1 /* Definitions for Intel 386 running Linux-based GNU systems with ELF format.
2 Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2001, 2002, 2004, 2005,
3 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
4 Contributed by Eric Youngdale.
5 Modified for stabs-in-ELF by H.J. Lu.
7 This file is part of GCC.
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 3, or (at your option)
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.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
23 /* Output at beginning of assembler file. */
24 /* The .file command should always begin the output. */
25 #define TARGET_ASM_FILE_START_FILE_DIRECTIVE true
27 #define TARGET_VERSION fprintf (stderr, " (i386 Linux/ELF)");
29 /* The svr4 ABI for the i386 says that records and unions are returned
31 #undef DEFAULT_PCC_STRUCT_RETURN
32 #define DEFAULT_PCC_STRUCT_RETURN 1
34 /* We arrange for the whole %gs segment to map the tls area. */
35 #undef TARGET_TLS_DIRECT_SEG_REFS_DEFAULT
36 #define TARGET_TLS_DIRECT_SEG_REFS_DEFAULT MASK_TLS_DIRECT_SEG_REFS
38 #undef ASM_COMMENT_START
39 #define ASM_COMMENT_START "#"
41 #undef DBX_REGISTER_NUMBER
42 #define DBX_REGISTER_NUMBER(n) \
43 (TARGET_64BIT ? dbx64_register_map[n] : svr4_dbx_register_map[n])
45 /* Output assembler code to FILE to call the profiler.
46 To the best of my knowledge, no Linux libc has required the label
47 argument to mcount. */
49 #define NO_PROFILE_COUNTERS 1
52 #define MCOUNT_NAME "mcount"
54 /* The GLIBC version of mcount for the x86 assumes that there is a
55 frame, so we cannot allow profiling without a frame pointer. */
57 #undef SUBTARGET_FRAME_POINTER_REQUIRED
58 #define SUBTARGET_FRAME_POINTER_REQUIRED crtl->profile
61 #define SIZE_TYPE "unsigned int"
64 #define PTRDIFF_TYPE "int"
67 #define WCHAR_TYPE "long int"
69 #undef WCHAR_TYPE_SIZE
70 #define WCHAR_TYPE_SIZE BITS_PER_WORD
72 #define TARGET_OS_CPP_BUILTINS() \
75 LINUX_TARGET_OS_CPP_BUILTINS(); \
80 #define CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
83 #define CC1_SPEC "%(cc1_cpu) %{profile:-p}"
85 /* Provide a LINK_SPEC appropriate for Linux. Here we provide support
86 for the special GCC options -static and -shared, which allow us to
87 link things in one of these three modes by applying the appropriate
88 combinations of options at link-time.
90 When the -shared link option is used a final link is not being
93 /* These macros may be overridden in k*bsd-gnu.h and i386/k*bsd-gnu.h. */
94 #define LINK_EMULATION "elf_i386"
95 #define GLIBC_DYNAMIC_LINKER "/lib/ld-linux.so.2"
99 "%{v} --32 %{!mno-sse2avx:%{mavx:-msse2avx}} %{msse2avx:%{!mavx:-msse2avx}}"
101 #undef SUBTARGET_EXTRA_SPECS
102 #define SUBTARGET_EXTRA_SPECS \
103 { "link_emulation", LINK_EMULATION },\
104 { "dynamic_linker", LINUX_DYNAMIC_LINKER }
107 #define LINK_SPEC "-m %(link_emulation) %{shared:-shared} \
111 %{rdynamic:-export-dynamic} \
112 %{!dynamic-linker:-dynamic-linker %(dynamic_linker)}} \
115 /* Similar to standard Linux, but adding -ffast-math support. */
117 #define ENDFILE_SPEC \
118 "%{ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
119 %{mpc32:crtprec32.o%s} \
120 %{mpc64:crtprec64.o%s} \
121 %{mpc80:crtprec80.o%s} \
122 %{shared|pie:crtendS.o%s;:crtend.o%s} crtn.o%s"
124 /* A C statement (sans semicolon) to output to the stdio stream
125 FILE the assembler definition of uninitialized global DECL named
126 NAME whose size is SIZE bytes and alignment is ALIGN bytes.
127 Try to use asm_output_aligned_bss to implement this macro. */
129 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
130 asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
132 /* A C statement to output to the stdio stream FILE an assembler
133 command to advance the location counter to a multiple of 1<<LOG
134 bytes if it is within MAX_SKIP bytes.
136 This is used to align code labels according to Intel recommendations. */
138 #ifdef HAVE_GAS_MAX_SKIP_P2ALIGN
139 #define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP) \
142 if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG)); \
144 fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \
145 /* Make sure that we have at least 8 byte alignment if > 8 byte \
146 alignment is preferred. */ \
148 && (1 << (LOG)) > ((MAX_SKIP) + 1) \
149 && (MAX_SKIP) >= 7) \
150 fputs ("\t.p2align 3\n", (FILE)); \
156 /* Handle special EH pointer encodings. Absolute, pc-relative, and
157 indirect are handled automatically. */
158 #define ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX(FILE, ENCODING, SIZE, ADDR, DONE) \
160 if ((SIZE) == 4 && ((ENCODING) & 0x70) == DW_EH_PE_datarel) \
162 fputs (ASM_LONG, FILE); \
163 assemble_name (FILE, XSTR (ADDR, 0)); \
164 fputs (((ENCODING) & DW_EH_PE_indirect ? "@GOT" : "@GOTOFF"), FILE); \
169 /* Used by crtstuff.c to initialize the base of data-relative relocations.
170 These are GOT relative on x86, so return the pic register. */
172 #define CRT_GET_RFIB_DATA(BASE) \
174 register void *ebx_ __asm__("ebx"); \
178 #define CRT_GET_RFIB_DATA(BASE) \
179 __asm__ ("call\t.LPR%=\n" \
182 /* Due to a GAS bug, this cannot use EAX. That encodes \
183 smaller than the traditional EBX, which results in the \
184 offset being off by one. */ \
185 "add{l}\t{$_GLOBAL_OFFSET_TABLE_+[.-.LPR%=],%0" \
186 "|%0,_GLOBAL_OFFSET_TABLE_+(.-.LPR%=)}" \
190 /* Put all *tf routines in libgcc. */
191 #undef LIBGCC2_HAS_TF_MODE
192 #define LIBGCC2_HAS_TF_MODE 1
193 #define LIBGCC2_TF_CEXT q
196 #define TARGET_ASM_FILE_END file_end_indicate_exec_stack
198 #define MD_UNWIND_SUPPORT "config/i386/linux-unwind.h"
200 /* The stack pointer needs to be moved while checking the stack. */
201 #define STACK_CHECK_MOVING_SP 1
203 /* Static stack checking is supported by means of probes. */
204 #define STACK_CHECK_STATIC_BUILTIN 1
206 /* This macro may be overridden in i386/k*bsd-gnu.h. */
207 #define REG_NAME(reg) reg
209 #ifdef TARGET_LIBC_PROVIDES_SSP
210 /* i386 glibc provides __stack_chk_guard in %gs:0x14. */
211 #define TARGET_THREAD_SSP_OFFSET 0x14
213 /* We steal the last transactional memory word. */
214 #define TARGET_CAN_SPLIT_STACK
215 #define TARGET_THREAD_SPLIT_STACK_OFFSET 0x30