gcc/config/m68k/linux.h

   1 /* Definitions for Motorola 68k running Linux-based GNU systems with
   2    ELF format.
   3    Copyright (C) 1995-2024 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 MUSL_DYNAMIC_LINKER
  77 #define MUSL_DYNAMIC_LINKER "/lib/ld-musl-m68k.so.1"
  78
  79 #undef LINK_SPEC
  80 #define LINK_SPEC "-m m68kelf %{shared} \
  81   %{!shared: \
  82     %{!static: \
  83       %{rdynamic:-export-dynamic} \
  84       -dynamic-linker " GNU_USER_DYNAMIC_LINKER "} \
  85     %{static}}"
  86
  87 /* For compatibility with linux/a.out */
  88
  89 #undef PCC_BITFIELD_TYPE_MATTERS
  90
  91 /* Currently, JUMP_TABLES_IN_TEXT_SECTION must be defined in order to
  92    keep switch tables in the text section.  */
  93
  94 #define JUMP_TABLES_IN_TEXT_SECTION 1
  95
  96 /* Use the default action for outputting the case label.  */
  97 #undef ASM_OUTPUT_CASE_LABEL
  98 #define ASM_RETURN_CASE_JUMP                            \
  99   do {                                                  \
 100     if (TARGET_COLDFIRE)                                \
 101       {                                                 \
 102         if (ADDRESS_REG_P (operands[0]))                \
 103           return "jmp %%pc@(2,%0:l)";                   \
 104         else if (TARGET_LONG_JUMP_TABLE_OFFSETS)        \
 105           return "jmp %%pc@(%l1,%0:l)";                 \
 106         else                                            \
 107           return "ext%.l %0\n\tjmp %%pc@(2,%0:l)";      \
 108       }                                                 \
 109     else if (TARGET_LONG_JUMP_TABLE_OFFSETS)            \
 110       return "jmp %%pc@(%l1,%0:l)";                     \
 111     else                                                \
 112       return "jmp %%pc@(2,%0:w)";                       \
 113   } while (0)
 114
 115 /* This is how to output an assembler line that says to advance the
 116    location counter to a multiple of 2**LOG bytes.  */
 117
 118 #undef ASM_OUTPUT_ALIGN
 119 #define ASM_OUTPUT_ALIGN(FILE,LOG)                              \
 120   if ((LOG) > 0)                                                \
 121     fprintf ((FILE), "%s%u\n", ALIGN_ASM_OP, 1 << (LOG));
 122
 123 /* If defined, a C expression whose value is a string containing the
 124    assembler operation to identify the following data as uninitialized global
 125    data.  */
 126
 127 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
 128
 129 /* A C statement (sans semicolon) to output to the stdio stream
 130    FILE the assembler definition of uninitialized global DECL named
 131    NAME whose size is SIZE bytes and alignment is ALIGN bytes.
 132    Try to use asm_output_aligned_bss to implement this macro.  */
 133
 134 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
 135   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
 136
 137 /* Output assembler code to FILE to increment profiler label # LABELNO
 138    for profiling a function entry.  */
 139 #define NO_PROFILE_COUNTERS 1
 140 #undef FUNCTION_PROFILER
 141 #define FUNCTION_PROFILER(FILE, LABELNO) \
 142 {                                                                       \
 143   if (flag_pic)                                                         \
 144     fprintf (FILE, "\tbsr.l _mcount@PLTPC\n");                          \
 145   else                                                                  \
 146     fprintf (FILE, "\tjbsr _mcount\n");                                 \
 147 }
 148
 149 /* 1 if N is a possible register number for a function value.  For
 150    m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
 151    pointer, or floating types, respectively.  Reject fp0 if not using
 152    a 68881 coprocessor.  */
 153
 154 #undef FUNCTION_VALUE_REGNO_P
 155 #define FUNCTION_VALUE_REGNO_P(N) \
 156   ((N) == D0_REG || (N) == A0_REG || (TARGET_68881 && (N) == FP0_REG))
 157
 158 /* Define this to be true when FUNCTION_VALUE_REGNO_P is true for
 159    more than one register.  */
 160
 161 #undef NEEDS_UNTYPED_CALL
 162 #define NEEDS_UNTYPED_CALL 1
 163
 164 /* Define how to generate (in the callee) the output value of a
 165    function and how to find (in the caller) the value returned by a
 166    function.  VALTYPE is the data type of the value (as a tree).  If
 167    the precise function being called is known, FUNC is its
 168    FUNCTION_DECL; otherwise, FUNC is 0.  For m68k/SVR4 generate the
 169    result in d0, a0, or fp0 as appropriate.  */
 170
 171 #undef FUNCTION_VALUE
 172 #define FUNCTION_VALUE(VALTYPE, FUNC)                                   \
 173   m68k_function_value (VALTYPE, FUNC)
 174
 175 /* Define how to find the value returned by a library function
 176    assuming the value has mode MODE.
 177    For m68k/SVR4 look for integer values in d0, pointer values in d0
 178    (returned in both d0 and a0), and floating values in fp0.  */
 179
 180 #undef LIBCALL_VALUE
 181 #define LIBCALL_VALUE(MODE)                                             \
 182   m68k_libcall_value (MODE)
 183
 184 /* For m68k SVR4, structures are returned using the reentrant
 185    technique.  */
 186 #undef PCC_STATIC_STRUCT_RETURN
 187 #define DEFAULT_PCC_STRUCT_RETURN 0
 188
 189 /* Finalize the trampoline by flushing the insn cache.  */
 190
 191 #undef FINALIZE_TRAMPOLINE
 192 #define FINALIZE_TRAMPOLINE(TRAMP)                                      \
 193   maybe_emit_call_builtin___clear_cache ((TRAMP),                       \
 194                                          plus_constant (Pmode,          \
 195                                                         (TRAMP),        \
 196                                                         TRAMPOLINE_SIZE))
 197
 198 /* Clear the instruction cache from `beg' to `end'.  This makes an
 199    inline system call to SYS_cacheflush.  The arguments are as
 200    follows:
 201
 202         cacheflush (addr, scope, cache, len)
 203
 204    addr   - the start address for the flush
 205    scope  - the scope of the flush (see the cpush insn)
 206    cache  - which cache to flush (see the cpush insn)
 207    len    - a factor relating to the number of flushes to perform:
 208             len/16 lines, or len/4096 pages.  */
 209
 210 #define CLEAR_INSN_CACHE(BEG, END)                                      \
 211 {                                                                       \
 212   register unsigned long _beg __asm ("%d1") = (unsigned long) (BEG);    \
 213   unsigned long _end = (unsigned long) (END);                           \
 214   register unsigned long _len __asm ("%d4") = (_end - _beg + 32);       \
 215   __asm __volatile                                                      \
 216     ("move%.l #123, %/d0\n\t"   /* system call nr */                    \
 217      "move%.l #1, %/d2\n\t"     /* clear lines */                       \
 218      "move%.l #3, %/d3\n\t"     /* insn+data caches */                  \
 219      "trap #0"                                                          \
 220      : /* no outputs */                                                 \
 221      : "d" (_beg), "d" (_len)                                           \
 222      : "%d0", "%d2", "%d3");                                            \
 223 }
 224
 225 #define TARGET_ASM_FILE_END file_end_indicate_exec_stack
 226
 227 #undef DEBUGGER_REGNO
 228 #define DEBUGGER_REGNO(REGNO) (REGNO)
 229
 230 #undef  SIZE_TYPE
 231 #define SIZE_TYPE "unsigned int"
 232
 233 #undef  PTRDIFF_TYPE
 234 #define PTRDIFF_TYPE "int"
 235
 236 #undef  WCHAR_TYPE
 237 #define WCHAR_TYPE "long int"
 238
 239 #undef  WCHAR_TYPE_SIZE
 240 #define WCHAR_TYPE_SIZE BITS_PER_WORD
 241
 242 /* Install the __sync libcalls.  */
 243 #undef TARGET_INIT_LIBFUNCS
 244 #define TARGET_INIT_LIBFUNCS  m68k_init_sync_libfuncs