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7306ed3f | 1 | /* C-compiler utilities for types and variables storage layout |
06ceef4e RK |
2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1996, 1998, |
3 | 1999, 2000 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 | |
770ae6cc | 53 | static void finalize_record_size PARAMS ((record_layout_info)); |
770ae6cc RK |
54 | static void finalize_type_size PARAMS ((tree)); |
55 | static void place_union_field PARAMS ((record_layout_info, tree)); | |
36244024 | 56 | extern void debug_rli PARAMS ((record_layout_info)); |
7306ed3f JW |
57 | \f |
58 | /* SAVE_EXPRs for sizes of types and decls, waiting to be expanded. */ | |
59 | ||
60 | static tree pending_sizes; | |
61 | ||
62 | /* Nonzero means cannot safely call expand_expr now, | |
63 | so put variable sizes onto `pending_sizes' instead. */ | |
64 | ||
65 | int immediate_size_expand; | |
66 | ||
770ae6cc RK |
67 | /* Get a list of all the objects put on the pending sizes list. */ |
68 | ||
7306ed3f JW |
69 | tree |
70 | get_pending_sizes () | |
71 | { | |
72 | tree chain = pending_sizes; | |
4e4b555d RS |
73 | tree t; |
74 | ||
75 | /* Put each SAVE_EXPR into the current function. */ | |
76 | for (t = chain; t; t = TREE_CHAIN (t)) | |
77 | SAVE_EXPR_CONTEXT (TREE_VALUE (t)) = current_function_decl; | |
d4b60170 | 78 | |
7306ed3f JW |
79 | pending_sizes = 0; |
80 | return chain; | |
81 | } | |
82 | ||
770ae6cc RK |
83 | /* Put a chain of objects into the pending sizes list, which must be |
84 | empty. */ | |
85 | ||
1fd7c4ac RK |
86 | void |
87 | put_pending_sizes (chain) | |
88 | tree chain; | |
89 | { | |
90 | if (pending_sizes) | |
91 | abort (); | |
92 | ||
93 | pending_sizes = chain; | |
94 | } | |
95 | ||
76ffb3a0 | 96 | /* Given a size SIZE that may not be a constant, return a SAVE_EXPR |
7306ed3f JW |
97 | to serve as the actual size-expression for a type or decl. */ |
98 | ||
4e4b555d | 99 | tree |
7306ed3f JW |
100 | variable_size (size) |
101 | tree size; | |
102 | { | |
5e9bec99 RK |
103 | /* If the language-processor is to take responsibility for variable-sized |
104 | items (e.g., languages which have elaboration procedures like Ada), | |
e5852cff | 105 | just return SIZE unchanged. Likewise for self-referential sizes. */ |
76ffb3a0 RK |
106 | if (TREE_CONSTANT (size) |
107 | || global_bindings_p () < 0 || contains_placeholder_p (size)) | |
5e9bec99 RK |
108 | return size; |
109 | ||
68de3831 RK |
110 | size = save_expr (size); |
111 | ||
d26f8097 MM |
112 | /* If an array with a variable number of elements is declared, and |
113 | the elements require destruction, we will emit a cleanup for the | |
114 | array. That cleanup is run both on normal exit from the block | |
115 | and in the exception-handler for the block. Normally, when code | |
116 | is used in both ordinary code and in an exception handler it is | |
117 | `unsaved', i.e., all SAVE_EXPRs are recalculated. However, we do | |
118 | not wish to do that here; the array-size is the same in both | |
119 | places. */ | |
120 | if (TREE_CODE (size) == SAVE_EXPR) | |
121 | SAVE_EXPR_PERSISTENT_P (size) = 1; | |
122 | ||
68de3831 | 123 | if (global_bindings_p ()) |
7306ed3f | 124 | { |
80f9c711 RS |
125 | if (TREE_CONSTANT (size)) |
126 | error ("type size can't be explicitly evaluated"); | |
127 | else | |
128 | error ("variable-size type declared outside of any function"); | |
129 | ||
fed3cef0 | 130 | return size_one_node; |
7306ed3f JW |
131 | } |
132 | ||
133 | if (immediate_size_expand) | |
93609dfb RK |
134 | /* NULL_RTX is not defined; neither is the rtx type. |
135 | Also, we would like to pass const0_rtx here, but don't have it. */ | |
136 | expand_expr (size, expand_expr (integer_zero_node, NULL_PTR, VOIDmode, 0), | |
137 | VOIDmode, 0); | |
770ae6cc | 138 | else if (cfun != 0 && cfun->x_dont_save_pending_sizes_p) |
d43163b7 MM |
139 | /* The front-end doesn't want us to keep a list of the expressions |
140 | that determine sizes for variable size objects. */ | |
141 | ; | |
7306ed3f | 142 | else |
c166a311 | 143 | pending_sizes = tree_cons (NULL_TREE, size, pending_sizes); |
7306ed3f JW |
144 | |
145 | return size; | |
146 | } | |
147 | \f | |
148 | #ifndef MAX_FIXED_MODE_SIZE | |
149 | #define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (DImode) | |
150 | #endif | |
151 | ||
152 | /* Return the machine mode to use for a nonscalar of SIZE bits. | |
153 | The mode must be in class CLASS, and have exactly that many bits. | |
154 | If LIMIT is nonzero, modes of wider than MAX_FIXED_MODE_SIZE will not | |
155 | be used. */ | |
156 | ||
157 | enum machine_mode | |
158 | mode_for_size (size, class, limit) | |
770ae6cc | 159 | unsigned int size; |
7306ed3f JW |
160 | enum mode_class class; |
161 | int limit; | |
162 | { | |
163 | register enum machine_mode mode; | |
164 | ||
72c602fc | 165 | if (limit && size > MAX_FIXED_MODE_SIZE) |
7306ed3f JW |
166 | return BLKmode; |
167 | ||
5e9bec99 | 168 | /* Get the first mode which has this size, in the specified class. */ |
7306ed3f JW |
169 | for (mode = GET_CLASS_NARROWEST_MODE (class); mode != VOIDmode; |
170 | mode = GET_MODE_WIDER_MODE (mode)) | |
72c602fc | 171 | if (GET_MODE_BITSIZE (mode) == size) |
7306ed3f JW |
172 | return mode; |
173 | ||
174 | return BLKmode; | |
175 | } | |
176 | ||
72c602fc RK |
177 | /* Similar, except passed a tree node. */ |
178 | ||
179 | enum machine_mode | |
180 | mode_for_size_tree (size, class, limit) | |
181 | tree size; | |
182 | enum mode_class class; | |
183 | int limit; | |
184 | { | |
185 | if (TREE_CODE (size) != INTEGER_CST | |
72c602fc RK |
186 | /* What we really want to say here is that the size can fit in a |
187 | host integer, but we know there's no way we'd find a mode for | |
188 | this many bits, so there's no point in doing the precise test. */ | |
05bccae2 | 189 | || compare_tree_int (size, 1000) > 0) |
72c602fc RK |
190 | return BLKmode; |
191 | else | |
192 | return mode_for_size (TREE_INT_CST_LOW (size), class, limit); | |
193 | } | |
194 | ||
5e9bec99 RK |
195 | /* Similar, but never return BLKmode; return the narrowest mode that |
196 | contains at least the requested number of bits. */ | |
197 | ||
27922c13 | 198 | enum machine_mode |
5e9bec99 | 199 | smallest_mode_for_size (size, class) |
770ae6cc | 200 | unsigned int size; |
5e9bec99 RK |
201 | enum mode_class class; |
202 | { | |
203 | register enum machine_mode mode; | |
204 | ||
205 | /* Get the first mode which has at least this size, in the | |
206 | specified class. */ | |
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) |
5e9bec99 RK |
210 | return mode; |
211 | ||
212 | abort (); | |
213 | } | |
214 | ||
d006aa54 RH |
215 | /* Find an integer mode of the exact same size, or BLKmode on failure. */ |
216 | ||
217 | enum machine_mode | |
218 | int_mode_for_mode (mode) | |
219 | enum machine_mode mode; | |
220 | { | |
221 | switch (GET_MODE_CLASS (mode)) | |
222 | { | |
223 | case MODE_INT: | |
224 | case MODE_PARTIAL_INT: | |
225 | break; | |
226 | ||
227 | case MODE_COMPLEX_INT: | |
228 | case MODE_COMPLEX_FLOAT: | |
229 | case MODE_FLOAT: | |
230 | mode = mode_for_size (GET_MODE_BITSIZE (mode), MODE_INT, 0); | |
231 | break; | |
232 | ||
233 | case MODE_RANDOM: | |
234 | if (mode == BLKmode) | |
235 | break; | |
d4b60170 RK |
236 | |
237 | /* ... fall through ... */ | |
d006aa54 RH |
238 | |
239 | case MODE_CC: | |
240 | default: | |
05bccae2 | 241 | abort (); |
d006aa54 RH |
242 | } |
243 | ||
244 | return mode; | |
245 | } | |
246 | ||
fed3cef0 RK |
247 | /* Return the value of VALUE, rounded up to a multiple of DIVISOR. |
248 | This can only be applied to objects of a sizetype. */ | |
7306ed3f JW |
249 | |
250 | tree | |
251 | round_up (value, divisor) | |
252 | tree value; | |
253 | int divisor; | |
254 | { | |
fed3cef0 RK |
255 | tree arg = size_int_type (divisor, TREE_TYPE (value)); |
256 | ||
257 | return size_binop (MULT_EXPR, size_binop (CEIL_DIV_EXPR, value, arg), arg); | |
258 | } | |
259 | ||
260 | /* Likewise, but round down. */ | |
261 | ||
262 | tree | |
263 | round_down (value, divisor) | |
264 | tree value; | |
265 | int divisor; | |
266 | { | |
267 | tree arg = size_int_type (divisor, TREE_TYPE (value)); | |
268 | ||
269 | return size_binop (MULT_EXPR, size_binop (FLOOR_DIV_EXPR, value, arg), arg); | |
7306ed3f JW |
270 | } |
271 | \f | |
272 | /* Set the size, mode and alignment of a ..._DECL node. | |
273 | TYPE_DECL does need this for C++. | |
274 | Note that LABEL_DECL and CONST_DECL nodes do not need this, | |
275 | and FUNCTION_DECL nodes have them set up in a special (and simple) way. | |
276 | Don't call layout_decl for them. | |
277 | ||
278 | KNOWN_ALIGN is the amount of alignment we can assume this | |
279 | decl has with no special effort. It is relevant only for FIELD_DECLs | |
280 | and depends on the previous fields. | |
281 | All that matters about KNOWN_ALIGN is which powers of 2 divide it. | |
282 | If KNOWN_ALIGN is 0, it means, "as much alignment as you like": | |
283 | the record will be aligned to suit. */ | |
284 | ||
285 | void | |
286 | layout_decl (decl, known_align) | |
287 | tree decl; | |
729a2125 | 288 | unsigned int known_align; |
7306ed3f JW |
289 | { |
290 | register tree type = TREE_TYPE (decl); | |
291 | register enum tree_code code = TREE_CODE (decl); | |
7306ed3f JW |
292 | |
293 | if (code == CONST_DECL) | |
294 | return; | |
9df2c88c | 295 | else if (code != VAR_DECL && code != PARM_DECL && code != RESULT_DECL |
33433751 | 296 | && code != TYPE_DECL && code != FIELD_DECL) |
7306ed3f JW |
297 | abort (); |
298 | ||
299 | if (type == error_mark_node) | |
33433751 | 300 | type = void_type_node; |
7306ed3f | 301 | |
770ae6cc RK |
302 | /* Usually the size and mode come from the data type without change, |
303 | however, the front-end may set the explicit width of the field, so its | |
304 | size may not be the same as the size of its type. This happens with | |
305 | bitfields, of course (an `int' bitfield may be only 2 bits, say), but it | |
306 | also happens with other fields. For example, the C++ front-end creates | |
307 | zero-sized fields corresponding to empty base classes, and depends on | |
308 | layout_type setting DECL_FIELD_BITPOS correctly for the field. Set the | |
4b6bf620 RK |
309 | size in bytes from the size in bits. If we have already set the mode, |
310 | don't set it again since we can be called twice for FIELD_DECLs. */ | |
770ae6cc | 311 | |
7306ed3f | 312 | TREE_UNSIGNED (decl) = TREE_UNSIGNED (type); |
4b6bf620 RK |
313 | if (DECL_MODE (decl) == VOIDmode) |
314 | DECL_MODE (decl) = TYPE_MODE (type); | |
770ae6cc | 315 | |
5e9bec99 | 316 | if (DECL_SIZE (decl) == 0) |
06ceef4e RK |
317 | { |
318 | DECL_SIZE (decl) = TYPE_SIZE (type); | |
319 | DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (type); | |
320 | } | |
770ae6cc RK |
321 | else |
322 | DECL_SIZE_UNIT (decl) | |
323 | = convert (sizetype, size_binop (CEIL_DIV_EXPR, DECL_SIZE (decl), | |
324 | bitsize_unit_node)); | |
06ceef4e | 325 | |
7306ed3f | 326 | /* Force alignment required for the data type. |
23ad4d41 RS |
327 | But if the decl itself wants greater alignment, don't override that. |
328 | Likewise, if the decl is packed, don't override it. */ | |
17aec3eb | 329 | if (! (code == FIELD_DECL && DECL_BIT_FIELD (decl)) |
33433751 | 330 | && (DECL_ALIGN (decl) == 0 |
17aec3eb RK |
331 | || (! (code == FIELD_DECL && DECL_PACKED (decl)) |
332 | && TYPE_ALIGN (type) > DECL_ALIGN (decl)))) | |
11cf4d18 JJ |
333 | { |
334 | DECL_ALIGN (decl) = TYPE_ALIGN (type); | |
335 | DECL_USER_ALIGN (decl) = TYPE_USER_ALIGN (type); | |
336 | } | |
7306ed3f | 337 | |
770ae6cc | 338 | /* For fields, set the bit field type and update the alignment. */ |
7306ed3f | 339 | if (code == FIELD_DECL) |
d4c40650 RS |
340 | { |
341 | DECL_BIT_FIELD_TYPE (decl) = DECL_BIT_FIELD (decl) ? type : 0; | |
342 | if (maximum_field_alignment != 0) | |
729a2125 | 343 | DECL_ALIGN (decl) = MIN (DECL_ALIGN (decl), maximum_field_alignment); |
3a369acd | 344 | else if (DECL_PACKED (decl)) |
11cf4d18 JJ |
345 | { |
346 | DECL_ALIGN (decl) = MIN (DECL_ALIGN (decl), BITS_PER_UNIT); | |
347 | DECL_USER_ALIGN (decl) = 0; | |
348 | } | |
d4c40650 RS |
349 | } |
350 | ||
770ae6cc RK |
351 | /* See if we can use an ordinary integer mode for a bit-field. |
352 | Conditions are: a fixed size that is correct for another mode | |
353 | and occupying a complete byte or bytes on proper boundary. */ | |
17aec3eb | 354 | if (code == FIELD_DECL && DECL_BIT_FIELD (decl) |
7306ed3f | 355 | && TYPE_SIZE (type) != 0 |
5bb3d1dd RK |
356 | && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST |
357 | && GET_MODE_CLASS (TYPE_MODE (type)) == MODE_INT) | |
7306ed3f JW |
358 | { |
359 | register enum machine_mode xmode | |
72c602fc | 360 | = mode_for_size_tree (DECL_SIZE (decl), MODE_INT, 1); |
7306ed3f | 361 | |
b1ba4cc3 | 362 | if (xmode != BLKmode && known_align >= GET_MODE_ALIGNMENT (xmode)) |
7306ed3f | 363 | { |
729a2125 | 364 | DECL_ALIGN (decl) = MAX (GET_MODE_ALIGNMENT (xmode), |
7306ed3f JW |
365 | DECL_ALIGN (decl)); |
366 | DECL_MODE (decl) = xmode; | |
7306ed3f JW |
367 | DECL_BIT_FIELD (decl) = 0; |
368 | } | |
369 | } | |
370 | ||
977a7752 | 371 | /* Turn off DECL_BIT_FIELD if we won't need it set. */ |
17aec3eb | 372 | if (code == FIELD_DECL && DECL_BIT_FIELD (decl) |
770ae6cc | 373 | && TYPE_MODE (type) == BLKmode && DECL_MODE (decl) == BLKmode |
b1ba4cc3 | 374 | && known_align >= TYPE_ALIGN (type) |
770ae6cc RK |
375 | && DECL_ALIGN (decl) >= TYPE_ALIGN (type) |
376 | && DECL_SIZE_UNIT (decl) != 0) | |
977a7752 RK |
377 | DECL_BIT_FIELD (decl) = 0; |
378 | ||
7306ed3f JW |
379 | /* Evaluate nonconstant size only once, either now or as soon as safe. */ |
380 | if (DECL_SIZE (decl) != 0 && TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST) | |
381 | DECL_SIZE (decl) = variable_size (DECL_SIZE (decl)); | |
06ceef4e RK |
382 | if (DECL_SIZE_UNIT (decl) != 0 |
383 | && TREE_CODE (DECL_SIZE_UNIT (decl)) != INTEGER_CST) | |
384 | DECL_SIZE_UNIT (decl) = variable_size (DECL_SIZE_UNIT (decl)); | |
385 | ||
386 | /* If requested, warn about definitions of large data objects. */ | |
387 | if (warn_larger_than | |
17aec3eb | 388 | && (code == VAR_DECL || code == PARM_DECL) |
06ceef4e RK |
389 | && ! DECL_EXTERNAL (decl)) |
390 | { | |
391 | tree size = DECL_SIZE_UNIT (decl); | |
392 | ||
393 | if (size != 0 && TREE_CODE (size) == INTEGER_CST | |
05bccae2 | 394 | && compare_tree_int (size, larger_than_size) > 0) |
06ceef4e | 395 | { |
05bccae2 | 396 | unsigned int size_as_int = TREE_INT_CST_LOW (size); |
06ceef4e | 397 | |
05bccae2 | 398 | if (compare_tree_int (size, size_as_int) == 0) |
06ceef4e RK |
399 | warning_with_decl (decl, "size of `%s' is %d bytes", size_as_int); |
400 | else | |
401 | warning_with_decl (decl, "size of `%s' is larger than %d bytes", | |
402 | larger_than_size); | |
403 | } | |
404 | } | |
7306ed3f JW |
405 | } |
406 | \f | |
770ae6cc RK |
407 | /* Begin laying out type T, which may be a RECORD_TYPE, UNION_TYPE, or |
408 | QUAL_UNION_TYPE. Return a pointer to a struct record_layout_info which | |
409 | is to be passed to all other layout functions for this record. It is the | |
410 | responsibility of the caller to call `free' for the storage returned. | |
411 | Note that garbage collection is not permitted until we finish laying | |
412 | out the record. */ | |
7306ed3f | 413 | |
9328904c | 414 | record_layout_info |
770ae6cc | 415 | start_record_layout (t) |
9328904c | 416 | tree t; |
7306ed3f | 417 | { |
9328904c | 418 | record_layout_info rli |
defd0dea | 419 | = (record_layout_info) xmalloc (sizeof (struct record_layout_info_s)); |
9328904c MM |
420 | |
421 | rli->t = t; | |
770ae6cc | 422 | |
9328904c MM |
423 | /* If the type has a minimum specified alignment (via an attribute |
424 | declaration, for example) use it -- otherwise, start with a | |
425 | one-byte alignment. */ | |
426 | rli->record_align = MAX (BITS_PER_UNIT, TYPE_ALIGN (t)); | |
427 | rli->unpacked_align = rli->record_align; | |
770ae6cc | 428 | rli->offset_align = MAX (rli->record_align, BIGGEST_ALIGNMENT); |
7306ed3f | 429 | |
5c19a356 MS |
430 | #ifdef STRUCTURE_SIZE_BOUNDARY |
431 | /* Packed structures don't need to have minimum size. */ | |
f132af85 | 432 | if (! TYPE_PACKED (t)) |
9328904c | 433 | rli->record_align = MAX (rli->record_align, STRUCTURE_SIZE_BOUNDARY); |
5c19a356 | 434 | #endif |
7306ed3f | 435 | |
770ae6cc RK |
436 | rli->offset = size_zero_node; |
437 | rli->bitpos = bitsize_zero_node; | |
438 | rli->pending_statics = 0; | |
439 | rli->packed_maybe_necessary = 0; | |
440 | ||
9328904c MM |
441 | return rli; |
442 | } | |
7306ed3f | 443 | |
f2704b9f RK |
444 | /* These four routines perform computations that convert between |
445 | the offset/bitpos forms and byte and bit offsets. */ | |
446 | ||
447 | tree | |
448 | bit_from_pos (offset, bitpos) | |
449 | tree offset, bitpos; | |
450 | { | |
451 | return size_binop (PLUS_EXPR, bitpos, | |
452 | size_binop (MULT_EXPR, convert (bitsizetype, offset), | |
453 | bitsize_unit_node)); | |
454 | } | |
455 | ||
456 | tree | |
457 | byte_from_pos (offset, bitpos) | |
458 | tree offset, bitpos; | |
459 | { | |
460 | return size_binop (PLUS_EXPR, offset, | |
461 | convert (sizetype, | |
f0fddb15 | 462 | size_binop (TRUNC_DIV_EXPR, bitpos, |
f2704b9f RK |
463 | bitsize_unit_node))); |
464 | } | |
465 | ||
466 | void | |
467 | pos_from_byte (poffset, pbitpos, off_align, pos) | |
468 | tree *poffset, *pbitpos; | |
469 | unsigned int off_align; | |
470 | tree pos; | |
471 | { | |
472 | *poffset | |
473 | = size_binop (MULT_EXPR, | |
474 | convert (sizetype, | |
475 | size_binop (FLOOR_DIV_EXPR, pos, | |
476 | bitsize_int (off_align | |
477 | / BITS_PER_UNIT))), | |
478 | size_int (off_align / BITS_PER_UNIT)); | |
479 | *pbitpos = size_binop (MULT_EXPR, | |
480 | size_binop (FLOOR_MOD_EXPR, pos, | |
481 | bitsize_int (off_align / BITS_PER_UNIT)), | |
482 | bitsize_unit_node); | |
483 | } | |
484 | ||
485 | void | |
486 | pos_from_bit (poffset, pbitpos, off_align, pos) | |
487 | tree *poffset, *pbitpos; | |
488 | unsigned int off_align; | |
489 | tree pos; | |
490 | { | |
491 | *poffset = size_binop (MULT_EXPR, | |
492 | convert (sizetype, | |
493 | size_binop (FLOOR_DIV_EXPR, pos, | |
494 | bitsize_int (off_align))), | |
495 | size_int (off_align / BITS_PER_UNIT)); | |
496 | *pbitpos = size_binop (FLOOR_MOD_EXPR, pos, bitsize_int (off_align)); | |
497 | } | |
498 | ||
499 | /* Given a pointer to bit and byte offsets and an offset alignment, | |
500 | normalize the offsets so they are within the alignment. */ | |
501 | ||
502 | void | |
503 | normalize_offset (poffset, pbitpos, off_align) | |
504 | tree *poffset, *pbitpos; | |
505 | unsigned int off_align; | |
506 | { | |
507 | /* If the bit position is now larger than it should be, adjust it | |
508 | downwards. */ | |
509 | if (compare_tree_int (*pbitpos, off_align) >= 0) | |
510 | { | |
511 | tree extra_aligns = size_binop (FLOOR_DIV_EXPR, *pbitpos, | |
512 | bitsize_int (off_align)); | |
513 | ||
514 | *poffset | |
515 | = size_binop (PLUS_EXPR, *poffset, | |
516 | size_binop (MULT_EXPR, convert (sizetype, extra_aligns), | |
517 | size_int (off_align / BITS_PER_UNIT))); | |
518 | ||
519 | *pbitpos | |
520 | = size_binop (FLOOR_MOD_EXPR, *pbitpos, bitsize_int (off_align)); | |
521 | } | |
522 | } | |
523 | ||
770ae6cc | 524 | /* Print debugging information about the information in RLI. */ |
cc9d4a85 | 525 | |
770ae6cc RK |
526 | void |
527 | debug_rli (rli) | |
cc9d4a85 | 528 | record_layout_info rli; |
cc9d4a85 | 529 | { |
770ae6cc RK |
530 | print_node_brief (stderr, "type", rli->t, 0); |
531 | print_node_brief (stderr, "\noffset", rli->offset, 0); | |
532 | print_node_brief (stderr, " bitpos", rli->bitpos, 0); | |
cc9d4a85 | 533 | |
770ae6cc RK |
534 | fprintf (stderr, "\nrec_align = %u, unpack_align = %u, off_align = %u\n", |
535 | rli->record_align, rli->unpacked_align, rli->offset_align); | |
536 | if (rli->packed_maybe_necessary) | |
537 | fprintf (stderr, "packed may be necessary\n"); | |
538 | ||
539 | if (rli->pending_statics) | |
540 | { | |
541 | fprintf (stderr, "pending statics:\n"); | |
542 | debug_tree (rli->pending_statics); | |
543 | } | |
544 | } | |
545 | ||
546 | /* Given an RLI with a possibly-incremented BITPOS, adjust OFFSET and | |
547 | BITPOS if necessary to keep BITPOS below OFFSET_ALIGN. */ | |
548 | ||
549 | void | |
550 | normalize_rli (rli) | |
551 | record_layout_info rli; | |
552 | { | |
f2704b9f | 553 | normalize_offset (&rli->offset, &rli->bitpos, rli->offset_align); |
770ae6cc | 554 | } |
cc9d4a85 | 555 | |
770ae6cc RK |
556 | /* Returns the size in bytes allocated so far. */ |
557 | ||
558 | tree | |
559 | rli_size_unit_so_far (rli) | |
560 | record_layout_info rli; | |
561 | { | |
f2704b9f | 562 | return byte_from_pos (rli->offset, rli->bitpos); |
770ae6cc RK |
563 | } |
564 | ||
565 | /* Returns the size in bits allocated so far. */ | |
566 | ||
567 | tree | |
568 | rli_size_so_far (rli) | |
569 | record_layout_info rli; | |
570 | { | |
f2704b9f | 571 | return bit_from_pos (rli->offset, rli->bitpos); |
770ae6cc RK |
572 | } |
573 | ||
574 | /* Called from place_field to handle unions. */ | |
575 | ||
576 | static void | |
577 | place_union_field (rli, field) | |
578 | record_layout_info rli; | |
579 | tree field; | |
580 | { | |
11cf4d18 JJ |
581 | unsigned int desired_align; |
582 | ||
cc9d4a85 | 583 | layout_decl (field, 0); |
770ae6cc RK |
584 | |
585 | DECL_FIELD_OFFSET (field) = size_zero_node; | |
586 | DECL_FIELD_BIT_OFFSET (field) = bitsize_zero_node; | |
2f5c7f45 | 587 | SET_DECL_OFFSET_ALIGN (field, BIGGEST_ALIGNMENT); |
cc9d4a85 | 588 | |
11cf4d18 JJ |
589 | desired_align = DECL_ALIGN (field); |
590 | ||
591 | #ifdef BIGGEST_FIELD_ALIGNMENT | |
592 | /* Some targets (i.e. i386) limit union field alignment | |
593 | to a lower boundary than alignment of variables unless | |
594 | it was overridden by attribute aligned. */ | |
595 | if (! DECL_USER_ALIGN (field)) | |
596 | desired_align = | |
597 | MIN (desired_align, (unsigned) BIGGEST_FIELD_ALIGNMENT); | |
598 | #endif | |
599 | ||
cc9d4a85 | 600 | /* Union must be at least as aligned as any field requires. */ |
11cf4d18 | 601 | rli->record_align = MAX (rli->record_align, desired_align); |
cc9d4a85 MM |
602 | |
603 | #ifdef PCC_BITFIELD_TYPE_MATTERS | |
604 | /* On the m88000, a bit field of declare type `int' forces the | |
605 | entire union to have `int' alignment. */ | |
606 | if (PCC_BITFIELD_TYPE_MATTERS && DECL_BIT_FIELD_TYPE (field)) | |
607 | rli->record_align = MAX (rli->record_align, | |
608 | TYPE_ALIGN (TREE_TYPE (field))); | |
609 | #endif | |
610 | ||
770ae6cc RK |
611 | /* We assume the union's size will be a multiple of a byte so we don't |
612 | bother with BITPOS. */ | |
cc9d4a85 | 613 | if (TREE_CODE (rli->t) == UNION_TYPE) |
770ae6cc | 614 | rli->offset = size_binop (MAX_EXPR, rli->offset, DECL_SIZE_UNIT (field)); |
cc9d4a85 | 615 | else if (TREE_CODE (rli->t) == QUAL_UNION_TYPE) |
770ae6cc RK |
616 | rli->offset = fold (build (COND_EXPR, sizetype, |
617 | DECL_QUALIFIER (field), | |
618 | DECL_SIZE_UNIT (field), rli->offset)); | |
cc9d4a85 MM |
619 | } |
620 | ||
9328904c MM |
621 | /* RLI contains information about the layout of a RECORD_TYPE. FIELD |
622 | is a FIELD_DECL to be added after those fields already present in | |
623 | T. (FIELD is not actually added to the TYPE_FIELDS list here; | |
624 | callers that desire that behavior must manually perform that step.) */ | |
d4b60170 | 625 | |
9328904c | 626 | void |
770ae6cc | 627 | place_field (rli, field) |
9328904c MM |
628 | record_layout_info rli; |
629 | tree field; | |
630 | { | |
631 | /* The alignment required for FIELD. */ | |
632 | unsigned int desired_align; | |
633 | /* The alignment FIELD would have if we just dropped it into the | |
634 | record as it presently stands. */ | |
635 | unsigned int known_align; | |
770ae6cc | 636 | unsigned int actual_align; |
11cf4d18 | 637 | unsigned int user_align; |
9328904c MM |
638 | /* The type of this field. */ |
639 | tree type = TREE_TYPE (field); | |
770ae6cc | 640 | |
5748b2cb RK |
641 | if (TREE_CODE (field) == ERROR_MARK || TREE_CODE (type) == ERROR_MARK) |
642 | return; | |
643 | ||
9328904c MM |
644 | /* If FIELD is static, then treat it like a separate variable, not |
645 | really like a structure field. If it is a FUNCTION_DECL, it's a | |
646 | method. In both cases, all we do is lay out the decl, and we do | |
647 | it *after* the record is laid out. */ | |
648 | if (TREE_CODE (field) == VAR_DECL) | |
649 | { | |
650 | rli->pending_statics = tree_cons (NULL_TREE, field, | |
651 | rli->pending_statics); | |
652 | return; | |
653 | } | |
770ae6cc | 654 | |
9328904c MM |
655 | /* Enumerators and enum types which are local to this class need not |
656 | be laid out. Likewise for initialized constant fields. */ | |
657 | else if (TREE_CODE (field) != FIELD_DECL) | |
658 | return; | |
770ae6cc RK |
659 | |
660 | /* Unions are laid out very differently than records, so split | |
661 | that code off to another function. */ | |
cc9d4a85 MM |
662 | else if (TREE_CODE (rli->t) != RECORD_TYPE) |
663 | { | |
770ae6cc | 664 | place_union_field (rli, field); |
cc9d4a85 MM |
665 | return; |
666 | } | |
7306ed3f | 667 | |
770ae6cc RK |
668 | /* Work out the known alignment so far. Note that A & (-A) is the |
669 | value of the least-significant bit in A that is one. */ | |
4b6bf620 | 670 | if (! integer_zerop (rli->bitpos)) |
770ae6cc RK |
671 | known_align = (tree_low_cst (rli->bitpos, 1) |
672 | & - tree_low_cst (rli->bitpos, 1)); | |
4b6bf620 RK |
673 | else if (integer_zerop (rli->offset)) |
674 | known_align = BIGGEST_ALIGNMENT; | |
770ae6cc RK |
675 | else if (host_integerp (rli->offset, 1)) |
676 | known_align = (BITS_PER_UNIT | |
677 | * (tree_low_cst (rli->offset, 1) | |
678 | & - tree_low_cst (rli->offset, 1))); | |
679 | else | |
680 | known_align = rli->offset_align; | |
9328904c MM |
681 | |
682 | /* Lay out the field so we know what alignment it needs. For a | |
683 | packed field, use the alignment as specified, disregarding what | |
684 | the type would want. */ | |
770ae6cc | 685 | desired_align = DECL_ALIGN (field); |
11cf4d18 | 686 | user_align = DECL_USER_ALIGN (field); |
9328904c MM |
687 | layout_decl (field, known_align); |
688 | if (! DECL_PACKED (field)) | |
11cf4d18 JJ |
689 | { |
690 | desired_align = DECL_ALIGN (field); | |
691 | user_align = DECL_USER_ALIGN (field); | |
692 | } | |
770ae6cc | 693 | |
7306ed3f | 694 | #ifdef BIGGEST_FIELD_ALIGNMENT |
11cf4d18 JJ |
695 | /* Some targets (i.e. i386, VMS) limit struct field alignment |
696 | to a lower boundary than alignment of variables unless | |
697 | it was overridden by attribute aligned. */ | |
698 | if (! user_align) | |
699 | desired_align = | |
700 | MIN (desired_align, (unsigned) BIGGEST_FIELD_ALIGNMENT); | |
7306ed3f | 701 | #endif |
d42d380a | 702 | #ifdef ADJUST_FIELD_ALIGN |
9328904c | 703 | desired_align = ADJUST_FIELD_ALIGN (field, desired_align); |
d42d380a | 704 | #endif |
7306ed3f | 705 | |
9328904c MM |
706 | /* Record must have at least as much alignment as any field. |
707 | Otherwise, the alignment of the field within the record is | |
708 | meaningless. */ | |
3c12fcc2 | 709 | #ifdef PCC_BITFIELD_TYPE_MATTERS |
9328904c MM |
710 | if (PCC_BITFIELD_TYPE_MATTERS && type != error_mark_node |
711 | && DECL_BIT_FIELD_TYPE (field) | |
712 | && ! integer_zerop (TYPE_SIZE (type))) | |
713 | { | |
714 | /* For these machines, a zero-length field does not | |
715 | affect the alignment of the structure as a whole. | |
716 | It does, however, affect the alignment of the next field | |
717 | within the structure. */ | |
718 | if (! integer_zerop (DECL_SIZE (field))) | |
719 | rli->record_align = MAX (rli->record_align, desired_align); | |
720 | else if (! DECL_PACKED (field)) | |
721 | desired_align = TYPE_ALIGN (type); | |
770ae6cc | 722 | |
9328904c MM |
723 | /* A named bit field of declared type `int' |
724 | forces the entire structure to have `int' alignment. */ | |
725 | if (DECL_NAME (field) != 0) | |
7306ed3f | 726 | { |
9328904c | 727 | unsigned int type_align = TYPE_ALIGN (type); |
729a2125 | 728 | |
9328904c MM |
729 | if (maximum_field_alignment != 0) |
730 | type_align = MIN (type_align, maximum_field_alignment); | |
731 | else if (DECL_PACKED (field)) | |
732 | type_align = MIN (type_align, BITS_PER_UNIT); | |
e2301a83 | 733 | |
9328904c | 734 | rli->record_align = MAX (rli->record_align, type_align); |
3c12fcc2 | 735 | if (warn_packed) |
9328904c MM |
736 | rli->unpacked_align = MAX (rli->unpacked_align, |
737 | TYPE_ALIGN (type)); | |
3c12fcc2 | 738 | } |
9328904c MM |
739 | } |
740 | else | |
741 | #endif | |
742 | { | |
743 | rli->record_align = MAX (rli->record_align, desired_align); | |
770ae6cc | 744 | rli->unpacked_align = MAX (rli->unpacked_align, TYPE_ALIGN (type)); |
9328904c | 745 | } |
3c12fcc2 | 746 | |
9328904c MM |
747 | if (warn_packed && DECL_PACKED (field)) |
748 | { | |
770ae6cc | 749 | if (known_align > TYPE_ALIGN (type)) |
3c12fcc2 | 750 | { |
9328904c | 751 | if (TYPE_ALIGN (type) > desired_align) |
3c12fcc2 | 752 | { |
9328904c MM |
753 | if (STRICT_ALIGNMENT) |
754 | warning_with_decl (field, "packed attribute causes inefficient alignment for `%s'"); | |
755 | else | |
756 | warning_with_decl (field, "packed attribute is unnecessary for `%s'"); | |
3c12fcc2 | 757 | } |
3c12fcc2 | 758 | } |
9328904c MM |
759 | else |
760 | rli->packed_maybe_necessary = 1; | |
761 | } | |
7306ed3f | 762 | |
9328904c MM |
763 | /* Does this field automatically have alignment it needs by virtue |
764 | of the fields that precede it and the record's own alignment? */ | |
770ae6cc | 765 | if (known_align < desired_align) |
9328904c MM |
766 | { |
767 | /* No, we need to skip space before this field. | |
768 | Bump the cumulative size to multiple of field alignment. */ | |
7306ed3f | 769 | |
9328904c MM |
770 | if (warn_padded) |
771 | warning_with_decl (field, "padding struct to align `%s'"); | |
3c12fcc2 | 772 | |
770ae6cc RK |
773 | /* If the alignment is still within offset_align, just align |
774 | the bit position. */ | |
775 | if (desired_align < rli->offset_align) | |
776 | rli->bitpos = round_up (rli->bitpos, desired_align); | |
9328904c MM |
777 | else |
778 | { | |
770ae6cc RK |
779 | /* First adjust OFFSET by the partial bits, then align. */ |
780 | rli->offset | |
781 | = size_binop (PLUS_EXPR, rli->offset, | |
782 | convert (sizetype, | |
783 | size_binop (CEIL_DIV_EXPR, rli->bitpos, | |
784 | bitsize_unit_node))); | |
785 | rli->bitpos = bitsize_zero_node; | |
786 | ||
787 | rli->offset = round_up (rli->offset, desired_align / BITS_PER_UNIT); | |
7306ed3f | 788 | } |
770ae6cc | 789 | |
b1254b72 RK |
790 | if (! TREE_CONSTANT (rli->offset)) |
791 | rli->offset_align = desired_align; | |
792 | ||
9328904c | 793 | } |
7306ed3f | 794 | |
770ae6cc RK |
795 | /* Handle compatibility with PCC. Note that if the record has any |
796 | variable-sized fields, we need not worry about compatibility. */ | |
7306ed3f | 797 | #ifdef PCC_BITFIELD_TYPE_MATTERS |
9328904c MM |
798 | if (PCC_BITFIELD_TYPE_MATTERS |
799 | && TREE_CODE (field) == FIELD_DECL | |
800 | && type != error_mark_node | |
770ae6cc RK |
801 | && DECL_BIT_FIELD (field) |
802 | && ! DECL_PACKED (field) | |
9328904c | 803 | && maximum_field_alignment == 0 |
770ae6cc RK |
804 | && ! integer_zerop (DECL_SIZE (field)) |
805 | && host_integerp (DECL_SIZE (field), 1) | |
806 | && host_integerp (rli->offset, 1) | |
807 | && host_integerp (TYPE_SIZE (type), 1)) | |
9328904c MM |
808 | { |
809 | unsigned int type_align = TYPE_ALIGN (type); | |
770ae6cc RK |
810 | tree dsize = DECL_SIZE (field); |
811 | HOST_WIDE_INT field_size = tree_low_cst (dsize, 1); | |
812 | HOST_WIDE_INT offset = tree_low_cst (rli->offset, 0); | |
813 | HOST_WIDE_INT bit_offset = tree_low_cst (rli->bitpos, 0); | |
9328904c MM |
814 | |
815 | /* A bit field may not span more units of alignment of its type | |
816 | than its type itself. Advance to next boundary if necessary. */ | |
770ae6cc RK |
817 | if ((((offset * BITS_PER_UNIT + bit_offset + field_size + |
818 | type_align - 1) | |
819 | / type_align) | |
820 | - (offset * BITS_PER_UNIT + bit_offset) / type_align) | |
821 | > tree_low_cst (TYPE_SIZE (type), 1) / type_align) | |
822 | rli->bitpos = round_up (rli->bitpos, type_align); | |
9328904c | 823 | } |
7306ed3f JW |
824 | #endif |
825 | ||
7306ed3f | 826 | #ifdef BITFIELD_NBYTES_LIMITED |
9328904c MM |
827 | if (BITFIELD_NBYTES_LIMITED |
828 | && TREE_CODE (field) == FIELD_DECL | |
829 | && type != error_mark_node | |
830 | && DECL_BIT_FIELD_TYPE (field) | |
770ae6cc RK |
831 | && ! DECL_PACKED (field) |
832 | && ! integer_zerop (DECL_SIZE (field)) | |
833 | && host_integerp (DECL_SIZE (field), 1) | |
163d3408 | 834 | && host_integerp (rli->offset, 1) |
770ae6cc | 835 | && host_integerp (TYPE_SIZE (type), 1)) |
9328904c MM |
836 | { |
837 | unsigned int type_align = TYPE_ALIGN (type); | |
770ae6cc RK |
838 | tree dsize = DECL_SIZE (field); |
839 | HOST_WIDE_INT field_size = tree_low_cst (dsize, 1); | |
840 | HOST_WIDE_INT offset = tree_low_cst (rli->offset, 0); | |
841 | HOST_WIDE_INT bit_offset = tree_low_cst (rli->bitpos, 0); | |
e2301a83 | 842 | |
9328904c MM |
843 | if (maximum_field_alignment != 0) |
844 | type_align = MIN (type_align, maximum_field_alignment); | |
845 | /* ??? This test is opposite the test in the containing if | |
846 | statement, so this code is unreachable currently. */ | |
847 | else if (DECL_PACKED (field)) | |
848 | type_align = MIN (type_align, BITS_PER_UNIT); | |
849 | ||
850 | /* A bit field may not span the unit of alignment of its type. | |
851 | Advance to next boundary if necessary. */ | |
852 | /* ??? This code should match the code above for the | |
853 | PCC_BITFIELD_TYPE_MATTERS case. */ | |
770ae6cc RK |
854 | if ((offset * BITS_PER_UNIT + bit_offset) / type_align |
855 | != ((offset * BITS_PER_UNIT + bit_offset + field_size - 1) | |
856 | / type_align)) | |
857 | rli->bitpos = round_up (rli->bitpos, type_align); | |
9328904c | 858 | } |
7306ed3f JW |
859 | #endif |
860 | ||
770ae6cc RK |
861 | /* Offset so far becomes the position of this field after normalizing. */ |
862 | normalize_rli (rli); | |
863 | DECL_FIELD_OFFSET (field) = rli->offset; | |
864 | DECL_FIELD_BIT_OFFSET (field) = rli->bitpos; | |
2f5c7f45 | 865 | SET_DECL_OFFSET_ALIGN (field, rli->offset_align); |
770ae6cc RK |
866 | |
867 | /* If this field ended up more aligned than we thought it would be (we | |
868 | approximate this by seeing if its position changed), lay out the field | |
869 | again; perhaps we can use an integral mode for it now. */ | |
4b6bf620 | 870 | if (! integer_zerop (DECL_FIELD_BIT_OFFSET (field))) |
770ae6cc RK |
871 | actual_align = (tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1) |
872 | & - tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1)); | |
4b6bf620 RK |
873 | else if (integer_zerop (DECL_FIELD_OFFSET (field))) |
874 | actual_align = BIGGEST_ALIGNMENT; | |
770ae6cc RK |
875 | else if (host_integerp (DECL_FIELD_OFFSET (field), 1)) |
876 | actual_align = (BITS_PER_UNIT | |
877 | * (tree_low_cst (DECL_FIELD_OFFSET (field), 1) | |
878 | & - tree_low_cst (DECL_FIELD_OFFSET (field), 1))); | |
9328904c | 879 | else |
770ae6cc RK |
880 | actual_align = DECL_OFFSET_ALIGN (field); |
881 | ||
882 | if (known_align != actual_align) | |
883 | layout_decl (field, actual_align); | |
884 | ||
885 | /* Now add size of this field to the size of the record. If the size is | |
886 | not constant, treat the field as being a multiple of bytes and just | |
887 | adjust the offset, resetting the bit position. Otherwise, apportion the | |
888 | size amongst the bit position and offset. First handle the case of an | |
889 | unspecified size, which can happen when we have an invalid nested struct | |
890 | definition, such as struct j { struct j { int i; } }. The error message | |
891 | is printed in finish_struct. */ | |
892 | if (DECL_SIZE (field) == 0) | |
893 | /* Do nothing. */; | |
894 | else if (! TREE_CONSTANT (DECL_SIZE_UNIT (field))) | |
9328904c | 895 | { |
770ae6cc RK |
896 | rli->offset |
897 | = size_binop (PLUS_EXPR, rli->offset, | |
898 | convert (sizetype, | |
899 | size_binop (CEIL_DIV_EXPR, rli->bitpos, | |
900 | bitsize_unit_node))); | |
901 | rli->offset | |
902 | = size_binop (PLUS_EXPR, rli->offset, DECL_SIZE_UNIT (field)); | |
903 | rli->bitpos = bitsize_zero_node; | |
b1254b72 | 904 | rli->offset_align = MIN (rli->offset_align, DECL_ALIGN (field)); |
9328904c | 905 | } |
9328904c MM |
906 | else |
907 | { | |
770ae6cc RK |
908 | rli->bitpos = size_binop (PLUS_EXPR, rli->bitpos, DECL_SIZE (field)); |
909 | normalize_rli (rli); | |
7306ed3f | 910 | } |
9328904c | 911 | } |
7306ed3f | 912 | |
9328904c MM |
913 | /* Assuming that all the fields have been laid out, this function uses |
914 | RLI to compute the final TYPE_SIZE, TYPE_ALIGN, etc. for the type | |
915 | inidicated by RLI. */ | |
7306ed3f | 916 | |
9328904c MM |
917 | static void |
918 | finalize_record_size (rli) | |
919 | record_layout_info rli; | |
920 | { | |
770ae6cc RK |
921 | tree unpadded_size, unpadded_size_unit; |
922 | ||
65e14bf5 RK |
923 | /* Now we want just byte and bit offsets, so set the offset alignment |
924 | to be a byte and then normalize. */ | |
925 | rli->offset_align = BITS_PER_UNIT; | |
926 | normalize_rli (rli); | |
7306ed3f JW |
927 | |
928 | /* Determine the desired alignment. */ | |
929 | #ifdef ROUND_TYPE_ALIGN | |
9328904c | 930 | TYPE_ALIGN (rli->t) = ROUND_TYPE_ALIGN (rli->t, TYPE_ALIGN (rli->t), |
b451555a | 931 | rli->record_align); |
7306ed3f | 932 | #else |
9328904c | 933 | TYPE_ALIGN (rli->t) = MAX (TYPE_ALIGN (rli->t), rli->record_align); |
7306ed3f | 934 | #endif |
11cf4d18 | 935 | TYPE_USER_ALIGN (rli->t) = 1; |
7306ed3f | 936 | |
65e14bf5 RK |
937 | /* Compute the size so far. Be sure to allow for extra bits in the |
938 | size in bytes. We have guaranteed above that it will be no more | |
939 | than a single byte. */ | |
940 | unpadded_size = rli_size_so_far (rli); | |
941 | unpadded_size_unit = rli_size_unit_so_far (rli); | |
942 | if (! integer_zerop (rli->bitpos)) | |
943 | unpadded_size_unit | |
944 | = size_binop (PLUS_EXPR, unpadded_size_unit, size_one_node); | |
770ae6cc | 945 | |
bbc0e641 JM |
946 | /* Record the un-rounded size in the binfo node. But first we check |
947 | the size of TYPE_BINFO to make sure that BINFO_SIZE is available. */ | |
9328904c | 948 | if (TYPE_BINFO (rli->t) && TREE_VEC_LENGTH (TYPE_BINFO (rli->t)) > 6) |
06ceef4e | 949 | { |
770ae6cc RK |
950 | TYPE_BINFO_SIZE (rli->t) = unpadded_size; |
951 | TYPE_BINFO_SIZE_UNIT (rli->t) = unpadded_size_unit; | |
06ceef4e | 952 | } |
729a2125 | 953 | |
770ae6cc | 954 | /* Round the size up to be a multiple of the required alignment */ |
7306ed3f | 955 | #ifdef ROUND_TYPE_SIZE |
770ae6cc RK |
956 | TYPE_SIZE (rli->t) = ROUND_TYPE_SIZE (rli->t, unpadded_size, |
957 | TYPE_ALIGN (rli->t)); | |
958 | TYPE_SIZE_UNIT (rli->t) | |
c5daf9c4 | 959 | = ROUND_TYPE_SIZE_UNIT (rli->t, unpadded_size_unit, |
770ae6cc | 960 | TYPE_ALIGN (rli->t) / BITS_PER_UNIT); |
7306ed3f | 961 | #else |
770ae6cc RK |
962 | TYPE_SIZE (rli->t) = round_up (unpadded_size, TYPE_ALIGN (rli->t)); |
963 | TYPE_SIZE_UNIT (rli->t) = round_up (unpadded_size_unit, | |
964 | TYPE_ALIGN (rli->t) / BITS_PER_UNIT); | |
7306ed3f | 965 | #endif |
729a2125 | 966 | |
770ae6cc RK |
967 | if (warn_padded && TREE_CONSTANT (unpadded_size) |
968 | && simple_cst_equal (unpadded_size, TYPE_SIZE (rli->t)) == 0) | |
969 | warning ("padding struct size to alignment boundary"); | |
3c12fcc2 | 970 | |
770ae6cc RK |
971 | if (warn_packed && TREE_CODE (rli->t) == RECORD_TYPE |
972 | && TYPE_PACKED (rli->t) && ! rli->packed_maybe_necessary | |
973 | && TREE_CONSTANT (unpadded_size)) | |
3c12fcc2 GM |
974 | { |
975 | tree unpacked_size; | |
729a2125 | 976 | |
3c12fcc2 | 977 | #ifdef ROUND_TYPE_ALIGN |
9328904c MM |
978 | rli->unpacked_align |
979 | = ROUND_TYPE_ALIGN (rli->t, TYPE_ALIGN (rli->t), rli->unpacked_align); | |
3c12fcc2 | 980 | #else |
9328904c | 981 | rli->unpacked_align = MAX (TYPE_ALIGN (rli->t), rli->unpacked_align); |
3c12fcc2 | 982 | #endif |
770ae6cc | 983 | |
3c12fcc2 | 984 | #ifdef ROUND_TYPE_SIZE |
9328904c MM |
985 | unpacked_size = ROUND_TYPE_SIZE (rli->t, TYPE_SIZE (rli->t), |
986 | rli->unpacked_align); | |
3c12fcc2 | 987 | #else |
9328904c | 988 | unpacked_size = round_up (TYPE_SIZE (rli->t), rli->unpacked_align); |
3c12fcc2 | 989 | #endif |
729a2125 | 990 | |
9328904c | 991 | if (simple_cst_equal (unpacked_size, TYPE_SIZE (rli->t))) |
3c12fcc2 | 992 | { |
770ae6cc RK |
993 | TYPE_PACKED (rli->t) = 0; |
994 | ||
9328904c | 995 | if (TYPE_NAME (rli->t)) |
3c12fcc2 | 996 | { |
63ad61ed | 997 | const char *name; |
729a2125 | 998 | |
9328904c MM |
999 | if (TREE_CODE (TYPE_NAME (rli->t)) == IDENTIFIER_NODE) |
1000 | name = IDENTIFIER_POINTER (TYPE_NAME (rli->t)); | |
3c12fcc2 | 1001 | else |
9328904c | 1002 | name = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (rli->t))); |
770ae6cc | 1003 | |
3c12fcc2 GM |
1004 | if (STRICT_ALIGNMENT) |
1005 | warning ("packed attribute causes inefficient alignment for `%s'", name); | |
1006 | else | |
1007 | warning ("packed attribute is unnecessary for `%s'", name); | |
1008 | } | |
1009 | else | |
1010 | { | |
1011 | if (STRICT_ALIGNMENT) | |
1012 | warning ("packed attribute causes inefficient alignment"); | |
1013 | else | |
1014 | warning ("packed attribute is unnecessary"); | |
1015 | } | |
1016 | } | |
3c12fcc2 | 1017 | } |
9328904c MM |
1018 | } |
1019 | ||
1020 | /* Compute the TYPE_MODE for the TYPE (which is a RECORD_TYPE). */ | |
7306ed3f | 1021 | |
65e14bf5 | 1022 | void |
9328904c MM |
1023 | compute_record_mode (type) |
1024 | tree type; | |
1025 | { | |
770ae6cc RK |
1026 | tree field; |
1027 | enum machine_mode mode = VOIDmode; | |
1028 | ||
9328904c MM |
1029 | /* Most RECORD_TYPEs have BLKmode, so we start off assuming that. |
1030 | However, if possible, we use a mode that fits in a register | |
1031 | instead, in order to allow for better optimization down the | |
1032 | line. */ | |
1033 | TYPE_MODE (type) = BLKmode; | |
9328904c | 1034 | |
770ae6cc RK |
1035 | if (! host_integerp (TYPE_SIZE (type), 1)) |
1036 | return; | |
9328904c | 1037 | |
770ae6cc RK |
1038 | /* A record which has any BLKmode members must itself be |
1039 | BLKmode; it can't go in a register. Unless the member is | |
1040 | BLKmode only because it isn't aligned. */ | |
1041 | for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) | |
1042 | { | |
1043 | unsigned HOST_WIDE_INT bitpos; | |
9328904c | 1044 | |
770ae6cc RK |
1045 | if (TREE_CODE (field) != FIELD_DECL) |
1046 | continue; | |
9328904c | 1047 | |
770ae6cc RK |
1048 | if (TREE_CODE (TREE_TYPE (field)) == ERROR_MARK |
1049 | || (TYPE_MODE (TREE_TYPE (field)) == BLKmode | |
1050 | && ! TYPE_NO_FORCE_BLK (TREE_TYPE (field))) | |
1051 | || ! host_integerp (bit_position (field), 1) | |
1052 | || ! host_integerp (DECL_SIZE (field), 1)) | |
1053 | return; | |
1054 | ||
1055 | bitpos = int_bit_position (field); | |
1056 | ||
1057 | /* Must be BLKmode if any field crosses a word boundary, | |
1058 | since extract_bit_field can't handle that in registers. */ | |
1059 | if (bitpos / BITS_PER_WORD | |
1060 | != ((TREE_INT_CST_LOW (DECL_SIZE (field)) + bitpos - 1) | |
1061 | / BITS_PER_WORD) | |
1062 | /* But there is no problem if the field is entire words. */ | |
1063 | && tree_low_cst (DECL_SIZE (field), 1) % BITS_PER_WORD != 0) | |
1064 | return; | |
1065 | ||
1066 | /* If this field is the whole struct, remember its mode so | |
1067 | that, say, we can put a double in a class into a DF | |
7d2950e5 RK |
1068 | register instead of forcing it to live in the stack. However, |
1069 | we don't support using such a mode if there is no integer mode | |
1070 | of the same size, so don't set it here. */ | |
1071 | if (field == TYPE_FIELDS (type) && TREE_CHAIN (field) == 0 | |
1072 | && int_mode_for_mode (DECL_MODE (field)) != BLKmode) | |
770ae6cc | 1073 | mode = DECL_MODE (field); |
9328904c MM |
1074 | |
1075 | #ifdef STRUCT_FORCE_BLK | |
770ae6cc RK |
1076 | /* With some targets, eg. c4x, it is sub-optimal |
1077 | to access an aligned BLKmode structure as a scalar. */ | |
1078 | if (mode == VOIDmode && STRUCT_FORCE_BLK (field)) | |
1079 | return; | |
9328904c | 1080 | #endif /* STRUCT_FORCE_BLK */ |
770ae6cc | 1081 | } |
9328904c | 1082 | |
770ae6cc RK |
1083 | if (mode != VOIDmode) |
1084 | /* We only have one real field; use its mode. */ | |
1085 | TYPE_MODE (type) = mode; | |
1086 | else | |
1087 | TYPE_MODE (type) = mode_for_size_tree (TYPE_SIZE (type), MODE_INT, 1); | |
1088 | ||
1089 | /* If structure's known alignment is less than what the scalar | |
1090 | mode would need, and it matters, then stick with BLKmode. */ | |
1091 | if (TYPE_MODE (type) != BLKmode | |
1092 | && STRICT_ALIGNMENT | |
1093 | && ! (TYPE_ALIGN (type) >= BIGGEST_ALIGNMENT | |
1094 | || TYPE_ALIGN (type) >= GET_MODE_ALIGNMENT (TYPE_MODE (type)))) | |
1095 | { | |
1096 | /* If this is the only reason this type is BLKmode, then | |
1097 | don't force containing types to be BLKmode. */ | |
1098 | TYPE_NO_FORCE_BLK (type) = 1; | |
1099 | TYPE_MODE (type) = BLKmode; | |
9328904c | 1100 | } |
7306ed3f | 1101 | } |
9328904c MM |
1102 | |
1103 | /* Compute TYPE_SIZE and TYPE_ALIGN for TYPE, once it has been laid | |
1104 | out. */ | |
1105 | ||
1106 | static void | |
1107 | finalize_type_size (type) | |
1108 | tree type; | |
1109 | { | |
1110 | /* Normally, use the alignment corresponding to the mode chosen. | |
1111 | However, where strict alignment is not required, avoid | |
1112 | over-aligning structures, since most compilers do not do this | |
1113 | alignment. */ | |
1114 | ||
1115 | if (TYPE_MODE (type) != BLKmode && TYPE_MODE (type) != VOIDmode | |
1116 | && (STRICT_ALIGNMENT | |
1117 | || (TREE_CODE (type) != RECORD_TYPE && TREE_CODE (type) != UNION_TYPE | |
1118 | && TREE_CODE (type) != QUAL_UNION_TYPE | |
1119 | && TREE_CODE (type) != ARRAY_TYPE))) | |
11cf4d18 JJ |
1120 | { |
1121 | TYPE_ALIGN (type) = GET_MODE_ALIGNMENT (TYPE_MODE (type)); | |
1122 | TYPE_USER_ALIGN (type) = 0; | |
1123 | } | |
9328904c MM |
1124 | |
1125 | /* Do machine-dependent extra alignment. */ | |
1126 | #ifdef ROUND_TYPE_ALIGN | |
1127 | TYPE_ALIGN (type) | |
1128 | = ROUND_TYPE_ALIGN (type, TYPE_ALIGN (type), BITS_PER_UNIT); | |
1129 | #endif | |
1130 | ||
9328904c | 1131 | /* If we failed to find a simple way to calculate the unit size |
770ae6cc | 1132 | of the type, find it by division. */ |
9328904c MM |
1133 | if (TYPE_SIZE_UNIT (type) == 0 && TYPE_SIZE (type) != 0) |
1134 | /* TYPE_SIZE (type) is computed in bitsizetype. After the division, the | |
1135 | result will fit in sizetype. We will get more efficient code using | |
1136 | sizetype, so we force a conversion. */ | |
1137 | TYPE_SIZE_UNIT (type) | |
1138 | = convert (sizetype, | |
1139 | size_binop (FLOOR_DIV_EXPR, TYPE_SIZE (type), | |
770ae6cc | 1140 | bitsize_unit_node)); |
9328904c | 1141 | |
770ae6cc RK |
1142 | if (TYPE_SIZE (type) != 0) |
1143 | { | |
1144 | #ifdef ROUND_TYPE_SIZE | |
1145 | TYPE_SIZE (type) | |
1146 | = ROUND_TYPE_SIZE (type, TYPE_SIZE (type), TYPE_ALIGN (type)); | |
1147 | TYPE_SIZE_UNIT (type) | |
1148 | = ROUND_TYPE_SIZE_UNIT (type, TYPE_SIZE_UNIT (type), | |
1149 | TYPE_ALIGN (type) / BITS_PER_UNIT); | |
1150 | #else | |
1151 | TYPE_SIZE (type) = round_up (TYPE_SIZE (type), TYPE_ALIGN (type)); | |
1152 | TYPE_SIZE_UNIT (type) | |
1153 | = round_up (TYPE_SIZE_UNIT (type), TYPE_ALIGN (type) / BITS_PER_UNIT); | |
1154 | #endif | |
1155 | } | |
1156 | ||
1157 | /* Evaluate nonconstant sizes only once, either now or as soon as safe. */ | |
1158 | if (TYPE_SIZE (type) != 0 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) | |
1159 | TYPE_SIZE (type) = variable_size (TYPE_SIZE (type)); | |
9328904c MM |
1160 | if (TYPE_SIZE_UNIT (type) != 0 |
1161 | && TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST) | |
1162 | TYPE_SIZE_UNIT (type) = variable_size (TYPE_SIZE_UNIT (type)); | |
1163 | ||
1164 | /* Also layout any other variants of the type. */ | |
1165 | if (TYPE_NEXT_VARIANT (type) | |
1166 | || type != TYPE_MAIN_VARIANT (type)) | |
1167 | { | |
1168 | tree variant; | |
1169 | /* Record layout info of this variant. */ | |
1170 | tree size = TYPE_SIZE (type); | |
1171 | tree size_unit = TYPE_SIZE_UNIT (type); | |
1172 | unsigned int align = TYPE_ALIGN (type); | |
11cf4d18 | 1173 | unsigned int user_align = TYPE_USER_ALIGN (type); |
9328904c MM |
1174 | enum machine_mode mode = TYPE_MODE (type); |
1175 | ||
1176 | /* Copy it into all variants. */ | |
1177 | for (variant = TYPE_MAIN_VARIANT (type); | |
1178 | variant != 0; | |
1179 | variant = TYPE_NEXT_VARIANT (variant)) | |
1180 | { | |
1181 | TYPE_SIZE (variant) = size; | |
1182 | TYPE_SIZE_UNIT (variant) = size_unit; | |
1183 | TYPE_ALIGN (variant) = align; | |
11cf4d18 | 1184 | TYPE_USER_ALIGN (variant) = user_align; |
9328904c MM |
1185 | TYPE_MODE (variant) = mode; |
1186 | } | |
1187 | } | |
1188 | } | |
1189 | ||
1190 | /* Do all of the work required to layout the type indicated by RLI, | |
1191 | once the fields have been laid out. This function will call `free' | |
1192 | for RLI. */ | |
1193 | ||
1194 | void | |
1195 | finish_record_layout (rli) | |
1196 | record_layout_info rli; | |
1197 | { | |
770ae6cc RK |
1198 | /* Compute the final size. */ |
1199 | finalize_record_size (rli); | |
1200 | ||
1201 | /* Compute the TYPE_MODE for the record. */ | |
1202 | compute_record_mode (rli->t); | |
cc9d4a85 | 1203 | |
8d8238b6 JM |
1204 | /* Perform any last tweaks to the TYPE_SIZE, etc. */ |
1205 | finalize_type_size (rli->t); | |
1206 | ||
9328904c MM |
1207 | /* Lay out any static members. This is done now because their type |
1208 | may use the record's type. */ | |
1209 | while (rli->pending_statics) | |
1210 | { | |
1211 | layout_decl (TREE_VALUE (rli->pending_statics), 0); | |
1212 | rli->pending_statics = TREE_CHAIN (rli->pending_statics); | |
1213 | } | |
cc9d4a85 | 1214 | |
9328904c MM |
1215 | /* Clean up. */ |
1216 | free (rli); | |
1217 | } | |
7306ed3f JW |
1218 | \f |
1219 | /* Calculate the mode, size, and alignment for TYPE. | |
1220 | For an array type, calculate the element separation as well. | |
1221 | Record TYPE on the chain of permanent or temporary types | |
1222 | so that dbxout will find out about it. | |
1223 | ||
1224 | TYPE_SIZE of a type is nonzero if the type has been laid out already. | |
1225 | layout_type does nothing on such a type. | |
1226 | ||
1227 | If the type is incomplete, its TYPE_SIZE remains zero. */ | |
1228 | ||
1229 | void | |
1230 | layout_type (type) | |
1231 | tree type; | |
1232 | { | |
7306ed3f JW |
1233 | if (type == 0) |
1234 | abort (); | |
1235 | ||
1236 | /* Do nothing if type has been laid out before. */ | |
1237 | if (TYPE_SIZE (type)) | |
1238 | return; | |
1239 | ||
7306ed3f JW |
1240 | switch (TREE_CODE (type)) |
1241 | { | |
1242 | case LANG_TYPE: | |
1243 | /* This kind of type is the responsibility | |
9faa82d8 | 1244 | of the language-specific code. */ |
7306ed3f JW |
1245 | abort (); |
1246 | ||
e9a25f70 JL |
1247 | case BOOLEAN_TYPE: /* Used for Java, Pascal, and Chill. */ |
1248 | if (TYPE_PRECISION (type) == 0) | |
1249 | TYPE_PRECISION (type) = 1; /* default to one byte/boolean. */ | |
d4b60170 | 1250 | |
e9a25f70 JL |
1251 | /* ... fall through ... */ |
1252 | ||
7306ed3f JW |
1253 | case INTEGER_TYPE: |
1254 | case ENUMERAL_TYPE: | |
fc69eca0 | 1255 | case CHAR_TYPE: |
e2a77f99 RK |
1256 | if (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST |
1257 | && tree_int_cst_sgn (TYPE_MIN_VALUE (type)) >= 0) | |
7306ed3f JW |
1258 | TREE_UNSIGNED (type) = 1; |
1259 | ||
5e9bec99 RK |
1260 | TYPE_MODE (type) = smallest_mode_for_size (TYPE_PRECISION (type), |
1261 | MODE_INT); | |
06ceef4e | 1262 | TYPE_SIZE (type) = bitsize_int (GET_MODE_BITSIZE (TYPE_MODE (type))); |
ead17059 | 1263 | TYPE_SIZE_UNIT (type) = size_int (GET_MODE_SIZE (TYPE_MODE (type))); |
7306ed3f JW |
1264 | break; |
1265 | ||
1266 | case REAL_TYPE: | |
1267 | TYPE_MODE (type) = mode_for_size (TYPE_PRECISION (type), MODE_FLOAT, 0); | |
06ceef4e | 1268 | TYPE_SIZE (type) = bitsize_int (GET_MODE_BITSIZE (TYPE_MODE (type))); |
ead17059 | 1269 | TYPE_SIZE_UNIT (type) = size_int (GET_MODE_SIZE (TYPE_MODE (type))); |
7306ed3f JW |
1270 | break; |
1271 | ||
1272 | case COMPLEX_TYPE: | |
1273 | TREE_UNSIGNED (type) = TREE_UNSIGNED (TREE_TYPE (type)); | |
1274 | TYPE_MODE (type) | |
1275 | = mode_for_size (2 * TYPE_PRECISION (TREE_TYPE (type)), | |
1276 | (TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE | |
1277 | ? MODE_COMPLEX_INT : MODE_COMPLEX_FLOAT), | |
1278 | 0); | |
06ceef4e | 1279 | TYPE_SIZE (type) = bitsize_int (GET_MODE_BITSIZE (TYPE_MODE (type))); |
ead17059 | 1280 | TYPE_SIZE_UNIT (type) = size_int (GET_MODE_SIZE (TYPE_MODE (type))); |
7306ed3f JW |
1281 | break; |
1282 | ||
0b4565c9 BS |
1283 | case VECTOR_TYPE: |
1284 | { | |
1285 | tree subtype; | |
1286 | ||
1287 | subtype = TREE_TYPE (type); | |
1288 | TREE_UNSIGNED (type) = TREE_UNSIGNED (subtype); | |
1289 | TYPE_SIZE (type) = bitsize_int (GET_MODE_BITSIZE (TYPE_MODE (type))); | |
1290 | TYPE_SIZE_UNIT (type) = size_int (GET_MODE_SIZE (TYPE_MODE (type))); | |
1291 | } | |
1292 | break; | |
1293 | ||
7306ed3f | 1294 | case VOID_TYPE: |
770ae6cc | 1295 | /* This is an incomplete type and so doesn't have a size. */ |
7306ed3f | 1296 | TYPE_ALIGN (type) = 1; |
11cf4d18 | 1297 | TYPE_USER_ALIGN (type) = 0; |
7306ed3f JW |
1298 | TYPE_MODE (type) = VOIDmode; |
1299 | break; | |
1300 | ||
321cb743 | 1301 | case OFFSET_TYPE: |
06ceef4e | 1302 | TYPE_SIZE (type) = bitsize_int (POINTER_SIZE); |
ead17059 | 1303 | TYPE_SIZE_UNIT (type) = size_int (POINTER_SIZE / BITS_PER_UNIT); |
9fe0563a | 1304 | TYPE_MODE (type) = ptr_mode; |
321cb743 MT |
1305 | break; |
1306 | ||
7306ed3f JW |
1307 | case FUNCTION_TYPE: |
1308 | case METHOD_TYPE: | |
13275056 | 1309 | TYPE_MODE (type) = mode_for_size (2 * POINTER_SIZE, MODE_INT, 0); |
06ceef4e | 1310 | TYPE_SIZE (type) = bitsize_int (2 * POINTER_SIZE); |
ead17059 | 1311 | TYPE_SIZE_UNIT (type) = size_int ((2 * POINTER_SIZE) / BITS_PER_UNIT); |
7306ed3f JW |
1312 | break; |
1313 | ||
1314 | case POINTER_TYPE: | |
1315 | case REFERENCE_TYPE: | |
9fe0563a | 1316 | TYPE_MODE (type) = ptr_mode; |
06ceef4e | 1317 | TYPE_SIZE (type) = bitsize_int (POINTER_SIZE); |
ead17059 | 1318 | TYPE_SIZE_UNIT (type) = size_int (POINTER_SIZE / BITS_PER_UNIT); |
7306ed3f | 1319 | TREE_UNSIGNED (type) = 1; |
13275056 | 1320 | TYPE_PRECISION (type) = POINTER_SIZE; |
7306ed3f JW |
1321 | break; |
1322 | ||
1323 | case ARRAY_TYPE: | |
1324 | { | |
1325 | register tree index = TYPE_DOMAIN (type); | |
1326 | register tree element = TREE_TYPE (type); | |
1327 | ||
1328 | build_pointer_type (element); | |
1329 | ||
1330 | /* We need to know both bounds in order to compute the size. */ | |
1331 | if (index && TYPE_MAX_VALUE (index) && TYPE_MIN_VALUE (index) | |
1332 | && TYPE_SIZE (element)) | |
1333 | { | |
e24ff973 RK |
1334 | tree ub = TYPE_MAX_VALUE (index); |
1335 | tree lb = TYPE_MIN_VALUE (index); | |
1336 | tree length; | |
74a4fbfc | 1337 | tree element_size; |
e24ff973 RK |
1338 | |
1339 | /* If UB is max (lb - 1, x), remove the MAX_EXPR since the | |
1340 | test for negative below covers it. */ | |
1341 | if (TREE_CODE (ub) == MAX_EXPR | |
1342 | && TREE_CODE (TREE_OPERAND (ub, 0)) == MINUS_EXPR | |
1343 | && integer_onep (TREE_OPERAND (TREE_OPERAND (ub, 0), 1)) | |
1344 | && operand_equal_p (TREE_OPERAND (TREE_OPERAND (ub, 0), 0), | |
1345 | lb, 0)) | |
1346 | ub = TREE_OPERAND (ub, 1); | |
1347 | else if (TREE_CODE (ub) == MAX_EXPR | |
1348 | && TREE_CODE (TREE_OPERAND (ub, 1)) == MINUS_EXPR | |
1349 | && integer_onep (TREE_OPERAND (TREE_OPERAND (ub, 1), 1)) | |
1350 | && operand_equal_p (TREE_OPERAND (TREE_OPERAND (ub, 1), | |
1351 | 0), | |
1352 | lb, 0)) | |
1353 | ub = TREE_OPERAND (ub, 0); | |
1354 | ||
a2d53b28 RH |
1355 | /* The initial subtraction should happen in the original type so |
1356 | that (possible) negative values are handled appropriately. */ | |
e24ff973 | 1357 | length = size_binop (PLUS_EXPR, size_one_node, |
fed3cef0 RK |
1358 | convert (sizetype, |
1359 | fold (build (MINUS_EXPR, | |
1360 | TREE_TYPE (lb), | |
1361 | ub, lb)))); | |
7306ed3f | 1362 | |
36427b78 RK |
1363 | /* If neither bound is a constant and sizetype is signed, make |
1364 | sure the size is never negative. We should really do this | |
1365 | if *either* bound is non-constant, but this is the best | |
1366 | compromise between C and Ada. */ | |
1367 | if (! TREE_UNSIGNED (sizetype) | |
1368 | && TREE_CODE (TYPE_MIN_VALUE (index)) != INTEGER_CST | |
1369 | && TREE_CODE (TYPE_MAX_VALUE (index)) != INTEGER_CST) | |
1370 | length = size_binop (MAX_EXPR, length, size_zero_node); | |
1371 | ||
74a4fbfc DB |
1372 | /* Special handling for arrays of bits (for Chill). */ |
1373 | element_size = TYPE_SIZE (element); | |
1374 | if (TYPE_PACKED (type) && INTEGRAL_TYPE_P (element)) | |
1375 | { | |
d4b60170 RK |
1376 | HOST_WIDE_INT maxvalue |
1377 | = TREE_INT_CST_LOW (TYPE_MAX_VALUE (element)); | |
1378 | HOST_WIDE_INT minvalue | |
1379 | = TREE_INT_CST_LOW (TYPE_MIN_VALUE (element)); | |
1380 | ||
74a4fbfc DB |
1381 | if (maxvalue - minvalue == 1 |
1382 | && (maxvalue == 1 || maxvalue == 0)) | |
1383 | element_size = integer_one_node; | |
1384 | } | |
1385 | ||
fed3cef0 RK |
1386 | TYPE_SIZE (type) = size_binop (MULT_EXPR, element_size, |
1387 | convert (bitsizetype, length)); | |
ead17059 RH |
1388 | |
1389 | /* If we know the size of the element, calculate the total | |
1390 | size directly, rather than do some division thing below. | |
1391 | This optimization helps Fortran assumed-size arrays | |
1392 | (where the size of the array is determined at runtime) | |
7771032e DB |
1393 | substantially. |
1394 | Note that we can't do this in the case where the size of | |
1395 | the elements is one bit since TYPE_SIZE_UNIT cannot be | |
1396 | set correctly in that case. */ | |
fed3cef0 | 1397 | if (TYPE_SIZE_UNIT (element) != 0 && ! integer_onep (element_size)) |
d4b60170 RK |
1398 | TYPE_SIZE_UNIT (type) |
1399 | = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (element), length); | |
7306ed3f JW |
1400 | } |
1401 | ||
1402 | /* Now round the alignment and size, | |
1403 | using machine-dependent criteria if any. */ | |
1404 | ||
1405 | #ifdef ROUND_TYPE_ALIGN | |
1406 | TYPE_ALIGN (type) | |
1407 | = ROUND_TYPE_ALIGN (type, TYPE_ALIGN (element), BITS_PER_UNIT); | |
1408 | #else | |
1409 | TYPE_ALIGN (type) = MAX (TYPE_ALIGN (element), BITS_PER_UNIT); | |
1410 | #endif | |
1411 | ||
1412 | #ifdef ROUND_TYPE_SIZE | |
1413 | if (TYPE_SIZE (type) != 0) | |
ead17059 | 1414 | { |
d4b60170 RK |
1415 | tree tmp |
1416 | = ROUND_TYPE_SIZE (type, TYPE_SIZE (type), TYPE_ALIGN (type)); | |
1417 | ||
ead17059 RH |
1418 | /* If the rounding changed the size of the type, remove any |
1419 | pre-calculated TYPE_SIZE_UNIT. */ | |
1420 | if (simple_cst_equal (TYPE_SIZE (type), tmp) != 1) | |
1421 | TYPE_SIZE_UNIT (type) = NULL; | |
d4b60170 | 1422 | |
ead17059 RH |
1423 | TYPE_SIZE (type) = tmp; |
1424 | } | |
7306ed3f JW |
1425 | #endif |
1426 | ||
1427 | TYPE_MODE (type) = BLKmode; | |
1428 | if (TYPE_SIZE (type) != 0 | |
7306ed3f JW |
1429 | /* BLKmode elements force BLKmode aggregate; |
1430 | else extract/store fields may lose. */ | |
1431 | && (TYPE_MODE (TREE_TYPE (type)) != BLKmode | |
1432 | || TYPE_NO_FORCE_BLK (TREE_TYPE (type)))) | |
1433 | { | |
1434 | TYPE_MODE (type) | |
72c602fc | 1435 | = mode_for_size_tree (TYPE_SIZE (type), MODE_INT, 1); |
7306ed3f | 1436 | |
72c602fc RK |
1437 | if (TYPE_MODE (type) != BLKmode |
1438 | && STRICT_ALIGNMENT && TYPE_ALIGN (type) < BIGGEST_ALIGNMENT | |
1439 | && TYPE_ALIGN (type) < GET_MODE_ALIGNMENT (TYPE_MODE (type)) | |
7306ed3f JW |
1440 | && TYPE_MODE (type) != BLKmode) |
1441 | { | |
1442 | TYPE_NO_FORCE_BLK (type) = 1; | |
1443 | TYPE_MODE (type) = BLKmode; | |
1444 | } | |
7306ed3f JW |
1445 | } |
1446 | break; | |
1447 | } | |
1448 | ||
1449 | case RECORD_TYPE: | |
cc9d4a85 MM |
1450 | case UNION_TYPE: |
1451 | case QUAL_UNION_TYPE: | |
9328904c MM |
1452 | { |
1453 | tree field; | |
1454 | record_layout_info rli; | |
1455 | ||
1456 | /* Initialize the layout information. */ | |
770ae6cc RK |
1457 | rli = start_record_layout (type); |
1458 | ||
cc9d4a85 MM |
1459 | /* If this is a QUAL_UNION_TYPE, we want to process the fields |
1460 | in the reverse order in building the COND_EXPR that denotes | |
1461 | its size. We reverse them again later. */ | |
1462 | if (TREE_CODE (type) == QUAL_UNION_TYPE) | |
1463 | TYPE_FIELDS (type) = nreverse (TYPE_FIELDS (type)); | |
770ae6cc RK |
1464 | |
1465 | /* Place all the fields. */ | |
9328904c | 1466 | for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) |
770ae6cc RK |
1467 | place_field (rli, field); |
1468 | ||
cc9d4a85 MM |
1469 | if (TREE_CODE (type) == QUAL_UNION_TYPE) |
1470 | TYPE_FIELDS (type) = nreverse (TYPE_FIELDS (type)); | |
770ae6cc | 1471 | |
9328904c MM |
1472 | /* Finish laying out the record. */ |
1473 | finish_record_layout (rli); | |
1474 | } | |
7306ed3f JW |
1475 | break; |
1476 | ||
e9a25f70 | 1477 | case SET_TYPE: /* Used by Chill and Pascal. */ |
b5d11e41 PB |
1478 | if (TREE_CODE (TYPE_MAX_VALUE (TYPE_DOMAIN (type))) != INTEGER_CST |
1479 | || TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (type))) != INTEGER_CST) | |
1480 | abort(); | |
1481 | else | |
1482 | { | |
1483 | #ifndef SET_WORD_SIZE | |
1484 | #define SET_WORD_SIZE BITS_PER_WORD | |
1485 | #endif | |
729a2125 RK |
1486 | unsigned int alignment |
1487 | = set_alignment ? set_alignment : SET_WORD_SIZE; | |
db3cf6fb MS |
1488 | int size_in_bits |
1489 | = (TREE_INT_CST_LOW (TYPE_MAX_VALUE (TYPE_DOMAIN (type))) | |
1490 | - TREE_INT_CST_LOW (TYPE_MIN_VALUE (TYPE_DOMAIN (type))) + 1); | |
b5d11e41 PB |
1491 | int rounded_size |
1492 | = ((size_in_bits + alignment - 1) / alignment) * alignment; | |
729a2125 RK |
1493 | |
1494 | if (rounded_size > (int) alignment) | |
b5d11e41 PB |
1495 | TYPE_MODE (type) = BLKmode; |
1496 | else | |
1497 | TYPE_MODE (type) = mode_for_size (alignment, MODE_INT, 1); | |
729a2125 | 1498 | |
06ceef4e | 1499 | TYPE_SIZE (type) = bitsize_int (rounded_size); |
ead17059 | 1500 | TYPE_SIZE_UNIT (type) = size_int (rounded_size / BITS_PER_UNIT); |
b5d11e41 | 1501 | TYPE_ALIGN (type) = alignment; |
11cf4d18 | 1502 | TYPE_USER_ALIGN (type) = 0; |
b5d11e41 PB |
1503 | TYPE_PRECISION (type) = size_in_bits; |
1504 | } | |
1505 | break; | |
1506 | ||
4cc89e53 RS |
1507 | case FILE_TYPE: |
1508 | /* The size may vary in different languages, so the language front end | |
1509 | should fill in the size. */ | |
1510 | TYPE_ALIGN (type) = BIGGEST_ALIGNMENT; | |
11cf4d18 | 1511 | TYPE_USER_ALIGN (type) = 0; |
4cc89e53 RS |
1512 | TYPE_MODE (type) = BLKmode; |
1513 | break; | |
1514 | ||
7306ed3f JW |
1515 | default: |
1516 | abort (); | |
729a2125 | 1517 | } |
7306ed3f | 1518 | |
9328904c | 1519 | /* Compute the final TYPE_SIZE, TYPE_ALIGN, etc. for TYPE. For |
cc9d4a85 MM |
1520 | records and unions, finish_record_layout already called this |
1521 | function. */ | |
1522 | if (TREE_CODE (type) != RECORD_TYPE | |
1523 | && TREE_CODE (type) != UNION_TYPE | |
1524 | && TREE_CODE (type) != QUAL_UNION_TYPE) | |
9328904c | 1525 | finalize_type_size (type); |
7306ed3f | 1526 | |
fed3cef0 RK |
1527 | /* If this type is created before sizetype has been permanently set, |
1528 | record it so set_sizetype can fix it up. */ | |
1529 | if (! sizetype_set) | |
ad41cc2a | 1530 | early_type_list = tree_cons (NULL_TREE, type, early_type_list); |
7306ed3f JW |
1531 | } |
1532 | \f | |
1533 | /* Create and return a type for signed integers of PRECISION bits. */ | |
1534 | ||
1535 | tree | |
1536 | make_signed_type (precision) | |
1537 | int precision; | |
1538 | { | |
1539 | register tree type = make_node (INTEGER_TYPE); | |
1540 | ||
1541 | TYPE_PRECISION (type) = precision; | |
1542 | ||
fed3cef0 | 1543 | fixup_signed_type (type); |
7306ed3f JW |
1544 | return type; |
1545 | } | |
1546 | ||
1547 | /* Create and return a type for unsigned integers of PRECISION bits. */ | |
1548 | ||
1549 | tree | |
1550 | make_unsigned_type (precision) | |
1551 | int precision; | |
1552 | { | |
1553 | register tree type = make_node (INTEGER_TYPE); | |
1554 | ||
1555 | TYPE_PRECISION (type) = precision; | |
1556 | ||
7306ed3f JW |
1557 | fixup_unsigned_type (type); |
1558 | return type; | |
1559 | } | |
fed3cef0 RK |
1560 | \f |
1561 | /* Initialize sizetype and bitsizetype to a reasonable and temporary | |
1562 | value to enable integer types to be created. */ | |
1563 | ||
1564 | void | |
1565 | initialize_sizetypes () | |
1566 | { | |
1567 | tree t = make_node (INTEGER_TYPE); | |
1568 | ||
1569 | /* Set this so we do something reasonable for the build_int_2 calls | |
1570 | below. */ | |
1571 | integer_type_node = t; | |
1572 | ||
1573 | TYPE_MODE (t) = SImode; | |
1574 | TYPE_ALIGN (t) = GET_MODE_ALIGNMENT (SImode); | |
11cf4d18 | 1575 | TYPE_USER_ALIGN (t) = 0; |
fed3cef0 RK |
1576 | TYPE_SIZE (t) = build_int_2 (GET_MODE_BITSIZE (SImode), 0); |
1577 | TYPE_SIZE_UNIT (t) = build_int_2 (GET_MODE_SIZE (SImode), 0); | |
1578 | TREE_UNSIGNED (t) = 1; | |
1579 | TYPE_PRECISION (t) = GET_MODE_BITSIZE (SImode); | |
1580 | TYPE_MIN_VALUE (t) = build_int_2 (0, 0); | |
770ae6cc | 1581 | TYPE_IS_SIZETYPE (t) = 1; |
fed3cef0 RK |
1582 | |
1583 | /* 1000 avoids problems with possible overflow and is certainly | |
1584 | larger than any size value we'd want to be storing. */ | |
1585 | TYPE_MAX_VALUE (t) = build_int_2 (1000, 0); | |
1586 | ||
1587 | /* These two must be different nodes because of the caching done in | |
1588 | size_int_wide. */ | |
1589 | sizetype = t; | |
1590 | bitsizetype = copy_node (t); | |
1591 | integer_type_node = 0; | |
1592 | } | |
7306ed3f | 1593 | |
896cced4 | 1594 | /* Set sizetype to TYPE, and initialize *sizetype accordingly. |
f8dac6eb R |
1595 | Also update the type of any standard type's sizes made so far. */ |
1596 | ||
1597 | void | |
1598 | set_sizetype (type) | |
1599 | tree type; | |
1600 | { | |
d4b60170 | 1601 | int oprecision = TYPE_PRECISION (type); |
f8dac6eb | 1602 | /* The *bitsizetype types use a precision that avoids overflows when |
d4b60170 RK |
1603 | calculating signed sizes / offsets in bits. However, when |
1604 | cross-compiling from a 32 bit to a 64 bit host, we are limited to 64 bit | |
1605 | precision. */ | |
11a6092b | 1606 | int precision = MIN (oprecision + BITS_PER_UNIT_LOG + 1, |
d4b60170 | 1607 | 2 * HOST_BITS_PER_WIDE_INT); |
fed3cef0 | 1608 | unsigned int i; |
ad41cc2a | 1609 | tree t; |
fed3cef0 RK |
1610 | |
1611 | if (sizetype_set) | |
1612 | abort (); | |
81b3411c | 1613 | |
fed3cef0 RK |
1614 | /* Make copies of nodes since we'll be setting TYPE_IS_SIZETYPE. */ |
1615 | sizetype = copy_node (type); | |
21318741 | 1616 | TYPE_DOMAIN (sizetype) = type; |
770ae6cc | 1617 | TYPE_IS_SIZETYPE (sizetype) = 1; |
81b3411c BS |
1618 | bitsizetype = make_node (INTEGER_TYPE); |
1619 | TYPE_NAME (bitsizetype) = TYPE_NAME (type); | |
f8dac6eb | 1620 | TYPE_PRECISION (bitsizetype) = precision; |
770ae6cc | 1621 | TYPE_IS_SIZETYPE (bitsizetype) = 1; |
d4b60170 | 1622 | |
896cced4 RH |
1623 | if (TREE_UNSIGNED (type)) |
1624 | fixup_unsigned_type (bitsizetype); | |
1625 | else | |
1626 | fixup_signed_type (bitsizetype); | |
d4b60170 | 1627 | |
f8dac6eb R |
1628 | layout_type (bitsizetype); |
1629 | ||
896cced4 RH |
1630 | if (TREE_UNSIGNED (type)) |
1631 | { | |
1632 | usizetype = sizetype; | |
1633 | ubitsizetype = bitsizetype; | |
fed3cef0 RK |
1634 | ssizetype = copy_node (make_signed_type (oprecision)); |
1635 | sbitsizetype = copy_node (make_signed_type (precision)); | |
896cced4 RH |
1636 | } |
1637 | else | |
1638 | { | |
1639 | ssizetype = sizetype; | |
1640 | sbitsizetype = bitsizetype; | |
fed3cef0 RK |
1641 | usizetype = copy_node (make_unsigned_type (oprecision)); |
1642 | ubitsizetype = copy_node (make_unsigned_type (precision)); | |
896cced4 | 1643 | } |
fed3cef0 RK |
1644 | |
1645 | TYPE_NAME (bitsizetype) = get_identifier ("bit_size_type"); | |
1646 | ||
21318741 | 1647 | /* Show is a sizetype, is a main type, and has no pointers to it. */ |
b6a1cbae | 1648 | for (i = 0; i < ARRAY_SIZE (sizetype_tab); i++) |
21318741 RK |
1649 | { |
1650 | TYPE_IS_SIZETYPE (sizetype_tab[i]) = 1; | |
1651 | TYPE_MAIN_VARIANT (sizetype_tab[i]) = sizetype_tab[i]; | |
1652 | TYPE_NEXT_VARIANT (sizetype_tab[i]) = 0; | |
1653 | TYPE_POINTER_TO (sizetype_tab[i]) = 0; | |
1654 | TYPE_REFERENCE_TO (sizetype_tab[i]) = 0; | |
1655 | } | |
d7db6646 | 1656 | |
d4b60170 RK |
1657 | ggc_add_tree_root ((tree *) &sizetype_tab, |
1658 | sizeof sizetype_tab / sizeof (tree)); | |
f8dac6eb | 1659 | |
fed3cef0 RK |
1660 | /* Go down each of the types we already made and set the proper type |
1661 | for the sizes in them. */ | |
ad41cc2a | 1662 | for (t = early_type_list; t != 0; t = TREE_CHAIN (t)) |
fed3cef0 | 1663 | { |
ad41cc2a | 1664 | if (TREE_CODE (TREE_VALUE (t)) != INTEGER_TYPE) |
fed3cef0 RK |
1665 | abort (); |
1666 | ||
ad41cc2a RK |
1667 | TREE_TYPE (TYPE_SIZE (TREE_VALUE (t))) = bitsizetype; |
1668 | TREE_TYPE (TYPE_SIZE_UNIT (TREE_VALUE (t))) = sizetype; | |
fed3cef0 RK |
1669 | } |
1670 | ||
1671 | early_type_list = 0; | |
1672 | sizetype_set = 1; | |
1673 | } | |
1674 | \f | |
4cc89e53 | 1675 | /* Set the extreme values of TYPE based on its precision in bits, |
13756074 | 1676 | then lay it out. Used when make_signed_type won't do |
4cc89e53 RS |
1677 | because the tree code is not INTEGER_TYPE. |
1678 | E.g. for Pascal, when the -fsigned-char option is given. */ | |
1679 | ||
1680 | void | |
1681 | fixup_signed_type (type) | |
1682 | tree type; | |
1683 | { | |
1684 | register int precision = TYPE_PRECISION (type); | |
1685 | ||
1686 | TYPE_MIN_VALUE (type) | |
13756074 JW |
1687 | = build_int_2 ((precision - HOST_BITS_PER_WIDE_INT > 0 |
1688 | ? 0 : (HOST_WIDE_INT) (-1) << (precision - 1)), | |
1689 | (((HOST_WIDE_INT) (-1) | |
1690 | << (precision - HOST_BITS_PER_WIDE_INT - 1 > 0 | |
1691 | ? precision - HOST_BITS_PER_WIDE_INT - 1 | |
1692 | : 0)))); | |
4cc89e53 | 1693 | TYPE_MAX_VALUE (type) |
13756074 JW |
1694 | = build_int_2 ((precision - HOST_BITS_PER_WIDE_INT > 0 |
1695 | ? -1 : ((HOST_WIDE_INT) 1 << (precision - 1)) - 1), | |
1696 | (precision - HOST_BITS_PER_WIDE_INT - 1 > 0 | |
1697 | ? (((HOST_WIDE_INT) 1 | |
1698 | << (precision - HOST_BITS_PER_WIDE_INT - 1))) - 1 | |
4cc89e53 RS |
1699 | : 0)); |
1700 | ||
1701 | TREE_TYPE (TYPE_MIN_VALUE (type)) = type; | |
1702 | TREE_TYPE (TYPE_MAX_VALUE (type)) = type; | |
1703 | ||
1704 | /* Lay out the type: set its alignment, size, etc. */ | |
4cc89e53 RS |
1705 | layout_type (type); |
1706 | } | |
1707 | ||
7306ed3f | 1708 | /* Set the extreme values of TYPE based on its precision in bits, |
13756074 | 1709 | then lay it out. This is used both in `make_unsigned_type' |
7306ed3f JW |
1710 | and for enumeral types. */ |
1711 | ||
1712 | void | |
1713 | fixup_unsigned_type (type) | |
1714 | tree type; | |
1715 | { | |
1716 | register int precision = TYPE_PRECISION (type); | |
1717 | ||
1718 | TYPE_MIN_VALUE (type) = build_int_2 (0, 0); | |
1719 | TYPE_MAX_VALUE (type) | |
c166a311 | 1720 | = build_int_2 (precision - HOST_BITS_PER_WIDE_INT >= 0 |
13756074 | 1721 | ? -1 : ((HOST_WIDE_INT) 1 << precision) - 1, |
c166a311 CH |
1722 | precision - HOST_BITS_PER_WIDE_INT > 0 |
1723 | ? ((unsigned HOST_WIDE_INT) ~0 | |
1724 | >> (HOST_BITS_PER_WIDE_INT | |
1725 | - (precision - HOST_BITS_PER_WIDE_INT))) | |
7306ed3f JW |
1726 | : 0); |
1727 | TREE_TYPE (TYPE_MIN_VALUE (type)) = type; | |
1728 | TREE_TYPE (TYPE_MAX_VALUE (type)) = type; | |
1729 | ||
1730 | /* Lay out the type: set its alignment, size, etc. */ | |
7306ed3f JW |
1731 | layout_type (type); |
1732 | } | |
1733 | \f | |
1734 | /* Find the best machine mode to use when referencing a bit field of length | |
1735 | BITSIZE bits starting at BITPOS. | |
1736 | ||
1737 | The underlying object is known to be aligned to a boundary of ALIGN bits. | |
1738 | If LARGEST_MODE is not VOIDmode, it means that we should not use a mode | |
1739 | larger than LARGEST_MODE (usually SImode). | |
1740 | ||
1741 | If no mode meets all these conditions, we return VOIDmode. Otherwise, if | |
1742 | VOLATILEP is true or SLOW_BYTE_ACCESS is false, we return the smallest | |
1743 | mode meeting these conditions. | |
1744 | ||
77fa0940 RK |
1745 | Otherwise (VOLATILEP is false and SLOW_BYTE_ACCESS is true), we return |
1746 | the largest mode (but a mode no wider than UNITS_PER_WORD) that meets | |
1747 | all the conditions. */ | |
7306ed3f JW |
1748 | |
1749 | enum machine_mode | |
1750 | get_best_mode (bitsize, bitpos, align, largest_mode, volatilep) | |
1751 | int bitsize, bitpos; | |
729a2125 | 1752 | unsigned int align; |
7306ed3f JW |
1753 | enum machine_mode largest_mode; |
1754 | int volatilep; | |
1755 | { | |
1756 | enum machine_mode mode; | |
770ae6cc | 1757 | unsigned int unit = 0; |
7306ed3f JW |
1758 | |
1759 | /* Find the narrowest integer mode that contains the bit field. */ | |
1760 | for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode; | |
1761 | mode = GET_MODE_WIDER_MODE (mode)) | |
1762 | { | |
1763 | unit = GET_MODE_BITSIZE (mode); | |
956d6950 | 1764 | if ((bitpos % unit) + bitsize <= unit) |
7306ed3f JW |
1765 | break; |
1766 | } | |
1767 | ||
0c61f541 | 1768 | if (mode == VOIDmode |
7306ed3f | 1769 | /* It is tempting to omit the following line |
4e4b555d | 1770 | if STRICT_ALIGNMENT is true. |
7306ed3f JW |
1771 | But that is incorrect, since if the bitfield uses part of 3 bytes |
1772 | and we use a 4-byte mode, we could get a spurious segv | |
1773 | if the extra 4th byte is past the end of memory. | |
1774 | (Though at least one Unix compiler ignores this problem: | |
1775 | that on the Sequent 386 machine. */ | |
770ae6cc | 1776 | || MIN (unit, BIGGEST_ALIGNMENT) > align |
7306ed3f JW |
1777 | || (largest_mode != VOIDmode && unit > GET_MODE_BITSIZE (largest_mode))) |
1778 | return VOIDmode; | |
1779 | ||
77fa0940 RK |
1780 | if (SLOW_BYTE_ACCESS && ! volatilep) |
1781 | { | |
1782 | enum machine_mode wide_mode = VOIDmode, tmode; | |
1783 | ||
1784 | for (tmode = GET_CLASS_NARROWEST_MODE (MODE_INT); tmode != VOIDmode; | |
1785 | tmode = GET_MODE_WIDER_MODE (tmode)) | |
1786 | { | |
1787 | unit = GET_MODE_BITSIZE (tmode); | |
1788 | if (bitpos / unit == (bitpos + bitsize - 1) / unit | |
1789 | && unit <= BITS_PER_WORD | |
770ae6cc | 1790 | && unit <= MIN (align, BIGGEST_ALIGNMENT) |
77fa0940 RK |
1791 | && (largest_mode == VOIDmode |
1792 | || unit <= GET_MODE_BITSIZE (largest_mode))) | |
1793 | wide_mode = tmode; | |
1794 | } | |
1795 | ||
1796 | if (wide_mode != VOIDmode) | |
1797 | return wide_mode; | |
1798 | } | |
7306ed3f JW |
1799 | |
1800 | return mode; | |
1801 | } | |
d7db6646 | 1802 | |
36c265b1 NS |
1803 | /* Return the alignment of MODE. This will be bounded by 1 and |
1804 | BIGGEST_ALIGNMENT. */ | |
1805 | ||
fed3cef0 RK |
1806 | unsigned int |
1807 | get_mode_alignment (mode) | |
36c265b1 NS |
1808 | enum machine_mode mode; |
1809 | { | |
19caa751 | 1810 | unsigned int alignment = GET_MODE_UNIT_SIZE (mode) * BITS_PER_UNIT; |
36c265b1 NS |
1811 | |
1812 | /* Extract the LSB of the size. */ | |
1813 | alignment = alignment & -alignment; | |
36c265b1 NS |
1814 | |
1815 | alignment = MIN (BIGGEST_ALIGNMENT, MAX (1, alignment)); | |
1816 | return alignment; | |
1817 | } | |
1818 | ||
d7db6646 RH |
1819 | /* This function is run once to initialize stor-layout.c. */ |
1820 | ||
1821 | void | |
1822 | init_stor_layout_once () | |
1823 | { | |
1824 | ggc_add_tree_root (&pending_sizes, 1); | |
1825 | } |