1 /* Definitions of target machine for GNU compiler,
2    for IBM RS/6000 POWER running AIX.
3    Copyright (C) 2000-2018 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 it
8    under the terms of the GNU General Public License as published
9    by the Free Software Foundation; either version 3, or (at your
10    option) any later version.
11 
12    GCC is distributed in the hope that it will be useful, but WITHOUT
13    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
15    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 /* Yes!  We are AIX!  */
22 #define DEFAULT_ABI ABI_AIX
23 #undef  TARGET_AIX
24 #define TARGET_AIX 1
25 
26 /* Linux64.h wants to redefine TARGET_AIX based on -m64, but it can't be used
27    in the #if conditional in options-default.h, so provide another macro.  */
28 #undef  TARGET_AIX_OS
29 #define TARGET_AIX_OS 1
30 
31 /* AIX always has a TOC.  */
32 #define TARGET_NO_TOC 0
33 #define TARGET_TOC 1
34 #define FIXED_R2 1
35 
36 /* AIX allows r13 to be used in 32-bit mode.  */
37 #define FIXED_R13 0
38 
39 /* 32-bit and 64-bit AIX stack boundary is 128.  */
40 #undef  STACK_BOUNDARY
41 #define STACK_BOUNDARY 128
42 
43 /* Offset within stack frame to start allocating local variables at.
44    If FRAME_GROWS_DOWNWARD, this is the offset to the END of the
45    first local allocated.  Otherwise, it is the offset to the BEGINNING
46    of the first local allocated.
47 
48    On the RS/6000, the frame pointer is the same as the stack pointer,
49    except for dynamic allocations.  So we start after the fixed area and
50    outgoing parameter area.
51 
52    If the function uses dynamic stack space (CALLS_ALLOCA is set), that
53    space needs to be aligned to STACK_BOUNDARY, i.e. the sum of the
54    sizes of the fixed area and the parameter area must be a multiple of
55    STACK_BOUNDARY.  */
56 
57 #undef RS6000_STARTING_FRAME_OFFSET
58 #define RS6000_STARTING_FRAME_OFFSET					\
59   (cfun->calls_alloca							\
60    ? RS6000_ALIGN (crtl->outgoing_args_size + RS6000_SAVE_AREA, 16)	\
61    : (RS6000_ALIGN (crtl->outgoing_args_size, 16) + RS6000_SAVE_AREA))
62 
63 /* Offset from the stack pointer register to an item dynamically
64    allocated on the stack, e.g., by `alloca'.
65 
66    The default value for this macro is `STACK_POINTER_OFFSET' plus the
67    length of the outgoing arguments.  The default is correct for most
68    machines.  See `function.c' for details.
69 
70    This value must be a multiple of STACK_BOUNDARY (hard coded in
71    `emit-rtl.c').  */
72 #undef STACK_DYNAMIC_OFFSET
73 #define STACK_DYNAMIC_OFFSET(FUNDECL)					\
74    RS6000_ALIGN (crtl->outgoing_args_size.to_constant ()		\
75 		 + STACK_POINTER_OFFSET, 16)
76 
77 #undef  TARGET_IEEEQUAD
78 #define TARGET_IEEEQUAD 0
79 
80 #undef  TARGET_IEEEQUAD_DEFAULT
81 #define TARGET_IEEEQUAD_DEFAULT 0
82 
83 /* The AIX linker will discard static constructors in object files before
84    collect has a chance to see them, so scan the object files directly.  */
85 #define COLLECT_EXPORT_LIST
86 
87 /* On AIX, initialisers specified with -binitfini are called in breadth-first
88    order.
89    e.g. if a.out depends on lib1.so, the init function for a.out is called before
90    the init function for lib1.so.
91 
92    To ensure global C++ constructors in linked libraries are run before global
93    C++ constructors from the current module, there is additional symbol scanning
94    logic in collect2.
95 
96    The global initialiser/finaliser functions are named __GLOBAL_AIXI_{libname}
97    and __GLOBAL_AIXD_{libname} and are exported from each shared library.
98 
99    collect2 will detect these symbols when they exist in shared libraries that
100    the current program is being linked against.  All such initiliser functions
101    will be called prior to the constructors of the current program, and
102    finaliser functions called after destructors.
103 
104    Reference counting generated by collect2 will ensure that constructors are
105    only invoked once in the case of multiple dependencies on a library.
106 
107    -binitfini is still used in parallel to this solution.
108    This handles the case where a library is loaded through dlopen(), and also
109    handles the option -blazy.
110 */
111 #define COLLECT_SHARED_INIT_FUNC(STREAM, FUNC) \
112 	  fprintf ((STREAM), "void %s() {\n\t%s();\n}\n", aix_shared_initname, (FUNC))
113 #define COLLECT_SHARED_FINI_FUNC(STREAM, FUNC) \
114 	  fprintf ((STREAM), "void %s() {\n\t%s();\n}\n", aix_shared_fininame, (FUNC))
115 
116 #if HAVE_AS_REF
117 /* Issue assembly directives that create a reference to the given DWARF table
118    identifier label from the current function section.  This is defined to
119    ensure we drag frame tables associated with needed function bodies in
120    a link with garbage collection activated.  */
121 #define ASM_OUTPUT_DWARF_TABLE_REF rs6000_aix_asm_output_dwarf_table_ref
122 #endif
123 
124 /* This is the only version of nm that collect2 can work with.  */
125 #define REAL_NM_FILE_NAME "/usr/ucb/nm"
126 
127 #define USER_LABEL_PREFIX  ""
128 
129 /* Don't turn -B into -L if the argument specifies a relative file name.  */
130 #define RELATIVE_PREFIX_NOT_LINKDIR
131 
132 /* Because of the above, we must have gcc search itself to find libgcc.a.  */
133 #define LINK_LIBGCC_SPECIAL_1
134 
135 /* Names to predefine in the preprocessor for this target machine.  */
136 #define TARGET_OS_AIX_CPP_BUILTINS()		\
137   do						\
138     {						\
139       builtin_define ("_IBMR2");		\
140       builtin_define ("_POWER");		\
141       builtin_define ("__unix__");              \
142       builtin_define ("_AIX");			\
143       builtin_define ("_AIX32");		\
144       builtin_define ("_AIX41");		\
145       builtin_define ("_LONG_LONG");		\
146       if (TARGET_LONG_DOUBLE_128)		\
147         builtin_define ("__LONGDOUBLE128");	\
148       builtin_assert ("system=unix");		\
149       builtin_assert ("system=aix");		\
150       if (TARGET_64BIT)				\
151 	{					\
152 	  builtin_define ("__PPC__");		\
153 	  builtin_define ("__PPC64__");		\
154 	  builtin_define ("__powerpc__");	\
155 	  builtin_define ("__powerpc64__");	\
156 	  builtin_assert ("cpu=powerpc64");	\
157 	  builtin_assert ("machine=powerpc64");	\
158 	}					\
159       else					\
160 	{					\
161 	  builtin_define ("__PPC__");		\
162 	  builtin_define ("__powerpc__");	\
163 	  builtin_assert ("cpu=powerpc");	\
164 	  builtin_assert ("machine=powerpc");	\
165 	}					\
166     }						\
167   while (0)
168 
169 /* Define appropriate architecture macros for preprocessor depending on
170    target switches.  */
171 
172 #define CPP_SPEC "%{posix: -D_POSIX_SOURCE}\
173    %{ansi: -D_ANSI_C_SOURCE}"
174 
175 #define CC1_SPEC "%(cc1_cpu)"
176 
177 #undef ASM_DEFAULT_SPEC
178 #define ASM_DEFAULT_SPEC ""
179 
180 /* Tell the assembler to assume that all undefined names are external.
181 
182    Don't do this until the fixed IBM assembler is more generally available.
183    When this becomes permanently defined, the ASM_OUTPUT_EXTERNAL,
184    ASM_OUTPUT_EXTERNAL_LIBCALL, and RS6000_OUTPUT_BASENAME macros will no
185    longer be needed.  Also, the extern declaration of mcount in
186    rs6000_xcoff_file_start will no longer be needed.  */
187 
188 /* #define ASM_SPEC "-u %(asm_cpu)" */
189 
190 /* Default location of syscalls.exp under AIX */
191 #define LINK_SYSCALLS_SPEC "-bI:%R/lib/syscalls.exp"
192 
193 /* Default location of libg.exp under AIX */
194 #define LINK_LIBG_SPEC "-bexport:%R/usr/lib/libg.exp"
195 
196 /* Define the options for the binder: Start text at 512, align all segments
197    to 512 bytes, and warn if there is text relocation.
198 
199    The -bhalt:4 option supposedly changes the level at which ld will abort,
200    but it also suppresses warnings about multiply defined symbols and is
201    used by the AIX cc command.  So we use it here.
202 
203    -bnodelcsect undoes a poor choice of default relating to multiply-defined
204    csects.  See AIX documentation for more information about this.
205 
206    -bM:SRE tells the linker that the output file is Shared REusable.  Note
207    that to actually build a shared library you will also need to specify an
208    export list with the -Wl,-bE option.  */
209 
210 #define LINK_SPEC "-T512 -H512 %{!r:-btextro} -bhalt:4 -bnodelcsect\
211 %{static:-bnso %(link_syscalls) } \
212 %{!shared:%{g*: %(link_libg) }} %{shared:-bM:SRE}"
213 
214 /* Profiled library versions are used by linking with special directories.  */
215 #define LIB_SPEC "%{pg:-L%R/lib/profiled -L%R/usr/lib/profiled}\
216 %{p:-L%R/lib/profiled -L%R/usr/lib/profiled} %{!shared:%{g*:-lg}} -lc"
217 
218 /* Static linking with shared libstdc++ requires libsupc++ as well.  */
219 #define LIBSTDCXX_STATIC "supc++"
220 
221 /* This now supports a natural alignment mode.  */
222 /* AIX word-aligns FP doubles but doubleword-aligns 64-bit ints.  */
223 #define ADJUST_FIELD_ALIGN(FIELD, TYPE, COMPUTED) \
224   ((TARGET_ALIGN_NATURAL == 0						\
225     && TYPE_MODE (strip_array_types (TYPE)) == DFmode)			\
226    ? MIN ((COMPUTED), 32)						\
227    : (COMPUTED))
228 
229 /* AIX increases natural record alignment to doubleword if the first
230    field is an FP double while the FP fields remain word aligned.  */
231 #define ROUND_TYPE_ALIGN(STRUCT, COMPUTED, SPECIFIED)			\
232   ((TREE_CODE (STRUCT) == RECORD_TYPE					\
233     || TREE_CODE (STRUCT) == UNION_TYPE					\
234     || TREE_CODE (STRUCT) == QUAL_UNION_TYPE)				\
235    && TARGET_ALIGN_NATURAL == 0						\
236    ? rs6000_special_round_type_align (STRUCT, COMPUTED, SPECIFIED)	\
237    : MAX ((COMPUTED), (SPECIFIED)))
238 
239 /* The AIX ABI isn't explicit on whether aggregates smaller than a
240    word/doubleword should be padded upward or downward.  One could
241    reasonably assume that they follow the normal rules for structure
242    layout treating the parameter area as any other block of memory,
243    then map the reg param area to registers, i.e., pad upward, which
244    is the way IBM Compilers for AIX behave.
245    Setting both of the following defines results in this behavior.  */
246 #define AGGREGATE_PADDING_FIXED 1
247 #define AGGREGATES_PAD_UPWARD_ALWAYS 1
248 
249 /* Specify padding for the last element of a block move between
250    registers and memory.  FIRST is nonzero if this is the only
251    element.  */
252 #define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
253   (!(FIRST) ? PAD_UPWARD : targetm.calls.function_arg_padding (MODE, TYPE))
254 
255 /* Indicate that jump tables go in the text section.  */
256 
257 #define JUMP_TABLES_IN_TEXT_SECTION 1
258 
259 /* Define any extra SPECS that the compiler needs to generate.  */
260 #undef  SUBTARGET_EXTRA_SPECS
261 #define SUBTARGET_EXTRA_SPECS						\
262   { "link_syscalls",            LINK_SYSCALLS_SPEC },			\
263   { "link_libg",                LINK_LIBG_SPEC }
264 
265 #define PROFILE_HOOK(LABEL)   output_profile_hook (LABEL)
266 
267 /* No version of AIX fully supports AltiVec or 64-bit instructions in
268    32-bit mode.  */
269 #define OS_MISSING_POWERPC64 1
270 #define OS_MISSING_ALTIVEC 1
271 
272 /* WINT_TYPE */
273 #define WINT_TYPE "int"
274 
275 /* Static stack checking is supported by means of probes.  */
276 #define STACK_CHECK_STATIC_BUILTIN 1
277 
278 /* Use standard DWARF numbering for DWARF debugging information.  */
279 #define RS6000_USE_DWARF_NUMBERING
280 
281