1 /* Definitions for Intel 386 running FreeBSD with either a.out or ELF format
2 Copyright (C) 1996-2000 Free Software Foundation, Inc.
3 Contributed by Eric Youngdale.
4 Modified for stabs-in-ELF by H.J. Lu.
5 Adapted from GNU/Linux version by John Polstra.
6 Added support for generating "old a.out gas" on the fly by Peter Wemm.
7 Continued development by David O'Brien <obrien@freebsd.org>
9 This file is part of GNU CC.
11 GNU CC is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 2, or (at your option)
16 GNU CC is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License for more details.
21 You should have received a copy of the GNU General Public License
22 along with GNU CC; see the file COPYING. If not, write to
23 the Free Software Foundation, 59 Temple Place - Suite 330,
24 Boston, MA 02111-1307, USA. */
26 /* $FreeBSD: src/contrib/gcc/config/i386/freebsd.h.fixed,v 1.34.2.3 2001/03/02 09:27:49 obrien Exp $ */
29 #define CPP_PREDEFINES \
30 "-Di386 -Acpu(i386) -Amachine(i386)" \
35 %{gline:%{!g:%{!g0:%{!g1:%{!g2: -g1}}}}} \
36 %{maout: %{!mno-underscores: %{!munderscores: -munderscores }}}"
39 #define ASM_SPEC "%{v*: -v} %{maout: %{fpic:-k} %{fPIC:-k}}"
42 #define ASM_FINAL_SPEC "%|"
44 /* Provide a LINK_SPEC appropriate for FreeBSD. Here we provide support
45 for the special GCC options -static and -shared, which allow us to
46 link things in one of these three modes by applying the appropriate
47 combinations of options at link-time. We like to support here for
48 as many of the other GNU linker options as possible. But I don't
49 have the time to search for those flags. I am sure how to add
50 support for -soname shared_object_name. H.J.
52 I took out %{v:%{!V:-V}}. It is too much :-(. They can use
55 When the -shared link option is used a final link is not being
60 %{p:%e`-p' not supported; use `-pg' and gprof(1)} \
61 %{maout: %{shared:-Bshareable} \
62 %{!shared:%{!nostdlib:%{!r:%{!e*:-e start}}} -dc -dp %{static:-Bstatic} \
63 %{pg:-Bstatic} %{Z}} \
68 %{assert*} %{R*} %{rpath*} %{defsym*} \
69 %{shared:-Bshareable %{h*} %{soname*}} \
70 %{symbolic:-Bsymbolic} \
73 %{rdynamic: -export-dynamic} \
74 %{!dynamic-linker: -dynamic-linker /usr/libexec/ld-elf.so.1}} \
78 #define STARTFILE_SPEC "\
79 %{maout: %{shared:c++rt0.o%s} \
81 %{pg:gcrt0.o%s}%{!pg: \
83 %{!static:crt0.o%s}}}} \
90 crti.o%s %{!shared:crtbegin.o%s} %{shared:crtbeginS.o%s}}"
92 /* Provide an ENDFILE_SPEC appropriate for FreeBSD/i386. Here we tack on our
93 own magical crtend.o file (compare w/crtstuff.c) which provides part of the
94 support for getting C++ file-scope static object constructed before
95 entering `main', followed by the normal "finalizer" file, `crtn.o'. */
98 #define ENDFILE_SPEC "\
100 %{!shared:crtend.o%s} \
101 %{shared:crtendS.o%s} crtn.o%s}"
104 /************************[ Target stuff ]***********************************/
106 /* Define the actual types of some ANSI-mandated types.
107 Needs to agree with <machine/ansi.h>. GCC defaults come from c-decl.c,
108 c-common.c, and config/<arch>/<arch>.h. */
111 #define SIZE_TYPE "unsigned int"
114 #define PTRDIFF_TYPE "int"
116 /* This is the pseudo-op used to generate a 32-bit word of data with a
117 specific value in some section. */
120 #define INT_ASM_OP ".long"
122 /* Biggest alignment supported by the object file format of this
123 machine. Use this macro to limit the alignment which can be
124 specified using the `__attribute__ ((aligned (N)))' construct. If
125 not defined, the default value is `BIGGEST_ALIGNMENT'. */
127 #define MAX_OFILE_ALIGNMENT (32768*8)
129 #undef TARGET_VERSION
130 #define TARGET_VERSION fprintf (stderr, " (i386 FreeBSD/ELF)");
132 #define MASK_PROFILER_EPILOGUE 010000000000
133 #define MASK_AOUT 004000000000 /* a.out not elf */
134 #define MASK_UNDERSCORES 002000000000 /* use leading _ */
136 #define TARGET_PROFILER_EPILOGUE (target_flags & MASK_PROFILER_EPILOGUE)
137 #define TARGET_AOUT (target_flags & MASK_AOUT)
138 #define TARGET_ELF ((target_flags & MASK_AOUT) == 0)
139 #define TARGET_UNDERSCORES ((target_flags & MASK_UNDERSCORES) != 0)
141 #undef SUBTARGET_SWITCHES
142 #define SUBTARGET_SWITCHES \
143 { "profiler-epilogue", MASK_PROFILER_EPILOGUE, "Function profiler epilogue"}, \
144 { "no-profiler-epilogue", -MASK_PROFILER_EPILOGUE, "No function profiler epilogue"}, \
145 { "aout", MASK_AOUT, "Generate an a.out (vs. ELF) binary"}, \
146 { "no-aout", -MASK_AOUT, "Do not generate an a.out binary"}, \
147 { "underscores", MASK_UNDERSCORES, "Add leading underscores to symbols"}, \
148 { "no-underscores", -MASK_UNDERSCORES, "Do not add leading underscores to symbols"},
150 /* This goes away when the math emulator is fixed. */
151 #undef TARGET_DEFAULT
152 #define TARGET_DEFAULT \
153 (MASK_80387 | MASK_IEEE_FP | MASK_FLOAT_RETURNS | MASK_NO_FANCY_MATH_387)
155 /* Prefix for internally generated assembler labels. If we aren't using
156 underscores, we are using prefix `.'s to identify labels that should
157 be ignored, as in `i386/gas.h' --karl@cs.umb.edu */
159 #define LPREFIX ((TARGET_UNDERSCORES) ? "L" : ".L")
161 /* The a.out tools do not support "linkonce" sections. */
162 #undef SUPPORTS_ONE_ONLY
163 #define SUPPORTS_ONE_ONLY TARGET_ELF
165 /* Enable alias attribute support. */
167 #define SET_ASM_OP ".set"
169 /* The a.out tools do not support "Lscope" .stabs symbols. */
170 #undef NO_DBX_FUNCTION_END
171 #define NO_DBX_FUNCTION_END TARGET_AOUT
173 /* In ELF, the function stabs come first, before the relative offsets. */
174 #undef DBX_FUNCTION_FIRST
175 #define DBX_CHECK_FUNCTION_FIRST TARGET_ELF
177 /* supply our own hook for calling __main() from main() */
180 #undef GEN_CALL__MAIN
181 #define GEN_CALL__MAIN \
184 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, NAME__MAIN), 0, \
188 /* Indicate that jump tables go in the text section. This is
189 necessary when compiling PIC code. */
190 #undef JUMP_TABLES_IN_TEXT_SECTION
191 #define JUMP_TABLES_IN_TEXT_SECTION (flag_pic)
193 /* override the exception table positioning */
194 #undef EXCEPTION_SECTION
195 #define EXCEPTION_SECTION() \
199 named_section (NULL_TREE, ".gcc_except_table", 0); \
206 readonly_data_section (); \
210 /* Tell final.c that we don't need a label passed to mcount. */
211 #undef NO_PROFILE_COUNTERS
212 #define NO_PROFILE_COUNTERS
214 /* Output assembler code to FILE to begin profiling of the current function.
215 LABELNO is an optional label. */
217 #undef FUNCTION_PROFILER
218 #define FUNCTION_PROFILER(FILE, LABELNO) \
220 char *_name = TARGET_AOUT ? "mcount" : ".mcount"; \
222 fprintf ((FILE), "\tcall *%s@GOT(%%ebx)\n", _name); \
224 fprintf ((FILE), "\tcall %s\n", _name); \
227 /* Output assembler code to FILE to end profiling of the current function. */
229 #undef FUNCTION_PROFILER_EPILOGUE
230 #define FUNCTION_PROFILER_EPILOGUE(FILE, DO_RTL) \
232 if (TARGET_PROFILER_EPILOGUE) \
236 /* ".mexitcount" is specially handled in \
237 ASM_HACK_SYMBOLREF () so that we don't need to handle \
238 flag_pic or TARGET_AOUT here. */ \
240 xop = gen_rtx_MEM (FUNCTION_MODE, \
241 gen_rtx_SYMBOL_REF (Pmode, ".mexitcount")); \
242 emit_call_insn (gen_rtx (CALL, VOIDmode, xop, const0_rtx)); \
246 /* XXX this !DO_RTL case is broken but not actually used. */ \
247 char *_name = TARGET_AOUT ? "mcount" : ".mcount"; \
249 fprintf (FILE, "\tcall *%s@GOT(%%ebx)\n", _name); \
251 fprintf (FILE, "\tcall %s\n", _name); \
257 /************************[ Assembler stuff ]********************************/
260 #define ASM_APP_ON "#APP\n"
263 #define ASM_APP_OFF "#NO_APP\n"
265 /* This is how to begin an assembly language file.
266 The .file command should always begin the output.
267 ELF also needs a .version. */
269 #undef ASM_FILE_START
270 #define ASM_FILE_START(FILE) \
272 output_file_directive ((FILE), main_input_filename); \
274 fprintf ((FILE), "\t.version\t\"01.01\"\n"); \
277 /* This is how to store into the string BUF
278 the symbol_ref name of an internal numbered label where
279 PREFIX is the class of label and NUM is the number within the class.
280 This is suitable for output with `assemble_name'. */
281 #undef ASM_GENERATE_INTERNAL_LABEL
282 #define ASM_GENERATE_INTERNAL_LABEL(BUF, PREFIX, NUMBER) \
283 sprintf ((BUF), "*%s%s%d", (TARGET_UNDERSCORES) ? "" : ".", \
286 /* This is how to output an internal numbered label where
287 PREFIX is the class of label and NUM is the number within the class.
288 For most svr4/ELF systems, the convention is that any symbol which begins
289 with a period is not put into the linker symbol table by the assembler. */
290 #undef ASM_OUTPUT_INTERNAL_LABEL
291 #define ASM_OUTPUT_INTERNAL_LABEL(FILE,PREFIX,NUM) \
292 fprintf ((FILE), "%s%s%d:\n", (TARGET_UNDERSCORES) ? "" : ".", \
295 /* This is how to output a reference to a user-level label named NAME. */
296 #undef ASM_OUTPUT_LABELREF
297 #define ASM_OUTPUT_LABELREF(FILE, NAME) \
299 char *_name = (NAME); \
300 /* Hack to avoid writing lots of rtl in \
301 FUNCTION_PROFILER_EPILOGUE (). */ \
302 if (*_name == '.' && strcmp(_name + 1, "mexitcount") == 0) \
307 fprintf ((FILE), "*%s@GOT(%%ebx)", _name); \
309 fprintf ((FILE), "%s", _name); \
312 fprintf (FILE, "%s%s", TARGET_UNDERSCORES ? "_" : "", _name); \
315 /* This is how to hack on the symbol code of certain relcalcitrant
316 symbols to modify their output in output_pic_addr_const (). */
318 #undef ASM_HACK_SYMBOLREF_CODE
319 #define ASM_HACK_SYMBOLREF_CODE(NAME, CODE) \
321 /* Part of hack to avoid writing lots of rtl in \
322 FUNCTION_PROFILER_EPILOGUE (). */ \
323 char *_name = (NAME); \
324 if (*_name == '.' && strcmp(_name + 1, "mexitcount") == 0) \
328 /* This is how to output an element of a case-vector that is relative.
329 This is only used for PIC code. See comments by the `casesi' insn in
330 i386.md for an explanation of the expression this outputs. */
331 #undef ASM_OUTPUT_ADDR_DIFF_ELT
332 #define ASM_OUTPUT_ADDR_DIFF_ELT(FILE, BODY, VALUE, REL) \
333 fprintf ((FILE), "\t.long _GLOBAL_OFFSET_TABLE_+[.-%s%d]\n", LPREFIX, (VALUE))
335 #undef ASM_OUTPUT_ALIGN
336 #define ASM_OUTPUT_ALIGN(FILE, LOG) \
338 if (in_text_section()) \
339 fprintf ((FILE), "\t.p2align %d,0x90\n", (LOG)); \
341 fprintf ((FILE), "\t.p2align %d\n", (LOG)); \
344 #undef ASM_OUTPUT_ALIGNED_COMMON
345 #define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN) \
349 fprintf ((FILE), "%s", COMMON_ASM_OP); \
350 assemble_name ((FILE), (NAME)); \
351 fprintf ((FILE), ",%u,%u\n", (SIZE), (ALIGN) / BITS_PER_UNIT); \
355 int rounded = (SIZE); \
356 if (rounded == 0) rounded = 1; \
357 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1; \
358 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT) \
359 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT)); \
360 fprintf ((FILE), "%s ", COMMON_ASM_OP); \
361 assemble_name ((FILE), (NAME)); \
362 fprintf ((FILE), ",%u\n", (rounded)); \
366 /* This says how to output assembler code to declare an
367 uninitialized internal linkage data object. Under SVR4,
368 the linker seems to want the alignment of data objects
369 to depend on their types. We do exactly that here. */
371 #undef ASM_OUTPUT_ALIGNED_LOCAL
372 #define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN) \
376 fprintf ((FILE), "%s", LOCAL_ASM_OP); \
377 assemble_name ((FILE), (NAME)); \
378 fprintf ((FILE), "\n"); \
379 ASM_OUTPUT_ALIGNED_COMMON ((FILE), (NAME), (SIZE), (ALIGN)); \
383 int rounded = (SIZE); \
384 if (rounded == 0) rounded = 1; \
385 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1; \
386 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT) \
387 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT)); \
388 fputs ("\t.lcomm\t", (FILE)); \
389 assemble_name ((FILE), (NAME)); \
390 fprintf ((FILE), ",%u\n", (rounded)); \
394 /* How to output some space. The rules are different depending on the
396 #undef ASM_OUTPUT_SKIP
397 #define ASM_OUTPUT_SKIP(FILE, SIZE) \
401 fprintf ((FILE), "%s%u\n", SKIP_ASM_OP, (SIZE)); \
405 fprintf ((FILE), "\t.space\t%u\n", (SIZE)); \
410 #undef ASM_OUTPUT_SOURCE_LINE
411 #define ASM_OUTPUT_SOURCE_LINE(FILE, LINE) \
413 static int sym_lineno = 1; \
416 fprintf ((FILE), ".stabn 68,0,%d,.LM%d-", (LINE), sym_lineno); \
417 assemble_name ((FILE), \
418 XSTR (XEXP (DECL_RTL (current_function_decl), 0), 0)); \
419 fprintf ((FILE), "\n.LM%d:\n", sym_lineno); \
424 fprintf ((FILE), "\t%s %d,0,%d\n", ASM_STABD_OP, N_SLINE, \
429 /* These macros generate the special .type and .size directives which
430 are used to set the corresponding fields of the linker symbol table
431 entries in an ELF object file under SVR4. These macros also output
432 the starting labels for the relevant functions/objects. */
434 /* Write the extra assembler code needed to declare a function properly.
435 Some svr4 assemblers need to also have something extra said about the
436 function's return value. We allow for that here. */
438 #undef ASM_DECLARE_FUNCTION_NAME
439 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
441 fprintf (FILE, "\t%s\t ", TYPE_ASM_OP); \
442 assemble_name (FILE, NAME); \
444 fprintf (FILE, TYPE_OPERAND_FMT, "function"); \
446 ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL)); \
447 ASM_OUTPUT_LABEL(FILE, NAME); \
450 /* This is how to declare the size of a function. */
452 #undef ASM_DECLARE_FUNCTION_SIZE
453 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL) \
455 if (!flag_inhibit_size_directive) \
458 static int labelno; \
460 ASM_GENERATE_INTERNAL_LABEL (label, "Lfe", labelno); \
461 ASM_OUTPUT_INTERNAL_LABEL (FILE, "Lfe", labelno); \
462 fprintf (FILE, "\t%s\t ", SIZE_ASM_OP); \
463 assemble_name (FILE, (FNAME)); \
464 fprintf (FILE, ","); \
465 assemble_name (FILE, label); \
466 fprintf (FILE, "-"); \
467 assemble_name (FILE, (FNAME)); \
473 /* The routine used to output NUL terminated strings. We use a special
474 version of this for most svr4 targets because doing so makes the
475 generated assembly code more compact (and thus faster to assemble)
476 as well as more readable, especially for targets like the i386
477 (where the only alternative is to output character sequences as
478 comma separated lists of numbers). */
480 #undef ASM_OUTPUT_LIMITED_STRING
481 #define ASM_OUTPUT_LIMITED_STRING(FILE, STR) \
483 register unsigned char *_limited_str = (unsigned char *) (STR); \
484 register unsigned ch; \
485 fprintf ((FILE), "\t%s\t\"", STRING_ASM_OP); \
486 for (; (ch = *_limited_str); _limited_str++) \
488 register int escape; \
489 switch (escape = ESCAPES[ch]) \
495 fprintf ((FILE), "\\%03o", ch); \
498 putc ('\\', (FILE)); \
499 putc (escape, (FILE)); \
503 fprintf ((FILE), "\"\n"); \
506 /* Switch into a generic section.
508 We make the section read-only and executable for a function decl,
509 read-only for a const data decl, and writable for a non-const data decl.
511 If the section has already been defined, we must not
512 emit the attributes here. The SVR4 assembler does not
513 recognize section redefinitions.
514 If DECL is NULL, no attributes are emitted. */
516 #undef ASM_OUTPUT_SECTION_NAME
517 #define ASM_OUTPUT_SECTION_NAME(FILE, DECL, NAME, RELOC) \
519 static struct section_info \
521 struct section_info *next; \
523 enum sect_enum {SECT_RW, SECT_RO, SECT_EXEC} type; \
525 struct section_info *s; \
527 enum sect_enum type; \
529 for (s = sections; s; s = s->next) \
530 if (!strcmp (NAME, s->name)) \
533 if (DECL && TREE_CODE (DECL) == FUNCTION_DECL) \
534 type = SECT_EXEC, mode = "ax"; \
535 else if (DECL && DECL_READONLY_SECTION (DECL, RELOC)) \
536 type = SECT_RO, mode = "a"; \
538 type = SECT_RW, mode = "aw"; \
542 s = (struct section_info *) xmalloc (sizeof (struct section_info)); \
543 s->name = xmalloc ((strlen (NAME) + 1) * sizeof (*NAME)); \
544 strcpy (s->name, NAME); \
546 s->next = sections; \
548 fprintf (FILE, ".section\t%s,\"%s\",@progbits\n", NAME, mode); \
552 if (DECL && s->type != type) \
553 error_with_decl (DECL, "%s causes a section type conflict"); \
555 fprintf (FILE, ".section\t%s\n", NAME); \
559 #undef MAKE_DECL_ONE_ONLY
560 #define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1)
561 #undef UNIQUE_SECTION_P
562 #define UNIQUE_SECTION_P(DECL) (DECL_ONE_ONLY (DECL))
563 #undef UNIQUE_SECTION
564 #define UNIQUE_SECTION(DECL,RELOC) \
567 char *name, *string, *prefix; \
569 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (DECL)); \
571 if (! DECL_ONE_ONLY (DECL)) \
574 if (TREE_CODE (DECL) == FUNCTION_DECL) \
576 else if (DECL_READONLY_SECTION (DECL, RELOC)) \
577 prefix = ".rodata."; \
581 else if (TREE_CODE (DECL) == FUNCTION_DECL) \
582 prefix = ".gnu.linkonce.t."; \
583 else if (DECL_READONLY_SECTION (DECL, RELOC)) \
584 prefix = ".gnu.linkonce.r."; \
586 prefix = ".gnu.linkonce.d."; \
588 len = strlen (name) + strlen (prefix); \
589 string = alloca (len + 1); \
590 sprintf (string, "%s%s", prefix, name); \
592 DECL_SECTION_NAME (DECL) = build_string (len, string); \
595 /* A C statement or statements to switch to the appropriate
596 section for output of DECL. DECL is either a `VAR_DECL' node
597 or a constant of some sort. RELOC indicates whether forming
598 the initial value of DECL requires link-time relocations. */
600 #undef SELECT_SECTION
601 #define SELECT_SECTION(DECL,RELOC) \
603 if (flag_pic && RELOC) \
605 else if (TREE_CODE (DECL) == STRING_CST) \
607 if (! flag_writable_strings) \
612 else if (TREE_CODE (DECL) == VAR_DECL) \
614 if (! DECL_READONLY_SECTION (DECL, RELOC)) \
623 /* A C statement (sans semicolon) to output an element in the table of
624 global constructors. */
625 #undef ASM_OUTPUT_CONSTRUCTOR
626 #define ASM_OUTPUT_CONSTRUCTOR(FILE, NAME) \
631 fprintf ((FILE), "%s ", INT_ASM_OP); \
632 assemble_name ((FILE), (NAME)); \
633 fprintf ((FILE), "\n"); \
637 fprintf (asm_out_file, "%s \"%s__CTOR_LIST__\",22,0,0,", \
638 ASM_STABS_OP, (TARGET_UNDERSCORES) ? "_" : ""); \
639 assemble_name (asm_out_file, name); \
640 fputc ('\n', asm_out_file); \
644 /* A C statement (sans semicolon) to output an element in the table of
645 global destructors. */
646 #undef ASM_OUTPUT_DESTRUCTOR
647 #define ASM_OUTPUT_DESTRUCTOR(FILE, NAME) \
652 fprintf ((FILE), "%s ", INT_ASM_OP); \
653 assemble_name ((FILE), (NAME)); \
654 fprintf ((FILE), "\n"); \
658 fprintf (asm_out_file, "%s \"%s__DTOR_LIST__\",22,0,0,", \
659 ASM_STABS_OP, (TARGET_UNDERSCORES) ? "_" : ""); \
660 assemble_name (asm_out_file, name); \
661 fputc ('\n', asm_out_file); \
665 /* Define macro used to output shift-double opcodes when the shift
666 count is in %cl. Some assemblers require %cl as an argument;
669 *OLD* GAS requires the %cl argument, so override i386/unix.h. */
671 #undef AS3_SHIFT_DOUBLE
672 #define AS3_SHIFT_DOUBLE(a,b,c,d) AS3 (a,b,c,d)
675 /************************[ Debugger stuff ]*********************************/
677 /* Copy this from the svr4 specifications... */
678 /* Define the register numbers to be used in Dwarf debugging information.
679 The SVR4 reference port C compiler uses the following register numbers
680 in its Dwarf output code:
681 0 for %eax (gnu regno = 0)
682 1 for %ecx (gnu regno = 2)
683 2 for %edx (gnu regno = 1)
684 3 for %ebx (gnu regno = 3)
685 4 for %esp (gnu regno = 7)
686 5 for %ebp (gnu regno = 6)
687 6 for %esi (gnu regno = 4)
688 7 for %edi (gnu regno = 5)
689 The following three DWARF register numbers are never generated by
690 the SVR4 C compiler or by the GNU compilers, but SDB on x86/svr4
691 believes these numbers have these meanings.
692 8 for %eip (no gnu equivalent)
693 9 for %eflags (no gnu equivalent)
694 10 for %trapno (no gnu equivalent)
695 It is not at all clear how we should number the FP stack registers
696 for the x86 architecture. If the version of SDB on x86/svr4 were
697 a bit less brain dead with respect to floating-point then we would
698 have a precedent to follow with respect to DWARF register numbers
699 for x86 FP registers, but the SDB on x86/svr4 is so completely
700 broken with respect to FP registers that it is hardly worth thinking
701 of it as something to strive for compatibility with.
702 The version of x86/svr4 SDB I have at the moment does (partially)
703 seem to believe that DWARF register number 11 is associated with
704 the x86 register %st(0), but that's about all. Higher DWARF
705 register numbers don't seem to be associated with anything in
706 particular, and even for DWARF regno 11, SDB only seems to under-
707 stand that it should say that a variable lives in %st(0) (when
708 asked via an `=' command) if we said it was in DWARF regno 11,
709 but SDB still prints garbage when asked for the value of the
710 variable in question (via a `/' command).
711 (Also note that the labels SDB prints for various FP stack regs
712 when doing an `x' command are all wrong.)
713 Note that these problems generally don't affect the native SVR4
714 C compiler because it doesn't allow the use of -O with -g and
715 because when it is *not* optimizing, it allocates a memory
716 location for each floating-point variable, and the memory
717 location is what gets described in the DWARF AT_location
718 attribute for the variable in question.
719 Regardless of the severe mental illness of the x86/svr4 SDB, we
720 do something sensible here and we use the following DWARF
721 register numbers. Note that these are all stack-top-relative
723 11 for %st(0) (gnu regno = 8)
724 12 for %st(1) (gnu regno = 9)
725 13 for %st(2) (gnu regno = 10)
726 14 for %st(3) (gnu regno = 11)
727 15 for %st(4) (gnu regno = 12)
728 16 for %st(5) (gnu regno = 13)
729 17 for %st(6) (gnu regno = 14)
730 18 for %st(7) (gnu regno = 15)
732 #undef DWARF_DBX_REGISTER_NUMBER
733 #define DWARF_DBX_REGISTER_NUMBER(n) \
742 : ((n) >= FIRST_STACK_REG && (n) <= LAST_STACK_REG) ? (n)+3 \
745 /* Now what stabs expects in the register. */
746 #undef STABS_DBX_REGISTER_NUMBER
747 #define STABS_DBX_REGISTER_NUMBER(n) \
758 #undef DBX_REGISTER_NUMBER
759 #define DBX_REGISTER_NUMBER(n) ((write_symbols == DWARF_DEBUG) \
760 ? DWARF_DBX_REGISTER_NUMBER(n) \
761 : STABS_DBX_REGISTER_NUMBER(n))
763 /* tag end of file in elf mode */
764 #undef DBX_OUTPUT_MAIN_SOURCE_FILE_END
765 #define DBX_OUTPUT_MAIN_SOURCE_FILE_END(FILE, FILENAME) \
768 fprintf ((FILE), "\t.text\n\t.stabs \"\",%d,0,0,.Letext\n.Letext:\n", \
773 /* stabs-in-elf has offsets relative to function beginning */
774 #undef DBX_OUTPUT_LBRAC
775 #define DBX_OUTPUT_LBRAC(FILE, NAME) \
777 fprintf (asmfile, "%s %d,0,0,", ASM_STABN_OP, N_LBRAC); \
778 assemble_name (asmfile, buf); \
781 fputc ('-', asmfile); \
782 assemble_name (asmfile, \
783 XSTR (XEXP (DECL_RTL (current_function_decl), 0), 0)); \
785 fprintf (asmfile, "\n"); \
788 #undef DBX_OUTPUT_RBRAC
789 #define DBX_OUTPUT_RBRAC(FILE, NAME) \
791 fprintf (asmfile, "%s %d,0,0,", ASM_STABN_OP, N_RBRAC); \
792 assemble_name (asmfile, buf); \
795 fputc ('-', asmfile); \
796 assemble_name (asmfile, \
797 XSTR (XEXP (DECL_RTL (current_function_decl), 0), 0)); \
799 fprintf (asmfile, "\n"); \