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c913f08a | 1 | /* High-level loop manipulation functions. |
66647d44 | 2 | Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc. |
c913f08a ZD |
3 | |
4 | This file is part of GCC. | |
5 | ||
6 | GCC is free software; you can redistribute it and/or modify it | |
7 | under the terms of the GNU General Public License as published by the | |
9dcd6f09 | 8 | Free Software Foundation; either version 3, or (at your option) any |
c913f08a ZD |
9 | later version. |
10 | ||
11 | GCC is distributed in the hope that it will be useful, but WITHOUT | |
12 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 | for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
c913f08a ZD |
19 | |
20 | #include "config.h" | |
21 | #include "system.h" | |
22 | #include "coretypes.h" | |
23 | #include "tm.h" | |
24 | #include "tree.h" | |
25 | #include "rtl.h" | |
26 | #include "tm_p.h" | |
27 | #include "hard-reg-set.h" | |
28 | #include "basic-block.h" | |
29 | #include "output.h" | |
30 | #include "diagnostic.h" | |
31 | #include "tree-flow.h" | |
32 | #include "tree-dump.h" | |
33 | #include "timevar.h" | |
34 | #include "cfgloop.h" | |
35 | #include "tree-pass.h" | |
36 | #include "cfglayout.h" | |
37 | #include "tree-scalar-evolution.h" | |
17684618 | 38 | #include "params.h" |
7f9bc51b | 39 | #include "tree-inline.h" |
08dab97a | 40 | #include "langhooks.h" |
c913f08a | 41 | |
82b85a85 ZD |
42 | /* Creates an induction variable with value BASE + STEP * iteration in LOOP. |
43 | It is expected that neither BASE nor STEP are shared with other expressions | |
44 | (unless the sharing rules allow this). Use VAR as a base var_decl for it | |
45 | (if NULL, a new temporary will be created). The increment will occur at | |
92d2b330 SP |
46 | INCR_POS (after it if AFTER is true, before it otherwise). INCR_POS and |
47 | AFTER can be computed using standard_iv_increment_position. The ssa versions | |
82b85a85 ZD |
48 | of the variable before and after increment will be stored in VAR_BEFORE and |
49 | VAR_AFTER (unless they are NULL). */ | |
50 | ||
51 | void | |
52 | create_iv (tree base, tree step, tree var, struct loop *loop, | |
726a989a | 53 | gimple_stmt_iterator *incr_pos, bool after, |
82b85a85 ZD |
54 | tree *var_before, tree *var_after) |
55 | { | |
726a989a RB |
56 | gimple stmt; |
57 | tree initial, step1; | |
58 | gimple_seq stmts; | |
82b85a85 ZD |
59 | tree vb, va; |
60 | enum tree_code incr_op = PLUS_EXPR; | |
9be872b7 | 61 | edge pe = loop_preheader_edge (loop); |
82b85a85 ZD |
62 | |
63 | if (!var) | |
64 | { | |
65 | var = create_tmp_var (TREE_TYPE (base), "ivtmp"); | |
f004ab02 | 66 | add_referenced_var (var); |
82b85a85 ZD |
67 | } |
68 | ||
726a989a | 69 | vb = make_ssa_name (var, NULL); |
82b85a85 ZD |
70 | if (var_before) |
71 | *var_before = vb; | |
726a989a | 72 | va = make_ssa_name (var, NULL); |
82b85a85 ZD |
73 | if (var_after) |
74 | *var_after = va; | |
75 | ||
76 | /* For easier readability of the created code, produce MINUS_EXPRs | |
77 | when suitable. */ | |
78 | if (TREE_CODE (step) == INTEGER_CST) | |
79 | { | |
80 | if (TYPE_UNSIGNED (TREE_TYPE (step))) | |
81 | { | |
987b67bc | 82 | step1 = fold_build1 (NEGATE_EXPR, TREE_TYPE (step), step); |
82b85a85 ZD |
83 | if (tree_int_cst_lt (step1, step)) |
84 | { | |
85 | incr_op = MINUS_EXPR; | |
86 | step = step1; | |
87 | } | |
88 | } | |
89 | else | |
90 | { | |
6ac01510 ILT |
91 | bool ovf; |
92 | ||
93 | if (!tree_expr_nonnegative_warnv_p (step, &ovf) | |
82b85a85 ZD |
94 | && may_negate_without_overflow_p (step)) |
95 | { | |
96 | incr_op = MINUS_EXPR; | |
987b67bc | 97 | step = fold_build1 (NEGATE_EXPR, TREE_TYPE (step), step); |
82b85a85 ZD |
98 | } |
99 | } | |
100 | } | |
5be014d5 AP |
101 | if (POINTER_TYPE_P (TREE_TYPE (base))) |
102 | { | |
628c189e RG |
103 | if (TREE_CODE (base) == ADDR_EXPR) |
104 | mark_addressable (TREE_OPERAND (base, 0)); | |
5be014d5 AP |
105 | step = fold_convert (sizetype, step); |
106 | if (incr_op == MINUS_EXPR) | |
107 | step = fold_build1 (NEGATE_EXPR, sizetype, step); | |
108 | incr_op = POINTER_PLUS_EXPR; | |
109 | } | |
9be872b7 ZD |
110 | /* Gimplify the step if necessary. We put the computations in front of the |
111 | loop (i.e. the step should be loop invariant). */ | |
1ffe34d9 | 112 | step = force_gimple_operand (step, &stmts, true, NULL_TREE); |
9be872b7 | 113 | if (stmts) |
726a989a | 114 | gsi_insert_seq_on_edge_immediate (pe, stmts); |
9be872b7 | 115 | |
726a989a | 116 | stmt = gimple_build_assign_with_ops (incr_op, va, vb, step); |
82b85a85 | 117 | if (after) |
726a989a | 118 | gsi_insert_after (incr_pos, stmt, GSI_NEW_STMT); |
82b85a85 | 119 | else |
726a989a | 120 | gsi_insert_before (incr_pos, stmt, GSI_NEW_STMT); |
82b85a85 | 121 | |
8b11a64c ZD |
122 | initial = force_gimple_operand (base, &stmts, true, var); |
123 | if (stmts) | |
726a989a | 124 | gsi_insert_seq_on_edge_immediate (pe, stmts); |
82b85a85 ZD |
125 | |
126 | stmt = create_phi_node (vb, loop->header); | |
127 | SSA_NAME_DEF_STMT (vb) = stmt; | |
f5045c96 AM |
128 | add_phi_arg (stmt, initial, loop_preheader_edge (loop), UNKNOWN_LOCATION); |
129 | add_phi_arg (stmt, va, loop_latch_edge (loop), UNKNOWN_LOCATION); | |
82b85a85 ZD |
130 | } |
131 | ||
c913f08a ZD |
132 | /* Add exit phis for the USE on EXIT. */ |
133 | ||
134 | static void | |
135 | add_exit_phis_edge (basic_block exit, tree use) | |
136 | { | |
726a989a RB |
137 | gimple phi, def_stmt = SSA_NAME_DEF_STMT (use); |
138 | basic_block def_bb = gimple_bb (def_stmt); | |
c913f08a ZD |
139 | struct loop *def_loop; |
140 | edge e; | |
628f6a4e | 141 | edge_iterator ei; |
c913f08a ZD |
142 | |
143 | /* Check that some of the edges entering the EXIT block exits a loop in | |
144 | that USE is defined. */ | |
628f6a4e | 145 | FOR_EACH_EDGE (e, ei, exit->preds) |
c913f08a ZD |
146 | { |
147 | def_loop = find_common_loop (def_bb->loop_father, e->src->loop_father); | |
148 | if (!flow_bb_inside_loop_p (def_loop, e->dest)) | |
149 | break; | |
150 | } | |
151 | ||
152 | if (!e) | |
153 | return; | |
154 | ||
155 | phi = create_phi_node (use, exit); | |
726a989a RB |
156 | create_new_def_for (gimple_phi_result (phi), phi, |
157 | gimple_phi_result_ptr (phi)); | |
628f6a4e | 158 | FOR_EACH_EDGE (e, ei, exit->preds) |
f5045c96 | 159 | add_phi_arg (phi, use, e, UNKNOWN_LOCATION); |
c913f08a ZD |
160 | } |
161 | ||
162 | /* Add exit phis for VAR that is used in LIVEIN. | |
163 | Exits of the loops are stored in EXITS. */ | |
164 | ||
165 | static void | |
166 | add_exit_phis_var (tree var, bitmap livein, bitmap exits) | |
167 | { | |
168 | bitmap def; | |
3cd8c58a | 169 | unsigned index; |
726a989a | 170 | basic_block def_bb = gimple_bb (SSA_NAME_DEF_STMT (var)); |
87c476a2 | 171 | bitmap_iterator bi; |
c913f08a | 172 | |
0bca51f0 DN |
173 | if (is_gimple_reg (var)) |
174 | bitmap_clear_bit (livein, def_bb->index); | |
175 | else | |
176 | bitmap_set_bit (livein, def_bb->index); | |
c913f08a | 177 | |
8bdbfff5 | 178 | def = BITMAP_ALLOC (NULL); |
c913f08a ZD |
179 | bitmap_set_bit (def, def_bb->index); |
180 | compute_global_livein (livein, def); | |
8bdbfff5 | 181 | BITMAP_FREE (def); |
c913f08a | 182 | |
87c476a2 ZD |
183 | EXECUTE_IF_AND_IN_BITMAP (exits, livein, 0, index, bi) |
184 | { | |
185 | add_exit_phis_edge (BASIC_BLOCK (index), var); | |
186 | } | |
c913f08a ZD |
187 | } |
188 | ||
189 | /* Add exit phis for the names marked in NAMES_TO_RENAME. | |
190 | Exits of the loops are stored in EXITS. Sets of blocks where the ssa | |
191 | names are used are stored in USE_BLOCKS. */ | |
192 | ||
193 | static void | |
194 | add_exit_phis (bitmap names_to_rename, bitmap *use_blocks, bitmap loop_exits) | |
195 | { | |
196 | unsigned i; | |
87c476a2 | 197 | bitmap_iterator bi; |
c913f08a | 198 | |
87c476a2 | 199 | EXECUTE_IF_SET_IN_BITMAP (names_to_rename, 0, i, bi) |
c913f08a ZD |
200 | { |
201 | add_exit_phis_var (ssa_name (i), use_blocks[i], loop_exits); | |
87c476a2 | 202 | } |
c913f08a ZD |
203 | } |
204 | ||
205 | /* Returns a bitmap of all loop exit edge targets. */ | |
206 | ||
207 | static bitmap | |
208 | get_loops_exits (void) | |
209 | { | |
8bdbfff5 | 210 | bitmap exits = BITMAP_ALLOC (NULL); |
c913f08a ZD |
211 | basic_block bb; |
212 | edge e; | |
628f6a4e | 213 | edge_iterator ei; |
c913f08a ZD |
214 | |
215 | FOR_EACH_BB (bb) | |
216 | { | |
628f6a4e | 217 | FOR_EACH_EDGE (e, ei, bb->preds) |
c913f08a ZD |
218 | if (e->src != ENTRY_BLOCK_PTR |
219 | && !flow_bb_inside_loop_p (e->src->loop_father, bb)) | |
220 | { | |
221 | bitmap_set_bit (exits, bb->index); | |
222 | break; | |
223 | } | |
224 | } | |
225 | ||
226 | return exits; | |
227 | } | |
228 | ||
229 | /* For USE in BB, if it is used outside of the loop it is defined in, | |
230 | mark it for rewrite. Record basic block BB where it is used | |
84d65814 | 231 | to USE_BLOCKS. Record the ssa name index to NEED_PHIS bitmap. */ |
c913f08a ZD |
232 | |
233 | static void | |
84d65814 DN |
234 | find_uses_to_rename_use (basic_block bb, tree use, bitmap *use_blocks, |
235 | bitmap need_phis) | |
c913f08a ZD |
236 | { |
237 | unsigned ver; | |
238 | basic_block def_bb; | |
239 | struct loop *def_loop; | |
240 | ||
241 | if (TREE_CODE (use) != SSA_NAME) | |
242 | return; | |
243 | ||
84d65814 DN |
244 | /* We don't need to keep virtual operands in loop-closed form. */ |
245 | if (!is_gimple_reg (use)) | |
246 | return; | |
247 | ||
c913f08a | 248 | ver = SSA_NAME_VERSION (use); |
726a989a | 249 | def_bb = gimple_bb (SSA_NAME_DEF_STMT (use)); |
c913f08a ZD |
250 | if (!def_bb) |
251 | return; | |
252 | def_loop = def_bb->loop_father; | |
253 | ||
d6e840ee | 254 | /* If the definition is not inside a loop, it is not interesting. */ |
9ba025a2 | 255 | if (!loop_outer (def_loop)) |
c913f08a ZD |
256 | return; |
257 | ||
d6e840ee RG |
258 | /* If the use is not outside of the loop it is defined in, it is not |
259 | interesting. */ | |
260 | if (flow_bb_inside_loop_p (def_loop, bb)) | |
261 | return; | |
262 | ||
c913f08a | 263 | if (!use_blocks[ver]) |
8bdbfff5 | 264 | use_blocks[ver] = BITMAP_ALLOC (NULL); |
c913f08a ZD |
265 | bitmap_set_bit (use_blocks[ver], bb->index); |
266 | ||
84d65814 | 267 | bitmap_set_bit (need_phis, ver); |
c913f08a ZD |
268 | } |
269 | ||
270 | /* For uses in STMT, mark names that are used outside of the loop they are | |
271 | defined to rewrite. Record the set of blocks in that the ssa | |
84d65814 DN |
272 | names are defined to USE_BLOCKS and the ssa names themselves to |
273 | NEED_PHIS. */ | |
c913f08a ZD |
274 | |
275 | static void | |
726a989a | 276 | find_uses_to_rename_stmt (gimple stmt, bitmap *use_blocks, bitmap need_phis) |
c913f08a | 277 | { |
4c124b4c AM |
278 | ssa_op_iter iter; |
279 | tree var; | |
726a989a | 280 | basic_block bb = gimple_bb (stmt); |
c913f08a | 281 | |
b5b8b0ac AO |
282 | if (is_gimple_debug (stmt)) |
283 | return; | |
284 | ||
38635499 | 285 | FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_USES) |
84d65814 | 286 | find_uses_to_rename_use (bb, var, use_blocks, need_phis); |
c913f08a ZD |
287 | } |
288 | ||
2b271002 ZD |
289 | /* Marks names that are used in BB and outside of the loop they are |
290 | defined in for rewrite. Records the set of blocks in that the ssa | |
84d65814 DN |
291 | names are defined to USE_BLOCKS. Record the SSA names that will |
292 | need exit PHIs in NEED_PHIS. */ | |
c913f08a ZD |
293 | |
294 | static void | |
84d65814 | 295 | find_uses_to_rename_bb (basic_block bb, bitmap *use_blocks, bitmap need_phis) |
c913f08a | 296 | { |
726a989a | 297 | gimple_stmt_iterator bsi; |
2b271002 ZD |
298 | edge e; |
299 | edge_iterator ei; | |
c913f08a | 300 | |
2b271002 | 301 | FOR_EACH_EDGE (e, ei, bb->succs) |
726a989a RB |
302 | for (bsi = gsi_start_phis (e->dest); !gsi_end_p (bsi); gsi_next (&bsi)) |
303 | find_uses_to_rename_use (bb, PHI_ARG_DEF_FROM_EDGE (gsi_stmt (bsi), e), | |
84d65814 | 304 | use_blocks, need_phis); |
2b271002 | 305 | |
726a989a RB |
306 | for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
307 | find_uses_to_rename_stmt (gsi_stmt (bsi), use_blocks, need_phis); | |
2b271002 ZD |
308 | } |
309 | ||
310 | /* Marks names that are used outside of the loop they are defined in | |
311 | for rewrite. Records the set of blocks in that the ssa | |
312 | names are defined to USE_BLOCKS. If CHANGED_BBS is not NULL, | |
313 | scan only blocks in this set. */ | |
314 | ||
315 | static void | |
84d65814 | 316 | find_uses_to_rename (bitmap changed_bbs, bitmap *use_blocks, bitmap need_phis) |
2b271002 ZD |
317 | { |
318 | basic_block bb; | |
319 | unsigned index; | |
320 | bitmap_iterator bi; | |
c913f08a | 321 | |
84d65814 | 322 | if (changed_bbs && !bitmap_empty_p (changed_bbs)) |
2b271002 ZD |
323 | { |
324 | EXECUTE_IF_SET_IN_BITMAP (changed_bbs, 0, index, bi) | |
325 | { | |
84d65814 | 326 | find_uses_to_rename_bb (BASIC_BLOCK (index), use_blocks, need_phis); |
2b271002 ZD |
327 | } |
328 | } | |
329 | else | |
330 | { | |
331 | FOR_EACH_BB (bb) | |
332 | { | |
84d65814 | 333 | find_uses_to_rename_bb (bb, use_blocks, need_phis); |
2b271002 | 334 | } |
c913f08a ZD |
335 | } |
336 | } | |
337 | ||
338 | /* Rewrites the program into a loop closed ssa form -- i.e. inserts extra | |
339 | phi nodes to ensure that no variable is used outside the loop it is | |
340 | defined in. | |
341 | ||
342 | This strengthening of the basic ssa form has several advantages: | |
343 | ||
344 | 1) Updating it during unrolling/peeling/versioning is trivial, since | |
345 | we do not need to care about the uses outside of the loop. | |
346 | 2) The behavior of all uses of an induction variable is the same. | |
347 | Without this, you need to distinguish the case when the variable | |
348 | is used outside of the loop it is defined in, for example | |
349 | ||
350 | for (i = 0; i < 100; i++) | |
351 | { | |
352 | for (j = 0; j < 100; j++) | |
353 | { | |
354 | k = i + j; | |
355 | use1 (k); | |
356 | } | |
357 | use2 (k); | |
358 | } | |
359 | ||
360 | Looking from the outer loop with the normal SSA form, the first use of k | |
361 | is not well-behaved, while the second one is an induction variable with | |
2b271002 ZD |
362 | base 99 and step 1. |
363 | ||
364 | If CHANGED_BBS is not NULL, we look for uses outside loops only in | |
84d65814 DN |
365 | the basic blocks in this set. |
366 | ||
367 | UPDATE_FLAG is used in the call to update_ssa. See | |
368 | TODO_update_ssa* for documentation. */ | |
c913f08a ZD |
369 | |
370 | void | |
84d65814 | 371 | rewrite_into_loop_closed_ssa (bitmap changed_bbs, unsigned update_flag) |
c913f08a | 372 | { |
c7b852c8 | 373 | bitmap loop_exits; |
c913f08a | 374 | bitmap *use_blocks; |
84d65814 | 375 | unsigned i, old_num_ssa_names; |
c7b852c8 ZD |
376 | bitmap names_to_rename; |
377 | ||
f87000d0 | 378 | loops_state_set (LOOP_CLOSED_SSA); |
d51157de | 379 | if (number_of_loops () <= 1) |
c7b852c8 ZD |
380 | return; |
381 | ||
382 | loop_exits = get_loops_exits (); | |
383 | names_to_rename = BITMAP_ALLOC (NULL); | |
c913f08a | 384 | |
84d65814 DN |
385 | /* If the pass has caused the SSA form to be out-of-date, update it |
386 | now. */ | |
387 | update_ssa (update_flag); | |
c913f08a | 388 | |
84d65814 | 389 | old_num_ssa_names = num_ssa_names; |
5ed6ace5 | 390 | use_blocks = XCNEWVEC (bitmap, old_num_ssa_names); |
c913f08a ZD |
391 | |
392 | /* Find the uses outside loops. */ | |
84d65814 | 393 | find_uses_to_rename (changed_bbs, use_blocks, names_to_rename); |
2b271002 | 394 | |
84d65814 | 395 | /* Add the PHI nodes on exits of the loops for the names we need to |
c913f08a | 396 | rewrite. */ |
c913f08a ZD |
397 | add_exit_phis (names_to_rename, use_blocks, loop_exits); |
398 | ||
84d65814 | 399 | for (i = 0; i < old_num_ssa_names; i++) |
8bdbfff5 | 400 | BITMAP_FREE (use_blocks[i]); |
c913f08a | 401 | free (use_blocks); |
8bdbfff5 NS |
402 | BITMAP_FREE (loop_exits); |
403 | BITMAP_FREE (names_to_rename); | |
c913f08a | 404 | |
84d65814 DN |
405 | /* Fix up all the names found to be used outside their original |
406 | loops. */ | |
407 | update_ssa (TODO_update_ssa); | |
c913f08a ZD |
408 | } |
409 | ||
410 | /* Check invariants of the loop closed ssa form for the USE in BB. */ | |
411 | ||
412 | static void | |
413 | check_loop_closed_ssa_use (basic_block bb, tree use) | |
414 | { | |
726a989a | 415 | gimple def; |
c913f08a ZD |
416 | basic_block def_bb; |
417 | ||
84d65814 | 418 | if (TREE_CODE (use) != SSA_NAME || !is_gimple_reg (use)) |
c913f08a ZD |
419 | return; |
420 | ||
421 | def = SSA_NAME_DEF_STMT (use); | |
726a989a | 422 | def_bb = gimple_bb (def); |
1e128c5f GB |
423 | gcc_assert (!def_bb |
424 | || flow_bb_inside_loop_p (def_bb->loop_father, bb)); | |
c913f08a ZD |
425 | } |
426 | ||
427 | /* Checks invariants of loop closed ssa form in statement STMT in BB. */ | |
428 | ||
429 | static void | |
726a989a | 430 | check_loop_closed_ssa_stmt (basic_block bb, gimple stmt) |
c913f08a | 431 | { |
4c124b4c AM |
432 | ssa_op_iter iter; |
433 | tree var; | |
c913f08a | 434 | |
b5b8b0ac AO |
435 | if (is_gimple_debug (stmt)) |
436 | return; | |
437 | ||
38635499 | 438 | FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_USES) |
4c124b4c | 439 | check_loop_closed_ssa_use (bb, var); |
c913f08a ZD |
440 | } |
441 | ||
442 | /* Checks that invariants of the loop closed ssa form are preserved. */ | |
443 | ||
444 | void | |
445 | verify_loop_closed_ssa (void) | |
446 | { | |
447 | basic_block bb; | |
726a989a RB |
448 | gimple_stmt_iterator bsi; |
449 | gimple phi; | |
450 | edge e; | |
451 | edge_iterator ei; | |
c913f08a | 452 | |
d51157de | 453 | if (number_of_loops () <= 1) |
84d65814 DN |
454 | return; |
455 | ||
f430bae8 | 456 | verify_ssa (false); |
c913f08a ZD |
457 | |
458 | FOR_EACH_BB (bb) | |
459 | { | |
726a989a RB |
460 | for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
461 | { | |
462 | phi = gsi_stmt (bsi); | |
463 | FOR_EACH_EDGE (e, ei, bb->preds) | |
464 | check_loop_closed_ssa_use (e->src, | |
465 | PHI_ARG_DEF_FROM_EDGE (phi, e)); | |
466 | } | |
c913f08a | 467 | |
726a989a RB |
468 | for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
469 | check_loop_closed_ssa_stmt (bb, gsi_stmt (bsi)); | |
c913f08a ZD |
470 | } |
471 | } | |
8b11a64c ZD |
472 | |
473 | /* Split loop exit edge EXIT. The things are a bit complicated by a need to | |
5f40b3cb | 474 | preserve the loop closed ssa form. The newly created block is returned. */ |
8b11a64c | 475 | |
5f40b3cb | 476 | basic_block |
8b11a64c ZD |
477 | split_loop_exit_edge (edge exit) |
478 | { | |
479 | basic_block dest = exit->dest; | |
598ec7bd | 480 | basic_block bb = split_edge (exit); |
726a989a RB |
481 | gimple phi, new_phi; |
482 | tree new_name, name; | |
8b11a64c | 483 | use_operand_p op_p; |
726a989a | 484 | gimple_stmt_iterator psi; |
f5045c96 | 485 | source_location locus; |
8b11a64c | 486 | |
726a989a | 487 | for (psi = gsi_start_phis (dest); !gsi_end_p (psi); gsi_next (&psi)) |
8b11a64c | 488 | { |
726a989a | 489 | phi = gsi_stmt (psi); |
c5cbcccf | 490 | op_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, single_succ_edge (bb)); |
f5045c96 | 491 | locus = gimple_phi_arg_location_from_edge (phi, single_succ_edge (bb)); |
8b11a64c | 492 | |
7fac6722 ZD |
493 | name = USE_FROM_PTR (op_p); |
494 | ||
38635499 | 495 | /* If the argument of the PHI node is a constant, we do not need |
7fac6722 ZD |
496 | to keep it inside loop. */ |
497 | if (TREE_CODE (name) != SSA_NAME) | |
498 | continue; | |
499 | ||
500 | /* Otherwise create an auxiliary phi node that will copy the value | |
38635499 | 501 | of the SSA name out of the loop. */ |
7fac6722 | 502 | new_name = duplicate_ssa_name (name, NULL); |
8b11a64c ZD |
503 | new_phi = create_phi_node (new_name, bb); |
504 | SSA_NAME_DEF_STMT (new_name) = new_phi; | |
f5045c96 | 505 | add_phi_arg (new_phi, name, exit, locus); |
8b11a64c ZD |
506 | SET_USE (op_p, new_name); |
507 | } | |
5f40b3cb ZD |
508 | |
509 | return bb; | |
8b11a64c ZD |
510 | } |
511 | ||
8b11a64c ZD |
512 | /* Returns the basic block in that statements should be emitted for induction |
513 | variables incremented at the end of the LOOP. */ | |
514 | ||
515 | basic_block | |
516 | ip_end_pos (struct loop *loop) | |
517 | { | |
518 | return loop->latch; | |
519 | } | |
520 | ||
521 | /* Returns the basic block in that statements should be emitted for induction | |
522 | variables incremented just before exit condition of a LOOP. */ | |
523 | ||
524 | basic_block | |
525 | ip_normal_pos (struct loop *loop) | |
526 | { | |
726a989a | 527 | gimple last; |
8b11a64c ZD |
528 | basic_block bb; |
529 | edge exit; | |
530 | ||
c5cbcccf | 531 | if (!single_pred_p (loop->latch)) |
8b11a64c ZD |
532 | return NULL; |
533 | ||
c5cbcccf | 534 | bb = single_pred (loop->latch); |
8b11a64c | 535 | last = last_stmt (bb); |
ae2cf11b | 536 | if (!last |
726a989a | 537 | || gimple_code (last) != GIMPLE_COND) |
8b11a64c ZD |
538 | return NULL; |
539 | ||
628f6a4e | 540 | exit = EDGE_SUCC (bb, 0); |
8b11a64c | 541 | if (exit->dest == loop->latch) |
628f6a4e | 542 | exit = EDGE_SUCC (bb, 1); |
8b11a64c ZD |
543 | |
544 | if (flow_bb_inside_loop_p (loop, exit->dest)) | |
545 | return NULL; | |
546 | ||
547 | return bb; | |
548 | } | |
549 | ||
550 | /* Stores the standard position for induction variable increment in LOOP | |
551 | (just before the exit condition if it is available and latch block is empty, | |
552 | end of the latch block otherwise) to BSI. INSERT_AFTER is set to true if | |
553 | the increment should be inserted after *BSI. */ | |
554 | ||
555 | void | |
726a989a | 556 | standard_iv_increment_position (struct loop *loop, gimple_stmt_iterator *bsi, |
8b11a64c ZD |
557 | bool *insert_after) |
558 | { | |
559 | basic_block bb = ip_normal_pos (loop), latch = ip_end_pos (loop); | |
726a989a | 560 | gimple last = last_stmt (latch); |
8b11a64c ZD |
561 | |
562 | if (!bb | |
726a989a | 563 | || (last && gimple_code (last) != GIMPLE_LABEL)) |
8b11a64c | 564 | { |
726a989a | 565 | *bsi = gsi_last_bb (latch); |
8b11a64c ZD |
566 | *insert_after = true; |
567 | } | |
568 | else | |
569 | { | |
726a989a | 570 | *bsi = gsi_last_bb (bb); |
8b11a64c ZD |
571 | *insert_after = false; |
572 | } | |
573 | } | |
92fc4a2f ZD |
574 | |
575 | /* Copies phi node arguments for duplicated blocks. The index of the first | |
576 | duplicated block is FIRST_NEW_BLOCK. */ | |
577 | ||
578 | static void | |
579 | copy_phi_node_args (unsigned first_new_block) | |
580 | { | |
581 | unsigned i; | |
582 | ||
583 | for (i = first_new_block; i < (unsigned) last_basic_block; i++) | |
6580ee77 | 584 | BASIC_BLOCK (i)->flags |= BB_DUPLICATED; |
92fc4a2f ZD |
585 | |
586 | for (i = first_new_block; i < (unsigned) last_basic_block; i++) | |
587 | add_phi_args_after_copy_bb (BASIC_BLOCK (i)); | |
588 | ||
589 | for (i = first_new_block; i < (unsigned) last_basic_block; i++) | |
6580ee77 | 590 | BASIC_BLOCK (i)->flags &= ~BB_DUPLICATED; |
92fc4a2f ZD |
591 | } |
592 | ||
92fc4a2f | 593 | |
84d65814 DN |
594 | /* The same as cfgloopmanip.c:duplicate_loop_to_header_edge, but also |
595 | updates the PHI nodes at start of the copied region. In order to | |
596 | achieve this, only loops whose exits all lead to the same location | |
597 | are handled. | |
92fc4a2f | 598 | |
84d65814 DN |
599 | Notice that we do not completely update the SSA web after |
600 | duplication. The caller is responsible for calling update_ssa | |
601 | after the loop has been duplicated. */ | |
92fc4a2f ZD |
602 | |
603 | bool | |
726a989a | 604 | gimple_duplicate_loop_to_header_edge (struct loop *loop, edge e, |
92fc4a2f | 605 | unsigned int ndupl, sbitmap wont_exit, |
ee8c1b05 ZD |
606 | edge orig, VEC (edge, heap) **to_remove, |
607 | int flags) | |
92fc4a2f ZD |
608 | { |
609 | unsigned first_new_block; | |
92fc4a2f | 610 | |
f87000d0 | 611 | if (!loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
92fc4a2f | 612 | return false; |
f87000d0 | 613 | if (!loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)) |
92fc4a2f ZD |
614 | return false; |
615 | ||
616 | #ifdef ENABLE_CHECKING | |
d6e840ee RG |
617 | if (loops_state_satisfies_p (LOOP_CLOSED_SSA)) |
618 | verify_loop_closed_ssa (); | |
92fc4a2f ZD |
619 | #endif |
620 | ||
92fc4a2f | 621 | first_new_block = last_basic_block; |
d73be268 | 622 | if (!duplicate_loop_to_header_edge (loop, e, ndupl, wont_exit, |
ee8c1b05 | 623 | orig, to_remove, flags)) |
92fc4a2f ZD |
624 | return false; |
625 | ||
626 | /* Readd the removed phi args for e. */ | |
71882046 | 627 | flush_pending_stmts (e); |
92fc4a2f ZD |
628 | |
629 | /* Copy the phi node arguments. */ | |
630 | copy_phi_node_args (first_new_block); | |
631 | ||
92fc4a2f | 632 | scev_reset (); |
92fc4a2f ZD |
633 | |
634 | return true; | |
635 | } | |
17684618 | 636 | |
17684618 ZD |
637 | /* Returns true if we can unroll LOOP FACTOR times. Number |
638 | of iterations of the loop is returned in NITER. */ | |
639 | ||
640 | bool | |
641 | can_unroll_loop_p (struct loop *loop, unsigned factor, | |
642 | struct tree_niter_desc *niter) | |
643 | { | |
644 | edge exit; | |
645 | ||
646 | /* Check whether unrolling is possible. We only want to unroll loops | |
647 | for that we are able to determine number of iterations. We also | |
648 | want to split the extra iterations of the loop from its end, | |
649 | therefore we require that the loop has precisely one | |
650 | exit. */ | |
651 | ||
652 | exit = single_dom_exit (loop); | |
653 | if (!exit) | |
654 | return false; | |
655 | ||
656 | if (!number_of_iterations_exit (loop, exit, niter, false) | |
bf8dbe38 ZD |
657 | || niter->cmp == ERROR_MARK |
658 | /* Scalar evolutions analysis might have copy propagated | |
659 | the abnormal ssa names into these expressions, hence | |
2f8e468b | 660 | emitting the computations based on them during loop |
bf8dbe38 ZD |
661 | unrolling might create overlapping life ranges for |
662 | them, and failures in out-of-ssa. */ | |
663 | || contains_abnormal_ssa_name_p (niter->may_be_zero) | |
664 | || contains_abnormal_ssa_name_p (niter->control.base) | |
665 | || contains_abnormal_ssa_name_p (niter->control.step) | |
666 | || contains_abnormal_ssa_name_p (niter->bound)) | |
17684618 ZD |
667 | return false; |
668 | ||
669 | /* And of course, we must be able to duplicate the loop. */ | |
670 | if (!can_duplicate_loop_p (loop)) | |
671 | return false; | |
672 | ||
673 | /* The final loop should be small enough. */ | |
7f9bc51b | 674 | if (tree_num_loop_insns (loop, &eni_size_weights) * factor |
17684618 ZD |
675 | > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLLED_INSNS)) |
676 | return false; | |
677 | ||
678 | return true; | |
679 | } | |
680 | ||
681 | /* Determines the conditions that control execution of LOOP unrolled FACTOR | |
682 | times. DESC is number of iterations of LOOP. ENTER_COND is set to | |
683 | condition that must be true if the main loop can be entered. | |
684 | EXIT_BASE, EXIT_STEP, EXIT_CMP and EXIT_BOUND are set to values describing | |
685 | how the exit from the unrolled loop should be controlled. */ | |
686 | ||
687 | static void | |
688 | determine_exit_conditions (struct loop *loop, struct tree_niter_desc *desc, | |
689 | unsigned factor, tree *enter_cond, | |
690 | tree *exit_base, tree *exit_step, | |
691 | enum tree_code *exit_cmp, tree *exit_bound) | |
692 | { | |
726a989a | 693 | gimple_seq stmts; |
17684618 ZD |
694 | tree base = desc->control.base; |
695 | tree step = desc->control.step; | |
696 | tree bound = desc->bound; | |
d24a32a1 | 697 | tree type = TREE_TYPE (step); |
17684618 ZD |
698 | tree bigstep, delta; |
699 | tree min = lower_bound_in_type (type, type); | |
700 | tree max = upper_bound_in_type (type, type); | |
701 | enum tree_code cmp = desc->cmp; | |
702 | tree cond = boolean_true_node, assum; | |
703 | ||
d24a32a1 ZD |
704 | /* For pointers, do the arithmetics in the type of step (sizetype). */ |
705 | base = fold_convert (type, base); | |
706 | bound = fold_convert (type, bound); | |
707 | ||
17684618 ZD |
708 | *enter_cond = boolean_false_node; |
709 | *exit_base = NULL_TREE; | |
710 | *exit_step = NULL_TREE; | |
711 | *exit_cmp = ERROR_MARK; | |
712 | *exit_bound = NULL_TREE; | |
713 | gcc_assert (cmp != ERROR_MARK); | |
714 | ||
715 | /* We only need to be correct when we answer question | |
716 | "Do at least FACTOR more iterations remain?" in the unrolled loop. | |
717 | Thus, transforming BASE + STEP * i <> BOUND to | |
718 | BASE + STEP * i < BOUND is ok. */ | |
719 | if (cmp == NE_EXPR) | |
720 | { | |
721 | if (tree_int_cst_sign_bit (step)) | |
722 | cmp = GT_EXPR; | |
723 | else | |
724 | cmp = LT_EXPR; | |
725 | } | |
726 | else if (cmp == LT_EXPR) | |
727 | { | |
728 | gcc_assert (!tree_int_cst_sign_bit (step)); | |
729 | } | |
730 | else if (cmp == GT_EXPR) | |
731 | { | |
732 | gcc_assert (tree_int_cst_sign_bit (step)); | |
733 | } | |
734 | else | |
735 | gcc_unreachable (); | |
736 | ||
737 | /* The main body of the loop may be entered iff: | |
738 | ||
739 | 1) desc->may_be_zero is false. | |
740 | 2) it is possible to check that there are at least FACTOR iterations | |
741 | of the loop, i.e., BOUND - step * FACTOR does not overflow. | |
742 | 3) # of iterations is at least FACTOR */ | |
743 | ||
6e682d7e | 744 | if (!integer_zerop (desc->may_be_zero)) |
17684618 ZD |
745 | cond = fold_build2 (TRUTH_AND_EXPR, boolean_type_node, |
746 | invert_truthvalue (desc->may_be_zero), | |
747 | cond); | |
748 | ||
749 | bigstep = fold_build2 (MULT_EXPR, type, step, | |
750 | build_int_cst_type (type, factor)); | |
751 | delta = fold_build2 (MINUS_EXPR, type, bigstep, step); | |
752 | if (cmp == LT_EXPR) | |
753 | assum = fold_build2 (GE_EXPR, boolean_type_node, | |
754 | bound, | |
755 | fold_build2 (PLUS_EXPR, type, min, delta)); | |
756 | else | |
757 | assum = fold_build2 (LE_EXPR, boolean_type_node, | |
758 | bound, | |
759 | fold_build2 (PLUS_EXPR, type, max, delta)); | |
760 | cond = fold_build2 (TRUTH_AND_EXPR, boolean_type_node, assum, cond); | |
761 | ||
762 | bound = fold_build2 (MINUS_EXPR, type, bound, delta); | |
763 | assum = fold_build2 (cmp, boolean_type_node, base, bound); | |
764 | cond = fold_build2 (TRUTH_AND_EXPR, boolean_type_node, assum, cond); | |
765 | ||
766 | cond = force_gimple_operand (unshare_expr (cond), &stmts, false, NULL_TREE); | |
767 | if (stmts) | |
726a989a | 768 | gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts); |
17684618 ZD |
769 | /* cond now may be a gimple comparison, which would be OK, but also any |
770 | other gimple rhs (say a && b). In this case we need to force it to | |
771 | operand. */ | |
772 | if (!is_gimple_condexpr (cond)) | |
773 | { | |
774 | cond = force_gimple_operand (cond, &stmts, true, NULL_TREE); | |
775 | if (stmts) | |
726a989a | 776 | gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts); |
17684618 ZD |
777 | } |
778 | *enter_cond = cond; | |
779 | ||
780 | base = force_gimple_operand (unshare_expr (base), &stmts, true, NULL_TREE); | |
781 | if (stmts) | |
726a989a | 782 | gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts); |
17684618 ZD |
783 | bound = force_gimple_operand (unshare_expr (bound), &stmts, true, NULL_TREE); |
784 | if (stmts) | |
726a989a | 785 | gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts); |
17684618 ZD |
786 | |
787 | *exit_base = base; | |
788 | *exit_step = bigstep; | |
789 | *exit_cmp = cmp; | |
790 | *exit_bound = bound; | |
791 | } | |
792 | ||
14fa2cc0 ZD |
793 | /* Scales the frequencies of all basic blocks in LOOP that are strictly |
794 | dominated by BB by NUM/DEN. */ | |
795 | ||
796 | static void | |
797 | scale_dominated_blocks_in_loop (struct loop *loop, basic_block bb, | |
798 | int num, int den) | |
799 | { | |
800 | basic_block son; | |
801 | ||
802 | if (den == 0) | |
803 | return; | |
804 | ||
805 | for (son = first_dom_son (CDI_DOMINATORS, bb); | |
806 | son; | |
807 | son = next_dom_son (CDI_DOMINATORS, son)) | |
808 | { | |
809 | if (!flow_bb_inside_loop_p (loop, son)) | |
810 | continue; | |
811 | scale_bbs_frequencies_int (&son, 1, num, den); | |
812 | scale_dominated_blocks_in_loop (loop, son, num, den); | |
813 | } | |
814 | } | |
815 | ||
d73be268 ZD |
816 | /* Unroll LOOP FACTOR times. DESC describes number of iterations of LOOP. |
817 | EXIT is the exit of the loop to that DESC corresponds. | |
818 | ||
17684618 ZD |
819 | If N is number of iterations of the loop and MAY_BE_ZERO is the condition |
820 | under that loop exits in the first iteration even if N != 0, | |
821 | ||
822 | while (1) | |
823 | { | |
824 | x = phi (init, next); | |
825 | ||
826 | pre; | |
827 | if (st) | |
828 | break; | |
829 | post; | |
830 | } | |
831 | ||
832 | becomes (with possibly the exit conditions formulated a bit differently, | |
833 | avoiding the need to create a new iv): | |
834 | ||
835 | if (MAY_BE_ZERO || N < FACTOR) | |
836 | goto rest; | |
837 | ||
838 | do | |
839 | { | |
840 | x = phi (init, next); | |
841 | ||
842 | pre; | |
843 | post; | |
844 | pre; | |
845 | post; | |
846 | ... | |
847 | pre; | |
848 | post; | |
849 | N -= FACTOR; | |
850 | ||
851 | } while (N >= FACTOR); | |
852 | ||
853 | rest: | |
854 | init' = phi (init, x); | |
855 | ||
856 | while (1) | |
857 | { | |
858 | x = phi (init', next); | |
859 | ||
860 | pre; | |
861 | if (st) | |
862 | break; | |
863 | post; | |
567b96ed ZD |
864 | } |
865 | ||
866 | Before the loop is unrolled, TRANSFORM is called for it (only for the | |
867 | unrolled loop, but not for its versioned copy). DATA is passed to | |
868 | TRANSFORM. */ | |
17684618 | 869 | |
03cb2019 ZD |
870 | /* Probability in % that the unrolled loop is entered. Just a guess. */ |
871 | #define PROB_UNROLLED_LOOP_ENTERED 90 | |
872 | ||
17684618 | 873 | void |
567b96ed ZD |
874 | tree_transform_and_unroll_loop (struct loop *loop, unsigned factor, |
875 | edge exit, struct tree_niter_desc *desc, | |
876 | transform_callback transform, | |
877 | void *data) | |
17684618 | 878 | { |
726a989a RB |
879 | gimple exit_if; |
880 | tree ctr_before, ctr_after; | |
17684618 ZD |
881 | tree enter_main_cond, exit_base, exit_step, exit_bound; |
882 | enum tree_code exit_cmp; | |
726a989a RB |
883 | gimple phi_old_loop, phi_new_loop, phi_rest; |
884 | gimple_stmt_iterator psi_old_loop, psi_new_loop; | |
885 | tree init, next, new_init, var; | |
17684618 ZD |
886 | struct loop *new_loop; |
887 | basic_block rest, exit_bb; | |
888 | edge old_entry, new_entry, old_latch, precond_edge, new_exit; | |
14fa2cc0 | 889 | edge new_nonexit, e; |
726a989a | 890 | gimple_stmt_iterator bsi; |
17684618 ZD |
891 | use_operand_p op; |
892 | bool ok; | |
03cb2019 | 893 | unsigned est_niter, prob_entry, scale_unrolled, scale_rest, freq_e, freq_h; |
14fa2cc0 | 894 | unsigned new_est_niter, i, prob; |
8e08deeb | 895 | unsigned irr = loop_preheader_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP; |
17684618 | 896 | sbitmap wont_exit; |
14fa2cc0 | 897 | VEC (edge, heap) *to_remove = NULL; |
17684618 ZD |
898 | |
899 | est_niter = expected_loop_iterations (loop); | |
900 | determine_exit_conditions (loop, desc, factor, | |
901 | &enter_main_cond, &exit_base, &exit_step, | |
902 | &exit_cmp, &exit_bound); | |
903 | ||
03cb2019 ZD |
904 | /* Let us assume that the unrolled loop is quite likely to be entered. */ |
905 | if (integer_nonzerop (enter_main_cond)) | |
906 | prob_entry = REG_BR_PROB_BASE; | |
907 | else | |
908 | prob_entry = PROB_UNROLLED_LOOP_ENTERED * REG_BR_PROB_BASE / 100; | |
909 | ||
910 | /* The values for scales should keep profile consistent, and somewhat close | |
911 | to correct. | |
912 | ||
913 | TODO: The current value of SCALE_REST makes it appear that the loop that | |
914 | is created by splitting the remaining iterations of the unrolled loop is | |
915 | executed the same number of times as the original loop, and with the same | |
916 | frequencies, which is obviously wrong. This does not appear to cause | |
917 | problems, so we do not bother with fixing it for now. To make the profile | |
918 | correct, we would need to change the probability of the exit edge of the | |
919 | loop, and recompute the distribution of frequencies in its body because | |
920 | of this change (scale the frequencies of blocks before and after the exit | |
921 | by appropriate factors). */ | |
922 | scale_unrolled = prob_entry; | |
923 | scale_rest = REG_BR_PROB_BASE; | |
924 | ||
925 | new_loop = loop_version (loop, enter_main_cond, NULL, | |
926 | prob_entry, scale_unrolled, scale_rest, true); | |
17684618 ZD |
927 | gcc_assert (new_loop != NULL); |
928 | update_ssa (TODO_update_ssa); | |
929 | ||
567b96ed | 930 | /* Determine the probability of the exit edge of the unrolled loop. */ |
03cb2019 ZD |
931 | new_est_niter = est_niter / factor; |
932 | ||
933 | /* Without profile feedback, loops for that we do not know a better estimate | |
934 | are assumed to roll 10 times. When we unroll such loop, it appears to | |
935 | roll too little, and it may even seem to be cold. To avoid this, we | |
936 | ensure that the created loop appears to roll at least 5 times (but at | |
937 | most as many times as before unrolling). */ | |
938 | if (new_est_niter < 5) | |
939 | { | |
940 | if (est_niter < 5) | |
941 | new_est_niter = est_niter; | |
942 | else | |
943 | new_est_niter = 5; | |
944 | } | |
945 | ||
14fa2cc0 ZD |
946 | /* Prepare the cfg and update the phi nodes. Move the loop exit to the |
947 | loop latch (and make its condition dummy, for the moment). */ | |
17684618 ZD |
948 | rest = loop_preheader_edge (new_loop)->src; |
949 | precond_edge = single_pred_edge (rest); | |
598ec7bd | 950 | split_edge (loop_latch_edge (loop)); |
17684618 ZD |
951 | exit_bb = single_pred (loop->latch); |
952 | ||
14fa2cc0 ZD |
953 | /* Since the exit edge will be removed, the frequency of all the blocks |
954 | in the loop that are dominated by it must be scaled by | |
955 | 1 / (1 - exit->probability). */ | |
956 | scale_dominated_blocks_in_loop (loop, exit->src, | |
957 | REG_BR_PROB_BASE, | |
958 | REG_BR_PROB_BASE - exit->probability); | |
959 | ||
726a989a RB |
960 | bsi = gsi_last_bb (exit_bb); |
961 | exit_if = gimple_build_cond (EQ_EXPR, integer_zero_node, | |
962 | integer_zero_node, | |
963 | NULL_TREE, NULL_TREE); | |
a9b77cd1 | 964 | |
726a989a | 965 | gsi_insert_after (&bsi, exit_if, GSI_NEW_STMT); |
8e08deeb | 966 | new_exit = make_edge (exit_bb, rest, EDGE_FALSE_VALUE | irr); |
6270df4c | 967 | rescan_loop_exit (new_exit, true, false); |
14fa2cc0 ZD |
968 | |
969 | /* Set the probability of new exit to the same of the old one. Fix | |
970 | the frequency of the latch block, by scaling it back by | |
971 | 1 - exit->probability. */ | |
972 | new_exit->count = exit->count; | |
973 | new_exit->probability = exit->probability; | |
17684618 | 974 | new_nonexit = single_pred_edge (loop->latch); |
14fa2cc0 | 975 | new_nonexit->probability = REG_BR_PROB_BASE - exit->probability; |
17684618 | 976 | new_nonexit->flags = EDGE_TRUE_VALUE; |
14fa2cc0 ZD |
977 | new_nonexit->count -= exit->count; |
978 | if (new_nonexit->count < 0) | |
979 | new_nonexit->count = 0; | |
980 | scale_bbs_frequencies_int (&loop->latch, 1, new_nonexit->probability, | |
981 | REG_BR_PROB_BASE); | |
17684618 ZD |
982 | |
983 | old_entry = loop_preheader_edge (loop); | |
984 | new_entry = loop_preheader_edge (new_loop); | |
985 | old_latch = loop_latch_edge (loop); | |
726a989a RB |
986 | for (psi_old_loop = gsi_start_phis (loop->header), |
987 | psi_new_loop = gsi_start_phis (new_loop->header); | |
988 | !gsi_end_p (psi_old_loop); | |
989 | gsi_next (&psi_old_loop), gsi_next (&psi_new_loop)) | |
17684618 | 990 | { |
726a989a RB |
991 | phi_old_loop = gsi_stmt (psi_old_loop); |
992 | phi_new_loop = gsi_stmt (psi_new_loop); | |
993 | ||
17684618 ZD |
994 | init = PHI_ARG_DEF_FROM_EDGE (phi_old_loop, old_entry); |
995 | op = PHI_ARG_DEF_PTR_FROM_EDGE (phi_new_loop, new_entry); | |
996 | gcc_assert (operand_equal_for_phi_arg_p (init, USE_FROM_PTR (op))); | |
997 | next = PHI_ARG_DEF_FROM_EDGE (phi_old_loop, old_latch); | |
998 | ||
999 | /* Prefer using original variable as a base for the new ssa name. | |
1000 | This is necessary for virtual ops, and useful in order to avoid | |
1001 | losing debug info for real ops. */ | |
182e00b1 RG |
1002 | if (TREE_CODE (next) == SSA_NAME |
1003 | && useless_type_conversion_p (TREE_TYPE (next), | |
1004 | TREE_TYPE (init))) | |
17684618 | 1005 | var = SSA_NAME_VAR (next); |
182e00b1 RG |
1006 | else if (TREE_CODE (init) == SSA_NAME |
1007 | && useless_type_conversion_p (TREE_TYPE (init), | |
1008 | TREE_TYPE (next))) | |
17684618 | 1009 | var = SSA_NAME_VAR (init); |
182e00b1 RG |
1010 | else if (useless_type_conversion_p (TREE_TYPE (next), TREE_TYPE (init))) |
1011 | { | |
1012 | var = create_tmp_var (TREE_TYPE (next), "unrinittmp"); | |
1013 | add_referenced_var (var); | |
1014 | } | |
17684618 ZD |
1015 | else |
1016 | { | |
1017 | var = create_tmp_var (TREE_TYPE (init), "unrinittmp"); | |
f004ab02 | 1018 | add_referenced_var (var); |
17684618 ZD |
1019 | } |
1020 | ||
726a989a | 1021 | new_init = make_ssa_name (var, NULL); |
17684618 ZD |
1022 | phi_rest = create_phi_node (new_init, rest); |
1023 | SSA_NAME_DEF_STMT (new_init) = phi_rest; | |
1024 | ||
f5045c96 AM |
1025 | add_phi_arg (phi_rest, init, precond_edge, UNKNOWN_LOCATION); |
1026 | add_phi_arg (phi_rest, next, new_exit, UNKNOWN_LOCATION); | |
17684618 ZD |
1027 | SET_USE (op, new_init); |
1028 | } | |
1029 | ||
14fa2cc0 ZD |
1030 | remove_path (exit); |
1031 | ||
567b96ed ZD |
1032 | /* Transform the loop. */ |
1033 | if (transform) | |
1034 | (*transform) (loop, data); | |
1035 | ||
14fa2cc0 ZD |
1036 | /* Unroll the loop and remove the exits in all iterations except for the |
1037 | last one. */ | |
567b96ed ZD |
1038 | wont_exit = sbitmap_alloc (factor); |
1039 | sbitmap_ones (wont_exit); | |
14fa2cc0 ZD |
1040 | RESET_BIT (wont_exit, factor - 1); |
1041 | ||
726a989a | 1042 | ok = gimple_duplicate_loop_to_header_edge |
567b96ed | 1043 | (loop, loop_latch_edge (loop), factor - 1, |
14fa2cc0 | 1044 | wont_exit, new_exit, &to_remove, DLTHE_FLAG_UPDATE_FREQ); |
567b96ed ZD |
1045 | free (wont_exit); |
1046 | gcc_assert (ok); | |
14fa2cc0 ZD |
1047 | |
1048 | for (i = 0; VEC_iterate (edge, to_remove, i, e); i++) | |
1049 | { | |
1050 | ok = remove_path (e); | |
1051 | gcc_assert (ok); | |
1052 | } | |
1053 | VEC_free (edge, heap, to_remove); | |
567b96ed ZD |
1054 | update_ssa (TODO_update_ssa); |
1055 | ||
1056 | /* Ensure that the frequencies in the loop match the new estimated | |
1057 | number of iterations, and change the probability of the new | |
1058 | exit edge. */ | |
1059 | freq_h = loop->header->frequency; | |
1060 | freq_e = EDGE_FREQUENCY (loop_preheader_edge (loop)); | |
1061 | if (freq_h != 0) | |
1062 | scale_loop_frequencies (loop, freq_e * (new_est_niter + 1), freq_h); | |
1063 | ||
1064 | exit_bb = single_pred (loop->latch); | |
1065 | new_exit = find_edge (exit_bb, rest); | |
1066 | new_exit->count = loop_preheader_edge (loop)->count; | |
1067 | new_exit->probability = REG_BR_PROB_BASE / (new_est_niter + 1); | |
1068 | ||
1069 | rest->count += new_exit->count; | |
1070 | rest->frequency += EDGE_FREQUENCY (new_exit); | |
1071 | ||
1072 | new_nonexit = single_pred_edge (loop->latch); | |
14fa2cc0 | 1073 | prob = new_nonexit->probability; |
567b96ed | 1074 | new_nonexit->probability = REG_BR_PROB_BASE - new_exit->probability; |
14fa2cc0 ZD |
1075 | new_nonexit->count = exit_bb->count - new_exit->count; |
1076 | if (new_nonexit->count < 0) | |
1077 | new_nonexit->count = 0; | |
87621e5f SE |
1078 | if (prob > 0) |
1079 | scale_bbs_frequencies_int (&loop->latch, 1, new_nonexit->probability, | |
1080 | prob); | |
567b96ed | 1081 | |
17684618 ZD |
1082 | /* Finally create the new counter for number of iterations and add the new |
1083 | exit instruction. */ | |
726a989a RB |
1084 | bsi = gsi_last_bb (exit_bb); |
1085 | exit_if = gsi_stmt (bsi); | |
17684618 | 1086 | create_iv (exit_base, exit_step, NULL_TREE, loop, |
567b96ed | 1087 | &bsi, false, &ctr_before, &ctr_after); |
726a989a RB |
1088 | gimple_cond_set_code (exit_if, exit_cmp); |
1089 | gimple_cond_set_lhs (exit_if, ctr_after); | |
1090 | gimple_cond_set_rhs (exit_if, exit_bound); | |
567b96ed | 1091 | update_stmt (exit_if); |
17684618 | 1092 | |
c0493b13 | 1093 | #ifdef ENABLE_CHECKING |
17684618 ZD |
1094 | verify_flow_info (); |
1095 | verify_dominators (CDI_DOMINATORS); | |
d73be268 | 1096 | verify_loop_structure (); |
17684618 | 1097 | verify_loop_closed_ssa (); |
c0493b13 | 1098 | #endif |
17684618 | 1099 | } |
567b96ed ZD |
1100 | |
1101 | /* Wrapper over tree_transform_and_unroll_loop for case we do not | |
1102 | want to transform the loop before unrolling. The meaning | |
1103 | of the arguments is the same as for tree_transform_and_unroll_loop. */ | |
1104 | ||
1105 | void | |
1106 | tree_unroll_loop (struct loop *loop, unsigned factor, | |
1107 | edge exit, struct tree_niter_desc *desc) | |
1108 | { | |
1109 | tree_transform_and_unroll_loop (loop, factor, exit, desc, | |
1110 | NULL, NULL); | |
1111 | } | |
08dab97a RL |
1112 | |
1113 | /* Rewrite the phi node at position PSI in function of the main | |
1114 | induction variable MAIN_IV and insert the generated code at GSI. */ | |
1115 | ||
1116 | static void | |
1117 | rewrite_phi_with_iv (loop_p loop, | |
1118 | gimple_stmt_iterator *psi, | |
1119 | gimple_stmt_iterator *gsi, | |
1120 | tree main_iv) | |
1121 | { | |
1122 | affine_iv iv; | |
1123 | gimple stmt, phi = gsi_stmt (*psi); | |
1124 | tree atype, mtype, val, res = PHI_RESULT (phi); | |
1125 | ||
1126 | if (!is_gimple_reg (res) || res == main_iv) | |
1127 | { | |
1128 | gsi_next (psi); | |
1129 | return; | |
1130 | } | |
1131 | ||
1132 | if (!simple_iv (loop, loop, res, &iv, true)) | |
1133 | { | |
1134 | gsi_next (psi); | |
1135 | return; | |
1136 | } | |
1137 | ||
1138 | remove_phi_node (psi, false); | |
1139 | ||
1140 | atype = TREE_TYPE (res); | |
1141 | mtype = POINTER_TYPE_P (atype) ? sizetype : atype; | |
1142 | val = fold_build2 (MULT_EXPR, mtype, unshare_expr (iv.step), | |
1143 | fold_convert (mtype, main_iv)); | |
1144 | val = fold_build2 (POINTER_TYPE_P (atype) | |
1145 | ? POINTER_PLUS_EXPR : PLUS_EXPR, | |
1146 | atype, unshare_expr (iv.base), val); | |
1147 | val = force_gimple_operand_gsi (gsi, val, false, NULL_TREE, true, | |
1148 | GSI_SAME_STMT); | |
1149 | stmt = gimple_build_assign (res, val); | |
1150 | gsi_insert_before (gsi, stmt, GSI_SAME_STMT); | |
1151 | SSA_NAME_DEF_STMT (res) = stmt; | |
1152 | } | |
1153 | ||
1154 | /* Rewrite all the phi nodes of LOOP in function of the main induction | |
1155 | variable MAIN_IV. */ | |
1156 | ||
1157 | static void | |
1158 | rewrite_all_phi_nodes_with_iv (loop_p loop, tree main_iv) | |
1159 | { | |
1160 | unsigned i; | |
1161 | basic_block *bbs = get_loop_body_in_dom_order (loop); | |
1162 | gimple_stmt_iterator psi; | |
1163 | ||
1164 | for (i = 0; i < loop->num_nodes; i++) | |
1165 | { | |
1166 | basic_block bb = bbs[i]; | |
1167 | gimple_stmt_iterator gsi = gsi_after_labels (bb); | |
1168 | ||
1169 | if (bb->loop_father != loop) | |
1170 | continue; | |
1171 | ||
1172 | for (psi = gsi_start_phis (bb); !gsi_end_p (psi); ) | |
1173 | rewrite_phi_with_iv (loop, &psi, &gsi, main_iv); | |
1174 | } | |
1175 | ||
1176 | free (bbs); | |
1177 | } | |
1178 | ||
1179 | /* Bases all the induction variables in LOOP on a single induction | |
1180 | variable (unsigned with base 0 and step 1), whose final value is | |
1181 | compared with *NIT. When the IV type precision has to be larger | |
1182 | than *NIT type precision, *NIT is converted to the larger type, the | |
1183 | conversion code is inserted before the loop, and *NIT is updated to | |
1184 | the new definition. The induction variable is incremented in the | |
1185 | loop latch. Return the induction variable that was created. */ | |
1186 | ||
1187 | tree | |
1188 | canonicalize_loop_ivs (struct loop *loop, tree *nit) | |
1189 | { | |
1190 | unsigned precision = TYPE_PRECISION (TREE_TYPE (*nit)); | |
1191 | unsigned original_precision = precision; | |
1192 | tree type, var_before; | |
1193 | gimple_stmt_iterator gsi, psi; | |
1194 | gimple stmt; | |
1195 | edge exit = single_dom_exit (loop); | |
1196 | gimple_seq stmts; | |
1197 | ||
1198 | for (psi = gsi_start_phis (loop->header); | |
1199 | !gsi_end_p (psi); gsi_next (&psi)) | |
1200 | { | |
1201 | gimple phi = gsi_stmt (psi); | |
1202 | tree res = PHI_RESULT (phi); | |
1203 | ||
1204 | if (is_gimple_reg (res) && TYPE_PRECISION (TREE_TYPE (res)) > precision) | |
1205 | precision = TYPE_PRECISION (TREE_TYPE (res)); | |
1206 | } | |
1207 | ||
1208 | type = lang_hooks.types.type_for_size (precision, 1); | |
1209 | ||
1210 | if (original_precision != precision) | |
1211 | { | |
1212 | *nit = fold_convert (type, *nit); | |
1213 | *nit = force_gimple_operand (*nit, &stmts, true, NULL_TREE); | |
1214 | if (stmts) | |
1215 | gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts); | |
1216 | } | |
1217 | ||
1218 | gsi = gsi_last_bb (loop->latch); | |
1219 | create_iv (build_int_cst_type (type, 0), build_int_cst (type, 1), NULL_TREE, | |
1220 | loop, &gsi, true, &var_before, NULL); | |
1221 | ||
1222 | rewrite_all_phi_nodes_with_iv (loop, var_before); | |
1223 | ||
1224 | stmt = last_stmt (exit->src); | |
1225 | /* Make the loop exit if the control condition is not satisfied. */ | |
1226 | if (exit->flags & EDGE_TRUE_VALUE) | |
1227 | { | |
1228 | edge te, fe; | |
1229 | ||
1230 | extract_true_false_edges_from_block (exit->src, &te, &fe); | |
1231 | te->flags = EDGE_FALSE_VALUE; | |
1232 | fe->flags = EDGE_TRUE_VALUE; | |
1233 | } | |
1234 | gimple_cond_set_code (stmt, LT_EXPR); | |
1235 | gimple_cond_set_lhs (stmt, var_before); | |
1236 | gimple_cond_set_rhs (stmt, *nit); | |
1237 | update_stmt (stmt); | |
1238 | ||
1239 | return var_before; | |
1240 | } |