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4ee9c684 | 1 | /* Generic routines for manipulating SSA_NAME expressions |
fbd26352 | 2 | Copyright (C) 2003-2019 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" |
26790f09 | 32 | #include "cfgloop.h" |
33 | #include "tree-scalar-evolution.h" | |
4ee9c684 | 34 | |
35 | /* Rewriting a function into SSA form can create a huge number of SSA_NAMEs, | |
36 | many of which may be thrown away shortly after their creation if jumps | |
48e1416a | 37 | were threaded through PHI nodes. |
4ee9c684 | 38 | |
39 | While our garbage collection mechanisms will handle this situation, it | |
40 | is extremely wasteful to create nodes and throw them away, especially | |
41 | when the nodes can be reused. | |
42 | ||
43 | For PR 8361, we can significantly reduce the number of nodes allocated | |
44 | and thus the total amount of memory allocated by managing SSA_NAMEs a | |
45 | little. This additionally helps reduce the amount of work done by the | |
46 | garbage collector. Similar results have been seen on a wider variety | |
47 | of tests (such as the compiler itself). | |
48 | ||
49 | Right now we maintain our free list on a per-function basis. It may | |
50 | or may not make sense to maintain the free list for the duration of | |
48e1416a | 51 | a compilation unit. |
4ee9c684 | 52 | |
53 | External code should rely solely upon HIGHEST_SSA_VERSION and the | |
54 | externally defined functions. External code should not know about | |
55 | the details of the free list management. | |
56 | ||
57 | External code should also not assume the version number on nodes is | |
58 | monotonically increasing. We reuse the version number when we | |
59 | reuse an SSA_NAME expression. This helps keep arrays and bitmaps | |
5cc13354 | 60 | more compact. */ |
4ee9c684 | 61 | |
4ee9c684 | 62 | |
63 | /* Version numbers with special meanings. We start allocating new version | |
64 | numbers after the special ones. */ | |
65 | #define UNUSED_NAME_VERSION 0 | |
66 | ||
4ee9c684 | 67 | unsigned int ssa_name_nodes_reused; |
68 | unsigned int ssa_name_nodes_created; | |
4ee9c684 | 69 | |
9e2e2283 | 70 | #define FREE_SSANAMES(fun) (fun)->gimple_df->free_ssanames |
16f88e4c | 71 | #define FREE_SSANAMES_QUEUE(fun) (fun)->gimple_df->free_ssanames_queue |
9e2e2283 | 72 | |
73 | ||
bcaa2770 | 74 | /* Initialize management of SSA_NAMEs to default SIZE. If SIZE is |
75 | zero use default. */ | |
4ee9c684 | 76 | |
77 | void | |
bcaa2770 | 78 | init_ssanames (struct function *fn, int size) |
4ee9c684 | 79 | { |
bcaa2770 | 80 | if (size < 50) |
81 | size = 50; | |
82 | ||
f1f41a6c | 83 | vec_alloc (SSANAMES (fn), size); |
c211d998 | 84 | |
85 | /* Version 0 is special, so reserve the first slot in the table. Though | |
86 | currently unused, we may use version 0 in alias analysis as part of | |
87 | the heuristics used to group aliases when the alias sets are too | |
8b292c7f | 88 | large. |
89 | ||
f1f41a6c | 90 | We use vec::quick_push here because we know that SSA_NAMES has at |
b62e1ab2 | 91 | least 50 elements reserved in it. */ |
f1f41a6c | 92 | SSANAMES (fn)->quick_push (NULL_TREE); |
bcaa2770 | 93 | FREE_SSANAMES (fn) = NULL; |
16f88e4c | 94 | FREE_SSANAMES_QUEUE (fn) = NULL; |
dd277d48 | 95 | |
e70e8b13 | 96 | fn->gimple_df->ssa_renaming_needed = 0; |
97 | fn->gimple_df->rename_vops = 0; | |
4ee9c684 | 98 | } |
99 | ||
100 | /* Finalize management of SSA_NAMEs. */ | |
101 | ||
102 | void | |
d4f078b5 | 103 | fini_ssanames (struct function *fn) |
4ee9c684 | 104 | { |
d4f078b5 | 105 | vec_free (SSANAMES (fn)); |
106 | vec_free (FREE_SSANAMES (fn)); | |
107 | vec_free (FREE_SSANAMES_QUEUE (fn)); | |
4ee9c684 | 108 | } |
109 | ||
110 | /* Dump some simple statistics regarding the re-use of SSA_NAME nodes. */ | |
111 | ||
4ee9c684 | 112 | void |
113 | ssanames_print_statistics (void) | |
114 | { | |
d7cc3e1c | 115 | fprintf (stderr, "%-32s" PRsa (11) "\n", "SSA_NAME nodes allocated:", |
7a413494 | 116 | SIZE_AMOUNT (ssa_name_nodes_created)); |
d7cc3e1c | 117 | fprintf (stderr, "%-32s" PRsa (11) "\n", "SSA_NAME nodes reused:", |
7a413494 | 118 | SIZE_AMOUNT (ssa_name_nodes_reused)); |
4ee9c684 | 119 | } |
4ee9c684 | 120 | |
0b0b7c83 | 121 | /* Verify the state of the SSA_NAME lists. |
122 | ||
123 | There must be no duplicates on the free list. | |
124 | Every name on the free list must be marked as on the free list. | |
125 | Any name on the free list must not appear in the IL. | |
126 | No names can be leaked. */ | |
127 | ||
128 | DEBUG_FUNCTION void | |
129 | verify_ssaname_freelists (struct function *fun) | |
130 | { | |
6dbbcdee | 131 | if (!gimple_in_ssa_p (fun)) |
132 | return; | |
0b0b7c83 | 133 | |
035def86 | 134 | auto_bitmap names_in_il; |
0b0b7c83 | 135 | |
136 | /* Walk the entire IL noting every SSA_NAME we see. */ | |
6dbbcdee | 137 | basic_block bb; |
0b0b7c83 | 138 | FOR_EACH_BB_FN (bb, fun) |
139 | { | |
140 | tree t; | |
141 | /* First note the result and arguments of PHI nodes. */ | |
142 | for (gphi_iterator gsi = gsi_start_phis (bb); | |
143 | !gsi_end_p (gsi); | |
144 | gsi_next (&gsi)) | |
145 | { | |
146 | gphi *phi = gsi.phi (); | |
147 | t = gimple_phi_result (phi); | |
148 | bitmap_set_bit (names_in_il, SSA_NAME_VERSION (t)); | |
149 | ||
150 | for (unsigned int i = 0; i < gimple_phi_num_args (phi); i++) | |
151 | { | |
152 | t = gimple_phi_arg_def (phi, i); | |
153 | if (TREE_CODE (t) == SSA_NAME) | |
154 | bitmap_set_bit (names_in_il, SSA_NAME_VERSION (t)); | |
155 | } | |
156 | } | |
157 | ||
158 | /* Then note the operands of each statement. */ | |
159 | for (gimple_stmt_iterator gsi = gsi_start_bb (bb); | |
160 | !gsi_end_p (gsi); | |
161 | gsi_next (&gsi)) | |
162 | { | |
163 | ssa_op_iter iter; | |
164 | gimple *stmt = gsi_stmt (gsi); | |
165 | FOR_EACH_SSA_TREE_OPERAND (t, stmt, iter, SSA_OP_ALL_OPERANDS) | |
6dbbcdee | 166 | bitmap_set_bit (names_in_il, SSA_NAME_VERSION (t)); |
0b0b7c83 | 167 | } |
168 | } | |
169 | ||
170 | /* Now walk the free list noting what we find there and verifying | |
171 | there are no duplicates. */ | |
035def86 | 172 | auto_bitmap names_in_freelists; |
0b0b7c83 | 173 | if (FREE_SSANAMES (fun)) |
174 | { | |
175 | for (unsigned int i = 0; i < FREE_SSANAMES (fun)->length (); i++) | |
176 | { | |
177 | tree t = (*FREE_SSANAMES (fun))[i]; | |
178 | ||
179 | /* Verify that the name is marked as being in the free list. */ | |
180 | gcc_assert (SSA_NAME_IN_FREE_LIST (t)); | |
181 | ||
182 | /* Verify the name has not already appeared in the free list and | |
183 | note it in the list of names found in the free list. */ | |
184 | gcc_assert (!bitmap_bit_p (names_in_freelists, SSA_NAME_VERSION (t))); | |
185 | bitmap_set_bit (names_in_freelists, SSA_NAME_VERSION (t)); | |
186 | } | |
187 | } | |
188 | ||
189 | /* Similarly for the names in the pending free list. */ | |
190 | if (FREE_SSANAMES_QUEUE (fun)) | |
191 | { | |
192 | for (unsigned int i = 0; i < FREE_SSANAMES_QUEUE (fun)->length (); i++) | |
193 | { | |
194 | tree t = (*FREE_SSANAMES_QUEUE (fun))[i]; | |
195 | ||
196 | /* Verify that the name is marked as being in the free list. */ | |
197 | gcc_assert (SSA_NAME_IN_FREE_LIST (t)); | |
198 | ||
199 | /* Verify the name has not already appeared in the free list and | |
200 | note it in the list of names found in the free list. */ | |
201 | gcc_assert (!bitmap_bit_p (names_in_freelists, SSA_NAME_VERSION (t))); | |
202 | bitmap_set_bit (names_in_freelists, SSA_NAME_VERSION (t)); | |
203 | } | |
204 | } | |
205 | ||
206 | /* If any name appears in both the IL and the freelists, then | |
207 | something horrible has happened. */ | |
208 | bool intersect_p = bitmap_intersect_p (names_in_il, names_in_freelists); | |
209 | gcc_assert (!intersect_p); | |
210 | ||
211 | /* Names can be queued up for release if there is an ssa update | |
212 | pending. Pretend we saw them in the IL. */ | |
213 | if (names_to_release) | |
214 | bitmap_ior_into (names_in_il, names_to_release); | |
215 | ||
216 | /* Function splitting can "lose" SSA_NAMEs in an effort to ensure that | |
217 | debug/non-debug compilations have the same SSA_NAMEs. So for each | |
218 | lost SSA_NAME, see if it's likely one from that wart. These will always | |
219 | be marked as default definitions. So we loosely assume that anything | |
6dbbcdee | 220 | marked as a default definition isn't leaked by pretending they are |
0b0b7c83 | 221 | in the IL. */ |
222 | for (unsigned int i = UNUSED_NAME_VERSION + 1; i < num_ssa_names; i++) | |
223 | if (ssa_name (i) && SSA_NAME_IS_DEFAULT_DEF (ssa_name (i))) | |
224 | bitmap_set_bit (names_in_il, i); | |
225 | ||
226 | unsigned int i; | |
227 | bitmap_iterator bi; | |
035def86 | 228 | auto_bitmap all_names; |
0b0b7c83 | 229 | bitmap_set_range (all_names, UNUSED_NAME_VERSION + 1, num_ssa_names - 1); |
230 | bitmap_ior_into (names_in_il, names_in_freelists); | |
231 | ||
232 | /* Any name not mentioned in the IL and not in the feelists | |
233 | has been leaked. */ | |
234 | EXECUTE_IF_AND_COMPL_IN_BITMAP(all_names, names_in_il, | |
235 | UNUSED_NAME_VERSION + 1, i, bi) | |
236 | gcc_assert (!ssa_name (i)); | |
0b0b7c83 | 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 | { | |
26790f09 | 248 | /* If there were any SSA names released reset the SCEV cache. */ |
249 | if (! vec_safe_is_empty (FREE_SSANAMES_QUEUE (cfun))) | |
250 | scev_reset_htab (); | |
388e5184 | 251 | vec_safe_splice (FREE_SSANAMES (cfun), FREE_SSANAMES_QUEUE (cfun)); |
252 | vec_safe_truncate (FREE_SSANAMES_QUEUE (cfun), 0); | |
16f88e4c | 253 | } |
254 | ||
bcaa2770 | 255 | /* Return an SSA_NAME node for variable VAR defined in statement STMT |
256 | in function FN. STMT may be an empty statement for artificial | |
257 | references (e.g., default definitions created when a variable is | |
b1f04d34 | 258 | used without a preceding definition). If VERISON is not zero then |
259 | allocate the SSA name with that version. */ | |
4ee9c684 | 260 | |
261 | tree | |
b1f04d34 | 262 | make_ssa_name_fn (struct function *fn, tree var, gimple *stmt, |
263 | unsigned int version) | |
4ee9c684 | 264 | { |
265 | tree t; | |
b66731e8 | 266 | use_operand_p imm; |
4ee9c684 | 267 | |
53e9c5c4 | 268 | gcc_assert (VAR_P (var) |
2f4ec87c | 269 | || TREE_CODE (var) == PARM_DECL |
ec11736b | 270 | || TREE_CODE (var) == RESULT_DECL |
271 | || (TYPE_P (var) && is_gimple_reg_type (var))); | |
4ee9c684 | 272 | |
b1f04d34 | 273 | /* Get the specified SSA name version. */ |
274 | if (version != 0) | |
275 | { | |
276 | t = make_node (SSA_NAME); | |
277 | SSA_NAME_VERSION (t) = version; | |
278 | if (version >= SSANAMES (fn)->length ()) | |
279 | vec_safe_grow_cleared (SSANAMES (fn), version + 1); | |
280 | gcc_assert ((*SSANAMES (fn))[version] == NULL); | |
281 | (*SSANAMES (fn))[version] = t; | |
282 | ssa_name_nodes_created++; | |
283 | } | |
fa0f49c6 | 284 | /* If our free list has an element, then use it. */ |
b1f04d34 | 285 | else if (!vec_safe_is_empty (FREE_SSANAMES (fn))) |
4ee9c684 | 286 | { |
f1f41a6c | 287 | t = FREE_SSANAMES (fn)->pop (); |
0ccdd20e | 288 | ssa_name_nodes_reused++; |
4ee9c684 | 289 | |
fa0f49c6 | 290 | /* The node was cleared out when we put it on the free list, so |
291 | there is no need to do so again here. */ | |
98107def | 292 | gcc_assert ((*SSANAMES (fn))[SSA_NAME_VERSION (t)] == NULL); |
f1f41a6c | 293 | (*SSANAMES (fn))[SSA_NAME_VERSION (t)] = t; |
4ee9c684 | 294 | } |
295 | else | |
296 | { | |
297 | t = make_node (SSA_NAME); | |
f1f41a6c | 298 | SSA_NAME_VERSION (t) = SSANAMES (fn)->length (); |
299 | vec_safe_push (SSANAMES (fn), t); | |
0ccdd20e | 300 | ssa_name_nodes_created++; |
4ee9c684 | 301 | } |
302 | ||
ec11736b | 303 | if (TYPE_P (var)) |
304 | { | |
5a987d87 | 305 | TREE_TYPE (t) = TYPE_MAIN_VARIANT (var); |
ec11736b | 306 | SET_SSA_NAME_VAR_OR_IDENTIFIER (t, NULL_TREE); |
307 | } | |
308 | else | |
309 | { | |
310 | TREE_TYPE (t) = TREE_TYPE (var); | |
311 | SET_SSA_NAME_VAR_OR_IDENTIFIER (t, var); | |
312 | } | |
4ee9c684 | 313 | SSA_NAME_DEF_STMT (t) = stmt; |
3c59e4a7 | 314 | if (POINTER_TYPE_P (TREE_TYPE (t))) |
315 | SSA_NAME_PTR_INFO (t) = NULL; | |
316 | else | |
317 | SSA_NAME_RANGE_INFO (t) = NULL; | |
318 | ||
81d08033 | 319 | SSA_NAME_IN_FREE_LIST (t) = 0; |
de6ed584 | 320 | SSA_NAME_IS_DEFAULT_DEF (t) = 0; |
22aa74c4 | 321 | imm = &(SSA_NAME_IMM_USE_NODE (t)); |
322 | imm->use = NULL; | |
323 | imm->prev = imm; | |
324 | imm->next = imm; | |
75a70cf9 | 325 | imm->loc.ssa_name = t; |
4ee9c684 | 326 | |
327 | return t; | |
328 | } | |
329 | ||
827fc709 | 330 | /* Helper function for set_range_info. |
331 | ||
332 | Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name | |
333 | NAME. */ | |
3c59e4a7 | 334 | |
335 | void | |
be44111e | 336 | set_range_info_raw (tree name, enum value_range_kind range_type, |
827fc709 | 337 | const wide_int_ref &min, const wide_int_ref &max) |
3c59e4a7 | 338 | { |
339 | gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); | |
0c20fe49 | 340 | gcc_assert (range_type == VR_RANGE || range_type == VR_ANTI_RANGE); |
3c59e4a7 | 341 | range_info_def *ri = SSA_NAME_RANGE_INFO (name); |
9c1be15e | 342 | unsigned int precision = TYPE_PRECISION (TREE_TYPE (name)); |
3c59e4a7 | 343 | |
344 | /* Allocate if not available. */ | |
345 | if (ri == NULL) | |
346 | { | |
9c1be15e | 347 | size_t size = (sizeof (range_info_def) |
348 | + trailing_wide_ints <3>::extra_size (precision)); | |
25a27413 | 349 | ri = static_cast<range_info_def *> (ggc_internal_alloc (size)); |
9c1be15e | 350 | ri->ints.set_precision (precision); |
3c59e4a7 | 351 | SSA_NAME_RANGE_INFO (name) = ri; |
9c1be15e | 352 | ri->set_nonzero_bits (wi::shwi (-1, precision)); |
3c59e4a7 | 353 | } |
354 | ||
0c20fe49 | 355 | /* Record the range type. */ |
356 | if (SSA_NAME_RANGE_TYPE (name) != range_type) | |
357 | SSA_NAME_ANTI_RANGE_P (name) = (range_type == VR_ANTI_RANGE); | |
358 | ||
3c59e4a7 | 359 | /* Set the values. */ |
9c1be15e | 360 | ri->set_min (min); |
361 | ri->set_max (max); | |
fc08b993 | 362 | |
363 | /* If it is a range, try to improve nonzero_bits from the min/max. */ | |
0c20fe49 | 364 | if (range_type == VR_RANGE) |
fc08b993 | 365 | { |
9c1be15e | 366 | wide_int xorv = ri->get_min () ^ ri->get_max (); |
aeb682a2 | 367 | if (xorv != 0) |
9c1be15e | 368 | xorv = wi::mask (precision - wi::clz (xorv), false, precision); |
369 | ri->set_nonzero_bits (ri->get_nonzero_bits () & (ri->get_min () | xorv)); | |
fc08b993 | 370 | } |
3c59e4a7 | 371 | } |
372 | ||
827fc709 | 373 | /* Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name |
374 | NAME while making sure we don't store useless range info. */ | |
375 | ||
376 | void | |
be44111e | 377 | set_range_info (tree name, enum value_range_kind range_type, |
827fc709 | 378 | const wide_int_ref &min, const wide_int_ref &max) |
379 | { | |
380 | gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); | |
381 | ||
382 | /* A range of the entire domain is really no range at all. */ | |
383 | tree type = TREE_TYPE (name); | |
384 | if (min == wi::min_value (TYPE_PRECISION (type), TYPE_SIGN (type)) | |
385 | && max == wi::max_value (TYPE_PRECISION (type), TYPE_SIGN (type))) | |
386 | { | |
387 | range_info_def *ri = SSA_NAME_RANGE_INFO (name); | |
388 | if (ri == NULL) | |
389 | return; | |
390 | if (ri->get_nonzero_bits () == -1) | |
391 | { | |
392 | ggc_free (ri); | |
393 | SSA_NAME_RANGE_INFO (name) = NULL; | |
394 | return; | |
395 | } | |
396 | } | |
397 | ||
398 | set_range_info_raw (name, range_type, min, max); | |
399 | } | |
400 | ||
3485e096 | 401 | /* Store range information for NAME from a value_range. */ |
402 | ||
403 | void | |
de9df22a | 404 | set_range_info (tree name, const value_range_base &vr) |
3485e096 | 405 | { |
406 | wide_int min = wi::to_wide (vr.min ()); | |
407 | wide_int max = wi::to_wide (vr.max ()); | |
408 | set_range_info (name, vr.kind (), min, max); | |
409 | } | |
3c59e4a7 | 410 | |
be44111e | 411 | /* Gets range information MIN, MAX and returns enum value_range_kind |
412 | corresponding to tree ssa_name NAME. enum value_range_kind returned | |
3c59e4a7 | 413 | is used to determine if MIN and MAX are valid values. */ |
414 | ||
be44111e | 415 | enum value_range_kind |
9c1be15e | 416 | get_range_info (const_tree name, wide_int *min, wide_int *max) |
3c59e4a7 | 417 | { |
3c59e4a7 | 418 | gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); |
419 | gcc_assert (min && max); | |
420 | range_info_def *ri = SSA_NAME_RANGE_INFO (name); | |
421 | ||
422 | /* Return VR_VARYING for SSA_NAMEs with NULL RANGE_INFO or SSA_NAMEs | |
423 | with integral types width > 2 * HOST_BITS_PER_WIDE_INT precision. */ | |
03b7a719 | 424 | if (!ri || (GET_MODE_PRECISION (SCALAR_INT_TYPE_MODE (TREE_TYPE (name))) |
0cf78115 | 425 | > 2 * HOST_BITS_PER_WIDE_INT)) |
3c59e4a7 | 426 | return VR_VARYING; |
427 | ||
9c1be15e | 428 | *min = ri->get_min (); |
429 | *max = ri->get_max (); | |
0c20fe49 | 430 | return SSA_NAME_RANGE_TYPE (name); |
3c59e4a7 | 431 | } |
c211d998 | 432 | |
3485e096 | 433 | /* Gets range information corresponding to ssa_name NAME and stores it |
434 | in a value_range VR. Returns the value_range_kind. */ | |
435 | ||
436 | enum value_range_kind | |
de9df22a | 437 | get_range_info (const_tree name, value_range_base &vr) |
3485e096 | 438 | { |
439 | tree min, max; | |
440 | wide_int wmin, wmax; | |
441 | enum value_range_kind kind = get_range_info (name, &wmin, &wmax); | |
442 | ||
443 | if (kind == VR_VARYING || kind == VR_UNDEFINED) | |
444 | min = max = NULL; | |
445 | else | |
446 | { | |
447 | min = wide_int_to_tree (TREE_TYPE (name), wmin); | |
448 | max = wide_int_to_tree (TREE_TYPE (name), wmax); | |
449 | } | |
48625f58 | 450 | vr.set (kind, min, max); |
3485e096 | 451 | return kind; |
452 | } | |
453 | ||
5b48910f | 454 | /* Set nonnull attribute to pointer NAME. */ |
455 | ||
456 | void | |
457 | set_ptr_nonnull (tree name) | |
458 | { | |
459 | gcc_assert (POINTER_TYPE_P (TREE_TYPE (name))); | |
460 | struct ptr_info_def *pi = get_ptr_info (name); | |
461 | pi->pt.null = 0; | |
462 | } | |
463 | ||
464 | /* Return nonnull attribute of pointer NAME. */ | |
465 | bool | |
466 | get_ptr_nonnull (const_tree name) | |
467 | { | |
468 | gcc_assert (POINTER_TYPE_P (TREE_TYPE (name))); | |
469 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (name); | |
470 | if (pi == NULL) | |
471 | return false; | |
472 | /* TODO Now pt->null is conservatively set to true in PTA | |
473 | analysis. vrp is the only pass (including ipa-vrp) | |
474 | that clears pt.null via set_ptr_nonull when it knows | |
475 | for sure. PTA will preserves the pt.null value set by VRP. | |
476 | ||
477 | When PTA analysis is improved, pt.anything, pt.nonlocal | |
478 | and pt.escaped may also has to be considered before | |
479 | deciding that pointer cannot point to NULL. */ | |
480 | return !pi->pt.null; | |
481 | } | |
482 | ||
fc08b993 | 483 | /* Change non-zero bits bitmask of NAME. */ |
484 | ||
485 | void | |
9c1be15e | 486 | set_nonzero_bits (tree name, const wide_int_ref &mask) |
fc08b993 | 487 | { |
488 | gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); | |
489 | if (SSA_NAME_RANGE_INFO (name) == NULL) | |
827fc709 | 490 | { |
491 | if (mask == -1) | |
492 | return; | |
493 | set_range_info_raw (name, VR_RANGE, | |
e3d0f65c | 494 | wi::to_wide (TYPE_MIN_VALUE (TREE_TYPE (name))), |
495 | wi::to_wide (TYPE_MAX_VALUE (TREE_TYPE (name)))); | |
827fc709 | 496 | } |
fc08b993 | 497 | range_info_def *ri = SSA_NAME_RANGE_INFO (name); |
9c1be15e | 498 | ri->set_nonzero_bits (mask); |
fc08b993 | 499 | } |
500 | ||
aeb682a2 | 501 | /* Return a widest_int with potentially non-zero bits in SSA_NAME |
ef820217 | 502 | NAME, the constant for INTEGER_CST, or -1 if unknown. */ |
fc08b993 | 503 | |
9c1be15e | 504 | wide_int |
c8a2b4ff | 505 | get_nonzero_bits (const_tree name) |
fc08b993 | 506 | { |
ef820217 | 507 | if (TREE_CODE (name) == INTEGER_CST) |
e3d0f65c | 508 | return wi::to_wide (name); |
ef820217 | 509 | |
bc4e06dc | 510 | /* Use element_precision instead of TYPE_PRECISION so complex and |
511 | vector types get a non-zero precision. */ | |
512 | unsigned int precision = element_precision (TREE_TYPE (name)); | |
fc08b993 | 513 | if (POINTER_TYPE_P (TREE_TYPE (name))) |
514 | { | |
515 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (name); | |
516 | if (pi && pi->align) | |
6e5e0d6b | 517 | return wi::shwi (-(HOST_WIDE_INT) pi->align |
518 | | (HOST_WIDE_INT) pi->misalign, precision); | |
9c1be15e | 519 | return wi::shwi (-1, precision); |
fc08b993 | 520 | } |
521 | ||
522 | range_info_def *ri = SSA_NAME_RANGE_INFO (name); | |
9c1be15e | 523 | if (!ri) |
524 | return wi::shwi (-1, precision); | |
fc08b993 | 525 | |
9c1be15e | 526 | return ri->get_nonzero_bits (); |
fc08b993 | 527 | } |
528 | ||
e390c57d | 529 | /* Return TRUE is OP, an SSA_NAME has a range of values [0..1], false |
530 | otherwise. | |
531 | ||
532 | This can be because it is a boolean type, any unsigned integral | |
533 | type with a single bit of precision, or has known range of [0..1] | |
534 | via VRP analysis. */ | |
535 | ||
536 | bool | |
537 | ssa_name_has_boolean_range (tree op) | |
538 | { | |
539 | gcc_assert (TREE_CODE (op) == SSA_NAME); | |
540 | ||
541 | /* Boolean types always have a range [0..1]. */ | |
542 | if (TREE_CODE (TREE_TYPE (op)) == BOOLEAN_TYPE) | |
543 | return true; | |
544 | ||
545 | /* An integral type with a single bit of precision. */ | |
546 | if (INTEGRAL_TYPE_P (TREE_TYPE (op)) | |
547 | && TYPE_UNSIGNED (TREE_TYPE (op)) | |
548 | && TYPE_PRECISION (TREE_TYPE (op)) == 1) | |
549 | return true; | |
550 | ||
551 | /* An integral type with more precision, but the object | |
552 | only takes on values [0..1] as determined by VRP | |
553 | analysis. */ | |
554 | if (INTEGRAL_TYPE_P (TREE_TYPE (op)) | |
56778b62 | 555 | && (TYPE_PRECISION (TREE_TYPE (op)) > 1) |
e390c57d | 556 | && wi::eq_p (get_nonzero_bits (op), 1)) |
557 | return true; | |
558 | ||
559 | return false; | |
560 | } | |
561 | ||
4ee9c684 | 562 | /* We no longer need the SSA_NAME expression VAR, release it so that |
48e1416a | 563 | it may be reused. |
4ee9c684 | 564 | |
565 | Note it is assumed that no calls to make_ssa_name will be made | |
566 | until all uses of the ssa name are released and that the only | |
567 | use of the SSA_NAME expression is to check its SSA_NAME_VAR. All | |
568 | other fields must be assumed clobbered. */ | |
569 | ||
570 | void | |
861b4e39 | 571 | release_ssa_name_fn (struct function *fn, tree var) |
4ee9c684 | 572 | { |
dec41e98 | 573 | if (!var) |
574 | return; | |
575 | ||
81d08033 | 576 | /* Never release the default definition for a symbol. It's a |
577 | special SSA name that should always exist once it's created. */ | |
de6ed584 | 578 | if (SSA_NAME_IS_DEFAULT_DEF (var)) |
81d08033 | 579 | return; |
580 | ||
095dcfa3 | 581 | /* If VAR has been registered for SSA updating, don't remove it. |
582 | After update_ssa has run, the name will be released. */ | |
583 | if (name_registered_for_update_p (var)) | |
584 | { | |
585 | release_ssa_name_after_update_ssa (var); | |
586 | return; | |
587 | } | |
deb78f9e | 588 | |
4ee9c684 | 589 | /* release_ssa_name can be called multiple times on a single SSA_NAME. |
590 | However, it should only end up on our free list one time. We | |
591 | keep a status bit in the SSA_NAME node itself to indicate it has | |
48e1416a | 592 | been put on the free list. |
4ee9c684 | 593 | |
f4d3c071 | 594 | Note that once on the freelist you cannot reference the SSA_NAME's |
4ee9c684 | 595 | defining statement. */ |
596 | if (! SSA_NAME_IN_FREE_LIST (var)) | |
597 | { | |
fa0f49c6 | 598 | int saved_ssa_name_version = SSA_NAME_VERSION (var); |
b66731e8 | 599 | use_operand_p imm = &(SSA_NAME_IMM_USE_NODE (var)); |
22aa74c4 | 600 | |
c64f38bf | 601 | if (MAY_HAVE_DEBUG_BIND_STMTS) |
688ff29b | 602 | insert_debug_temp_for_var_def (NULL, var); |
9845d120 | 603 | |
382ecba7 | 604 | if (flag_checking) |
605 | verify_imm_links (stderr, var); | |
22aa74c4 | 606 | while (imm->next != imm) |
1fa3a8f6 | 607 | delink_imm_use (imm->next); |
fa0f49c6 | 608 | |
861b4e39 | 609 | (*SSANAMES (fn))[SSA_NAME_VERSION (var)] = NULL_TREE; |
fa0f49c6 | 610 | memset (var, 0, tree_size (var)); |
611 | ||
22aa74c4 | 612 | imm->prev = imm; |
613 | imm->next = imm; | |
75a70cf9 | 614 | imm->loc.ssa_name = var; |
615 | ||
fa0f49c6 | 616 | /* First put back the right tree node so that the tree checking |
617 | macros do not complain. */ | |
618 | TREE_SET_CODE (var, SSA_NAME); | |
619 | ||
620 | /* Restore the version number. */ | |
621 | SSA_NAME_VERSION (var) = saved_ssa_name_version; | |
622 | ||
fa0f49c6 | 623 | /* Note this SSA_NAME is now in the first list. */ |
4ee9c684 | 624 | SSA_NAME_IN_FREE_LIST (var) = 1; |
fa0f49c6 | 625 | |
92bb50f3 | 626 | /* Put in a non-NULL TREE_TYPE so dumping code will not ICE |
627 | if it happens to come along a released SSA name and tries | |
628 | to inspect its type. */ | |
629 | TREE_TYPE (var) = error_mark_node; | |
630 | ||
16f88e4c | 631 | /* And finally queue it so that it will be put on the free list. */ |
632 | vec_safe_push (FREE_SSANAMES_QUEUE (fn), var); | |
4ee9c684 | 633 | } |
634 | } | |
635 | ||
ceea063b | 636 | /* If the alignment of the pointer described by PI is known, return true and |
637 | store the alignment and the deviation from it into *ALIGNP and *MISALIGNP | |
638 | respectively. Otherwise return false. */ | |
639 | ||
640 | bool | |
641 | get_ptr_info_alignment (struct ptr_info_def *pi, unsigned int *alignp, | |
642 | unsigned int *misalignp) | |
643 | { | |
644 | if (pi->align) | |
645 | { | |
646 | *alignp = pi->align; | |
647 | *misalignp = pi->misalign; | |
648 | return true; | |
649 | } | |
650 | else | |
651 | return false; | |
652 | } | |
653 | ||
654 | /* State that the pointer described by PI has unknown alignment. */ | |
655 | ||
656 | void | |
657 | mark_ptr_info_alignment_unknown (struct ptr_info_def *pi) | |
658 | { | |
659 | pi->align = 0; | |
660 | pi->misalign = 0; | |
661 | } | |
662 | ||
47ae02b7 | 663 | /* Store the power-of-two byte alignment and the deviation from that |
ceea063b | 664 | alignment of pointer described by PI to ALIOGN and MISALIGN |
665 | respectively. */ | |
666 | ||
667 | void | |
668 | set_ptr_info_alignment (struct ptr_info_def *pi, unsigned int align, | |
669 | unsigned int misalign) | |
670 | { | |
671 | gcc_checking_assert (align != 0); | |
672 | gcc_assert ((align & (align - 1)) == 0); | |
673 | gcc_assert ((misalign & ~(align - 1)) == 0); | |
674 | ||
675 | pi->align = align; | |
676 | pi->misalign = misalign; | |
677 | } | |
678 | ||
9d75589a | 679 | /* If pointer described by PI has known alignment, increase its known |
ceea063b | 680 | misalignment by INCREMENT modulo its current alignment. */ |
681 | ||
682 | void | |
fa6faa50 | 683 | adjust_ptr_info_misalignment (struct ptr_info_def *pi, poly_uint64 increment) |
ceea063b | 684 | { |
685 | if (pi->align != 0) | |
686 | { | |
fa6faa50 | 687 | increment += pi->misalign; |
688 | if (!known_misalignment (increment, pi->align, &pi->misalign)) | |
689 | { | |
690 | pi->align = known_alignment (increment); | |
691 | pi->misalign = 0; | |
692 | } | |
ceea063b | 693 | } |
694 | } | |
3aaaf63f | 695 | |
153c3b50 | 696 | /* Return the alias information associated with pointer T. It creates a |
697 | new instance if none existed. */ | |
698 | ||
699 | struct ptr_info_def * | |
700 | get_ptr_info (tree t) | |
3aaaf63f | 701 | { |
153c3b50 | 702 | struct ptr_info_def *pi; |
abb91f0b | 703 | |
153c3b50 | 704 | gcc_assert (POINTER_TYPE_P (TREE_TYPE (t))); |
abb91f0b | 705 | |
153c3b50 | 706 | pi = SSA_NAME_PTR_INFO (t); |
707 | if (pi == NULL) | |
708 | { | |
25a27413 | 709 | pi = ggc_cleared_alloc<ptr_info_def> (); |
153c3b50 | 710 | pt_solution_reset (&pi->pt); |
ceea063b | 711 | mark_ptr_info_alignment_unknown (pi); |
153c3b50 | 712 | SSA_NAME_PTR_INFO (t) = pi; |
713 | } | |
abb91f0b | 714 | |
153c3b50 | 715 | return pi; |
716 | } | |
abb91f0b | 717 | |
874117c8 | 718 | |
719 | /* Creates a new SSA name using the template NAME tobe defined by | |
720 | statement STMT in function FN. */ | |
721 | ||
722 | tree | |
42acab1c | 723 | copy_ssa_name_fn (struct function *fn, tree name, gimple *stmt) |
874117c8 | 724 | { |
ec11736b | 725 | tree new_name; |
726 | ||
727 | if (SSA_NAME_VAR (name)) | |
728 | new_name = make_ssa_name_fn (fn, SSA_NAME_VAR (name), stmt); | |
729 | else | |
730 | { | |
731 | new_name = make_ssa_name_fn (fn, TREE_TYPE (name), stmt); | |
732 | SET_SSA_NAME_VAR_OR_IDENTIFIER (new_name, SSA_NAME_IDENTIFIER (name)); | |
733 | } | |
734 | ||
735 | return new_name; | |
874117c8 | 736 | } |
737 | ||
738 | ||
abb91f0b | 739 | /* Creates a duplicate of the ptr_info_def at PTR_INFO for use by |
095dcfa3 | 740 | the SSA name NAME. */ |
abb91f0b | 741 | |
742 | void | |
743 | duplicate_ssa_name_ptr_info (tree name, struct ptr_info_def *ptr_info) | |
744 | { | |
3aaaf63f | 745 | struct ptr_info_def *new_ptr_info; |
746 | ||
abb91f0b | 747 | gcc_assert (POINTER_TYPE_P (TREE_TYPE (name))); |
748 | gcc_assert (!SSA_NAME_PTR_INFO (name)); | |
749 | ||
750 | if (!ptr_info) | |
751 | return; | |
3aaaf63f | 752 | |
25a27413 | 753 | new_ptr_info = ggc_alloc<ptr_info_def> (); |
abb91f0b | 754 | *new_ptr_info = *ptr_info; |
3aaaf63f | 755 | |
abb91f0b | 756 | SSA_NAME_PTR_INFO (name) = new_ptr_info; |
3aaaf63f | 757 | } |
758 | ||
0c20fe49 | 759 | /* Creates a duplicate of the range_info_def at RANGE_INFO of type |
760 | RANGE_TYPE for use by the SSA name NAME. */ | |
3c59e4a7 | 761 | void |
be44111e | 762 | duplicate_ssa_name_range_info (tree name, enum value_range_kind range_type, |
0c20fe49 | 763 | struct range_info_def *range_info) |
3c59e4a7 | 764 | { |
765 | struct range_info_def *new_range_info; | |
766 | ||
767 | gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); | |
768 | gcc_assert (!SSA_NAME_RANGE_INFO (name)); | |
769 | ||
770 | if (!range_info) | |
771 | return; | |
772 | ||
9c1be15e | 773 | unsigned int precision = TYPE_PRECISION (TREE_TYPE (name)); |
774 | size_t size = (sizeof (range_info_def) | |
775 | + trailing_wide_ints <3>::extra_size (precision)); | |
25a27413 | 776 | new_range_info = static_cast<range_info_def *> (ggc_internal_alloc (size)); |
9c1be15e | 777 | memcpy (new_range_info, range_info, size); |
3c59e4a7 | 778 | |
0c20fe49 | 779 | gcc_assert (range_type == VR_RANGE || range_type == VR_ANTI_RANGE); |
780 | SSA_NAME_ANTI_RANGE_P (name) = (range_type == VR_ANTI_RANGE); | |
3c59e4a7 | 781 | SSA_NAME_RANGE_INFO (name) = new_range_info; |
782 | } | |
783 | ||
784 | ||
81d08033 | 785 | |
874117c8 | 786 | /* Creates a duplicate of a ssa name NAME tobe defined by statement STMT |
787 | in function FN. */ | |
153c3b50 | 788 | |
789 | tree | |
42acab1c | 790 | duplicate_ssa_name_fn (struct function *fn, tree name, gimple *stmt) |
153c3b50 | 791 | { |
874117c8 | 792 | tree new_name = copy_ssa_name_fn (fn, name, stmt); |
3c59e4a7 | 793 | if (POINTER_TYPE_P (TREE_TYPE (name))) |
794 | { | |
795 | struct ptr_info_def *old_ptr_info = SSA_NAME_PTR_INFO (name); | |
796 | ||
797 | if (old_ptr_info) | |
0cf78115 | 798 | duplicate_ssa_name_ptr_info (new_name, old_ptr_info); |
3c59e4a7 | 799 | } |
800 | else | |
801 | { | |
802 | struct range_info_def *old_range_info = SSA_NAME_RANGE_INFO (name); | |
153c3b50 | 803 | |
3c59e4a7 | 804 | if (old_range_info) |
0c20fe49 | 805 | duplicate_ssa_name_range_info (new_name, SSA_NAME_RANGE_TYPE (name), |
806 | old_range_info); | |
3c59e4a7 | 807 | } |
153c3b50 | 808 | |
809 | return new_name; | |
810 | } | |
811 | ||
812 | ||
ace499f6 | 813 | /* Reset all flow sensitive data on NAME such as range-info, nonzero |
814 | bits and alignment. */ | |
815 | ||
816 | void | |
817 | reset_flow_sensitive_info (tree name) | |
818 | { | |
819 | if (POINTER_TYPE_P (TREE_TYPE (name))) | |
820 | { | |
821 | /* points-to info is not flow-sensitive. */ | |
822 | if (SSA_NAME_PTR_INFO (name)) | |
823 | mark_ptr_info_alignment_unknown (SSA_NAME_PTR_INFO (name)); | |
824 | } | |
825 | else | |
826 | SSA_NAME_RANGE_INFO (name) = NULL; | |
827 | } | |
828 | ||
43725011 | 829 | /* Clear all flow sensitive data from all statements and PHI definitions |
830 | in BB. */ | |
831 | ||
832 | void | |
833 | reset_flow_sensitive_info_in_bb (basic_block bb) | |
834 | { | |
835 | for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); | |
836 | gsi_next (&gsi)) | |
837 | { | |
838 | gimple *stmt = gsi_stmt (gsi); | |
839 | ssa_op_iter i; | |
840 | tree op; | |
841 | FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_DEF) | |
842 | reset_flow_sensitive_info (op); | |
843 | } | |
844 | ||
845 | for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); | |
846 | gsi_next (&gsi)) | |
847 | { | |
848 | tree phi_def = gimple_phi_result (gsi.phi ()); | |
849 | reset_flow_sensitive_info (phi_def); | |
850 | } | |
851 | } | |
ace499f6 | 852 | |
81d08033 | 853 | /* Release all the SSA_NAMEs created by STMT. */ |
854 | ||
855 | void | |
42acab1c | 856 | release_defs (gimple *stmt) |
81d08033 | 857 | { |
43daa21e | 858 | tree def; |
859 | ssa_op_iter iter; | |
81d08033 | 860 | |
43daa21e | 861 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
ac6db781 | 862 | if (TREE_CODE (def) == SSA_NAME) |
863 | release_ssa_name (def); | |
81d08033 | 864 | } |
865 | ||
cbbefea4 | 866 | |
867 | /* Replace the symbol associated with SSA_NAME with SYM. */ | |
868 | ||
869 | void | |
870 | replace_ssa_name_symbol (tree ssa_name, tree sym) | |
871 | { | |
ec11736b | 872 | SET_SSA_NAME_VAR_OR_IDENTIFIER (ssa_name, sym); |
cbbefea4 | 873 | TREE_TYPE (ssa_name) = TREE_TYPE (sym); |
874 | } | |
49290934 | 875 | |
4bec4fee | 876 | /* Release the vector of free SSA_NAMEs and compact the vector of SSA_NAMEs |
877 | that are live. */ | |
0b0b7c83 | 878 | |
879 | static void | |
880 | release_free_names_and_compact_live_names (function *fun) | |
881 | { | |
882 | unsigned i, j; | |
883 | int n = vec_safe_length (FREE_SSANAMES (fun)); | |
884 | ||
885 | /* Now release the freelist. */ | |
886 | vec_free (FREE_SSANAMES (fun)); | |
887 | ||
888 | /* And compact the SSA number space. We make sure to not change the | |
889 | relative order of SSA versions. */ | |
890 | for (i = 1, j = 1; i < fun->gimple_df->ssa_names->length (); ++i) | |
891 | { | |
892 | tree name = ssa_name (i); | |
893 | if (name) | |
894 | { | |
895 | if (i != j) | |
896 | { | |
897 | SSA_NAME_VERSION (name) = j; | |
898 | (*fun->gimple_df->ssa_names)[j] = name; | |
899 | } | |
900 | j++; | |
901 | } | |
902 | } | |
903 | fun->gimple_df->ssa_names->truncate (j); | |
904 | ||
905 | statistics_counter_event (fun, "SSA names released", n); | |
906 | statistics_counter_event (fun, "SSA name holes removed", i - j); | |
907 | if (dump_file) | |
908 | fprintf (dump_file, "Released %i names, %.2f%%, removed %i holes\n", | |
909 | n, n * 100.0 / num_ssa_names, i - j); | |
910 | } | |
911 | ||
f901fae2 | 912 | /* Return SSA names that are unused to GGC memory and compact the SSA |
913 | version namespace. This is used to keep footprint of compiler during | |
914 | interprocedural optimization. */ | |
49290934 | 915 | |
7620bc82 | 916 | namespace { |
917 | ||
918 | const pass_data pass_data_release_ssa_names = | |
49290934 | 919 | { |
cbe8bda8 | 920 | GIMPLE_PASS, /* type */ |
921 | "release_ssa", /* name */ | |
922 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 923 | TV_TREE_SSA_OTHER, /* tv_id */ |
924 | PROP_ssa, /* properties_required */ | |
925 | 0, /* properties_provided */ | |
926 | 0, /* properties_destroyed */ | |
927 | TODO_remove_unused_locals, /* todo_flags_start */ | |
928 | 0, /* todo_flags_finish */ | |
49290934 | 929 | }; |
cbe8bda8 | 930 | |
7620bc82 | 931 | class pass_release_ssa_names : public gimple_opt_pass |
cbe8bda8 | 932 | { |
933 | public: | |
9af5ce0c | 934 | pass_release_ssa_names (gcc::context *ctxt) |
935 | : gimple_opt_pass (pass_data_release_ssa_names, ctxt) | |
cbe8bda8 | 936 | {} |
937 | ||
938 | /* opt_pass methods: */ | |
65b0537f | 939 | virtual unsigned int execute (function *); |
cbe8bda8 | 940 | |
941 | }; // class pass_release_ssa_names | |
942 | ||
65b0537f | 943 | unsigned int |
944 | pass_release_ssa_names::execute (function *fun) | |
945 | { | |
0b0b7c83 | 946 | release_free_names_and_compact_live_names (fun); |
65b0537f | 947 | return 0; |
948 | } | |
949 | ||
7620bc82 | 950 | } // anon namespace |
951 | ||
cbe8bda8 | 952 | gimple_opt_pass * |
953 | make_pass_release_ssa_names (gcc::context *ctxt) | |
954 | { | |
955 | return new pass_release_ssa_names (ctxt); | |
956 | } |