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