gcc/config/m68k/linux.h

   1 /* Definitions for Motorola 68k running Linux-based GNU systems with
   2    ELF format.
   3    Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC 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 GNU CC 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 GNU CC; 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 #define LINUX_DEFAULT_ELF
  23 #define MOTOROLA                /* Use Motorola syntax */
  24 #define USE_GAS                 /* But GAS wants jbsr instead of jsr */
  25
  26 /* TODO: convert includes to ${tm_file} list in config.gcc.  */
  27 #include <m68k/m68k.h>
  28
  29 /* Make sure CC1 is undefined.  */
  30 #undef CC1_SPEC
  31
  32 #include "dbxelf.h"
  33 #include "elfos.h"
  34 #include "svr4.h"
  35 #include <linux.h>              /* some common stuff */
  36
  37 #undef TARGET_VERSION
  38 #define TARGET_VERSION fprintf (stderr, " (68k GNU/Linux with ELF)");
  39
  40 /* 68020 with 68881 */
  41 #define TARGET_DEFAULT (MASK_BITFIELD|MASK_68881|MASK_68020)
  42
  43 /* for 68k machines this only needs to be TRUE for the 68000 */
  44
  45 #undef STRICT_ALIGNMENT
  46 #define STRICT_ALIGNMENT 0
  47
  48 #undef SUBTARGET_SWITCHES
  49 #define SUBTARGET_SWITCHES      {"ieee-fp", 0, \
  50   N_("Use IEEE math for fp comparisons")},
  51
  52 /* Here are four prefixes that are used by asm_fprintf to
  53    facilitate customization for alternate assembler syntaxes.
  54    Machines with no likelihood of an alternate syntax need not
  55    define these and need not use asm_fprintf.  */
  56
  57 /* The prefix for register names.  Note that REGISTER_NAMES
  58    is supposed to include this prefix. Also note that this is NOT an
  59    fprintf format string, it is a literal string */
  60
  61 #undef REGISTER_PREFIX
  62 #define REGISTER_PREFIX "%"
  63
  64 /* The prefix for local (compiler generated) labels.
  65    These labels will not appear in the symbol table.  */
  66
  67 #undef LOCAL_LABEL_PREFIX
  68 #define LOCAL_LABEL_PREFIX "."
  69
  70 /* The prefix to add to user-visible assembler symbols.  */
  71
  72 #undef USER_LABEL_PREFIX
  73 #define USER_LABEL_PREFIX ""
  74
  75 #define ASM_COMMENT_START "|"
  76
  77 /* How to refer to registers in assembler output.
  78    This sequence is indexed by compiler's hard-register-number.
  79    Motorola format uses different register names than defined in m68k.h.  */
  80
  81 #undef REGISTER_NAMES
  82
  83 #ifndef SUPPORT_SUN_FPA
  84
  85 #define REGISTER_NAMES \
  86 {"%d0", "%d1", "%d2", "%d3", "%d4", "%d5", "%d6", "%d7", \
  87  "%a0", "%a1", "%a2", "%a3", "%a4", "%a5", "%a6", "%sp", \
  88  "%fp0", "%fp1", "%fp2", "%fp3", "%fp4", "%fp5", "%fp6", "%fp7" }
  89
  90 #else /* SUPPORTED_SUN_FPA */
  91
  92 #define REGISTER_NAMES \
  93 {"%d0", "%d1", "%d2", "%d3", "%d4", "%d5", "%d6", "%d7", \
  94  "%a0", "%a1", "%a2", "%a3", "%a4", "%a5", "%a6", "%sp", \
  95  "%fp0", "%fp1", "%fp2", "%fp3", "%fp4", "%fp5", "%fp6", "%fp7", \
  96  "%fpa0", "%fpa1", "%fpa2", "%fpa3", "%fpa4", "%fpa5", "%fpa6", "%fpa7", \
  97  "%fpa8", "%fpa9", "%fpa10","%fpa11","%fpa12","%fpa13","%fpa14","%fpa15", \
  98  "%fpa16","%fpa17","%fpa18","%fpa19","%fpa20","%fpa21","%fpa22","%fpa23", \
  99  "%fpa24","%fpa25","%fpa26","%fpa27","%fpa28","%fpa29","%fpa30","%fpa31" }
 100
 101 #endif /* defined SUPPORT_SUN_FPA */
 102
 103 #undef SIZE_TYPE
 104 #define SIZE_TYPE "unsigned int"
 105
 106 #undef PTRDIFF_TYPE
 107 #define PTRDIFF_TYPE "int"
 108
 109 #undef WCHAR_TYPE
 110 #define WCHAR_TYPE "long int"
 111
 112 #undef WCHAR_TYPE_SIZE
 113 #define WCHAR_TYPE_SIZE BITS_PER_WORD
 114
 115 #define CPP_PREDEFINES \
 116   "-D__ELF__ -Dunix -Dmc68000 -Dmc68020 -Dlinux -Asystem=unix -Asystem=posix -Acpu=m68k -Amachine=m68k"
 117
 118 #undef CPP_SPEC
 119 #ifdef USE_GNULIBC_1
 120 #if TARGET_DEFAULT & MASK_68881
 121 #define CPP_SPEC \
 122   "%{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{!msoft-float:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE}"
 123 #else
 124 #define CPP_SPEC \
 125   "%{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{m68881:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE}"
 126 #endif
 127 #else
 128 #if TARGET_DEFAULT & MASK_68881
 129 #define CPP_SPEC \
 130   "%{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{!msoft-float:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
 131 #else
 132 #define CPP_SPEC \
 133   "%{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{m68881:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
 134 #endif
 135 #endif
 136
 137 /* We override the ASM_SPEC from svr4.h because we must pass -m68040 down
 138    to the assembler.  */
 139 #undef ASM_SPEC
 140 #define ASM_SPEC \
 141   "%{v:-V} %{Qy:} %{!Qn:-Qy} %{n} %{T} %{Ym,*} %{Yd,*} %{Wa,*:%*} \
 142 %{m68040} %{m68060:-m68040}"
 143
 144 /* Provide a LINK_SPEC appropriate for GNU/Linux.  Here we provide support
 145    for the special GCC options -static and -shared, which allow us to
 146    link things in one of these three modes by applying the appropriate
 147    combinations of options at link-time.  We like to support here for
 148    as many of the other GNU linker options as possible.  But I don't
 149    have the time to search for those flags.  I am sure how to add
 150    support for -soname shared_object_name. H.J.
 151
 152    I took out %{v:%{!V:-V}}.  It is too much :-(.  They can use
 153    -Wl,-V.
 154
 155    When the -shared link option is used a final link is not being
 156    done.  */
 157
 158 /* If ELF is the default format, we should not use /lib/elf.  */
 159
 160 #undef  LINK_SPEC
 161 #ifdef USE_GNULIBC_1
 162 #ifndef LINUX_DEFAULT_ELF
 163 #define LINK_SPEC "-m m68kelf %{shared} %{symbolic:-shared -Bsymbolic} \
 164   %{!shared:%{!symbolic: \
 165     %{!static: \
 166       %{rdynamic:-export-dynamic} \
 167       %{!dynamic-linker*:-dynamic-linker /lib/elf/ld-linux.so.1} \
 168       %{!rpath*:-rpath /lib/elf/}} %{static}}}"
 169 #else
 170 #define LINK_SPEC "-m m68kelf %{shared} %{symbolic:-shared -Bsymbolic} \
 171   %{!shared:%{!symbolic: \
 172     %{!static: \
 173       %{rdynamic:-export-dynamic} \
 174       %{!dynamic-linker*:-dynamic-linker /lib/ld-linux.so.1}} \
 175     %{static}}}"
 176 #endif
 177 #else
 178 #define LINK_SPEC "-m m68kelf %{shared} \
 179   %{!shared: \
 180     %{!static: \
 181       %{rdynamic:-export-dynamic} \
 182       %{!dynamic-linker*:-dynamic-linker /lib/ld.so.1}} \
 183     %{static}}"
 184 #endif
 185
 186 /* For compatibility with linux/a.out */
 187
 188 #undef PCC_BITFIELD_TYPE_MATTERS
 189
 190 /* Currently, JUMP_TABLES_IN_TEXT_SECTION must be defined in order to
 191    keep switch tables in the text section.  */
 192
 193 #define JUMP_TABLES_IN_TEXT_SECTION 1
 194
 195 /* Use the default action for outputting the case label.  */
 196 #undef ASM_OUTPUT_CASE_LABEL
 197 #define ASM_RETURN_CASE_JUMP                    \
 198   do {                                          \
 199     if (TARGET_5200)                            \
 200       return "ext%.l %0\n\tjmp %%pc@(2,%0:l)";  \
 201     else                                        \
 202       return "jmp %%pc@(2,%0:w)";               \
 203   } while (0)
 204
 205 /* This is how to output an assembler line that says to advance the
 206    location counter to a multiple of 2**LOG bytes.  */
 207
 208 #undef ASM_OUTPUT_ALIGN
 209 #define ASM_OUTPUT_ALIGN(FILE,LOG)                              \
 210   if ((LOG) > 0)                                                \
 211     fprintf ((FILE), "%s%u\n", ALIGN_ASM_OP, 1 << (LOG));
 212
 213 /* If defined, a C expression whose value is a string containing the
 214    assembler operation to identify the following data as uninitialized global
 215    data.  */
 216
 217 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
 218
 219 /* A C statement (sans semicolon) to output to the stdio stream
 220    FILE the assembler definition of uninitialized global DECL named
 221    NAME whose size is SIZE bytes and alignment is ALIGN bytes.
 222    Try to use asm_output_aligned_bss to implement this macro.  */
 223
 224 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
 225   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
 226
 227 /* Output assembler code to FILE to increment profiler label # LABELNO
 228    for profiling a function entry.  */
 229
 230 #undef FUNCTION_PROFILER
 231 #define FUNCTION_PROFILER(FILE, LABELNO) \
 232 {                                                                       \
 233   asm_fprintf (FILE, "\tlea (%LLP%d,%Rpc),%Ra1\n", (LABELNO));          \
 234   if (flag_pic)                                                         \
 235     fprintf (FILE, "\tbsr.l _mcount@PLTPC\n");                          \
 236   else                                                                  \
 237     fprintf (FILE, "\tjbsr _mcount\n");                                 \
 238 }
 239
 240 /* How to renumber registers for dbx and gdb.
 241    On the Sun-3, the floating point registers have numbers
 242    18 to 25, not 16 to 23 as they do in the compiler.  */
 243
 244 #define DBX_REGISTER_NUMBER(REGNO) ((REGNO) < 16 ? (REGNO) : (REGNO) + 2)
 245
 246 /* Do not break .stabs pseudos into continuations.  */
 247
 248 #define DBX_CONTIN_LENGTH 0
 249
 250 /* Allow folding division by zero.  */
 251 #define REAL_INFINITY
 252
 253 /* 1 if N is a possible register number for a function value.  For
 254    m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
 255    pointer, or floating types, respectively.  Reject fp0 if not using
 256    a 68881 coprocessor.  */
 257
 258 #undef FUNCTION_VALUE_REGNO_P
 259 #define FUNCTION_VALUE_REGNO_P(N) \
 260   ((N) == 0 || (N) == 8 || (TARGET_68881 && (N) == 16))
 261
 262 /* Define this to be true when FUNCTION_VALUE_REGNO_P is true for
 263    more than one register.  */
 264
 265 #undef NEEDS_UNTYPED_CALL
 266 #define NEEDS_UNTYPED_CALL 1
 267
 268 /* Define how to generate (in the callee) the output value of a
 269    function and how to find (in the caller) the value returned by a
 270    function.  VALTYPE is the data type of the value (as a tree).  If
 271    the precise function being called is known, FUNC is its
 272    FUNCTION_DECL; otherwise, FUNC is 0.  For m68k/SVR4 generate the
 273    result in d0, a0, or fp0 as appropriate.  */
 274
 275 #undef FUNCTION_VALUE
 276 #define FUNCTION_VALUE(VALTYPE, FUNC)                                   \
 277   (TREE_CODE (VALTYPE) == REAL_TYPE && TARGET_68881                     \
 278    ? gen_rtx_REG (TYPE_MODE (VALTYPE), 16)                              \
 279    : (POINTER_TYPE_P (VALTYPE)                                          \
 280       ? gen_rtx_REG (TYPE_MODE (VALTYPE), 8)                            \
 281       : gen_rtx_REG (TYPE_MODE (VALTYPE), 0)))
 282
 283 /* For compatibility with the large body of existing code which does
 284    not always properly declare external functions returning pointer
 285    types, the m68k/SVR4 convention is to copy the value returned for
 286    pointer functions from a0 to d0 in the function epilogue, so that
 287    callers that have neglected to properly declare the callee can
 288    still find the correct return value.  */
 289
 290 #define FUNCTION_EXTRA_EPILOGUE(FILE, SIZE)                             \
 291 do {                                                                    \
 292   if (current_function_returns_pointer                                  \
 293       && ! find_equiv_reg (0, get_last_insn (), 0, 0, 0, 8, Pmode))     \
 294     asm_fprintf (FILE, "\tmove.l %Ra0,%Rd0\n");                         \
 295 } while (0);
 296
 297 /* Define how to find the value returned by a library function
 298    assuming the value has mode MODE.
 299    For m68k/SVR4 look for integer values in d0, pointer values in d0
 300    (returned in both d0 and a0), and floating values in fp0.  */
 301
 302 #undef LIBCALL_VALUE
 303 #define LIBCALL_VALUE(MODE)                                             \
 304   ((((MODE) == SFmode || (MODE) == DFmode || (MODE) == XFmode)          \
 305     && TARGET_68881)                                                    \
 306    ? gen_rtx_REG ((MODE), 16)                                           \
 307    : gen_rtx_REG ((MODE), 0))
 308
 309 /* In m68k svr4, a symbol_ref rtx can be a valid PIC operand if it is
 310    an operand of a function call.  */
 311 #undef LEGITIMATE_PIC_OPERAND_P
 312 #define LEGITIMATE_PIC_OPERAND_P(X) \
 313   ((! symbolic_operand (X, VOIDmode) \
 314     && ! (GET_CODE (X) == CONST_DOUBLE && mem_for_const_double (X) != 0 \
 315           && GET_CODE (mem_for_const_double (X)) == MEM                 \
 316           && symbolic_operand (XEXP (mem_for_const_double (X), 0),      \
 317                                VOIDmode)))                              \
 318    || (GET_CODE (X) == SYMBOL_REF && SYMBOL_REF_FLAG (X))               \
 319    || PCREL_GENERAL_OPERAND_OK)
 320
 321 /* Turn off function cse if we are doing PIC. We always want function
 322    call to be done as `bsr foo@PLTPC', so it will force the assembler
 323    to create the PLT entry for `foo'.  Doing function cse will cause
 324    the address of `foo' to be loaded into a register, which is exactly
 325    what we want to avoid when we are doing PIC on svr4 m68k.  */
 326 #undef SUBTARGET_OVERRIDE_OPTIONS
 327 #define SUBTARGET_OVERRIDE_OPTIONS \
 328   if (flag_pic) flag_no_function_cse = 1;
 329
 330 /* For m68k SVR4, structures are returned using the reentrant
 331    technique.  */
 332 #undef PCC_STATIC_STRUCT_RETURN
 333 #define DEFAULT_PCC_STRUCT_RETURN 0
 334
 335 /* Finalize the trampoline by flushing the insn cache.  */
 336
 337 #undef FINALIZE_TRAMPOLINE
 338 #define FINALIZE_TRAMPOLINE(TRAMP)                                      \
 339   emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__clear_cache"),       \
 340                      0, VOIDmode, 2, TRAMP, Pmode,                      \
 341                      plus_constant (TRAMP, TRAMPOLINE_SIZE), Pmode);
 342
 343 /* Clear the instruction cache from `beg' to `end'.  This makes an
 344    inline system call to SYS_cacheflush.  The arguments are as
 345    follows:
 346
 347         cacheflush (addr, scope, cache, len)
 348
 349    addr   - the start address for the flush
 350    scope  - the scope of the flush (see the cpush insn)
 351    cache  - which cache to flush (see the cpush insn)
 352    len    - a factor relating to the number of flushes to perform:
 353             len/16 lines, or len/4096 pages.  */
 354
 355 #define CLEAR_INSN_CACHE(BEG, END)                                      \
 356 {                                                                       \
 357   register unsigned long _beg __asm ("%d1") = (unsigned long) (BEG);    \
 358   unsigned long _end = (unsigned long) (END);                           \
 359   register unsigned long _len __asm ("%d4") = (_end - _beg + 32);       \
 360   __asm __volatile                                                      \
 361     ("move%.l %#123, %/d0\n\t"  /* system call nr */                    \
 362      "move%.l %#1, %/d2\n\t"    /* clear lines */                       \
 363      "move%.l %#3, %/d3\n\t"    /* insn+data caches */                  \
 364      "trap %#0"                                                         \
 365      : /* no outputs */                                                 \
 366      : "d" (_beg), "d" (_len)                                           \
 367      : "%d0", "%d2", "%d3");                                            \
 368 }
 369 \f
 370 /* Output code to add DELTA to the first argument, and then jump to FUNCTION.
 371    Used for C++ multiple inheritance.  */
 372 #define ASM_OUTPUT_MI_THUNK(FILE, THUNK_FNDECL, DELTA, FUNCTION)        \
 373 do {                                                                    \
 374   if (DELTA > 0 && DELTA <= 8)                                          \
 375     asm_fprintf (FILE, "\taddq.l %I%d,4(%Rsp)\n", DELTA);               \
 376   else if (DELTA < 0 && DELTA >= -8)                                    \
 377     asm_fprintf (FILE, "\tsubq.l %I%d,4(%Rsp)\n", -DELTA);              \
 378   else                                                                  \
 379     asm_fprintf (FILE, "\tadd.l %I%d,4(%Rsp)\n", DELTA);                \
 380                                                                         \
 381   if (flag_pic)                                                         \
 382     {                                                                   \
 383       fprintf (FILE, "\tbra.l ");                                       \
 384       assemble_name (FILE, XSTR (XEXP (DECL_RTL (FUNCTION), 0), 0));    \
 385       fprintf (FILE, "@PLTPC\n");                                       \
 386     }                                                                   \
 387   else                                                                  \
 388     {                                                                   \
 389       fprintf (FILE, "\tjmp ");                                         \
 390       assemble_name (FILE, XSTR (XEXP (DECL_RTL (FUNCTION), 0), 0));    \
 391       fprintf (FILE, "\n");                                             \
 392     }                                                                   \
 393 } while (0)