[deliverable/binutils-gdb.git] / gdb / sparc64-tdep.c

/* Target-dependent code for UltraSPARC.

   Copyright 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 "arch-utils.h"
#include "floatformat.h"
#include "frame.h"
#include "frame-base.h"
#include "frame-unwind.h"
#include "gdbcore.h"
#include "gdbtypes.h"
#include "osabi.h"
#include "regcache.h"
#include "target.h"
#include "value.h"

#include "gdb_assert.h"
#include "gdb_string.h"

#include "sparc64-tdep.h"

/* This file implements the The SPARC 64-bit ABI as defined by the
   section "Low-Level System Information" of the SPARC Compliance
   Definition (SCD) 2.4.1, which is the 64-bit System V psABI for
   SPARC.  */

/* Please use the sparc32_-prefix for 32-bit specific code, the
   sparc64_-prefix for 64-bit specific code and the sparc_-prefix for
   code can handle both.  */

/* The stack pointer is offset from the stack frame by a BIAS of 2047
   (0x7ff) for 64-bit code.  BIAS is likely to be defined on SPARC
   hosts, so undefine it first.  */
#undef BIAS
#define BIAS 2047

/* Macros to extract fields from SPARC instructions.  */
#define X_OP(i) (((i) >> 30) & 0x3)
#define X_A(i) (((i) >> 29) & 1)
#define X_COND(i) (((i) >> 25) & 0xf)
#define X_OP2(i) (((i) >> 22) & 0x7)
#define X_IMM22(i) ((i) & 0x3fffff)
#define X_OP3(i) (((i) >> 19) & 0x3f)
/* Sign extension macros.  */
#define X_DISP22(i) ((X_IMM22 (i) ^ 0x200000) - 0x200000)
#define X_DISP19(i) ((((i) & 0x7ffff) ^ 0x40000) - 0x40000)

/* Fetch the instruction at PC.  Instructions are always big-endian
   even if the processor operates in little-endian mode.  */

static unsigned long
sparc_fetch_instruction (CORE_ADDR pc)
{
  unsigned char buf[4];
  unsigned long insn;
  int i;

  read_memory (pc, buf, sizeof (buf));

  insn = 0;
  for (i = 0; i < sizeof (buf); i++)
    insn = (insn << 8) | buf[i];
  return insn;
}
\f
/* The functions on this page are intended to be used to classify
   function arguments.  */

/* Return the contents if register REGNUM as an address.  */

static CORE_ADDR
sparc_address_from_register (int regnum)
{
  ULONGEST addr;

  regcache_cooked_read_unsigned (current_regcache, regnum, &addr);
  return addr;
}

/* Check whether TYPE is "Integral or Pointer".  */

static int
sparc64_integral_or_pointer_p (const struct type *type)
{
  switch (TYPE_CODE (type))
    {
    case TYPE_CODE_INT:
    case TYPE_CODE_BOOL:
    case TYPE_CODE_CHAR:
    case TYPE_CODE_ENUM:
    case TYPE_CODE_RANGE:
      {
        int len = TYPE_LENGTH (type);
        gdb_assert (len == 1 || len == 2 || len == 4 || len == 8);
      }
      return 1;
    case TYPE_CODE_PTR:
    case TYPE_CODE_REF:
      {
        int len = TYPE_LENGTH (type);
        gdb_assert (len == 8);
      }
      return 1;
    default:
      break;
    }

  return 0;
}

/* Check whether TYPE is "Floating".  */

static int
sparc64_floating_p (const struct type *type)
{
  switch (TYPE_CODE (type))
    {
    case TYPE_CODE_FLT:
      {
        int len = TYPE_LENGTH (type);
        gdb_assert (len == 4 || len == 8 || len == 16);
      }
      return 1;
    default:
      break;
    }

  return 0;
}

/* Check whether TYPE is "Structure or Union".  */

static int
sparc64_structure_or_union_p (const struct type *type)
{
  switch (TYPE_CODE (type))
    {
    case TYPE_CODE_STRUCT:
    case TYPE_CODE_UNION:
      return 1;
    default:
      break;
    }

  return 0;
}

/* UltraSPARC architecture specific information.  */

struct gdbarch_tdep
{
  /* Offset of saved PC in jmp_buf.  */
  int jb_pc_offset;
};

/* Register information.  */

struct sparc64_register_info
{
  char *name;
  struct type **type;
};

static struct sparc64_register_info sparc64_register_info[] =
{
  { "g0", &builtin_type_int64 },
  { "g1", &builtin_type_int64 },
  { "g2", &builtin_type_int64 },
  { "g3", &builtin_type_int64 },
  { "g4", &builtin_type_int64 },
  { "g5", &builtin_type_int64 },
  { "g6", &builtin_type_int64 },
  { "g7", &builtin_type_int64 },

  { "o0", &builtin_type_int64 },
  { "o1", &builtin_type_int64 },
  { "o2", &builtin_type_int64 },
  { "o3", &builtin_type_int64 },
  { "o4", &builtin_type_int64 },
  { "o5", &builtin_type_int64 },
  { "sp", &builtin_type_void_data_ptr },
  { "o7", &builtin_type_int64 },

  { "l0", &builtin_type_int64 },
  { "l1", &builtin_type_int64 },
  { "l2", &builtin_type_int64 },
  { "l3", &builtin_type_int64 },
  { "l4", &builtin_type_int64 },
  { "l5", &builtin_type_int64 },
  { "l6", &builtin_type_int64 },
  { "l7", &builtin_type_int64 },

  { "i0", &builtin_type_int64 },
  { "i1", &builtin_type_int64 },
  { "i2", &builtin_type_int64 },
  { "i3", &builtin_type_int64 },
  { "i4", &builtin_type_int64 },
  { "i5", &builtin_type_int64 },
  { "fp", &builtin_type_void_data_ptr },
  { "i7", &builtin_type_int64 },

  { "f0", &builtin_type_float },
  { "f1", &builtin_type_float },
  { "f2", &builtin_type_float },
  { "f3", &builtin_type_float },
  { "f4", &builtin_type_float },
  { "f5", &builtin_type_float },
  { "f6", &builtin_type_float },
  { "f7", &builtin_type_float },
  { "f8", &builtin_type_float },
  { "f9", &builtin_type_float },
  { "f10", &builtin_type_float },
  { "f11", &builtin_type_float },
  { "f12", &builtin_type_float },
  { "f13", &builtin_type_float },
  { "f14", &builtin_type_float },
  { "f15", &builtin_type_float },
  { "f16", &builtin_type_float },
  { "f17", &builtin_type_float },
  { "f18", &builtin_type_float },
  { "f19", &builtin_type_float },
  { "f20", &builtin_type_float },
  { "f21", &builtin_type_float },
  { "f22", &builtin_type_float },
  { "f23", &builtin_type_float },
  { "f24", &builtin_type_float },
  { "f25", &builtin_type_float },
  { "f26", &builtin_type_float },
  { "f27", &builtin_type_float },
  { "f28", &builtin_type_float },
  { "f29", &builtin_type_float },
  { "f30", &builtin_type_float },
  { "f31", &builtin_type_float },
  { "f32", &builtin_type_double },
  { "f34", &builtin_type_double },
  { "f36", &builtin_type_double },
  { "f38", &builtin_type_double },
  { "f40", &builtin_type_double },
  { "f42", &builtin_type_double },
  { "f44", &builtin_type_double },
  { "f46", &builtin_type_double },
  { "f48", &builtin_type_double },
  { "f50", &builtin_type_double },
  { "f52", &builtin_type_double },
  { "f54", &builtin_type_double },
  { "f56", &builtin_type_double },
  { "f58", &builtin_type_double },
  { "f60", &builtin_type_double },
  { "f62", &builtin_type_double },

  { "pc", &builtin_type_void_func_ptr },
  { "npc", &builtin_type_void_func_ptr },
  
  /* This raw register contains the contents of %cwp, %pstate, %asi
     and %ccr as laid out in a %tstate register.  */
  { NULL, &builtin_type_int64 },

  { "fsr", &builtin_type_int64 },
  { "fprs", &builtin_type_int64 },

  /* "Although Y is a 64-bit register, its high-order 32 bits are
     reserved and always read as 0."  */
  { "y", &builtin_type_int64 }
};

/* Total number of registers.  */
#define SPARC64_NUM_REGS \
  (sizeof (sparc64_register_info) / sizeof (sparc64_register_info[0]))

/* We provide the aliases %d0..%d62 and %q0..%q60 for the floating
   registers as "psuedo" registers.  */

static struct sparc64_register_info sparc64_pseudo_register_info[] =
{
  { "cwp", &builtin_type_int64 },
  { "pstate", &builtin_type_int64 },
  { "asi", &builtin_type_int64 },
  { "ccr", &builtin_type_int64 },

  { "d0", &builtin_type_double },
  { "d2", &builtin_type_double },
  { "d4", &builtin_type_double },
  { "d6", &builtin_type_double },
  { "d8", &builtin_type_double },
  { "d10", &builtin_type_double },
  { "d12", &builtin_type_double },
  { "d14", &builtin_type_double },
  { "d16", &builtin_type_double },
  { "d18", &builtin_type_double },
  { "d20", &builtin_type_double },
  { "d22", &builtin_type_double },
  { "d24", &builtin_type_double },
  { "d26", &builtin_type_double },
  { "d28", &builtin_type_double },
  { "d30", &builtin_type_double },
  { "d32", &builtin_type_double },
  { "d34", &builtin_type_double },
  { "d36", &builtin_type_double },
  { "d38", &builtin_type_double },
  { "d40", &builtin_type_double },
  { "d42", &builtin_type_double },
  { "d44", &builtin_type_double },
  { "d46", &builtin_type_double },
  { "d48", &builtin_type_double },
  { "d50", &builtin_type_double },
  { "d52", &builtin_type_double },
  { "d54", &builtin_type_double },
  { "d56", &builtin_type_double },
  { "d58", &builtin_type_double },
  { "d60", &builtin_type_double },
  { "d62", &builtin_type_double },

  { "q0", &builtin_type_long_double },
  { "q4", &builtin_type_long_double },
  { "q8", &builtin_type_long_double },
  { "q12", &builtin_type_long_double },
  { "q16", &builtin_type_long_double },
  { "q20", &builtin_type_long_double },
  { "q24", &builtin_type_long_double },
  { "q28", &builtin_type_long_double },
  { "q32", &builtin_type_long_double },
  { "q36", &builtin_type_long_double },
  { "q40", &builtin_type_long_double },
  { "q44", &builtin_type_long_double },
  { "q48", &builtin_type_long_double },
  { "q52", &builtin_type_long_double },
  { "q56", &builtin_type_long_double },
  { "q60", &builtin_type_long_double }
};

/* Total number of pseudo registers.  */
#define SPARC64_NUM_PSEUDO_REGS \
  (sizeof (sparc64_pseudo_register_info) \
   / sizeof (sparc64_pseudo_register_info[0]))

/* Return the name of register REGNUM.  */

static const char *
sparc64_register_name (int regnum)
{
  if (regnum >= 0 && regnum < SPARC64_NUM_REGS)
    return sparc64_register_info[regnum].name;

  if (regnum >= SPARC64_NUM_REGS
      && regnum < SPARC64_NUM_REGS + SPARC64_NUM_PSEUDO_REGS)
    return sparc64_pseudo_register_info[regnum - SPARC64_NUM_REGS].name;

  return NULL;
}

/* Return the GDB type object for the "standard" data type of data in
   register REGNUM. */

static struct type *
sparc64_register_type (struct gdbarch *gdbarch, int regnum)
{
  if (regnum >= SPARC64_NUM_REGS
      && regnum < SPARC64_NUM_REGS + SPARC64_NUM_PSEUDO_REGS)
    return *sparc64_pseudo_register_info[regnum - SPARC64_NUM_REGS].type;

  gdb_assert (regnum >= 0 && regnum < SPARC64_NUM_REGS);
  return *sparc64_register_info[regnum].type;
}

static void
sparc64_pseudo_register_read (struct gdbarch *gdbarch,
                              struct regcache *regcache,
                              int regnum, void *buf)
{
  gdb_assert (regnum >= SPARC64_NUM_REGS);

  if (regnum >= SPARC64_D0_REGNUM && regnum <= SPARC64_D30_REGNUM)
    {
      regnum = SPARC_F0_REGNUM + 2 * (regnum - SPARC64_D0_REGNUM);
      regcache_raw_read (regcache, regnum, buf);
      regcache_raw_read (regcache, regnum + 1, ((char *)buf) + 4);
    }
  else if (regnum >= SPARC64_D32_REGNUM && regnum <= SPARC64_D62_REGNUM)
    {
      regnum = SPARC64_F32_REGNUM + (regnum - SPARC64_D32_REGNUM);
      regcache_raw_read (regcache, regnum, buf);
    }
  else if (regnum >= SPARC64_Q0_REGNUM && regnum <= SPARC64_Q28_REGNUM)
    {
      regnum = SPARC_F0_REGNUM + 4 * (regnum - SPARC64_Q0_REGNUM);
      regcache_raw_read (regcache, regnum, buf);
      regcache_raw_read (regcache, regnum + 1, ((char *)buf) + 4);
      regcache_raw_read (regcache, regnum + 2, ((char *)buf) + 8);
      regcache_raw_read (regcache, regnum + 3, ((char *)buf) + 12);
    }
  else if (regnum >= SPARC64_Q32_REGNUM && regnum <= SPARC64_Q60_REGNUM)
    {
      regnum = SPARC64_F32_REGNUM + 2 * (regnum - SPARC64_Q32_REGNUM);
      regcache_raw_read (regcache, regnum, buf);
      regcache_raw_read (regcache, regnum + 1, ((char *)buf) + 8);
    }
  else if (regnum == SPARC64_CWP_REGNUM
           || regnum == SPARC64_PSTATE_REGNUM
           || regnum == SPARC64_ASI_REGNUM
           || regnum == SPARC64_CCR_REGNUM)
    {
      ULONGEST state;

      regcache_raw_read_unsigned (regcache, SPARC64_STATE_REGNUM, &state);
      switch (regnum)
        {
        SPARC64_CWP_REGNUM:
          state = (state >> 0) & ((1 << 5) - 1);
          break;
        SPARC64_PSTATE_REGNUM:
          state = (state >> 8) & ((1 << 12) - 1);
          break;
        SPARC64_ASI_REGNUM:
          state = (state >> 24) & ((1 << 8) - 1);
          break;
        SPARC64_CCR_REGNUM:
          state = (state >> 32) & ((1 << 8) - 1);
          break;
        }
      store_unsigned_integer (buf, 8, state);
    }
}

static void
sparc64_pseudo_register_write (struct gdbarch *gdbarch,
                               struct regcache *regcache,
                               int regnum, const void *buf)
{
  gdb_assert (regnum >= SPARC64_NUM_REGS);

  if (regnum >= SPARC64_D0_REGNUM && regnum <= SPARC64_D30_REGNUM)
    {
      regnum = SPARC_F0_REGNUM + 2 * (regnum - SPARC64_D0_REGNUM);
      regcache_raw_write (regcache, regnum, buf);
      regcache_raw_write (regcache, regnum + 1, ((const char *)buf) + 4);
    }
  else if (regnum >= SPARC64_D32_REGNUM && regnum <= SPARC64_D62_REGNUM)
    {
      regnum = SPARC64_F32_REGNUM + (regnum - SPARC64_D32_REGNUM);
      regcache_raw_write (regcache, regnum, buf);
    }
  else if (regnum >= SPARC64_Q0_REGNUM && regnum <= SPARC64_Q28_REGNUM)
    {
      regnum = SPARC_F0_REGNUM + 4 * (regnum - SPARC64_Q0_REGNUM);
      regcache_raw_write (regcache, regnum, buf);
      regcache_raw_write (regcache, regnum + 1, ((const char *)buf) + 4);
      regcache_raw_write (regcache, regnum + 2, ((const char *)buf) + 8);
      regcache_raw_write (regcache, regnum + 3, ((const char *)buf) + 12);
    }
  else if (regnum >= SPARC64_Q32_REGNUM && regnum <= SPARC64_Q60_REGNUM)
    {
      regnum = SPARC64_F32_REGNUM + 2 * (regnum - SPARC64_Q32_REGNUM);
      regcache_raw_write (regcache, regnum, buf);
      regcache_raw_write (regcache, regnum + 1, ((const char *)buf) + 8);
    }
}

/* Use the program counter to determine the contents and size of a
   breakpoint instruction.  Return a pointer to a string of bytes that
   encode a breakpoint instruction, store the length of the string in
   *LEN and optionally adjust *PC to point to the correct memory
   location for inserting the breakpoint.  */
   
static const unsigned char *
sparc_breakpoint_from_pc (CORE_ADDR *pc, int *len)
{
  static unsigned char break_insn[] = { 0x91, 0xd0, 0x20, 0x01 };

  *len = sizeof (break_insn);
  return break_insn;
}
\f

struct sparc64_frame_cache
{
  /* Base address.  */
  CORE_ADDR base;
  CORE_ADDR pc;

  /* Do we have a frame?  */
  int frameless_p;
};

/* Allocate and initialize a frame cache.  */

static struct sparc64_frame_cache *
sparc64_alloc_frame_cache (void)
{
  struct sparc64_frame_cache *cache;
  int i;

  cache = FRAME_OBSTACK_ZALLOC (struct sparc64_frame_cache);

  /* Base address.  */
  cache->base = 0;
  cache->pc = 0;

  /* Frameless until proven otherwise.  */
  cache->frameless_p = 1;

  return cache;
}

static CORE_ADDR
sparc64_analyze_prologue (CORE_ADDR pc, CORE_ADDR current_pc,
                          struct sparc64_frame_cache *cache)
{
  unsigned long insn;

  if (current_pc <= pc)
    return current_pc;

  /* Check whether the function starts with a SAVE instruction.  */
  insn = sparc_fetch_instruction (pc);
  if (X_OP (insn) == 2 && X_OP3 (insn) == 0x3c)
    {
      cache->frameless_p = 0;
      return pc + 4;
    }

  return pc;
}

static CORE_ADDR
sparc64_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
{
  return frame_unwind_register_unsigned (next_frame, SPARC64_PC_REGNUM);
}

/* Return PC of first real instruction of the function starting at
   START_PC.  */

static CORE_ADDR
sparc64_skip_prologue (CORE_ADDR start_pc)
{
  struct symtab_and_line sal;
  CORE_ADDR func_start, func_end;
  struct sparc64_frame_cache cache;

  /* This is the preferred method, find the end of the prologue by
     using the debugging information.  */
  if (find_pc_partial_function (start_pc, NULL, &func_start, &func_end))
    {
      sal = find_pc_line (func_start, 0);

      if (sal.end < func_end
          && start_pc <= sal.end)
        return sal.end;
    }

  return sparc64_analyze_prologue (start_pc, 0xffffffffffffffffUL, &cache);
}

/* Normal frames.  */

static struct sparc64_frame_cache *
sparc64_frame_cache (struct frame_info *next_frame, void **this_cache)
{
  struct sparc64_frame_cache *cache;

  if (*this_cache)
    return *this_cache;

  cache = sparc64_alloc_frame_cache ();
  *this_cache = cache;

  /* In priciple, for normal frames, %fp (%i6) holds the frame
     pointer, which holds the base address for the current stack
     frame.  */

  cache->base = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM);
  if (cache->base == 0)
    return cache;

  cache->pc = frame_func_unwind (next_frame);
  if (cache->pc != 0)
    sparc64_analyze_prologue (cache->pc, frame_pc_unwind (next_frame), cache);

  if (cache->frameless_p)
    {
      /* We didn't find a valid frame, which means that CACHE->base
         currently holds the frame pointer for our calling frame.  */
      cache->base = frame_unwind_register_unsigned (next_frame,
                                                    SPARC_SP_REGNUM);
    }

  return cache;
}

static void
sparc64_frame_this_id (struct frame_info *next_frame, void **this_cache,
                       struct frame_id *this_id)
{
  struct sparc64_frame_cache *cache =
    sparc64_frame_cache (next_frame, this_cache);

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

  (*this_id) = frame_id_build (cache->base, cache->pc);
}

static void
sparc64_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 sparc64_frame_cache *cache =
    sparc64_frame_cache (next_frame, this_cache);

  if (regnum == SPARC64_PC_REGNUM || regnum == SPARC64_NPC_REGNUM)
    {
      *optimizedp = 0;
      *lvalp = not_lval;
      *addrp = 0;
      *realnump = -1;
      if (valuep)
        {
          CORE_ADDR pc = (regnum == SPARC64_NPC_REGNUM) ? 4 : 0;

          regnum = cache->frameless_p ? SPARC_O7_REGNUM : SPARC_I7_REGNUM;
          pc += frame_unwind_register_unsigned (next_frame, regnum) + 8;
          store_unsigned_integer (valuep, 8, pc);
        }
      return;
    }

  /* The previous frame's `local' and `in' registers have been saved
     in the register save area.  */
  if (!cache->frameless_p
      && regnum >= SPARC_L0_REGNUM && regnum <= SPARC_I7_REGNUM)
    {
      *optimizedp = 0;
      *lvalp = lval_memory;
      *addrp = cache->base + BIAS + (regnum - SPARC_L0_REGNUM) * 8;
      *realnump = -1;
      if (valuep)
        {
          struct gdbarch *gdbarch = get_frame_arch (next_frame);

          /* Read the value in from memory.  */
          read_memory (*addrp, valuep, register_size (gdbarch, regnum));
        }
      return;
    }

  /* The previous frame's `out' registers are accessable as the
     current frame's `in' registers.  */
  if (!cache->frameless_p
      && regnum >= SPARC_O0_REGNUM && regnum <= SPARC_O7_REGNUM)
    regnum += (SPARC_I0_REGNUM - SPARC_O0_REGNUM);

  frame_register_unwind (next_frame, regnum,
                         optimizedp, lvalp, addrp, realnump, valuep);
}

static const struct frame_unwind sparc64_frame_unwind =
{
  NORMAL_FRAME,
  sparc64_frame_this_id,
  sparc64_frame_prev_register
};

static const struct frame_unwind *
sparc64_frame_sniffer (struct frame_info *next_frame)
{
  return &sparc64_frame_unwind;
}
\f

static CORE_ADDR
sparc64_frame_base_address (struct frame_info *next_frame, void **this_cache)
{
  struct sparc64_frame_cache *cache =
    sparc64_frame_cache (next_frame, this_cache);

  /* ??? Should we take BIAS into account here?  */
  return cache->base;
}

static const struct frame_base sparc64_frame_base =
{
  &sparc64_frame_unwind,
  sparc64_frame_base_address,
  sparc64_frame_base_address,
  sparc64_frame_base_address
};

static struct frame_id
sparc_unwind_dummy_id (struct gdbarch *gdbarch, struct frame_info *next_frame)
{
  CORE_ADDR sp;

  sp = frame_unwind_register_unsigned (next_frame, SPARC_SP_REGNUM);
  return frame_id_build (sp, frame_pc_unwind (next_frame));
}
\f
/* Check whether TYPE must be 16-byte aligned.  */

static int
sparc64_16_byte_align_p (struct type *type)
{
  if (sparc64_floating_p (type) && TYPE_LENGTH (type) == 16)
    return 1;

  if (sparc64_structure_or_union_p (type))
    {
      int i;

      for (i = 0; i < TYPE_NFIELDS (type); i++)
        if (sparc64_16_byte_align_p (TYPE_FIELD_TYPE (type, i)))
          return 1;
    }

  return 0;
}

/* Store floating fields of element ELEMENT of an "parameter array"
   that has type TYPE and is stored at BITPOS in VALBUF in the
   apropriate registers of REGCACHE.  This function can be called
   recursively and therefore handles floating types in addition to
   structures.  */

static void
sparc64_store_floating_fields (struct regcache *regcache, struct type *type,
                               char *valbuf, int element, int bitpos)
{
  gdb_assert (element < 16);

  if (sparc64_floating_p (type))
    {
      int len = TYPE_LENGTH (type);
      int regnum;

      if (len == 16)
        {
          gdb_assert (bitpos == 0);
          gdb_assert ((element % 2) == 0);

          regnum = SPARC64_Q0_REGNUM + element / 2;
          regcache_cooked_write (regcache, regnum, valbuf);
        }
      else if (len == 8)
        {
          gdb_assert (bitpos == 0 || bitpos == 64);

          regnum = SPARC64_D0_REGNUM + element + bitpos / 64;
          regcache_cooked_write (regcache, regnum, valbuf + (bitpos / 8));
        }
      else
        {
          gdb_assert (len == 4);
          gdb_assert (bitpos % 32 == 0 && bitpos >= 0 && bitpos < 128);

          regnum = SPARC_F0_REGNUM + element * 2 + bitpos / 32;
          regcache_cooked_write (regcache, regnum, valbuf + (bitpos / 8));
        }
    }
  else if (sparc64_structure_or_union_p (type))
    {
      int i;

      for (i = 0; i < TYPE_NFIELDS (type); i++)
        sparc64_store_floating_fields (regcache, TYPE_FIELD_TYPE (type, i),
                                       valbuf, element,
                                       bitpos + TYPE_FIELD_BITPOS (type, i));
    }
}

/* Fetch floating fields from a variable of type TYPE from the
   appropriate registers for BITPOS in REGCACHE and store it at BITPOS
   in VALBUF.  This function can be called recursively and therefore
   handles floating types in addition to structures.  */

static void
sparc64_extract_floating_fields (struct regcache *regcache, struct type *type,
                                 char *valbuf, int bitpos)
{
  if (sparc64_floating_p (type))
    {
      int len = TYPE_LENGTH (type);
      int regnum;

      if (len == 16)
        {
          gdb_assert (bitpos == 0 || bitpos == 128);

          regnum = SPARC64_Q0_REGNUM + bitpos / 128;
          regcache_cooked_read (regcache, regnum, valbuf + (bitpos / 8));
        }
      else if (len == 8)
        {
          gdb_assert (bitpos % 64 == 0 && bitpos >= 0 && bitpos < 256);

          regnum = SPARC64_D0_REGNUM + bitpos / 64;
          regcache_cooked_read (regcache, regnum, valbuf + (bitpos / 8));
        }
      else
        {
          gdb_assert (len == 4);
          gdb_assert (bitpos % 32 == 0 && bitpos >= 0 && bitpos < 256);

          regnum = SPARC_F0_REGNUM + bitpos / 32;
          regcache_cooked_read (regcache, regnum, valbuf + (bitpos / 8));
        }
    }
  else if (sparc64_structure_or_union_p (type))
    {
      int i;

      for (i = 0; i < TYPE_NFIELDS (type); i++)
        sparc64_extract_floating_fields (regcache, TYPE_FIELD_TYPE (type, i),
                                         valbuf,
                                         bitpos + TYPE_FIELD_BITPOS (type, i));
    }
}

/* Store the NARGS arguments ARGS and STRUCT_ADDR (if STRUCT_RETURN is
   non-zero) in REGCACHE and on the stack (starting from address SP).  */

static CORE_ADDR
sparc64_store_arguments (struct regcache *regcache, int nargs,
                         struct value **args, CORE_ADDR sp,
                         int struct_return, CORE_ADDR struct_addr)
{
  /* Number of extended words in the "parameter array".  */
  int num_elements = 0;
  int element = 0;
  int i;

  /* Take BIAS into account.  */
  sp += BIAS;

  /* First we calculate the number of extended words in the "parameter
     array".  While doing so we also convert some of the arguments.  */

  if (struct_return)
    num_elements++;

  for (i = 0; i < nargs; i++)
    {
      struct type *type = VALUE_TYPE (args[i]);
      int len = TYPE_LENGTH (type);

      if (sparc64_structure_or_union_p (type))
        {
          /* Structure or Union arguments.  */
          if (len <= 16)
            {
              if (num_elements % 2 && sparc64_16_byte_align_p (type))
                num_elements++;
              num_elements += ((len + 7) / 8);
            }
          else
            {
              /* The psABI says that "Structures or unions larger than
                 sixteen bytes are copied by the caller and passed
                 indirectly; the caller will pass the address of a
                 correctly aligned structure value.  This sixty-four
                 bit address will occupy one word in the parameter
                 array, and may be promoted to an %o register like any
                 other pointer value."  Allocate memory for these
                 values on the stack.  */
              sp -= len;

              /* Use 16-byte alignment for these values.  That's
                 always correct, and wasting a few bytes shouldn't be
                 a problem.  */
              sp &= ~0xf;

              write_memory (sp, VALUE_CONTENTS (args[i]), len);
              args[i] = value_from_pointer (lookup_pointer_type (type), sp);
              num_elements++;
            }
        }
      else if (sparc64_floating_p (type))
        {
          /* Floating arguments.  */

          if (len == 16)
            {
              /* The psABI says that "Each quad-precision parameter
                 value will be assigned to two extended words in the
                 parameter array.  */
              num_elements += 2;

              /* The psABI says that "Long doubles must be
                 quad-aligned, and thus a hole might be introduced
                 into the parameter array to force alignment."  Skip
                 an element if necessary.  */
              if (num_elements % 2)
                num_elements++;
            }
          else
            num_elements++;
        }
      else
        {
          /* Integral and pointer arguments.  */
          gdb_assert (sparc64_integral_or_pointer_p (type));

          /* The psABI says that "Each argument value of integral type
             smaller than an extended word will be widened by the
             caller to an extended word according to the signed-ness
             of the argument type."  */
          if (len < 8)
            args[i] = value_cast (builtin_type_int64, args[i]);
          num_elements++;
        }
    }

  /* Allocate the "parameter array".  */
  sp -= num_elements * 8;

  /* The psABI says that "Every stack frame must be 16-byte aligned."  */
  sp &= ~0xf;

  /* Now we store the arguments in to the "paramater array".  Some
     Integer or Pointer arguments and Structure or Union arguments
     will be passed in %o registers.  Some Floating arguments and
     floating members of structures are passed in floating-point
     registers.  However, for functions with variable arguments,
     floating arguments are stored in an %0 register, and for
     functions without a prototype floating arguments are stored in
     both a floating-point and an %o registers, or a floating-point
     register and memory.  To simplify the logic here we always pass
     arguments in memory, an %o register, and a floating-point
     register if appropriate.  This should be no problem since the
     contents of any unused memory or registers in the "parameter
     array" are undefined.  */

  if (struct_return)
    {
      regcache_cooked_write_unsigned (regcache, SPARC_O0_REGNUM, struct_addr);
      element++;
    }

  for (i = 0; i < nargs; i++)
    {
      char *valbuf = VALUE_CONTENTS (args[i]);
      struct type *type = VALUE_TYPE (args[i]);
      int len = TYPE_LENGTH (type);
      int regnum = -1;
      char buf[16];

      if (sparc64_structure_or_union_p (type))
        {
          /* Structure or Union arguments.  */
          gdb_assert (len <= 16);
          memset (buf, 0, sizeof (buf));
          valbuf = memcpy (buf, valbuf, len);

          if (element % 2 && sparc64_16_byte_align_p (type))
            element++;

          if (element < 6)
            {
              regnum = SPARC_O0_REGNUM + element;
              if (len > 8 && element < 5)
                regcache_cooked_write (regcache, regnum + 1, valbuf + 8);
            }

          if (element < 16)
            sparc64_store_floating_fields (regcache, type, valbuf, element, 0);
        }
      else if (sparc64_floating_p (type))
        {
          /* Floating arguments.  */
          if (len == 16)
            {
              if (element % 2)
                element++;
              if (element < 16)
                regnum = SPARC64_Q0_REGNUM + element / 2;
            }
          else if (len == 8)
            {
              if (element < 16)
                regnum = SPARC64_D0_REGNUM + element;
            }
          else
            {
              /* The psABI says "Each single-precision parameter value
                 will be assigned to one extended word in the
                 parameter array, and right-justified within that
                 word; the left half (even floatregister) is
                 undefined."  Even though the psABI says that "the
                 left half is undefined", set it to zero here.  */
              memset (buf, 0, 4);
              valbuf = memcpy (buf + 4, valbuf, 4);
              len = 8;
              if (element < 16)
                regnum = SPARC64_D0_REGNUM;
            }
        }
      else
        {
          /* Integral and pointer arguments.  */
          gdb_assert (len == 8);
          if (element < 6)
            regnum = SPARC_O0_REGNUM + element;
        }

      if (regnum != -1)
        {
          regcache_cooked_write (regcache, regnum, valbuf);

          /* If we're storing the value in a floating-point register,
             also store it in the corresponding %0 register(s).  */
          if (regnum >= SPARC64_D0_REGNUM && regnum <= SPARC64_D10_REGNUM)
            {
              gdb_assert (element < 6);
              regnum = SPARC_O0_REGNUM + element;
              regcache_cooked_write (regcache, regnum, valbuf);
            }
          else if (regnum >= SPARC64_Q0_REGNUM && regnum <= SPARC64_Q8_REGNUM)
            {
              gdb_assert (element < 6);
              regnum = SPARC_O0_REGNUM + element;
              regcache_cooked_write (regcache, regnum, valbuf);
              regcache_cooked_write (regcache, regnum + 1, valbuf);
            }
        }

      /* Always store the argument in memeory.  */
      write_memory (sp + element * 8, valbuf, len);
      element += ((len + 7) / 8);
    }

  gdb_assert (element == num_elements);

  /* Take BIAS into account.  */
  sp -= BIAS;
  return sp;
}

static CORE_ADDR
sparc64_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)
{
  /* Set return address.  */
  regcache_cooked_write_unsigned (regcache, SPARC_O7_REGNUM, bp_addr - 8);

  /* Set up function arguments.  */
  sp = sparc64_store_arguments (regcache, nargs, args, sp,
                                struct_return, struct_addr);

  /* Allocate the register save area.  */
  sp -= 16 * 8;

  /* Stack should be 16-byte aligned at this point.  */
  gdb_assert (sp % 16 == 0);

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

  return sp;
}
\f

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

static void
sparc64_extract_return_value (struct type *type, struct regcache *regcache,
                              void *valbuf)
{
  int len = TYPE_LENGTH (type);
  char buf[32];
  int i;

  if (sparc64_structure_or_union_p (type))
    {
      /* Structure or Union return values.  */
      gdb_assert (len <= 32);

      for (i = 0; i < ((len + 7) / 8); i++)
        regcache_cooked_read (regcache, SPARC_O0_REGNUM + i, buf + i * 8);
      if (TYPE_CODE (type) != TYPE_CODE_UNION)
        sparc64_extract_floating_fields (regcache, type, buf, 0);
      memcpy (valbuf, buf, len);
    }
  else if (sparc64_floating_p (type))
    {
      /* Floating return values.  */
      for (i = 0; i < len / 4; i++)
        regcache_cooked_read (regcache, SPARC_F0_REGNUM + i, buf + i * 4);
      memcpy (valbuf, buf, len);
    }
  else
    {
      /* Integral and pointer return values.  */
      gdb_assert (sparc64_integral_or_pointer_p (type));

      /* Just stripping off any unused bytes should preserve the
         signed-ness just fine.  */
      regcache_cooked_read (regcache, SPARC_O0_REGNUM, buf);
      memcpy (valbuf, buf + 8 - len, len);
    }
}

/* Write into the appropriate registers a function return value stored
   in VALBUF of type TYPE.  */

static void
sparc64_store_return_value (struct type *type, struct regcache *regcache,
                            const void *valbuf)
{
  int len = TYPE_LENGTH (type);
  char buf[16];
  int i;

  if (sparc64_structure_or_union_p (type))
    {
      /* Structure or Union return values.  */
      gdb_assert (len <= 32);

      /* Simplify matters by storing the complete value (including
         floating members) into %o0 and %o1.  Floating members are
         also store in the appropriate floating-point registers.  */
      memset (buf, 0, sizeof (buf));
      memcpy (buf, valbuf, len);
      for (i = 0; i < ((len + 7) / 8); i++)
        regcache_cooked_write (regcache, SPARC_O0_REGNUM + i, buf + i * 4);
      if (TYPE_CODE (type) != TYPE_CODE_UNION)
        sparc64_store_floating_fields (regcache, type, buf, 0, 0);
    }
  else if (sparc64_floating_p (type))
    {
      /* Floating return values.  */
      memcpy (buf, valbuf, len);
      for (i = 0; i < len / 4; i++)
        regcache_cooked_write (regcache, SPARC_F0_REGNUM + i, buf + i * 4);
    }
  else
    {
      /* Integral and pointer return values.  */
      gdb_assert (sparc64_integral_or_pointer_p (type));

      /* ??? Do we need to do any sign-extension here?  */
      memset (buf, 0, 8);
      memcpy (buf + 8 - len, valbuf, len);
      regcache_cooked_write (regcache, SPARC_O0_REGNUM, buf);
    }
}

/* Extract from REGCACHE, which contains the (raw) register state, the
   address in which a function should return its structure value, as a
   CORE_ADDR.  */

static CORE_ADDR
sparc_extract_struct_value_address (struct regcache *regcache)
{
  ULONGEST addr;

  regcache_cooked_read_unsigned (regcache, SPARC_O0_REGNUM, &addr);
  return addr;
}

static int
sparc64_use_struct_convention (int gcc_p, struct type *type)
{
  /* Structure and union types up to 32 bytes in size are returned in
     registers.  */
  return (TYPE_LENGTH (type) > 32);
}

\f
/* The SPARC Architecture doesn't have hardware single-step support,
   and most operating systems don't implement it either, so we provide
   software single-step mechanism.  */

static CORE_ADDR
sparc_analyze_control_transfer (CORE_ADDR pc, CORE_ADDR *npc)
{
  unsigned long insn = sparc_fetch_instruction (pc);
  int conditional_p = X_COND (insn) & 0x7;
  int branch_p = 0;
  long offset = 0;                      /* Must be signed for sign-extend.  */

  if (X_OP (insn) == 0 && X_OP2 (insn) == 3 && (insn & 0x1000000) == 0)
    {
      /* Branch on Integer Register with Prediction (BPr).  */
      branch_p = 1;
      conditional_p = 1;
    }
  else if (X_OP (insn) == 0 && X_OP2 (insn) == 6)
    {
      /* Branch on Floating-Point Condition Codes (FBfcc).  */
      branch_p = 1;
      offset = 4 * X_DISP22 (insn);
    }
  else if (X_OP (insn) == 0 && X_OP2 (insn) == 5)
    {
      /* Branch on Floating-Point Condition Codes with Prediction
         (FBPfcc).  */
      branch_p = 1;
      offset = 4 * X_DISP19 (insn);
    }
  else if (X_OP (insn) == 0 && X_OP2 (insn) == 2)
    {
      /* Branch on Integer Condition Codes (Bicc).  */
      branch_p = 1;
      offset = 4 * X_DISP22 (insn);
    }
  else if (X_OP (insn) == 0 && X_OP2 (insn) == 1)
    {
      /* Branch on Integer Condition Codes with Prediction (BPcc).  */
      branch_p = 1;
      offset = 4 * X_DISP19 (insn);
    }

  /* FIXME: Handle DONE and RETRY instructions.  */

  /* FIXME: Handle the Trap instruction.  */

  if (branch_p)
    {
      if (conditional_p)
        {
          /* For conditional branches, return nPC + 4 iff the annul
             bit is 1.  */
          return (X_A (insn) ? *npc + 4 : 0);
        }
      else
        {
          /* For unconditional branches, return the target if its
             specified condition is "always" and return nPC + 4 if the
             condition is "never".  If the annul bit is 1, set *NPC to
             zero.  */
          if (X_COND (insn) == 0x0)
            pc = *npc, offset = 4;
          if (X_A (insn))
            *npc = 0;

          gdb_assert (offset != 0);
          return pc + offset;
        }
    }

  return 0;
}

void
sparc_software_single_step (enum target_signal sig, int insert_breakpoints_p)
{
  static CORE_ADDR npc, nnpc;
  static char npc_save[4], nnpc_save[4];

  if (insert_breakpoints_p)
    {
      CORE_ADDR pc;

      gdb_assert (npc == 0);
      gdb_assert (nnpc == 0);

      pc = sparc_address_from_register (SPARC64_PC_REGNUM);
      npc = sparc_address_from_register (SPARC64_NPC_REGNUM);

      /* Analyze the instruction at PC.  */
      nnpc = sparc_analyze_control_transfer (pc, &npc);
      if (npc != 0)
        target_insert_breakpoint (npc, npc_save);
      if (nnpc != 0)
        target_insert_breakpoint (nnpc, nnpc_save);

      /* Assert that we have set at least one breakpoint.  */
      gdb_assert (npc != 0 || nnpc != 0);
    }
  else
    {
      if (npc != 0)
        target_remove_breakpoint (npc, npc_save);
      if (nnpc != 0)
        target_remove_breakpoint (nnpc, nnpc_save);

      npc = 0;
      nnpc = 0;
    }
}
\f

static struct gdbarch *
sparc64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
{
  struct gdbarch_tdep *tdep;
  struct gdbarch *gdbarch;

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

  /* Allocate space for the new architecture.  */
  tdep = XMALLOC (struct gdbarch_tdep);
  gdbarch = gdbarch_alloc (&info, tdep);

  set_gdbarch_long_bit (gdbarch, 64);
  set_gdbarch_long_long_bit (gdbarch, 64);
  set_gdbarch_ptr_bit (gdbarch, 64);
  set_gdbarch_long_double_bit (gdbarch, 128);

  set_gdbarch_num_regs (gdbarch, SPARC64_NUM_REGS);
  set_gdbarch_register_name (gdbarch, sparc64_register_name);
  set_gdbarch_register_type (gdbarch, sparc64_register_type);
  set_gdbarch_num_pseudo_regs (gdbarch, SPARC64_NUM_PSEUDO_REGS);
  set_gdbarch_pseudo_register_read (gdbarch, sparc64_pseudo_register_read);
  set_gdbarch_pseudo_register_write (gdbarch, sparc64_pseudo_register_write);

  /* Register numbers of various important registers.  */
  set_gdbarch_sp_regnum (gdbarch, SPARC_SP_REGNUM); /* %sp */
  set_gdbarch_pc_regnum (gdbarch, SPARC64_PC_REGNUM); /* %pc */
  set_gdbarch_npc_regnum (gdbarch, SPARC64_NPC_REGNUM);
  set_gdbarch_fp0_regnum (gdbarch, SPARC_F0_REGNUM); /* %f0 */

  /* Call dummy code.  */
  set_gdbarch_push_dummy_call (gdbarch, sparc64_push_dummy_call);

  set_gdbarch_extract_return_value (gdbarch, sparc64_extract_return_value);
  set_gdbarch_store_return_value (gdbarch, sparc64_store_return_value);
  set_gdbarch_extract_struct_value_address
    (gdbarch, sparc_extract_struct_value_address);
  set_gdbarch_use_struct_convention (gdbarch, sparc64_use_struct_convention);

  set_gdbarch_skip_prologue (gdbarch, sparc64_skip_prologue);

  /* Stack grows downward.  */
  set_gdbarch_inner_than (gdbarch, core_addr_lessthan);

  set_gdbarch_breakpoint_from_pc (gdbarch, sparc_breakpoint_from_pc);
  set_gdbarch_decr_pc_after_break (gdbarch, 0);
  set_gdbarch_function_start_offset (gdbarch, 0);

  set_gdbarch_frame_args_skip (gdbarch, 8);

  set_gdbarch_print_insn (gdbarch, print_insn_sparc);

  set_gdbarch_software_single_step (gdbarch, sparc_software_single_step);

  set_gdbarch_unwind_dummy_id (gdbarch, sparc_unwind_dummy_id);

  set_gdbarch_unwind_pc (gdbarch, sparc64_unwind_pc);

  frame_base_set_default (gdbarch, &sparc64_frame_base);

  /* Hook in ABI-specific overrides, if they have been registered.  */
  gdbarch_init_osabi (info, gdbarch);

  frame_unwind_append_sniffer (gdbarch, sparc64_frame_sniffer);

  return gdbarch;
}
\f
/* Helper functions for dealing with register windows.  */

static void
sparc_supply_rwindow (CORE_ADDR sp, int regnum)
{
  int offset = 0;
  char buf[8];
  int i;

  /* Clear out the top half of the temporary buffer, and put the
     register value in the bottom half if we're in 64-bit mode.  */
  if (gdbarch_ptr_bit (current_gdbarch) == 64)
    {
      memset (buf, 0, 4);
      offset = 4;
    }

  for (i = SPARC_L0_REGNUM; i <= SPARC_I7_REGNUM; i++)
    {
      if (regnum == i || regnum == -1)
        {
          target_read_memory (sp + ((i - SPARC_L0_REGNUM) * 4),
                              buf + offset, 4);
          supply_register (i, buf);
        }
    }
}

void
sparc64_supply_rwindow (CORE_ADDR sp, int regnum)
{
  if (sp & 1)
    {
      char buf[8];
      int i;

      /* Registers are 64-bit.  */
      sp += BIAS;

      for (i = SPARC_L0_REGNUM; i <= SPARC_I7_REGNUM; i++)
        {
          if (regnum == i || regnum == -1)
            {
              target_read_memory (sp + ((i - SPARC_L0_REGNUM) * 8),
                                  buf, sizeof (buf));
              supply_register (i, buf);
            }
        }
    }
  else
    {
      /* Registers are 32-bit.  Toss any sign-extension of the stack
         pointer.  */
      sparc_supply_rwindow (sp & 0xffffffffUL, regnum);
    }
}

static void
sparc_fill_rwindow (CORE_ADDR sp, int regnum)
{
  int offset = 0;
  char buf[8];
  int i;

  /* Only use the bottom half if we're in 64-bit mode.  */
  if (gdbarch_ptr_bit (current_gdbarch) == 64)
    offset = 4;

  for (i = SPARC_L0_REGNUM; i <= SPARC_I7_REGNUM; i++)
    {
      if (regnum == -1 || regnum == SPARC_SP_REGNUM || regnum == i)
        {
          regcache_collect (i, buf);
          target_write_memory (sp + ((i - SPARC_L0_REGNUM) * 4), buf, 4);
        }
    }
}

void
sparc64_fill_rwindow (CORE_ADDR sp, int regnum)
{
  if (sp & 1)
    {
      char buf[8];
      int i;

      /* Registers are 64-bit.  */
      sp += BIAS;

      for (i = SPARC_L0_REGNUM; i <= SPARC_I7_REGNUM; i++)
        {
          if (regnum == -1 || regnum == SPARC_SP_REGNUM || regnum == i)
            {
              regcache_collect (i, buf);
              target_write_memory (sp + ((i - SPARC_L0_REGNUM) * 8),
                                   buf, sizeof (buf));
            }
        }
    }
  else
    {
      /* Registers are 32-bit.  Toss any sign-extension of the stack
         pointer.  */
      sparc_fill_rwindow (sp & 0xffffffffUL, regnum);
    }
}
\f

/* Provide a prototype to silence -Wmissing-prototypes.  */
void _initialize_sparc64_tdep (void);

void
_initialize_sparc64_tdep (void)
{
  register_gdbarch_init (bfd_arch_sparc, sparc64_gdbarch_init);
}