gcc/config/m68k/m68kv4.h

   1 /* Target definitions for GNU compiler for mc680x0 running System V.4
   2    Copyright (C) 1991, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2003
   3    Free Software Foundation, Inc.
   4    Contributed by Ron Guilmette (rfg@monkeys.com) and
   5    Fred Fish (fnf@cygnus.com).
   6
   7 This file is part of GCC.
   8
   9 GCC is free software; you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation; either version 2, or (at your option)
  12 any later version.
  13
  14 GCC is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GCC; see the file COPYING.  If not, write to
  21 the Free Software Foundation, 59 Temple Place - Suite 330,
  22 Boston, MA 02111-1307, USA.  */
  23
  24 /* Target OS builtins.  */
  25 #define TARGET_OS_CPP_BUILTINS()                \
  26   do                                            \
  27     {                                           \
  28         builtin_define_std ("unix");            \
  29         builtin_define_std ("m68k");            \
  30         builtin_define ("__svr4__");            \
  31         builtin_define ("__motorola__");        \
  32         builtin_assert ("system=unix");         \
  33         builtin_assert ("system=svr4");         \
  34    }                                            \
  35   while (0)
  36
  37 #ifndef TARGET_DEFAULT
  38 #define TARGET_DEFAULT (MASK_BITFIELD|MASK_68881|MASK_68020)
  39 #endif
  40
  41 /*  Override the definition of NO_DOLLAR_IN_LABEL in svr4.h, for special
  42     g++ assembler names.  When this is defined, g++ uses embedded '.'
  43     characters and some m68k assemblers have problems with this.  The
  44     chances are much greater that any particular assembler will permit
  45     embedded '$' characters.  */
  46
  47 #undef NO_DOLLAR_IN_LABEL
  48
  49 /* Define PCC_STATIC_STRUCT_RETURN if the convention on the target machine
  50    is to use the nonreentrant technique for returning structure and union
  51    values, as commonly implemented by the AT&T Portable C Compiler (PCC).
  52    When defined, the gcc option -fpcc-struct-return can be used to cause
  53    this form to be generated.  When undefined, the option does nothing.
  54    For m68k SVR4, the convention is to use a reentrant technique compatible
  55    with the gcc default, so override the definition of this macro in m68k.h */
  56
  57 #undef PCC_STATIC_STRUCT_RETURN
  58
  59 /* Test to see if the target includes a 68881 by default, and use CPP_SPEC
  60    to control whether or not __HAVE_68881__ is defined by default or not.
  61    If a 68881 is the default, gcc will use inline 68881 instructions, by
  62    predefining __HAVE_68881__, unless -msoft-float is specified.
  63    If a 68881 is not the default, gcc will only define __HAVE_68881__ if
  64    -m68881 is specified.  */
  65
  66 #if TARGET_DEFAULT & MASK_68881
  67 #define CPP_SPEC "%{!msoft-float:-D__HAVE_68881__}"
  68 #else
  69 #define CPP_SPEC "%{m68881:-D__HAVE_68881__}"
  70 #endif
  71
  72 /* Output assembler code to FILE to increment profiler label # LABELNO
  73    for profiling a function entry.  We override the definition in m68k.h
  74    and match the way the native m68k/SVR4 compiler does profiling, with the
  75    address of the profile counter in a1, not a0, and using bsr rather
  76    than jsr.  */
  77
  78 #undef FUNCTION_PROFILER
  79 #define FUNCTION_PROFILER(FILE, LABELNO)                                \
  80   asm_fprintf ((FILE), "\tlea.l\t(%LLP%d,%Rpc),%Ra1\n\tbsr\t_mcount\n", \
  81                (LABELNO))
  82
  83 /* Local common symbols are declared to the assembler with ".lcomm" rather
  84    than ".bss", so override the definition in svr4.h */
  85 /* ??? svr4.h no longer defines this, and this is only used by m68k/amix.h.  */
  86
  87 #undef BSS_ASM_OP
  88 #define BSS_ASM_OP      "\t.lcomm\t"
  89
  90 /* Register in which address to store a structure value is passed to a
  91    function.  The default in m68k.h is a1.  For m68k/SVR4 it is a0.  */
  92
  93 #undef STRUCT_VALUE_REGNUM
  94 #define STRUCT_VALUE_REGNUM 8
  95
  96 /* Register in which static-chain is passed to a function.  The
  97    default in m68k.h is a0, but that is already the struct value
  98    regnum.  Make it a1 instead.  */
  99
 100 #undef STATIC_CHAIN_REGNUM
 101 #define STATIC_CHAIN_REGNUM 9
 102
 103 #define ASM_COMMENT_START "#"
 104
 105 /* Define how the m68k registers should be numbered for Dwarf output.
 106    The numbering provided here should be compatible with the native
 107    SVR4 SDB debugger in the m68k/SVR4 reference port, where d0-d7
 108    are 0-7, a0-a8 are 8-15, and fp0-fp7 are 16-23.  */
 109
 110 #define DBX_REGISTER_NUMBER(REGNO) (REGNO)
 111
 112 /* The ASM_OUTPUT_SKIP macro is first defined in m68k.h, using ".skip".
 113    It is then overridden by m68k/sgs.h to use ".space", and again by svr4.h
 114    to use ".zero".  The m68k/SVR4 assembler uses ".space", so repeat the
 115    definition from m68k/sgs.h here.  Note that ASM_NO_SKIP_IN_TEXT is
 116    defined in m68k/sgs.h, so we don't have to repeat it here.  */
 117
 118 #undef ASM_OUTPUT_SKIP
 119 #define ASM_OUTPUT_SKIP(FILE,SIZE)  \
 120   fprintf (FILE, "%s%u\n", SPACE_ASM_OP, (int)(SIZE))
 121
 122 /* 1 if N is a possible register number for a function value.
 123    For m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
 124    pointer, or floating types, respectively. Reject fp0 if not using a
 125    68881 coprocessor.  */
 126
 127 #undef FUNCTION_VALUE_REGNO_P
 128 #define FUNCTION_VALUE_REGNO_P(N) \
 129   ((N) == 0 || (N) == 8 || (TARGET_68881 && (N) == 16))
 130
 131 /* Define this to be true when FUNCTION_VALUE_REGNO_P is true for
 132    more than one register.  */
 133
 134 #undef NEEDS_UNTYPED_CALL
 135 #define NEEDS_UNTYPED_CALL 1
 136
 137 /* Define how to generate (in the callee) the output value of a function
 138    and how to find (in the caller) the value returned by a function.  VALTYPE
 139    is the data type of the value (as a tree).  If the precise function being
 140    called is known, FUNC is its FUNCTION_DECL; otherwise, FUNC is 0.
 141    For m68k/SVR4 generate the result in d0, a0, or fp0 as appropriate.  */
 142
 143 #undef FUNCTION_VALUE
 144 #define FUNCTION_VALUE(VALTYPE, FUNC)                                   \
 145   (TREE_CODE (VALTYPE) == REAL_TYPE && TARGET_68881                     \
 146    ? gen_rtx_REG (TYPE_MODE (VALTYPE), 16)                              \
 147    : (POINTER_TYPE_P (VALTYPE)                                          \
 148       ? gen_rtx_REG (TYPE_MODE (VALTYPE), 8)                            \
 149       : gen_rtx_REG (TYPE_MODE (VALTYPE), 0)))
 150
 151 /* For compatibility with the large body of existing code which does not
 152    always properly declare external functions returning pointer types, the
 153    m68k/SVR4 convention is to copy the value returned for pointer functions
 154    from a0 to d0 in the function epilogue, so that callers that have
 155    neglected to properly declare the callee can still find the correct return
 156    value.  */
 157
 158 #define FUNCTION_EXTRA_EPILOGUE(FILE, SIZE)                             \
 159 do {                                                                    \
 160   if (current_function_returns_pointer                                  \
 161       && ! find_equiv_reg (0, get_last_insn (), 0, 0, 0, 8, Pmode))     \
 162     asm_fprintf (FILE, "\tmov.l %Ra0,%Rd0\n");                          \
 163 } while (0);
 164
 165 /* Define how to find the value returned by a library function assuming the
 166    value has mode MODE.
 167    For m68k/SVR4 look for integer values in d0, pointer values in d0
 168    (returned in both d0 and a0), and floating values in fp0.  */
 169
 170 #undef LIBCALL_VALUE
 171 #define LIBCALL_VALUE(MODE)                                             \
 172   ((((MODE) == SFmode || (MODE) == DFmode || (MODE) == XFmode)          \
 173     && TARGET_68881)                                                    \
 174    ? gen_rtx_REG ((MODE), 16)                                           \
 175    : gen_rtx_REG ((MODE), 0))
 176
 177 /* Boundary (in *bits*) on which stack pointer should be aligned.
 178    The m68k/SVR4 convention is to keep the stack pointer longword aligned.  */
 179
 180 #undef STACK_BOUNDARY
 181 #define STACK_BOUNDARY 32
 182
 183 /* Alignment of field after `int : 0' in a structure.
 184    For m68k/SVR4, this is the next longword boundary.  */
 185
 186 #undef EMPTY_FIELD_BOUNDARY
 187 #define EMPTY_FIELD_BOUNDARY 32
 188
 189 /* No data type wants to be aligned rounder than this.
 190    For m68k/SVR4, some types (doubles for example) are aligned on 8 byte
 191    boundaries */
 192
 193 #undef BIGGEST_ALIGNMENT
 194 #define BIGGEST_ALIGNMENT 64
 195
 196 /* SVR4 m68k assembler is bitching on the `comm i,1,1' which asks for
 197    1 byte alignment. Don't generate alignment for COMMON seems to be
 198    safer until we the assembler is fixed.  */
 199 #undef ASM_OUTPUT_ALIGNED_COMMON
 200 /* Same problem with this one.  */
 201 #undef ASM_OUTPUT_ALIGNED_LOCAL
 202
 203 /* The `string' directive on m68k svr4 does not handle string with
 204    escape char (ie., `\') right. Use normal way to output ASCII bytes
 205    seems to be safer.  */
 206 #undef ASM_OUTPUT_ASCII
 207 #define ASM_OUTPUT_ASCII(FILE,PTR,LEN)                          \
 208 do {                                                            \
 209   register size_t sp = 0, limit = (LEN);                        \
 210   fputs (integer_asm_op (1, TRUE), (FILE));                     \
 211   do {                                                          \
 212     int ch = (PTR)[sp];                                         \
 213     if (ch > ' ' && ! (ch & 0x80) && ch != '\\')                \
 214       {                                                         \
 215         fprintf ((FILE), "'%c", ch);                            \
 216       }                                                         \
 217     else                                                        \
 218       {                                                         \
 219         fprintf ((FILE), "0x%x", ch);                           \
 220       }                                                         \
 221     if (++sp < limit)                                           \
 222       {                                                         \
 223         if ((sp % 10) == 0)                                     \
 224           {                                                     \
 225             fprintf ((FILE), "\n%s", integer_asm_op (1, TRUE)); \
 226           }                                                     \
 227         else                                                    \
 228           {                                                     \
 229             putc (',', (FILE));                                 \
 230           }                                                     \
 231       }                                                         \
 232   } while (sp < limit);                                         \
 233   putc ('\n', (FILE));                                          \
 234 } while (0)
 235
 236 /* SVR4 m68k assembler is bitching on the syntax `2.b'.
 237    So use the "LLDnnn-LLnnn" format.  Define LLDnnn after the table.  */
 238
 239 #undef ASM_OUTPUT_CASE_END
 240 #define ASM_OUTPUT_CASE_END(FILE,NUM,TABLE)                             \
 241 do {                                                                    \
 242   if (switch_table_difference_label_flag)                               \
 243     asm_fprintf ((FILE), "%s%LLD%d,%LL%d\n", SET_ASM_OP, (NUM), (NUM)); \
 244   switch_table_difference_label_flag = 0;                               \
 245 } while (0)
 246
 247 extern int switch_table_difference_label_flag;
 248
 249 #undef ASM_OUTPUT_COMMON
 250 #undef ASM_OUTPUT_LOCAL
 251 #define ASM_OUTPUT_COMMON(FILE, NAME, SIZE, ROUNDED)  \
 252 ( fputs (".comm ", (FILE)),                     \
 253   assemble_name ((FILE), (NAME)),               \
 254   fprintf ((FILE), ",%u\n", (int)(SIZE)))
 255
 256 #define ASM_OUTPUT_LOCAL(FILE, NAME, SIZE, ROUNDED)  \
 257 ( fputs (".lcomm ", (FILE)),                    \
 258   assemble_name ((FILE), (NAME)),               \
 259   fprintf ((FILE), ",%u\n", (int)(SIZE)))
 260
 261 /* Override the definition in svr4.h. In m68k svr4, using swbeg is the
 262    standard way to do switch table.  */
 263 #undef ASM_OUTPUT_BEFORE_CASE_LABEL
 264 #define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE,PREFIX,NUM,TABLE)             \
 265   fprintf ((FILE), "%s&%d\n", SWBEG_ASM_OP, XVECLEN (PATTERN (TABLE), 1));
 266
 267 /* Output assembler code for a block containing the constant parts
 268    of a trampoline, leaving space for the variable parts.  */
 269
 270 /* On m68k svr4, the trampoline is different from the generic version
 271    in that we use a1 as the static call chain.  */
 272
 273 #undef TRAMPOLINE_TEMPLATE
 274 #define TRAMPOLINE_TEMPLATE(FILE)                                       \
 275 {                                                                       \
 276   assemble_aligned_integer (2, GEN_INT (0x227a));                       \
 277   assemble_aligned_integer (2, GEN_INT (8));                            \
 278   assemble_aligned_integer (2, GEN_INT (0x2f3a));                       \
 279   assemble_aligned_integer (2, GEN_INT (8));                            \
 280   assemble_aligned_integer (2, GEN_INT (0x4e75));                       \
 281   assemble_aligned_integer (4, const0_rtx);                             \
 282   assemble_aligned_integer (4, const0_rtx);                             \
 283 }
 284
 285 /* Redefine since we are using a different trampoline */
 286 #undef TRAMPOLINE_SIZE
 287 #define TRAMPOLINE_SIZE 18
 288
 289 /* Emit RTL insns to initialize the variable parts of a trampoline.
 290    FNADDR is an RTX for the address of the function's pure code.
 291    CXT is an RTX for the static chain value for the function.  */
 292
 293 #undef INITIALIZE_TRAMPOLINE
 294 #define INITIALIZE_TRAMPOLINE(TRAMP, FNADDR, CXT)                       \
 295 {                                                                       \
 296   emit_move_insn (gen_rtx_MEM (SImode, plus_constant (TRAMP, 10)), CXT); \
 297   emit_move_insn (gen_rtx_MEM (SImode, plus_constant (TRAMP, 14)), FNADDR); \
 298 }