static CORE_ADDR
sparc32_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 call_pc = (struct_return ? (bp_addr - 12) : (bp_addr - 8));

  /* Set return address.  */
  regcache_cooked_write_unsigned (regcache, SPARC_O7_REGNUM, call_pc);

  /* Set up function arguments.  */
  sp = sparc32_store_arguments (regcache, nargs, args, sp,
				struct_return, struct_addr);

  /* Allocate the 16-word window save area.  */
  sp -= 16 * 4;

  /* Stack should be doubleword aligned at this point.  */
  gdb_assert (sp % 8 == 0);

  /* Finally, update the stack pointer.  */
  regcache_cooked_write_unsigned (regcache, SPARC_SP_REGNUM, sp);

  return sp;
}

static void
mips_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
{
  struct gdbarch *gdbarch = get_regcache_arch (regcache);
  regcache_cooked_write_unsigned (regcache, gdbarch_pc_regnum (gdbarch), pc);

  /* Clear the syscall restart flag.  */
  if (mips_linux_restart_reg_p (gdbarch))
    regcache_cooked_write_unsigned (regcache, MIPS_RESTART_REGNUM, 0);
}

static void
moxie_store_return_value (struct type *type, struct regcache *regcache,
			 const void *valbuf)
{
  CORE_ADDR regval;
  int len = TYPE_LENGTH (type);

  /* Things always get returned in RET1_REGNUM, RET2_REGNUM.  */
  regval = extract_unsigned_integer (valbuf, len > 4 ? 4 : len);
  regcache_cooked_write_unsigned (regcache, RET1_REGNUM, regval);
  if (len > 4)
    {
      regval = extract_unsigned_integer ((gdb_byte *) valbuf + 4, len - 4);
      regcache_cooked_write_unsigned (regcache, RET1_REGNUM + 1, regval);
    }
}

static void
ppc_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
{
  struct gdbarch *gdbarch = get_regcache_arch (regcache);

  regcache_cooked_write_unsigned (regcache, gdbarch_pc_regnum (gdbarch), pc);

  /* Set special TRAP register to -1 to prevent the kernel from
     messing with the PC we just installed, if we happen to be
     within an interrupted system call that the kernel wants to
     restart.

     Note that after we return from the dummy call, the TRAP and
     ORIG_R3 registers will be automatically restored, and the
     kernel continues to restart the system call at this point.  */
  if (ppc_linux_trap_reg_p (gdbarch))
    regcache_cooked_write_unsigned (regcache, PPC_TRAP_REGNUM, -1);
}

static void
ft32_store_return_value (struct type *type, struct regcache *regcache,
			 const gdb_byte *valbuf)
{
  struct gdbarch *gdbarch = regcache->arch ();
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  CORE_ADDR regval;
  int len = TYPE_LENGTH (type);

  /* Things always get returned in RET1_REGNUM, RET2_REGNUM.  */
  regval = extract_unsigned_integer (valbuf, len > 4 ? 4 : len, byte_order);
  regcache_cooked_write_unsigned (regcache, FT32_R0_REGNUM, regval);
  if (len > 4)
    {
      regval = extract_unsigned_integer (valbuf + 4,
					 len - 4, byte_order);
      regcache_cooked_write_unsigned (regcache, FT32_R1_REGNUM, regval);
    }
}

static void
sparc64_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
  ULONGEST state;

  regcache_cooked_write_unsigned (regcache, tdep->pc_regnum, pc);
  regcache_cooked_write_unsigned (regcache, tdep->npc_regnum, pc + 4);

  /* Clear the "in syscall" bit to prevent the kernel from
     messing with the PCs we just installed, if we happen to be
     within an interrupted system call that the kernel wants to
     restart.

     Note that after we return from the dummy call, the TSTATE et al.
     registers will be automatically restored, and the kernel
     continues to restart the system call at this point.  */
  regcache_cooked_read_unsigned (regcache, SPARC64_STATE_REGNUM, &state);
  state &= ~TSTATE_SYSCALL;
  regcache_cooked_write_unsigned (regcache, SPARC64_STATE_REGNUM, state);
}

static void
i386_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
{
  regcache_cooked_write_unsigned (regcache, I386_EIP_REGNUM, pc);

  /* We must be careful with modifying the program counter.  If we
     just interrupted a system call, the kernel might try to restart
     it when we resume the inferior.  On restarting the system call,
     the kernel will try backing up the program counter even though it
     no longer points at the system call.  This typically results in a
     SIGSEGV or SIGILL.  We can prevent this by writing `-1' in the
     "orig_eax" pseudo-register.

     Note that "orig_eax" is saved when setting up a dummy call frame.
     This means that it is properly restored when that frame is
     popped, and that the interrupted system call will be restarted
     when we resume the inferior on return from a function call from
     within GDB.  In all other cases the system call will not be
     restarted.  */
  regcache_cooked_write_unsigned (regcache, I386_LINUX_ORIG_EAX_REGNUM, -1);
}

static void
tilegx_write_pc (struct regcache *regcache, CORE_ADDR pc)
{
  regcache_cooked_write_unsigned (regcache, TILEGX_PC_REGNUM, pc);

  /* We must be careful with modifying the program counter.  If we
     just interrupted a system call, the kernel might try to restart
     it when we resume the inferior.  On restarting the system call,
     the kernel will try backing up the program counter even though it
     no longer points at the system call.  This typically results in a
     SIGSEGV or SIGILL.  We can prevent this by writing INT_SWINT_1_SIGRETURN
     in the "faultnum" pseudo-register.

     Note that "faultnum" is saved when setting up a dummy call frame.
     This means that it is properly restored when that frame is
     popped, and that the interrupted system call will be restarted
     when we resume the inferior on return from a function call from
     within GDB.  In all other cases the system call will not be
     restarted.  */
  regcache_cooked_write_unsigned (regcache, TILEGX_FAULTNUM_REGNUM,
                                  INT_SWINT_1_SIGRETURN);
}

/* Write into appropriate registers a function return value of type
   TYPE, given in virtual format.  */
static void
lm32_store_return_value (struct type *type, struct regcache *regcache,
			 const gdb_byte *valbuf)
{
  ULONGEST val;
  int len = TYPE_LENGTH (type);

  if (len <= 4)
    {
      val = extract_unsigned_integer (valbuf, len);
      regcache_cooked_write_unsigned (regcache, SIM_LM32_R1_REGNUM, val);
    }
  else if (len <= 8)
    {
      val = extract_unsigned_integer (valbuf, 4);
      regcache_cooked_write_unsigned (regcache, SIM_LM32_R1_REGNUM, val);
      val = extract_unsigned_integer (valbuf + 4, len - 4);
      regcache_cooked_write_unsigned (regcache, SIM_LM32_R2_REGNUM, val);
    }
  else
    error (_("lm32_store_return_value: type length too large."));
}

static void
enable_watchpoints_in_psr (ptid_t ptid)
{
  struct regcache *regcache = get_thread_regcache (ptid);
  ULONGEST psr;

  regcache_cooked_read_unsigned (regcache, IA64_PSR_REGNUM, &psr);
  if (!(psr & IA64_PSR_DB))
    {
      psr |= IA64_PSR_DB;	/* Set the db bit - this enables hardware
			           watchpoints and breakpoints.  */
      regcache_cooked_write_unsigned (regcache, IA64_PSR_REGNUM, psr);
    }
}

static void
m88k_write_pc (struct regcache *regcache, CORE_ADDR pc)
{
  /* According to the MC88100 RISC Microprocessor User's Manual,
     section 6.4.3.1.2:

     "... can be made to return to a particular instruction by placing
     a valid instruction address in the SNIP and the next sequential
     instruction address in the SFIP (with V bits set and E bits
     clear).  The rte resumes execution at the instruction pointed to
     by the SNIP, then the SFIP."

     The E bit is the least significant bit (bit 0).  The V (valid)
     bit is bit 1.  This is why we logical or 2 into the values we are
     writing below.  It turns out that SXIP plays no role when
     returning from an exception so nothing special has to be done
     with it.  We could even (presumably) give it a totally bogus
     value.  */

  regcache_cooked_write_unsigned (regcache, M88K_SXIP_REGNUM, pc);
  regcache_cooked_write_unsigned (regcache, M88K_SNIP_REGNUM, pc | 2);
  regcache_cooked_write_unsigned (regcache, M88K_SFIP_REGNUM, (pc + 4) | 2);
}

static CORE_ADDR
vax_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
		     struct regcache *regcache, CORE_ADDR bp_addr, int nargs,
		     struct value **args, CORE_ADDR sp,
		     function_call_return_method return_method,
		     CORE_ADDR struct_addr)
{
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  CORE_ADDR fp = sp;
  gdb_byte buf[4];

  /* Set up the function arguments.  */
  sp = vax_store_arguments (regcache, nargs, args, sp);

  /* Store return value address.  */
  if (return_method == return_method_struct)
    regcache_cooked_write_unsigned (regcache, VAX_R1_REGNUM, struct_addr);

  /* Store return address in the PC slot.  */
  sp -= 4;
  store_unsigned_integer (buf, 4, byte_order, bp_addr);
  write_memory (sp, buf, 4);

  /* Store the (fake) frame pointer in the FP slot.  */
  sp -= 4;
  store_unsigned_integer (buf, 4, byte_order, fp);
  write_memory (sp, buf, 4);

  /* Skip the AP slot.  */
  sp -= 4;

  /* Store register save mask and control bits.  */
  sp -= 4;
  store_unsigned_integer (buf, 4, byte_order, 0);
  write_memory (sp, buf, 4);

  /* Store condition handler.  */
  sp -= 4;
  store_unsigned_integer (buf, 4, byte_order, 0);
  write_memory (sp, buf, 4);

  /* Update the stack pointer and frame pointer.  */
  store_unsigned_integer (buf, 4, byte_order, sp);
  regcache->cooked_write (VAX_SP_REGNUM, buf);
  regcache->cooked_write (VAX_FP_REGNUM, buf);

  /* Return the saved (fake) frame pointer.  */
  return fp;
}

/* Write into appropriate registers a function return value of type
   TYPE, given in virtual format.  */
static void
lm32_store_return_value (struct type *type, struct regcache *regcache,
			 const gdb_byte *valbuf)
{
  struct gdbarch *gdbarch = get_regcache_arch (regcache);
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  ULONGEST val;
  int len = TYPE_LENGTH (type);

  if (len <= 4)
    {
      val = extract_unsigned_integer (valbuf, len, byte_order);
      regcache_cooked_write_unsigned (regcache, SIM_LM32_R1_REGNUM, val);
    }
  else if (len <= 8)
    {
      val = extract_unsigned_integer (valbuf, 4, byte_order);
      regcache_cooked_write_unsigned (regcache, SIM_LM32_R1_REGNUM, val);
      val = extract_unsigned_integer (valbuf + 4, len - 4, byte_order);
      regcache_cooked_write_unsigned (regcache, SIM_LM32_R2_REGNUM, val);
    }
  else
    error (_("lm32_store_return_value: type length too large."));
}

static void
i386fbsd_resume (struct target_ops *ops,
		 ptid_t ptid, int step, enum gdb_signal signal)
{
  pid_t pid = ptid_get_pid (ptid);
  int request = PT_STEP;

  if (pid == -1)
    /* Resume all threads.  This only gets used in the non-threaded
       case, where "resume all threads" and "resume inferior_ptid" are
       the same.  */
    pid = ptid_get_pid (inferior_ptid);

  if (!step)
    {
      struct regcache *regcache = get_current_regcache ();
      ULONGEST eflags;

      /* Workaround for a bug in FreeBSD.  Make sure that the trace
 	 flag is off when doing a continue.  There is a code path
 	 through the kernel which leaves the flag set when it should
 	 have been cleared.  If a process has a signal pending (such
 	 as SIGALRM) and we do a PT_STEP, the process never really has
 	 a chance to run because the kernel needs to notify the
 	 debugger that a signal is being sent.  Therefore, the process
 	 never goes through the kernel's trap() function which would
 	 normally clear it.  */

      regcache_cooked_read_unsigned (regcache, I386_EFLAGS_REGNUM,
				     &eflags);
      if (eflags & 0x0100)
	regcache_cooked_write_unsigned (regcache, I386_EFLAGS_REGNUM,
					eflags & ~0x0100);

      request = PT_CONTINUE;
    }

  /* An addres of (caddr_t) 1 tells ptrace to continue from where it
     was.  (If GDB wanted it to start some other way, we have already
     written a new PC value to the child.)  */
  if (ptrace (request, pid, (caddr_t) 1,
	      gdb_signal_to_host (signal)) == -1)
    perror_with_name (("ptrace"));
}

static int
ia64_linux_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
{
  CORE_ADDR psr;
  siginfo_t siginfo;
  struct regcache *regcache = get_current_regcache ();

  if (!linux_nat_get_siginfo (inferior_ptid, &siginfo))
    return 0;

  if (siginfo.si_signo != SIGTRAP
      || (siginfo.si_code & 0xffff) != 0x0004 /* TRAP_HWBKPT */)
    return 0;

  regcache_cooked_read_unsigned (regcache, IA64_PSR_REGNUM, &psr);
  psr |= IA64_PSR_DD;	/* Set the dd bit - this will disable the watchpoint
                           for the next instruction.  */
  regcache_cooked_write_unsigned (regcache, IA64_PSR_REGNUM, psr);

  *addr_p = (CORE_ADDR) siginfo.si_addr;
  return 1;
}

static void
ft32_write_pc (struct regcache *regcache, CORE_ADDR val)
{
  regcache_cooked_write_unsigned (regcache, FT32_PC_REGNUM, val);
}

//.........这里部分代码省略.........
		  if (write_pass)
		    write_memory (sp + argoffset, val, 8);
		  argoffset += 8;
		}
	    }
	  else
	    {
	      /* Reduce the parameter down to something that fits in a
	         "word".  */
	      gdb_byte word[MAX_REGISTER_SIZE];
	      memset (word, 0, MAX_REGISTER_SIZE);
	      if (len > tdep->wordsize
		  || TYPE_CODE (type) == TYPE_CODE_STRUCT
		  || TYPE_CODE (type) == TYPE_CODE_UNION)
		{
		  /* Structs and large values are put in an
		     aligned stack slot ... */
		  if (TYPE_CODE (type) == TYPE_CODE_ARRAY
		      && TYPE_VECTOR (type)
		      && len >= 16)
		    structoffset = align_up (structoffset, 16);
		  else
		    structoffset = align_up (structoffset, 8);

		  if (write_pass)
		    write_memory (sp + structoffset, val, len);
		  /* ... and then a "word" pointing to that address is
		     passed as the parameter.  */
		  store_unsigned_integer (word, tdep->wordsize, byte_order,
					  sp + structoffset);
		  structoffset += len;
		}
	      else if (TYPE_CODE (type) == TYPE_CODE_INT)
		/* Sign or zero extend the "int" into a "word".  */
		store_unsigned_integer (word, tdep->wordsize, byte_order,
					unpack_long (type, val));
	      else
		/* Always goes in the low address.  */
		memcpy (word, val, len);
	      /* Store that "word" in a register, or on the stack.
	         The words have "4" byte alignment.  */
	      if (greg <= 10)
		{
		  if (write_pass)
		    regcache_cooked_write (regcache,
					   tdep->ppc_gp0_regnum + greg, word);
		  greg++;
		}
	      else
		{
		  argoffset = align_up (argoffset, tdep->wordsize);
		  if (write_pass)
		    write_memory (sp + argoffset, word, tdep->wordsize);
		  argoffset += tdep->wordsize;
		}
	    }
	}

      /* Compute the actual stack space requirements.  */
      if (!write_pass)
	{
	  /* Remember the amount of space needed by the arguments.  */
	  argspace = argoffset;
	  /* Allocate space for both the arguments and the structures.  */
	  sp -= (argoffset + structoffset);
	  /* Ensure that the stack is still 16 byte aligned.  */
	  sp = align_down (sp, 16);
	}

      /* The psABI says that "A caller of a function that takes a
	 variable argument list shall set condition register bit 6 to
	 1 if it passes one or more arguments in the floating-point
	 registers. It is strongly recommended that the caller set the
	 bit to 0 otherwise..."  Doing this for normal functions too
	 shouldn't hurt.  */
      if (write_pass)
	{
	  ULONGEST cr;

	  regcache_cooked_read_unsigned (regcache, tdep->ppc_cr_regnum, &cr);
	  if (freg > 1)
	    cr |= 0x02000000;
	  else
	    cr &= ~0x02000000;
	  regcache_cooked_write_unsigned (regcache, tdep->ppc_cr_regnum, cr);
	}
    }

  /* 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, saved_sp);

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

  return sp;
}

static CORE_ADDR
lm32_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)
{
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  int first_arg_reg = SIM_LM32_R1_REGNUM;
  int num_arg_regs = 8;
  int i;

  /* Set the return address.  */
  regcache_cooked_write_signed (regcache, SIM_LM32_RA_REGNUM, bp_addr);

  /* If we're returning a large struct, a pointer to the address to
     store it at is passed as a first hidden parameter.  */
  if (struct_return)
    {
      regcache_cooked_write_unsigned (regcache, first_arg_reg, struct_addr);
      first_arg_reg++;
      num_arg_regs--;
      sp -= 4;
    }

  /* Setup parameters.  */
  for (i = 0; i < nargs; i++)
    {
      struct value *arg = args[i];
      struct type *arg_type = check_typedef (value_type (arg));
      gdb_byte *contents;
      int len;
      int j;
      int reg;
      ULONGEST val;

      /* Promote small integer types to int.  */
      switch (TYPE_CODE (arg_type))
	{
	case TYPE_CODE_INT:
	case TYPE_CODE_BOOL:
	case TYPE_CODE_CHAR:
	case TYPE_CODE_RANGE:
	case TYPE_CODE_ENUM:
	  if (TYPE_LENGTH (arg_type) < 4)
	    {
	      arg_type = builtin_type (gdbarch)->builtin_int32;
	      arg = value_cast (arg_type, arg);
	    }
	  break;
	}

      /* FIXME: Handle structures.  */

      contents = (gdb_byte *) value_contents (arg);
      len = TYPE_LENGTH (arg_type);
      val = extract_unsigned_integer (contents, len, byte_order);

      /* First num_arg_regs parameters are passed by registers, 
         and the rest are passed on the stack.  */
      if (i < num_arg_regs)
	regcache_cooked_write_unsigned (regcache, first_arg_reg + i, val);
      else
	{
	  write_memory (sp, (void *) &val, len);
	  sp -= 4;
	}
    }

  /* Update stack pointer.  */
  regcache_cooked_write_signed (regcache, SIM_LM32_SP_REGNUM, sp);

  /* Return adjusted stack pointer.  */
  return sp;
}

//.........这里部分代码省略.........
	  regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 3,
				 writebuf + 0);
	  regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 4,
				 writebuf + 4);
	}
      return RETURN_VALUE_REGISTER_CONVENTION;
    }
  if (TYPE_CODE (type) == TYPE_CODE_DECFLOAT && !tdep->soft_float)
    return get_decimal_float_return_value (gdbarch, type, regcache, readbuf,
					   writebuf);
  else if ((TYPE_CODE (type) == TYPE_CODE_INT
	    || TYPE_CODE (type) == TYPE_CODE_CHAR
	    || TYPE_CODE (type) == TYPE_CODE_BOOL
	    || TYPE_CODE (type) == TYPE_CODE_PTR
	    || TYPE_CODE (type) == TYPE_CODE_REF
	    || TYPE_CODE (type) == TYPE_CODE_ENUM)
	   && TYPE_LENGTH (type) <= tdep->wordsize)
    {
      if (readbuf)
	{
	  /* Some sort of integer stored in r3.  Since TYPE isn't
	     bigger than the register, sign extension isn't a problem
	     - just do everything unsigned.  */
	  ULONGEST regval;
	  regcache_cooked_read_unsigned (regcache, tdep->ppc_gp0_regnum + 3,
					 &regval);
	  store_unsigned_integer (readbuf, TYPE_LENGTH (type), byte_order,
				  regval);
	}
      if (writebuf)
	{
	  /* Some sort of integer stored in r3.  Use unpack_long since
	     that should handle any required sign extension.  */
	  regcache_cooked_write_unsigned (regcache, tdep->ppc_gp0_regnum + 3,
					  unpack_long (type, writebuf));
	}
      return RETURN_VALUE_REGISTER_CONVENTION;
    }
  if (TYPE_LENGTH (type) == 16
      && TYPE_CODE (type) == TYPE_CODE_ARRAY
      && TYPE_VECTOR (type)
      && tdep->vector_abi == POWERPC_VEC_ALTIVEC)
    {
      if (readbuf)
	{
	  /* Altivec places the return value in "v2".  */
	  regcache_cooked_read (regcache, tdep->ppc_vr0_regnum + 2, readbuf);
	}
      if (writebuf)
	{
	  /* Altivec places the return value in "v2".  */
	  regcache_cooked_write (regcache, tdep->ppc_vr0_regnum + 2, writebuf);
	}
      return RETURN_VALUE_REGISTER_CONVENTION;
    }
  if (TYPE_LENGTH (type) == 16
      && TYPE_CODE (type) == TYPE_CODE_ARRAY
      && TYPE_VECTOR (type)
      && tdep->vector_abi == POWERPC_VEC_GENERIC)
    {
      /* GCC -maltivec -mabi=no-altivec returns vectors in r3/r4/r5/r6.
	 GCC without AltiVec returns them in memory, but it warns about
	 ABI risks in that case; we don't try to support it.  */
      if (readbuf)
	{
	  regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 3,

static enum return_value_convention
rs6000_lynx178_return_value (struct gdbarch *gdbarch, struct value *function,
			     struct type *valtype, struct regcache *regcache,
			     gdb_byte *readbuf, const gdb_byte *writebuf)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);

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

  /* AltiVec extension: Functions that declare a vector data type as a
     return value place that return value in VR2.  */
  if (TYPE_CODE (valtype) == TYPE_CODE_ARRAY && TYPE_VECTOR (valtype)
      && TYPE_LENGTH (valtype) == 16)
    {
      if (readbuf)
	regcache_cooked_read (regcache, tdep->ppc_vr0_regnum + 2, readbuf);
      if (writebuf)
	regcache_cooked_write (regcache, tdep->ppc_vr0_regnum + 2, writebuf);

      return RETURN_VALUE_REGISTER_CONVENTION;
    }

  /* If the called subprogram returns an aggregate, there exists an
     implicit first argument, whose value is the address of a caller-
     allocated buffer into which the callee is assumed to store its
     return value.  All explicit parameters are appropriately
     relabeled.  */
  if (TYPE_CODE (valtype) == TYPE_CODE_STRUCT
      || TYPE_CODE (valtype) == TYPE_CODE_UNION
      || TYPE_CODE (valtype) == TYPE_CODE_ARRAY)
    return RETURN_VALUE_STRUCT_CONVENTION;

  /* Scalar floating-point values are returned in FPR1 for float or
     double, and in FPR1:FPR2 for quadword precision.  Fortran
     complex*8 and complex*16 are returned in FPR1:FPR2, and
     complex*32 is returned in FPR1:FPR4.  */
  if (TYPE_CODE (valtype) == TYPE_CODE_FLT
      && (TYPE_LENGTH (valtype) == 4 || TYPE_LENGTH (valtype) == 8))
    {
      struct type *regtype = register_type (gdbarch, tdep->ppc_fp0_regnum);
      gdb_byte regval[8];

      /* FIXME: kettenis/2007-01-01: Add support for quadword
	 precision and complex.  */

      if (readbuf)
	{
	  regcache_cooked_read (regcache, tdep->ppc_fp0_regnum + 1, regval);
	  convert_typed_floating (regval, regtype, readbuf, valtype);
	}
      if (writebuf)
	{
	  convert_typed_floating (writebuf, valtype, regval, regtype);
	  regcache_cooked_write (regcache, tdep->ppc_fp0_regnum + 1, regval);
	}

      return RETURN_VALUE_REGISTER_CONVENTION;
  }

  /* Values of the types int, long, short, pointer, and char (length
     is less than or equal to four bytes), as well as bit values of
     lengths less than or equal to 32 bits, must be returned right
     justified in GPR3 with signed values sign extended and unsigned
     values zero extended, as necessary.  */
  if (TYPE_LENGTH (valtype) <= tdep->wordsize)
    {
      if (readbuf)
	{
	  ULONGEST regval;

	  /* For reading we don't have to worry about sign extension.  */
	  regcache_cooked_read_unsigned (regcache, tdep->ppc_gp0_regnum + 3,
					 &regval);
	  store_unsigned_integer (readbuf, TYPE_LENGTH (valtype), byte_order,
				  regval);
	}
      if (writebuf)
	{
	  /* For writing, use unpack_long since that should handle any
	     required sign extension.  */
	  regcache_cooked_write_unsigned (regcache, tdep->ppc_gp0_regnum + 3,
					  unpack_long (valtype, writebuf));
	}

      return RETURN_VALUE_REGISTER_CONVENTION;
    }

  /* Eight-byte non-floating-point scalar values must be returned in
     GPR3:GPR4.  */

  if (TYPE_LENGTH (valtype) == 8)
    {
      gdb_assert (TYPE_CODE (valtype) != TYPE_CODE_FLT);
      gdb_assert (tdep->wordsize == 4);

      if (readbuf)
//.........这里部分代码省略.........