path: root/gdb/x86-64-tdep.c

/* Target-dependent code for the x86-64 for GDB, the GNU debugger.

   Copyright 2001, 2002 Free Software Foundation, Inc.

   Contributed by Jiri Smid, SuSE Labs.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "inferior.h"
#include "gdbcore.h"
#include "gdbcmd.h"
#include "arch-utils.h"
#include "regcache.h"
#include "symfile.h"
#include "x86-64-tdep.h"
#include "dwarf2cfi.h"
#include "gdb_assert.h"

/* Register numbers of various important registers.  */
#define RAX_REGNUM 0
#define RDX_REGNUM 3
#define RDI_REGNUM 5
#define EFLAGS_REGNUM 17
#define XMM1_REGNUM  39

struct register_info
{
  int size;
  char *name;
  struct type **type;
};

/* x86_64_register_raw_size_table[i] is the number of bytes of storage in
   GDB's register array occupied by register i.  */
static struct register_info x86_64_register_info_table[] = {
  {8, "rax", &builtin_type_int64},
  {8, "rbx", &builtin_type_int64},
  {8, "rcx", &builtin_type_int64},
  {8, "rdx", &builtin_type_int64},
  {8, "rsi", &builtin_type_int64},
  {8, "rdi", &builtin_type_int64},
  {8, "rbp", &builtin_type_void_func_ptr},
  {8, "rsp", &builtin_type_void_func_ptr},
  {8, "r8", &builtin_type_int64},
  {8, "r9", &builtin_type_int64},
  {8, "r10", &builtin_type_int64},
  {8, "r11", &builtin_type_int64},
  {8, "r12", &builtin_type_int64},
  {8, "r13", &builtin_type_int64},
  {8, "r14", &builtin_type_int64},
  {8, "r15", &builtin_type_int64},
  {8, "rip", &builtin_type_void_func_ptr},
  {4, "eflags", &builtin_type_int32},
  {4, "ds", &builtin_type_int32},
  {4, "es", &builtin_type_int32},
  {4, "fs", &builtin_type_int32},
  {4, "gs", &builtin_type_int32},
  {10, "st0", &builtin_type_i387_ext},
  {10, "st1", &builtin_type_i387_ext},
  {10, "st2", &builtin_type_i387_ext},
  {10, "st3", &builtin_type_i387_ext},
  {10, "st4", &builtin_type_i387_ext},
  {10, "st5", &builtin_type_i387_ext},
  {10, "st6", &builtin_type_i387_ext},
  {10, "st7", &builtin_type_i387_ext},
  {4, "fctrl", &builtin_type_int32},
  {4, "fstat", &builtin_type_int32},
  {4, "ftag", &builtin_type_int32},
  {4, "fiseg", &builtin_type_int32},
  {4, "fioff", &builtin_type_int32},
  {4, "foseg", &builtin_type_int32},
  {4, "fooff", &builtin_type_int32},
  {4, "fop", &builtin_type_int32},
  {16, "xmm0", &builtin_type_v4sf},
  {16, "xmm1", &builtin_type_v4sf},
  {16, "xmm2", &builtin_type_v4sf},
  {16, "xmm3", &builtin_type_v4sf},
  {16, "xmm4", &builtin_type_v4sf},
  {16, "xmm5", &builtin_type_v4sf},
  {16, "xmm6", &builtin_type_v4sf},
  {16, "xmm7", &builtin_type_v4sf},
  {16, "xmm8", &builtin_type_v4sf},
  {16, "xmm9", &builtin_type_v4sf},
  {16, "xmm10", &builtin_type_v4sf},
  {16, "xmm11", &builtin_type_v4sf},
  {16, "xmm12", &builtin_type_v4sf},
  {16, "xmm13", &builtin_type_v4sf},
  {16, "xmm14", &builtin_type_v4sf},
  {16, "xmm15", &builtin_type_v4sf},
  {4, "mxcsr", &builtin_type_int32}
};

/* Number of all registers */
#define X86_64_NUM_REGS (sizeof (x86_64_register_info_table) / \
  sizeof (x86_64_register_info_table[0]))

/* Number of general registers.  */
#define X86_64_NUM_GREGS (22)

int x86_64_num_regs = X86_64_NUM_REGS;
int x86_64_num_gregs = X86_64_NUM_GREGS;

/* Number of bytes of storage in the actual machine representation for
   register REGNO.  */
int
x86_64_register_raw_size (int regno)
{
  return x86_64_register_info_table[regno].size;
}

/* x86_64_register_byte_table[i] is the offset into the register file of the
   start of register number i.  We initialize this from
   x86_64_register_info_table.  */
int x86_64_register_byte_table[X86_64_NUM_REGS];

/* Index within `registers' of the first byte of the space for register REGNO.  */
int
x86_64_register_byte (int regno)
{
  return x86_64_register_byte_table[regno];
}

/* Return the GDB type object for the "standard" data type of data in
   register N. */
static struct type *
x86_64_register_virtual_type (int regno)
{
  return *x86_64_register_info_table[regno].type;
}

/* x86_64_register_convertible is true if register N's virtual format is
   different from its raw format.  Note that this definition assumes
   that the host supports IEEE 32-bit floats, since it doesn't say
   that SSE registers need conversion.  Even if we can't find a
   counterexample, this is still sloppy.  */
int
x86_64_register_convertible (int regno)
{
  return IS_FP_REGNUM (regno);
}

/* Convert data from raw format for register REGNUM in buffer FROM to
   virtual format with type TYPE in buffer TO.  In principle both
   formats are identical except that the virtual format has two extra
   bytes appended that aren't used.  We set these to zero.  */
void
x86_64_register_convert_to_virtual (int regnum, struct type *type,
				    char *from, char *to)
{
  char buf[12];
  DOUBLEST d;
  /* We only support floating-point values.  */
  if (TYPE_CODE (type) != TYPE_CODE_FLT)
    {
      warning ("Cannot convert floating-point register value "
	       "to non-floating-point type.");
      memset (to, 0, TYPE_LENGTH (type));
      return;
    }
  /* First add the necessary padding.  */
  memcpy (buf, from, FPU_REG_RAW_SIZE);
  memset (buf + FPU_REG_RAW_SIZE, 0, sizeof buf - FPU_REG_RAW_SIZE);
  /* Convert to TYPE.  This should be a no-op, if TYPE is equivalent
     to the extended floating-point format used by the FPU.  */
  convert_typed_floating (to, type, buf,
			  x86_64_register_virtual_type (regnum));
}

/* Convert data from virtual format with type TYPE in buffer FROM to
   raw format for register REGNUM in buffer TO.  Simply omit the two
   unused bytes.  */

void
x86_64_register_convert_to_raw (struct type *type, int regnum,
				char *from, char *to)
{
  gdb_assert (TYPE_CODE (type) == TYPE_CODE_FLT && TYPE_LENGTH (type) == 12);
  /* Simply omit the two unused bytes.  */
  memcpy (to, from, FPU_REG_RAW_SIZE);
}

/* This is the variable that is set with "set disassembly-flavour", and
   its legitimate values.  */
static const char att_flavour[] = "att";
static const char intel_flavour[] = "intel";
static const char *valid_flavours[] = {
  att_flavour,
  intel_flavour,
  NULL
};
static const char *disassembly_flavour = att_flavour;

static CORE_ADDR
x86_64_push_return_address (CORE_ADDR pc, CORE_ADDR sp)
{
  char buf[8];

  store_unsigned_integer (buf, 8, CALL_DUMMY_ADDRESS ());

  write_memory (sp - 8, buf, 8);
  return sp - 8;
}

void
x86_64_pop_frame (void)
{
  generic_pop_current_frame (cfi_pop_frame);
}


/* The returning of values is done according to the special algorithm.
   Some types are returned in registers an some (big structures) in memory.
   See ABI for details.
 */

#define MAX_CLASSES 4

enum x86_64_reg_class
{
  X86_64_NO_CLASS,
  X86_64_INTEGER_CLASS,
  X86_64_INTEGERSI_CLASS,
  X86_64_SSE_CLASS,
  X86_64_SSESF_CLASS,
  X86_64_SSEDF_CLASS,
  X86_64_SSEUP_CLASS,
  X86_64_X87_CLASS,
  X86_64_X87UP_CLASS,
  X86_64_MEMORY_CLASS
};

/* Return the union class of CLASS1 and CLASS2.
   See the x86-64 ABI for details.  */

static enum x86_64_reg_class
merge_classes (enum x86_64_reg_class class1, enum x86_64_reg_class class2)
{
  /* Rule #1: If both classes are equal, this is the resulting class.  */
  if (class1 == class2)
    return class1;

  /* Rule #2: If one of the classes is NO_CLASS, the resulting class is
     the other class.  */
  if (class1 == X86_64_NO_CLASS)
    return class2;
  if (class2 == X86_64_NO_CLASS)
    return class1;

  /* Rule #3: If one of the classes is MEMORY, the result is MEMORY.  */
  if (class1 == X86_64_MEMORY_CLASS || class2 == X86_64_MEMORY_CLASS)
    return X86_64_MEMORY_CLASS;

  /* Rule #4: If one of the classes is INTEGER, the result is INTEGER.  */
  if ((class1 == X86_64_INTEGERSI_CLASS && class2 == X86_64_SSESF_CLASS)
      || (class2 == X86_64_INTEGERSI_CLASS && class1 == X86_64_SSESF_CLASS))
    return X86_64_INTEGERSI_CLASS;
  if (class1 == X86_64_INTEGER_CLASS || class1 == X86_64_INTEGERSI_CLASS
      || class2 == X86_64_INTEGER_CLASS || class2 == X86_64_INTEGERSI_CLASS)
    return X86_64_INTEGER_CLASS;

  /* Rule #5: If one of the classes is X87 or X87UP class, MEMORY is used.  */
  if (class1 == X86_64_X87_CLASS || class1 == X86_64_X87UP_CLASS
      || class2 == X86_64_X87_CLASS || class2 == X86_64_X87UP_CLASS)
    return X86_64_MEMORY_CLASS;

  /* Rule #6: Otherwise class SSE is used.  */
  return X86_64_SSE_CLASS;
}


/* Classify the argument type.
   CLASSES will be filled by the register class used to pass each word
   of the operand.  The number of words is returned.  In case the parameter
   should be passed in memory, 0 is returned. As a special case for zero
   sized containers, classes[0] will be NO_CLASS and 1 is returned.

   See the x86-64 PS ABI for details.
*/

static int
classify_argument (struct type *type,
		   enum x86_64_reg_class classes[MAX_CLASSES], int bit_offset)
{
  int bytes = TYPE_LENGTH (type);
  int words = (bytes + 8 - 1) / 8;

  switch (TYPE_CODE (type))
    {
    case TYPE_CODE_ARRAY:
    case TYPE_CODE_STRUCT:
    case TYPE_CODE_UNION:
      {
	int i;
	enum x86_64_reg_class subclasses[MAX_CLASSES];

	/* On x86-64 we pass structures larger than 16 bytes on the stack.  */
	if (bytes > 16)
	  return 0;

	for (i = 0; i < words; i++)
	  classes[i] = X86_64_NO_CLASS;

	/* Zero sized arrays or structures are NO_CLASS.  We return 0 to
	   signalize memory class, so handle it as special case.  */
	if (!words)
	  {
	    classes[0] = X86_64_NO_CLASS;
	    return 1;
	  }
	switch (TYPE_CODE (type))
	  {
	  case TYPE_CODE_STRUCT:
	    {
	      int j;
	      for (j = 0; j < type->nfields; ++j)
		{
		  int num = classify_argument (type->fields[j].type,
					       subclasses,
					       (type->fields[j].loc.bitpos
						+ bit_offset) % 256);
		  if (!num)
		    return 0;
		  for (i = 0; i < num; i++)
		    {
		      int pos =
			(type->fields[j].loc.bitpos + bit_offset) / 8 / 8;
		      classes[i + pos] =
			merge_classes (subclasses[i], classes[i + pos]);
		    }
		}
	    }
	    break;
	  case TYPE_CODE_ARRAY:
	    {
	      int num;

	      num = classify_argument (type->target_type,
				       subclasses, bit_offset);
	      if (!num)
		return 0;

	      /* The partial classes are now full classes.  */
	      if (subclasses[0] == X86_64_SSESF_CLASS && bytes != 4)
		subclasses[0] = X86_64_SSE_CLASS;
	      if (subclasses[0] == X86_64_INTEGERSI_CLASS && bytes != 4)
		subclasses[0] = X86_64_INTEGER_CLASS;

	      for (i = 0; i < words; i++)
		classes[i] = subclasses[i % num];
	    }
	    break;
	  case TYPE_CODE_UNION:
	    {
	      int j;
	      {
		for (j = 0; j < type->nfields; ++j)
		  {
		    int num;
		    num = classify_argument (type->fields[j].type,
					     subclasses, bit_offset);
		    if (!num)
		      return 0;
		    for (i = 0; i < num; i++)
		      classes[i] = merge_classes (subclasses[i], classes[i]);
		  }
	      }
	    }
	    break;
	  }
	/* Final merger cleanup.  */
	for (i = 0; i < words; i++)
	  {
	    /* If one class is MEMORY, everything should be passed in
	       memory.  */
	    if (classes[i] == X86_64_MEMORY_CLASS)
	      return 0;

	    /* The X86_64_SSEUP_CLASS should be always preceeded by
	       X86_64_SSE_CLASS.  */
	    if (classes[i] == X86_64_SSEUP_CLASS
		&& (i == 0 || classes[i - 1] != X86_64_SSE_CLASS))
	      classes[i] = X86_64_SSE_CLASS;

	    /*  X86_64_X87UP_CLASS should be preceeded by X86_64_X87_CLASS.  */
	    if (classes[i] == X86_64_X87UP_CLASS
		&& (i == 0 || classes[i - 1] != X86_64_X87_CLASS))
	      classes[i] = X86_64_SSE_CLASS;
	  }
	return words;
      }
      break;
    case TYPE_CODE_FLT:
      switch (bytes)
	{
	case 4:
	  if (!(bit_offset % 64))
	    classes[0] = X86_64_SSESF_CLASS;
	  else
	    classes[0] = X86_64_SSE_CLASS;
	  return 1;
	case 8:
	  classes[0] = X86_64_SSEDF_CLASS;
	  return 1;
	case 16:
	  classes[0] = X86_64_X87_CLASS;
	  classes[1] = X86_64_X87UP_CLASS;
	  return 2;
	}
      break;
    case TYPE_CODE_INT:
    case TYPE_CODE_PTR:
      switch (bytes)
	{
	case 1:
	case 2:
	case 4:
	case 8:
	  if (bytes * 8 + bit_offset <= 32)
	    classes[0] = X86_64_INTEGERSI_CLASS;
	  else
	    classes[0] = X86_64_INTEGER_CLASS;
	  return 1;
	case 16:
	  classes[0] = classes[1] = X86_64_INTEGER_CLASS;
	  return 2;
	default:
	  break;
	}
    case TYPE_CODE_VOID:
      return 0;
    }
  internal_error (__FILE__, __LINE__,
		  "classify_argument: unknown argument type");
}

/* Examine the argument and return set number of register required in each
   class.  Return 0 ifif parameter should be passed in memory.  */

static int
examine_argument (enum x86_64_reg_class classes[MAX_CLASSES],
		  int n, int *int_nregs, int *sse_nregs)
{
  *int_nregs = 0;
  *sse_nregs = 0;
  if (!n)
    return 0;
  for (n--; n >= 0; n--)
    switch (classes[n])
      {
      case X86_64_INTEGER_CLASS:
      case X86_64_INTEGERSI_CLASS:
	(*int_nregs)++;
	break;
      case X86_64_SSE_CLASS:
      case X86_64_SSESF_CLASS:
      case X86_64_SSEDF_CLASS:
	(*sse_nregs)++;
	break;
      case X86_64_NO_CLASS:
      case X86_64_SSEUP_CLASS:
      case X86_64_X87_CLASS:
      case X86_64_X87UP_CLASS:
	break;
      case X86_64_MEMORY_CLASS:
	internal_error (__FILE__, __LINE__,
			"examine_argument: unexpected memory class");
      }
  return 1;
}

#define RET_INT_REGS 2
#define RET_SSE_REGS 2

/* Check if the structure in value_type is returned in registers or in
   memory. If this function returns 1, gdb will call STORE_STRUCT_RETURN and
   EXTRACT_STRUCT_VALUE_ADDRESS else STORE_RETURN_VALUE and EXTRACT_RETURN_VALUE
   will be used.  */
int
x86_64_use_struct_convention (int gcc_p, struct type *value_type)
{
  enum x86_64_reg_class class[MAX_CLASSES];
  int n = classify_argument (value_type, class, 0);
  int needed_intregs;
  int needed_sseregs;

  return (!n ||
	  !examine_argument (class, n, &needed_intregs, &needed_sseregs) ||
	  needed_intregs > RET_INT_REGS || needed_sseregs > RET_SSE_REGS);
}


/* Extract from an array REGBUF containing the (raw) register state, a
   function return value of TYPE, and copy that, in virtual format,
   into VALBUF.  */

void
x86_64_extract_return_value (struct type *type, char *regbuf, char *valbuf)
{
  enum x86_64_reg_class class[MAX_CLASSES];
  int n = classify_argument (type, class, 0);
  int needed_intregs;
  int needed_sseregs;
  int intreg = 0;
  int ssereg = 0;
  int offset = 0;
  int ret_int_r[RET_INT_REGS] = { RAX_REGNUM, RDX_REGNUM };
  int ret_sse_r[RET_SSE_REGS] = { XMM0_REGNUM, XMM1_REGNUM };

  if (!n ||
      !examine_argument (class, n, &needed_intregs, &needed_sseregs) ||
      needed_intregs > RET_INT_REGS || needed_sseregs > RET_SSE_REGS)
    {				/* memory class */
      CORE_ADDR addr;
      memcpy (&addr, regbuf, REGISTER_RAW_SIZE (RAX_REGNUM));
      read_memory (addr, valbuf, TYPE_LENGTH (type));
      return;
    }
  else
    {
      int i;
      for (i = 0; i < n; i++)
	{
	  switch (class[i])
	    {
	    case X86_64_NO_CLASS:
	      break;
	    case X86_64_INTEGER_CLASS:
	      memcpy (valbuf + offset,
		      regbuf + REGISTER_BYTE (ret_int_r[(intreg + 1) / 2]),
		      8);
	      offset += 8;
	      intreg += 2;
	      break;
	    case X86_64_INTEGERSI_CLASS:
	      memcpy (valbuf + offset,
		      regbuf + REGISTER_BYTE (ret_int_r[intreg / 2]), 4);
	      offset += 8;
	      intreg++;
	      break;
	    case X86_64_SSEDF_CLASS:
	    case X86_64_SSESF_CLASS:
	    case X86_64_SSE_CLASS:
	      memcpy (valbuf + offset,
		      regbuf + REGISTER_BYTE (ret_sse_r[(ssereg + 1) / 2]),
		      8);
	      offset += 8;
	      ssereg += 2;
	      break;
	    case X86_64_SSEUP_CLASS:
	      memcpy (valbuf + offset + 8,
		      regbuf + REGISTER_BYTE (ret_sse_r[ssereg / 2]), 8);
	      offset += 8;
	      ssereg++;
	      break;
	    case X86_64_X87_CLASS:
	      memcpy (valbuf + offset, regbuf + REGISTER_BYTE (FP0_REGNUM),
		      8);
	      offset += 8;
	      break;
	    case X86_64_X87UP_CLASS:
	      memcpy (valbuf + offset,
		      regbuf + REGISTER_BYTE (FP0_REGNUM) + 8, 8);
	      offset += 8;
	      break;
	    case X86_64_MEMORY_CLASS:
	    default:
	      internal_error (__FILE__, __LINE__,
			      "Unexpected argument class");
	    }
	}
    }
}

/* Handled by unwind informations.  */
static void
x86_64_frame_init_saved_regs (struct frame_info *fi)
{
}

#define INT_REGS 6
#define SSE_REGS 16

CORE_ADDR
x86_64_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
		       int struct_return, CORE_ADDR struct_addr)
{
  int intreg = 0;
  int ssereg = 0;
  int i;
  static int int_parameter_registers[INT_REGS] = {
    5 /* RDI */ , 4 /* RSI */ ,
    3 /* RDX */ , 2 /* RCX */ ,
    8 /* R8  */ , 9 /* R9  */
  };
  /* XMM0 - XMM15  */
  static int sse_parameter_registers[SSE_REGS] = {
    XMM1_REGNUM - 1, XMM1_REGNUM, XMM1_REGNUM + 1, XMM1_REGNUM + 2,
    XMM1_REGNUM + 3, XMM1_REGNUM + 4, XMM1_REGNUM + 5, XMM1_REGNUM + 6,
    XMM1_REGNUM + 7, XMM1_REGNUM + 8, XMM1_REGNUM + 9, XMM1_REGNUM + 10,
    XMM1_REGNUM + 11, XMM1_REGNUM + 12, XMM1_REGNUM + 13, XMM1_REGNUM + 14
  };
  int stack_values_count = 0;
  int *stack_values;
  stack_values = alloca (nargs * sizeof (int));
  for (i = 0; i < nargs; i++)
    {
      enum x86_64_reg_class class[MAX_CLASSES];
      int n = classify_argument (args[i]->type, class, 0);
      int needed_intregs;
      int needed_sseregs;

      if (!n ||
	  !examine_argument (class, n, &needed_intregs, &needed_sseregs)
	  || intreg / 2 + needed_intregs > INT_REGS
	  || ssereg / 2 + needed_sseregs > SSE_REGS)
	{			/* memory class */
	  stack_values[stack_values_count++] = i;
	}
      else
	{
	  int j;
	  for (j = 0; j < n; j++)
	    {
	      int offset = 0;
	      switch (class[j])
		{
		case X86_64_NO_CLASS:
		  break;
		case X86_64_INTEGER_CLASS:
		  write_register_gen (int_parameter_registers
				      [(intreg + 1) / 2],
				      VALUE_CONTENTS_ALL (args[i]) + offset);
		  offset += 8;
		  intreg += 2;
		  break;
		case X86_64_INTEGERSI_CLASS:
		  write_register_gen (int_parameter_registers[intreg / 2],
				      VALUE_CONTENTS_ALL (args[i]) + offset);
		  offset += 8;
		  intreg++;
		  break;
		case X86_64_SSEDF_CLASS:
		case X86_64_SSESF_CLASS:
		case X86_64_SSE_CLASS:
		  write_register_gen (sse_parameter_registers
				      [(ssereg + 1) / 2],
				      VALUE_CONTENTS_ALL (args[i]) + offset);
		  offset += 8;
		  ssereg += 2;
		  break;
		case X86_64_SSEUP_CLASS:
		  write_register_gen (sse_parameter_registers[ssereg / 2],
				      VALUE_CONTENTS_ALL (args[i]) + offset);
		  offset += 8;
		  ssereg++;
		  break;
		case X86_64_X87_CLASS:
		case X86_64_MEMORY_CLASS:
		  stack_values[stack_values_count++] = i;
		  break;
		case X86_64_X87UP_CLASS:
		  break;
		default:
		  internal_error (__FILE__, __LINE__,
				  "Unexpected argument class");
		}
	      intreg += intreg % 2;
	      ssereg += ssereg % 2;
	    }
	}
    }
  while (--stack_values_count >= 0)
    {
      struct value *arg = args[stack_values[stack_values_count]];
      int len = TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg));
      len += 7;
      len -= len % 8;
      sp -= len;
      write_memory (sp, VALUE_CONTENTS_ALL (arg), len);
    }
  return sp;
}

/* Write into the appropriate registers a function return value stored
   in VALBUF of type TYPE, given in virtual format.  */
void
x86_64_store_return_value (struct type *type, char *valbuf)
{
  int len = TYPE_LENGTH (type);

  if (TYPE_CODE_FLT == TYPE_CODE (type))
    {
      /* Floating-point return values can be found in %st(0).  */
      if (len == TARGET_LONG_DOUBLE_BIT / TARGET_CHAR_BIT
	  && TARGET_LONG_DOUBLE_FORMAT == &floatformat_i387_ext)
	{
	  /* Copy straight over.  */
	  write_register_bytes (REGISTER_BYTE (FP0_REGNUM), valbuf,
				FPU_REG_RAW_SIZE);
	}
      else
	{
	  char buf[FPU_REG_RAW_SIZE];
	  DOUBLEST val;

	  /* Convert the value found in VALBUF to the extended
	     floating point format used by the FPU.  This is probably
	     not exactly how it would happen on the target itself, but
	     it is the best we can do.  */
	  val = extract_floating (valbuf, TYPE_LENGTH (type));
	  floatformat_from_doublest (&floatformat_i387_ext, &val, buf);
	  write_register_bytes (REGISTER_BYTE (FP0_REGNUM), buf,
				FPU_REG_RAW_SIZE);
	}
    }
  else
    {
      int low_size = REGISTER_RAW_SIZE (0);
      int high_size = REGISTER_RAW_SIZE (1);

      if (len <= low_size)
	write_register_bytes (REGISTER_BYTE (0), valbuf, len);
      else if (len <= (low_size + high_size))
	{
	  write_register_bytes (REGISTER_BYTE (0), valbuf, low_size);
	  write_register_bytes (REGISTER_BYTE (1),
				valbuf + low_size, len - low_size);
	}
      else
	internal_error (__FILE__, __LINE__,
			"Cannot store return value of %d bytes long.", len);
    }
}


static char *
x86_64_register_name (int reg_nr)
{
  if (reg_nr < 0 || reg_nr >= X86_64_NUM_REGS)
    return NULL;
  return x86_64_register_info_table[reg_nr].name;
}



/* We have two flavours of disassembly.  The machinery on this page
   deals with switching between those.  */

static int
gdb_print_insn_x86_64 (bfd_vma memaddr, disassemble_info * info)
{
  if (disassembly_flavour == att_flavour)
    return print_insn_i386_att (memaddr, info);
  else if (disassembly_flavour == intel_flavour)
    return print_insn_i386_intel (memaddr, info);
  /* Never reached -- disassembly_flavour is always either att_flavour
     or intel_flavour.  */
  internal_error (__FILE__, __LINE__, "failed internal consistency check");
}


/* Store the address of the place in which to copy the structure the
   subroutine will return.  This is called from call_function. */
void
x86_64_store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
{
  write_register (RDI_REGNUM, addr);
}

int
x86_64_frameless_function_invocation (struct frame_info *frame)
{
  return 0;
}

/* If a function with debugging information and known beginning
   is detected, we will return pc of the next line in the source 
   code. With this approach we effectively skip the prolog.  */

#define PROLOG_BUFSIZE 4
CORE_ADDR
x86_64_skip_prologue (CORE_ADDR pc)
{
  int i, firstline, currline;
  struct symtab_and_line v_sal;
  struct symbol *v_function;
  CORE_ADDR salendaddr = 0, endaddr = 0;

  /* We will handle only functions beginning with:
     55          pushq %rbp
     48 89 e5    movq %rsp,%rbp 
   */
  unsigned char prolog_expect[PROLOG_BUFSIZE] = { 0x55, 0x48, 0x89, 0xe5 },
    prolog_buf[PROLOG_BUFSIZE];

  read_memory (pc, (char *) prolog_buf, PROLOG_BUFSIZE);

  /* First check, whether pc points to pushq %rbp, movq %rsp,%rbp.  */
  for (i = 0; i < PROLOG_BUFSIZE; i++)
    if (prolog_expect[i] != prolog_buf[i])
      return pc;

  v_function = find_pc_function (pc);
  v_sal = find_pc_line (pc, 0);

  /* If pc doesn't point to a function with debuginfo, 
     some of the following may be NULL.  */
  if (!v_function || !v_function->ginfo.value.block || !v_sal.symtab)
    return pc;

  firstline = v_sal.line;
  currline = firstline;
  salendaddr = v_sal.end;
  endaddr = v_function->ginfo.value.block->endaddr;

  for (i = 0; i < v_sal.symtab->linetable->nitems; i++)
    if (v_sal.symtab->linetable->item[i].line > firstline
	&& v_sal.symtab->linetable->item[i].pc >= salendaddr
	&& v_sal.symtab->linetable->item[i].pc < endaddr)
      {
	pc = v_sal.symtab->linetable->item[i].pc;
	currline = v_sal.symtab->linetable->item[i].line;
	break;
      }

  return pc;
}

/* Sequence of bytes for breakpoint instruction.  */
static unsigned char *
x86_64_breakpoint_from_pc (CORE_ADDR * pc, int *lenptr)
{
  static unsigned char breakpoint[] = { 0xcc };
  *lenptr = 1;
  return breakpoint;
}

static struct gdbarch *
i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
{
  struct gdbarch *gdbarch;
  struct gdbarch_tdep *tdep;
  int i, sum;

  /* Find a candidate among the list of pre-declared architectures. */
  for (arches = gdbarch_list_lookup_by_info (arches, &info);
       arches != NULL;
       arches = gdbarch_list_lookup_by_info (arches->next, &info))
    {
      switch (info.bfd_arch_info->mach)
	{
	case bfd_mach_x86_64:
	case bfd_mach_x86_64_intel_syntax:
	  switch (gdbarch_bfd_arch_info (arches->gdbarch)->mach)
	    {
	    case bfd_mach_x86_64:
	    case bfd_mach_x86_64_intel_syntax:
	      return arches->gdbarch;
	    case bfd_mach_i386_i386:
	    case bfd_mach_i386_i8086:
	    case bfd_mach_i386_i386_intel_syntax:
	      break;
	    default:
	      internal_error (__FILE__, __LINE__,
			      "i386_gdbarch_init: unknown machine type");
	    }
	  break;
	case bfd_mach_i386_i386:
	case bfd_mach_i386_i8086:
	case bfd_mach_i386_i386_intel_syntax:
	  switch (gdbarch_bfd_arch_info (arches->gdbarch)->mach)
	    {
	    case bfd_mach_x86_64:
	    case bfd_mach_x86_64_intel_syntax:
	      break;
	    case bfd_mach_i386_i386:
	    case bfd_mach_i386_i8086:
	    case bfd_mach_i386_i386_intel_syntax:
	      return arches->gdbarch;
	    default:
	      internal_error (__FILE__, __LINE__,
			      "i386_gdbarch_init: unknown machine type");
	    }
	  break;
	default:
	  internal_error (__FILE__, __LINE__,
			  "i386_gdbarch_init: unknown machine type");
	}
    }

  tdep = (struct gdbarch_tdep *) xmalloc (sizeof (struct gdbarch_tdep));
  gdbarch = gdbarch_alloc (&info, tdep);

  switch (info.bfd_arch_info->mach)
    {
    case bfd_mach_x86_64:
    case bfd_mach_x86_64_intel_syntax:
      tdep->num_xmm_regs = 16;
      break;
    case bfd_mach_i386_i386:
    case bfd_mach_i386_i8086:
    case bfd_mach_i386_i386_intel_syntax:
      /* This is place for definition of i386 target vector.  */
      break;
    default:
      internal_error (__FILE__, __LINE__,
		      "i386_gdbarch_init: unknown machine type");
    }

  set_gdbarch_long_bit (gdbarch, 64);
  set_gdbarch_long_long_bit (gdbarch, 64);
  set_gdbarch_ptr_bit (gdbarch, 64);

  set_gdbarch_long_double_format (gdbarch, &floatformat_i387_ext);

  set_gdbarch_num_regs (gdbarch, X86_64_NUM_REGS);
  set_gdbarch_register_name (gdbarch, x86_64_register_name);
  set_gdbarch_register_size (gdbarch, 8);
  set_gdbarch_register_raw_size (gdbarch, x86_64_register_raw_size);
  set_gdbarch_max_register_raw_size (gdbarch, 16);
  set_gdbarch_register_byte (gdbarch, x86_64_register_byte);

  /* Total amount of space needed to store our copies of the machine's register
     (SIZEOF_GREGS + SIZEOF_FPU_REGS + SIZEOF_FPU_CTRL_REGS + SIZEOF_SSE_REGS) */
  for (i = 0, sum = 0; i < X86_64_NUM_REGS; i++)
    sum += x86_64_register_info_table[i].size;
  set_gdbarch_register_bytes (gdbarch, sum);
  set_gdbarch_register_virtual_size (gdbarch, generic_register_virtual_size);
  set_gdbarch_max_register_virtual_size (gdbarch, 16);

  set_gdbarch_register_virtual_type (gdbarch, x86_64_register_virtual_type);

  set_gdbarch_register_convertible (gdbarch, x86_64_register_convertible);
  set_gdbarch_register_convert_to_virtual (gdbarch,
					   x86_64_register_convert_to_virtual);
  set_gdbarch_register_convert_to_raw (gdbarch,
				       x86_64_register_convert_to_raw);

/* Register numbers of various important registers.  */
  set_gdbarch_sp_regnum (gdbarch, 7);	/* (rsp) Contains address of top of stack.  */
  set_gdbarch_fp_regnum (gdbarch, 6);	/* (rbp) */
  set_gdbarch_pc_regnum (gdbarch, 16);	/* (rip) Contains program counter.  */

  set_gdbarch_fp0_regnum (gdbarch, X86_64_NUM_GREGS);	/* First FPU floating-point register.  */

  set_gdbarch_read_fp (gdbarch, cfi_read_fp);

/* Discard from the stack the innermost frame, restoring all registers.  */
  set_gdbarch_pop_frame (gdbarch, x86_64_pop_frame);

  /* FRAME_CHAIN takes a frame's nominal address and produces the frame's
     chain-pointer.  */
  set_gdbarch_frame_chain (gdbarch, cfi_frame_chain);

  set_gdbarch_frameless_function_invocation (gdbarch,
					     x86_64_frameless_function_invocation);
  set_gdbarch_frame_saved_pc (gdbarch, x86_64_linux_frame_saved_pc);

  set_gdbarch_frame_args_address (gdbarch, default_frame_address);
  set_gdbarch_frame_locals_address (gdbarch, default_frame_address);

/* Return number of bytes at start of arglist that are not really args.  */
  set_gdbarch_frame_args_skip (gdbarch, 8);

  set_gdbarch_frame_init_saved_regs (gdbarch, x86_64_frame_init_saved_regs);

/* Frame pc initialization is handled by unwind informations.  */
  set_gdbarch_init_frame_pc (gdbarch, cfi_init_frame_pc);

/* Initialization of unwind informations.  */
  set_gdbarch_init_extra_frame_info (gdbarch, cfi_init_extra_frame_info);

/* Getting saved registers is handled by unwind informations.  */
  set_gdbarch_get_saved_register (gdbarch, cfi_get_saved_register);

  set_gdbarch_frame_init_saved_regs (gdbarch, x86_64_frame_init_saved_regs);

/* Cons up virtual frame pointer for trace */
  set_gdbarch_virtual_frame_pointer (gdbarch, cfi_virtual_frame_pointer);


  set_gdbarch_frame_chain_valid (gdbarch, generic_file_frame_chain_valid);

  set_gdbarch_use_generic_dummy_frames (gdbarch, 1);
  set_gdbarch_call_dummy_location (gdbarch, AT_ENTRY_POINT);
  set_gdbarch_call_dummy_address (gdbarch, entry_point_address);
  set_gdbarch_call_dummy_length (gdbarch, 0);
  set_gdbarch_call_dummy_breakpoint_offset (gdbarch, 0);
  set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1);
  set_gdbarch_pc_in_call_dummy (gdbarch, pc_in_call_dummy_at_entry_point);
  set_gdbarch_call_dummy_words (gdbarch, 0);
  set_gdbarch_sizeof_call_dummy_words (gdbarch, 0);
  set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0);
  set_gdbarch_call_dummy_p (gdbarch, 1);
  set_gdbarch_call_dummy_start_offset (gdbarch, 0);
  set_gdbarch_push_dummy_frame (gdbarch, generic_push_dummy_frame);
  set_gdbarch_fix_call_dummy (gdbarch, generic_fix_call_dummy);
  set_gdbarch_push_return_address (gdbarch, x86_64_push_return_address);
  set_gdbarch_push_arguments (gdbarch, x86_64_push_arguments);

/* Return number of args passed to a frame, no way to tell.  */
  set_gdbarch_frame_num_args (gdbarch, frame_num_args_unknown);
/* Don't use default structure extract routine */
  set_gdbarch_extract_struct_value_address (gdbarch, 0);

/* If USE_STRUCT_CONVENTION retruns 0, then gdb uses STORE_RETURN_VALUE
   and EXTRACT_RETURN_VALUE to store/fetch the functions return value.  It is
   the case when structure is returned in registers.  */
  set_gdbarch_use_struct_convention (gdbarch, x86_64_use_struct_convention);

/* Store the address of the place in which to copy the structure the
   subroutine will return.  This is called from call_function. */
  set_gdbarch_store_struct_return (gdbarch, x86_64_store_struct_return);

/* Extract from an array REGBUF containing the (raw) register state
   a function return value of type TYPE, and copy that, in virtual format,
   into VALBUF.  */
  set_gdbarch_extract_return_value (gdbarch, x86_64_extract_return_value);


/* Write into the appropriate registers a function return value stored
   in VALBUF of type TYPE, given in virtual format.  */
  set_gdbarch_store_return_value (gdbarch, x86_64_store_return_value);


/* Offset from address of function to start of its code.  */
  set_gdbarch_function_start_offset (gdbarch, 0);

  set_gdbarch_skip_prologue (gdbarch, x86_64_skip_prologue);

  set_gdbarch_saved_pc_after_call (gdbarch, x86_64_linux_saved_pc_after_call);

  set_gdbarch_inner_than (gdbarch, core_addr_lessthan);

  set_gdbarch_breakpoint_from_pc (gdbarch, x86_64_breakpoint_from_pc);


/* Amount PC must be decremented by after a breakpoint.  This is often the
   number of bytes in BREAKPOINT but not always.  */
  set_gdbarch_decr_pc_after_break (gdbarch, 1);

/* Use dwarf2 debug frame informations.  */
  set_gdbarch_dwarf2_build_frame_info (gdbarch, dwarf2_build_frame_info);
  return gdbarch;
}

void
_initialize_x86_64_tdep (void)
{
  register_gdbarch_init (bfd_arch_i386, i386_gdbarch_init);

  /* Initialize the table saying where each register starts in the
     register file.  */
  {
    int i, offset;

    offset = 0;
    for (i = 0; i < X86_64_NUM_REGS; i++)
      {
	x86_64_register_byte_table[i] = offset;
	offset += x86_64_register_info_table[i].size;
      }
  }

  tm_print_insn = gdb_print_insn_x86_64;
  tm_print_insn_info.mach = bfd_lookup_arch (bfd_arch_i386, 3)->mach;

  /* Add the variable that controls the disassembly flavour.  */
  {
    struct cmd_list_element *new_cmd;

    new_cmd = add_set_enum_cmd ("disassembly-flavour", no_class,
				valid_flavours, &disassembly_flavour, "\
Set the disassembly flavour, the valid values are \"att\" and \"intel\", \
and the default value is \"att\".", &setlist);
    add_show_from_set (new_cmd, &showlist);
  }
}