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7306ed3f | 1 | /* C-compiler utilities for types and variables storage layout |
06ceef4e | 2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1996, 1998, |
b5d6a2ff | 3 | 1999, 2000, 2001 Free Software Foundation, Inc. |
7306ed3f JW |
4 | |
5 | This file is part of GNU CC. | |
6 | ||
7 | GNU CC 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 2, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GNU CC 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 GNU CC; see the file COPYING. If not, write to | |
e9fa0c7c RK |
19 | the Free Software Foundation, 59 Temple Place - Suite 330, |
20 | Boston, MA 02111-1307, USA. */ | |
7306ed3f JW |
21 | |
22 | ||
23 | #include "config.h" | |
670ee920 | 24 | #include "system.h" |
7306ed3f | 25 | #include "tree.h" |
d05a5492 | 26 | #include "rtl.h" |
6baf1cc8 | 27 | #include "tm_p.h" |
566cdc73 | 28 | #include "flags.h" |
7306ed3f | 29 | #include "function.h" |
234042f4 | 30 | #include "expr.h" |
10f0ad3d | 31 | #include "toplev.h" |
d7db6646 | 32 | #include "ggc.h" |
7306ed3f | 33 | |
fed3cef0 RK |
34 | /* Set to one when set_sizetype has been called. */ |
35 | static int sizetype_set; | |
36 | ||
37 | /* List of types created before set_sizetype has been called. We do not | |
38 | make this a GGC root since we want these nodes to be reclaimed. */ | |
39 | static tree early_type_list; | |
40 | ||
7306ed3f | 41 | /* Data type for the expressions representing sizes of data types. |
896cced4 | 42 | It is the first integer type laid out. */ |
fed3cef0 | 43 | tree sizetype_tab[(int) TYPE_KIND_LAST]; |
7306ed3f | 44 | |
d4c40650 RS |
45 | /* If nonzero, this is an upper limit on alignment of structure fields. |
46 | The value is measured in bits. */ | |
729a2125 | 47 | unsigned int maximum_field_alignment; |
d4c40650 | 48 | |
abc95ed3 | 49 | /* If non-zero, the alignment of a bitstring or (power-)set value, in bits. |
b5d11e41 | 50 | May be overridden by front-ends. */ |
729a2125 | 51 | unsigned int set_alignment = 0; |
b5d11e41 | 52 | |
b5d6a2ff RK |
53 | /* Nonzero if all REFERENCE_TYPEs are internal and hence should be |
54 | allocated in Pmode, not ptr_mode. Set only by internal_reference_types | |
55 | called only by a front end. */ | |
56 | static int reference_types_internal = 0; | |
57 | ||
770ae6cc | 58 | static void finalize_record_size PARAMS ((record_layout_info)); |
770ae6cc RK |
59 | static void finalize_type_size PARAMS ((tree)); |
60 | static void place_union_field PARAMS ((record_layout_info, tree)); | |
36244024 | 61 | extern void debug_rli PARAMS ((record_layout_info)); |
7306ed3f JW |
62 | \f |
63 | /* SAVE_EXPRs for sizes of types and decls, waiting to be expanded. */ | |
64 | ||
65 | static tree pending_sizes; | |
66 | ||
67 | /* Nonzero means cannot safely call expand_expr now, | |
68 | so put variable sizes onto `pending_sizes' instead. */ | |
69 | ||
70 | int immediate_size_expand; | |
71 | ||
b5d6a2ff RK |
72 | /* Show that REFERENCE_TYPES are internal and should be Pmode. Called only |
73 | by front end. */ | |
74 | ||
75 | void | |
76 | internal_reference_types () | |
77 | { | |
78 | reference_types_internal = 1; | |
79 | } | |
80 | ||
770ae6cc RK |
81 | /* Get a list of all the objects put on the pending sizes list. */ |
82 | ||
7306ed3f JW |
83 | tree |
84 | get_pending_sizes () | |
85 | { | |
86 | tree chain = pending_sizes; | |
4e4b555d RS |
87 | tree t; |
88 | ||
89 | /* Put each SAVE_EXPR into the current function. */ | |
90 | for (t = chain; t; t = TREE_CHAIN (t)) | |
91 | SAVE_EXPR_CONTEXT (TREE_VALUE (t)) = current_function_decl; | |
d4b60170 | 92 | |
7306ed3f JW |
93 | pending_sizes = 0; |
94 | return chain; | |
95 | } | |
96 | ||
fe375cf1 JJ |
97 | /* Return non-zero if EXPR is present on the pending sizes list. */ |
98 | ||
99 | int | |
100 | is_pending_size (expr) | |
101 | tree expr; | |
102 | { | |
103 | tree t; | |
104 | ||
105 | for (t = pending_sizes; t; t = TREE_CHAIN (t)) | |
106 | if (TREE_VALUE (t) == expr) | |
107 | return 1; | |
108 | return 0; | |
109 | } | |
110 | ||
111 | /* Add EXPR to the pending sizes list. */ | |
112 | ||
113 | void | |
114 | put_pending_size (expr) | |
115 | tree expr; | |
116 | { | |
117 | if (TREE_CODE (expr) == SAVE_EXPR) | |
118 | pending_sizes = tree_cons (NULL_TREE, expr, pending_sizes); | |
119 | } | |
120 | ||
770ae6cc RK |
121 | /* Put a chain of objects into the pending sizes list, which must be |
122 | empty. */ | |
123 | ||
1fd7c4ac RK |
124 | void |
125 | put_pending_sizes (chain) | |
126 | tree chain; | |
127 | { | |
128 | if (pending_sizes) | |
129 | abort (); | |
130 | ||
131 | pending_sizes = chain; | |
132 | } | |
133 | ||
76ffb3a0 | 134 | /* Given a size SIZE that may not be a constant, return a SAVE_EXPR |
7306ed3f JW |
135 | to serve as the actual size-expression for a type or decl. */ |
136 | ||
4e4b555d | 137 | tree |
7306ed3f JW |
138 | variable_size (size) |
139 | tree size; | |
140 | { | |
5e9bec99 RK |
141 | /* If the language-processor is to take responsibility for variable-sized |
142 | items (e.g., languages which have elaboration procedures like Ada), | |
e5852cff | 143 | just return SIZE unchanged. Likewise for self-referential sizes. */ |
76ffb3a0 RK |
144 | if (TREE_CONSTANT (size) |
145 | || global_bindings_p () < 0 || contains_placeholder_p (size)) | |
5e9bec99 RK |
146 | return size; |
147 | ||
68de3831 RK |
148 | size = save_expr (size); |
149 | ||
d26f8097 MM |
150 | /* If an array with a variable number of elements is declared, and |
151 | the elements require destruction, we will emit a cleanup for the | |
152 | array. That cleanup is run both on normal exit from the block | |
153 | and in the exception-handler for the block. Normally, when code | |
154 | is used in both ordinary code and in an exception handler it is | |
155 | `unsaved', i.e., all SAVE_EXPRs are recalculated. However, we do | |
156 | not wish to do that here; the array-size is the same in both | |
157 | places. */ | |
158 | if (TREE_CODE (size) == SAVE_EXPR) | |
159 | SAVE_EXPR_PERSISTENT_P (size) = 1; | |
160 | ||
68de3831 | 161 | if (global_bindings_p ()) |
7306ed3f | 162 | { |
80f9c711 RS |
163 | if (TREE_CONSTANT (size)) |
164 | error ("type size can't be explicitly evaluated"); | |
165 | else | |
166 | error ("variable-size type declared outside of any function"); | |
167 | ||
fed3cef0 | 168 | return size_one_node; |
7306ed3f JW |
169 | } |
170 | ||
171 | if (immediate_size_expand) | |
93609dfb RK |
172 | /* NULL_RTX is not defined; neither is the rtx type. |
173 | Also, we would like to pass const0_rtx here, but don't have it. */ | |
9714cf43 | 174 | expand_expr (size, expand_expr (integer_zero_node, NULL_RTX, VOIDmode, 0), |
93609dfb | 175 | VOIDmode, 0); |
770ae6cc | 176 | else if (cfun != 0 && cfun->x_dont_save_pending_sizes_p) |
d43163b7 MM |
177 | /* The front-end doesn't want us to keep a list of the expressions |
178 | that determine sizes for variable size objects. */ | |
179 | ; | |
fe375cf1 JJ |
180 | else |
181 | put_pending_size (size); | |
7306ed3f JW |
182 | |
183 | return size; | |
184 | } | |
185 | \f | |
186 | #ifndef MAX_FIXED_MODE_SIZE | |
187 | #define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (DImode) | |
188 | #endif | |
189 | ||
190 | /* Return the machine mode to use for a nonscalar of SIZE bits. | |
191 | The mode must be in class CLASS, and have exactly that many bits. | |
192 | If LIMIT is nonzero, modes of wider than MAX_FIXED_MODE_SIZE will not | |
193 | be used. */ | |
194 | ||
195 | enum machine_mode | |
196 | mode_for_size (size, class, limit) | |
770ae6cc | 197 | unsigned int size; |
7306ed3f JW |
198 | enum mode_class class; |
199 | int limit; | |
200 | { | |
201 | register enum machine_mode mode; | |
202 | ||
72c602fc | 203 | if (limit && size > MAX_FIXED_MODE_SIZE) |
7306ed3f JW |
204 | return BLKmode; |
205 | ||
5e9bec99 | 206 | /* Get the first mode which has this size, in the specified class. */ |
7306ed3f JW |
207 | for (mode = GET_CLASS_NARROWEST_MODE (class); mode != VOIDmode; |
208 | mode = GET_MODE_WIDER_MODE (mode)) | |
72c602fc | 209 | if (GET_MODE_BITSIZE (mode) == size) |
7306ed3f JW |
210 | return mode; |
211 | ||
212 | return BLKmode; | |
213 | } | |
214 | ||
72c602fc RK |
215 | /* Similar, except passed a tree node. */ |
216 | ||
217 | enum machine_mode | |
218 | mode_for_size_tree (size, class, limit) | |
219 | tree size; | |
220 | enum mode_class class; | |
221 | int limit; | |
222 | { | |
223 | if (TREE_CODE (size) != INTEGER_CST | |
72c602fc RK |
224 | /* What we really want to say here is that the size can fit in a |
225 | host integer, but we know there's no way we'd find a mode for | |
226 | this many bits, so there's no point in doing the precise test. */ | |
05bccae2 | 227 | || compare_tree_int (size, 1000) > 0) |
72c602fc RK |
228 | return BLKmode; |
229 | else | |
230 | return mode_for_size (TREE_INT_CST_LOW (size), class, limit); | |
231 | } | |
232 | ||
5e9bec99 RK |
233 | /* Similar, but never return BLKmode; return the narrowest mode that |
234 | contains at least the requested number of bits. */ | |
235 | ||
27922c13 | 236 | enum machine_mode |
5e9bec99 | 237 | smallest_mode_for_size (size, class) |
770ae6cc | 238 | unsigned int size; |
5e9bec99 RK |
239 | enum mode_class class; |
240 | { | |
241 | register enum machine_mode mode; | |
242 | ||
243 | /* Get the first mode which has at least this size, in the | |
244 | specified class. */ | |
245 | for (mode = GET_CLASS_NARROWEST_MODE (class); mode != VOIDmode; | |
246 | mode = GET_MODE_WIDER_MODE (mode)) | |
72c602fc | 247 | if (GET_MODE_BITSIZE (mode) >= size) |
5e9bec99 RK |
248 | return mode; |
249 | ||
250 | abort (); | |
251 | } | |
252 | ||
d006aa54 RH |
253 | /* Find an integer mode of the exact same size, or BLKmode on failure. */ |
254 | ||
255 | enum machine_mode | |
256 | int_mode_for_mode (mode) | |
257 | enum machine_mode mode; | |
258 | { | |
259 | switch (GET_MODE_CLASS (mode)) | |
260 | { | |
261 | case MODE_INT: | |
262 | case MODE_PARTIAL_INT: | |
263 | break; | |
264 | ||
265 | case MODE_COMPLEX_INT: | |
266 | case MODE_COMPLEX_FLOAT: | |
267 | case MODE_FLOAT: | |
62c07905 JM |
268 | case MODE_VECTOR_INT: |
269 | case MODE_VECTOR_FLOAT: | |
d006aa54 RH |
270 | mode = mode_for_size (GET_MODE_BITSIZE (mode), MODE_INT, 0); |
271 | break; | |
272 | ||
273 | case MODE_RANDOM: | |
274 | if (mode == BLKmode) | |
275 | break; | |
d4b60170 RK |
276 | |
277 | /* ... fall through ... */ | |
d006aa54 RH |
278 | |
279 | case MODE_CC: | |
280 | default: | |
05bccae2 | 281 | abort (); |
d006aa54 RH |
282 | } |
283 | ||
284 | return mode; | |
285 | } | |
286 | ||
fed3cef0 RK |
287 | /* Return the value of VALUE, rounded up to a multiple of DIVISOR. |
288 | This can only be applied to objects of a sizetype. */ | |
7306ed3f JW |
289 | |
290 | tree | |
291 | round_up (value, divisor) | |
292 | tree value; | |
293 | int divisor; | |
294 | { | |
fed3cef0 RK |
295 | tree arg = size_int_type (divisor, TREE_TYPE (value)); |
296 | ||
297 | return size_binop (MULT_EXPR, size_binop (CEIL_DIV_EXPR, value, arg), arg); | |
298 | } | |
299 | ||
300 | /* Likewise, but round down. */ | |
301 | ||
302 | tree | |
303 | round_down (value, divisor) | |
304 | tree value; | |
305 | int divisor; | |
306 | { | |
307 | tree arg = size_int_type (divisor, TREE_TYPE (value)); | |
308 | ||
309 | return size_binop (MULT_EXPR, size_binop (FLOOR_DIV_EXPR, value, arg), arg); | |
7306ed3f JW |
310 | } |
311 | \f | |
312 | /* Set the size, mode and alignment of a ..._DECL node. | |
313 | TYPE_DECL does need this for C++. | |
314 | Note that LABEL_DECL and CONST_DECL nodes do not need this, | |
315 | and FUNCTION_DECL nodes have them set up in a special (and simple) way. | |
316 | Don't call layout_decl for them. | |
317 | ||
318 | KNOWN_ALIGN is the amount of alignment we can assume this | |
319 | decl has with no special effort. It is relevant only for FIELD_DECLs | |
320 | and depends on the previous fields. | |
321 | All that matters about KNOWN_ALIGN is which powers of 2 divide it. | |
322 | If KNOWN_ALIGN is 0, it means, "as much alignment as you like": | |
323 | the record will be aligned to suit. */ | |
324 | ||
325 | void | |
326 | layout_decl (decl, known_align) | |
327 | tree decl; | |
729a2125 | 328 | unsigned int known_align; |
7306ed3f JW |
329 | { |
330 | register tree type = TREE_TYPE (decl); | |
331 | register enum tree_code code = TREE_CODE (decl); | |
7306ed3f JW |
332 | |
333 | if (code == CONST_DECL) | |
334 | return; | |
9df2c88c | 335 | else if (code != VAR_DECL && code != PARM_DECL && code != RESULT_DECL |
33433751 | 336 | && code != TYPE_DECL && code != FIELD_DECL) |
7306ed3f JW |
337 | abort (); |
338 | ||
339 | if (type == error_mark_node) | |
33433751 | 340 | type = void_type_node; |
7306ed3f | 341 | |
770ae6cc RK |
342 | /* Usually the size and mode come from the data type without change, |
343 | however, the front-end may set the explicit width of the field, so its | |
344 | size may not be the same as the size of its type. This happens with | |
345 | bitfields, of course (an `int' bitfield may be only 2 bits, say), but it | |
346 | also happens with other fields. For example, the C++ front-end creates | |
347 | zero-sized fields corresponding to empty base classes, and depends on | |
348 | layout_type setting DECL_FIELD_BITPOS correctly for the field. Set the | |
4b6bf620 RK |
349 | size in bytes from the size in bits. If we have already set the mode, |
350 | don't set it again since we can be called twice for FIELD_DECLs. */ | |
770ae6cc | 351 | |
7306ed3f | 352 | TREE_UNSIGNED (decl) = TREE_UNSIGNED (type); |
4b6bf620 RK |
353 | if (DECL_MODE (decl) == VOIDmode) |
354 | DECL_MODE (decl) = TYPE_MODE (type); | |
770ae6cc | 355 | |
5e9bec99 | 356 | if (DECL_SIZE (decl) == 0) |
06ceef4e RK |
357 | { |
358 | DECL_SIZE (decl) = TYPE_SIZE (type); | |
359 | DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (type); | |
360 | } | |
770ae6cc RK |
361 | else |
362 | DECL_SIZE_UNIT (decl) | |
363 | = convert (sizetype, size_binop (CEIL_DIV_EXPR, DECL_SIZE (decl), | |
364 | bitsize_unit_node)); | |
06ceef4e | 365 | |
7306ed3f | 366 | /* Force alignment required for the data type. |
23ad4d41 RS |
367 | But if the decl itself wants greater alignment, don't override that. |
368 | Likewise, if the decl is packed, don't override it. */ | |
17aec3eb | 369 | if (! (code == FIELD_DECL && DECL_BIT_FIELD (decl)) |
33433751 | 370 | && (DECL_ALIGN (decl) == 0 |
17aec3eb RK |
371 | || (! (code == FIELD_DECL && DECL_PACKED (decl)) |
372 | && TYPE_ALIGN (type) > DECL_ALIGN (decl)))) | |
11cf4d18 JJ |
373 | { |
374 | DECL_ALIGN (decl) = TYPE_ALIGN (type); | |
7256efa6 | 375 | DECL_USER_ALIGN (decl) = 0; |
11cf4d18 | 376 | } |
7306ed3f | 377 | |
770ae6cc | 378 | /* For fields, set the bit field type and update the alignment. */ |
7306ed3f | 379 | if (code == FIELD_DECL) |
d4c40650 RS |
380 | { |
381 | DECL_BIT_FIELD_TYPE (decl) = DECL_BIT_FIELD (decl) ? type : 0; | |
382 | if (maximum_field_alignment != 0) | |
729a2125 | 383 | DECL_ALIGN (decl) = MIN (DECL_ALIGN (decl), maximum_field_alignment); |
3aa12a58 | 384 | else if (DECL_PACKED (decl)) |
11cf4d18 JJ |
385 | { |
386 | DECL_ALIGN (decl) = MIN (DECL_ALIGN (decl), BITS_PER_UNIT); | |
387 | DECL_USER_ALIGN (decl) = 0; | |
388 | } | |
d4c40650 RS |
389 | } |
390 | ||
770ae6cc RK |
391 | /* See if we can use an ordinary integer mode for a bit-field. |
392 | Conditions are: a fixed size that is correct for another mode | |
393 | and occupying a complete byte or bytes on proper boundary. */ | |
17aec3eb | 394 | if (code == FIELD_DECL && DECL_BIT_FIELD (decl) |
7306ed3f | 395 | && TYPE_SIZE (type) != 0 |
5bb3d1dd RK |
396 | && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST |
397 | && GET_MODE_CLASS (TYPE_MODE (type)) == MODE_INT) | |
7306ed3f JW |
398 | { |
399 | register enum machine_mode xmode | |
72c602fc | 400 | = mode_for_size_tree (DECL_SIZE (decl), MODE_INT, 1); |
7306ed3f | 401 | |
b1ba4cc3 | 402 | if (xmode != BLKmode && known_align >= GET_MODE_ALIGNMENT (xmode)) |
7306ed3f | 403 | { |
729a2125 | 404 | DECL_ALIGN (decl) = MAX (GET_MODE_ALIGNMENT (xmode), |
7306ed3f JW |
405 | DECL_ALIGN (decl)); |
406 | DECL_MODE (decl) = xmode; | |
7306ed3f JW |
407 | DECL_BIT_FIELD (decl) = 0; |
408 | } | |
409 | } | |
410 | ||
977a7752 | 411 | /* Turn off DECL_BIT_FIELD if we won't need it set. */ |
17aec3eb | 412 | if (code == FIELD_DECL && DECL_BIT_FIELD (decl) |
770ae6cc | 413 | && TYPE_MODE (type) == BLKmode && DECL_MODE (decl) == BLKmode |
b1ba4cc3 | 414 | && known_align >= TYPE_ALIGN (type) |
770ae6cc RK |
415 | && DECL_ALIGN (decl) >= TYPE_ALIGN (type) |
416 | && DECL_SIZE_UNIT (decl) != 0) | |
977a7752 RK |
417 | DECL_BIT_FIELD (decl) = 0; |
418 | ||
7306ed3f JW |
419 | /* Evaluate nonconstant size only once, either now or as soon as safe. */ |
420 | if (DECL_SIZE (decl) != 0 && TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST) | |
421 | DECL_SIZE (decl) = variable_size (DECL_SIZE (decl)); | |
06ceef4e RK |
422 | if (DECL_SIZE_UNIT (decl) != 0 |
423 | && TREE_CODE (DECL_SIZE_UNIT (decl)) != INTEGER_CST) | |
424 | DECL_SIZE_UNIT (decl) = variable_size (DECL_SIZE_UNIT (decl)); | |
425 | ||
426 | /* If requested, warn about definitions of large data objects. */ | |
427 | if (warn_larger_than | |
17aec3eb | 428 | && (code == VAR_DECL || code == PARM_DECL) |
06ceef4e RK |
429 | && ! DECL_EXTERNAL (decl)) |
430 | { | |
431 | tree size = DECL_SIZE_UNIT (decl); | |
432 | ||
433 | if (size != 0 && TREE_CODE (size) == INTEGER_CST | |
05bccae2 | 434 | && compare_tree_int (size, larger_than_size) > 0) |
06ceef4e | 435 | { |
05bccae2 | 436 | unsigned int size_as_int = TREE_INT_CST_LOW (size); |
06ceef4e | 437 | |
05bccae2 | 438 | if (compare_tree_int (size, size_as_int) == 0) |
06ceef4e RK |
439 | warning_with_decl (decl, "size of `%s' is %d bytes", size_as_int); |
440 | else | |
441 | warning_with_decl (decl, "size of `%s' is larger than %d bytes", | |
442 | larger_than_size); | |
443 | } | |
444 | } | |
7306ed3f JW |
445 | } |
446 | \f | |
e0cea8d9 RK |
447 | /* Hook for a front-end function that can modify the record layout as needed |
448 | immediately before it is finalized. */ | |
449 | ||
450 | void (*lang_adjust_rli) PARAMS ((record_layout_info)) = 0; | |
451 | ||
452 | void | |
453 | set_lang_adjust_rli (f) | |
454 | void (*f) PARAMS ((record_layout_info)); | |
455 | { | |
456 | lang_adjust_rli = f; | |
457 | } | |
458 | ||
770ae6cc RK |
459 | /* Begin laying out type T, which may be a RECORD_TYPE, UNION_TYPE, or |
460 | QUAL_UNION_TYPE. Return a pointer to a struct record_layout_info which | |
461 | is to be passed to all other layout functions for this record. It is the | |
462 | responsibility of the caller to call `free' for the storage returned. | |
463 | Note that garbage collection is not permitted until we finish laying | |
464 | out the record. */ | |
7306ed3f | 465 | |
9328904c | 466 | record_layout_info |
770ae6cc | 467 | start_record_layout (t) |
9328904c | 468 | tree t; |
7306ed3f | 469 | { |
9328904c | 470 | record_layout_info rli |
defd0dea | 471 | = (record_layout_info) xmalloc (sizeof (struct record_layout_info_s)); |
9328904c MM |
472 | |
473 | rli->t = t; | |
770ae6cc | 474 | |
9328904c MM |
475 | /* If the type has a minimum specified alignment (via an attribute |
476 | declaration, for example) use it -- otherwise, start with a | |
477 | one-byte alignment. */ | |
478 | rli->record_align = MAX (BITS_PER_UNIT, TYPE_ALIGN (t)); | |
e0cea8d9 | 479 | rli->unpacked_align = rli->unpadded_align = rli->record_align; |
770ae6cc | 480 | rli->offset_align = MAX (rli->record_align, BIGGEST_ALIGNMENT); |
7306ed3f | 481 | |
5c19a356 MS |
482 | #ifdef STRUCTURE_SIZE_BOUNDARY |
483 | /* Packed structures don't need to have minimum size. */ | |
f132af85 | 484 | if (! TYPE_PACKED (t)) |
9328904c | 485 | rli->record_align = MAX (rli->record_align, STRUCTURE_SIZE_BOUNDARY); |
5c19a356 | 486 | #endif |
7306ed3f | 487 | |
770ae6cc RK |
488 | rli->offset = size_zero_node; |
489 | rli->bitpos = bitsize_zero_node; | |
490 | rli->pending_statics = 0; | |
491 | rli->packed_maybe_necessary = 0; | |
492 | ||
9328904c MM |
493 | return rli; |
494 | } | |
7306ed3f | 495 | |
f2704b9f RK |
496 | /* These four routines perform computations that convert between |
497 | the offset/bitpos forms and byte and bit offsets. */ | |
498 | ||
499 | tree | |
500 | bit_from_pos (offset, bitpos) | |
501 | tree offset, bitpos; | |
502 | { | |
503 | return size_binop (PLUS_EXPR, bitpos, | |
504 | size_binop (MULT_EXPR, convert (bitsizetype, offset), | |
505 | bitsize_unit_node)); | |
506 | } | |
507 | ||
508 | tree | |
509 | byte_from_pos (offset, bitpos) | |
510 | tree offset, bitpos; | |
511 | { | |
512 | return size_binop (PLUS_EXPR, offset, | |
513 | convert (sizetype, | |
f0fddb15 | 514 | size_binop (TRUNC_DIV_EXPR, bitpos, |
f2704b9f RK |
515 | bitsize_unit_node))); |
516 | } | |
517 | ||
518 | void | |
519 | pos_from_byte (poffset, pbitpos, off_align, pos) | |
520 | tree *poffset, *pbitpos; | |
521 | unsigned int off_align; | |
522 | tree pos; | |
523 | { | |
524 | *poffset | |
525 | = size_binop (MULT_EXPR, | |
526 | convert (sizetype, | |
527 | size_binop (FLOOR_DIV_EXPR, pos, | |
528 | bitsize_int (off_align | |
529 | / BITS_PER_UNIT))), | |
530 | size_int (off_align / BITS_PER_UNIT)); | |
531 | *pbitpos = size_binop (MULT_EXPR, | |
532 | size_binop (FLOOR_MOD_EXPR, pos, | |
533 | bitsize_int (off_align / BITS_PER_UNIT)), | |
534 | bitsize_unit_node); | |
535 | } | |
536 | ||
537 | void | |
538 | pos_from_bit (poffset, pbitpos, off_align, pos) | |
539 | tree *poffset, *pbitpos; | |
540 | unsigned int off_align; | |
541 | tree pos; | |
542 | { | |
543 | *poffset = size_binop (MULT_EXPR, | |
544 | convert (sizetype, | |
545 | size_binop (FLOOR_DIV_EXPR, pos, | |
546 | bitsize_int (off_align))), | |
547 | size_int (off_align / BITS_PER_UNIT)); | |
548 | *pbitpos = size_binop (FLOOR_MOD_EXPR, pos, bitsize_int (off_align)); | |
549 | } | |
550 | ||
551 | /* Given a pointer to bit and byte offsets and an offset alignment, | |
552 | normalize the offsets so they are within the alignment. */ | |
553 | ||
554 | void | |
555 | normalize_offset (poffset, pbitpos, off_align) | |
556 | tree *poffset, *pbitpos; | |
557 | unsigned int off_align; | |
558 | { | |
559 | /* If the bit position is now larger than it should be, adjust it | |
560 | downwards. */ | |
561 | if (compare_tree_int (*pbitpos, off_align) >= 0) | |
562 | { | |
563 | tree extra_aligns = size_binop (FLOOR_DIV_EXPR, *pbitpos, | |
564 | bitsize_int (off_align)); | |
565 | ||
566 | *poffset | |
567 | = size_binop (PLUS_EXPR, *poffset, | |
568 | size_binop (MULT_EXPR, convert (sizetype, extra_aligns), | |
569 | size_int (off_align / BITS_PER_UNIT))); | |
570 | ||
571 | *pbitpos | |
572 | = size_binop (FLOOR_MOD_EXPR, *pbitpos, bitsize_int (off_align)); | |
573 | } | |
574 | } | |
575 | ||
770ae6cc | 576 | /* Print debugging information about the information in RLI. */ |
cc9d4a85 | 577 | |
770ae6cc RK |
578 | void |
579 | debug_rli (rli) | |
cc9d4a85 | 580 | record_layout_info rli; |
cc9d4a85 | 581 | { |
770ae6cc RK |
582 | print_node_brief (stderr, "type", rli->t, 0); |
583 | print_node_brief (stderr, "\noffset", rli->offset, 0); | |
584 | print_node_brief (stderr, " bitpos", rli->bitpos, 0); | |
cc9d4a85 | 585 | |
e0cea8d9 RK |
586 | fprintf (stderr, "\naligns: rec = %u, unpack = %u, unpad = %u, off = %u\n", |
587 | rli->record_align, rli->unpacked_align, rli->unpadded_align, | |
588 | rli->offset_align); | |
770ae6cc RK |
589 | if (rli->packed_maybe_necessary) |
590 | fprintf (stderr, "packed may be necessary\n"); | |
591 | ||
592 | if (rli->pending_statics) | |
593 | { | |
594 | fprintf (stderr, "pending statics:\n"); | |
595 | debug_tree (rli->pending_statics); | |
596 | } | |
597 | } | |
598 | ||
599 | /* Given an RLI with a possibly-incremented BITPOS, adjust OFFSET and | |
600 | BITPOS if necessary to keep BITPOS below OFFSET_ALIGN. */ | |
601 | ||
602 | void | |
603 | normalize_rli (rli) | |
604 | record_layout_info rli; | |
605 | { | |
f2704b9f | 606 | normalize_offset (&rli->offset, &rli->bitpos, rli->offset_align); |
770ae6cc | 607 | } |
cc9d4a85 | 608 | |
770ae6cc RK |
609 | /* Returns the size in bytes allocated so far. */ |
610 | ||
611 | tree | |
612 | rli_size_unit_so_far (rli) | |
613 | record_layout_info rli; | |
614 | { | |
f2704b9f | 615 | return byte_from_pos (rli->offset, rli->bitpos); |
770ae6cc RK |
616 | } |
617 | ||
618 | /* Returns the size in bits allocated so far. */ | |
619 | ||
620 | tree | |
621 | rli_size_so_far (rli) | |
622 | record_layout_info rli; | |
623 | { | |
f2704b9f | 624 | return bit_from_pos (rli->offset, rli->bitpos); |
770ae6cc RK |
625 | } |
626 | ||
627 | /* Called from place_field to handle unions. */ | |
628 | ||
629 | static void | |
630 | place_union_field (rli, field) | |
631 | record_layout_info rli; | |
632 | tree field; | |
633 | { | |
11cf4d18 JJ |
634 | unsigned int desired_align; |
635 | ||
cc9d4a85 | 636 | layout_decl (field, 0); |
770ae6cc RK |
637 | |
638 | DECL_FIELD_OFFSET (field) = size_zero_node; | |
639 | DECL_FIELD_BIT_OFFSET (field) = bitsize_zero_node; | |
2f5c7f45 | 640 | SET_DECL_OFFSET_ALIGN (field, BIGGEST_ALIGNMENT); |
cc9d4a85 | 641 | |
11cf4d18 JJ |
642 | desired_align = DECL_ALIGN (field); |
643 | ||
644 | #ifdef BIGGEST_FIELD_ALIGNMENT | |
645 | /* Some targets (i.e. i386) limit union field alignment | |
646 | to a lower boundary than alignment of variables unless | |
647 | it was overridden by attribute aligned. */ | |
648 | if (! DECL_USER_ALIGN (field)) | |
649 | desired_align = | |
650 | MIN (desired_align, (unsigned) BIGGEST_FIELD_ALIGNMENT); | |
651 | #endif | |
652 | ||
cc9d4a85 | 653 | /* Union must be at least as aligned as any field requires. */ |
11cf4d18 | 654 | rli->record_align = MAX (rli->record_align, desired_align); |
e0cea8d9 | 655 | rli->unpadded_align = MAX (rli->unpadded_align, desired_align); |
cc9d4a85 MM |
656 | |
657 | #ifdef PCC_BITFIELD_TYPE_MATTERS | |
658 | /* On the m88000, a bit field of declare type `int' forces the | |
659 | entire union to have `int' alignment. */ | |
660 | if (PCC_BITFIELD_TYPE_MATTERS && DECL_BIT_FIELD_TYPE (field)) | |
e0cea8d9 RK |
661 | { |
662 | rli->record_align = MAX (rli->record_align, | |
663 | TYPE_ALIGN (TREE_TYPE (field))); | |
664 | rli->unpadded_align = MAX (rli->unpadded_align, | |
665 | TYPE_ALIGN (TREE_TYPE (field))); | |
666 | } | |
cc9d4a85 MM |
667 | #endif |
668 | ||
770ae6cc RK |
669 | /* We assume the union's size will be a multiple of a byte so we don't |
670 | bother with BITPOS. */ | |
cc9d4a85 | 671 | if (TREE_CODE (rli->t) == UNION_TYPE) |
770ae6cc | 672 | rli->offset = size_binop (MAX_EXPR, rli->offset, DECL_SIZE_UNIT (field)); |
cc9d4a85 | 673 | else if (TREE_CODE (rli->t) == QUAL_UNION_TYPE) |
770ae6cc RK |
674 | rli->offset = fold (build (COND_EXPR, sizetype, |
675 | DECL_QUALIFIER (field), | |
676 | DECL_SIZE_UNIT (field), rli->offset)); | |
cc9d4a85 MM |
677 | } |
678 | ||
9328904c MM |
679 | /* RLI contains information about the layout of a RECORD_TYPE. FIELD |
680 | is a FIELD_DECL to be added after those fields already present in | |
681 | T. (FIELD is not actually added to the TYPE_FIELDS list here; | |
682 | callers that desire that behavior must manually perform that step.) */ | |
d4b60170 | 683 | |
9328904c | 684 | void |
770ae6cc | 685 | place_field (rli, field) |
9328904c MM |
686 | record_layout_info rli; |
687 | tree field; | |
688 | { | |
689 | /* The alignment required for FIELD. */ | |
690 | unsigned int desired_align; | |
691 | /* The alignment FIELD would have if we just dropped it into the | |
692 | record as it presently stands. */ | |
693 | unsigned int known_align; | |
770ae6cc | 694 | unsigned int actual_align; |
11cf4d18 | 695 | unsigned int user_align; |
9328904c MM |
696 | /* The type of this field. */ |
697 | tree type = TREE_TYPE (field); | |
770ae6cc | 698 | |
5748b2cb RK |
699 | if (TREE_CODE (field) == ERROR_MARK || TREE_CODE (type) == ERROR_MARK) |
700 | return; | |
701 | ||
9328904c MM |
702 | /* If FIELD is static, then treat it like a separate variable, not |
703 | really like a structure field. If it is a FUNCTION_DECL, it's a | |
704 | method. In both cases, all we do is lay out the decl, and we do | |
705 | it *after* the record is laid out. */ | |
706 | if (TREE_CODE (field) == VAR_DECL) | |
707 | { | |
708 | rli->pending_statics = tree_cons (NULL_TREE, field, | |
709 | rli->pending_statics); | |
710 | return; | |
711 | } | |
770ae6cc | 712 | |
9328904c MM |
713 | /* Enumerators and enum types which are local to this class need not |
714 | be laid out. Likewise for initialized constant fields. */ | |
715 | else if (TREE_CODE (field) != FIELD_DECL) | |
716 | return; | |
770ae6cc RK |
717 | |
718 | /* Unions are laid out very differently than records, so split | |
719 | that code off to another function. */ | |
cc9d4a85 MM |
720 | else if (TREE_CODE (rli->t) != RECORD_TYPE) |
721 | { | |
770ae6cc | 722 | place_union_field (rli, field); |
cc9d4a85 MM |
723 | return; |
724 | } | |
7306ed3f | 725 | |
770ae6cc RK |
726 | /* Work out the known alignment so far. Note that A & (-A) is the |
727 | value of the least-significant bit in A that is one. */ | |
4b6bf620 | 728 | if (! integer_zerop (rli->bitpos)) |
770ae6cc RK |
729 | known_align = (tree_low_cst (rli->bitpos, 1) |
730 | & - tree_low_cst (rli->bitpos, 1)); | |
4b6bf620 RK |
731 | else if (integer_zerop (rli->offset)) |
732 | known_align = BIGGEST_ALIGNMENT; | |
770ae6cc RK |
733 | else if (host_integerp (rli->offset, 1)) |
734 | known_align = (BITS_PER_UNIT | |
735 | * (tree_low_cst (rli->offset, 1) | |
736 | & - tree_low_cst (rli->offset, 1))); | |
737 | else | |
738 | known_align = rli->offset_align; | |
9328904c MM |
739 | |
740 | /* Lay out the field so we know what alignment it needs. For a | |
741 | packed field, use the alignment as specified, disregarding what | |
742 | the type would want. */ | |
770ae6cc | 743 | desired_align = DECL_ALIGN (field); |
11cf4d18 | 744 | user_align = DECL_USER_ALIGN (field); |
9328904c MM |
745 | layout_decl (field, known_align); |
746 | if (! DECL_PACKED (field)) | |
11cf4d18 JJ |
747 | { |
748 | desired_align = DECL_ALIGN (field); | |
749 | user_align = DECL_USER_ALIGN (field); | |
750 | } | |
770ae6cc | 751 | |
11cf4d18 JJ |
752 | /* Some targets (i.e. i386, VMS) limit struct field alignment |
753 | to a lower boundary than alignment of variables unless | |
754 | it was overridden by attribute aligned. */ | |
5005666b | 755 | #ifdef BIGGEST_FIELD_ALIGNMENT |
11cf4d18 | 756 | if (! user_align) |
5005666b RK |
757 | desired_align |
758 | = MIN (desired_align, (unsigned) BIGGEST_FIELD_ALIGNMENT); | |
7306ed3f | 759 | #endif |
5005666b | 760 | |
d42d380a | 761 | #ifdef ADJUST_FIELD_ALIGN |
9328904c | 762 | desired_align = ADJUST_FIELD_ALIGN (field, desired_align); |
d42d380a | 763 | #endif |
7306ed3f | 764 | |
9328904c MM |
765 | /* Record must have at least as much alignment as any field. |
766 | Otherwise, the alignment of the field within the record is | |
767 | meaningless. */ | |
3c12fcc2 | 768 | #ifdef PCC_BITFIELD_TYPE_MATTERS |
9328904c MM |
769 | if (PCC_BITFIELD_TYPE_MATTERS && type != error_mark_node |
770 | && DECL_BIT_FIELD_TYPE (field) | |
771 | && ! integer_zerop (TYPE_SIZE (type))) | |
772 | { | |
773 | /* For these machines, a zero-length field does not | |
774 | affect the alignment of the structure as a whole. | |
775 | It does, however, affect the alignment of the next field | |
776 | within the structure. */ | |
777 | if (! integer_zerop (DECL_SIZE (field))) | |
778 | rli->record_align = MAX (rli->record_align, desired_align); | |
779 | else if (! DECL_PACKED (field)) | |
780 | desired_align = TYPE_ALIGN (type); | |
770ae6cc | 781 | |
9328904c MM |
782 | /* A named bit field of declared type `int' |
783 | forces the entire structure to have `int' alignment. */ | |
784 | if (DECL_NAME (field) != 0) | |
7306ed3f | 785 | { |
9328904c | 786 | unsigned int type_align = TYPE_ALIGN (type); |
729a2125 | 787 | |
9328904c MM |
788 | if (maximum_field_alignment != 0) |
789 | type_align = MIN (type_align, maximum_field_alignment); | |
790 | else if (DECL_PACKED (field)) | |
791 | type_align = MIN (type_align, BITS_PER_UNIT); | |
e2301a83 | 792 | |
9328904c | 793 | rli->record_align = MAX (rli->record_align, type_align); |
e0cea8d9 | 794 | rli->unpadded_align = MAX (rli->unpadded_align, DECL_ALIGN (field)); |
3c12fcc2 | 795 | if (warn_packed) |
e0cea8d9 | 796 | rli->unpacked_align = MAX (rli->unpacked_align, TYPE_ALIGN (type)); |
3c12fcc2 | 797 | } |
9328904c MM |
798 | } |
799 | else | |
800 | #endif | |
801 | { | |
802 | rli->record_align = MAX (rli->record_align, desired_align); | |
770ae6cc | 803 | rli->unpacked_align = MAX (rli->unpacked_align, TYPE_ALIGN (type)); |
e0cea8d9 | 804 | rli->unpadded_align = MAX (rli->unpadded_align, DECL_ALIGN (field)); |
9328904c | 805 | } |
3c12fcc2 | 806 | |
9328904c MM |
807 | if (warn_packed && DECL_PACKED (field)) |
808 | { | |
770ae6cc | 809 | if (known_align > TYPE_ALIGN (type)) |
3c12fcc2 | 810 | { |
9328904c | 811 | if (TYPE_ALIGN (type) > desired_align) |
3c12fcc2 | 812 | { |
9328904c MM |
813 | if (STRICT_ALIGNMENT) |
814 | warning_with_decl (field, "packed attribute causes inefficient alignment for `%s'"); | |
815 | else | |
816 | warning_with_decl (field, "packed attribute is unnecessary for `%s'"); | |
3c12fcc2 | 817 | } |
3c12fcc2 | 818 | } |
9328904c MM |
819 | else |
820 | rli->packed_maybe_necessary = 1; | |
821 | } | |
7306ed3f | 822 | |
9328904c MM |
823 | /* Does this field automatically have alignment it needs by virtue |
824 | of the fields that precede it and the record's own alignment? */ | |
770ae6cc | 825 | if (known_align < desired_align) |
9328904c MM |
826 | { |
827 | /* No, we need to skip space before this field. | |
828 | Bump the cumulative size to multiple of field alignment. */ | |
7306ed3f | 829 | |
9328904c MM |
830 | if (warn_padded) |
831 | warning_with_decl (field, "padding struct to align `%s'"); | |
3c12fcc2 | 832 | |
770ae6cc RK |
833 | /* If the alignment is still within offset_align, just align |
834 | the bit position. */ | |
835 | if (desired_align < rli->offset_align) | |
836 | rli->bitpos = round_up (rli->bitpos, desired_align); | |
9328904c MM |
837 | else |
838 | { | |
770ae6cc RK |
839 | /* First adjust OFFSET by the partial bits, then align. */ |
840 | rli->offset | |
841 | = size_binop (PLUS_EXPR, rli->offset, | |
842 | convert (sizetype, | |
843 | size_binop (CEIL_DIV_EXPR, rli->bitpos, | |
844 | bitsize_unit_node))); | |
845 | rli->bitpos = bitsize_zero_node; | |
846 | ||
847 | rli->offset = round_up (rli->offset, desired_align / BITS_PER_UNIT); | |
7306ed3f | 848 | } |
770ae6cc | 849 | |
b1254b72 RK |
850 | if (! TREE_CONSTANT (rli->offset)) |
851 | rli->offset_align = desired_align; | |
852 | ||
9328904c | 853 | } |
7306ed3f | 854 | |
770ae6cc RK |
855 | /* Handle compatibility with PCC. Note that if the record has any |
856 | variable-sized fields, we need not worry about compatibility. */ | |
7306ed3f | 857 | #ifdef PCC_BITFIELD_TYPE_MATTERS |
9328904c MM |
858 | if (PCC_BITFIELD_TYPE_MATTERS |
859 | && TREE_CODE (field) == FIELD_DECL | |
860 | && type != error_mark_node | |
770ae6cc RK |
861 | && DECL_BIT_FIELD (field) |
862 | && ! DECL_PACKED (field) | |
9328904c | 863 | && maximum_field_alignment == 0 |
770ae6cc RK |
864 | && ! integer_zerop (DECL_SIZE (field)) |
865 | && host_integerp (DECL_SIZE (field), 1) | |
866 | && host_integerp (rli->offset, 1) | |
867 | && host_integerp (TYPE_SIZE (type), 1)) | |
9328904c MM |
868 | { |
869 | unsigned int type_align = TYPE_ALIGN (type); | |
770ae6cc RK |
870 | tree dsize = DECL_SIZE (field); |
871 | HOST_WIDE_INT field_size = tree_low_cst (dsize, 1); | |
872 | HOST_WIDE_INT offset = tree_low_cst (rli->offset, 0); | |
873 | HOST_WIDE_INT bit_offset = tree_low_cst (rli->bitpos, 0); | |
9328904c MM |
874 | |
875 | /* A bit field may not span more units of alignment of its type | |
876 | than its type itself. Advance to next boundary if necessary. */ | |
770ae6cc RK |
877 | if ((((offset * BITS_PER_UNIT + bit_offset + field_size + |
878 | type_align - 1) | |
879 | / type_align) | |
880 | - (offset * BITS_PER_UNIT + bit_offset) / type_align) | |
881 | > tree_low_cst (TYPE_SIZE (type), 1) / type_align) | |
882 | rli->bitpos = round_up (rli->bitpos, type_align); | |
9328904c | 883 | } |
7306ed3f JW |
884 | #endif |
885 | ||
7306ed3f | 886 | #ifdef BITFIELD_NBYTES_LIMITED |
9328904c MM |
887 | if (BITFIELD_NBYTES_LIMITED |
888 | && TREE_CODE (field) == FIELD_DECL | |
889 | && type != error_mark_node | |
890 | && DECL_BIT_FIELD_TYPE (field) | |
770ae6cc RK |
891 | && ! DECL_PACKED (field) |
892 | && ! integer_zerop (DECL_SIZE (field)) | |
893 | && host_integerp (DECL_SIZE (field), 1) | |
163d3408 | 894 | && host_integerp (rli->offset, 1) |
770ae6cc | 895 | && host_integerp (TYPE_SIZE (type), 1)) |
9328904c MM |
896 | { |
897 | unsigned int type_align = TYPE_ALIGN (type); | |
770ae6cc RK |
898 | tree dsize = DECL_SIZE (field); |
899 | HOST_WIDE_INT field_size = tree_low_cst (dsize, 1); | |
900 | HOST_WIDE_INT offset = tree_low_cst (rli->offset, 0); | |
901 | HOST_WIDE_INT bit_offset = tree_low_cst (rli->bitpos, 0); | |
e2301a83 | 902 | |
9328904c MM |
903 | if (maximum_field_alignment != 0) |
904 | type_align = MIN (type_align, maximum_field_alignment); | |
905 | /* ??? This test is opposite the test in the containing if | |
906 | statement, so this code is unreachable currently. */ | |
907 | else if (DECL_PACKED (field)) | |
908 | type_align = MIN (type_align, BITS_PER_UNIT); | |
909 | ||
910 | /* A bit field may not span the unit of alignment of its type. | |
911 | Advance to next boundary if necessary. */ | |
912 | /* ??? This code should match the code above for the | |
913 | PCC_BITFIELD_TYPE_MATTERS case. */ | |
770ae6cc RK |
914 | if ((offset * BITS_PER_UNIT + bit_offset) / type_align |
915 | != ((offset * BITS_PER_UNIT + bit_offset + field_size - 1) | |
916 | / type_align)) | |
917 | rli->bitpos = round_up (rli->bitpos, type_align); | |
9328904c | 918 | } |
7306ed3f JW |
919 | #endif |
920 | ||
770ae6cc RK |
921 | /* Offset so far becomes the position of this field after normalizing. */ |
922 | normalize_rli (rli); | |
923 | DECL_FIELD_OFFSET (field) = rli->offset; | |
924 | DECL_FIELD_BIT_OFFSET (field) = rli->bitpos; | |
2f5c7f45 | 925 | SET_DECL_OFFSET_ALIGN (field, rli->offset_align); |
770ae6cc RK |
926 | |
927 | /* If this field ended up more aligned than we thought it would be (we | |
928 | approximate this by seeing if its position changed), lay out the field | |
929 | again; perhaps we can use an integral mode for it now. */ | |
4b6bf620 | 930 | if (! integer_zerop (DECL_FIELD_BIT_OFFSET (field))) |
770ae6cc RK |
931 | actual_align = (tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1) |
932 | & - tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1)); | |
4b6bf620 RK |
933 | else if (integer_zerop (DECL_FIELD_OFFSET (field))) |
934 | actual_align = BIGGEST_ALIGNMENT; | |
770ae6cc RK |
935 | else if (host_integerp (DECL_FIELD_OFFSET (field), 1)) |
936 | actual_align = (BITS_PER_UNIT | |
937 | * (tree_low_cst (DECL_FIELD_OFFSET (field), 1) | |
938 | & - tree_low_cst (DECL_FIELD_OFFSET (field), 1))); | |
9328904c | 939 | else |
770ae6cc RK |
940 | actual_align = DECL_OFFSET_ALIGN (field); |
941 | ||
942 | if (known_align != actual_align) | |
943 | layout_decl (field, actual_align); | |
944 | ||
945 | /* Now add size of this field to the size of the record. If the size is | |
946 | not constant, treat the field as being a multiple of bytes and just | |
947 | adjust the offset, resetting the bit position. Otherwise, apportion the | |
948 | size amongst the bit position and offset. First handle the case of an | |
949 | unspecified size, which can happen when we have an invalid nested struct | |
950 | definition, such as struct j { struct j { int i; } }. The error message | |
951 | is printed in finish_struct. */ | |
952 | if (DECL_SIZE (field) == 0) | |
953 | /* Do nothing. */; | |
67011d81 RK |
954 | else if (TREE_CODE (DECL_SIZE_UNIT (field)) != INTEGER_CST |
955 | || TREE_CONSTANT_OVERFLOW (DECL_SIZE_UNIT (field))) | |
9328904c | 956 | { |
770ae6cc RK |
957 | rli->offset |
958 | = size_binop (PLUS_EXPR, rli->offset, | |
959 | convert (sizetype, | |
960 | size_binop (CEIL_DIV_EXPR, rli->bitpos, | |
961 | bitsize_unit_node))); | |
962 | rli->offset | |
963 | = size_binop (PLUS_EXPR, rli->offset, DECL_SIZE_UNIT (field)); | |
964 | rli->bitpos = bitsize_zero_node; | |
b1254b72 | 965 | rli->offset_align = MIN (rli->offset_align, DECL_ALIGN (field)); |
9328904c | 966 | } |
9328904c MM |
967 | else |
968 | { | |
770ae6cc RK |
969 | rli->bitpos = size_binop (PLUS_EXPR, rli->bitpos, DECL_SIZE (field)); |
970 | normalize_rli (rli); | |
7306ed3f | 971 | } |
9328904c | 972 | } |
7306ed3f | 973 | |
9328904c MM |
974 | /* Assuming that all the fields have been laid out, this function uses |
975 | RLI to compute the final TYPE_SIZE, TYPE_ALIGN, etc. for the type | |
976 | inidicated by RLI. */ | |
7306ed3f | 977 | |
9328904c MM |
978 | static void |
979 | finalize_record_size (rli) | |
980 | record_layout_info rli; | |
981 | { | |
770ae6cc RK |
982 | tree unpadded_size, unpadded_size_unit; |
983 | ||
65e14bf5 RK |
984 | /* Now we want just byte and bit offsets, so set the offset alignment |
985 | to be a byte and then normalize. */ | |
986 | rli->offset_align = BITS_PER_UNIT; | |
987 | normalize_rli (rli); | |
7306ed3f JW |
988 | |
989 | /* Determine the desired alignment. */ | |
990 | #ifdef ROUND_TYPE_ALIGN | |
9328904c | 991 | TYPE_ALIGN (rli->t) = ROUND_TYPE_ALIGN (rli->t, TYPE_ALIGN (rli->t), |
b451555a | 992 | rli->record_align); |
7306ed3f | 993 | #else |
9328904c | 994 | TYPE_ALIGN (rli->t) = MAX (TYPE_ALIGN (rli->t), rli->record_align); |
7306ed3f | 995 | #endif |
7256efa6 | 996 | TYPE_USER_ALIGN (rli->t) = 0; |
7306ed3f | 997 | |
65e14bf5 RK |
998 | /* Compute the size so far. Be sure to allow for extra bits in the |
999 | size in bytes. We have guaranteed above that it will be no more | |
1000 | than a single byte. */ | |
1001 | unpadded_size = rli_size_so_far (rli); | |
1002 | unpadded_size_unit = rli_size_unit_so_far (rli); | |
1003 | if (! integer_zerop (rli->bitpos)) | |
1004 | unpadded_size_unit | |
1005 | = size_binop (PLUS_EXPR, unpadded_size_unit, size_one_node); | |
770ae6cc | 1006 | |
bbc0e641 JM |
1007 | /* Record the un-rounded size in the binfo node. But first we check |
1008 | the size of TYPE_BINFO to make sure that BINFO_SIZE is available. */ | |
9328904c | 1009 | if (TYPE_BINFO (rli->t) && TREE_VEC_LENGTH (TYPE_BINFO (rli->t)) > 6) |
06ceef4e | 1010 | { |
770ae6cc RK |
1011 | TYPE_BINFO_SIZE (rli->t) = unpadded_size; |
1012 | TYPE_BINFO_SIZE_UNIT (rli->t) = unpadded_size_unit; | |
06ceef4e | 1013 | } |
729a2125 | 1014 | |
770ae6cc | 1015 | /* Round the size up to be a multiple of the required alignment */ |
7306ed3f | 1016 | #ifdef ROUND_TYPE_SIZE |
770ae6cc RK |
1017 | TYPE_SIZE (rli->t) = ROUND_TYPE_SIZE (rli->t, unpadded_size, |
1018 | TYPE_ALIGN (rli->t)); | |
1019 | TYPE_SIZE_UNIT (rli->t) | |
c5daf9c4 | 1020 | = ROUND_TYPE_SIZE_UNIT (rli->t, unpadded_size_unit, |
770ae6cc | 1021 | TYPE_ALIGN (rli->t) / BITS_PER_UNIT); |
7306ed3f | 1022 | #else |
770ae6cc RK |
1023 | TYPE_SIZE (rli->t) = round_up (unpadded_size, TYPE_ALIGN (rli->t)); |
1024 | TYPE_SIZE_UNIT (rli->t) = round_up (unpadded_size_unit, | |
1025 | TYPE_ALIGN (rli->t) / BITS_PER_UNIT); | |
7306ed3f | 1026 | #endif |
729a2125 | 1027 | |
770ae6cc RK |
1028 | if (warn_padded && TREE_CONSTANT (unpadded_size) |
1029 | && simple_cst_equal (unpadded_size, TYPE_SIZE (rli->t)) == 0) | |
1030 | warning ("padding struct size to alignment boundary"); | |
3c12fcc2 | 1031 | |
770ae6cc RK |
1032 | if (warn_packed && TREE_CODE (rli->t) == RECORD_TYPE |
1033 | && TYPE_PACKED (rli->t) && ! rli->packed_maybe_necessary | |
1034 | && TREE_CONSTANT (unpadded_size)) | |
3c12fcc2 GM |
1035 | { |
1036 | tree unpacked_size; | |
729a2125 | 1037 | |
3c12fcc2 | 1038 | #ifdef ROUND_TYPE_ALIGN |
9328904c MM |
1039 | rli->unpacked_align |
1040 | = ROUND_TYPE_ALIGN (rli->t, TYPE_ALIGN (rli->t), rli->unpacked_align); | |
3c12fcc2 | 1041 | #else |
9328904c | 1042 | rli->unpacked_align = MAX (TYPE_ALIGN (rli->t), rli->unpacked_align); |
3c12fcc2 | 1043 | #endif |
770ae6cc | 1044 | |
3c12fcc2 | 1045 | #ifdef ROUND_TYPE_SIZE |
9328904c MM |
1046 | unpacked_size = ROUND_TYPE_SIZE (rli->t, TYPE_SIZE (rli->t), |
1047 | rli->unpacked_align); | |
3c12fcc2 | 1048 | #else |
9328904c | 1049 | unpacked_size = round_up (TYPE_SIZE (rli->t), rli->unpacked_align); |
3c12fcc2 | 1050 | #endif |
729a2125 | 1051 | |
9328904c | 1052 | if (simple_cst_equal (unpacked_size, TYPE_SIZE (rli->t))) |
3c12fcc2 | 1053 | { |
770ae6cc RK |
1054 | TYPE_PACKED (rli->t) = 0; |
1055 | ||
9328904c | 1056 | if (TYPE_NAME (rli->t)) |
3c12fcc2 | 1057 | { |
63ad61ed | 1058 | const char *name; |
729a2125 | 1059 | |
9328904c MM |
1060 | if (TREE_CODE (TYPE_NAME (rli->t)) == IDENTIFIER_NODE) |
1061 | name = IDENTIFIER_POINTER (TYPE_NAME (rli->t)); | |
3c12fcc2 | 1062 | else |
9328904c | 1063 | name = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (rli->t))); |
770ae6cc | 1064 | |
3c12fcc2 GM |
1065 | if (STRICT_ALIGNMENT) |
1066 | warning ("packed attribute causes inefficient alignment for `%s'", name); | |
1067 | else | |
1068 | warning ("packed attribute is unnecessary for `%s'", name); | |
1069 | } | |
1070 | else | |
1071 | { | |
1072 | if (STRICT_ALIGNMENT) | |
1073 | warning ("packed attribute causes inefficient alignment"); | |
1074 | else | |
1075 | warning ("packed attribute is unnecessary"); | |
1076 | } | |
1077 | } | |
3c12fcc2 | 1078 | } |
9328904c MM |
1079 | } |
1080 | ||
1081 | /* Compute the TYPE_MODE for the TYPE (which is a RECORD_TYPE). */ | |
7306ed3f | 1082 | |
65e14bf5 | 1083 | void |
9328904c MM |
1084 | compute_record_mode (type) |
1085 | tree type; | |
1086 | { | |
770ae6cc RK |
1087 | tree field; |
1088 | enum machine_mode mode = VOIDmode; | |
1089 | ||
9328904c MM |
1090 | /* Most RECORD_TYPEs have BLKmode, so we start off assuming that. |
1091 | However, if possible, we use a mode that fits in a register | |
1092 | instead, in order to allow for better optimization down the | |
1093 | line. */ | |
1094 | TYPE_MODE (type) = BLKmode; | |
9328904c | 1095 | |
770ae6cc RK |
1096 | if (! host_integerp (TYPE_SIZE (type), 1)) |
1097 | return; | |
9328904c | 1098 | |
770ae6cc RK |
1099 | /* A record which has any BLKmode members must itself be |
1100 | BLKmode; it can't go in a register. Unless the member is | |
1101 | BLKmode only because it isn't aligned. */ | |
1102 | for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) | |
1103 | { | |
1104 | unsigned HOST_WIDE_INT bitpos; | |
9328904c | 1105 | |
770ae6cc RK |
1106 | if (TREE_CODE (field) != FIELD_DECL) |
1107 | continue; | |
9328904c | 1108 | |
770ae6cc RK |
1109 | if (TREE_CODE (TREE_TYPE (field)) == ERROR_MARK |
1110 | || (TYPE_MODE (TREE_TYPE (field)) == BLKmode | |
1111 | && ! TYPE_NO_FORCE_BLK (TREE_TYPE (field))) | |
1112 | || ! host_integerp (bit_position (field), 1) | |
1113 | || ! host_integerp (DECL_SIZE (field), 1)) | |
1114 | return; | |
1115 | ||
1116 | bitpos = int_bit_position (field); | |
1117 | ||
1118 | /* Must be BLKmode if any field crosses a word boundary, | |
1119 | since extract_bit_field can't handle that in registers. */ | |
1120 | if (bitpos / BITS_PER_WORD | |
382110c0 | 1121 | != ((tree_low_cst (DECL_SIZE (field), 1) + bitpos - 1) |
770ae6cc RK |
1122 | / BITS_PER_WORD) |
1123 | /* But there is no problem if the field is entire words. */ | |
1124 | && tree_low_cst (DECL_SIZE (field), 1) % BITS_PER_WORD != 0) | |
1125 | return; | |
1126 | ||
1127 | /* If this field is the whole struct, remember its mode so | |
1128 | that, say, we can put a double in a class into a DF | |
a8ca7756 JW |
1129 | register instead of forcing it to live in the stack. */ |
1130 | if (simple_cst_equal (TYPE_SIZE (type), DECL_SIZE (field))) | |
770ae6cc | 1131 | mode = DECL_MODE (field); |
9328904c | 1132 | |
31a02448 | 1133 | #ifdef MEMBER_TYPE_FORCES_BLK |
770ae6cc RK |
1134 | /* With some targets, eg. c4x, it is sub-optimal |
1135 | to access an aligned BLKmode structure as a scalar. */ | |
31a02448 | 1136 | if (mode == VOIDmode && MEMBER_TYPE_FORCES_BLK (field)) |
770ae6cc | 1137 | return; |
31a02448 | 1138 | #endif /* MEMBER_TYPE_FORCES_BLK */ |
770ae6cc | 1139 | } |
9328904c | 1140 | |
a8ca7756 JW |
1141 | /* If we only have one real field; use its mode. This only applies to |
1142 | RECORD_TYPE. This does not apply to unions. */ | |
1143 | if (TREE_CODE (type) == RECORD_TYPE && mode != VOIDmode) | |
770ae6cc RK |
1144 | TYPE_MODE (type) = mode; |
1145 | else | |
1146 | TYPE_MODE (type) = mode_for_size_tree (TYPE_SIZE (type), MODE_INT, 1); | |
1147 | ||
1148 | /* If structure's known alignment is less than what the scalar | |
1149 | mode would need, and it matters, then stick with BLKmode. */ | |
1150 | if (TYPE_MODE (type) != BLKmode | |
1151 | && STRICT_ALIGNMENT | |
1152 | && ! (TYPE_ALIGN (type) >= BIGGEST_ALIGNMENT | |
1153 | || TYPE_ALIGN (type) >= GET_MODE_ALIGNMENT (TYPE_MODE (type)))) | |
1154 | { | |
1155 | /* If this is the only reason this type is BLKmode, then | |
1156 | don't force containing types to be BLKmode. */ | |
1157 | TYPE_NO_FORCE_BLK (type) = 1; | |
1158 | TYPE_MODE (type) = BLKmode; | |
9328904c | 1159 | } |
7306ed3f | 1160 | } |
9328904c MM |
1161 | |
1162 | /* Compute TYPE_SIZE and TYPE_ALIGN for TYPE, once it has been laid | |
1163 | out. */ | |
1164 | ||
1165 | static void | |
1166 | finalize_type_size (type) | |
1167 | tree type; | |
1168 | { | |
1169 | /* Normally, use the alignment corresponding to the mode chosen. | |
1170 | However, where strict alignment is not required, avoid | |
1171 | over-aligning structures, since most compilers do not do this | |
1172 | alignment. */ | |
1173 | ||
1174 | if (TYPE_MODE (type) != BLKmode && TYPE_MODE (type) != VOIDmode | |
1175 | && (STRICT_ALIGNMENT | |
1176 | || (TREE_CODE (type) != RECORD_TYPE && TREE_CODE (type) != UNION_TYPE | |
1177 | && TREE_CODE (type) != QUAL_UNION_TYPE | |
1178 | && TREE_CODE (type) != ARRAY_TYPE))) | |
11cf4d18 JJ |
1179 | { |
1180 | TYPE_ALIGN (type) = GET_MODE_ALIGNMENT (TYPE_MODE (type)); | |
1181 | TYPE_USER_ALIGN (type) = 0; | |
1182 | } | |
9328904c MM |
1183 | |
1184 | /* Do machine-dependent extra alignment. */ | |
1185 | #ifdef ROUND_TYPE_ALIGN | |
1186 | TYPE_ALIGN (type) | |
1187 | = ROUND_TYPE_ALIGN (type, TYPE_ALIGN (type), BITS_PER_UNIT); | |
1188 | #endif | |
1189 | ||
9328904c | 1190 | /* If we failed to find a simple way to calculate the unit size |
770ae6cc | 1191 | of the type, find it by division. */ |
9328904c MM |
1192 | if (TYPE_SIZE_UNIT (type) == 0 && TYPE_SIZE (type) != 0) |
1193 | /* TYPE_SIZE (type) is computed in bitsizetype. After the division, the | |
1194 | result will fit in sizetype. We will get more efficient code using | |
1195 | sizetype, so we force a conversion. */ | |
1196 | TYPE_SIZE_UNIT (type) | |
1197 | = convert (sizetype, | |
1198 | size_binop (FLOOR_DIV_EXPR, TYPE_SIZE (type), | |
770ae6cc | 1199 | bitsize_unit_node)); |
9328904c | 1200 | |
770ae6cc RK |
1201 | if (TYPE_SIZE (type) != 0) |
1202 | { | |
1203 | #ifdef ROUND_TYPE_SIZE | |
1204 | TYPE_SIZE (type) | |
1205 | = ROUND_TYPE_SIZE (type, TYPE_SIZE (type), TYPE_ALIGN (type)); | |
1206 | TYPE_SIZE_UNIT (type) | |
1207 | = ROUND_TYPE_SIZE_UNIT (type, TYPE_SIZE_UNIT (type), | |
1208 | TYPE_ALIGN (type) / BITS_PER_UNIT); | |
1209 | #else | |
1210 | TYPE_SIZE (type) = round_up (TYPE_SIZE (type), TYPE_ALIGN (type)); | |
1211 | TYPE_SIZE_UNIT (type) | |
1212 | = round_up (TYPE_SIZE_UNIT (type), TYPE_ALIGN (type) / BITS_PER_UNIT); | |
1213 | #endif | |
1214 | } | |
1215 | ||
1216 | /* Evaluate nonconstant sizes only once, either now or as soon as safe. */ | |
1217 | if (TYPE_SIZE (type) != 0 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) | |
1218 | TYPE_SIZE (type) = variable_size (TYPE_SIZE (type)); | |
9328904c MM |
1219 | if (TYPE_SIZE_UNIT (type) != 0 |
1220 | && TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST) | |
1221 | TYPE_SIZE_UNIT (type) = variable_size (TYPE_SIZE_UNIT (type)); | |
1222 | ||
1223 | /* Also layout any other variants of the type. */ | |
1224 | if (TYPE_NEXT_VARIANT (type) | |
1225 | || type != TYPE_MAIN_VARIANT (type)) | |
1226 | { | |
1227 | tree variant; | |
1228 | /* Record layout info of this variant. */ | |
1229 | tree size = TYPE_SIZE (type); | |
1230 | tree size_unit = TYPE_SIZE_UNIT (type); | |
1231 | unsigned int align = TYPE_ALIGN (type); | |
11cf4d18 | 1232 | unsigned int user_align = TYPE_USER_ALIGN (type); |
9328904c MM |
1233 | enum machine_mode mode = TYPE_MODE (type); |
1234 | ||
1235 | /* Copy it into all variants. */ | |
1236 | for (variant = TYPE_MAIN_VARIANT (type); | |
1237 | variant != 0; | |
1238 | variant = TYPE_NEXT_VARIANT (variant)) | |
1239 | { | |
1240 | TYPE_SIZE (variant) = size; | |
1241 | TYPE_SIZE_UNIT (variant) = size_unit; | |
1242 | TYPE_ALIGN (variant) = align; | |
11cf4d18 | 1243 | TYPE_USER_ALIGN (variant) = user_align; |
9328904c MM |
1244 | TYPE_MODE (variant) = mode; |
1245 | } | |
1246 | } | |
1247 | } | |
1248 | ||
1249 | /* Do all of the work required to layout the type indicated by RLI, | |
1250 | once the fields have been laid out. This function will call `free' | |
1251 | for RLI. */ | |
1252 | ||
1253 | void | |
1254 | finish_record_layout (rli) | |
1255 | record_layout_info rli; | |
1256 | { | |
770ae6cc RK |
1257 | /* Compute the final size. */ |
1258 | finalize_record_size (rli); | |
1259 | ||
1260 | /* Compute the TYPE_MODE for the record. */ | |
1261 | compute_record_mode (rli->t); | |
cc9d4a85 | 1262 | |
8d8238b6 JM |
1263 | /* Perform any last tweaks to the TYPE_SIZE, etc. */ |
1264 | finalize_type_size (rli->t); | |
1265 | ||
9328904c MM |
1266 | /* Lay out any static members. This is done now because their type |
1267 | may use the record's type. */ | |
1268 | while (rli->pending_statics) | |
1269 | { | |
1270 | layout_decl (TREE_VALUE (rli->pending_statics), 0); | |
1271 | rli->pending_statics = TREE_CHAIN (rli->pending_statics); | |
1272 | } | |
cc9d4a85 | 1273 | |
9328904c MM |
1274 | /* Clean up. */ |
1275 | free (rli); | |
1276 | } | |
7306ed3f JW |
1277 | \f |
1278 | /* Calculate the mode, size, and alignment for TYPE. | |
1279 | For an array type, calculate the element separation as well. | |
1280 | Record TYPE on the chain of permanent or temporary types | |
1281 | so that dbxout will find out about it. | |
1282 | ||
1283 | TYPE_SIZE of a type is nonzero if the type has been laid out already. | |
1284 | layout_type does nothing on such a type. | |
1285 | ||
1286 | If the type is incomplete, its TYPE_SIZE remains zero. */ | |
1287 | ||
1288 | void | |
1289 | layout_type (type) | |
1290 | tree type; | |
1291 | { | |
7306ed3f JW |
1292 | if (type == 0) |
1293 | abort (); | |
1294 | ||
1295 | /* Do nothing if type has been laid out before. */ | |
1296 | if (TYPE_SIZE (type)) | |
1297 | return; | |
1298 | ||
7306ed3f JW |
1299 | switch (TREE_CODE (type)) |
1300 | { | |
1301 | case LANG_TYPE: | |
1302 | /* This kind of type is the responsibility | |
9faa82d8 | 1303 | of the language-specific code. */ |
7306ed3f JW |
1304 | abort (); |
1305 | ||
e9a25f70 JL |
1306 | case BOOLEAN_TYPE: /* Used for Java, Pascal, and Chill. */ |
1307 | if (TYPE_PRECISION (type) == 0) | |
1308 | TYPE_PRECISION (type) = 1; /* default to one byte/boolean. */ | |
d4b60170 | 1309 | |
e9a25f70 JL |
1310 | /* ... fall through ... */ |
1311 | ||
7306ed3f JW |
1312 | case INTEGER_TYPE: |
1313 | case ENUMERAL_TYPE: | |
fc69eca0 | 1314 | case CHAR_TYPE: |
e2a77f99 RK |
1315 | if (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST |
1316 | && tree_int_cst_sgn (TYPE_MIN_VALUE (type)) >= 0) | |
7306ed3f JW |
1317 | TREE_UNSIGNED (type) = 1; |
1318 | ||
5e9bec99 RK |
1319 | TYPE_MODE (type) = smallest_mode_for_size (TYPE_PRECISION (type), |
1320 | MODE_INT); | |
06ceef4e | 1321 | TYPE_SIZE (type) = bitsize_int (GET_MODE_BITSIZE (TYPE_MODE (type))); |
ead17059 | 1322 | TYPE_SIZE_UNIT (type) = size_int (GET_MODE_SIZE (TYPE_MODE (type))); |
7306ed3f JW |
1323 | break; |
1324 | ||
1325 | case REAL_TYPE: | |
1326 | TYPE_MODE (type) = mode_for_size (TYPE_PRECISION (type), MODE_FLOAT, 0); | |
06ceef4e | 1327 | TYPE_SIZE (type) = bitsize_int (GET_MODE_BITSIZE (TYPE_MODE (type))); |
ead17059 | 1328 | TYPE_SIZE_UNIT (type) = size_int (GET_MODE_SIZE (TYPE_MODE (type))); |
7306ed3f JW |
1329 | break; |
1330 | ||
1331 | case COMPLEX_TYPE: | |
1332 | TREE_UNSIGNED (type) = TREE_UNSIGNED (TREE_TYPE (type)); | |
1333 | TYPE_MODE (type) | |
1334 | = mode_for_size (2 * TYPE_PRECISION (TREE_TYPE (type)), | |
1335 | (TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE | |
1336 | ? MODE_COMPLEX_INT : MODE_COMPLEX_FLOAT), | |
1337 | 0); | |
06ceef4e | 1338 | TYPE_SIZE (type) = bitsize_int (GET_MODE_BITSIZE (TYPE_MODE (type))); |
ead17059 | 1339 | TYPE_SIZE_UNIT (type) = size_int (GET_MODE_SIZE (TYPE_MODE (type))); |
7306ed3f JW |
1340 | break; |
1341 | ||
0b4565c9 BS |
1342 | case VECTOR_TYPE: |
1343 | { | |
1344 | tree subtype; | |
1345 | ||
1346 | subtype = TREE_TYPE (type); | |
1347 | TREE_UNSIGNED (type) = TREE_UNSIGNED (subtype); | |
1348 | TYPE_SIZE (type) = bitsize_int (GET_MODE_BITSIZE (TYPE_MODE (type))); | |
1349 | TYPE_SIZE_UNIT (type) = size_int (GET_MODE_SIZE (TYPE_MODE (type))); | |
1350 | } | |
1351 | break; | |
1352 | ||
7306ed3f | 1353 | case VOID_TYPE: |
770ae6cc | 1354 | /* This is an incomplete type and so doesn't have a size. */ |
7306ed3f | 1355 | TYPE_ALIGN (type) = 1; |
11cf4d18 | 1356 | TYPE_USER_ALIGN (type) = 0; |
7306ed3f JW |
1357 | TYPE_MODE (type) = VOIDmode; |
1358 | break; | |
1359 | ||
321cb743 | 1360 | case OFFSET_TYPE: |
06ceef4e | 1361 | TYPE_SIZE (type) = bitsize_int (POINTER_SIZE); |
ead17059 | 1362 | TYPE_SIZE_UNIT (type) = size_int (POINTER_SIZE / BITS_PER_UNIT); |
25caaba8 R |
1363 | /* A pointer might be MODE_PARTIAL_INT, |
1364 | but ptrdiff_t must be integral. */ | |
1365 | TYPE_MODE (type) = mode_for_size (POINTER_SIZE, MODE_INT, 0); | |
321cb743 MT |
1366 | break; |
1367 | ||
7306ed3f JW |
1368 | case FUNCTION_TYPE: |
1369 | case METHOD_TYPE: | |
13275056 | 1370 | TYPE_MODE (type) = mode_for_size (2 * POINTER_SIZE, MODE_INT, 0); |
06ceef4e | 1371 | TYPE_SIZE (type) = bitsize_int (2 * POINTER_SIZE); |
ead17059 | 1372 | TYPE_SIZE_UNIT (type) = size_int ((2 * POINTER_SIZE) / BITS_PER_UNIT); |
7306ed3f JW |
1373 | break; |
1374 | ||
1375 | case POINTER_TYPE: | |
1376 | case REFERENCE_TYPE: | |
b5d6a2ff RK |
1377 | { |
1378 | int nbits = ((TREE_CODE (type) == REFERENCE_TYPE | |
1379 | && reference_types_internal) | |
1380 | ? GET_MODE_BITSIZE (Pmode) : POINTER_SIZE); | |
1381 | ||
1382 | TYPE_MODE (type) = nbits == POINTER_SIZE ? ptr_mode : Pmode; | |
1383 | TYPE_SIZE (type) = bitsize_int (nbits); | |
1384 | TYPE_SIZE_UNIT (type) = size_int (nbits / BITS_PER_UNIT); | |
1385 | TREE_UNSIGNED (type) = 1; | |
1386 | TYPE_PRECISION (type) = nbits; | |
1387 | } | |
7306ed3f JW |
1388 | break; |
1389 | ||
1390 | case ARRAY_TYPE: | |
1391 | { | |
1392 | register tree index = TYPE_DOMAIN (type); | |
1393 | register tree element = TREE_TYPE (type); | |
1394 | ||
1395 | build_pointer_type (element); | |
1396 | ||
1397 | /* We need to know both bounds in order to compute the size. */ | |
1398 | if (index && TYPE_MAX_VALUE (index) && TYPE_MIN_VALUE (index) | |
1399 | && TYPE_SIZE (element)) | |
1400 | { | |
e24ff973 RK |
1401 | tree ub = TYPE_MAX_VALUE (index); |
1402 | tree lb = TYPE_MIN_VALUE (index); | |
1403 | tree length; | |
74a4fbfc | 1404 | tree element_size; |
e24ff973 | 1405 | |
a2d53b28 RH |
1406 | /* The initial subtraction should happen in the original type so |
1407 | that (possible) negative values are handled appropriately. */ | |
e24ff973 | 1408 | length = size_binop (PLUS_EXPR, size_one_node, |
fed3cef0 RK |
1409 | convert (sizetype, |
1410 | fold (build (MINUS_EXPR, | |
1411 | TREE_TYPE (lb), | |
1412 | ub, lb)))); | |
7306ed3f | 1413 | |
74a4fbfc DB |
1414 | /* Special handling for arrays of bits (for Chill). */ |
1415 | element_size = TYPE_SIZE (element); | |
382110c0 RK |
1416 | if (TYPE_PACKED (type) && INTEGRAL_TYPE_P (element) |
1417 | && (integer_zerop (TYPE_MAX_VALUE (element)) | |
1418 | || integer_onep (TYPE_MAX_VALUE (element))) | |
1419 | && host_integerp (TYPE_MIN_VALUE (element), 1)) | |
74a4fbfc | 1420 | { |
d4b60170 | 1421 | HOST_WIDE_INT maxvalue |
382110c0 | 1422 | = tree_low_cst (TYPE_MAX_VALUE (element), 1); |
d4b60170 | 1423 | HOST_WIDE_INT minvalue |
382110c0 | 1424 | = tree_low_cst (TYPE_MIN_VALUE (element), 1); |
d4b60170 | 1425 | |
74a4fbfc DB |
1426 | if (maxvalue - minvalue == 1 |
1427 | && (maxvalue == 1 || maxvalue == 0)) | |
1428 | element_size = integer_one_node; | |
1429 | } | |
1430 | ||
fed3cef0 RK |
1431 | TYPE_SIZE (type) = size_binop (MULT_EXPR, element_size, |
1432 | convert (bitsizetype, length)); | |
ead17059 RH |
1433 | |
1434 | /* If we know the size of the element, calculate the total | |
1435 | size directly, rather than do some division thing below. | |
1436 | This optimization helps Fortran assumed-size arrays | |
1437 | (where the size of the array is determined at runtime) | |
7771032e DB |
1438 | substantially. |
1439 | Note that we can't do this in the case where the size of | |
1440 | the elements is one bit since TYPE_SIZE_UNIT cannot be | |
1441 | set correctly in that case. */ | |
fed3cef0 | 1442 | if (TYPE_SIZE_UNIT (element) != 0 && ! integer_onep (element_size)) |
d4b60170 RK |
1443 | TYPE_SIZE_UNIT (type) |
1444 | = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (element), length); | |
7306ed3f JW |
1445 | } |
1446 | ||
1447 | /* Now round the alignment and size, | |
1448 | using machine-dependent criteria if any. */ | |
1449 | ||
1450 | #ifdef ROUND_TYPE_ALIGN | |
1451 | TYPE_ALIGN (type) | |
1452 | = ROUND_TYPE_ALIGN (type, TYPE_ALIGN (element), BITS_PER_UNIT); | |
1453 | #else | |
1454 | TYPE_ALIGN (type) = MAX (TYPE_ALIGN (element), BITS_PER_UNIT); | |
1455 | #endif | |
1456 | ||
1457 | #ifdef ROUND_TYPE_SIZE | |
1458 | if (TYPE_SIZE (type) != 0) | |
ead17059 | 1459 | { |
d4b60170 RK |
1460 | tree tmp |
1461 | = ROUND_TYPE_SIZE (type, TYPE_SIZE (type), TYPE_ALIGN (type)); | |
1462 | ||
ead17059 RH |
1463 | /* If the rounding changed the size of the type, remove any |
1464 | pre-calculated TYPE_SIZE_UNIT. */ | |
1465 | if (simple_cst_equal (TYPE_SIZE (type), tmp) != 1) | |
1466 | TYPE_SIZE_UNIT (type) = NULL; | |
d4b60170 | 1467 | |
ead17059 RH |
1468 | TYPE_SIZE (type) = tmp; |
1469 | } | |
7306ed3f JW |
1470 | #endif |
1471 | ||
1472 | TYPE_MODE (type) = BLKmode; | |
1473 | if (TYPE_SIZE (type) != 0 | |
31a02448 R |
1474 | #ifdef MEMBER_TYPE_FORCES_BLK |
1475 | && ! MEMBER_TYPE_FORCES_BLK (type) | |
1476 | #endif | |
7306ed3f JW |
1477 | /* BLKmode elements force BLKmode aggregate; |
1478 | else extract/store fields may lose. */ | |
1479 | && (TYPE_MODE (TREE_TYPE (type)) != BLKmode | |
1480 | || TYPE_NO_FORCE_BLK (TREE_TYPE (type)))) | |
1481 | { | |
1482 | TYPE_MODE (type) | |
72c602fc | 1483 | = mode_for_size_tree (TYPE_SIZE (type), MODE_INT, 1); |
7306ed3f | 1484 | |
72c602fc RK |
1485 | if (TYPE_MODE (type) != BLKmode |
1486 | && STRICT_ALIGNMENT && TYPE_ALIGN (type) < BIGGEST_ALIGNMENT | |
1487 | && TYPE_ALIGN (type) < GET_MODE_ALIGNMENT (TYPE_MODE (type)) | |
7306ed3f JW |
1488 | && TYPE_MODE (type) != BLKmode) |
1489 | { | |
1490 | TYPE_NO_FORCE_BLK (type) = 1; | |
1491 | TYPE_MODE (type) = BLKmode; | |
1492 | } | |
7306ed3f JW |
1493 | } |
1494 | break; | |
1495 | } | |
1496 | ||
1497 | case RECORD_TYPE: | |
cc9d4a85 MM |
1498 | case UNION_TYPE: |
1499 | case QUAL_UNION_TYPE: | |
9328904c MM |
1500 | { |
1501 | tree field; | |
1502 | record_layout_info rli; | |
1503 | ||
1504 | /* Initialize the layout information. */ | |
770ae6cc RK |
1505 | rli = start_record_layout (type); |
1506 | ||
cc9d4a85 MM |
1507 | /* If this is a QUAL_UNION_TYPE, we want to process the fields |
1508 | in the reverse order in building the COND_EXPR that denotes | |
1509 | its size. We reverse them again later. */ | |
1510 | if (TREE_CODE (type) == QUAL_UNION_TYPE) | |
1511 | TYPE_FIELDS (type) = nreverse (TYPE_FIELDS (type)); | |
770ae6cc RK |
1512 | |
1513 | /* Place all the fields. */ | |
9328904c | 1514 | for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) |
770ae6cc RK |
1515 | place_field (rli, field); |
1516 | ||
cc9d4a85 MM |
1517 | if (TREE_CODE (type) == QUAL_UNION_TYPE) |
1518 | TYPE_FIELDS (type) = nreverse (TYPE_FIELDS (type)); | |
770ae6cc | 1519 | |
e0cea8d9 RK |
1520 | if (lang_adjust_rli) |
1521 | (*lang_adjust_rli) (rli); | |
1522 | ||
9328904c MM |
1523 | /* Finish laying out the record. */ |
1524 | finish_record_layout (rli); | |
1525 | } | |
7306ed3f JW |
1526 | break; |
1527 | ||
e9a25f70 | 1528 | case SET_TYPE: /* Used by Chill and Pascal. */ |
b5d11e41 PB |
1529 | if (TREE_CODE (TYPE_MAX_VALUE (TYPE_DOMAIN (type))) != INTEGER_CST |
1530 | || TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (type))) != INTEGER_CST) | |
1531 | abort(); | |
1532 | else | |
1533 | { | |
1534 | #ifndef SET_WORD_SIZE | |
1535 | #define SET_WORD_SIZE BITS_PER_WORD | |
1536 | #endif | |
729a2125 RK |
1537 | unsigned int alignment |
1538 | = set_alignment ? set_alignment : SET_WORD_SIZE; | |
db3cf6fb MS |
1539 | int size_in_bits |
1540 | = (TREE_INT_CST_LOW (TYPE_MAX_VALUE (TYPE_DOMAIN (type))) | |
1541 | - TREE_INT_CST_LOW (TYPE_MIN_VALUE (TYPE_DOMAIN (type))) + 1); | |
b5d11e41 PB |
1542 | int rounded_size |
1543 | = ((size_in_bits + alignment - 1) / alignment) * alignment; | |
729a2125 RK |
1544 | |
1545 | if (rounded_size > (int) alignment) | |
b5d11e41 PB |
1546 | TYPE_MODE (type) = BLKmode; |
1547 | else | |
1548 | TYPE_MODE (type) = mode_for_size (alignment, MODE_INT, 1); | |
729a2125 | 1549 | |
06ceef4e | 1550 | TYPE_SIZE (type) = bitsize_int (rounded_size); |
ead17059 | 1551 | TYPE_SIZE_UNIT (type) = size_int (rounded_size / BITS_PER_UNIT); |
b5d11e41 | 1552 | TYPE_ALIGN (type) = alignment; |
11cf4d18 | 1553 | TYPE_USER_ALIGN (type) = 0; |
b5d11e41 PB |
1554 | TYPE_PRECISION (type) = size_in_bits; |
1555 | } | |
1556 | break; | |
1557 | ||
4cc89e53 RS |
1558 | case FILE_TYPE: |
1559 | /* The size may vary in different languages, so the language front end | |
1560 | should fill in the size. */ | |
1561 | TYPE_ALIGN (type) = BIGGEST_ALIGNMENT; | |
11cf4d18 | 1562 | TYPE_USER_ALIGN (type) = 0; |
4cc89e53 RS |
1563 | TYPE_MODE (type) = BLKmode; |
1564 | break; | |
1565 | ||
7306ed3f JW |
1566 | default: |
1567 | abort (); | |
729a2125 | 1568 | } |
7306ed3f | 1569 | |
9328904c | 1570 | /* Compute the final TYPE_SIZE, TYPE_ALIGN, etc. for TYPE. For |
cc9d4a85 MM |
1571 | records and unions, finish_record_layout already called this |
1572 | function. */ | |
1573 | if (TREE_CODE (type) != RECORD_TYPE | |
1574 | && TREE_CODE (type) != UNION_TYPE | |
1575 | && TREE_CODE (type) != QUAL_UNION_TYPE) | |
9328904c | 1576 | finalize_type_size (type); |
7306ed3f | 1577 | |
fed3cef0 RK |
1578 | /* If this type is created before sizetype has been permanently set, |
1579 | record it so set_sizetype can fix it up. */ | |
1580 | if (! sizetype_set) | |
ad41cc2a | 1581 | early_type_list = tree_cons (NULL_TREE, type, early_type_list); |
dc5041ab JJ |
1582 | |
1583 | /* If an alias set has been set for this aggregate when it was incomplete, | |
1584 | force it into alias set 0. | |
1585 | This is too conservative, but we cannot call record_component_aliases | |
1586 | here because some frontends still change the aggregates after | |
1587 | layout_type. */ | |
1588 | if (AGGREGATE_TYPE_P (type) && TYPE_ALIAS_SET_KNOWN_P (type)) | |
1589 | TYPE_ALIAS_SET (type) = 0; | |
7306ed3f JW |
1590 | } |
1591 | \f | |
1592 | /* Create and return a type for signed integers of PRECISION bits. */ | |
1593 | ||
1594 | tree | |
1595 | make_signed_type (precision) | |
1596 | int precision; | |
1597 | { | |
1598 | register tree type = make_node (INTEGER_TYPE); | |
1599 | ||
1600 | TYPE_PRECISION (type) = precision; | |
1601 | ||
fed3cef0 | 1602 | fixup_signed_type (type); |
7306ed3f JW |
1603 | return type; |
1604 | } | |
1605 | ||
1606 | /* Create and return a type for unsigned integers of PRECISION bits. */ | |
1607 | ||
1608 | tree | |
1609 | make_unsigned_type (precision) | |
1610 | int precision; | |
1611 | { | |
1612 | register tree type = make_node (INTEGER_TYPE); | |
1613 | ||
1614 | TYPE_PRECISION (type) = precision; | |
1615 | ||
7306ed3f JW |
1616 | fixup_unsigned_type (type); |
1617 | return type; | |
1618 | } | |
fed3cef0 RK |
1619 | \f |
1620 | /* Initialize sizetype and bitsizetype to a reasonable and temporary | |
1621 | value to enable integer types to be created. */ | |
1622 | ||
1623 | void | |
1624 | initialize_sizetypes () | |
1625 | { | |
1626 | tree t = make_node (INTEGER_TYPE); | |
1627 | ||
1628 | /* Set this so we do something reasonable for the build_int_2 calls | |
1629 | below. */ | |
1630 | integer_type_node = t; | |
1631 | ||
1632 | TYPE_MODE (t) = SImode; | |
1633 | TYPE_ALIGN (t) = GET_MODE_ALIGNMENT (SImode); | |
11cf4d18 | 1634 | TYPE_USER_ALIGN (t) = 0; |
fed3cef0 RK |
1635 | TYPE_SIZE (t) = build_int_2 (GET_MODE_BITSIZE (SImode), 0); |
1636 | TYPE_SIZE_UNIT (t) = build_int_2 (GET_MODE_SIZE (SImode), 0); | |
1637 | TREE_UNSIGNED (t) = 1; | |
1638 | TYPE_PRECISION (t) = GET_MODE_BITSIZE (SImode); | |
1639 | TYPE_MIN_VALUE (t) = build_int_2 (0, 0); | |
770ae6cc | 1640 | TYPE_IS_SIZETYPE (t) = 1; |
fed3cef0 RK |
1641 | |
1642 | /* 1000 avoids problems with possible overflow and is certainly | |
1643 | larger than any size value we'd want to be storing. */ | |
1644 | TYPE_MAX_VALUE (t) = build_int_2 (1000, 0); | |
1645 | ||
1646 | /* These two must be different nodes because of the caching done in | |
1647 | size_int_wide. */ | |
1648 | sizetype = t; | |
1649 | bitsizetype = copy_node (t); | |
1650 | integer_type_node = 0; | |
1651 | } | |
7306ed3f | 1652 | |
896cced4 | 1653 | /* Set sizetype to TYPE, and initialize *sizetype accordingly. |
f8dac6eb R |
1654 | Also update the type of any standard type's sizes made so far. */ |
1655 | ||
1656 | void | |
1657 | set_sizetype (type) | |
1658 | tree type; | |
1659 | { | |
d4b60170 | 1660 | int oprecision = TYPE_PRECISION (type); |
f8dac6eb | 1661 | /* The *bitsizetype types use a precision that avoids overflows when |
d4b60170 RK |
1662 | calculating signed sizes / offsets in bits. However, when |
1663 | cross-compiling from a 32 bit to a 64 bit host, we are limited to 64 bit | |
1664 | precision. */ | |
11a6092b | 1665 | int precision = MIN (oprecision + BITS_PER_UNIT_LOG + 1, |
d4b60170 | 1666 | 2 * HOST_BITS_PER_WIDE_INT); |
fed3cef0 | 1667 | unsigned int i; |
ad41cc2a | 1668 | tree t; |
fed3cef0 RK |
1669 | |
1670 | if (sizetype_set) | |
1671 | abort (); | |
81b3411c | 1672 | |
fed3cef0 RK |
1673 | /* Make copies of nodes since we'll be setting TYPE_IS_SIZETYPE. */ |
1674 | sizetype = copy_node (type); | |
21318741 | 1675 | TYPE_DOMAIN (sizetype) = type; |
770ae6cc | 1676 | TYPE_IS_SIZETYPE (sizetype) = 1; |
81b3411c BS |
1677 | bitsizetype = make_node (INTEGER_TYPE); |
1678 | TYPE_NAME (bitsizetype) = TYPE_NAME (type); | |
f8dac6eb | 1679 | TYPE_PRECISION (bitsizetype) = precision; |
770ae6cc | 1680 | TYPE_IS_SIZETYPE (bitsizetype) = 1; |
d4b60170 | 1681 | |
896cced4 RH |
1682 | if (TREE_UNSIGNED (type)) |
1683 | fixup_unsigned_type (bitsizetype); | |
1684 | else | |
1685 | fixup_signed_type (bitsizetype); | |
d4b60170 | 1686 | |
f8dac6eb R |
1687 | layout_type (bitsizetype); |
1688 | ||
896cced4 RH |
1689 | if (TREE_UNSIGNED (type)) |
1690 | { | |
1691 | usizetype = sizetype; | |
1692 | ubitsizetype = bitsizetype; | |
fed3cef0 RK |
1693 | ssizetype = copy_node (make_signed_type (oprecision)); |
1694 | sbitsizetype = copy_node (make_signed_type (precision)); | |
896cced4 RH |
1695 | } |
1696 | else | |
1697 | { | |
1698 | ssizetype = sizetype; | |
1699 | sbitsizetype = bitsizetype; | |
fed3cef0 RK |
1700 | usizetype = copy_node (make_unsigned_type (oprecision)); |
1701 | ubitsizetype = copy_node (make_unsigned_type (precision)); | |
896cced4 | 1702 | } |
fed3cef0 RK |
1703 | |
1704 | TYPE_NAME (bitsizetype) = get_identifier ("bit_size_type"); | |
1705 | ||
21318741 | 1706 | /* Show is a sizetype, is a main type, and has no pointers to it. */ |
b6a1cbae | 1707 | for (i = 0; i < ARRAY_SIZE (sizetype_tab); i++) |
21318741 RK |
1708 | { |
1709 | TYPE_IS_SIZETYPE (sizetype_tab[i]) = 1; | |
1710 | TYPE_MAIN_VARIANT (sizetype_tab[i]) = sizetype_tab[i]; | |
1711 | TYPE_NEXT_VARIANT (sizetype_tab[i]) = 0; | |
1712 | TYPE_POINTER_TO (sizetype_tab[i]) = 0; | |
1713 | TYPE_REFERENCE_TO (sizetype_tab[i]) = 0; | |
1714 | } | |
d7db6646 | 1715 | |
d4b60170 RK |
1716 | ggc_add_tree_root ((tree *) &sizetype_tab, |
1717 | sizeof sizetype_tab / sizeof (tree)); | |
f8dac6eb | 1718 | |
fed3cef0 RK |
1719 | /* Go down each of the types we already made and set the proper type |
1720 | for the sizes in them. */ | |
ad41cc2a | 1721 | for (t = early_type_list; t != 0; t = TREE_CHAIN (t)) |
fed3cef0 | 1722 | { |
ad41cc2a | 1723 | if (TREE_CODE (TREE_VALUE (t)) != INTEGER_TYPE) |
fed3cef0 RK |
1724 | abort (); |
1725 | ||
ad41cc2a RK |
1726 | TREE_TYPE (TYPE_SIZE (TREE_VALUE (t))) = bitsizetype; |
1727 | TREE_TYPE (TYPE_SIZE_UNIT (TREE_VALUE (t))) = sizetype; | |
fed3cef0 RK |
1728 | } |
1729 | ||
1730 | early_type_list = 0; | |
1731 | sizetype_set = 1; | |
1732 | } | |
1733 | \f | |
4cc89e53 | 1734 | /* Set the extreme values of TYPE based on its precision in bits, |
13756074 | 1735 | then lay it out. Used when make_signed_type won't do |
4cc89e53 RS |
1736 | because the tree code is not INTEGER_TYPE. |
1737 | E.g. for Pascal, when the -fsigned-char option is given. */ | |
1738 | ||
1739 | void | |
1740 | fixup_signed_type (type) | |
1741 | tree type; | |
1742 | { | |
1743 | register int precision = TYPE_PRECISION (type); | |
1744 | ||
1745 | TYPE_MIN_VALUE (type) | |
13756074 JW |
1746 | = build_int_2 ((precision - HOST_BITS_PER_WIDE_INT > 0 |
1747 | ? 0 : (HOST_WIDE_INT) (-1) << (precision - 1)), | |
1748 | (((HOST_WIDE_INT) (-1) | |
1749 | << (precision - HOST_BITS_PER_WIDE_INT - 1 > 0 | |
1750 | ? precision - HOST_BITS_PER_WIDE_INT - 1 | |
1751 | : 0)))); | |
4cc89e53 | 1752 | TYPE_MAX_VALUE (type) |
13756074 JW |
1753 | = build_int_2 ((precision - HOST_BITS_PER_WIDE_INT > 0 |
1754 | ? -1 : ((HOST_WIDE_INT) 1 << (precision - 1)) - 1), | |
1755 | (precision - HOST_BITS_PER_WIDE_INT - 1 > 0 | |
1756 | ? (((HOST_WIDE_INT) 1 | |
1757 | << (precision - HOST_BITS_PER_WIDE_INT - 1))) - 1 | |
4cc89e53 RS |
1758 | : 0)); |
1759 | ||
1760 | TREE_TYPE (TYPE_MIN_VALUE (type)) = type; | |
1761 | TREE_TYPE (TYPE_MAX_VALUE (type)) = type; | |
1762 | ||
1763 | /* Lay out the type: set its alignment, size, etc. */ | |
4cc89e53 RS |
1764 | layout_type (type); |
1765 | } | |
1766 | ||
7306ed3f | 1767 | /* Set the extreme values of TYPE based on its precision in bits, |
13756074 | 1768 | then lay it out. This is used both in `make_unsigned_type' |
7306ed3f JW |
1769 | and for enumeral types. */ |
1770 | ||
1771 | void | |
1772 | fixup_unsigned_type (type) | |
1773 | tree type; | |
1774 | { | |
1775 | register int precision = TYPE_PRECISION (type); | |
1776 | ||
1777 | TYPE_MIN_VALUE (type) = build_int_2 (0, 0); | |
1778 | TYPE_MAX_VALUE (type) | |
c166a311 | 1779 | = build_int_2 (precision - HOST_BITS_PER_WIDE_INT >= 0 |
13756074 | 1780 | ? -1 : ((HOST_WIDE_INT) 1 << precision) - 1, |
c166a311 CH |
1781 | precision - HOST_BITS_PER_WIDE_INT > 0 |
1782 | ? ((unsigned HOST_WIDE_INT) ~0 | |
1783 | >> (HOST_BITS_PER_WIDE_INT | |
1784 | - (precision - HOST_BITS_PER_WIDE_INT))) | |
7306ed3f JW |
1785 | : 0); |
1786 | TREE_TYPE (TYPE_MIN_VALUE (type)) = type; | |
1787 | TREE_TYPE (TYPE_MAX_VALUE (type)) = type; | |
1788 | ||
1789 | /* Lay out the type: set its alignment, size, etc. */ | |
7306ed3f JW |
1790 | layout_type (type); |
1791 | } | |
1792 | \f | |
1793 | /* Find the best machine mode to use when referencing a bit field of length | |
1794 | BITSIZE bits starting at BITPOS. | |
1795 | ||
1796 | The underlying object is known to be aligned to a boundary of ALIGN bits. | |
1797 | If LARGEST_MODE is not VOIDmode, it means that we should not use a mode | |
1798 | larger than LARGEST_MODE (usually SImode). | |
1799 | ||
1800 | If no mode meets all these conditions, we return VOIDmode. Otherwise, if | |
1801 | VOLATILEP is true or SLOW_BYTE_ACCESS is false, we return the smallest | |
1802 | mode meeting these conditions. | |
1803 | ||
77fa0940 RK |
1804 | Otherwise (VOLATILEP is false and SLOW_BYTE_ACCESS is true), we return |
1805 | the largest mode (but a mode no wider than UNITS_PER_WORD) that meets | |
1806 | all the conditions. */ | |
7306ed3f JW |
1807 | |
1808 | enum machine_mode | |
1809 | get_best_mode (bitsize, bitpos, align, largest_mode, volatilep) | |
1810 | int bitsize, bitpos; | |
729a2125 | 1811 | unsigned int align; |
7306ed3f JW |
1812 | enum machine_mode largest_mode; |
1813 | int volatilep; | |
1814 | { | |
1815 | enum machine_mode mode; | |
770ae6cc | 1816 | unsigned int unit = 0; |
7306ed3f JW |
1817 | |
1818 | /* Find the narrowest integer mode that contains the bit field. */ | |
1819 | for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode; | |
1820 | mode = GET_MODE_WIDER_MODE (mode)) | |
1821 | { | |
1822 | unit = GET_MODE_BITSIZE (mode); | |
956d6950 | 1823 | if ((bitpos % unit) + bitsize <= unit) |
7306ed3f JW |
1824 | break; |
1825 | } | |
1826 | ||
0c61f541 | 1827 | if (mode == VOIDmode |
7306ed3f | 1828 | /* It is tempting to omit the following line |
4e4b555d | 1829 | if STRICT_ALIGNMENT is true. |
7306ed3f JW |
1830 | But that is incorrect, since if the bitfield uses part of 3 bytes |
1831 | and we use a 4-byte mode, we could get a spurious segv | |
1832 | if the extra 4th byte is past the end of memory. | |
1833 | (Though at least one Unix compiler ignores this problem: | |
1834 | that on the Sequent 386 machine. */ | |
770ae6cc | 1835 | || MIN (unit, BIGGEST_ALIGNMENT) > align |
7306ed3f JW |
1836 | || (largest_mode != VOIDmode && unit > GET_MODE_BITSIZE (largest_mode))) |
1837 | return VOIDmode; | |
1838 | ||
77fa0940 RK |
1839 | if (SLOW_BYTE_ACCESS && ! volatilep) |
1840 | { | |
1841 | enum machine_mode wide_mode = VOIDmode, tmode; | |
1842 | ||
1843 | for (tmode = GET_CLASS_NARROWEST_MODE (MODE_INT); tmode != VOIDmode; | |
1844 | tmode = GET_MODE_WIDER_MODE (tmode)) | |
1845 | { | |
1846 | unit = GET_MODE_BITSIZE (tmode); | |
1847 | if (bitpos / unit == (bitpos + bitsize - 1) / unit | |
1848 | && unit <= BITS_PER_WORD | |
770ae6cc | 1849 | && unit <= MIN (align, BIGGEST_ALIGNMENT) |
77fa0940 RK |
1850 | && (largest_mode == VOIDmode |
1851 | || unit <= GET_MODE_BITSIZE (largest_mode))) | |
1852 | wide_mode = tmode; | |
1853 | } | |
1854 | ||
1855 | if (wide_mode != VOIDmode) | |
1856 | return wide_mode; | |
1857 | } | |
7306ed3f JW |
1858 | |
1859 | return mode; | |
1860 | } | |
d7db6646 | 1861 | |
36c265b1 NS |
1862 | /* Return the alignment of MODE. This will be bounded by 1 and |
1863 | BIGGEST_ALIGNMENT. */ | |
1864 | ||
fed3cef0 RK |
1865 | unsigned int |
1866 | get_mode_alignment (mode) | |
36c265b1 NS |
1867 | enum machine_mode mode; |
1868 | { | |
0c237688 | 1869 | unsigned int alignment = GET_MODE_UNIT_SIZE (mode); |
36c265b1 NS |
1870 | |
1871 | /* Extract the LSB of the size. */ | |
1872 | alignment = alignment & -alignment; | |
0c237688 | 1873 | alignment *= BITS_PER_UNIT; |
36c265b1 NS |
1874 | |
1875 | alignment = MIN (BIGGEST_ALIGNMENT, MAX (1, alignment)); | |
1876 | return alignment; | |
1877 | } | |
1878 | ||
d7db6646 RH |
1879 | /* This function is run once to initialize stor-layout.c. */ |
1880 | ||
1881 | void | |
1882 | init_stor_layout_once () | |
1883 | { | |
1884 | ggc_add_tree_root (&pending_sizes, 1); | |
1885 | } |