1 /* Default target hook functions.
2 Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 2, or (at your option) any later
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING. If not, write to the Free
18 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
21 /* The migration of target macros to target hooks works as follows:
23 1. Create a target hook that uses the existing target macros to
24 implement the same functionality.
26 2. Convert all the MI files to use the hook instead of the macro.
28 3. Repeat for a majority of the remaining target macros. This will
31 4. Tell target maintainers to start migrating.
33 5. Eventually convert the backends to override the hook instead of
34 defining the macros. This will take some time too.
36 6. TBD when, poison the macros. Unmigrated targets will break at
39 Note that we expect steps 1-3 to be done by the people that
40 understand what the MI does with each macro, and step 5 to be done
41 by the target maintainers for their respective targets.
43 Note that steps 1 and 2 don't have to be done together, but no
44 target can override the new hook until step 2 is complete for it.
46 Once the macros are poisoned, we will revert to the old migration
47 rules - migrate the macro, callers, and targets all at once. This
48 comment can thus be removed at that point. */
52 #include "coretypes.h"
63 #include "target-def.h"
68 default_external_libcall (rtx fun ATTRIBUTE_UNUSED
)
70 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
71 ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file
, fun
);
76 default_cc_modes_compatible (enum machine_mode m1
, enum machine_mode m2
)
84 default_return_in_memory (tree type
,
85 tree fntype ATTRIBUTE_UNUSED
)
87 #ifndef RETURN_IN_MEMORY
88 return (TYPE_MODE (type
) == BLKmode
);
90 return RETURN_IN_MEMORY (type
);
95 default_expand_builtin_saveregs (void)
97 error ("__builtin_saveregs not supported by this target");
102 default_setup_incoming_varargs (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
103 enum machine_mode mode ATTRIBUTE_UNUSED
,
104 tree type ATTRIBUTE_UNUSED
,
105 int *pretend_arg_size ATTRIBUTE_UNUSED
,
106 int second_time ATTRIBUTE_UNUSED
)
110 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE. */
113 default_builtin_setjmp_frame_value (void)
115 return virtual_stack_vars_rtx
;
118 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false. */
121 hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
)
127 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
)
129 return (targetm
.calls
.setup_incoming_varargs
130 != default_setup_incoming_varargs
);
134 default_eh_return_filter_mode (void)
139 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK. */
141 unsigned HOST_WIDE_INT
142 default_shift_truncation_mask (enum machine_mode mode
)
144 return SHIFT_COUNT_TRUNCATED
? GET_MODE_BITSIZE (mode
) - 1 : 0;
147 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true. */
150 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS
* a ATTRIBUTE_UNUSED
)
156 /* The generic C++ ABI specifies this is a 64-bit value. */
158 default_cxx_guard_type (void)
160 return long_long_integer_type_node
;
164 /* Returns the size of the cookie to use when allocating an array
165 whose elements have the indicated TYPE. Assumes that it is already
166 known that a cookie is needed. */
169 default_cxx_get_cookie_size (tree type
)
173 /* We need to allocate an additional max (sizeof (size_t), alignof
174 (true_type)) bytes. */
178 sizetype_size
= size_in_bytes (sizetype
);
179 type_align
= size_int (TYPE_ALIGN_UNIT (type
));
180 if (INT_CST_LT_UNSIGNED (type_align
, sizetype_size
))
181 cookie_size
= sizetype_size
;
183 cookie_size
= type_align
;
188 /* Return true if a parameter must be passed by reference. This version
189 of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK. */
192 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS
*c ATTRIBUTE_UNUSED
,
193 enum machine_mode mode ATTRIBUTE_UNUSED
, tree type ATTRIBUTE_UNUSED
,
194 bool named_arg ATTRIBUTE_UNUSED
)
196 return targetm
.calls
.must_pass_in_stack (mode
, type
);
199 /* Return true if a parameter follows callee copies conventions. This
200 version of the hook is true for all named arguments. */
203 hook_callee_copies_named (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
204 enum machine_mode mode ATTRIBUTE_UNUSED
,
205 tree type ATTRIBUTE_UNUSED
, bool named
)
210 /* Emit any directives required to unwind this instruction. */
213 default_unwind_emit (FILE * stream ATTRIBUTE_UNUSED
,
214 rtx insn ATTRIBUTE_UNUSED
)
216 /* Should never happen. */
220 /* True if MODE is valid for the target. By "valid", we mean able to
221 be manipulated in non-trivial ways. In particular, this means all
222 the arithmetic is supported.
224 By default we guess this means that any C type is supported. If
225 we can't map the mode back to a type that would be available in C,
226 then reject it. Special case, here, is the double-word arithmetic
227 supported by optabs.c. */
230 default_scalar_mode_supported_p (enum machine_mode mode
)
232 int precision
= GET_MODE_PRECISION (mode
);
234 switch (GET_MODE_CLASS (mode
))
236 case MODE_PARTIAL_INT
:
238 if (precision
== CHAR_TYPE_SIZE
)
240 if (precision
== SHORT_TYPE_SIZE
)
242 if (precision
== INT_TYPE_SIZE
)
244 if (precision
== LONG_TYPE_SIZE
)
246 if (precision
== LONG_LONG_TYPE_SIZE
)
248 if (precision
== 2 * BITS_PER_WORD
)
253 if (precision
== FLOAT_TYPE_SIZE
)
255 if (precision
== DOUBLE_TYPE_SIZE
)
257 if (precision
== LONG_DOUBLE_TYPE_SIZE
)
266 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
269 This function checks whether a given INSN is valid within a low-overhead
270 loop. If INSN is invalid it returns the reason for that, otherwise it
271 returns NULL. A called function may clobber any special registers required
272 for low-overhead looping. Additionally, some targets (eg, PPC) use the count
273 register for branch on table instructions. We reject the doloop pattern in
277 default_invalid_within_doloop (rtx insn
)
280 return "Function call in loop.";
283 && (GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
284 || GET_CODE (PATTERN (insn
)) == ADDR_VEC
))
285 return "Computed branch in the loop.";
291 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
292 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
293 enum machine_mode mode ATTRIBUTE_UNUSED
,
294 tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
300 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
301 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
302 enum machine_mode mode ATTRIBUTE_UNUSED
,
303 tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
309 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
310 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
311 enum machine_mode mode ATTRIBUTE_UNUSED
,
312 tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
318 hook_invalid_arg_for_unprototyped_fn (
319 tree typelist ATTRIBUTE_UNUSED
,
320 tree funcdecl ATTRIBUTE_UNUSED
,
321 tree val ATTRIBUTE_UNUSED
)
326 /* Initialize the stack protection decls. */
328 /* Stack protection related decls living in libgcc. */
329 static GTY(()) tree stack_chk_guard_decl
;
332 default_stack_protect_guard (void)
334 tree t
= stack_chk_guard_decl
;
338 t
= build_decl (VAR_DECL
, get_identifier ("__stack_chk_guard"),
342 DECL_EXTERNAL (t
) = 1;
344 TREE_THIS_VOLATILE (t
) = 1;
345 DECL_ARTIFICIAL (t
) = 1;
346 DECL_IGNORED_P (t
) = 1;
348 stack_chk_guard_decl
= t
;
354 static GTY(()) tree stack_chk_fail_decl
;
357 default_external_stack_protect_fail (void)
359 tree t
= stack_chk_fail_decl
;
363 t
= build_function_type_list (void_type_node
, NULL_TREE
);
364 t
= build_decl (FUNCTION_DECL
, get_identifier ("__stack_chk_fail"), t
);
367 DECL_EXTERNAL (t
) = 1;
369 TREE_THIS_VOLATILE (t
) = 1;
370 TREE_NOTHROW (t
) = 1;
371 DECL_ARTIFICIAL (t
) = 1;
372 DECL_IGNORED_P (t
) = 1;
374 stack_chk_fail_decl
= t
;
377 return build_function_call_expr (t
, NULL_TREE
);
381 default_hidden_stack_protect_fail (void)
383 #ifndef HAVE_GAS_HIDDEN
384 return default_external_stack_protect_fail ();
386 tree t
= stack_chk_fail_decl
;
389 return default_external_stack_protect_fail ();
393 t
= build_function_type_list (void_type_node
, NULL_TREE
);
394 t
= build_decl (FUNCTION_DECL
,
395 get_identifier ("__stack_chk_fail_local"), t
);
398 DECL_EXTERNAL (t
) = 1;
400 TREE_THIS_VOLATILE (t
) = 1;
401 TREE_NOTHROW (t
) = 1;
402 DECL_ARTIFICIAL (t
) = 1;
403 DECL_IGNORED_P (t
) = 1;
404 DECL_VISIBILITY_SPECIFIED (t
) = 1;
405 DECL_VISIBILITY (t
) = VISIBILITY_HIDDEN
;
407 stack_chk_fail_decl
= t
;
410 return build_function_call_expr (t
, NULL_TREE
);
414 #include "gt-targhooks.h"