1 /* Definitions for Intel 386 systems using GNU userspace.
2 Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2001, 2002, 2004, 2005,
3 2006, 2007, 2008, 2009, 2010, 2011 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 /* The svr4 ABI for the i386 says that records and unions are returned
29 #undef DEFAULT_PCC_STRUCT_RETURN
30 #define DEFAULT_PCC_STRUCT_RETURN 1
32 /* We arrange for the whole %gs segment to map the tls area. */
33 #undef TARGET_TLS_DIRECT_SEG_REFS_DEFAULT
34 #define TARGET_TLS_DIRECT_SEG_REFS_DEFAULT MASK_TLS_DIRECT_SEG_REFS
36 #undef ASM_COMMENT_START
37 #define ASM_COMMENT_START "#"
39 #undef DBX_REGISTER_NUMBER
40 #define DBX_REGISTER_NUMBER(n) \
41 (TARGET_64BIT ? dbx64_register_map[n] : svr4_dbx_register_map[n])
43 /* Output assembler code to FILE to call the profiler.
44 To the best of my knowledge, no GNU userspace libc has required the label
45 argument to mcount. */
47 #define NO_PROFILE_COUNTERS 1
50 #define MCOUNT_NAME "mcount"
52 /* The GLIBC version of mcount for the x86 assumes that there is a
53 frame, so we cannot allow profiling without a frame pointer. */
55 #undef SUBTARGET_FRAME_POINTER_REQUIRED
56 #define SUBTARGET_FRAME_POINTER_REQUIRED crtl->profile
59 #define SIZE_TYPE "unsigned int"
62 #define PTRDIFF_TYPE "int"
65 #define WCHAR_TYPE "long int"
67 #undef WCHAR_TYPE_SIZE
68 #define WCHAR_TYPE_SIZE BITS_PER_WORD
70 #define TARGET_OS_CPP_BUILTINS() \
73 GNU_USER_TARGET_OS_CPP_BUILTINS(); \
78 #define CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
81 #define CC1_SPEC "%(cc1_cpu) %{profile:-p}"
83 /* Provide a LINK_SPEC appropriate for GNU userspace. Here we provide support
84 for the special GCC options -static and -shared, which allow us to
85 link things in one of these three modes by applying the appropriate
86 combinations of options at link-time.
88 When the -shared link option is used a final link is not being
93 "--32 %{!mno-sse2avx:%{mavx:-msse2avx}} %{msse2avx:%{!mavx:-msse2avx}}"
95 #undef SUBTARGET_EXTRA_SPECS
96 #define SUBTARGET_EXTRA_SPECS \
97 { "link_emulation", GNU_USER_LINK_EMULATION },\
98 { "dynamic_linker", GNU_USER_DYNAMIC_LINKER }
101 #define LINK_SPEC "-m %(link_emulation) %{shared:-shared} \
104 %{rdynamic:-export-dynamic} \
105 -dynamic-linker %(dynamic_linker)} \
108 /* Similar to standard GNU userspace, but adding -ffast-math support. */
110 #define ENDFILE_SPEC \
111 "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
112 %{mpc32:crtprec32.o%s} \
113 %{mpc64:crtprec64.o%s} \
114 %{mpc80:crtprec80.o%s} \
115 %{shared|pie:crtendS.o%s;:crtend.o%s} crtn.o%s"
117 /* A C statement (sans semicolon) to output to the stdio stream
118 FILE the assembler definition of uninitialized global DECL named
119 NAME whose size is SIZE bytes and alignment is ALIGN bytes.
120 Try to use asm_output_aligned_bss to implement this macro. */
122 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
123 asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
125 /* A C statement to output to the stdio stream FILE an assembler
126 command to advance the location counter to a multiple of 1<<LOG
127 bytes if it is within MAX_SKIP bytes.
129 This is used to align code labels according to Intel recommendations. */
131 #ifdef HAVE_GAS_MAX_SKIP_P2ALIGN
132 #define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP) \
135 if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG)); \
137 fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \
138 /* Make sure that we have at least 8 byte alignment if > 8 byte \
139 alignment is preferred. */ \
141 && (1 << (LOG)) > ((MAX_SKIP) + 1) \
142 && (MAX_SKIP) >= 7) \
143 fputs ("\t.p2align 3\n", (FILE)); \
149 /* Handle special EH pointer encodings. Absolute, pc-relative, and
150 indirect are handled automatically. */
151 #define ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX(FILE, ENCODING, SIZE, ADDR, DONE) \
153 if ((SIZE) == 4 && ((ENCODING) & 0x70) == DW_EH_PE_datarel) \
155 fputs (ASM_LONG, FILE); \
156 assemble_name (FILE, XSTR (ADDR, 0)); \
157 fputs (((ENCODING) & DW_EH_PE_indirect ? "@GOT" : "@GOTOFF"), FILE); \
162 /* Used by crtstuff.c to initialize the base of data-relative relocations.
163 These are GOT relative on x86, so return the pic register. */
165 #define CRT_GET_RFIB_DATA(BASE) \
167 register void *ebx_ __asm__("ebx"); \
171 #define CRT_GET_RFIB_DATA(BASE) \
172 __asm__ ("call\t.LPR%=\n" \
175 /* Due to a GAS bug, this cannot use EAX. That encodes \
176 smaller than the traditional EBX, which results in the \
177 offset being off by one. */ \
178 "add{l}\t{$_GLOBAL_OFFSET_TABLE_+[.-.LPR%=],%0" \
179 "|%0,_GLOBAL_OFFSET_TABLE_+(.-.LPR%=)}" \
183 /* Put all *tf routines in libgcc. */
184 #undef LIBGCC2_HAS_TF_MODE
185 #define LIBGCC2_HAS_TF_MODE 1
186 #define LIBGCC2_TF_CEXT q
189 #define TARGET_ASM_FILE_END file_end_indicate_exec_stack
191 /* The stack pointer needs to be moved while checking the stack. */
192 #define STACK_CHECK_MOVING_SP 1
194 /* Static stack checking is supported by means of probes. */
195 #define STACK_CHECK_STATIC_BUILTIN 1
197 #ifdef TARGET_LIBC_PROVIDES_SSP
198 /* i386 glibc provides __stack_chk_guard in %gs:0x14. */
199 #define TARGET_THREAD_SSP_OFFSET 0x14
201 /* We only build the -fsplit-stack support in libgcc if the
202 assembler has full support for the CFI directives. */
203 #if HAVE_GAS_CFI_PERSONALITY_DIRECTIVE
204 #define TARGET_CAN_SPLIT_STACK
206 /* We steal the last transactional memory word. */
207 #define TARGET_THREAD_SPLIT_STACK_OFFSET 0x30