gcc/config/rs6000/xcoff.h

   1 /* Definitions of target machine for GNU compiler,
   2    for some generic XCOFF file format
   3    Copyright (C) 2001, 2002 Free Software Foundation, Inc.
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC 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 2, or (at your option)
  10 any later version.
  11
  12 GNU CC 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 GNU CC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22
  23 #define TARGET_OBJECT_FORMAT OBJECT_XCOFF
  24
  25 /* The RS/6000 uses the XCOFF format.  */
  26 #define XCOFF_DEBUGGING_INFO
  27
  28 /* Define if the object format being used is COFF or a superset.  */
  29 #define OBJECT_FORMAT_COFF
  30
  31 /* Define the magic numbers that we recognize as COFF.
  32
  33     AIX 4.3 adds U803XTOCMAGIC (0757) for 64-bit objects and AIX V5 adds
  34     U64_TOCMAGIC (0767), but collect2.c does not include files in the
  35     correct order to conditionally define the symbolic name in this macro.
  36
  37     The AIX linker accepts import/export files as object files,
  38     so accept "#!" (0x2321) magic number.  */
  39 #define MY_ISCOFF(magic) \
  40   ((magic) == U802WRMAGIC || (magic) == U802ROMAGIC \
  41    || (magic) == U802TOCMAGIC || (magic) == 0757 || (magic) == 0767 \
  42    || (magic) == 0x2321)
  43
  44 /* We don't have GAS for the RS/6000 yet, so don't write out special
  45     .stabs in cc1plus.  */
  46
  47 #define FASCIST_ASSEMBLER
  48
  49 /* We define this to prevent the name mangler from putting dollar signs into
  50    function names.  */
  51
  52 #define NO_DOLLAR_IN_LABEL
  53
  54 /* We define this to 0 so that gcc will never accept a dollar sign in a
  55    variable name.  This is needed because the AIX assembler will not accept
  56    dollar signs.  */
  57
  58 #define DOLLARS_IN_IDENTIFIERS 0
  59
  60 /* Define the extra sections we need.  We define three: one is the read-only
  61    data section which is used for constants.  This is a csect whose name is
  62    derived from the name of the input file.  The second is for initialized
  63    global variables.  This is a csect whose name is that of the variable.
  64    The third is the TOC.  */
  65
  66 #define EXTRA_SECTIONS \
  67    read_only_data, private_data, read_only_private_data, toc, bss
  68
  69 /* Define the routines to implement these extra sections.
  70    BIGGEST_ALIGNMENT is 64, so align the sections that much.  */
  71
  72 #define EXTRA_SECTION_FUNCTIONS                         \
  73                                                         \
  74 void                                                    \
  75 read_only_data_section ()                               \
  76 {                                                       \
  77   if (in_section != read_only_data)                     \
  78     {                                                   \
  79       fprintf (asm_out_file, "\t.csect %s[RO],3\n",     \
  80                xcoff_read_only_section_name);           \
  81       in_section = read_only_data;                      \
  82     }                                                   \
  83 }                                                       \
  84                                                         \
  85 void                                                    \
  86 private_data_section ()                                 \
  87 {                                                       \
  88   if (in_section != private_data)                       \
  89     {                                                   \
  90       fprintf (asm_out_file, "\t.csect %s[RW],3\n",     \
  91                xcoff_private_data_section_name);        \
  92       in_section = private_data;                        \
  93     }                                                   \
  94 }                                                       \
  95                                                         \
  96 void                                                    \
  97 read_only_private_data_section ()                       \
  98 {                                                       \
  99   if (in_section != read_only_private_data)             \
 100     {                                                   \
 101       fprintf (asm_out_file, "\t.csect %s[RO],3\n",     \
 102                xcoff_private_data_section_name);        \
 103       in_section = read_only_private_data;              \
 104     }                                                   \
 105 }                                                       \
 106                                                         \
 107 void                                                    \
 108 toc_section ()                                          \
 109 {                                                       \
 110   if (TARGET_MINIMAL_TOC)                               \
 111     {                                                   \
 112       /* toc_section is always called at least once from ASM_FILE_START, \
 113          so this is guaranteed to always be defined once and only once   \
 114          in each file.  */                                               \
 115       if (! toc_initialized)                            \
 116         {                                               \
 117           fputs ("\t.toc\nLCTOC..1:\n", asm_out_file);  \
 118           fputs ("\t.tc toc_table[TC],toc_table[RW]\n", asm_out_file); \
 119           toc_initialized = 1;                          \
 120         }                                               \
 121                                                         \
 122       if (in_section != toc)                            \
 123         fprintf (asm_out_file, "\t.csect toc_table[RW]%s\n",    \
 124                  (TARGET_32BIT ? "" : ",3"));           \
 125     }                                                   \
 126   else                                                  \
 127     {                                                   \
 128       if (in_section != toc)                            \
 129         fputs ("\t.toc\n", asm_out_file);               \
 130     }                                                   \
 131   in_section = toc;                                     \
 132 }
 133
 134 /* Define the name of our readonly data section.  */
 135
 136 #define READONLY_DATA_SECTION read_only_data_section
 137
 138 /* Select the section for an initialized data object.
 139
 140    On the RS/6000, we have a special section for all variables except those
 141    that are static.  */
 142
 143 #define TARGET_ASM_SELECT_SECTION  rs6000_xcoff_select_section
 144
 145 /* Return non-zero if this entry is to be written into the constant
 146    pool in a special way.  We do so if this is a SYMBOL_REF, LABEL_REF
 147    or a CONST containing one of them.  If -mfp-in-toc (the default),
 148    we also do this for floating-point constants.  We actually can only
 149    do this if the FP formats of the target and host machines are the
 150    same, but we can't check that since not every file that uses
 151    GO_IF_LEGITIMATE_ADDRESS_P includes real.h.  We also do this when
 152    we can write the entry into the TOC and the entry is not larger
 153    than a TOC entry.  */
 154
 155 #define ASM_OUTPUT_SPECIAL_POOL_ENTRY_P(X, MODE)                        \
 156   (TARGET_TOC                                                           \
 157    && (GET_CODE (X) == SYMBOL_REF                                       \
 158        || (GET_CODE (X) == CONST && GET_CODE (XEXP (X, 0)) == PLUS      \
 159            && GET_CODE (XEXP (XEXP (X, 0), 0)) == SYMBOL_REF)           \
 160        || GET_CODE (X) == LABEL_REF                                     \
 161        || (GET_CODE (X) == CONST_INT                                    \
 162            && GET_MODE_BITSIZE (MODE) <= GET_MODE_BITSIZE (Pmode))      \
 163        || (GET_CODE (X) == CONST_DOUBLE                                 \
 164            && (TARGET_POWERPC64                                         \
 165                || TARGET_MINIMAL_TOC                                    \
 166                || (GET_MODE_CLASS (GET_MODE (X)) == MODE_FLOAT          \
 167                    && ! TARGET_NO_FP_IN_TOC)))))
 168
 169 /* Select section for constant in constant pool.
 170
 171    On RS/6000, all constants are in the private read-only data area.
 172    However, if this is being placed in the TOC it must be output as a
 173    toc entry.  */
 174
 175 #define SELECT_RTX_SECTION(MODE, X, ALIGN)              \
 176 { if (ASM_OUTPUT_SPECIAL_POOL_ENTRY_P (X, MODE))        \
 177     toc_section ();                                     \
 178   else                                                  \
 179     read_only_private_data_section ();                  \
 180 }
 181
 182 /* If we are referencing a function that is static or is known to be
 183    in this file, make the SYMBOL_REF special.  We can use this to indicate
 184    that we can branch to this function without emitting a no-op after the
 185    call.  Do not set this flag if the function is weakly defined.  */
 186
 187 #define ENCODE_SECTION_INFO(DECL, FIRST)                \
 188   if (TREE_CODE (DECL) == FUNCTION_DECL                 \
 189       && !TREE_PUBLIC (DECL)                            \
 190       && !DECL_WEAK (DECL))                             \
 191     SYMBOL_REF_FLAG (XEXP (DECL_RTL (DECL), 0)) = 1;
 192
 193 /* FP save and restore routines.  */
 194 #define SAVE_FP_PREFIX "._savef"
 195 #define SAVE_FP_SUFFIX ""
 196 #define RESTORE_FP_PREFIX "._restf"
 197 #define RESTORE_FP_SUFFIX ""
 198
 199 /* Function name to call to do profiling.  */
 200 #undef RS6000_MCOUNT
 201 #define RS6000_MCOUNT ".__mcount"
 202
 203 /* Function names to call to do floating point truncation.  */
 204
 205 #undef RS6000_ITRUNC
 206 #define RS6000_ITRUNC "__itrunc"
 207 #undef RS6000_UITRUNC
 208 #define RS6000_UITRUNC "__uitrunc"
 209
 210 /* This outputs NAME to FILE up to the first null or '['.  */
 211
 212 #define RS6000_OUTPUT_BASENAME(FILE, NAME)      \
 213   {                                             \
 214     const char *_p;                             \
 215                                                 \
 216     STRIP_NAME_ENCODING (_p, (NAME));           \
 217     assemble_name ((FILE), _p);                 \
 218   }
 219
 220 /* This is how to output the definition of a user-level label named NAME,
 221    such as the label on a static function or variable NAME.  */
 222
 223 #define ASM_OUTPUT_LABEL(FILE,NAME)     \
 224   do { RS6000_OUTPUT_BASENAME (FILE, NAME); fputs (":\n", FILE); } while (0)
 225
 226 /* This is how to output a command to make the user-level label named NAME
 227    defined for reference from other files.  */
 228
 229 #define ASM_GLOBALIZE_LABEL(FILE,NAME)  \
 230   do { fputs ("\t.globl ", FILE);       \
 231        RS6000_OUTPUT_BASENAME (FILE, NAME); putc ('\n', FILE);} while (0)
 232
 233 /* Remove any trailing [DS] or the like from the symbol name.  */
 234
 235 #define STRIP_NAME_ENCODING(VAR,NAME)                   \
 236   do                                                    \
 237     {                                                   \
 238       const char *_name = (NAME);                       \
 239       size_t _len;                                      \
 240       if (*_name == '*')                                \
 241         _name++;                                        \
 242       _len = strlen (_name);                            \
 243       if (_name[_len - 1] != ']')                       \
 244         (VAR) = _name;                                  \
 245       else                                              \
 246         {                                               \
 247           char *_new_name = (char *) alloca (_len + 1); \
 248           strcpy (_new_name, _name);                    \
 249           _new_name[_len - 4] = '\0';                   \
 250           (VAR) = _new_name;                            \
 251         }                                               \
 252     }                                                   \
 253   while (0)
 254
 255 /* Output at beginning of assembler file.
 256
 257    Initialize the section names for the RS/6000 at this point.
 258
 259    Specify filename, including full path, to assembler.
 260
 261    We want to go into the TOC section so at least one .toc will be emitted.
 262    Also, in order to output proper .bs/.es pairs, we need at least one static
 263    [RW] section emitted.
 264
 265    Finally, declare mcount when profiling to make the assembler happy.  */
 266
 267 #define ASM_FILE_START(FILE)                                    \
 268 {                                                               \
 269   rs6000_gen_section_name (&xcoff_bss_section_name,             \
 270                            main_input_filename, ".bss_");       \
 271   rs6000_gen_section_name (&xcoff_private_data_section_name,    \
 272                            main_input_filename, ".rw_");        \
 273   rs6000_gen_section_name (&xcoff_read_only_section_name,       \
 274                            main_input_filename, ".ro_");        \
 275                                                                 \
 276   fprintf (FILE, "\t.file\t\"%s\"\n", main_input_filename);     \
 277   if (TARGET_64BIT)                                             \
 278     fputs ("\t.machine\t\"ppc64\"\n", FILE);                    \
 279   toc_section ();                                               \
 280   if (write_symbols != NO_DEBUG)                                \
 281     private_data_section ();                                    \
 282   text_section ();                                              \
 283   if (profile_flag)                                             \
 284     fprintf (FILE, "\t.extern %s\n", RS6000_MCOUNT);            \
 285   rs6000_file_start (FILE, TARGET_CPU_DEFAULT);                 \
 286 }
 287
 288 /* Output at end of assembler file.
 289
 290    On the RS/6000, referencing data should automatically pull in text.  */
 291
 292 #define ASM_FILE_END(FILE)                                      \
 293 {                                                               \
 294   text_section ();                                              \
 295   fputs ("_section_.text:\n", FILE);                            \
 296   data_section ();                                              \
 297   fputs (TARGET_32BIT                                           \
 298          ? "\t.long _section_.text\n" : "\t.llong _section_.text\n", FILE); \
 299 }
 300
 301 /* This macro produces the initial definition of a function name.
 302    On the RS/6000, we need to place an extra '.' in the function name and
 303    output the function descriptor.
 304
 305    The csect for the function will have already been created by the
 306    `text_section' call previously done.  We do have to go back to that
 307    csect, however.
 308
 309    We also record that the function exists in the current compilation
 310    unit, reachable by short branch, by setting SYMBOL_REF_FLAG.
 311
 312    The third and fourth parameters to the .function pseudo-op (16 and 044)
 313    are placeholders which no longer have any use.  */
 314
 315 #define ASM_DECLARE_FUNCTION_NAME(FILE,NAME,DECL)               \
 316 { rtx sym_ref = XEXP (DECL_RTL (DECL), 0);                      \
 317   if (!DECL_WEAK (DECL))                                        \
 318     SYMBOL_REF_FLAG (sym_ref) = 1;                              \
 319   if (TREE_PUBLIC (DECL))                                       \
 320     {                                                           \
 321       if (!RS6000_WEAK || !DECL_WEAK (decl))                    \
 322         {                                                       \
 323           fputs ("\t.globl .", FILE);                           \
 324           RS6000_OUTPUT_BASENAME (FILE, NAME);                  \
 325           putc ('\n', FILE);                                    \
 326         }                                                       \
 327     }                                                           \
 328   else                                                          \
 329     {                                                           \
 330       fputs ("\t.lglobl .", FILE);                              \
 331       RS6000_OUTPUT_BASENAME (FILE, NAME);                      \
 332       putc ('\n', FILE);                                        \
 333     }                                                           \
 334   fputs ("\t.csect ", FILE);                                    \
 335   RS6000_OUTPUT_BASENAME (FILE, NAME);                          \
 336   fputs (TARGET_32BIT ? "[DS]\n" : "[DS],3\n", FILE);           \
 337   RS6000_OUTPUT_BASENAME (FILE, NAME);                          \
 338   fputs (":\n", FILE);                                          \
 339   fputs (TARGET_32BIT ? "\t.long ." : "\t.llong .", FILE);      \
 340   RS6000_OUTPUT_BASENAME (FILE, NAME);                          \
 341   fputs (", TOC[tc0], 0\n", FILE);                              \
 342   in_section = no_section;                                      \
 343   function_section(DECL);                                       \
 344   putc ('.', FILE);                                             \
 345   RS6000_OUTPUT_BASENAME (FILE, NAME);                          \
 346   fputs (":\n", FILE);                                          \
 347   if (write_symbols == XCOFF_DEBUG)                             \
 348     xcoffout_declare_function (FILE, DECL, NAME);               \
 349 }
 350
 351 /* Output a reference to SYM on FILE.  */
 352
 353 #define ASM_OUTPUT_SYMBOL_REF(FILE, SYM) \
 354   rs6000_output_symbol_ref (FILE, SYM)
 355
 356 /* This says how to output an external.  */
 357
 358 #undef ASM_OUTPUT_EXTERNAL
 359 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME)   \
 360 { rtx _symref = XEXP (DECL_RTL (DECL), 0);      \
 361   if ((TREE_CODE (DECL) == VAR_DECL             \
 362        || TREE_CODE (DECL) == FUNCTION_DECL)    \
 363       && (NAME)[strlen (NAME) - 1] != ']')      \
 364     {                                           \
 365       char *_name = (char *) permalloc (strlen (XSTR (_symref, 0)) + 5); \
 366       strcpy (_name, XSTR (_symref, 0));        \
 367       strcat (_name, TREE_CODE (DECL) == FUNCTION_DECL ? "[DS]" : "[RW]"); \
 368       XSTR (_symref, 0) = _name;                \
 369     }                                           \
 370 }
 371
 372 /* This is how to output an internal numbered label where
 373    PREFIX is the class of label and NUM is the number within the class.  */
 374
 375 #define ASM_OUTPUT_INTERNAL_LABEL(FILE,PREFIX,NUM)      \
 376   fprintf (FILE, "%s..%u:\n", (PREFIX), (unsigned) (NUM))
 377
 378 /* This is how to output an internal label prefix.  rs6000.c uses this
 379    when generating traceback tables.  */
 380
 381 #define ASM_OUTPUT_INTERNAL_LABEL_PREFIX(FILE,PREFIX)   \
 382   fprintf (FILE, "%s..", PREFIX)
 383
 384 /* This is how to output a label for a jump table.  Arguments are the same as
 385    for ASM_OUTPUT_INTERNAL_LABEL, except the insn for the jump table is
 386    passed.  */
 387
 388 #define ASM_OUTPUT_CASE_LABEL(FILE,PREFIX,NUM,TABLEINSN)        \
 389 { ASM_OUTPUT_ALIGN (FILE, 2); ASM_OUTPUT_INTERNAL_LABEL (FILE, PREFIX, NUM); }
 390
 391 /* This is how to store into the string LABEL
 392    the symbol_ref name of an internal numbered label where
 393    PREFIX is the class of label and NUM is the number within the class.
 394    This is suitable for output with `assemble_name'.  */
 395
 396 #define ASM_GENERATE_INTERNAL_LABEL(LABEL,PREFIX,NUM)   \
 397   sprintf (LABEL, "*%s..%u", (PREFIX), (unsigned) (NUM))
 398
 399 /* This is how to output an assembler line to define N characters starting
 400    at P to FILE.  */
 401
 402 #define ASM_OUTPUT_ASCII(FILE, P, N)  output_ascii ((FILE), (P), (N))
 403
 404 /* This is how to advance the location counter by SIZE bytes.  */
 405
 406 #define ASM_OUTPUT_SKIP(FILE,SIZE)  \
 407   fprintf (FILE, "\t.space %d\n", (SIZE))
 408
 409 /* This says how to output an assembler line
 410    to define a global common symbol.  */
 411
 412 #define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGNMENT)  \
 413   do { fputs ("\t.comm ", (FILE));                      \
 414        RS6000_OUTPUT_BASENAME ((FILE), (NAME));         \
 415        if ( (SIZE) > 4)                                 \
 416          fprintf ((FILE), ",%d,3\n", (SIZE));           \
 417        else                                             \
 418          fprintf ((FILE), ",%d\n", (SIZE));             \
 419   } while (0)
 420
 421 /* This says how to output an assembler line
 422    to define a local common symbol.
 423    Alignment cannot be specified, but we can try to maintain
 424    alignment after preceding TOC section if it was aligned
 425    for 64-bit mode.  */
 426
 427 #define ASM_OUTPUT_LOCAL(FILE, NAME, SIZE, ROUNDED)     \
 428   do { fputs ("\t.lcomm ", (FILE));                     \
 429        RS6000_OUTPUT_BASENAME ((FILE), (NAME));         \
 430        fprintf ((FILE), ",%d,%s\n", (TARGET_32BIT ? (SIZE) : (ROUNDED)), \
 431                 xcoff_bss_section_name);                \
 432      } while (0)
 433
 434 /* This is how we tell the assembler that two symbols have the same value.  */
 435 #define SET_ASM_OP "\t.set "
 436
 437 /* Used by rs6000_assemble_integer, among others.  */
 438 #define DOUBLE_INT_ASM_OP "\t.llong\t"
 439
 440 /* Output before instructions.  */
 441 #define TEXT_SECTION_ASM_OP "\t.csect .text[PR]"
 442
 443 /* Output before writable data.
 444    Align entire section to BIGGEST_ALIGNMENT.  */
 445 #define DATA_SECTION_ASM_OP "\t.csect .data[RW],3"
 446
 447 /* Define unique section name -- functions only.  */
 448 #define TARGET_ASM_UNIQUE_SECTION  rs6000_xcoff_unique_section
 449
 450 /* Switch into a generic section.  */
 451 #define TARGET_ASM_NAMED_SECTION  xcoff_asm_named_section
 452
 453 /* Define the name of the section to use for the EH language specific
 454    data areas (.gcc_except_table on most other systems).  */
 455 #define TARGET_ASM_EXCEPTION_SECTION data_section
 456
 457 /* Define to prevent DWARF2 unwind info in the data section rather
 458    than in the .eh_frame section.  We do this because the AIX linker
 459    would otherwise garbage collect these sections.  */
 460 #define EH_FRAME_IN_DATA_SECTION 1