gcc/config/mmix/mmix.h

   1 /* Definitions of target machine for GNU compiler, for MMIX.
   2    Copyright (C) 2000, 2001, 2002, 2004, 2005, 2007, 2008, 2009, 2010, 2011
   3    Free Software Foundation, Inc.
   4    Contributed by Hans-Peter Nilsson (hp@bitrange.com)
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  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 /* Per-function machine data.  This is normally an opaque type just
  85    defined and used in the tm.c file, but we need to see the definition in
  86    mmix.md too.  */
  87 struct GTY(()) machine_function
  88  {
  89    int has_landing_pad;
  90    int highest_saved_stack_register;
  91    int in_prologue;
  92  };
  93
  94 /* For these target macros, there is no generic documentation here.  You
  95    should read `Using and Porting GCC' for that.  Only comments specific
  96    to the MMIX target are here.
  97
  98    There are however references to the specific texinfo node (comments
  99    with "Node:"), so there should be little or nothing amiss.  Probably
 100    the opposite, since we don't have to care about old littering and
 101    soon outdated generic comments.  */
 102
 103 /* Node: Driver */
 104
 105 /* User symbols are in the same name-space as built-in symbols, but we
 106    don't need the built-in symbols, so remove those and instead apply
 107    stricter operand checking.  Don't warn when expanding insns.  */
 108 #define ASM_SPEC "-no-predefined-syms -x"
 109
 110 /* Pass on -mset-program-start=N and -mset-data-start=M to the linker.
 111    Provide default program start 0x100 unless -mno-set-program-start.
 112    Don't do this if linking relocatably, with -r.  For a final link,
 113    produce mmo, unless ELF is requested or when linking relocatably.  */
 114 #define LINK_SPEC \
 115  "%{mset-program-start=*:--defsym __.MMIX.start..text=%*}\
 116   %{mset-data-start=*:--defsym __.MMIX.start..data=%*}\
 117   %{!mset-program-start=*:\
 118     %{!mno-set-program-start:\
 119      %{!r:--defsym __.MMIX.start..text=0x100}}}\
 120   %{!melf:%{!r:-m mmo}}%{melf|r:-m elf64mmix}"
 121
 122 /* FIXME: There's no provision for profiling here.  */
 123 #define STARTFILE_SPEC  \
 124   "crti%O%s crtbegin%O%s"
 125
 126 #define ENDFILE_SPEC "crtend%O%s crtn%O%s"
 127
 128 /* Node: Run-time Target */
 129
 130 /* Define __LONG_MAX__, since we're advised not to change glimits.h.  */
 131 #define TARGET_CPU_CPP_BUILTINS()                               \
 132   do                                                            \
 133     {                                                           \
 134       builtin_define ("__mmix__");                              \
 135       builtin_define ("__MMIX__");                              \
 136       if (TARGET_ABI_GNU)                                       \
 137         builtin_define ("__MMIX_ABI_GNU__");                    \
 138       else                                                      \
 139         builtin_define ("__MMIX_ABI_MMIXWARE__");               \
 140     }                                                           \
 141   while (0)
 142
 143 #define TARGET_DEFAULT \
 144  (MASK_BRANCH_PREDICT | MASK_BASE_ADDRESSES | MASK_USE_RETURN_INSN)
 145
 146
 147 /* Node: Per-Function Data */
 148 #define INIT_EXPANDERS mmix_init_expanders ()
 149
 150
 151 /* Node: Storage Layout */
 152 /* I see no bit-field instructions.  Anyway, the common order is from low
 153    to high, as the power of two, hence little-endian.  */
 154 #define BITS_BIG_ENDIAN 0
 155 #define BYTES_BIG_ENDIAN 1
 156 #define WORDS_BIG_ENDIAN 1
 157 #define FLOAT_WORDS_BIG_ENDIAN 1
 158 #define UNITS_PER_WORD 8
 159
 160 /* We need to align everything to 64 bits that can affect the alignment
 161    of other types.  Since address N is interpreted in MMIX as (N modulo
 162    access_size), we must align.  */
 163 #define PARM_BOUNDARY 64
 164 #define STACK_BOUNDARY 64
 165 #define FUNCTION_BOUNDARY 32
 166 #define BIGGEST_ALIGNMENT 64
 167
 168 /* This one is only used in the ADA front end.  */
 169 #define MINIMUM_ATOMIC_ALIGNMENT 8
 170
 171 /* Copied from elfos.h.  */
 172 #define MAX_OFILE_ALIGNMENT (32768 * 8)
 173
 174 #define DATA_ALIGNMENT(TYPE, BASIC_ALIGN) \
 175  mmix_data_alignment (TYPE, BASIC_ALIGN)
 176
 177 #define CONSTANT_ALIGNMENT(CONSTANT, BASIC_ALIGN) \
 178  mmix_constant_alignment (CONSTANT, BASIC_ALIGN)
 179
 180 #define LOCAL_ALIGNMENT(TYPE, BASIC_ALIGN) \
 181  mmix_local_alignment (TYPE, BASIC_ALIGN)
 182
 183 /* Following other ports, this seems to most commonly be the word-size,
 184    so let's do that here too.  */
 185 #define EMPTY_FIELD_BOUNDARY 64
 186
 187 /* We chose to have this low solely for similarity with the alpha.  It has
 188    nothing to do with passing the tests dg/c99-scope-2 and
 189    execute/align-1.c.  Nothing.  Though the tests seem wrong.  Padding of
 190    the structure is automatically added to get alignment when needed if we
 191    set this to just byte-boundary.  */
 192 #define STRUCTURE_SIZE_BOUNDARY 8
 193
 194 /* The lower bits are ignored.  */
 195 #define STRICT_ALIGNMENT 1
 196
 197
 198 /* Node: Type Layout */
 199
 200 /* It might seem more natural to have 64-bit ints on a 64-bit machine,
 201    but then an occasional MMIX programmer needs to know how to put a lot
 202    of __attribute__ stuff to get to the 8, 16 and 32-bit modes rather
 203    than the "intuitive" char, short and int types.  */
 204 #define INT_TYPE_SIZE 32
 205 #define SHORT_TYPE_SIZE 16
 206 #define LONG_LONG_TYPE_SIZE 64
 207
 208 #define FLOAT_TYPE_SIZE 32
 209 #define DOUBLE_TYPE_SIZE 64
 210 #define LONG_DOUBLE_TYPE_SIZE 64
 211
 212 #define DEFAULT_SIGNED_CHAR 1
 213
 214
 215 /* Node: Register Basics */
 216 /* We tell GCC about all 256 general registers, and we also include
 217    rD, rE, rH, rJ, rR and rO (in that order) so we can describe what insns
 218    clobber them.  We use a faked register for the argument pointer.  It is
 219    always eliminated towards the frame-pointer or the stack-pointer, never
 220    output in assembly.  Any fixed register would do for this, like $255,
 221    but future debugging is easier when using a separate register.  It
 222    counts as a global register for pseudorandom reasons.  */
 223 #define FIRST_PSEUDO_REGISTER 263
 224
 225 /* We treat general registers with no assigned purpose as fixed.  The
 226    stack pointer, $254, is also fixed.  Register $255 is referred to as a
 227    temporary register in the MMIX papers, and used as such in mmixal, so
 228    it should not be used as a stack pointer.  We set it to fixed, and use
 229    it "manually" at times of despair.  */
 230 #define FIXED_REGISTERS \
 231  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
 232    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
 233    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 234    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 235    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 236    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 237    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 238    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 239    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 240    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 241    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 242    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 243    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 244    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 245    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 246    1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, \
 247    1, 1, 0, 0, 0, 1, 1 \
 248  }
 249
 250 /* General registers are fixed and therefore "historically" marked
 251    call-used.  (FIXME: This has changed).  Registers $15..$31 are
 252    call-clobbered; we'll put arguments in $16 and up, and we need $15 for
 253    the MMIX register-stack "hole".  */
 254 #define CALL_USED_REGISTERS \
 255  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, \
 256    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 257    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 258    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 259    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 260    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 261    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 262    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 263    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 264    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 265    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 266    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 267    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 268    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 269    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
 270    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, \
 271    1, 1, 1, 1, 1, 1, 1 \
 272  }
 273
 274 #define INCOMING_REGNO(OUT) mmix_opposite_regno (OUT, 0)
 275
 276 #define OUTGOING_REGNO(IN) mmix_opposite_regno (IN, 1)
 277
 278 /* Defining LOCAL_REGNO is necessary in presence of prologue/epilogue,
 279    else GCC will be confused that those registers aren't saved and
 280    restored.  */
 281 #define LOCAL_REGNO(REGNO) mmix_local_regno (REGNO)
 282
 283 /* Node: Allocation Order */
 284
 285 /* We should allocate registers from 0 to 31 by increasing number, because
 286    I think that's what people expect.  Beyond that, just use
 287    call-clobbered global registers first, then call-clobbered special
 288    registers.  Last, the fixed registers.  */
 289 #define MMIX_MMIXWARE_ABI_REG_ALLOC_ORDER       \
 290  { 0, 1, 2, 3, 4, 5, 6, 7,                      \
 291    8, 9, 10, 11, 12, 13, 14, 15,                \
 292    16, 17, 18, 19, 20, 21, 22, 23,              \
 293    24, 25, 26, 27, 28, 29, 30, 31,              \
 294                                                 \
 295    252, 251, 250, 249, 248, 247,                \
 296                                                 \
 297    253,                                         \
 298                                                 \
 299    258, 260, 259,                               \
 300                                                 \
 301    32, 33, 34, 35, 36, 37, 38, 39,              \
 302    40, 41, 42, 43, 44, 45, 46, 47,              \
 303    48, 49, 50, 51, 52, 53, 54, 55,              \
 304    56, 57, 58, 59, 60, 61, 62, 63,              \
 305    64, 65, 66, 67, 68, 69, 70, 71,              \
 306    72, 73, 74, 75, 76, 77, 78, 79,              \
 307    80, 81, 82, 83, 84, 85, 86, 87,              \
 308    88, 89, 90, 91, 92, 93, 94, 95,              \
 309    96, 97, 98, 99, 100, 101, 102, 103,          \
 310    104, 105, 106, 107, 108, 109, 110, 111,      \
 311    112, 113, 114, 115, 116, 117, 118, 119,      \
 312    120, 121, 122, 123, 124, 125, 126, 127,      \
 313    128, 129, 130, 131, 132, 133, 134, 135,      \
 314    136, 137, 138, 139, 140, 141, 142, 143,      \
 315    144, 145, 146, 147, 148, 149, 150, 151,      \
 316    152, 153, 154, 155, 156, 157, 158, 159,      \
 317    160, 161, 162, 163, 164, 165, 166, 167,      \
 318    168, 169, 170, 171, 172, 173, 174, 175,      \
 319    176, 177, 178, 179, 180, 181, 182, 183,      \
 320    184, 185, 186, 187, 188, 189, 190, 191,      \
 321    192, 193, 194, 195, 196, 197, 198, 199,      \
 322    200, 201, 202, 203, 204, 205, 206, 207,      \
 323    208, 209, 210, 211, 212, 213, 214, 215,      \
 324    216, 217, 218, 219, 220, 221, 222, 223,      \
 325    224, 225, 226, 227, 228, 229, 230, 231,      \
 326    232, 233, 234, 235, 236, 237, 238, 239,      \
 327    240, 241, 242, 243, 244, 245, 246,           \
 328                                                 \
 329    254, 255, 256, 257, 261, 262                 \
 330  }
 331
 332 /* As a convenience, we put this nearby, for ease of comparison.
 333    First, call-clobbered registers in reverse order of assignment as
 334    parameters (also the top ones; not because they're parameters, but
 335    for continuity).
 336
 337    Second, saved registers that go on the register-stack.
 338
 339    Third, special registers rH, rR and rJ.  They should not normally be
 340    allocated, but since they're call-clobbered, it is cheaper to use one
 341    of them than using a call-saved register for a call-clobbered use,
 342    assuming it is referenced a very limited number of times.  Other global
 343    and fixed registers come next; they are never allocated.  */
 344 #define MMIX_GNU_ABI_REG_ALLOC_ORDER            \
 345  { 252, 251, 250, 249, 248, 247, 246,           \
 346    245, 244, 243, 242, 241, 240, 239, 238,      \
 347    237, 236, 235, 234, 233, 232, 231,           \
 348                                                 \
 349    0, 1, 2, 3, 4, 5, 6, 7,                      \
 350    8, 9, 10, 11, 12, 13, 14, 15,                \
 351    16, 17, 18, 19, 20, 21, 22, 23,              \
 352    24, 25, 26, 27, 28, 29, 30, 31,              \
 353                                                 \
 354    253,                                         \
 355                                                 \
 356    258, 260, 259,                               \
 357                                                 \
 358    32, 33, 34, 35, 36, 37, 38, 39,              \
 359    40, 41, 42, 43, 44, 45, 46, 47,              \
 360    48, 49, 50, 51, 52, 53, 54, 55,              \
 361    56, 57, 58, 59, 60, 61, 62, 63,              \
 362    64, 65, 66, 67, 68, 69, 70, 71,              \
 363    72, 73, 74, 75, 76, 77, 78, 79,              \
 364    80, 81, 82, 83, 84, 85, 86, 87,              \
 365    88, 89, 90, 91, 92, 93, 94, 95,              \
 366    96, 97, 98, 99, 100, 101, 102, 103,          \
 367    104, 105, 106, 107, 108, 109, 110, 111,      \
 368    112, 113, 114, 115, 116, 117, 118, 119,      \
 369    120, 121, 122, 123, 124, 125, 126, 127,      \
 370    128, 129, 130, 131, 132, 133, 134, 135,      \
 371    136, 137, 138, 139, 140, 141, 142, 143,      \
 372    144, 145, 146, 147, 148, 149, 150, 151,      \
 373    152, 153, 154, 155, 156, 157, 158, 159,      \
 374    160, 161, 162, 163, 164, 165, 166, 167,      \
 375    168, 169, 170, 171, 172, 173, 174, 175,      \
 376    176, 177, 178, 179, 180, 181, 182, 183,      \
 377    184, 185, 186, 187, 188, 189, 190, 191,      \
 378    192, 193, 194, 195, 196, 197, 198, 199,      \
 379    200, 201, 202, 203, 204, 205, 206, 207,      \
 380    208, 209, 210, 211, 212, 213, 214, 215,      \
 381    216, 217, 218, 219, 220, 221, 222, 223,      \
 382    224, 225, 226, 227, 228, 229, 230,           \
 383                                                 \
 384    254, 255, 256, 257, 261, 262                 \
 385  }
 386
 387 /* The default one.  */
 388 #define REG_ALLOC_ORDER MMIX_MMIXWARE_ABI_REG_ALLOC_ORDER
 389
 390 /* Node: Values in Registers */
 391
 392 #define HARD_REGNO_NREGS(REGNO, MODE)                   \
 393    ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1)         \
 394     / UNITS_PER_WORD)
 395
 396 #define HARD_REGNO_MODE_OK(REGNO, MODE) 1
 397
 398 /* Note that no register can really be accessed in single-float mode, so
 399    we *can* say 1 here.  FIXME:  Will TRT happen for single-float, or do
 400    we have to punt to libgcc1.asm?  */
 401 #define MODES_TIEABLE_P(MODE1, MODE2) 1
 402
 403
 404 /* Node: Leaf Functions */
 405 /* (empty) */
 406
 407
 408 /* Node: Register Classes */
 409
 410 enum reg_class
 411  {
 412    NO_REGS, GENERAL_REGS, REMAINDER_REG, HIMULT_REG,
 413    SYSTEM_REGS, ALL_REGS, LIM_REG_CLASSES
 414  };
 415
 416 #define N_REG_CLASSES (int) LIM_REG_CLASSES
 417
 418 #define REG_CLASS_NAMES                                         \
 419  {"NO_REGS", "GENERAL_REGS", "REMAINDER_REG", "HIMULT_REG",     \
 420   "SYSTEM_REGS", "ALL_REGS"}
 421
 422 /* Note that the contents of each item is always 32 bits.  */
 423 #define REG_CLASS_CONTENTS                      \
 424  {{0, 0, 0, 0, 0, 0, 0, 0, 0},                  \
 425   {~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, 0x20},       \
 426   {0, 0, 0, 0, 0, 0, 0, 0, 0x10},               \
 427   {0, 0, 0, 0, 0, 0, 0, 0, 4},                  \
 428   {0, 0, 0, 0, 0, 0, 0, 0, 0x7f},               \
 429   {~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, 0x7f}}
 430
 431 #define REGNO_REG_CLASS(REGNO)                                  \
 432  ((REGNO) <= MMIX_LAST_GENERAL_REGISTER                         \
 433   || (REGNO) == MMIX_ARG_POINTER_REGNUM                         \
 434   ? GENERAL_REGS                                                \
 435   : (REGNO) == MMIX_REMAINDER_REGNUM ? REMAINDER_REG            \
 436   : (REGNO) == MMIX_HIMULT_REGNUM ? HIMULT_REG : SYSTEM_REGS)
 437
 438 #define BASE_REG_CLASS GENERAL_REGS
 439
 440 #define INDEX_REG_CLASS GENERAL_REGS
 441
 442 #define REG_CLASS_FROM_LETTER(CHAR)             \
 443  ((CHAR) == 'x' ? SYSTEM_REGS                   \
 444   : (CHAR) == 'y' ? REMAINDER_REG               \
 445   : (CHAR) == 'z' ? HIMULT_REG : NO_REGS)
 446
 447 #define REGNO_OK_FOR_BASE_P(REGNO)                              \
 448  ((REGNO) <= MMIX_LAST_GENERAL_REGISTER                         \
 449   || (REGNO) == MMIX_ARG_POINTER_REGNUM                         \
 450   || (reg_renumber[REGNO] > 0                                   \
 451       && reg_renumber[REGNO] <= MMIX_LAST_GENERAL_REGISTER))
 452
 453 #define REGNO_OK_FOR_INDEX_P(REGNO) REGNO_OK_FOR_BASE_P (REGNO)
 454
 455 #define PREFERRED_RELOAD_CLASS(X, CLASS) \
 456  mmix_preferred_reload_class (X, CLASS)
 457
 458 #define PREFERRED_OUTPUT_RELOAD_CLASS(X, CLASS) \
 459  mmix_preferred_output_reload_class (X, CLASS)
 460
 461 #define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \
 462  mmix_secondary_reload_class (CLASS, MODE, X, 1)
 463
 464 #define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \
 465  mmix_secondary_reload_class (CLASS, MODE, X, 0)
 466
 467 #define CLASS_MAX_NREGS(CLASS, MODE) HARD_REGNO_NREGS (CLASS, MODE)
 468
 469 #define CONST_OK_FOR_LETTER_P(VALUE, C) \
 470  mmix_const_ok_for_letter_p (VALUE, C)
 471
 472 #define EXTRA_CONSTRAINT(VALUE, C)      \
 473  mmix_extra_constraint (VALUE, C, MMIX_REG_OK_STRICT)
 474
 475 /* Do we need anything serious here?  Yes, any FLOT constant.  */
 476 #define CONST_DOUBLE_OK_FOR_LETTER_P(VALUE, C)                  \
 477  mmix_const_double_ok_for_letter_p (VALUE, C)
 478
 479
 480 /* Node: Frame Layout */
 481
 482 #define STACK_GROWS_DOWNWARD
 483 #define FRAME_GROWS_DOWNWARD 1
 484
 485 #define STARTING_FRAME_OFFSET \
 486   mmix_starting_frame_offset ()
 487
 488 #define FIRST_PARM_OFFSET(FUNDECL) 0
 489
 490 #define DYNAMIC_CHAIN_ADDRESS(FRAMEADDR) \
 491  mmix_dynamic_chain_address (FRAMEADDR)
 492
 493 /* FIXME: It seems RETURN_ADDR_OFFSET is undocumented.  */
 494
 495 #define SETUP_FRAME_ADDRESSES() \
 496  mmix_setup_frame_addresses ()
 497
 498 #define RETURN_ADDR_RTX(COUNT, FRAME)           \
 499  mmix_return_addr_rtx (COUNT, FRAME)
 500
 501 /* It's in rJ before we store it somewhere.  */
 502 #define INCOMING_RETURN_ADDR_RTX \
 503  gen_rtx_REG (Pmode, MMIX_INCOMING_RETURN_ADDRESS_REGNUM)
 504
 505 /* FIXME: This does not seem properly documented or cross-indexed.
 506    Nowhere except in the code does it say it *has* to be in the range
 507    0..255, or else it will be truncated.  That goes for the default too.  */
 508 #define DWARF_FRAME_RETURN_COLUMN \
 509  DWARF_FRAME_REGNUM (MMIX_INCOMING_RETURN_ADDRESS_REGNUM)
 510
 511 /* No return address is stored there.  */
 512 #define INCOMING_FRAME_SP_OFFSET 0
 513
 514 /* Node: Stack Checking */
 515 /* (empty) */
 516
 517
 518 /* Node: Exception Handling */
 519
 520 #define EH_RETURN_DATA_REGNO(N) \
 521  mmix_eh_return_data_regno (N)
 522
 523 #define EH_RETURN_STACKADJ_RTX \
 524  mmix_eh_return_stackadj_rtx ()
 525
 526 #define EH_RETURN_HANDLER_RTX \
 527  mmix_eh_return_handler_rtx ()
 528
 529 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
 530  mmix_asm_preferred_eh_data_format (CODE, GLOBAL)
 531
 532 /* Node: Frame Registers */
 533 #define STACK_POINTER_REGNUM MMIX_STACK_POINTER_REGNUM
 534
 535 /* Perhaps we can use HARD_FRAME_POINTER_REGNUM and decide later on
 536    what register we want to use.  */
 537 #define FRAME_POINTER_REGNUM MMIX_FRAME_POINTER_REGNUM
 538 #define ARG_POINTER_REGNUM MMIX_ARG_POINTER_REGNUM
 539
 540 #define STATIC_CHAIN_REGNUM MMIX_STATIC_CHAIN_REGNUM
 541
 542
 543 /* Node: Elimination */
 544
 545 /* The frame-pointer is stored in a location that either counts to the
 546    offset of incoming parameters, or that counts to the offset of the
 547    frame, so we can't use a single offset.  We therefore eliminate those
 548    two separately.  */
 549 #define ELIMINABLE_REGS                         \
 550  {{ARG_POINTER_REGNUM, STACK_POINTER_REGNUM},   \
 551   {ARG_POINTER_REGNUM, FRAME_POINTER_REGNUM},   \
 552   {FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}}
 553
 554 #define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
 555  (OFFSET) = mmix_initial_elimination_offset (FROM, TO)
 556
 557
 558 /* Node: Stack Arguments */
 559
 560 #define ACCUMULATE_OUTGOING_ARGS 1
 561
 562
 563 /* Node: Register Arguments */
 564
 565 typedef struct { int regs; int lib; } CUMULATIVE_ARGS;
 566
 567 #define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, INDIRECT, N_NAMED_ARGS) \
 568  ((CUM).regs = 0, (CUM).lib = ((LIBNAME) != 0))
 569
 570 #define FUNCTION_ARG_REGNO_P(REGNO)             \
 571  mmix_function_arg_regno_p (REGNO, 0)
 572
 573
 574 /* Node: Caller Saves */
 575 /* (empty) */
 576
 577
 578 /* Node: Function Entry */
 579
 580 /* See mmix.c for TARGET_ASM_FUNCTION_PROLOGUE and
 581    TARGET_ASM_FUNCTION_EPILOGUE.  */
 582
 583 /* We need to say that the epilogue uses the return address, so the
 584    initial-value machinery restores it.  FIXME: Some targets
 585    conditionalize on "reload_completed &&".  Investigate difference.
 586    FIXME: Not needed if nonlocal_goto_stack_level.  */
 587 #define EPILOGUE_USES(REGNO) \
 588  ((REGNO) == MMIX_INCOMING_RETURN_ADDRESS_REGNUM)
 589
 590 /* Node: Profiling */
 591 #define FUNCTION_PROFILER(FILE, LABELNO)        \
 592  mmix_function_profiler (FILE, LABELNO)
 593
 594 /* Node: Trampolines */
 595
 596 #define TRAMPOLINE_SIZE         (4*UNITS_PER_WORD)
 597 #define TRAMPOLINE_ALIGNMENT    BITS_PER_WORD
 598
 599 /* Node: Addressing Modes */
 600
 601 #define CONSTANT_ADDRESS_P(X) \
 602  mmix_constant_address_p (X)
 603
 604 #define MAX_REGS_PER_ADDRESS 2
 605
 606 #ifndef REG_OK_STRICT
 607 # define REG_OK_FOR_BASE_P(X)                   \
 608   (REGNO (X) <= MMIX_LAST_GENERAL_REGISTER      \
 609    || REGNO (X) == MMIX_ARG_POINTER_REGNUM      \
 610    || REGNO (X) >= FIRST_PSEUDO_REGISTER)
 611 #else
 612 # define REG_OK_FOR_BASE_P(X) REGNO_OK_FOR_BASE_P (REGNO (X))
 613 #endif /* REG_OK_STRICT */
 614
 615 #define REG_OK_FOR_INDEX_P(X) REG_OK_FOR_BASE_P (X)
 616
 617
 618 /* Node: Condition Code */
 619
 620 #define SELECT_CC_MODE(OP, X, Y)                \
 621  mmix_select_cc_mode (OP, X, Y)
 622
 623 /* A definition of CANONICALIZE_COMPARISON that changed LE and GT
 624    comparisons with -1 to LT and GE respectively, and LT, LTU, GE or GEU
 625    comparisons with 256 to 255 and LE, LEU, GT and GTU has been
 626    ineffective; the code path for performing the changes did not trig for
 627    neither the GCC testsuite nor ghostscript-6.52 nor Knuth's mmix.tar.gz
 628    itself (core GCC functionality supposedly handling it) with sources
 629    from 2002-06-06.  */
 630
 631 #define REVERSIBLE_CC_MODE(MODE)                \
 632  mmix_reversible_cc_mode (MODE)
 633
 634
 635 /* Node: Costs */
 636
 637 /* The special registers can only move to and from general regs, and we
 638    need to check that their constraints match, so say 3 for them.  */
 639 /* WARNING: gcc-2.7.2.2 i686-pc-linux-gnulibc1 (as shipped with RH 4.2)
 640    miscompiles reload1.c:reload_cse_simplify_set; a call to
 641    reload_cse_regno_equal_p is missing when checking if a substitution of
 642    a register setting is valid if this is defined to just the expression
 643    in mmix_register_move_cost.
 644
 645    Symptom: a (all?) register setting is optimized away for e.g.
 646    "char *p1(char *p) { return p+1; }" and the value of register zero ($0)
 647    is returned.
 648
 649    We can workaround by making this a function call - unknown if this
 650    causes dire speed effects.  */
 651 #define REGISTER_MOVE_COST(MODE, FROM, TO) \
 652  mmix_register_move_cost (MODE, FROM, TO)
 653
 654 #define SLOW_BYTE_ACCESS 0
 655
 656
 657 /* Node: Sections */
 658
 659 /* This must be a constant string, since it's used in crtstuff.c.  */
 660 #define TEXT_SECTION_ASM_OP \
 661  "\t.text ! mmixal:= 9H LOC 8B"
 662
 663 /* FIXME: Not documented.  */
 664 #define DATA_SECTION_ASM_OP \
 665  mmix_data_section_asm_op ()
 666
 667 #define READONLY_DATA_SECTION_ASM_OP    "\t.section\t.rodata"
 668
 669 /* Node: PIC */
 670 /* (empty) */
 671
 672
 673 /* Node: File Framework */
 674
 675 /* While any other punctuation character but ";" would do, we prefer "%"
 676    or "!"; "!" is an unary operator and so will not be mistakenly included
 677    in correctly formed expressions.  The hash character adds mass; catches
 678    the eye.  We can't have it as a comment char by itself, since it's a
 679    hex-number prefix.  */
 680 #define ASM_COMMENT_START "!#"
 681
 682 /* These aren't currently functional.  We just keep them as markers.  */
 683 #define ASM_APP_ON "%APP\n"
 684 #define ASM_APP_OFF "%NO_APP\n"
 685
 686 #define OUTPUT_QUOTED_STRING(STREAM, STRING) \
 687  mmix_output_quoted_string (STREAM, STRING, strlen (STRING))
 688
 689 #define TARGET_ASM_NAMED_SECTION default_elf_asm_named_section
 690
 691 /* Node: Data Output */
 692
 693 #define ASM_OUTPUT_ASCII(STREAM, PTR, LEN) \
 694  mmix_asm_output_ascii (STREAM, PTR, LEN)
 695
 696 /* Node: Uninitialized Data */
 697
 698 #define ASM_OUTPUT_ALIGNED_COMMON(ST, N, S, A) \
 699  mmix_asm_output_aligned_common (ST, N, S, A)
 700
 701 #define ASM_OUTPUT_ALIGNED_LOCAL(ST, N, S, A) \
 702  mmix_asm_output_aligned_local (ST, N, S, A)
 703
 704
 705 /* Node: Label Output */
 706
 707 #define ASM_OUTPUT_LABEL(STREAM, NAME) \
 708  mmix_asm_output_label (STREAM, NAME)
 709
 710 #define ASM_OUTPUT_INTERNAL_LABEL(STREAM, NAME) \
 711  mmix_asm_output_internal_label (STREAM, NAME)
 712
 713 #define ASM_DECLARE_REGISTER_GLOBAL(STREAM, DECL, REGNO, NAME) \
 714  mmix_asm_declare_register_global (STREAM, DECL, REGNO, NAME)
 715
 716 #define GLOBAL_ASM_OP "\t.global "
 717
 718 #define ASM_WEAKEN_LABEL(STREAM, NAME) \
 719  mmix_asm_weaken_label (STREAM, NAME)
 720
 721 #define MAKE_DECL_ONE_ONLY(DECL) \
 722  mmix_make_decl_one_only (DECL)
 723
 724 #define ASM_OUTPUT_LABELREF(STREAM, NAME) \
 725  mmix_asm_output_labelref (STREAM, NAME)
 726
 727 /* We insert a ":" to disambiguate against user symbols like L5.  */
 728 #define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM) \
 729  sprintf (LABEL, "*%s:%ld", PREFIX, (long)(NUM))
 730
 731 /* Insert "::"; these are rarer than internal labels.  FIXME: Make sure no
 732    ":" is seen in the object file; we don't really want that mmixal
 733    feature visible there.  We don't want the default, which uses a dot;
 734    that'd be incompatible with mmixal.  */
 735 #define ASM_PN_FORMAT "%s::%lu"
 736
 737 #define ASM_OUTPUT_DEF(STREAM, NAME, VALUE) \
 738  mmix_asm_output_def (STREAM, NAME, VALUE)
 739
 740 /* Node: Macros for Initialization */
 741 /* We're compiling to ELF and linking to MMO; fundamental ELF features
 742    that GCC depend on are there.  */
 743
 744 /* These must be constant strings, since they're used in crtstuff.c.  */
 745 #define INIT_SECTION_ASM_OP "\t.section .init,\"ax\" ! mmixal-incompatible"
 746
 747 #define FINI_SECTION_ASM_OP "\t.section .fini,\"ax\" ! mmixal-incompatible"
 748
 749 #define OBJECT_FORMAT_ELF
 750
 751
 752 /* Node: Instruction Output */
 753
 754 /* The non-$ register names must be prefixed with ":", since they're
 755    affected by PREFIX.  We provide the non-colon names as additional
 756    names.  */
 757 #define REGISTER_NAMES                                                  \
 758  {"$0", "$1", "$2", "$3", "$4", "$5", "$6", "$7",                       \
 759   "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15",                 \
 760   "$16", "$17", "$18", "$19", "$20", "$21", "$22", "$23",               \
 761   "$24", "$25", "$26", "$27", "$28", "$29", "$30", "$31",               \
 762   "$32", "$33", "$34", "$35", "$36", "$37", "$38", "$39",               \
 763   "$40", "$41", "$42", "$43", "$44", "$45", "$46", "$47",               \
 764   "$48", "$49", "$50", "$51", "$52", "$53", "$54", "$55",               \
 765   "$56", "$57", "$58", "$59", "$60", "$61", "$62", "$63",               \
 766   "$64", "$65", "$66", "$67", "$68", "$69", "$70", "$71",               \
 767   "$72", "$73", "$74", "$75", "$76", "$77", "$78", "$79",               \
 768   "$80", "$81", "$82", "$83", "$84", "$85", "$86", "$87",               \
 769   "$88", "$89", "$90", "$91", "$92", "$93", "$94", "$95",               \
 770   "$96", "$97", "$98", "$99", "$100", "$101", "$102", "$103",           \
 771   "$104", "$105", "$106", "$107", "$108", "$109", "$110", "$111",       \
 772   "$112", "$113", "$114", "$115", "$116", "$117", "$118", "$119",       \
 773   "$120", "$121", "$122", "$123", "$124", "$125", "$126", "$127",       \
 774   "$128", "$129", "$130", "$131", "$132", "$133", "$134", "$135",       \
 775   "$136", "$137", "$138", "$139", "$140", "$141", "$142", "$143",       \
 776   "$144", "$145", "$146", "$147", "$148", "$149", "$150", "$151",       \
 777   "$152", "$153", "$154", "$155", "$156", "$157", "$158", "$159",       \
 778   "$160", "$161", "$162", "$163", "$164", "$165", "$166", "$167",       \
 779   "$168", "$169", "$170", "$171", "$172", "$173", "$174", "$175",       \
 780   "$176", "$177", "$178", "$179", "$180", "$181", "$182", "$183",       \
 781   "$184", "$185", "$186", "$187", "$188", "$189", "$190", "$191",       \
 782   "$192", "$193", "$194", "$195", "$196", "$197", "$198", "$199",       \
 783   "$200", "$201", "$202", "$203", "$204", "$205", "$206", "$207",       \
 784   "$208", "$209", "$210", "$211", "$212", "$213", "$214", "$215",       \
 785   "$216", "$217", "$218", "$219", "$220", "$221", "$222", "$223",       \
 786   "$224", "$225", "$226", "$227", "$228", "$229", "$230", "$231",       \
 787   "$232", "$233", "$234", "$235", "$236", "$237", "$238", "$239",       \
 788   "$240", "$241", "$242", "$243", "$244", "$245", "$246", "$247",       \
 789   "$248", "$249", "$250", "$251", "$252", "$253", "$254", "$255",       \
 790   ":rD",  ":rE",  ":rH",  ":rJ",  ":rR",  "ap_!BAD!", ":rO"}
 791
 792 #define ADDITIONAL_REGISTER_NAMES                       \
 793  {{"sp", 254}, {":sp", 254}, {"rD", 256}, {"rE", 257},  \
 794   {"rH", 258}, {"rJ", MMIX_rJ_REGNUM}, {"rO", MMIX_rO_REGNUM}}
 795
 796 #define PRINT_OPERAND(STREAM, X, CODE) \
 797  mmix_print_operand (STREAM, X, CODE)
 798
 799 #define PRINT_OPERAND_PUNCT_VALID_P(CODE) \
 800  mmix_print_operand_punct_valid_p (CODE)
 801
 802 #define PRINT_OPERAND_ADDRESS(STREAM, X) \
 803  mmix_print_operand_address (STREAM, X)
 804
 805 #define ASM_OUTPUT_REG_PUSH(STREAM, REGNO) \
 806  mmix_asm_output_reg_push (STREAM, REGNO)
 807
 808 #define ASM_OUTPUT_REG_POP(STREAM, REGNO) \
 809  mmix_asm_output_reg_pop (STREAM, REGNO)
 810
 811
 812 /* Node: Dispatch Tables */
 813
 814 /* We define both types, since SImode is the better, but DImode the only
 815    possible for mmixal so that's the one actually used.  */
 816 #define ASM_OUTPUT_ADDR_DIFF_ELT(STREAM, BODY, VALUE, REL) \
 817  mmix_asm_output_addr_diff_elt (STREAM, BODY, VALUE, REL)
 818
 819 #define ASM_OUTPUT_ADDR_VEC_ELT(STREAM, VALUE) \
 820  mmix_asm_output_addr_vec_elt (STREAM, VALUE)
 821
 822
 823 /* Node: Exception Region Output */
 824 /* (empty) */
 825
 826 /* Node: Alignment Output */
 827
 828 #define ASM_OUTPUT_SKIP(STREAM, NBYTES) \
 829  mmix_asm_output_skip (STREAM, NBYTES)
 830
 831 #define ASM_OUTPUT_ALIGN(STREAM, POWER) \
 832  mmix_asm_output_align (STREAM, POWER)
 833
 834
 835 /* Node: All Debuggers */
 836
 837 #define DBX_REGISTER_NUMBER(REGNO) \
 838  mmix_dbx_register_number (REGNO)
 839
 840
 841 /* Node: DBX Options */
 842 /* (empty) */
 843 /* Node: DBX Hooks */
 844 /* (empty) */
 845 /* Node: File Names and DBX */
 846 /* (empty) */
 847
 848
 849 /* Node: SDB and DWARF */
 850 #define DWARF2_DEBUGGING_INFO 1
 851 #define DWARF2_ASM_LINE_DEBUG_INFO 1
 852
 853 /* Node: Misc */
 854
 855 /* There's no way to get a PC-relative offset into tables for SImode, so
 856    for the moment we have absolute entries in DImode.
 857    When we're going ELF, these should be SImode and 1.  */
 858 #define CASE_VECTOR_MODE DImode
 859 #define CASE_VECTOR_PC_RELATIVE 0
 860
 861 #define WORD_REGISTER_OPERATIONS
 862
 863 /* We have a choice, which makes this yet another parameter to tweak.  The
 864    gut feeling is currently that SIGN_EXTEND wins; "int" is more frequent
 865    than "unsigned int", and we have signed characters.  FIXME: measure.  */
 866 #define LOAD_EXTEND_OP(MODE) (TARGET_ZERO_EXTEND ? ZERO_EXTEND : SIGN_EXTEND)
 867
 868 #define MOVE_MAX 8
 869
 870 #define TRULY_NOOP_TRUNCATION(OUTPREC, INPREC) 1
 871
 872 /* ??? MMIX allows a choice of STORE_FLAG_VALUE.  Revisit later,
 873    we don't have scc expanders yet.  */
 874
 875 #define Pmode DImode
 876
 877 #define FUNCTION_MODE QImode
 878
 879 #define NO_IMPLICIT_EXTERN_C
 880
 881 /* These are checked.  */
 882 #define DOLLARS_IN_IDENTIFIERS 0
 883 #define NO_DOLLAR_IN_LABEL
 884 #define NO_DOT_IN_LABEL
 885
 886 #endif /* GCC_MMIX_H */
 887 /*
 888  * Local variables:
 889  * eval: (c-set-style "gnu")
 890  * indent-tabs-mode: t
 891  * End:
 892  */