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c913f08a | 1 | /* High-level loop manipulation functions. |
5624e564 | 2 | Copyright (C) 2004-2015 Free Software Foundation, Inc. |
b8698a0f | 3 | |
c913f08a | 4 | This file is part of GCC. |
b8698a0f | 5 | |
c913f08a ZD |
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 | 9 | later version. |
b8698a0f | 10 | |
c913f08a ZD |
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. | |
b8698a0f | 15 | |
c913f08a | 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" | |
40e23961 MC |
24 | #include "hash-set.h" |
25 | #include "machmode.h" | |
26 | #include "vec.h" | |
27 | #include "double-int.h" | |
28 | #include "input.h" | |
29 | #include "alias.h" | |
30 | #include "symtab.h" | |
31 | #include "wide-int.h" | |
32 | #include "inchash.h" | |
c913f08a | 33 | #include "tree.h" |
40e23961 | 34 | #include "fold-const.h" |
c913f08a | 35 | #include "tm_p.h" |
60393bbc | 36 | #include "predict.h" |
60393bbc AM |
37 | #include "hard-reg-set.h" |
38 | #include "input.h" | |
39 | #include "function.h" | |
40 | #include "dominance.h" | |
41 | #include "cfg.h" | |
42 | #include "cfganal.h" | |
c913f08a | 43 | #include "basic-block.h" |
2fb9a547 AM |
44 | #include "tree-ssa-alias.h" |
45 | #include "internal-fn.h" | |
46 | #include "gimple-expr.h" | |
47 | #include "is-a.h" | |
18f429e2 | 48 | #include "gimple.h" |
45b0be94 | 49 | #include "gimplify.h" |
5be5c238 | 50 | #include "gimple-iterator.h" |
18f429e2 | 51 | #include "gimplify-me.h" |
442b4905 AM |
52 | #include "gimple-ssa.h" |
53 | #include "tree-cfg.h" | |
54 | #include "tree-phinodes.h" | |
55 | #include "ssa-iterators.h" | |
d8a2d370 | 56 | #include "stringpool.h" |
442b4905 | 57 | #include "tree-ssanames.h" |
e28030cf AM |
58 | #include "tree-ssa-loop-ivopts.h" |
59 | #include "tree-ssa-loop-manip.h" | |
60 | #include "tree-ssa-loop-niter.h" | |
442b4905 AM |
61 | #include "tree-ssa-loop.h" |
62 | #include "tree-into-ssa.h" | |
7a300452 | 63 | #include "tree-ssa.h" |
7ee2468b | 64 | #include "dumpfile.h" |
01273677 | 65 | #include "gimple-pretty-print.h" |
c913f08a | 66 | #include "cfgloop.h" |
7ee2468b | 67 | #include "tree-pass.h" /* ??? for TODO_update_ssa but this isn't a pass. */ |
c913f08a | 68 | #include "tree-scalar-evolution.h" |
17684618 | 69 | #include "params.h" |
7f9bc51b | 70 | #include "tree-inline.h" |
08dab97a | 71 | #include "langhooks.h" |
c913f08a | 72 | |
c302207e SB |
73 | /* All bitmaps for rewriting into loop-closed SSA go on this obstack, |
74 | so that we can free them all at once. */ | |
75 | static bitmap_obstack loop_renamer_obstack; | |
76 | ||
82b85a85 ZD |
77 | /* Creates an induction variable with value BASE + STEP * iteration in LOOP. |
78 | It is expected that neither BASE nor STEP are shared with other expressions | |
79 | (unless the sharing rules allow this). Use VAR as a base var_decl for it | |
80 | (if NULL, a new temporary will be created). The increment will occur at | |
b8698a0f | 81 | INCR_POS (after it if AFTER is true, before it otherwise). INCR_POS and |
92d2b330 | 82 | AFTER can be computed using standard_iv_increment_position. The ssa versions |
82b85a85 ZD |
83 | of the variable before and after increment will be stored in VAR_BEFORE and |
84 | VAR_AFTER (unless they are NULL). */ | |
85 | ||
86 | void | |
87 | create_iv (tree base, tree step, tree var, struct loop *loop, | |
726a989a | 88 | gimple_stmt_iterator *incr_pos, bool after, |
82b85a85 ZD |
89 | tree *var_before, tree *var_after) |
90 | { | |
538dd0b7 DM |
91 | gassign *stmt; |
92 | gphi *phi; | |
726a989a RB |
93 | tree initial, step1; |
94 | gimple_seq stmts; | |
82b85a85 ZD |
95 | tree vb, va; |
96 | enum tree_code incr_op = PLUS_EXPR; | |
9be872b7 | 97 | edge pe = loop_preheader_edge (loop); |
82b85a85 | 98 | |
83d5977e RG |
99 | if (var != NULL_TREE) |
100 | { | |
b731b390 JJ |
101 | vb = make_ssa_name (var); |
102 | va = make_ssa_name (var); | |
83d5977e RG |
103 | } |
104 | else | |
105 | { | |
106 | vb = make_temp_ssa_name (TREE_TYPE (base), NULL, "ivtmp"); | |
107 | va = make_temp_ssa_name (TREE_TYPE (base), NULL, "ivtmp"); | |
108 | } | |
82b85a85 ZD |
109 | if (var_before) |
110 | *var_before = vb; | |
82b85a85 ZD |
111 | if (var_after) |
112 | *var_after = va; | |
113 | ||
114 | /* For easier readability of the created code, produce MINUS_EXPRs | |
115 | when suitable. */ | |
116 | if (TREE_CODE (step) == INTEGER_CST) | |
117 | { | |
118 | if (TYPE_UNSIGNED (TREE_TYPE (step))) | |
119 | { | |
987b67bc | 120 | step1 = fold_build1 (NEGATE_EXPR, TREE_TYPE (step), step); |
82b85a85 ZD |
121 | if (tree_int_cst_lt (step1, step)) |
122 | { | |
123 | incr_op = MINUS_EXPR; | |
124 | step = step1; | |
125 | } | |
126 | } | |
127 | else | |
128 | { | |
6ac01510 ILT |
129 | bool ovf; |
130 | ||
131 | if (!tree_expr_nonnegative_warnv_p (step, &ovf) | |
82b85a85 ZD |
132 | && may_negate_without_overflow_p (step)) |
133 | { | |
134 | incr_op = MINUS_EXPR; | |
987b67bc | 135 | step = fold_build1 (NEGATE_EXPR, TREE_TYPE (step), step); |
82b85a85 ZD |
136 | } |
137 | } | |
138 | } | |
5be014d5 AP |
139 | if (POINTER_TYPE_P (TREE_TYPE (base))) |
140 | { | |
628c189e RG |
141 | if (TREE_CODE (base) == ADDR_EXPR) |
142 | mark_addressable (TREE_OPERAND (base, 0)); | |
0d82a1c8 | 143 | step = convert_to_ptrofftype (step); |
5be014d5 | 144 | if (incr_op == MINUS_EXPR) |
0d82a1c8 | 145 | step = fold_build1 (NEGATE_EXPR, TREE_TYPE (step), step); |
5be014d5 AP |
146 | incr_op = POINTER_PLUS_EXPR; |
147 | } | |
9be872b7 ZD |
148 | /* Gimplify the step if necessary. We put the computations in front of the |
149 | loop (i.e. the step should be loop invariant). */ | |
1ffe34d9 | 150 | step = force_gimple_operand (step, &stmts, true, NULL_TREE); |
9be872b7 | 151 | if (stmts) |
726a989a | 152 | gsi_insert_seq_on_edge_immediate (pe, stmts); |
9be872b7 | 153 | |
0d0e4a03 | 154 | stmt = gimple_build_assign (va, incr_op, vb, step); |
82b85a85 | 155 | if (after) |
726a989a | 156 | gsi_insert_after (incr_pos, stmt, GSI_NEW_STMT); |
82b85a85 | 157 | else |
726a989a | 158 | gsi_insert_before (incr_pos, stmt, GSI_NEW_STMT); |
82b85a85 | 159 | |
8b11a64c ZD |
160 | initial = force_gimple_operand (base, &stmts, true, var); |
161 | if (stmts) | |
726a989a | 162 | gsi_insert_seq_on_edge_immediate (pe, stmts); |
82b85a85 | 163 | |
538dd0b7 DM |
164 | phi = create_phi_node (vb, loop->header); |
165 | add_phi_arg (phi, initial, loop_preheader_edge (loop), UNKNOWN_LOCATION); | |
166 | add_phi_arg (phi, va, loop_latch_edge (loop), UNKNOWN_LOCATION); | |
82b85a85 ZD |
167 | } |
168 | ||
3f9b14ff | 169 | /* Return the innermost superloop LOOP of USE_LOOP that is a superloop of |
01273677 SB |
170 | both DEF_LOOP and USE_LOOP. */ |
171 | ||
172 | static inline struct loop * | |
173 | find_sibling_superloop (struct loop *use_loop, struct loop *def_loop) | |
174 | { | |
175 | unsigned ud = loop_depth (use_loop); | |
176 | unsigned dd = loop_depth (def_loop); | |
177 | gcc_assert (ud > 0 && dd > 0); | |
178 | if (ud > dd) | |
179 | use_loop = superloop_at_depth (use_loop, dd); | |
180 | if (ud < dd) | |
181 | def_loop = superloop_at_depth (def_loop, ud); | |
182 | while (loop_outer (use_loop) != loop_outer (def_loop)) | |
183 | { | |
184 | use_loop = loop_outer (use_loop); | |
185 | def_loop = loop_outer (def_loop); | |
186 | gcc_assert (use_loop && def_loop); | |
187 | } | |
188 | return use_loop; | |
189 | } | |
190 | ||
191 | /* DEF_BB is a basic block containing a DEF that needs rewriting into | |
192 | loop-closed SSA form. USE_BLOCKS is the set of basic blocks containing | |
193 | uses of DEF that "escape" from the loop containing DEF_BB (i.e. blocks in | |
194 | USE_BLOCKS are dominated by DEF_BB but not in the loop father of DEF_B). | |
195 | ALL_EXITS[I] is the set of all basic blocks that exit loop I. | |
196 | ||
197 | Compute the subset of LOOP_EXITS that exit the loop containing DEF_BB | |
198 | or one of its loop fathers, in which DEF is live. This set is returned | |
199 | in the bitmap LIVE_EXITS. | |
200 | ||
201 | Instead of computing the complete livein set of the def, we use the loop | |
202 | nesting tree as a form of poor man's structure analysis. This greatly | |
203 | speeds up the analysis, which is important because this function may be | |
204 | called on all SSA names that need rewriting, one at a time. */ | |
c913f08a ZD |
205 | |
206 | static void | |
01273677 SB |
207 | compute_live_loop_exits (bitmap live_exits, bitmap use_blocks, |
208 | bitmap *loop_exits, basic_block def_bb) | |
c913f08a | 209 | { |
01273677 SB |
210 | unsigned i; |
211 | bitmap_iterator bi; | |
01273677 SB |
212 | struct loop *def_loop = def_bb->loop_father; |
213 | unsigned def_loop_depth = loop_depth (def_loop); | |
214 | bitmap def_loop_exits; | |
215 | ||
216 | /* Normally the work list size is bounded by the number of basic | |
217 | blocks in the largest loop. We don't know this number, but we | |
218 | can be fairly sure that it will be relatively small. */ | |
ef062b13 | 219 | auto_vec<basic_block> worklist (MAX (8, n_basic_blocks_for_fn (cfun) / 128)); |
01273677 SB |
220 | |
221 | EXECUTE_IF_SET_IN_BITMAP (use_blocks, 0, i, bi) | |
222 | { | |
06e28de2 | 223 | basic_block use_bb = BASIC_BLOCK_FOR_FN (cfun, i); |
01273677 SB |
224 | struct loop *use_loop = use_bb->loop_father; |
225 | gcc_checking_assert (def_loop != use_loop | |
226 | && ! flow_loop_nested_p (def_loop, use_loop)); | |
227 | if (! flow_loop_nested_p (use_loop, def_loop)) | |
228 | use_bb = find_sibling_superloop (use_loop, def_loop)->header; | |
229 | if (bitmap_set_bit (live_exits, use_bb->index)) | |
9771b263 | 230 | worklist.safe_push (use_bb); |
01273677 SB |
231 | } |
232 | ||
233 | /* Iterate until the worklist is empty. */ | |
9771b263 | 234 | while (! worklist.is_empty ()) |
01273677 SB |
235 | { |
236 | edge e; | |
237 | edge_iterator ei; | |
238 | ||
239 | /* Pull a block off the worklist. */ | |
9771b263 | 240 | basic_block bb = worklist.pop (); |
01273677 SB |
241 | |
242 | /* Make sure we have at least enough room in the work list | |
243 | for all predecessors of this block. */ | |
9771b263 | 244 | worklist.reserve (EDGE_COUNT (bb->preds)); |
01273677 SB |
245 | |
246 | /* For each predecessor block. */ | |
247 | FOR_EACH_EDGE (e, ei, bb->preds) | |
248 | { | |
249 | basic_block pred = e->src; | |
250 | struct loop *pred_loop = pred->loop_father; | |
251 | unsigned pred_loop_depth = loop_depth (pred_loop); | |
252 | bool pred_visited; | |
253 | ||
254 | /* We should have met DEF_BB along the way. */ | |
fefa31b5 | 255 | gcc_assert (pred != ENTRY_BLOCK_PTR_FOR_FN (cfun)); |
01273677 SB |
256 | |
257 | if (pred_loop_depth >= def_loop_depth) | |
258 | { | |
259 | if (pred_loop_depth > def_loop_depth) | |
260 | pred_loop = superloop_at_depth (pred_loop, def_loop_depth); | |
261 | /* If we've reached DEF_LOOP, our train ends here. */ | |
262 | if (pred_loop == def_loop) | |
263 | continue; | |
264 | } | |
265 | else if (! flow_loop_nested_p (pred_loop, def_loop)) | |
266 | pred = find_sibling_superloop (pred_loop, def_loop)->header; | |
267 | ||
268 | /* Add PRED to the LIVEIN set. PRED_VISITED is true if | |
269 | we had already added PRED to LIVEIN before. */ | |
270 | pred_visited = !bitmap_set_bit (live_exits, pred->index); | |
271 | ||
272 | /* If we have visited PRED before, don't add it to the worklist. | |
273 | If BB dominates PRED, then we're probably looking at a loop. | |
274 | We're only interested in looking up in the dominance tree | |
275 | because DEF_BB dominates all the uses. */ | |
276 | if (pred_visited || dominated_by_p (CDI_DOMINATORS, pred, bb)) | |
277 | continue; | |
278 | ||
9771b263 | 279 | worklist.quick_push (pred); |
01273677 SB |
280 | } |
281 | } | |
01273677 SB |
282 | |
283 | def_loop_exits = BITMAP_ALLOC (&loop_renamer_obstack); | |
284 | for (struct loop *loop = def_loop; | |
285 | loop != current_loops->tree_root; | |
286 | loop = loop_outer (loop)) | |
287 | bitmap_ior_into (def_loop_exits, loop_exits[loop->num]); | |
288 | bitmap_and_into (live_exits, def_loop_exits); | |
289 | BITMAP_FREE (def_loop_exits); | |
290 | } | |
291 | ||
292 | /* Add a loop-closing PHI for VAR in basic block EXIT. */ | |
293 | ||
294 | static void | |
295 | add_exit_phi (basic_block exit, tree var) | |
296 | { | |
538dd0b7 | 297 | gphi *phi; |
c913f08a | 298 | edge e; |
628f6a4e | 299 | edge_iterator ei; |
c913f08a | 300 | |
01273677 SB |
301 | #ifdef ENABLE_CHECKING |
302 | /* Check that at least one of the edges entering the EXIT block exits | |
303 | the loop, or a superloop of that loop, that VAR is defined in. */ | |
304 | gimple def_stmt = SSA_NAME_DEF_STMT (var); | |
305 | basic_block def_bb = gimple_bb (def_stmt); | |
628f6a4e | 306 | FOR_EACH_EDGE (e, ei, exit->preds) |
c913f08a | 307 | { |
01273677 SB |
308 | struct loop *aloop = find_common_loop (def_bb->loop_father, |
309 | e->src->loop_father); | |
310 | if (!flow_bb_inside_loop_p (aloop, e->dest)) | |
c913f08a ZD |
311 | break; |
312 | } | |
313 | ||
01273677 SB |
314 | gcc_checking_assert (e); |
315 | #endif | |
c913f08a | 316 | |
dcc748dd | 317 | phi = create_phi_node (NULL_TREE, exit); |
01273677 | 318 | create_new_def_for (var, phi, gimple_phi_result_ptr (phi)); |
628f6a4e | 319 | FOR_EACH_EDGE (e, ei, exit->preds) |
01273677 SB |
320 | add_phi_arg (phi, var, e, UNKNOWN_LOCATION); |
321 | ||
322 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
323 | { | |
324 | fprintf (dump_file, ";; Created LCSSA PHI: "); | |
325 | print_gimple_stmt (dump_file, phi, 0, dump_flags); | |
326 | } | |
c913f08a ZD |
327 | } |
328 | ||
329 | /* Add exit phis for VAR that is used in LIVEIN. | |
01273677 | 330 | Exits of the loops are stored in LOOP_EXITS. */ |
c913f08a ZD |
331 | |
332 | static void | |
01273677 | 333 | add_exit_phis_var (tree var, bitmap use_blocks, bitmap *loop_exits) |
c913f08a | 334 | { |
3cd8c58a | 335 | unsigned index; |
87c476a2 | 336 | bitmap_iterator bi; |
01273677 SB |
337 | basic_block def_bb = gimple_bb (SSA_NAME_DEF_STMT (var)); |
338 | bitmap live_exits = BITMAP_ALLOC (&loop_renamer_obstack); | |
c913f08a | 339 | |
ceb16be3 | 340 | gcc_checking_assert (! bitmap_bit_p (use_blocks, def_bb->index)); |
c913f08a | 341 | |
01273677 | 342 | compute_live_loop_exits (live_exits, use_blocks, loop_exits, def_bb); |
c913f08a | 343 | |
01273677 | 344 | EXECUTE_IF_SET_IN_BITMAP (live_exits, 0, index, bi) |
87c476a2 | 345 | { |
06e28de2 | 346 | add_exit_phi (BASIC_BLOCK_FOR_FN (cfun, index), var); |
87c476a2 | 347 | } |
c302207e | 348 | |
01273677 | 349 | BITMAP_FREE (live_exits); |
c913f08a ZD |
350 | } |
351 | ||
352 | /* Add exit phis for the names marked in NAMES_TO_RENAME. | |
353 | Exits of the loops are stored in EXITS. Sets of blocks where the ssa | |
354 | names are used are stored in USE_BLOCKS. */ | |
355 | ||
356 | static void | |
01273677 | 357 | add_exit_phis (bitmap names_to_rename, bitmap *use_blocks, bitmap *loop_exits) |
c913f08a ZD |
358 | { |
359 | unsigned i; | |
87c476a2 | 360 | bitmap_iterator bi; |
c913f08a | 361 | |
87c476a2 | 362 | EXECUTE_IF_SET_IN_BITMAP (names_to_rename, 0, i, bi) |
c913f08a ZD |
363 | { |
364 | add_exit_phis_var (ssa_name (i), use_blocks[i], loop_exits); | |
87c476a2 | 365 | } |
c913f08a ZD |
366 | } |
367 | ||
01273677 | 368 | /* Fill the array of bitmaps LOOP_EXITS with all loop exit edge targets. */ |
c913f08a | 369 | |
01273677 SB |
370 | static void |
371 | get_loops_exits (bitmap *loop_exits) | |
c913f08a | 372 | { |
01273677 SB |
373 | struct loop *loop; |
374 | unsigned j; | |
c913f08a ZD |
375 | edge e; |
376 | ||
f0bd40b1 | 377 | FOR_EACH_LOOP (loop, 0) |
c913f08a | 378 | { |
9771b263 | 379 | vec<edge> exit_edges = get_loop_exit_edges (loop); |
01273677 | 380 | loop_exits[loop->num] = BITMAP_ALLOC (&loop_renamer_obstack); |
9771b263 | 381 | FOR_EACH_VEC_ELT (exit_edges, j, e) |
01273677 | 382 | bitmap_set_bit (loop_exits[loop->num], e->dest->index); |
9771b263 | 383 | exit_edges.release (); |
c913f08a | 384 | } |
c913f08a ZD |
385 | } |
386 | ||
387 | /* For USE in BB, if it is used outside of the loop it is defined in, | |
388 | mark it for rewrite. Record basic block BB where it is used | |
84d65814 | 389 | to USE_BLOCKS. Record the ssa name index to NEED_PHIS bitmap. */ |
c913f08a ZD |
390 | |
391 | static void | |
84d65814 DN |
392 | find_uses_to_rename_use (basic_block bb, tree use, bitmap *use_blocks, |
393 | bitmap need_phis) | |
c913f08a ZD |
394 | { |
395 | unsigned ver; | |
396 | basic_block def_bb; | |
397 | struct loop *def_loop; | |
398 | ||
399 | if (TREE_CODE (use) != SSA_NAME) | |
400 | return; | |
401 | ||
402 | ver = SSA_NAME_VERSION (use); | |
726a989a | 403 | def_bb = gimple_bb (SSA_NAME_DEF_STMT (use)); |
c913f08a ZD |
404 | if (!def_bb) |
405 | return; | |
406 | def_loop = def_bb->loop_father; | |
407 | ||
d6e840ee | 408 | /* If the definition is not inside a loop, it is not interesting. */ |
9ba025a2 | 409 | if (!loop_outer (def_loop)) |
c913f08a ZD |
410 | return; |
411 | ||
d6e840ee RG |
412 | /* If the use is not outside of the loop it is defined in, it is not |
413 | interesting. */ | |
414 | if (flow_bb_inside_loop_p (def_loop, bb)) | |
415 | return; | |
416 | ||
c302207e SB |
417 | /* If we're seeing VER for the first time, we still have to allocate |
418 | a bitmap for its uses. */ | |
419 | if (bitmap_set_bit (need_phis, ver)) | |
420 | use_blocks[ver] = BITMAP_ALLOC (&loop_renamer_obstack); | |
c913f08a | 421 | bitmap_set_bit (use_blocks[ver], bb->index); |
c913f08a ZD |
422 | } |
423 | ||
424 | /* For uses in STMT, mark names that are used outside of the loop they are | |
425 | defined to rewrite. Record the set of blocks in that the ssa | |
84d65814 DN |
426 | names are defined to USE_BLOCKS and the ssa names themselves to |
427 | NEED_PHIS. */ | |
c913f08a ZD |
428 | |
429 | static void | |
726a989a | 430 | find_uses_to_rename_stmt (gimple stmt, bitmap *use_blocks, bitmap need_phis) |
c913f08a | 431 | { |
4c124b4c AM |
432 | ssa_op_iter iter; |
433 | tree var; | |
726a989a | 434 | basic_block bb = gimple_bb (stmt); |
c913f08a | 435 | |
b5b8b0ac AO |
436 | if (is_gimple_debug (stmt)) |
437 | return; | |
438 | ||
636f59cf | 439 | FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_USE) |
84d65814 | 440 | find_uses_to_rename_use (bb, var, use_blocks, need_phis); |
c913f08a ZD |
441 | } |
442 | ||
2b271002 ZD |
443 | /* Marks names that are used in BB and outside of the loop they are |
444 | defined in for rewrite. Records the set of blocks in that the ssa | |
84d65814 DN |
445 | names are defined to USE_BLOCKS. Record the SSA names that will |
446 | need exit PHIs in NEED_PHIS. */ | |
c913f08a ZD |
447 | |
448 | static void | |
84d65814 | 449 | find_uses_to_rename_bb (basic_block bb, bitmap *use_blocks, bitmap need_phis) |
c913f08a | 450 | { |
2b271002 ZD |
451 | edge e; |
452 | edge_iterator ei; | |
c913f08a | 453 | |
2b271002 | 454 | FOR_EACH_EDGE (e, ei, bb->succs) |
538dd0b7 DM |
455 | for (gphi_iterator bsi = gsi_start_phis (e->dest); !gsi_end_p (bsi); |
456 | gsi_next (&bsi)) | |
01273677 | 457 | { |
538dd0b7 | 458 | gphi *phi = bsi.phi (); |
636f59cf RB |
459 | if (! virtual_operand_p (gimple_phi_result (phi))) |
460 | find_uses_to_rename_use (bb, PHI_ARG_DEF_FROM_EDGE (phi, e), | |
461 | use_blocks, need_phis); | |
01273677 | 462 | } |
b8698a0f | 463 | |
538dd0b7 DM |
464 | for (gimple_stmt_iterator bsi = gsi_start_bb (bb); !gsi_end_p (bsi); |
465 | gsi_next (&bsi)) | |
726a989a | 466 | find_uses_to_rename_stmt (gsi_stmt (bsi), use_blocks, need_phis); |
2b271002 | 467 | } |
b8698a0f | 468 | |
2b271002 ZD |
469 | /* Marks names that are used outside of the loop they are defined in |
470 | for rewrite. Records the set of blocks in that the ssa | |
471 | names are defined to USE_BLOCKS. If CHANGED_BBS is not NULL, | |
472 | scan only blocks in this set. */ | |
473 | ||
474 | static void | |
84d65814 | 475 | find_uses_to_rename (bitmap changed_bbs, bitmap *use_blocks, bitmap need_phis) |
2b271002 ZD |
476 | { |
477 | basic_block bb; | |
478 | unsigned index; | |
479 | bitmap_iterator bi; | |
c913f08a | 480 | |
789c34e3 RB |
481 | if (changed_bbs) |
482 | EXECUTE_IF_SET_IN_BITMAP (changed_bbs, 0, index, bi) | |
06e28de2 | 483 | find_uses_to_rename_bb (BASIC_BLOCK_FOR_FN (cfun, index), use_blocks, need_phis); |
2b271002 | 484 | else |
11cd3bed | 485 | FOR_EACH_BB_FN (bb, cfun) |
789c34e3 | 486 | find_uses_to_rename_bb (bb, use_blocks, need_phis); |
c913f08a ZD |
487 | } |
488 | ||
489 | /* Rewrites the program into a loop closed ssa form -- i.e. inserts extra | |
490 | phi nodes to ensure that no variable is used outside the loop it is | |
491 | defined in. | |
492 | ||
493 | This strengthening of the basic ssa form has several advantages: | |
494 | ||
495 | 1) Updating it during unrolling/peeling/versioning is trivial, since | |
496 | we do not need to care about the uses outside of the loop. | |
ceb16be3 RG |
497 | The same applies to virtual operands which are also rewritten into |
498 | loop closed SSA form. Note that virtual operands are always live | |
499 | until function exit. | |
c913f08a ZD |
500 | 2) The behavior of all uses of an induction variable is the same. |
501 | Without this, you need to distinguish the case when the variable | |
502 | is used outside of the loop it is defined in, for example | |
503 | ||
504 | for (i = 0; i < 100; i++) | |
505 | { | |
506 | for (j = 0; j < 100; j++) | |
507 | { | |
508 | k = i + j; | |
509 | use1 (k); | |
510 | } | |
511 | use2 (k); | |
512 | } | |
513 | ||
514 | Looking from the outer loop with the normal SSA form, the first use of k | |
515 | is not well-behaved, while the second one is an induction variable with | |
2b271002 | 516 | base 99 and step 1. |
b8698a0f | 517 | |
2b271002 | 518 | If CHANGED_BBS is not NULL, we look for uses outside loops only in |
84d65814 DN |
519 | the basic blocks in this set. |
520 | ||
521 | UPDATE_FLAG is used in the call to update_ssa. See | |
522 | TODO_update_ssa* for documentation. */ | |
c913f08a ZD |
523 | |
524 | void | |
84d65814 | 525 | rewrite_into_loop_closed_ssa (bitmap changed_bbs, unsigned update_flag) |
c913f08a | 526 | { |
c913f08a | 527 | bitmap *use_blocks; |
c7b852c8 ZD |
528 | bitmap names_to_rename; |
529 | ||
f87000d0 | 530 | loops_state_set (LOOP_CLOSED_SSA); |
0fc822d0 | 531 | if (number_of_loops (cfun) <= 1) |
c7b852c8 ZD |
532 | return; |
533 | ||
01273677 SB |
534 | /* If the pass has caused the SSA form to be out-of-date, update it |
535 | now. */ | |
536 | update_ssa (update_flag); | |
537 | ||
c302207e SB |
538 | bitmap_obstack_initialize (&loop_renamer_obstack); |
539 | ||
c302207e | 540 | names_to_rename = BITMAP_ALLOC (&loop_renamer_obstack); |
c913f08a | 541 | |
c302207e SB |
542 | /* Uses of names to rename. We don't have to initialize this array, |
543 | because we know that we will only have entries for the SSA names | |
544 | in NAMES_TO_RENAME. */ | |
0fc4dd09 | 545 | use_blocks = XNEWVEC (bitmap, num_ssa_names); |
c913f08a ZD |
546 | |
547 | /* Find the uses outside loops. */ | |
84d65814 | 548 | find_uses_to_rename (changed_bbs, use_blocks, names_to_rename); |
2b271002 | 549 | |
3d741091 RB |
550 | if (!bitmap_empty_p (names_to_rename)) |
551 | { | |
552 | /* An array of bitmaps where LOOP_EXITS[I] is the set of basic blocks | |
553 | that are the destination of an edge exiting loop number I. */ | |
0fc822d0 | 554 | bitmap *loop_exits = XNEWVEC (bitmap, number_of_loops (cfun)); |
3d741091 RB |
555 | get_loops_exits (loop_exits); |
556 | ||
557 | /* Add the PHI nodes on exits of the loops for the names we need to | |
558 | rewrite. */ | |
559 | add_exit_phis (names_to_rename, use_blocks, loop_exits); | |
560 | ||
561 | free (loop_exits); | |
562 | ||
563 | /* Fix up all the names found to be used outside their original | |
564 | loops. */ | |
565 | update_ssa (TODO_update_ssa); | |
566 | } | |
c913f08a | 567 | |
c302207e | 568 | bitmap_obstack_release (&loop_renamer_obstack); |
c913f08a | 569 | free (use_blocks); |
c913f08a ZD |
570 | } |
571 | ||
572 | /* Check invariants of the loop closed ssa form for the USE in BB. */ | |
573 | ||
574 | static void | |
575 | check_loop_closed_ssa_use (basic_block bb, tree use) | |
576 | { | |
726a989a | 577 | gimple def; |
c913f08a | 578 | basic_block def_bb; |
b8698a0f | 579 | |
ea057359 | 580 | if (TREE_CODE (use) != SSA_NAME || virtual_operand_p (use)) |
c913f08a ZD |
581 | return; |
582 | ||
583 | def = SSA_NAME_DEF_STMT (use); | |
726a989a | 584 | def_bb = gimple_bb (def); |
1e128c5f GB |
585 | gcc_assert (!def_bb |
586 | || flow_bb_inside_loop_p (def_bb->loop_father, bb)); | |
c913f08a ZD |
587 | } |
588 | ||
589 | /* Checks invariants of loop closed ssa form in statement STMT in BB. */ | |
590 | ||
591 | static void | |
726a989a | 592 | check_loop_closed_ssa_stmt (basic_block bb, gimple stmt) |
c913f08a | 593 | { |
4c124b4c AM |
594 | ssa_op_iter iter; |
595 | tree var; | |
c913f08a | 596 | |
b5b8b0ac AO |
597 | if (is_gimple_debug (stmt)) |
598 | return; | |
599 | ||
c302207e | 600 | FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_USE) |
4c124b4c | 601 | check_loop_closed_ssa_use (bb, var); |
c913f08a ZD |
602 | } |
603 | ||
a3b9e73c SP |
604 | /* Checks that invariants of the loop closed ssa form are preserved. |
605 | Call verify_ssa when VERIFY_SSA_P is true. */ | |
c913f08a | 606 | |
24e47c76 | 607 | DEBUG_FUNCTION void |
a3b9e73c | 608 | verify_loop_closed_ssa (bool verify_ssa_p) |
c913f08a ZD |
609 | { |
610 | basic_block bb; | |
726a989a RB |
611 | edge e; |
612 | edge_iterator ei; | |
c913f08a | 613 | |
0fc822d0 | 614 | if (number_of_loops (cfun) <= 1) |
84d65814 DN |
615 | return; |
616 | ||
a3b9e73c | 617 | if (verify_ssa_p) |
e9ff9caf | 618 | verify_ssa (false, true); |
c913f08a | 619 | |
a222c01a MM |
620 | timevar_push (TV_VERIFY_LOOP_CLOSED); |
621 | ||
11cd3bed | 622 | FOR_EACH_BB_FN (bb, cfun) |
c913f08a | 623 | { |
538dd0b7 DM |
624 | for (gphi_iterator bsi = gsi_start_phis (bb); !gsi_end_p (bsi); |
625 | gsi_next (&bsi)) | |
726a989a | 626 | { |
538dd0b7 | 627 | gphi *phi = bsi.phi (); |
726a989a RB |
628 | FOR_EACH_EDGE (e, ei, bb->preds) |
629 | check_loop_closed_ssa_use (e->src, | |
630 | PHI_ARG_DEF_FROM_EDGE (phi, e)); | |
631 | } | |
c913f08a | 632 | |
538dd0b7 DM |
633 | for (gimple_stmt_iterator bsi = gsi_start_bb (bb); !gsi_end_p (bsi); |
634 | gsi_next (&bsi)) | |
726a989a | 635 | check_loop_closed_ssa_stmt (bb, gsi_stmt (bsi)); |
c913f08a | 636 | } |
a222c01a MM |
637 | |
638 | timevar_pop (TV_VERIFY_LOOP_CLOSED); | |
c913f08a | 639 | } |
8b11a64c ZD |
640 | |
641 | /* Split loop exit edge EXIT. The things are a bit complicated by a need to | |
5f40b3cb | 642 | preserve the loop closed ssa form. The newly created block is returned. */ |
8b11a64c | 643 | |
5f40b3cb | 644 | basic_block |
8b11a64c ZD |
645 | split_loop_exit_edge (edge exit) |
646 | { | |
647 | basic_block dest = exit->dest; | |
598ec7bd | 648 | basic_block bb = split_edge (exit); |
538dd0b7 | 649 | gphi *phi, *new_phi; |
726a989a | 650 | tree new_name, name; |
8b11a64c | 651 | use_operand_p op_p; |
538dd0b7 | 652 | gphi_iterator psi; |
f5045c96 | 653 | source_location locus; |
8b11a64c | 654 | |
726a989a | 655 | for (psi = gsi_start_phis (dest); !gsi_end_p (psi); gsi_next (&psi)) |
8b11a64c | 656 | { |
538dd0b7 | 657 | phi = psi.phi (); |
c5cbcccf | 658 | op_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, single_succ_edge (bb)); |
f5045c96 | 659 | locus = gimple_phi_arg_location_from_edge (phi, single_succ_edge (bb)); |
8b11a64c | 660 | |
7fac6722 ZD |
661 | name = USE_FROM_PTR (op_p); |
662 | ||
38635499 | 663 | /* If the argument of the PHI node is a constant, we do not need |
7fac6722 ZD |
664 | to keep it inside loop. */ |
665 | if (TREE_CODE (name) != SSA_NAME) | |
666 | continue; | |
667 | ||
668 | /* Otherwise create an auxiliary phi node that will copy the value | |
38635499 | 669 | of the SSA name out of the loop. */ |
7fac6722 | 670 | new_name = duplicate_ssa_name (name, NULL); |
8b11a64c | 671 | new_phi = create_phi_node (new_name, bb); |
9e227d60 | 672 | add_phi_arg (new_phi, name, exit, locus); |
8b11a64c ZD |
673 | SET_USE (op_p, new_name); |
674 | } | |
5f40b3cb ZD |
675 | |
676 | return bb; | |
8b11a64c ZD |
677 | } |
678 | ||
8b11a64c ZD |
679 | /* Returns the basic block in that statements should be emitted for induction |
680 | variables incremented at the end of the LOOP. */ | |
681 | ||
682 | basic_block | |
683 | ip_end_pos (struct loop *loop) | |
684 | { | |
685 | return loop->latch; | |
686 | } | |
687 | ||
688 | /* Returns the basic block in that statements should be emitted for induction | |
689 | variables incremented just before exit condition of a LOOP. */ | |
690 | ||
691 | basic_block | |
692 | ip_normal_pos (struct loop *loop) | |
693 | { | |
726a989a | 694 | gimple last; |
8b11a64c ZD |
695 | basic_block bb; |
696 | edge exit; | |
697 | ||
c5cbcccf | 698 | if (!single_pred_p (loop->latch)) |
8b11a64c ZD |
699 | return NULL; |
700 | ||
c5cbcccf | 701 | bb = single_pred (loop->latch); |
8b11a64c | 702 | last = last_stmt (bb); |
ae2cf11b | 703 | if (!last |
726a989a | 704 | || gimple_code (last) != GIMPLE_COND) |
8b11a64c ZD |
705 | return NULL; |
706 | ||
628f6a4e | 707 | exit = EDGE_SUCC (bb, 0); |
8b11a64c | 708 | if (exit->dest == loop->latch) |
628f6a4e | 709 | exit = EDGE_SUCC (bb, 1); |
8b11a64c ZD |
710 | |
711 | if (flow_bb_inside_loop_p (loop, exit->dest)) | |
712 | return NULL; | |
713 | ||
714 | return bb; | |
715 | } | |
716 | ||
717 | /* Stores the standard position for induction variable increment in LOOP | |
718 | (just before the exit condition if it is available and latch block is empty, | |
719 | end of the latch block otherwise) to BSI. INSERT_AFTER is set to true if | |
720 | the increment should be inserted after *BSI. */ | |
721 | ||
722 | void | |
726a989a | 723 | standard_iv_increment_position (struct loop *loop, gimple_stmt_iterator *bsi, |
8b11a64c ZD |
724 | bool *insert_after) |
725 | { | |
726 | basic_block bb = ip_normal_pos (loop), latch = ip_end_pos (loop); | |
726a989a | 727 | gimple last = last_stmt (latch); |
8b11a64c ZD |
728 | |
729 | if (!bb | |
726a989a | 730 | || (last && gimple_code (last) != GIMPLE_LABEL)) |
8b11a64c | 731 | { |
726a989a | 732 | *bsi = gsi_last_bb (latch); |
8b11a64c ZD |
733 | *insert_after = true; |
734 | } | |
735 | else | |
736 | { | |
726a989a | 737 | *bsi = gsi_last_bb (bb); |
8b11a64c ZD |
738 | *insert_after = false; |
739 | } | |
740 | } | |
92fc4a2f ZD |
741 | |
742 | /* Copies phi node arguments for duplicated blocks. The index of the first | |
743 | duplicated block is FIRST_NEW_BLOCK. */ | |
744 | ||
745 | static void | |
746 | copy_phi_node_args (unsigned first_new_block) | |
747 | { | |
748 | unsigned i; | |
749 | ||
8b1c6fd7 | 750 | for (i = first_new_block; i < (unsigned) last_basic_block_for_fn (cfun); i++) |
06e28de2 | 751 | BASIC_BLOCK_FOR_FN (cfun, i)->flags |= BB_DUPLICATED; |
92fc4a2f | 752 | |
8b1c6fd7 | 753 | for (i = first_new_block; i < (unsigned) last_basic_block_for_fn (cfun); i++) |
06e28de2 | 754 | add_phi_args_after_copy_bb (BASIC_BLOCK_FOR_FN (cfun, i)); |
92fc4a2f | 755 | |
8b1c6fd7 | 756 | for (i = first_new_block; i < (unsigned) last_basic_block_for_fn (cfun); i++) |
06e28de2 | 757 | BASIC_BLOCK_FOR_FN (cfun, i)->flags &= ~BB_DUPLICATED; |
92fc4a2f ZD |
758 | } |
759 | ||
92fc4a2f | 760 | |
84d65814 DN |
761 | /* The same as cfgloopmanip.c:duplicate_loop_to_header_edge, but also |
762 | updates the PHI nodes at start of the copied region. In order to | |
763 | achieve this, only loops whose exits all lead to the same location | |
764 | are handled. | |
92fc4a2f | 765 | |
84d65814 DN |
766 | Notice that we do not completely update the SSA web after |
767 | duplication. The caller is responsible for calling update_ssa | |
768 | after the loop has been duplicated. */ | |
92fc4a2f ZD |
769 | |
770 | bool | |
726a989a | 771 | gimple_duplicate_loop_to_header_edge (struct loop *loop, edge e, |
92fc4a2f | 772 | unsigned int ndupl, sbitmap wont_exit, |
9771b263 | 773 | edge orig, vec<edge> *to_remove, |
ee8c1b05 | 774 | int flags) |
92fc4a2f ZD |
775 | { |
776 | unsigned first_new_block; | |
92fc4a2f | 777 | |
f87000d0 | 778 | if (!loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
92fc4a2f | 779 | return false; |
f87000d0 | 780 | if (!loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)) |
92fc4a2f ZD |
781 | return false; |
782 | ||
8b1c6fd7 | 783 | first_new_block = last_basic_block_for_fn (cfun); |
d73be268 | 784 | if (!duplicate_loop_to_header_edge (loop, e, ndupl, wont_exit, |
ee8c1b05 | 785 | orig, to_remove, flags)) |
92fc4a2f ZD |
786 | return false; |
787 | ||
788 | /* Readd the removed phi args for e. */ | |
71882046 | 789 | flush_pending_stmts (e); |
92fc4a2f ZD |
790 | |
791 | /* Copy the phi node arguments. */ | |
792 | copy_phi_node_args (first_new_block); | |
793 | ||
92fc4a2f | 794 | scev_reset (); |
92fc4a2f ZD |
795 | |
796 | return true; | |
797 | } | |
17684618 | 798 | |
17684618 ZD |
799 | /* Returns true if we can unroll LOOP FACTOR times. Number |
800 | of iterations of the loop is returned in NITER. */ | |
801 | ||
802 | bool | |
803 | can_unroll_loop_p (struct loop *loop, unsigned factor, | |
804 | struct tree_niter_desc *niter) | |
805 | { | |
806 | edge exit; | |
807 | ||
808 | /* Check whether unrolling is possible. We only want to unroll loops | |
809 | for that we are able to determine number of iterations. We also | |
810 | want to split the extra iterations of the loop from its end, | |
811 | therefore we require that the loop has precisely one | |
812 | exit. */ | |
813 | ||
814 | exit = single_dom_exit (loop); | |
815 | if (!exit) | |
816 | return false; | |
817 | ||
818 | if (!number_of_iterations_exit (loop, exit, niter, false) | |
bf8dbe38 ZD |
819 | || niter->cmp == ERROR_MARK |
820 | /* Scalar evolutions analysis might have copy propagated | |
821 | the abnormal ssa names into these expressions, hence | |
2f8e468b | 822 | emitting the computations based on them during loop |
bf8dbe38 ZD |
823 | unrolling might create overlapping life ranges for |
824 | them, and failures in out-of-ssa. */ | |
825 | || contains_abnormal_ssa_name_p (niter->may_be_zero) | |
826 | || contains_abnormal_ssa_name_p (niter->control.base) | |
827 | || contains_abnormal_ssa_name_p (niter->control.step) | |
828 | || contains_abnormal_ssa_name_p (niter->bound)) | |
17684618 ZD |
829 | return false; |
830 | ||
831 | /* And of course, we must be able to duplicate the loop. */ | |
832 | if (!can_duplicate_loop_p (loop)) | |
833 | return false; | |
834 | ||
835 | /* The final loop should be small enough. */ | |
7f9bc51b | 836 | if (tree_num_loop_insns (loop, &eni_size_weights) * factor |
17684618 ZD |
837 | > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLLED_INSNS)) |
838 | return false; | |
839 | ||
840 | return true; | |
841 | } | |
842 | ||
843 | /* Determines the conditions that control execution of LOOP unrolled FACTOR | |
844 | times. DESC is number of iterations of LOOP. ENTER_COND is set to | |
845 | condition that must be true if the main loop can be entered. | |
846 | EXIT_BASE, EXIT_STEP, EXIT_CMP and EXIT_BOUND are set to values describing | |
847 | how the exit from the unrolled loop should be controlled. */ | |
848 | ||
849 | static void | |
850 | determine_exit_conditions (struct loop *loop, struct tree_niter_desc *desc, | |
851 | unsigned factor, tree *enter_cond, | |
852 | tree *exit_base, tree *exit_step, | |
853 | enum tree_code *exit_cmp, tree *exit_bound) | |
854 | { | |
726a989a | 855 | gimple_seq stmts; |
17684618 ZD |
856 | tree base = desc->control.base; |
857 | tree step = desc->control.step; | |
858 | tree bound = desc->bound; | |
d24a32a1 | 859 | tree type = TREE_TYPE (step); |
17684618 ZD |
860 | tree bigstep, delta; |
861 | tree min = lower_bound_in_type (type, type); | |
862 | tree max = upper_bound_in_type (type, type); | |
863 | enum tree_code cmp = desc->cmp; | |
864 | tree cond = boolean_true_node, assum; | |
865 | ||
0d82a1c8 | 866 | /* For pointers, do the arithmetics in the type of step. */ |
d24a32a1 ZD |
867 | base = fold_convert (type, base); |
868 | bound = fold_convert (type, bound); | |
869 | ||
17684618 ZD |
870 | *enter_cond = boolean_false_node; |
871 | *exit_base = NULL_TREE; | |
872 | *exit_step = NULL_TREE; | |
873 | *exit_cmp = ERROR_MARK; | |
874 | *exit_bound = NULL_TREE; | |
875 | gcc_assert (cmp != ERROR_MARK); | |
876 | ||
877 | /* We only need to be correct when we answer question | |
878 | "Do at least FACTOR more iterations remain?" in the unrolled loop. | |
879 | Thus, transforming BASE + STEP * i <> BOUND to | |
880 | BASE + STEP * i < BOUND is ok. */ | |
881 | if (cmp == NE_EXPR) | |
882 | { | |
883 | if (tree_int_cst_sign_bit (step)) | |
884 | cmp = GT_EXPR; | |
885 | else | |
886 | cmp = LT_EXPR; | |
887 | } | |
888 | else if (cmp == LT_EXPR) | |
889 | { | |
890 | gcc_assert (!tree_int_cst_sign_bit (step)); | |
891 | } | |
892 | else if (cmp == GT_EXPR) | |
893 | { | |
894 | gcc_assert (tree_int_cst_sign_bit (step)); | |
895 | } | |
896 | else | |
897 | gcc_unreachable (); | |
898 | ||
899 | /* The main body of the loop may be entered iff: | |
900 | ||
901 | 1) desc->may_be_zero is false. | |
902 | 2) it is possible to check that there are at least FACTOR iterations | |
903 | of the loop, i.e., BOUND - step * FACTOR does not overflow. | |
904 | 3) # of iterations is at least FACTOR */ | |
905 | ||
6e682d7e | 906 | if (!integer_zerop (desc->may_be_zero)) |
17684618 ZD |
907 | cond = fold_build2 (TRUTH_AND_EXPR, boolean_type_node, |
908 | invert_truthvalue (desc->may_be_zero), | |
909 | cond); | |
910 | ||
911 | bigstep = fold_build2 (MULT_EXPR, type, step, | |
912 | build_int_cst_type (type, factor)); | |
913 | delta = fold_build2 (MINUS_EXPR, type, bigstep, step); | |
914 | if (cmp == LT_EXPR) | |
915 | assum = fold_build2 (GE_EXPR, boolean_type_node, | |
916 | bound, | |
917 | fold_build2 (PLUS_EXPR, type, min, delta)); | |
918 | else | |
919 | assum = fold_build2 (LE_EXPR, boolean_type_node, | |
920 | bound, | |
921 | fold_build2 (PLUS_EXPR, type, max, delta)); | |
922 | cond = fold_build2 (TRUTH_AND_EXPR, boolean_type_node, assum, cond); | |
923 | ||
924 | bound = fold_build2 (MINUS_EXPR, type, bound, delta); | |
925 | assum = fold_build2 (cmp, boolean_type_node, base, bound); | |
926 | cond = fold_build2 (TRUTH_AND_EXPR, boolean_type_node, assum, cond); | |
927 | ||
928 | cond = force_gimple_operand (unshare_expr (cond), &stmts, false, NULL_TREE); | |
929 | if (stmts) | |
726a989a | 930 | gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts); |
17684618 ZD |
931 | /* cond now may be a gimple comparison, which would be OK, but also any |
932 | other gimple rhs (say a && b). In this case we need to force it to | |
933 | operand. */ | |
934 | if (!is_gimple_condexpr (cond)) | |
935 | { | |
936 | cond = force_gimple_operand (cond, &stmts, true, NULL_TREE); | |
937 | if (stmts) | |
726a989a | 938 | gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts); |
17684618 ZD |
939 | } |
940 | *enter_cond = cond; | |
941 | ||
942 | base = force_gimple_operand (unshare_expr (base), &stmts, true, NULL_TREE); | |
943 | if (stmts) | |
726a989a | 944 | gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts); |
17684618 ZD |
945 | bound = force_gimple_operand (unshare_expr (bound), &stmts, true, NULL_TREE); |
946 | if (stmts) | |
726a989a | 947 | gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts); |
17684618 ZD |
948 | |
949 | *exit_base = base; | |
950 | *exit_step = bigstep; | |
951 | *exit_cmp = cmp; | |
952 | *exit_bound = bound; | |
953 | } | |
954 | ||
14fa2cc0 ZD |
955 | /* Scales the frequencies of all basic blocks in LOOP that are strictly |
956 | dominated by BB by NUM/DEN. */ | |
957 | ||
958 | static void | |
959 | scale_dominated_blocks_in_loop (struct loop *loop, basic_block bb, | |
960 | int num, int den) | |
961 | { | |
962 | basic_block son; | |
963 | ||
964 | if (den == 0) | |
965 | return; | |
966 | ||
967 | for (son = first_dom_son (CDI_DOMINATORS, bb); | |
968 | son; | |
969 | son = next_dom_son (CDI_DOMINATORS, son)) | |
970 | { | |
971 | if (!flow_bb_inside_loop_p (loop, son)) | |
972 | continue; | |
973 | scale_bbs_frequencies_int (&son, 1, num, den); | |
974 | scale_dominated_blocks_in_loop (loop, son, num, den); | |
975 | } | |
976 | } | |
977 | ||
d73be268 ZD |
978 | /* Unroll LOOP FACTOR times. DESC describes number of iterations of LOOP. |
979 | EXIT is the exit of the loop to that DESC corresponds. | |
980 | ||
17684618 ZD |
981 | If N is number of iterations of the loop and MAY_BE_ZERO is the condition |
982 | under that loop exits in the first iteration even if N != 0, | |
b8698a0f | 983 | |
17684618 ZD |
984 | while (1) |
985 | { | |
986 | x = phi (init, next); | |
987 | ||
988 | pre; | |
989 | if (st) | |
990 | break; | |
991 | post; | |
992 | } | |
993 | ||
994 | becomes (with possibly the exit conditions formulated a bit differently, | |
995 | avoiding the need to create a new iv): | |
b8698a0f | 996 | |
17684618 ZD |
997 | if (MAY_BE_ZERO || N < FACTOR) |
998 | goto rest; | |
999 | ||
1000 | do | |
1001 | { | |
1002 | x = phi (init, next); | |
1003 | ||
1004 | pre; | |
1005 | post; | |
1006 | pre; | |
1007 | post; | |
1008 | ... | |
1009 | pre; | |
1010 | post; | |
1011 | N -= FACTOR; | |
b8698a0f | 1012 | |
17684618 ZD |
1013 | } while (N >= FACTOR); |
1014 | ||
1015 | rest: | |
1016 | init' = phi (init, x); | |
1017 | ||
1018 | while (1) | |
1019 | { | |
1020 | x = phi (init', next); | |
1021 | ||
1022 | pre; | |
1023 | if (st) | |
1024 | break; | |
1025 | post; | |
567b96ed | 1026 | } |
b8698a0f | 1027 | |
567b96ed ZD |
1028 | Before the loop is unrolled, TRANSFORM is called for it (only for the |
1029 | unrolled loop, but not for its versioned copy). DATA is passed to | |
1030 | TRANSFORM. */ | |
17684618 | 1031 | |
03cb2019 ZD |
1032 | /* Probability in % that the unrolled loop is entered. Just a guess. */ |
1033 | #define PROB_UNROLLED_LOOP_ENTERED 90 | |
1034 | ||
17684618 | 1035 | void |
567b96ed ZD |
1036 | tree_transform_and_unroll_loop (struct loop *loop, unsigned factor, |
1037 | edge exit, struct tree_niter_desc *desc, | |
1038 | transform_callback transform, | |
1039 | void *data) | |
17684618 | 1040 | { |
538dd0b7 | 1041 | gcond *exit_if; |
726a989a | 1042 | tree ctr_before, ctr_after; |
17684618 ZD |
1043 | tree enter_main_cond, exit_base, exit_step, exit_bound; |
1044 | enum tree_code exit_cmp; | |
538dd0b7 DM |
1045 | gphi *phi_old_loop, *phi_new_loop, *phi_rest; |
1046 | gphi_iterator psi_old_loop, psi_new_loop; | |
70b5e7dc | 1047 | tree init, next, new_init; |
17684618 ZD |
1048 | struct loop *new_loop; |
1049 | basic_block rest, exit_bb; | |
1050 | edge old_entry, new_entry, old_latch, precond_edge, new_exit; | |
14fa2cc0 | 1051 | edge new_nonexit, e; |
726a989a | 1052 | gimple_stmt_iterator bsi; |
17684618 ZD |
1053 | use_operand_p op; |
1054 | bool ok; | |
03cb2019 | 1055 | unsigned est_niter, prob_entry, scale_unrolled, scale_rest, freq_e, freq_h; |
14fa2cc0 | 1056 | unsigned new_est_niter, i, prob; |
8e08deeb | 1057 | unsigned irr = loop_preheader_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP; |
17684618 | 1058 | sbitmap wont_exit; |
ef062b13 | 1059 | auto_vec<edge> to_remove; |
17684618 ZD |
1060 | |
1061 | est_niter = expected_loop_iterations (loop); | |
1062 | determine_exit_conditions (loop, desc, factor, | |
1063 | &enter_main_cond, &exit_base, &exit_step, | |
1064 | &exit_cmp, &exit_bound); | |
1065 | ||
03cb2019 ZD |
1066 | /* Let us assume that the unrolled loop is quite likely to be entered. */ |
1067 | if (integer_nonzerop (enter_main_cond)) | |
1068 | prob_entry = REG_BR_PROB_BASE; | |
1069 | else | |
1070 | prob_entry = PROB_UNROLLED_LOOP_ENTERED * REG_BR_PROB_BASE / 100; | |
1071 | ||
1072 | /* The values for scales should keep profile consistent, and somewhat close | |
1073 | to correct. | |
1074 | ||
1075 | TODO: The current value of SCALE_REST makes it appear that the loop that | |
1076 | is created by splitting the remaining iterations of the unrolled loop is | |
1077 | executed the same number of times as the original loop, and with the same | |
1078 | frequencies, which is obviously wrong. This does not appear to cause | |
1079 | problems, so we do not bother with fixing it for now. To make the profile | |
1080 | correct, we would need to change the probability of the exit edge of the | |
1081 | loop, and recompute the distribution of frequencies in its body because | |
1082 | of this change (scale the frequencies of blocks before and after the exit | |
1083 | by appropriate factors). */ | |
1084 | scale_unrolled = prob_entry; | |
1085 | scale_rest = REG_BR_PROB_BASE; | |
1086 | ||
1087 | new_loop = loop_version (loop, enter_main_cond, NULL, | |
1088 | prob_entry, scale_unrolled, scale_rest, true); | |
17684618 ZD |
1089 | gcc_assert (new_loop != NULL); |
1090 | update_ssa (TODO_update_ssa); | |
1091 | ||
567b96ed | 1092 | /* Determine the probability of the exit edge of the unrolled loop. */ |
03cb2019 ZD |
1093 | new_est_niter = est_niter / factor; |
1094 | ||
1095 | /* Without profile feedback, loops for that we do not know a better estimate | |
1096 | are assumed to roll 10 times. When we unroll such loop, it appears to | |
1097 | roll too little, and it may even seem to be cold. To avoid this, we | |
1098 | ensure that the created loop appears to roll at least 5 times (but at | |
1099 | most as many times as before unrolling). */ | |
1100 | if (new_est_niter < 5) | |
1101 | { | |
1102 | if (est_niter < 5) | |
1103 | new_est_niter = est_niter; | |
1104 | else | |
1105 | new_est_niter = 5; | |
1106 | } | |
1107 | ||
14fa2cc0 ZD |
1108 | /* Prepare the cfg and update the phi nodes. Move the loop exit to the |
1109 | loop latch (and make its condition dummy, for the moment). */ | |
17684618 ZD |
1110 | rest = loop_preheader_edge (new_loop)->src; |
1111 | precond_edge = single_pred_edge (rest); | |
598ec7bd | 1112 | split_edge (loop_latch_edge (loop)); |
17684618 ZD |
1113 | exit_bb = single_pred (loop->latch); |
1114 | ||
14fa2cc0 ZD |
1115 | /* Since the exit edge will be removed, the frequency of all the blocks |
1116 | in the loop that are dominated by it must be scaled by | |
1117 | 1 / (1 - exit->probability). */ | |
1118 | scale_dominated_blocks_in_loop (loop, exit->src, | |
1119 | REG_BR_PROB_BASE, | |
1120 | REG_BR_PROB_BASE - exit->probability); | |
1121 | ||
726a989a RB |
1122 | bsi = gsi_last_bb (exit_bb); |
1123 | exit_if = gimple_build_cond (EQ_EXPR, integer_zero_node, | |
1124 | integer_zero_node, | |
1125 | NULL_TREE, NULL_TREE); | |
a9b77cd1 | 1126 | |
726a989a | 1127 | gsi_insert_after (&bsi, exit_if, GSI_NEW_STMT); |
8e08deeb | 1128 | new_exit = make_edge (exit_bb, rest, EDGE_FALSE_VALUE | irr); |
6270df4c | 1129 | rescan_loop_exit (new_exit, true, false); |
14fa2cc0 ZD |
1130 | |
1131 | /* Set the probability of new exit to the same of the old one. Fix | |
1132 | the frequency of the latch block, by scaling it back by | |
1133 | 1 - exit->probability. */ | |
1134 | new_exit->count = exit->count; | |
1135 | new_exit->probability = exit->probability; | |
17684618 | 1136 | new_nonexit = single_pred_edge (loop->latch); |
14fa2cc0 | 1137 | new_nonexit->probability = REG_BR_PROB_BASE - exit->probability; |
17684618 | 1138 | new_nonexit->flags = EDGE_TRUE_VALUE; |
14fa2cc0 ZD |
1139 | new_nonexit->count -= exit->count; |
1140 | if (new_nonexit->count < 0) | |
1141 | new_nonexit->count = 0; | |
1142 | scale_bbs_frequencies_int (&loop->latch, 1, new_nonexit->probability, | |
1143 | REG_BR_PROB_BASE); | |
17684618 ZD |
1144 | |
1145 | old_entry = loop_preheader_edge (loop); | |
1146 | new_entry = loop_preheader_edge (new_loop); | |
1147 | old_latch = loop_latch_edge (loop); | |
726a989a RB |
1148 | for (psi_old_loop = gsi_start_phis (loop->header), |
1149 | psi_new_loop = gsi_start_phis (new_loop->header); | |
1150 | !gsi_end_p (psi_old_loop); | |
1151 | gsi_next (&psi_old_loop), gsi_next (&psi_new_loop)) | |
17684618 | 1152 | { |
538dd0b7 DM |
1153 | phi_old_loop = psi_old_loop.phi (); |
1154 | phi_new_loop = psi_new_loop.phi (); | |
726a989a | 1155 | |
17684618 ZD |
1156 | init = PHI_ARG_DEF_FROM_EDGE (phi_old_loop, old_entry); |
1157 | op = PHI_ARG_DEF_PTR_FROM_EDGE (phi_new_loop, new_entry); | |
1158 | gcc_assert (operand_equal_for_phi_arg_p (init, USE_FROM_PTR (op))); | |
1159 | next = PHI_ARG_DEF_FROM_EDGE (phi_old_loop, old_latch); | |
1160 | ||
1161 | /* Prefer using original variable as a base for the new ssa name. | |
1162 | This is necessary for virtual ops, and useful in order to avoid | |
1163 | losing debug info for real ops. */ | |
182e00b1 RG |
1164 | if (TREE_CODE (next) == SSA_NAME |
1165 | && useless_type_conversion_p (TREE_TYPE (next), | |
1166 | TREE_TYPE (init))) | |
b731b390 | 1167 | new_init = copy_ssa_name (next); |
182e00b1 RG |
1168 | else if (TREE_CODE (init) == SSA_NAME |
1169 | && useless_type_conversion_p (TREE_TYPE (init), | |
1170 | TREE_TYPE (next))) | |
b731b390 | 1171 | new_init = copy_ssa_name (init); |
182e00b1 | 1172 | else if (useless_type_conversion_p (TREE_TYPE (next), TREE_TYPE (init))) |
70b5e7dc | 1173 | new_init = make_temp_ssa_name (TREE_TYPE (next), NULL, "unrinittmp"); |
17684618 | 1174 | else |
70b5e7dc | 1175 | new_init = make_temp_ssa_name (TREE_TYPE (init), NULL, "unrinittmp"); |
17684618 | 1176 | |
17684618 | 1177 | phi_rest = create_phi_node (new_init, rest); |
17684618 | 1178 | |
9e227d60 DC |
1179 | add_phi_arg (phi_rest, init, precond_edge, UNKNOWN_LOCATION); |
1180 | add_phi_arg (phi_rest, next, new_exit, UNKNOWN_LOCATION); | |
17684618 ZD |
1181 | SET_USE (op, new_init); |
1182 | } | |
1183 | ||
14fa2cc0 ZD |
1184 | remove_path (exit); |
1185 | ||
567b96ed ZD |
1186 | /* Transform the loop. */ |
1187 | if (transform) | |
1188 | (*transform) (loop, data); | |
1189 | ||
14fa2cc0 ZD |
1190 | /* Unroll the loop and remove the exits in all iterations except for the |
1191 | last one. */ | |
567b96ed | 1192 | wont_exit = sbitmap_alloc (factor); |
f61e445a | 1193 | bitmap_ones (wont_exit); |
d7c028c0 | 1194 | bitmap_clear_bit (wont_exit, factor - 1); |
14fa2cc0 | 1195 | |
726a989a | 1196 | ok = gimple_duplicate_loop_to_header_edge |
567b96ed | 1197 | (loop, loop_latch_edge (loop), factor - 1, |
14fa2cc0 | 1198 | wont_exit, new_exit, &to_remove, DLTHE_FLAG_UPDATE_FREQ); |
567b96ed ZD |
1199 | free (wont_exit); |
1200 | gcc_assert (ok); | |
14fa2cc0 | 1201 | |
9771b263 | 1202 | FOR_EACH_VEC_ELT (to_remove, i, e) |
14fa2cc0 ZD |
1203 | { |
1204 | ok = remove_path (e); | |
1205 | gcc_assert (ok); | |
1206 | } | |
567b96ed ZD |
1207 | update_ssa (TODO_update_ssa); |
1208 | ||
1209 | /* Ensure that the frequencies in the loop match the new estimated | |
1210 | number of iterations, and change the probability of the new | |
1211 | exit edge. */ | |
1212 | freq_h = loop->header->frequency; | |
1213 | freq_e = EDGE_FREQUENCY (loop_preheader_edge (loop)); | |
1214 | if (freq_h != 0) | |
1215 | scale_loop_frequencies (loop, freq_e * (new_est_niter + 1), freq_h); | |
1216 | ||
1217 | exit_bb = single_pred (loop->latch); | |
1218 | new_exit = find_edge (exit_bb, rest); | |
1219 | new_exit->count = loop_preheader_edge (loop)->count; | |
1220 | new_exit->probability = REG_BR_PROB_BASE / (new_est_niter + 1); | |
1221 | ||
1222 | rest->count += new_exit->count; | |
1223 | rest->frequency += EDGE_FREQUENCY (new_exit); | |
1224 | ||
1225 | new_nonexit = single_pred_edge (loop->latch); | |
14fa2cc0 | 1226 | prob = new_nonexit->probability; |
567b96ed | 1227 | new_nonexit->probability = REG_BR_PROB_BASE - new_exit->probability; |
14fa2cc0 ZD |
1228 | new_nonexit->count = exit_bb->count - new_exit->count; |
1229 | if (new_nonexit->count < 0) | |
1230 | new_nonexit->count = 0; | |
87621e5f SE |
1231 | if (prob > 0) |
1232 | scale_bbs_frequencies_int (&loop->latch, 1, new_nonexit->probability, | |
1233 | prob); | |
567b96ed | 1234 | |
17684618 ZD |
1235 | /* Finally create the new counter for number of iterations and add the new |
1236 | exit instruction. */ | |
22963fee | 1237 | bsi = gsi_last_nondebug_bb (exit_bb); |
538dd0b7 | 1238 | exit_if = as_a <gcond *> (gsi_stmt (bsi)); |
17684618 | 1239 | create_iv (exit_base, exit_step, NULL_TREE, loop, |
567b96ed | 1240 | &bsi, false, &ctr_before, &ctr_after); |
726a989a RB |
1241 | gimple_cond_set_code (exit_if, exit_cmp); |
1242 | gimple_cond_set_lhs (exit_if, ctr_after); | |
1243 | gimple_cond_set_rhs (exit_if, exit_bound); | |
567b96ed | 1244 | update_stmt (exit_if); |
17684618 | 1245 | |
c0493b13 | 1246 | #ifdef ENABLE_CHECKING |
17684618 | 1247 | verify_flow_info (); |
d73be268 | 1248 | verify_loop_structure (); |
a3b9e73c | 1249 | verify_loop_closed_ssa (true); |
c0493b13 | 1250 | #endif |
17684618 | 1251 | } |
567b96ed ZD |
1252 | |
1253 | /* Wrapper over tree_transform_and_unroll_loop for case we do not | |
1254 | want to transform the loop before unrolling. The meaning | |
1255 | of the arguments is the same as for tree_transform_and_unroll_loop. */ | |
1256 | ||
1257 | void | |
1258 | tree_unroll_loop (struct loop *loop, unsigned factor, | |
1259 | edge exit, struct tree_niter_desc *desc) | |
1260 | { | |
1261 | tree_transform_and_unroll_loop (loop, factor, exit, desc, | |
1262 | NULL, NULL); | |
1263 | } | |
08dab97a RL |
1264 | |
1265 | /* Rewrite the phi node at position PSI in function of the main | |
1266 | induction variable MAIN_IV and insert the generated code at GSI. */ | |
1267 | ||
1268 | static void | |
1269 | rewrite_phi_with_iv (loop_p loop, | |
538dd0b7 | 1270 | gphi_iterator *psi, |
08dab97a RL |
1271 | gimple_stmt_iterator *gsi, |
1272 | tree main_iv) | |
1273 | { | |
1274 | affine_iv iv; | |
538dd0b7 DM |
1275 | gassign *stmt; |
1276 | gphi *phi = psi->phi (); | |
08dab97a RL |
1277 | tree atype, mtype, val, res = PHI_RESULT (phi); |
1278 | ||
ea057359 | 1279 | if (virtual_operand_p (res) || res == main_iv) |
08dab97a RL |
1280 | { |
1281 | gsi_next (psi); | |
1282 | return; | |
1283 | } | |
1284 | ||
1285 | if (!simple_iv (loop, loop, res, &iv, true)) | |
1286 | { | |
1287 | gsi_next (psi); | |
1288 | return; | |
1289 | } | |
1290 | ||
1291 | remove_phi_node (psi, false); | |
1292 | ||
1293 | atype = TREE_TYPE (res); | |
1294 | mtype = POINTER_TYPE_P (atype) ? sizetype : atype; | |
1295 | val = fold_build2 (MULT_EXPR, mtype, unshare_expr (iv.step), | |
1296 | fold_convert (mtype, main_iv)); | |
1297 | val = fold_build2 (POINTER_TYPE_P (atype) | |
1298 | ? POINTER_PLUS_EXPR : PLUS_EXPR, | |
1299 | atype, unshare_expr (iv.base), val); | |
1300 | val = force_gimple_operand_gsi (gsi, val, false, NULL_TREE, true, | |
1301 | GSI_SAME_STMT); | |
1302 | stmt = gimple_build_assign (res, val); | |
1303 | gsi_insert_before (gsi, stmt, GSI_SAME_STMT); | |
08dab97a RL |
1304 | } |
1305 | ||
1306 | /* Rewrite all the phi nodes of LOOP in function of the main induction | |
1307 | variable MAIN_IV. */ | |
1308 | ||
1309 | static void | |
1310 | rewrite_all_phi_nodes_with_iv (loop_p loop, tree main_iv) | |
1311 | { | |
1312 | unsigned i; | |
1313 | basic_block *bbs = get_loop_body_in_dom_order (loop); | |
538dd0b7 | 1314 | gphi_iterator psi; |
08dab97a RL |
1315 | |
1316 | for (i = 0; i < loop->num_nodes; i++) | |
1317 | { | |
1318 | basic_block bb = bbs[i]; | |
1319 | gimple_stmt_iterator gsi = gsi_after_labels (bb); | |
1320 | ||
1321 | if (bb->loop_father != loop) | |
1322 | continue; | |
1323 | ||
1324 | for (psi = gsi_start_phis (bb); !gsi_end_p (psi); ) | |
1325 | rewrite_phi_with_iv (loop, &psi, &gsi, main_iv); | |
1326 | } | |
1327 | ||
1328 | free (bbs); | |
1329 | } | |
1330 | ||
1331 | /* Bases all the induction variables in LOOP on a single induction | |
1332 | variable (unsigned with base 0 and step 1), whose final value is | |
1333 | compared with *NIT. When the IV type precision has to be larger | |
1334 | than *NIT type precision, *NIT is converted to the larger type, the | |
1335 | conversion code is inserted before the loop, and *NIT is updated to | |
c80a5403 SP |
1336 | the new definition. When BUMP_IN_LATCH is true, the induction |
1337 | variable is incremented in the loop latch, otherwise it is | |
1338 | incremented in the loop header. Return the induction variable that | |
1339 | was created. */ | |
08dab97a RL |
1340 | |
1341 | tree | |
c80a5403 | 1342 | canonicalize_loop_ivs (struct loop *loop, tree *nit, bool bump_in_latch) |
08dab97a RL |
1343 | { |
1344 | unsigned precision = TYPE_PRECISION (TREE_TYPE (*nit)); | |
1345 | unsigned original_precision = precision; | |
1346 | tree type, var_before; | |
538dd0b7 DM |
1347 | gimple_stmt_iterator gsi; |
1348 | gphi_iterator psi; | |
1349 | gcond *stmt; | |
08dab97a RL |
1350 | edge exit = single_dom_exit (loop); |
1351 | gimple_seq stmts; | |
ef4bddc2 | 1352 | machine_mode mode; |
3689198d | 1353 | bool unsigned_p = false; |
08dab97a RL |
1354 | |
1355 | for (psi = gsi_start_phis (loop->header); | |
1356 | !gsi_end_p (psi); gsi_next (&psi)) | |
1357 | { | |
538dd0b7 | 1358 | gphi *phi = psi.phi (); |
08dab97a | 1359 | tree res = PHI_RESULT (phi); |
3689198d | 1360 | bool uns; |
08dab97a | 1361 | |
3689198d | 1362 | type = TREE_TYPE (res); |
ea057359 | 1363 | if (virtual_operand_p (res) |
3689198d SP |
1364 | || (!INTEGRAL_TYPE_P (type) |
1365 | && !POINTER_TYPE_P (type)) | |
1366 | || TYPE_PRECISION (type) < precision) | |
1367 | continue; | |
1368 | ||
1369 | uns = POINTER_TYPE_P (type) | TYPE_UNSIGNED (type); | |
1370 | ||
1371 | if (TYPE_PRECISION (type) > precision) | |
1372 | unsigned_p = uns; | |
1373 | else | |
1374 | unsigned_p |= uns; | |
1375 | ||
1376 | precision = TYPE_PRECISION (type); | |
08dab97a RL |
1377 | } |
1378 | ||
3689198d SP |
1379 | mode = smallest_mode_for_size (precision, MODE_INT); |
1380 | precision = GET_MODE_PRECISION (mode); | |
1381 | type = build_nonstandard_integer_type (precision, unsigned_p); | |
08dab97a RL |
1382 | |
1383 | if (original_precision != precision) | |
1384 | { | |
1385 | *nit = fold_convert (type, *nit); | |
1386 | *nit = force_gimple_operand (*nit, &stmts, true, NULL_TREE); | |
1387 | if (stmts) | |
1388 | gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts); | |
1389 | } | |
1390 | ||
f5b77e7d JJ |
1391 | if (bump_in_latch) |
1392 | gsi = gsi_last_bb (loop->latch); | |
1393 | else | |
1394 | gsi = gsi_last_nondebug_bb (loop->header); | |
08dab97a | 1395 | create_iv (build_int_cst_type (type, 0), build_int_cst (type, 1), NULL_TREE, |
c80a5403 | 1396 | loop, &gsi, bump_in_latch, &var_before, NULL); |
08dab97a RL |
1397 | |
1398 | rewrite_all_phi_nodes_with_iv (loop, var_before); | |
1399 | ||
538dd0b7 | 1400 | stmt = as_a <gcond *> (last_stmt (exit->src)); |
08dab97a RL |
1401 | /* Make the loop exit if the control condition is not satisfied. */ |
1402 | if (exit->flags & EDGE_TRUE_VALUE) | |
1403 | { | |
1404 | edge te, fe; | |
1405 | ||
1406 | extract_true_false_edges_from_block (exit->src, &te, &fe); | |
1407 | te->flags = EDGE_FALSE_VALUE; | |
1408 | fe->flags = EDGE_TRUE_VALUE; | |
1409 | } | |
1410 | gimple_cond_set_code (stmt, LT_EXPR); | |
1411 | gimple_cond_set_lhs (stmt, var_before); | |
1412 | gimple_cond_set_rhs (stmt, *nit); | |
1413 | update_stmt (stmt); | |
1414 | ||
1415 | return var_before; | |
1416 | } |