2005-05-13 Josh Conner <jconner@apple.com>
[official-gcc.git] / gcc / targhooks.c
blob2bf11a431eb0df0c66f67116863fab0f00654da2
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
9 version.
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
14 for more details.
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, 59 Temple Place - Suite 330, Boston, MA
19 02111-1307, USA. */
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
29 take some time.
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
37 this point.
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. */
50 #include "config.h"
51 #include "system.h"
52 #include "coretypes.h"
53 #include "tm.h"
54 #include "machmode.h"
55 #include "rtl.h"
56 #include "tree.h"
57 #include "expr.h"
58 #include "output.h"
59 #include "toplev.h"
60 #include "function.h"
61 #include "target.h"
62 #include "tm_p.h"
63 #include "target-def.h"
66 void
67 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
69 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
70 ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file, fun);
71 #endif
74 enum machine_mode
75 default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
77 if (m1 == m2)
78 return m1;
79 return VOIDmode;
82 bool
83 default_return_in_memory (tree type,
84 tree fntype ATTRIBUTE_UNUSED)
86 #ifndef RETURN_IN_MEMORY
87 return (TYPE_MODE (type) == BLKmode);
88 #else
89 return RETURN_IN_MEMORY (type);
90 #endif
93 rtx
94 default_expand_builtin_saveregs (void)
96 error ("__builtin_saveregs not supported by this target");
97 return const0_rtx;
100 void
101 default_setup_incoming_varargs (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
102 enum machine_mode mode ATTRIBUTE_UNUSED,
103 tree type ATTRIBUTE_UNUSED,
104 int *pretend_arg_size ATTRIBUTE_UNUSED,
105 int second_time ATTRIBUTE_UNUSED)
109 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE. */
112 default_builtin_setjmp_frame_value (void)
114 return virtual_stack_vars_rtx;
117 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false. */
119 bool
120 hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
122 return false;
125 bool
126 default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
128 return (targetm.calls.setup_incoming_varargs
129 != default_setup_incoming_varargs);
132 enum machine_mode
133 default_eh_return_filter_mode (void)
135 return word_mode;
138 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK. */
140 unsigned HOST_WIDE_INT
141 default_shift_truncation_mask (enum machine_mode mode)
143 return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
146 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true. */
148 bool
149 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS * a ATTRIBUTE_UNUSED)
151 return true;
155 /* The generic C++ ABI specifies this is a 64-bit value. */
156 tree
157 default_cxx_guard_type (void)
159 return long_long_integer_type_node;
163 /* Returns the size of the cookie to use when allocating an array
164 whose elements have the indicated TYPE. Assumes that it is already
165 known that a cookie is needed. */
167 tree
168 default_cxx_get_cookie_size (tree type)
170 tree cookie_size;
172 /* We need to allocate an additional max (sizeof (size_t), alignof
173 (true_type)) bytes. */
174 tree sizetype_size;
175 tree type_align;
177 sizetype_size = size_in_bytes (sizetype);
178 type_align = size_int (TYPE_ALIGN_UNIT (type));
179 if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
180 cookie_size = sizetype_size;
181 else
182 cookie_size = type_align;
184 return cookie_size;
187 /* Return true if a parameter must be passed by reference. This version
188 of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK. */
190 bool
191 hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS *c ATTRIBUTE_UNUSED,
192 enum machine_mode mode ATTRIBUTE_UNUSED, tree type ATTRIBUTE_UNUSED,
193 bool named_arg ATTRIBUTE_UNUSED)
195 return targetm.calls.must_pass_in_stack (mode, type);
198 /* Return true if a parameter follows callee copies conventions. This
199 version of the hook is true for all named arguments. */
201 bool
202 hook_callee_copies_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
203 enum machine_mode mode ATTRIBUTE_UNUSED,
204 tree type ATTRIBUTE_UNUSED, bool named)
206 return named;
209 /* Emit any directives required to unwind this instruction. */
211 void
212 default_unwind_emit (FILE * stream ATTRIBUTE_UNUSED,
213 rtx insn ATTRIBUTE_UNUSED)
215 /* Should never happen. */
216 gcc_unreachable ();
219 /* True if MODE is valid for the target. By "valid", we mean able to
220 be manipulated in non-trivial ways. In particular, this means all
221 the arithmetic is supported.
223 By default we guess this means that any C type is supported. If
224 we can't map the mode back to a type that would be available in C,
225 then reject it. Special case, here, is the double-word arithmetic
226 supported by optabs.c. */
228 bool
229 default_scalar_mode_supported_p (enum machine_mode mode)
231 int precision = GET_MODE_PRECISION (mode);
233 switch (GET_MODE_CLASS (mode))
235 case MODE_PARTIAL_INT:
236 case MODE_INT:
237 if (precision == CHAR_TYPE_SIZE)
238 return true;
239 if (precision == SHORT_TYPE_SIZE)
240 return true;
241 if (precision == INT_TYPE_SIZE)
242 return true;
243 if (precision == LONG_TYPE_SIZE)
244 return true;
245 if (precision == LONG_LONG_TYPE_SIZE)
246 return true;
247 if (precision == 2 * BITS_PER_WORD)
248 return true;
249 return false;
251 case MODE_FLOAT:
252 if (precision == FLOAT_TYPE_SIZE)
253 return true;
254 if (precision == DOUBLE_TYPE_SIZE)
255 return true;
256 if (precision == LONG_DOUBLE_TYPE_SIZE)
257 return true;
258 return false;
260 default:
261 gcc_unreachable ();
265 bool
266 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
267 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
268 enum machine_mode mode ATTRIBUTE_UNUSED,
269 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
271 return false;
274 bool
275 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
276 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
277 enum machine_mode mode ATTRIBUTE_UNUSED,
278 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
280 return true;
284 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
285 CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
286 enum machine_mode mode ATTRIBUTE_UNUSED,
287 tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
289 return 0;
292 const char *
293 hook_invalid_arg_for_unprototyped_fn (
294 tree typelist ATTRIBUTE_UNUSED,
295 tree funcdecl ATTRIBUTE_UNUSED,
296 tree val ATTRIBUTE_UNUSED)
298 return NULL;