gcc/config/m68k/linux.h

   1 /* Definitions for Motorola 68k running Linux-based GNU systems with
   2    ELF format.
   3    Copyright (C) 1995-2018 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 if (TARGET_LONG_JUMP_TABLE_OFFSETS)        \
 102           return "jmp %%pc@(2,%0:l)";                   \
 103         else                                            \
 104           return "ext%.l %0\n\tjmp %%pc@(2,%0:l)";      \
 105       }                                                 \
 106     else if (TARGET_LONG_JUMP_TABLE_OFFSETS)            \
 107       return "jmp %%pc@(2,%0:l)";                       \
 108     else                                                \
 109       return "jmp %%pc@(2,%0:w)";                       \
 110   } while (0)
 111
 112 /* This is how to output an assembler line that says to advance the
 113    location counter to a multiple of 2**LOG bytes.  */
 114
 115 #undef ASM_OUTPUT_ALIGN
 116 #define ASM_OUTPUT_ALIGN(FILE,LOG)                              \
 117   if ((LOG) > 0)                                                \
 118     fprintf ((FILE), "%s%u\n", ALIGN_ASM_OP, 1 << (LOG));
 119
 120 /* If defined, a C expression whose value is a string containing the
 121    assembler operation to identify the following data as uninitialized global
 122    data.  */
 123
 124 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
 125
 126 /* A C statement (sans semicolon) to output to the stdio stream
 127    FILE the assembler definition of uninitialized global DECL named
 128    NAME whose size is SIZE bytes and alignment is ALIGN bytes.
 129    Try to use asm_output_aligned_bss to implement this macro.  */
 130
 131 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
 132   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
 133
 134 /* Output assembler code to FILE to increment profiler label # LABELNO
 135    for profiling a function entry.  */
 136 #define NO_PROFILE_COUNTERS 1
 137 #undef FUNCTION_PROFILER
 138 #define FUNCTION_PROFILER(FILE, LABELNO) \
 139 {                                                                       \
 140   if (flag_pic)                                                         \
 141     fprintf (FILE, "\tbsr.l _mcount@PLTPC\n");                          \
 142   else                                                                  \
 143     fprintf (FILE, "\tjbsr _mcount\n");                                 \
 144 }
 145
 146 /* Do not break .stabs pseudos into continuations.  */
 147
 148 #define DBX_CONTIN_LENGTH 0
 149
 150 /* 1 if N is a possible register number for a function value.  For
 151    m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
 152    pointer, or floating types, respectively.  Reject fp0 if not using
 153    a 68881 coprocessor.  */
 154
 155 #undef FUNCTION_VALUE_REGNO_P
 156 #define FUNCTION_VALUE_REGNO_P(N) \
 157   ((N) == D0_REG || (N) == A0_REG || (TARGET_68881 && (N) == FP0_REG))
 158
 159 /* Define this to be true when FUNCTION_VALUE_REGNO_P is true for
 160    more than one register.  */
 161
 162 #undef NEEDS_UNTYPED_CALL
 163 #define NEEDS_UNTYPED_CALL 1
 164
 165 /* Define how to generate (in the callee) the output value of a
 166    function and how to find (in the caller) the value returned by a
 167    function.  VALTYPE is the data type of the value (as a tree).  If
 168    the precise function being called is known, FUNC is its
 169    FUNCTION_DECL; otherwise, FUNC is 0.  For m68k/SVR4 generate the
 170    result in d0, a0, or fp0 as appropriate.  */
 171
 172 #undef FUNCTION_VALUE
 173 #define FUNCTION_VALUE(VALTYPE, FUNC)                                   \
 174   m68k_function_value (VALTYPE, FUNC)
 175
 176 /* Define how to find the value returned by a library function
 177    assuming the value has mode MODE.
 178    For m68k/SVR4 look for integer values in d0, pointer values in d0
 179    (returned in both d0 and a0), and floating values in fp0.  */
 180
 181 #undef LIBCALL_VALUE
 182 #define LIBCALL_VALUE(MODE)                                             \
 183   m68k_libcall_value (MODE)
 184
 185 /* For m68k SVR4, structures are returned using the reentrant
 186    technique.  */
 187 #undef PCC_STATIC_STRUCT_RETURN
 188 #define DEFAULT_PCC_STRUCT_RETURN 0
 189
 190 /* Finalize the trampoline by flushing the insn cache.  */
 191
 192 #undef FINALIZE_TRAMPOLINE
 193 #define FINALIZE_TRAMPOLINE(TRAMP)                                      \
 194   emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__clear_cache"),       \
 195                      LCT_NORMAL, VOIDmode, TRAMP, Pmode,                \
 196                      plus_constant (Pmode, TRAMP, TRAMPOLINE_SIZE),     \
 197                      Pmode);
 198
 199 /* Clear the instruction cache from `beg' to `end'.  This makes an
 200    inline system call to SYS_cacheflush.  The arguments are as
 201    follows:
 202
 203         cacheflush (addr, scope, cache, len)
 204
 205    addr   - the start address for the flush
 206    scope  - the scope of the flush (see the cpush insn)
 207    cache  - which cache to flush (see the cpush insn)
 208    len    - a factor relating to the number of flushes to perform:
 209             len/16 lines, or len/4096 pages.  */
 210
 211 #define CLEAR_INSN_CACHE(BEG, END)                                      \
 212 {                                                                       \
 213   register unsigned long _beg __asm ("%d1") = (unsigned long) (BEG);    \
 214   unsigned long _end = (unsigned long) (END);                           \
 215   register unsigned long _len __asm ("%d4") = (_end - _beg + 32);       \
 216   __asm __volatile                                                      \
 217     ("move%.l #123, %/d0\n\t"   /* system call nr */                    \
 218      "move%.l #1, %/d2\n\t"     /* clear lines */                       \
 219      "move%.l #3, %/d3\n\t"     /* insn+data caches */                  \
 220      "trap #0"                                                          \
 221      : /* no outputs */                                                 \
 222      : "d" (_beg), "d" (_len)                                           \
 223      : "%d0", "%d2", "%d3");                                            \
 224 }
 225
 226 #define TARGET_ASM_FILE_END file_end_indicate_exec_stack
 227
 228 #undef DBX_REGISTER_NUMBER
 229 #define DBX_REGISTER_NUMBER(REGNO) (REGNO)
 230
 231 #undef  SIZE_TYPE
 232 #define SIZE_TYPE "unsigned int"
 233
 234 #undef  PTRDIFF_TYPE
 235 #define PTRDIFF_TYPE "int"
 236
 237 #undef  WCHAR_TYPE
 238 #define WCHAR_TYPE "long int"
 239
 240 #undef  WCHAR_TYPE_SIZE
 241 #define WCHAR_TYPE_SIZE BITS_PER_WORD
 242
 243 /* Install the __sync libcalls.  */
 244 #undef TARGET_INIT_LIBFUNCS
 245 #define TARGET_INIT_LIBFUNCS  m68k_init_sync_libfuncs