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"
65 #include "hard-reg-set.h"
69 default_external_libcall (rtx fun ATTRIBUTE_UNUSED
)
71 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
72 ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file
, fun
);
77 default_cc_modes_compatible (enum machine_mode m1
, enum machine_mode m2
)
85 default_return_in_memory (tree type
,
86 tree fntype ATTRIBUTE_UNUSED
)
88 #ifndef RETURN_IN_MEMORY
89 return (TYPE_MODE (type
) == BLKmode
);
91 return RETURN_IN_MEMORY (type
);
96 default_expand_builtin_saveregs (void)
98 error ("__builtin_saveregs not supported by this target");
103 default_setup_incoming_varargs (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
104 enum machine_mode mode ATTRIBUTE_UNUSED
,
105 tree type ATTRIBUTE_UNUSED
,
106 int *pretend_arg_size ATTRIBUTE_UNUSED
,
107 int second_time ATTRIBUTE_UNUSED
)
111 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE. */
114 default_builtin_setjmp_frame_value (void)
116 return virtual_stack_vars_rtx
;
119 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false. */
122 hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
)
128 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
)
130 return (targetm
.calls
.setup_incoming_varargs
131 != default_setup_incoming_varargs
);
135 default_eh_return_filter_mode (void)
140 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK. */
142 unsigned HOST_WIDE_INT
143 default_shift_truncation_mask (enum machine_mode mode
)
145 return SHIFT_COUNT_TRUNCATED
? GET_MODE_BITSIZE (mode
) - 1 : 0;
148 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true. */
151 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS
* a ATTRIBUTE_UNUSED
)
157 /* The generic C++ ABI specifies this is a 64-bit value. */
159 default_cxx_guard_type (void)
161 return long_long_integer_type_node
;
165 /* Returns the size of the cookie to use when allocating an array
166 whose elements have the indicated TYPE. Assumes that it is already
167 known that a cookie is needed. */
170 default_cxx_get_cookie_size (tree type
)
174 /* We need to allocate an additional max (sizeof (size_t), alignof
175 (true_type)) bytes. */
179 sizetype_size
= size_in_bytes (sizetype
);
180 type_align
= size_int (TYPE_ALIGN_UNIT (type
));
181 if (INT_CST_LT_UNSIGNED (type_align
, sizetype_size
))
182 cookie_size
= sizetype_size
;
184 cookie_size
= type_align
;
189 /* Return true if a parameter must be passed by reference. This version
190 of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK. */
193 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS
*c ATTRIBUTE_UNUSED
,
194 enum machine_mode mode ATTRIBUTE_UNUSED
, tree type ATTRIBUTE_UNUSED
,
195 bool named_arg ATTRIBUTE_UNUSED
)
197 return targetm
.calls
.must_pass_in_stack (mode
, type
);
200 /* Return true if a parameter follows callee copies conventions. This
201 version of the hook is true for all named arguments. */
204 hook_callee_copies_named (CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
205 enum machine_mode mode ATTRIBUTE_UNUSED
,
206 tree type ATTRIBUTE_UNUSED
, bool named
)
211 /* Emit any directives required to unwind this instruction. */
214 default_unwind_emit (FILE * stream ATTRIBUTE_UNUSED
,
215 rtx insn ATTRIBUTE_UNUSED
)
217 /* Should never happen. */
221 /* True if MODE is valid for the target. By "valid", we mean able to
222 be manipulated in non-trivial ways. In particular, this means all
223 the arithmetic is supported.
225 By default we guess this means that any C type is supported. If
226 we can't map the mode back to a type that would be available in C,
227 then reject it. Special case, here, is the double-word arithmetic
228 supported by optabs.c. */
231 default_scalar_mode_supported_p (enum machine_mode mode
)
233 int precision
= GET_MODE_PRECISION (mode
);
235 switch (GET_MODE_CLASS (mode
))
237 case MODE_PARTIAL_INT
:
239 if (precision
== CHAR_TYPE_SIZE
)
241 if (precision
== SHORT_TYPE_SIZE
)
243 if (precision
== INT_TYPE_SIZE
)
245 if (precision
== LONG_TYPE_SIZE
)
247 if (precision
== LONG_LONG_TYPE_SIZE
)
249 if (precision
== 2 * BITS_PER_WORD
)
254 if (precision
== FLOAT_TYPE_SIZE
)
256 if (precision
== DOUBLE_TYPE_SIZE
)
258 if (precision
== LONG_DOUBLE_TYPE_SIZE
)
267 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
270 This function checks whether a given INSN is valid within a low-overhead
271 loop. If INSN is invalid it returns the reason for that, otherwise it
272 returns NULL. A called function may clobber any special registers required
273 for low-overhead looping. Additionally, some targets (eg, PPC) use the count
274 register for branch on table instructions. We reject the doloop pattern in
278 default_invalid_within_doloop (rtx insn
)
281 return "Function call in loop.";
284 && (GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
285 || GET_CODE (PATTERN (insn
)) == ADDR_VEC
))
286 return "Computed branch in the loop.";
292 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
293 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
294 enum machine_mode mode ATTRIBUTE_UNUSED
,
295 tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
301 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
302 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
303 enum machine_mode mode ATTRIBUTE_UNUSED
,
304 tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
310 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
311 CUMULATIVE_ARGS
*ca ATTRIBUTE_UNUSED
,
312 enum machine_mode mode ATTRIBUTE_UNUSED
,
313 tree type ATTRIBUTE_UNUSED
, bool named ATTRIBUTE_UNUSED
)
319 hook_invalid_arg_for_unprototyped_fn (
320 tree typelist ATTRIBUTE_UNUSED
,
321 tree funcdecl ATTRIBUTE_UNUSED
,
322 tree val ATTRIBUTE_UNUSED
)
327 /* Initialize the stack protection decls. */
329 /* Stack protection related decls living in libgcc. */
330 static GTY(()) tree stack_chk_guard_decl
;
333 default_stack_protect_guard (void)
335 tree t
= stack_chk_guard_decl
;
339 t
= build_decl (VAR_DECL
, get_identifier ("__stack_chk_guard"),
343 DECL_EXTERNAL (t
) = 1;
345 TREE_THIS_VOLATILE (t
) = 1;
346 DECL_ARTIFICIAL (t
) = 1;
347 DECL_IGNORED_P (t
) = 1;
349 stack_chk_guard_decl
= t
;
355 static GTY(()) tree stack_chk_fail_decl
;
358 default_external_stack_protect_fail (void)
360 tree t
= stack_chk_fail_decl
;
364 t
= build_function_type_list (void_type_node
, NULL_TREE
);
365 t
= build_decl (FUNCTION_DECL
, get_identifier ("__stack_chk_fail"), t
);
368 DECL_EXTERNAL (t
) = 1;
370 TREE_THIS_VOLATILE (t
) = 1;
371 TREE_NOTHROW (t
) = 1;
372 DECL_ARTIFICIAL (t
) = 1;
373 DECL_IGNORED_P (t
) = 1;
375 stack_chk_fail_decl
= t
;
378 return build_function_call_expr (t
, NULL_TREE
);
382 default_hidden_stack_protect_fail (void)
384 #ifndef HAVE_GAS_HIDDEN
385 return default_external_stack_protect_fail ();
387 tree t
= stack_chk_fail_decl
;
390 return default_external_stack_protect_fail ();
394 t
= build_function_type_list (void_type_node
, NULL_TREE
);
395 t
= build_decl (FUNCTION_DECL
,
396 get_identifier ("__stack_chk_fail_local"), t
);
399 DECL_EXTERNAL (t
) = 1;
401 TREE_THIS_VOLATILE (t
) = 1;
402 TREE_NOTHROW (t
) = 1;
403 DECL_ARTIFICIAL (t
) = 1;
404 DECL_IGNORED_P (t
) = 1;
405 DECL_VISIBILITY_SPECIFIED (t
) = 1;
406 DECL_VISIBILITY (t
) = VISIBILITY_HIDDEN
;
408 stack_chk_fail_decl
= t
;
411 return build_function_call_expr (t
, NULL_TREE
);
416 hook_bool_rtx_commutative_p (rtx x
, int outer_code ATTRIBUTE_UNUSED
)
418 return COMMUTATIVE_P (x
);
422 default_function_value (tree ret_type ATTRIBUTE_UNUSED
,
423 tree fn_decl_or_type
,
424 bool outgoing ATTRIBUTE_UNUSED
)
426 /* The old interface doesn't handle receiving the function type. */
428 && !DECL_P (fn_decl_or_type
))
429 fn_decl_or_type
= NULL
;
431 #ifdef FUNCTION_OUTGOING_VALUE
433 return FUNCTION_OUTGOING_VALUE (ret_type
, fn_decl_or_type
);
436 #ifdef FUNCTION_VALUE
437 return FUNCTION_VALUE (ret_type
, fn_decl_or_type
);
444 default_internal_arg_pointer (void)
446 /* If the reg that the virtual arg pointer will be translated into is
447 not a fixed reg or is the stack pointer, make a copy of the virtual
448 arg pointer, and address parms via the copy. The frame pointer is
449 considered fixed even though it is not marked as such. */
450 if ((ARG_POINTER_REGNUM
== STACK_POINTER_REGNUM
451 || ! (fixed_regs
[ARG_POINTER_REGNUM
]
452 || ARG_POINTER_REGNUM
== FRAME_POINTER_REGNUM
)))
453 return copy_to_reg (virtual_incoming_args_rtx
);
455 return virtual_incoming_args_rtx
;
458 #include "gt-targhooks.h"