

  /* Go through the argument list twice.

     Pass 1: Compute the function call's stack space and register
     requirements.

     Pass 2: Replay the same computation but this time also write the
     values out to the target.  */

  for (write_pass = 0; write_pass < 2; write_pass++)
    {
      int argno;
      /* Next available floating point register for float and double
         arguments.  */
      int freg = 1;
      /* Next available general register for non-vector (but possibly
         float) arguments.  */
      int greg = 3;
      /* Next available vector register for vector arguments.  */
      int vreg = 2;
      /* The address, at which the next general purpose parameter
         (integer, struct, float, ...) should be saved.  */
      CORE_ADDR gparam;
      /* Address, at which the next Altivec vector parameter should be
         saved.  */
      CORE_ADDR vparam;

      if (!write_pass)
	{
	  /* During the first pass, GPARAM and VPARAM are more like
	     offsets (start address zero) than addresses.  That way
	     they accumulate the total stack space each region
	     requires.  */
	  gparam = 0;
	  vparam = 0;
	}
      else
	{
	  /* Decrement the stack pointer making space for the Altivec
	     and general on-stack parameters.  Set vparam and gparam
	     to their corresponding regions.  */
	  vparam = align_down (sp - vparam_size, 16);
	  gparam = align_down (vparam - gparam_size, 16);
	  /* Add in space for the TOC, link editor double word,
	     compiler double word, LR save area, CR save area.  */
	  sp = align_down (gparam - 48, 16);
	}

      /* If the function is returning a `struct', then there is an
         extra hidden parameter (which will be passed in r3)
         containing the address of that struct..  In that case we
         should advance one word and start from r4 register to copy
         parameters.  This also consumes one on-stack parameter slot.  */
      if (struct_return)
	{
	  if (write_pass)
	    regcache_cooked_write_signed (regcache,
					  tdep->ppc_gp0_regnum + greg,
					  struct_addr);
	  greg++;
	  gparam = align_up (gparam + tdep->wordsize, tdep->wordsize);
	}

      for (argno = 0; argno < nargs; argno++)
	{
	  struct value *arg = args[argno];
	  struct type *type = check_typedef (value_type (arg));
	  const bfd_byte *val = value_contents (arg);

	  if (TYPE_CODE (type) == TYPE_CODE_FLT && TYPE_LENGTH (type) <= 8)
	    {
	      /* Floats and Doubles go in f1 .. f13.  They also
	         consume a left aligned GREG,, and can end up in
	         memory.  */
	      if (write_pass)
		{
		  gdb_byte regval[MAX_REGISTER_SIZE];
		  const gdb_byte *p;

		  /* Version 1.7 of the 64-bit PowerPC ELF ABI says:

		     "Single precision floating point values are mapped to
		     the first word in a single doubleword."

		     And version 1.9 says:

		     "Single precision floating point values are mapped to
		     the second word in a single doubleword."

		     GDB then writes single precision floating point values
		     at both words in a doubleword, to support both ABIs.  */
		  if (TYPE_LENGTH (type) == 4)
		    {
		      memcpy (regval, val, 4);
		      memcpy (regval + 4, val, 4);
		      p = regval;
		    }
		  else
		    p = val;

		  /* Write value in the stack's parameter save area.  */
		  write_memory (gparam, p, 8);

		  if (freg <= 13)
		    {
		      struct type *regtype
                        = register_type (gdbarch, tdep->ppc_fp0_regnum);

		      convert_typed_floating (val, type, regval, regtype);
		      regcache_cooked_write (regcache,
                                             tdep->ppc_fp0_regnum + freg,
					     regval);
		    }
		  if (greg <= 10)
		    regcache_cooked_write (regcache,
					   tdep->ppc_gp0_regnum + greg,
					   regval);
		}

	      freg++;
	      greg++;
	      /* Always consume parameter stack space.  */
	      gparam = align_up (gparam + 8, tdep->wordsize);
	    }
	  else if (TYPE_CODE (type) == TYPE_CODE_FLT
		   && TYPE_LENGTH (type) == 16
		   && (gdbarch_long_double_format (gdbarch)
		       == floatformats_ibm_long_double))
	    {
	      /* IBM long double stored in two doublewords of the
		 parameter save area and corresponding registers.  */
	      if (write_pass)
		{
		  if (!tdep->soft_float && freg <= 13)
		    {
		      regcache_cooked_write (regcache,
                                             tdep->ppc_fp0_regnum + freg,
					     val);
		      if (freg <= 12)
			regcache_cooked_write (regcache,
					       tdep->ppc_fp0_regnum + freg + 1,
					       val + 8);
		    }
		  if (greg <= 10)
		    {
		      regcache_cooked_write (regcache,
					     tdep->ppc_gp0_regnum + greg,
					     val);
		      if (greg <= 9)
			regcache_cooked_write (regcache,
					       tdep->ppc_gp0_regnum + greg + 1,
					       val + 8);
		    }
		  write_memory (gparam, val, TYPE_LENGTH (type));
		}
	      freg += 2;
	      greg += 2;
	      gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
	    }
	  else if (TYPE_CODE (type) == TYPE_CODE_DECFLOAT
		   && TYPE_LENGTH (type) <= 8)
	    {
	      /* 32-bit and 64-bit decimal floats go in f1 .. f13.  They can
	         end up in memory.  */
	      if (write_pass)
		{
		  gdb_byte regval[MAX_REGISTER_SIZE];
		  const gdb_byte *p;

		  /* 32-bit decimal floats are right aligned in the
		     doubleword.  */
		  if (TYPE_LENGTH (type) == 4)
		    {
		      memcpy (regval + 4, val, 4);
		      p = regval;
		    }
		  else
		    p = val;

		  /* Write value in the stack's parameter save area.  */
		  write_memory (gparam, p, 8);

		  if (freg <= 13)
		    regcache_cooked_write (regcache,
					   tdep->ppc_fp0_regnum + freg, p);
		}

	      freg++;
	      greg++;
	      /* Always consume parameter stack space.  */
	      gparam = align_up (gparam + 8, tdep->wordsize);
	    }
	  else if (TYPE_CODE (type) == TYPE_CODE_DECFLOAT &&
		   TYPE_LENGTH (type) == 16)
	    {
	      /* 128-bit decimal floats go in f2 .. f12, always in even/odd
	         pairs.  They can end up in memory, using two doublewords.  */
	      if (write_pass)
		{
		  if (freg <= 12)
		    {
		      /* Make sure freg is even.  */
		      freg += freg & 1;
		      regcache_cooked_write (regcache,
                                             tdep->ppc_fp0_regnum + freg, val);
		      regcache_cooked_write (regcache,
			  tdep->ppc_fp0_regnum + freg + 1, val + 8);
		    }

		  write_memory (gparam, val, TYPE_LENGTH (type));
		}

	      freg += 2;
	      greg += 2;
	      gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
	    }
	  else if (TYPE_LENGTH (type) == 16 && TYPE_VECTOR (type)
		   && TYPE_CODE (type) == TYPE_CODE_ARRAY
		   && tdep->ppc_vr0_regnum >= 0)
	    {
	      /* In the Altivec ABI, vectors go in the vector
	         registers v2 .. v13, or when that runs out, a vector
	         annex which goes above all the normal parameters.
	         NOTE: cagney/2003-09-21: This is a guess based on the
	         PowerOpen Altivec ABI.  */
	      if (vreg <= 13)
		{
		  if (write_pass)
		    regcache_cooked_write (regcache,
					   tdep->ppc_vr0_regnum + vreg, val);
		  vreg++;
		}
	      else
		{
		  if (write_pass)
		    write_memory (vparam, val, TYPE_LENGTH (type));
		  vparam = align_up (vparam + TYPE_LENGTH (type), 16);
		}
	    }
	  else if ((TYPE_CODE (type) == TYPE_CODE_INT
		    || TYPE_CODE (type) == TYPE_CODE_ENUM
		    || TYPE_CODE (type) == TYPE_CODE_BOOL
		    || TYPE_CODE (type) == TYPE_CODE_CHAR
		    || TYPE_CODE (type) == TYPE_CODE_PTR
		    || TYPE_CODE (type) == TYPE_CODE_REF)
		   && TYPE_LENGTH (type) <= 8)
	    {
	      /* Scalars and Pointers get sign[un]extended and go in
	         gpr3 .. gpr10.  They can also end up in memory.  */
	      if (write_pass)
		{
		  /* Sign extend the value, then store it unsigned.  */
		  ULONGEST word = unpack_long (type, val);
		  /* Convert any function code addresses into
		     descriptors.  */
		  if (TYPE_CODE (type) == TYPE_CODE_PTR
		      || TYPE_CODE (type) == TYPE_CODE_REF)
		    {
		      struct type *target_type;
		      target_type = check_typedef (TYPE_TARGET_TYPE (type));

		      if (TYPE_CODE (target_type) == TYPE_CODE_FUNC
			  || TYPE_CODE (target_type) == TYPE_CODE_METHOD)
			{
			  CORE_ADDR desc = word;
			  convert_code_addr_to_desc_addr (word, &desc);
			  word = desc;
			}
		    }
		  if (greg <= 10)
		    regcache_cooked_write_unsigned (regcache,
						    tdep->ppc_gp0_regnum +
						    greg, word);
		  write_memory_unsigned_integer (gparam, tdep->wordsize,
						 byte_order, word);
		}
	      greg++;
	      gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
	    }
	  else
	    {
	      int byte;
	      for (byte = 0; byte < TYPE_LENGTH (type);
		   byte += tdep->wordsize)
		{
		  if (write_pass && greg <= 10)
		    {
		      gdb_byte regval[MAX_REGISTER_SIZE];
		      int len = TYPE_LENGTH (type) - byte;
		      if (len > tdep->wordsize)
			len = tdep->wordsize;
		      memset (regval, 0, sizeof regval);
		      /* The ABI (version 1.9) specifies that values
			 smaller than one doubleword are right-aligned
			 and those larger are left-aligned.  GCC
			 versions before 3.4 implemented this
			 incorrectly; see
			 <http://gcc.gnu.org/gcc-3.4/powerpc-abi.html>.  */
		      if (byte == 0)
			memcpy (regval + tdep->wordsize - len,
				val + byte, len);
		      else
			memcpy (regval, val + byte, len);
		      regcache_cooked_write (regcache, greg, regval);
		    }
		  greg++;
		}
	      if (write_pass)
		{
		  /* WARNING: cagney/2003-09-21: Strictly speaking, this
		     isn't necessary, unfortunately, GCC appears to get
		     "struct convention" parameter passing wrong putting
		     odd sized structures in memory instead of in a
		     register.  Work around this by always writing the
		     value to memory.  Fortunately, doing this
		     simplifies the code.  */
		  int len = TYPE_LENGTH (type);
		  if (len < tdep->wordsize)
		    write_memory (gparam + tdep->wordsize - len, val, len);
		  else
		    write_memory (gparam, val, len);
		}
	      if (freg <= 13
		  && TYPE_CODE (type) == TYPE_CODE_STRUCT
		  && TYPE_NFIELDS (type) == 1
		  && TYPE_LENGTH (type) <= 16)
		{
		  /* The ABI (version 1.9) specifies that structs
		     containing a single floating-point value, at any
		     level of nesting of single-member structs, are
		     passed in floating-point registers.  */
		  while (TYPE_CODE (type) == TYPE_CODE_STRUCT
			 && TYPE_NFIELDS (type) == 1)
		    type = check_typedef (TYPE_FIELD_TYPE (type, 0));
		  if (TYPE_CODE (type) == TYPE_CODE_FLT)
		    {
		      if (TYPE_LENGTH (type) <= 8)
			{
			  if (write_pass)
			    {
			      gdb_byte regval[MAX_REGISTER_SIZE];
			      struct type *regtype
				= register_type (gdbarch,
						 tdep->ppc_fp0_regnum);
			      convert_typed_floating (val, type, regval,
						      regtype);
			      regcache_cooked_write (regcache,
						     (tdep->ppc_fp0_regnum
						      + freg),
						     regval);
			    }
			  freg++;
			}
		      else if (TYPE_LENGTH (type) == 16
			       && (gdbarch_long_double_format (gdbarch)
				   == floatformats_ibm_long_double))
			{
			  if (write_pass)
			    {
			      regcache_cooked_write (regcache,
						     (tdep->ppc_fp0_regnum
						      + freg),
						     val);
			      if (freg <= 12)
				regcache_cooked_write (regcache,
						       (tdep->ppc_fp0_regnum
							+ freg + 1),
						       val + 8);
			    }
			  freg += 2;
			}
		    }
		}
	      /* Always consume parameter stack space.  */
	      gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
	    }
	}

      if (!write_pass)
	{
	  /* Save the true region sizes ready for the second pass.  */
	  vparam_size = vparam;
	  /* Make certain that the general parameter save area is at
	     least the minimum 8 registers (or doublewords) in size.  */
	  if (greg < 8)
	    gparam_size = 8 * tdep->wordsize;
	  else
	    gparam_size = gparam;
	}
    }

  /* Update %sp.   */
  regcache_cooked_write_signed (regcache, gdbarch_sp_regnum (gdbarch), sp);

  /* Write the backchain (it occupies WORDSIZED bytes).  */
  write_memory_signed_integer (sp, tdep->wordsize, byte_order, back_chain);

  /* Point the inferior function call's return address at the dummy's
     breakpoint.  */
  regcache_cooked_write_signed (regcache, tdep->ppc_lr_regnum, bp_addr);

  /* Use the func_addr to find the descriptor, and use that to find
     the TOC.  If we're calling via a function pointer, the pointer
     itself identifies the descriptor.  */
  {
    struct type *ftype = check_typedef (value_type (function));
    CORE_ADDR desc_addr = value_as_address (function);

    if (TYPE_CODE (ftype) == TYPE_CODE_PTR
	|| convert_code_addr_to_desc_addr (func_addr, &desc_addr))
      {
	/* The TOC is the second double word in the descriptor.  */
	CORE_ADDR toc =
	  read_memory_unsigned_integer (desc_addr + tdep->wordsize,
					tdep->wordsize, byte_order);
	regcache_cooked_write_unsigned (regcache,
					tdep->ppc_gp0_regnum + 2, toc);
      }
  }

  return sp;
}