xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/config/i386/gnu-user.h (revision 8feb0f0b7eaff0608f8350bbfa3098827b4bb91b)
1 /* Definitions for Intel 386 systems using GNU userspace.
2    Copyright (C) 1994-2020 Free Software Foundation, Inc.
3    Contributed by Eric Youngdale.
4    Modified for stabs-in-ELF by H.J. Lu.
5 
6 This file is part of GCC.
7 
8 GCC 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 3, or (at your option)
11 any later version.
12 
13 GCC 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.
17 
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3.  If not see
20 <http://www.gnu.org/licenses/>.  */
21 
22 /* Output at beginning of assembler file.  */
23 /* The .file command should always begin the output.  */
24 #define TARGET_ASM_FILE_START_FILE_DIRECTIVE true
25 
26 #undef ASM_COMMENT_START
27 #define ASM_COMMENT_START "#"
28 
29 #undef DBX_REGISTER_NUMBER
30 #define DBX_REGISTER_NUMBER(n) \
31   (TARGET_64BIT ? dbx64_register_map[n] : svr4_dbx_register_map[n])
32 
33 /* Output assembler code to FILE to call the profiler.
34    To the best of my knowledge, no GNU userspace libc has required the label
35    argument to mcount.  */
36 
37 #define NO_PROFILE_COUNTERS	1
38 
39 #undef MCOUNT_NAME
40 #define MCOUNT_NAME "mcount"
41 
42 /* The GLIBC version of mcount for the x86 assumes that there is a
43    frame, so we cannot allow profiling without a frame pointer.  */
44 
45 #undef SUBTARGET_FRAME_POINTER_REQUIRED
46 #define SUBTARGET_FRAME_POINTER_REQUIRED crtl->profile
47 
48 #undef SIZE_TYPE
49 #define SIZE_TYPE "unsigned int"
50 
51 #undef PTRDIFF_TYPE
52 #define PTRDIFF_TYPE "int"
53 
54 #undef WCHAR_TYPE
55 #define WCHAR_TYPE "long int"
56 
57 #undef WCHAR_TYPE_SIZE
58 #define WCHAR_TYPE_SIZE BITS_PER_WORD
59 
60 /* Provide a LINK_SPEC appropriate for GNU userspace.  Here we provide support
61    for the special GCC options -static and -shared, which allow us to
62    link things in one of these three modes by applying the appropriate
63    combinations of options at link-time.
64 
65    When the -shared link option is used a final link is not being
66    done.  */
67 
68 #undef  ASM_SPEC
69 #define ASM_SPEC \
70   "--32 %{msse2avx:%{!mavx:-msse2avx}}"
71 
72 #undef  SUBTARGET_EXTRA_SPECS
73 #define SUBTARGET_EXTRA_SPECS \
74   { "link_emulation", GNU_USER_LINK_EMULATION },\
75   { "dynamic_linker", GNU_USER_DYNAMIC_LINKER }
76 
77 #define GNU_USER_TARGET_LINK_SPEC "-m %(link_emulation) %{shared:-shared} \
78   %{!shared: \
79     %{!static: \
80       %{!static-pie: \
81 	%{rdynamic:-export-dynamic} \
82 	-dynamic-linker %(dynamic_linker)}} \
83     %{static:-static} %{static-pie:-static -pie --no-dynamic-linker -z text}}"
84 
85 #undef	LINK_SPEC
86 #define LINK_SPEC GNU_USER_TARGET_LINK_SPEC
87 
88 /* A C statement (sans semicolon) to output to the stdio stream
89    FILE the assembler definition of uninitialized global DECL named
90    NAME whose size is SIZE bytes and alignment is ALIGN bytes.
91    Try to use asm_output_aligned_bss to implement this macro.  */
92 
93 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
94   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
95 
96 /* A C statement to output to the stdio stream FILE an assembler
97    command to advance the location counter to a multiple of 1<<LOG
98    bytes if it is within MAX_SKIP bytes.  */
99 
100 #define SUBALIGN_LOG 3
101 
102 #ifdef HAVE_GAS_MAX_SKIP_P2ALIGN
103 #define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP)			\
104   do {									\
105     if ((LOG) != 0) {							\
106       if ((MAX_SKIP) == 0 || (MAX_SKIP) >= (1 << (LOG)) - 1)		\
107 	fprintf ((FILE), "\t.p2align %d\n", (LOG));			\
108       else								\
109 	fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP));	\
110     }									\
111   } while (0)
112 #endif
113 
114 /* Handle special EH pointer encodings.  Absolute, pc-relative, and
115    indirect are handled automatically.  */
116 #define ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX(FILE, ENCODING, SIZE, ADDR, DONE) \
117   do {									\
118     if ((SIZE) == 4 && ((ENCODING) & 0x70) == DW_EH_PE_datarel)		\
119       {									\
120         fputs (ASM_LONG, FILE);			\
121         assemble_name (FILE, XSTR (ADDR, 0));				\
122 	fputs (((ENCODING) & DW_EH_PE_indirect ? "@GOT" : "@GOTOFF"), FILE); \
123         goto DONE;							\
124       }									\
125   } while (0)
126 
127 #ifdef TARGET_LIBC_PROVIDES_SSP
128 /* i386 glibc provides __stack_chk_guard in %gs:0x14.  */
129 #define TARGET_THREAD_SSP_OFFSET	0x14
130 
131 /* i386 glibc provides __private_ss in %gs:0x30.  */
132 #define TARGET_THREAD_SPLIT_STACK_OFFSET 0x30
133 #endif
134