gcc/config/mmix/mmix.h

   1 /* Definitions of target machine for GNU compiler, for MMIX.
   2    Copyright (C) 2000, 2001, 2002, 2004 Free Software Foundation, Inc.
   3    Contributed by Hans-Peter Nilsson (hp@bitrange.com)
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #ifndef GCC_MMIX_H
  23 #define GCC_MMIX_H
  24
  25 /* First, some local helper macros.  Note that the "default" value of
  26    FIXED_REGISTERS, CALL_USED_REGISTERS, REG_ALLOC_ORDER and
  27    REG_CLASS_CONTENTS depend on these values.  */
  28 #define MMIX_RESERVED_GNU_ARG_0_REGNUM 231
  29 #define MMIX_FIRST_ARG_REGNUM \
  30   (TARGET_ABI_GNU ? MMIX_RESERVED_GNU_ARG_0_REGNUM : 16)
  31 #define MMIX_FIRST_INCOMING_ARG_REGNUM \
  32   (TARGET_ABI_GNU ? MMIX_RESERVED_GNU_ARG_0_REGNUM : 0)
  33 #define MMIX_MAX_ARGS_IN_REGS 16
  34
  35 /* FIXME: This one isn't fully implemented yet.  Return values larger than
  36    one register are passed by reference in MMIX_STRUCT_VALUE_REGNUM by the
  37    caller, except for return values of type "complex".  */
  38 #define MMIX_MAX_REGS_FOR_VALUE 16
  39 #define MMIX_RETURN_VALUE_REGNUM \
  40   (TARGET_ABI_GNU ? MMIX_RESERVED_GNU_ARG_0_REGNUM : 15)
  41 #define MMIX_OUTGOING_RETURN_VALUE_REGNUM \
  42   (TARGET_ABI_GNU ? MMIX_RESERVED_GNU_ARG_0_REGNUM : 0)
  43 #define MMIX_STRUCT_VALUE_REGNUM 251
  44 #define MMIX_STATIC_CHAIN_REGNUM 252
  45 #define MMIX_FRAME_POINTER_REGNUM 253
  46 #define MMIX_STACK_POINTER_REGNUM 254
  47 #define MMIX_LAST_GENERAL_REGISTER 255
  48 #define MMIX_INCOMING_RETURN_ADDRESS_REGNUM MMIX_rJ_REGNUM
  49 #define MMIX_HIMULT_REGNUM 258
  50 #define MMIX_REMAINDER_REGNUM MMIX_rR_REGNUM
  51 #define MMIX_ARG_POINTER_REGNUM 261
  52 #define MMIX_rO_REGNUM 262
  53 #define MMIX_LAST_STACK_REGISTER_REGNUM 31
  54
  55 /* Four registers; "ideally, these registers should be call-clobbered", so
  56    just grab a bunch of the common clobbered registers.  FIXME: Last
  57    registers of return-value should be used, with an error if there's a
  58    return-value (that collides in size).  */
  59 #define MMIX_EH_RETURN_DATA_REGNO_START (MMIX_STRUCT_VALUE_REGNUM - 4)
  60
  61 /* Try to keep the definitions from running away on their own.  */
  62 #if (MMIX_EH_RETURN_DATA_REGNO_START \
  63      != MMIX_RESERVED_GNU_ARG_0_REGNUM + MMIX_MAX_ARGS_IN_REGS)
  64  #error MMIX register definition inconsistency
  65 #endif
  66
  67 #if (MMIX_MAX_REGS_FOR_VALUE + MMIX_MAX_ARGS_IN_REGS > 32)
  68  #error MMIX parameters and return values bad, more than 32 registers
  69 #endif
  70
  71 /* This chosen as "a call-clobbered hard register that is otherwise
  72    untouched by the epilogue".  */
  73 #define MMIX_EH_RETURN_STACKADJ_REGNUM MMIX_STATIC_CHAIN_REGNUM
  74
  75 #ifdef REG_OK_STRICT
  76 # define MMIX_REG_OK_STRICT 1
  77 #else
  78 # define MMIX_REG_OK_STRICT 0
  79 #endif
  80
  81 #define MMIX_FUNCTION_ARG_SIZE(MODE, TYPE) \
  82  ((MODE) != BLKmode ? GET_MODE_SIZE (MODE) : int_size_in_bytes (TYPE))
  83
  84 /* Declarations for helper variables that are not tied to a particular
  85    target macro.  */
  86 extern GTY(()) rtx mmix_compare_op0;
  87 extern GTY(()) rtx mmix_compare_op1;
  88
  89 /* Per-function machine data.  This is normally an opaque type just
  90    defined and used in the tm.c file, but we need to see the definition in
  91    mmix.md too.  */
  92 struct machine_function GTY(())
  93  {
  94    int has_landing_pad;
  95    int highest_saved_stack_register;
  96    int in_prologue;
  97  };
  98
  99 /* For these target macros, there is no generic documentation here.  You
 100    should read `Using and Porting GCC' for that.  Only comments specific
 101    to the MMIX target are here.
 102
 103    There are however references to the specific texinfo node (comments
 104    with "Node:"), so there should be little or nothing amiss.  Probably
 105    the opposite, since we don't have to care about old littering and
 106    soon outdated generic comments.  */
 107
 108 /* Node: Driver */
 109
 110 /* User symbols are in the same name-space as built-in symbols, but we
 111    don't need the built-in symbols, so remove those and instead apply
 112    stricter operand checking.  Don't warn when expanding insns.  */
 113 #define ASM_SPEC "-no-predefined-syms -x"
 114
 115 /* Pass on -mset-program-start=N and -mset-data-start=M to the linker.
 116    Provide default program start 0x100 unless -mno-set-program-start.
 117    Don't do this if linking relocatably, with -r.  For a final link,
 118    produce mmo, unless ELF is requested or when linking relocatably.  */
 119 #define LINK_SPEC \
 120  "%{mset-program-start=*:--defsym __.MMIX.start..text=%*}\
 121   %{mset-data-start=*:--defsym __.MMIX.start..data=%*}\
 122   %{!mset-program-start=*:\
 123     %{!mno-set-program-start:\
 124      %{!r:--defsym __.MMIX.start..text=0x100}}}\
 125   %{!melf:%{!r:-m mmo}}%{melf|r:-m elf64mmix}"
 126
 127 /* Put unused option values here.  */
 128 extern const char *mmix_cc1_ignored_option;
 129
 130 #define TARGET_OPTIONS                                  \
 131    {{"set-program-start=", &mmix_cc1_ignored_option,    \
 132   N_("Set start-address of the program"), 0},           \
 133     {"set-data-start=", &mmix_cc1_ignored_option,       \
 134   N_("Set start-address of data"), 0} }
 135
 136 /* FIXME: There's no provision for profiling here.  */
 137 #define STARTFILE_SPEC  \
 138   "crti%O%s crtbegin%O%s"
 139
 140 #define ENDFILE_SPEC "crtend%O%s crtn%O%s"
 141
 142 /* Node: Run-time Target */
 143
 144 /* Define __LONG_MAX__, since we're advised not to change glimits.h.  */
 145 #define TARGET_CPU_CPP_BUILTINS()                               \
 146   do                                                            \
 147     {                                                           \
 148       builtin_define ("__mmix__");                              \
 149       builtin_define ("__MMIX__");                              \
 150       if (TARGET_ABI_GNU)                                       \
 151         builtin_define ("__MMIX_ABI_GNU__");                    \
 152       else                                                      \
 153         builtin_define ("__MMIX_ABI_MMIXWARE__");               \
 154     }                                                           \
 155   while (0)
 156
 157 extern int target_flags;
 158
 159 #define TARGET_MASK_LIBFUNCS 1
 160 #define TARGET_MASK_ABI_GNU 2
 161 #define TARGET_MASK_FCMP_EPSILON 4
 162 #define TARGET_MASK_ZERO_EXTEND 8
 163 #define TARGET_MASK_KNUTH_DIVISION 16
 164 #define TARGET_MASK_TOPLEVEL_SYMBOLS 32
 165 #define TARGET_MASK_BRANCH_PREDICT 64
 166 #define TARGET_MASK_USE_RETURN_INSN 128
 167
 168 /* We use the term "base address" since that's what Knuth uses.  The base
 169    address goes in a global register.  When addressing, it's more like
 170    "base address plus offset", with the offset being 0..255 from the base,
 171    which itself can be a symbol plus an offset.  The effect is like having
 172    a constant pool in global registers, code offsetting from those
 173    registers (automatically causing a request for a suitable constant base
 174    address register) without having to know the specific register or the
 175    specific offset.  The setback is that there's a limited number of
 176    registers, and you'll not find out until link time whether you
 177    should have compiled with -mno-base-addresses.  */
 178 #define TARGET_MASK_BASE_ADDRESSES 128
 179
 180 /* FIXME: Get rid of this one.  */
 181 #define TARGET_LIBFUNC (target_flags & TARGET_MASK_LIBFUNCS)
 182 #define TARGET_ABI_GNU (target_flags & TARGET_MASK_ABI_GNU)
 183 #define TARGET_FCMP_EPSILON (target_flags & TARGET_MASK_FCMP_EPSILON)
 184 #define TARGET_ZERO_EXTEND (target_flags & TARGET_MASK_ZERO_EXTEND)
 185 #define TARGET_KNUTH_DIVISION (target_flags & TARGET_MASK_KNUTH_DIVISION)
 186 #define TARGET_TOPLEVEL_SYMBOLS (target_flags & TARGET_MASK_TOPLEVEL_SYMBOLS)
 187 #define TARGET_BRANCH_PREDICT (target_flags & TARGET_MASK_BRANCH_PREDICT)
 188 #define TARGET_BASE_ADDRESSES (target_flags & TARGET_MASK_BASE_ADDRESSES)
 189 #define TARGET_USE_RETURN_INSN (target_flags & TARGET_MASK_USE_RETURN_INSN)
 190
 191 #define TARGET_DEFAULT \
 192  (TARGET_MASK_BRANCH_PREDICT | TARGET_MASK_BASE_ADDRESSES \
 193   | TARGET_MASK_USE_RETURN_INSN)
 194
 195 /* FIXME: Provide a way to *load* the epsilon register.  */
 196 #define TARGET_SWITCHES                                                 \
 197  {{"libfuncs",          TARGET_MASK_LIBFUNCS,                           \
 198    N_("For intrinsics library: pass all parameters in registers")},     \
 199   {"no-libfuncs",       -TARGET_MASK_LIBFUNCS, ""},                     \
 200   {"abi=mmixware",      -TARGET_MASK_ABI_GNU,                           \
 201    N_("Use register stack for parameters and return value")},           \
 202   {"abi=gnu",           TARGET_MASK_ABI_GNU,                            \
 203    N_("Use call-clobbered registers for parameters and return value")}, \
 204   {"epsilon",           TARGET_MASK_FCMP_EPSILON,                       \
 205    N_("Use epsilon-respecting floating point compare instructions")},   \
 206   {"no-epsilon",        -TARGET_MASK_FCMP_EPSILON, ""},                 \
 207   {"zero-extend",       TARGET_MASK_ZERO_EXTEND,                        \
 208    N_("Use zero-extending memory loads, not sign-extending ones")},     \
 209   {"no-zero-extend",    -TARGET_MASK_ZERO_EXTEND,  ""},                 \
 210   {"knuthdiv",          TARGET_MASK_KNUTH_DIVISION,                     \
 211    N_("Generate divide results with reminder having the same sign as the\
 212  divisor (not the dividend)")},                                         \
 213   {"no-knuthdiv",       -TARGET_MASK_KNUTH_DIVISION, ""},               \
 214   {"toplevel-symbols",  TARGET_MASK_TOPLEVEL_SYMBOLS,                   \
 215    N_("Prepend global symbols with \":\" (for use with PREFIX)")},      \
 216   {"no-toplevel-symbols", -TARGET_MASK_TOPLEVEL_SYMBOLS,                \
 217    N_("Do not provide a default start-address 0x100 of the program")},  \
 218   {"elf", 0,                                                            \
 219    N_("Link to emit program in ELF format (rather than mmo)")},         \
 220   {"branch-predict",    TARGET_MASK_BRANCH_PREDICT,                     \
 221    N_("Use P-mnemonics for branches statically predicted as taken")},   \
 222   {"no-branch-predict", -TARGET_MASK_BRANCH_PREDICT,                    \
 223    N_("Don't use P-mnemonics for branches")},                           \
 224   {"base-addresses",    TARGET_MASK_BASE_ADDRESSES,                     \
 225    N_("Use addresses that allocate global registers")},                 \
 226   {"no-base-addresses", -TARGET_MASK_BASE_ADDRESSES,                    \
 227    N_("Do not use addresses that allocate global registers")},          \
 228   {"single-exit",       -TARGET_MASK_USE_RETURN_INSN,                   \
 229    N_("Generate a single exit point for each function")},               \
 230   {"no-single-exit",    TARGET_MASK_USE_RETURN_INSN,                    \
 231    N_("Do not generate a single exit point for each function")},        \
 232   {"",                  TARGET_DEFAULT, ""}}
 233
 234 /* Unfortunately, this must not reference anything in "mmix.c".  */
 235 #define TARGET_VERSION \
 236   fprintf (stderr, " (MMIX)")
 237
 238 #define OVERRIDE_OPTIONS mmix_override_options ()
 239
 240 #define OPTIMIZATION_OPTIONS(LEVEL, SIZE)       \
 241   do                                            \
 242     {                                           \
 243       if (LEVEL >= 1)                           \
 244         flag_regmove = TRUE;                    \
 245                                                 \
 246       if (SIZE || LEVEL > 1)                    \
 247         {                                       \
 248           flag_omit_frame_pointer = TRUE;       \
 249           flag_strength_reduce = FALSE;         \
 250         }                                       \
 251     }                                           \
 252   while (0)
 253
 254 /* This one will have to wait a little bit; right now we can't debug
 255    neither with or without a frame-pointer.  */
 256 /* #define CAN_DEBUG_WITHOUT_FP */
 257
 258
 259 /* Node: Per-Function Data */
 260 #define INIT_EXPANDERS mmix_init_expanders ()
 261
 262
 263 /* Node: Storage Layout */
 264 /* I see no bit-field instructions.  Anyway, the common order is from low
 265    to high, as the power of two, hence little-endian.  */
 266 #define BITS_BIG_ENDIAN 0
 267 #define BYTES_BIG_ENDIAN 1
 268 #define WORDS_BIG_ENDIAN 1
 269 #define FLOAT_WORDS_BIG_ENDIAN 1
 270 #define UNITS_PER_WORD 8
 271
 272 /* FIXME: This macro is correlated to MAX_FIXED_MODE_SIZE in that
 273    e.g. this macro must not be 8 (default, UNITS_PER_WORD) when
 274    MAX_FIXED_MODE_SIZE is 64 (default, DImode), or really: this must be
 275    set manually if MAX_FIXED_MODE_SIZE is not at least twice the register
 276    size.  By setting it to 4, we don't have to worry about TImode things
 277    yet.  Revisit, perhaps get TImode going or get some solution that does
 278    not mandate TImode or lie in other ways.  */
 279 #define MIN_UNITS_PER_WORD 4
 280
 281 /* FIXME: Promotion of modes currently generates slow code, extending
 282    before every operation.  */
 283 /* I'm a little bit undecided about this one.  It might be beneficial to
 284    promote all operations.  */
 285
 286 #define PROMOTE_FUNCTION_MODE(MODE, UNSIGNEDP, TYPE)    \
 287  do {                                           \
 288   if (GET_MODE_CLASS (MODE) == MODE_INT         \
 289       && GET_MODE_SIZE (MODE) < 8)              \
 290    {                                            \
 291      (MODE) = DImode;                           \
 292      /* Do the following some time later,       \
 293         scrutinizing differences.  */           \
 294      if (0) (UNSIGNEDP) = 0;                    \
 295    }                                            \
 296  } while (0)
 297
 298 /* We need to align everything to 64 bits that can affect the alignment
 299    of other types.  Since address N is interpreted in MMIX as (N modulo
 300    access_size), we must align.  */
 301 #define PARM_BOUNDARY 64
 302 #define STACK_BOUNDARY 64
 303 #define FUNCTION_BOUNDARY 32
 304 #define BIGGEST_ALIGNMENT 64
 305
 306 /* This one is only used in the ADA front end.  */
 307 #define MINIMUM_ATOMIC_ALIGNMENT 8
 308
 309 /* Copied from elfos.h.  */
 310 #define MAX_OFILE_ALIGNMENT (32768 * 8)
 311
 312 #define DATA_ALIGNMENT(TYPE, BASIC_ALIGN) \
 313  mmix_data_alignment (TYPE, BASIC_ALIGN)
 314
 315 #define CONSTANT_ALIGNMENT(CONSTANT, BASIC_ALIGN) \
 316  mmix_constant_alignment (CONSTANT, BASIC_ALIGN)
 317
 318 #define LOCAL_ALIGNMENT(TYPE, BASIC_ALIGN) \
 319  mmix_local_alignment (TYPE, BASIC_ALIGN)
 320
 321 /* Following other ports, this seems to most commonly be the word-size,
 322    so let's do that here too.  */
 323 #define EMPTY_FIELD_BOUNDARY 64
 324
 325 /* We chose to have this low solely for similarity with the alpha.  It has
 326    nothing to do with passing the tests dg/c99-scope-2 and
 327    execute/align-1.c.  Nothing.  Though the tests seem wrong.  Padding of
 328    the structure is automatically added to get alignment when needed if we
 329    set this to just byte-boundary.  */
 330 #define STRUCTURE_SIZE_BOUNDARY 8
 331
 332 /* The lower bits are ignored.  */
 333 #define STRICT_ALIGNMENT 1
 334
 335
 336 /* Node: Type Layout */
 337
 338 /* It might seem more natural to have 64-bit ints on a 64-bit machine,
 339    but then an occasional MMIX programmer needs to know how to put a lot
 340    of __attribute__ stuff to get to the 8, 16 and 32-bit modes rather
 341    than the "intuitive" char, short and int types.  */
 342 #define INT_TYPE_SIZE 32
 343 #define SHORT_TYPE_SIZE 16
 344 #define LONG_LONG_TYPE_SIZE 64
 345
 346 #define FLOAT_TYPE_SIZE 32
 347 #define DOUBLE_TYPE_SIZE 64
 348 #define LONG_DOUBLE_TYPE_SIZE 64
 349
 350 #define DEFAULT_SIGNED_CHAR 1
 351
 352
 353 /* Node: Register Basics */
 354 /* We tell GCC about all 256 general registers, and we also include
 355    rD, rE, rH, rJ, rR and rO (in that order) so we can describe what insns
 356    clobber them.  We use a faked register for the argument pointer.  It is
 357    always eliminated towards the frame-pointer or the stack-pointer, never
 358    output in assembly.  Any fixed register would do for this, like $255,
 359    but future debugging is easier when using a separate register.  It
 360    counts as a global register for pseudorandom reasons.  */
 361 #define FIRST_PSEUDO_REGISTER 263
 362
 363 /* We treat general registers with no assigned purpose as fixed.  The
 364    stack pointer, $254, is also fixed.  Register $255 is referred to as a
 365    temporary register in the MMIX papers, and used as such in mmixal, so
 366    it should not be used as a stack pointer.  We set it to fixed, and use
 367    it "manually" at times of despair.  */
 368 #define FIXED_REGISTERS \
 369  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
 370    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
 371    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 372    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 373    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 374    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 375    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 376    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 377    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 378    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 379    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 380    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 381    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 382    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 383    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 384    1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, \
 385    1, 1, 0, 0, 0, 1, 1 \
 386  }
 387
 388 /* General registers are fixed and therefore "historically" marked
 389    call-used.  (FIXME: This has changed).  Registers $15..$31 are
 390    call-clobbered; we'll put arguments in $16 and up, and we need $15 for
 391    the MMIX register-stack "hole".  */
 392 #define CALL_USED_REGISTERS \
 393  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, \
 394    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 395    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 396    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 397    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 398    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 399    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 400    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 401    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 402    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 403    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 404    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 405    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 406    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 407    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 408    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, \
 409    1, 1, 1, 1, 1, 1, 1 \
 410  }
 411
 412 #define CONDITIONAL_REGISTER_USAGE mmix_conditional_register_usage ()
 413
 414 /* No INCOMING_REGNO or OUTGOING_REGNO, since those macros are not usable
 415    for MMIX: it doesn't have a fixed register window size.  FIXME: Perhaps
 416    we should say something about $0..$15 may sometimes be the incoming
 417    $16..$31.  Those macros need better documentation; it looks like
 418    they're just bogus and that FUNCTION_INCOMING_ARG_REGNO_P and
 419    FUNCTION_OUTGOING_VALUE should be used where they're used.  For the
 420    moment, do nothing; things seem to work anyway.  */
 421
 422 /* Defining LOCAL_REGNO is necessary in presence of prologue/epilogue,
 423    else GCC will be confused that those registers aren't saved and
 424    restored.  */
 425 #define LOCAL_REGNO(REGNO) mmix_local_regno (REGNO)
 426
 427 /* Node: Allocation Order */
 428
 429 /* We should allocate registers from 0 to 31 by increasing number, because
 430    I think that's what people expect.  Beyond that, just use
 431    call-clobbered global registers first, then call-clobbered special
 432    registers.  Last, the fixed registers.  */
 433 #define MMIX_MMIXWARE_ABI_REG_ALLOC_ORDER       \
 434  { 0, 1, 2, 3, 4, 5, 6, 7,                      \
 435    8, 9, 10, 11, 12, 13, 14, 15,                \
 436    16, 17, 18, 19, 20, 21, 22, 23,              \
 437    24, 25, 26, 27, 28, 29, 30, 31,              \
 438                                                 \
 439    252, 251, 250, 249, 248, 247,                \
 440                                                 \
 441    253,                                         \
 442                                                 \
 443    258, 260, 259,                               \
 444                                                 \
 445    32, 33, 34, 35, 36, 37, 38, 39,              \
 446    40, 41, 42, 43, 44, 45, 46, 47,              \
 447    48, 49, 50, 51, 52, 53, 54, 55,              \
 448    56, 57, 58, 59, 60, 61, 62, 63,              \
 449    64, 65, 66, 67, 68, 69, 70, 71,              \
 450    72, 73, 74, 75, 76, 77, 78, 79,              \
 451    80, 81, 82, 83, 84, 85, 86, 87,              \
 452    88, 89, 90, 91, 92, 93, 94, 95,              \
 453    96, 97, 98, 99, 100, 101, 102, 103,          \
 454    104, 105, 106, 107, 108, 109, 110, 111,      \
 455    112, 113, 114, 115, 116, 117, 118, 119,      \
 456    120, 121, 122, 123, 124, 125, 126, 127,      \
 457    128, 129, 130, 131, 132, 133, 134, 135,      \
 458    136, 137, 138, 139, 140, 141, 142, 143,      \
 459    144, 145, 146, 147, 148, 149, 150, 151,      \
 460    152, 153, 154, 155, 156, 157, 158, 159,      \
 461    160, 161, 162, 163, 164, 165, 166, 167,      \
 462    168, 169, 170, 171, 172, 173, 174, 175,      \
 463    176, 177, 178, 179, 180, 181, 182, 183,      \
 464    184, 185, 186, 187, 188, 189, 190, 191,      \
 465    192, 193, 194, 195, 196, 197, 198, 199,      \
 466    200, 201, 202, 203, 204, 205, 206, 207,      \
 467    208, 209, 210, 211, 212, 213, 214, 215,      \
 468    216, 217, 218, 219, 220, 221, 222, 223,      \
 469    224, 225, 226, 227, 228, 229, 230, 231,      \
 470    232, 233, 234, 235, 236, 237, 238, 239,      \
 471    240, 241, 242, 243, 244, 245, 246,           \
 472                                                 \
 473    254, 255, 256, 257, 261, 262                 \
 474  }
 475
 476 /* As a convenience, we put this nearby, for ease of comparison.
 477    First, call-clobbered registers in reverse order of assignment as
 478    parameters (also the top ones; not because they're parameters, but
 479    for continuity).
 480
 481    Second, saved registers that go on the register-stack.
 482
 483    Third, special registers rH, rR and rJ.  They should not normally be
 484    allocated, but since they're call-clobbered, it is cheaper to use one
 485    of them than using a call-saved register for a call-clobbered use,
 486    assuming it is referenced a very limited number of times.  Other global
 487    and fixed registers come next; they are never allocated.  */
 488 #define MMIX_GNU_ABI_REG_ALLOC_ORDER            \
 489  { 252, 251, 250, 249, 248, 247, 246,           \
 490    245, 244, 243, 242, 241, 240, 239, 238,      \
 491    237, 236, 235, 234, 233, 232, 231,           \
 492                                                 \
 493    0, 1, 2, 3, 4, 5, 6, 7,                      \
 494    8, 9, 10, 11, 12, 13, 14, 15,                \
 495    16, 17, 18, 19, 20, 21, 22, 23,              \
 496    24, 25, 26, 27, 28, 29, 30, 31,              \
 497                                                 \
 498    253,                                         \
 499                                                 \
 500    258, 260, 259,                               \
 501                                                 \
 502    32, 33, 34, 35, 36, 37, 38, 39,              \
 503    40, 41, 42, 43, 44, 45, 46, 47,              \
 504    48, 49, 50, 51, 52, 53, 54, 55,              \
 505    56, 57, 58, 59, 60, 61, 62, 63,              \
 506    64, 65, 66, 67, 68, 69, 70, 71,              \
 507    72, 73, 74, 75, 76, 77, 78, 79,              \
 508    80, 81, 82, 83, 84, 85, 86, 87,              \
 509    88, 89, 90, 91, 92, 93, 94, 95,              \
 510    96, 97, 98, 99, 100, 101, 102, 103,          \
 511    104, 105, 106, 107, 108, 109, 110, 111,      \
 512    112, 113, 114, 115, 116, 117, 118, 119,      \
 513    120, 121, 122, 123, 124, 125, 126, 127,      \
 514    128, 129, 130, 131, 132, 133, 134, 135,      \
 515    136, 137, 138, 139, 140, 141, 142, 143,      \
 516    144, 145, 146, 147, 148, 149, 150, 151,      \
 517    152, 153, 154, 155, 156, 157, 158, 159,      \
 518    160, 161, 162, 163, 164, 165, 166, 167,      \
 519    168, 169, 170, 171, 172, 173, 174, 175,      \
 520    176, 177, 178, 179, 180, 181, 182, 183,      \
 521    184, 185, 186, 187, 188, 189, 190, 191,      \
 522    192, 193, 194, 195, 196, 197, 198, 199,      \
 523    200, 201, 202, 203, 204, 205, 206, 207,      \
 524    208, 209, 210, 211, 212, 213, 214, 215,      \
 525    216, 217, 218, 219, 220, 221, 222, 223,      \
 526    224, 225, 226, 227, 228, 229, 230,           \
 527                                                 \
 528    254, 255, 256, 257, 261, 262                 \
 529  }
 530
 531 /* The default one.  */
 532 #define REG_ALLOC_ORDER MMIX_MMIXWARE_ABI_REG_ALLOC_ORDER
 533
 534 /* Node: Values in Registers */
 535
 536 #define HARD_REGNO_NREGS(REGNO, MODE)                   \
 537    ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1)         \
 538     / UNITS_PER_WORD)
 539
 540 #define HARD_REGNO_MODE_OK(REGNO, MODE) 1
 541
 542 /* Note that no register can really be accessed in single-float mode, so
 543    we *can* say 1 here.  FIXME:  Will TRT happen for single-float, or do
 544    we have to punt to libgcc1.asm?  */
 545 #define MODES_TIEABLE_P(MODE1, MODE2) 1
 546
 547
 548 /* Node: Leaf Functions */
 549 /* (empty) */
 550
 551
 552 /* Node: Register Classes */
 553
 554 enum reg_class
 555  {
 556    NO_REGS, GENERAL_REGS, REMAINDER_REG, HIMULT_REG,
 557    SYSTEM_REGS, ALL_REGS, LIM_REG_CLASSES
 558  };
 559
 560 #define N_REG_CLASSES (int) LIM_REG_CLASSES
 561
 562 #define REG_CLASS_NAMES                                         \
 563  {"NO_REGS", "GENERAL_REGS", "REMAINDER_REG", "HIMULT_REG",     \
 564   "SYSTEM_REGS", "ALL_REGS"}
 565
 566 /* Note that the contents of each item is always 32 bits.  */
 567 #define REG_CLASS_CONTENTS                      \
 568  {{0, 0, 0, 0, 0, 0, 0, 0, 0},                  \
 569   {~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, 0x20},       \
 570   {0, 0, 0, 0, 0, 0, 0, 0, 0x10},               \
 571   {0, 0, 0, 0, 0, 0, 0, 0, 4},                  \
 572   {0, 0, 0, 0, 0, 0, 0, 0, 0x7f},               \
 573   {~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, 0x7f}}
 574
 575 #define REGNO_REG_CLASS(REGNO)                                  \
 576  ((REGNO) <= MMIX_LAST_GENERAL_REGISTER                         \
 577   || (REGNO) == MMIX_ARG_POINTER_REGNUM                         \
 578   ? GENERAL_REGS                                                \
 579   : (REGNO) == MMIX_REMAINDER_REGNUM ? REMAINDER_REG            \
 580   : (REGNO) == MMIX_HIMULT_REGNUM ? HIMULT_REG : SYSTEM_REGS)
 581
 582 #define BASE_REG_CLASS GENERAL_REGS
 583
 584 #define INDEX_REG_CLASS GENERAL_REGS
 585
 586 #define REG_CLASS_FROM_LETTER(CHAR)             \
 587  ((CHAR) == 'x' ? SYSTEM_REGS                   \
 588   : (CHAR) == 'y' ? REMAINDER_REG               \
 589   : (CHAR) == 'z' ? HIMULT_REG : NO_REGS)
 590
 591 #define REGNO_OK_FOR_BASE_P(REGNO)                              \
 592  ((REGNO) <= MMIX_LAST_GENERAL_REGISTER                         \
 593   || (REGNO) == MMIX_ARG_POINTER_REGNUM                         \
 594   || (reg_renumber[REGNO] > 0                                   \
 595       && reg_renumber[REGNO] <= MMIX_LAST_GENERAL_REGISTER))
 596
 597 #define REGNO_OK_FOR_INDEX_P(REGNO) REGNO_OK_FOR_BASE_P (REGNO)
 598
 599 #define PREFERRED_RELOAD_CLASS(X, CLASS) \
 600  mmix_preferred_reload_class (X, CLASS)
 601
 602 #define PREFERRED_OUTPUT_RELOAD_CLASS(X, CLASS) \
 603  mmix_preferred_output_reload_class (X, CLASS)
 604
 605 #define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \
 606  mmix_secondary_reload_class (CLASS, MODE, X, 1)
 607
 608 #define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \
 609  mmix_secondary_reload_class (CLASS, MODE, X, 0)
 610
 611 #define CLASS_MAX_NREGS(CLASS, MODE) HARD_REGNO_NREGS (CLASS, MODE)
 612
 613 #define CONST_OK_FOR_LETTER_P(VALUE, C) \
 614  mmix_const_ok_for_letter_p (VALUE, C)
 615
 616 #define EXTRA_CONSTRAINT(VALUE, C)      \
 617  mmix_extra_constraint (VALUE, C, MMIX_REG_OK_STRICT)
 618
 619 /* Do we need anything serious here?  Yes, any FLOT constant.  */
 620 #define CONST_DOUBLE_OK_FOR_LETTER_P(VALUE, C)                  \
 621  mmix_const_double_ok_for_letter_p (VALUE, C)
 622
 623
 624 /* Node: Frame Layout */
 625
 626 #define STACK_GROWS_DOWNWARD
 627 #define FRAME_GROWS_DOWNWARD
 628
 629 #define STARTING_FRAME_OFFSET \
 630   mmix_starting_frame_offset ()
 631
 632 #define FIRST_PARM_OFFSET(FUNDECL) 0
 633
 634 #define DYNAMIC_CHAIN_ADDRESS(FRAMEADDR) \
 635  mmix_dynamic_chain_address (FRAMEADDR)
 636
 637 /* FIXME: It seems RETURN_ADDR_OFFSET is undocumented.  */
 638
 639 #define SETUP_FRAME_ADDRESSES() \
 640  mmix_setup_frame_addresses ()
 641
 642 #define RETURN_ADDR_RTX(COUNT, FRAME)           \
 643  mmix_return_addr_rtx (COUNT, FRAME)
 644
 645 /* It's in rJ before we store it somewhere.  */
 646 #define INCOMING_RETURN_ADDR_RTX \
 647  gen_rtx_REG (Pmode, MMIX_INCOMING_RETURN_ADDRESS_REGNUM)
 648
 649 /* FIXME: This does not seem properly documented or cross-indexed.
 650    Nowhere except in the code does it say it *has* to be in the range
 651    0..255, or else it will be truncated.  That goes for the default too.  */
 652 #define DWARF_FRAME_RETURN_COLUMN \
 653  DWARF_FRAME_REGNUM (MMIX_INCOMING_RETURN_ADDRESS_REGNUM)
 654
 655 /* No return address is stored there.  */
 656 #define INCOMING_FRAME_SP_OFFSET 0
 657
 658 /* Node: Stack Checking */
 659 /* (empty) */
 660
 661
 662 /* Node: Exception Handling */
 663
 664 #define EH_RETURN_DATA_REGNO(N) \
 665  mmix_eh_return_data_regno (N)
 666
 667 #define EH_RETURN_STACKADJ_RTX \
 668  mmix_eh_return_stackadj_rtx ()
 669
 670 #define EH_RETURN_HANDLER_RTX \
 671  mmix_eh_return_handler_rtx ()
 672
 673 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
 674  mmix_asm_preferred_eh_data_format (CODE, GLOBAL)
 675
 676 /* Node: Frame Registers */
 677 #define STACK_POINTER_REGNUM MMIX_STACK_POINTER_REGNUM
 678
 679 /* Perhaps we can use HARD_FRAME_POINTER_REGNUM and decide later on
 680    what register we want to use.  */
 681 #define FRAME_POINTER_REGNUM MMIX_FRAME_POINTER_REGNUM
 682 #define ARG_POINTER_REGNUM MMIX_ARG_POINTER_REGNUM
 683
 684 #define STATIC_CHAIN_REGNUM MMIX_STATIC_CHAIN_REGNUM
 685
 686
 687 /* Node: Elimination */
 688 /* FIXME: Is this requirement built-in?  Anyway, we should try to get rid
 689    of it; we can deduce the value.  */
 690 #define FRAME_POINTER_REQUIRED (nonlocal_goto_stack_level != NULL_RTX)
 691
 692 /* The frame-pointer is stored in a location that either counts to the
 693    offset of incoming parameters, or that counts to the offset of the
 694    frame, so we can't use a single offset.  We therefore eliminate those
 695    two separately.  */
 696 #define ELIMINABLE_REGS                         \
 697  {{ARG_POINTER_REGNUM, STACK_POINTER_REGNUM},   \
 698   {ARG_POINTER_REGNUM, FRAME_POINTER_REGNUM},   \
 699   {FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}}
 700
 701 /* We need not worry about when the frame-pointer is required for other
 702    reasons; GCC takes care of those cases.  */
 703 #define CAN_ELIMINATE(FROM, TO) 1
 704
 705 #define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
 706  (OFFSET) = mmix_initial_elimination_offset (FROM, TO)
 707
 708
 709 /* Node: Stack Arguments */
 710
 711 #define ACCUMULATE_OUTGOING_ARGS 1
 712
 713 #define RETURN_POPS_ARGS(FUNDECL, FUNTYPE, STACKSIZE) 0
 714
 715
 716 /* Node: Register Arguments */
 717 #define FUNCTION_ARG(CUM, MODE, TYPE, NAMED)    \
 718  mmix_function_arg (&(CUM), MODE, TYPE, NAMED, 0)
 719
 720 #define FUNCTION_INCOMING_ARG(CUM, MODE, TYPE, NAMED)   \
 721  mmix_function_arg (&(CUM), MODE, TYPE, NAMED, 1)
 722
 723 #define FUNCTION_ARG_PASS_BY_REFERENCE(CUM, MODE, TYPE, NAMED)  \
 724  mmix_function_arg_pass_by_reference (&(CUM), MODE, TYPE, NAMED)
 725
 726 /* This *sounds* good, but does not seem to be implemented correctly to
 727    be a win; at least it wasn't in 2.7.2.  FIXME: Check and perhaps
 728    replace with a big comment.
 729    The definition needs to match or be a subset of
 730    FUNCTION_ARG_PASS_BY_REFERENCE, since not all callers check that before
 731    usage.  Watch lots of C++ testcases fail if set to 1, for example
 732    g++.dg/init/byval1.C.  */
 733 #define FUNCTION_ARG_CALLEE_COPIES(CUM, MODE, TYPE, NAMED) \
 734  mmix_function_arg_pass_by_reference (&(CUM), MODE, TYPE, NAMED)
 735
 736 typedef struct { int regs; int lib; } CUMULATIVE_ARGS;
 737
 738 #define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, INDIRECT, N_NAMED_ARGS) \
 739  ((CUM).regs = 0, (CUM).lib = ((LIBNAME) != 0))
 740
 741 #define FUNCTION_ARG_ADVANCE(CUM, MODE, TYPE, NAMED)            \
 742  ((CUM).regs                                                    \
 743   = ((MUST_PASS_IN_STACK (MODE, TYPE))                          \
 744      || (MMIX_FUNCTION_ARG_SIZE (MODE, TYPE) > 8                \
 745          && !TARGET_LIBFUNC && !(CUM).lib))                     \
 746   ? (MMIX_MAX_ARGS_IN_REGS) + 1                                 \
 747   : (CUM).regs + (7 + (MMIX_FUNCTION_ARG_SIZE (MODE, TYPE))) / 8)
 748
 749 #define FUNCTION_ARG_REGNO_P(REGNO)             \
 750  mmix_function_arg_regno_p (REGNO, 0)
 751
 752 #define FUNCTION_INCOMING_ARG_REGNO_P(REGNO)            \
 753  mmix_function_arg_regno_p (REGNO, 1)
 754
 755
 756 /* Node: Register Arguments */
 757
 758 #define FUNCTION_VALUE(VALTYPE, FUNC)  \
 759  gen_rtx_REG (TYPE_MODE (VALTYPE), MMIX_RETURN_VALUE_REGNUM)
 760
 761 /* This needs to take care of the register hole for complex return values.  */
 762 #define FUNCTION_OUTGOING_VALUE(VALTYPE, FUNC)  \
 763  mmix_function_outgoing_value (VALTYPE, FUNC)
 764
 765 #define LIBCALL_VALUE(MODE) \
 766  gen_rtx_REG (MODE, MMIX_RETURN_VALUE_REGNUM)
 767
 768 #define FUNCTION_VALUE_REGNO_P(REGNO) \
 769  mmix_function_value_regno_p (REGNO)
 770
 771
 772 /* Node: Caller Saves */
 773 /* (empty) */
 774
 775
 776 /* Node: Function Entry */
 777
 778 /* See mmix.c for TARGET_ASM_FUNCTION_PROLOGUE and
 779    TARGET_ASM_FUNCTION_EPILOGUE.  */
 780
 781 /* We need to say that the epilogue uses the return address, so the
 782    initial-value machinery restores it.  FIXME: Some targets
 783    conditionalize on "reload_completed &&".  Investigate difference.
 784    FIXME: Not needed if nonlocal_goto_stack_level.  */
 785 #define EPILOGUE_USES(REGNO) \
 786  ((REGNO) == MMIX_INCOMING_RETURN_ADDRESS_REGNUM)
 787
 788 /* Node: Profiling */
 789 #define FUNCTION_PROFILER(FILE, LABELNO)        \
 790  mmix_function_profiler (FILE, LABELNO)
 791
 792 /* Node: Varargs */
 793
 794 /* FIXME: This and other EXPAND_BUILTIN_VA_... target macros are not
 795    documented, although used by several targets.  */
 796 #define EXPAND_BUILTIN_VA_ARG(VALIST, TYPE) \
 797  mmix_expand_builtin_va_arg (VALIST, TYPE)
 798
 799 /* Node: Trampolines */
 800
 801 #define TRAMPOLINE_TEMPLATE(FILE) \
 802  mmix_trampoline_template (FILE)
 803
 804 #define TRAMPOLINE_SIZE mmix_trampoline_size
 805 #define INITIALIZE_TRAMPOLINE(ADDR, FNADDR, STATIC_CHAIN) \
 806  mmix_initialize_trampoline (ADDR, FNADDR, STATIC_CHAIN)
 807
 808
 809 /* Node: Addressing Modes */
 810
 811 #define CONSTANT_ADDRESS_P(X) \
 812  mmix_constant_address_p (X)
 813
 814 #define MAX_REGS_PER_ADDRESS 2
 815
 816 #define GO_IF_LEGITIMATE_ADDRESS(MODE, X, LABEL)                \
 817  if (mmix_legitimate_address (MODE, X, MMIX_REG_OK_STRICT))     \
 818    goto LABEL
 819
 820 #ifndef REG_OK_STRICT
 821 # define REG_OK_FOR_BASE_P(X)                   \
 822   (REGNO (X) <= MMIX_LAST_GENERAL_REGISTER      \
 823    || REGNO (X) == MMIX_ARG_POINTER_REGNUM      \
 824    || REGNO (X) >= FIRST_PSEUDO_REGISTER)
 825 #else
 826 # define REG_OK_FOR_BASE_P(X) REGNO_OK_FOR_BASE_P (REGNO (X))
 827 #endif /* REG_OK_STRICT */
 828
 829 #define REG_OK_FOR_INDEX_P(X) REG_OK_FOR_BASE_P (X)
 830
 831 #define GO_IF_MODE_DEPENDENT_ADDRESS(ADDR, LABEL)
 832
 833 #define LEGITIMATE_CONSTANT_P(X) \
 834  mmix_legitimate_constant_p (X)
 835
 836
 837 /* Node: Condition Code */
 838
 839 #define SELECT_CC_MODE(OP, X, Y)                \
 840  mmix_select_cc_mode (OP, X, Y)
 841
 842 /* A definition of CANONICALIZE_COMPARISON that changed LE and GT
 843    comparisons with -1 to LT and GE respectively, and LT, LTU, GE or GEU
 844    comparisons with 256 to 255 and LE, LEU, GT and GTU has been
 845    ineffective; the code path for performing the changes did not trig for
 846    neither the GCC testsuite nor ghostscript-6.52 nor Knuth's mmix.tar.gz
 847    itself (core GCC functionality supposedly handling it) with sources
 848    from 2002-06-06.  */
 849
 850 #define REVERSIBLE_CC_MODE(MODE)                \
 851  mmix_reversible_cc_mode (MODE)
 852
 853
 854 /* Node: Costs */
 855
 856 /* The special registers can only move to and from general regs, and we
 857    need to check that their constraints match, so say 3 for them.  */
 858 /* WARNING: gcc-2.7.2.2 i686-pc-linux-gnulibc1 (as shipped with RH 4.2)
 859    miscompiles reload1.c:reload_cse_simplify_set; a call to
 860    reload_cse_regno_equal_p is missing when checking if a substitution of
 861    a register setting is valid if this is defined to just the expression
 862    in mmix_register_move_cost.
 863
 864    Symptom: a (all?) register setting is optimized away for e.g.
 865    "char *p1(char *p) { return p+1; }" and the value of register zero ($0)
 866    is returned.
 867
 868    We can workaround by making this a function call - unknown if this
 869    causes dire speed effects.  */
 870 #define REGISTER_MOVE_COST(MODE, FROM, TO) \
 871  mmix_register_move_cost (MODE, FROM, TO)
 872
 873 #define SLOW_BYTE_ACCESS 0
 874
 875
 876 /* Node: Sections */
 877
 878 /* This must be a constant string, since it's used in crtstuff.c.  */
 879 #define TEXT_SECTION_ASM_OP \
 880  "\t.text ! mmixal:= 9H LOC 8B"
 881
 882 /* FIXME: Not documented.  */
 883 #define DATA_SECTION_ASM_OP \
 884  mmix_data_section_asm_op ()
 885
 886 #define READONLY_DATA_SECTION_ASM_OP    "\t.section\t.rodata"
 887
 888 /* Node: PIC */
 889 /* (empty) */
 890
 891
 892 /* Node: File Framework */
 893
 894 /* While any other punctuation character but ";" would do, we prefer "%"
 895    or "!"; "!" is an unary operator and so will not be mistakenly included
 896    in correctly formed expressions.  The hash character adds mass; catches
 897    the eye.  We can't have it as a comment char by itself, since it's a
 898    hex-number prefix.  */
 899 #define ASM_COMMENT_START "!#"
 900
 901 /* These aren't currently functional.  We just keep them as markers.  */
 902 #define ASM_APP_ON "%APP\n"
 903 #define ASM_APP_OFF "%NO_APP\n"
 904
 905 #define ASM_OUTPUT_SOURCE_FILENAME(STREAM, NAME) \
 906  mmix_asm_output_source_filename (STREAM, NAME)
 907
 908 #define OUTPUT_QUOTED_STRING(STREAM, STRING) \
 909  mmix_output_quoted_string (STREAM, STRING, strlen (STRING))
 910
 911 #define ASM_OUTPUT_SOURCE_LINE(STREAM, LINE, COUNTER) \
 912  mmix_asm_output_source_line  (STREAM, LINE)
 913
 914 #define TARGET_ASM_NAMED_SECTION default_elf_asm_named_section
 915
 916
 917 /* Node: Data Output */
 918
 919 #define ASM_OUTPUT_ASCII(STREAM, PTR, LEN) \
 920  mmix_asm_output_ascii (STREAM, PTR, LEN)
 921
 922 /* Node: Uninitialized Data */
 923
 924 #define ASM_OUTPUT_ALIGNED_COMMON(ST, N, S, A) \
 925  mmix_asm_output_aligned_common (ST, N, S, A)
 926
 927 #define ASM_OUTPUT_ALIGNED_LOCAL(ST, N, S, A) \
 928  mmix_asm_output_aligned_local (ST, N, S, A)
 929
 930
 931 /* Node: Label Output */
 932
 933 #define ASM_OUTPUT_LABEL(STREAM, NAME) \
 934  mmix_asm_output_label (STREAM, NAME)
 935
 936 #define ASM_DECLARE_REGISTER_GLOBAL(STREAM, DECL, REGNO, NAME) \
 937  mmix_asm_declare_register_global (STREAM, DECL, REGNO, NAME)
 938
 939 #define GLOBAL_ASM_OP "\t.global "
 940
 941 #define ASM_WEAKEN_LABEL(STREAM, NAME) \
 942  mmix_asm_weaken_label (STREAM, NAME)
 943
 944 #define MAKE_DECL_ONE_ONLY(DECL) \
 945  mmix_make_decl_one_only (DECL)
 946
 947 #define ASM_OUTPUT_LABELREF(STREAM, NAME) \
 948  mmix_asm_output_labelref (STREAM, NAME)
 949
 950 /* We insert a ":" to disambiguate against user symbols like L5.  */
 951 #define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM) \
 952  sprintf (LABEL, "*%s:%ld", PREFIX, (long)(NUM))
 953
 954 /* Insert "::"; these are rarer than internal labels.  FIXME: Make sure no
 955    ":" is seen in the object file; we don't really want that mmixal
 956    feature visible there.  We don't want the default, which uses a dot;
 957    that'd be incompatible with mmixal.  */
 958 #define ASM_PN_FORMAT "%s::%lu"
 959
 960 #define ASM_OUTPUT_DEF(STREAM, NAME, VALUE) \
 961  mmix_asm_output_def (STREAM, NAME, VALUE)
 962
 963 /* Node: Macros for Initialization */
 964 /* We're compiling to ELF and linking to MMO; fundamental ELF features
 965    that GCC depend on are there.  */
 966
 967 /* These must be constant strings, since they're used in crtstuff.c.  */
 968 #define INIT_SECTION_ASM_OP "\t.section .init,\"ax\" ! mmixal-incompatible"
 969
 970 #define FINI_SECTION_ASM_OP "\t.section .fini,\"ax\" ! mmixal-incompatible"
 971
 972 #define OBJECT_FORMAT_ELF
 973
 974
 975 /* Node: Instruction Output */
 976
 977 /* The non-$ register names must be prefixed with ":", since they're
 978    affected by PREFIX.  We provide the non-colon names as additional
 979    names.  */
 980 #define REGISTER_NAMES                                                  \
 981  {"$0", "$1", "$2", "$3", "$4", "$5", "$6", "$7",                       \
 982   "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15",                 \
 983   "$16", "$17", "$18", "$19", "$20", "$21", "$22", "$23",               \
 984   "$24", "$25", "$26", "$27", "$28", "$29", "$30", "$31",               \
 985   "$32", "$33", "$34", "$35", "$36", "$37", "$38", "$39",               \
 986   "$40", "$41", "$42", "$43", "$44", "$45", "$46", "$47",               \
 987   "$48", "$49", "$50", "$51", "$52", "$53", "$54", "$55",               \
 988   "$56", "$57", "$58", "$59", "$60", "$61", "$62", "$63",               \
 989   "$64", "$65", "$66", "$67", "$68", "$69", "$70", "$71",               \
 990   "$72", "$73", "$74", "$75", "$76", "$77", "$78", "$79",               \
 991   "$80", "$81", "$82", "$83", "$84", "$85", "$86", "$87",               \
 992   "$88", "$89", "$90", "$91", "$92", "$93", "$94", "$95",               \
 993   "$96", "$97", "$98", "$99", "$100", "$101", "$102", "$103",           \
 994   "$104", "$105", "$106", "$107", "$108", "$109", "$110", "$111",       \
 995   "$112", "$113", "$114", "$115", "$116", "$117", "$118", "$119",       \
 996   "$120", "$121", "$122", "$123", "$124", "$125", "$126", "$127",       \
 997   "$128", "$129", "$130", "$131", "$132", "$133", "$134", "$135",       \
 998   "$136", "$137", "$138", "$139", "$140", "$141", "$142", "$143",       \
 999   "$144", "$145", "$146", "$147", "$148", "$149", "$150", "$151",       \
1000   "$152", "$153", "$154", "$155", "$156", "$157", "$158", "$159",       \
1001   "$160", "$161", "$162", "$163", "$164", "$165", "$166", "$167",       \
1002   "$168", "$169", "$170", "$171", "$172", "$173", "$174", "$175",       \
1003   "$176", "$177", "$178", "$179", "$180", "$181", "$182", "$183",       \
1004   "$184", "$185", "$186", "$187", "$188", "$189", "$190", "$191",       \
1005   "$192", "$193", "$194", "$195", "$196", "$197", "$198", "$199",       \
1006   "$200", "$201", "$202", "$203", "$204", "$205", "$206", "$207",       \
1007   "$208", "$209", "$210", "$211", "$212", "$213", "$214", "$215",       \
1008   "$216", "$217", "$218", "$219", "$220", "$221", "$222", "$223",       \
1009   "$224", "$225", "$226", "$227", "$228", "$229", "$230", "$231",       \
1010   "$232", "$233", "$234", "$235", "$236", "$237", "$238", "$239",       \
1011   "$240", "$241", "$242", "$243", "$244", "$245", "$246", "$247",       \
1012   "$248", "$249", "$250", "$251", "$252", "$253", "$254", "$255",       \
1013   ":rD",  ":rE",  ":rH",  ":rJ",  ":rR",  "ap_!BAD!", ":rO"}
1014
1015 #define ADDITIONAL_REGISTER_NAMES                       \
1016  {{"sp", 254}, {":sp", 254}, {"rD", 256}, {"rE", 257},  \
1017   {"rH", 258}, {"rJ", MMIX_rJ_REGNUM}, {"rO", MMIX_rO_REGNUM}}
1018
1019 #define PRINT_OPERAND(STREAM, X, CODE) \
1020  mmix_print_operand (STREAM, X, CODE)
1021
1022 #define PRINT_OPERAND_PUNCT_VALID_P(CODE) \
1023  mmix_print_operand_punct_valid_p (CODE)
1024
1025 #define PRINT_OPERAND_ADDRESS(STREAM, X) \
1026  mmix_print_operand_address (STREAM, X)
1027
1028 #define ASM_OUTPUT_REG_PUSH(STREAM, REGNO) \
1029  mmix_asm_output_reg_push (STREAM, REGNO)
1030
1031 #define ASM_OUTPUT_REG_POP(STREAM, REGNO) \
1032  mmix_asm_output_reg_pop (STREAM, REGNO)
1033
1034
1035 /* Node: Dispatch Tables */
1036
1037 /* We define both types, since SImode is the better, but DImode the only
1038    possible for mmixal so that's the one actually used.  */
1039 #define ASM_OUTPUT_ADDR_DIFF_ELT(STREAM, BODY, VALUE, REL) \
1040  mmix_asm_output_addr_diff_elt (STREAM, BODY, VALUE, REL)
1041
1042 #define ASM_OUTPUT_ADDR_VEC_ELT(STREAM, VALUE) \
1043  mmix_asm_output_addr_vec_elt (STREAM, VALUE)
1044
1045
1046 /* Node: Exception Region Output */
1047 /* (empty) */
1048
1049 /* Node: Alignment Output */
1050
1051 #define ASM_OUTPUT_SKIP(STREAM, NBYTES) \
1052  mmix_asm_output_skip (STREAM, NBYTES)
1053
1054 #define ASM_OUTPUT_ALIGN(STREAM, POWER) \
1055  mmix_asm_output_align (STREAM, POWER)
1056
1057
1058 /* Node: All Debuggers */
1059
1060 #define DBX_REGISTER_NUMBER(REGNO) \
1061  mmix_dbx_register_number (REGNO)
1062
1063
1064 /* Node: DBX Options */
1065 /* (empty) */
1066 /* Node: DBX Hooks */
1067 /* (empty) */
1068 /* Node: File Names and DBX */
1069 /* (empty) */
1070
1071
1072 /* Node: SDB and DWARF */
1073 #define DWARF2_DEBUGGING_INFO 1
1074 #define DWARF2_ASM_LINE_DEBUG_INFO 1
1075
1076 /* Node: Misc */
1077
1078 #define PREDICATE_CODES                         \
1079  {"mmix_reg_cc_operand", {SUBREG, REG}},        \
1080  {"mmix_foldable_comparison_operator",          \
1081   {NE, EQ, GE, GT, LE, LT}},                    \
1082  /* All '<', actually.  */                      \
1083  {"mmix_comparison_operator",                   \
1084   {NE, EQ, GE, GT, LE, LT, GEU, GTU, LEU,       \
1085    LTU, UNORDERED, ORDERED, UNEQ, UNGE, UNLE,   \
1086    UNLT, LTGT}},                                \
1087  {"mmix_symbolic_or_address_operand",           \
1088   {SYMBOL_REF, LABEL_REF, CONST,                \
1089    SUBREG, REG, PLUS}},                         \
1090  {"mmix_reg_or_constant_operand",               \
1091   {CONST_INT, CONST_DOUBLE, SUBREG, REG}},      \
1092  {"mmix_reg_or_8bit_operand",                   \
1093   {CONST_INT, CONST_DOUBLE, SUBREG, REG}},      \
1094  {"mmix_reg_or_0_operand",                      \
1095   {CONST_INT, CONST_DOUBLE, SUBREG, REG}},
1096
1097 #define SPECIAL_MODE_PREDICATES "mmix_symbolic_or_address_operand",
1098
1099 /* There's no way to get a PC-relative offset into tables for SImode, so
1100    for the moment we have absolute entries in DImode.
1101    When we're going ELF, these should be SImode and 1.  */
1102 #define CASE_VECTOR_MODE DImode
1103 #define CASE_VECTOR_PC_RELATIVE 0
1104
1105 #define WORD_REGISTER_OPERATIONS
1106
1107 /* We have a choice, which makes this yet another parameter to tweak.  The
1108    gut feeling is currently that SIGN_EXTEND wins; "int" is more frequent
1109    than "unsigned int", and we have signed characters.  FIXME: measure.  */
1110 #define LOAD_EXTEND_OP(MODE) (TARGET_ZERO_EXTEND ? ZERO_EXTEND : SIGN_EXTEND)
1111
1112 #define MOVE_MAX 8
1113
1114 #define TRULY_NOOP_TRUNCATION(OUTPREC, INPREC) 1
1115
1116 /* ??? MMIX allows a choice of STORE_FLAG_VALUE.  Revisit later,
1117    we don't have scc expanders yet.  */
1118
1119 #define Pmode DImode
1120
1121 #define FUNCTION_MODE QImode
1122
1123 #define NO_IMPLICIT_EXTERN_C
1124
1125 #define HANDLE_SYSV_PRAGMA 1
1126
1127 /* These are checked.  */
1128 #define DOLLARS_IN_IDENTIFIERS 0
1129 #define NO_DOLLAR_IN_LABEL
1130 #define NO_DOT_IN_LABEL
1131
1132 #endif /* GCC_MMIX_H */
1133 /*
1134  * Local variables:
1135  * eval: (c-set-style "gnu")
1136  * indent-tabs-mode: t
1137  * End:
1138  */