Mercurial > hg > truffle
annotate src/share/vm/opto/loopnode.hpp @ 2194:face83fc8882
7012088: jump to 0 address because of lack of memory ordering in SignatureHandlerLibrary::add
Summary: Write method signature handler under lock to prevent race with growable array resizing
Reviewed-by: dsamersoff, dholmes
author | coleenp |
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date | Wed, 02 Feb 2011 18:38:40 -0500 |
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0 | 1 /* |
1972 | 2 * Copyright (c) 1998, 2010, Oracle and/or its affiliates. All rights reserved. |
0 | 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 * | |
15 * You should have received a copy of the GNU General Public License version | |
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. | |
18 * | |
1552
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #ifndef SHARE_VM_OPTO_LOOPNODE_HPP |
26 #define SHARE_VM_OPTO_LOOPNODE_HPP | |
27 | |
28 #include "opto/cfgnode.hpp" | |
29 #include "opto/multnode.hpp" | |
30 #include "opto/phaseX.hpp" | |
31 #include "opto/subnode.hpp" | |
32 #include "opto/type.hpp" | |
33 | |
0 | 34 class CmpNode; |
35 class CountedLoopEndNode; | |
36 class CountedLoopNode; | |
37 class IdealLoopTree; | |
38 class LoopNode; | |
39 class Node; | |
40 class PhaseIdealLoop; | |
41 class VectorSet; | |
1172 | 42 class Invariance; |
0 | 43 struct small_cache; |
44 | |
45 // | |
46 // I D E A L I Z E D L O O P S | |
47 // | |
48 // Idealized loops are the set of loops I perform more interesting | |
49 // transformations on, beyond simple hoisting. | |
50 | |
51 //------------------------------LoopNode--------------------------------------- | |
52 // Simple loop header. Fall in path on left, loop-back path on right. | |
53 class LoopNode : public RegionNode { | |
54 // Size is bigger to hold the flags. However, the flags do not change | |
55 // the semantics so it does not appear in the hash & cmp functions. | |
56 virtual uint size_of() const { return sizeof(*this); } | |
57 protected: | |
58 short _loop_flags; | |
59 // Names for flag bitfields | |
60 enum { pre_post_main=0, inner_loop=8, partial_peel_loop=16, partial_peel_failed=32 }; | |
61 char _unswitch_count; | |
62 enum { _unswitch_max=3 }; | |
63 | |
64 public: | |
65 // Names for edge indices | |
66 enum { Self=0, EntryControl, LoopBackControl }; | |
67 | |
68 int is_inner_loop() const { return _loop_flags & inner_loop; } | |
69 void set_inner_loop() { _loop_flags |= inner_loop; } | |
70 | |
71 int is_partial_peel_loop() const { return _loop_flags & partial_peel_loop; } | |
72 void set_partial_peel_loop() { _loop_flags |= partial_peel_loop; } | |
73 int partial_peel_has_failed() const { return _loop_flags & partial_peel_failed; } | |
74 void mark_partial_peel_failed() { _loop_flags |= partial_peel_failed; } | |
75 | |
76 int unswitch_max() { return _unswitch_max; } | |
77 int unswitch_count() { return _unswitch_count; } | |
78 void set_unswitch_count(int val) { | |
79 assert (val <= unswitch_max(), "too many unswitches"); | |
80 _unswitch_count = val; | |
81 } | |
82 | |
83 LoopNode( Node *entry, Node *backedge ) : RegionNode(3), _loop_flags(0), _unswitch_count(0) { | |
84 init_class_id(Class_Loop); | |
85 init_req(EntryControl, entry); | |
86 init_req(LoopBackControl, backedge); | |
87 } | |
88 | |
89 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); | |
90 virtual int Opcode() const; | |
91 bool can_be_counted_loop(PhaseTransform* phase) const { | |
92 return req() == 3 && in(0) != NULL && | |
93 in(1) != NULL && phase->type(in(1)) != Type::TOP && | |
94 in(2) != NULL && phase->type(in(2)) != Type::TOP; | |
95 } | |
96 #ifndef PRODUCT | |
97 virtual void dump_spec(outputStream *st) const; | |
98 #endif | |
99 }; | |
100 | |
101 //------------------------------Counted Loops---------------------------------- | |
102 // Counted loops are all trip-counted loops, with exactly 1 trip-counter exit | |
103 // path (and maybe some other exit paths). The trip-counter exit is always | |
104 // last in the loop. The trip-counter does not have to stride by a constant, | |
105 // but it does have to stride by a loop-invariant amount; the exit value is | |
106 // also loop invariant. | |
107 | |
108 // CountedLoopNodes and CountedLoopEndNodes come in matched pairs. The | |
109 // CountedLoopNode has the incoming loop control and the loop-back-control | |
110 // which is always the IfTrue before the matching CountedLoopEndNode. The | |
111 // CountedLoopEndNode has an incoming control (possibly not the | |
112 // CountedLoopNode if there is control flow in the loop), the post-increment | |
113 // trip-counter value, and the limit. The trip-counter value is always of | |
114 // the form (Op old-trip-counter stride). The old-trip-counter is produced | |
115 // by a Phi connected to the CountedLoopNode. The stride is loop invariant. | |
116 // The Op is any commutable opcode, including Add, Mul, Xor. The | |
117 // CountedLoopEndNode also takes in the loop-invariant limit value. | |
118 | |
119 // From a CountedLoopNode I can reach the matching CountedLoopEndNode via the | |
120 // loop-back control. From CountedLoopEndNodes I can reach CountedLoopNodes | |
121 // via the old-trip-counter from the Op node. | |
122 | |
123 //------------------------------CountedLoopNode-------------------------------- | |
124 // CountedLoopNodes head simple counted loops. CountedLoopNodes have as | |
125 // inputs the incoming loop-start control and the loop-back control, so they | |
126 // act like RegionNodes. They also take in the initial trip counter, the | |
127 // loop-invariant stride and the loop-invariant limit value. CountedLoopNodes | |
128 // produce a loop-body control and the trip counter value. Since | |
129 // CountedLoopNodes behave like RegionNodes I still have a standard CFG model. | |
130 | |
131 class CountedLoopNode : public LoopNode { | |
132 // Size is bigger to hold _main_idx. However, _main_idx does not change | |
133 // the semantics so it does not appear in the hash & cmp functions. | |
134 virtual uint size_of() const { return sizeof(*this); } | |
135 | |
136 // For Pre- and Post-loops during debugging ONLY, this holds the index of | |
137 // the Main CountedLoop. Used to assert that we understand the graph shape. | |
138 node_idx_t _main_idx; | |
139 | |
140 // Known trip count calculated by policy_maximally_unroll | |
141 int _trip_count; | |
142 | |
143 // Expected trip count from profile data | |
144 float _profile_trip_cnt; | |
145 | |
146 // Log2 of original loop bodies in unrolled loop | |
147 int _unrolled_count_log2; | |
148 | |
149 // Node count prior to last unrolling - used to decide if | |
150 // unroll,optimize,unroll,optimize,... is making progress | |
151 int _node_count_before_unroll; | |
152 | |
153 public: | |
154 CountedLoopNode( Node *entry, Node *backedge ) | |
155 : LoopNode(entry, backedge), _trip_count(max_jint), | |
156 _profile_trip_cnt(COUNT_UNKNOWN), _unrolled_count_log2(0), | |
157 _node_count_before_unroll(0) { | |
158 init_class_id(Class_CountedLoop); | |
159 // Initialize _trip_count to the largest possible value. | |
160 // Will be reset (lower) if the loop's trip count is known. | |
161 } | |
162 | |
163 virtual int Opcode() const; | |
164 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape); | |
165 | |
166 Node *init_control() const { return in(EntryControl); } | |
167 Node *back_control() const { return in(LoopBackControl); } | |
168 CountedLoopEndNode *loopexit() const; | |
169 Node *init_trip() const; | |
170 Node *stride() const; | |
171 int stride_con() const; | |
172 bool stride_is_con() const; | |
173 Node *limit() const; | |
174 Node *incr() const; | |
175 Node *phi() const; | |
176 | |
177 // Match increment with optional truncation | |
178 static Node* match_incr_with_optional_truncation(Node* expr, Node** trunc1, Node** trunc2, const TypeInt** trunc_type); | |
179 | |
180 // A 'main' loop has a pre-loop and a post-loop. The 'main' loop | |
181 // can run short a few iterations and may start a few iterations in. | |
182 // It will be RCE'd and unrolled and aligned. | |
183 | |
184 // A following 'post' loop will run any remaining iterations. Used | |
185 // during Range Check Elimination, the 'post' loop will do any final | |
186 // iterations with full checks. Also used by Loop Unrolling, where | |
187 // the 'post' loop will do any epilog iterations needed. Basically, | |
188 // a 'post' loop can not profitably be further unrolled or RCE'd. | |
189 | |
190 // A preceding 'pre' loop will run at least 1 iteration (to do peeling), | |
191 // it may do under-flow checks for RCE and may do alignment iterations | |
192 // so the following main loop 'knows' that it is striding down cache | |
193 // lines. | |
194 | |
195 // A 'main' loop that is ONLY unrolled or peeled, never RCE'd or | |
196 // Aligned, may be missing it's pre-loop. | |
197 enum { Normal=0, Pre=1, Main=2, Post=3, PrePostFlagsMask=3, Main_Has_No_Pre_Loop=4 }; | |
198 int is_normal_loop() const { return (_loop_flags&PrePostFlagsMask) == Normal; } | |
199 int is_pre_loop () const { return (_loop_flags&PrePostFlagsMask) == Pre; } | |
200 int is_main_loop () const { return (_loop_flags&PrePostFlagsMask) == Main; } | |
201 int is_post_loop () const { return (_loop_flags&PrePostFlagsMask) == Post; } | |
202 int is_main_no_pre_loop() const { return _loop_flags & Main_Has_No_Pre_Loop; } | |
203 void set_main_no_pre_loop() { _loop_flags |= Main_Has_No_Pre_Loop; } | |
204 | |
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205 int main_idx() const { return _main_idx; } |
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206 |
0 | 207 |
208 void set_pre_loop (CountedLoopNode *main) { assert(is_normal_loop(),""); _loop_flags |= Pre ; _main_idx = main->_idx; } | |
209 void set_main_loop ( ) { assert(is_normal_loop(),""); _loop_flags |= Main; } | |
210 void set_post_loop (CountedLoopNode *main) { assert(is_normal_loop(),""); _loop_flags |= Post; _main_idx = main->_idx; } | |
211 void set_normal_loop( ) { _loop_flags &= ~PrePostFlagsMask; } | |
212 | |
213 void set_trip_count(int tc) { _trip_count = tc; } | |
214 int trip_count() { return _trip_count; } | |
215 | |
216 void set_profile_trip_cnt(float ptc) { _profile_trip_cnt = ptc; } | |
217 float profile_trip_cnt() { return _profile_trip_cnt; } | |
218 | |
219 void double_unrolled_count() { _unrolled_count_log2++; } | |
220 int unrolled_count() { return 1 << MIN2(_unrolled_count_log2, BitsPerInt-3); } | |
221 | |
222 void set_node_count_before_unroll(int ct) { _node_count_before_unroll = ct; } | |
223 int node_count_before_unroll() { return _node_count_before_unroll; } | |
224 | |
225 #ifndef PRODUCT | |
226 virtual void dump_spec(outputStream *st) const; | |
227 #endif | |
228 }; | |
229 | |
230 //------------------------------CountedLoopEndNode----------------------------- | |
231 // CountedLoopEndNodes end simple trip counted loops. They act much like | |
232 // IfNodes. | |
233 class CountedLoopEndNode : public IfNode { | |
234 public: | |
235 enum { TestControl, TestValue }; | |
236 | |
237 CountedLoopEndNode( Node *control, Node *test, float prob, float cnt ) | |
238 : IfNode( control, test, prob, cnt) { | |
239 init_class_id(Class_CountedLoopEnd); | |
240 } | |
241 virtual int Opcode() const; | |
242 | |
243 Node *cmp_node() const { return (in(TestValue)->req() >=2) ? in(TestValue)->in(1) : NULL; } | |
244 Node *incr() const { Node *tmp = cmp_node(); return (tmp && tmp->req()==3) ? tmp->in(1) : NULL; } | |
245 Node *limit() const { Node *tmp = cmp_node(); return (tmp && tmp->req()==3) ? tmp->in(2) : NULL; } | |
246 Node *stride() const { Node *tmp = incr (); return (tmp && tmp->req()==3) ? tmp->in(2) : NULL; } | |
247 Node *phi() const { Node *tmp = incr (); return (tmp && tmp->req()==3) ? tmp->in(1) : NULL; } | |
248 Node *init_trip() const { Node *tmp = phi (); return (tmp && tmp->req()==3) ? tmp->in(1) : NULL; } | |
249 int stride_con() const; | |
250 bool stride_is_con() const { Node *tmp = stride (); return (tmp != NULL && tmp->is_Con()); } | |
251 BoolTest::mask test_trip() const { return in(TestValue)->as_Bool()->_test._test; } | |
252 CountedLoopNode *loopnode() const { | |
253 Node *ln = phi()->in(0); | |
254 assert( ln->Opcode() == Op_CountedLoop, "malformed loop" ); | |
255 return (CountedLoopNode*)ln; } | |
256 | |
257 #ifndef PRODUCT | |
258 virtual void dump_spec(outputStream *st) const; | |
259 #endif | |
260 }; | |
261 | |
262 | |
263 inline CountedLoopEndNode *CountedLoopNode::loopexit() const { | |
264 Node *bc = back_control(); | |
265 if( bc == NULL ) return NULL; | |
266 Node *le = bc->in(0); | |
267 if( le->Opcode() != Op_CountedLoopEnd ) | |
268 return NULL; | |
269 return (CountedLoopEndNode*)le; | |
270 } | |
271 inline Node *CountedLoopNode::init_trip() const { return loopexit() ? loopexit()->init_trip() : NULL; } | |
272 inline Node *CountedLoopNode::stride() const { return loopexit() ? loopexit()->stride() : NULL; } | |
273 inline int CountedLoopNode::stride_con() const { return loopexit() ? loopexit()->stride_con() : 0; } | |
274 inline bool CountedLoopNode::stride_is_con() const { return loopexit() && loopexit()->stride_is_con(); } | |
275 inline Node *CountedLoopNode::limit() const { return loopexit() ? loopexit()->limit() : NULL; } | |
276 inline Node *CountedLoopNode::incr() const { return loopexit() ? loopexit()->incr() : NULL; } | |
277 inline Node *CountedLoopNode::phi() const { return loopexit() ? loopexit()->phi() : NULL; } | |
278 | |
279 | |
280 // -----------------------------IdealLoopTree---------------------------------- | |
281 class IdealLoopTree : public ResourceObj { | |
282 public: | |
283 IdealLoopTree *_parent; // Parent in loop tree | |
284 IdealLoopTree *_next; // Next sibling in loop tree | |
285 IdealLoopTree *_child; // First child in loop tree | |
286 | |
287 // The head-tail backedge defines the loop. | |
288 // If tail is NULL then this loop has multiple backedges as part of the | |
289 // same loop. During cleanup I'll peel off the multiple backedges; merge | |
290 // them at the loop bottom and flow 1 real backedge into the loop. | |
291 Node *_head; // Head of loop | |
292 Node *_tail; // Tail of loop | |
293 inline Node *tail(); // Handle lazy update of _tail field | |
294 PhaseIdealLoop* _phase; | |
295 | |
296 Node_List _body; // Loop body for inner loops | |
297 | |
298 uint8 _nest; // Nesting depth | |
299 uint8 _irreducible:1, // True if irreducible | |
300 _has_call:1, // True if has call safepoint | |
301 _has_sfpt:1, // True if has non-call safepoint | |
302 _rce_candidate:1; // True if candidate for range check elimination | |
303 | |
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304 Node_List* _required_safept; // A inner loop cannot delete these safepts; |
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305 bool _allow_optimizations; // Allow loop optimizations |
0 | 306 |
307 IdealLoopTree( PhaseIdealLoop* phase, Node *head, Node *tail ) | |
308 : _parent(0), _next(0), _child(0), | |
309 _head(head), _tail(tail), | |
310 _phase(phase), | |
311 _required_safept(NULL), | |
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312 _allow_optimizations(true), |
0 | 313 _nest(0), _irreducible(0), _has_call(0), _has_sfpt(0), _rce_candidate(0) |
314 { } | |
315 | |
316 // Is 'l' a member of 'this'? | |
317 int is_member( const IdealLoopTree *l ) const; // Test for nested membership | |
318 | |
319 // Set loop nesting depth. Accumulate has_call bits. | |
320 int set_nest( uint depth ); | |
321 | |
322 // Split out multiple fall-in edges from the loop header. Move them to a | |
323 // private RegionNode before the loop. This becomes the loop landing pad. | |
324 void split_fall_in( PhaseIdealLoop *phase, int fall_in_cnt ); | |
325 | |
326 // Split out the outermost loop from this shared header. | |
327 void split_outer_loop( PhaseIdealLoop *phase ); | |
328 | |
329 // Merge all the backedges from the shared header into a private Region. | |
330 // Feed that region as the one backedge to this loop. | |
331 void merge_many_backedges( PhaseIdealLoop *phase ); | |
332 | |
333 // Split shared headers and insert loop landing pads. | |
334 // Insert a LoopNode to replace the RegionNode. | |
335 // Returns TRUE if loop tree is structurally changed. | |
336 bool beautify_loops( PhaseIdealLoop *phase ); | |
337 | |
1172 | 338 // Perform optimization to use the loop predicates for null checks and range checks. |
339 // Applies to any loop level (not just the innermost one) | |
340 bool loop_predication( PhaseIdealLoop *phase); | |
341 | |
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342 // Perform iteration-splitting on inner loops. Split iterations to |
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343 // avoid range checks or one-shot null checks. Returns false if the |
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344 // current round of loop opts should stop. |
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345 bool iteration_split( PhaseIdealLoop *phase, Node_List &old_new ); |
0 | 346 |
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347 // Driver for various flavors of iteration splitting. Returns false |
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348 // if the current round of loop opts should stop. |
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349 bool iteration_split_impl( PhaseIdealLoop *phase, Node_List &old_new ); |
0 | 350 |
351 // Given dominators, try to find loops with calls that must always be | |
352 // executed (call dominates loop tail). These loops do not need non-call | |
353 // safepoints (ncsfpt). | |
354 void check_safepts(VectorSet &visited, Node_List &stack); | |
355 | |
356 // Allpaths backwards scan from loop tail, terminating each path at first safepoint | |
357 // encountered. | |
358 void allpaths_check_safepts(VectorSet &visited, Node_List &stack); | |
359 | |
360 // Convert to counted loops where possible | |
361 void counted_loop( PhaseIdealLoop *phase ); | |
362 | |
363 // Check for Node being a loop-breaking test | |
364 Node *is_loop_exit(Node *iff) const; | |
365 | |
366 // Returns true if ctrl is executed on every complete iteration | |
367 bool dominates_backedge(Node* ctrl); | |
368 | |
369 // Remove simplistic dead code from loop body | |
370 void DCE_loop_body(); | |
371 | |
372 // Look for loop-exit tests with my 50/50 guesses from the Parsing stage. | |
373 // Replace with a 1-in-10 exit guess. | |
374 void adjust_loop_exit_prob( PhaseIdealLoop *phase ); | |
375 | |
376 // Return TRUE or FALSE if the loop should never be RCE'd or aligned. | |
377 // Useful for unrolling loops with NO array accesses. | |
378 bool policy_peel_only( PhaseIdealLoop *phase ) const; | |
379 | |
380 // Return TRUE or FALSE if the loop should be unswitched -- clone | |
381 // loop with an invariant test | |
382 bool policy_unswitching( PhaseIdealLoop *phase ) const; | |
383 | |
384 // Micro-benchmark spamming. Remove empty loops. | |
385 bool policy_do_remove_empty_loop( PhaseIdealLoop *phase ); | |
386 | |
387 // Return TRUE or FALSE if the loop should be peeled or not. Peel if we can | |
388 // make some loop-invariant test (usually a null-check) happen before the | |
389 // loop. | |
390 bool policy_peeling( PhaseIdealLoop *phase ) const; | |
391 | |
392 // Return TRUE or FALSE if the loop should be maximally unrolled. Stash any | |
393 // known trip count in the counted loop node. | |
394 bool policy_maximally_unroll( PhaseIdealLoop *phase ) const; | |
395 | |
396 // Return TRUE or FALSE if the loop should be unrolled or not. Unroll if | |
397 // the loop is a CountedLoop and the body is small enough. | |
398 bool policy_unroll( PhaseIdealLoop *phase ) const; | |
399 | |
400 // Return TRUE or FALSE if the loop should be range-check-eliminated. | |
401 // Gather a list of IF tests that are dominated by iteration splitting; | |
402 // also gather the end of the first split and the start of the 2nd split. | |
403 bool policy_range_check( PhaseIdealLoop *phase ) const; | |
404 | |
405 // Return TRUE or FALSE if the loop should be cache-line aligned. | |
406 // Gather the expression that does the alignment. Note that only | |
605 | 407 // one array base can be aligned in a loop (unless the VM guarantees |
0 | 408 // mutual alignment). Note that if we vectorize short memory ops |
409 // into longer memory ops, we may want to increase alignment. | |
410 bool policy_align( PhaseIdealLoop *phase ) const; | |
411 | |
1172 | 412 // Return TRUE if "iff" is a range check. |
413 bool is_range_check_if(IfNode *iff, PhaseIdealLoop *phase, Invariance& invar) const; | |
414 | |
0 | 415 // Compute loop trip count from profile data |
416 void compute_profile_trip_cnt( PhaseIdealLoop *phase ); | |
417 | |
418 // Reassociate invariant expressions. | |
419 void reassociate_invariants(PhaseIdealLoop *phase); | |
420 // Reassociate invariant add and subtract expressions. | |
421 Node* reassociate_add_sub(Node* n1, PhaseIdealLoop *phase); | |
422 // Return nonzero index of invariant operand if invariant and variant | |
605 | 423 // are combined with an Add or Sub. Helper for reassociate_invariants. |
0 | 424 int is_invariant_addition(Node* n, PhaseIdealLoop *phase); |
425 | |
426 // Return true if n is invariant | |
427 bool is_invariant(Node* n) const; | |
428 | |
429 // Put loop body on igvn work list | |
430 void record_for_igvn(); | |
431 | |
432 bool is_loop() { return !_irreducible && _tail && !_tail->is_top(); } | |
433 bool is_inner() { return is_loop() && _child == NULL; } | |
434 bool is_counted() { return is_loop() && _head != NULL && _head->is_CountedLoop(); } | |
435 | |
436 #ifndef PRODUCT | |
437 void dump_head( ) const; // Dump loop head only | |
438 void dump() const; // Dump this loop recursively | |
439 void verify_tree(IdealLoopTree *loop, const IdealLoopTree *parent) const; | |
440 #endif | |
441 | |
442 }; | |
443 | |
444 // -----------------------------PhaseIdealLoop--------------------------------- | |
445 // Computes the mapping from Nodes to IdealLoopTrees. Organizes IdealLoopTrees into a | |
446 // loop tree. Drives the loop-based transformations on the ideal graph. | |
447 class PhaseIdealLoop : public PhaseTransform { | |
448 friend class IdealLoopTree; | |
449 friend class SuperWord; | |
450 // Pre-computed def-use info | |
451 PhaseIterGVN &_igvn; | |
452 | |
453 // Head of loop tree | |
454 IdealLoopTree *_ltree_root; | |
455 | |
456 // Array of pre-order numbers, plus post-visited bit. | |
457 // ZERO for not pre-visited. EVEN for pre-visited but not post-visited. | |
458 // ODD for post-visited. Other bits are the pre-order number. | |
459 uint *_preorders; | |
460 uint _max_preorder; | |
461 | |
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462 const PhaseIdealLoop* _verify_me; |
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463 bool _verify_only; |
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464 |
0 | 465 // Allocate _preorders[] array |
466 void allocate_preorders() { | |
467 _max_preorder = C->unique()+8; | |
468 _preorders = NEW_RESOURCE_ARRAY(uint, _max_preorder); | |
469 memset(_preorders, 0, sizeof(uint) * _max_preorder); | |
470 } | |
471 | |
472 // Allocate _preorders[] array | |
473 void reallocate_preorders() { | |
474 if ( _max_preorder < C->unique() ) { | |
475 _preorders = REALLOC_RESOURCE_ARRAY(uint, _preorders, _max_preorder, C->unique()); | |
476 _max_preorder = C->unique(); | |
477 } | |
478 memset(_preorders, 0, sizeof(uint) * _max_preorder); | |
479 } | |
480 | |
481 // Check to grow _preorders[] array for the case when build_loop_tree_impl() | |
482 // adds new nodes. | |
483 void check_grow_preorders( ) { | |
484 if ( _max_preorder < C->unique() ) { | |
485 uint newsize = _max_preorder<<1; // double size of array | |
486 _preorders = REALLOC_RESOURCE_ARRAY(uint, _preorders, _max_preorder, newsize); | |
487 memset(&_preorders[_max_preorder],0,sizeof(uint)*(newsize-_max_preorder)); | |
488 _max_preorder = newsize; | |
489 } | |
490 } | |
491 // Check for pre-visited. Zero for NOT visited; non-zero for visited. | |
492 int is_visited( Node *n ) const { return _preorders[n->_idx]; } | |
493 // Pre-order numbers are written to the Nodes array as low-bit-set values. | |
494 void set_preorder_visited( Node *n, int pre_order ) { | |
495 assert( !is_visited( n ), "already set" ); | |
496 _preorders[n->_idx] = (pre_order<<1); | |
497 }; | |
498 // Return pre-order number. | |
499 int get_preorder( Node *n ) const { assert( is_visited(n), "" ); return _preorders[n->_idx]>>1; } | |
500 | |
501 // Check for being post-visited. | |
502 // Should be previsited already (checked with assert(is_visited(n))). | |
503 int is_postvisited( Node *n ) const { assert( is_visited(n), "" ); return _preorders[n->_idx]&1; } | |
504 | |
505 // Mark as post visited | |
506 void set_postvisited( Node *n ) { assert( !is_postvisited( n ), "" ); _preorders[n->_idx] |= 1; } | |
507 | |
508 // Set/get control node out. Set lower bit to distinguish from IdealLoopTree | |
509 // Returns true if "n" is a data node, false if it's a control node. | |
510 bool has_ctrl( Node *n ) const { return ((intptr_t)_nodes[n->_idx]) & 1; } | |
511 | |
512 // clear out dead code after build_loop_late | |
513 Node_List _deadlist; | |
514 | |
515 // Support for faster execution of get_late_ctrl()/dom_lca() | |
516 // when a node has many uses and dominator depth is deep. | |
517 Node_Array _dom_lca_tags; | |
518 void init_dom_lca_tags(); | |
519 void clear_dom_lca_tags(); | |
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520 |
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521 // Helper for debugging bad dominance relationships |
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522 bool verify_dominance(Node* n, Node* use, Node* LCA, Node* early); |
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523 |
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524 Node* compute_lca_of_uses(Node* n, Node* early, bool verify = false); |
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525 |
0 | 526 // Inline wrapper for frequent cases: |
527 // 1) only one use | |
528 // 2) a use is the same as the current LCA passed as 'n1' | |
529 Node *dom_lca_for_get_late_ctrl( Node *lca, Node *n, Node *tag ) { | |
530 assert( n->is_CFG(), "" ); | |
531 // Fast-path NULL lca | |
532 if( lca != NULL && lca != n ) { | |
533 assert( lca->is_CFG(), "" ); | |
534 // find LCA of all uses | |
535 n = dom_lca_for_get_late_ctrl_internal( lca, n, tag ); | |
536 } | |
537 return find_non_split_ctrl(n); | |
538 } | |
539 Node *dom_lca_for_get_late_ctrl_internal( Node *lca, Node *n, Node *tag ); | |
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540 |
0 | 541 // Helper function for directing control inputs away from CFG split |
542 // points. | |
543 Node *find_non_split_ctrl( Node *ctrl ) const { | |
544 if (ctrl != NULL) { | |
545 if (ctrl->is_MultiBranch()) { | |
546 ctrl = ctrl->in(0); | |
547 } | |
548 assert(ctrl->is_CFG(), "CFG"); | |
549 } | |
550 return ctrl; | |
551 } | |
552 | |
553 public: | |
554 bool has_node( Node* n ) const { return _nodes[n->_idx] != NULL; } | |
555 // check if transform created new nodes that need _ctrl recorded | |
556 Node *get_late_ctrl( Node *n, Node *early ); | |
557 Node *get_early_ctrl( Node *n ); | |
558 void set_early_ctrl( Node *n ); | |
559 void set_subtree_ctrl( Node *root ); | |
560 void set_ctrl( Node *n, Node *ctrl ) { | |
561 assert( !has_node(n) || has_ctrl(n), "" ); | |
562 assert( ctrl->in(0), "cannot set dead control node" ); | |
563 assert( ctrl == find_non_split_ctrl(ctrl), "must set legal crtl" ); | |
564 _nodes.map( n->_idx, (Node*)((intptr_t)ctrl + 1) ); | |
565 } | |
566 // Set control and update loop membership | |
567 void set_ctrl_and_loop(Node* n, Node* ctrl) { | |
568 IdealLoopTree* old_loop = get_loop(get_ctrl(n)); | |
569 IdealLoopTree* new_loop = get_loop(ctrl); | |
570 if (old_loop != new_loop) { | |
571 if (old_loop->_child == NULL) old_loop->_body.yank(n); | |
572 if (new_loop->_child == NULL) new_loop->_body.push(n); | |
573 } | |
574 set_ctrl(n, ctrl); | |
575 } | |
576 // Control nodes can be replaced or subsumed. During this pass they | |
577 // get their replacement Node in slot 1. Instead of updating the block | |
578 // location of all Nodes in the subsumed block, we lazily do it. As we | |
579 // pull such a subsumed block out of the array, we write back the final | |
580 // correct block. | |
581 Node *get_ctrl( Node *i ) { | |
582 assert(has_node(i), ""); | |
583 Node *n = get_ctrl_no_update(i); | |
584 _nodes.map( i->_idx, (Node*)((intptr_t)n + 1) ); | |
585 assert(has_node(i) && has_ctrl(i), ""); | |
586 assert(n == find_non_split_ctrl(n), "must return legal ctrl" ); | |
587 return n; | |
588 } | |
1172 | 589 // true if CFG node d dominates CFG node n |
590 bool is_dominator(Node *d, Node *n); | |
591 // return get_ctrl for a data node and self(n) for a CFG node | |
592 Node* ctrl_or_self(Node* n) { | |
593 if (has_ctrl(n)) | |
594 return get_ctrl(n); | |
595 else { | |
596 assert (n->is_CFG(), "must be a CFG node"); | |
597 return n; | |
598 } | |
599 } | |
0 | 600 |
601 private: | |
602 Node *get_ctrl_no_update( Node *i ) const { | |
603 assert( has_ctrl(i), "" ); | |
604 Node *n = (Node*)(((intptr_t)_nodes[i->_idx]) & ~1); | |
605 if (!n->in(0)) { | |
606 // Skip dead CFG nodes | |
607 do { | |
608 n = (Node*)(((intptr_t)_nodes[n->_idx]) & ~1); | |
609 } while (!n->in(0)); | |
610 n = find_non_split_ctrl(n); | |
611 } | |
612 return n; | |
613 } | |
614 | |
615 // Check for loop being set | |
616 // "n" must be a control node. Returns true if "n" is known to be in a loop. | |
617 bool has_loop( Node *n ) const { | |
618 assert(!has_node(n) || !has_ctrl(n), ""); | |
619 return has_node(n); | |
620 } | |
621 // Set loop | |
622 void set_loop( Node *n, IdealLoopTree *loop ) { | |
623 _nodes.map(n->_idx, (Node*)loop); | |
624 } | |
625 // Lazy-dazy update of 'get_ctrl' and 'idom_at' mechanisms. Replace | |
626 // the 'old_node' with 'new_node'. Kill old-node. Add a reference | |
627 // from old_node to new_node to support the lazy update. Reference | |
1172 | 628 // replaces loop reference, since that is not needed for dead node. |
0 | 629 public: |
630 void lazy_update( Node *old_node, Node *new_node ) { | |
631 assert( old_node != new_node, "no cycles please" ); | |
632 //old_node->set_req( 1, new_node /*NO DU INFO*/ ); | |
633 // Nodes always have DU info now, so re-use the side array slot | |
634 // for this node to provide the forwarding pointer. | |
635 _nodes.map( old_node->_idx, (Node*)((intptr_t)new_node + 1) ); | |
636 } | |
637 void lazy_replace( Node *old_node, Node *new_node ) { | |
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638 _igvn.replace_node( old_node, new_node ); |
0 | 639 lazy_update( old_node, new_node ); |
640 } | |
641 void lazy_replace_proj( Node *old_node, Node *new_node ) { | |
642 assert( old_node->req() == 1, "use this for Projs" ); | |
643 _igvn.hash_delete(old_node); // Must hash-delete before hacking edges | |
644 old_node->add_req( NULL ); | |
645 lazy_replace( old_node, new_node ); | |
646 } | |
647 | |
648 private: | |
649 | |
650 // Place 'n' in some loop nest, where 'n' is a CFG node | |
651 void build_loop_tree(); | |
652 int build_loop_tree_impl( Node *n, int pre_order ); | |
653 // Insert loop into the existing loop tree. 'innermost' is a leaf of the | |
654 // loop tree, not the root. | |
655 IdealLoopTree *sort( IdealLoopTree *loop, IdealLoopTree *innermost ); | |
656 | |
657 // Place Data nodes in some loop nest | |
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658 void build_loop_early( VectorSet &visited, Node_List &worklist, Node_Stack &nstack ); |
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659 void build_loop_late ( VectorSet &visited, Node_List &worklist, Node_Stack &nstack ); |
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660 void build_loop_late_post ( Node* n ); |
0 | 661 |
662 // Array of immediate dominance info for each CFG node indexed by node idx | |
663 private: | |
664 uint _idom_size; | |
665 Node **_idom; // Array of immediate dominators | |
666 uint *_dom_depth; // Used for fast LCA test | |
667 GrowableArray<uint>* _dom_stk; // For recomputation of dom depth | |
668 | |
669 Node* idom_no_update(Node* d) const { | |
670 assert(d->_idx < _idom_size, "oob"); | |
671 Node* n = _idom[d->_idx]; | |
672 assert(n != NULL,"Bad immediate dominator info."); | |
673 while (n->in(0) == NULL) { // Skip dead CFG nodes | |
674 //n = n->in(1); | |
675 n = (Node*)(((intptr_t)_nodes[n->_idx]) & ~1); | |
676 assert(n != NULL,"Bad immediate dominator info."); | |
677 } | |
678 return n; | |
679 } | |
680 Node *idom(Node* d) const { | |
681 uint didx = d->_idx; | |
682 Node *n = idom_no_update(d); | |
683 _idom[didx] = n; // Lazily remove dead CFG nodes from table. | |
684 return n; | |
685 } | |
686 uint dom_depth(Node* d) const { | |
687 assert(d->_idx < _idom_size, ""); | |
688 return _dom_depth[d->_idx]; | |
689 } | |
690 void set_idom(Node* d, Node* n, uint dom_depth); | |
691 // Locally compute IDOM using dom_lca call | |
692 Node *compute_idom( Node *region ) const; | |
693 // Recompute dom_depth | |
694 void recompute_dom_depth(); | |
695 | |
696 // Is safept not required by an outer loop? | |
697 bool is_deleteable_safept(Node* sfpt); | |
698 | |
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699 // Perform verification that the graph is valid. |
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700 PhaseIdealLoop( PhaseIterGVN &igvn) : |
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701 PhaseTransform(Ideal_Loop), |
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702 _igvn(igvn), |
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703 _dom_lca_tags(C->comp_arena()), |
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704 _verify_me(NULL), |
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705 _verify_only(true) { |
1172 | 706 build_and_optimize(false, false); |
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707 } |
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708 |
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709 // build the loop tree and perform any requested optimizations |
1172 | 710 void build_and_optimize(bool do_split_if, bool do_loop_pred); |
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711 |
0 | 712 public: |
713 // Dominators for the sea of nodes | |
714 void Dominators(); | |
715 Node *dom_lca( Node *n1, Node *n2 ) const { | |
716 return find_non_split_ctrl(dom_lca_internal(n1, n2)); | |
717 } | |
718 Node *dom_lca_internal( Node *n1, Node *n2 ) const; | |
719 | |
720 // Compute the Ideal Node to Loop mapping | |
1172 | 721 PhaseIdealLoop( PhaseIterGVN &igvn, bool do_split_ifs, bool do_loop_pred) : |
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722 PhaseTransform(Ideal_Loop), |
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723 _igvn(igvn), |
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724 _dom_lca_tags(C->comp_arena()), |
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725 _verify_me(NULL), |
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726 _verify_only(false) { |
1172 | 727 build_and_optimize(do_split_ifs, do_loop_pred); |
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728 } |
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729 |
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730 // Verify that verify_me made the same decisions as a fresh run. |
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731 PhaseIdealLoop( PhaseIterGVN &igvn, const PhaseIdealLoop *verify_me) : |
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732 PhaseTransform(Ideal_Loop), |
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733 _igvn(igvn), |
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734 _dom_lca_tags(C->comp_arena()), |
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735 _verify_me(verify_me), |
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736 _verify_only(false) { |
1172 | 737 build_and_optimize(false, false); |
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738 } |
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739 |
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740 // Build and verify the loop tree without modifying the graph. This |
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741 // is useful to verify that all inputs properly dominate their uses. |
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742 static void verify(PhaseIterGVN& igvn) { |
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743 #ifdef ASSERT |
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744 PhaseIdealLoop v(igvn); |
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745 #endif |
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746 } |
0 | 747 |
748 // True if the method has at least 1 irreducible loop | |
749 bool _has_irreducible_loops; | |
750 | |
751 // Per-Node transform | |
752 virtual Node *transform( Node *a_node ) { return 0; } | |
753 | |
754 Node *is_counted_loop( Node *x, IdealLoopTree *loop ); | |
755 | |
756 // Return a post-walked LoopNode | |
757 IdealLoopTree *get_loop( Node *n ) const { | |
758 // Dead nodes have no loop, so return the top level loop instead | |
759 if (!has_node(n)) return _ltree_root; | |
760 assert(!has_ctrl(n), ""); | |
761 return (IdealLoopTree*)_nodes[n->_idx]; | |
762 } | |
763 | |
764 // Is 'n' a (nested) member of 'loop'? | |
765 int is_member( const IdealLoopTree *loop, Node *n ) const { | |
766 return loop->is_member(get_loop(n)); } | |
767 | |
768 // This is the basic building block of the loop optimizations. It clones an | |
769 // entire loop body. It makes an old_new loop body mapping; with this | |
770 // mapping you can find the new-loop equivalent to an old-loop node. All | |
771 // new-loop nodes are exactly equal to their old-loop counterparts, all | |
772 // edges are the same. All exits from the old-loop now have a RegionNode | |
773 // that merges the equivalent new-loop path. This is true even for the | |
774 // normal "loop-exit" condition. All uses of loop-invariant old-loop values | |
775 // now come from (one or more) Phis that merge their new-loop equivalents. | |
776 // Parameter side_by_side_idom: | |
777 // When side_by_size_idom is NULL, the dominator tree is constructed for | |
778 // the clone loop to dominate the original. Used in construction of | |
779 // pre-main-post loop sequence. | |
780 // When nonnull, the clone and original are side-by-side, both are | |
781 // dominated by the passed in side_by_side_idom node. Used in | |
782 // construction of unswitched loops. | |
783 void clone_loop( IdealLoopTree *loop, Node_List &old_new, int dom_depth, | |
784 Node* side_by_side_idom = NULL); | |
785 | |
786 // If we got the effect of peeling, either by actually peeling or by | |
787 // making a pre-loop which must execute at least once, we can remove | |
788 // all loop-invariant dominated tests in the main body. | |
789 void peeled_dom_test_elim( IdealLoopTree *loop, Node_List &old_new ); | |
790 | |
791 // Generate code to do a loop peel for the given loop (and body). | |
792 // old_new is a temp array. | |
793 void do_peeling( IdealLoopTree *loop, Node_List &old_new ); | |
794 | |
795 // Add pre and post loops around the given loop. These loops are used | |
796 // during RCE, unrolling and aligning loops. | |
797 void insert_pre_post_loops( IdealLoopTree *loop, Node_List &old_new, bool peel_only ); | |
798 // If Node n lives in the back_ctrl block, we clone a private version of n | |
799 // in preheader_ctrl block and return that, otherwise return n. | |
800 Node *clone_up_backedge_goo( Node *back_ctrl, Node *preheader_ctrl, Node *n ); | |
801 | |
802 // Take steps to maximally unroll the loop. Peel any odd iterations, then | |
803 // unroll to do double iterations. The next round of major loop transforms | |
804 // will repeat till the doubled loop body does all remaining iterations in 1 | |
805 // pass. | |
806 void do_maximally_unroll( IdealLoopTree *loop, Node_List &old_new ); | |
807 | |
808 // Unroll the loop body one step - make each trip do 2 iterations. | |
809 void do_unroll( IdealLoopTree *loop, Node_List &old_new, bool adjust_min_trip ); | |
810 | |
811 // Return true if exp is a constant times an induction var | |
812 bool is_scaled_iv(Node* exp, Node* iv, int* p_scale); | |
813 | |
814 // Return true if exp is a scaled induction var plus (or minus) constant | |
815 bool is_scaled_iv_plus_offset(Node* exp, Node* iv, int* p_scale, Node** p_offset, int depth = 0); | |
816 | |
1172 | 817 // Return true if proj is for "proj->[region->..]call_uct" |
818 bool is_uncommon_trap_proj(ProjNode* proj, bool must_reason_predicate = false); | |
819 // Return true for "if(test)-> proj -> ... | |
820 // | | |
821 // V | |
822 // other_proj->[region->..]call_uct" | |
823 bool is_uncommon_trap_if_pattern(ProjNode* proj, bool must_reason_predicate = false); | |
824 // Create a new if above the uncommon_trap_if_pattern for the predicate to be promoted | |
825 ProjNode* create_new_if_for_predicate(ProjNode* cont_proj); | |
826 // Find a good location to insert a predicate | |
827 ProjNode* find_predicate_insertion_point(Node* start_c); | |
828 // Construct a range check for a predicate if | |
829 BoolNode* rc_predicate(Node* ctrl, | |
830 int scale, Node* offset, | |
831 Node* init, Node* limit, Node* stride, | |
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6930043: C2: SIGSEGV in javasoft.sqe.tests.lang.arr017.arr01702.arr01702.loop_forw(II)I
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832 Node* range, bool upper); |
1172 | 833 |
834 // Implementation of the loop predication to promote checks outside the loop | |
835 bool loop_predication_impl(IdealLoopTree *loop); | |
836 | |
837 // Helper function to collect predicate for eliminating the useless ones | |
838 void collect_potentially_useful_predicates(IdealLoopTree *loop, Unique_Node_List &predicate_opaque1); | |
839 void eliminate_useless_predicates(); | |
840 | |
0 | 841 // Eliminate range-checks and other trip-counter vs loop-invariant tests. |
842 void do_range_check( IdealLoopTree *loop, Node_List &old_new ); | |
843 | |
844 // Create a slow version of the loop by cloning the loop | |
845 // and inserting an if to select fast-slow versions. | |
846 ProjNode* create_slow_version_of_loop(IdealLoopTree *loop, | |
847 Node_List &old_new); | |
848 | |
849 // Clone loop with an invariant test (that does not exit) and | |
850 // insert a clone of the test that selects which version to | |
851 // execute. | |
852 void do_unswitching (IdealLoopTree *loop, Node_List &old_new); | |
853 | |
854 // Find candidate "if" for unswitching | |
855 IfNode* find_unswitching_candidate(const IdealLoopTree *loop) const; | |
856 | |
857 // Range Check Elimination uses this function! | |
858 // Constrain the main loop iterations so the affine function: | |
859 // scale_con * I + offset < limit | |
860 // always holds true. That is, either increase the number of iterations in | |
861 // the pre-loop or the post-loop until the condition holds true in the main | |
862 // loop. Scale_con, offset and limit are all loop invariant. | |
863 void add_constraint( int stride_con, int scale_con, Node *offset, Node *limit, Node *pre_ctrl, Node **pre_limit, Node **main_limit ); | |
864 | |
865 // Partially peel loop up through last_peel node. | |
866 bool partial_peel( IdealLoopTree *loop, Node_List &old_new ); | |
867 | |
868 // Create a scheduled list of nodes control dependent on ctrl set. | |
869 void scheduled_nodelist( IdealLoopTree *loop, VectorSet& ctrl, Node_List &sched ); | |
870 // Has a use in the vector set | |
871 bool has_use_in_set( Node* n, VectorSet& vset ); | |
872 // Has use internal to the vector set (ie. not in a phi at the loop head) | |
873 bool has_use_internal_to_set( Node* n, VectorSet& vset, IdealLoopTree *loop ); | |
874 // clone "n" for uses that are outside of loop | |
875 void clone_for_use_outside_loop( IdealLoopTree *loop, Node* n, Node_List& worklist ); | |
876 // clone "n" for special uses that are in the not_peeled region | |
877 void clone_for_special_use_inside_loop( IdealLoopTree *loop, Node* n, | |
878 VectorSet& not_peel, Node_List& sink_list, Node_List& worklist ); | |
879 // Insert phi(lp_entry_val, back_edge_val) at use->in(idx) for loop lp if phi does not already exist | |
880 void insert_phi_for_loop( Node* use, uint idx, Node* lp_entry_val, Node* back_edge_val, LoopNode* lp ); | |
881 #ifdef ASSERT | |
882 // Validate the loop partition sets: peel and not_peel | |
883 bool is_valid_loop_partition( IdealLoopTree *loop, VectorSet& peel, Node_List& peel_list, VectorSet& not_peel ); | |
884 // Ensure that uses outside of loop are of the right form | |
885 bool is_valid_clone_loop_form( IdealLoopTree *loop, Node_List& peel_list, | |
886 uint orig_exit_idx, uint clone_exit_idx); | |
887 bool is_valid_clone_loop_exit_use( IdealLoopTree *loop, Node* use, uint exit_idx); | |
888 #endif | |
889 | |
890 // Returns nonzero constant stride if-node is a possible iv test (otherwise returns zero.) | |
891 int stride_of_possible_iv( Node* iff ); | |
892 bool is_possible_iv_test( Node* iff ) { return stride_of_possible_iv(iff) != 0; } | |
893 // Return the (unique) control output node that's in the loop (if it exists.) | |
894 Node* stay_in_loop( Node* n, IdealLoopTree *loop); | |
895 // Insert a signed compare loop exit cloned from an unsigned compare. | |
896 IfNode* insert_cmpi_loop_exit(IfNode* if_cmpu, IdealLoopTree *loop); | |
897 void remove_cmpi_loop_exit(IfNode* if_cmp, IdealLoopTree *loop); | |
898 // Utility to register node "n" with PhaseIdealLoop | |
899 void register_node(Node* n, IdealLoopTree *loop, Node* pred, int ddepth); | |
900 // Utility to create an if-projection | |
901 ProjNode* proj_clone(ProjNode* p, IfNode* iff); | |
902 // Force the iff control output to be the live_proj | |
903 Node* short_circuit_if(IfNode* iff, ProjNode* live_proj); | |
904 // Insert a region before an if projection | |
905 RegionNode* insert_region_before_proj(ProjNode* proj); | |
906 // Insert a new if before an if projection | |
907 ProjNode* insert_if_before_proj(Node* left, bool Signed, BoolTest::mask relop, Node* right, ProjNode* proj); | |
908 | |
909 // Passed in a Phi merging (recursively) some nearly equivalent Bool/Cmps. | |
910 // "Nearly" because all Nodes have been cloned from the original in the loop, | |
911 // but the fall-in edges to the Cmp are different. Clone bool/Cmp pairs | |
912 // through the Phi recursively, and return a Bool. | |
913 BoolNode *clone_iff( PhiNode *phi, IdealLoopTree *loop ); | |
914 CmpNode *clone_bool( PhiNode *phi, IdealLoopTree *loop ); | |
915 | |
916 | |
917 // Rework addressing expressions to get the most loop-invariant stuff | |
918 // moved out. We'd like to do all associative operators, but it's especially | |
919 // important (common) to do address expressions. | |
920 Node *remix_address_expressions( Node *n ); | |
921 | |
922 // Attempt to use a conditional move instead of a phi/branch | |
923 Node *conditional_move( Node *n ); | |
924 | |
925 // Reorganize offset computations to lower register pressure. | |
926 // Mostly prevent loop-fallout uses of the pre-incremented trip counter | |
927 // (which are then alive with the post-incremented trip counter | |
928 // forcing an extra register move) | |
929 void reorg_offsets( IdealLoopTree *loop ); | |
930 | |
931 // Check for aggressive application of 'split-if' optimization, | |
932 // using basic block level info. | |
933 void split_if_with_blocks ( VectorSet &visited, Node_Stack &nstack ); | |
934 Node *split_if_with_blocks_pre ( Node *n ); | |
935 void split_if_with_blocks_post( Node *n ); | |
936 Node *has_local_phi_input( Node *n ); | |
937 // Mark an IfNode as being dominated by a prior test, | |
938 // without actually altering the CFG (and hence IDOM info). | |
939 void dominated_by( Node *prevdom, Node *iff ); | |
940 | |
941 // Split Node 'n' through merge point | |
942 Node *split_thru_region( Node *n, Node *region ); | |
943 // Split Node 'n' through merge point if there is enough win. | |
944 Node *split_thru_phi( Node *n, Node *region, int policy ); | |
945 // Found an If getting its condition-code input from a Phi in the | |
946 // same block. Split thru the Region. | |
947 void do_split_if( Node *iff ); | |
948 | |
1763 | 949 // Conversion of fill/copy patterns into intrisic versions |
950 bool do_intrinsify_fill(); | |
951 bool intrinsify_fill(IdealLoopTree* lpt); | |
952 bool match_fill_loop(IdealLoopTree* lpt, Node*& store, Node*& store_value, | |
953 Node*& shift, Node*& offset); | |
954 | |
0 | 955 private: |
956 // Return a type based on condition control flow | |
957 const TypeInt* filtered_type( Node *n, Node* n_ctrl); | |
958 const TypeInt* filtered_type( Node *n ) { return filtered_type(n, NULL); } | |
959 // Helpers for filtered type | |
960 const TypeInt* filtered_type_from_dominators( Node* val, Node *val_ctrl); | |
961 | |
962 // Helper functions | |
963 Node *spinup( Node *iff, Node *new_false, Node *new_true, Node *region, Node *phi, small_cache *cache ); | |
964 Node *find_use_block( Node *use, Node *def, Node *old_false, Node *new_false, Node *old_true, Node *new_true ); | |
965 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 ); | |
966 bool split_up( Node *n, Node *blk1, Node *blk2 ); | |
967 void sink_use( Node *use, Node *post_loop ); | |
968 Node *place_near_use( Node *useblock ) const; | |
969 | |
970 bool _created_loop_node; | |
971 public: | |
972 void set_created_loop_node() { _created_loop_node = true; } | |
973 bool created_loop_node() { return _created_loop_node; } | |
1172 | 974 void register_new_node( Node *n, Node *blk ); |
0 | 975 |
976 #ifndef PRODUCT | |
977 void dump( ) const; | |
978 void dump( IdealLoopTree *loop, uint rpo_idx, Node_List &rpo_list ) const; | |
979 void rpo( Node *start, Node_Stack &stk, VectorSet &visited, Node_List &rpo_list ) const; | |
980 void verify() const; // Major slow :-) | |
981 void verify_compare( Node *n, const PhaseIdealLoop *loop_verify, VectorSet &visited ) const; | |
982 IdealLoopTree *get_loop_idx(Node* n) const { | |
983 // Dead nodes have no loop, so return the top level loop instead | |
984 return _nodes[n->_idx] ? (IdealLoopTree*)_nodes[n->_idx] : _ltree_root; | |
985 } | |
986 // Print some stats | |
987 static void print_statistics(); | |
988 static int _loop_invokes; // Count of PhaseIdealLoop invokes | |
989 static int _loop_work; // Sum of PhaseIdealLoop x _unique | |
990 #endif | |
991 }; | |
992 | |
993 inline Node* IdealLoopTree::tail() { | |
994 // Handle lazy update of _tail field | |
995 Node *n = _tail; | |
996 //while( !n->in(0) ) // Skip dead CFG nodes | |
997 //n = n->in(1); | |
998 if (n->in(0) == NULL) | |
999 n = _phase->get_ctrl(n); | |
1000 _tail = n; | |
1001 return n; | |
1002 } | |
1003 | |
1004 | |
1005 // Iterate over the loop tree using a preorder, left-to-right traversal. | |
1006 // | |
1007 // Example that visits all counted loops from within PhaseIdealLoop | |
1008 // | |
1009 // for (LoopTreeIterator iter(_ltree_root); !iter.done(); iter.next()) { | |
1010 // IdealLoopTree* lpt = iter.current(); | |
1011 // if (!lpt->is_counted()) continue; | |
1012 // ... | |
1013 class LoopTreeIterator : public StackObj { | |
1014 private: | |
1015 IdealLoopTree* _root; | |
1016 IdealLoopTree* _curnt; | |
1017 | |
1018 public: | |
1019 LoopTreeIterator(IdealLoopTree* root) : _root(root), _curnt(root) {} | |
1020 | |
1021 bool done() { return _curnt == NULL; } // Finished iterating? | |
1022 | |
1023 void next(); // Advance to next loop tree | |
1024 | |
1025 IdealLoopTree* current() { return _curnt; } // Return current value of iterator. | |
1026 }; | |
1972 | 1027 |
1028 #endif // SHARE_VM_OPTO_LOOPNODE_HPP |