xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/config/m68k/linux.h (revision aef5eb5f59cdfe8314f1b5f78ac04eb144e44010)
1 /* Definitions for Motorola 68k running Linux-based GNU systems with
2    ELF format.
3    Copyright (C) 1995-2019 Free Software Foundation, Inc.
4 
5 This file is part of GCC.
6 
7 GCC 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 3, or (at your option)
10 any later version.
11 
12 GCC 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.
16 
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3.  If not see
19 <http://www.gnu.org/licenses/>.  */
20 
21 /* Add %(asm_cpu_spec) to a generic definition of ASM_SPEC.  */
22 #undef ASM_SPEC
23 #define ASM_SPEC "%(asm_cpu_spec) %(asm_pcrel_spec)"
24 
25 #undef PREFERRED_STACK_BOUNDARY
26 #define PREFERRED_STACK_BOUNDARY 32
27 
28 /* for 68k machines this only needs to be TRUE for the 68000 */
29 
30 #undef STRICT_ALIGNMENT
31 #define STRICT_ALIGNMENT 0
32 #undef M68K_HONOR_TARGET_STRICT_ALIGNMENT
33 #define M68K_HONOR_TARGET_STRICT_ALIGNMENT 0
34 
35 /* Here are four prefixes that are used by asm_fprintf to
36    facilitate customization for alternate assembler syntaxes.
37    Machines with no likelihood of an alternate syntax need not
38    define these and need not use asm_fprintf.  */
39 
40 /* The prefix for register names.  Note that REGISTER_NAMES
41    is supposed to include this prefix. Also note that this is NOT an
42    fprintf format string, it is a literal string */
43 
44 #undef REGISTER_PREFIX
45 #define REGISTER_PREFIX "%"
46 
47 /* The prefix for local (compiler generated) labels.
48    These labels will not appear in the symbol table.  */
49 
50 #undef LOCAL_LABEL_PREFIX
51 #define LOCAL_LABEL_PREFIX "."
52 
53 /* The prefix to add to user-visible assembler symbols.  */
54 
55 #undef USER_LABEL_PREFIX
56 #define USER_LABEL_PREFIX ""
57 
58 #define ASM_COMMENT_START "|"
59 
60 /* Target OS builtins.  */
61 #define TARGET_OS_CPP_BUILTINS() GNU_USER_TARGET_OS_CPP_BUILTINS()
62 
63 #undef CPP_SPEC
64 #define CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
65 
66 /* Provide a LINK_SPEC appropriate for GNU/Linux.  Here we provide support
67    for the special GCC options -static and -shared, which allow us to
68    link things in one of these three modes by applying the appropriate
69    combinations of options at link-time.
70 
71    When the -shared link option is used a final link is not being
72    done.  */
73 
74 #define GLIBC_DYNAMIC_LINKER "/lib/ld.so.1"
75 
76 #undef LINK_SPEC
77 #define LINK_SPEC "-m m68kelf %{shared} \
78   %{!shared: \
79     %{!static: \
80       %{rdynamic:-export-dynamic} \
81       -dynamic-linker " GNU_USER_DYNAMIC_LINKER "} \
82     %{static}}"
83 
84 /* For compatibility with linux/a.out */
85 
86 #undef PCC_BITFIELD_TYPE_MATTERS
87 
88 /* Currently, JUMP_TABLES_IN_TEXT_SECTION must be defined in order to
89    keep switch tables in the text section.  */
90 
91 #define JUMP_TABLES_IN_TEXT_SECTION 1
92 
93 /* Use the default action for outputting the case label.  */
94 #undef ASM_OUTPUT_CASE_LABEL
95 #define ASM_RETURN_CASE_JUMP				\
96   do {							\
97     if (TARGET_COLDFIRE)				\
98       {							\
99 	if (ADDRESS_REG_P (operands[0]))		\
100 	  return "jmp %%pc@(2,%0:l)";			\
101 	else if (TARGET_LONG_JUMP_TABLE_OFFSETS)	\
102 	  return "jmp %%pc@(2,%0:l)";			\
103 	else						\
104 	  return "ext%.l %0\n\tjmp %%pc@(2,%0:l)";	\
105       }							\
106     else if (TARGET_LONG_JUMP_TABLE_OFFSETS)		\
107       return "jmp %%pc@(2,%0:l)";			\
108     else						\
109       return "jmp %%pc@(2,%0:w)";			\
110   } while (0)
111 
112 /* This is how to output an assembler line that says to advance the
113    location counter to a multiple of 2**LOG bytes.  */
114 
115 #undef ASM_OUTPUT_ALIGN
116 #define ASM_OUTPUT_ALIGN(FILE,LOG)				\
117   if ((LOG) > 0)						\
118     fprintf ((FILE), "%s%u\n", ALIGN_ASM_OP, 1 << (LOG));
119 
120 /* If defined, a C expression whose value is a string containing the
121    assembler operation to identify the following data as uninitialized global
122    data.  */
123 
124 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
125 
126 /* A C statement (sans semicolon) to output to the stdio stream
127    FILE the assembler definition of uninitialized global DECL named
128    NAME whose size is SIZE bytes and alignment is ALIGN bytes.
129    Try to use asm_output_aligned_bss to implement this macro.  */
130 
131 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
132   asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
133 
134 /* Output assembler code to FILE to increment profiler label # LABELNO
135    for profiling a function entry.  */
136 #define NO_PROFILE_COUNTERS 1
137 #undef FUNCTION_PROFILER
138 #define FUNCTION_PROFILER(FILE, LABELNO) \
139 {									\
140   if (flag_pic)								\
141     fprintf (FILE, "\tbsr.l _mcount@PLTPC\n");				\
142   else									\
143     fprintf (FILE, "\tjbsr _mcount\n");					\
144 }
145 
146 /* Do not break .stabs pseudos into continuations.  */
147 
148 #define DBX_CONTIN_LENGTH 0
149 
150 /* 1 if N is a possible register number for a function value.  For
151    m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
152    pointer, or floating types, respectively.  Reject fp0 if not using
153    a 68881 coprocessor.  */
154 
155 #undef FUNCTION_VALUE_REGNO_P
156 #define FUNCTION_VALUE_REGNO_P(N) \
157   ((N) == D0_REG || (N) == A0_REG || (TARGET_68881 && (N) == FP0_REG))
158 
159 /* Define this to be true when FUNCTION_VALUE_REGNO_P is true for
160    more than one register.  */
161 
162 #undef NEEDS_UNTYPED_CALL
163 #define NEEDS_UNTYPED_CALL 1
164 
165 /* Define how to generate (in the callee) the output value of a
166    function and how to find (in the caller) the value returned by a
167    function.  VALTYPE is the data type of the value (as a tree).  If
168    the precise function being called is known, FUNC is its
169    FUNCTION_DECL; otherwise, FUNC is 0.  For m68k/SVR4 generate the
170    result in d0, a0, or fp0 as appropriate.  */
171 
172 #undef FUNCTION_VALUE
173 #define FUNCTION_VALUE(VALTYPE, FUNC)					\
174   m68k_function_value (VALTYPE, FUNC)
175 
176 /* Define how to find the value returned by a library function
177    assuming the value has mode MODE.
178    For m68k/SVR4 look for integer values in d0, pointer values in d0
179    (returned in both d0 and a0), and floating values in fp0.  */
180 
181 #undef LIBCALL_VALUE
182 #define LIBCALL_VALUE(MODE)						\
183   m68k_libcall_value (MODE)
184 
185 /* For m68k SVR4, structures are returned using the reentrant
186    technique.  */
187 #undef PCC_STATIC_STRUCT_RETURN
188 #define DEFAULT_PCC_STRUCT_RETURN 0
189 
190 /* Finalize the trampoline by flushing the insn cache.  */
191 
192 #undef FINALIZE_TRAMPOLINE
193 #define FINALIZE_TRAMPOLINE(TRAMP)					\
194   emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__clear_cache"),	\
195 		     LCT_NORMAL, VOIDmode, TRAMP, Pmode,		\
196 		     plus_constant (Pmode, TRAMP, TRAMPOLINE_SIZE), 	\
197 		     Pmode);
198 
199 /* Clear the instruction cache from `beg' to `end'.  This makes an
200    inline system call to SYS_cacheflush.  The arguments are as
201    follows:
202 
203 	cacheflush (addr, scope, cache, len)
204 
205    addr	  - the start address for the flush
206    scope  - the scope of the flush (see the cpush insn)
207    cache  - which cache to flush (see the cpush insn)
208    len    - a factor relating to the number of flushes to perform:
209 	    len/16 lines, or len/4096 pages.  */
210 
211 #define CLEAR_INSN_CACHE(BEG, END)					\
212 {									\
213   register unsigned long _beg __asm ("%d1") = (unsigned long) (BEG);	\
214   unsigned long _end = (unsigned long) (END);				\
215   register unsigned long _len __asm ("%d4") = (_end - _beg + 32);	\
216   __asm __volatile							\
217     ("move%.l #123, %/d0\n\t"	/* system call nr */			\
218      "move%.l #1, %/d2\n\t"	/* clear lines */			\
219      "move%.l #3, %/d3\n\t"	/* insn+data caches */			\
220      "trap #0"								\
221      : /* no outputs */							\
222      : "d" (_beg), "d" (_len)						\
223      : "%d0", "%d2", "%d3");						\
224 }
225 
226 #define TARGET_ASM_FILE_END file_end_indicate_exec_stack
227 
228 #undef DBX_REGISTER_NUMBER
229 #define DBX_REGISTER_NUMBER(REGNO) (REGNO)
230 
231 #undef  SIZE_TYPE
232 #define SIZE_TYPE "unsigned int"
233 
234 #undef  PTRDIFF_TYPE
235 #define PTRDIFF_TYPE "int"
236 
237 #undef  WCHAR_TYPE
238 #define WCHAR_TYPE "long int"
239 
240 #undef  WCHAR_TYPE_SIZE
241 #define WCHAR_TYPE_SIZE BITS_PER_WORD
242 
243 /* Install the __sync libcalls.  */
244 #undef TARGET_INIT_LIBFUNCS
245 #define TARGET_INIT_LIBFUNCS  m68k_init_sync_libfuncs
246