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/* Target-dependent code for Hitachi Super-H, for GDB.

   Copyright 1993, 1994, 1995, 1996, 1997, 1998 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.  */

/*

   Contributed by Steve Chamberlain

   sac@cygnus.com

 */

#include "defs.h"

#include "frame.h"

#include "obstack.h"

#include "symtab.h"

#include "symfile.h"

#include "gdbtypes.h"

#include "gdbcmd.h"

#include "gdbcore.h"

#include "value.h"

#include "dis-asm.h"

#include "inferior.h"           /* for BEFORE_TEXT_END etc. */

#include "gdb_string.h"

/* A set of original names, to be used when restoring back to generic

   registers from a specific set.  */

/* *INDENT-OFF* */

static char *sh_generic_reg_names[] = {

  "r0",   "r1",   "r2",   "r3",   "r4",   "r5",   "r6",   "r7",

  "r8",   "r9",   "r10",  "r11",  "r12",  "r13",  "r14",  "r15",

  "pc",   "pr",   "gbr",  "vbr",  "mach", "macl", "sr",

  "fpul", "fpscr",

  "fr0",  "fr1",  "fr2",  "fr3",  "fr4",  "fr5",  "fr6",  "fr7",

  "fr8",  "fr9",  "fr10", "fr11", "fr12", "fr13", "fr14", "fr15",

  "ssr",  "spc",

  "r0b0", "r1b0", "r2b0", "r3b0", "r4b0", "r5b0", "r6b0", "r7b0",

  "r0b1", "r1b1", "r2b1", "r3b1", "r4b1", "r5b1", "r6b1", "r7b1",

};

static char *sh_reg_names[] = {

  "r0",   "r1",   "r2",   "r3",   "r4",   "r5",   "r6",   "r7",

  "r8",   "r9",   "r10",  "r11",  "r12",  "r13",  "r14",  "r15",

  "pc",   "pr",   "gbr",  "vbr",  "mach", "macl", "sr",

  "",     "",

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

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

  "",     "",

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

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

};

static char *sh3_reg_names[] = {

  "r0",   "r1",   "r2",   "r3",   "r4",   "r5",   "r6",   "r7",

  "r8",   "r9",   "r10",  "r11",  "r12",  "r13",  "r14",  "r15",

  "pc",   "pr",   "gbr",  "vbr",  "mach", "macl", "sr",

  "",     "",

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

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

  "ssr",  "spc",

  "r0b0", "r1b0", "r2b0", "r3b0", "r4b0", "r5b0", "r6b0", "r7b0",

  "r0b1", "r1b1", "r2b1", "r3b1", "r4b1", "r5b1", "r6b1", "r7b1"

};

static char *sh3e_reg_names[] = {

  "r0",   "r1",   "r2",   "r3",   "r4",   "r5",   "r6",   "r7",

  "r8",   "r9",   "r10",  "r11",  "r12",  "r13",  "r14",  "r15",

  "pc",   "pr",   "gbr",  "vbr",  "mach", "macl", "sr",

  "fpul", "fpscr",

  "fr0",  "fr1",  "fr2",  "fr3",  "fr4",  "fr5",  "fr6",  "fr7",

  "fr8",  "fr9",  "fr10", "fr11", "fr12", "fr13", "fr14", "fr15",

  "ssr",  "spc",

  "r0b0", "r1b0", "r2b0", "r3b0", "r4b0", "r5b0", "r6b0", "r7b0",

  "r0b1", "r1b1", "r2b1", "r3b1", "r4b1", "r5b1", "r6b1", "r7b1",

};

/* *INDENT-ON* */

#ifdef _WIN32_WCE

char **sh_register_names = sh3_reg_names;

#else

char **sh_register_names = sh_generic_reg_names;

#endif

struct

  {

    char **regnames;

    int mach;

  }

sh_processor_type_table[] =

{

  {

    sh_reg_names, bfd_mach_sh

  }

  ,

  {

    sh_reg_names, bfd_mach_sh2

  }

  ,

  {

    sh3_reg_names, bfd_mach_sh3

  }

  ,

  {

    sh3e_reg_names, bfd_mach_sh3e

  }

  ,

  {

    NULL, 0

  }

};

/* Prologue looks like

   [mov.l       <regs>,@-r15]...

   [sts.l       pr,@-r15]

   [mov.l       r14,@-r15]

   [mov         r15,r14]

 */

#define IS_STS(x)               ((x) == 0x4f22)

#define IS_PUSH(x)              (((x) & 0xff0f) == 0x2f06)

#define GET_PUSHED_REG(x)       (((x) >> 4) & 0xf)

#define IS_MOV_SP_FP(x)         ((x) == 0x6ef3)

#define IS_ADD_SP(x)            (((x) & 0xff00) == 0x7f00)

#define IS_MOV_R3(x)            (((x) & 0xff00) == 0x1a00)

#define IS_SHLL_R3(x)           ((x) == 0x4300)

#define IS_ADD_R3SP(x)          ((x) == 0x3f3c)

#define IS_FMOV(x)              (((x) & 0xf00f) == 0xf00b)

#define FPSCR_SZ                (1 << 20)

/* Should call_function allocate stack space for a struct return?  */

int

sh_use_struct_convention (gcc_p, type)

     int gcc_p;

     struct type *type;

{

  return (TYPE_LENGTH (type) > 1);

}

/* Skip any prologue before the guts of a function */

CORE_ADDR

sh_skip_prologue (start_pc)

     CORE_ADDR start_pc;

{

  int w;

  w = read_memory_integer (start_pc, 2);

  while (IS_STS (w)

         || IS_FMOV (w)

         || IS_PUSH (w)

         || IS_MOV_SP_FP (w)

         || IS_MOV_R3 (w)

         || IS_ADD_R3SP (w)

         || IS_ADD_SP (w)

         || IS_SHLL_R3 (w))

    {

      start_pc += 2;

      w = read_memory_integer (start_pc, 2);

    }

  return start_pc;

}

/* Disassemble an instruction.  */

int

gdb_print_insn_sh (memaddr, info)

     bfd_vma memaddr;

     disassemble_info *info;

{

  if (TARGET_BYTE_ORDER == BIG_ENDIAN)

    return print_insn_sh (memaddr, info);

  else

    return print_insn_shl (memaddr, info);

}

/* Given a GDB frame, determine the address of the calling function's frame.

   This will be used to create a new GDB frame struct, and then

   INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame.

   For us, the frame address is its stack pointer value, so we look up

   the function prologue to determine the caller's sp value, and return it.  */

CORE_ADDR

sh_frame_chain (frame)

     struct frame_info *frame;

{

  if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))

    return frame->frame;        /* dummy frame same as caller's frame */

  if (!inside_entry_file (frame->pc))

    return read_memory_integer (FRAME_FP (frame) + frame->f_offset, 4);

  else

    return 0;

}

/* Find REGNUM on the stack.  Otherwise, it's in an active register.  One thing

   we might want to do here is to check REGNUM against the clobber mask, and

   somehow flag it as invalid if it isn't saved on the stack somewhere.  This

   would provide a graceful failure mode when trying to get the value of

   caller-saves registers for an inner frame.  */

CORE_ADDR

sh_find_callers_reg (fi, regnum)

     struct frame_info *fi;

     int regnum;

{

  struct frame_saved_regs fsr;

  for (; fi; fi = fi->next)

    if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))

      /* When the caller requests PR from the dummy frame, we return PC because

         that's where the previous routine appears to have done a call from. */

      return generic_read_register_dummy (fi->pc, fi->frame, regnum);

    else

      {

        FRAME_FIND_SAVED_REGS (fi, fsr);

        if (fsr.regs[regnum] != 0)

          return read_memory_integer (fsr.regs[regnum],

                                      REGISTER_RAW_SIZE (regnum));

      }

  return read_register (regnum);

}

/* Put here the code to store, into a struct frame_saved_regs, the

   addresses of the saved registers of frame described by FRAME_INFO.

   This includes special registers such as pc and fp saved in special

   ways in the stack frame.  sp is even more special: the address we

   return for it IS the sp for the next frame. */

void

sh_frame_find_saved_regs (fi, fsr)

     struct frame_info *fi;

     struct frame_saved_regs *fsr;

{

  int where[NUM_REGS];

  int rn;

  int have_fp = 0;

  int depth;

  int pc;

  int opc;

  int insn;

  int r3_val = 0;

  char *dummy_regs = generic_find_dummy_frame (fi->pc, fi->frame);

  if (dummy_regs)

    {

      /* DANGER!  This is ONLY going to work if the char buffer format of

         the saved registers is byte-for-byte identical to the

         CORE_ADDR regs[NUM_REGS] format used by struct frame_saved_regs! */

      memcpy (&fsr->regs, dummy_regs, sizeof (fsr));

      return;

    }

  opc = pc = get_pc_function_start (fi->pc);

  insn = read_memory_integer (pc, 2);

  fi->leaf_function = 1;

  fi->f_offset = 0;

  for (rn = 0; rn < NUM_REGS; rn++)

    where[rn] = -1;

  depth = 0;

  /* Loop around examining the prologue insns until we find something

     that does not appear to be part of the prologue.  But give up

     after 20 of them, since we're getting silly then. */

  while (pc < opc + 20 * 2)

    {

      /* See where the registers will be saved to */

      if (IS_PUSH (insn))

        {

          pc += 2;

          rn = GET_PUSHED_REG (insn);

          where[rn] = depth;

          insn = read_memory_integer (pc, 2);

          depth += 4;

        }

      else if (IS_STS (insn))

        {

          pc += 2;

          where[PR_REGNUM] = depth;

          insn = read_memory_integer (pc, 2);

          /* If we're storing the pr then this isn't a leaf */

          fi->leaf_function = 0;

          depth += 4;

        }

      else if (IS_MOV_R3 (insn))

        {

          r3_val = ((insn & 0xff) ^ 0x80) - 0x80;

          pc += 2;

          insn = read_memory_integer (pc, 2);

        }

      else if (IS_SHLL_R3 (insn))

        {

          r3_val <<= 1;

          pc += 2;

          insn = read_memory_integer (pc, 2);

        }

      else if (IS_ADD_R3SP (insn))

        {

          depth += -r3_val;

          pc += 2;

          insn = read_memory_integer (pc, 2);

        }

      else if (IS_ADD_SP (insn))

        {

          pc += 2;

          depth -= ((insn & 0xff) ^ 0x80) - 0x80;

          insn = read_memory_integer (pc, 2);

        }

      else if (IS_FMOV (insn))

        {

          pc += 2;

          insn = read_memory_integer (pc, 2);

          if (read_register (FPSCR_REGNUM) & FPSCR_SZ)

            {

              depth += 8;

            }

          else

            {

              depth += 4;

            }

        }

      else

        break;

    }

  /* Now we know how deep things are, we can work out their addresses */

  for (rn = 0; rn < NUM_REGS; rn++)

    {

      if (where[rn] >= 0)

        {

          if (rn == FP_REGNUM)

            have_fp = 1;

          fsr->regs[rn] = fi->frame - where[rn] + depth - 4;

        }

      else

        {

          fsr->regs[rn] = 0;

        }

    }

  if (have_fp)

    {

      fsr->regs[SP_REGNUM] = read_memory_integer (fsr->regs[FP_REGNUM], 4);

    }

  else

    {

      fsr->regs[SP_REGNUM] = fi->frame - 4;

    }

  fi->f_offset = depth - where[FP_REGNUM] - 4;

  /* Work out the return pc - either from the saved pr or the pr

     value */

}

/* initialize the extra info saved in a FRAME */

void

sh_init_extra_frame_info (fromleaf, fi)

     int fromleaf;

     struct frame_info *fi;

{

  struct frame_saved_regs fsr;

  if (fi->next)

    fi->pc = FRAME_SAVED_PC (fi->next);

  if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))

    {

      /* We need to setup fi->frame here because run_stack_dummy gets it wrong

         by assuming it's always FP.  */

      fi->frame = generic_read_register_dummy (fi->pc, fi->frame,

                                               SP_REGNUM);

      fi->return_pc = generic_read_register_dummy (fi->pc, fi->frame,

                                                   PC_REGNUM);

      fi->f_offset = -(CALL_DUMMY_LENGTH + 4);

      fi->leaf_function = 0;

      return;

    }

  else

    {

      FRAME_FIND_SAVED_REGS (fi, fsr);

      fi->return_pc = sh_find_callers_reg (fi, PR_REGNUM);

    }

}

/* Discard from the stack the innermost frame,

   restoring all saved registers.  */

void

sh_pop_frame ()

{

  register struct frame_info *frame = get_current_frame ();

  register CORE_ADDR fp;

  register int regnum;

  struct frame_saved_regs fsr;

  if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))

    generic_pop_dummy_frame ();

  else

    {

      fp = FRAME_FP (frame);

      get_frame_saved_regs (frame, &fsr);

      /* Copy regs from where they were saved in the frame */

      for (regnum = 0; regnum < NUM_REGS; regnum++)

        if (fsr.regs[regnum])

          write_register (regnum, read_memory_integer (fsr.regs[regnum], 4));

      write_register (PC_REGNUM, frame->return_pc);

      write_register (SP_REGNUM, fp + 4);

    }

  flush_cached_frames ();

}

/* Function: push_arguments

   Setup the function arguments for calling a function in the inferior.

   On the Hitachi SH architecture, there are four registers (R4 to R7)

   which are dedicated for passing function arguments.  Up to the first

   four arguments (depending on size) may go into these registers.

   The rest go on the stack.

   Arguments that are smaller than 4 bytes will still take up a whole

   register or a whole 32-bit word on the stack, and will be

   right-justified in the register or the stack word.  This includes

   chars, shorts, and small aggregate types.

   Arguments that are larger than 4 bytes may be split between two or

   more registers.  If there are not enough registers free, an argument

   may be passed partly in a register (or registers), and partly on the

   stack.  This includes doubles, long longs, and larger aggregates.

   As far as I know, there is no upper limit to the size of aggregates

   that will be passed in this way; in other words, the convention of

   passing a pointer to a large aggregate instead of a copy is not used.

   An exceptional case exists for struct arguments (and possibly other

   aggregates such as arrays) if the size is larger than 4 bytes but

   not a multiple of 4 bytes.  In this case the argument is never split

   between the registers and the stack, but instead is copied in its

   entirety onto the stack, AND also copied into as many registers as

   there is room for.  In other words, space in registers permitting,

   two copies of the same argument are passed in.  As far as I can tell,

   only the one on the stack is used, although that may be a function

   of the level of compiler optimization.  I suspect this is a compiler

   bug.  Arguments of these odd sizes are left-justified within the

   word (as opposed to arguments smaller than 4 bytes, which are

   right-justified).

   If the function is to return an aggregate type such as a struct, it

   is either returned in the normal return value register R0 (if its

   size is no greater than one byte), or else the caller must allocate

   space into which the callee will copy the return value (if the size

   is greater than one byte).  In this case, a pointer to the return

   value location is passed into the callee in register R2, which does

   not displace any of the other arguments passed in via registers R4

   to R7.   */

CORE_ADDR

sh_push_arguments (nargs, args, sp, struct_return, struct_addr)

     int nargs;

     value_ptr *args;

     CORE_ADDR sp;

     unsigned char struct_return;

     CORE_ADDR struct_addr;

{

  int stack_offset, stack_alloc;

  int argreg;

  int argnum;

  struct type *type;

  CORE_ADDR regval;

  char *val;

  char valbuf[4];

  int len;

  int odd_sized_struct;

  /* first force sp to a 4-byte alignment */

  sp = sp & ~3;

  /* The "struct return pointer" pseudo-argument has its own dedicated

     register */

  if (struct_return)

    write_register (STRUCT_RETURN_REGNUM, struct_addr);

  /* Now make sure there's space on the stack */

  for (argnum = 0, stack_alloc = 0;

       argnum < nargs; argnum++)

    stack_alloc += ((TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 3) & ~3);

  sp -= stack_alloc;            /* make room on stack for args */

  /* Now load as many as possible of the first arguments into

     registers, and push the rest onto the stack.  There are 16 bytes

     in four registers available.  Loop thru args from first to last.  */

  argreg = ARG0_REGNUM;

  for (argnum = 0, stack_offset = 0; argnum < nargs; argnum++)

    {

      type = VALUE_TYPE (args[argnum]);

      len = TYPE_LENGTH (type);

      memset (valbuf, 0, sizeof (valbuf));

      if (len < 4)

        {                       /* value gets right-justified in the register or stack word */

          memcpy (valbuf + (4 - len),

                  (char *) VALUE_CONTENTS (args[argnum]), len);

          val = valbuf;

        }

      else

        val = (char *) VALUE_CONTENTS (args[argnum]);

      if (len > 4 && (len & 3) != 0)

        odd_sized_struct = 1;   /* such structs go entirely on stack */

      else

        odd_sized_struct = 0;

      while (len > 0)

        {

          if (argreg > ARGLAST_REGNUM || odd_sized_struct)

            {                   /* must go on the stack */

              write_memory (sp + stack_offset, val, 4);

              stack_offset += 4;

            }

          /* NOTE WELL!!!!!  This is not an "else if" clause!!!

             That's because some *&^%$ things get passed on the stack

             AND in the registers!   */

          if (argreg <= ARGLAST_REGNUM)

            {                   /* there's room in a register */

              regval = extract_address (val, REGISTER_RAW_SIZE (argreg));

              write_register (argreg++, regval);

            }

          /* Store the value 4 bytes at a time.  This means that things

             larger than 4 bytes may go partly in registers and partly

             on the stack.  */

          len -= REGISTER_RAW_SIZE (argreg);

          val += REGISTER_RAW_SIZE (argreg);

        }

    }

  return sp;

}

/* Function: push_return_address (pc)

   Set up the return address for the inferior function call.

   Needed for targets where we don't actually execute a JSR/BSR instruction */

CORE_ADDR

sh_push_return_address (pc, sp)

     CORE_ADDR pc;

     CORE_ADDR sp;

{

  write_register (PR_REGNUM, CALL_DUMMY_ADDRESS ());

  return sp;

}

/* Function: fix_call_dummy

   Poke the callee function's address into the destination part of

   the CALL_DUMMY.  The address is actually stored in a data word

   following the actualy CALL_DUMMY instructions, which will load

   it into a register using PC-relative addressing.  This function

   expects the CALL_DUMMY to look like this:

   mov.w @(2,PC), R8

   jsr   @R8

   nop

   trap

   <destination>

 */

#if 0

void

sh_fix_call_dummy (dummy, pc, fun, nargs, args, type, gcc_p)

     char *dummy;

     CORE_ADDR pc;

     CORE_ADDR fun;

     int nargs;

     value_ptr *args;

     struct type *type;

     int gcc_p;

{

  *(unsigned long *) (dummy + 8) = fun;

}

#endif

/* Modify the actual processor type. */

int

sh_target_architecture_hook (ap)

     const bfd_arch_info_type *ap;

{

  int i, j;

  if (ap->arch != bfd_arch_sh)

    return 0;

  for (i = 0; sh_processor_type_table[i].regnames != NULL; i++)

    {

      if (sh_processor_type_table[i].mach == ap->mach)

        {

          sh_register_names = sh_processor_type_table[i].regnames;

          return 1;

        }

    }

  internal_error ("Architecture `%s' unreconized", ap->printable_name);

}

/* Print the registers in a form similar to the E7000 */

static void

sh_show_regs (args, from_tty)

     char *args;

     int from_tty;

{

  int cpu;

  if (TARGET_ARCHITECTURE->arch == bfd_arch_sh)

    cpu = TARGET_ARCHITECTURE->mach;

  else

    cpu = 0;

  printf_filtered ("PC=%s SR=%08lx PR=%08lx MACH=%08lx MACHL=%08lx\n",

                   paddr (read_register (PC_REGNUM)),

                   (long) read_register (SR_REGNUM),

                   (long) read_register (PR_REGNUM),

                   (long) read_register (MACH_REGNUM),

                   (long) read_register (MACL_REGNUM));

  printf_filtered ("GBR=%08lx VBR=%08lx",

                   (long) read_register (GBR_REGNUM),

                   (long) read_register (VBR_REGNUM));

  if (cpu == bfd_mach_sh3 || cpu == bfd_mach_sh3e)

    {

      printf_filtered (" SSR=%08lx SPC=%08lx",

                       (long) read_register (SSR_REGNUM),

                       (long) read_register (SPC_REGNUM));

      if (cpu == bfd_mach_sh3e)

        {

          printf_filtered (" FPUL=%08lx FPSCR=%08lx",

                           (long) read_register (FPUL_REGNUM),

                           (long) read_register (FPSCR_REGNUM));

        }

    }

  printf_filtered ("\nR0-R7  %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",

                   (long) read_register (0),

                   (long) read_register (1),

                   (long) read_register (2),

                   (long) read_register (3),

                   (long) read_register (4),

                   (long) read_register (5),

                   (long) read_register (6),

                   (long) read_register (7));