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, 2006
   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, 51 Franklin Street, Fifth Floor,
  21 Boston, MA 02110-1301, 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 /* Here are four prefixes that are used by asm_fprintf to
  41    facilitate customization for alternate assembler syntaxes.
  42    Machines with no likelihood of an alternate syntax need not
  43    define these and need not use asm_fprintf.  */
  44
  45 /* The prefix for register names.  Note that REGISTER_NAMES
  46    is supposed to include this prefix. Also note that this is NOT an
  47    fprintf format string, it is a literal string */
  48
  49 #undef REGISTER_PREFIX
  50 #define REGISTER_PREFIX "%"
  51
  52 /* The prefix for local (compiler generated) labels.
  53    These labels will not appear in the symbol table.  */
  54
  55 #undef LOCAL_LABEL_PREFIX
  56 #define LOCAL_LABEL_PREFIX "."
  57
  58 /* The prefix to add to user-visible assembler symbols.  */
  59
  60 #undef USER_LABEL_PREFIX
  61 #define USER_LABEL_PREFIX ""
  62
  63 #define ASM_COMMENT_START "|"
  64
  65 #undef SIZE_TYPE
  66 #define SIZE_TYPE "unsigned int"
  67
  68 #undef PTRDIFF_TYPE
  69 #define PTRDIFF_TYPE "int"
  70
  71 #undef WCHAR_TYPE
  72 #define WCHAR_TYPE "long int"
  73
  74 #undef WCHAR_TYPE_SIZE
  75 #define WCHAR_TYPE_SIZE BITS_PER_WORD
  76
  77 /* Target OS builtins.  */
  78 #define TARGET_OS_CPP_BUILTINS()                \
  79   do                                            \
  80     {                                           \
  81         LINUX_TARGET_OS_CPP_BUILTINS();         \
  82         builtin_define_std ("mc68000");         \
  83         builtin_define_std ("mc68020");         \
  84    }                                            \
  85   while (0)
  86
  87 #define TARGET_OBJFMT_CPP_BUILTINS()            \
  88   do                                            \
  89     {                                           \
  90         builtin_define ("__ELF__");             \
  91     }                                           \
  92   while (0)
  93
  94 #undef CPP_SPEC
  95 #if TARGET_DEFAULT & MASK_68881
  96 #define CPP_SPEC \
  97   "%{!msoft-float:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
  98 #else
  99 #define CPP_SPEC \
 100   "%{m68881:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
 101 #endif
 102
 103 /* We override the ASM_SPEC from svr4.h because we must pass -m68040 down
 104    to the assembler.  */
 105 #undef ASM_SPEC
 106 #define ASM_SPEC \
 107   "%{v:-V} %{Qy:} %{!Qn:-Qy} %{n} %{T} %{Ym,*} %{Yd,*} %{Wa,*:%*} \
 108 %{m68040} %{m68060:-m68040}"
 109
 110 /* Provide a LINK_SPEC appropriate for GNU/Linux.  Here we provide support
 111    for the special GCC options -static and -shared, which allow us to
 112    link things in one of these three modes by applying the appropriate
 113    combinations of options at link-time.  We like to support here for
 114    as many of the other GNU linker options as possible.  But I don't
 115    have the time to search for those flags.  I am sure how to add
 116    support for -soname shared_object_name. H.J.
 117
 118    I took out %{v:%{!V:-V}}.  It is too much :-(.  They can use
 119    -Wl,-V.
 120
 121    When the -shared link option is used a final link is not being
 122    done.  */
 123
 124 /* If ELF is the default format, we should not use /lib/elf.  */
 125
 126 #define GLIBC_DYNAMIC_LINKER "/lib/ld.so.1"
 127
 128 #undef  LINK_SPEC
 129 #define LINK_SPEC "-m m68kelf %{shared} \
 130   %{!shared: \
 131     %{!static: \
 132       %{rdynamic:-export-dynamic} \
 133       %{!dynamic-linker*:-dynamic-linker " LINUX_DYNAMIC_LINKER "}} \
 134     %{static}}"
 135
 136 /* For compatibility with linux/a.out */
 137
 138 #undef PCC_BITFIELD_TYPE_MATTERS
 139
 140 /* Currently, JUMP_TABLES_IN_TEXT_SECTION must be defined in order to
 141    keep switch tables in the text section.  */
 142
 143 #define JUMP_TABLES_IN_TEXT_SECTION 1
 144
 145 /* Use the default action for outputting the case label.  */
 146 #undef ASM_OUTPUT_CASE_LABEL
 147 #define ASM_RETURN_CASE_JUMP                            \
 148   do {                                                  \
 149     if (TARGET_COLDFIRE)                                \
 150       {                                                 \
 151         if (ADDRESS_REG_P (operands[0]))                \
 152           return "jmp %%pc@(2,%0:l)";                   \
 153         else                                            \
 154           return "ext%.l %0\n\tjmp %%pc@(2,%0:l)";      \
 155       }                                                 \
 156     else                                                \
 157       return "jmp %%pc@(2,%0:w)";                       \
 158   } while (0)
 159
 160 /* This is how to output an assembler line that says to advance the
 161    location counter to a multiple of 2**LOG bytes.  */
 162
 163 #undef ASM_OUTPUT_ALIGN
 164 #define ASM_OUTPUT_ALIGN(FILE,LOG)                              \
 165   if ((LOG) > 0)                                                \
 166     fprintf ((FILE), "%s%u\n", ALIGN_ASM_OP, 1 << (LOG));
 167
 168 /* If defined, a C expression whose value is a string containing the
 169    assembler operation to identify the following data as uninitialized global
 170    data.  */
 171
 172 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
 173
 174 /* A C statement (sans semicolon) to output to the stdio stream
 175    FILE the assembler definition of uninitialized global DECL named
 176    NAME whose size is SIZE bytes and alignment is ALIGN bytes.
 177    Try to use asm_output_aligned_bss to implement this macro.  */
 178
 179 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
 180   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
 181
 182 /* Output assembler code to FILE to increment profiler label # LABELNO
 183    for profiling a function entry.  */
 184
 185 #undef FUNCTION_PROFILER
 186 #define FUNCTION_PROFILER(FILE, LABELNO) \
 187 {                                                                       \
 188   asm_fprintf (FILE, "\tlea (%LLP%d,%Rpc),%Ra1\n", (LABELNO));          \
 189   if (flag_pic)                                                         \
 190     fprintf (FILE, "\tbsr.l _mcount@PLTPC\n");                          \
 191   else                                                                  \
 192     fprintf (FILE, "\tjbsr _mcount\n");                                 \
 193 }
 194
 195 /* How to renumber registers for dbx and gdb.
 196    On the Sun-3, the floating point registers have numbers
 197    18 to 25, not 16 to 23 as they do in the compiler.  */
 198
 199 #define DBX_REGISTER_NUMBER(REGNO) ((REGNO) < 16 ? (REGNO) : (REGNO) + 2)
 200
 201 /* Do not break .stabs pseudos into continuations.  */
 202
 203 #define DBX_CONTIN_LENGTH 0
 204
 205 /* 1 if N is a possible register number for a function value.  For
 206    m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
 207    pointer, or floating types, respectively.  Reject fp0 if not using
 208    a 68881 coprocessor.  */
 209
 210 #undef FUNCTION_VALUE_REGNO_P
 211 #define FUNCTION_VALUE_REGNO_P(N) \
 212   ((N) == 0 || (N) == 8 || (TARGET_68881 && (N) == 16))
 213
 214 /* Define this to be true when FUNCTION_VALUE_REGNO_P is true for
 215    more than one register.  */
 216
 217 #undef NEEDS_UNTYPED_CALL
 218 #define NEEDS_UNTYPED_CALL 1
 219
 220 /* Define how to generate (in the callee) the output value of a
 221    function and how to find (in the caller) the value returned by a
 222    function.  VALTYPE is the data type of the value (as a tree).  If
 223    the precise function being called is known, FUNC is its
 224    FUNCTION_DECL; otherwise, FUNC is 0.  For m68k/SVR4 generate the
 225    result in d0, a0, or fp0 as appropriate.  */
 226
 227 #undef FUNCTION_VALUE
 228 #define FUNCTION_VALUE(VALTYPE, FUNC)                                   \
 229   m68k_function_value (VALTYPE, FUNC)
 230
 231 /* For compatibility with the large body of existing code which does
 232    not always properly declare external functions returning pointer
 233    types, the m68k/SVR4 convention is to copy the value returned for
 234    pointer functions from a0 to d0 in the function epilogue, so that
 235    callers that have neglected to properly declare the callee can
 236    still find the correct return value.  */
 237
 238 #define FUNCTION_EXTRA_EPILOGUE(FILE, SIZE)                             \
 239 do {                                                                    \
 240   if (current_function_returns_pointer                                  \
 241       && ! find_equiv_reg (0, get_last_insn (), 0, 0, 0, 8, Pmode))     \
 242     asm_fprintf (FILE, "\tmove.l %Ra0,%Rd0\n");                         \
 243 } while (0);
 244
 245 /* Define how to find the value returned by a library function
 246    assuming the value has mode MODE.
 247    For m68k/SVR4 look for integer values in d0, pointer values in d0
 248    (returned in both d0 and a0), and floating values in fp0.  */
 249
 250 #undef LIBCALL_VALUE
 251 #define LIBCALL_VALUE(MODE)                                             \
 252   m68k_libcall_value (MODE)
 253
 254 /* For m68k SVR4, structures are returned using the reentrant
 255    technique.  */
 256 #undef PCC_STATIC_STRUCT_RETURN
 257 #define DEFAULT_PCC_STRUCT_RETURN 0
 258
 259 /* Finalize the trampoline by flushing the insn cache.  */
 260
 261 #undef FINALIZE_TRAMPOLINE
 262 #define FINALIZE_TRAMPOLINE(TRAMP)                                      \
 263   emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__clear_cache"),       \
 264                      0, VOIDmode, 2, TRAMP, Pmode,                      \
 265                      plus_constant (TRAMP, TRAMPOLINE_SIZE), Pmode);
 266
 267 /* Clear the instruction cache from `beg' to `end'.  This makes an
 268    inline system call to SYS_cacheflush.  The arguments are as
 269    follows:
 270
 271         cacheflush (addr, scope, cache, len)
 272
 273    addr   - the start address for the flush
 274    scope  - the scope of the flush (see the cpush insn)
 275    cache  - which cache to flush (see the cpush insn)
 276    len    - a factor relating to the number of flushes to perform:
 277             len/16 lines, or len/4096 pages.  */
 278
 279 #define CLEAR_INSN_CACHE(BEG, END)                                      \
 280 {                                                                       \
 281   register unsigned long _beg __asm ("%d1") = (unsigned long) (BEG);    \
 282   unsigned long _end = (unsigned long) (END);                           \
 283   register unsigned long _len __asm ("%d4") = (_end - _beg + 32);       \
 284   __asm __volatile                                                      \
 285     ("move%.l #123, %/d0\n\t"   /* system call nr */                    \
 286      "move%.l #1, %/d2\n\t"     /* clear lines */                       \
 287      "move%.l #3, %/d3\n\t"     /* insn+data caches */                  \
 288      "trap #0"                                                          \
 289      : /* no outputs */                                                 \
 290      : "d" (_beg), "d" (_len)                                           \
 291      : "%d0", "%d2", "%d3");                                            \
 292 }
 293
 294 #define TARGET_ASM_FILE_END file_end_indicate_exec_stack