gcc/config/m68k/m68kv4.h

   1 /* Target definitions for GNU compiler for mc680x0 running System V.4
   2    Copyright (C) 1991, 93, 94, 95, 96, 1998, 1999 Free Software Foundation, Inc.
   3    Contributed by Ron Guilmette (rfg@monkeys.com) and
   4    Fred Fish (fnf@cygnus.com).
   5
   6 This file is part of GNU CC.
   7
   8 GNU CC 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 2, or (at your option)
  11 any later version.
  12
  13 GNU CC 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 GNU CC; see the file COPYING.  If not, write to
  20 the Free Software Foundation, 59 Temple Place - Suite 330,
  21 Boston, MA 02111-1307, USA.  */
  22
  23 /* Use SGS_* macros to control compilation in m68k.md */
  24
  25 #define SGS_SWITCH_TABLES       /* Different switch table handling */
  26
  27 #include "m68k/sgs.h"           /* The m68k/SVR4 assembler is SGS based */
  28
  29 /* The SGS assembler requires a special definition of
  30    ASM_IDENTIFY_GCC.  We combine the m68k/sgs.h and the svr4.h
  31    definitions below.  */
  32 #undef ASM_IDENTIFY_GCC
  33
  34 #include "svr4.h"               /* Pick up the generic SVR4 macros */
  35
  36 /* See m68k.h.  7 means 68020 with 68881.  */
  37
  38 #ifndef TARGET_DEFAULT
  39 #define TARGET_DEFAULT (MASK_BITFIELD|MASK_68881|MASK_68020)
  40 #endif
  41
  42 /* When using an SGS assembler, modify the name of the artificial label which
  43    identifies this file as having been compiled with gcc, and the macro that
  44    emits such a label in the assembly output, to use '%' rather than '.'  */
  45
  46 #undef ASM_IDENTIFY_GCC
  47 #define ASM_IDENTIFY_GCC(FILE)                                          \
  48 do                                                                      \
  49   {                                                                     \
  50     if (write_symbols != DBX_DEBUG)                                     \
  51       fputs ("gcc2_compiled%:\n", FILE);                                \
  52   }                                                                     \
  53 while (0)
  54
  55 /*  Override the definition of NO_DOLLAR_IN_LABEL in svr4.h, for special
  56     g++ assembler names.  When this is defined, g++ uses embedded '.'
  57     characters and some m68k assemblers have problems with this.  The
  58     chances are much greater that any particular assembler will permit
  59     embedded '$' characters. */
  60
  61 #undef NO_DOLLAR_IN_LABEL
  62
  63 /* Define PCC_STATIC_STRUCT_RETURN if the convention on the target machine
  64    is to use the nonreentrant technique for returning structure and union
  65    values, as commonly implemented by the AT&T Portable C Compiler (PCC).
  66    When defined, the gcc option -fpcc-struct-return can be used to cause
  67    this form to be generated.  When undefined, the option does nothing.
  68    For m68k SVR4, the convention is to use a reentrant technique compatible
  69    with the gcc default, so override the definition of this macro in m68k.h */
  70
  71 #undef PCC_STATIC_STRUCT_RETURN
  72
  73 /* Provide a set of pre-definitions and pre-assertions appropriate for
  74    the m68k running svr4.  __svr4__ is our extension.  */
  75
  76 #define CPP_PREDEFINES \
  77   "-Dm68k -Dunix -D__svr4__ -D__motorola__ \
  78  -Asystem(unix) -Asystem(svr4) -Acpu(m68k) -Amachine(m68k)"
  79
  80 /* Test to see if the target includes a 68881 by default, and use CPP_SPEC
  81    to control whether or not __HAVE_68881__ is defined by default or not.
  82    If a 68881 is the default, gcc will use inline 68881 instructions, by
  83    predefining __HAVE_68881__, unless -msoft-float is specified.
  84    If a 68881 is not the default, gcc will only define __HAVE_68881__ if
  85    -m68881 is specified. */
  86
  87 #if TARGET_DEFAULT & MASK_68881
  88 #define CPP_SPEC "%{!msoft-float:-D__HAVE_68881__}"
  89 #else
  90 #define CPP_SPEC "%{m68881:-D__HAVE_68881__}"
  91 #endif
  92
  93 /* Output assembler code to FILE to increment profiler label # LABELNO
  94    for profiling a function entry.  We override the definition in m68k.h
  95    and match the way the native m68k/SVR4 compiler does profiling, with the
  96    address of the profile counter in a1, not a0, and using bsr rather
  97    than jsr. */
  98
  99 #undef FUNCTION_PROFILER
 100 #define FUNCTION_PROFILER(FILE, LABELNO)                                \
 101   asm_fprintf ((FILE), "\tlea.l\t(%LLP%d,%Rpc),%Ra1\n\tbsr\t_mcount\n", \
 102                (LABELNO))
 103
 104 /* Local common symbols are declared to the assembler with ".lcomm" rather
 105    than ".bss", so override the definition in svr4.h */
 106 /* ??? svr4.h no longer defines this, and this is only used by m68k/amix.h.  */
 107
 108 #undef BSS_ASM_OP
 109 #define BSS_ASM_OP      ".lcomm"
 110
 111 /* Register in which address to store a structure value is passed to a
 112    function.  The default in m68k.h is a1.  For m68k/SVR4 it is a0. */
 113
 114 #undef STRUCT_VALUE_REGNUM
 115 #define STRUCT_VALUE_REGNUM 8
 116
 117 /* Register in which static-chain is passed to a function.  The
 118    default in m68k.h is a0, but that is already the struct value
 119    regnum.  Make it a1 instead.  */
 120
 121 #undef STATIC_CHAIN_REGNUM
 122 #define STATIC_CHAIN_REGNUM 9
 123
 124 #define ASM_COMMENT_START "#"
 125
 126 #undef TYPE_OPERAND_FMT
 127 #define TYPE_OPERAND_FMT      "@%s"
 128
 129 /* Define how the m68k registers should be numbered for Dwarf output.
 130    The numbering provided here should be compatible with the native
 131    SVR4 SDB debugger in the m68k/SVR4 reference port, where d0-d7
 132    are 0-7, a0-a8 are 8-15, and fp0-fp7 are 16-23. */
 133
 134 #define DBX_REGISTER_NUMBER(REGNO) (REGNO)
 135
 136 /* The ASM_OUTPUT_SKIP macro is first defined in m68k.h, using ".skip".
 137    It is then overridden by m68k/sgs.h to use ".space", and again by svr4.h
 138    to use ".zero".  The m68k/SVR4 assembler uses ".space", so repeat the
 139    definition from m68k/sgs.h here.  Note that ASM_NO_SKIP_IN_TEXT is
 140    defined in m68k/sgs.h, so we don't have to repeat it here. */
 141
 142 #undef ASM_OUTPUT_SKIP
 143 #define ASM_OUTPUT_SKIP(FILE,SIZE)  \
 144   fprintf (FILE, "\t%s %u\n", SPACE_ASM_OP, (SIZE))
 145
 146 /* 1 if N is a possible register number for a function value.
 147    For m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
 148    pointer, or floating types, respectively. Reject fp0 if not using a
 149    68881 coprocessor. */
 150
 151 #undef FUNCTION_VALUE_REGNO_P
 152 #define FUNCTION_VALUE_REGNO_P(N) \
 153   ((N) == 0 || (N) == 8 || (TARGET_68881 && (N) == 16))
 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 function
 162    and how to find (in the caller) the value returned by a function.  VALTYPE
 163    is the data type of the value (as a tree).  If the precise function being
 164    called is known, FUNC is its FUNCTION_DECL; otherwise, FUNC is 0.
 165    For m68k/SVR4 generate the result in d0, a0, or fp0 as appropriate. */
 166
 167 #undef FUNCTION_VALUE
 168 #define FUNCTION_VALUE(VALTYPE, FUNC)                                   \
 169   (TREE_CODE (VALTYPE) == REAL_TYPE && TARGET_68881                     \
 170    ? gen_rtx_REG (TYPE_MODE (VALTYPE), 16)                              \
 171    : (POINTER_TYPE_P (VALTYPE)                                          \
 172       ? gen_rtx_REG (TYPE_MODE (VALTYPE), 8)                            \
 173       : gen_rtx_REG (TYPE_MODE (VALTYPE), 0)))
 174
 175 /* For compatibility with the large body of existing code which does not
 176    always properly declare external functions returning pointer types, the
 177    m68k/SVR4 convention is to copy the value returned for pointer functions
 178    from a0 to d0 in the function epilogue, so that callers that have
 179    neglected to properly declare the callee can still find the correct return
 180    value. */
 181
 182 #define FUNCTION_EXTRA_EPILOGUE(FILE, SIZE)                             \
 183 do {                                                                    \
 184   if (current_function_returns_pointer                                  \
 185       && ! find_equiv_reg (0, get_last_insn (), 0, 0, 0, 8, Pmode))     \
 186     asm_fprintf (FILE, "\tmov.l %Ra0,%Rd0\n");                          \
 187 } while (0);
 188
 189 /* Define how to find the value returned by a library function assuming the
 190    value has mode MODE.
 191    For m68k/SVR4 look for integer values in d0, pointer values in d0
 192    (returned in both d0 and a0), and floating values in fp0. */
 193
 194 #undef LIBCALL_VALUE
 195 #define LIBCALL_VALUE(MODE)                                             \
 196   ((((MODE) == SFmode || (MODE) == DFmode || (MODE) == XFmode)          \
 197     && TARGET_68881)                                                    \
 198    ? gen_rtx_REG ((MODE), 16)                                           \
 199    : gen_rtx_REG ((MODE), 0))
 200
 201 /* Boundary (in *bits*) on which stack pointer should be aligned.
 202    The m68k/SVR4 convention is to keep the stack pointer longword aligned. */
 203
 204 #undef STACK_BOUNDARY
 205 #define STACK_BOUNDARY 32
 206
 207 /* Alignment of field after `int : 0' in a structure.
 208    For m68k/SVR4, this is the next longword boundary. */
 209
 210 #undef EMPTY_FIELD_BOUNDARY
 211 #define EMPTY_FIELD_BOUNDARY 32
 212
 213 /* No data type wants to be aligned rounder than this.
 214    For m68k/SVR4, some types (doubles for example) are aligned on 8 byte
 215    boundaries */
 216
 217 #undef BIGGEST_ALIGNMENT
 218 #define BIGGEST_ALIGNMENT 64
 219
 220 /* SVR4 m68k assembler is bitching on the `comm i,1,1' which asks for
 221    1 byte alignment. Don't generate alignment for COMMON seems to be
 222    safer until we the assembler is fixed. */
 223 #undef ASM_OUTPUT_ALIGNED_COMMON
 224 /* Same problem with this one.  */
 225 #undef ASM_OUTPUT_ALIGNED_LOCAL
 226
 227 /* The `string' directive on m68k svr4 does not handle string with
 228    escape char (ie., `\') right. Use normal way to output ASCII bytes
 229    seems to be safer. */
 230 #undef ASM_OUTPUT_ASCII
 231 #define ASM_OUTPUT_ASCII(FILE,PTR,LEN)                          \
 232 do {                                                            \
 233   register int sp = 0, lp = 0, ch;                              \
 234   fprintf ((FILE), "\t%s ", BYTE_ASM_OP);                       \
 235   do {                                                          \
 236     ch = (PTR)[sp];                                             \
 237     if (ch > ' ' && ! (ch & 0x80) && ch != '\\')                \
 238       {                                                         \
 239         fprintf ((FILE), "'%c", ch);                            \
 240       }                                                         \
 241     else                                                        \
 242       {                                                         \
 243         fprintf ((FILE), "0x%x", ch);                           \
 244       }                                                         \
 245     if (++sp < (LEN))                                           \
 246       {                                                         \
 247         if ((sp % 10) == 0)                                     \
 248           {                                                     \
 249             fprintf ((FILE), "\n\t%s ", BYTE_ASM_OP);           \
 250           }                                                     \
 251         else                                                    \
 252           {                                                     \
 253             putc (',', (FILE));                                 \
 254           }                                                     \
 255       }                                                         \
 256   } while (sp < (LEN));                                         \
 257   putc ('\n', (FILE));                                          \
 258 } while (0)
 259
 260 /* SVR4 m68k assembler is bitching on the syntax `2.b'.
 261    So use the "LLDnnn-LLnnn" format.  Define LLDnnn after the table.  */
 262
 263 #undef ASM_OUTPUT_CASE_END
 264 #define ASM_OUTPUT_CASE_END(FILE,NUM,TABLE)                             \
 265 do {                                                                    \
 266   if (switch_table_difference_label_flag)                               \
 267     asm_fprintf ((FILE), "\t%s %LLD%d,%LL%d\n", SET_ASM_OP, (NUM), (NUM));\
 268   switch_table_difference_label_flag = 0;                               \
 269 } while (0)
 270
 271 int switch_table_difference_label_flag;
 272
 273 #undef ASM_OUTPUT_COMMON
 274 #undef ASM_OUTPUT_LOCAL
 275 #define ASM_OUTPUT_COMMON(FILE, NAME, SIZE, ROUNDED)  \
 276 ( fputs (".comm ", (FILE)),                     \
 277   assemble_name ((FILE), (NAME)),               \
 278   fprintf ((FILE), ",%u\n", (SIZE)))
 279
 280 #define ASM_OUTPUT_LOCAL(FILE, NAME, SIZE, ROUNDED)  \
 281 ( fputs (".lcomm ", (FILE)),                    \
 282   assemble_name ((FILE), (NAME)),               \
 283   fprintf ((FILE), ",%u\n", (SIZE)))
 284
 285 /* Override the definition in svr4.h. In m68k svr4, using swbeg is the
 286    standard way to do switch table. */
 287 #undef ASM_OUTPUT_BEFORE_CASE_LABEL
 288 #define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE,PREFIX,NUM,TABLE)             \
 289   fprintf ((FILE), "\t%s &%d\n", SWBEG_ASM_OP, XVECLEN (PATTERN (TABLE), 1));
 290
 291 /* In m68k svr4, a symbol_ref rtx can be a valid PIC operand if it is an
 292    operand of a function call. */
 293 #undef LEGITIMATE_PIC_OPERAND_P
 294 #define LEGITIMATE_PIC_OPERAND_P(X) \
 295   ((! symbolic_operand (X, VOIDmode) \
 296     && ! (GET_CODE (X) == CONST_DOUBLE && CONST_DOUBLE_MEM (X)  \
 297           && GET_CODE (CONST_DOUBLE_MEM (X)) == MEM             \
 298           && symbolic_operand (XEXP (CONST_DOUBLE_MEM (X), 0), VOIDmode))) \
 299    || (GET_CODE (X) == SYMBOL_REF && SYMBOL_REF_FLAG (X))       \
 300    || PCREL_GENERAL_OPERAND_OK)
 301
 302 /* Turn off function cse if we are doing PIC. We always want function call
 303    to be done as `bsr foo@PLTPC', so it will force the assembler to create
 304    the PLT entry for `foo'. Doing function cse will cause the address of `foo'
 305    to be loaded into a register, which is exactly what we want to avoid when
 306    we are doing PIC on svr4 m68k. */
 307 #undef OVERRIDE_OPTIONS
 308 #define OVERRIDE_OPTIONS                \
 309 {                                       \
 310   if (flag_pic) flag_no_function_cse = 1; \
 311   if (! TARGET_68020 && flag_pic == 2)  \
 312     error("-fPIC is not currently supported on the 68000 or 68010\n");  \
 313 }
 314
 315 /* Output assembler code for a block containing the constant parts
 316    of a trampoline, leaving space for the variable parts.  */
 317
 318 /* On m68k svr4, the trampoline is different from the generic version
 319    in that we use a1 as the static call chain.  */
 320
 321 #undef TRAMPOLINE_TEMPLATE
 322 #define TRAMPOLINE_TEMPLATE(FILE)                                       \
 323 {                                                                       \
 324   ASM_OUTPUT_SHORT (FILE, GEN_INT (0x227a));    \
 325   ASM_OUTPUT_SHORT (FILE, GEN_INT (8));         \
 326   ASM_OUTPUT_SHORT (FILE, GEN_INT (0x2f3a));    \
 327   ASM_OUTPUT_SHORT (FILE, GEN_INT (8));         \
 328   ASM_OUTPUT_SHORT (FILE, GEN_INT (0x4e75));    \
 329   ASM_OUTPUT_INT (FILE, const0_rtx);            \
 330   ASM_OUTPUT_INT (FILE, const0_rtx);            \
 331 }
 332
 333 /* Redefine since we are using a different trampoline */
 334 #undef TRAMPOLINE_SIZE
 335 #define TRAMPOLINE_SIZE 18
 336
 337 /* Emit RTL insns to initialize the variable parts of a trampoline.
 338    FNADDR is an RTX for the address of the function's pure code.
 339    CXT is an RTX for the static chain value for the function.  */
 340
 341 #undef INITIALIZE_TRAMPOLINE
 342 #define INITIALIZE_TRAMPOLINE(TRAMP, FNADDR, CXT)                       \
 343 {                                                                       \
 344   emit_move_insn (gen_rtx_MEM (SImode, plus_constant (TRAMP, 10)), CXT); \
 345   emit_move_insn (gen_rtx_MEM (SImode, plus_constant (TRAMP, 14)), FNADDR); \
 346 }