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, 2004
   4    Free Software Foundation, Inc.
   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 2, 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 COPYING.  If not, write to
  20 the Free Software Foundation, 59 Temple Place - Suite 330,
  21 Boston, MA 02111-1307, USA.  */
  22
  23 #undef TARGET_VERSION
  24 #define TARGET_VERSION fprintf (stderr, " (68k GNU/Linux with ELF)");
  25
  26 /* Default target comes from config.gcc.  */
  27
  28 #undef TARGET_DEFAULT
  29 #ifdef TARGET_CPU_DEFAULT
  30 #define TARGET_DEFAULT TARGET_CPU_DEFAULT
  31 #else
  32 #define TARGET_DEFAULT (MASK_BITFIELD|MASK_68881|MASK_68020)
  33 #endif
  34
  35 /* for 68k machines this only needs to be TRUE for the 68000 */
  36
  37 #undef STRICT_ALIGNMENT
  38 #define STRICT_ALIGNMENT 0
  39
  40 #undef SUBTARGET_SWITCHES
  41 #define SUBTARGET_SWITCHES      {"ieee-fp", 0, \
  42   N_("Use IEEE math for fp comparisons")},
  43
  44 /* Here are four prefixes that are used by asm_fprintf to
  45    facilitate customization for alternate assembler syntaxes.
  46    Machines with no likelihood of an alternate syntax need not
  47    define these and need not use asm_fprintf.  */
  48
  49 /* The prefix for register names.  Note that REGISTER_NAMES
  50    is supposed to include this prefix. Also note that this is NOT an
  51    fprintf format string, it is a literal string */
  52
  53 #undef REGISTER_PREFIX
  54 #define REGISTER_PREFIX "%"
  55
  56 /* The prefix for local (compiler generated) labels.
  57    These labels will not appear in the symbol table.  */
  58
  59 #undef LOCAL_LABEL_PREFIX
  60 #define LOCAL_LABEL_PREFIX "."
  61
  62 /* The prefix to add to user-visible assembler symbols.  */
  63
  64 #undef USER_LABEL_PREFIX
  65 #define USER_LABEL_PREFIX ""
  66
  67 #define ASM_COMMENT_START "|"
  68
  69 #undef SIZE_TYPE
  70 #define SIZE_TYPE "unsigned int"
  71
  72 #undef PTRDIFF_TYPE
  73 #define PTRDIFF_TYPE "int"
  74
  75 #undef WCHAR_TYPE
  76 #define WCHAR_TYPE "long int"
  77
  78 #undef WCHAR_TYPE_SIZE
  79 #define WCHAR_TYPE_SIZE BITS_PER_WORD
  80
  81 /* Target OS builtins.  */
  82 #define TARGET_OS_CPP_BUILTINS()                \
  83   do                                            \
  84     {                                           \
  85         LINUX_TARGET_OS_CPP_BUILTINS();         \
  86         builtin_define_std ("mc68000");         \
  87         builtin_define_std ("mc68020");         \
  88    }                                            \
  89   while (0)
  90
  91 #define TARGET_OBJFMT_CPP_BUILTINS()            \
  92   do                                            \
  93     {                                           \
  94         builtin_define ("__ELF__");             \
  95     }                                           \
  96   while (0)
  97
  98 #undef CPP_SPEC
  99 #if TARGET_DEFAULT & MASK_68881
 100 #define CPP_SPEC \
 101   "%{fPIC|fpic|fPIE|fpie:-D__PIC__ -D__pic__} %{!msoft-float:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
 102 #else
 103 #define CPP_SPEC \
 104   "%{fPIC|fpic|fPIE|fpie:-D__PIC__ -D__pic__} %{m68881:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
 105 #endif
 106
 107 /* We override the ASM_SPEC from svr4.h because we must pass -m68040 down
 108    to the assembler.  */
 109 #undef ASM_SPEC
 110 #define ASM_SPEC \
 111   "%{v:-V} %{Qy:} %{!Qn:-Qy} %{n} %{T} %{Ym,*} %{Yd,*} %{Wa,*:%*} \
 112 %{m68040} %{m68060:-m68040}"
 113
 114 /* Provide a LINK_SPEC appropriate for GNU/Linux.  Here we provide support
 115    for the special GCC options -static and -shared, which allow us to
 116    link things in one of these three modes by applying the appropriate
 117    combinations of options at link-time.  We like to support here for
 118    as many of the other GNU linker options as possible.  But I don't
 119    have the time to search for those flags.  I am sure how to add
 120    support for -soname shared_object_name. H.J.
 121
 122    I took out %{v:%{!V:-V}}.  It is too much :-(.  They can use
 123    -Wl,-V.
 124
 125    When the -shared link option is used a final link is not being
 126    done.  */
 127
 128 /* If ELF is the default format, we should not use /lib/elf.  */
 129
 130 #undef  LINK_SPEC
 131 #define LINK_SPEC "-m m68kelf %{shared} \
 132   %{!shared: \
 133     %{!static: \
 134       %{rdynamic:-export-dynamic} \
 135       %{!dynamic-linker*:-dynamic-linker /lib/ld.so.1}} \
 136     %{static}}"
 137
 138 /* For compatibility with linux/a.out */
 139
 140 #undef PCC_BITFIELD_TYPE_MATTERS
 141
 142 /* Currently, JUMP_TABLES_IN_TEXT_SECTION must be defined in order to
 143    keep switch tables in the text section.  */
 144
 145 #define JUMP_TABLES_IN_TEXT_SECTION 1
 146
 147 /* Use the default action for outputting the case label.  */
 148 #undef ASM_OUTPUT_CASE_LABEL
 149 #define ASM_RETURN_CASE_JUMP                            \
 150   do {                                                  \
 151     if (TARGET_COLDFIRE)                                \
 152       {                                                 \
 153         if (ADDRESS_REG_P (operands[0]))                \
 154           return "jmp %%pc@(2,%0:l)";                   \
 155         else                                            \
 156           return "ext%.l %0\n\tjmp %%pc@(2,%0:l)";      \
 157       }                                                 \
 158     else                                                \
 159       return "jmp %%pc@(2,%0:w)";                       \
 160   } while (0)
 161
 162 /* This is how to output an assembler line that says to advance the
 163    location counter to a multiple of 2**LOG bytes.  */
 164
 165 #undef ASM_OUTPUT_ALIGN
 166 #define ASM_OUTPUT_ALIGN(FILE,LOG)                              \
 167   if ((LOG) > 0)                                                \
 168     fprintf ((FILE), "%s%u\n", ALIGN_ASM_OP, 1 << (LOG));
 169
 170 /* If defined, a C expression whose value is a string containing the
 171    assembler operation to identify the following data as uninitialized global
 172    data.  */
 173
 174 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
 175
 176 /* A C statement (sans semicolon) to output to the stdio stream
 177    FILE the assembler definition of uninitialized global DECL named
 178    NAME whose size is SIZE bytes and alignment is ALIGN bytes.
 179    Try to use asm_output_aligned_bss to implement this macro.  */
 180
 181 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
 182   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
 183
 184 /* Output assembler code to FILE to increment profiler label # LABELNO
 185    for profiling a function entry.  */
 186
 187 #undef FUNCTION_PROFILER
 188 #define FUNCTION_PROFILER(FILE, LABELNO) \
 189 {                                                                       \
 190   asm_fprintf (FILE, "\tlea (%LLP%d,%Rpc),%Ra1\n", (LABELNO));          \
 191   if (flag_pic)                                                         \
 192     fprintf (FILE, "\tbsr.l _mcount@PLTPC\n");                          \
 193   else                                                                  \
 194     fprintf (FILE, "\tjbsr _mcount\n");                                 \
 195 }
 196
 197 /* How to renumber registers for dbx and gdb.
 198    On the Sun-3, the floating point registers have numbers
 199    18 to 25, not 16 to 23 as they do in the compiler.  */
 200
 201 #define DBX_REGISTER_NUMBER(REGNO) ((REGNO) < 16 ? (REGNO) : (REGNO) + 2)
 202
 203 /* Do not break .stabs pseudos into continuations.  */
 204
 205 #define DBX_CONTIN_LENGTH 0
 206
 207 /* 1 if N is a possible register number for a function value.  For
 208    m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
 209    pointer, or floating types, respectively.  Reject fp0 if not using
 210    a 68881 coprocessor.  */
 211
 212 #undef FUNCTION_VALUE_REGNO_P
 213 #define FUNCTION_VALUE_REGNO_P(N) \
 214   ((N) == 0 || (N) == 8 || (TARGET_68881 && (N) == 16))
 215
 216 /* Define this to be true when FUNCTION_VALUE_REGNO_P is true for
 217    more than one register.  */
 218
 219 #undef NEEDS_UNTYPED_CALL
 220 #define NEEDS_UNTYPED_CALL 1
 221
 222 /* Define how to generate (in the callee) the output value of a
 223    function and how to find (in the caller) the value returned by a
 224    function.  VALTYPE is the data type of the value (as a tree).  If
 225    the precise function being called is known, FUNC is its
 226    FUNCTION_DECL; otherwise, FUNC is 0.  For m68k/SVR4 generate the
 227    result in d0, a0, or fp0 as appropriate.  */
 228
 229 #undef FUNCTION_VALUE
 230 #define FUNCTION_VALUE(VALTYPE, FUNC)                                   \
 231   (TREE_CODE (VALTYPE) == REAL_TYPE && TARGET_68881                     \
 232    ? gen_rtx_REG (TYPE_MODE (VALTYPE), 16)                              \
 233    : (POINTER_TYPE_P (VALTYPE)                                          \
 234       ? gen_rtx_REG (TYPE_MODE (VALTYPE), 8)                            \
 235       : gen_rtx_REG (TYPE_MODE (VALTYPE), 0)))
 236
 237 /* For compatibility with the large body of existing code which does
 238    not always properly declare external functions returning pointer
 239    types, the m68k/SVR4 convention is to copy the value returned for
 240    pointer functions from a0 to d0 in the function epilogue, so that
 241    callers that have neglected to properly declare the callee can
 242    still find the correct return value.  */
 243
 244 #define FUNCTION_EXTRA_EPILOGUE(FILE, SIZE)                             \
 245 do {                                                                    \
 246   if (current_function_returns_pointer                                  \
 247       && ! find_equiv_reg (0, get_last_insn (), 0, 0, 0, 8, Pmode))     \
 248     asm_fprintf (FILE, "\tmove.l %Ra0,%Rd0\n");                         \
 249 } while (0);
 250
 251 /* Define how to find the value returned by a library function
 252    assuming the value has mode MODE.
 253    For m68k/SVR4 look for integer values in d0, pointer values in d0
 254    (returned in both d0 and a0), and floating values in fp0.  */
 255
 256 #undef LIBCALL_VALUE
 257 #define LIBCALL_VALUE(MODE)                                             \
 258   ((((MODE) == SFmode || (MODE) == DFmode || (MODE) == XFmode)          \
 259     && TARGET_68881)                                                    \
 260    ? gen_rtx_REG ((MODE), 16)                                           \
 261    : gen_rtx_REG ((MODE), 0))
 262
 263 /* For m68k SVR4, structures are returned using the reentrant
 264    technique.  */
 265 #undef PCC_STATIC_STRUCT_RETURN
 266 #define DEFAULT_PCC_STRUCT_RETURN 0
 267
 268 /* Finalize the trampoline by flushing the insn cache.  */
 269
 270 #undef FINALIZE_TRAMPOLINE
 271 #define FINALIZE_TRAMPOLINE(TRAMP)                                      \
 272   emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__clear_cache"),       \
 273                      0, VOIDmode, 2, TRAMP, Pmode,                      \
 274                      plus_constant (TRAMP, TRAMPOLINE_SIZE), Pmode);
 275
 276 /* Clear the instruction cache from `beg' to `end'.  This makes an
 277    inline system call to SYS_cacheflush.  The arguments are as
 278    follows:
 279
 280         cacheflush (addr, scope, cache, len)
 281
 282    addr   - the start address for the flush
 283    scope  - the scope of the flush (see the cpush insn)
 284    cache  - which cache to flush (see the cpush insn)
 285    len    - a factor relating to the number of flushes to perform:
 286             len/16 lines, or len/4096 pages.  */
 287
 288 #define CLEAR_INSN_CACHE(BEG, END)                                      \
 289 {                                                                       \
 290   register unsigned long _beg __asm ("%d1") = (unsigned long) (BEG);    \
 291   unsigned long _end = (unsigned long) (END);                           \
 292   register unsigned long _len __asm ("%d4") = (_end - _beg + 32);       \
 293   __asm __volatile                                                      \
 294     ("move%.l #123, %/d0\n\t"   /* system call nr */                    \
 295      "move%.l #1, %/d2\n\t"     /* clear lines */                       \
 296      "move%.l #3, %/d3\n\t"     /* insn+data caches */                  \
 297      "trap #0"                                                          \
 298      : /* no outputs */                                                 \
 299      : "d" (_beg), "d" (_len)                                           \
 300      : "%d0", "%d2", "%d3");                                            \
 301 }
 302
 303 #define TARGET_ASM_FILE_END file_end_indicate_exec_stack