1 /* Definitions for Intel 386 running Linux with ELF format
2 Copyright (C) 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
3 Contributed by Eric Youngdale.
4 Modified for stabs-in-ELF by H.J. Lu.
6 This file is part of GNU CC.
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)
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.
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. */
23 #define LINUX_DEFAULT_ELF
25 /* A lie, I guess, but the general idea behind linux/ELF is that we are
26 supposed to be outputting something that will assemble under SVr4.
27 This gets us pretty close. */
28 #include <i386/i386.h> /* Base i386 target machine definitions */
29 #include <i386/att.h> /* Use the i386 AT&T assembler syntax */
30 #include <linux.h> /* some common stuff */
33 #define TARGET_VERSION fprintf (stderr, " (i386 Linux/ELF)");
35 /* The svr4 ABI for the i386 says that records and unions are returned
37 #undef DEFAULT_PCC_STRUCT_RETURN
38 #define DEFAULT_PCC_STRUCT_RETURN 1
40 #undef ASM_COMMENT_START
41 #define ASM_COMMENT_START "#"
43 /* This is how to output an element of a case-vector that is relative.
44 This is only used for PIC code. See comments by the `casesi' insn in
45 i386.md for an explanation of the expression this outputs. */
46 #undef ASM_OUTPUT_ADDR_DIFF_ELT
47 #define ASM_OUTPUT_ADDR_DIFF_ELT(FILE, BODY, VALUE, REL) \
48 fprintf (FILE, "\t.long _GLOBAL_OFFSET_TABLE_+[.-%s%d]\n", LPREFIX, VALUE)
50 /* Indicate that jump tables go in the text section. This is
51 necessary when compiling PIC code. */
52 #define JUMP_TABLES_IN_TEXT_SECTION
54 /* Copy this from the svr4 specifications... */
55 /* Define the register numbers to be used in Dwarf debugging information.
56 The SVR4 reference port C compiler uses the following register numbers
57 in its Dwarf output code:
58 0 for %eax (gnu regno = 0)
59 1 for %ecx (gnu regno = 2)
60 2 for %edx (gnu regno = 1)
61 3 for %ebx (gnu regno = 3)
62 4 for %esp (gnu regno = 7)
63 5 for %ebp (gnu regno = 6)
64 6 for %esi (gnu regno = 4)
65 7 for %edi (gnu regno = 5)
66 The following three DWARF register numbers are never generated by
67 the SVR4 C compiler or by the GNU compilers, but SDB on x86/svr4
68 believes these numbers have these meanings.
69 8 for %eip (no gnu equivalent)
70 9 for %eflags (no gnu equivalent)
71 10 for %trapno (no gnu equivalent)
72 It is not at all clear how we should number the FP stack registers
73 for the x86 architecture. If the version of SDB on x86/svr4 were
74 a bit less brain dead with respect to floating-point then we would
75 have a precedent to follow with respect to DWARF register numbers
76 for x86 FP registers, but the SDB on x86/svr4 is so completely
77 broken with respect to FP registers that it is hardly worth thinking
78 of it as something to strive for compatibility with.
79 The version of x86/svr4 SDB I have at the moment does (partially)
80 seem to believe that DWARF register number 11 is associated with
81 the x86 register %st(0), but that's about all. Higher DWARF
82 register numbers don't seem to be associated with anything in
83 particular, and even for DWARF regno 11, SDB only seems to under-
84 stand that it should say that a variable lives in %st(0) (when
85 asked via an `=' command) if we said it was in DWARF regno 11,
86 but SDB still prints garbage when asked for the value of the
87 variable in question (via a `/' command).
88 (Also note that the labels SDB prints for various FP stack regs
89 when doing an `x' command are all wrong.)
90 Note that these problems generally don't affect the native SVR4
91 C compiler because it doesn't allow the use of -O with -g and
92 because when it is *not* optimizing, it allocates a memory
93 location for each floating-point variable, and the memory
94 location is what gets described in the DWARF AT_location
95 attribute for the variable in question.
96 Regardless of the severe mental illness of the x86/svr4 SDB, we
97 do something sensible here and we use the following DWARF
98 register numbers. Note that these are all stack-top-relative
100 11 for %st(0) (gnu regno = 8)
101 12 for %st(1) (gnu regno = 9)
102 13 for %st(2) (gnu regno = 10)
103 14 for %st(3) (gnu regno = 11)
104 15 for %st(4) (gnu regno = 12)
105 16 for %st(5) (gnu regno = 13)
106 17 for %st(6) (gnu regno = 14)
107 18 for %st(7) (gnu regno = 15)
109 #undef DBX_REGISTER_NUMBER
110 #define DBX_REGISTER_NUMBER(n) \
119 : ((n) >= FIRST_STACK_REG && (n) <= LAST_STACK_REG) ? (n)+3 \
122 /* Output assembler code to FILE to increment profiler label # LABELNO
123 for profiling a function entry. */
125 #undef FUNCTION_PROFILER
126 #define FUNCTION_PROFILER(FILE, LABELNO) \
130 fprintf (FILE, "\tleal %sP%d@GOTOFF(%%ebx),%%edx\n", \
131 LPREFIX, (LABELNO)); \
132 fprintf (FILE, "\tcall *mcount@GOT(%%ebx)\n"); \
136 fprintf (FILE, "\tmovl $%sP%d,%%edx\n", LPREFIX, (LABELNO)); \
137 fprintf (FILE, "\tcall mcount\n"); \
142 #define SIZE_TYPE "unsigned int"
145 #define PTRDIFF_TYPE "int"
148 #define WCHAR_TYPE "long int"
150 #undef WCHAR_TYPE_SIZE
151 #define WCHAR_TYPE_SIZE BITS_PER_WORD
153 #undef CPP_PREDEFINES
154 #define CPP_PREDEFINES "-D__ELF__ -Dunix -Dlinux -Asystem(posix)"
158 #define CPP_SPEC "%(cpp_cpu) %[cpp_cpu] %{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{posix:-D_POSIX_SOURCE}"
160 #define CPP_SPEC "%(cpp_cpu) %[cpp_cpu] %{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
164 #define CC1_SPEC "%(cc1_cpu) %{profile:-p}"
166 /* Provide a LINK_SPEC appropriate for Linux. Here we provide support
167 for the special GCC options -static and -shared, which allow us to
168 link things in one of these three modes by applying the appropriate
169 combinations of options at link-time. We like to support here for
170 as many of the other GNU linker options as possible. But I don't
171 have the time to search for those flags. I am sure how to add
172 support for -soname shared_object_name. H.J.
174 I took out %{v:%{!V:-V}}. It is too much :-(. They can use
177 When the -shared link option is used a final link is not being
180 /* If ELF is the default format, we should not use /lib/elf. */
184 #ifndef LINUX_DEFAULT_ELF
185 #define LINK_SPEC "-m elf_i386 %{shared:-shared} \
189 %{rdynamic:-export-dynamic} \
190 %{!dynamic-linker:-dynamic-linker /lib/elf/ld-linux.so.1} \
191 %{!rpath:-rpath /lib/elf/}} %{static:-static}}}"
193 #define LINK_SPEC "-m elf_i386 %{shared:-shared} \
197 %{rdynamic:-export-dynamic} \
198 %{!dynamic-linker:-dynamic-linker /lib/ld-linux.so.1}} \
202 #define LINK_SPEC "-m elf_i386 %{shared:-shared} \
206 %{rdynamic:-export-dynamic} \
207 %{!dynamic-linker:-dynamic-linker /lib/ld-linux.so.2}} \
211 /* Get perform_* macros to build libgcc.a. */
212 #include "i386/perform.h"
214 /* A C statement (sans semicolon) to output to the stdio stream
215 FILE the assembler definition of uninitialized global DECL named
216 NAME whose size is SIZE bytes and alignment is ALIGN bytes.
217 Try to use asm_output_aligned_bss to implement this macro. */
219 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
220 asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)