gcc/config/m68k/linux.h

   1 /* Definitions for Motorola 68k running Linux-based GNU systems with
   2    ELF format.
   3    Copyright (C) 1995-2013 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC 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 3, or (at your option)
  10 any later version.
  11
  12 GCC 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 GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 /* Add %(asm_cpu_spec) to a generic definition of ASM_SPEC.  */
  22 #undef ASM_SPEC
  23 #define ASM_SPEC "%(asm_cpu_spec) %(asm_pcrel_spec)"
  24
  25 #undef PREFERRED_STACK_BOUNDARY
  26 #define PREFERRED_STACK_BOUNDARY 32
  27
  28 /* for 68k machines this only needs to be TRUE for the 68000 */
  29
  30 #undef STRICT_ALIGNMENT
  31 #define STRICT_ALIGNMENT 0
  32 #undef M68K_HONOR_TARGET_STRICT_ALIGNMENT
  33 #define M68K_HONOR_TARGET_STRICT_ALIGNMENT 0
  34
  35 /* Here are four prefixes that are used by asm_fprintf to
  36    facilitate customization for alternate assembler syntaxes.
  37    Machines with no likelihood of an alternate syntax need not
  38    define these and need not use asm_fprintf.  */
  39
  40 /* The prefix for register names.  Note that REGISTER_NAMES
  41    is supposed to include this prefix. Also note that this is NOT an
  42    fprintf format string, it is a literal string */
  43
  44 #undef REGISTER_PREFIX
  45 #define REGISTER_PREFIX "%"
  46
  47 /* The prefix for local (compiler generated) labels.
  48    These labels will not appear in the symbol table.  */
  49
  50 #undef LOCAL_LABEL_PREFIX
  51 #define LOCAL_LABEL_PREFIX "."
  52
  53 /* The prefix to add to user-visible assembler symbols.  */
  54
  55 #undef USER_LABEL_PREFIX
  56 #define USER_LABEL_PREFIX ""
  57
  58 #define ASM_COMMENT_START "|"
  59
  60 /* Target OS builtins.  */
  61 #define TARGET_OS_CPP_BUILTINS() GNU_USER_TARGET_OS_CPP_BUILTINS()
  62
  63 #undef CPP_SPEC
  64 #define CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
  65
  66 /* Provide a LINK_SPEC appropriate for GNU/Linux.  Here we provide support
  67    for the special GCC options -static and -shared, which allow us to
  68    link things in one of these three modes by applying the appropriate
  69    combinations of options at link-time.
  70
  71    When the -shared link option is used a final link is not being
  72    done.  */
  73
  74 #define GLIBC_DYNAMIC_LINKER "/lib/ld.so.1"
  75
  76 #undef LINK_SPEC
  77 #define LINK_SPEC "-m m68kelf %{shared} \
  78   %{!shared: \
  79     %{!static: \
  80       %{rdynamic:-export-dynamic} \
  81       -dynamic-linker " GNU_USER_DYNAMIC_LINKER "} \
  82     %{static}}"
  83
  84 /* For compatibility with linux/a.out */
  85
  86 #undef PCC_BITFIELD_TYPE_MATTERS
  87
  88 /* Currently, JUMP_TABLES_IN_TEXT_SECTION must be defined in order to
  89    keep switch tables in the text section.  */
  90
  91 #define JUMP_TABLES_IN_TEXT_SECTION 1
  92
  93 /* Use the default action for outputting the case label.  */
  94 #undef ASM_OUTPUT_CASE_LABEL
  95 #define ASM_RETURN_CASE_JUMP                            \
  96   do {                                                  \
  97     if (TARGET_COLDFIRE)                                \
  98       {                                                 \
  99         if (ADDRESS_REG_P (operands[0]))                \
 100           return "jmp %%pc@(2,%0:l)";                   \
 101         else                                            \
 102           return "ext%.l %0\n\tjmp %%pc@(2,%0:l)";      \
 103       }                                                 \
 104     else                                                \
 105       return "jmp %%pc@(2,%0:w)";                       \
 106   } while (0)
 107
 108 /* This is how to output an assembler line that says to advance the
 109    location counter to a multiple of 2**LOG bytes.  */
 110
 111 #undef ASM_OUTPUT_ALIGN
 112 #define ASM_OUTPUT_ALIGN(FILE,LOG)                              \
 113   if ((LOG) > 0)                                                \
 114     fprintf ((FILE), "%s%u\n", ALIGN_ASM_OP, 1 << (LOG));
 115
 116 /* If defined, a C expression whose value is a string containing the
 117    assembler operation to identify the following data as uninitialized global
 118    data.  */
 119
 120 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
 121
 122 /* A C statement (sans semicolon) to output to the stdio stream
 123    FILE the assembler definition of uninitialized global DECL named
 124    NAME whose size is SIZE bytes and alignment is ALIGN bytes.
 125    Try to use asm_output_aligned_bss to implement this macro.  */
 126
 127 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
 128   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
 129
 130 /* Output assembler code to FILE to increment profiler label # LABELNO
 131    for profiling a function entry.  */
 132 #define NO_PROFILE_COUNTERS 1
 133 #undef FUNCTION_PROFILER
 134 #define FUNCTION_PROFILER(FILE, LABELNO) \
 135 {                                                                       \
 136   if (flag_pic)                                                         \
 137     fprintf (FILE, "\tbsr.l _mcount@PLTPC\n");                          \
 138   else                                                                  \
 139     fprintf (FILE, "\tjbsr _mcount\n");                                 \
 140 }
 141
 142 /* Do not break .stabs pseudos into continuations.  */
 143
 144 #define DBX_CONTIN_LENGTH 0
 145
 146 /* 1 if N is a possible register number for a function value.  For
 147    m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
 148    pointer, or floating types, respectively.  Reject fp0 if not using
 149    a 68881 coprocessor.  */
 150
 151 #undef FUNCTION_VALUE_REGNO_P
 152 #define FUNCTION_VALUE_REGNO_P(N) \
 153   ((N) == D0_REG || (N) == A0_REG || (TARGET_68881 && (N) == FP0_REG))
 154
 155 /* Define this to be true when FUNCTION_VALUE_REGNO_P is true for
 156    more than one register.  */
 157
 158 #undef NEEDS_UNTYPED_CALL
 159 #define NEEDS_UNTYPED_CALL 1
 160
 161 /* Define how to generate (in the callee) the output value of a
 162    function and how to find (in the caller) the value returned by a
 163    function.  VALTYPE is the data type of the value (as a tree).  If
 164    the precise function being called is known, FUNC is its
 165    FUNCTION_DECL; otherwise, FUNC is 0.  For m68k/SVR4 generate the
 166    result in d0, a0, or fp0 as appropriate.  */
 167
 168 #undef FUNCTION_VALUE
 169 #define FUNCTION_VALUE(VALTYPE, FUNC)                                   \
 170   m68k_function_value (VALTYPE, FUNC)
 171
 172 /* Define how to find the value returned by a library function
 173    assuming the value has mode MODE.
 174    For m68k/SVR4 look for integer values in d0, pointer values in d0
 175    (returned in both d0 and a0), and floating values in fp0.  */
 176
 177 #undef LIBCALL_VALUE
 178 #define LIBCALL_VALUE(MODE)                                             \
 179   m68k_libcall_value (MODE)
 180
 181 /* For m68k SVR4, structures are returned using the reentrant
 182    technique.  */
 183 #undef PCC_STATIC_STRUCT_RETURN
 184 #define DEFAULT_PCC_STRUCT_RETURN 0
 185
 186 /* Finalize the trampoline by flushing the insn cache.  */
 187
 188 #undef FINALIZE_TRAMPOLINE
 189 #define FINALIZE_TRAMPOLINE(TRAMP)                                      \
 190   emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__clear_cache"),       \
 191                      LCT_NORMAL, VOIDmode, 2, TRAMP, Pmode,             \
 192                      plus_constant (Pmode, TRAMP, TRAMPOLINE_SIZE), \
 193                      Pmode);
 194
 195 /* Clear the instruction cache from `beg' to `end'.  This makes an
 196    inline system call to SYS_cacheflush.  The arguments are as
 197    follows:
 198
 199         cacheflush (addr, scope, cache, len)
 200
 201    addr   - the start address for the flush
 202    scope  - the scope of the flush (see the cpush insn)
 203    cache  - which cache to flush (see the cpush insn)
 204    len    - a factor relating to the number of flushes to perform:
 205             len/16 lines, or len/4096 pages.  */
 206
 207 #define CLEAR_INSN_CACHE(BEG, END)                                      \
 208 {                                                                       \
 209   register unsigned long _beg __asm ("%d1") = (unsigned long) (BEG);    \
 210   unsigned long _end = (unsigned long) (END);                           \
 211   register unsigned long _len __asm ("%d4") = (_end - _beg + 32);       \
 212   __asm __volatile                                                      \
 213     ("move%.l #123, %/d0\n\t"   /* system call nr */                    \
 214      "move%.l #1, %/d2\n\t"     /* clear lines */                       \
 215      "move%.l #3, %/d3\n\t"     /* insn+data caches */                  \
 216      "trap #0"                                                          \
 217      : /* no outputs */                                                 \
 218      : "d" (_beg), "d" (_len)                                           \
 219      : "%d0", "%d2", "%d3");                                            \
 220 }
 221
 222 #define TARGET_ASM_FILE_END file_end_indicate_exec_stack
 223
 224 #undef DBX_REGISTER_NUMBER
 225 #define DBX_REGISTER_NUMBER(REGNO) (REGNO)
 226
 227 #undef  SIZE_TYPE
 228 #define SIZE_TYPE "unsigned int"
 229
 230 #undef  PTRDIFF_TYPE
 231 #define PTRDIFF_TYPE "int"
 232
 233 #undef  WCHAR_TYPE
 234 #define WCHAR_TYPE "long int"
 235
 236 #undef  WCHAR_TYPE_SIZE
 237 #define WCHAR_TYPE_SIZE BITS_PER_WORD
 238
 239 /* Install the __sync libcalls.  */
 240 #undef TARGET_INIT_LIBFUNCS
 241 #define TARGET_INIT_LIBFUNCS  m68k_init_sync_libfuncs