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4ee9c684 | 1 | /* Generic routines for manipulating SSA_NAME expressions |
f1717362 | 2 | Copyright (C) 2003-2016 Free Software Foundation, Inc. |
0b1615c1 | 3 | |
4ee9c684 | 4 | This file is part of GCC. |
48e1416a | 5 | |
4ee9c684 | 6 | GCC is free software; you can redistribute it and/or modify |
7 | it under the terms of the GNU General Public License as published by | |
8c4c00c1 | 8 | the Free Software Foundation; either version 3, or (at your option) |
4ee9c684 | 9 | any later version. |
48e1416a | 10 | |
4ee9c684 | 11 | GCC is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
48e1416a | 15 | |
4ee9c684 | 16 | You should have received a copy of the GNU General Public License |
8c4c00c1 | 17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
1fa3a8f6 | 19 | |
4ee9c684 | 20 | #include "config.h" |
21 | #include "system.h" | |
22 | #include "coretypes.h" | |
9ef16211 | 23 | #include "backend.h" |
4ee9c684 | 24 | #include "tree.h" |
9ef16211 | 25 | #include "gimple.h" |
7c29e30e | 26 | #include "tree-pass.h" |
9ef16211 | 27 | #include "ssa.h" |
7c29e30e | 28 | #include "gimple-iterator.h" |
9ed99284 | 29 | #include "stor-layout.h" |
073c1fd5 | 30 | #include "tree-into-ssa.h" |
69ee5dbb | 31 | #include "tree-ssa.h" |
4ee9c684 | 32 | |
33 | /* Rewriting a function into SSA form can create a huge number of SSA_NAMEs, | |
34 | many of which may be thrown away shortly after their creation if jumps | |
48e1416a | 35 | were threaded through PHI nodes. |
4ee9c684 | 36 | |
37 | While our garbage collection mechanisms will handle this situation, it | |
38 | is extremely wasteful to create nodes and throw them away, especially | |
39 | when the nodes can be reused. | |
40 | ||
41 | For PR 8361, we can significantly reduce the number of nodes allocated | |
42 | and thus the total amount of memory allocated by managing SSA_NAMEs a | |
43 | little. This additionally helps reduce the amount of work done by the | |
44 | garbage collector. Similar results have been seen on a wider variety | |
45 | of tests (such as the compiler itself). | |
46 | ||
47 | Right now we maintain our free list on a per-function basis. It may | |
48 | or may not make sense to maintain the free list for the duration of | |
48e1416a | 49 | a compilation unit. |
4ee9c684 | 50 | |
51 | External code should rely solely upon HIGHEST_SSA_VERSION and the | |
52 | externally defined functions. External code should not know about | |
53 | the details of the free list management. | |
54 | ||
55 | External code should also not assume the version number on nodes is | |
56 | monotonically increasing. We reuse the version number when we | |
57 | reuse an SSA_NAME expression. This helps keep arrays and bitmaps | |
5cc13354 | 58 | more compact. */ |
4ee9c684 | 59 | |
4ee9c684 | 60 | |
61 | /* Version numbers with special meanings. We start allocating new version | |
62 | numbers after the special ones. */ | |
63 | #define UNUSED_NAME_VERSION 0 | |
64 | ||
4ee9c684 | 65 | unsigned int ssa_name_nodes_reused; |
66 | unsigned int ssa_name_nodes_created; | |
4ee9c684 | 67 | |
9e2e2283 | 68 | #define FREE_SSANAMES(fun) (fun)->gimple_df->free_ssanames |
16f88e4c | 69 | #define FREE_SSANAMES_QUEUE(fun) (fun)->gimple_df->free_ssanames_queue |
9e2e2283 | 70 | |
71 | ||
bcaa2770 | 72 | /* Initialize management of SSA_NAMEs to default SIZE. If SIZE is |
73 | zero use default. */ | |
4ee9c684 | 74 | |
75 | void | |
bcaa2770 | 76 | init_ssanames (struct function *fn, int size) |
4ee9c684 | 77 | { |
bcaa2770 | 78 | if (size < 50) |
79 | size = 50; | |
80 | ||
f1f41a6c | 81 | vec_alloc (SSANAMES (fn), size); |
c211d998 | 82 | |
83 | /* Version 0 is special, so reserve the first slot in the table. Though | |
84 | currently unused, we may use version 0 in alias analysis as part of | |
85 | the heuristics used to group aliases when the alias sets are too | |
8b292c7f | 86 | large. |
87 | ||
f1f41a6c | 88 | We use vec::quick_push here because we know that SSA_NAMES has at |
b62e1ab2 | 89 | least 50 elements reserved in it. */ |
f1f41a6c | 90 | SSANAMES (fn)->quick_push (NULL_TREE); |
bcaa2770 | 91 | FREE_SSANAMES (fn) = NULL; |
16f88e4c | 92 | FREE_SSANAMES_QUEUE (fn) = NULL; |
dd277d48 | 93 | |
e70e8b13 | 94 | fn->gimple_df->ssa_renaming_needed = 0; |
95 | fn->gimple_df->rename_vops = 0; | |
4ee9c684 | 96 | } |
97 | ||
98 | /* Finalize management of SSA_NAMEs. */ | |
99 | ||
100 | void | |
d4f078b5 | 101 | fini_ssanames (struct function *fn) |
4ee9c684 | 102 | { |
d4f078b5 | 103 | vec_free (SSANAMES (fn)); |
104 | vec_free (FREE_SSANAMES (fn)); | |
105 | vec_free (FREE_SSANAMES_QUEUE (fn)); | |
4ee9c684 | 106 | } |
107 | ||
108 | /* Dump some simple statistics regarding the re-use of SSA_NAME nodes. */ | |
109 | ||
4ee9c684 | 110 | void |
111 | ssanames_print_statistics (void) | |
112 | { | |
113 | fprintf (stderr, "SSA_NAME nodes allocated: %u\n", ssa_name_nodes_created); | |
114 | fprintf (stderr, "SSA_NAME nodes reused: %u\n", ssa_name_nodes_reused); | |
115 | } | |
4ee9c684 | 116 | |
0b0b7c83 | 117 | /* Verify the state of the SSA_NAME lists. |
118 | ||
119 | There must be no duplicates on the free list. | |
120 | Every name on the free list must be marked as on the free list. | |
121 | Any name on the free list must not appear in the IL. | |
122 | No names can be leaked. */ | |
123 | ||
124 | DEBUG_FUNCTION void | |
125 | verify_ssaname_freelists (struct function *fun) | |
126 | { | |
6dbbcdee | 127 | if (!gimple_in_ssa_p (fun)) |
128 | return; | |
0b0b7c83 | 129 | |
130 | bitmap names_in_il = BITMAP_ALLOC (NULL); | |
131 | ||
132 | /* Walk the entire IL noting every SSA_NAME we see. */ | |
6dbbcdee | 133 | basic_block bb; |
0b0b7c83 | 134 | FOR_EACH_BB_FN (bb, fun) |
135 | { | |
136 | tree t; | |
137 | /* First note the result and arguments of PHI nodes. */ | |
138 | for (gphi_iterator gsi = gsi_start_phis (bb); | |
139 | !gsi_end_p (gsi); | |
140 | gsi_next (&gsi)) | |
141 | { | |
142 | gphi *phi = gsi.phi (); | |
143 | t = gimple_phi_result (phi); | |
144 | bitmap_set_bit (names_in_il, SSA_NAME_VERSION (t)); | |
145 | ||
146 | for (unsigned int i = 0; i < gimple_phi_num_args (phi); i++) | |
147 | { | |
148 | t = gimple_phi_arg_def (phi, i); | |
149 | if (TREE_CODE (t) == SSA_NAME) | |
150 | bitmap_set_bit (names_in_il, SSA_NAME_VERSION (t)); | |
151 | } | |
152 | } | |
153 | ||
154 | /* Then note the operands of each statement. */ | |
155 | for (gimple_stmt_iterator gsi = gsi_start_bb (bb); | |
156 | !gsi_end_p (gsi); | |
157 | gsi_next (&gsi)) | |
158 | { | |
159 | ssa_op_iter iter; | |
160 | gimple *stmt = gsi_stmt (gsi); | |
161 | FOR_EACH_SSA_TREE_OPERAND (t, stmt, iter, SSA_OP_ALL_OPERANDS) | |
6dbbcdee | 162 | bitmap_set_bit (names_in_il, SSA_NAME_VERSION (t)); |
0b0b7c83 | 163 | } |
164 | } | |
165 | ||
166 | /* Now walk the free list noting what we find there and verifying | |
167 | there are no duplicates. */ | |
168 | bitmap names_in_freelists = BITMAP_ALLOC (NULL); | |
169 | if (FREE_SSANAMES (fun)) | |
170 | { | |
171 | for (unsigned int i = 0; i < FREE_SSANAMES (fun)->length (); i++) | |
172 | { | |
173 | tree t = (*FREE_SSANAMES (fun))[i]; | |
174 | ||
175 | /* Verify that the name is marked as being in the free list. */ | |
176 | gcc_assert (SSA_NAME_IN_FREE_LIST (t)); | |
177 | ||
178 | /* Verify the name has not already appeared in the free list and | |
179 | note it in the list of names found in the free list. */ | |
180 | gcc_assert (!bitmap_bit_p (names_in_freelists, SSA_NAME_VERSION (t))); | |
181 | bitmap_set_bit (names_in_freelists, SSA_NAME_VERSION (t)); | |
182 | } | |
183 | } | |
184 | ||
185 | /* Similarly for the names in the pending free list. */ | |
186 | if (FREE_SSANAMES_QUEUE (fun)) | |
187 | { | |
188 | for (unsigned int i = 0; i < FREE_SSANAMES_QUEUE (fun)->length (); i++) | |
189 | { | |
190 | tree t = (*FREE_SSANAMES_QUEUE (fun))[i]; | |
191 | ||
192 | /* Verify that the name is marked as being in the free list. */ | |
193 | gcc_assert (SSA_NAME_IN_FREE_LIST (t)); | |
194 | ||
195 | /* Verify the name has not already appeared in the free list and | |
196 | note it in the list of names found in the free list. */ | |
197 | gcc_assert (!bitmap_bit_p (names_in_freelists, SSA_NAME_VERSION (t))); | |
198 | bitmap_set_bit (names_in_freelists, SSA_NAME_VERSION (t)); | |
199 | } | |
200 | } | |
201 | ||
202 | /* If any name appears in both the IL and the freelists, then | |
203 | something horrible has happened. */ | |
204 | bool intersect_p = bitmap_intersect_p (names_in_il, names_in_freelists); | |
205 | gcc_assert (!intersect_p); | |
206 | ||
207 | /* Names can be queued up for release if there is an ssa update | |
208 | pending. Pretend we saw them in the IL. */ | |
209 | if (names_to_release) | |
210 | bitmap_ior_into (names_in_il, names_to_release); | |
211 | ||
212 | /* Function splitting can "lose" SSA_NAMEs in an effort to ensure that | |
213 | debug/non-debug compilations have the same SSA_NAMEs. So for each | |
214 | lost SSA_NAME, see if it's likely one from that wart. These will always | |
215 | be marked as default definitions. So we loosely assume that anything | |
6dbbcdee | 216 | marked as a default definition isn't leaked by pretending they are |
0b0b7c83 | 217 | in the IL. */ |
218 | for (unsigned int i = UNUSED_NAME_VERSION + 1; i < num_ssa_names; i++) | |
219 | if (ssa_name (i) && SSA_NAME_IS_DEFAULT_DEF (ssa_name (i))) | |
220 | bitmap_set_bit (names_in_il, i); | |
221 | ||
222 | unsigned int i; | |
223 | bitmap_iterator bi; | |
224 | bitmap all_names = BITMAP_ALLOC (NULL); | |
225 | bitmap_set_range (all_names, UNUSED_NAME_VERSION + 1, num_ssa_names - 1); | |
226 | bitmap_ior_into (names_in_il, names_in_freelists); | |
227 | ||
228 | /* Any name not mentioned in the IL and not in the feelists | |
229 | has been leaked. */ | |
230 | EXECUTE_IF_AND_COMPL_IN_BITMAP(all_names, names_in_il, | |
231 | UNUSED_NAME_VERSION + 1, i, bi) | |
232 | gcc_assert (!ssa_name (i)); | |
233 | ||
234 | BITMAP_FREE (all_names); | |
235 | BITMAP_FREE (names_in_freelists); | |
236 | BITMAP_FREE (names_in_il); | |
237 | } | |
238 | ||
16f88e4c | 239 | /* Move all SSA_NAMEs from FREE_SSA_NAMES_QUEUE to FREE_SSA_NAMES. |
240 | ||
241 | We do not, but should have a mode to verify the state of the SSA_NAMEs | |
242 | lists. In particular at this point every name must be in the IL, | |
243 | on the free list or in the queue. Anything else is an error. */ | |
244 | ||
245 | void | |
246 | flush_ssaname_freelist (void) | |
247 | { | |
388e5184 | 248 | vec_safe_splice (FREE_SSANAMES (cfun), FREE_SSANAMES_QUEUE (cfun)); |
249 | vec_safe_truncate (FREE_SSANAMES_QUEUE (cfun), 0); | |
16f88e4c | 250 | } |
251 | ||
bcaa2770 | 252 | /* Return an SSA_NAME node for variable VAR defined in statement STMT |
253 | in function FN. STMT may be an empty statement for artificial | |
254 | references (e.g., default definitions created when a variable is | |
255 | used without a preceding definition). */ | |
4ee9c684 | 256 | |
257 | tree | |
42acab1c | 258 | make_ssa_name_fn (struct function *fn, tree var, gimple *stmt) |
4ee9c684 | 259 | { |
260 | tree t; | |
b66731e8 | 261 | use_operand_p imm; |
4ee9c684 | 262 | |
53e9c5c4 | 263 | gcc_assert (VAR_P (var) |
2f4ec87c | 264 | || TREE_CODE (var) == PARM_DECL |
ec11736b | 265 | || TREE_CODE (var) == RESULT_DECL |
266 | || (TYPE_P (var) && is_gimple_reg_type (var))); | |
4ee9c684 | 267 | |
fa0f49c6 | 268 | /* If our free list has an element, then use it. */ |
f1f41a6c | 269 | if (!vec_safe_is_empty (FREE_SSANAMES (fn))) |
4ee9c684 | 270 | { |
f1f41a6c | 271 | t = FREE_SSANAMES (fn)->pop (); |
0ccdd20e | 272 | ssa_name_nodes_reused++; |
4ee9c684 | 273 | |
fa0f49c6 | 274 | /* The node was cleared out when we put it on the free list, so |
275 | there is no need to do so again here. */ | |
98107def | 276 | gcc_assert ((*SSANAMES (fn))[SSA_NAME_VERSION (t)] == NULL); |
f1f41a6c | 277 | (*SSANAMES (fn))[SSA_NAME_VERSION (t)] = t; |
4ee9c684 | 278 | } |
279 | else | |
280 | { | |
281 | t = make_node (SSA_NAME); | |
f1f41a6c | 282 | SSA_NAME_VERSION (t) = SSANAMES (fn)->length (); |
283 | vec_safe_push (SSANAMES (fn), t); | |
0ccdd20e | 284 | ssa_name_nodes_created++; |
4ee9c684 | 285 | } |
286 | ||
ec11736b | 287 | if (TYPE_P (var)) |
288 | { | |
5a987d87 | 289 | TREE_TYPE (t) = TYPE_MAIN_VARIANT (var); |
ec11736b | 290 | SET_SSA_NAME_VAR_OR_IDENTIFIER (t, NULL_TREE); |
291 | } | |
292 | else | |
293 | { | |
294 | TREE_TYPE (t) = TREE_TYPE (var); | |
295 | SET_SSA_NAME_VAR_OR_IDENTIFIER (t, var); | |
296 | } | |
4ee9c684 | 297 | SSA_NAME_DEF_STMT (t) = stmt; |
3c59e4a7 | 298 | if (POINTER_TYPE_P (TREE_TYPE (t))) |
299 | SSA_NAME_PTR_INFO (t) = NULL; | |
300 | else | |
301 | SSA_NAME_RANGE_INFO (t) = NULL; | |
302 | ||
81d08033 | 303 | SSA_NAME_IN_FREE_LIST (t) = 0; |
de6ed584 | 304 | SSA_NAME_IS_DEFAULT_DEF (t) = 0; |
22aa74c4 | 305 | imm = &(SSA_NAME_IMM_USE_NODE (t)); |
306 | imm->use = NULL; | |
307 | imm->prev = imm; | |
308 | imm->next = imm; | |
75a70cf9 | 309 | imm->loc.ssa_name = t; |
4ee9c684 | 310 | |
311 | return t; | |
312 | } | |
313 | ||
0c20fe49 | 314 | /* Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name NAME. */ |
3c59e4a7 | 315 | |
316 | void | |
0c20fe49 | 317 | set_range_info (tree name, enum value_range_type range_type, |
9c1be15e | 318 | const wide_int_ref &min, const wide_int_ref &max) |
3c59e4a7 | 319 | { |
320 | gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); | |
0c20fe49 | 321 | gcc_assert (range_type == VR_RANGE || range_type == VR_ANTI_RANGE); |
3c59e4a7 | 322 | range_info_def *ri = SSA_NAME_RANGE_INFO (name); |
9c1be15e | 323 | unsigned int precision = TYPE_PRECISION (TREE_TYPE (name)); |
3c59e4a7 | 324 | |
325 | /* Allocate if not available. */ | |
326 | if (ri == NULL) | |
327 | { | |
9c1be15e | 328 | size_t size = (sizeof (range_info_def) |
329 | + trailing_wide_ints <3>::extra_size (precision)); | |
25a27413 | 330 | ri = static_cast<range_info_def *> (ggc_internal_alloc (size)); |
9c1be15e | 331 | ri->ints.set_precision (precision); |
3c59e4a7 | 332 | SSA_NAME_RANGE_INFO (name) = ri; |
9c1be15e | 333 | ri->set_nonzero_bits (wi::shwi (-1, precision)); |
3c59e4a7 | 334 | } |
335 | ||
0c20fe49 | 336 | /* Record the range type. */ |
337 | if (SSA_NAME_RANGE_TYPE (name) != range_type) | |
338 | SSA_NAME_ANTI_RANGE_P (name) = (range_type == VR_ANTI_RANGE); | |
339 | ||
3c59e4a7 | 340 | /* Set the values. */ |
9c1be15e | 341 | ri->set_min (min); |
342 | ri->set_max (max); | |
fc08b993 | 343 | |
344 | /* If it is a range, try to improve nonzero_bits from the min/max. */ | |
0c20fe49 | 345 | if (range_type == VR_RANGE) |
fc08b993 | 346 | { |
9c1be15e | 347 | wide_int xorv = ri->get_min () ^ ri->get_max (); |
aeb682a2 | 348 | if (xorv != 0) |
9c1be15e | 349 | xorv = wi::mask (precision - wi::clz (xorv), false, precision); |
350 | ri->set_nonzero_bits (ri->get_nonzero_bits () & (ri->get_min () | xorv)); | |
fc08b993 | 351 | } |
3c59e4a7 | 352 | } |
353 | ||
354 | ||
355 | /* Gets range information MIN, MAX and returns enum value_range_type | |
356 | corresponding to tree ssa_name NAME. enum value_range_type returned | |
357 | is used to determine if MIN and MAX are valid values. */ | |
358 | ||
359 | enum value_range_type | |
9c1be15e | 360 | get_range_info (const_tree name, wide_int *min, wide_int *max) |
3c59e4a7 | 361 | { |
3c59e4a7 | 362 | gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); |
363 | gcc_assert (min && max); | |
364 | range_info_def *ri = SSA_NAME_RANGE_INFO (name); | |
365 | ||
366 | /* Return VR_VARYING for SSA_NAMEs with NULL RANGE_INFO or SSA_NAMEs | |
367 | with integral types width > 2 * HOST_BITS_PER_WIDE_INT precision. */ | |
368 | if (!ri || (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (name))) | |
0cf78115 | 369 | > 2 * HOST_BITS_PER_WIDE_INT)) |
3c59e4a7 | 370 | return VR_VARYING; |
371 | ||
9c1be15e | 372 | *min = ri->get_min (); |
373 | *max = ri->get_max (); | |
0c20fe49 | 374 | return SSA_NAME_RANGE_TYPE (name); |
3c59e4a7 | 375 | } |
c211d998 | 376 | |
5b48910f | 377 | /* Set nonnull attribute to pointer NAME. */ |
378 | ||
379 | void | |
380 | set_ptr_nonnull (tree name) | |
381 | { | |
382 | gcc_assert (POINTER_TYPE_P (TREE_TYPE (name))); | |
383 | struct ptr_info_def *pi = get_ptr_info (name); | |
384 | pi->pt.null = 0; | |
385 | } | |
386 | ||
387 | /* Return nonnull attribute of pointer NAME. */ | |
388 | bool | |
389 | get_ptr_nonnull (const_tree name) | |
390 | { | |
391 | gcc_assert (POINTER_TYPE_P (TREE_TYPE (name))); | |
392 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (name); | |
393 | if (pi == NULL) | |
394 | return false; | |
395 | /* TODO Now pt->null is conservatively set to true in PTA | |
396 | analysis. vrp is the only pass (including ipa-vrp) | |
397 | that clears pt.null via set_ptr_nonull when it knows | |
398 | for sure. PTA will preserves the pt.null value set by VRP. | |
399 | ||
400 | When PTA analysis is improved, pt.anything, pt.nonlocal | |
401 | and pt.escaped may also has to be considered before | |
402 | deciding that pointer cannot point to NULL. */ | |
403 | return !pi->pt.null; | |
404 | } | |
405 | ||
fc08b993 | 406 | /* Change non-zero bits bitmask of NAME. */ |
407 | ||
408 | void | |
9c1be15e | 409 | set_nonzero_bits (tree name, const wide_int_ref &mask) |
fc08b993 | 410 | { |
411 | gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); | |
412 | if (SSA_NAME_RANGE_INFO (name) == NULL) | |
0c20fe49 | 413 | set_range_info (name, VR_RANGE, |
9c1be15e | 414 | TYPE_MIN_VALUE (TREE_TYPE (name)), |
415 | TYPE_MAX_VALUE (TREE_TYPE (name))); | |
fc08b993 | 416 | range_info_def *ri = SSA_NAME_RANGE_INFO (name); |
9c1be15e | 417 | ri->set_nonzero_bits (mask); |
fc08b993 | 418 | } |
419 | ||
aeb682a2 | 420 | /* Return a widest_int with potentially non-zero bits in SSA_NAME |
421 | NAME, or -1 if unknown. */ | |
fc08b993 | 422 | |
9c1be15e | 423 | wide_int |
c8a2b4ff | 424 | get_nonzero_bits (const_tree name) |
fc08b993 | 425 | { |
9c1be15e | 426 | unsigned int precision = TYPE_PRECISION (TREE_TYPE (name)); |
fc08b993 | 427 | if (POINTER_TYPE_P (TREE_TYPE (name))) |
428 | { | |
429 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (name); | |
430 | if (pi && pi->align) | |
6e5e0d6b | 431 | return wi::shwi (-(HOST_WIDE_INT) pi->align |
432 | | (HOST_WIDE_INT) pi->misalign, precision); | |
9c1be15e | 433 | return wi::shwi (-1, precision); |
fc08b993 | 434 | } |
435 | ||
436 | range_info_def *ri = SSA_NAME_RANGE_INFO (name); | |
9c1be15e | 437 | if (!ri) |
438 | return wi::shwi (-1, precision); | |
fc08b993 | 439 | |
9c1be15e | 440 | return ri->get_nonzero_bits (); |
fc08b993 | 441 | } |
442 | ||
e390c57d | 443 | /* Return TRUE is OP, an SSA_NAME has a range of values [0..1], false |
444 | otherwise. | |
445 | ||
446 | This can be because it is a boolean type, any unsigned integral | |
447 | type with a single bit of precision, or has known range of [0..1] | |
448 | via VRP analysis. */ | |
449 | ||
450 | bool | |
451 | ssa_name_has_boolean_range (tree op) | |
452 | { | |
453 | gcc_assert (TREE_CODE (op) == SSA_NAME); | |
454 | ||
455 | /* Boolean types always have a range [0..1]. */ | |
456 | if (TREE_CODE (TREE_TYPE (op)) == BOOLEAN_TYPE) | |
457 | return true; | |
458 | ||
459 | /* An integral type with a single bit of precision. */ | |
460 | if (INTEGRAL_TYPE_P (TREE_TYPE (op)) | |
461 | && TYPE_UNSIGNED (TREE_TYPE (op)) | |
462 | && TYPE_PRECISION (TREE_TYPE (op)) == 1) | |
463 | return true; | |
464 | ||
465 | /* An integral type with more precision, but the object | |
466 | only takes on values [0..1] as determined by VRP | |
467 | analysis. */ | |
468 | if (INTEGRAL_TYPE_P (TREE_TYPE (op)) | |
56778b62 | 469 | && (TYPE_PRECISION (TREE_TYPE (op)) > 1) |
e390c57d | 470 | && wi::eq_p (get_nonzero_bits (op), 1)) |
471 | return true; | |
472 | ||
473 | return false; | |
474 | } | |
475 | ||
4ee9c684 | 476 | /* We no longer need the SSA_NAME expression VAR, release it so that |
48e1416a | 477 | it may be reused. |
4ee9c684 | 478 | |
479 | Note it is assumed that no calls to make_ssa_name will be made | |
480 | until all uses of the ssa name are released and that the only | |
481 | use of the SSA_NAME expression is to check its SSA_NAME_VAR. All | |
482 | other fields must be assumed clobbered. */ | |
483 | ||
484 | void | |
861b4e39 | 485 | release_ssa_name_fn (struct function *fn, tree var) |
4ee9c684 | 486 | { |
dec41e98 | 487 | if (!var) |
488 | return; | |
489 | ||
81d08033 | 490 | /* Never release the default definition for a symbol. It's a |
491 | special SSA name that should always exist once it's created. */ | |
de6ed584 | 492 | if (SSA_NAME_IS_DEFAULT_DEF (var)) |
81d08033 | 493 | return; |
494 | ||
095dcfa3 | 495 | /* If VAR has been registered for SSA updating, don't remove it. |
496 | After update_ssa has run, the name will be released. */ | |
497 | if (name_registered_for_update_p (var)) | |
498 | { | |
499 | release_ssa_name_after_update_ssa (var); | |
500 | return; | |
501 | } | |
deb78f9e | 502 | |
4ee9c684 | 503 | /* release_ssa_name can be called multiple times on a single SSA_NAME. |
504 | However, it should only end up on our free list one time. We | |
505 | keep a status bit in the SSA_NAME node itself to indicate it has | |
48e1416a | 506 | been put on the free list. |
4ee9c684 | 507 | |
508 | Note that once on the freelist you can not reference the SSA_NAME's | |
509 | defining statement. */ | |
510 | if (! SSA_NAME_IN_FREE_LIST (var)) | |
511 | { | |
fa0f49c6 | 512 | tree saved_ssa_name_var = SSA_NAME_VAR (var); |
513 | int saved_ssa_name_version = SSA_NAME_VERSION (var); | |
b66731e8 | 514 | use_operand_p imm = &(SSA_NAME_IMM_USE_NODE (var)); |
22aa74c4 | 515 | |
9845d120 | 516 | if (MAY_HAVE_DEBUG_STMTS) |
688ff29b | 517 | insert_debug_temp_for_var_def (NULL, var); |
9845d120 | 518 | |
382ecba7 | 519 | if (flag_checking) |
520 | verify_imm_links (stderr, var); | |
22aa74c4 | 521 | while (imm->next != imm) |
1fa3a8f6 | 522 | delink_imm_use (imm->next); |
fa0f49c6 | 523 | |
861b4e39 | 524 | (*SSANAMES (fn))[SSA_NAME_VERSION (var)] = NULL_TREE; |
fa0f49c6 | 525 | memset (var, 0, tree_size (var)); |
526 | ||
22aa74c4 | 527 | imm->prev = imm; |
528 | imm->next = imm; | |
75a70cf9 | 529 | imm->loc.ssa_name = var; |
530 | ||
fa0f49c6 | 531 | /* First put back the right tree node so that the tree checking |
532 | macros do not complain. */ | |
533 | TREE_SET_CODE (var, SSA_NAME); | |
534 | ||
535 | /* Restore the version number. */ | |
536 | SSA_NAME_VERSION (var) = saved_ssa_name_version; | |
537 | ||
538 | /* Hopefully this can go away once we have the new incremental | |
539 | SSA updating code installed. */ | |
ec11736b | 540 | SET_SSA_NAME_VAR_OR_IDENTIFIER (var, saved_ssa_name_var); |
fa0f49c6 | 541 | |
542 | /* Note this SSA_NAME is now in the first list. */ | |
4ee9c684 | 543 | SSA_NAME_IN_FREE_LIST (var) = 1; |
fa0f49c6 | 544 | |
16f88e4c | 545 | /* And finally queue it so that it will be put on the free list. */ |
546 | vec_safe_push (FREE_SSANAMES_QUEUE (fn), var); | |
4ee9c684 | 547 | } |
548 | } | |
549 | ||
ceea063b | 550 | /* If the alignment of the pointer described by PI is known, return true and |
551 | store the alignment and the deviation from it into *ALIGNP and *MISALIGNP | |
552 | respectively. Otherwise return false. */ | |
553 | ||
554 | bool | |
555 | get_ptr_info_alignment (struct ptr_info_def *pi, unsigned int *alignp, | |
556 | unsigned int *misalignp) | |
557 | { | |
558 | if (pi->align) | |
559 | { | |
560 | *alignp = pi->align; | |
561 | *misalignp = pi->misalign; | |
562 | return true; | |
563 | } | |
564 | else | |
565 | return false; | |
566 | } | |
567 | ||
568 | /* State that the pointer described by PI has unknown alignment. */ | |
569 | ||
570 | void | |
571 | mark_ptr_info_alignment_unknown (struct ptr_info_def *pi) | |
572 | { | |
573 | pi->align = 0; | |
574 | pi->misalign = 0; | |
575 | } | |
576 | ||
47ae02b7 | 577 | /* Store the power-of-two byte alignment and the deviation from that |
ceea063b | 578 | alignment of pointer described by PI to ALIOGN and MISALIGN |
579 | respectively. */ | |
580 | ||
581 | void | |
582 | set_ptr_info_alignment (struct ptr_info_def *pi, unsigned int align, | |
583 | unsigned int misalign) | |
584 | { | |
585 | gcc_checking_assert (align != 0); | |
586 | gcc_assert ((align & (align - 1)) == 0); | |
587 | gcc_assert ((misalign & ~(align - 1)) == 0); | |
588 | ||
589 | pi->align = align; | |
590 | pi->misalign = misalign; | |
591 | } | |
592 | ||
9d75589a | 593 | /* If pointer described by PI has known alignment, increase its known |
ceea063b | 594 | misalignment by INCREMENT modulo its current alignment. */ |
595 | ||
596 | void | |
597 | adjust_ptr_info_misalignment (struct ptr_info_def *pi, | |
598 | unsigned int increment) | |
599 | { | |
600 | if (pi->align != 0) | |
601 | { | |
602 | pi->misalign += increment; | |
603 | pi->misalign &= (pi->align - 1); | |
604 | } | |
605 | } | |
3aaaf63f | 606 | |
153c3b50 | 607 | /* Return the alias information associated with pointer T. It creates a |
608 | new instance if none existed. */ | |
609 | ||
610 | struct ptr_info_def * | |
611 | get_ptr_info (tree t) | |
3aaaf63f | 612 | { |
153c3b50 | 613 | struct ptr_info_def *pi; |
abb91f0b | 614 | |
153c3b50 | 615 | gcc_assert (POINTER_TYPE_P (TREE_TYPE (t))); |
abb91f0b | 616 | |
153c3b50 | 617 | pi = SSA_NAME_PTR_INFO (t); |
618 | if (pi == NULL) | |
619 | { | |
25a27413 | 620 | pi = ggc_cleared_alloc<ptr_info_def> (); |
153c3b50 | 621 | pt_solution_reset (&pi->pt); |
ceea063b | 622 | mark_ptr_info_alignment_unknown (pi); |
153c3b50 | 623 | SSA_NAME_PTR_INFO (t) = pi; |
624 | } | |
abb91f0b | 625 | |
153c3b50 | 626 | return pi; |
627 | } | |
abb91f0b | 628 | |
874117c8 | 629 | |
630 | /* Creates a new SSA name using the template NAME tobe defined by | |
631 | statement STMT in function FN. */ | |
632 | ||
633 | tree | |
42acab1c | 634 | copy_ssa_name_fn (struct function *fn, tree name, gimple *stmt) |
874117c8 | 635 | { |
ec11736b | 636 | tree new_name; |
637 | ||
638 | if (SSA_NAME_VAR (name)) | |
639 | new_name = make_ssa_name_fn (fn, SSA_NAME_VAR (name), stmt); | |
640 | else | |
641 | { | |
642 | new_name = make_ssa_name_fn (fn, TREE_TYPE (name), stmt); | |
643 | SET_SSA_NAME_VAR_OR_IDENTIFIER (new_name, SSA_NAME_IDENTIFIER (name)); | |
644 | } | |
645 | ||
646 | return new_name; | |
874117c8 | 647 | } |
648 | ||
649 | ||
abb91f0b | 650 | /* Creates a duplicate of the ptr_info_def at PTR_INFO for use by |
095dcfa3 | 651 | the SSA name NAME. */ |
abb91f0b | 652 | |
653 | void | |
654 | duplicate_ssa_name_ptr_info (tree name, struct ptr_info_def *ptr_info) | |
655 | { | |
3aaaf63f | 656 | struct ptr_info_def *new_ptr_info; |
657 | ||
abb91f0b | 658 | gcc_assert (POINTER_TYPE_P (TREE_TYPE (name))); |
659 | gcc_assert (!SSA_NAME_PTR_INFO (name)); | |
660 | ||
661 | if (!ptr_info) | |
662 | return; | |
3aaaf63f | 663 | |
25a27413 | 664 | new_ptr_info = ggc_alloc<ptr_info_def> (); |
abb91f0b | 665 | *new_ptr_info = *ptr_info; |
3aaaf63f | 666 | |
abb91f0b | 667 | SSA_NAME_PTR_INFO (name) = new_ptr_info; |
3aaaf63f | 668 | } |
669 | ||
0c20fe49 | 670 | /* Creates a duplicate of the range_info_def at RANGE_INFO of type |
671 | RANGE_TYPE for use by the SSA name NAME. */ | |
3c59e4a7 | 672 | void |
0c20fe49 | 673 | duplicate_ssa_name_range_info (tree name, enum value_range_type range_type, |
674 | struct range_info_def *range_info) | |
3c59e4a7 | 675 | { |
676 | struct range_info_def *new_range_info; | |
677 | ||
678 | gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); | |
679 | gcc_assert (!SSA_NAME_RANGE_INFO (name)); | |
680 | ||
681 | if (!range_info) | |
682 | return; | |
683 | ||
9c1be15e | 684 | unsigned int precision = TYPE_PRECISION (TREE_TYPE (name)); |
685 | size_t size = (sizeof (range_info_def) | |
686 | + trailing_wide_ints <3>::extra_size (precision)); | |
25a27413 | 687 | new_range_info = static_cast<range_info_def *> (ggc_internal_alloc (size)); |
9c1be15e | 688 | memcpy (new_range_info, range_info, size); |
3c59e4a7 | 689 | |
0c20fe49 | 690 | gcc_assert (range_type == VR_RANGE || range_type == VR_ANTI_RANGE); |
691 | SSA_NAME_ANTI_RANGE_P (name) = (range_type == VR_ANTI_RANGE); | |
3c59e4a7 | 692 | SSA_NAME_RANGE_INFO (name) = new_range_info; |
693 | } | |
694 | ||
695 | ||
81d08033 | 696 | |
874117c8 | 697 | /* Creates a duplicate of a ssa name NAME tobe defined by statement STMT |
698 | in function FN. */ | |
153c3b50 | 699 | |
700 | tree | |
42acab1c | 701 | duplicate_ssa_name_fn (struct function *fn, tree name, gimple *stmt) |
153c3b50 | 702 | { |
874117c8 | 703 | tree new_name = copy_ssa_name_fn (fn, name, stmt); |
3c59e4a7 | 704 | if (POINTER_TYPE_P (TREE_TYPE (name))) |
705 | { | |
706 | struct ptr_info_def *old_ptr_info = SSA_NAME_PTR_INFO (name); | |
707 | ||
708 | if (old_ptr_info) | |
0cf78115 | 709 | duplicate_ssa_name_ptr_info (new_name, old_ptr_info); |
3c59e4a7 | 710 | } |
711 | else | |
712 | { | |
713 | struct range_info_def *old_range_info = SSA_NAME_RANGE_INFO (name); | |
153c3b50 | 714 | |
3c59e4a7 | 715 | if (old_range_info) |
0c20fe49 | 716 | duplicate_ssa_name_range_info (new_name, SSA_NAME_RANGE_TYPE (name), |
717 | old_range_info); | |
3c59e4a7 | 718 | } |
153c3b50 | 719 | |
720 | return new_name; | |
721 | } | |
722 | ||
723 | ||
ace499f6 | 724 | /* Reset all flow sensitive data on NAME such as range-info, nonzero |
725 | bits and alignment. */ | |
726 | ||
727 | void | |
728 | reset_flow_sensitive_info (tree name) | |
729 | { | |
730 | if (POINTER_TYPE_P (TREE_TYPE (name))) | |
731 | { | |
732 | /* points-to info is not flow-sensitive. */ | |
733 | if (SSA_NAME_PTR_INFO (name)) | |
734 | mark_ptr_info_alignment_unknown (SSA_NAME_PTR_INFO (name)); | |
735 | } | |
736 | else | |
737 | SSA_NAME_RANGE_INFO (name) = NULL; | |
738 | } | |
739 | ||
43725011 | 740 | /* Clear all flow sensitive data from all statements and PHI definitions |
741 | in BB. */ | |
742 | ||
743 | void | |
744 | reset_flow_sensitive_info_in_bb (basic_block bb) | |
745 | { | |
746 | for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); | |
747 | gsi_next (&gsi)) | |
748 | { | |
749 | gimple *stmt = gsi_stmt (gsi); | |
750 | ssa_op_iter i; | |
751 | tree op; | |
752 | FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_DEF) | |
753 | reset_flow_sensitive_info (op); | |
754 | } | |
755 | ||
756 | for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); | |
757 | gsi_next (&gsi)) | |
758 | { | |
759 | tree phi_def = gimple_phi_result (gsi.phi ()); | |
760 | reset_flow_sensitive_info (phi_def); | |
761 | } | |
762 | } | |
ace499f6 | 763 | |
81d08033 | 764 | /* Release all the SSA_NAMEs created by STMT. */ |
765 | ||
766 | void | |
42acab1c | 767 | release_defs (gimple *stmt) |
81d08033 | 768 | { |
43daa21e | 769 | tree def; |
770 | ssa_op_iter iter; | |
81d08033 | 771 | |
43daa21e | 772 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
ac6db781 | 773 | if (TREE_CODE (def) == SSA_NAME) |
774 | release_ssa_name (def); | |
81d08033 | 775 | } |
776 | ||
cbbefea4 | 777 | |
778 | /* Replace the symbol associated with SSA_NAME with SYM. */ | |
779 | ||
780 | void | |
781 | replace_ssa_name_symbol (tree ssa_name, tree sym) | |
782 | { | |
ec11736b | 783 | SET_SSA_NAME_VAR_OR_IDENTIFIER (ssa_name, sym); |
cbbefea4 | 784 | TREE_TYPE (ssa_name) = TREE_TYPE (sym); |
785 | } | |
49290934 | 786 | |
4bec4fee | 787 | /* Release the vector of free SSA_NAMEs and compact the vector of SSA_NAMEs |
788 | that are live. */ | |
0b0b7c83 | 789 | |
790 | static void | |
791 | release_free_names_and_compact_live_names (function *fun) | |
792 | { | |
793 | unsigned i, j; | |
794 | int n = vec_safe_length (FREE_SSANAMES (fun)); | |
795 | ||
796 | /* Now release the freelist. */ | |
797 | vec_free (FREE_SSANAMES (fun)); | |
798 | ||
799 | /* And compact the SSA number space. We make sure to not change the | |
800 | relative order of SSA versions. */ | |
801 | for (i = 1, j = 1; i < fun->gimple_df->ssa_names->length (); ++i) | |
802 | { | |
803 | tree name = ssa_name (i); | |
804 | if (name) | |
805 | { | |
806 | if (i != j) | |
807 | { | |
808 | SSA_NAME_VERSION (name) = j; | |
809 | (*fun->gimple_df->ssa_names)[j] = name; | |
810 | } | |
811 | j++; | |
812 | } | |
813 | } | |
814 | fun->gimple_df->ssa_names->truncate (j); | |
815 | ||
816 | statistics_counter_event (fun, "SSA names released", n); | |
817 | statistics_counter_event (fun, "SSA name holes removed", i - j); | |
818 | if (dump_file) | |
819 | fprintf (dump_file, "Released %i names, %.2f%%, removed %i holes\n", | |
820 | n, n * 100.0 / num_ssa_names, i - j); | |
821 | } | |
822 | ||
f901fae2 | 823 | /* Return SSA names that are unused to GGC memory and compact the SSA |
824 | version namespace. This is used to keep footprint of compiler during | |
825 | interprocedural optimization. */ | |
49290934 | 826 | |
7620bc82 | 827 | namespace { |
828 | ||
829 | const pass_data pass_data_release_ssa_names = | |
49290934 | 830 | { |
cbe8bda8 | 831 | GIMPLE_PASS, /* type */ |
832 | "release_ssa", /* name */ | |
833 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 834 | TV_TREE_SSA_OTHER, /* tv_id */ |
835 | PROP_ssa, /* properties_required */ | |
836 | 0, /* properties_provided */ | |
837 | 0, /* properties_destroyed */ | |
838 | TODO_remove_unused_locals, /* todo_flags_start */ | |
839 | 0, /* todo_flags_finish */ | |
49290934 | 840 | }; |
cbe8bda8 | 841 | |
7620bc82 | 842 | class pass_release_ssa_names : public gimple_opt_pass |
cbe8bda8 | 843 | { |
844 | public: | |
9af5ce0c | 845 | pass_release_ssa_names (gcc::context *ctxt) |
846 | : gimple_opt_pass (pass_data_release_ssa_names, ctxt) | |
cbe8bda8 | 847 | {} |
848 | ||
849 | /* opt_pass methods: */ | |
65b0537f | 850 | virtual unsigned int execute (function *); |
cbe8bda8 | 851 | |
852 | }; // class pass_release_ssa_names | |
853 | ||
65b0537f | 854 | unsigned int |
855 | pass_release_ssa_names::execute (function *fun) | |
856 | { | |
0b0b7c83 | 857 | release_free_names_and_compact_live_names (fun); |
65b0537f | 858 | return 0; |
859 | } | |
860 | ||
7620bc82 | 861 | } // anon namespace |
862 | ||
cbe8bda8 | 863 | gimple_opt_pass * |
864 | make_pass_release_ssa_names (gcc::context *ctxt) | |
865 | { | |
866 | return new pass_release_ssa_names (ctxt); | |
867 | } |