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 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 #ifndef SUPPORT_SUN_FPA
  84
  85 #define REGISTER_NAMES \
  86 {"%d0", "%d1", "%d2", "%d3", "%d4", "%d5", "%d6", "%d7", \
  87  "%a0", "%a1", "%a2", "%a3", "%a4", "%a5", "%a6", "%sp", \
  88  "%fp0", "%fp1", "%fp2", "%fp3", "%fp4", "%fp5", "%fp6", "%fp7" }
  89
  90 #else /* SUPPORTED_SUN_FPA */
  91
  92 #define REGISTER_NAMES \
  93 {"%d0", "%d1", "%d2", "%d3", "%d4", "%d5", "%d6", "%d7", \
  94  "%a0", "%a1", "%a2", "%a3", "%a4", "%a5", "%a6", "%sp", \
  95  "%fp0", "%fp1", "%fp2", "%fp3", "%fp4", "%fp5", "%fp6", "%fp7", \
  96  "%fpa0", "%fpa1", "%fpa2", "%fpa3", "%fpa4", "%fpa5", "%fpa6", "%fpa7", \
  97  "%fpa8", "%fpa9", "%fpa10","%fpa11","%fpa12","%fpa13","%fpa14","%fpa15", \
  98  "%fpa16","%fpa17","%fpa18","%fpa19","%fpa20","%fpa21","%fpa22","%fpa23", \
  99  "%fpa24","%fpa25","%fpa26","%fpa27","%fpa28","%fpa29","%fpa30","%fpa31" }
 100
 101 #endif /* defined SUPPORT_SUN_FPA */
 102
 103 #undef SIZE_TYPE
 104 #define SIZE_TYPE "unsigned int"
 105
 106 #undef PTRDIFF_TYPE
 107 #define PTRDIFF_TYPE "int"
 108
 109 #undef WCHAR_TYPE
 110 #define WCHAR_TYPE "long int"
 111
 112 #undef WCHAR_TYPE_SIZE
 113 #define WCHAR_TYPE_SIZE BITS_PER_WORD
 114
 115 #define CPP_PREDEFINES \
 116   "-D__ELF__ -Dunix -Dmc68000 -Dmc68020 -D__gnu_linux__ -Dlinux -Asystem=unix -Asystem=posix -Acpu=m68k -Amachine=m68k"
 117
 118 #undef CPP_SPEC
 119 #ifdef USE_GNULIBC_1
 120 #if TARGET_DEFAULT & MASK_68881
 121 #define CPP_SPEC \
 122   "%{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{!msoft-float:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE}"
 123 #else
 124 #define CPP_SPEC \
 125   "%{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{m68881:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE}"
 126 #endif
 127 #else
 128 #if TARGET_DEFAULT & MASK_68881
 129 #define CPP_SPEC \
 130   "%{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{!msoft-float:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
 131 #else
 132 #define CPP_SPEC \
 133   "%{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{m68881:-D__HAVE_68881__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
 134 #endif
 135 #endif
 136
 137 /* We override the ASM_SPEC from svr4.h because we must pass -m68040 down
 138    to the assembler.  */
 139 #undef ASM_SPEC
 140 #define ASM_SPEC \
 141   "%{v:-V} %{Qy:} %{!Qn:-Qy} %{n} %{T} %{Ym,*} %{Yd,*} %{Wa,*:%*} \
 142 %{m68040} %{m68060:-m68040}"
 143
 144 /* Provide a LINK_SPEC appropriate for GNU/Linux.  Here we provide support
 145    for the special GCC options -static and -shared, which allow us to
 146    link things in one of these three modes by applying the appropriate
 147    combinations of options at link-time.  We like to support here for
 148    as many of the other GNU linker options as possible.  But I don't
 149    have the time to search for those flags.  I am sure how to add
 150    support for -soname shared_object_name. H.J.
 151
 152    I took out %{v:%{!V:-V}}.  It is too much :-(.  They can use
 153    -Wl,-V.
 154
 155    When the -shared link option is used a final link is not being
 156    done.  */
 157
 158 /* If ELF is the default format, we should not use /lib/elf.  */
 159
 160 #undef  LINK_SPEC
 161 #ifdef USE_GNULIBC_1
 162 #ifndef LINUX_DEFAULT_ELF
 163 #define LINK_SPEC "-m m68kelf %{shared} %{symbolic:-shared -Bsymbolic} \
 164   %{!shared:%{!symbolic: \
 165     %{!static: \
 166       %{rdynamic:-export-dynamic} \
 167       %{!dynamic-linker*:-dynamic-linker /lib/elf/ld-linux.so.1} \
 168       %{!rpath*:-rpath /lib/elf/}} %{static}}}"
 169 #else
 170 #define LINK_SPEC "-m m68kelf %{shared} %{symbolic:-shared -Bsymbolic} \
 171   %{!shared:%{!symbolic: \
 172     %{!static: \
 173       %{rdynamic:-export-dynamic} \
 174       %{!dynamic-linker*:-dynamic-linker /lib/ld-linux.so.1}} \
 175     %{static}}}"
 176 #endif
 177 #else
 178 #define LINK_SPEC "-m m68kelf %{shared} \
 179   %{!shared: \
 180     %{!static: \
 181       %{rdynamic:-export-dynamic} \
 182       %{!dynamic-linker*:-dynamic-linker /lib/ld.so.1}} \
 183     %{static}}"
 184 #endif
 185
 186 /* For compatibility with linux/a.out */
 187
 188 #undef PCC_BITFIELD_TYPE_MATTERS
 189
 190 /* Currently, JUMP_TABLES_IN_TEXT_SECTION must be defined in order to
 191    keep switch tables in the text section.  */
 192
 193 #define JUMP_TABLES_IN_TEXT_SECTION 1
 194
 195 /* Use the default action for outputting the case label.  */
 196 #undef ASM_OUTPUT_CASE_LABEL
 197 #define ASM_RETURN_CASE_JUMP                            \
 198   do {                                                  \
 199     if (TARGET_5200)                                    \
 200       {                                                 \
 201         if (ADDRESS_REG_P (operands[0]))                \
 202           return "jmp %%pc@(2,%0:l)";                   \
 203         else                                            \
 204           return "ext%.l %0\n\tjmp %%pc@(2,%0:l)";      \
 205       }                                                 \
 206     else                                                \
 207       return "jmp %%pc@(2,%0:w)";                       \
 208   } while (0)
 209
 210 /* This is how to output an assembler line that says to advance the
 211    location counter to a multiple of 2**LOG bytes.  */
 212
 213 #undef ASM_OUTPUT_ALIGN
 214 #define ASM_OUTPUT_ALIGN(FILE,LOG)                              \
 215   if ((LOG) > 0)                                                \
 216     fprintf ((FILE), "%s%u\n", ALIGN_ASM_OP, 1 << (LOG));
 217
 218 /* If defined, a C expression whose value is a string containing the
 219    assembler operation to identify the following data as uninitialized global
 220    data.  */
 221
 222 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
 223
 224 /* A C statement (sans semicolon) to output to the stdio stream
 225    FILE the assembler definition of uninitialized global DECL named
 226    NAME whose size is SIZE bytes and alignment is ALIGN bytes.
 227    Try to use asm_output_aligned_bss to implement this macro.  */
 228
 229 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
 230   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
 231
 232 /* Output assembler code to FILE to increment profiler label # LABELNO
 233    for profiling a function entry.  */
 234
 235 #undef FUNCTION_PROFILER
 236 #define FUNCTION_PROFILER(FILE, LABELNO) \
 237 {                                                                       \
 238   asm_fprintf (FILE, "\tlea (%LLP%d,%Rpc),%Ra1\n", (LABELNO));          \
 239   if (flag_pic)                                                         \
 240     fprintf (FILE, "\tbsr.l _mcount@PLTPC\n");                          \
 241   else                                                                  \
 242     fprintf (FILE, "\tjbsr _mcount\n");                                 \
 243 }
 244
 245 /* How to renumber registers for dbx and gdb.
 246    On the Sun-3, the floating point registers have numbers
 247    18 to 25, not 16 to 23 as they do in the compiler.  */
 248
 249 #define DBX_REGISTER_NUMBER(REGNO) ((REGNO) < 16 ? (REGNO) : (REGNO) + 2)
 250
 251 /* Do not break .stabs pseudos into continuations.  */
 252
 253 #define DBX_CONTIN_LENGTH 0
 254
 255 /* 1 if N is a possible register number for a function value.  For
 256    m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
 257    pointer, or floating types, respectively.  Reject fp0 if not using
 258    a 68881 coprocessor.  */
 259
 260 #undef FUNCTION_VALUE_REGNO_P
 261 #define FUNCTION_VALUE_REGNO_P(N) \
 262   ((N) == 0 || (N) == 8 || (TARGET_68881 && (N) == 16))
 263
 264 /* Define this to be true when FUNCTION_VALUE_REGNO_P is true for
 265    more than one register.  */
 266
 267 #undef NEEDS_UNTYPED_CALL
 268 #define NEEDS_UNTYPED_CALL 1
 269
 270 /* Define how to generate (in the callee) the output value of a
 271    function and how to find (in the caller) the value returned by a
 272    function.  VALTYPE is the data type of the value (as a tree).  If
 273    the precise function being called is known, FUNC is its
 274    FUNCTION_DECL; otherwise, FUNC is 0.  For m68k/SVR4 generate the
 275    result in d0, a0, or fp0 as appropriate.  */
 276
 277 #undef FUNCTION_VALUE
 278 #define FUNCTION_VALUE(VALTYPE, FUNC)                                   \
 279   (TREE_CODE (VALTYPE) == REAL_TYPE && TARGET_68881                     \
 280    ? gen_rtx_REG (TYPE_MODE (VALTYPE), 16)                              \
 281    : (POINTER_TYPE_P (VALTYPE)                                          \
 282       ? gen_rtx_REG (TYPE_MODE (VALTYPE), 8)                            \
 283       : gen_rtx_REG (TYPE_MODE (VALTYPE), 0)))
 284
 285 /* For compatibility with the large body of existing code which does
 286    not always properly declare external functions returning pointer
 287    types, the m68k/SVR4 convention is to copy the value returned for
 288    pointer functions from a0 to d0 in the function epilogue, so that
 289    callers that have neglected to properly declare the callee can
 290    still find the correct return value.  */
 291
 292 #define FUNCTION_EXTRA_EPILOGUE(FILE, SIZE)                             \
 293 do {                                                                    \
 294   if (current_function_returns_pointer                                  \
 295       && ! find_equiv_reg (0, get_last_insn (), 0, 0, 0, 8, Pmode))     \
 296     asm_fprintf (FILE, "\tmove.l %Ra0,%Rd0\n");                         \
 297 } while (0);
 298
 299 /* Define how to find the value returned by a library function
 300    assuming the value has mode MODE.
 301    For m68k/SVR4 look for integer values in d0, pointer values in d0
 302    (returned in both d0 and a0), and floating values in fp0.  */
 303
 304 #undef LIBCALL_VALUE
 305 #define LIBCALL_VALUE(MODE)                                             \
 306   ((((MODE) == SFmode || (MODE) == DFmode || (MODE) == XFmode)          \
 307     && TARGET_68881)                                                    \
 308    ? gen_rtx_REG ((MODE), 16)                                           \
 309    : gen_rtx_REG ((MODE), 0))
 310
 311 /* In m68k svr4, a symbol_ref rtx can be a valid PIC operand if it is
 312    an operand of a function call.  */
 313 #undef LEGITIMATE_PIC_OPERAND_P
 314 #define LEGITIMATE_PIC_OPERAND_P(X) \
 315   ((! symbolic_operand (X, VOIDmode) \
 316     && ! (GET_CODE (X) == CONST_DOUBLE && mem_for_const_double (X) != 0 \
 317           && GET_CODE (mem_for_const_double (X)) == MEM                 \
 318           && symbolic_operand (XEXP (mem_for_const_double (X), 0),      \
 319                                VOIDmode)))                              \
 320    || (GET_CODE (X) == SYMBOL_REF && SYMBOL_REF_FLAG (X))               \
 321    || PCREL_GENERAL_OPERAND_OK)
 322
 323 /* For m68k SVR4, structures are returned using the reentrant
 324    technique.  */
 325 #undef PCC_STATIC_STRUCT_RETURN
 326 #define DEFAULT_PCC_STRUCT_RETURN 0
 327
 328 /* Finalize the trampoline by flushing the insn cache.  */
 329
 330 #undef FINALIZE_TRAMPOLINE
 331 #define FINALIZE_TRAMPOLINE(TRAMP)                                      \
 332   emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__clear_cache"),       \
 333                      0, VOIDmode, 2, TRAMP, Pmode,                      \
 334                      plus_constant (TRAMP, TRAMPOLINE_SIZE), Pmode);
 335
 336 /* Clear the instruction cache from `beg' to `end'.  This makes an
 337    inline system call to SYS_cacheflush.  The arguments are as
 338    follows:
 339
 340         cacheflush (addr, scope, cache, len)
 341
 342    addr   - the start address for the flush
 343    scope  - the scope of the flush (see the cpush insn)
 344    cache  - which cache to flush (see the cpush insn)
 345    len    - a factor relating to the number of flushes to perform:
 346             len/16 lines, or len/4096 pages.  */
 347
 348 #define CLEAR_INSN_CACHE(BEG, END)                                      \
 349 {                                                                       \
 350   register unsigned long _beg __asm ("%d1") = (unsigned long) (BEG);    \
 351   unsigned long _end = (unsigned long) (END);                           \
 352   register unsigned long _len __asm ("%d4") = (_end - _beg + 32);       \
 353   __asm __volatile                                                      \
 354     ("move%.l %#123, %/d0\n\t"  /* system call nr */                    \
 355      "move%.l %#1, %/d2\n\t"    /* clear lines */                       \
 356      "move%.l %#3, %/d3\n\t"    /* insn+data caches */                  \
 357      "trap %#0"                                                         \
 358      : /* no outputs */                                                 \
 359      : "d" (_beg), "d" (_len)                                           \
 360      : "%d0", "%d2", "%d3");                                            \
 361 }