1 /* Definitions of target machine for GNU compiler. MIPS R3000 version with
2 GOFAST floating point library.
3 Copyright (C) 1994, 1997, 1999 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
23 #define OBJECT_FORMAT_ELF
25 /* Until we figure out what MIPS ELF targets normally use, just do
27 #ifndef PREFERRED_DEBUGGING_TYPE
28 #define PREFERRED_DEBUGGING_TYPE DBX_DEBUG
31 /* Mostly like ECOFF. */
33 #include "mips/ecoff.h"
35 /* We need to use .esize and .etype instead of .size and .type to
36 avoid conflicting with ELF directives. */
38 #define PUT_SDB_SIZE(a) \
40 extern FILE *asm_out_text_file; \
41 fprintf (asm_out_text_file, "\t.esize\t%d;", (a)); \
45 #define PUT_SDB_TYPE(a) \
47 extern FILE *asm_out_text_file; \
48 fprintf (asm_out_text_file, "\t.etype\t0x%x;", (a)); \
51 /* Biggest alignment supported by the object file format of this
52 machine. Use this macro to limit the alignment which can be
53 specified using the `__attribute__ ((aligned (N)))' construct. If
54 not defined, the default value is `BIGGEST_ALIGNMENT'. */
56 #define MAX_OFILE_ALIGNMENT (32768*8)
58 /* A C statement to output something to the assembler file to switch to section
59 NAME for object DECL which is either a FUNCTION_DECL, a VAR_DECL or
60 NULL_TREE. Some target formats do not support arbitrary sections. Do not
61 define this macro in such cases. */
63 #define ASM_OUTPUT_SECTION_NAME(F, DECL, NAME, RELOC) \
65 extern FILE *asm_out_text_file; \
66 if ((DECL) && TREE_CODE (DECL) == FUNCTION_DECL) \
67 fprintf (asm_out_text_file, "\t.section %s,\"ax\",@progbits\n", (NAME)); \
68 else if ((DECL) && DECL_READONLY_SECTION (DECL, RELOC)) \
69 fprintf (F, "\t.section %s,\"a\",@progbits\n", (NAME)); \
71 fprintf (F, "\t.section %s,\"aw\",@progbits\n", (NAME)); \
74 /* The following macro defines the format used to output the second
75 operand of the .type assembler directive. Different svr4 assemblers
76 expect various different forms for this operand. The one given here
77 is just a default. You may need to override it in your machine-
78 specific tm.h file (depending upon the particulars of your assembler). */
80 #define TYPE_OPERAND_FMT "@%s"
82 /* Define the strings used for the special svr4 .type and .size directives.
83 These strings generally do not vary from one system running svr4 to
84 another, but if a given system (e.g. m88k running svr) needs to use
85 different pseudo-op names for these, they may be overridden in the
86 file which includes this one. */
90 #define TYPE_ASM_OP ".type"
91 #define SIZE_ASM_OP ".size"
93 /* If defined, a C expression whose value is a string containing the
94 assembler operation to identify the following data as
95 uninitialized global data. If not defined, and neither
96 `ASM_OUTPUT_BSS' nor `ASM_OUTPUT_ALIGNED_BSS' are defined,
97 uninitialized global data will be output in the data section if
98 `-fno-common' is passed, otherwise `ASM_OUTPUT_COMMON' will be
100 #ifndef BSS_SECTION_ASM_OP
101 #define BSS_SECTION_ASM_OP ".section\t.bss"
104 #define SBSS_SECTION_ASM_OP "\t.section .sbss"
106 /* Like `ASM_OUTPUT_BSS' except takes the required alignment as a
107 separate, explicit argument. If you define this macro, it is used
108 in place of `ASM_OUTPUT_BSS', and gives you more flexibility in
109 handling the required alignment of the variable. The alignment is
110 specified as the number of bits.
112 Try to use function `asm_output_aligned_bss' defined in file
113 `varasm.c' when defining this macro. */
114 #ifndef ASM_OUTPUT_ALIGNED_BSS
115 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
117 ASM_GLOBALIZE_LABEL (FILE, NAME); \
118 if (SIZE > 0 && SIZE <= mips_section_threshold) \
122 ASM_OUTPUT_ALIGN (FILE, floor_log2 (ALIGN / BITS_PER_UNIT)); \
123 last_assemble_variable_decl = DECL; \
124 ASM_DECLARE_OBJECT_NAME (FILE, NAME, DECL); \
125 ASM_OUTPUT_SKIP (FILE, SIZE ? SIZE : 1); \
129 /* These macros generate the special .type and .size directives which
130 are used to set the corresponding fields of the linker symbol table
131 entries in an ELF object file under SVR4. These macros also output
132 the starting labels for the relevant functions/objects. */
134 /* Write the extra assembler code needed to declare an object properly. */
136 #undef ASM_DECLARE_OBJECT_NAME
137 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL) \
139 fprintf (FILE, "\t%s\t ", TYPE_ASM_OP); \
140 assemble_name (FILE, NAME); \
142 fprintf (FILE, TYPE_OPERAND_FMT, "object"); \
144 size_directive_output = 0; \
145 if (!flag_inhibit_size_directive && DECL_SIZE (DECL)) \
147 size_directive_output = 1; \
148 fprintf (FILE, "\t%s\t ", SIZE_ASM_OP); \
149 assemble_name (FILE, NAME); \
150 fprintf (FILE, ",%d\n", int_size_in_bytes (TREE_TYPE (DECL))); \
152 mips_declare_object (FILE, NAME, "", ":\n", 0); \
155 /* Output the size directive for a decl in rest_of_decl_compilation
156 in the case where we did not do so before the initializer.
157 Once we find the error_mark_node, we know that the value of
158 size_directive_output was set
159 by ASM_DECLARE_OBJECT_NAME when it was run for the same decl. */
161 #undef ASM_FINISH_DECLARE_OBJECT
162 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END) \
164 char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0); \
165 if (!flag_inhibit_size_directive && DECL_SIZE (DECL) \
166 && ! AT_END && TOP_LEVEL \
167 && DECL_INITIAL (DECL) == error_mark_node \
168 && !size_directive_output) \
170 size_directive_output = 1; \
171 fprintf (FILE, "\t%s\t ", SIZE_ASM_OP); \
172 assemble_name (FILE, name); \
173 fprintf (FILE, ",%d\n", int_size_in_bytes (TREE_TYPE (DECL))); \
177 #define ASM_OUTPUT_DEF(FILE,LABEL1,LABEL2) \
178 do { fputc ( '\t', FILE); \
179 assemble_name (FILE, LABEL1); \
180 fputs ( " = ", FILE); \
181 assemble_name (FILE, LABEL2); \
182 fputc ( '\n', FILE); \
185 /* Note about .weak vs. .weakext
186 The mips native assemblers support .weakext, but not .weak.
187 mips-elf gas supports .weak, but not .weakext.
188 mips-elf gas has been changed to support both .weak and .weakext,
189 but until that support is generally available, the 'if' below
192 #define ASM_WEAKEN_LABEL(FILE,NAME) ASM_OUTPUT_WEAK_ALIAS(FILE,NAME,0)
193 #define ASM_OUTPUT_WEAK_ALIAS(FILE,NAME,VALUE) \
196 fputs ("\t.weak\t", FILE); \
198 fputs ("\t.weakext\t", FILE); \
199 assemble_name (FILE, NAME); \
203 assemble_name (FILE, VALUE); \
205 fputc ('\n', FILE); \
208 #define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1)
209 #undef UNIQUE_SECTION_P
210 #define UNIQUE_SECTION_P(DECL) (DECL_ONE_ONLY (DECL))
211 #define UNIQUE_SECTION(DECL,RELOC) \
213 int len, size, sec; \
214 char *name, *string, *prefix; \
215 static char *prefixes[4][2] = { \
216 { ".text.", ".gnu.linkonce.t." }, \
217 { ".rodata.", ".gnu.linkonce.r." }, \
218 { ".data.", ".gnu.linkonce.d." }, \
219 { ".sdata.", ".gnu.linkonce.s." } \
222 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (DECL)); \
223 size = int_size_in_bytes (TREE_TYPE (decl)); \
225 /* Determine the base section we are interested in: \
226 0=text, 1=rodata, 2=data, 3=sdata. */ \
227 if (TREE_CODE (DECL) == FUNCTION_DECL) \
229 else if ((TARGET_EMBEDDED_PIC || TARGET_MIPS16) \
230 && TREE_CODE (decl) == STRING_CST \
231 && !flag_writable_strings) \
233 /* For embedded position independent code, put constant strings \
234 in the text section, because the data section is limited to \
235 64K in size. For mips16 code, put strings in the text \
236 section so that a PC relative load instruction can be used to \
237 get their address. */ \
240 else if (TARGET_EMBEDDED_DATA) \
242 /* For embedded applications, always put an object in read-only data \
243 if possible, in order to reduce RAM usage. */ \
245 if (DECL_READONLY_SECTION (DECL, RELOC)) \
247 else if (size > 0 && size <= mips_section_threshold) \
254 /* For hosted applications, always put an object in small data if \
255 possible, as this gives the best performance. */ \
257 if (size > 0 && size <= mips_section_threshold) \
259 else if (DECL_READONLY_SECTION (DECL, RELOC)) \
265 prefix = prefixes[sec][DECL_ONE_ONLY (DECL)]; \
266 len = strlen (name) + strlen (prefix); \
267 string = alloca (len + 1); \
268 sprintf (string, "%s%s", prefix, name); \
270 DECL_SECTION_NAME (DECL) = build_string (len, string); \
273 /* Support the ctors/dtors and other sections. */
275 /* Define the pseudo-ops used to switch to the .ctors and .dtors sections.
277 Note that we want to give these sections the SHF_WRITE attribute
278 because these sections will actually contain data (i.e. tables of
279 addresses of functions in the current root executable or shared library
280 file) and, in the case of a shared library, the relocatable addresses
281 will have to be properly resolved/relocated (and then written into) by
282 the dynamic linker when it actually attaches the given shared library
283 to the executing process. (Note that on SVR4, you may wish to use the
284 `-z text' option to the ELF linker, when building a shared library, as
285 an additional check that you are doing everything right. But if you do
286 use the `-z text' option when building a shared library, you will get
287 errors unless the .ctors and .dtors sections are marked as writable
288 via the SHF_WRITE attribute.) */
290 #define CTORS_SECTION_ASM_OP "\t.section\t.ctors,\"aw\""
291 #define DTORS_SECTION_ASM_OP "\t.section\t.dtors,\"aw\""
293 /* A list of other sections which the compiler might be "in" at any
295 #undef EXTRA_SECTIONS
296 #define EXTRA_SECTIONS in_sdata, in_sbss, in_rdata, in_ctors, in_dtors
299 #define NAME__MAIN "__gccmain"
300 #define SYMBOL__MAIN __gccmain
302 #undef EXTRA_SECTION_FUNCTIONS
303 #define EXTRA_SECTION_FUNCTIONS \
304 SECTION_FUNCTION_TEMPLATE(sdata_section, in_sdata, SDATA_SECTION_ASM_OP) \
305 SECTION_FUNCTION_TEMPLATE(sbss_section, in_sbss, SBSS_SECTION_ASM_OP) \
306 SECTION_FUNCTION_TEMPLATE(rdata_section, in_rdata, RDATA_SECTION_ASM_OP) \
307 SECTION_FUNCTION_TEMPLATE(ctors_section, in_ctors, CTORS_SECTION_ASM_OP) \
308 SECTION_FUNCTION_TEMPLATE(dtors_section, in_dtors, DTORS_SECTION_ASM_OP)
310 #define SECTION_FUNCTION_TEMPLATE(FN, ENUM, OP) \
313 if (in_section != ENUM) \
315 fprintf (asm_out_file, "%s\n", OP); \
321 /* A C statement (sans semicolon) to output an element in the table of
322 global constructors. */
323 #define ASM_OUTPUT_CONSTRUCTOR(FILE,NAME) \
326 fprintf (FILE, "\t%s\t", TARGET_LONG64 ? ".dword" : ".word"); \
327 assemble_name (FILE, NAME); \
328 fprintf (FILE, "\n"); \
332 /* A C statement (sans semicolon) to output an element in the table of
333 global destructors. */
334 #define ASM_OUTPUT_DESTRUCTOR(FILE,NAME) \
337 fprintf (FILE, "\t%s\t", TARGET_LONG64 ? ".dword" : ".word"); \
338 assemble_name (FILE, NAME); \
339 fprintf (FILE, "\n"); \
342 #define CTOR_LIST_BEGIN \
343 asm (CTORS_SECTION_ASM_OP); \
344 func_ptr __CTOR_LIST__[1] = { (func_ptr) (-1) }
346 #define CTOR_LIST_END \
347 asm (CTORS_SECTION_ASM_OP); \
348 func_ptr __CTOR_END__[1] = { (func_ptr) 0 };
350 #define DTOR_LIST_BEGIN \
351 asm (DTORS_SECTION_ASM_OP); \
352 func_ptr __DTOR_LIST__[1] = { (func_ptr) (-1) }
354 #define DTOR_LIST_END \
355 asm (DTORS_SECTION_ASM_OP); \
356 func_ptr __DTOR_END__[1] = { (func_ptr) 0 };
358 /* Don't set the target flags, this is done by the linker script */
362 #undef STARTFILE_SPEC
363 #define STARTFILE_SPEC "crtbegin%O%s crt0%O%s"
366 #define ENDFILE_SPEC "crtend%O%s"