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, 2003, 2004, 2006,
   4    2007, 2009 Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #undef TARGET_VERSION
  23 #define TARGET_VERSION fprintf (stderr, " (68k GNU/Linux with ELF)");
  24
  25 /* Add %(asm_cpu_spec) to the svr4.h definition of ASM_SPEC.  */
  26 #undef ASM_SPEC
  27 #define ASM_SPEC "%(asm_cpu_spec) %(asm_pcrel_spec) \
  28   %{v:-V} %{Qy:} %{!Qn:-Qy} %{n} %{T} %{Ym,*} %{Yd,*}"
  29
  30 #undef PREFERRED_STACK_BOUNDARY
  31 #define PREFERRED_STACK_BOUNDARY 32
  32
  33 /* for 68k machines this only needs to be TRUE for the 68000 */
  34
  35 #undef STRICT_ALIGNMENT
  36 #define STRICT_ALIGNMENT 0
  37 #undef M68K_HONOR_TARGET_STRICT_ALIGNMENT
  38 #define M68K_HONOR_TARGET_STRICT_ALIGNMENT 0
  39
  40 /* Here are four prefixes that are used by asm_fprintf to
  41    facilitate customization for alternate assembler syntaxes.
  42    Machines with no likelihood of an alternate syntax need not
  43    define these and need not use asm_fprintf.  */
  44
  45 /* The prefix for register names.  Note that REGISTER_NAMES
  46    is supposed to include this prefix. Also note that this is NOT an
  47    fprintf format string, it is a literal string */
  48
  49 #undef REGISTER_PREFIX
  50 #define REGISTER_PREFIX "%"
  51
  52 /* The prefix for local (compiler generated) labels.
  53    These labels will not appear in the symbol table.  */
  54
  55 #undef LOCAL_LABEL_PREFIX
  56 #define LOCAL_LABEL_PREFIX "."
  57
  58 /* The prefix to add to user-visible assembler symbols.  */
  59
  60 #undef USER_LABEL_PREFIX
  61 #define USER_LABEL_PREFIX ""
  62
  63 #define ASM_COMMENT_START "|"
  64
  65 /* Target OS builtins.  */
  66 #define TARGET_OS_CPP_BUILTINS() LINUX_TARGET_OS_CPP_BUILTINS()
  67
  68 #undef CPP_SPEC
  69 #define CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
  70
  71 /* Provide a LINK_SPEC appropriate for GNU/Linux.  Here we provide support
  72    for the special GCC options -static and -shared, which allow us to
  73    link things in one of these three modes by applying the appropriate
  74    combinations of options at link-time.  We like to support here for
  75    as many of the other GNU linker options as possible.  But I don't
  76    have the time to search for those flags.  I am sure how to add
  77    support for -soname shared_object_name. H.J.
  78
  79    I took out %{v:%{!V:-V}}.  It is too much :-(.  They can use
  80    -Wl,-V.
  81
  82    When the -shared link option is used a final link is not being
  83    done.  */
  84
  85 /* If ELF is the default format, we should not use /lib/elf.  */
  86
  87 #define GLIBC_DYNAMIC_LINKER "/lib/ld.so.1"
  88
  89 #undef LINK_SPEC
  90 #define LINK_SPEC "-m m68kelf %{shared} \
  91   %{!shared: \
  92     %{!static: \
  93       %{rdynamic:-export-dynamic} \
  94       %{!dynamic-linker*:-dynamic-linker " LINUX_DYNAMIC_LINKER "}} \
  95     %{static}}"
  96
  97 /* For compatibility with linux/a.out */
  98
  99 #undef PCC_BITFIELD_TYPE_MATTERS
 100
 101 /* Currently, JUMP_TABLES_IN_TEXT_SECTION must be defined in order to
 102    keep switch tables in the text section.  */
 103
 104 #define JUMP_TABLES_IN_TEXT_SECTION 1
 105
 106 /* Use the default action for outputting the case label.  */
 107 #undef ASM_OUTPUT_CASE_LABEL
 108 #define ASM_RETURN_CASE_JUMP                            \
 109   do {                                                  \
 110     if (TARGET_COLDFIRE)                                \
 111       {                                                 \
 112         if (ADDRESS_REG_P (operands[0]))                \
 113           return "jmp %%pc@(2,%0:l)";                   \
 114         else                                            \
 115           return "ext%.l %0\n\tjmp %%pc@(2,%0:l)";      \
 116       }                                                 \
 117     else                                                \
 118       return "jmp %%pc@(2,%0:w)";                       \
 119   } while (0)
 120
 121 /* This is how to output an assembler line that says to advance the
 122    location counter to a multiple of 2**LOG bytes.  */
 123
 124 #undef ASM_OUTPUT_ALIGN
 125 #define ASM_OUTPUT_ALIGN(FILE,LOG)                              \
 126   if ((LOG) > 0)                                                \
 127     fprintf ((FILE), "%s%u\n", ALIGN_ASM_OP, 1 << (LOG));
 128
 129 /* If defined, a C expression whose value is a string containing the
 130    assembler operation to identify the following data as uninitialized global
 131    data.  */
 132
 133 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
 134
 135 /* A C statement (sans semicolon) to output to the stdio stream
 136    FILE the assembler definition of uninitialized global DECL named
 137    NAME whose size is SIZE bytes and alignment is ALIGN bytes.
 138    Try to use asm_output_aligned_bss to implement this macro.  */
 139
 140 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
 141   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
 142
 143 /* Output assembler code to FILE to increment profiler label # LABELNO
 144    for profiling a function entry.  */
 145
 146 #undef FUNCTION_PROFILER
 147 #define FUNCTION_PROFILER(FILE, LABELNO) \
 148 {                                                                       \
 149   asm_fprintf (FILE, "\tlea (%LLP%d,%Rpc),%Ra1\n", (LABELNO));          \
 150   if (flag_pic)                                                         \
 151     fprintf (FILE, "\tbsr.l _mcount@PLTPC\n");                          \
 152   else                                                                  \
 153     fprintf (FILE, "\tjbsr _mcount\n");                                 \
 154 }
 155
 156 /* Do not break .stabs pseudos into continuations.  */
 157
 158 #define DBX_CONTIN_LENGTH 0
 159
 160 /* 1 if N is a possible register number for a function value.  For
 161    m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
 162    pointer, or floating types, respectively.  Reject fp0 if not using
 163    a 68881 coprocessor.  */
 164
 165 #undef FUNCTION_VALUE_REGNO_P
 166 #define FUNCTION_VALUE_REGNO_P(N) \
 167   ((N) == D0_REG || (N) == A0_REG || (TARGET_68881 && (N) == FP0_REG))
 168
 169 /* Define this to be true when FUNCTION_VALUE_REGNO_P is true for
 170    more than one register.  */
 171
 172 #undef NEEDS_UNTYPED_CALL
 173 #define NEEDS_UNTYPED_CALL 1
 174
 175 /* Define how to generate (in the callee) the output value of a
 176    function and how to find (in the caller) the value returned by a
 177    function.  VALTYPE is the data type of the value (as a tree).  If
 178    the precise function being called is known, FUNC is its
 179    FUNCTION_DECL; otherwise, FUNC is 0.  For m68k/SVR4 generate the
 180    result in d0, a0, or fp0 as appropriate.  */
 181
 182 #undef FUNCTION_VALUE
 183 #define FUNCTION_VALUE(VALTYPE, FUNC)                                   \
 184   m68k_function_value (VALTYPE, FUNC)
 185
 186 /* Define how to find the value returned by a library function
 187    assuming the value has mode MODE.
 188    For m68k/SVR4 look for integer values in d0, pointer values in d0
 189    (returned in both d0 and a0), and floating values in fp0.  */
 190
 191 #undef LIBCALL_VALUE
 192 #define LIBCALL_VALUE(MODE)                                             \
 193   m68k_libcall_value (MODE)
 194
 195 /* For m68k SVR4, structures are returned using the reentrant
 196    technique.  */
 197 #undef PCC_STATIC_STRUCT_RETURN
 198 #define DEFAULT_PCC_STRUCT_RETURN 0
 199
 200 /* Finalize the trampoline by flushing the insn cache.  */
 201
 202 #undef FINALIZE_TRAMPOLINE
 203 #define FINALIZE_TRAMPOLINE(TRAMP)                                      \
 204   emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__clear_cache"),       \
 205                      LCT_NORMAL, VOIDmode, 2, TRAMP, Pmode,             \
 206                      plus_constant (TRAMP, TRAMPOLINE_SIZE), Pmode);
 207
 208 /* Clear the instruction cache from `beg' to `end'.  This makes an
 209    inline system call to SYS_cacheflush.  The arguments are as
 210    follows:
 211
 212         cacheflush (addr, scope, cache, len)
 213
 214    addr   - the start address for the flush
 215    scope  - the scope of the flush (see the cpush insn)
 216    cache  - which cache to flush (see the cpush insn)
 217    len    - a factor relating to the number of flushes to perform:
 218             len/16 lines, or len/4096 pages.  */
 219
 220 #define CLEAR_INSN_CACHE(BEG, END)                                      \
 221 {                                                                       \
 222   register unsigned long _beg __asm ("%d1") = (unsigned long) (BEG);    \
 223   unsigned long _end = (unsigned long) (END);                           \
 224   register unsigned long _len __asm ("%d4") = (_end - _beg + 32);       \
 225   __asm __volatile                                                      \
 226     ("move%.l #123, %/d0\n\t"   /* system call nr */                    \
 227      "move%.l #1, %/d2\n\t"     /* clear lines */                       \
 228      "move%.l #3, %/d3\n\t"     /* insn+data caches */                  \
 229      "trap #0"                                                          \
 230      : /* no outputs */                                                 \
 231      : "d" (_beg), "d" (_len)                                           \
 232      : "%d0", "%d2", "%d3");                                            \
 233 }
 234
 235 #define TARGET_ASM_FILE_END file_end_indicate_exec_stack
 236
 237 #define MD_UNWIND_SUPPORT "config/m68k/linux-unwind.h"