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6de9cd9a | 1 | /* Conditional constant propagation pass for the GNU compiler. |
06a9b53f | 2 | Copyright (C) 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc. |
6de9cd9a DN |
3 | Adapted from original RTL SSA-CCP by Daniel Berlin <dberlin@dberlin.org> |
4 | Adapted to GIMPLE trees by Diego Novillo <dnovillo@redhat.com> | |
5 | ||
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU General Public License as published by the | |
10 | Free Software Foundation; either version 2, or (at your option) any | |
11 | later version. | |
12 | ||
13 | GCC is distributed in the hope that it will be useful, but WITHOUT | |
14 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with GCC; see the file COPYING. If not, write to the Free | |
20 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
21 | 02111-1307, USA. */ | |
22 | ||
23 | /* Conditional constant propagation. | |
24 | ||
25 | References: | |
26 | ||
27 | Constant propagation with conditional branches, | |
28 | Wegman and Zadeck, ACM TOPLAS 13(2):181-210. | |
29 | ||
30 | Building an Optimizing Compiler, | |
31 | Robert Morgan, Butterworth-Heinemann, 1998, Section 8.9. | |
32 | ||
33 | Advanced Compiler Design and Implementation, | |
34 | Steven Muchnick, Morgan Kaufmann, 1997, Section 12.6 */ | |
35 | ||
36 | #include "config.h" | |
37 | #include "system.h" | |
38 | #include "coretypes.h" | |
39 | #include "tm.h" | |
40 | #include "errors.h" | |
41 | #include "ggc.h" | |
42 | #include "tree.h" | |
43 | #include "langhooks.h" | |
44 | ||
45 | /* These RTL headers are needed for basic-block.h. */ | |
46 | #include "rtl.h" | |
47 | #include "tm_p.h" | |
48 | #include "hard-reg-set.h" | |
49 | #include "basic-block.h" | |
50 | ||
51 | #include "diagnostic.h" | |
52 | #include "tree-inline.h" | |
53 | #include "tree-flow.h" | |
eadf906f | 54 | #include "tree-gimple.h" |
6de9cd9a DN |
55 | #include "tree-dump.h" |
56 | #include "tree-pass.h" | |
57 | #include "timevar.h" | |
58 | #include "expr.h" | |
59 | #include "flags.h" | |
60 | ||
61 | ||
62 | /* Possible lattice values. */ | |
63 | typedef enum | |
64 | { | |
65 | UNINITIALIZED = 0, | |
66 | UNDEFINED, | |
173b818d | 67 | UNKNOWN_VAL, |
6de9cd9a DN |
68 | CONSTANT, |
69 | VARYING | |
70 | } latticevalue; | |
71 | ||
72 | /* Use the TREE_VISITED bitflag to mark statements and PHI nodes that have | |
73 | been deemed VARYING and shouldn't be simulated again. */ | |
74 | #define DONT_SIMULATE_AGAIN(T) TREE_VISITED (T) | |
75 | ||
76 | /* Main structure for CCP. Contains the lattice value and, if it's a | |
77 | constant, the constant value. */ | |
78 | typedef struct | |
79 | { | |
80 | latticevalue lattice_val; | |
81 | tree const_val; | |
82 | } value; | |
83 | ||
84 | /* A bitmap to keep track of executable blocks in the CFG. */ | |
85 | static sbitmap executable_blocks; | |
86 | ||
87 | /* Array of control flow edges on the worklist. */ | |
88 | static GTY(()) varray_type cfg_blocks = NULL; | |
89 | ||
90 | static unsigned int cfg_blocks_num = 0; | |
91 | static int cfg_blocks_tail; | |
92 | static int cfg_blocks_head; | |
93 | ||
94 | static sbitmap bb_in_list; | |
95 | ||
96 | /* This is used to track the current value of each variable. */ | |
97 | static value *value_vector; | |
98 | ||
99 | /* Worklist of SSA edges which will need reexamination as their definition | |
100 | has changed. SSA edges are def-use edges in the SSA web. For each | |
101 | edge, we store the definition statement or PHI node D. The destination | |
95eec0d6 DB |
102 | nodes that need to be visited are accessed using immediate_uses |
103 | (D). */ | |
6de9cd9a DN |
104 | static GTY(()) varray_type ssa_edges; |
105 | ||
95eec0d6 DB |
106 | /* Identical to SSA_EDGES. For performance reasons, the list of SSA |
107 | edges is split into two. One contains all SSA edges who need to be | |
108 | reexamined because their lattice value changed to varying (this | |
109 | worklist), and the other contains all other SSA edges to be | |
110 | reexamined (ssa_edges). | |
111 | ||
112 | Since most values in the program are varying, the ideal situation | |
113 | is to move them to that lattice value as quickly as possible. | |
114 | Thus, it doesn't make sense to process any other type of lattice | |
115 | value until all varying values are propagated fully, which is one | |
116 | thing using the varying worklist achieves. In addition, if you | |
117 | don't use a separate worklist for varying edges, you end up with | |
118 | situations where lattice values move from | |
119 | undefined->constant->varying instead of undefined->varying. | |
120 | */ | |
121 | static GTY(()) varray_type varying_ssa_edges; | |
122 | ||
123 | ||
6de9cd9a DN |
124 | static void initialize (void); |
125 | static void finalize (void); | |
126 | static void visit_phi_node (tree); | |
127 | static tree ccp_fold (tree); | |
128 | static value cp_lattice_meet (value, value); | |
129 | static void visit_stmt (tree); | |
130 | static void visit_cond_stmt (tree); | |
131 | static void visit_assignment (tree); | |
95eec0d6 | 132 | static void add_var_to_ssa_edges_worklist (tree, value); |
6de9cd9a DN |
133 | static void add_outgoing_control_edges (basic_block); |
134 | static void add_control_edge (edge); | |
135 | static void def_to_varying (tree); | |
136 | static void set_lattice_value (tree, value); | |
137 | static void simulate_block (basic_block); | |
138 | static void simulate_stmt (tree); | |
139 | static void substitute_and_fold (void); | |
140 | static value evaluate_stmt (tree); | |
141 | static void dump_lattice_value (FILE *, const char *, value); | |
142 | static bool replace_uses_in (tree, bool *); | |
173b818d | 143 | static bool replace_vuse_in (tree, bool *); |
6de9cd9a DN |
144 | static latticevalue likely_value (tree); |
145 | static tree get_rhs (tree); | |
06a9b53f | 146 | static bool set_rhs (tree *, tree); |
6de9cd9a DN |
147 | static value *get_value (tree); |
148 | static value get_default_value (tree); | |
149 | static tree ccp_fold_builtin (tree, tree); | |
150 | static bool get_strlen (tree, tree *, bitmap); | |
151 | static inline bool cfg_blocks_empty_p (void); | |
152 | static void cfg_blocks_add (basic_block); | |
153 | static basic_block cfg_blocks_get (void); | |
154 | static bool need_imm_uses_for (tree var); | |
155 | ||
95eec0d6 DB |
156 | /* Process an SSA edge worklist. WORKLIST is the SSA edge worklist to |
157 | drain. This pops statements off the given WORKLIST and processes | |
158 | them until there are no more statements on WORKLIST. */ | |
159 | ||
160 | static void | |
161 | process_ssa_edge_worklist (varray_type *worklist) | |
162 | { | |
163 | /* Drain the entire worklist. */ | |
164 | while (VARRAY_ACTIVE_SIZE (*worklist) > 0) | |
165 | { | |
166 | /* Pull the statement to simulate off the worklist. */ | |
167 | tree stmt = VARRAY_TOP_TREE (*worklist); | |
168 | stmt_ann_t ann = stmt_ann (stmt); | |
169 | VARRAY_POP (*worklist); | |
170 | ||
171 | /* visit_stmt can "cancel" reevaluation of some statements. | |
172 | If it does, then in_ccp_worklist will be zero. */ | |
173 | if (ann->in_ccp_worklist) | |
174 | { | |
175 | ann->in_ccp_worklist = 0; | |
176 | simulate_stmt (stmt); | |
177 | } | |
178 | } | |
179 | } | |
180 | ||
6de9cd9a DN |
181 | /* Main entry point for SSA Conditional Constant Propagation. FNDECL is |
182 | the declaration for the function to optimize. | |
183 | ||
184 | On exit, VARS_TO_RENAME will contain the symbols that have been exposed by | |
185 | the propagation of ADDR_EXPR expressions into pointer dereferences and need | |
186 | to be renamed into SSA. | |
187 | ||
188 | PHASE indicates which dump file from the DUMP_FILES array to use when | |
189 | dumping debugging information. */ | |
190 | ||
191 | static void | |
192 | tree_ssa_ccp (void) | |
193 | { | |
194 | initialize (); | |
195 | ||
196 | /* Iterate until the worklists are empty. */ | |
95eec0d6 DB |
197 | while (!cfg_blocks_empty_p () |
198 | || VARRAY_ACTIVE_SIZE (ssa_edges) > 0 | |
199 | || VARRAY_ACTIVE_SIZE (varying_ssa_edges) > 0) | |
6de9cd9a DN |
200 | { |
201 | if (!cfg_blocks_empty_p ()) | |
202 | { | |
203 | /* Pull the next block to simulate off the worklist. */ | |
204 | basic_block dest_block = cfg_blocks_get (); | |
205 | simulate_block (dest_block); | |
206 | } | |
207 | ||
95eec0d6 DB |
208 | /* In order to move things to varying as quickly as |
209 | possible,process the VARYING_SSA_EDGES worklist first. */ | |
210 | process_ssa_edge_worklist (&varying_ssa_edges); | |
211 | ||
212 | /* Now process the SSA_EDGES worklist. */ | |
213 | process_ssa_edge_worklist (&ssa_edges); | |
6de9cd9a DN |
214 | } |
215 | ||
216 | /* Now perform substitutions based on the known constant values. */ | |
217 | substitute_and_fold (); | |
218 | ||
219 | /* Now cleanup any unreachable code. */ | |
220 | cleanup_tree_cfg (); | |
221 | ||
222 | /* Free allocated memory. */ | |
223 | finalize (); | |
224 | ||
225 | /* Debugging dumps. */ | |
226 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
227 | { | |
228 | dump_referenced_vars (dump_file); | |
229 | fprintf (dump_file, "\n\n"); | |
230 | } | |
231 | } | |
232 | ||
233 | static bool | |
234 | gate_ccp (void) | |
235 | { | |
236 | return flag_tree_ccp != 0; | |
237 | } | |
238 | ||
239 | struct tree_opt_pass pass_ccp = | |
240 | { | |
241 | "ccp", /* name */ | |
242 | gate_ccp, /* gate */ | |
243 | tree_ssa_ccp, /* execute */ | |
244 | NULL, /* sub */ | |
245 | NULL, /* next */ | |
246 | 0, /* static_pass_number */ | |
247 | TV_TREE_CCP, /* tv_id */ | |
c1b763fa | 248 | PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */ |
6de9cd9a DN |
249 | 0, /* properties_provided */ |
250 | 0, /* properties_destroyed */ | |
251 | 0, /* todo_flags_start */ | |
252 | TODO_dump_func | TODO_rename_vars | |
1eaba2f2 RH |
253 | | TODO_ggc_collect | TODO_verify_ssa |
254 | | TODO_verify_stmts /* todo_flags_finish */ | |
6de9cd9a DN |
255 | }; |
256 | ||
257 | ||
258 | /* Get the constant value associated with variable VAR. */ | |
259 | ||
260 | static value * | |
261 | get_value (tree var) | |
262 | { | |
263 | value *val; | |
264 | ||
265 | #if defined ENABLE_CHECKING | |
266 | if (TREE_CODE (var) != SSA_NAME) | |
267 | abort (); | |
268 | #endif | |
269 | ||
270 | val = &value_vector[SSA_NAME_VERSION (var)]; | |
271 | if (val->lattice_val == UNINITIALIZED) | |
272 | *val = get_default_value (var); | |
273 | ||
274 | return val; | |
275 | } | |
276 | ||
277 | ||
278 | /* Simulate the execution of BLOCK. Evaluate the statement associated | |
279 | with each variable reference inside the block. */ | |
280 | ||
281 | static void | |
282 | simulate_block (basic_block block) | |
283 | { | |
284 | tree phi; | |
285 | ||
286 | /* There is nothing to do for the exit block. */ | |
287 | if (block == EXIT_BLOCK_PTR) | |
288 | return; | |
289 | ||
290 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
291 | fprintf (dump_file, "\nSimulating block %d\n", block->index); | |
292 | ||
293 | /* Always simulate PHI nodes, even if we have simulated this block | |
294 | before. */ | |
17192884 | 295 | for (phi = phi_nodes (block); phi; phi = PHI_CHAIN (phi)) |
6de9cd9a DN |
296 | visit_phi_node (phi); |
297 | ||
298 | /* If this is the first time we've simulated this block, then we | |
299 | must simulate each of its statements. */ | |
300 | if (!TEST_BIT (executable_blocks, block->index)) | |
301 | { | |
302 | block_stmt_iterator j; | |
303 | unsigned int normal_edge_count; | |
304 | edge e, normal_edge; | |
305 | ||
306 | /* Note that we have simulated this block. */ | |
307 | SET_BIT (executable_blocks, block->index); | |
308 | ||
309 | for (j = bsi_start (block); !bsi_end_p (j); bsi_next (&j)) | |
310 | visit_stmt (bsi_stmt (j)); | |
311 | ||
312 | /* We can not predict when abnormal edges will be executed, so | |
313 | once a block is considered executable, we consider any | |
314 | outgoing abnormal edges as executable. | |
315 | ||
316 | At the same time, if this block has only one successor that is | |
317 | reached by non-abnormal edges, then add that successor to the | |
318 | worklist. */ | |
319 | normal_edge_count = 0; | |
320 | normal_edge = NULL; | |
321 | for (e = block->succ; e; e = e->succ_next) | |
322 | { | |
323 | if (e->flags & EDGE_ABNORMAL) | |
324 | { | |
325 | add_control_edge (e); | |
326 | } | |
327 | else | |
328 | { | |
329 | normal_edge_count++; | |
330 | normal_edge = e; | |
331 | } | |
332 | } | |
333 | ||
334 | if (normal_edge_count == 1) | |
335 | add_control_edge (normal_edge); | |
336 | } | |
337 | } | |
338 | ||
339 | ||
340 | /* Follow the def-use edges for statement DEF_STMT and simulate all the | |
341 | statements reached by it. */ | |
342 | ||
343 | static void | |
344 | simulate_stmt (tree use_stmt) | |
345 | { | |
346 | basic_block use_bb = bb_for_stmt (use_stmt); | |
347 | ||
348 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
349 | { | |
350 | fprintf (dump_file, "\nSimulating statement (from ssa_edges): "); | |
351 | print_generic_stmt (dump_file, use_stmt, dump_flags); | |
352 | } | |
353 | ||
354 | if (TREE_CODE (use_stmt) == PHI_NODE) | |
355 | { | |
356 | /* PHI nodes are always visited, regardless of whether or not the | |
357 | destination block is executable. */ | |
358 | visit_phi_node (use_stmt); | |
359 | } | |
360 | else if (TEST_BIT (executable_blocks, use_bb->index)) | |
361 | { | |
362 | /* Otherwise, visit the statement containing the use reached by | |
363 | DEF, only if the destination block is marked executable. */ | |
364 | visit_stmt (use_stmt); | |
365 | } | |
366 | } | |
367 | ||
368 | ||
369 | /* Perform final substitution and folding. After this pass the program | |
370 | should still be in SSA form. */ | |
371 | ||
372 | static void | |
373 | substitute_and_fold (void) | |
374 | { | |
375 | basic_block bb; | |
376 | ||
377 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
378 | fprintf (dump_file, | |
379 | "\nSubstituing constants and folding statements\n\n"); | |
380 | ||
381 | /* Substitute constants in every statement of every basic block. */ | |
382 | FOR_EACH_BB (bb) | |
383 | { | |
384 | block_stmt_iterator i; | |
385 | tree phi; | |
386 | ||
387 | /* Propagate our known constants into PHI nodes. */ | |
17192884 | 388 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) |
6de9cd9a DN |
389 | { |
390 | int i; | |
391 | ||
392 | for (i = 0; i < PHI_NUM_ARGS (phi); i++) | |
393 | { | |
394 | value *new_val; | |
d00ad49b AM |
395 | use_operand_p orig_p = PHI_ARG_DEF_PTR (phi, i); |
396 | tree orig = USE_FROM_PTR (orig_p); | |
6de9cd9a | 397 | |
d00ad49b | 398 | if (! SSA_VAR_P (orig)) |
6de9cd9a DN |
399 | break; |
400 | ||
d00ad49b | 401 | new_val = get_value (orig); |
6de9cd9a | 402 | if (new_val->lattice_val == CONSTANT |
d00ad49b AM |
403 | && may_propagate_copy (orig, new_val->const_val)) |
404 | SET_USE (orig_p, new_val->const_val); | |
6de9cd9a DN |
405 | } |
406 | } | |
407 | ||
408 | for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i)) | |
409 | { | |
410 | bool replaced_address; | |
411 | tree stmt = bsi_stmt (i); | |
412 | ||
413 | /* Skip statements that have been folded already. */ | |
414 | if (stmt_modified_p (stmt) || !is_exec_stmt (stmt)) | |
415 | continue; | |
416 | ||
417 | /* Replace the statement with its folded version and mark it | |
418 | folded. */ | |
419 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
420 | { | |
421 | fprintf (dump_file, "Line %d: replaced ", get_lineno (stmt)); | |
422 | print_generic_stmt (dump_file, stmt, TDF_SLIM); | |
423 | } | |
424 | ||
173b818d BB |
425 | if (replace_uses_in (stmt, &replaced_address) |
426 | || replace_vuse_in (stmt, &replaced_address)) | |
6de9cd9a DN |
427 | { |
428 | bool changed = fold_stmt (bsi_stmt_ptr (i)); | |
429 | stmt = bsi_stmt(i); | |
430 | modify_stmt (stmt); | |
431 | /* If we folded a builtin function, we'll likely | |
432 | need to rename VDEFs. */ | |
433 | if (replaced_address || changed) | |
1eaba2f2 RH |
434 | { |
435 | mark_new_vars_to_rename (stmt, vars_to_rename); | |
436 | if (maybe_clean_eh_stmt (stmt)) | |
437 | tree_purge_dead_eh_edges (bb); | |
438 | } | |
6de9cd9a DN |
439 | } |
440 | ||
441 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
442 | { | |
443 | fprintf (dump_file, " with "); | |
444 | print_generic_stmt (dump_file, stmt, TDF_SLIM); | |
445 | fprintf (dump_file, "\n"); | |
446 | } | |
447 | } | |
448 | } | |
449 | } | |
450 | ||
451 | ||
452 | /* Loop through the PHI_NODE's parameters for BLOCK and compare their | |
453 | lattice values to determine PHI_NODE's lattice value. The value of a | |
454 | PHI node is determined calling cp_lattice_meet() with all the arguments | |
455 | of the PHI node that are incoming via executable edges. */ | |
456 | ||
457 | static void | |
458 | visit_phi_node (tree phi) | |
459 | { | |
460 | bool short_circuit = 0; | |
461 | value phi_val, *curr_val; | |
462 | int i; | |
463 | ||
464 | /* If the PHI node has already been deemed to be VARYING, don't simulate | |
465 | it again. */ | |
466 | if (DONT_SIMULATE_AGAIN (phi)) | |
467 | return; | |
468 | ||
469 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
470 | { | |
471 | fprintf (dump_file, "\nVisiting PHI node: "); | |
472 | print_generic_expr (dump_file, phi, dump_flags); | |
473 | } | |
474 | ||
475 | curr_val = get_value (PHI_RESULT (phi)); | |
476 | switch (curr_val->lattice_val) | |
477 | { | |
478 | case VARYING: | |
479 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
480 | fprintf (dump_file, "\n Shortcircuit. Default of VARYING."); | |
481 | short_circuit = 1; | |
482 | break; | |
483 | ||
484 | case CONSTANT: | |
485 | phi_val = *curr_val; | |
486 | break; | |
487 | ||
173b818d BB |
488 | case UNKNOWN_VAL: |
489 | /* To avoid the default value of UNKNOWN_VAL overriding | |
490 | that of its possible constant arguments, temporarily | |
491 | set the phi node's default lattice value to be | |
492 | UNDEFINED. At the same time, place something other | |
493 | than NULL_TREE in phi_val.const_val as a flag to | |
494 | check when setting a new state for this phi node to | |
495 | ensure that we avoid incorrect state transitions from | |
496 | UNKNOWN_VAL to UNDEFINED. */ | |
497 | phi_val.lattice_val = UNDEFINED; | |
498 | phi_val.const_val = phi; | |
499 | break; | |
500 | ||
6de9cd9a DN |
501 | case UNDEFINED: |
502 | case UNINITIALIZED: | |
503 | phi_val.lattice_val = UNDEFINED; | |
504 | phi_val.const_val = NULL_TREE; | |
505 | break; | |
506 | ||
507 | default: | |
508 | abort (); | |
509 | } | |
510 | ||
511 | /* If the variable is volatile or the variable is never referenced in a | |
512 | real operand, then consider the PHI node VARYING. */ | |
513 | if (short_circuit || TREE_THIS_VOLATILE (SSA_NAME_VAR (PHI_RESULT (phi)))) | |
514 | { | |
515 | phi_val.lattice_val = VARYING; | |
516 | phi_val.const_val = NULL; | |
517 | } | |
518 | else | |
519 | for (i = 0; i < PHI_NUM_ARGS (phi); i++) | |
520 | { | |
9cf737f8 | 521 | /* Compute the meet operator over all the PHI arguments. */ |
6de9cd9a DN |
522 | edge e = PHI_ARG_EDGE (phi, i); |
523 | ||
524 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
525 | { | |
526 | fprintf (dump_file, | |
527 | "\n Argument #%d (%d -> %d %sexecutable)\n", | |
528 | i, e->src->index, e->dest->index, | |
529 | (e->flags & EDGE_EXECUTABLE) ? "" : "not "); | |
530 | } | |
531 | ||
532 | /* If the incoming edge is executable, Compute the meet operator for | |
533 | the existing value of the PHI node and the current PHI argument. */ | |
534 | if (e->flags & EDGE_EXECUTABLE) | |
535 | { | |
536 | tree rdef = PHI_ARG_DEF (phi, i); | |
537 | value *rdef_val, val; | |
538 | ||
539 | if (is_gimple_min_invariant (rdef)) | |
540 | { | |
541 | val.lattice_val = CONSTANT; | |
542 | val.const_val = rdef; | |
543 | rdef_val = &val; | |
544 | } | |
545 | else | |
546 | rdef_val = get_value (rdef); | |
547 | ||
548 | phi_val = cp_lattice_meet (phi_val, *rdef_val); | |
549 | ||
550 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
551 | { | |
552 | fprintf (dump_file, "\t"); | |
553 | print_generic_expr (dump_file, rdef, dump_flags); | |
554 | dump_lattice_value (dump_file, "\tValue: ", *rdef_val); | |
555 | fprintf (dump_file, "\n"); | |
556 | } | |
557 | ||
558 | if (phi_val.lattice_val == VARYING) | |
559 | break; | |
560 | } | |
561 | } | |
562 | ||
563 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
564 | { | |
565 | dump_lattice_value (dump_file, "\n PHI node value: ", phi_val); | |
566 | fprintf (dump_file, "\n\n"); | |
567 | } | |
568 | ||
173b818d BB |
569 | /* Check for an invalid change from UNKNOWN_VAL to UNDEFINED. */ |
570 | if (phi_val.lattice_val != UNDEFINED || phi_val.const_val == NULL_TREE) | |
571 | { | |
572 | set_lattice_value (PHI_RESULT (phi), phi_val); | |
573 | if (phi_val.lattice_val == VARYING) | |
574 | DONT_SIMULATE_AGAIN (phi) = 1; | |
575 | } | |
6de9cd9a DN |
576 | } |
577 | ||
578 | ||
579 | /* Compute the meet operator between VAL1 and VAL2: | |
580 | ||
173b818d BB |
581 | any M UNDEFINED = any |
582 | any M VARYING = VARYING | |
583 | any M UNKNOWN_VAL = UNKNOWN_VAL | |
584 | Ci M Cj = Ci if (i == j) | |
585 | Ci M Cj = VARYING if (i != j) */ | |
6de9cd9a DN |
586 | static value |
587 | cp_lattice_meet (value val1, value val2) | |
588 | { | |
589 | value result; | |
590 | ||
591 | /* any M UNDEFINED = any. */ | |
592 | if (val1.lattice_val == UNDEFINED) | |
593 | return val2; | |
594 | else if (val2.lattice_val == UNDEFINED) | |
595 | return val1; | |
596 | ||
597 | /* any M VARYING = VARYING. */ | |
598 | if (val1.lattice_val == VARYING || val2.lattice_val == VARYING) | |
599 | { | |
600 | result.lattice_val = VARYING; | |
601 | result.const_val = NULL_TREE; | |
602 | return result; | |
603 | } | |
604 | ||
173b818d BB |
605 | /* any M UNKNOWN_VAL = UNKNOWN_VAL. */ |
606 | if (val1.lattice_val == UNKNOWN_VAL | |
607 | || val2.lattice_val == UNKNOWN_VAL) | |
608 | { | |
609 | result.lattice_val = UNKNOWN_VAL; | |
610 | result.const_val = NULL_TREE; | |
611 | return result; | |
612 | } | |
613 | ||
6de9cd9a DN |
614 | /* Ci M Cj = Ci if (i == j) |
615 | Ci M Cj = VARYING if (i != j) */ | |
616 | if (simple_cst_equal (val1.const_val, val2.const_val) == 1) | |
617 | { | |
618 | result.lattice_val = CONSTANT; | |
619 | result.const_val = val1.const_val; | |
620 | } | |
621 | else | |
622 | { | |
623 | result.lattice_val = VARYING; | |
624 | result.const_val = NULL_TREE; | |
625 | } | |
626 | ||
627 | return result; | |
628 | } | |
629 | ||
630 | ||
631 | /* Evaluate statement STMT. If the statement produces an output value and | |
632 | its evaluation changes the lattice value of its output, do the following: | |
633 | ||
634 | - If the statement is an assignment, add all the SSA edges starting at | |
635 | this definition. | |
636 | ||
637 | - If the statement is a conditional branch: | |
638 | . If the statement evaluates to non-constant, add all edges to | |
639 | worklist. | |
640 | . If the statement is constant, add the edge executed as the | |
641 | result of the branch. */ | |
642 | ||
643 | static void | |
644 | visit_stmt (tree stmt) | |
645 | { | |
646 | size_t i; | |
647 | stmt_ann_t ann; | |
648 | def_optype defs; | |
a32b97a2 BB |
649 | v_may_def_optype v_may_defs; |
650 | v_must_def_optype v_must_defs; | |
6de9cd9a DN |
651 | |
652 | /* If the statement has already been deemed to be VARYING, don't simulate | |
653 | it again. */ | |
654 | if (DONT_SIMULATE_AGAIN (stmt)) | |
655 | return; | |
656 | ||
657 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
658 | { | |
659 | fprintf (dump_file, "\nVisiting statement: "); | |
660 | print_generic_stmt (dump_file, stmt, TDF_SLIM); | |
661 | fprintf (dump_file, "\n"); | |
662 | } | |
663 | ||
664 | ann = stmt_ann (stmt); | |
665 | ||
666 | /* If this statement is already in the worklist then "cancel" it. The | |
667 | reevaluation implied by the worklist entry will produce the same | |
668 | value we generate here and thus reevaluating it again from the | |
669 | worklist is pointless. */ | |
670 | if (ann->in_ccp_worklist) | |
671 | ann->in_ccp_worklist = 0; | |
672 | ||
673 | /* Now examine the statement. If the statement is an assignment that | |
674 | produces a single output value, evaluate its RHS to see if the lattice | |
675 | value of its output has changed. */ | |
173b818d BB |
676 | v_must_defs = V_MUST_DEF_OPS (ann); |
677 | v_may_defs = V_MAY_DEF_OPS (ann); | |
6de9cd9a | 678 | if (TREE_CODE (stmt) == MODIFY_EXPR |
173b818d BB |
679 | && NUM_V_MAY_DEFS (v_may_defs) == 0 |
680 | && (NUM_V_MUST_DEFS (v_must_defs) == 1 | |
681 | || TREE_CODE (TREE_OPERAND (stmt, 0)) == SSA_NAME)) | |
6de9cd9a DN |
682 | visit_assignment (stmt); |
683 | ||
684 | /* Definitions made by statements other than assignments to SSA_NAMEs | |
685 | represent unknown modifications to their outputs. Mark them VARYING. */ | |
686 | else if (NUM_DEFS (defs = DEF_OPS (ann)) != 0) | |
687 | { | |
688 | DONT_SIMULATE_AGAIN (stmt) = 1; | |
689 | for (i = 0; i < NUM_DEFS (defs); i++) | |
690 | { | |
691 | tree def = DEF_OP (defs, i); | |
692 | def_to_varying (def); | |
693 | } | |
694 | } | |
695 | ||
696 | /* If STMT is a conditional branch, see if we can determine which branch | |
697 | will be taken. */ | |
698 | else if (TREE_CODE (stmt) == COND_EXPR || TREE_CODE (stmt) == SWITCH_EXPR) | |
699 | visit_cond_stmt (stmt); | |
700 | ||
701 | /* Any other kind of statement is not interesting for constant | |
702 | propagation and, therefore, not worth simulating. */ | |
703 | else | |
704 | { | |
705 | DONT_SIMULATE_AGAIN (stmt) = 1; | |
706 | ||
707 | /* If STMT is a computed goto, then mark all the output edges | |
708 | executable. */ | |
709 | if (computed_goto_p (stmt)) | |
710 | add_outgoing_control_edges (bb_for_stmt (stmt)); | |
711 | } | |
712 | ||
a32b97a2 BB |
713 | /* Mark all V_MAY_DEF operands VARYING. */ |
714 | v_may_defs = V_MAY_DEF_OPS (ann); | |
715 | for (i = 0; i < NUM_V_MAY_DEFS (v_may_defs); i++) | |
716 | def_to_varying (V_MAY_DEF_RESULT (v_may_defs, i)); | |
717 | ||
6de9cd9a DN |
718 | } |
719 | ||
720 | ||
721 | /* Visit the assignment statement STMT. Set the value of its LHS to the | |
722 | value computed by the RHS. */ | |
723 | ||
724 | static void | |
725 | visit_assignment (tree stmt) | |
726 | { | |
727 | value val; | |
728 | tree lhs, rhs; | |
173b818d BB |
729 | vuse_optype vuses; |
730 | v_must_def_optype v_must_defs; | |
6de9cd9a DN |
731 | |
732 | lhs = TREE_OPERAND (stmt, 0); | |
733 | rhs = TREE_OPERAND (stmt, 1); | |
173b818d BB |
734 | vuses = STMT_VUSE_OPS (stmt); |
735 | v_must_defs = STMT_V_MUST_DEF_OPS (stmt); | |
736 | ||
737 | #if defined ENABLE_CHECKING | |
738 | if (NUM_V_MAY_DEFS (STMT_V_MAY_DEF_OPS (stmt)) > 0 | |
739 | || (NUM_V_MUST_DEFS (v_must_defs) != 1 | |
740 | && TREE_CODE (lhs) != SSA_NAME)) | |
741 | abort (); | |
742 | #endif | |
6de9cd9a | 743 | |
173b818d BB |
744 | /* We require the SSA version number of the lhs for the value_vector. |
745 | Make sure we have it. */ | |
746 | if (TREE_CODE (lhs) != SSA_NAME) | |
6de9cd9a | 747 | { |
173b818d BB |
748 | /* If we make it here, then stmt only has one definition: |
749 | a V_MUST_DEF. */ | |
750 | lhs = V_MUST_DEF_OP (v_must_defs, 0); | |
6de9cd9a | 751 | } |
173b818d BB |
752 | |
753 | if (TREE_CODE (rhs) == SSA_NAME) | |
6de9cd9a DN |
754 | { |
755 | /* For a simple copy operation, we copy the lattice values. */ | |
756 | value *nval = get_value (rhs); | |
757 | val = *nval; | |
173b818d BB |
758 | } |
759 | else if (DECL_P (rhs) | |
760 | && NUM_VUSES (vuses) == 1 | |
761 | && rhs == SSA_NAME_VAR (VUSE_OP (vuses, 0))) | |
762 | { | |
763 | /* Same as above, but the rhs is not a gimple register and yet | |
764 | has a known VUSE. */ | |
765 | value *nval = get_value (VUSE_OP (vuses, 0)); | |
766 | val = *nval; | |
6de9cd9a DN |
767 | } |
768 | else | |
769 | { | |
770 | /* Evaluate the statement. */ | |
771 | val = evaluate_stmt (stmt); | |
772 | } | |
773 | ||
774 | /* FIXME: Hack. If this was a definition of a bitfield, we need to widen | |
775 | the constant value into the type of the destination variable. This | |
776 | should not be necessary if GCC represented bitfields properly. */ | |
777 | { | |
778 | tree lhs = TREE_OPERAND (stmt, 0); | |
779 | if (val.lattice_val == CONSTANT | |
780 | && TREE_CODE (lhs) == COMPONENT_REF | |
781 | && DECL_BIT_FIELD (TREE_OPERAND (lhs, 1))) | |
782 | { | |
783 | tree w = widen_bitfield (val.const_val, TREE_OPERAND (lhs, 1), lhs); | |
784 | ||
785 | if (w && is_gimple_min_invariant (w)) | |
786 | val.const_val = w; | |
787 | else | |
788 | { | |
789 | val.lattice_val = VARYING; | |
790 | val.const_val = NULL; | |
791 | } | |
792 | } | |
793 | } | |
794 | ||
4fa204da DN |
795 | /* If LHS is not a gimple register, then it cannot take on an |
796 | UNDEFINED value. */ | |
797 | if (!is_gimple_reg (SSA_NAME_VAR (lhs)) | |
798 | && val.lattice_val == UNDEFINED) | |
799 | val.lattice_val = UNKNOWN_VAL; | |
800 | ||
6de9cd9a DN |
801 | /* Set the lattice value of the statement's output. */ |
802 | set_lattice_value (lhs, val); | |
803 | if (val.lattice_val == VARYING) | |
804 | DONT_SIMULATE_AGAIN (stmt) = 1; | |
805 | } | |
806 | ||
807 | ||
808 | /* Visit the conditional statement STMT. If it evaluates to a constant value, | |
809 | mark outgoing edges appropriately. */ | |
810 | ||
811 | static void | |
812 | visit_cond_stmt (tree stmt) | |
813 | { | |
814 | edge e; | |
815 | value val; | |
816 | basic_block block; | |
817 | ||
818 | block = bb_for_stmt (stmt); | |
819 | val = evaluate_stmt (stmt); | |
820 | ||
821 | /* Find which edge out of the conditional block will be taken and add it | |
822 | to the worklist. If no single edge can be determined statically, add | |
823 | all outgoing edges from BLOCK. */ | |
824 | e = find_taken_edge (block, val.const_val); | |
825 | if (e) | |
826 | add_control_edge (e); | |
827 | else | |
828 | { | |
829 | DONT_SIMULATE_AGAIN (stmt) = 1; | |
830 | add_outgoing_control_edges (block); | |
831 | } | |
832 | } | |
833 | ||
834 | ||
835 | /* Add all the edges coming out of BB to the control flow worklist. */ | |
836 | ||
837 | static void | |
838 | add_outgoing_control_edges (basic_block bb) | |
839 | { | |
840 | edge e; | |
841 | ||
842 | for (e = bb->succ; e; e = e->succ_next) | |
843 | add_control_edge (e); | |
844 | } | |
845 | ||
846 | ||
847 | /* Add edge E to the control flow worklist. */ | |
848 | ||
849 | static void | |
850 | add_control_edge (edge e) | |
851 | { | |
852 | basic_block bb = e->dest; | |
853 | if (bb == EXIT_BLOCK_PTR) | |
854 | return; | |
855 | ||
856 | /* If the edge had already been executed, skip it. */ | |
857 | if (e->flags & EDGE_EXECUTABLE) | |
858 | return; | |
859 | ||
860 | e->flags |= EDGE_EXECUTABLE; | |
861 | ||
862 | /* If the block is already in the list, we're done. */ | |
863 | if (TEST_BIT (bb_in_list, bb->index)) | |
864 | return; | |
865 | ||
866 | cfg_blocks_add (bb); | |
867 | ||
868 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
869 | fprintf (dump_file, "Adding Destination of edge (%d -> %d) to worklist\n\n", | |
870 | e->src->index, e->dest->index); | |
871 | } | |
872 | ||
873 | ||
874 | /* CCP specific front-end to the non-destructive constant folding routines. | |
875 | ||
876 | Attempt to simplify the RHS of STMT knowing that one or more | |
877 | operands are constants. | |
878 | ||
879 | If simplification is possible, return the simplified RHS, | |
880 | otherwise return the original RHS. */ | |
881 | ||
882 | static tree | |
883 | ccp_fold (tree stmt) | |
884 | { | |
885 | tree rhs = get_rhs (stmt); | |
886 | enum tree_code code = TREE_CODE (rhs); | |
887 | int kind = TREE_CODE_CLASS (code); | |
888 | tree retval = NULL_TREE; | |
173b818d BB |
889 | vuse_optype vuses; |
890 | ||
891 | vuses = STMT_VUSE_OPS (stmt); | |
6de9cd9a DN |
892 | |
893 | /* If the RHS is just a variable, then that variable must now have | |
894 | a constant value that we can return directly. */ | |
895 | if (TREE_CODE (rhs) == SSA_NAME) | |
896 | return get_value (rhs)->const_val; | |
173b818d BB |
897 | else if (DECL_P (rhs) |
898 | && NUM_VUSES (vuses) == 1 | |
899 | && rhs == SSA_NAME_VAR (VUSE_OP (vuses, 0))) | |
900 | return get_value (VUSE_OP (vuses, 0))->const_val; | |
6de9cd9a DN |
901 | |
902 | /* Unary operators. Note that we know the single operand must | |
903 | be a constant. So this should almost always return a | |
904 | simplified RHS. */ | |
905 | if (kind == '1') | |
906 | { | |
907 | /* Handle unary operators which can appear in GIMPLE form. */ | |
908 | tree op0 = TREE_OPERAND (rhs, 0); | |
909 | ||
910 | /* Simplify the operand down to a constant. */ | |
911 | if (TREE_CODE (op0) == SSA_NAME) | |
912 | { | |
913 | value *val = get_value (op0); | |
914 | if (val->lattice_val == CONSTANT) | |
915 | op0 = get_value (op0)->const_val; | |
916 | } | |
917 | ||
918 | retval = nondestructive_fold_unary_to_constant (code, | |
919 | TREE_TYPE (rhs), | |
920 | op0); | |
921 | ||
922 | /* If we folded, but did not create an invariant, then we can not | |
923 | use this expression. */ | |
924 | if (retval && ! is_gimple_min_invariant (retval)) | |
925 | return NULL; | |
926 | ||
927 | /* If we could not fold the expression, but the arguments are all | |
928 | constants and gimple values, then build and return the new | |
929 | expression. | |
930 | ||
931 | In some cases the new expression is still something we can | |
932 | use as a replacement for an argument. This happens with | |
933 | NOP conversions of types for example. | |
934 | ||
935 | In other cases the new expression can not be used as a | |
936 | replacement for an argument (as it would create non-gimple | |
937 | code). But the new expression can still be used to derive | |
938 | other constants. */ | |
939 | if (! retval && is_gimple_min_invariant (op0)) | |
940 | return build1 (code, TREE_TYPE (rhs), op0); | |
941 | } | |
942 | ||
943 | /* Binary and comparison operators. We know one or both of the | |
944 | operands are constants. */ | |
945 | else if (kind == '2' | |
946 | || kind == '<' | |
947 | || code == TRUTH_AND_EXPR | |
948 | || code == TRUTH_OR_EXPR | |
949 | || code == TRUTH_XOR_EXPR) | |
950 | { | |
951 | /* Handle binary and comparison operators that can appear in | |
952 | GIMPLE form. */ | |
953 | tree op0 = TREE_OPERAND (rhs, 0); | |
954 | tree op1 = TREE_OPERAND (rhs, 1); | |
955 | ||
956 | /* Simplify the operands down to constants when appropriate. */ | |
957 | if (TREE_CODE (op0) == SSA_NAME) | |
958 | { | |
959 | value *val = get_value (op0); | |
960 | if (val->lattice_val == CONSTANT) | |
961 | op0 = val->const_val; | |
962 | } | |
963 | ||
964 | if (TREE_CODE (op1) == SSA_NAME) | |
965 | { | |
966 | value *val = get_value (op1); | |
967 | if (val->lattice_val == CONSTANT) | |
968 | op1 = val->const_val; | |
969 | } | |
970 | ||
971 | retval = nondestructive_fold_binary_to_constant (code, | |
972 | TREE_TYPE (rhs), | |
973 | op0, op1); | |
974 | ||
975 | /* If we folded, but did not create an invariant, then we can not | |
976 | use this expression. */ | |
977 | if (retval && ! is_gimple_min_invariant (retval)) | |
978 | return NULL; | |
979 | ||
980 | /* If we could not fold the expression, but the arguments are all | |
981 | constants and gimple values, then build and return the new | |
982 | expression. | |
983 | ||
984 | In some cases the new expression is still something we can | |
985 | use as a replacement for an argument. This happens with | |
986 | NOP conversions of types for example. | |
987 | ||
988 | In other cases the new expression can not be used as a | |
989 | replacement for an argument (as it would create non-gimple | |
990 | code). But the new expression can still be used to derive | |
991 | other constants. */ | |
992 | if (! retval | |
993 | && is_gimple_min_invariant (op0) | |
994 | && is_gimple_min_invariant (op1)) | |
995 | return build (code, TREE_TYPE (rhs), op0, op1); | |
996 | } | |
997 | ||
998 | /* We may be able to fold away calls to builtin functions if their | |
9cf737f8 | 999 | arguments are constants. */ |
6de9cd9a DN |
1000 | else if (code == CALL_EXPR |
1001 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == ADDR_EXPR | |
1002 | && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (rhs, 0), 0)) | |
1003 | == FUNCTION_DECL) | |
1004 | && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (rhs, 0), 0))) | |
1005 | { | |
1006 | use_optype uses = STMT_USE_OPS (stmt); | |
1007 | if (NUM_USES (uses) != 0) | |
1008 | { | |
1009 | tree *orig; | |
1010 | size_t i; | |
1011 | ||
1012 | /* Preserve the original values of every operand. */ | |
1013 | orig = xmalloc (sizeof (tree) * NUM_USES (uses)); | |
1014 | for (i = 0; i < NUM_USES (uses); i++) | |
1015 | orig[i] = USE_OP (uses, i); | |
1016 | ||
1017 | /* Substitute operands with their values and try to fold. */ | |
1018 | replace_uses_in (stmt, NULL); | |
a32e70c3 | 1019 | retval = fold_builtin (rhs, false); |
6de9cd9a DN |
1020 | |
1021 | /* Restore operands to their original form. */ | |
1022 | for (i = 0; i < NUM_USES (uses); i++) | |
d00ad49b | 1023 | SET_USE_OP (uses, i, orig[i]); |
6de9cd9a DN |
1024 | free (orig); |
1025 | } | |
1026 | } | |
1027 | else | |
1028 | return rhs; | |
1029 | ||
1030 | /* If we got a simplified form, see if we need to convert its type. */ | |
1031 | if (retval) | |
a32e70c3 | 1032 | return fold_convert (TREE_TYPE (rhs), retval); |
6de9cd9a DN |
1033 | |
1034 | /* No simplification was possible. */ | |
1035 | return rhs; | |
1036 | } | |
1037 | ||
1038 | ||
1039 | /* Evaluate statement STMT. */ | |
1040 | ||
1041 | static value | |
1042 | evaluate_stmt (tree stmt) | |
1043 | { | |
1044 | value val; | |
1045 | tree simplified; | |
1046 | latticevalue likelyvalue = likely_value (stmt); | |
1047 | ||
1048 | /* If the statement is likely to have a CONSTANT result, then try | |
1049 | to fold the statement to determine the constant value. */ | |
1050 | if (likelyvalue == CONSTANT) | |
1051 | simplified = ccp_fold (stmt); | |
1052 | /* If the statement is likely to have a VARYING result, then do not | |
1053 | bother folding the statement. */ | |
1054 | else if (likelyvalue == VARYING) | |
1055 | simplified = get_rhs (stmt); | |
1056 | /* Otherwise the statement is likely to have an UNDEFINED value and | |
1057 | there will be nothing to do. */ | |
1058 | else | |
1059 | simplified = NULL_TREE; | |
1060 | ||
1061 | if (simplified && is_gimple_min_invariant (simplified)) | |
1062 | { | |
1063 | /* The statement produced a constant value. */ | |
1064 | val.lattice_val = CONSTANT; | |
1065 | val.const_val = simplified; | |
1066 | } | |
1067 | else | |
1068 | { | |
1069 | /* The statement produced a nonconstant value. If the statement | |
173b818d BB |
1070 | had undefined or virtual operands, then the result of the |
1071 | statement should be undefined or virtual respectively. | |
1072 | Else the result of the statement is VARYING. */ | |
6de9cd9a | 1073 | val.lattice_val = (likelyvalue == UNDEFINED ? UNDEFINED : VARYING); |
173b818d BB |
1074 | val.lattice_val = (likelyvalue == UNKNOWN_VAL |
1075 | ? UNKNOWN_VAL : val.lattice_val); | |
6de9cd9a DN |
1076 | val.const_val = NULL_TREE; |
1077 | } | |
1078 | ||
1079 | return val; | |
1080 | } | |
1081 | ||
1082 | ||
1083 | /* Debugging dumps. */ | |
1084 | ||
1085 | static void | |
1086 | dump_lattice_value (FILE *outf, const char *prefix, value val) | |
1087 | { | |
1088 | switch (val.lattice_val) | |
1089 | { | |
1090 | case UNDEFINED: | |
1091 | fprintf (outf, "%sUNDEFINED", prefix); | |
1092 | break; | |
1093 | case VARYING: | |
1094 | fprintf (outf, "%sVARYING", prefix); | |
1095 | break; | |
173b818d BB |
1096 | case UNKNOWN_VAL: |
1097 | fprintf (outf, "%sUNKNOWN_VAL", prefix); | |
1098 | break; | |
6de9cd9a DN |
1099 | case CONSTANT: |
1100 | fprintf (outf, "%sCONSTANT ", prefix); | |
1101 | print_generic_expr (outf, val.const_val, dump_flags); | |
1102 | break; | |
1103 | default: | |
1104 | abort (); | |
1105 | } | |
1106 | } | |
1107 | ||
1108 | /* Given a constant value VAL for bitfield FIELD, and a destination | |
1109 | variable VAR, return VAL appropriately widened to fit into VAR. If | |
1110 | FIELD is wider than HOST_WIDE_INT, NULL is returned. */ | |
1111 | ||
1112 | tree | |
1113 | widen_bitfield (tree val, tree field, tree var) | |
1114 | { | |
44de5aeb | 1115 | unsigned HOST_WIDE_INT var_size, field_size; |
6de9cd9a DN |
1116 | tree wide_val; |
1117 | unsigned HOST_WIDE_INT mask; | |
44de5aeb | 1118 | unsigned int i; |
6de9cd9a | 1119 | |
44de5aeb RK |
1120 | /* We can only do this if the size of the type and field and VAL are |
1121 | all constants representable in HOST_WIDE_INT. */ | |
1122 | if (!host_integerp (TYPE_SIZE (TREE_TYPE (var)), 1) | |
1123 | || !host_integerp (DECL_SIZE (field), 1) | |
1124 | || !host_integerp (val, 0)) | |
1125 | return NULL_TREE; | |
1126 | ||
1127 | var_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (var)), 1); | |
1128 | field_size = tree_low_cst (DECL_SIZE (field), 1); | |
6de9cd9a DN |
1129 | |
1130 | /* Give up if either the bitfield or the variable are too wide. */ | |
1131 | if (field_size > HOST_BITS_PER_WIDE_INT || var_size > HOST_BITS_PER_WIDE_INT) | |
44de5aeb | 1132 | return NULL_TREE; |
6de9cd9a DN |
1133 | |
1134 | #if defined ENABLE_CHECKING | |
1135 | if (var_size < field_size) | |
1136 | abort (); | |
1137 | #endif | |
1138 | ||
44de5aeb RK |
1139 | /* If the sign bit of the value is not set or the field's type is unsigned, |
1140 | just mask off the high order bits of the value. */ | |
1141 | if (DECL_UNSIGNED (field) | |
1142 | || !(tree_low_cst (val, 0) & (((HOST_WIDE_INT)1) << (field_size - 1)))) | |
6de9cd9a DN |
1143 | { |
1144 | /* Zero extension. Build a mask with the lower 'field_size' bits | |
1145 | set and a BIT_AND_EXPR node to clear the high order bits of | |
1146 | the value. */ | |
1147 | for (i = 0, mask = 0; i < field_size; i++) | |
44de5aeb | 1148 | mask |= ((HOST_WIDE_INT) 1) << i; |
6de9cd9a DN |
1149 | |
1150 | wide_val = build (BIT_AND_EXPR, TREE_TYPE (var), val, | |
44de5aeb | 1151 | fold_convert (TREE_TYPE (var), build_int_2 (mask, 0))); |
6de9cd9a DN |
1152 | } |
1153 | else | |
1154 | { | |
1155 | /* Sign extension. Create a mask with the upper 'field_size' | |
1156 | bits set and a BIT_IOR_EXPR to set the high order bits of the | |
1157 | value. */ | |
1158 | for (i = 0, mask = 0; i < (var_size - field_size); i++) | |
44de5aeb | 1159 | mask |= ((HOST_WIDE_INT) 1) << (var_size - i - 1); |
6de9cd9a DN |
1160 | |
1161 | wide_val = build (BIT_IOR_EXPR, TREE_TYPE (var), val, | |
44de5aeb | 1162 | fold_convert (TREE_TYPE (var), build_int_2 (mask, 0))); |
6de9cd9a DN |
1163 | } |
1164 | ||
1165 | return fold (wide_val); | |
1166 | } | |
1167 | ||
1168 | ||
1169 | /* Function indicating whether we ought to include information for 'var' | |
1170 | when calculating immediate uses. */ | |
1171 | ||
1172 | static bool | |
1173 | need_imm_uses_for (tree var) | |
1174 | { | |
1175 | return get_value (var)->lattice_val != VARYING; | |
1176 | } | |
1177 | ||
1178 | ||
1179 | /* Initialize local data structures and worklists for CCP. */ | |
1180 | ||
1181 | static void | |
1182 | initialize (void) | |
1183 | { | |
1184 | edge e; | |
1185 | basic_block bb; | |
1186 | sbitmap virtual_var; | |
1187 | ||
95eec0d6 | 1188 | /* Worklists of SSA edges. */ |
6de9cd9a | 1189 | VARRAY_TREE_INIT (ssa_edges, 20, "ssa_edges"); |
95eec0d6 | 1190 | VARRAY_TREE_INIT (varying_ssa_edges, 20, "varying_ssa_edges"); |
6de9cd9a DN |
1191 | |
1192 | executable_blocks = sbitmap_alloc (last_basic_block); | |
1193 | sbitmap_zero (executable_blocks); | |
1194 | ||
1195 | bb_in_list = sbitmap_alloc (last_basic_block); | |
1196 | sbitmap_zero (bb_in_list); | |
1197 | ||
95a3742c DN |
1198 | value_vector = (value *) xmalloc (num_ssa_names * sizeof (value)); |
1199 | memset (value_vector, 0, num_ssa_names * sizeof (value)); | |
6de9cd9a DN |
1200 | |
1201 | /* 1 if ssa variable is used in a virtual variable context. */ | |
95a3742c | 1202 | virtual_var = sbitmap_alloc (num_ssa_names); |
6de9cd9a DN |
1203 | sbitmap_zero (virtual_var); |
1204 | ||
1205 | /* Initialize default values and simulation flags for PHI nodes, statements | |
1206 | and edges. */ | |
1207 | FOR_EACH_BB (bb) | |
1208 | { | |
1209 | block_stmt_iterator i; | |
1210 | tree stmt; | |
1211 | stmt_ann_t ann; | |
1212 | def_optype defs; | |
a32b97a2 BB |
1213 | v_may_def_optype v_may_defs; |
1214 | v_must_def_optype v_must_defs; | |
6de9cd9a DN |
1215 | size_t x; |
1216 | int vary; | |
1217 | ||
1218 | /* Get the default value for each definition. */ | |
1219 | for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i)) | |
1220 | { | |
1221 | vary = 0; | |
1222 | stmt = bsi_stmt (i); | |
1223 | get_stmt_operands (stmt); | |
1224 | ann = stmt_ann (stmt); | |
1225 | defs = DEF_OPS (ann); | |
1226 | for (x = 0; x < NUM_DEFS (defs); x++) | |
1227 | { | |
1228 | tree def = DEF_OP (defs, x); | |
1229 | if (get_value (def)->lattice_val == VARYING) | |
1230 | vary = 1; | |
1231 | } | |
173b818d BB |
1232 | |
1233 | /* Get the default value for each V_MUST_DEF. */ | |
1234 | v_must_defs = V_MUST_DEF_OPS (ann); | |
1235 | for (x = 0; x < NUM_V_MUST_DEFS (v_must_defs); x++) | |
1236 | { | |
1237 | tree v_must_def = V_MUST_DEF_OP (v_must_defs, x); | |
1238 | if (get_value (v_must_def)->lattice_val == VARYING) | |
1239 | vary = 1; | |
1240 | } | |
1241 | ||
6de9cd9a DN |
1242 | DONT_SIMULATE_AGAIN (stmt) = vary; |
1243 | ||
a32b97a2 BB |
1244 | /* Mark all V_MAY_DEF operands VARYING. */ |
1245 | v_may_defs = V_MAY_DEF_OPS (ann); | |
1246 | for (x = 0; x < NUM_V_MAY_DEFS (v_may_defs); x++) | |
6de9cd9a | 1247 | { |
a32b97a2 | 1248 | tree res = V_MAY_DEF_RESULT (v_may_defs, x); |
6de9cd9a DN |
1249 | get_value (res)->lattice_val = VARYING; |
1250 | SET_BIT (virtual_var, SSA_NAME_VERSION (res)); | |
1251 | } | |
1252 | } | |
1253 | ||
1254 | for (e = bb->succ; e; e = e->succ_next) | |
1255 | e->flags &= ~EDGE_EXECUTABLE; | |
1256 | } | |
1257 | ||
1258 | /* Now process PHI nodes. */ | |
1259 | FOR_EACH_BB (bb) | |
1260 | { | |
1261 | tree phi, var; | |
1262 | int x; | |
17192884 | 1263 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) |
6de9cd9a DN |
1264 | { |
1265 | value *val; | |
1266 | val = get_value (PHI_RESULT (phi)); | |
1267 | if (val->lattice_val != VARYING) | |
1268 | { | |
1269 | for (x = 0; x < PHI_NUM_ARGS (phi); x++) | |
1270 | { | |
1271 | var = PHI_ARG_DEF (phi, x); | |
173b818d BB |
1272 | /* If one argument has a V_MAY_DEF, |
1273 | the result is varying. */ | |
6de9cd9a DN |
1274 | if (TREE_CODE (var) == SSA_NAME) |
1275 | { | |
1276 | if (TEST_BIT (virtual_var, SSA_NAME_VERSION (var))) | |
1277 | { | |
1278 | val->lattice_val = VARYING; | |
1279 | SET_BIT (virtual_var, | |
1280 | SSA_NAME_VERSION (PHI_RESULT (phi))); | |
1281 | break; | |
1282 | } | |
1283 | } | |
1284 | } | |
1285 | } | |
1286 | DONT_SIMULATE_AGAIN (phi) = ((val->lattice_val == VARYING) ? 1 : 0); | |
1287 | } | |
1288 | } | |
1289 | ||
1290 | sbitmap_free (virtual_var); | |
1291 | /* Compute immediate uses for variables we care about. */ | |
173b818d | 1292 | compute_immediate_uses (TDFA_USE_OPS | TDFA_USE_VOPS, need_imm_uses_for); |
6de9cd9a DN |
1293 | |
1294 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1295 | dump_immediate_uses (dump_file); | |
1296 | ||
1297 | VARRAY_BB_INIT (cfg_blocks, 20, "cfg_blocks"); | |
1298 | ||
1299 | /* Seed the algorithm by adding the successors of the entry block to the | |
1300 | edge worklist. */ | |
1301 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
1302 | { | |
1303 | if (e->dest != EXIT_BLOCK_PTR) | |
1304 | { | |
1305 | e->flags |= EDGE_EXECUTABLE; | |
1306 | cfg_blocks_add (e->dest); | |
1307 | } | |
1308 | } | |
1309 | } | |
1310 | ||
1311 | ||
1312 | /* Free allocated storage. */ | |
1313 | ||
1314 | static void | |
1315 | finalize (void) | |
1316 | { | |
1317 | ssa_edges = NULL; | |
95eec0d6 | 1318 | varying_ssa_edges = NULL; |
6de9cd9a DN |
1319 | cfg_blocks = NULL; |
1320 | free (value_vector); | |
1321 | sbitmap_free (bb_in_list); | |
1322 | sbitmap_free (executable_blocks); | |
1323 | free_df (); | |
1324 | } | |
1325 | ||
1326 | /* Is the block worklist empty. */ | |
1327 | ||
1328 | static inline bool | |
1329 | cfg_blocks_empty_p (void) | |
1330 | { | |
1331 | return (cfg_blocks_num == 0); | |
1332 | } | |
1333 | ||
1334 | /* Add a basic block to the worklist. */ | |
1335 | ||
1336 | static void | |
1337 | cfg_blocks_add (basic_block bb) | |
1338 | { | |
1339 | if (bb == ENTRY_BLOCK_PTR || bb == EXIT_BLOCK_PTR) | |
1340 | return; | |
1341 | ||
1342 | if (TEST_BIT (bb_in_list, bb->index)) | |
1343 | return; | |
1344 | ||
1345 | if (cfg_blocks_empty_p ()) | |
1346 | { | |
1347 | cfg_blocks_tail = cfg_blocks_head = 0; | |
1348 | cfg_blocks_num = 1; | |
1349 | } | |
1350 | else | |
1351 | { | |
1352 | cfg_blocks_num++; | |
1353 | if (cfg_blocks_num > VARRAY_SIZE (cfg_blocks)) | |
1354 | { | |
1355 | /* We have to grow the array now. Adjust to queue to occupy the | |
1356 | full space of the original array. */ | |
1357 | cfg_blocks_tail = VARRAY_SIZE (cfg_blocks); | |
1358 | cfg_blocks_head = 0; | |
1359 | VARRAY_GROW (cfg_blocks, 2 * VARRAY_SIZE (cfg_blocks)); | |
1360 | } | |
1361 | else | |
1362 | cfg_blocks_tail = (cfg_blocks_tail + 1) % VARRAY_SIZE (cfg_blocks); | |
1363 | } | |
1364 | VARRAY_BB (cfg_blocks, cfg_blocks_tail) = bb; | |
1365 | SET_BIT (bb_in_list, bb->index); | |
1366 | } | |
1367 | ||
1368 | /* Remove a block from the worklist. */ | |
1369 | ||
1370 | static basic_block | |
1371 | cfg_blocks_get (void) | |
1372 | { | |
1373 | basic_block bb; | |
1374 | ||
1375 | bb = VARRAY_BB (cfg_blocks, cfg_blocks_head); | |
1376 | ||
1377 | #ifdef ENABLE_CHECKING | |
1378 | if (cfg_blocks_empty_p () || !bb) | |
1379 | abort (); | |
1380 | #endif | |
1381 | ||
1382 | cfg_blocks_head = (cfg_blocks_head + 1) % VARRAY_SIZE (cfg_blocks); | |
1383 | --cfg_blocks_num; | |
1384 | RESET_BIT (bb_in_list, bb->index); | |
1385 | ||
1386 | return bb; | |
1387 | } | |
1388 | ||
1389 | /* We have just defined a new value for VAR. Add all immediate uses | |
95eec0d6 | 1390 | of VAR to the ssa_edges or varying_ssa_edges worklist. */ |
6de9cd9a | 1391 | static void |
95eec0d6 | 1392 | add_var_to_ssa_edges_worklist (tree var, value val) |
6de9cd9a DN |
1393 | { |
1394 | tree stmt = SSA_NAME_DEF_STMT (var); | |
1395 | dataflow_t df = get_immediate_uses (stmt); | |
1396 | int num_uses = num_immediate_uses (df); | |
1397 | int i; | |
1398 | ||
1399 | for (i = 0; i < num_uses; i++) | |
1400 | { | |
1401 | tree use = immediate_use (df, i); | |
1402 | ||
1403 | if (!DONT_SIMULATE_AGAIN (use)) | |
1404 | { | |
1405 | stmt_ann_t ann = stmt_ann (use); | |
1406 | if (ann->in_ccp_worklist == 0) | |
1407 | { | |
1408 | ann->in_ccp_worklist = 1; | |
95eec0d6 DB |
1409 | if (val.lattice_val == VARYING) |
1410 | VARRAY_PUSH_TREE (varying_ssa_edges, use); | |
1411 | else | |
1412 | VARRAY_PUSH_TREE (ssa_edges, use); | |
6de9cd9a DN |
1413 | } |
1414 | } | |
1415 | } | |
1416 | } | |
1417 | ||
1418 | /* Set the lattice value for the variable VAR to VARYING. */ | |
1419 | ||
1420 | static void | |
1421 | def_to_varying (tree var) | |
1422 | { | |
1423 | value val; | |
1424 | val.lattice_val = VARYING; | |
1425 | val.const_val = NULL_TREE; | |
1426 | set_lattice_value (var, val); | |
1427 | } | |
1428 | ||
1429 | /* Set the lattice value for variable VAR to VAL. */ | |
1430 | ||
1431 | static void | |
1432 | set_lattice_value (tree var, value val) | |
1433 | { | |
1434 | value *old = get_value (var); | |
1435 | ||
1436 | #ifdef ENABLE_CHECKING | |
1437 | if (val.lattice_val == UNDEFINED) | |
1438 | { | |
1439 | /* CONSTANT->UNDEFINED is never a valid state transition. */ | |
1440 | if (old->lattice_val == CONSTANT) | |
1441 | abort (); | |
173b818d BB |
1442 | |
1443 | /* UNKNOWN_VAL->UNDEFINED is never a valid state transition. */ | |
1444 | if (old->lattice_val == UNKNOWN_VAL) | |
1445 | abort (); | |
6de9cd9a DN |
1446 | |
1447 | /* VARYING->UNDEFINED is generally not a valid state transition, | |
1448 | except for values which are initialized to VARYING. */ | |
1449 | if (old->lattice_val == VARYING | |
1450 | && get_default_value (var).lattice_val != VARYING) | |
1451 | abort (); | |
1452 | } | |
1453 | else if (val.lattice_val == CONSTANT) | |
1454 | { | |
1455 | /* VARYING -> CONSTANT is an invalid state transition, except | |
1456 | for objects which start off in a VARYING state. */ | |
1457 | if (old->lattice_val == VARYING | |
1458 | && get_default_value (var).lattice_val != VARYING) | |
1459 | abort (); | |
1460 | } | |
1461 | #endif | |
1462 | ||
1463 | /* If the constant for VAR has changed, then this VAR is really varying. */ | |
1464 | if (old->lattice_val == CONSTANT && val.lattice_val == CONSTANT | |
1465 | && !simple_cst_equal (old->const_val, val.const_val)) | |
1466 | { | |
1467 | val.lattice_val = VARYING; | |
1468 | val.const_val = NULL_TREE; | |
1469 | } | |
1470 | ||
1471 | if (old->lattice_val != val.lattice_val) | |
1472 | { | |
1473 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1474 | { | |
1475 | dump_lattice_value (dump_file, | |
1476 | "Lattice value changed to ", val); | |
1477 | fprintf (dump_file, ". Adding definition to SSA edges.\n"); | |
1478 | } | |
1479 | ||
95eec0d6 | 1480 | add_var_to_ssa_edges_worklist (var, val); |
6de9cd9a DN |
1481 | *old = val; |
1482 | } | |
1483 | } | |
1484 | ||
1485 | /* Replace USE references in statement STMT with their immediate reaching | |
1486 | definition. Return true if at least one reference was replaced. If | |
1487 | REPLACED_ADDRESSES_P is given, it will be set to true if an address | |
1488 | constant was replaced. */ | |
1489 | ||
1490 | static bool | |
1491 | replace_uses_in (tree stmt, bool *replaced_addresses_p) | |
1492 | { | |
1493 | bool replaced = false; | |
1494 | use_optype uses; | |
1495 | size_t i; | |
1496 | ||
1497 | if (replaced_addresses_p) | |
1498 | *replaced_addresses_p = false; | |
1499 | ||
1500 | get_stmt_operands (stmt); | |
1501 | ||
1502 | uses = STMT_USE_OPS (stmt); | |
1503 | for (i = 0; i < NUM_USES (uses); i++) | |
1504 | { | |
d00ad49b AM |
1505 | use_operand_p use = USE_OP_PTR (uses, i); |
1506 | value *val = get_value (USE_FROM_PTR (use)); | |
6de9cd9a DN |
1507 | |
1508 | if (val->lattice_val == CONSTANT) | |
1509 | { | |
d00ad49b | 1510 | SET_USE (use, val->const_val); |
6de9cd9a | 1511 | replaced = true; |
d00ad49b AM |
1512 | if (POINTER_TYPE_P (TREE_TYPE (USE_FROM_PTR (use))) |
1513 | && replaced_addresses_p) | |
6de9cd9a DN |
1514 | *replaced_addresses_p = true; |
1515 | } | |
1516 | } | |
1517 | ||
1518 | return replaced; | |
1519 | } | |
1520 | ||
173b818d BB |
1521 | /* Replace the VUSE references in statement STMT with its immediate reaching |
1522 | definition. Return true if the reference was replaced. If | |
1523 | REPLACED_ADDRESSES_P is given, it will be set to true if an address | |
1524 | constant was replaced. */ | |
1525 | ||
1526 | static bool | |
1527 | replace_vuse_in (tree stmt, bool *replaced_addresses_p) | |
1528 | { | |
1529 | bool replaced = false; | |
1530 | vuse_optype vuses; | |
1531 | use_operand_p vuse; | |
1532 | value *val; | |
1533 | ||
1534 | if (replaced_addresses_p) | |
1535 | *replaced_addresses_p = false; | |
1536 | ||
1537 | get_stmt_operands (stmt); | |
1538 | ||
1539 | vuses = STMT_VUSE_OPS (stmt); | |
1540 | ||
1541 | if (NUM_VUSES (vuses) != 1) | |
1542 | return false; | |
1543 | ||
1544 | vuse = VUSE_OP_PTR (vuses, 0); | |
1545 | val = get_value (USE_FROM_PTR (vuse)); | |
1546 | ||
1547 | if (val->lattice_val == CONSTANT | |
1548 | && TREE_CODE (stmt) == MODIFY_EXPR | |
1549 | && DECL_P (TREE_OPERAND (stmt, 1)) | |
1550 | && TREE_OPERAND (stmt, 1) == SSA_NAME_VAR (USE_FROM_PTR (vuse))) | |
1551 | { | |
1552 | TREE_OPERAND (stmt, 1) = val->const_val; | |
1553 | replaced = true; | |
1554 | if (POINTER_TYPE_P (TREE_TYPE (USE_FROM_PTR (vuse))) | |
1555 | && replaced_addresses_p) | |
1556 | *replaced_addresses_p = true; | |
1557 | } | |
1558 | ||
1559 | return replaced; | |
1560 | } | |
1561 | ||
6de9cd9a DN |
1562 | /* Return the likely latticevalue for STMT. |
1563 | ||
1564 | If STMT has no operands, then return CONSTANT. | |
1565 | ||
1566 | Else if any operands of STMT are undefined, then return UNDEFINED. | |
1567 | ||
1568 | Else if any operands of STMT are constants, then return CONSTANT. | |
1569 | ||
1570 | Else return VARYING. */ | |
1571 | ||
1572 | static latticevalue | |
1573 | likely_value (tree stmt) | |
1574 | { | |
1575 | use_optype uses; | |
173b818d | 1576 | vuse_optype vuses; |
6de9cd9a DN |
1577 | size_t i; |
1578 | int found_constant = 0; | |
1579 | stmt_ann_t ann; | |
1580 | ||
1581 | /* If the statement makes aliased loads or has volatile operands, it | |
1582 | won't fold to a constant value. */ | |
1583 | ann = stmt_ann (stmt); | |
1584 | if (ann->makes_aliased_loads || ann->has_volatile_ops) | |
1585 | return VARYING; | |
1586 | ||
1587 | /* A CALL_EXPR is assumed to be varying. This may be overly conservative, | |
1588 | in the presence of const and pure calls. */ | |
1589 | if (get_call_expr_in (stmt) != NULL_TREE) | |
1590 | return VARYING; | |
1591 | ||
1592 | get_stmt_operands (stmt); | |
1593 | ||
1594 | uses = USE_OPS (ann); | |
1595 | for (i = 0; i < NUM_USES (uses); i++) | |
1596 | { | |
1597 | tree use = USE_OP (uses, i); | |
1598 | value *val = get_value (use); | |
1599 | ||
1600 | if (val->lattice_val == UNDEFINED) | |
1601 | return UNDEFINED; | |
1602 | ||
1603 | if (val->lattice_val == CONSTANT) | |
1604 | found_constant = 1; | |
1605 | } | |
173b818d BB |
1606 | |
1607 | vuses = VUSE_OPS (ann); | |
1608 | ||
1609 | if (NUM_VUSES (vuses)) | |
1610 | { | |
1611 | tree vuse = VUSE_OP (vuses, 0); | |
1612 | value *val = get_value (vuse); | |
1613 | ||
1614 | if (val->lattice_val == UNKNOWN_VAL) | |
1615 | return UNKNOWN_VAL; | |
1616 | ||
1617 | #ifdef ENABLE_CHECKING | |
1618 | /* There should be no VUSE operands that are UNDEFINED. */ | |
1619 | if (val->lattice_val == UNDEFINED) | |
1620 | abort (); | |
1621 | #endif | |
1622 | ||
1623 | if (val->lattice_val == CONSTANT) | |
1624 | found_constant = 1; | |
1625 | } | |
6de9cd9a | 1626 | |
173b818d | 1627 | return ((found_constant || (!uses && !vuses)) ? CONSTANT : VARYING); |
6de9cd9a DN |
1628 | } |
1629 | ||
1630 | /* A subroutine of fold_stmt_r. Attempts to fold *(A+O) to A[X]. | |
1631 | BASE is an array type. OFFSET is a byte displacement. ORIG_TYPE | |
9cf737f8 | 1632 | is the desired result type. */ |
6de9cd9a DN |
1633 | |
1634 | static tree | |
1635 | maybe_fold_offset_to_array_ref (tree base, tree offset, tree orig_type) | |
1636 | { | |
44de5aeb RK |
1637 | tree min_idx, idx, elt_offset = integer_zero_node; |
1638 | tree array_type, elt_type, elt_size; | |
1639 | ||
1640 | /* If BASE is an ARRAY_REF, we can pick up another offset (this time | |
1641 | measured in units of the size of elements type) from that ARRAY_REF). | |
1642 | We can't do anything if either is variable. | |
1643 | ||
1644 | The case we handle here is *(&A[N]+O). */ | |
1645 | if (TREE_CODE (base) == ARRAY_REF) | |
1646 | { | |
1647 | tree low_bound = array_ref_low_bound (base); | |
1648 | ||
1649 | elt_offset = TREE_OPERAND (base, 1); | |
1650 | if (TREE_CODE (low_bound) != INTEGER_CST | |
1651 | || TREE_CODE (elt_offset) != INTEGER_CST) | |
1652 | return NULL_TREE; | |
1653 | ||
1654 | elt_offset = int_const_binop (MINUS_EXPR, elt_offset, low_bound, 0); | |
1655 | base = TREE_OPERAND (base, 0); | |
1656 | } | |
6de9cd9a DN |
1657 | |
1658 | /* Ignore stupid user tricks of indexing non-array variables. */ | |
1659 | array_type = TREE_TYPE (base); | |
1660 | if (TREE_CODE (array_type) != ARRAY_TYPE) | |
1661 | return NULL_TREE; | |
1662 | elt_type = TREE_TYPE (array_type); | |
1663 | if (!lang_hooks.types_compatible_p (orig_type, elt_type)) | |
1664 | return NULL_TREE; | |
1665 | ||
44de5aeb RK |
1666 | /* If OFFSET and ELT_OFFSET are zero, we don't care about the size of the |
1667 | element type (so we can use the alignment if it's not constant). | |
1668 | Otherwise, compute the offset as an index by using a division. If the | |
1669 | division isn't exact, then don't do anything. */ | |
6de9cd9a | 1670 | elt_size = TYPE_SIZE_UNIT (elt_type); |
44de5aeb RK |
1671 | if (integer_zerop (offset)) |
1672 | { | |
1673 | if (TREE_CODE (elt_size) != INTEGER_CST) | |
1674 | elt_size = size_int (TYPE_ALIGN (elt_type)); | |
6de9cd9a | 1675 | |
44de5aeb RK |
1676 | idx = integer_zero_node; |
1677 | } | |
1678 | else | |
1679 | { | |
1680 | unsigned HOST_WIDE_INT lquo, lrem; | |
1681 | HOST_WIDE_INT hquo, hrem; | |
1682 | ||
1683 | if (TREE_CODE (elt_size) != INTEGER_CST | |
1684 | || div_and_round_double (TRUNC_DIV_EXPR, 1, | |
1685 | TREE_INT_CST_LOW (offset), | |
1686 | TREE_INT_CST_HIGH (offset), | |
1687 | TREE_INT_CST_LOW (elt_size), | |
1688 | TREE_INT_CST_HIGH (elt_size), | |
1689 | &lquo, &hquo, &lrem, &hrem) | |
1690 | || lrem || hrem) | |
1691 | return NULL_TREE; | |
6de9cd9a | 1692 | |
3e95a7cb | 1693 | idx = build_int_2 (lquo, hquo); |
44de5aeb RK |
1694 | } |
1695 | ||
1696 | /* Assume the low bound is zero. If there is a domain type, get the | |
1697 | low bound, if any, convert the index into that type, and add the | |
1698 | low bound. */ | |
1699 | min_idx = integer_zero_node; | |
1700 | if (TYPE_DOMAIN (array_type)) | |
6de9cd9a | 1701 | { |
44de5aeb RK |
1702 | if (TYPE_MIN_VALUE (TYPE_DOMAIN (array_type))) |
1703 | min_idx = TYPE_MIN_VALUE (TYPE_DOMAIN (array_type)); | |
1704 | else | |
1705 | min_idx = fold_convert (TYPE_DOMAIN (array_type), min_idx); | |
1706 | ||
1707 | if (TREE_CODE (min_idx) != INTEGER_CST) | |
1708 | return NULL_TREE; | |
1709 | ||
1710 | idx = fold_convert (TYPE_DOMAIN (array_type), idx); | |
1711 | elt_offset = fold_convert (TYPE_DOMAIN (array_type), elt_offset); | |
6de9cd9a DN |
1712 | } |
1713 | ||
44de5aeb RK |
1714 | if (!integer_zerop (min_idx)) |
1715 | idx = int_const_binop (PLUS_EXPR, idx, min_idx, 0); | |
1716 | if (!integer_zerop (elt_offset)) | |
1717 | idx = int_const_binop (PLUS_EXPR, idx, elt_offset, 0); | |
1718 | ||
1719 | return build (ARRAY_REF, orig_type, base, idx, min_idx, | |
1720 | size_int (tree_low_cst (elt_size, 1) | |
1721 | / (TYPE_ALIGN (elt_type) / BITS_PER_UNIT))); | |
6de9cd9a DN |
1722 | } |
1723 | ||
1724 | /* A subroutine of fold_stmt_r. Attempts to fold *(S+O) to S.X. | |
1725 | BASE is a record type. OFFSET is a byte displacement. ORIG_TYPE | |
1726 | is the desired result type. */ | |
1727 | /* ??? This doesn't handle class inheritance. */ | |
1728 | ||
1729 | static tree | |
1730 | maybe_fold_offset_to_component_ref (tree record_type, tree base, tree offset, | |
1731 | tree orig_type, bool base_is_ptr) | |
1732 | { | |
1733 | tree f, t, field_type, tail_array_field; | |
1734 | ||
1735 | if (TREE_CODE (record_type) != RECORD_TYPE | |
1736 | && TREE_CODE (record_type) != UNION_TYPE | |
1737 | && TREE_CODE (record_type) != QUAL_UNION_TYPE) | |
1738 | return NULL_TREE; | |
1739 | ||
1740 | /* Short-circuit silly cases. */ | |
1741 | if (lang_hooks.types_compatible_p (record_type, orig_type)) | |
1742 | return NULL_TREE; | |
1743 | ||
1744 | tail_array_field = NULL_TREE; | |
1745 | for (f = TYPE_FIELDS (record_type); f ; f = TREE_CHAIN (f)) | |
1746 | { | |
1747 | int cmp; | |
1748 | ||
1749 | if (TREE_CODE (f) != FIELD_DECL) | |
1750 | continue; | |
1751 | if (DECL_BIT_FIELD (f)) | |
1752 | continue; | |
1753 | if (TREE_CODE (DECL_FIELD_OFFSET (f)) != INTEGER_CST) | |
1754 | continue; | |
1755 | ||
1756 | /* ??? Java creates "interesting" fields for representing base classes. | |
1757 | They have no name, and have no context. With no context, we get into | |
1758 | trouble with nonoverlapping_component_refs_p. Skip them. */ | |
1759 | if (!DECL_FIELD_CONTEXT (f)) | |
1760 | continue; | |
1761 | ||
1762 | /* The previous array field isn't at the end. */ | |
1763 | tail_array_field = NULL_TREE; | |
1764 | ||
1765 | /* Check to see if this offset overlaps with the field. */ | |
1766 | cmp = tree_int_cst_compare (DECL_FIELD_OFFSET (f), offset); | |
1767 | if (cmp > 0) | |
1768 | continue; | |
1769 | ||
1770 | field_type = TREE_TYPE (f); | |
1771 | if (cmp < 0) | |
1772 | { | |
1773 | /* Don't care about offsets into the middle of scalars. */ | |
1774 | if (!AGGREGATE_TYPE_P (field_type)) | |
1775 | continue; | |
1776 | ||
1777 | /* Check for array at the end of the struct. This is often | |
1778 | used as for flexible array members. We should be able to | |
1779 | turn this into an array access anyway. */ | |
1780 | if (TREE_CODE (field_type) == ARRAY_TYPE) | |
1781 | tail_array_field = f; | |
1782 | ||
1783 | /* Check the end of the field against the offset. */ | |
1784 | if (!DECL_SIZE_UNIT (f) | |
1785 | || TREE_CODE (DECL_SIZE_UNIT (f)) != INTEGER_CST) | |
1786 | continue; | |
1787 | t = int_const_binop (MINUS_EXPR, offset, DECL_FIELD_OFFSET (f), 1); | |
1788 | if (!tree_int_cst_lt (t, DECL_SIZE_UNIT (f))) | |
1789 | continue; | |
1790 | ||
1791 | /* If we matched, then set offset to the displacement into | |
1792 | this field. */ | |
1793 | offset = t; | |
1794 | } | |
1795 | ||
1796 | /* Here we exactly match the offset being checked. If the types match, | |
1797 | then we can return that field. */ | |
1798 | else if (lang_hooks.types_compatible_p (orig_type, field_type)) | |
1799 | { | |
1800 | if (base_is_ptr) | |
1801 | base = build1 (INDIRECT_REF, record_type, base); | |
44de5aeb | 1802 | t = build (COMPONENT_REF, field_type, base, f, NULL_TREE); |
6de9cd9a DN |
1803 | return t; |
1804 | } | |
1805 | ||
1806 | /* Don't care about type-punning of scalars. */ | |
1807 | else if (!AGGREGATE_TYPE_P (field_type)) | |
1808 | return NULL_TREE; | |
1809 | ||
1810 | goto found; | |
1811 | } | |
1812 | ||
1813 | if (!tail_array_field) | |
1814 | return NULL_TREE; | |
1815 | ||
1816 | f = tail_array_field; | |
1817 | field_type = TREE_TYPE (f); | |
1818 | ||
1819 | found: | |
1820 | /* If we get here, we've got an aggregate field, and a possibly | |
1ea7e6ad | 1821 | nonzero offset into them. Recurse and hope for a valid match. */ |
6de9cd9a DN |
1822 | if (base_is_ptr) |
1823 | base = build1 (INDIRECT_REF, record_type, base); | |
44de5aeb | 1824 | base = build (COMPONENT_REF, field_type, base, f, NULL_TREE); |
6de9cd9a DN |
1825 | |
1826 | t = maybe_fold_offset_to_array_ref (base, offset, orig_type); | |
1827 | if (t) | |
1828 | return t; | |
1829 | return maybe_fold_offset_to_component_ref (field_type, base, offset, | |
1830 | orig_type, false); | |
1831 | } | |
1832 | ||
1833 | /* A subroutine of fold_stmt_r. Attempt to simplify *(BASE+OFFSET). | |
1834 | Return the simplified expression, or NULL if nothing could be done. */ | |
1835 | ||
1836 | static tree | |
1837 | maybe_fold_stmt_indirect (tree expr, tree base, tree offset) | |
1838 | { | |
1839 | tree t; | |
1840 | ||
1841 | /* We may well have constructed a double-nested PLUS_EXPR via multiple | |
1842 | substitutions. Fold that down to one. Remove NON_LVALUE_EXPRs that | |
1843 | are sometimes added. */ | |
1844 | base = fold (base); | |
1845 | STRIP_NOPS (base); | |
1846 | TREE_OPERAND (expr, 0) = base; | |
1847 | ||
1848 | /* One possibility is that the address reduces to a string constant. */ | |
1849 | t = fold_read_from_constant_string (expr); | |
1850 | if (t) | |
1851 | return t; | |
1852 | ||
1853 | /* Add in any offset from a PLUS_EXPR. */ | |
1854 | if (TREE_CODE (base) == PLUS_EXPR) | |
1855 | { | |
1856 | tree offset2; | |
1857 | ||
1858 | offset2 = TREE_OPERAND (base, 1); | |
1859 | if (TREE_CODE (offset2) != INTEGER_CST) | |
1860 | return NULL_TREE; | |
1861 | base = TREE_OPERAND (base, 0); | |
1862 | ||
1863 | offset = int_const_binop (PLUS_EXPR, offset, offset2, 1); | |
1864 | } | |
1865 | ||
1866 | if (TREE_CODE (base) == ADDR_EXPR) | |
1867 | { | |
1868 | /* Strip the ADDR_EXPR. */ | |
1869 | base = TREE_OPERAND (base, 0); | |
1870 | ||
1871 | /* Try folding *(&B+O) to B[X]. */ | |
1872 | t = maybe_fold_offset_to_array_ref (base, offset, TREE_TYPE (expr)); | |
1873 | if (t) | |
1874 | return t; | |
1875 | ||
1876 | /* Try folding *(&B+O) to B.X. */ | |
1877 | t = maybe_fold_offset_to_component_ref (TREE_TYPE (base), base, offset, | |
1878 | TREE_TYPE (expr), false); | |
1879 | if (t) | |
1880 | return t; | |
1881 | ||
44de5aeb RK |
1882 | /* Fold *&B to B. We can only do this if EXPR is the same type |
1883 | as BASE. We can't do this if EXPR is the element type of an array | |
1884 | and BASE is the array. */ | |
1885 | if (integer_zerop (offset) | |
1886 | && lang_hooks.types_compatible_p (TREE_TYPE (base), | |
1887 | TREE_TYPE (expr))) | |
6de9cd9a DN |
1888 | return base; |
1889 | } | |
1890 | else | |
1891 | { | |
1892 | /* We can get here for out-of-range string constant accesses, | |
1893 | such as "_"[3]. Bail out of the entire substitution search | |
1894 | and arrange for the entire statement to be replaced by a | |
1895 | call to __builtin_trap. In all likelyhood this will all be | |
1896 | constant-folded away, but in the meantime we can't leave with | |
1897 | something that get_expr_operands can't understand. */ | |
1898 | ||
1899 | t = base; | |
1900 | STRIP_NOPS (t); | |
1901 | if (TREE_CODE (t) == ADDR_EXPR | |
1902 | && TREE_CODE (TREE_OPERAND (t, 0)) == STRING_CST) | |
1903 | { | |
1904 | /* FIXME: Except that this causes problems elsewhere with dead | |
1905 | code not being deleted, and we abort in the rtl expanders | |
1906 | because we failed to remove some ssa_name. In the meantime, | |
1907 | just return zero. */ | |
1908 | /* FIXME2: This condition should be signaled by | |
1909 | fold_read_from_constant_string directly, rather than | |
1910 | re-checking for it here. */ | |
1911 | return integer_zero_node; | |
1912 | } | |
1913 | ||
1914 | /* Try folding *(B+O) to B->X. Still an improvement. */ | |
1915 | if (POINTER_TYPE_P (TREE_TYPE (base))) | |
1916 | { | |
1917 | t = maybe_fold_offset_to_component_ref (TREE_TYPE (TREE_TYPE (base)), | |
1918 | base, offset, | |
1919 | TREE_TYPE (expr), true); | |
1920 | if (t) | |
1921 | return t; | |
1922 | } | |
1923 | } | |
1924 | ||
1925 | /* Otherwise we had an offset that we could not simplify. */ | |
1926 | return NULL_TREE; | |
1927 | } | |
1928 | ||
1929 | /* A subroutine of fold_stmt_r. EXPR is a PLUS_EXPR. | |
1930 | ||
1931 | A quaint feature extant in our address arithmetic is that there | |
1932 | can be hidden type changes here. The type of the result need | |
1933 | not be the same as the type of the input pointer. | |
1934 | ||
1935 | What we're after here is an expression of the form | |
1936 | (T *)(&array + const) | |
1937 | where the cast doesn't actually exist, but is implicit in the | |
1938 | type of the PLUS_EXPR. We'd like to turn this into | |
1939 | &array[x] | |
1940 | which may be able to propagate further. */ | |
1941 | ||
1942 | static tree | |
1943 | maybe_fold_stmt_addition (tree expr) | |
1944 | { | |
1945 | tree op0 = TREE_OPERAND (expr, 0); | |
1946 | tree op1 = TREE_OPERAND (expr, 1); | |
1947 | tree ptr_type = TREE_TYPE (expr); | |
1948 | tree ptd_type; | |
1949 | tree t; | |
1950 | bool subtract = (TREE_CODE (expr) == MINUS_EXPR); | |
1951 | ||
1952 | /* We're only interested in pointer arithmetic. */ | |
1953 | if (!POINTER_TYPE_P (ptr_type)) | |
1954 | return NULL_TREE; | |
1955 | /* Canonicalize the integral operand to op1. */ | |
1956 | if (INTEGRAL_TYPE_P (TREE_TYPE (op0))) | |
1957 | { | |
1958 | if (subtract) | |
1959 | return NULL_TREE; | |
1960 | t = op0, op0 = op1, op1 = t; | |
1961 | } | |
1962 | /* It had better be a constant. */ | |
1963 | if (TREE_CODE (op1) != INTEGER_CST) | |
1964 | return NULL_TREE; | |
1965 | /* The first operand should be an ADDR_EXPR. */ | |
1966 | if (TREE_CODE (op0) != ADDR_EXPR) | |
1967 | return NULL_TREE; | |
1968 | op0 = TREE_OPERAND (op0, 0); | |
1969 | ||
1970 | /* If the first operand is an ARRAY_REF, expand it so that we can fold | |
1971 | the offset into it. */ | |
1972 | while (TREE_CODE (op0) == ARRAY_REF) | |
1973 | { | |
1974 | tree array_obj = TREE_OPERAND (op0, 0); | |
1975 | tree array_idx = TREE_OPERAND (op0, 1); | |
1976 | tree elt_type = TREE_TYPE (op0); | |
1977 | tree elt_size = TYPE_SIZE_UNIT (elt_type); | |
1978 | tree min_idx; | |
1979 | ||
1980 | if (TREE_CODE (array_idx) != INTEGER_CST) | |
1981 | break; | |
1982 | if (TREE_CODE (elt_size) != INTEGER_CST) | |
1983 | break; | |
1984 | ||
1985 | /* Un-bias the index by the min index of the array type. */ | |
1986 | min_idx = TYPE_DOMAIN (TREE_TYPE (array_obj)); | |
1987 | if (min_idx) | |
1988 | { | |
1989 | min_idx = TYPE_MIN_VALUE (min_idx); | |
1990 | if (min_idx) | |
1991 | { | |
44de5aeb RK |
1992 | if (TREE_CODE (min_idx) != INTEGER_CST) |
1993 | break; | |
1994 | ||
6de9cd9a DN |
1995 | array_idx = convert (TREE_TYPE (min_idx), array_idx); |
1996 | if (!integer_zerop (min_idx)) | |
1997 | array_idx = int_const_binop (MINUS_EXPR, array_idx, | |
1998 | min_idx, 0); | |
1999 | } | |
2000 | } | |
2001 | ||
2002 | /* Convert the index to a byte offset. */ | |
2003 | array_idx = convert (sizetype, array_idx); | |
2004 | array_idx = int_const_binop (MULT_EXPR, array_idx, elt_size, 0); | |
2005 | ||
2006 | /* Update the operands for the next round, or for folding. */ | |
2007 | /* If we're manipulating unsigned types, then folding into negative | |
2008 | values can produce incorrect results. Particularly if the type | |
2009 | is smaller than the width of the pointer. */ | |
2010 | if (subtract | |
2011 | && TYPE_UNSIGNED (TREE_TYPE (op1)) | |
2012 | && tree_int_cst_lt (array_idx, op1)) | |
2013 | return NULL; | |
2014 | op1 = int_const_binop (subtract ? MINUS_EXPR : PLUS_EXPR, | |
2015 | array_idx, op1, 0); | |
2016 | subtract = false; | |
2017 | op0 = array_obj; | |
2018 | } | |
2019 | ||
2020 | /* If we weren't able to fold the subtraction into another array reference, | |
2021 | canonicalize the integer for passing to the array and component ref | |
2022 | simplification functions. */ | |
2023 | if (subtract) | |
2024 | { | |
2025 | if (TYPE_UNSIGNED (TREE_TYPE (op1))) | |
2026 | return NULL; | |
2027 | op1 = fold (build1 (NEGATE_EXPR, TREE_TYPE (op1), op1)); | |
2028 | /* ??? In theory fold should always produce another integer. */ | |
2029 | if (TREE_CODE (op1) != INTEGER_CST) | |
2030 | return NULL; | |
2031 | } | |
2032 | ||
2033 | ptd_type = TREE_TYPE (ptr_type); | |
2034 | ||
2035 | /* At which point we can try some of the same things as for indirects. */ | |
2036 | t = maybe_fold_offset_to_array_ref (op0, op1, ptd_type); | |
2037 | if (!t) | |
2038 | t = maybe_fold_offset_to_component_ref (TREE_TYPE (op0), op0, op1, | |
2039 | ptd_type, false); | |
2040 | if (t) | |
2041 | t = build1 (ADDR_EXPR, ptr_type, t); | |
2042 | ||
2043 | return t; | |
2044 | } | |
2045 | ||
2046 | /* Subroutine of fold_stmt called via walk_tree. We perform several | |
2047 | simplifications of EXPR_P, mostly having to do with pointer arithmetic. */ | |
2048 | ||
2049 | static tree | |
2050 | fold_stmt_r (tree *expr_p, int *walk_subtrees, void *data) | |
2051 | { | |
2052 | bool *changed_p = data; | |
2053 | tree expr = *expr_p, t; | |
2054 | ||
2055 | /* ??? It'd be nice if walk_tree had a pre-order option. */ | |
2056 | switch (TREE_CODE (expr)) | |
2057 | { | |
2058 | case INDIRECT_REF: | |
2059 | t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL); | |
2060 | if (t) | |
2061 | return t; | |
2062 | *walk_subtrees = 0; | |
2063 | ||
2064 | t = maybe_fold_stmt_indirect (expr, TREE_OPERAND (expr, 0), | |
2065 | integer_zero_node); | |
2066 | break; | |
2067 | ||
2068 | /* ??? Could handle ARRAY_REF here, as a variant of INDIRECT_REF. | |
2069 | We'd only want to bother decomposing an existing ARRAY_REF if | |
2070 | the base array is found to have another offset contained within. | |
2071 | Otherwise we'd be wasting time. */ | |
2072 | ||
2073 | case ADDR_EXPR: | |
2074 | t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL); | |
2075 | if (t) | |
2076 | return t; | |
2077 | *walk_subtrees = 0; | |
2078 | ||
2079 | /* Set TREE_INVARIANT properly so that the value is properly | |
2080 | considered constant, and so gets propagated as expected. */ | |
2081 | if (*changed_p) | |
2082 | recompute_tree_invarant_for_addr_expr (expr); | |
2083 | return NULL_TREE; | |
2084 | ||
2085 | case PLUS_EXPR: | |
2086 | case MINUS_EXPR: | |
2087 | t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL); | |
2088 | if (t) | |
2089 | return t; | |
2090 | t = walk_tree (&TREE_OPERAND (expr, 1), fold_stmt_r, data, NULL); | |
2091 | if (t) | |
2092 | return t; | |
2093 | *walk_subtrees = 0; | |
2094 | ||
2095 | t = maybe_fold_stmt_addition (expr); | |
2096 | break; | |
2097 | ||
2098 | case COMPONENT_REF: | |
2099 | t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL); | |
2100 | if (t) | |
2101 | return t; | |
2102 | *walk_subtrees = 0; | |
2103 | ||
fa27426e RH |
2104 | /* Make sure the FIELD_DECL is actually a field in the type on the lhs. |
2105 | We've already checked that the records are compatible, so we should | |
2106 | come up with a set of compatible fields. */ | |
2107 | { | |
2108 | tree expr_record = TREE_TYPE (TREE_OPERAND (expr, 0)); | |
2109 | tree expr_field = TREE_OPERAND (expr, 1); | |
2110 | ||
2111 | if (DECL_FIELD_CONTEXT (expr_field) != TYPE_MAIN_VARIANT (expr_record)) | |
2112 | { | |
2113 | expr_field = find_compatible_field (expr_record, expr_field); | |
2114 | TREE_OPERAND (expr, 1) = expr_field; | |
2115 | } | |
2116 | } | |
6de9cd9a DN |
2117 | break; |
2118 | ||
2119 | default: | |
2120 | return NULL_TREE; | |
2121 | } | |
2122 | ||
2123 | if (t) | |
2124 | { | |
2125 | *expr_p = t; | |
2126 | *changed_p = true; | |
2127 | } | |
2128 | ||
2129 | return NULL_TREE; | |
2130 | } | |
2131 | ||
2132 | /* Fold the statement pointed by STMT_P. In some cases, this function may | |
2133 | replace the whole statement with a new one. Returns true iff folding | |
2134 | makes any changes. */ | |
2135 | ||
2136 | bool | |
2137 | fold_stmt (tree *stmt_p) | |
2138 | { | |
2139 | tree rhs, result, stmt; | |
2140 | bool changed = false; | |
2141 | ||
2142 | stmt = *stmt_p; | |
2143 | ||
2144 | /* If we replaced constants and the statement makes pointer dereferences, | |
2145 | then we may need to fold instances of *&VAR into VAR, etc. */ | |
2146 | if (walk_tree (stmt_p, fold_stmt_r, &changed, NULL)) | |
2147 | { | |
2148 | *stmt_p | |
2149 | = build_function_call_expr (implicit_built_in_decls[BUILT_IN_TRAP], | |
2150 | NULL); | |
2151 | return true; | |
2152 | } | |
2153 | ||
2154 | rhs = get_rhs (stmt); | |
2155 | if (!rhs) | |
2156 | return changed; | |
2157 | result = NULL_TREE; | |
2158 | ||
6de9cd9a DN |
2159 | if (TREE_CODE (rhs) == CALL_EXPR) |
2160 | { | |
0f59171d RH |
2161 | tree callee; |
2162 | ||
2163 | /* Check for builtins that CCP can handle using information not | |
2164 | available in the generic fold routines. */ | |
2165 | callee = get_callee_fndecl (rhs); | |
6de9cd9a DN |
2166 | if (callee && DECL_BUILT_IN (callee)) |
2167 | result = ccp_fold_builtin (stmt, rhs); | |
0f59171d RH |
2168 | else |
2169 | { | |
2170 | /* Check for resolvable OBJ_TYPE_REF. The only sorts we can resolve | |
2171 | here are when we've propagated the address of a decl into the | |
2172 | object slot. */ | |
2173 | /* ??? Should perhaps do this in fold proper. However, doing it | |
2174 | there requires that we create a new CALL_EXPR, and that requires | |
2175 | copying EH region info to the new node. Easier to just do it | |
2176 | here where we can just smash the call operand. */ | |
2177 | callee = TREE_OPERAND (rhs, 0); | |
2178 | if (TREE_CODE (callee) == OBJ_TYPE_REF | |
2179 | && lang_hooks.fold_obj_type_ref | |
2180 | && TREE_CODE (OBJ_TYPE_REF_OBJECT (callee)) == ADDR_EXPR | |
2181 | && DECL_P (TREE_OPERAND (OBJ_TYPE_REF_OBJECT (callee), 0))) | |
2182 | { | |
2183 | tree t; | |
2184 | ||
5df6d966 RH |
2185 | /* ??? Caution: Broken ADDR_EXPR semantics means that |
2186 | looking at the type of the operand of the addr_expr | |
2187 | can yield an array type. See silly exception in | |
2188 | check_pointer_types_r. */ | |
2189 | ||
2190 | t = TREE_TYPE (TREE_TYPE (OBJ_TYPE_REF_OBJECT (callee))); | |
0f59171d RH |
2191 | t = lang_hooks.fold_obj_type_ref (callee, t); |
2192 | if (t) | |
2193 | { | |
2194 | TREE_OPERAND (rhs, 0) = t; | |
2195 | changed = true; | |
2196 | } | |
2197 | } | |
2198 | } | |
6de9cd9a DN |
2199 | } |
2200 | ||
2201 | /* If we couldn't fold the RHS, hand over to the generic fold routines. */ | |
2202 | if (result == NULL_TREE) | |
2203 | result = fold (rhs); | |
2204 | ||
2205 | /* Strip away useless type conversions. Both the NON_LVALUE_EXPR that | |
2206 | may have been added by fold, and "useless" type conversions that might | |
2207 | now be apparent due to propagation. */ | |
6de9cd9a DN |
2208 | STRIP_USELESS_TYPE_CONVERSION (result); |
2209 | ||
2210 | if (result != rhs) | |
06a9b53f | 2211 | changed |= set_rhs (stmt_p, result); |
6de9cd9a DN |
2212 | |
2213 | return changed; | |
2214 | } | |
2215 | ||
2216 | /* Get the main expression from statement STMT. */ | |
2217 | ||
2218 | static tree | |
2219 | get_rhs (tree stmt) | |
2220 | { | |
2221 | enum tree_code code = TREE_CODE (stmt); | |
2222 | ||
cd709752 | 2223 | switch (code) |
6de9cd9a | 2224 | { |
cd709752 RH |
2225 | case RETURN_EXPR: |
2226 | stmt = TREE_OPERAND (stmt, 0); | |
d25cee4d RH |
2227 | if (!stmt || TREE_CODE (stmt) != MODIFY_EXPR) |
2228 | return stmt; | |
2229 | /* FALLTHRU */ | |
cd709752 RH |
2230 | |
2231 | case MODIFY_EXPR: | |
d25cee4d RH |
2232 | stmt = TREE_OPERAND (stmt, 1); |
2233 | if (TREE_CODE (stmt) == WITH_SIZE_EXPR) | |
2234 | return TREE_OPERAND (stmt, 0); | |
2235 | else | |
2236 | return stmt; | |
cd709752 RH |
2237 | |
2238 | case COND_EXPR: | |
2239 | return COND_EXPR_COND (stmt); | |
2240 | case SWITCH_EXPR: | |
2241 | return SWITCH_COND (stmt); | |
2242 | case GOTO_EXPR: | |
2243 | return GOTO_DESTINATION (stmt); | |
2244 | case LABEL_EXPR: | |
2245 | return LABEL_EXPR_LABEL (stmt); | |
2246 | ||
2247 | default: | |
2248 | return stmt; | |
6de9cd9a | 2249 | } |
6de9cd9a DN |
2250 | } |
2251 | ||
2252 | ||
2253 | /* Set the main expression of *STMT_P to EXPR. */ | |
2254 | ||
06a9b53f | 2255 | static bool |
6de9cd9a DN |
2256 | set_rhs (tree *stmt_p, tree expr) |
2257 | { | |
cd709752 | 2258 | tree stmt = *stmt_p, op; |
06a9b53f | 2259 | enum tree_code code = TREE_CODE (expr); |
cd709752 | 2260 | stmt_ann_t ann; |
6de9cd9a | 2261 | |
06a9b53f RS |
2262 | /* Verify the constant folded result is valid gimple. */ |
2263 | if (TREE_CODE_CLASS (code) == '2') | |
2264 | { | |
2265 | if (!is_gimple_val (TREE_OPERAND (expr, 0)) | |
2266 | || !is_gimple_val (TREE_OPERAND (expr, 1))) | |
2267 | return false; | |
2268 | } | |
2269 | else if (TREE_CODE_CLASS (code) == '1') | |
2270 | { | |
2271 | if (!is_gimple_val (TREE_OPERAND (expr, 0))) | |
2272 | return false; | |
2273 | } | |
2274 | ||
cd709752 | 2275 | switch (TREE_CODE (stmt)) |
6de9cd9a | 2276 | { |
cd709752 RH |
2277 | case RETURN_EXPR: |
2278 | op = TREE_OPERAND (stmt, 0); | |
2279 | if (TREE_CODE (op) != MODIFY_EXPR) | |
2280 | { | |
2281 | TREE_OPERAND (stmt, 0) = expr; | |
2282 | break; | |
2283 | } | |
2284 | stmt = op; | |
2285 | /* FALLTHRU */ | |
2286 | ||
2287 | case MODIFY_EXPR: | |
d25cee4d RH |
2288 | op = TREE_OPERAND (stmt, 1); |
2289 | if (TREE_CODE (op) == WITH_SIZE_EXPR) | |
2290 | stmt = op; | |
cd709752 RH |
2291 | TREE_OPERAND (stmt, 1) = expr; |
2292 | break; | |
2293 | ||
2294 | case COND_EXPR: | |
2295 | COND_EXPR_COND (stmt) = expr; | |
2296 | break; | |
2297 | case SWITCH_EXPR: | |
2298 | SWITCH_COND (stmt) = expr; | |
2299 | break; | |
2300 | case GOTO_EXPR: | |
2301 | GOTO_DESTINATION (stmt) = expr; | |
2302 | break; | |
2303 | case LABEL_EXPR: | |
2304 | LABEL_EXPR_LABEL (stmt) = expr; | |
2305 | break; | |
2306 | ||
2307 | default: | |
6de9cd9a DN |
2308 | /* Replace the whole statement with EXPR. If EXPR has no side |
2309 | effects, then replace *STMT_P with an empty statement. */ | |
cd709752 | 2310 | ann = stmt_ann (stmt); |
6de9cd9a | 2311 | *stmt_p = TREE_SIDE_EFFECTS (expr) ? expr : build_empty_stmt (); |
06d72ee6 | 2312 | (*stmt_p)->common.ann = (tree_ann_t) ann; |
6de9cd9a DN |
2313 | |
2314 | if (TREE_SIDE_EFFECTS (expr)) | |
2315 | { | |
2316 | def_optype defs; | |
a32b97a2 BB |
2317 | v_may_def_optype v_may_defs; |
2318 | v_must_def_optype v_must_defs; | |
6de9cd9a DN |
2319 | size_t i; |
2320 | ||
2321 | /* Fix all the SSA_NAMEs created by *STMT_P to point to its new | |
2322 | replacement. */ | |
2323 | defs = DEF_OPS (ann); | |
2324 | for (i = 0; i < NUM_DEFS (defs); i++) | |
2325 | { | |
2326 | tree var = DEF_OP (defs, i); | |
2327 | if (TREE_CODE (var) == SSA_NAME) | |
2328 | SSA_NAME_DEF_STMT (var) = *stmt_p; | |
2329 | } | |
2330 | ||
a32b97a2 BB |
2331 | v_may_defs = V_MAY_DEF_OPS (ann); |
2332 | for (i = 0; i < NUM_V_MAY_DEFS (v_may_defs); i++) | |
2333 | { | |
2334 | tree var = V_MAY_DEF_RESULT (v_may_defs, i); | |
2335 | if (TREE_CODE (var) == SSA_NAME) | |
2336 | SSA_NAME_DEF_STMT (var) = *stmt_p; | |
2337 | } | |
2338 | ||
2339 | v_must_defs = V_MUST_DEF_OPS (ann); | |
2340 | for (i = 0; i < NUM_V_MUST_DEFS (v_must_defs); i++) | |
6de9cd9a | 2341 | { |
a32b97a2 | 2342 | tree var = V_MUST_DEF_OP (v_must_defs, i); |
6de9cd9a DN |
2343 | if (TREE_CODE (var) == SSA_NAME) |
2344 | SSA_NAME_DEF_STMT (var) = *stmt_p; | |
2345 | } | |
2346 | } | |
cd709752 | 2347 | break; |
6de9cd9a | 2348 | } |
06a9b53f RS |
2349 | |
2350 | return true; | |
6de9cd9a DN |
2351 | } |
2352 | ||
2353 | ||
2354 | /* Return a default value for variable VAR using the following rules: | |
2355 | ||
173b818d BB |
2356 | 1- Function arguments are considered VARYING. |
2357 | ||
2358 | 2- Global and static variables that are declared constant are | |
2359 | considered CONSTANT. | |
6de9cd9a | 2360 | |
173b818d | 2361 | 3- Any other virtually defined variable is considered UNKNOWN_VAL. |
6de9cd9a | 2362 | |
173b818d | 2363 | 4- Any other value is considered UNDEFINED. This is useful when |
6de9cd9a DN |
2364 | considering PHI nodes. PHI arguments that are undefined do not |
2365 | change the constant value of the PHI node, which allows for more | |
2366 | constants to be propagated. */ | |
2367 | ||
2368 | static value | |
2369 | get_default_value (tree var) | |
2370 | { | |
2371 | value val; | |
2372 | tree sym; | |
2373 | ||
2374 | if (TREE_CODE (var) == SSA_NAME) | |
2375 | sym = SSA_NAME_VAR (var); | |
2376 | else | |
2377 | { | |
2378 | #ifdef ENABLE_CHECKING | |
2379 | if (!DECL_P (var)) | |
2380 | abort (); | |
2381 | #endif | |
2382 | sym = var; | |
2383 | } | |
2384 | ||
2385 | val.lattice_val = UNDEFINED; | |
2386 | val.const_val = NULL_TREE; | |
2387 | ||
2388 | if (TREE_CODE (sym) == PARM_DECL || TREE_THIS_VOLATILE (sym)) | |
2389 | { | |
2390 | /* Function arguments and volatile variables are considered VARYING. */ | |
2391 | val.lattice_val = VARYING; | |
2392 | } | |
ab8907ef | 2393 | else if (TREE_STATIC (sym)) |
6de9cd9a | 2394 | { |
173b818d BB |
2395 | /* Globals and static variables are considered UNKNOWN_VAL, |
2396 | unless they are declared 'const'. */ | |
6de9cd9a DN |
2397 | if (TREE_READONLY (sym) |
2398 | && DECL_INITIAL (sym) | |
2399 | && is_gimple_min_invariant (DECL_INITIAL (sym))) | |
2400 | { | |
2401 | val.lattice_val = CONSTANT; | |
2402 | val.const_val = DECL_INITIAL (sym); | |
2403 | } | |
173b818d BB |
2404 | else |
2405 | { | |
2406 | val.const_val = NULL_TREE; | |
2407 | val.lattice_val = UNKNOWN_VAL; | |
2408 | } | |
2409 | } | |
2410 | else if (!is_gimple_reg (sym)) | |
2411 | { | |
2412 | val.const_val = NULL_TREE; | |
2413 | val.lattice_val = UNKNOWN_VAL; | |
6de9cd9a DN |
2414 | } |
2415 | else | |
2416 | { | |
2417 | enum tree_code code; | |
2418 | tree stmt = SSA_NAME_DEF_STMT (var); | |
2419 | ||
2420 | if (!IS_EMPTY_STMT (stmt)) | |
2421 | { | |
2422 | code = TREE_CODE (stmt); | |
2423 | if (code != MODIFY_EXPR && code != PHI_NODE) | |
2424 | val.lattice_val = VARYING; | |
2425 | } | |
2426 | } | |
2427 | ||
2428 | return val; | |
2429 | } | |
2430 | ||
2431 | ||
2432 | /* Fold builtin call FN in statement STMT. If it cannot be folded into a | |
2433 | constant, return NULL_TREE. Otherwise, return its constant value. */ | |
2434 | ||
2435 | static tree | |
2436 | ccp_fold_builtin (tree stmt, tree fn) | |
2437 | { | |
2438 | tree result, strlen_val[2]; | |
a32e70c3 | 2439 | tree callee, arglist, a; |
6de9cd9a | 2440 | int strlen_arg, i; |
a32e70c3 RS |
2441 | bitmap visited; |
2442 | bool ignore; | |
6de9cd9a | 2443 | |
a32e70c3 | 2444 | ignore = TREE_CODE (stmt) != MODIFY_EXPR; |
6de9cd9a DN |
2445 | |
2446 | /* First try the generic builtin folder. If that succeeds, return the | |
2447 | result directly. */ | |
a32e70c3 | 2448 | result = fold_builtin (fn, ignore); |
6de9cd9a | 2449 | if (result) |
a32e70c3 RS |
2450 | { |
2451 | if (ignore) | |
2452 | STRIP_NOPS (result); | |
6de9cd9a | 2453 | return result; |
a32e70c3 RS |
2454 | } |
2455 | ||
2456 | /* Ignore MD builtins. */ | |
2457 | callee = get_callee_fndecl (fn); | |
2458 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD) | |
2459 | return NULL_TREE; | |
6de9cd9a DN |
2460 | |
2461 | /* If the builtin could not be folded, and it has no argument list, | |
2462 | we're done. */ | |
a32e70c3 | 2463 | arglist = TREE_OPERAND (fn, 1); |
6de9cd9a DN |
2464 | if (!arglist) |
2465 | return NULL_TREE; | |
2466 | ||
2467 | /* Limit the work only for builtins we know how to simplify. */ | |
2468 | switch (DECL_FUNCTION_CODE (callee)) | |
2469 | { | |
2470 | case BUILT_IN_STRLEN: | |
2471 | case BUILT_IN_FPUTS: | |
2472 | case BUILT_IN_FPUTS_UNLOCKED: | |
2473 | strlen_arg = 1; | |
2474 | break; | |
2475 | case BUILT_IN_STRCPY: | |
2476 | case BUILT_IN_STRNCPY: | |
2477 | strlen_arg = 2; | |
2478 | break; | |
2479 | default: | |
2480 | return NULL_TREE; | |
2481 | } | |
2482 | ||
2483 | /* Try to use the dataflow information gathered by the CCP process. */ | |
2484 | visited = BITMAP_XMALLOC (); | |
2485 | ||
2486 | memset (strlen_val, 0, sizeof (strlen_val)); | |
2487 | for (i = 0, a = arglist; | |
2488 | strlen_arg; | |
2489 | i++, strlen_arg >>= 1, a = TREE_CHAIN (a)) | |
2490 | if (strlen_arg & 1) | |
2491 | { | |
2492 | bitmap_clear (visited); | |
2493 | if (!get_strlen (TREE_VALUE (a), &strlen_val[i], visited)) | |
2494 | strlen_val[i] = NULL_TREE; | |
2495 | } | |
2496 | ||
2497 | BITMAP_XFREE (visited); | |
2498 | ||
a32e70c3 | 2499 | result = NULL_TREE; |
6de9cd9a DN |
2500 | switch (DECL_FUNCTION_CODE (callee)) |
2501 | { | |
2502 | case BUILT_IN_STRLEN: | |
a32e70c3 | 2503 | if (strlen_val[0]) |
6de9cd9a | 2504 | { |
a32e70c3 | 2505 | tree new = fold_convert (TREE_TYPE (fn), strlen_val[0]); |
6de9cd9a DN |
2506 | |
2507 | /* If the result is not a valid gimple value, or not a cast | |
2508 | of a valid gimple value, then we can not use the result. */ | |
2509 | if (is_gimple_val (new) | |
2510 | || (is_gimple_cast (new) | |
2511 | && is_gimple_val (TREE_OPERAND (new, 0)))) | |
2512 | return new; | |
6de9cd9a | 2513 | } |
a32e70c3 RS |
2514 | break; |
2515 | ||
6de9cd9a | 2516 | case BUILT_IN_STRCPY: |
a32e70c3 RS |
2517 | if (strlen_val[1] && is_gimple_val (strlen_val[1])) |
2518 | result = fold_builtin_strcpy (fn, strlen_val[1]); | |
2519 | break; | |
2520 | ||
6de9cd9a | 2521 | case BUILT_IN_STRNCPY: |
a32e70c3 RS |
2522 | if (strlen_val[1] && is_gimple_val (strlen_val[1])) |
2523 | result = fold_builtin_strncpy (fn, strlen_val[1]); | |
2524 | break; | |
2525 | ||
6de9cd9a | 2526 | case BUILT_IN_FPUTS: |
a32e70c3 RS |
2527 | result = fold_builtin_fputs (arglist, |
2528 | TREE_CODE (stmt) != MODIFY_EXPR, 0, | |
2529 | strlen_val[0]); | |
2530 | break; | |
2531 | ||
6de9cd9a | 2532 | case BUILT_IN_FPUTS_UNLOCKED: |
a32e70c3 RS |
2533 | result = fold_builtin_fputs (arglist, |
2534 | TREE_CODE (stmt) != MODIFY_EXPR, 1, | |
2535 | strlen_val[0]); | |
2536 | break; | |
6de9cd9a DN |
2537 | |
2538 | default: | |
2539 | abort (); | |
2540 | } | |
2541 | ||
a32e70c3 | 2542 | if (result && ignore) |
9675412f | 2543 | result = fold_ignored_result (result); |
a32e70c3 | 2544 | return result; |
6de9cd9a DN |
2545 | } |
2546 | ||
2547 | ||
2548 | /* Return the string length of ARG in LENGTH. If ARG is an SSA name variable, | |
2549 | follow its use-def chains. If LENGTH is not NULL and its value is not | |
2550 | equal to the length we determine, or if we are unable to determine the | |
2551 | length, return false. VISITED is a bitmap of visited variables. */ | |
2552 | ||
2553 | static bool | |
2554 | get_strlen (tree arg, tree *length, bitmap visited) | |
2555 | { | |
2556 | tree var, def_stmt, val; | |
2557 | ||
2558 | if (TREE_CODE (arg) != SSA_NAME) | |
2559 | { | |
2560 | val = c_strlen (arg, 1); | |
2561 | if (!val) | |
2562 | return false; | |
2563 | ||
2564 | if (*length && simple_cst_equal (val, *length) != 1) | |
2565 | return false; | |
2566 | ||
2567 | *length = val; | |
2568 | return true; | |
2569 | } | |
2570 | ||
2571 | /* If we were already here, break the infinite cycle. */ | |
2572 | if (bitmap_bit_p (visited, SSA_NAME_VERSION (arg))) | |
2573 | return true; | |
2574 | bitmap_set_bit (visited, SSA_NAME_VERSION (arg)); | |
2575 | ||
2576 | var = arg; | |
2577 | def_stmt = SSA_NAME_DEF_STMT (var); | |
2578 | ||
2579 | switch (TREE_CODE (def_stmt)) | |
2580 | { | |
2581 | case MODIFY_EXPR: | |
2582 | { | |
2583 | tree len, rhs; | |
2584 | ||
2585 | /* The RHS of the statement defining VAR must either have a | |
2586 | constant length or come from another SSA_NAME with a constant | |
2587 | length. */ | |
2588 | rhs = TREE_OPERAND (def_stmt, 1); | |
2589 | STRIP_NOPS (rhs); | |
2590 | if (TREE_CODE (rhs) == SSA_NAME) | |
2591 | return get_strlen (rhs, length, visited); | |
2592 | ||
2593 | /* See if the RHS is a constant length. */ | |
2594 | len = c_strlen (rhs, 1); | |
2595 | if (len) | |
2596 | { | |
2597 | if (*length && simple_cst_equal (len, *length) != 1) | |
2598 | return false; | |
2599 | ||
2600 | *length = len; | |
2601 | return true; | |
2602 | } | |
2603 | ||
2604 | break; | |
2605 | } | |
2606 | ||
2607 | case PHI_NODE: | |
2608 | { | |
2609 | /* All the arguments of the PHI node must have the same constant | |
2610 | length. */ | |
2611 | int i; | |
2612 | ||
2613 | for (i = 0; i < PHI_NUM_ARGS (def_stmt); i++) | |
2614 | { | |
2615 | tree arg = PHI_ARG_DEF (def_stmt, i); | |
2616 | ||
2617 | /* If this PHI has itself as an argument, we cannot | |
2618 | determine the string length of this argument. However, | |
2619 | if we can find a constant string length for the other | |
2620 | PHI args then we can still be sure that this is a | |
2621 | constant string length. So be optimistic and just | |
2622 | continue with the next argument. */ | |
2623 | if (arg == PHI_RESULT (def_stmt)) | |
2624 | continue; | |
2625 | ||
2626 | if (!get_strlen (arg, length, visited)) | |
2627 | return false; | |
2628 | } | |
2629 | ||
2630 | return true; | |
2631 | } | |
2632 | ||
2633 | default: | |
2634 | break; | |
2635 | } | |
2636 | ||
2637 | ||
2638 | return false; | |
2639 | } | |
2640 | ||
2641 | \f | |
2642 | /* A simple pass that attempts to fold all builtin functions. This pass | |
2643 | is run after we've propagated as many constants as we can. */ | |
2644 | ||
2645 | static void | |
2646 | execute_fold_all_builtins (void) | |
2647 | { | |
2648 | basic_block bb; | |
2649 | FOR_EACH_BB (bb) | |
2650 | { | |
2651 | block_stmt_iterator i; | |
2652 | for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i)) | |
2653 | { | |
2654 | tree *stmtp = bsi_stmt_ptr (i); | |
2655 | tree call = get_rhs (*stmtp); | |
2656 | tree callee, result; | |
2657 | ||
2658 | if (!call || TREE_CODE (call) != CALL_EXPR) | |
2659 | continue; | |
2660 | callee = get_callee_fndecl (call); | |
2661 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) | |
2662 | continue; | |
2663 | ||
2664 | result = ccp_fold_builtin (*stmtp, call); | |
2665 | if (!result) | |
2666 | switch (DECL_FUNCTION_CODE (callee)) | |
2667 | { | |
2668 | case BUILT_IN_CONSTANT_P: | |
2669 | /* Resolve __builtin_constant_p. If it hasn't been | |
2670 | folded to integer_one_node by now, it's fairly | |
2671 | certain that the value simply isn't constant. */ | |
2672 | result = integer_zero_node; | |
2673 | break; | |
2674 | ||
2675 | default: | |
2676 | continue; | |
2677 | } | |
2678 | ||
2679 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2680 | { | |
2681 | fprintf (dump_file, "Simplified\n "); | |
2682 | print_generic_stmt (dump_file, *stmtp, dump_flags); | |
2683 | } | |
2684 | ||
06a9b53f RS |
2685 | if (set_rhs (stmtp, result)) |
2686 | modify_stmt (*stmtp); | |
6de9cd9a DN |
2687 | |
2688 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2689 | { | |
2690 | fprintf (dump_file, "to\n "); | |
2691 | print_generic_stmt (dump_file, *stmtp, dump_flags); | |
2692 | fprintf (dump_file, "\n"); | |
2693 | } | |
2694 | } | |
2695 | } | |
2696 | } | |
2697 | ||
2698 | struct tree_opt_pass pass_fold_builtins = | |
2699 | { | |
2700 | "fab", /* name */ | |
2701 | NULL, /* gate */ | |
2702 | execute_fold_all_builtins, /* execute */ | |
2703 | NULL, /* sub */ | |
2704 | NULL, /* next */ | |
2705 | 0, /* static_pass_number */ | |
2706 | 0, /* tv_id */ | |
c1b763fa | 2707 | PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */ |
6de9cd9a DN |
2708 | 0, /* properties_provided */ |
2709 | 0, /* properties_destroyed */ | |
2710 | 0, /* todo_flags_start */ | |
2711 | TODO_dump_func | TODO_verify_ssa /* todo_flags_finish */ | |
2712 | }; | |
2713 | ||
2714 | ||
2715 | #include "gt-tree-ssa-ccp.h" |