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, 2002, 2003 Free Software Foundation, Inc.
   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 #undef TARGET_VERSION
  23 #define TARGET_VERSION fprintf (stderr, " (68k GNU/Linux with ELF)");
  24
  25 /* 68020 with 68881 */
  26 #define TARGET_DEFAULT (MASK_BITFIELD|MASK_68881|MASK_68020)
  27
  28 /* for 68k machines this only needs to be TRUE for the 68000 */
  29
  30 #undef STRICT_ALIGNMENT
  31 #define STRICT_ALIGNMENT 0
  32
  33 #undef SUBTARGET_SWITCHES
  34 #define SUBTARGET_SWITCHES      {"ieee-fp", 0, \
  35   N_("Use IEEE math for fp comparisons")},
  36
  37 /* Here are four prefixes that are used by asm_fprintf to
  38    facilitate customization for alternate assembler syntaxes.
  39    Machines with no likelihood of an alternate syntax need not
  40    define these and need not use asm_fprintf.  */
  41
  42 /* The prefix for register names.  Note that REGISTER_NAMES
  43    is supposed to include this prefix. Also note that this is NOT an
  44    fprintf format string, it is a literal string */
  45
  46 #undef REGISTER_PREFIX
  47 #define REGISTER_PREFIX "%"
  48
  49 /* The prefix for local (compiler generated) labels.
  50    These labels will not appear in the symbol table.  */
  51
  52 #undef LOCAL_LABEL_PREFIX
  53 #define LOCAL_LABEL_PREFIX "."
  54
  55 /* The prefix to add to user-visible assembler symbols.  */
  56
  57 #undef USER_LABEL_PREFIX
  58 #define USER_LABEL_PREFIX ""
  59
  60 #define ASM_COMMENT_START "|"
  61
  62 /* How to refer to registers in assembler output.
  63    This sequence is indexed by compiler's hard-register-number.
  64    Motorola format uses different register names than defined in m68k.h.  */
  65
  66 #undef REGISTER_NAMES
  67
  68 #define REGISTER_NAMES \
  69 {"%d0", "%d1", "%d2", "%d3", "%d4", "%d5", "%d6", "%d7", \
  70  "%a0", "%a1", "%a2", "%a3", "%a4", "%a5", "%a6", "%sp", \
  71  "%fp0", "%fp1", "%fp2", "%fp3", "%fp4", "%fp5", "%fp6", "%fp7", "argptr" }
  72
  73 #undef SIZE_TYPE
  74 #define SIZE_TYPE "unsigned int"
  75
  76 #undef PTRDIFF_TYPE
  77 #define PTRDIFF_TYPE "int"
  78
  79 #undef WCHAR_TYPE
  80 #define WCHAR_TYPE "long int"
  81
  82 #undef WCHAR_TYPE_SIZE
  83 #define WCHAR_TYPE_SIZE BITS_PER_WORD
  84
  85 /* Target OS builtins.  */
  86 #define TARGET_OS_CPP_BUILTINS()                \
  87   do                                            \
  88     {                                           \
  89         builtin_define_std ("mc68000");         \
  90         builtin_define_std ("mc68020");         \
  91         builtin_define_std ("linux");           \
  92         builtin_define_std ("unix");            \
  93         builtin_define ("__gnu_linux__");       \
  94         builtin_assert ("system=unix");         \
  95         builtin_assert ("system=posix");        \
  96    }                                            \
  97   while (0)
  98
  99 #define TARGET_OBJFMT_CPP_BUILTINS()            \
 100   do                                            \
 101     {                                           \
 102         builtin_define ("__ELF__");             \
 103     }                                           \
 104   while (0)
 105
 106 #undef CPP_SPEC
 107 #if TARGET_DEFAULT & MASK_68881
 108 #define CPP_SPEC \
 109   "%{fPIC|fpic|fPIE|fpie:-D__PIC__ -D__pic__} %{!msoft-float:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
 110 #else
 111 #define CPP_SPEC \
 112   "%{fPIC|fpic|fPIE|fpie:-D__PIC__ -D__pic__} %{m68881:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
 113 #endif
 114
 115 /* We override the ASM_SPEC from svr4.h because we must pass -m68040 down
 116    to the assembler.  */
 117 #undef ASM_SPEC
 118 #define ASM_SPEC \
 119   "%{v:-V} %{Qy:} %{!Qn:-Qy} %{n} %{T} %{Ym,*} %{Yd,*} %{Wa,*:%*} \
 120 %{m68040} %{m68060:-m68040}"
 121
 122 /* Provide a LINK_SPEC appropriate for GNU/Linux.  Here we provide support
 123    for the special GCC options -static and -shared, which allow us to
 124    link things in one of these three modes by applying the appropriate
 125    combinations of options at link-time.  We like to support here for
 126    as many of the other GNU linker options as possible.  But I don't
 127    have the time to search for those flags.  I am sure how to add
 128    support for -soname shared_object_name. H.J.
 129
 130    I took out %{v:%{!V:-V}}.  It is too much :-(.  They can use
 131    -Wl,-V.
 132
 133    When the -shared link option is used a final link is not being
 134    done.  */
 135
 136 /* If ELF is the default format, we should not use /lib/elf.  */
 137
 138 #undef  LINK_SPEC
 139 #define LINK_SPEC "-m m68kelf %{shared} \
 140   %{!shared: \
 141     %{!static: \
 142       %{rdynamic:-export-dynamic} \
 143       %{!dynamic-linker*:-dynamic-linker /lib/ld.so.1}} \
 144     %{static}}"
 145
 146 /* For compatibility with linux/a.out */
 147
 148 #undef PCC_BITFIELD_TYPE_MATTERS
 149
 150 /* Currently, JUMP_TABLES_IN_TEXT_SECTION must be defined in order to
 151    keep switch tables in the text section.  */
 152
 153 #define JUMP_TABLES_IN_TEXT_SECTION 1
 154
 155 /* Use the default action for outputting the case label.  */
 156 #undef ASM_OUTPUT_CASE_LABEL
 157 #define ASM_RETURN_CASE_JUMP                            \
 158   do {                                                  \
 159     if (TARGET_COLDFIRE)                                \
 160       {                                                 \
 161         if (ADDRESS_REG_P (operands[0]))                \
 162           return "jmp %%pc@(2,%0:l)";                   \
 163         else                                            \
 164           return "ext%.l %0\n\tjmp %%pc@(2,%0:l)";      \
 165       }                                                 \
 166     else                                                \
 167       return "jmp %%pc@(2,%0:w)";                       \
 168   } while (0)
 169
 170 /* This is how to output an assembler line that says to advance the
 171    location counter to a multiple of 2**LOG bytes.  */
 172
 173 #undef ASM_OUTPUT_ALIGN
 174 #define ASM_OUTPUT_ALIGN(FILE,LOG)                              \
 175   if ((LOG) > 0)                                                \
 176     fprintf ((FILE), "%s%u\n", ALIGN_ASM_OP, 1 << (LOG));
 177
 178 /* If defined, a C expression whose value is a string containing the
 179    assembler operation to identify the following data as uninitialized global
 180    data.  */
 181
 182 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
 183
 184 /* A C statement (sans semicolon) to output to the stdio stream
 185    FILE the assembler definition of uninitialized global DECL named
 186    NAME whose size is SIZE bytes and alignment is ALIGN bytes.
 187    Try to use asm_output_aligned_bss to implement this macro.  */
 188
 189 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
 190   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
 191
 192 /* Output assembler code to FILE to increment profiler label # LABELNO
 193    for profiling a function entry.  */
 194
 195 #undef FUNCTION_PROFILER
 196 #define FUNCTION_PROFILER(FILE, LABELNO) \
 197 {                                                                       \
 198   asm_fprintf (FILE, "\tlea (%LLP%d,%Rpc),%Ra1\n", (LABELNO));          \
 199   if (flag_pic)                                                         \
 200     fprintf (FILE, "\tbsr.l _mcount@PLTPC\n");                          \
 201   else                                                                  \
 202     fprintf (FILE, "\tjbsr _mcount\n");                                 \
 203 }
 204
 205 /* How to renumber registers for dbx and gdb.
 206    On the Sun-3, the floating point registers have numbers
 207    18 to 25, not 16 to 23 as they do in the compiler.  */
 208
 209 #define DBX_REGISTER_NUMBER(REGNO) ((REGNO) < 16 ? (REGNO) : (REGNO) + 2)
 210
 211 /* Do not break .stabs pseudos into continuations.  */
 212
 213 #define DBX_CONTIN_LENGTH 0
 214
 215 /* 1 if N is a possible register number for a function value.  For
 216    m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
 217    pointer, or floating types, respectively.  Reject fp0 if not using
 218    a 68881 coprocessor.  */
 219
 220 #undef FUNCTION_VALUE_REGNO_P
 221 #define FUNCTION_VALUE_REGNO_P(N) \
 222   ((N) == 0 || (N) == 8 || (TARGET_68881 && (N) == 16))
 223
 224 /* Define this to be true when FUNCTION_VALUE_REGNO_P is true for
 225    more than one register.  */
 226
 227 #undef NEEDS_UNTYPED_CALL
 228 #define NEEDS_UNTYPED_CALL 1
 229
 230 /* Define how to generate (in the callee) the output value of a
 231    function and how to find (in the caller) the value returned by a
 232    function.  VALTYPE is the data type of the value (as a tree).  If
 233    the precise function being called is known, FUNC is its
 234    FUNCTION_DECL; otherwise, FUNC is 0.  For m68k/SVR4 generate the
 235    result in d0, a0, or fp0 as appropriate.  */
 236
 237 #undef FUNCTION_VALUE
 238 #define FUNCTION_VALUE(VALTYPE, FUNC)                                   \
 239   (TREE_CODE (VALTYPE) == REAL_TYPE && TARGET_68881                     \
 240    ? gen_rtx_REG (TYPE_MODE (VALTYPE), 16)                              \
 241    : (POINTER_TYPE_P (VALTYPE)                                          \
 242       ? gen_rtx_REG (TYPE_MODE (VALTYPE), 8)                            \
 243       : gen_rtx_REG (TYPE_MODE (VALTYPE), 0)))
 244
 245 /* For compatibility with the large body of existing code which does
 246    not always properly declare external functions returning pointer
 247    types, the m68k/SVR4 convention is to copy the value returned for
 248    pointer functions from a0 to d0 in the function epilogue, so that
 249    callers that have neglected to properly declare the callee can
 250    still find the correct return value.  */
 251
 252 #define FUNCTION_EXTRA_EPILOGUE(FILE, SIZE)                             \
 253 do {                                                                    \
 254   if (current_function_returns_pointer                                  \
 255       && ! find_equiv_reg (0, get_last_insn (), 0, 0, 0, 8, Pmode))     \
 256     asm_fprintf (FILE, "\tmove.l %Ra0,%Rd0\n");                         \
 257 } while (0);
 258
 259 /* Define how to find the value returned by a library function
 260    assuming the value has mode MODE.
 261    For m68k/SVR4 look for integer values in d0, pointer values in d0
 262    (returned in both d0 and a0), and floating values in fp0.  */
 263
 264 #undef LIBCALL_VALUE
 265 #define LIBCALL_VALUE(MODE)                                             \
 266   ((((MODE) == SFmode || (MODE) == DFmode || (MODE) == XFmode)          \
 267     && TARGET_68881)                                                    \
 268    ? gen_rtx_REG ((MODE), 16)                                           \
 269    : gen_rtx_REG ((MODE), 0))
 270
 271 /* For m68k SVR4, structures are returned using the reentrant
 272    technique.  */
 273 #undef PCC_STATIC_STRUCT_RETURN
 274 #define DEFAULT_PCC_STRUCT_RETURN 0
 275
 276 /* Finalize the trampoline by flushing the insn cache.  */
 277
 278 #undef FINALIZE_TRAMPOLINE
 279 #define FINALIZE_TRAMPOLINE(TRAMP)                                      \
 280   emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__clear_cache"),       \
 281                      0, VOIDmode, 2, TRAMP, Pmode,                      \
 282                      plus_constant (TRAMP, TRAMPOLINE_SIZE), Pmode);
 283
 284 /* Clear the instruction cache from `beg' to `end'.  This makes an
 285    inline system call to SYS_cacheflush.  The arguments are as
 286    follows:
 287
 288         cacheflush (addr, scope, cache, len)
 289
 290    addr   - the start address for the flush
 291    scope  - the scope of the flush (see the cpush insn)
 292    cache  - which cache to flush (see the cpush insn)
 293    len    - a factor relating to the number of flushes to perform:
 294             len/16 lines, or len/4096 pages.  */
 295
 296 #define CLEAR_INSN_CACHE(BEG, END)                                      \
 297 {                                                                       \
 298   register unsigned long _beg __asm ("%d1") = (unsigned long) (BEG);    \
 299   unsigned long _end = (unsigned long) (END);                           \
 300   register unsigned long _len __asm ("%d4") = (_end - _beg + 32);       \
 301   __asm __volatile                                                      \
 302     ("move%.l %#123, %/d0\n\t"  /* system call nr */                    \
 303      "move%.l %#1, %/d2\n\t"    /* clear lines */                       \
 304      "move%.l %#3, %/d3\n\t"    /* insn+data caches */                  \
 305      "trap %#0"                                                         \
 306      : /* no outputs */                                                 \
 307      : "d" (_beg), "d" (_len)                                           \
 308      : "%d0", "%d2", "%d3");                                            \
 309 }
 310
 311 #define TARGET_ASM_FILE_END file_end_indicate_exec_stack