1 /*
2 * Copyright (c) 1998, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
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16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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23 */
24
25 #ifndef SHARE_OPTO_LOOPNODE_HPP
26 #define SHARE_OPTO_LOOPNODE_HPP
27
28 #include "opto/cfgnode.hpp"
29 #include "opto/multnode.hpp"
30 #include "opto/phaseX.hpp"
31 #include "opto/predicates.hpp"
32 #include "opto/subnode.hpp"
33 #include "opto/type.hpp"
34 #include "utilities/checkedCast.hpp"
35
36 class CmpNode;
37 class BaseCountedLoopEndNode;
38 class CountedLoopNode;
39 class IdealLoopTree;
40 class LoopNode;
41 class Node;
42 class OuterStripMinedLoopEndNode;
43 class PredicateBlock;
44 class PathFrequency;
45 class PhaseIdealLoop;
46 class UnswitchCandidate;
47 class LoopSelector;
48 class UnswitchedLoopSelector;
49 class VectorSet;
50 class VSharedData;
51 class Invariance;
52 struct small_cache;
53
54 //
55 // I D E A L I Z E D L O O P S
56 //
57 // Idealized loops are the set of loops I perform more interesting
58 // transformations on, beyond simple hoisting.
59
60 //------------------------------LoopNode---------------------------------------
61 // Simple loop header. Fall in path on left, loop-back path on right.
62 class LoopNode : public RegionNode {
63 // Size is bigger to hold the flags. However, the flags do not change
64 // the semantics so it does not appear in the hash & cmp functions.
65 virtual uint size_of() const { return sizeof(*this); }
66 protected:
67 uint _loop_flags;
68 // Names for flag bitfields
69 enum { Normal=0, Pre=1, Main=2, Post=3, PreMainPostFlagsMask=3,
70 MainHasNoPreLoop = 1<<2,
71 HasExactTripCount = 1<<3,
72 InnerLoop = 1<<4,
73 PartialPeelLoop = 1<<5,
74 PartialPeelFailed = 1<<6,
75 WasSlpAnalyzed = 1<<7,
76 PassedSlpAnalysis = 1<<8,
77 DoUnrollOnly = 1<<9,
78 VectorizedLoop = 1<<10,
79 HasAtomicPostLoop = 1<<11,
80 StripMined = 1<<12,
81 SubwordLoop = 1<<13,
82 ProfileTripFailed = 1<<14,
83 LoopNestInnerLoop = 1<<15,
84 LoopNestLongOuterLoop = 1<<16,
85 MultiversionFastLoop = 1<<17,
86 MultiversionSlowLoop = 2<<17,
87 MultiversionDelayedSlowLoop = 3<<17,
88 MultiversionFlagsMask = 3<<17,
89 FlatArrays = 1<<18};
90 char _unswitch_count;
91 enum { _unswitch_max=3 };
92
93 // Expected trip count from profile data
94 float _profile_trip_cnt;
95
96 public:
97 // Names for edge indices
98 enum { Self=0, EntryControl, LoopBackControl };
99
100 bool is_inner_loop() const { return _loop_flags & InnerLoop; }
101 void set_inner_loop() { _loop_flags |= InnerLoop; }
102
103 bool is_vectorized_loop() const { return _loop_flags & VectorizedLoop; }
104 bool is_partial_peel_loop() const { return _loop_flags & PartialPeelLoop; }
105 void set_partial_peel_loop() { _loop_flags |= PartialPeelLoop; }
106 bool partial_peel_has_failed() const { return _loop_flags & PartialPeelFailed; }
107 bool is_strip_mined() const { return _loop_flags & StripMined; }
108 bool is_profile_trip_failed() const { return _loop_flags & ProfileTripFailed; }
109 bool is_subword_loop() const { return _loop_flags & SubwordLoop; }
110 bool is_loop_nest_inner_loop() const { return _loop_flags & LoopNestInnerLoop; }
111 bool is_loop_nest_outer_loop() const { return _loop_flags & LoopNestLongOuterLoop; }
112 bool is_flat_arrays() const { return _loop_flags & FlatArrays; }
113
114 void mark_partial_peel_failed() { _loop_flags |= PartialPeelFailed; }
115 void mark_was_slp() { _loop_flags |= WasSlpAnalyzed; }
116 void mark_passed_slp() { _loop_flags |= PassedSlpAnalysis; }
117 void mark_do_unroll_only() { _loop_flags |= DoUnrollOnly; }
118 void mark_loop_vectorized() { _loop_flags |= VectorizedLoop; }
119 void mark_has_atomic_post_loop() { _loop_flags |= HasAtomicPostLoop; }
120 void mark_strip_mined() { _loop_flags |= StripMined; }
121 void clear_strip_mined() { _loop_flags &= ~StripMined; }
122 void mark_profile_trip_failed() { _loop_flags |= ProfileTripFailed; }
123 void mark_subword_loop() { _loop_flags |= SubwordLoop; }
124 void mark_loop_nest_inner_loop() { _loop_flags |= LoopNestInnerLoop; }
125 void mark_loop_nest_outer_loop() { _loop_flags |= LoopNestLongOuterLoop; }
126 void mark_flat_arrays() { _loop_flags |= FlatArrays; }
127
128 int unswitch_max() { return _unswitch_max; }
129 int unswitch_count() { return _unswitch_count; }
130
131 void set_unswitch_count(int val) {
132 assert (val <= unswitch_max(), "too many unswitches");
133 _unswitch_count = val;
134 }
135
136 void set_profile_trip_cnt(float ptc) { _profile_trip_cnt = ptc; }
137 float profile_trip_cnt() { return _profile_trip_cnt; }
138
139 #ifndef PRODUCT
140 uint _stress_peeling_attempts = 0;
141 #endif
142
143 LoopNode(Node *entry, Node *backedge)
144 : RegionNode(3), _loop_flags(0), _unswitch_count(0),
145 _profile_trip_cnt(COUNT_UNKNOWN) {
146 init_class_id(Class_Loop);
147 init_req(EntryControl, entry);
148 init_req(LoopBackControl, backedge);
149 }
150
151 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
152 virtual int Opcode() const;
153 bool can_be_counted_loop(PhaseValues* phase) const {
154 return req() == 3 && in(0) != nullptr &&
155 in(1) != nullptr && phase->type(in(1)) != Type::TOP &&
156 in(2) != nullptr && phase->type(in(2)) != Type::TOP;
157 }
158 bool is_valid_counted_loop(BasicType bt) const;
159 #ifndef PRODUCT
160 virtual void dump_spec(outputStream *st) const;
161 #endif
162
163 void verify_strip_mined(int expect_skeleton) const NOT_DEBUG_RETURN;
164 virtual LoopNode* skip_strip_mined(int expect_skeleton = 1) { return this; }
165 virtual IfTrueNode* outer_loop_tail() const { ShouldNotReachHere(); return nullptr; }
166 virtual OuterStripMinedLoopEndNode* outer_loop_end() const { ShouldNotReachHere(); return nullptr; }
167 virtual IfFalseNode* outer_loop_exit() const { ShouldNotReachHere(); return nullptr; }
168 virtual SafePointNode* outer_safepoint() const { ShouldNotReachHere(); return nullptr; }
169 };
170
171 //------------------------------Counted Loops----------------------------------
172 // Counted loops are all trip-counted loops, with exactly 1 trip-counter exit
173 // path (and maybe some other exit paths). The trip-counter exit is always
174 // last in the loop. The trip-counter have to stride by a constant;
175 // the exit value is also loop invariant.
176
177 // CountedLoopNodes and CountedLoopEndNodes come in matched pairs. The
178 // CountedLoopNode has the incoming loop control and the loop-back-control
179 // which is always the IfTrue before the matching CountedLoopEndNode. The
180 // CountedLoopEndNode has an incoming control (possibly not the
181 // CountedLoopNode if there is control flow in the loop), the post-increment
182 // trip-counter value, and the limit. The trip-counter value is always of
183 // the form (Op old-trip-counter stride). The old-trip-counter is produced
184 // by a Phi connected to the CountedLoopNode. The stride is constant.
185 // The Op is any commutable opcode, including Add, Mul, Xor. The
186 // CountedLoopEndNode also takes in the loop-invariant limit value.
187
188 // From a CountedLoopNode I can reach the matching CountedLoopEndNode via the
189 // loop-back control. From CountedLoopEndNodes I can reach CountedLoopNodes
190 // via the old-trip-counter from the Op node.
191
192 //------------------------------CountedLoopNode--------------------------------
193 // CountedLoopNodes head simple counted loops. CountedLoopNodes have as
194 // inputs the incoming loop-start control and the loop-back control, so they
195 // act like RegionNodes. They also take in the initial trip counter, the
196 // loop-invariant stride and the loop-invariant limit value. CountedLoopNodes
197 // produce a loop-body control and the trip counter value. Since
198 // CountedLoopNodes behave like RegionNodes I still have a standard CFG model.
199
200 class BaseCountedLoopNode : public LoopNode {
201 public:
202 BaseCountedLoopNode(Node *entry, Node *backedge)
203 : LoopNode(entry, backedge) {
204 }
205
206 Node *init_control() const { return in(EntryControl); }
207 Node *back_control() const { return in(LoopBackControl); }
208
209 Node* init_trip() const;
210 Node* stride() const;
211 bool stride_is_con() const;
212 Node* limit() const;
213 Node* incr() const;
214 Node* phi() const;
215
216 BaseCountedLoopEndNode* loopexit_or_null() const;
217 BaseCountedLoopEndNode* loopexit() const;
218
219 virtual BasicType bt() const = 0;
220
221 jlong stride_con() const;
222
223 static BaseCountedLoopNode* make(Node* entry, Node* backedge, BasicType bt);
224 };
225
226
227 class CountedLoopNode : public BaseCountedLoopNode {
228 // Size is bigger to hold _main_idx. However, _main_idx does not change
229 // the semantics so it does not appear in the hash & cmp functions.
230 virtual uint size_of() const { return sizeof(*this); }
231
232 // For Pre- and Post-loops during debugging ONLY, this holds the index of
233 // the Main CountedLoop. Used to assert that we understand the graph shape.
234 node_idx_t _main_idx;
235
236 // Known trip count calculated by compute_exact_trip_count()
237 uint _trip_count;
238
239 // Log2 of original loop bodies in unrolled loop
240 int _unrolled_count_log2;
241
242 // Node count prior to last unrolling - used to decide if
243 // unroll,optimize,unroll,optimize,... is making progress
244 int _node_count_before_unroll;
245
246 // If slp analysis is performed we record the maximum
247 // vector mapped unroll factor here
248 int _slp_maximum_unroll_factor;
249
250 public:
251 CountedLoopNode(Node *entry, Node *backedge)
252 : BaseCountedLoopNode(entry, backedge), _main_idx(0), _trip_count(max_juint),
253 _unrolled_count_log2(0), _node_count_before_unroll(0),
254 _slp_maximum_unroll_factor(0) {
255 init_class_id(Class_CountedLoop);
256 // Initialize _trip_count to the largest possible value.
257 // Will be reset (lower) if the loop's trip count is known.
258 }
259
260 virtual int Opcode() const;
261 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
262
263 CountedLoopEndNode* loopexit_or_null() const { return (CountedLoopEndNode*) BaseCountedLoopNode::loopexit_or_null(); }
264 CountedLoopEndNode* loopexit() const { return (CountedLoopEndNode*) BaseCountedLoopNode::loopexit(); }
265 int stride_con() const;
266
267 // Match increment with optional truncation
268 static Node*
269 match_incr_with_optional_truncation(Node* expr, Node** trunc1, Node** trunc2, const TypeInteger** trunc_type,
270 BasicType bt);
271
272 // A 'main' loop has a pre-loop and a post-loop. The 'main' loop
273 // can run short a few iterations and may start a few iterations in.
274 // It will be RCE'd and unrolled and aligned.
275
276 // A following 'post' loop will run any remaining iterations. Used
277 // during Range Check Elimination, the 'post' loop will do any final
278 // iterations with full checks. Also used by Loop Unrolling, where
279 // the 'post' loop will do any epilog iterations needed. Basically,
280 // a 'post' loop can not profitably be further unrolled or RCE'd.
281
282 // A preceding 'pre' loop will run at least 1 iteration (to do peeling),
283 // it may do under-flow checks for RCE and may do alignment iterations
284 // so the following main loop 'knows' that it is striding down cache
285 // lines.
286
287 // A 'main' loop that is ONLY unrolled or peeled, never RCE'd or
288 // Aligned, may be missing it's pre-loop.
289 bool is_normal_loop () const { return (_loop_flags&PreMainPostFlagsMask) == Normal; }
290 bool is_pre_loop () const { return (_loop_flags&PreMainPostFlagsMask) == Pre; }
291 bool is_main_loop () const { return (_loop_flags&PreMainPostFlagsMask) == Main; }
292 bool is_post_loop () const { return (_loop_flags&PreMainPostFlagsMask) == Post; }
293 bool was_slp_analyzed () const { return (_loop_flags&WasSlpAnalyzed) == WasSlpAnalyzed; }
294 bool has_passed_slp () const { return (_loop_flags&PassedSlpAnalysis) == PassedSlpAnalysis; }
295 bool is_unroll_only () const { return (_loop_flags&DoUnrollOnly) == DoUnrollOnly; }
296 bool is_main_no_pre_loop() const { return _loop_flags & MainHasNoPreLoop; }
297 bool has_atomic_post_loop () const { return (_loop_flags & HasAtomicPostLoop) == HasAtomicPostLoop; }
298 void set_main_no_pre_loop() { _loop_flags |= MainHasNoPreLoop; }
299
300 IfNode* find_multiversion_if_from_multiversion_fast_main_loop();
301
302 int main_idx() const { return _main_idx; }
303
304
305 void set_pre_loop (CountedLoopNode *main) { assert(is_normal_loop(),""); _loop_flags |= Pre ; _main_idx = main->_idx; }
306 void set_main_loop ( ) { assert(is_normal_loop(),""); _loop_flags |= Main; }
307 void set_post_loop (CountedLoopNode *main) { assert(is_normal_loop(),""); _loop_flags |= Post; _main_idx = main->_idx; }
308 void set_normal_loop( ) { _loop_flags &= ~PreMainPostFlagsMask; }
309
310 // We use max_juint for the default value of _trip_count to signal it wasn't set.
311 // We shouldn't set _trip_count to max_juint explicitly.
312 void set_trip_count(uint tc) { assert(tc < max_juint, "Cannot set trip count to max_juint"); _trip_count = tc; }
313 uint trip_count() { return _trip_count; }
314
315 bool has_exact_trip_count() const { return (_loop_flags & HasExactTripCount) != 0; }
316 void set_exact_trip_count(uint tc) {
317 assert(tc < max_juint, "Cannot set trip count to max_juint");
318 _trip_count = tc;
319 _loop_flags |= HasExactTripCount;
320 }
321 void set_nonexact_trip_count() {
322 _loop_flags &= ~HasExactTripCount;
323 }
324 void set_notpassed_slp() {
325 _loop_flags &= ~PassedSlpAnalysis;
326 }
327
328 void double_unrolled_count() { _unrolled_count_log2++; }
329 int unrolled_count() { return 1 << MIN2(_unrolled_count_log2, BitsPerInt-3); }
330
331 void set_node_count_before_unroll(int ct) { _node_count_before_unroll = ct; }
332 int node_count_before_unroll() { return _node_count_before_unroll; }
333 void set_slp_max_unroll(int unroll_factor) { _slp_maximum_unroll_factor = unroll_factor; }
334 int slp_max_unroll() const { return _slp_maximum_unroll_factor; }
335
336 // Multiversioning allows us to duplicate a CountedLoop, and have two versions, and the multiversion_if
337 // decides which one is taken:
338 // (1) fast_loop: We enter this loop by default, by default the multiversion_if has its condition set to
339 // "true", guarded by a OpaqueMultiversioning. If we want to make a speculative assumption
340 // for an optimization, we can add the runtime-check to the multiversion_if, and if the
341 // assumption fails we take the slow_loop instead, where we do not make the same speculative
342 // assumption.
343 // We call it the "fast_loop" because it has more optimizations, enabled by the speculative
344 // runtime-checks at the multiversion_if, and we expect the fast_loop to execute faster.
345 // (2) slow_loop: By default, it is not taken, until a runtime-check is added to the multiversion_if while
346 // optimizing the fast_looop. If such a runtime-check is never added, then after loop-opts
347 // the multiversion_if constant folds to true, and the slow_loop is folded away. To save
348 // compile time, we delay the optimization of the slow_loop until a runtime-check is added
349 // to the multiversion_if, at which point we resume optimizations for the slow_loop.
350 // We call it the "slow_loop" because it has fewer optimizations, since this is the fall-back
351 // loop where we do not make any of the speculative assumptions we make for the fast_loop.
352 // Hence, we expect the slow_loop to execute slower.
353 bool is_multiversion() const { return (_loop_flags & MultiversionFlagsMask) != Normal; }
354 bool is_multiversion_fast_loop() const { return (_loop_flags & MultiversionFlagsMask) == MultiversionFastLoop; }
355 bool is_multiversion_slow_loop() const { return (_loop_flags & MultiversionFlagsMask) == MultiversionSlowLoop; }
356 bool is_multiversion_delayed_slow_loop() const { return (_loop_flags & MultiversionFlagsMask) == MultiversionDelayedSlowLoop; }
357 void set_multiversion_fast_loop() { assert(!is_multiversion(), ""); _loop_flags |= MultiversionFastLoop; }
358 void set_multiversion_slow_loop() { assert(!is_multiversion(), ""); _loop_flags |= MultiversionSlowLoop; }
359 void set_multiversion_delayed_slow_loop() { assert(!is_multiversion(), ""); _loop_flags |= MultiversionDelayedSlowLoop; }
360 void set_no_multiversion() { assert( is_multiversion(), ""); _loop_flags &= ~MultiversionFlagsMask; }
361
362 virtual LoopNode* skip_strip_mined(int expect_skeleton = 1);
363 OuterStripMinedLoopNode* outer_loop() const;
364 virtual IfTrueNode* outer_loop_tail() const;
365 virtual OuterStripMinedLoopEndNode* outer_loop_end() const;
366 virtual IfFalseNode* outer_loop_exit() const;
367 virtual SafePointNode* outer_safepoint() const;
368
369 Node* skip_assertion_predicates_with_halt();
370
371 virtual BasicType bt() const {
372 return T_INT;
373 }
374
375 Node* is_canonical_loop_entry();
376 CountedLoopEndNode* find_pre_loop_end();
377
378 Node* uncasted_init_trip(bool uncasted);
379
380 #ifndef PRODUCT
381 virtual void dump_spec(outputStream *st) const;
382 #endif
383 };
384
385 class LongCountedLoopNode : public BaseCountedLoopNode {
386 public:
387 LongCountedLoopNode(Node *entry, Node *backedge)
388 : BaseCountedLoopNode(entry, backedge) {
389 init_class_id(Class_LongCountedLoop);
390 }
391
392 virtual int Opcode() const;
393
394 virtual BasicType bt() const {
395 return T_LONG;
396 }
397
398 LongCountedLoopEndNode* loopexit_or_null() const { return (LongCountedLoopEndNode*) BaseCountedLoopNode::loopexit_or_null(); }
399 LongCountedLoopEndNode* loopexit() const { return (LongCountedLoopEndNode*) BaseCountedLoopNode::loopexit(); }
400 };
401
402
403 //------------------------------CountedLoopEndNode-----------------------------
404 // CountedLoopEndNodes end simple trip counted loops. They act much like
405 // IfNodes.
406
407 class BaseCountedLoopEndNode : public IfNode {
408 public:
409 enum { TestControl, TestValue };
410 BaseCountedLoopEndNode(Node *control, Node *test, float prob, float cnt)
411 : IfNode(control, test, prob, cnt) {
412 init_class_id(Class_BaseCountedLoopEnd);
413 }
414
415 Node *cmp_node() const { return (in(TestValue)->req() >=2) ? in(TestValue)->in(1) : nullptr; }
416 Node* incr() const { Node* tmp = cmp_node(); return (tmp && tmp->req() == 3) ? tmp->in(1) : nullptr; }
417 Node* limit() const { Node* tmp = cmp_node(); return (tmp && tmp->req() == 3) ? tmp->in(2) : nullptr; }
418 Node* stride() const { Node* tmp = incr(); return (tmp && tmp->req() == 3) ? tmp->in(2) : nullptr; }
419 Node* init_trip() const { Node* tmp = phi(); return (tmp && tmp->req() == 3) ? tmp->in(1) : nullptr; }
420 bool stride_is_con() const { Node *tmp = stride(); return (tmp != nullptr && tmp->is_Con()); }
421
422 PhiNode* phi() const {
423 Node* tmp = incr();
424 if (tmp && tmp->req() == 3) {
425 Node* phi = tmp->in(1);
426 if (phi->is_Phi()) {
427 return phi->as_Phi();
428 }
429 }
430 return nullptr;
431 }
432
433 BaseCountedLoopNode* loopnode() const {
434 // The CountedLoopNode that goes with this CountedLoopEndNode may
435 // have been optimized out by the IGVN so be cautious with the
436 // pattern matching on the graph
437 PhiNode* iv_phi = phi();
438 if (iv_phi == nullptr) {
439 return nullptr;
440 }
441 Node* ln = iv_phi->in(0);
442 if (!ln->is_BaseCountedLoop() || ln->as_BaseCountedLoop()->loopexit_or_null() != this) {
443 return nullptr;
444 }
445 if (ln->as_BaseCountedLoop()->bt() != bt()) {
446 return nullptr;
447 }
448 return ln->as_BaseCountedLoop();
449 }
450
451 BoolTest::mask test_trip() const { return in(TestValue)->as_Bool()->_test._test; }
452
453 jlong stride_con() const;
454 virtual BasicType bt() const = 0;
455
456 static BaseCountedLoopEndNode* make(Node* control, Node* test, float prob, float cnt, BasicType bt);
457 };
458
459 class CountedLoopEndNode : public BaseCountedLoopEndNode {
460 public:
461
462 CountedLoopEndNode(Node *control, Node *test, float prob, float cnt)
463 : BaseCountedLoopEndNode(control, test, prob, cnt) {
464 init_class_id(Class_CountedLoopEnd);
465 }
466 virtual int Opcode() const;
467
468 CountedLoopNode* loopnode() const {
469 return (CountedLoopNode*) BaseCountedLoopEndNode::loopnode();
470 }
471
472 virtual BasicType bt() const {
473 return T_INT;
474 }
475
476 #ifndef PRODUCT
477 virtual void dump_spec(outputStream *st) const;
478 #endif
479 };
480
481 class LongCountedLoopEndNode : public BaseCountedLoopEndNode {
482 public:
483 LongCountedLoopEndNode(Node *control, Node *test, float prob, float cnt)
484 : BaseCountedLoopEndNode(control, test, prob, cnt) {
485 init_class_id(Class_LongCountedLoopEnd);
486 }
487
488 LongCountedLoopNode* loopnode() const {
489 return (LongCountedLoopNode*) BaseCountedLoopEndNode::loopnode();
490 }
491
492 virtual int Opcode() const;
493
494 virtual BasicType bt() const {
495 return T_LONG;
496 }
497 };
498
499
500 inline BaseCountedLoopEndNode* BaseCountedLoopNode::loopexit_or_null() const {
501 Node* bctrl = back_control();
502 if (bctrl == nullptr) return nullptr;
503
504 Node* lexit = bctrl->in(0);
505 if (!lexit->is_BaseCountedLoopEnd()) {
506 return nullptr;
507 }
508 BaseCountedLoopEndNode* result = lexit->as_BaseCountedLoopEnd();
509 if (result->bt() != bt()) {
510 return nullptr;
511 }
512 return result;
513 }
514
515 inline BaseCountedLoopEndNode* BaseCountedLoopNode::loopexit() const {
516 BaseCountedLoopEndNode* cle = loopexit_or_null();
517 assert(cle != nullptr, "loopexit is null");
518 return cle;
519 }
520
521 inline Node* BaseCountedLoopNode::init_trip() const {
522 BaseCountedLoopEndNode* cle = loopexit_or_null();
523 return cle != nullptr ? cle->init_trip() : nullptr;
524 }
525 inline Node* BaseCountedLoopNode::stride() const {
526 BaseCountedLoopEndNode* cle = loopexit_or_null();
527 return cle != nullptr ? cle->stride() : nullptr;
528 }
529
530 inline bool BaseCountedLoopNode::stride_is_con() const {
531 BaseCountedLoopEndNode* cle = loopexit_or_null();
532 return cle != nullptr && cle->stride_is_con();
533 }
534 inline Node* BaseCountedLoopNode::limit() const {
535 BaseCountedLoopEndNode* cle = loopexit_or_null();
536 return cle != nullptr ? cle->limit() : nullptr;
537 }
538 inline Node* BaseCountedLoopNode::incr() const {
539 BaseCountedLoopEndNode* cle = loopexit_or_null();
540 return cle != nullptr ? cle->incr() : nullptr;
541 }
542 inline Node* BaseCountedLoopNode::phi() const {
543 BaseCountedLoopEndNode* cle = loopexit_or_null();
544 return cle != nullptr ? cle->phi() : nullptr;
545 }
546
547 inline jlong BaseCountedLoopNode::stride_con() const {
548 BaseCountedLoopEndNode* cle = loopexit_or_null();
549 return cle != nullptr ? cle->stride_con() : 0;
550 }
551
552
553 //------------------------------LoopLimitNode-----------------------------
554 // Counted Loop limit node which represents exact final iterator value:
555 // trip_count = (limit - init_trip + stride - 1)/stride
556 // final_value= trip_count * stride + init_trip.
557 // Use HW instructions to calculate it when it can overflow in integer.
558 // Note, final_value should fit into integer since counted loop has
559 // limit check: limit <= max_int-stride.
560 class LoopLimitNode : public Node {
561 enum { Init=1, Limit=2, Stride=3 };
562 public:
563 LoopLimitNode( Compile* C, Node *init, Node *limit, Node *stride ) : Node(nullptr,init,limit,stride) {
564 // Put it on the Macro nodes list to optimize during macro nodes expansion.
565 init_flags(Flag_is_macro);
566 C->add_macro_node(this);
567 }
568 virtual int Opcode() const;
569 virtual const Type *bottom_type() const { return TypeInt::INT; }
570 virtual uint ideal_reg() const { return Op_RegI; }
571 virtual const Type* Value(PhaseGVN* phase) const;
572 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
573 virtual Node* Identity(PhaseGVN* phase);
574 };
575
576 // Support for strip mining
577 class OuterStripMinedLoopNode : public LoopNode {
578 private:
579 void fix_sunk_stores_when_back_to_counted_loop(PhaseIterGVN* igvn, PhaseIdealLoop* iloop) const;
580 void handle_sunk_stores_when_finishing_construction(PhaseIterGVN* igvn);
581
582 public:
583 OuterStripMinedLoopNode(Compile* C, Node *entry, Node *backedge)
584 : LoopNode(entry, backedge) {
585 init_class_id(Class_OuterStripMinedLoop);
586 init_flags(Flag_is_macro);
587 C->add_macro_node(this);
588 }
589
590 virtual int Opcode() const;
591
592 virtual IfTrueNode* outer_loop_tail() const;
593 virtual OuterStripMinedLoopEndNode* outer_loop_end() const;
594 virtual IfFalseNode* outer_loop_exit() const;
595 virtual SafePointNode* outer_safepoint() const;
596 CountedLoopNode* inner_counted_loop() const { return unique_ctrl_out()->as_CountedLoop(); }
597 CountedLoopEndNode* inner_counted_loop_end() const { return inner_counted_loop()->loopexit(); }
598 IfFalseNode* inner_loop_exit() const { return inner_counted_loop_end()->proj_out(false)->as_IfFalse(); }
599
600 void adjust_strip_mined_loop(PhaseIterGVN* igvn);
601
602 void remove_outer_loop_and_safepoint(PhaseIterGVN* igvn) const;
603
604 void transform_to_counted_loop(PhaseIterGVN* igvn, PhaseIdealLoop* iloop);
605
606 static Node* register_new_node(Node* node, LoopNode* ctrl, PhaseIterGVN* igvn, PhaseIdealLoop* iloop);
607
608 Node* register_control(Node* node, Node* loop, Node* idom, PhaseIterGVN* igvn,
609 PhaseIdealLoop* iloop);
610 };
611
612 class OuterStripMinedLoopEndNode : public IfNode {
613 public:
614 OuterStripMinedLoopEndNode(Node *control, Node *test, float prob, float cnt)
615 : IfNode(control, test, prob, cnt) {
616 init_class_id(Class_OuterStripMinedLoopEnd);
617 }
618
619 virtual int Opcode() const;
620
621 virtual const Type* Value(PhaseGVN* phase) const;
622 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
623
624 bool is_expanded(PhaseGVN *phase) const;
625 };
626
627 // -----------------------------IdealLoopTree----------------------------------
628 class IdealLoopTree : public ResourceObj {
629 public:
630 IdealLoopTree *_parent; // Parent in loop tree
631 IdealLoopTree *_next; // Next sibling in loop tree
632 IdealLoopTree *_child; // First child in loop tree
633
634 // The head-tail backedge defines the loop.
635 // If a loop has multiple backedges, this is addressed during cleanup where
636 // we peel off the multiple backedges, merging all edges at the bottom and
637 // ensuring that one proper backedge flow into the loop.
638 Node *_head; // Head of loop
639 Node *_tail; // Tail of loop
640 inline Node *tail(); // Handle lazy update of _tail field
641 inline Node *head(); // Handle lazy update of _head field
642 PhaseIdealLoop* _phase;
643 int _local_loop_unroll_limit;
644 int _local_loop_unroll_factor;
645
646 Node_List _body; // Loop body for inner loops
647
648 uint16_t _nest; // Nesting depth
649 uint8_t _irreducible:1, // True if irreducible
650 _has_call:1, // True if has call safepoint
651 _has_sfpt:1, // True if has non-call safepoint
652 _rce_candidate:1, // True if candidate for range check elimination
653 _has_range_checks:1,
654 _has_range_checks_computed:1;
655
656 Node_List* _safepts; // List of safepoints in this loop
657 Node_List* _required_safept; // A inner loop cannot delete these safepts;
658 bool _allow_optimizations; // Allow loop optimizations
659
660 IdealLoopTree( PhaseIdealLoop* phase, Node *head, Node *tail )
661 : _parent(nullptr), _next(nullptr), _child(nullptr),
662 _head(head), _tail(tail),
663 _phase(phase),
664 _local_loop_unroll_limit(0), _local_loop_unroll_factor(0),
665 _body(Compile::current()->comp_arena()),
666 _nest(0), _irreducible(0), _has_call(0), _has_sfpt(0), _rce_candidate(0),
667 _has_range_checks(0), _has_range_checks_computed(0),
668 _safepts(nullptr),
669 _required_safept(nullptr),
670 _allow_optimizations(true)
671 {
672 precond(_head != nullptr);
673 precond(_tail != nullptr);
674 }
675
676 // Is 'l' a member of 'this'?
677 bool is_member(const IdealLoopTree *l) const; // Test for nested membership
678
679 // Set loop nesting depth. Accumulate has_call bits.
680 int set_nest( uint depth );
681
682 // Split out multiple fall-in edges from the loop header. Move them to a
683 // private RegionNode before the loop. This becomes the loop landing pad.
684 void split_fall_in( PhaseIdealLoop *phase, int fall_in_cnt );
685
686 // Split out the outermost loop from this shared header.
687 void split_outer_loop( PhaseIdealLoop *phase );
688
689 // Merge all the backedges from the shared header into a private Region.
690 // Feed that region as the one backedge to this loop.
691 void merge_many_backedges( PhaseIdealLoop *phase );
692
693 // Split shared headers and insert loop landing pads.
694 // Insert a LoopNode to replace the RegionNode.
695 // Returns TRUE if loop tree is structurally changed.
696 bool beautify_loops( PhaseIdealLoop *phase );
697
698 // Perform optimization to use the loop predicates for null checks and range checks.
699 // Applies to any loop level (not just the innermost one)
700 bool loop_predication( PhaseIdealLoop *phase);
701 bool can_apply_loop_predication();
702
703 // Perform iteration-splitting on inner loops. Split iterations to
704 // avoid range checks or one-shot null checks. Returns false if the
705 // current round of loop opts should stop.
706 bool iteration_split( PhaseIdealLoop *phase, Node_List &old_new );
707
708 // Driver for various flavors of iteration splitting. Returns false
709 // if the current round of loop opts should stop.
710 bool iteration_split_impl( PhaseIdealLoop *phase, Node_List &old_new );
711
712 // Given dominators, try to find loops with calls that must always be
713 // executed (call dominates loop tail). These loops do not need non-call
714 // safepoints (ncsfpt).
715 void check_safepts(VectorSet &visited, Node_List &stack);
716
717 // Allpaths backwards scan from loop tail, terminating each path at first safepoint
718 // encountered.
719 void allpaths_check_safepts(VectorSet &visited, Node_List &stack);
720
721 // Remove safepoints from loop. Optionally keeping one.
722 void remove_safepoints(PhaseIdealLoop* phase, bool keep_one);
723
724 // Convert to counted loops where possible
725 void counted_loop( PhaseIdealLoop *phase );
726
727 // Check for Node being a loop-breaking test
728 Node *is_loop_exit(Node *iff) const;
729
730 // Remove simplistic dead code from loop body
731 void DCE_loop_body();
732
733 // Look for loop-exit tests with my 50/50 guesses from the Parsing stage.
734 // Replace with a 1-in-10 exit guess.
735 void adjust_loop_exit_prob( PhaseIdealLoop *phase );
736
737 // Return TRUE or FALSE if the loop should never be RCE'd or aligned.
738 // Useful for unrolling loops with NO array accesses.
739 bool policy_peel_only( PhaseIdealLoop *phase ) const;
740
741 // Return TRUE or FALSE if the loop should be unswitched -- clone
742 // loop with an invariant test
743 bool policy_unswitching( PhaseIdealLoop *phase ) const;
744 bool no_unswitch_candidate() const;
745
746 // Micro-benchmark spamming. Remove empty loops.
747 bool do_remove_empty_loop( PhaseIdealLoop *phase );
748
749 // Convert one iteration loop into normal code.
750 bool do_one_iteration_loop( PhaseIdealLoop *phase );
751
752 // Return TRUE or FALSE if the loop should be peeled or not. Peel if we can
753 // move some loop-invariant test (usually a null-check) before the loop.
754 bool policy_peeling(PhaseIdealLoop *phase);
755
756 uint estimate_peeling(PhaseIdealLoop *phase);
757
758 // Return TRUE or FALSE if the loop should be maximally unrolled. Stash any
759 // known trip count in the counted loop node.
760 bool policy_maximally_unroll(PhaseIdealLoop *phase) const;
761
762 // Return TRUE or FALSE if the loop should be unrolled or not. Apply unroll
763 // if the loop is a counted loop and the loop body is small enough.
764 bool policy_unroll(PhaseIdealLoop *phase);
765
766 // Loop analyses to map to a maximal superword unrolling for vectorization.
767 void policy_unroll_slp_analysis(CountedLoopNode *cl, PhaseIdealLoop *phase, int future_unroll_ct);
768
769 // Return TRUE or FALSE if the loop should be range-check-eliminated.
770 // Gather a list of IF tests that are dominated by iteration splitting;
771 // also gather the end of the first split and the start of the 2nd split.
772 bool policy_range_check(PhaseIdealLoop* phase, bool provisional, BasicType bt) const;
773
774 // Return TRUE if "iff" is a range check.
775 bool is_range_check_if(IfProjNode* if_success_proj, PhaseIdealLoop* phase, Invariance& invar DEBUG_ONLY(COMMA ProjNode* predicate_proj)) const;
776 bool is_range_check_if(IfProjNode* if_success_proj, PhaseIdealLoop* phase, BasicType bt, Node* iv, Node*& range, Node*& offset,
777 jlong& scale) const;
778
779 // Estimate the number of nodes required when cloning a loop (body).
780 uint est_loop_clone_sz(uint factor) const;
781 // Estimate the number of nodes required when unrolling a loop (body).
782 uint est_loop_unroll_sz(uint factor) const;
783
784 // Compute loop trip count if possible
785 void compute_trip_count(PhaseIdealLoop* phase);
786
787 // Compute loop trip count from profile data
788 float compute_profile_trip_cnt_helper(Node* n);
789 void compute_profile_trip_cnt( PhaseIdealLoop *phase );
790
791 // Reassociate invariant expressions.
792 void reassociate_invariants(PhaseIdealLoop *phase);
793 // Reassociate invariant binary expressions.
794 Node* reassociate(Node* n1, PhaseIdealLoop *phase);
795 // Reassociate invariant add, subtract, and compare expressions.
796 Node* reassociate_add_sub_cmp(Node* n1, int inv1_idx, int inv2_idx, PhaseIdealLoop* phase);
797 // Return nonzero index of invariant operand if invariant and variant
798 // are combined with an associative binary. Helper for reassociate_invariants.
799 int find_invariant(Node* n, PhaseIdealLoop *phase);
800 // Return TRUE if "n" is associative.
801 bool is_associative(Node* n, Node* base=nullptr);
802 // Return TRUE if "n" is an associative cmp node.
803 bool is_associative_cmp(Node* n);
804
805 // Return true if n is invariant
806 bool is_invariant(Node* n) const;
807
808 // Put loop body on igvn work list
809 void record_for_igvn();
810
811 bool is_root() { return _parent == nullptr; }
812 // A proper/reducible loop w/o any (occasional) dead back-edge.
813 bool is_loop() { return !_irreducible && !tail()->is_top(); }
814 bool is_counted() { return is_loop() && _head->is_CountedLoop(); }
815 bool is_innermost() { return is_loop() && _child == nullptr; }
816
817 void remove_main_post_loops(CountedLoopNode *cl, PhaseIdealLoop *phase);
818
819 bool compute_has_range_checks() const;
820 bool range_checks_present() {
821 if (!_has_range_checks_computed) {
822 if (compute_has_range_checks()) {
823 _has_range_checks = 1;
824 }
825 _has_range_checks_computed = 1;
826 }
827 return _has_range_checks;
828 }
829
830 // Return the parent's IdealLoopTree for a strip mined loop which is the outer strip mined loop.
831 // In all other cases, return this.
832 IdealLoopTree* skip_strip_mined() {
833 return _head->as_Loop()->is_strip_mined() ? _parent : this;
834 }
835
836 #ifndef PRODUCT
837 void dump_head(); // Dump loop head only
838 void dump(); // Dump this loop recursively
839 #endif
840
841 #ifdef ASSERT
842 GrowableArray<IdealLoopTree*> collect_sorted_children() const;
843 bool verify_tree(IdealLoopTree* loop_verify) const;
844 #endif
845
846 private:
847 enum { EMPTY_LOOP_SIZE = 7 }; // Number of nodes in an empty loop.
848
849 // Estimate the number of nodes resulting from control and data flow merge.
850 uint est_loop_flow_merge_sz() const;
851
852 // Check if the number of residual iterations is large with unroll_cnt.
853 // Return true if the residual iterations are more than 10% of the trip count.
854 bool is_residual_iters_large(int unroll_cnt, CountedLoopNode *cl) const {
855 return (unroll_cnt - 1) * (100.0 / LoopPercentProfileLimit) > cl->profile_trip_cnt();
856 }
857
858 void collect_loop_core_nodes(PhaseIdealLoop* phase, Unique_Node_List& wq) const;
859
860 bool empty_loop_with_data_nodes(PhaseIdealLoop* phase) const;
861
862 void enqueue_data_nodes(PhaseIdealLoop* phase, Unique_Node_List& empty_loop_nodes, Unique_Node_List& wq) const;
863
864 bool process_safepoint(PhaseIdealLoop* phase, Unique_Node_List& empty_loop_nodes, Unique_Node_List& wq,
865 Node* sfpt) const;
866
867 bool empty_loop_candidate(PhaseIdealLoop* phase) const;
868
869 bool empty_loop_with_extra_nodes_candidate(PhaseIdealLoop* phase) const;
870 };
871
872 // -----------------------------PhaseIdealLoop---------------------------------
873 // Computes the mapping from Nodes to IdealLoopTrees. Organizes IdealLoopTrees
874 // into a loop tree. Drives the loop-based transformations on the ideal graph.
875 class PhaseIdealLoop : public PhaseTransform {
876 friend class IdealLoopTree;
877 friend class SuperWord;
878 friend class ShenandoahBarrierC2Support;
879 friend class AutoNodeBudget;
880
881 // Map loop membership for CFG nodes, and ctrl for non-CFG nodes.
882 Node_List _loop_or_ctrl;
883
884 // Pre-computed def-use info
885 PhaseIterGVN &_igvn;
886
887 // Head of loop tree
888 IdealLoopTree* _ltree_root;
889
890 // Array of pre-order numbers, plus post-visited bit.
891 // ZERO for not pre-visited. EVEN for pre-visited but not post-visited.
892 // ODD for post-visited. Other bits are the pre-order number.
893 uint *_preorders;
894 uint _max_preorder;
895
896 ReallocMark _nesting; // Safety checks for arena reallocation
897
898 const PhaseIdealLoop* _verify_me;
899 bool _verify_only;
900
901 // Allocate _preorders[] array
902 void allocate_preorders() {
903 _max_preorder = C->unique()+8;
904 _preorders = NEW_RESOURCE_ARRAY(uint, _max_preorder);
905 memset(_preorders, 0, sizeof(uint) * _max_preorder);
906 }
907
908 // Allocate _preorders[] array
909 void reallocate_preorders() {
910 _nesting.check(); // Check if a potential re-allocation in the resource arena is safe
911 if ( _max_preorder < C->unique() ) {
912 _preorders = REALLOC_RESOURCE_ARRAY(uint, _preorders, _max_preorder, C->unique());
913 _max_preorder = C->unique();
914 }
915 memset(_preorders, 0, sizeof(uint) * _max_preorder);
916 }
917
918 // Check to grow _preorders[] array for the case when build_loop_tree_impl()
919 // adds new nodes.
920 void check_grow_preorders( ) {
921 _nesting.check(); // Check if a potential re-allocation in the resource arena is safe
922 if ( _max_preorder < C->unique() ) {
923 uint newsize = _max_preorder<<1; // double size of array
924 _preorders = REALLOC_RESOURCE_ARRAY(uint, _preorders, _max_preorder, newsize);
925 memset(&_preorders[_max_preorder],0,sizeof(uint)*(newsize-_max_preorder));
926 _max_preorder = newsize;
927 }
928 }
929 // Check for pre-visited. Zero for NOT visited; non-zero for visited.
930 int is_visited( Node *n ) const { return _preorders[n->_idx]; }
931 // Pre-order numbers are written to the Nodes array as low-bit-set values.
932 void set_preorder_visited( Node *n, int pre_order ) {
933 assert( !is_visited( n ), "already set" );
934 _preorders[n->_idx] = (pre_order<<1);
935 };
936 // Return pre-order number.
937 int get_preorder( Node *n ) const { assert( is_visited(n), "" ); return _preorders[n->_idx]>>1; }
938
939 // Check for being post-visited.
940 // Should be previsited already (checked with assert(is_visited(n))).
941 int is_postvisited( Node *n ) const { assert( is_visited(n), "" ); return _preorders[n->_idx]&1; }
942
943 // Mark as post visited
944 void set_postvisited( Node *n ) { assert( !is_postvisited( n ), "" ); _preorders[n->_idx] |= 1; }
945
946 public:
947 // Set/get control node out. Set lower bit to distinguish from IdealLoopTree
948 // Returns true if "n" is a data node, false if it's a control node.
949 bool has_ctrl(const Node* n) const { return ((intptr_t)_loop_or_ctrl[n->_idx]) & 1; }
950
951 private:
952 // clear out dead code after build_loop_late
953 Node_List _deadlist;
954 Node_List _zero_trip_guard_opaque_nodes;
955 Node_List _multiversion_opaque_nodes;
956
957 // Support for faster execution of get_late_ctrl()/dom_lca()
958 // when a node has many uses and dominator depth is deep.
959 GrowableArray<jlong> _dom_lca_tags;
960 uint _dom_lca_tags_round;
961 void init_dom_lca_tags();
962
963 // Helper for debugging bad dominance relationships
964 bool verify_dominance(Node* n, Node* use, Node* LCA, Node* early);
965
966 Node* compute_lca_of_uses(Node* n, Node* early, bool verify = false);
967
968 // Inline wrapper for frequent cases:
969 // 1) only one use
970 // 2) a use is the same as the current LCA passed as 'n1'
971 Node *dom_lca_for_get_late_ctrl( Node *lca, Node *n, Node *tag ) {
972 assert( n->is_CFG(), "" );
973 // Fast-path null lca
974 if( lca != nullptr && lca != n ) {
975 assert( lca->is_CFG(), "" );
976 // find LCA of all uses
977 n = dom_lca_for_get_late_ctrl_internal( lca, n, tag );
978 }
979 return find_non_split_ctrl(n);
980 }
981 Node *dom_lca_for_get_late_ctrl_internal( Node *lca, Node *n, Node *tag );
982
983 // Helper function for directing control inputs away from CFG split points.
984 Node *find_non_split_ctrl( Node *ctrl ) const {
985 if (ctrl != nullptr) {
986 if (ctrl->is_MultiBranch()) {
987 ctrl = ctrl->in(0);
988 }
989 assert(ctrl->is_CFG(), "CFG");
990 }
991 return ctrl;
992 }
993
994 void cast_incr_before_loop(Node* incr, Node* ctrl, CountedLoopNode* loop);
995
996 #ifdef ASSERT
997 static void ensure_zero_trip_guard_proj(Node* node, bool is_main_loop);
998 #endif
999 private:
1000 static void get_opaque_template_assertion_predicate_nodes(ParsePredicateSuccessProj* parse_predicate_proj,
1001 Unique_Node_List& list);
1002 void update_main_loop_assertion_predicates(CountedLoopNode* new_main_loop_head, int stride_con_before_unroll);
1003 void initialize_assertion_predicates_for_peeled_loop(CountedLoopNode* peeled_loop_head,
1004 CountedLoopNode* remaining_loop_head,
1005 uint first_node_index_in_cloned_loop_body,
1006 const Node_List& old_new);
1007 void initialize_assertion_predicates_for_main_loop(CountedLoopNode* pre_loop_head,
1008 CountedLoopNode* main_loop_head,
1009 uint first_node_index_in_pre_loop_body,
1010 uint last_node_index_in_pre_loop_body,
1011 DEBUG_ONLY(uint last_node_index_from_backedge_goo COMMA)
1012 const Node_List& old_new);
1013 void initialize_assertion_predicates_for_post_loop(CountedLoopNode* main_loop_head, CountedLoopNode* post_loop_head,
1014 uint first_node_index_in_cloned_loop_body);
1015 void create_assertion_predicates_at_loop(CountedLoopNode* source_loop_head, CountedLoopNode* target_loop_head,
1016 const NodeInLoopBody& _node_in_loop_body, bool kill_old_template);
1017 void create_assertion_predicates_at_main_or_post_loop(CountedLoopNode* source_loop_head,
1018 CountedLoopNode* target_loop_head,
1019 const NodeInLoopBody& _node_in_loop_body,
1020 bool kill_old_template);
1021 void rewire_old_target_loop_entry_dependency_to_new_entry(CountedLoopNode* target_loop_head,
1022 const Node* old_target_loop_entry,
1023 uint node_index_before_new_assertion_predicate_nodes);
1024 void insert_loop_limit_check_predicate(ParsePredicateSuccessProj* loop_limit_check_parse_proj, Node* cmp_limit,
1025 Node* bol);
1026 void log_loop_tree();
1027
1028 public:
1029
1030 PhaseIterGVN &igvn() const { return _igvn; }
1031
1032 bool has_node(const Node* n) const {
1033 guarantee(n != nullptr, "No Node.");
1034 return _loop_or_ctrl[n->_idx] != nullptr;
1035 }
1036 // check if transform created new nodes that need _ctrl recorded
1037 Node *get_late_ctrl( Node *n, Node *early );
1038 Node *get_early_ctrl( Node *n );
1039 Node *get_early_ctrl_for_expensive(Node *n, Node* earliest);
1040 void set_early_ctrl(Node* n, bool update_body);
1041 void set_subtree_ctrl(Node* n, bool update_body);
1042 void set_ctrl( Node *n, Node *ctrl ) {
1043 assert( !has_node(n) || has_ctrl(n), "" );
1044 assert( ctrl->in(0), "cannot set dead control node" );
1045 assert( ctrl == find_non_split_ctrl(ctrl), "must set legal crtl" );
1046 _loop_or_ctrl.map(n->_idx, (Node*)((intptr_t)ctrl + 1));
1047 }
1048 void set_root_as_ctrl(Node* n) {
1049 assert(!has_node(n) || has_ctrl(n), "");
1050 _loop_or_ctrl.map(n->_idx, (Node*)((intptr_t)C->root() + 1));
1051 }
1052 // Set control and update loop membership
1053 void set_ctrl_and_loop(Node* n, Node* ctrl) {
1054 IdealLoopTree* old_loop = get_loop(get_ctrl(n));
1055 IdealLoopTree* new_loop = get_loop(ctrl);
1056 if (old_loop != new_loop) {
1057 if (old_loop->_child == nullptr) old_loop->_body.yank(n);
1058 if (new_loop->_child == nullptr) new_loop->_body.push(n);
1059 }
1060 set_ctrl(n, ctrl);
1061 }
1062 // Control nodes can be replaced or subsumed. During this pass they
1063 // get their replacement Node in slot 1. Instead of updating the block
1064 // location of all Nodes in the subsumed block, we lazily do it. As we
1065 // pull such a subsumed block out of the array, we write back the final
1066 // correct block.
1067 Node* get_ctrl(const Node* i) {
1068 assert(has_node(i), "");
1069 Node *n = get_ctrl_no_update(i);
1070 _loop_or_ctrl.map(i->_idx, (Node*)((intptr_t)n + 1));
1071 assert(has_node(i) && has_ctrl(i), "");
1072 assert(n == find_non_split_ctrl(n), "must return legal ctrl" );
1073 return n;
1074 }
1075
1076 bool is_dominator(Node* dominator, Node* n);
1077 bool is_strict_dominator(Node* dominator, Node* n);
1078
1079 // return get_ctrl for a data node and self(n) for a CFG node
1080 Node* ctrl_or_self(Node* n) {
1081 if (has_ctrl(n))
1082 return get_ctrl(n);
1083 else {
1084 assert (n->is_CFG(), "must be a CFG node");
1085 return n;
1086 }
1087 }
1088
1089 Node* get_ctrl_no_update_helper(const Node* i) const {
1090 assert(has_ctrl(i), "should be control, not loop");
1091 return (Node*)(((intptr_t)_loop_or_ctrl[i->_idx]) & ~1);
1092 }
1093
1094 Node* get_ctrl_no_update(const Node* i) const {
1095 assert( has_ctrl(i), "" );
1096 Node *n = get_ctrl_no_update_helper(i);
1097 if (!n->in(0)) {
1098 // Skip dead CFG nodes
1099 do {
1100 n = get_ctrl_no_update_helper(n);
1101 } while (!n->in(0));
1102 n = find_non_split_ctrl(n);
1103 }
1104 return n;
1105 }
1106
1107 // Check for loop being set
1108 // "n" must be a control node. Returns true if "n" is known to be in a loop.
1109 bool has_loop( Node *n ) const {
1110 assert(!has_node(n) || !has_ctrl(n), "");
1111 return has_node(n);
1112 }
1113 // Set loop
1114 void set_loop( Node *n, IdealLoopTree *loop ) {
1115 _loop_or_ctrl.map(n->_idx, (Node*)loop);
1116 }
1117 // Lazy-dazy update of 'get_ctrl' and 'idom_at' mechanisms. Replace
1118 // the 'old_node' with 'new_node'. Kill old-node. Add a reference
1119 // from old_node to new_node to support the lazy update. Reference
1120 // replaces loop reference, since that is not needed for dead node.
1121 void lazy_update(Node *old_node, Node *new_node) {
1122 assert(old_node != new_node, "no cycles please");
1123 // Re-use the side array slot for this node to provide the
1124 // forwarding pointer.
1125 _loop_or_ctrl.map(old_node->_idx, (Node*)((intptr_t)new_node + 1));
1126 }
1127 void lazy_replace(Node *old_node, Node *new_node) {
1128 _igvn.replace_node(old_node, new_node);
1129 lazy_update(old_node, new_node);
1130 }
1131
1132 private:
1133
1134 // Place 'n' in some loop nest, where 'n' is a CFG node
1135 void build_loop_tree();
1136 int build_loop_tree_impl(Node* n, int pre_order);
1137 // Insert loop into the existing loop tree. 'innermost' is a leaf of the
1138 // loop tree, not the root.
1139 IdealLoopTree *sort( IdealLoopTree *loop, IdealLoopTree *innermost );
1140
1141 #ifdef ASSERT
1142 // verify that regions in irreducible loops are marked is_in_irreducible_loop
1143 void verify_regions_in_irreducible_loops();
1144 bool is_in_irreducible_loop(RegionNode* region);
1145 #endif
1146
1147 // Place Data nodes in some loop nest
1148 void build_loop_early( VectorSet &visited, Node_List &worklist, Node_Stack &nstack );
1149 void build_loop_late ( VectorSet &visited, Node_List &worklist, Node_Stack &nstack );
1150 void build_loop_late_post_work(Node* n, bool pinned);
1151 void build_loop_late_post(Node* n);
1152 void verify_strip_mined_scheduling(Node *n, Node* least);
1153
1154 // Array of immediate dominance info for each CFG node indexed by node idx
1155 private:
1156 uint _idom_size;
1157 Node **_idom; // Array of immediate dominators
1158 uint *_dom_depth; // Used for fast LCA test
1159 GrowableArray<uint>* _dom_stk; // For recomputation of dom depth
1160 LoopOptsMode _mode;
1161
1162 // build the loop tree and perform any requested optimizations
1163 void build_and_optimize();
1164
1165 // Dominators for the sea of nodes
1166 void Dominators();
1167
1168 // Compute the Ideal Node to Loop mapping
1169 PhaseIdealLoop(PhaseIterGVN& igvn, LoopOptsMode mode) :
1170 PhaseTransform(Ideal_Loop),
1171 _loop_or_ctrl(igvn.C->comp_arena()),
1172 _igvn(igvn),
1173 _verify_me(nullptr),
1174 _verify_only(false),
1175 _mode(mode),
1176 _nodes_required(UINT_MAX) {
1177 assert(mode != LoopOptsVerify, "wrong constructor to verify IdealLoop");
1178 build_and_optimize();
1179 }
1180
1181 #ifndef PRODUCT
1182 // Verify that verify_me made the same decisions as a fresh run
1183 // or only verify that the graph is valid if verify_me is null.
1184 PhaseIdealLoop(PhaseIterGVN& igvn, const PhaseIdealLoop* verify_me = nullptr) :
1185 PhaseTransform(Ideal_Loop),
1186 _loop_or_ctrl(igvn.C->comp_arena()),
1187 _igvn(igvn),
1188 _verify_me(verify_me),
1189 _verify_only(verify_me == nullptr),
1190 _mode(LoopOptsVerify),
1191 _nodes_required(UINT_MAX) {
1192 DEBUG_ONLY(C->set_phase_verify_ideal_loop();)
1193 build_and_optimize();
1194 DEBUG_ONLY(C->reset_phase_verify_ideal_loop();)
1195 }
1196 #endif
1197
1198 Node* insert_convert_node_if_needed(BasicType target, Node* input);
1199
1200 public:
1201 Node* idom_no_update(Node* d) const {
1202 return idom_no_update(d->_idx);
1203 }
1204
1205 Node* idom_no_update(uint didx) const {
1206 assert(didx < _idom_size, "oob");
1207 Node* n = _idom[didx];
1208 assert(n != nullptr,"Bad immediate dominator info.");
1209 while (n->in(0) == nullptr) { // Skip dead CFG nodes
1210 n = (Node*)(((intptr_t)_loop_or_ctrl[n->_idx]) & ~1);
1211 assert(n != nullptr,"Bad immediate dominator info.");
1212 }
1213 return n;
1214 }
1215
1216 Node *idom(Node* d) const {
1217 return idom(d->_idx);
1218 }
1219
1220 Node *idom(uint didx) const {
1221 Node *n = idom_no_update(didx);
1222 _idom[didx] = n; // Lazily remove dead CFG nodes from table.
1223 return n;
1224 }
1225
1226 uint dom_depth(Node* d) const {
1227 guarantee(d != nullptr, "Null dominator info.");
1228 guarantee(d->_idx < _idom_size, "");
1229 return _dom_depth[d->_idx];
1230 }
1231 void set_idom(Node* d, Node* n, uint dom_depth);
1232 // Locally compute IDOM using dom_lca call
1233 Node *compute_idom( Node *region ) const;
1234 // Recompute dom_depth
1235 void recompute_dom_depth();
1236
1237 // Is safept not required by an outer loop?
1238 bool is_deleteable_safept(Node* sfpt);
1239
1240 // Replace parallel induction variable (parallel to trip counter)
1241 void replace_parallel_iv(IdealLoopTree *loop);
1242
1243 Node *dom_lca( Node *n1, Node *n2 ) const {
1244 return find_non_split_ctrl(dom_lca_internal(n1, n2));
1245 }
1246 Node *dom_lca_internal( Node *n1, Node *n2 ) const;
1247
1248 Node* dominated_node(Node* c1, Node* c2) {
1249 assert(is_dominator(c1, c2) || is_dominator(c2, c1), "nodes must be related");
1250 return is_dominator(c1, c2) ? c2 : c1;
1251 }
1252
1253 // Return control node that's dominated by the 2 others
1254 Node* dominated_node(Node* c1, Node* c2, Node* c3) {
1255 return dominated_node(c1, dominated_node(c2, c3));
1256 }
1257
1258 // Build and verify the loop tree without modifying the graph. This
1259 // is useful to verify that all inputs properly dominate their uses.
1260 static void verify(PhaseIterGVN& igvn) {
1261 #ifdef ASSERT
1262 ResourceMark rm;
1263 Compile::TracePhase tp(_t_idealLoopVerify);
1264 PhaseIdealLoop v(igvn);
1265 #endif
1266 }
1267
1268 // Recommended way to use PhaseIdealLoop.
1269 // Run PhaseIdealLoop in some mode and allocates a local scope for memory allocations.
1270 static void optimize(PhaseIterGVN &igvn, LoopOptsMode mode) {
1271 ResourceMark rm;
1272 PhaseIdealLoop v(igvn, mode);
1273
1274 Compile* C = Compile::current();
1275 if (!C->failing()) {
1276 // Cleanup any modified bits
1277 igvn.optimize();
1278 if (C->failing()) { return; }
1279 v.log_loop_tree();
1280 }
1281 }
1282
1283 // True if the method has at least 1 irreducible loop
1284 bool _has_irreducible_loops;
1285
1286 // Per-Node transform
1287 virtual Node* transform(Node* n) { return nullptr; }
1288
1289 Node* loop_exit_control(Node* x, IdealLoopTree* loop);
1290 Node* loop_exit_test(Node* back_control, IdealLoopTree* loop, Node*& incr, Node*& limit, BoolTest::mask& bt, float& cl_prob);
1291 Node* loop_iv_incr(Node* incr, Node* x, IdealLoopTree* loop, Node*& phi_incr);
1292 Node* loop_iv_stride(Node* incr, Node*& xphi);
1293 PhiNode* loop_iv_phi(Node* xphi, Node* phi_incr, Node* x);
1294
1295 bool is_counted_loop(Node* x, IdealLoopTree*&loop, BasicType iv_bt);
1296
1297 Node* loop_nest_replace_iv(Node* iv_to_replace, Node* inner_iv, Node* outer_phi, Node* inner_head, BasicType bt);
1298 bool create_loop_nest(IdealLoopTree* loop, Node_List &old_new);
1299 #ifdef ASSERT
1300 bool convert_to_long_loop(Node* cmp, Node* phi, IdealLoopTree* loop);
1301 #endif
1302 void add_parse_predicate(Deoptimization::DeoptReason reason, Node* inner_head, IdealLoopTree* loop, SafePointNode* sfpt);
1303 SafePointNode* find_safepoint(Node* back_control, Node* x, IdealLoopTree* loop);
1304 IdealLoopTree* insert_outer_loop(IdealLoopTree* loop, LoopNode* outer_l, Node* outer_ift);
1305 IdealLoopTree* create_outer_strip_mined_loop(Node* init_control,
1306 IdealLoopTree* loop, float cl_prob, float le_fcnt,
1307 Node*& entry_control, Node*& iffalse);
1308
1309 Node* exact_limit( IdealLoopTree *loop );
1310
1311 // Return a post-walked LoopNode
1312 IdealLoopTree *get_loop( Node *n ) const {
1313 // Dead nodes have no loop, so return the top level loop instead
1314 if (!has_node(n)) return _ltree_root;
1315 assert(!has_ctrl(n), "");
1316 return (IdealLoopTree*)_loop_or_ctrl[n->_idx];
1317 }
1318
1319 IdealLoopTree* ltree_root() const { return _ltree_root; }
1320
1321 // Is 'n' a (nested) member of 'loop'?
1322 int is_member( const IdealLoopTree *loop, Node *n ) const {
1323 return loop->is_member(get_loop(n)); }
1324
1325 // This is the basic building block of the loop optimizations. It clones an
1326 // entire loop body. It makes an old_new loop body mapping; with this
1327 // mapping you can find the new-loop equivalent to an old-loop node. All
1328 // new-loop nodes are exactly equal to their old-loop counterparts, all
1329 // edges are the same. All exits from the old-loop now have a RegionNode
1330 // that merges the equivalent new-loop path. This is true even for the
1331 // normal "loop-exit" condition. All uses of loop-invariant old-loop values
1332 // now come from (one or more) Phis that merge their new-loop equivalents.
1333 // Parameter side_by_side_idom:
1334 // When side_by_size_idom is null, the dominator tree is constructed for
1335 // the clone loop to dominate the original. Used in construction of
1336 // pre-main-post loop sequence.
1337 // When nonnull, the clone and original are side-by-side, both are
1338 // dominated by the passed in side_by_side_idom node. Used in
1339 // construction of unswitched loops.
1340 enum CloneLoopMode {
1341 IgnoreStripMined = 0, // Only clone inner strip mined loop
1342 CloneIncludesStripMined = 1, // clone both inner and outer strip mined loops
1343 ControlAroundStripMined = 2 // Only clone inner strip mined loop,
1344 // result control flow branches
1345 // either to inner clone or outer
1346 // strip mined loop.
1347 };
1348 void clone_loop( IdealLoopTree *loop, Node_List &old_new, int dom_depth,
1349 CloneLoopMode mode, Node* side_by_side_idom = nullptr);
1350 void clone_loop_handle_data_uses(Node* old, Node_List &old_new,
1351 IdealLoopTree* loop, IdealLoopTree* companion_loop,
1352 Node_List*& split_if_set, Node_List*& split_bool_set,
1353 Node_List*& split_cex_set, Node_List& worklist,
1354 uint new_counter, CloneLoopMode mode);
1355 void clone_outer_loop(LoopNode* head, CloneLoopMode mode, IdealLoopTree *loop,
1356 IdealLoopTree* outer_loop, int dd, Node_List &old_new,
1357 Node_List& extra_data_nodes);
1358
1359 // If we got the effect of peeling, either by actually peeling or by
1360 // making a pre-loop which must execute at least once, we can remove
1361 // all loop-invariant dominated tests in the main body.
1362 void peeled_dom_test_elim( IdealLoopTree *loop, Node_List &old_new );
1363
1364 // Generate code to do a loop peel for the given loop (and body).
1365 // old_new is a temp array.
1366 void do_peeling( IdealLoopTree *loop, Node_List &old_new );
1367
1368 // Add pre and post loops around the given loop. These loops are used
1369 // during RCE, unrolling and aligning loops.
1370 void insert_pre_post_loops( IdealLoopTree *loop, Node_List &old_new, bool peel_only );
1371
1372 // Add post loop after the given loop.
1373 Node *insert_post_loop(IdealLoopTree* loop, Node_List& old_new,
1374 CountedLoopNode* main_head, CountedLoopEndNode* main_end,
1375 Node* incr, Node* limit, CountedLoopNode*& post_head);
1376
1377 // Add a vector post loop between a vector main loop and the current post loop
1378 void insert_vector_post_loop(IdealLoopTree *loop, Node_List &old_new);
1379 // If Node n lives in the back_ctrl block, we clone a private version of n
1380 // in preheader_ctrl block and return that, otherwise return n.
1381 Node *clone_up_backedge_goo( Node *back_ctrl, Node *preheader_ctrl, Node *n, VectorSet &visited, Node_Stack &clones );
1382
1383 // Take steps to maximally unroll the loop. Peel any odd iterations, then
1384 // unroll to do double iterations. The next round of major loop transforms
1385 // will repeat till the doubled loop body does all remaining iterations in 1
1386 // pass.
1387 void do_maximally_unroll( IdealLoopTree *loop, Node_List &old_new );
1388
1389 // Unroll the loop body one step - make each trip do 2 iterations.
1390 void do_unroll( IdealLoopTree *loop, Node_List &old_new, bool adjust_min_trip );
1391
1392 // Return true if exp is a constant times an induction var
1393 bool is_scaled_iv(Node* exp, Node* iv, BasicType bt, jlong* p_scale, bool* p_short_scale, int depth = 0);
1394
1395 bool is_iv(Node* exp, Node* iv, BasicType bt);
1396
1397 // Return true if exp is a scaled induction var plus (or minus) constant
1398 bool is_scaled_iv_plus_offset(Node* exp, Node* iv, BasicType bt, jlong* p_scale, Node** p_offset, bool* p_short_scale = nullptr, int depth = 0);
1399 bool is_scaled_iv_plus_offset(Node* exp, Node* iv, int* p_scale, Node** p_offset) {
1400 jlong long_scale;
1401 if (is_scaled_iv_plus_offset(exp, iv, T_INT, &long_scale, p_offset)) {
1402 int int_scale = checked_cast<int>(long_scale);
1403 if (p_scale != nullptr) {
1404 *p_scale = int_scale;
1405 }
1406 return true;
1407 }
1408 return false;
1409 }
1410 // Helper for finding more complex matches to is_scaled_iv_plus_offset.
1411 bool is_scaled_iv_plus_extra_offset(Node* exp1, Node* offset2, Node* iv,
1412 BasicType bt,
1413 jlong* p_scale, Node** p_offset,
1414 bool* p_short_scale, int depth);
1415
1416 // Create a new if above the uncommon_trap_if_pattern for the predicate to be promoted
1417 IfTrueNode* create_new_if_for_predicate(const ParsePredicateSuccessProj* parse_predicate_proj, Node* new_entry,
1418 Deoptimization::DeoptReason reason, int opcode,
1419 bool rewire_uncommon_proj_phi_inputs = false);
1420
1421 private:
1422 // Helper functions for create_new_if_for_predicate()
1423 void set_ctrl_of_nodes_with_same_ctrl(Node* start_node, ProjNode* old_uncommon_proj, Node* new_uncommon_proj);
1424 Unique_Node_List find_nodes_with_same_ctrl(Node* node, const ProjNode* ctrl);
1425 Node* clone_nodes_with_same_ctrl(Node* start_node, ProjNode* old_uncommon_proj, Node* new_uncommon_proj);
1426 void fix_cloned_data_node_controls(const ProjNode* orig, Node* new_uncommon_proj,
1427 const OrigToNewHashtable& orig_to_clone);
1428 bool has_dominating_loop_limit_check(Node* init_trip, Node* limit, jlong stride_con, BasicType iv_bt,
1429 Node* loop_entry);
1430
1431 public:
1432 void register_control(Node* n, IdealLoopTree *loop, Node* pred, bool update_body = true);
1433
1434 // Replace the control input of 'node' with 'new_control' and set the dom depth to the one of 'new_control'.
1435 void replace_control(Node* node, Node* new_control) {
1436 _igvn.replace_input_of(node, 0, new_control);
1437 set_idom(node, new_control, dom_depth(new_control));
1438 }
1439
1440 void replace_loop_entry(LoopNode* loop_head, Node* new_entry) {
1441 _igvn.replace_input_of(loop_head, LoopNode::EntryControl, new_entry);
1442 set_idom(loop_head, new_entry, dom_depth(new_entry));
1443 }
1444
1445 // Construct a range check for a predicate if
1446 BoolNode* rc_predicate(Node* ctrl, int scale, Node* offset, Node* init, Node* limit,
1447 jint stride, Node* range, bool upper, bool& overflow);
1448
1449 // Implementation of the loop predication to promote checks outside the loop
1450 bool loop_predication_impl(IdealLoopTree *loop);
1451
1452 private:
1453 bool loop_predication_impl_helper(IdealLoopTree* loop, IfProjNode* if_success_proj,
1454 ParsePredicateSuccessProj* parse_predicate_proj, CountedLoopNode* cl, ConNode* zero,
1455 Invariance& invar, Deoptimization::DeoptReason deopt_reason);
1456 bool can_create_loop_predicates(const PredicateBlock* profiled_loop_predicate_block) const;
1457 bool loop_predication_should_follow_branches(IdealLoopTree* loop, float& loop_trip_cnt);
1458 void loop_predication_follow_branches(Node *c, IdealLoopTree *loop, float loop_trip_cnt,
1459 PathFrequency& pf, Node_Stack& stack, VectorSet& seen,
1460 Node_List& if_proj_list);
1461 IfTrueNode* create_template_assertion_predicate(CountedLoopNode* loop_head, ParsePredicateNode* parse_predicate,
1462 IfProjNode* new_control, int scale, Node* offset, Node* range);
1463 void eliminate_hoisted_range_check(IfTrueNode* hoisted_check_proj, IfTrueNode* template_assertion_predicate_proj);
1464
1465 // Helper function to collect predicate for eliminating the useless ones
1466 void eliminate_useless_predicates() const;
1467
1468 void eliminate_useless_zero_trip_guard();
1469 void eliminate_useless_multiversion_if();
1470
1471 public:
1472 // Change the control input of expensive nodes to allow commoning by
1473 // IGVN when it is guaranteed to not result in a more frequent
1474 // execution of the expensive node. Return true if progress.
1475 bool process_expensive_nodes();
1476
1477 // Check whether node has become unreachable
1478 bool is_node_unreachable(Node *n) const {
1479 return !has_node(n) || n->is_unreachable(_igvn);
1480 }
1481
1482 // Eliminate range-checks and other trip-counter vs loop-invariant tests.
1483 void do_range_check(IdealLoopTree* loop);
1484
1485 // Clone loop with an invariant test (that does not exit) and
1486 // insert a clone of the test that selects which version to
1487 // execute.
1488 void do_unswitching(IdealLoopTree* loop, Node_List& old_new);
1489
1490 IfNode* find_unswitch_candidates(const IdealLoopTree* loop, Node_List& flat_array_checks) const;
1491 IfNode* find_unswitch_candidate_from_idoms(const IdealLoopTree* loop) const;
1492
1493 private:
1494 static bool has_control_dependencies_from_predicates(LoopNode* head);
1495 static void revert_to_normal_loop(const LoopNode* loop_head);
1496
1497 void hoist_invariant_check_casts(const IdealLoopTree* loop, const Node_List& old_new,
1498 const UnswitchCandidate& unswitch_candidate, const IfNode* loop_selector);
1499 void add_unswitched_loop_version_bodies_to_igvn(IdealLoopTree* loop, const Node_List& old_new);
1500 static void increment_unswitch_counts(LoopNode* original_head, LoopNode* new_head);
1501 void remove_unswitch_candidate_from_loops(const Node_List& old_new, const UnswitchedLoopSelector& unswitched_loop_selector);
1502 #ifndef PRODUCT
1503 static void trace_loop_unswitching_count(IdealLoopTree* loop, LoopNode* original_head);
1504 static void trace_loop_unswitching_impossible(const LoopNode* original_head);
1505 static void trace_loop_unswitching_result(const UnswitchedLoopSelector& unswitched_loop_selector,
1506 const UnswitchCandidate& unswitch_candidate,
1507 const LoopNode* original_head, const LoopNode* new_head);
1508 static void trace_loop_multiversioning_result(const LoopSelector& loop_selector,
1509 const LoopNode* original_head, const LoopNode* new_head);
1510 #endif
1511
1512 public:
1513
1514 // Range Check Elimination uses this function!
1515 // Constrain the main loop iterations so the affine function:
1516 // low_limit <= scale_con * I + offset < upper_limit
1517 // always holds true. That is, either increase the number of iterations in
1518 // the pre-loop or the post-loop until the condition holds true in the main
1519 // loop. Scale_con, offset and limit are all loop invariant.
1520 void add_constraint(jlong stride_con, jlong scale_con, Node* offset, Node* low_limit, Node* upper_limit, Node* pre_ctrl, Node** pre_limit, Node** main_limit);
1521 // Helper function for add_constraint().
1522 Node* adjust_limit(bool reduce, Node* scale, Node* offset, Node* rc_limit, Node* old_limit, Node* pre_ctrl, bool round);
1523
1524 // Partially peel loop up through last_peel node.
1525 bool partial_peel( IdealLoopTree *loop, Node_List &old_new );
1526 bool duplicate_loop_backedge(IdealLoopTree *loop, Node_List &old_new);
1527
1528 // AutoVectorize the loop: replace scalar ops with vector ops.
1529 enum AutoVectorizeStatus {
1530 Impossible, // This loop has the wrong shape to even try vectorization.
1531 Success, // We just successfully vectorized the loop.
1532 TriedAndFailed, // We tried to vectorize, but failed.
1533 };
1534 AutoVectorizeStatus auto_vectorize(IdealLoopTree* lpt, VSharedData &vshared);
1535
1536 void maybe_multiversion_for_auto_vectorization_runtime_checks(IdealLoopTree* lpt, Node_List& old_new);
1537 void do_multiversioning(IdealLoopTree* lpt, Node_List& old_new);
1538 IfTrueNode* create_new_if_for_multiversion(IfTrueNode* multiversioning_fast_proj);
1539 bool try_resume_optimizations_for_delayed_slow_loop(IdealLoopTree* lpt);
1540
1541 // Move an unordered Reduction out of loop if possible
1542 void move_unordered_reduction_out_of_loop(IdealLoopTree* loop);
1543
1544 // Create a scheduled list of nodes control dependent on ctrl set.
1545 void scheduled_nodelist( IdealLoopTree *loop, VectorSet& ctrl, Node_List &sched );
1546 // Has a use in the vector set
1547 bool has_use_in_set( Node* n, VectorSet& vset );
1548 // Has use internal to the vector set (ie. not in a phi at the loop head)
1549 bool has_use_internal_to_set( Node* n, VectorSet& vset, IdealLoopTree *loop );
1550 // clone "n" for uses that are outside of loop
1551 int clone_for_use_outside_loop( IdealLoopTree *loop, Node* n, Node_List& worklist );
1552 // clone "n" for special uses that are in the not_peeled region
1553 void clone_for_special_use_inside_loop( IdealLoopTree *loop, Node* n,
1554 VectorSet& not_peel, Node_List& sink_list, Node_List& worklist );
1555 // Insert phi(lp_entry_val, back_edge_val) at use->in(idx) for loop lp if phi does not already exist
1556 void insert_phi_for_loop( Node* use, uint idx, Node* lp_entry_val, Node* back_edge_val, LoopNode* lp );
1557 #ifdef ASSERT
1558 // Validate the loop partition sets: peel and not_peel
1559 bool is_valid_loop_partition( IdealLoopTree *loop, VectorSet& peel, Node_List& peel_list, VectorSet& not_peel );
1560 // Ensure that uses outside of loop are of the right form
1561 bool is_valid_clone_loop_form( IdealLoopTree *loop, Node_List& peel_list,
1562 uint orig_exit_idx, uint clone_exit_idx);
1563 bool is_valid_clone_loop_exit_use( IdealLoopTree *loop, Node* use, uint exit_idx);
1564 #endif
1565
1566 // Returns nonzero constant stride if-node is a possible iv test (otherwise returns zero.)
1567 int stride_of_possible_iv( Node* iff );
1568 bool is_possible_iv_test( Node* iff ) { return stride_of_possible_iv(iff) != 0; }
1569 // Return the (unique) control output node that's in the loop (if it exists.)
1570 Node* stay_in_loop( Node* n, IdealLoopTree *loop);
1571 // Insert a signed compare loop exit cloned from an unsigned compare.
1572 IfNode* insert_cmpi_loop_exit(IfNode* if_cmpu, IdealLoopTree *loop);
1573 void remove_cmpi_loop_exit(IfNode* if_cmp, IdealLoopTree *loop);
1574 // Utility to register node "n" with PhaseIdealLoop
1575 void register_node(Node* n, IdealLoopTree* loop, Node* pred, uint ddepth);
1576 // Utility to create an if-projection
1577 ProjNode* proj_clone(ProjNode* p, IfNode* iff);
1578 // Force the iff control output to be the live_proj
1579 Node* short_circuit_if(IfNode* iff, ProjNode* live_proj);
1580 // Insert a region before an if projection
1581 RegionNode* insert_region_before_proj(ProjNode* proj);
1582 // Insert a new if before an if projection
1583 ProjNode* insert_if_before_proj(Node* left, bool Signed, BoolTest::mask relop, Node* right, ProjNode* proj);
1584
1585 // Passed in a Phi merging (recursively) some nearly equivalent Bool/Cmps.
1586 // "Nearly" because all Nodes have been cloned from the original in the loop,
1587 // but the fall-in edges to the Cmp are different. Clone bool/Cmp pairs
1588 // through the Phi recursively, and return a Bool.
1589 Node* clone_iff(PhiNode* phi);
1590 CmpNode* clone_bool(PhiNode* phi);
1591
1592
1593 // Rework addressing expressions to get the most loop-invariant stuff
1594 // moved out. We'd like to do all associative operators, but it's especially
1595 // important (common) to do address expressions.
1596 Node* remix_address_expressions(Node* n);
1597 Node* remix_address_expressions_add_left_shift(Node* n, IdealLoopTree* n_loop, Node* n_ctrl, BasicType bt);
1598
1599 // Convert add to muladd to generate MuladdS2I under certain criteria
1600 Node * convert_add_to_muladd(Node * n);
1601
1602 // Attempt to use a conditional move instead of a phi/branch
1603 Node *conditional_move( Node *n );
1604
1605 // Check for aggressive application of 'split-if' optimization,
1606 // using basic block level info.
1607 void split_if_with_blocks ( VectorSet &visited, Node_Stack &nstack);
1608 Node *split_if_with_blocks_pre ( Node *n );
1609 void split_if_with_blocks_post( Node *n );
1610 Node *has_local_phi_input( Node *n );
1611 // Mark an IfNode as being dominated by a prior test,
1612 // without actually altering the CFG (and hence IDOM info).
1613 void dominated_by(IfProjNode* prevdom, IfNode* iff, bool flip = false, bool pin_array_access_nodes = false);
1614 void rewire_safe_outputs_to_dominator(Node* source, Node* dominator, bool pin_array_access_nodes);
1615
1616 // Split Node 'n' through merge point
1617 RegionNode* split_thru_region(Node* n, RegionNode* region);
1618 // Split Node 'n' through merge point if there is enough win.
1619 Node *split_thru_phi( Node *n, Node *region, int policy );
1620 // Found an If getting its condition-code input from a Phi in the
1621 // same block. Split thru the Region.
1622 void do_split_if(Node *iff, RegionNode** new_false_region = nullptr, RegionNode** new_true_region = nullptr);
1623
1624 // Conversion of fill/copy patterns into intrinsic versions
1625 bool do_intrinsify_fill();
1626 bool intrinsify_fill(IdealLoopTree* lpt);
1627 bool match_fill_loop(IdealLoopTree* lpt, Node*& store, Node*& store_value,
1628 Node*& shift, Node*& offset);
1629
1630 private:
1631 // Return a type based on condition control flow
1632 const TypeInt* filtered_type( Node *n, Node* n_ctrl);
1633 const TypeInt* filtered_type( Node *n ) { return filtered_type(n, nullptr); }
1634 // Helpers for filtered type
1635 const TypeInt* filtered_type_from_dominators( Node* val, Node *val_ctrl);
1636
1637 // Helper functions
1638 Node *spinup( Node *iff, Node *new_false, Node *new_true, Node *region, Node *phi, small_cache *cache );
1639 Node *find_use_block( Node *use, Node *def, Node *old_false, Node *new_false, Node *old_true, Node *new_true );
1640 void handle_use( Node *use, Node *def, small_cache *cache, Node *region_dom, Node *new_false, Node *new_true, Node *old_false, Node *old_true );
1641 bool split_up( Node *n, Node *blk1, Node *blk2 );
1642
1643 Node* place_outside_loop(Node* useblock, IdealLoopTree* loop) const;
1644 Node* try_move_store_before_loop(Node* n, Node *n_ctrl);
1645 void try_move_store_after_loop(Node* n);
1646 void move_flat_array_check_out_of_loop(Node* n);
1647 bool identical_backtoback_ifs(Node *n);
1648 bool flat_array_element_type_check(Node *n);
1649 bool can_split_if(Node *n_ctrl);
1650 bool cannot_split_division(const Node* n, const Node* region) const;
1651 static bool is_divisor_loop_phi(const Node* divisor, const Node* loop);
1652 bool loop_phi_backedge_type_contains_zero(const Node* phi_divisor, const Type* zero) const;
1653
1654 // Determine if a method is too big for a/another round of split-if, based on
1655 // a magic (approximate) ratio derived from the equally magic constant 35000,
1656 // previously used for this purpose (but without relating to the node limit).
1657 bool must_throttle_split_if() {
1658 uint threshold = C->max_node_limit() * 2 / 5;
1659 return C->live_nodes() > threshold;
1660 }
1661
1662 // A simplistic node request tracking mechanism, where
1663 // = UINT_MAX Request not valid or made final.
1664 // < UINT_MAX Nodes currently requested (estimate).
1665 uint _nodes_required;
1666
1667 enum { REQUIRE_MIN = 70 };
1668
1669 uint nodes_required() const { return _nodes_required; }
1670
1671 // Given the _currently_ available number of nodes, check whether there is
1672 // "room" for an additional request or not, considering the already required
1673 // number of nodes. Return TRUE if the new request is exceeding the node
1674 // budget limit, otherwise return FALSE. Note that this interpretation will
1675 // act pessimistic on additional requests when new nodes have already been
1676 // generated since the 'begin'. This behaviour fits with the intention that
1677 // node estimates/requests should be made upfront.
1678 bool exceeding_node_budget(uint required = 0) {
1679 assert(C->live_nodes() < C->max_node_limit(), "sanity");
1680 uint available = C->max_node_limit() - C->live_nodes();
1681 return available < required + _nodes_required + REQUIRE_MIN;
1682 }
1683
1684 uint require_nodes(uint require, uint minreq = REQUIRE_MIN) {
1685 precond(require > 0);
1686 _nodes_required += MAX2(require, minreq);
1687 return _nodes_required;
1688 }
1689
1690 bool may_require_nodes(uint require, uint minreq = REQUIRE_MIN) {
1691 return !exceeding_node_budget(require) && require_nodes(require, minreq) > 0;
1692 }
1693
1694 uint require_nodes_begin() {
1695 assert(_nodes_required == UINT_MAX, "Bad state (begin).");
1696 _nodes_required = 0;
1697 return C->live_nodes();
1698 }
1699
1700 // When a node request is final, optionally check that the requested number
1701 // of nodes was reasonably correct with respect to the number of new nodes
1702 // introduced since the last 'begin'. Always check that we have not exceeded
1703 // the maximum node limit.
1704 void require_nodes_final(uint live_at_begin, bool check_estimate) {
1705 assert(_nodes_required < UINT_MAX, "Bad state (final).");
1706
1707 #ifdef ASSERT
1708 if (check_estimate) {
1709 // Check that the node budget request was not off by too much (x2).
1710 // Should this be the case we _surely_ need to improve the estimates
1711 // used in our budget calculations.
1712 if (C->live_nodes() - live_at_begin > 2 * _nodes_required) {
1713 log_info(compilation)("Bad node estimate: actual = %d >> request = %d",
1714 C->live_nodes() - live_at_begin, _nodes_required);
1715 }
1716 }
1717 #endif
1718 // Assert that we have stayed within the node budget limit.
1719 assert(C->live_nodes() < C->max_node_limit(),
1720 "Exceeding node budget limit: %d + %d > %d (request = %d)",
1721 C->live_nodes() - live_at_begin, live_at_begin,
1722 C->max_node_limit(), _nodes_required);
1723
1724 _nodes_required = UINT_MAX;
1725 }
1726
1727 private:
1728
1729 bool _created_loop_node;
1730 DEBUG_ONLY(void dump_idoms(Node* early, Node* wrong_lca);)
1731 NOT_PRODUCT(void dump_idoms_in_reverse(const Node* n, const Node_List& idom_list) const;)
1732
1733 public:
1734 void set_created_loop_node() { _created_loop_node = true; }
1735 bool created_loop_node() { return _created_loop_node; }
1736 void register_new_node(Node* n, Node* blk);
1737 void register_new_node_with_ctrl_of(Node* new_node, Node* ctrl_of) {
1738 register_new_node(new_node, get_ctrl(ctrl_of));
1739 }
1740
1741 Node* clone_and_register(Node* n, Node* ctrl) {
1742 n = n->clone();
1743 register_new_node(n, ctrl);
1744 return n;
1745 }
1746
1747 #ifdef ASSERT
1748 void dump_bad_graph(const char* msg, Node* n, Node* early, Node* LCA);
1749 #endif
1750
1751 #ifndef PRODUCT
1752 void dump() const;
1753 void dump_idom(Node* n) const { dump_idom(n, 1000); } // For debugging
1754 void dump_idom(Node* n, uint count) const;
1755 void get_idoms(Node* n, uint count, Unique_Node_List& idoms) const;
1756 void dump(IdealLoopTree* loop, uint rpo_idx, Node_List &rpo_list) const;
1757 IdealLoopTree* get_loop_idx(Node* n) const {
1758 // Dead nodes have no loop, so return the top level loop instead
1759 return _loop_or_ctrl[n->_idx] ? (IdealLoopTree*)_loop_or_ctrl[n->_idx] : _ltree_root;
1760 }
1761 // Print some stats
1762 static void print_statistics();
1763 static int _loop_invokes; // Count of PhaseIdealLoop invokes
1764 static int _loop_work; // Sum of PhaseIdealLoop x _unique
1765 static volatile int _long_loop_candidates;
1766 static volatile int _long_loop_nests;
1767 static volatile int _long_loop_counted_loops;
1768 #endif
1769
1770 #ifdef ASSERT
1771 void verify() const;
1772 bool verify_idom_and_nodes(Node* root, const PhaseIdealLoop* phase_verify) const;
1773 bool verify_idom(Node* n, const PhaseIdealLoop* phase_verify) const;
1774 bool verify_loop_ctrl(Node* n, const PhaseIdealLoop* phase_verify) const;
1775 #endif
1776
1777 void rpo(Node* start, Node_Stack &stk, VectorSet &visited, Node_List &rpo_list) const;
1778
1779 void check_counted_loop_shape(IdealLoopTree* loop, Node* x, BasicType bt) NOT_DEBUG_RETURN;
1780
1781 LoopNode* create_inner_head(IdealLoopTree* loop, BaseCountedLoopNode* head, IfNode* exit_test);
1782
1783
1784 int extract_long_range_checks(const IdealLoopTree* loop, jint stride_con, int iters_limit, PhiNode* phi,
1785 Node_List &range_checks);
1786
1787 void transform_long_range_checks(int stride_con, const Node_List &range_checks, Node* outer_phi,
1788 Node* inner_iters_actual_int, Node* inner_phi,
1789 Node* iv_add, LoopNode* inner_head);
1790
1791 Node* get_late_ctrl_with_anti_dep(LoadNode* n, Node* early, Node* LCA);
1792
1793 bool ctrl_of_use_out_of_loop(const Node* n, Node* n_ctrl, IdealLoopTree* n_loop, Node* ctrl);
1794
1795 bool ctrl_of_all_uses_out_of_loop(const Node* n, Node* n_ctrl, IdealLoopTree* n_loop);
1796
1797 Node* compute_early_ctrl(Node* n, Node* n_ctrl);
1798
1799 void try_sink_out_of_loop(Node* n);
1800
1801 Node* clamp(Node* R, Node* L, Node* H);
1802
1803 bool safe_for_if_replacement(const Node* dom) const;
1804
1805 void push_pinned_nodes_thru_region(IfNode* dom_if, Node* region);
1806
1807 bool try_merge_identical_ifs(Node* n);
1808
1809 void clone_loop_body(const Node_List& body, Node_List &old_new, CloneMap* cm);
1810
1811 void fix_body_edges(const Node_List &body, IdealLoopTree* loop, const Node_List &old_new, int dd,
1812 IdealLoopTree* parent, bool partial);
1813
1814 void fix_ctrl_uses(const Node_List& body, const IdealLoopTree* loop, Node_List &old_new, CloneLoopMode mode,
1815 Node* side_by_side_idom, CloneMap* cm, Node_List &worklist);
1816
1817 void fix_data_uses(Node_List& body, IdealLoopTree* loop, CloneLoopMode mode, IdealLoopTree* outer_loop,
1818 uint new_counter, Node_List& old_new, Node_List& worklist, Node_List*& split_if_set,
1819 Node_List*& split_bool_set, Node_List*& split_cex_set);
1820
1821 void finish_clone_loop(Node_List* split_if_set, Node_List* split_bool_set, Node_List* split_cex_set);
1822
1823 bool at_relevant_ctrl(Node* n, const Node* blk1, const Node* blk2);
1824
1825 bool clone_cmp_loadklass_down(Node* n, const Node* blk1, const Node* blk2);
1826 void clone_loadklass_nodes_at_cmp_index(const Node* n, Node* cmp, int i);
1827 bool clone_cmp_down(Node* n, const Node* blk1, const Node* blk2);
1828 void clone_template_assertion_expression_down(Node* node);
1829
1830 Node* similar_subtype_check(const Node* x, Node* r_in);
1831
1832 void update_addp_chain_base(Node* x, Node* old_base, Node* new_base);
1833
1834 bool can_move_to_inner_loop(Node* n, LoopNode* n_loop, Node* x);
1835
1836 void pin_array_access_nodes_dependent_on(Node* ctrl);
1837
1838 void collect_flat_array_checks(const IdealLoopTree* loop, Node_List& flat_array_checks) const;
1839
1840 Node* ensure_node_and_inputs_are_above_pre_end(CountedLoopEndNode* pre_end, Node* node);
1841
1842 ConINode* intcon(jint i);
1843
1844 ConLNode* longcon(jlong i);
1845
1846 ConNode* makecon(const Type* t);
1847
1848 ConNode* integercon(jlong l, BasicType bt);
1849
1850 ConNode* zerocon(BasicType bt);
1851 };
1852
1853
1854 class AutoNodeBudget : public StackObj
1855 {
1856 public:
1857 enum budget_check_t { BUDGET_CHECK, NO_BUDGET_CHECK };
1858
1859 AutoNodeBudget(PhaseIdealLoop* phase, budget_check_t chk = BUDGET_CHECK)
1860 : _phase(phase),
1861 _check_at_final(chk == BUDGET_CHECK),
1862 _nodes_at_begin(0)
1863 {
1864 precond(_phase != nullptr);
1865
1866 _nodes_at_begin = _phase->require_nodes_begin();
1867 }
1868
1869 ~AutoNodeBudget() {
1870 #ifndef PRODUCT
1871 if (TraceLoopOpts) {
1872 uint request = _phase->nodes_required();
1873 uint delta = _phase->C->live_nodes() - _nodes_at_begin;
1874
1875 if (request < delta) {
1876 tty->print_cr("Exceeding node budget: %d < %d", request, delta);
1877 } else {
1878 uint const REQUIRE_MIN = PhaseIdealLoop::REQUIRE_MIN;
1879 // Identify the worst estimates as "poor" ones.
1880 if (request > REQUIRE_MIN && delta > 0) {
1881 if ((delta > REQUIRE_MIN && request > 3 * delta) ||
1882 (delta <= REQUIRE_MIN && request > 10 * delta)) {
1883 tty->print_cr("Poor node estimate: %d >> %d", request, delta);
1884 }
1885 }
1886 }
1887 }
1888 #endif // PRODUCT
1889 _phase->require_nodes_final(_nodes_at_begin, _check_at_final);
1890 }
1891
1892 private:
1893 PhaseIdealLoop* _phase;
1894 bool _check_at_final;
1895 uint _nodes_at_begin;
1896 };
1897
1898 inline Node* IdealLoopTree::tail() {
1899 // Handle lazy update of _tail field.
1900 if (_tail->in(0) == nullptr) {
1901 _tail = _phase->get_ctrl(_tail);
1902 }
1903 return _tail;
1904 }
1905
1906 inline Node* IdealLoopTree::head() {
1907 // Handle lazy update of _head field.
1908 if (_head->in(0) == nullptr) {
1909 _head = _phase->get_ctrl(_head);
1910 }
1911 return _head;
1912 }
1913
1914 // Iterate over the loop tree using a preorder, left-to-right traversal.
1915 //
1916 // Example that visits all counted loops from within PhaseIdealLoop
1917 //
1918 // for (LoopTreeIterator iter(_ltree_root); !iter.done(); iter.next()) {
1919 // IdealLoopTree* lpt = iter.current();
1920 // if (!lpt->is_counted()) continue;
1921 // ...
1922 class LoopTreeIterator : public StackObj {
1923 private:
1924 IdealLoopTree* _root;
1925 IdealLoopTree* _curnt;
1926
1927 public:
1928 LoopTreeIterator(IdealLoopTree* root) : _root(root), _curnt(root) {}
1929
1930 bool done() { return _curnt == nullptr; } // Finished iterating?
1931
1932 void next(); // Advance to next loop tree
1933
1934 IdealLoopTree* current() { return _curnt; } // Return current value of iterator.
1935 };
1936
1937 // Compute probability of reaching some CFG node from a fixed
1938 // dominating CFG node
1939 class PathFrequency {
1940 private:
1941 Node* _dom; // frequencies are computed relative to this node
1942 Node_Stack _stack;
1943 GrowableArray<float> _freqs_stack; // keep track of intermediate result at regions
1944 GrowableArray<float> _freqs; // cache frequencies
1945 PhaseIdealLoop* _phase;
1946
1947 float check_and_truncate_frequency(float f) {
1948 assert(f >= 0, "Incorrect frequency");
1949 // We do not perform an exact (f <= 1) check
1950 // this would be error prone with rounding of floats.
1951 // Performing a check like (f <= 1+eps) would be of benefit,
1952 // however, it is not evident how to determine such an eps,
1953 // given that an arbitrary number of add/mul operations
1954 // are performed on these frequencies.
1955 return (f > 1) ? 1 : f;
1956 }
1957
1958 public:
1959 PathFrequency(Node* dom, PhaseIdealLoop* phase)
1960 : _dom(dom), _stack(0), _phase(phase) {
1961 }
1962
1963 float to(Node* n);
1964 };
1965
1966 // Class to clone a data node graph by taking a list of data nodes. This is done in 2 steps:
1967 // 1. Clone the data nodes
1968 // 2. Fix the cloned data inputs pointing to the old nodes to the cloned inputs by using an old->new mapping.
1969 class DataNodeGraph : public StackObj {
1970 PhaseIdealLoop* const _phase;
1971 const Unique_Node_List& _data_nodes;
1972 OrigToNewHashtable _orig_to_new;
1973
1974 public:
1975 DataNodeGraph(const Unique_Node_List& data_nodes, PhaseIdealLoop* phase)
1976 : _phase(phase),
1977 _data_nodes(data_nodes),
1978 // Use 107 as best guess which is the first resize value in ResizeableResourceHashtable::large_table_sizes.
1979 _orig_to_new(107, MaxNodeLimit)
1980 {
1981 #ifdef ASSERT
1982 for (uint i = 0; i < data_nodes.size(); i++) {
1983 assert(!data_nodes[i]->is_CFG(), "only data nodes");
1984 }
1985 #endif
1986 }
1987 NONCOPYABLE(DataNodeGraph);
1988
1989 private:
1990 void clone(Node* node, Node* new_ctrl);
1991 void clone_data_nodes(Node* new_ctrl);
1992 void clone_data_nodes_and_transform_opaque_loop_nodes(const TransformStrategyForOpaqueLoopNodes& transform_strategy,
1993 Node* new_ctrl);
1994 void rewire_clones_to_cloned_inputs();
1995 void transform_opaque_node(const TransformStrategyForOpaqueLoopNodes& transform_strategy, Node* node);
1996
1997 public:
1998 // Clone the provided data node collection and rewire the clones in such a way to create an identical graph copy.
1999 // Set 'new_ctrl' as ctrl for the cloned nodes.
2000 const OrigToNewHashtable& clone(Node* new_ctrl) {
2001 assert(_orig_to_new.number_of_entries() == 0, "should not call this method twice in a row");
2002 clone_data_nodes(new_ctrl);
2003 rewire_clones_to_cloned_inputs();
2004 return _orig_to_new;
2005 }
2006
2007 // Create a copy of the data nodes provided to the constructor by doing the following:
2008 // Clone all non-OpaqueLoop* nodes and rewire them to create an identical subgraph copy. For the OpaqueLoop* nodes,
2009 // apply the provided transformation strategy and include the transformed node into the subgraph copy to get a complete
2010 // "cloned-and-transformed" graph copy. For all newly cloned nodes (which could also be new OpaqueLoop* nodes), set
2011 // `new_ctrl` as ctrl.
2012 const OrigToNewHashtable& clone_with_opaque_loop_transform_strategy(
2013 const TransformStrategyForOpaqueLoopNodes& transform_strategy,
2014 Node* new_ctrl) {
2015 clone_data_nodes_and_transform_opaque_loop_nodes(transform_strategy, new_ctrl);
2016 rewire_clones_to_cloned_inputs();
2017 return _orig_to_new;
2018 }
2019 };
2020 #endif // SHARE_OPTO_LOOPNODE_HPP