gdb/m-sun3.h

   1 /* Parameters for execution on a Sun, for GDB, the GNU debugger.
   2    Copyright (C) 1986, 1987, 1989 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 GDB is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 1, or (at your option)
   9 any later version.
  10
  11 GDB is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GDB; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #ifndef sun3
  21 #define sun3
  22 #endif
  23
  24 /* Define the bit, byte, and word ordering of the machine.  */
  25 #define BITS_BIG_ENDIAN
  26 #define BYTES_BIG_ENDIAN
  27 #define WORDS_BIG_ENDIAN
  28
  29 /* Get rid of any system-imposed stack limit if possible.  */
  30
  31 #define SET_STACK_LIMIT_HUGE
  32
  33 /* Define this if the C compiler puts an underscore at the front
  34    of external names before giving them to the linker.  */
  35
  36 #define NAMES_HAVE_UNDERSCORE
  37
  38 /* Debugger information will be in DBX format.  */
  39
  40 #define READ_DBX_FORMAT
  41
  42 /* Offset from address of function to start of its code.
  43    Zero on most machines.  */
  44
  45 #define FUNCTION_START_OFFSET 0
  46
  47 /* Advance PC across any function entry prologue instructions
  48    to reach some "real" code.  */
  49
  50 #define SKIP_PROLOGUE(pc)   \
  51 { register int op = read_memory_integer (pc, 2);        \
  52   if (op == 0047126)                                    \
  53     pc += 4;   /* Skip link #word */                    \
  54   else if (op == 0044016)                               \
  55     pc += 6;   /* Skip link #long */                    \
  56 }
  57
  58 /* Immediately after a function call, return the saved pc.
  59    Can't go through the frames for this because on some machines
  60    the new frame is not set up until the new function executes
  61    some instructions.  */
  62
  63 #define SAVED_PC_AFTER_CALL(frame) \
  64 read_memory_integer (read_register (SP_REGNUM), 4)
  65
  66 /* Address of end of stack space.  */
  67
  68 #define STACK_END_ADDR 0xf000000
  69
  70 /* Stack grows downward.  */
  71
  72 #define INNER_THAN <
  73
  74 /* Sequence of bytes for breakpoint instruction.  */
  75
  76 #define BREAKPOINT {0x4e, 0x4f}
  77
  78 /* Amount PC must be decremented by after a breakpoint.
  79    This is often the number of bytes in BREAKPOINT
  80    but not always.  */
  81
  82 #define DECR_PC_AFTER_BREAK 2
  83
  84 /* Nonzero if instruction at PC is a return instruction.  */
  85 /* Allow any of the return instructions, including a trapv and a return
  86    from interupt.  */
  87
  88 #define ABOUT_TO_RETURN(pc) ((read_memory_integer (pc, 2) & ~0x3) == 0x4e74)
  89
  90 /* Return 1 if P points to an invalid floating point value.  */
  91
  92 #define INVALID_FLOAT(p, len) 0   /* Just a first guess; not checked */
  93
  94 /* Largest integer type */
  95 #define LONGEST long
  96
  97 /* Name of the builtin type for the LONGEST type above. */
  98 #define BUILTIN_TYPE_LONGEST builtin_type_long
  99
 100 /* Say how long (ordinary) registers are.  */
 101
 102 #define REGISTER_TYPE long
 103
 104 /* Number of machine registers */
 105
 106 #define NUM_REGS 31
 107
 108 /* Initializer for an array of names of registers.
 109    There should be NUM_REGS strings in this initializer.  */
 110
 111 #define REGISTER_NAMES  \
 112  {"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", \
 113   "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp", \
 114   "ps", "pc",  \
 115   "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7", \
 116   "fpcontrol", "fpstatus", "fpiaddr", "fpcode", "fpflags" }
 117
 118 /* Register numbers of various important registers.
 119    Note that some of these values are "real" register numbers,
 120    and correspond to the general registers of the machine,
 121    and some are "phony" register numbers which are too large
 122    to be actual register numbers as far as the user is concerned
 123    but do serve to get the desired values when passed to read_register.  */
 124
 125 #define FP_REGNUM 14            /* Contains address of executing stack frame */
 126 #define SP_REGNUM 15            /* Contains address of top of stack */
 127 #define PS_REGNUM 16            /* Contains processor status */
 128 #define PC_REGNUM 17            /* Contains program counter */
 129 #define FP0_REGNUM 18           /* Floating point register 0 */
 130 #define FPC_REGNUM 26           /* 68881 control register */
 131
 132 /* Total amount of space needed to store our copies of the machine's
 133    register state, the array `registers'.  */
 134 #define REGISTER_BYTES (16*4+8*12+8+20)
 135
 136 /* Index within `registers' of the first byte of the space for
 137    register N.  */
 138
 139 #define REGISTER_BYTE(N)  \
 140  ((N) >= FPC_REGNUM ? (((N) - FPC_REGNUM) * 4) + 168    \
 141   : (N) >= FP0_REGNUM ? (((N) - FP0_REGNUM) * 12) + 72  \
 142   : (N) * 4)
 143
 144 /* Number of bytes of storage in the actual machine representation
 145    for register N.  On the 68000, all regs are 4 bytes
 146    except the floating point regs which are 12 bytes.  */
 147 /* Note that the unsigned cast here forces the result of the
 148    subtractiion to very high positive values if N < FP0_REGNUM */
 149
 150 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 12 : 4)
 151
 152 /* Number of bytes of storage in the program's representation
 153    for register N.  On the 68000, all regs are 4 bytes
 154    except the floating point regs which are 8-byte doubles.  */
 155
 156 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 8 : 4)
 157
 158 /* Largest value REGISTER_RAW_SIZE can have.  */
 159
 160 #define MAX_REGISTER_RAW_SIZE 12
 161
 162 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 163
 164 #define MAX_REGISTER_VIRTUAL_SIZE 8
 165
 166 /* Nonzero if register N requires conversion
 167    from raw format to virtual format.  */
 168
 169 #define REGISTER_CONVERTIBLE(N) (((unsigned)(N) - FP0_REGNUM) < 8)
 170
 171 /* Convert data from raw format for register REGNUM
 172    to virtual format for register REGNUM.  */
 173
 174 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO)     \
 175 { if ((REGNUM) >= FP0_REGNUM && (REGNUM) < FPC_REGNUM)  \
 176     convert_from_68881 ((FROM), (TO));  \
 177   else                                  \
 178     bcopy ((FROM), (TO), 4); }
 179
 180 /* Convert data from virtual format for register REGNUM
 181    to raw format for register REGNUM.  */
 182
 183 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
 184 { if ((REGNUM) >= FP0_REGNUM && (REGNUM) < FPC_REGNUM)  \
 185     convert_to_68881 ((FROM), (TO));    \
 186   else                                  \
 187     bcopy ((FROM), (TO), 4); }
 188
 189 /* Return the GDB type object for the "standard" data type
 190    of data in register N.  */
 191
 192 #define REGISTER_VIRTUAL_TYPE(N) \
 193  (((unsigned)(N) - FP0_REGNUM) < 8 ? builtin_type_double : builtin_type_int)
 194
 195 /* Store the address of the place in which to copy the structure the
 196    subroutine will return.  This is called from call_function. */
 197
 198 #define STORE_STRUCT_RETURN(ADDR, SP) \
 199   { write_register (9, (ADDR)); }
 200
 201 /* Extract from an array REGBUF containing the (raw) register state
 202    a function return value of type TYPE, and copy that, in virtual format,
 203    into VALBUF.  */
 204
 205 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 206   bcopy (REGBUF, VALBUF, TYPE_LENGTH (TYPE))
 207
 208 /* Write into appropriate registers a function return value
 209    of type TYPE, given in virtual format.  */
 210
 211 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 212   write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
 213
 214 /* Extract from an array REGBUF containing the (raw) register state
 215    the address in which a function should return its structure value,
 216    as a CORE_ADDR (or an expression that can be used as one).  */
 217
 218 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF))
 219
 220 /* Enable use of alternate code to read and write registers.  */
 221
 222 #define NEW_SUN_PTRACE
 223
 224 /* Enable use of alternate code for Sun's format of core dump file.  */
 225
 226 #define NEW_SUN_CORE
 227
 228 /* Do implement the attach and detach commands.  */
 229
 230 #define ATTACH_DETACH
 231
 232 \f
 233 /* Describe the pointer in each stack frame to the previous stack frame
 234    (its caller).  */
 235
 236 /* FRAME_CHAIN takes a frame's nominal address
 237    and produces the frame's chain-pointer.
 238
 239    FRAME_CHAIN_COMBINE takes the chain pointer and the frame's nominal address
 240    and produces the nominal address of the caller frame.
 241
 242    However, if FRAME_CHAIN_VALID returns zero,
 243    it means the given frame is the outermost one and has no caller.
 244    In that case, FRAME_CHAIN_COMBINE is not used.  */
 245
 246 /* In the case of the Sun, the frame's nominal address
 247    is the address of a 4-byte word containing the calling frame's address.  */
 248
 249 #define FRAME_CHAIN(thisframe)  \
 250   (outside_startup_file ((thisframe)->pc) ?     \
 251    read_memory_integer ((thisframe)->frame, 4) :\
 252    0)
 253
 254 #define FRAME_CHAIN_VALID(chain, thisframe) \
 255   (chain != 0 && (outside_startup_file (FRAME_SAVED_PC (thisframe))))
 256
 257 #define FRAME_CHAIN_COMBINE(chain, thisframe) (chain)
 258
 259 /* Define other aspects of the stack frame.  */
 260
 261 /* A macro that tells us whether the function invocation represented
 262    by FI does not have a frame on the stack associated with it.  If it
 263    does not, FRAMELESS is set to 1, else 0.  */
 264 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 265   FRAMELESS_LOOK_FOR_PROLOGUE(FI, FRAMELESS)
 266
 267 #define FRAME_SAVED_PC(FRAME) (read_memory_integer ((FRAME)->frame + 4, 4))
 268
 269 #define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
 270
 271 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
 272
 273 /* Set VAL to the number of args passed to frame described by FI.
 274    Can set VAL to -1, meaning no way to tell.  */
 275
 276 /* We can't tell how many args there are
 277    now that the C compiler delays popping them.  */
 278 #define FRAME_NUM_ARGS(val,fi) (val = -1)
 279
 280 #if 0
 281 #define FRAME_NUM_ARGS(val, fi)  \
 282 { register CORE_ADDR pc = FRAME_SAVED_PC (fi);                  \
 283   register int insn = 0177777 & read_memory_integer (pc, 2);    \
 284   val = 0;                                                      \
 285   if (insn == 0047757 || insn == 0157374)  /* lea W(sp),sp or addaw #W,sp */ \
 286     val = read_memory_integer (pc + 2, 2);                      \
 287   else if ((insn & 0170777) == 0050217 /* addql #N, sp */       \
 288            || (insn & 0170777) == 0050117)  /* addqw */         \
 289     { val = (insn >> 9) & 7; if (val == 0) val = 8; }           \
 290   else if (insn == 0157774) /* addal #WW, sp */                 \
 291     val = read_memory_integer (pc + 2, 4);                      \
 292   val >>= 2; }
 293 #endif
 294
 295 /* Return number of bytes at start of arglist that are not really args.  */
 296
 297 #define FRAME_ARGS_SKIP 8
 298
 299 /* Put here the code to store, into a struct frame_saved_regs,
 300    the addresses of the saved registers of frame described by FRAME_INFO.
 301    This includes special registers such as pc and fp saved in special
 302    ways in the stack frame.  sp is even more special:
 303    the address we return for it IS the sp for the next frame.  */
 304
 305 #define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs)             \
 306 { register int regnum;                                                  \
 307   register int regmask;                                                 \
 308   register CORE_ADDR next_addr;                                         \
 309   register CORE_ADDR pc;                                                \
 310   int nextinsn;                                                         \
 311   bzero (&frame_saved_regs, sizeof frame_saved_regs);                   \
 312   if ((frame_info)->pc >= (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM*4 - 8*12 - 4 \
 313       && (frame_info)->pc <= (frame_info)->frame)                               \
 314     { next_addr = (frame_info)->frame;                                  \
 315       pc = (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM * 4 - 8*12 - 4; }\
 316   else                                                                  \
 317     { pc = get_pc_function_start ((frame_info)->pc);                    \
 318       /* Verify we have a link a6 instruction next;                     \
 319          if not we lose.  If we win, find the address above the saved   \
 320          regs using the amount of storage from the link instruction.  */\
 321       if (044016 == read_memory_integer (pc, 2))                        \
 322         next_addr = (frame_info)->frame + read_memory_integer (pc += 2, 4), pc+=4; \
 323       else if (047126 == read_memory_integer (pc, 2))                   \
 324         next_addr = (frame_info)->frame + read_memory_integer (pc += 2, 2), pc+=2; \
 325       else goto lose;                                                   \
 326       /* If have an addal #-n, sp next, adjust next_addr.  */           \
 327       if ((0177777 & read_memory_integer (pc, 2)) == 0157774)           \
 328         next_addr += read_memory_integer (pc += 2, 4), pc += 4;         \
 329     }                                                                   \
 330   /* next should be a moveml to (sp) or -(sp) or a movl r,-(sp) */      \
 331   regmask = read_memory_integer (pc + 2, 2);                            \
 332   /* But before that can come an fmovem.  Check for it.  */             \
 333   nextinsn = 0xffff & read_memory_integer (pc, 2);                      \
 334   if (0xf227 == nextinsn                                                \
 335       && (regmask & 0xff00) == 0xe000)                                  \
 336     { pc += 4; /* Regmask's low bit is for register fp7, the first pushed */ \
 337       for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--, regmask >>= 1)              \
 338         if (regmask & 1)                                                \
 339           (frame_saved_regs).regs[regnum] = (next_addr -= 12);          \
 340       regmask = read_memory_integer (pc + 2, 2); }                      \
 341   if (0044327 == read_memory_integer (pc, 2))                           \
 342     { pc += 4; /* Regmask's low bit is for register 0, the first written */ \
 343       for (regnum = 0; regnum < 16; regnum++, regmask >>= 1)            \
 344         if (regmask & 1)                                                \
 345           (frame_saved_regs).regs[regnum] = (next_addr += 4) - 4; }     \
 346   else if (0044347 == read_memory_integer (pc, 2))                      \
 347     { pc += 4; /* Regmask's low bit is for register 15, the first pushed */ \
 348       for (regnum = 15; regnum >= 0; regnum--, regmask >>= 1)           \
 349         if (regmask & 1)                                                \
 350           (frame_saved_regs).regs[regnum] = (next_addr -= 4); }         \
 351   else if (0x2f00 == (0xfff0 & read_memory_integer (pc, 2)))            \
 352     { regnum = 0xf & read_memory_integer (pc, 2); pc += 2;              \
 353       (frame_saved_regs).regs[regnum] = (next_addr -= 4); }             \
 354   /* fmovemx to index of sp may follow.  */                             \
 355   regmask = read_memory_integer (pc + 2, 2);                            \
 356   nextinsn = 0xffff & read_memory_integer (pc, 2);                      \
 357   if (0xf236 == nextinsn                                                \
 358       && (regmask & 0xff00) == 0xf000)                                  \
 359     { pc += 10; /* Regmask's low bit is for register fp0, the first written */ \
 360       for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--, regmask >>= 1)              \
 361         if (regmask & 1)                                                \
 362           (frame_saved_regs).regs[regnum] = (next_addr += 12) - 12;     \
 363       regmask = read_memory_integer (pc + 2, 2); }                      \
 364   /* clrw -(sp); movw ccr,-(sp) may follow.  */                         \
 365   if (0x426742e7 == read_memory_integer (pc, 4))                        \
 366     (frame_saved_regs).regs[PS_REGNUM] = (next_addr -= 4);              \
 367   lose: ;                                                               \
 368   (frame_saved_regs).regs[SP_REGNUM] = (frame_info)->frame + 8;         \
 369   (frame_saved_regs).regs[FP_REGNUM] = (frame_info)->frame;             \
 370   (frame_saved_regs).regs[PC_REGNUM] = (frame_info)->frame + 4;         \
 371 }
 372 \f
 373 /* Things needed for making the inferior call functions.  */
 374
 375 /* Push an empty stack frame, to record the current PC, etc.  */
 376
 377 #define PUSH_DUMMY_FRAME \
 378 { register CORE_ADDR sp = read_register (SP_REGNUM);                    \
 379   register int regnum;                                                  \
 380   char raw_buffer[12];                                                  \
 381   sp = push_word (sp, read_register (PC_REGNUM));                       \
 382   sp = push_word (sp, read_register (FP_REGNUM));                       \
 383   write_register (FP_REGNUM, sp);                                       \
 384   for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--)         \
 385     { read_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12);     \
 386       sp = push_bytes (sp, raw_buffer, 12); }                           \
 387   for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--)                   \
 388     sp = push_word (sp, read_register (regnum));                        \
 389   sp = push_word (sp, read_register (PS_REGNUM));                       \
 390   write_register (SP_REGNUM, sp);  }
 391
 392 /* Discard from the stack the innermost frame,
 393    restoring all saved registers.  */
 394
 395 #define POP_FRAME  \
 396 { register FRAME frame = get_current_frame ();                          \
 397   register CORE_ADDR fp;                                                \
 398   register int regnum;                                                  \
 399   struct frame_saved_regs fsr;                                          \
 400   struct frame_info *fi;                                                \
 401   char raw_buffer[12];                                                  \
 402   fi = get_frame_info (frame);                                          \
 403   fp = fi->frame;                                                       \
 404   get_frame_saved_regs (fi, &fsr);                                      \
 405   for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--)         \
 406     if (fsr.regs[regnum])                                               \
 407       { read_memory (fsr.regs[regnum], raw_buffer, 12);                 \
 408         write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12); }\
 409   for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--)                   \
 410     if (fsr.regs[regnum])                                               \
 411       write_register (regnum, read_memory_integer (fsr.regs[regnum], 4)); \
 412   if (fsr.regs[PS_REGNUM])                                              \
 413     write_register (PS_REGNUM, read_memory_integer (fsr.regs[PS_REGNUM], 4)); \
 414   write_register (FP_REGNUM, read_memory_integer (fp, 4));              \
 415   write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));          \
 416   write_register (SP_REGNUM, fp + 8);                                   \
 417   flush_cached_frames ();                                               \
 418   set_current_frame (create_new_frame (read_register (FP_REGNUM),       \
 419                                         read_pc ())); }
 420
 421 /* This sequence of words is the instructions
 422      fmovem 0xff,-(sp)
 423      moveml 0xfffc,-(sp)
 424      clrw -(sp)
 425      movew ccr,-(sp)
 426      /..* The arguments are pushed at this point by GDB;
 427         no code is needed in the dummy for this.
 428         The CALL_DUMMY_START_OFFSET gives the position of
 429         the following jsr instruction.  *../
 430      jsr @#32323232
 431      addl #69696969,sp
 432      trap #15
 433      nop
 434 Note this is 28 bytes.
 435 We actually start executing at the jsr, since the pushing of the
 436 registers is done by PUSH_DUMMY_FRAME.  If this were real code,
 437 the arguments for the function called by the jsr would be pushed
 438 between the moveml and the jsr, and we could allow it to execute through.
 439 But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is done,
 440 and we cannot allow the moveml to push the registers again lest they be
 441 taken for the arguments.  */
 442
 443 #define CALL_DUMMY {0xf227e0ff, 0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, 0x4e4f4e71}
 444
 445 #define CALL_DUMMY_LENGTH 28
 446
 447 #define CALL_DUMMY_START_OFFSET 12
 448
 449 /* Insert the specified number of args and function address
 450    into a call sequence of the above form stored at DUMMYNAME.  */
 451
 452 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, type)     \
 453 { *(int *)((char *) dummyname + 20) = nargs * 4;  \
 454   *(int *)((char *) dummyname + 14) = fun; }
 455 \f
 456 /* Interface definitions for kernel debugger KDB.  */
 457
 458 /* Map machine fault codes into signal numbers.
 459    First subtract 0, divide by 4, then index in a table.
 460    Faults for which the entry in this table is 0
 461    are not handled by KDB; the program's own trap handler
 462    gets to handle then.  */
 463
 464 #define FAULT_CODE_ORIGIN 0
 465 #define FAULT_CODE_UNITS 4
 466 #define FAULT_TABLE    \
 467 { 0, 0, 0, 0, SIGTRAP, 0, 0, 0, \
 468   0, SIGTRAP, 0, 0, 0, 0, 0, SIGKILL, \
 469   0, 0, 0, 0, 0, 0, 0, 0, \
 470   SIGILL }
 471
 472 /* Start running with a stack stretching from BEG to END.
 473    BEG and END should be symbols meaningful to the assembler.
 474    This is used only for kdb.  */
 475
 476 #define INIT_STACK(beg, end)  \
 477 { asm (".globl end");         \
 478   asm ("movel #end, sp");      \
 479   asm ("movel #0,a6"); }
 480
 481 /* Push the frame pointer register on the stack.  */
 482 #define PUSH_FRAME_PTR        \
 483   asm ("movel a6,sp@-");
 484
 485 /* Copy the top-of-stack to the frame pointer register.  */
 486 #define POP_FRAME_PTR  \
 487   asm ("movl sp@,a6");
 488
 489 /* After KDB is entered by a fault, push all registers
 490    that GDB thinks about (all NUM_REGS of them),
 491    so that they appear in order of ascending GDB register number.
 492    The fault code will be on the stack beyond the last register.  */
 493
 494 #define PUSH_REGISTERS        \
 495 { asm ("clrw -(sp)");         \
 496   asm ("pea sp@(10)");        \
 497   asm ("movem #0xfffe,sp@-"); }
 498
 499 /* Assuming the registers (including processor status) have been
 500    pushed on the stack in order of ascending GDB register number,
 501    restore them and return to the address in the saved PC register.  */
 502
 503 #define POP_REGISTERS          \
 504 { asm ("subil #8,sp@(28)");     \
 505   asm ("movem sp@,#0xffff"); \
 506   asm ("rte"); }