2003-12-05 Jeff Johnston <jjohnstn@redhat.com>

[binutils-gdb.git] / gdb / ia64-tdep.c

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

   Copyright 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.

   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 "symfile.h"            /* for entry_point_address */
#include "gdbcore.h"
#include "arch-utils.h"
#include "floatformat.h"
#include "regcache.h"
#include "reggroups.h"
#include "frame.h"
#include "frame-base.h"
#include "frame-unwind.h"
#include "doublest.h"
#include "value.h"
#include "gdb_assert.h"
#include "objfiles.h"
#include "elf/common.h"         /* for DT_PLTGOT value */
#include "elf-bfd.h"
#include "elf.h"                /* for PT_IA64_UNWIND value */
#include "dis-asm.h"

#ifdef HAVE_LIBUNWIND_IA64_H
#include "libunwind-frame.h"
#include "libunwind-ia64.h"
#endif

/* Hook for determining the global pointer when calling functions in
   the inferior under AIX.  The initialization code in ia64-aix-nat.c
   sets this hook to the address of a function which will find the
   global pointer for a given address.  
   
   The generic code which uses the dynamic section in the inferior for
   finding the global pointer is not of much use on AIX since the
   values obtained from the inferior have not been relocated.  */

CORE_ADDR (*native_find_global_pointer) (CORE_ADDR) = 0;

/* An enumeration of the different IA-64 instruction types.  */

typedef enum instruction_type
{
  A,                    /* Integer ALU ;    I-unit or M-unit */
  I,                    /* Non-ALU integer; I-unit */
  M,                    /* Memory ;         M-unit */
  F,                    /* Floating-point ; F-unit */
  B,                    /* Branch ;         B-unit */
  L,                    /* Extended (L+X) ; I-unit */
  X,                    /* Extended (L+X) ; I-unit */
  undefined             /* undefined or reserved */
} instruction_type;

/* We represent IA-64 PC addresses as the value of the instruction
   pointer or'd with some bit combination in the low nibble which
   represents the slot number in the bundle addressed by the
   instruction pointer.  The problem is that the Linux kernel
   multiplies its slot numbers (for exceptions) by one while the
   disassembler multiplies its slot numbers by 6.  In addition, I've
   heard it said that the simulator uses 1 as the multiplier.
   
   I've fixed the disassembler so that the bytes_per_line field will
   be the slot multiplier.  If bytes_per_line comes in as zero, it
   is set to six (which is how it was set up initially). -- objdump
   displays pretty disassembly dumps with this value.  For our purposes,
   we'll set bytes_per_line to SLOT_MULTIPLIER. This is okay since we
   never want to also display the raw bytes the way objdump does. */

#define SLOT_MULTIPLIER 1

/* Length in bytes of an instruction bundle */

#define BUNDLE_LEN 16

/* FIXME: These extern declarations should go in ia64-tdep.h.  */
extern CORE_ADDR ia64_linux_sigcontext_register_address (CORE_ADDR, int);
extern CORE_ADDR ia64_aix_sigcontext_register_address (CORE_ADDR, int);
extern unsigned long ia64_linux_getunwind_table (void *, size_t);

static gdbarch_init_ftype ia64_gdbarch_init;

static gdbarch_register_name_ftype ia64_register_name;
static gdbarch_register_type_ftype ia64_register_type;
static gdbarch_breakpoint_from_pc_ftype ia64_breakpoint_from_pc;
static gdbarch_skip_prologue_ftype ia64_skip_prologue;
static gdbarch_extract_return_value_ftype ia64_extract_return_value;
static gdbarch_extract_struct_value_address_ftype ia64_extract_struct_value_address;
static gdbarch_use_struct_convention_ftype ia64_use_struct_convention;
static struct type *is_float_or_hfa_type (struct type *t);

static struct type *builtin_type_ia64_ext;

#define NUM_IA64_RAW_REGS 462

static int sp_regnum = IA64_GR12_REGNUM;
static int fp_regnum = IA64_VFP_REGNUM;
static int lr_regnum = IA64_VRAP_REGNUM;

/* NOTE: we treat the register stack registers r32-r127 as pseudo-registers because
   they may not be accessible via the ptrace register get/set interfaces.  */
enum pseudo_regs { FIRST_PSEUDO_REGNUM = NUM_IA64_RAW_REGS, VBOF_REGNUM = IA64_NAT127_REGNUM + 1, V32_REGNUM, 
                   V127_REGNUM = V32_REGNUM + 95, 
                   VP0_REGNUM, VP16_REGNUM = VP0_REGNUM + 16, VP63_REGNUM = VP0_REGNUM + 63, LAST_PSEUDO_REGNUM };

/* Array of register names; There should be ia64_num_regs strings in
   the initializer.  */

static char *ia64_register_names[] = 
{ "r0",   "r1",   "r2",   "r3",   "r4",   "r5",   "r6",   "r7",
  "r8",   "r9",   "r10",  "r11",  "r12",  "r13",  "r14",  "r15",
  "r16",  "r17",  "r18",  "r19",  "r20",  "r21",  "r22",  "r23",
  "r24",  "r25",  "r26",  "r27",  "r28",  "r29",  "r30",  "r31",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",

  "f0",   "f1",   "f2",   "f3",   "f4",   "f5",   "f6",   "f7",
  "f8",   "f9",   "f10",  "f11",  "f12",  "f13",  "f14",  "f15",
  "f16",  "f17",  "f18",  "f19",  "f20",  "f21",  "f22",  "f23",
  "f24",  "f25",  "f26",  "f27",  "f28",  "f29",  "f30",  "f31",
  "f32",  "f33",  "f34",  "f35",  "f36",  "f37",  "f38",  "f39",
  "f40",  "f41",  "f42",  "f43",  "f44",  "f45",  "f46",  "f47",
  "f48",  "f49",  "f50",  "f51",  "f52",  "f53",  "f54",  "f55",
  "f56",  "f57",  "f58",  "f59",  "f60",  "f61",  "f62",  "f63",
  "f64",  "f65",  "f66",  "f67",  "f68",  "f69",  "f70",  "f71",
  "f72",  "f73",  "f74",  "f75",  "f76",  "f77",  "f78",  "f79",
  "f80",  "f81",  "f82",  "f83",  "f84",  "f85",  "f86",  "f87",
  "f88",  "f89",  "f90",  "f91",  "f92",  "f93",  "f94",  "f95",
  "f96",  "f97",  "f98",  "f99",  "f100", "f101", "f102", "f103",
  "f104", "f105", "f106", "f107", "f108", "f109", "f110", "f111",
  "f112", "f113", "f114", "f115", "f116", "f117", "f118", "f119",
  "f120", "f121", "f122", "f123", "f124", "f125", "f126", "f127",

  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",
  "",     "",     "",     "",     "",     "",     "",     "",

  "b0",   "b1",   "b2",   "b3",   "b4",   "b5",   "b6",   "b7",

  "vfp", "vrap",

  "pr", "ip", "psr", "cfm",

  "kr0",   "kr1",   "kr2",   "kr3",   "kr4",   "kr5",   "kr6",   "kr7",
  "", "", "", "", "", "", "", "",
  "rsc", "bsp", "bspstore", "rnat",
  "", "fcr", "", "",
  "eflag", "csd", "ssd", "cflg", "fsr", "fir", "fdr",  "",
  "ccv", "", "", "", "unat", "", "", "",
  "fpsr", "", "", "", "itc",
  "", "", "", "", "", "", "", "", "", "",
  "", "", "", "", "", "", "", "", "",
  "pfs", "lc", "ec",
  "", "", "", "", "", "", "", "", "", "",
  "", "", "", "", "", "", "", "", "", "",
  "", "", "", "", "", "", "", "", "", "",
  "", "", "", "", "", "", "", "", "", "",
  "", "", "", "", "", "", "", "", "", "",
  "", "", "", "", "", "", "", "", "", "",
  "",
  "nat0",  "nat1",  "nat2",  "nat3",  "nat4",  "nat5",  "nat6",  "nat7",
  "nat8",  "nat9",  "nat10", "nat11", "nat12", "nat13", "nat14", "nat15",
  "nat16", "nat17", "nat18", "nat19", "nat20", "nat21", "nat22", "nat23",
  "nat24", "nat25", "nat26", "nat27", "nat28", "nat29", "nat30", "nat31",
  "nat32", "nat33", "nat34", "nat35", "nat36", "nat37", "nat38", "nat39",
  "nat40", "nat41", "nat42", "nat43", "nat44", "nat45", "nat46", "nat47",
  "nat48", "nat49", "nat50", "nat51", "nat52", "nat53", "nat54", "nat55",
  "nat56", "nat57", "nat58", "nat59", "nat60", "nat61", "nat62", "nat63",
  "nat64", "nat65", "nat66", "nat67", "nat68", "nat69", "nat70", "nat71",
  "nat72", "nat73", "nat74", "nat75", "nat76", "nat77", "nat78", "nat79",
  "nat80", "nat81", "nat82", "nat83", "nat84", "nat85", "nat86", "nat87",
  "nat88", "nat89", "nat90", "nat91", "nat92", "nat93", "nat94", "nat95",
  "nat96", "nat97", "nat98", "nat99", "nat100","nat101","nat102","nat103",
  "nat104","nat105","nat106","nat107","nat108","nat109","nat110","nat111",
  "nat112","nat113","nat114","nat115","nat116","nat117","nat118","nat119",
  "nat120","nat121","nat122","nat123","nat124","nat125","nat126","nat127",

  "bof",
  
  "r32",  "r33",  "r34",  "r35",  "r36",  "r37",  "r38",  "r39",   
  "r40",  "r41",  "r42",  "r43",  "r44",  "r45",  "r46",  "r47",
  "r48",  "r49",  "r50",  "r51",  "r52",  "r53",  "r54",  "r55",
  "r56",  "r57",  "r58",  "r59",  "r60",  "r61",  "r62",  "r63",
  "r64",  "r65",  "r66",  "r67",  "r68",  "r69",  "r70",  "r71",
  "r72",  "r73",  "r74",  "r75",  "r76",  "r77",  "r78",  "r79",
  "r80",  "r81",  "r82",  "r83",  "r84",  "r85",  "r86",  "r87",
  "r88",  "r89",  "r90",  "r91",  "r92",  "r93",  "r94",  "r95",
  "r96",  "r97",  "r98",  "r99",  "r100", "r101", "r102", "r103",
  "r104", "r105", "r106", "r107", "r108", "r109", "r110", "r111",
  "r112", "r113", "r114", "r115", "r116", "r117", "r118", "r119",
  "r120", "r121", "r122", "r123", "r124", "r125", "r126", "r127",

  "p0",   "p1",   "p2",   "p3",   "p4",   "p5",   "p6",   "p7",
  "p8",   "p9",   "p10",  "p11",  "p12",  "p13",  "p14",  "p15",
  "p16",  "p17",  "p18",  "p19",  "p20",  "p21",  "p22",  "p23",
  "p24",  "p25",  "p26",  "p27",  "p28",  "p29",  "p30",  "p31",
  "p32",  "p33",  "p34",  "p35",  "p36",  "p37",  "p38",  "p39",
  "p40",  "p41",  "p42",  "p43",  "p44",  "p45",  "p46",  "p47",
  "p48",  "p49",  "p50",  "p51",  "p52",  "p53",  "p54",  "p55",
  "p56",  "p57",  "p58",  "p59",  "p60",  "p61",  "p62",  "p63",
};

struct ia64_frame_cache
{
  CORE_ADDR base;       /* frame pointer base for frame */
  CORE_ADDR pc;         /* function start pc for frame */
  CORE_ADDR saved_sp;   /* stack pointer for frame */
  CORE_ADDR bsp;        /* points at r32 for the current frame */
  CORE_ADDR cfm;        /* cfm value for current frame */
  CORE_ADDR prev_cfm;   /* cfm value for previous frame */
  int   frameless;
  int   sof;            /* Size of frame  (decoded from cfm value) */
  int   sol;            /* Size of locals (decoded from cfm value) */
  int   sor;            /* Number of rotating registers. (decoded from cfm value) */
  CORE_ADDR after_prologue;
  /* Address of first instruction after the last
     prologue instruction;  Note that there may
     be instructions from the function's body
     intermingled with the prologue. */
  int mem_stack_frame_size;
  /* Size of the memory stack frame (may be zero),
     or -1 if it has not been determined yet. */
  int   fp_reg;         /* Register number (if any) used a frame pointer
                           for this frame.  0 if no register is being used
                           as the frame pointer. */
  
  /* Saved registers.  */
  CORE_ADDR saved_regs[NUM_IA64_RAW_REGS];

};

struct gdbarch_tdep
  {
    CORE_ADDR (*sigcontext_register_address) (CORE_ADDR, int);
                        /* OS specific function which, given a frame address
                           and register number, returns the offset to the
                           given register from the start of the frame. */
    CORE_ADDR (*find_global_pointer) (CORE_ADDR);
  };

#define SIGCONTEXT_REGISTER_ADDRESS \
  (gdbarch_tdep (current_gdbarch)->sigcontext_register_address)
#define FIND_GLOBAL_POINTER \
  (gdbarch_tdep (current_gdbarch)->find_global_pointer)

int
ia64_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
                          struct reggroup *group)
{
  int vector_p;
  int float_p;
  int raw_p;
  if (group == all_reggroup)
    return 1;
  vector_p = TYPE_VECTOR (register_type (gdbarch, regnum));
  float_p = TYPE_CODE (register_type (gdbarch, regnum)) == TYPE_CODE_FLT;
  raw_p = regnum < NUM_IA64_RAW_REGS;
  if (group == float_reggroup)
    return float_p;
  if (group == vector_reggroup)
    return vector_p;
  if (group == general_reggroup)
    return (!vector_p && !float_p);
  if (group == save_reggroup || group == restore_reggroup)
    return raw_p; 
  return 0;
}

static const char *
ia64_register_name (int reg)
{
  return ia64_register_names[reg];
}

struct type *
ia64_register_type (struct gdbarch *arch, int reg)
{
  if (reg >= IA64_FR0_REGNUM && reg <= IA64_FR127_REGNUM)
    return builtin_type_ia64_ext;
  else
    return builtin_type_long;
}

static int
ia64_dwarf_reg_to_regnum (int reg)
{
  if (reg >= IA64_GR32_REGNUM && reg <= IA64_GR127_REGNUM)
    return V32_REGNUM + (reg - IA64_GR32_REGNUM);
  return reg;
}

static int
floatformat_valid (const struct floatformat *fmt, const char *from)
{
  return 1;
}

const struct floatformat floatformat_ia64_ext =
{
  floatformat_little, 82, 0, 1, 17, 65535, 0x1ffff, 18, 64,
  floatformat_intbit_yes, "floatformat_ia64_ext", floatformat_valid
};


/* Read the given register from a sigcontext structure in the
   specified frame.  */

static CORE_ADDR
read_sigcontext_register (struct frame_info *frame, int regnum)
{
  CORE_ADDR regaddr;

  if (frame == NULL)
    internal_error (__FILE__, __LINE__,
                    "read_sigcontext_register: NULL frame");
  if (!(get_frame_type (frame) == SIGTRAMP_FRAME))
    internal_error (__FILE__, __LINE__,
                    "read_sigcontext_register: frame not a signal trampoline");
  if (SIGCONTEXT_REGISTER_ADDRESS == 0)
    internal_error (__FILE__, __LINE__,
                    "read_sigcontext_register: SIGCONTEXT_REGISTER_ADDRESS is 0");

  regaddr = SIGCONTEXT_REGISTER_ADDRESS (get_frame_base (frame), regnum);
  if (regaddr)
    return read_memory_integer (regaddr, register_size (current_gdbarch, regnum));
  else
    internal_error (__FILE__, __LINE__,
                    "read_sigcontext_register: Register %d not in struct sigcontext", regnum);
}

/* Extract ``len'' bits from an instruction bundle starting at
   bit ``from''.  */

static long long
extract_bit_field (char *bundle, int from, int len)
{
  long long result = 0LL;
  int to = from + len;
  int from_byte = from / 8;
  int to_byte = to / 8;
  unsigned char *b = (unsigned char *) bundle;
  unsigned char c;
  int lshift;
  int i;

  c = b[from_byte];
  if (from_byte == to_byte)
    c = ((unsigned char) (c << (8 - to % 8))) >> (8 - to % 8);
  result = c >> (from % 8);
  lshift = 8 - (from % 8);

  for (i = from_byte+1; i < to_byte; i++)
    {
      result |= ((long long) b[i]) << lshift;
      lshift += 8;
    }

  if (from_byte < to_byte && (to % 8 != 0))
    {
      c = b[to_byte];
      c = ((unsigned char) (c << (8 - to % 8))) >> (8 - to % 8);
      result |= ((long long) c) << lshift;
    }

  return result;
}

/* Replace the specified bits in an instruction bundle */

static void
replace_bit_field (char *bundle, long long val, int from, int len)
{
  int to = from + len;
  int from_byte = from / 8;
  int to_byte = to / 8;
  unsigned char *b = (unsigned char *) bundle;
  unsigned char c;

  if (from_byte == to_byte)
    {
      unsigned char left, right;
      c = b[from_byte];
      left = (c >> (to % 8)) << (to % 8);
      right = ((unsigned char) (c << (8 - from % 8))) >> (8 - from % 8);
      c = (unsigned char) (val & 0xff);
      c = (unsigned char) (c << (from % 8 + 8 - to % 8)) >> (8 - to % 8);
      c |= right | left;
      b[from_byte] = c;
    }
  else
    {
      int i;
      c = b[from_byte];
      c = ((unsigned char) (c << (8 - from % 8))) >> (8 - from % 8);
      c = c | (val << (from % 8));
      b[from_byte] = c;
      val >>= 8 - from % 8;

      for (i = from_byte+1; i < to_byte; i++)
        {
          c = val & 0xff;
          val >>= 8;
          b[i] = c;
        }

      if (to % 8 != 0)
        {
          unsigned char cv = (unsigned char) val;
          c = b[to_byte];
          c = c >> (to % 8) << (to % 8);
          c |= ((unsigned char) (cv << (8 - to % 8))) >> (8 - to % 8);
          b[to_byte] = c;
        }
    }
}

/* Return the contents of slot N (for N = 0, 1, or 2) in
   and instruction bundle */

static long long
slotN_contents (char *bundle, int slotnum)
{
  return extract_bit_field (bundle, 5+41*slotnum, 41);
}

/* Store an instruction in an instruction bundle */

static void
replace_slotN_contents (char *bundle, long long instr, int slotnum)
{
  replace_bit_field (bundle, instr, 5+41*slotnum, 41);
}

static enum instruction_type template_encoding_table[32][3] =
{
  { M, I, I },                          /* 00 */
  { M, I, I },                          /* 01 */
  { M, I, I },                          /* 02 */
  { M, I, I },                          /* 03 */
  { M, L, X },                          /* 04 */
  { M, L, X },                          /* 05 */
  { undefined, undefined, undefined },  /* 06 */
  { undefined, undefined, undefined },  /* 07 */
  { M, M, I },                          /* 08 */
  { M, M, I },                          /* 09 */
  { M, M, I },                          /* 0A */
  { M, M, I },                          /* 0B */
  { M, F, I },                          /* 0C */
  { M, F, I },                          /* 0D */
  { M, M, F },                          /* 0E */
  { M, M, F },                          /* 0F */
  { M, I, B },                          /* 10 */
  { M, I, B },                          /* 11 */
  { M, B, B },                          /* 12 */
  { M, B, B },                          /* 13 */
  { undefined, undefined, undefined },  /* 14 */
  { undefined, undefined, undefined },  /* 15 */
  { B, B, B },                          /* 16 */
  { B, B, B },                          /* 17 */
  { M, M, B },                          /* 18 */
  { M, M, B },                          /* 19 */
  { undefined, undefined, undefined },  /* 1A */
  { undefined, undefined, undefined },  /* 1B */
  { M, F, B },                          /* 1C */
  { M, F, B },                          /* 1D */
  { undefined, undefined, undefined },  /* 1E */
  { undefined, undefined, undefined },  /* 1F */
};

/* Fetch and (partially) decode an instruction at ADDR and return the
   address of the next instruction to fetch.  */

static CORE_ADDR
fetch_instruction (CORE_ADDR addr, instruction_type *it, long long *instr)
{
  char bundle[BUNDLE_LEN];
  int slotnum = (int) (addr & 0x0f) / SLOT_MULTIPLIER;
  long long template;
  int val;

  /* Warn about slot numbers greater than 2.  We used to generate
     an error here on the assumption that the user entered an invalid
     address.  But, sometimes GDB itself requests an invalid address.
     This can (easily) happen when execution stops in a function for
     which there are no symbols.  The prologue scanner will attempt to
     find the beginning of the function - if the nearest symbol
     happens to not be aligned on a bundle boundary (16 bytes), the
     resulting starting address will cause GDB to think that the slot
     number is too large.

     So we warn about it and set the slot number to zero.  It is
     not necessarily a fatal condition, particularly if debugging
     at the assembly language level.  */
  if (slotnum > 2)
    {
      warning ("Can't fetch instructions for slot numbers greater than 2.\n"
               "Using slot 0 instead");
      slotnum = 0;
    }

  addr &= ~0x0f;

  val = target_read_memory (addr, bundle, BUNDLE_LEN);

  if (val != 0)
    return 0;

  *instr = slotN_contents (bundle, slotnum);
  template = extract_bit_field (bundle, 0, 5);
  *it = template_encoding_table[(int)template][slotnum];

  if (slotnum == 2 || (slotnum == 1 && *it == L))
    addr += 16;
  else
    addr += (slotnum + 1) * SLOT_MULTIPLIER;

  return addr;
}

/* There are 5 different break instructions (break.i, break.b,
   break.m, break.f, and break.x), but they all have the same
   encoding.  (The five bit template in the low five bits of the
   instruction bundle distinguishes one from another.)
   
   The runtime architecture manual specifies that break instructions
   used for debugging purposes must have the upper two bits of the 21
   bit immediate set to a 0 and a 1 respectively.  A breakpoint
   instruction encodes the most significant bit of its 21 bit
   immediate at bit 36 of the 41 bit instruction.  The penultimate msb
   is at bit 25 which leads to the pattern below.  
   
   Originally, I had this set up to do, e.g, a "break.i 0x80000"  But
   it turns out that 0x80000 was used as the syscall break in the early
   simulators.  So I changed the pattern slightly to do "break.i 0x080001"
   instead.  But that didn't work either (I later found out that this
   pattern was used by the simulator that I was using.)  So I ended up
   using the pattern seen below. */

#if 0
#define IA64_BREAKPOINT 0x00002000040LL
#endif
#define IA64_BREAKPOINT 0x00003333300LL

static int
ia64_memory_insert_breakpoint (CORE_ADDR addr, char *contents_cache)
{
  char bundle[BUNDLE_LEN];
  int slotnum = (int) (addr & 0x0f) / SLOT_MULTIPLIER;
  long long instr;
  int val;
  int template;

  if (slotnum > 2)
    error("Can't insert breakpoint for slot numbers greater than 2.");

  addr &= ~0x0f;

  val = target_read_memory (addr, bundle, BUNDLE_LEN);

  /* Check for L type instruction in 2nd slot, if present then
     bump up the slot number to the 3rd slot */
  template = extract_bit_field (bundle, 0, 5);
  if (slotnum == 1 && template_encoding_table[template][1] == L)
    {
      slotnum = 2;
    }

  instr = slotN_contents (bundle, slotnum);
  memcpy(contents_cache, &instr, sizeof(instr));
  replace_slotN_contents (bundle, IA64_BREAKPOINT, slotnum);
  if (val == 0)
    target_write_memory (addr, bundle, BUNDLE_LEN);

  return val;
}

static int
ia64_memory_remove_breakpoint (CORE_ADDR addr, char *contents_cache)
{
  char bundle[BUNDLE_LEN];
  int slotnum = (addr & 0x0f) / SLOT_MULTIPLIER;
  long long instr;
  int val;
  int template;

  addr &= ~0x0f;

  val = target_read_memory (addr, bundle, BUNDLE_LEN);

  /* Check for L type instruction in 2nd slot, if present then
     bump up the slot number to the 3rd slot */
  template = extract_bit_field (bundle, 0, 5);
  if (slotnum == 1 && template_encoding_table[template][1] == L)
    {
      slotnum = 2;
    }

  memcpy (&instr, contents_cache, sizeof instr);
  replace_slotN_contents (bundle, instr, slotnum);
  if (val == 0)
    target_write_memory (addr, bundle, BUNDLE_LEN);

  return val;
}

/* We don't really want to use this, but remote.c needs to call it in order
   to figure out if Z-packets are supported or not.  Oh, well. */
const unsigned char *
ia64_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr)
{
  static unsigned char breakpoint[] =
    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
  *lenptr = sizeof (breakpoint);
#if 0
  *pcptr &= ~0x0f;
#endif
  return breakpoint;
}

static CORE_ADDR
ia64_read_fp (void)
{
  /* We won't necessarily have a frame pointer and even if we do, it
     winds up being extraordinarly messy when attempting to find the
     frame chain.  So for the purposes of creating frames (which is
     all deprecated_read_fp() is used for), simply use the stack
     pointer value instead.  */
  gdb_assert (SP_REGNUM >= 0);
  return read_register (SP_REGNUM);
}

static CORE_ADDR
ia64_read_pc (ptid_t ptid)
{
  CORE_ADDR psr_value = read_register_pid (IA64_PSR_REGNUM, ptid);
  CORE_ADDR pc_value   = read_register_pid (IA64_IP_REGNUM, ptid);
  int slot_num = (psr_value >> 41) & 3;

  return pc_value | (slot_num * SLOT_MULTIPLIER);
}

static void
ia64_write_pc (CORE_ADDR new_pc, ptid_t ptid)
{
  int slot_num = (int) (new_pc & 0xf) / SLOT_MULTIPLIER;
  CORE_ADDR psr_value = read_register_pid (IA64_PSR_REGNUM, ptid);
  psr_value &= ~(3LL << 41);
  psr_value |= (CORE_ADDR)(slot_num & 0x3) << 41;

  new_pc &= ~0xfLL;

  write_register_pid (IA64_PSR_REGNUM, psr_value, ptid);
  write_register_pid (IA64_IP_REGNUM, new_pc, ptid);
}

#define IS_NaT_COLLECTION_ADDR(addr) ((((addr) >> 3) & 0x3f) == 0x3f)

/* Returns the address of the slot that's NSLOTS slots away from
   the address ADDR. NSLOTS may be positive or negative. */
static CORE_ADDR
rse_address_add(CORE_ADDR addr, int nslots)
{
  CORE_ADDR new_addr;
  int mandatory_nat_slots = nslots / 63;
  int direction = nslots < 0 ? -1 : 1;

  new_addr = addr + 8 * (nslots + mandatory_nat_slots);

  if ((new_addr >> 9)  != ((addr + 8 * 64 * mandatory_nat_slots) >> 9))
    new_addr += 8 * direction;

  if (IS_NaT_COLLECTION_ADDR(new_addr))
    new_addr += 8 * direction;

  return new_addr;
}

static void
ia64_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache,
                           int regnum, void *buf)
{
  if (regnum >= V32_REGNUM && regnum <= V127_REGNUM)
    {
      ULONGEST bsp;
      ULONGEST cfm;
      CORE_ADDR reg;
      regcache_cooked_read_unsigned (regcache, IA64_BSP_REGNUM, &bsp);
      regcache_cooked_read_unsigned (regcache, IA64_CFM_REGNUM, &cfm);

      /* The bsp points at the end of the register frame so we
         subtract the size of frame from it to get start of register frame.  */
      bsp = rse_address_add (bsp, -(cfm & 0x7f));
 
      if ((cfm & 0x7f) > regnum - V32_REGNUM) 
        {
          ULONGEST reg_addr = rse_address_add (bsp, (regnum - V32_REGNUM));
          reg = read_memory_integer ((CORE_ADDR)reg_addr, 8);
          store_unsigned_integer (buf, register_size (current_gdbarch, regnum), reg);
        }
      else
        store_unsigned_integer (buf, register_size (current_gdbarch, regnum), 0);
    }
  else if (IA64_NAT0_REGNUM <= regnum && regnum <= IA64_NAT31_REGNUM)
    {
      ULONGEST unatN_val;
      ULONGEST unat;
      regcache_cooked_read_unsigned (regcache, IA64_UNAT_REGNUM, &unat);
      unatN_val = (unat & (1LL << (regnum - IA64_NAT0_REGNUM))) != 0;
      store_unsigned_integer (buf, register_size (current_gdbarch, regnum), unatN_val);
    }
  else if (IA64_NAT32_REGNUM <= regnum && regnum <= IA64_NAT127_REGNUM)
    {
      ULONGEST natN_val = 0;
      ULONGEST bsp;
      ULONGEST cfm;
      CORE_ADDR gr_addr = 0;
      regcache_cooked_read_unsigned (regcache, IA64_BSP_REGNUM, &bsp);
      regcache_cooked_read_unsigned (regcache, IA64_CFM_REGNUM, &cfm);

      /* The bsp points at the end of the register frame so we
         subtract the size of frame from it to get start of register frame.  */
      bsp = rse_address_add (bsp, -(cfm & 0x7f));
 
      if ((cfm & 0x7f) > regnum - V32_REGNUM) 
        gr_addr = rse_address_add (bsp, (regnum - V32_REGNUM));
      
      if (gr_addr != 0)
        {
          /* Compute address of nat collection bits.  */
          CORE_ADDR nat_addr = gr_addr | 0x1f8;
          CORE_ADDR nat_collection;
          int nat_bit;
          /* If our nat collection address is bigger than bsp, we have to get
             the nat collection from rnat.  Otherwise, we fetch the nat
             collection from the computed address.  */
          if (nat_addr >= bsp)
            regcache_cooked_read_unsigned (regcache, IA64_RNAT_REGNUM, &nat_collection);
          else
            nat_collection = read_memory_integer (nat_addr, 8);
          nat_bit = (gr_addr >> 3) & 0x3f;
          natN_val = (nat_collection >> nat_bit) & 1;
        }
      
      store_unsigned_integer (buf, register_size (current_gdbarch, regnum), natN_val);
    }
  else if (regnum == VBOF_REGNUM)
    {
      /* A virtual register frame start is provided for user convenience.
         It can be calculated as the bsp - sof (sizeof frame). */
      ULONGEST bsp, vbsp;
      ULONGEST cfm;
      CORE_ADDR reg;
      regcache_cooked_read_unsigned (regcache, IA64_BSP_REGNUM, &bsp);
      regcache_cooked_read_unsigned (regcache, IA64_CFM_REGNUM, &cfm);

      /* The bsp points at the end of the register frame so we
         subtract the size of frame from it to get beginning of frame.  */
      vbsp = rse_address_add (bsp, -(cfm & 0x7f));
      store_unsigned_integer (buf, register_size (current_gdbarch, regnum), vbsp);
    }
  else if (VP0_REGNUM <= regnum && regnum <= VP63_REGNUM)
    {
      ULONGEST pr;
      ULONGEST cfm;
      ULONGEST prN_val;
      CORE_ADDR reg;
      regcache_cooked_read_unsigned (regcache, IA64_PR_REGNUM, &pr);
      regcache_cooked_read_unsigned (regcache, IA64_CFM_REGNUM, &cfm);

      if (VP16_REGNUM <= regnum && regnum <= VP63_REGNUM)
        {
          /* Fetch predicate register rename base from current frame
             marker for this frame. */
          int rrb_pr = (cfm >> 32) & 0x3f;

          /* Adjust the register number to account for register rotation. */
          regnum = VP16_REGNUM 
                 + ((regnum - VP16_REGNUM) + rrb_pr) % 48;
        }
      prN_val = (pr & (1LL << (regnum - VP0_REGNUM))) != 0;
      store_unsigned_integer (buf, register_size (current_gdbarch, regnum), prN_val);
    }
  else
    memset (buf, 0, register_size (current_gdbarch, regnum));
}

static void
ia64_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache,
                            int regnum, const void *buf)
{
  if (regnum >= V32_REGNUM && regnum <= V127_REGNUM)
    {
      ULONGEST bsp;
      ULONGEST cfm;
      CORE_ADDR reg;
      regcache_cooked_read_unsigned (regcache, IA64_BSP_REGNUM, &bsp);
      regcache_cooked_read_unsigned (regcache, IA64_CFM_REGNUM, &cfm);

      bsp = rse_address_add (bsp, -(cfm & 0x7f));
 
      if ((cfm & 0x7f) > regnum - V32_REGNUM) 
        {
          ULONGEST reg_addr = rse_address_add (bsp, (regnum - V32_REGNUM));
          write_memory (reg_addr, (void *)buf, 8);
        }
    }
  else if (IA64_NAT0_REGNUM <= regnum && regnum <= IA64_NAT31_REGNUM)
    {
      ULONGEST unatN_val, unat, unatN_mask;
      regcache_cooked_read_unsigned (regcache, IA64_UNAT_REGNUM, &unat);
      unatN_val = extract_unsigned_integer (buf, register_size (current_gdbarch, regnum)); 
      unatN_mask = (1LL << (regnum - IA64_NAT0_REGNUM));
      if (unatN_val == 0)
        unat &= ~unatN_mask;
      else if (unatN_val == 1)
        unat |= unatN_mask;
      regcache_cooked_write_unsigned (regcache, IA64_UNAT_REGNUM, unat);
    }
  else if (IA64_NAT32_REGNUM <= regnum && regnum <= IA64_NAT127_REGNUM)
    {
      ULONGEST natN_val;
      ULONGEST bsp;
      ULONGEST cfm;
      CORE_ADDR gr_addr = 0;
      regcache_cooked_read_unsigned (regcache, IA64_BSP_REGNUM, &bsp);
      regcache_cooked_read_unsigned (regcache, IA64_CFM_REGNUM, &cfm);

      /* The bsp points at the end of the register frame so we
         subtract the size of frame from it to get start of register frame.  */
      bsp = rse_address_add (bsp, -(cfm & 0x7f));
 
      if ((cfm & 0x7f) > regnum - V32_REGNUM) 
        gr_addr = rse_address_add (bsp, (regnum - V32_REGNUM));
      
      natN_val = extract_unsigned_integer (buf, register_size (current_gdbarch, regnum)); 

      if (gr_addr != 0 && (natN_val == 0 || natN_val == 1))
        {
          /* Compute address of nat collection bits.  */
          CORE_ADDR nat_addr = gr_addr | 0x1f8;
          CORE_ADDR nat_collection;
          int natN_bit = (gr_addr >> 3) & 0x3f;
          ULONGEST natN_mask = (1LL << natN_bit);
          /* If our nat collection address is bigger than bsp, we have to get
             the nat collection from rnat.  Otherwise, we fetch the nat
             collection from the computed address.  */
          if (nat_addr >= bsp)
            {
              regcache_cooked_read_unsigned (regcache, IA64_RNAT_REGNUM, &nat_collection);
              if (natN_val)
                nat_collection |= natN_mask;
              else
                nat_collection &= ~natN_mask;
              regcache_cooked_write_unsigned (regcache, IA64_RNAT_REGNUM, nat_collection);
            }
          else
            {
              char nat_buf[8];
              nat_collection = read_memory_integer (nat_addr, 8);
              if (natN_val)
                nat_collection |= natN_mask;
              else
                nat_collection &= ~natN_mask;
              store_unsigned_integer (nat_buf, register_size (current_gdbarch, regnum), nat_collection);
              write_memory (nat_addr, nat_buf, 8);
            }
        }
    }
  else if (VP0_REGNUM <= regnum && regnum <= VP63_REGNUM)
    {
      ULONGEST pr;
      ULONGEST cfm;
      ULONGEST prN_val;
      ULONGEST prN_mask;

      regcache_cooked_read_unsigned (regcache, IA64_PR_REGNUM, &pr);
      regcache_cooked_read_unsigned (regcache, IA64_CFM_REGNUM, &cfm);

      if (VP16_REGNUM <= regnum && regnum <= VP63_REGNUM)
        {
          /* Fetch predicate register rename base from current frame
             marker for this frame. */
          int rrb_pr = (cfm >> 32) & 0x3f;

          /* Adjust the register number to account for register rotation. */
          regnum = VP16_REGNUM 
                 + ((regnum - VP16_REGNUM) + rrb_pr) % 48;
        }
      prN_val = extract_unsigned_integer (buf, register_size (current_gdbarch, regnum)); 
      prN_mask = (1LL << (regnum - VP0_REGNUM));
      if (prN_val == 0)
        pr &= ~prN_mask;
      else if (prN_val == 1)
        pr |= prN_mask;
      regcache_cooked_write_unsigned (regcache, IA64_PR_REGNUM, pr);
    }
}

/* The ia64 needs to convert between various ieee floating-point formats
   and the special ia64 floating point register format.  */

static int
ia64_convert_register_p (int regno, struct type *type)
{
  return (regno >= IA64_FR0_REGNUM && regno <= IA64_FR127_REGNUM);
}

static void
ia64_register_to_value (struct frame_info *frame, int regnum,
                         struct type *valtype, void *out)
{
  char in[MAX_REGISTER_SIZE];
  frame_register_read (frame, regnum, in);
  convert_typed_floating (in, builtin_type_ia64_ext, out, valtype);
}

static void
ia64_value_to_register (struct frame_info *frame, int regnum,
                         struct type *valtype, const void *in)
{
  char out[MAX_REGISTER_SIZE];
  convert_typed_floating (in, valtype, out, builtin_type_ia64_ext);
  put_frame_register (frame, regnum, out);
}


/* Limit the number of skipped non-prologue instructions since examining
   of the prologue is expensive.  */
static int max_skip_non_prologue_insns = 40;

/* Given PC representing the starting address of a function, and
   LIM_PC which is the (sloppy) limit to which to scan when looking
   for a prologue, attempt to further refine this limit by using
   the line data in the symbol table.  If successful, a better guess
   on where the prologue ends is returned, otherwise the previous
   value of lim_pc is returned.  TRUST_LIMIT is a pointer to a flag
   which will be set to indicate whether the returned limit may be
   used with no further scanning in the event that the function is
   frameless.  */

static CORE_ADDR
refine_prologue_limit (CORE_ADDR pc, CORE_ADDR lim_pc, int *trust_limit)
{
  struct symtab_and_line prologue_sal;
  CORE_ADDR start_pc = pc;

  /* Start off not trusting the limit.  */
  *trust_limit = 0;

  prologue_sal = find_pc_line (pc, 0);
  if (prologue_sal.line != 0)
    {
      int i;
      CORE_ADDR addr = prologue_sal.end;

      /* Handle the case in which compiler's optimizer/scheduler
         has moved instructions into the prologue.  We scan ahead
         in the function looking for address ranges whose corresponding
         line number is less than or equal to the first one that we
         found for the function.  (It can be less than when the
         scheduler puts a body instruction before the first prologue
         instruction.)  */
      for (i = 2 * max_skip_non_prologue_insns; 
           i > 0 && (lim_pc == 0 || addr < lim_pc);
           i--)
        {
          struct symtab_and_line sal;

          sal = find_pc_line (addr, 0);
          if (sal.line == 0)
            break;
          if (sal.line <= prologue_sal.line 
              && sal.symtab == prologue_sal.symtab)
            {
              prologue_sal = sal;
            }
          addr = sal.end;
        }

      if (lim_pc == 0 || prologue_sal.end < lim_pc)
        {
          lim_pc = prologue_sal.end;
          if (start_pc == get_pc_function_start (lim_pc))
            *trust_limit = 1;
        }
    }
  return lim_pc;
}

#define isScratch(_regnum_) ((_regnum_) == 2 || (_regnum_) == 3 \
  || (8 <= (_regnum_) && (_regnum_) <= 11) \
  || (14 <= (_regnum_) && (_regnum_) <= 31))
#define imm9(_instr_) \
  ( ((((_instr_) & 0x01000000000LL) ? -1 : 0) << 8) \
   | (((_instr_) & 0x00008000000LL) >> 20) \
   | (((_instr_) & 0x00000001fc0LL) >> 6))

/* Allocate and initialize a frame cache.  */

static struct ia64_frame_cache *
ia64_alloc_frame_cache (void)
{
  struct ia64_frame_cache *cache;
  int i;

  cache = FRAME_OBSTACK_ZALLOC (struct ia64_frame_cache);

  /* Base address.  */
  cache->base = 0;
  cache->pc = 0;
  cache->cfm = 0;
  cache->prev_cfm = 0;
  cache->sof = 0;
  cache->sol = 0;
  cache->sor = 0;
  cache->bsp = 0;
  cache->fp_reg = 0;
  cache->frameless = 1;

  for (i = 0; i < NUM_IA64_RAW_REGS; i++)
    cache->saved_regs[i] = 0;

  return cache;
}

static CORE_ADDR
examine_prologue (CORE_ADDR pc, CORE_ADDR lim_pc, struct frame_info *next_frame, struct ia64_frame_cache *cache)
{
  CORE_ADDR next_pc;
  CORE_ADDR last_prologue_pc = pc;
  instruction_type it;
  long long instr;
  int cfm_reg  = 0;
  int ret_reg  = 0;
  int fp_reg   = 0;
  int unat_save_reg = 0;
  int pr_save_reg = 0;
  int mem_stack_frame_size = 0;
  int spill_reg   = 0;
  CORE_ADDR spill_addr = 0;
  char instores[8];
  char infpstores[8];
  char reg_contents[256];
  int trust_limit;
  int frameless = 1;
  int i;
  CORE_ADDR addr;
  char buf[8];
  CORE_ADDR bof, sor, sol, sof, cfm, rrb_gr;

  memset (instores, 0, sizeof instores);
  memset (infpstores, 0, sizeof infpstores);
  memset (reg_contents, 0, sizeof reg_contents);

  if (cache->after_prologue != 0
      && cache->after_prologue <= lim_pc)
    return cache->after_prologue;

  lim_pc = refine_prologue_limit (pc, lim_pc, &trust_limit);
  next_pc = fetch_instruction (pc, &it, &instr);

  /* We want to check if we have a recognizable function start before we
     look ahead for a prologue.  */
  if (pc < lim_pc && next_pc 
      && it == M && ((instr & 0x1ee0000003fLL) == 0x02c00000000LL))
    {
      /* alloc - start of a regular function.  */
      int sor = (int) ((instr & 0x00078000000LL) >> 27);
      int sol = (int) ((instr & 0x00007f00000LL) >> 20);
      int sof = (int) ((instr & 0x000000fe000LL) >> 13);
      int rN = (int) ((instr & 0x00000001fc0LL) >> 6);

      /* Verify that the current cfm matches what we think is the
         function start.  If we have somehow jumped within a function,
         we do not want to interpret the prologue and calculate the
         addresses of various registers such as the return address.  
         We will instead treat the frame as frameless. */
      if (!next_frame ||
          (sof == (cache->cfm & 0x7f) &&
           sol == ((cache->cfm >> 7) & 0x7f)))
        frameless = 0;

      cfm_reg = rN;
      last_prologue_pc = next_pc;
      pc = next_pc;
    }
  else
    {
      /* Look for a leaf routine.  */
      if (pc < lim_pc && next_pc
          && (it == I || it == M) 
          && ((instr & 0x1ee00000000LL) == 0x10800000000LL))
        {
          /* adds rN = imm14, rM   (or mov rN, rM  when imm14 is 0) */
          int imm = (int) ((((instr & 0x01000000000LL) ? -1 : 0) << 13) 
                           | ((instr & 0x001f8000000LL) >> 20)
                           | ((instr & 0x000000fe000LL) >> 13));
          int rM = (int) ((instr & 0x00007f00000LL) >> 20);
          int rN = (int) ((instr & 0x00000001fc0LL) >> 6);
          int qp = (int) (instr & 0x0000000003fLL);
          if (qp == 0 && rN == 2 && imm == 0 && rM == 12 && fp_reg == 0)
            {
              /* mov r2, r12 - beginning of leaf routine */
              fp_reg = rN;
              last_prologue_pc = next_pc;
            }
        } 

      /* If we don't recognize a regular function or leaf routine, we are
         done.  */
      if (!fp_reg)
        {
          pc = lim_pc;  
          if (trust_limit)
            last_prologue_pc = lim_pc;
        }
    }

  /* Loop, looking for prologue instructions, keeping track of
     where preserved registers were spilled. */
  while (pc < lim_pc)
    {
      next_pc = fetch_instruction (pc, &it, &instr);
      if (next_pc == 0)
        break;

      if (it == B && ((instr & 0x1e1f800003f) != 0x04000000000))
        {
          /* Exit loop upon hitting a non-nop branch instruction. */ 
          if (trust_limit)
            lim_pc = pc;
          break;
        }
      else if (((instr & 0x3fLL) != 0LL) && 
               (frameless || ret_reg != 0))
        {
          /* Exit loop upon hitting a predicated instruction if
             we already have the return register or if we are frameless.  */ 
          if (trust_limit)
            lim_pc = pc;
          break;
        }
      else if (it == I && ((instr & 0x1eff8000000LL) == 0x00188000000LL))
        {
          /* Move from BR */
          int b2 = (int) ((instr & 0x0000000e000LL) >> 13);
          int rN = (int) ((instr & 0x00000001fc0LL) >> 6);
          int qp = (int) (instr & 0x0000000003f);

          if (qp == 0 && b2 == 0 && rN >= 32 && ret_reg == 0)
            {
              ret_reg = rN;
              last_prologue_pc = next_pc;
            }
        }
      else if ((it == I || it == M) 
          && ((instr & 0x1ee00000000LL) == 0x10800000000LL))
        {
          /* adds rN = imm14, rM   (or mov rN, rM  when imm14 is 0) */
          int imm = (int) ((((instr & 0x01000000000LL) ? -1 : 0) << 13) 
                           | ((instr & 0x001f8000000LL) >> 20)
                           | ((instr & 0x000000fe000LL) >> 13));
          int rM = (int) ((instr & 0x00007f00000LL) >> 20);
          int rN = (int) ((instr & 0x00000001fc0LL) >> 6);
          int qp = (int) (instr & 0x0000000003fLL);

          if (qp == 0 && rN >= 32 && imm == 0 && rM == 12 && fp_reg == 0)
            {
              /* mov rN, r12 */
              fp_reg = rN;
              last_prologue_pc = next_pc;
            }
          else if (qp == 0 && rN == 12 && rM == 12)
            {
              /* adds r12, -mem_stack_frame_size, r12 */
              mem_stack_frame_size -= imm;
              last_prologue_pc = next_pc;
            }
          else if (qp == 0 && rN == 2 
                && ((rM == fp_reg && fp_reg != 0) || rM == 12))
            {
              char buf[MAX_REGISTER_SIZE];
              CORE_ADDR saved_sp = 0;
              /* adds r2, spilloffset, rFramePointer 
                   or
                 adds r2, spilloffset, r12

                 Get ready for stf.spill or st8.spill instructions.
                 The address to start spilling at is loaded into r2. 
                 FIXME:  Why r2?  That's what gcc currently uses; it
                 could well be different for other compilers.  */

              /* Hmm... whether or not this will work will depend on
                 where the pc is.  If it's still early in the prologue
                 this'll be wrong.  FIXME */
              if (next_frame)
                {
                  frame_unwind_register (next_frame, sp_regnum, buf);
                  saved_sp = extract_unsigned_integer (buf, 8);
                }
              spill_addr  = saved_sp
                          + (rM == 12 ? 0 : mem_stack_frame_size) 
                          + imm;
              spill_reg   = rN;
              last_prologue_pc = next_pc;
            }
          else if (qp == 0 && rM >= 32 && rM < 40 && !instores[rM] && 
                   rN < 256 && imm == 0)
            {
              /* mov rN, rM where rM is an input register */
              reg_contents[rN] = rM;
              last_prologue_pc = next_pc;
            }
          else if (frameless && qp == 0 && rN == fp_reg && imm == 0 && 
                   rM == 2)
            {
              /* mov r12, r2 */
              last_prologue_pc = next_pc;
              break;
            }
        }
      else if (it == M 
            && (   ((instr & 0x1efc0000000LL) == 0x0eec0000000LL)
                || ((instr & 0x1ffc8000000LL) == 0x0cec0000000LL) ))
        {
          /* stf.spill [rN] = fM, imm9
             or
             stf.spill [rN] = fM  */

          int imm = imm9(instr);
          int rN = (int) ((instr & 0x00007f00000LL) >> 20);
          int fM = (int) ((instr & 0x000000fe000LL) >> 13);
          int qp = (int) (instr & 0x0000000003fLL);
          if (qp == 0 && rN == spill_reg && spill_addr != 0
              && ((2 <= fM && fM <= 5) || (16 <= fM && fM <= 31)))
            {
              cache->saved_regs[IA64_FR0_REGNUM + fM] = spill_addr;

              if ((instr & 0x1efc0000000) == 0x0eec0000000)
                spill_addr += imm;
              else
                spill_addr = 0;         /* last one; must be done */
              last_prologue_pc = next_pc;
            }
        }
      else if ((it == M && ((instr & 0x1eff8000000LL) == 0x02110000000LL))
            || (it == I && ((instr & 0x1eff8000000LL) == 0x00050000000LL)) )
        {
          /* mov.m rN = arM   
               or 
             mov.i rN = arM */

          int arM = (int) ((instr & 0x00007f00000LL) >> 20);
          int rN  = (int) ((instr & 0x00000001fc0LL) >> 6);
          int qp  = (int) (instr & 0x0000000003fLL);
          if (qp == 0 && isScratch (rN) && arM == 36 /* ar.unat */)
            {
              /* We have something like "mov.m r3 = ar.unat".  Remember the
                 r3 (or whatever) and watch for a store of this register... */
              unat_save_reg = rN;
              last_prologue_pc = next_pc;
            }
        }
      else if (it == I && ((instr & 0x1eff8000000LL) == 0x00198000000LL))
        {
          /* mov rN = pr */
          int rN  = (int) ((instr & 0x00000001fc0LL) >> 6);
          int qp  = (int) (instr & 0x0000000003fLL);
          if (qp == 0 && isScratch (rN))
            {
              pr_save_reg = rN;
              last_prologue_pc = next_pc;
            }
        }
      else if (it == M 
            && (   ((instr & 0x1ffc8000000LL) == 0x08cc0000000LL)
                || ((instr & 0x1efc0000000LL) == 0x0acc0000000LL)))
        {
          /* st8 [rN] = rM 
              or
             st8 [rN] = rM, imm9 */
          int rN = (int) ((instr & 0x00007f00000LL) >> 20);
          int rM = (int) ((instr & 0x000000fe000LL) >> 13);
          int qp = (int) (instr & 0x0000000003fLL);
          int indirect = rM < 256 ? reg_contents[rM] : 0;
          if (qp == 0 && rN == spill_reg && spill_addr != 0
              && (rM == unat_save_reg || rM == pr_save_reg))
            {
              /* We've found a spill of either the UNAT register or the PR
                 register.  (Well, not exactly; what we've actually found is
                 a spill of the register that UNAT or PR was moved to).
                 Record that fact and move on... */
              if (rM == unat_save_reg)
                {
                  /* Track UNAT register */
                  cache->saved_regs[IA64_UNAT_REGNUM] = spill_addr;
                  unat_save_reg = 0;
                }
              else
                {
                  /* Track PR register */
                  cache->saved_regs[IA64_PR_REGNUM] = spill_addr;
                  pr_save_reg = 0;
                }
              if ((instr & 0x1efc0000000LL) == 0x0acc0000000LL)
                /* st8 [rN] = rM, imm9 */
                spill_addr += imm9(instr);
              else
                spill_addr = 0;         /* must be done spilling */
              last_prologue_pc = next_pc;
            }
          else if (qp == 0 && 32 <= rM && rM < 40 && !instores[rM-32])
            {
              /* Allow up to one store of each input register. */
              instores[rM-32] = 1;
              last_prologue_pc = next_pc;
            }
          else if (qp == 0 && 32 <= indirect && indirect < 40 && 
                   !instores[indirect-32])
            {
              /* Allow an indirect store of an input register.  */
              instores[indirect-32] = 1;
              last_prologue_pc = next_pc;
            }
        }
      else if (it == M && ((instr & 0x1ff08000000LL) == 0x08c00000000LL))
        {
          /* One of
               st1 [rN] = rM
               st2 [rN] = rM
               st4 [rN] = rM
               st8 [rN] = rM
             Note that the st8 case is handled in the clause above.
             
             Advance over stores of input registers. One store per input
             register is permitted. */
          int rM = (int) ((instr & 0x000000fe000LL) >> 13);
          int qp = (int) (instr & 0x0000000003fLL);
          int indirect = rM < 256 ? reg_contents[rM] : 0;
          if (qp == 0 && 32 <= rM && rM < 40 && !instores[rM-32])
            {
              instores[rM-32] = 1;
              last_prologue_pc = next_pc;
            }
          else if (qp == 0 && 32 <= indirect && indirect < 40 && 
                   !instores[indirect-32])
            {
              /* Allow an indirect store of an input register.  */
              instores[indirect-32] = 1;
              last_prologue_pc = next_pc;
            }
        }
      else if (it == M && ((instr & 0x1ff88000000LL) == 0x0cc80000000LL))
        {
          /* Either
               stfs [rN] = fM
             or
               stfd [rN] = fM

             Advance over stores of floating point input registers.  Again
             one store per register is permitted */
          int fM = (int) ((instr & 0x000000fe000LL) >> 13);
          int qp = (int) (instr & 0x0000000003fLL);
          if (qp == 0 && 8 <= fM && fM < 16 && !infpstores[fM - 8])
            {
              infpstores[fM-8] = 1;
              last_prologue_pc = next_pc;
            }
        }
      else if (it == M
            && (   ((instr & 0x1ffc8000000LL) == 0x08ec0000000LL)
                || ((instr & 0x1efc0000000LL) == 0x0aec0000000LL)))
        {
          /* st8.spill [rN] = rM
               or
             st8.spill [rN] = rM, imm9 */
          int rN = (int) ((instr & 0x00007f00000LL) >> 20);
          int rM = (int) ((instr & 0x000000fe000LL) >> 13);
          int qp = (int) (instr & 0x0000000003fLL);
          if (qp == 0 && rN == spill_reg && 4 <= rM && rM <= 7)
            {
              /* We've found a spill of one of the preserved general purpose
                 regs.  Record the spill address and advance the spill
                 register if appropriate. */
              cache->saved_regs[IA64_GR0_REGNUM + rM] = spill_addr;
              if ((instr & 0x1efc0000000LL) == 0x0aec0000000LL)
                /* st8.spill [rN] = rM, imm9 */
                spill_addr += imm9(instr);
              else
                spill_addr = 0;         /* Done spilling */
              last_prologue_pc = next_pc;
            }
        }

      pc = next_pc;
    }

  /* If not frameless and we aren't called by skip_prologue, then we need to calculate
     registers for the previous frame which will be needed later.  */

  if (!frameless && next_frame)
    {
      /* Extract the size of the rotating portion of the stack
         frame and the register rename base from the current
         frame marker. */
      cfm = cache->cfm;
      sor = cache->sor;
      sof = cache->sof;
      sol = cache->sol;
      rrb_gr = (cfm >> 18) & 0x7f;

      /* Find the bof (beginning of frame).  */
      bof = rse_address_add (cache->bsp, -sof);
      
      for (i = 0, addr = bof;
           i < sof;
           i++, addr += 8)
        {
          if (IS_NaT_COLLECTION_ADDR (addr))
            {
              addr += 8;
            }
          if (i+32 == cfm_reg)
            cache->saved_regs[IA64_CFM_REGNUM] = addr;
          if (i+32 == ret_reg)
            cache->saved_regs[IA64_VRAP_REGNUM] = addr;
          if (i+32 == fp_reg)
            cache->saved_regs[IA64_VFP_REGNUM] = addr;
        }

      /* For the previous argument registers we require the previous bof.  
         If we can't find the previous cfm, then we can do nothing.  */
      cfm = 0;
      if (cache->saved_regs[IA64_CFM_REGNUM] != 0)
        {
          cfm = read_memory_integer (cache->saved_regs[IA64_CFM_REGNUM], 8);
        }
      else if (cfm_reg != 0)
        {
          frame_unwind_register (next_frame, cfm_reg, buf);
          cfm = extract_unsigned_integer (buf, 8);
        }
      cache->prev_cfm = cfm;
      
      if (cfm != 0)
        {
          sor = ((cfm >> 14) & 0xf) * 8;
          sof = (cfm & 0x7f);
          sol = (cfm >> 7) & 0x7f;
          rrb_gr = (cfm >> 18) & 0x7f;

          /* The previous bof only requires subtraction of the sol (size of locals)
             due to the overlap between output and input of subsequent frames.  */
          bof = rse_address_add (bof, -sol);
          
          for (i = 0, addr = bof;
               i < sof;
               i++, addr += 8)
            {
              if (IS_NaT_COLLECTION_ADDR (addr))
                {
                  addr += 8;
                }
              if (i < sor)
                cache->saved_regs[IA64_GR32_REGNUM + ((i + (sor - rrb_gr)) % sor)] 
                  = addr;
              else
                cache->saved_regs[IA64_GR32_REGNUM + i] = addr;
            }
          
        }
    }
      
  /* Try and trust the lim_pc value whenever possible.  */
  if (trust_limit && lim_pc >= last_prologue_pc)
    last_prologue_pc = lim_pc;

  cache->frameless = frameless;
  cache->after_prologue = last_prologue_pc;
  cache->mem_stack_frame_size = mem_stack_frame_size;
  cache->fp_reg = fp_reg;

  return last_prologue_pc;
}

CORE_ADDR
ia64_skip_prologue (CORE_ADDR pc)
{
  struct ia64_frame_cache cache;
  cache.base = 0;
  cache.after_prologue = 0;
  cache.cfm = 0;
  cache.bsp = 0;

  /* Call examine_prologue with - as third argument since we don't have a next frame pointer to send.  */
  return examine_prologue (pc, pc+1024, 0, &cache);
}


/* Normal frames.  */

static struct ia64_frame_cache *
ia64_frame_cache (struct frame_info *next_frame, void **this_cache)
{
  struct ia64_frame_cache *cache;
  char buf[8];
  CORE_ADDR cfm, sof, sol, bsp, psr;
  int i;

  if (*this_cache)
    return *this_cache;

  cache = ia64_alloc_frame_cache ();
  *this_cache = cache;

  frame_unwind_register (next_frame, sp_regnum, buf);
  cache->saved_sp = extract_unsigned_integer (buf, 8);

  /* We always want the bsp to point to the end of frame.
     This way, we can always get the beginning of frame (bof)
     by subtracting frame size.  */
  frame_unwind_register (next_frame, IA64_BSP_REGNUM, buf);
  cache->bsp = extract_unsigned_integer (buf, 8);
  
  frame_unwind_register (next_frame, IA64_PSR_REGNUM, buf);
  psr = extract_unsigned_integer (buf, 8);

  frame_unwind_register (next_frame, IA64_CFM_REGNUM, buf);
  cfm = extract_unsigned_integer (buf, 8);

  cache->sof = (cfm & 0x7f);
  cache->sol = (cfm >> 7) & 0x7f;
  cache->sor = ((cfm >> 14) & 0xf) * 8;

  cache->cfm = cfm;

  cache->pc = frame_func_unwind (next_frame);

  if (cache->pc != 0)
    examine_prologue (cache->pc, frame_pc_unwind (next_frame), next_frame, cache);
  
  cache->base = cache->saved_sp + cache->mem_stack_frame_size;

  return cache;
}

static void
ia64_frame_this_id (struct frame_info *next_frame, void **this_cache,
                    struct frame_id *this_id)
{
  struct ia64_frame_cache *cache =
    ia64_frame_cache (next_frame, this_cache);

  /* This marks the outermost frame.  */
  if (cache->base == 0)
    return;

  (*this_id) = frame_id_build_special (cache->base, cache->pc, cache->bsp);
  if (gdbarch_debug >= 1)
    fprintf_unfiltered (gdb_stdlog,
                        "regular frame id: code %lx, stack %lx, special %lx, next_frame %p\n",
                        this_id->code_addr, this_id->stack_addr, cache->bsp, next_frame);
}

static void
ia64_frame_prev_register (struct frame_info *next_frame, void **this_cache,
                          int regnum, int *optimizedp,
                          enum lval_type *lvalp, CORE_ADDR *addrp,
                          int *realnump, void *valuep)
{
  struct ia64_frame_cache *cache =
    ia64_frame_cache (next_frame, this_cache);
  char dummy_valp[MAX_REGISTER_SIZE];
  char buf[8];

  gdb_assert (regnum >= 0);

  if (!target_has_registers)
    error ("No registers.");

  *optimizedp = 0;
  *addrp = 0;
  *lvalp = not_lval;
  *realnump = -1;

  /* Rather than check each time if valuep is non-null, supply a dummy buffer
     when valuep is not supplied.  */
  if (!valuep)
    valuep = dummy_valp;
  
  memset (valuep, 0, register_size (current_gdbarch, regnum));
 
  if (regnum == SP_REGNUM)
    {
      /* Handle SP values for all frames but the topmost. */
      store_unsigned_integer (valuep, register_size (current_gdbarch, regnum),
                              cache->base);
    }
  else if (regnum == IA64_BSP_REGNUM)
    {
      char cfm_valuep[MAX_REGISTER_SIZE];
      int  cfm_optim;
      int  cfm_realnum;
      enum lval_type cfm_lval;
      CORE_ADDR cfm_addr;
      CORE_ADDR bsp, prev_cfm, prev_bsp;

      /* We want to calculate the previous bsp as the end of the previous register stack frame.
         This corresponds to what the hardware bsp register will be if we pop the frame
         back which is why we might have been called.  We know the beginning of the current
         frame is cache->bsp - cache->sof.  This value in the previous frame points to
         the start of the output registers.  We can calculate the end of that frame by adding
         the size of output (sof (size of frame) - sol (size of locals)).  */
      ia64_frame_prev_register (next_frame, this_cache, IA64_CFM_REGNUM,
                                &cfm_optim, &cfm_lval, &cfm_addr, &cfm_realnum, cfm_valuep);
      prev_cfm = extract_unsigned_integer (cfm_valuep, 8);

      bsp = rse_address_add (cache->bsp, -(cache->sof));
      prev_bsp = rse_address_add (bsp, (prev_cfm & 0x7f) - ((prev_cfm >> 7) & 0x7f));

      store_unsigned_integer (valuep, register_size (current_gdbarch, regnum), 
                              prev_bsp);
    }
  else if (regnum == IA64_CFM_REGNUM)
    {
      CORE_ADDR addr = cache->saved_regs[IA64_CFM_REGNUM];
      
      if (addr != 0)
        {
          *lvalp = lval_memory;
          *addrp = addr;
          read_memory (addr, valuep, register_size (current_gdbarch, regnum));
        }
      else if (cache->prev_cfm)
        store_unsigned_integer (valuep, register_size (current_gdbarch, regnum), cache->prev_cfm);
      else if (cache->frameless)
        {
          CORE_ADDR cfm = 0;
          frame_unwind_register (next_frame, IA64_PFS_REGNUM, valuep);
        }
    }
  else if (regnum == IA64_VFP_REGNUM)
    {
      /* If the function in question uses an automatic register (r32-r127)
         for the frame pointer, it'll be found by ia64_find_saved_register()
         above.  If the function lacks one of these frame pointers, we can
         still provide a value since we know the size of the frame.  */
      CORE_ADDR vfp = cache->base;
      store_unsigned_integer (valuep, register_size (current_gdbarch, IA64_VFP_REGNUM), vfp);
    }
  else if (VP0_REGNUM <= regnum && regnum <= VP63_REGNUM)
    {
      char pr_valuep[MAX_REGISTER_SIZE];
      int  pr_optim;
      int  pr_realnum;
      enum lval_type pr_lval;
      CORE_ADDR pr_addr;
      ULONGEST prN_val;
      ia64_frame_prev_register (next_frame, this_cache, IA64_PR_REGNUM,
                                &pr_optim, &pr_lval, &pr_addr, &pr_realnum, pr_valuep);
      if (VP16_REGNUM <= regnum && regnum <= VP63_REGNUM)
        {
          /* Fetch predicate register rename base from current frame
             marker for this frame.  */
          int rrb_pr = (cache->cfm >> 32) & 0x3f;

          /* Adjust the register number to account for register rotation.  */
          regnum = VP16_REGNUM 
                 + ((regnum - VP16_REGNUM) + rrb_pr) % 48;
        }
      prN_val = extract_bit_field ((unsigned char *) pr_valuep,
                                   regnum - VP0_REGNUM, 1);
      store_unsigned_integer (valuep, register_size (current_gdbarch, regnum), prN_val);
    }
  else if (IA64_NAT0_REGNUM <= regnum && regnum <= IA64_NAT31_REGNUM)
    {
      char unat_valuep[MAX_REGISTER_SIZE];
      int  unat_optim;
      int  unat_realnum;
      enum lval_type unat_lval;
      CORE_ADDR unat_addr;
      ULONGEST unatN_val;
      ia64_frame_prev_register (next_frame, this_cache, IA64_UNAT_REGNUM,
                                &unat_optim, &unat_lval, &unat_addr, &unat_realnum, unat_valuep);
      unatN_val = extract_bit_field ((unsigned char *) unat_valuep,
                                   regnum - IA64_NAT0_REGNUM, 1);
      store_unsigned_integer (valuep, register_size (current_gdbarch, regnum), 
                              unatN_val);
    }
  else if (IA64_NAT32_REGNUM <= regnum && regnum <= IA64_NAT127_REGNUM)
    {
      int natval = 0;
      /* Find address of general register corresponding to nat bit we're
         interested in.  */
      CORE_ADDR gr_addr;

      gr_addr = cache->saved_regs[regnum - IA64_NAT0_REGNUM 
                                  + IA64_GR0_REGNUM];
      if (gr_addr != 0)
        {
          /* Compute address of nat collection bits.  */
          CORE_ADDR nat_addr = gr_addr | 0x1f8;
          CORE_ADDR bsp;
          CORE_ADDR nat_collection;
          int nat_bit;
          /* If our nat collection address is bigger than bsp, we have to get
             the nat collection from rnat.  Otherwise, we fetch the nat
             collection from the computed address.  */
          frame_unwind_register (next_frame, IA64_BSP_REGNUM, buf);
          bsp = extract_unsigned_integer (buf, 8); 
          if (nat_addr >= bsp)
            {
              frame_unwind_register (next_frame, IA64_RNAT_REGNUM, buf);
              nat_collection = extract_unsigned_integer (buf, 8);
            }
          else
            nat_collection = read_memory_integer (nat_addr, 8);
          nat_bit = (gr_addr >> 3) & 0x3f;
          natval = (nat_collection >> nat_bit) & 1;
        }

      store_unsigned_integer (valuep, register_size (current_gdbarch, regnum), natval);
    }
  else if (regnum == IA64_IP_REGNUM)
    {
      CORE_ADDR pc = 0;
      CORE_ADDR addr = cache->saved_regs[IA64_VRAP_REGNUM];

      if (addr != 0)
        {
          *lvalp = lval_memory;
          *addrp = addr;
          read_memory (addr, buf, register_size (current_gdbarch, IA64_IP_REGNUM));
          pc = extract_unsigned_integer (buf, 8);
        }
      else if (cache->frameless)
        {
          frame_unwind_register (next_frame, IA64_BR0_REGNUM, buf);
          pc = extract_unsigned_integer (buf, 8);
        }
      pc &= ~0xf;
      store_unsigned_integer (valuep, 8, pc);
    }
  else if (regnum == IA64_PSR_REGNUM)
    {
      /* We don't know how to get the complete previous PSR, but we need it for
         the slot information when we unwind the pc (pc is formed of IP register
         plus slot information from PSR).  To get the previous slot information, 
         we mask it off the return address.  */
      ULONGEST slot_num = 0;
      CORE_ADDR pc= 0;
      CORE_ADDR psr = 0;
      CORE_ADDR addr = cache->saved_regs[IA64_VRAP_REGNUM];

      frame_unwind_register (next_frame, IA64_PSR_REGNUM, buf);
      psr = extract_unsigned_integer (buf, 8);

      if (addr != 0)
        {
          *lvalp = lval_memory;
          *addrp = addr;
          read_memory (addr, buf, register_size (current_gdbarch, IA64_IP_REGNUM));
          pc = extract_unsigned_integer (buf, 8);
        }
      else if (cache->frameless)
        {
          CORE_ADDR pc;
          frame_unwind_register (next_frame, IA64_BR0_REGNUM, buf);
          pc = extract_unsigned_integer (buf, 8);
        }
      psr &= ~(3LL << 41);
      slot_num = pc & 0x3LL;
      psr |= (CORE_ADDR)slot_num << 41;
      store_unsigned_integer (valuep, 8, psr);
    }
  else if (regnum == IA64_BR0_REGNUM)
    {
      CORE_ADDR br0 = 0;
      CORE_ADDR addr = cache->saved_regs[IA64_BR0_REGNUM];
      if (addr != 0)
        {
          *lvalp = lval_memory;
          *addrp = addr;
          read_memory (addr, buf, register_size (current_gdbarch, IA64_BR0_REGNUM));
          br0 = extract_unsigned_integer (buf, 8);
        }
      store_unsigned_integer (valuep, 8, br0);
    }
 else if ((regnum >= IA64_GR32_REGNUM && regnum <= IA64_GR127_REGNUM) ||
           (regnum >= V32_REGNUM && regnum <= V127_REGNUM))
    {
      CORE_ADDR addr = 0;
      if (regnum >= V32_REGNUM)
        regnum = IA64_GR32_REGNUM + (regnum - V32_REGNUM);
      addr = cache->saved_regs[regnum];
      if (addr != 0)
        {
          *lvalp = lval_memory;
          *addrp = addr;
          read_memory (addr, valuep, register_size (current_gdbarch, regnum));
        }
      else if (cache->frameless)
        {
          char r_valuep[MAX_REGISTER_SIZE];
          int  r_optim;
          int  r_realnum;
          enum lval_type r_lval;
          CORE_ADDR r_addr;
          CORE_ADDR prev_cfm, prev_bsp, prev_bof;
          CORE_ADDR addr = 0;
          if (regnum >= V32_REGNUM)
            regnum = IA64_GR32_REGNUM + (regnum - V32_REGNUM);
          ia64_frame_prev_register (next_frame, this_cache, IA64_CFM_REGNUM,
                                    &r_optim, &r_lval, &r_addr, &r_realnum, r_valuep); 
          prev_cfm = extract_unsigned_integer (r_valuep, 8);
          ia64_frame_prev_register (next_frame, this_cache, IA64_BSP_REGNUM,
                                    &r_optim, &r_lval, &r_addr, &r_realnum, r_valuep);
          prev_bsp = extract_unsigned_integer (r_valuep, 8);
          prev_bof = rse_address_add (prev_bsp, -(prev_cfm & 0x7f));

          addr = rse_address_add (prev_bof, (regnum - IA64_GR32_REGNUM));
          *lvalp = lval_memory;
          *addrp = addr;
          read_memory (addr, valuep, register_size (current_gdbarch, regnum));
        }
    }
  else
    {
      CORE_ADDR addr = 0;
      if (IA64_FR32_REGNUM <= regnum && regnum <= IA64_FR127_REGNUM)
        {
          /* Fetch floating point register rename base from current
             frame marker for this frame.  */
          int rrb_fr = (cache->cfm >> 25) & 0x7f;

          /* Adjust the floating point register number to account for
             register rotation.  */
          regnum = IA64_FR32_REGNUM
                 + ((regnum - IA64_FR32_REGNUM) + rrb_fr) % 96;
        }

      /* If we have stored a memory address, access the register.  */
      addr = cache->saved_regs[regnum];
      if (addr != 0)
        {
          *lvalp = lval_memory;
          *addrp = addr;
          read_memory (addr, valuep, register_size (current_gdbarch, regnum));
        }
      /* Otherwise, punt and get the current value of the register.  */
      else 
        frame_unwind_register (next_frame, regnum, valuep);
    }

  if (gdbarch_debug >= 1)
    fprintf_unfiltered (gdb_stdlog,
                        "regular prev register <%d> <%s> is %lx\n", regnum, 
                        (((unsigned) regnum <= IA64_NAT127_REGNUM)
                         ? ia64_register_names[regnum] : "r??"), extract_unsigned_integer (valuep, 8));
}
 
static const struct frame_unwind ia64_frame_unwind =
{
  NORMAL_FRAME,
  &ia64_frame_this_id,
  &ia64_frame_prev_register
};

static const struct frame_unwind *
ia64_frame_sniffer (struct frame_info *next_frame)
{
  return &ia64_frame_unwind;
}

/* Signal trampolines.  */

static void
ia64_sigtramp_frame_init_saved_regs (struct ia64_frame_cache *cache)
{
  if (SIGCONTEXT_REGISTER_ADDRESS)
    {
      int regno;

      cache->saved_regs[IA64_VRAP_REGNUM] = 
        SIGCONTEXT_REGISTER_ADDRESS (cache->base, IA64_IP_REGNUM);
      cache->saved_regs[IA64_CFM_REGNUM] = 
        SIGCONTEXT_REGISTER_ADDRESS (cache->base, IA64_CFM_REGNUM);
      cache->saved_regs[IA64_PSR_REGNUM] = 
        SIGCONTEXT_REGISTER_ADDRESS (cache->base, IA64_PSR_REGNUM);
      cache->saved_regs[IA64_BSP_REGNUM] = 
        SIGCONTEXT_REGISTER_ADDRESS (cache->base, IA64_BSP_REGNUM);
      cache->saved_regs[IA64_RNAT_REGNUM] = 
        SIGCONTEXT_REGISTER_ADDRESS (cache->base, IA64_RNAT_REGNUM);
      cache->saved_regs[IA64_CCV_REGNUM] = 
        SIGCONTEXT_REGISTER_ADDRESS (cache->base, IA64_CCV_REGNUM);
      cache->saved_regs[IA64_UNAT_REGNUM] = 
        SIGCONTEXT_REGISTER_ADDRESS (cache->base, IA64_UNAT_REGNUM);
      cache->saved_regs[IA64_FPSR_REGNUM] = 
        SIGCONTEXT_REGISTER_ADDRESS (cache->base, IA64_FPSR_REGNUM);
      cache->saved_regs[IA64_PFS_REGNUM] = 
        SIGCONTEXT_REGISTER_ADDRESS (cache->base, IA64_PFS_REGNUM);
      cache->saved_regs[IA64_LC_REGNUM] = 
        SIGCONTEXT_REGISTER_ADDRESS (cache->base, IA64_LC_REGNUM);
      for (regno = IA64_GR1_REGNUM; regno <= IA64_GR31_REGNUM; regno++)
        cache->saved_regs[regno] =
          SIGCONTEXT_REGISTER_ADDRESS (cache->base, regno);
      for (regno = IA64_BR0_REGNUM; regno <= IA64_BR7_REGNUM; regno++)
        cache->saved_regs[regno] =
          SIGCONTEXT_REGISTER_ADDRESS (cache->base, regno);
      for (regno = IA64_FR2_REGNUM; regno <= IA64_FR31_REGNUM; regno++)
        cache->saved_regs[regno] =
          SIGCONTEXT_REGISTER_ADDRESS (cache->base, regno);
    }
}

static struct ia64_frame_cache *
ia64_sigtramp_frame_cache (struct frame_info *next_frame, void **this_cache)
{
  struct ia64_frame_cache *cache;
  CORE_ADDR addr;
  char buf[8];
  int i;

  if (*this_cache)
    return *this_cache;

  cache = ia64_alloc_frame_cache ();

  frame_unwind_register (next_frame, sp_regnum, buf);
  /* Note that frame size is hard-coded below.  We cannot calculate it
     via prologue examination.  */
  cache->base = extract_unsigned_integer (buf, 8) + 16;

  frame_unwind_register (next_frame, IA64_BSP_REGNUM, buf);
  cache->bsp = extract_unsigned_integer (buf, 8);

  frame_unwind_register (next_frame, IA64_CFM_REGNUM, buf);
  cache->cfm = extract_unsigned_integer (buf, 8);
  cache->sof = cache->cfm & 0x7f;

  ia64_sigtramp_frame_init_saved_regs (cache);

  *this_cache = cache;
  return cache;
}

static void
ia64_sigtramp_frame_this_id (struct frame_info *next_frame,
                               void **this_cache, struct frame_id *this_id)
{
  struct ia64_frame_cache *cache =
    ia64_sigtramp_frame_cache (next_frame, this_cache);

  (*this_id) = frame_id_build_special (cache->base, frame_pc_unwind (next_frame), cache->bsp);
  if (gdbarch_debug >= 1)
    fprintf_unfiltered (gdb_stdlog,
                        "sigtramp frame id: code %lx, stack %lx, special %lx, next_frame %p\n",
                        this_id->code_addr, this_id->stack_addr, cache->bsp, next_frame);
}

static void
ia64_sigtramp_frame_prev_register (struct frame_info *next_frame,
                                   void **this_cache,
                                   int regnum, int *optimizedp,
                                   enum lval_type *lvalp, CORE_ADDR *addrp,
                                   int *realnump, void *valuep)
{
  char dummy_valp[MAX_REGISTER_SIZE];
  char buf[MAX_REGISTER_SIZE];

  struct ia64_frame_cache *cache =
    ia64_sigtramp_frame_cache (next_frame, this_cache);

  gdb_assert (regnum >= 0);

  if (!target_has_registers)
    error ("No registers.");

  *optimizedp = 0;
  *addrp = 0;
  *lvalp = not_lval;
  *realnump = -1;

  /* Rather than check each time if valuep is non-null, supply a dummy buffer
     when valuep is not supplied.  */
  if (!valuep)
    valuep = dummy_valp;
  
  memset (valuep, 0, register_size (current_gdbarch, regnum));
 
  if (regnum == IA64_IP_REGNUM)
    {
      CORE_ADDR pc = 0;
      CORE_ADDR addr = cache->saved_regs[IA64_VRAP_REGNUM];

      if (addr != 0)
        {
          *lvalp = lval_memory;
          *addrp = addr;
          read_memory (addr, buf, register_size (current_gdbarch, IA64_IP_REGNUM));
          pc = extract_unsigned_integer (buf, 8);
        }
      pc &= ~0xf;
      store_unsigned_integer (valuep, 8, pc);
    }
 else if ((regnum >= IA64_GR32_REGNUM && regnum <= IA64_GR127_REGNUM) ||
           (regnum >= V32_REGNUM && regnum <= V127_REGNUM))
    {
      CORE_ADDR addr = 0;
      if (regnum >= V32_REGNUM)
        regnum = IA64_GR32_REGNUM + (regnum - V32_REGNUM);
      addr = cache->saved_regs[regnum];
      if (addr != 0)
        {
          *lvalp = lval_memory;
          *addrp = addr;
          read_memory (addr, valuep, register_size (current_gdbarch, regnum));
        }
    }
  else
    {
      /* All other registers not listed above.  */
      CORE_ADDR addr = cache->saved_regs[regnum];
      if (addr != 0)
        {
          *lvalp = lval_memory;
          *addrp = addr;
          read_memory (addr, valuep, register_size (current_gdbarch, regnum));
        }
    }

  if (gdbarch_debug >= 1)
    fprintf_unfiltered (gdb_stdlog,
                        "sigtramp prev register <%s> is %lx\n",
                        (((unsigned) regnum <= IA64_NAT127_REGNUM)
                         ? ia64_register_names[regnum] : "r??"), extract_unsigned_integer (valuep, 8));
}

static const struct frame_unwind ia64_sigtramp_frame_unwind =
{
  SIGTRAMP_FRAME,
  ia64_sigtramp_frame_this_id,
  ia64_sigtramp_frame_prev_register
};

static const struct frame_unwind *
ia64_sigtramp_frame_sniffer (struct frame_info *next_frame)
{
  char *name;
  CORE_ADDR pc = frame_pc_unwind (next_frame);

  find_pc_partial_function (pc, &name, NULL, NULL);
  if (PC_IN_SIGTRAMP (pc, name))
    return &ia64_sigtramp_frame_unwind;

  return NULL;
}
\f

static CORE_ADDR
ia64_frame_base_address (struct frame_info *next_frame, void **this_cache)
{
  struct ia64_frame_cache *cache =
    ia64_frame_cache (next_frame, this_cache);

  return cache->base;
}

static const struct frame_base ia64_frame_base =
{
  &ia64_frame_unwind,
  ia64_frame_base_address,
  ia64_frame_base_address,
  ia64_frame_base_address
};

#ifdef HAVE_LIBUNWIND_IA64_H

struct ia64_unwind_table_entry
  {
    unw_word_t start_offset;
    unw_word_t end_offset;
    unw_word_t info_offset;
  };

static __inline__ uint64_t
ia64_rse_slot_num (uint64_t addr)
{
  return (addr >> 3) & 0x3f;
}

/* Skip over a designated number of registers in the backing
   store, remembering every 64th position is for NAT.  */
static __inline__ uint64_t
ia64_rse_skip_regs (uint64_t addr, long num_regs)
{
  long delta = ia64_rse_slot_num(addr) + num_regs;

  if (num_regs < 0)
    delta -= 0x3e;
  return addr + ((num_regs + delta/0x3f) << 3);
}
  
/* Gdb libunwind-frame callback function to convert from an ia64 gdb register 
   number to a libunwind register number.  */
static int
ia64_gdb2uw_regnum (int regnum)
{
  if (regnum == sp_regnum)
    return UNW_IA64_SP;
  else if (regnum == IA64_BSP_REGNUM)
    return UNW_IA64_BSP;
  else if ((unsigned) (regnum - IA64_GR0_REGNUM) < 128)
    return UNW_IA64_GR + (regnum - IA64_GR0_REGNUM);
  else if ((unsigned) (regnum - V32_REGNUM) < 95)
    return UNW_IA64_GR + 32 + (regnum - V32_REGNUM);
  else if ((unsigned) (regnum - IA64_FR0_REGNUM) < 128)
    return UNW_IA64_FR + (regnum - IA64_FR0_REGNUM);
  else if ((unsigned) (regnum - IA64_PR0_REGNUM) < 64)
    return -1;
  else if ((unsigned) (regnum - IA64_BR0_REGNUM) < 8)
    return UNW_IA64_BR + (regnum - IA64_BR0_REGNUM);
  else if (regnum == IA64_PR_REGNUM)
    return UNW_IA64_PR;
  else if (regnum == IA64_IP_REGNUM)
    return UNW_REG_IP;
  else if (regnum == IA64_CFM_REGNUM)
    return UNW_IA64_CFM;
  else if ((unsigned) (regnum - IA64_AR0_REGNUM) < 128)
    return UNW_IA64_AR + (regnum - IA64_AR0_REGNUM);
  else if ((unsigned) (regnum - IA64_NAT0_REGNUM) < 128)
    return UNW_IA64_NAT + (regnum - IA64_NAT0_REGNUM);
  else
    return -1;
}
  
/* Gdb libunwind-frame callback function to convert from a libunwind register 
   number to a ia64 gdb register number.  */
static int
ia64_uw2gdb_regnum (int uw_regnum)
{
  if (uw_regnum == UNW_IA64_SP)
    return sp_regnum;
  else if (uw_regnum == UNW_IA64_BSP)
    return IA64_BSP_REGNUM;
  else if ((unsigned) (uw_regnum - UNW_IA64_GR) < 32)
    return IA64_GR0_REGNUM + (uw_regnum - UNW_IA64_GR);
  else if ((unsigned) (uw_regnum - UNW_IA64_GR) < 128)
    return V32_REGNUM + (uw_regnum - (IA64_GR0_REGNUM + 32));
  else if ((unsigned) (uw_regnum - UNW_IA64_FR) < 128)
    return IA64_FR0_REGNUM + (uw_regnum - UNW_IA64_FR);
  else if ((unsigned) (uw_regnum - UNW_IA64_BR) < 8)
    return IA64_BR0_REGNUM + (uw_regnum - UNW_IA64_BR);
  else if (uw_regnum == UNW_IA64_PR)
    return IA64_PR_REGNUM;
  else if (uw_regnum == UNW_REG_IP)
    return IA64_IP_REGNUM;
  else if (uw_regnum == UNW_IA64_CFM)
    return IA64_CFM_REGNUM;
  else if ((unsigned) (uw_regnum - UNW_IA64_AR) < 128)
    return IA64_AR0_REGNUM + (uw_regnum - UNW_IA64_AR);
  else if ((unsigned) (uw_regnum - UNW_IA64_NAT) < 128)
    return IA64_NAT0_REGNUM + (uw_regnum - UNW_IA64_NAT);
  else
    return -1;
}

/* Gdb libunwind-frame callback function to reveal if register is a float 
   register or not.  */
static int
ia64_is_fpreg (int uw_regnum)
{
  return unw_is_fpreg (uw_regnum);
}
  
/* Libunwind callback accessor function for general registers.  */
static int
ia64_access_reg (unw_addr_space_t as, unw_regnum_t uw_regnum, unw_word_t *val, 
                 int write, void *arg)
{
  int regnum = ia64_uw2gdb_regnum (uw_regnum);
  unw_word_t bsp, sof, sol, cfm, psr, ip;
  struct frame_info *next_frame = arg;
  long new_sof, old_sof;
  char buf[MAX_REGISTER_SIZE];
  
  if (write)
    {
      if (regnum < 0)
        /* ignore writes to pseudo-registers such as UNW_IA64_PROC_STARTI.  */
        return 0;
  
      switch (uw_regnum)
        {
        case UNW_REG_IP:
          ia64_write_pc (*val, inferior_ptid);
          break;

        case UNW_IA64_AR_BSPSTORE:
          write_register (IA64_BSP_REGNUM, *val);
          break;
          
        case UNW_IA64_AR_BSP:
        case UNW_IA64_BSP:
          /* Account for the fact that ptrace() expects bsp to point
             after the current register frame.  */
          cfm = read_register (IA64_CFM_REGNUM);
          sof = (cfm & 0x7f);
          bsp = ia64_rse_skip_regs (*val, sof);
          write_register (IA64_BSP_REGNUM, bsp);
          break;
          
        case UNW_IA64_CFM:
          /* If we change CFM, we need to adjust ptrace's notion of
             bsp accordingly, so that the real bsp remains
             unchanged.  */
          bsp = read_register (IA64_BSP_REGNUM);
          cfm = read_register (IA64_CFM_REGNUM);
          old_sof = (cfm & 0x7f);
          new_sof = (*val & 0x7f);
          if (old_sof != new_sof)
            {
              bsp = ia64_rse_skip_regs (bsp, -old_sof + new_sof);
              write_register (IA64_BSP_REGNUM, bsp);
            }
          write_register (IA64_CFM_REGNUM, *val);
          break;
          
        default:
          write_register (regnum, *val);
          break;
        }
      if (gdbarch_debug >= 1)
        fprintf_unfiltered (gdb_stdlog, 
                            "  access_reg: to cache: %4s=%016lx\n",
                            (((unsigned) regnum <= IA64_NAT127_REGNUM)
                             ? ia64_register_names[regnum] : "r??"), *val);
    }
  else
    {
      switch (uw_regnum)
        {
        case UNW_REG_IP:
          /* Libunwind expects to see the pc value which means the slot number
             from the psr must be merged with the ip word address.  */
          frame_unwind_register (next_frame, IA64_IP_REGNUM, buf);
          ip = extract_unsigned_integer (buf, 8); 
          frame_unwind_register (next_frame, IA64_PSR_REGNUM, buf);
          psr = extract_unsigned_integer (buf, 8); 
          *val = ip | ((psr >> 41) & 0x3);
          break;
          
        case UNW_IA64_AR_BSP:
          /* Libunwind expects to see the beginning of the current register
             frame so we must account for the fact that ptrace() will return a value
             for bsp that points *after* the current register frame.  */
          frame_unwind_register (next_frame, IA64_BSP_REGNUM, buf);
          bsp = extract_unsigned_integer (buf, 8);
          frame_unwind_register (next_frame, IA64_CFM_REGNUM, buf);
          cfm = extract_unsigned_integer (buf, 8); 
          sof = (cfm & 0x7f);
          *val = ia64_rse_skip_regs (bsp, -sof);
          break;
          
        case UNW_IA64_AR_BSPSTORE:
          /* Libunwind wants bspstore to be after the current register frame.
             This is what ptrace() and gdb treats as the regular bsp value.  */
          frame_unwind_register (next_frame, IA64_BSP_REGNUM, buf);
          *val = extract_unsigned_integer (buf, 8);
          break;

        default:
          /* For all other registers, just unwind the value directly.  */
          frame_unwind_register (next_frame, regnum, buf);
          *val = extract_unsigned_integer (buf, 8); 
          break;
        }
      
      if (gdbarch_debug >= 1)
        fprintf_unfiltered (gdb_stdlog, 
                            "  access_reg: from cache: %4s=%016lx\n",
                            (((unsigned) regnum <= IA64_NAT127_REGNUM)
                             ? ia64_register_names[regnum] : "r??"), *val);
    }
  return 0;
}

/* Libunwind callback accessor function for floating-point registers.  */
static int
ia64_access_fpreg (unw_addr_space_t as, unw_regnum_t uw_regnum, unw_fpreg_t *val, 
                   int write, void *arg)
{
  int regnum = ia64_uw2gdb_regnum (uw_regnum);
  
  if (write)
    regcache_cooked_write (current_regcache, regnum, (char *) val);
  else
    regcache_cooked_read (current_regcache, regnum, (char *) val);
  return 0;
}

/* Libunwind callback accessor function for accessing memory.  */
static int
ia64_access_mem (unw_addr_space_t as,
                 unw_word_t addr, unw_word_t *val,
                 int write, void *arg)
{
  /* XXX do we need to normalize byte-order here?  */
  if (write)
    return target_write_memory (addr, (char *) val, sizeof (unw_word_t));
  else
    return target_read_memory (addr, (char *) val, sizeof (unw_word_t));
}

/* Call low-level function to access the kernel unwind table.  */
static int
getunwind_table (void *buf, size_t len)
{
  LONGEST x;
  x = target_read_partial (&current_target, TARGET_OBJECT_UNWIND_TABLE, NULL,
                           buf, 0, len);

  return (int)x;
}
        
/* Get the kernel unwind table.  */                              
static int
get_kernel_table (unw_word_t ip, unw_dyn_info_t *di)
{
  size_t size;
  struct ia64_table_entry
  {
    uint64_t start_offset;
    uint64_t end_offset;
    uint64_t info_offset;
  };
  static struct ia64_table_entry *ktab = NULL, *etab;

  if (!ktab)
    {
      size = getunwind_table (NULL, 0);
      if ((int)size < 0)
        return -UNW_ENOINFO;
      ktab = xmalloc (size);
      getunwind_table (ktab, size);
  
      /* Determine length of kernel's unwind table and relocate
         it's entries.  */
      for (etab = ktab; etab->start_offset; ++etab)
        etab->info_offset += (uint64_t) ktab;
    }
  
  if (ip < ktab[0].start_offset || ip >= etab[-1].end_offset)
    return -UNW_ENOINFO;
  
  di->format = UNW_INFO_FORMAT_TABLE;
  di->gp = 0;
  di->start_ip = ktab[0].start_offset;
  di->end_ip = etab[-1].end_offset;
  di->u.ti.name_ptr = (unw_word_t) "<kernel>";
  di->u.ti.segbase = 0;
  di->u.ti.table_len = ((char *) etab - (char *) ktab) / sizeof (unw_word_t);
  di->u.ti.table_data = (unw_word_t *) ktab;
  
  if (gdbarch_debug >= 1)
    fprintf_unfiltered (gdb_stdlog, "get_kernel_table: found table `%s': "
                        "segbase=%lx, length=%lu, gp=%lx\n",
                        (char *) di->u.ti.name_ptr, di->u.ti.segbase, 
                        di->u.ti.table_len, di->gp);
  return 0;
}

/* Find the unwind table entry for a specified address.  */
static int
ia64_find_unwind_table (struct objfile *objfile, unw_word_t ip,
                        unw_dyn_info_t *dip, void **buf)
{
  Elf_Internal_Phdr *phdr, *p_text = NULL, *p_unwind = NULL;
  Elf_Internal_Ehdr *ehdr;
  unw_word_t segbase = 0;
  CORE_ADDR load_base;
  bfd *bfd;
  int i;

  bfd = objfile->obfd;
  
  ehdr = elf_tdata (bfd)->elf_header;
  phdr = elf_tdata (bfd)->phdr;

  load_base = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));

  for (i = 0; i < ehdr->e_phnum; ++i)
    {
      switch (phdr[i].p_type)
        {
        case PT_LOAD:
          if ((unw_word_t) (ip - load_base - phdr[i].p_vaddr)
              < phdr[i].p_memsz)
            p_text = phdr + i;
          break;

        case PT_IA_64_UNWIND:
          p_unwind = phdr + i;
          break;

        default:
          break;
        }
    }

  if (!p_text || !p_unwind
      /* Verify that the segment that contains the IP also contains
         the static unwind table.  If not, we are dealing with
         runtime-generated code, for which we have no info here.  */
      || (p_unwind->p_vaddr - p_text->p_vaddr) >= p_text->p_memsz)
    return -UNW_ENOINFO;

  segbase = p_text->p_vaddr + load_base;

  dip->start_ip = segbase;
  dip->end_ip = dip->start_ip + p_text->p_memsz;
  dip->gp = FIND_GLOBAL_POINTER (ip);
  dip->format = UNW_INFO_FORMAT_TABLE;
  dip->u.ti.name_ptr = (unw_word_t) bfd_get_filename (bfd);
  dip->u.ti.segbase = segbase;
  dip->u.ti.table_len = p_unwind->p_memsz / sizeof (unw_word_t);

  /* The following can happen in corner cases where dynamically
     generated code falls into the same page that contains the
     data-segment and the page-offset of the code is within the first
     page of the executable.  */
  if (ip < dip->start_ip || ip >= dip->end_ip)
    return -UNW_ENOINFO;

  /* Read in the libunwind table.  */
  *buf = xmalloc (p_unwind->p_memsz);
  target_read_memory (p_unwind->p_vaddr + load_base, (char *)(*buf), p_unwind->p_memsz);

  dip->u.ti.table_data = (unw_word_t *)(*buf);

  return 0;
}

/* Libunwind callback accessor function to acquire procedure unwind-info.  */
static int
ia64_find_proc_info_x (unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi,
                       int need_unwind_info, void *arg)
{
  struct obj_section *sec = find_pc_section (ip);
  unw_dyn_info_t di;
  int ret;
  void *buf = NULL;

  if (!sec)
    {
      /* XXX This only works if the host and the target architecture are
         both ia64 and if the have (more or less) the same kernel
         version.  */
      if (get_kernel_table (ip, &di) < 0)
        return -UNW_ENOINFO;
    }
  else
    {
      ret = ia64_find_unwind_table (sec->objfile, ip, &di, &buf);
      if (ret < 0)
        return ret;
    }

  if (gdbarch_debug >= 1)
    fprintf_unfiltered (gdb_stdlog, "acquire_unwind_info: %lx -> "
                        "(name=`%s',segbase=%lx,start=%lx,end=%lx,gp=%lx,"
                        "length=%lu,data=%p)\n", ip, (char *)di.u.ti.name_ptr,
                        di.u.ti.segbase, di.start_ip, di.end_ip,
                        di.gp, di.u.ti.table_len, di.u.ti.table_data);

  ret = libunwind_search_unwind_table (&as, ip, &di, pi, need_unwind_info, arg);

  /* We no longer need the dyn info storage so free it.  */
  xfree (buf);

  return ret;
}

/* Libunwind callback accessor function for cleanup.  */
static void
ia64_put_unwind_info (unw_addr_space_t as,
                      unw_proc_info_t *pip, void *arg)
{
  /* Nothing required for now.  */
}

/* Libunwind callback accessor function to get head of the dynamic 
   unwind-info registration list.  */ 
static int
ia64_get_dyn_info_list (unw_addr_space_t as,
                        unw_word_t *dilap, void *arg)
{
  struct obj_section *text_sec;
  struct objfile *objfile;
  unw_word_t ip, addr;
  unw_dyn_info_t di;
  int ret;

  if (!libunwind_is_initialized ())
    return -UNW_ENOINFO;

  for (objfile = object_files; objfile; objfile = objfile->next)
    {
      void *buf = NULL;

      text_sec = objfile->sections + SECT_OFF_TEXT (objfile);
      ip = text_sec->addr;
      ret = ia64_find_unwind_table (objfile, ip, &di, &buf);
      if (ret >= 0)
        {
          addr = libunwind_find_dyn_list (as, di.u.ti.table_data,
                                          (di.u.ti.table_len
                                           * sizeof (di.u.ti.table_data[0])),
                                          di.u.ti.segbase, di.gp, arg);
          /* We no longer need the dyn info storage so free it.  */
          xfree (buf);

          if (addr)
            {
              if (gdbarch_debug >= 1)
                fprintf_unfiltered (gdb_stdlog,
                                    "dynamic unwind table in objfile %s "
                                    "at %lx (gp=%lx)\n",
                                    bfd_get_filename (objfile->obfd),
                                    addr, di.gp);
              *dilap = addr;
              return 0;
            }
        }
    }
  return -UNW_ENOINFO;
}


/* Frame interface functions for libunwind.  */

static void
ia64_libunwind_frame_this_id (struct frame_info *next_frame, void **this_cache,
                      struct frame_id *this_id)
{
  char buf[8];
  CORE_ADDR bsp;
  struct frame_id id;

  libunwind_frame_this_id (next_frame, this_cache, &id);

  /* We must add the bsp as the special address for frame comparison purposes.  */
  frame_unwind_register (next_frame, IA64_BSP_REGNUM, buf);
  bsp = extract_unsigned_integer (buf, 8);

  (*this_id) = frame_id_build_special (id.stack_addr, id.code_addr, bsp);

  if (gdbarch_debug >= 1)
    fprintf_unfiltered (gdb_stdlog,
                        "libunwind frame id: code %lx, stack %lx, special %lx, next_frame %p\n",
                        id.code_addr, id.stack_addr, bsp, next_frame);
}

static void
ia64_libunwind_frame_prev_register (struct frame_info *next_frame,
                                    void **this_cache,
                                    int regnum, int *optimizedp,
                                    enum lval_type *lvalp, CORE_ADDR *addrp,
                                    int *realnump, void *valuep)
{
  int reg = regnum;

  if (VP0_REGNUM <= regnum && regnum <= VP63_REGNUM)
    reg = IA64_PR_REGNUM;
  else if (IA64_NAT0_REGNUM <= regnum && regnum <= IA64_NAT127_REGNUM)
    reg = IA64_UNAT_REGNUM;

  /* Let libunwind do most of the work.  */
  libunwind_frame_prev_register (next_frame, this_cache, reg,
                                 optimizedp, lvalp, addrp, realnump, valuep);

  if (VP0_REGNUM <= regnum && regnum <= VP63_REGNUM)
    {
      ULONGEST prN_val;

      if (VP16_REGNUM <= regnum && regnum <= VP63_REGNUM)
        {
          int rrb_pr = 0;
          ULONGEST cfm;
          unsigned char buf[MAX_REGISTER_SIZE];

          /* Fetch predicate register rename base from current frame
             marker for this frame.  */
          frame_unwind_register (next_frame, IA64_CFM_REGNUM, buf);
          cfm = extract_unsigned_integer (buf, 8); 
          rrb_pr = (cfm >> 32) & 0x3f;
          
          /* Adjust the register number to account for register rotation.  */
          regnum = VP16_REGNUM 
            + ((regnum - VP16_REGNUM) + rrb_pr) % 48;
        }
      prN_val = extract_bit_field ((unsigned char *) valuep,
                                   regnum - VP0_REGNUM, 1);
      store_unsigned_integer (valuep, register_size (current_gdbarch, regnum), prN_val);
    }
  else if (IA64_NAT0_REGNUM <= regnum && regnum <= IA64_NAT127_REGNUM)
    {
      ULONGEST unatN_val;

      unatN_val = extract_bit_field ((unsigned char *) valuep,
                                   regnum - IA64_NAT0_REGNUM, 1);
      store_unsigned_integer (valuep, register_size (current_gdbarch, regnum), 
                              unatN_val);
    }
  else if (regnum == IA64_BSP_REGNUM)
    {
      char cfm_valuep[MAX_REGISTER_SIZE];
      int  cfm_optim;
      int  cfm_realnum;
      enum lval_type cfm_lval;
      CORE_ADDR cfm_addr;
      CORE_ADDR bsp, prev_cfm, prev_bsp;

      /* We want to calculate the previous bsp as the end of the previous register stack frame.
         This corresponds to what the hardware bsp register will be if we pop the frame
         back which is why we might have been called.  We know that libunwind will pass us back
         the beginning of the current frame so we should just add sof to it. */
      prev_bsp = extract_unsigned_integer (valuep, 8);
      libunwind_frame_prev_register (next_frame, this_cache, IA64_CFM_REGNUM,
                                     &cfm_optim, &cfm_lval, &cfm_addr, &cfm_realnum, cfm_valuep);
      prev_cfm = extract_unsigned_integer (cfm_valuep, 8);
      prev_bsp = rse_address_add (prev_bsp, (prev_cfm & 0x7f));

      store_unsigned_integer (valuep, register_size (current_gdbarch, regnum), 
                              prev_bsp);
    }

  if (gdbarch_debug >= 1)
    fprintf_unfiltered (gdb_stdlog,
                        "libunwind prev register <%s> is %lx\n",
                        (((unsigned) regnum <= IA64_NAT127_REGNUM)
                         ? ia64_register_names[regnum] : "r??"), extract_unsigned_integer (valuep, 8));
}

static const struct frame_unwind ia64_libunwind_frame_unwind =
{
  NORMAL_FRAME,
  ia64_libunwind_frame_this_id,
  ia64_libunwind_frame_prev_register
};

static const struct frame_unwind *
ia64_libunwind_frame_sniffer (struct frame_info *next_frame)
{
  if (libunwind_is_initialized () && libunwind_frame_sniffer (next_frame))
    return &ia64_libunwind_frame_unwind;

  return NULL;
}

/* Set of libunwind callback acccessor functions.  */
static unw_accessors_t ia64_unw_accessors =
{
  ia64_find_proc_info_x,
  ia64_put_unwind_info,
  ia64_get_dyn_info_list,
  ia64_access_mem,
  ia64_access_reg,
  ia64_access_fpreg,
  /* resume */
  /* get_proc_name */
};

/* Set of ia64 gdb libunwind-frame callbacks and data for generic libunwind-frame code to use.  */
static struct libunwind_descr ia64_libunwind_descr =
{
  ia64_gdb2uw_regnum, 
  ia64_uw2gdb_regnum, 
  ia64_is_fpreg, 
  &ia64_unw_accessors,
};

#endif /* HAVE_LIBUNWIND_IA64_H  */

/* Should we use EXTRACT_STRUCT_VALUE_ADDRESS instead of
   EXTRACT_RETURN_VALUE?  GCC_P is true if compiled with gcc
   and TYPE is the type (which is known to be struct, union or array).  */
int
ia64_use_struct_convention (int gcc_p, struct type *type)
{
  struct type *float_elt_type;

  /* HFAs are structures (or arrays) consisting entirely of floating
     point values of the same length.  Up to 8 of these are returned
     in registers.  Don't use the struct convention when this is the
     case.  */
  float_elt_type = is_float_or_hfa_type (type);
  if (float_elt_type != NULL
      && TYPE_LENGTH (type) / TYPE_LENGTH (float_elt_type) <= 8)
    return 0;

  /* Other structs of length 32 or less are returned in r8-r11.
     Don't use the struct convention for those either.  */
  return TYPE_LENGTH (type) > 32;
}

void
ia64_extract_return_value (struct type *type, struct regcache *regcache, void *valbuf)
{
  struct type *float_elt_type;

  float_elt_type = is_float_or_hfa_type (type);
  if (float_elt_type != NULL)
    {
      char from[MAX_REGISTER_SIZE];
      int offset = 0;
      int regnum = IA64_FR8_REGNUM;
      int n = TYPE_LENGTH (type) / TYPE_LENGTH (float_elt_type);

      while (n-- > 0)
        {
          regcache_cooked_read (regcache, regnum, from);
          convert_typed_floating (from, builtin_type_ia64_ext,
                                  (char *)valbuf + offset, float_elt_type);       
          offset += TYPE_LENGTH (float_elt_type);
          regnum++;
        }
    }
  else
    {
      ULONGEST val;
      int offset = 0;
      int regnum = IA64_GR8_REGNUM;
      int reglen = TYPE_LENGTH (ia64_register_type (NULL, IA64_GR8_REGNUM));
      int n = TYPE_LENGTH (type) / reglen;
      int m = TYPE_LENGTH (type) % reglen;

      while (n-- > 0)
        {
          ULONGEST val;
          regcache_cooked_read_unsigned (regcache, regnum, &val);
          memcpy ((char *)valbuf + offset, &val, reglen);
          offset += reglen;
          regnum++;
        }

      if (m)
        {
          regcache_cooked_read_unsigned (regcache, regnum, &val);
          memcpy ((char *)valbuf + offset, &val, m);
        }
    }
}

CORE_ADDR
ia64_extract_struct_value_address (struct regcache *regcache)
{
  error ("ia64_extract_struct_value_address called and cannot get struct value address");
  return 0;
}


static int
is_float_or_hfa_type_recurse (struct type *t, struct type **etp)
{
  switch (TYPE_CODE (t))
    {
    case TYPE_CODE_FLT:
      if (*etp)
        return TYPE_LENGTH (*etp) == TYPE_LENGTH (t);
      else
        {
          *etp = t;
          return 1;
        }
      break;
    case TYPE_CODE_ARRAY:
      return
        is_float_or_hfa_type_recurse (check_typedef (TYPE_TARGET_TYPE (t)),
                                      etp);
      break;
    case TYPE_CODE_STRUCT:
      {
        int i;

        for (i = 0; i < TYPE_NFIELDS (t); i++)
          if (!is_float_or_hfa_type_recurse
              (check_typedef (TYPE_FIELD_TYPE (t, i)), etp))
            return 0;
        return 1;
      }
      break;
    default:
      return 0;
      break;
    }
}

/* Determine if the given type is one of the floating point types or
   and HFA (which is a struct, array, or combination thereof whose
   bottom-most elements are all of the same floating point type).  */

static struct type *
is_float_or_hfa_type (struct type *t)
{
  struct type *et = 0;

  return is_float_or_hfa_type_recurse (t, &et) ? et : 0;
}


/* Return 1 if the alignment of T is such that the next even slot
   should be used.  Return 0, if the next available slot should
   be used.  (See section 8.5.1 of the IA-64 Software Conventions
   and Runtime manual).  */

static int
slot_alignment_is_next_even (struct type *t)
{
  switch (TYPE_CODE (t))
    {
    case TYPE_CODE_INT:
    case TYPE_CODE_FLT:
      if (TYPE_LENGTH (t) > 8)
        return 1;
      else
        return 0;
    case TYPE_CODE_ARRAY:
      return
        slot_alignment_is_next_even (check_typedef (TYPE_TARGET_TYPE (t)));
    case TYPE_CODE_STRUCT:
      {
        int i;

        for (i = 0; i < TYPE_NFIELDS (t); i++)
          if (slot_alignment_is_next_even
              (check_typedef (TYPE_FIELD_TYPE (t, i))))
            return 1;
        return 0;
      }
    default:
      return 0;
    }
}

/* Attempt to find (and return) the global pointer for the given
   function.

   This is a rather nasty bit of code searchs for the .dynamic section
   in the objfile corresponding to the pc of the function we're trying
   to call.  Once it finds the addresses at which the .dynamic section
   lives in the child process, it scans the Elf64_Dyn entries for a
   DT_PLTGOT tag.  If it finds one of these, the corresponding
   d_un.d_ptr value is the global pointer.  */

static CORE_ADDR
generic_elf_find_global_pointer (CORE_ADDR faddr)
{
  struct obj_section *faddr_sect;
     
  faddr_sect = find_pc_section (faddr);
  if (faddr_sect != NULL)
    {
      struct obj_section *osect;

      ALL_OBJFILE_OSECTIONS (faddr_sect->objfile, osect)
        {
          if (strcmp (osect->the_bfd_section->name, ".dynamic") == 0)
            break;
        }

      if (osect < faddr_sect->objfile->sections_end)
        {
          CORE_ADDR addr;

          addr = osect->addr;
          while (addr < osect->endaddr)
            {
              int status;
              LONGEST tag;
              char buf[8];

              status = target_read_memory (addr, buf, sizeof (buf));
              if (status != 0)
                break;
              tag = extract_signed_integer (buf, sizeof (buf));

              if (tag == DT_PLTGOT)
                {
                  CORE_ADDR global_pointer;

                  status = target_read_memory (addr + 8, buf, sizeof (buf));
                  if (status != 0)
                    break;
                  global_pointer = extract_unsigned_integer (buf, sizeof (buf));

                  /* The payoff... */
                  return global_pointer;
                }

              if (tag == DT_NULL)
                break;

              addr += 16;
            }
        }
    }
  return 0;
}

/* Given a function's address, attempt to find (and return) the
   corresponding (canonical) function descriptor.  Return 0 if
   not found.  */
static CORE_ADDR
find_extant_func_descr (CORE_ADDR faddr)
{
  struct obj_section *faddr_sect;

  /* Return early if faddr is already a function descriptor.  */
  faddr_sect = find_pc_section (faddr);
  if (faddr_sect && strcmp (faddr_sect->the_bfd_section->name, ".opd") == 0)
    return faddr;

  if (faddr_sect != NULL)
    {
      struct obj_section *osect;
      ALL_OBJFILE_OSECTIONS (faddr_sect->objfile, osect)
        {
          if (strcmp (osect->the_bfd_section->name, ".opd") == 0)
            break;
        }

      if (osect < faddr_sect->objfile->sections_end)
        {
          CORE_ADDR addr;

          addr = osect->addr;
          while (addr < osect->endaddr)
            {
              int status;
              LONGEST faddr2;
              char buf[8];

              status = target_read_memory (addr, buf, sizeof (buf));
              if (status != 0)
                break;
              faddr2 = extract_signed_integer (buf, sizeof (buf));

              if (faddr == faddr2)
                return addr;

              addr += 16;
            }
        }
    }
  return 0;
}

/* Attempt to find a function descriptor corresponding to the
   given address.  If none is found, construct one on the
   stack using the address at fdaptr.  */

static CORE_ADDR
find_func_descr (CORE_ADDR faddr, CORE_ADDR *fdaptr)
{
  CORE_ADDR fdesc;

  fdesc = find_extant_func_descr (faddr);

  if (fdesc == 0)
    {
      CORE_ADDR global_pointer;
      char buf[16];

      fdesc = *fdaptr;
      *fdaptr += 16;

      global_pointer = FIND_GLOBAL_POINTER (faddr);

      if (global_pointer == 0)
        global_pointer = read_register (IA64_GR1_REGNUM);

      store_unsigned_integer (buf, 8, faddr);
      store_unsigned_integer (buf + 8, 8, global_pointer);

      write_memory (fdesc, buf, 16);
    }

  return fdesc; 
}

/* Use the following routine when printing out function pointers
   so the user can see the function address rather than just the
   function descriptor.  */
static CORE_ADDR
ia64_convert_from_func_ptr_addr (struct gdbarch *gdbarch, CORE_ADDR addr,
                                 struct target_ops *targ)
{
  struct obj_section *s;

  s = find_pc_section (addr);

  /* check if ADDR points to a function descriptor.  */
  if (s && strcmp (s->the_bfd_section->name, ".opd") == 0)
    return read_memory_unsigned_integer (addr, 8);

  return addr;
}

static CORE_ADDR
ia64_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp)
{
  return sp & ~0xfLL;
}

static CORE_ADDR
ia64_push_dummy_call (struct gdbarch *gdbarch, CORE_ADDR func_addr, 
                      struct regcache *regcache, CORE_ADDR bp_addr,
                      int nargs, struct value **args, CORE_ADDR sp,
                      int struct_return, CORE_ADDR struct_addr)
{
  int argno;
  struct value *arg;
  struct type *type;
  int len, argoffset;
  int nslots, rseslots, memslots, slotnum, nfuncargs;
  int floatreg;
  CORE_ADDR bsp, cfm, pfs, new_bsp, funcdescaddr, pc, global_pointer;

  nslots = 0;
  nfuncargs = 0;
  /* Count the number of slots needed for the arguments.  */
  for (argno = 0; argno < nargs; argno++)
    {
      arg = args[argno];
      type = check_typedef (VALUE_TYPE (arg));
      len = TYPE_LENGTH (type);

      if ((nslots & 1) && slot_alignment_is_next_even (type))
        nslots++;

      if (TYPE_CODE (type) == TYPE_CODE_FUNC)
        nfuncargs++;

      nslots += (len + 7) / 8;
    }

  /* Divvy up the slots between the RSE and the memory stack.  */
  rseslots = (nslots > 8) ? 8 : nslots;
  memslots = nslots - rseslots;

  /* Allocate a new RSE frame.  */
  cfm = read_register (IA64_CFM_REGNUM);

  bsp = read_register (IA64_BSP_REGNUM);
  new_bsp = rse_address_add (bsp, rseslots);
  write_register (IA64_BSP_REGNUM, new_bsp);

  pfs = read_register (IA64_PFS_REGNUM);
  pfs &= 0xc000000000000000LL;
  pfs |= (cfm & 0xffffffffffffLL);
  write_register (IA64_PFS_REGNUM, pfs);

  cfm &= 0xc000000000000000LL;
  cfm |= rseslots;
  write_register (IA64_CFM_REGNUM, cfm);
  
  /* We will attempt to find function descriptors in the .opd segment,
     but if we can't we'll construct them ourselves.  That being the
     case, we'll need to reserve space on the stack for them.  */
  funcdescaddr = sp - nfuncargs * 16;
  funcdescaddr &= ~0xfLL;

  /* Adjust the stack pointer to it's new value.  The calling conventions
     require us to have 16 bytes of scratch, plus whatever space is
     necessary for the memory slots and our function descriptors.  */
  sp = sp - 16 - (memslots + nfuncargs) * 8;
  sp &= ~0xfLL;                         /* Maintain 16 byte alignment.  */

  /* Place the arguments where they belong.  The arguments will be
     either placed in the RSE backing store or on the memory stack.
     In addition, floating point arguments or HFAs are placed in
     floating point registers.  */
  slotnum = 0;
  floatreg = IA64_FR8_REGNUM;
  for (argno = 0; argno < nargs; argno++)
    {
      struct type *float_elt_type;

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

      /* Special handling for function parameters.  */
      if (len == 8 
          && TYPE_CODE (type) == TYPE_CODE_PTR 
          && TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_FUNC)
        {
          char val_buf[8];

          store_unsigned_integer (val_buf, 8,
                                  find_func_descr (extract_unsigned_integer (VALUE_CONTENTS (arg), 8),
                                                   &funcdescaddr));
          if (slotnum < rseslots)
            write_memory (rse_address_add (bsp, slotnum), val_buf, 8);
          else
            write_memory (sp + 16 + 8 * (slotnum - rseslots), val_buf, 8);
          slotnum++;
          continue;
        }

      /* Normal slots.  */

      /* Skip odd slot if necessary...  */
      if ((slotnum & 1) && slot_alignment_is_next_even (type))
        slotnum++;

      argoffset = 0;
      while (len > 0)
        {
          char val_buf[8];

          memset (val_buf, 0, 8);
          memcpy (val_buf, VALUE_CONTENTS (arg) + argoffset, (len > 8) ? 8 : len);

          if (slotnum < rseslots)
            write_memory (rse_address_add (bsp, slotnum), val_buf, 8);
          else
            write_memory (sp + 16 + 8 * (slotnum - rseslots), val_buf, 8);

          argoffset += 8;
          len -= 8;
          slotnum++;
        }

      /* Handle floating point types (including HFAs).  */
      float_elt_type = is_float_or_hfa_type (type);
      if (float_elt_type != NULL)
        {
          argoffset = 0;
          len = TYPE_LENGTH (type);
          while (len > 0 && floatreg < IA64_FR16_REGNUM)
            {
              char to[MAX_REGISTER_SIZE];
              convert_typed_floating (VALUE_CONTENTS (arg) + argoffset, float_elt_type,
                                      to, builtin_type_ia64_ext);
              regcache_cooked_write (regcache, floatreg, (void *)to);
              floatreg++;
              argoffset += TYPE_LENGTH (float_elt_type);
              len -= TYPE_LENGTH (float_elt_type);
            }
        }
    }

  /* Store the struct return value in r8 if necessary.  */
  if (struct_return)
    {
      regcache_cooked_write_unsigned (regcache, IA64_GR8_REGNUM, (ULONGEST)struct_addr);
    }

  global_pointer = FIND_GLOBAL_POINTER (func_addr);

  if (global_pointer != 0)
    write_register (IA64_GR1_REGNUM, global_pointer);

  write_register (IA64_BR0_REGNUM, bp_addr);

  write_register (sp_regnum, sp);

  return sp;
}

static struct frame_id
ia64_unwind_dummy_id (struct gdbarch *gdbarch, struct frame_info *next_frame)
{
  char buf[8];
  CORE_ADDR sp, bsp;

  frame_unwind_register (next_frame, sp_regnum, buf);
  sp = extract_unsigned_integer (buf, 8);

  frame_unwind_register (next_frame, IA64_BSP_REGNUM, buf);
  bsp = extract_unsigned_integer (buf, 8);

  if (gdbarch_debug >= 1)
    fprintf_unfiltered (gdb_stdlog,
                        "dummy frame id: code %lx, stack %lx, special %lx\n",
                        frame_pc_unwind (next_frame), sp, bsp);

  return frame_id_build_special (sp, frame_pc_unwind (next_frame), bsp);
}

static CORE_ADDR 
ia64_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
{
  char buf[8];
  CORE_ADDR ip, psr, pc;

  frame_unwind_register (next_frame, IA64_IP_REGNUM, buf);
  ip = extract_unsigned_integer (buf, 8);
  frame_unwind_register (next_frame, IA64_PSR_REGNUM, buf);
  psr = extract_unsigned_integer (buf, 8);
 
  pc = (ip & ~0xf) | ((psr >> 41) & 3);
  return pc;
}

static void
ia64_store_return_value (struct type *type, struct regcache *regcache, const void *valbuf)
{
  if (TYPE_CODE (type) == TYPE_CODE_FLT)
    {
      char to[MAX_REGISTER_SIZE];
      convert_typed_floating (valbuf, type, to, builtin_type_ia64_ext);
      regcache_cooked_write (regcache, IA64_FR8_REGNUM, (void *)to);
      target_store_registers (IA64_FR8_REGNUM);
    }
  else
    regcache_cooked_write (regcache, IA64_GR8_REGNUM, valbuf);
}

static void
ia64_remote_translate_xfer_address (struct gdbarch *gdbarch,
                                    struct regcache *regcache,
                                    CORE_ADDR memaddr, int nr_bytes,
                                    CORE_ADDR *targ_addr, int *targ_len)
{
  *targ_addr = memaddr;
  *targ_len  = nr_bytes;
}

static void
process_note_abi_tag_sections (bfd *abfd, asection *sect, void *obj)
{
  int *os_ident_ptr = obj;
  const char *name;
  unsigned int sectsize;

  name = bfd_get_section_name (abfd, sect);
  sectsize = bfd_section_size (abfd, sect);
  if (strcmp (name, ".note.ABI-tag") == 0 && sectsize > 0)
    {
      unsigned int name_length, data_length, note_type;
      char *note = alloca (sectsize);

      bfd_get_section_contents (abfd, sect, note,
                                (file_ptr) 0, (bfd_size_type) sectsize);

      name_length = bfd_h_get_32 (abfd, note);
      data_length = bfd_h_get_32 (abfd, note + 4);
      note_type   = bfd_h_get_32 (abfd, note + 8);

      if (name_length == 4 && data_length == 16 && note_type == 1
          && strcmp (note + 12, "GNU") == 0)
        {
          int os_number = bfd_h_get_32 (abfd, note + 16);

          /* The case numbers are from abi-tags in glibc.  */
          switch (os_number)
            {
            case 0 :
              *os_ident_ptr = ELFOSABI_LINUX;
              break;
            case 1 :
              *os_ident_ptr = ELFOSABI_HURD;
              break;
            case 2 :
              *os_ident_ptr = ELFOSABI_SOLARIS;
              break;
            default :
              internal_error (__FILE__, __LINE__,
                              "process_note_abi_sections: unknown OS number %d", os_number);
              break;
            }
        }
    }
}

static int
ia64_print_insn (bfd_vma memaddr, struct disassemble_info *info)
{
  info->bytes_per_line = SLOT_MULTIPLIER;
  return print_insn_ia64 (memaddr, info);
}

static struct gdbarch *
ia64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
{
  struct gdbarch *gdbarch;
  struct gdbarch_tdep *tdep;

  /* If there is already a candidate, use it.  */
  arches = gdbarch_list_lookup_by_info (arches, &info);
  if (arches != NULL)
    return arches->gdbarch;

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

  /* Set the method of obtaining the sigcontext addresses at which
     registers are saved.  The method of checking to see if
     native_find_global_pointer is nonzero to indicate that we're
     on AIX is kind of hokey, but I can't think of a better way
     to do it.  */
  if (info.osabi == GDB_OSABI_LINUX)
    tdep->sigcontext_register_address = ia64_linux_sigcontext_register_address;
  else if (native_find_global_pointer != 0)
    tdep->sigcontext_register_address = ia64_aix_sigcontext_register_address;
  else
    tdep->sigcontext_register_address = 0;

  /* We know that GNU/Linux won't have to resort to the
     native_find_global_pointer hackery.  But that's the only one we
     know about so far, so if native_find_global_pointer is set to
     something non-zero, then use it.  Otherwise fall back to using
     generic_elf_find_global_pointer.  This arrangement should (in
     theory) allow us to cross debug GNU/Linux binaries from an AIX
     machine.  */
  if (info.osabi == GDB_OSABI_LINUX)
    tdep->find_global_pointer = generic_elf_find_global_pointer;
  else if (native_find_global_pointer != 0)
    tdep->find_global_pointer = native_find_global_pointer;
  else
    tdep->find_global_pointer = generic_elf_find_global_pointer;

  /* Define the ia64 floating-point format to gdb.  */
  builtin_type_ia64_ext =
    init_type (TYPE_CODE_FLT, 128 / 8,
               0, "builtin_type_ia64_ext", NULL);
  TYPE_FLOATFORMAT (builtin_type_ia64_ext) = &floatformat_ia64_ext;

  /* According to the ia64 specs, instructions that store long double floats 
     in memory use a long-double format different than that used in the floating
     registers.  The memory format matches the x86 extended float format which is
     80 bits.  An OS may choose to use this format (e.g. Linux) or choose to use
     a different format for storing long doubles (e.g. HPUX).  In the latter case,
     the setting of the format may be moved/overridden in an OS-specific tdep file.  */
  set_gdbarch_long_double_format (gdbarch, &floatformat_i387_ext);

  set_gdbarch_short_bit (gdbarch, 16);
  set_gdbarch_int_bit (gdbarch, 32);
  set_gdbarch_long_bit (gdbarch, 64);
  set_gdbarch_long_long_bit (gdbarch, 64);
  set_gdbarch_float_bit (gdbarch, 32);
  set_gdbarch_double_bit (gdbarch, 64);
  set_gdbarch_long_double_bit (gdbarch, 128);
  set_gdbarch_ptr_bit (gdbarch, 64);

  set_gdbarch_num_regs (gdbarch, NUM_IA64_RAW_REGS);
  set_gdbarch_num_pseudo_regs (gdbarch, LAST_PSEUDO_REGNUM - FIRST_PSEUDO_REGNUM);
  set_gdbarch_sp_regnum (gdbarch, sp_regnum);
  set_gdbarch_fp0_regnum (gdbarch, IA64_FR0_REGNUM);

  set_gdbarch_register_name (gdbarch, ia64_register_name);
  /* FIXME:  Following interface should not be needed, however, without it recurse.exp
     gets a number of extra failures.  */
  set_gdbarch_deprecated_register_size (gdbarch, 8);
  set_gdbarch_register_type (gdbarch, ia64_register_type);

  set_gdbarch_pseudo_register_read (gdbarch, ia64_pseudo_register_read);
  set_gdbarch_pseudo_register_write (gdbarch, ia64_pseudo_register_write);
  set_gdbarch_dwarf2_reg_to_regnum (gdbarch, ia64_dwarf_reg_to_regnum);
  set_gdbarch_register_reggroup_p (gdbarch, ia64_register_reggroup_p);
  set_gdbarch_convert_register_p (gdbarch, ia64_convert_register_p);
  set_gdbarch_register_to_value (gdbarch, ia64_register_to_value);
  set_gdbarch_value_to_register (gdbarch, ia64_value_to_register);

  set_gdbarch_skip_prologue (gdbarch, ia64_skip_prologue);

  set_gdbarch_use_struct_convention (gdbarch, ia64_use_struct_convention);
  set_gdbarch_extract_return_value (gdbarch, ia64_extract_return_value);

  set_gdbarch_store_return_value (gdbarch, ia64_store_return_value);
  set_gdbarch_extract_struct_value_address (gdbarch, ia64_extract_struct_value_address);

  set_gdbarch_memory_insert_breakpoint (gdbarch, ia64_memory_insert_breakpoint);
  set_gdbarch_memory_remove_breakpoint (gdbarch, ia64_memory_remove_breakpoint);
  set_gdbarch_breakpoint_from_pc (gdbarch, ia64_breakpoint_from_pc);
  set_gdbarch_read_pc (gdbarch, ia64_read_pc);
  set_gdbarch_write_pc (gdbarch, ia64_write_pc);

  /* Settings for calling functions in the inferior.  */
  set_gdbarch_push_dummy_call (gdbarch, ia64_push_dummy_call);
  set_gdbarch_frame_align (gdbarch, ia64_frame_align);
  set_gdbarch_unwind_dummy_id (gdbarch, ia64_unwind_dummy_id);

  set_gdbarch_unwind_pc (gdbarch, ia64_unwind_pc);
  frame_unwind_append_sniffer (gdbarch, ia64_sigtramp_frame_sniffer);
#ifdef HAVE_LIBUNWIND_IA64_H
  frame_unwind_append_sniffer (gdbarch, ia64_libunwind_frame_sniffer);
  libunwind_frame_set_descr (gdbarch, &ia64_libunwind_descr);
#endif
  frame_unwind_append_sniffer (gdbarch, ia64_frame_sniffer);
  frame_base_set_default (gdbarch, &ia64_frame_base);

  /* Settings that should be unnecessary.  */
  set_gdbarch_inner_than (gdbarch, core_addr_lessthan);

  set_gdbarch_decr_pc_after_break (gdbarch, 0);
  set_gdbarch_function_start_offset (gdbarch, 0);
  set_gdbarch_frame_args_skip (gdbarch, 0);

  set_gdbarch_remote_translate_xfer_address (
    gdbarch, ia64_remote_translate_xfer_address);

  set_gdbarch_print_insn (gdbarch, ia64_print_insn);
  set_gdbarch_convert_from_func_ptr_addr (gdbarch, ia64_convert_from_func_ptr_addr);

  return gdbarch;
}

extern initialize_file_ftype _initialize_ia64_tdep; /* -Wmissing-prototypes */

void
_initialize_ia64_tdep (void)
{
  register_gdbarch_init (bfd_arch_ia64, ia64_gdbarch_init);
}