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 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 #define REGISTER_NAMES \
  84 {"%d0", "%d1", "%d2", "%d3", "%d4", "%d5", "%d6", "%d7", \
  85  "%a0", "%a1", "%a2", "%a3", "%a4", "%a5", "%a6", "%sp", \
  86  "%fp0", "%fp1", "%fp2", "%fp3", "%fp4", "%fp5", "%fp6", "%fp7" }
  87
  88 #undef SIZE_TYPE
  89 #define SIZE_TYPE "unsigned int"
  90
  91 #undef PTRDIFF_TYPE
  92 #define PTRDIFF_TYPE "int"
  93
  94 #undef WCHAR_TYPE
  95 #define WCHAR_TYPE "long int"
  96
  97 #undef WCHAR_TYPE_SIZE
  98 #define WCHAR_TYPE_SIZE BITS_PER_WORD
  99
 100 /* Target OS builtins.  */
 101 #define TARGET_OS_CPP_BUILTINS()                \
 102   do                                            \
 103     {                                           \
 104         builtin_define_std ("mc68000");         \
 105         builtin_define_std ("mc68020");         \
 106         builtin_define_std ("linux");           \
 107         builtin_define_std ("unix");            \
 108         builtin_define ("__gnu_linux__");       \
 109         builtin_assert ("system=unix");         \
 110         builtin_assert ("system=posix");        \
 111    }                                            \
 112   while (0)
 113
 114 #define TARGET_OBJFMT_CPP_BUILTINS()            \
 115   do                                            \
 116     {                                           \
 117         builtin_define ("__ELF__");             \
 118     }                                           \
 119   while (0)
 120
 121 #undef CPP_SPEC
 122 #if TARGET_DEFAULT & MASK_68881
 123 #define CPP_SPEC \
 124   "%{fPIC|fpic|fPIE|fpie:-D__PIC__ -D__pic__} %{!msoft-float:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
 125 #else
 126 #define CPP_SPEC \
 127   "%{fPIC|fpic|fPIE|fpie:-D__PIC__ -D__pic__} %{m68881:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
 128 #endif
 129
 130 /* We override the ASM_SPEC from svr4.h because we must pass -m68040 down
 131    to the assembler.  */
 132 #undef ASM_SPEC
 133 #define ASM_SPEC \
 134   "%{v:-V} %{Qy:} %{!Qn:-Qy} %{n} %{T} %{Ym,*} %{Yd,*} %{Wa,*:%*} \
 135 %{m68040} %{m68060:-m68040}"
 136
 137 /* Provide a LINK_SPEC appropriate for GNU/Linux.  Here we provide support
 138    for the special GCC options -static and -shared, which allow us to
 139    link things in one of these three modes by applying the appropriate
 140    combinations of options at link-time.  We like to support here for
 141    as many of the other GNU linker options as possible.  But I don't
 142    have the time to search for those flags.  I am sure how to add
 143    support for -soname shared_object_name. H.J.
 144
 145    I took out %{v:%{!V:-V}}.  It is too much :-(.  They can use
 146    -Wl,-V.
 147
 148    When the -shared link option is used a final link is not being
 149    done.  */
 150
 151 /* If ELF is the default format, we should not use /lib/elf.  */
 152
 153 #undef  LINK_SPEC
 154 #define LINK_SPEC "-m m68kelf %{shared} \
 155   %{!shared: \
 156     %{!static: \
 157       %{rdynamic:-export-dynamic} \
 158       %{!dynamic-linker*:-dynamic-linker /lib/ld.so.1}} \
 159     %{static}}"
 160
 161 /* For compatibility with linux/a.out */
 162
 163 #undef PCC_BITFIELD_TYPE_MATTERS
 164
 165 /* Currently, JUMP_TABLES_IN_TEXT_SECTION must be defined in order to
 166    keep switch tables in the text section.  */
 167
 168 #define JUMP_TABLES_IN_TEXT_SECTION 1
 169
 170 /* Use the default action for outputting the case label.  */
 171 #undef ASM_OUTPUT_CASE_LABEL
 172 #define ASM_RETURN_CASE_JUMP                            \
 173   do {                                                  \
 174     if (TARGET_5200)                                    \
 175       {                                                 \
 176         if (ADDRESS_REG_P (operands[0]))                \
 177           return "jmp %%pc@(2,%0:l)";                   \
 178         else                                            \
 179           return "ext%.l %0\n\tjmp %%pc@(2,%0:l)";      \
 180       }                                                 \
 181     else                                                \
 182       return "jmp %%pc@(2,%0:w)";                       \
 183   } while (0)
 184
 185 /* This is how to output an assembler line that says to advance the
 186    location counter to a multiple of 2**LOG bytes.  */
 187
 188 #undef ASM_OUTPUT_ALIGN
 189 #define ASM_OUTPUT_ALIGN(FILE,LOG)                              \
 190   if ((LOG) > 0)                                                \
 191     fprintf ((FILE), "%s%u\n", ALIGN_ASM_OP, 1 << (LOG));
 192
 193 /* If defined, a C expression whose value is a string containing the
 194    assembler operation to identify the following data as uninitialized global
 195    data.  */
 196
 197 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
 198
 199 /* A C statement (sans semicolon) to output to the stdio stream
 200    FILE the assembler definition of uninitialized global DECL named
 201    NAME whose size is SIZE bytes and alignment is ALIGN bytes.
 202    Try to use asm_output_aligned_bss to implement this macro.  */
 203
 204 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
 205   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
 206
 207 /* Output assembler code to FILE to increment profiler label # LABELNO
 208    for profiling a function entry.  */
 209
 210 #undef FUNCTION_PROFILER
 211 #define FUNCTION_PROFILER(FILE, LABELNO) \
 212 {                                                                       \
 213   asm_fprintf (FILE, "\tlea (%LLP%d,%Rpc),%Ra1\n", (LABELNO));          \
 214   if (flag_pic)                                                         \
 215     fprintf (FILE, "\tbsr.l _mcount@PLTPC\n");                          \
 216   else                                                                  \
 217     fprintf (FILE, "\tjbsr _mcount\n");                                 \
 218 }
 219
 220 /* How to renumber registers for dbx and gdb.
 221    On the Sun-3, the floating point registers have numbers
 222    18 to 25, not 16 to 23 as they do in the compiler.  */
 223
 224 #define DBX_REGISTER_NUMBER(REGNO) ((REGNO) < 16 ? (REGNO) : (REGNO) + 2)
 225
 226 /* Do not break .stabs pseudos into continuations.  */
 227
 228 #define DBX_CONTIN_LENGTH 0
 229
 230 /* 1 if N is a possible register number for a function value.  For
 231    m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
 232    pointer, or floating types, respectively.  Reject fp0 if not using
 233    a 68881 coprocessor.  */
 234
 235 #undef FUNCTION_VALUE_REGNO_P
 236 #define FUNCTION_VALUE_REGNO_P(N) \
 237   ((N) == 0 || (N) == 8 || (TARGET_68881 && (N) == 16))
 238
 239 /* Define this to be true when FUNCTION_VALUE_REGNO_P is true for
 240    more than one register.  */
 241
 242 #undef NEEDS_UNTYPED_CALL
 243 #define NEEDS_UNTYPED_CALL 1
 244
 245 /* Define how to generate (in the callee) the output value of a
 246    function and how to find (in the caller) the value returned by a
 247    function.  VALTYPE is the data type of the value (as a tree).  If
 248    the precise function being called is known, FUNC is its
 249    FUNCTION_DECL; otherwise, FUNC is 0.  For m68k/SVR4 generate the
 250    result in d0, a0, or fp0 as appropriate.  */
 251
 252 #undef FUNCTION_VALUE
 253 #define FUNCTION_VALUE(VALTYPE, FUNC)                                   \
 254   (TREE_CODE (VALTYPE) == REAL_TYPE && TARGET_68881                     \
 255    ? gen_rtx_REG (TYPE_MODE (VALTYPE), 16)                              \
 256    : (POINTER_TYPE_P (VALTYPE)                                          \
 257       ? gen_rtx_REG (TYPE_MODE (VALTYPE), 8)                            \
 258       : gen_rtx_REG (TYPE_MODE (VALTYPE), 0)))
 259
 260 /* For compatibility with the large body of existing code which does
 261    not always properly declare external functions returning pointer
 262    types, the m68k/SVR4 convention is to copy the value returned for
 263    pointer functions from a0 to d0 in the function epilogue, so that
 264    callers that have neglected to properly declare the callee can
 265    still find the correct return value.  */
 266
 267 #define FUNCTION_EXTRA_EPILOGUE(FILE, SIZE)                             \
 268 do {                                                                    \
 269   if (current_function_returns_pointer                                  \
 270       && ! find_equiv_reg (0, get_last_insn (), 0, 0, 0, 8, Pmode))     \
 271     asm_fprintf (FILE, "\tmove.l %Ra0,%Rd0\n");                         \
 272 } while (0);
 273
 274 /* Define how to find the value returned by a library function
 275    assuming the value has mode MODE.
 276    For m68k/SVR4 look for integer values in d0, pointer values in d0
 277    (returned in both d0 and a0), and floating values in fp0.  */
 278
 279 #undef LIBCALL_VALUE
 280 #define LIBCALL_VALUE(MODE)                                             \
 281   ((((MODE) == SFmode || (MODE) == DFmode || (MODE) == XFmode)          \
 282     && TARGET_68881)                                                    \
 283    ? gen_rtx_REG ((MODE), 16)                                           \
 284    : gen_rtx_REG ((MODE), 0))
 285
 286 /* In m68k svr4, a symbol_ref rtx can be a valid PIC operand if it is
 287    an operand of a function call.  */
 288 #undef LEGITIMATE_PIC_OPERAND_P
 289 #define LEGITIMATE_PIC_OPERAND_P(X) \
 290   ((! symbolic_operand (X, VOIDmode) \
 291     && ! (GET_CODE (X) == CONST_DOUBLE && mem_for_const_double (X) != 0 \
 292           && GET_CODE (mem_for_const_double (X)) == MEM                 \
 293           && symbolic_operand (XEXP (mem_for_const_double (X), 0),      \
 294                                VOIDmode)))                              \
 295    || (GET_CODE (X) == SYMBOL_REF && SYMBOL_REF_FLAG (X))               \
 296    || PCREL_GENERAL_OPERAND_OK)
 297
 298 /* For m68k SVR4, structures are returned using the reentrant
 299    technique.  */
 300 #undef PCC_STATIC_STRUCT_RETURN
 301 #define DEFAULT_PCC_STRUCT_RETURN 0
 302
 303 /* Finalize the trampoline by flushing the insn cache.  */
 304
 305 #undef FINALIZE_TRAMPOLINE
 306 #define FINALIZE_TRAMPOLINE(TRAMP)                                      \
 307   emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__clear_cache"),       \
 308                      0, VOIDmode, 2, TRAMP, Pmode,                      \
 309                      plus_constant (TRAMP, TRAMPOLINE_SIZE), Pmode);
 310
 311 /* Clear the instruction cache from `beg' to `end'.  This makes an
 312    inline system call to SYS_cacheflush.  The arguments are as
 313    follows:
 314
 315         cacheflush (addr, scope, cache, len)
 316
 317    addr   - the start address for the flush
 318    scope  - the scope of the flush (see the cpush insn)
 319    cache  - which cache to flush (see the cpush insn)
 320    len    - a factor relating to the number of flushes to perform:
 321             len/16 lines, or len/4096 pages.  */
 322
 323 #define CLEAR_INSN_CACHE(BEG, END)                                      \
 324 {                                                                       \
 325   register unsigned long _beg __asm ("%d1") = (unsigned long) (BEG);    \
 326   unsigned long _end = (unsigned long) (END);                           \
 327   register unsigned long _len __asm ("%d4") = (_end - _beg + 32);       \
 328   __asm __volatile                                                      \
 329     ("move%.l %#123, %/d0\n\t"  /* system call nr */                    \
 330      "move%.l %#1, %/d2\n\t"    /* clear lines */                       \
 331      "move%.l %#3, %/d3\n\t"    /* insn+data caches */                  \
 332      "trap %#0"                                                         \
 333      : /* no outputs */                                                 \
 334      : "d" (_beg), "d" (_len)                                           \
 335      : "%d0", "%d2", "%d3");                                            \
 336 }