0
|
1 /*
|
|
2 * Copyright 1998-2007 Sun Microsystems, Inc. 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 *
|
|
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 *
|
|
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
|
|
20 * CA 95054 USA or visit www.sun.com if you need additional information or
|
|
21 * have any questions.
|
|
22 *
|
|
23 */
|
|
24
|
|
25 class CmpNode;
|
|
26 class CountedLoopEndNode;
|
|
27 class CountedLoopNode;
|
|
28 class IdealLoopTree;
|
|
29 class LoopNode;
|
|
30 class Node;
|
|
31 class PhaseIdealLoop;
|
|
32 class VectorSet;
|
|
33 struct small_cache;
|
|
34
|
|
35 //
|
|
36 // I D E A L I Z E D L O O P S
|
|
37 //
|
|
38 // Idealized loops are the set of loops I perform more interesting
|
|
39 // transformations on, beyond simple hoisting.
|
|
40
|
|
41 //------------------------------LoopNode---------------------------------------
|
|
42 // Simple loop header. Fall in path on left, loop-back path on right.
|
|
43 class LoopNode : public RegionNode {
|
|
44 // Size is bigger to hold the flags. However, the flags do not change
|
|
45 // the semantics so it does not appear in the hash & cmp functions.
|
|
46 virtual uint size_of() const { return sizeof(*this); }
|
|
47 protected:
|
|
48 short _loop_flags;
|
|
49 // Names for flag bitfields
|
|
50 enum { pre_post_main=0, inner_loop=8, partial_peel_loop=16, partial_peel_failed=32 };
|
|
51 char _unswitch_count;
|
|
52 enum { _unswitch_max=3 };
|
|
53
|
|
54 public:
|
|
55 // Names for edge indices
|
|
56 enum { Self=0, EntryControl, LoopBackControl };
|
|
57
|
|
58 int is_inner_loop() const { return _loop_flags & inner_loop; }
|
|
59 void set_inner_loop() { _loop_flags |= inner_loop; }
|
|
60
|
|
61 int is_partial_peel_loop() const { return _loop_flags & partial_peel_loop; }
|
|
62 void set_partial_peel_loop() { _loop_flags |= partial_peel_loop; }
|
|
63 int partial_peel_has_failed() const { return _loop_flags & partial_peel_failed; }
|
|
64 void mark_partial_peel_failed() { _loop_flags |= partial_peel_failed; }
|
|
65
|
|
66 int unswitch_max() { return _unswitch_max; }
|
|
67 int unswitch_count() { return _unswitch_count; }
|
|
68 void set_unswitch_count(int val) {
|
|
69 assert (val <= unswitch_max(), "too many unswitches");
|
|
70 _unswitch_count = val;
|
|
71 }
|
|
72
|
|
73 LoopNode( Node *entry, Node *backedge ) : RegionNode(3), _loop_flags(0), _unswitch_count(0) {
|
|
74 init_class_id(Class_Loop);
|
|
75 init_req(EntryControl, entry);
|
|
76 init_req(LoopBackControl, backedge);
|
|
77 }
|
|
78
|
|
79 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
|
|
80 virtual int Opcode() const;
|
|
81 bool can_be_counted_loop(PhaseTransform* phase) const {
|
|
82 return req() == 3 && in(0) != NULL &&
|
|
83 in(1) != NULL && phase->type(in(1)) != Type::TOP &&
|
|
84 in(2) != NULL && phase->type(in(2)) != Type::TOP;
|
|
85 }
|
|
86 #ifndef PRODUCT
|
|
87 virtual void dump_spec(outputStream *st) const;
|
|
88 #endif
|
|
89 };
|
|
90
|
|
91 //------------------------------Counted Loops----------------------------------
|
|
92 // Counted loops are all trip-counted loops, with exactly 1 trip-counter exit
|
|
93 // path (and maybe some other exit paths). The trip-counter exit is always
|
|
94 // last in the loop. The trip-counter does not have to stride by a constant,
|
|
95 // but it does have to stride by a loop-invariant amount; the exit value is
|
|
96 // also loop invariant.
|
|
97
|
|
98 // CountedLoopNodes and CountedLoopEndNodes come in matched pairs. The
|
|
99 // CountedLoopNode has the incoming loop control and the loop-back-control
|
|
100 // which is always the IfTrue before the matching CountedLoopEndNode. The
|
|
101 // CountedLoopEndNode has an incoming control (possibly not the
|
|
102 // CountedLoopNode if there is control flow in the loop), the post-increment
|
|
103 // trip-counter value, and the limit. The trip-counter value is always of
|
|
104 // the form (Op old-trip-counter stride). The old-trip-counter is produced
|
|
105 // by a Phi connected to the CountedLoopNode. The stride is loop invariant.
|
|
106 // The Op is any commutable opcode, including Add, Mul, Xor. The
|
|
107 // CountedLoopEndNode also takes in the loop-invariant limit value.
|
|
108
|
|
109 // From a CountedLoopNode I can reach the matching CountedLoopEndNode via the
|
|
110 // loop-back control. From CountedLoopEndNodes I can reach CountedLoopNodes
|
|
111 // via the old-trip-counter from the Op node.
|
|
112
|
|
113 //------------------------------CountedLoopNode--------------------------------
|
|
114 // CountedLoopNodes head simple counted loops. CountedLoopNodes have as
|
|
115 // inputs the incoming loop-start control and the loop-back control, so they
|
|
116 // act like RegionNodes. They also take in the initial trip counter, the
|
|
117 // loop-invariant stride and the loop-invariant limit value. CountedLoopNodes
|
|
118 // produce a loop-body control and the trip counter value. Since
|
|
119 // CountedLoopNodes behave like RegionNodes I still have a standard CFG model.
|
|
120
|
|
121 class CountedLoopNode : public LoopNode {
|
|
122 // Size is bigger to hold _main_idx. However, _main_idx does not change
|
|
123 // the semantics so it does not appear in the hash & cmp functions.
|
|
124 virtual uint size_of() const { return sizeof(*this); }
|
|
125
|
|
126 // For Pre- and Post-loops during debugging ONLY, this holds the index of
|
|
127 // the Main CountedLoop. Used to assert that we understand the graph shape.
|
|
128 node_idx_t _main_idx;
|
|
129
|
|
130 // Known trip count calculated by policy_maximally_unroll
|
|
131 int _trip_count;
|
|
132
|
|
133 // Expected trip count from profile data
|
|
134 float _profile_trip_cnt;
|
|
135
|
|
136 // Log2 of original loop bodies in unrolled loop
|
|
137 int _unrolled_count_log2;
|
|
138
|
|
139 // Node count prior to last unrolling - used to decide if
|
|
140 // unroll,optimize,unroll,optimize,... is making progress
|
|
141 int _node_count_before_unroll;
|
|
142
|
|
143 public:
|
|
144 CountedLoopNode( Node *entry, Node *backedge )
|
|
145 : LoopNode(entry, backedge), _trip_count(max_jint),
|
|
146 _profile_trip_cnt(COUNT_UNKNOWN), _unrolled_count_log2(0),
|
|
147 _node_count_before_unroll(0) {
|
|
148 init_class_id(Class_CountedLoop);
|
|
149 // Initialize _trip_count to the largest possible value.
|
|
150 // Will be reset (lower) if the loop's trip count is known.
|
|
151 }
|
|
152
|
|
153 virtual int Opcode() const;
|
|
154 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
|
|
155
|
|
156 Node *init_control() const { return in(EntryControl); }
|
|
157 Node *back_control() const { return in(LoopBackControl); }
|
|
158 CountedLoopEndNode *loopexit() const;
|
|
159 Node *init_trip() const;
|
|
160 Node *stride() const;
|
|
161 int stride_con() const;
|
|
162 bool stride_is_con() const;
|
|
163 Node *limit() const;
|
|
164 Node *incr() const;
|
|
165 Node *phi() const;
|
|
166
|
|
167 // Match increment with optional truncation
|
|
168 static Node* match_incr_with_optional_truncation(Node* expr, Node** trunc1, Node** trunc2, const TypeInt** trunc_type);
|
|
169
|
|
170 // A 'main' loop has a pre-loop and a post-loop. The 'main' loop
|
|
171 // can run short a few iterations and may start a few iterations in.
|
|
172 // It will be RCE'd and unrolled and aligned.
|
|
173
|
|
174 // A following 'post' loop will run any remaining iterations. Used
|
|
175 // during Range Check Elimination, the 'post' loop will do any final
|
|
176 // iterations with full checks. Also used by Loop Unrolling, where
|
|
177 // the 'post' loop will do any epilog iterations needed. Basically,
|
|
178 // a 'post' loop can not profitably be further unrolled or RCE'd.
|
|
179
|
|
180 // A preceding 'pre' loop will run at least 1 iteration (to do peeling),
|
|
181 // it may do under-flow checks for RCE and may do alignment iterations
|
|
182 // so the following main loop 'knows' that it is striding down cache
|
|
183 // lines.
|
|
184
|
|
185 // A 'main' loop that is ONLY unrolled or peeled, never RCE'd or
|
|
186 // Aligned, may be missing it's pre-loop.
|
|
187 enum { Normal=0, Pre=1, Main=2, Post=3, PrePostFlagsMask=3, Main_Has_No_Pre_Loop=4 };
|
|
188 int is_normal_loop() const { return (_loop_flags&PrePostFlagsMask) == Normal; }
|
|
189 int is_pre_loop () const { return (_loop_flags&PrePostFlagsMask) == Pre; }
|
|
190 int is_main_loop () const { return (_loop_flags&PrePostFlagsMask) == Main; }
|
|
191 int is_post_loop () const { return (_loop_flags&PrePostFlagsMask) == Post; }
|
|
192 int is_main_no_pre_loop() const { return _loop_flags & Main_Has_No_Pre_Loop; }
|
|
193 void set_main_no_pre_loop() { _loop_flags |= Main_Has_No_Pre_Loop; }
|
|
194
|
|
195
|
|
196 void set_pre_loop (CountedLoopNode *main) { assert(is_normal_loop(),""); _loop_flags |= Pre ; _main_idx = main->_idx; }
|
|
197 void set_main_loop ( ) { assert(is_normal_loop(),""); _loop_flags |= Main; }
|
|
198 void set_post_loop (CountedLoopNode *main) { assert(is_normal_loop(),""); _loop_flags |= Post; _main_idx = main->_idx; }
|
|
199 void set_normal_loop( ) { _loop_flags &= ~PrePostFlagsMask; }
|
|
200
|
|
201 void set_trip_count(int tc) { _trip_count = tc; }
|
|
202 int trip_count() { return _trip_count; }
|
|
203
|
|
204 void set_profile_trip_cnt(float ptc) { _profile_trip_cnt = ptc; }
|
|
205 float profile_trip_cnt() { return _profile_trip_cnt; }
|
|
206
|
|
207 void double_unrolled_count() { _unrolled_count_log2++; }
|
|
208 int unrolled_count() { return 1 << MIN2(_unrolled_count_log2, BitsPerInt-3); }
|
|
209
|
|
210 void set_node_count_before_unroll(int ct) { _node_count_before_unroll = ct; }
|
|
211 int node_count_before_unroll() { return _node_count_before_unroll; }
|
|
212
|
|
213 #ifndef PRODUCT
|
|
214 virtual void dump_spec(outputStream *st) const;
|
|
215 #endif
|
|
216 };
|
|
217
|
|
218 //------------------------------CountedLoopEndNode-----------------------------
|
|
219 // CountedLoopEndNodes end simple trip counted loops. They act much like
|
|
220 // IfNodes.
|
|
221 class CountedLoopEndNode : public IfNode {
|
|
222 public:
|
|
223 enum { TestControl, TestValue };
|
|
224
|
|
225 CountedLoopEndNode( Node *control, Node *test, float prob, float cnt )
|
|
226 : IfNode( control, test, prob, cnt) {
|
|
227 init_class_id(Class_CountedLoopEnd);
|
|
228 }
|
|
229 virtual int Opcode() const;
|
|
230
|
|
231 Node *cmp_node() const { return (in(TestValue)->req() >=2) ? in(TestValue)->in(1) : NULL; }
|
|
232 Node *incr() const { Node *tmp = cmp_node(); return (tmp && tmp->req()==3) ? tmp->in(1) : NULL; }
|
|
233 Node *limit() const { Node *tmp = cmp_node(); return (tmp && tmp->req()==3) ? tmp->in(2) : NULL; }
|
|
234 Node *stride() const { Node *tmp = incr (); return (tmp && tmp->req()==3) ? tmp->in(2) : NULL; }
|
|
235 Node *phi() const { Node *tmp = incr (); return (tmp && tmp->req()==3) ? tmp->in(1) : NULL; }
|
|
236 Node *init_trip() const { Node *tmp = phi (); return (tmp && tmp->req()==3) ? tmp->in(1) : NULL; }
|
|
237 int stride_con() const;
|
|
238 bool stride_is_con() const { Node *tmp = stride (); return (tmp != NULL && tmp->is_Con()); }
|
|
239 BoolTest::mask test_trip() const { return in(TestValue)->as_Bool()->_test._test; }
|
|
240 CountedLoopNode *loopnode() const {
|
|
241 Node *ln = phi()->in(0);
|
|
242 assert( ln->Opcode() == Op_CountedLoop, "malformed loop" );
|
|
243 return (CountedLoopNode*)ln; }
|
|
244
|
|
245 #ifndef PRODUCT
|
|
246 virtual void dump_spec(outputStream *st) const;
|
|
247 #endif
|
|
248 };
|
|
249
|
|
250
|
|
251 inline CountedLoopEndNode *CountedLoopNode::loopexit() const {
|
|
252 Node *bc = back_control();
|
|
253 if( bc == NULL ) return NULL;
|
|
254 Node *le = bc->in(0);
|
|
255 if( le->Opcode() != Op_CountedLoopEnd )
|
|
256 return NULL;
|
|
257 return (CountedLoopEndNode*)le;
|
|
258 }
|
|
259 inline Node *CountedLoopNode::init_trip() const { return loopexit() ? loopexit()->init_trip() : NULL; }
|
|
260 inline Node *CountedLoopNode::stride() const { return loopexit() ? loopexit()->stride() : NULL; }
|
|
261 inline int CountedLoopNode::stride_con() const { return loopexit() ? loopexit()->stride_con() : 0; }
|
|
262 inline bool CountedLoopNode::stride_is_con() const { return loopexit() && loopexit()->stride_is_con(); }
|
|
263 inline Node *CountedLoopNode::limit() const { return loopexit() ? loopexit()->limit() : NULL; }
|
|
264 inline Node *CountedLoopNode::incr() const { return loopexit() ? loopexit()->incr() : NULL; }
|
|
265 inline Node *CountedLoopNode::phi() const { return loopexit() ? loopexit()->phi() : NULL; }
|
|
266
|
|
267
|
|
268 // -----------------------------IdealLoopTree----------------------------------
|
|
269 class IdealLoopTree : public ResourceObj {
|
|
270 public:
|
|
271 IdealLoopTree *_parent; // Parent in loop tree
|
|
272 IdealLoopTree *_next; // Next sibling in loop tree
|
|
273 IdealLoopTree *_child; // First child in loop tree
|
|
274
|
|
275 // The head-tail backedge defines the loop.
|
|
276 // If tail is NULL then this loop has multiple backedges as part of the
|
|
277 // same loop. During cleanup I'll peel off the multiple backedges; merge
|
|
278 // them at the loop bottom and flow 1 real backedge into the loop.
|
|
279 Node *_head; // Head of loop
|
|
280 Node *_tail; // Tail of loop
|
|
281 inline Node *tail(); // Handle lazy update of _tail field
|
|
282 PhaseIdealLoop* _phase;
|
|
283
|
|
284 Node_List _body; // Loop body for inner loops
|
|
285
|
|
286 uint8 _nest; // Nesting depth
|
|
287 uint8 _irreducible:1, // True if irreducible
|
|
288 _has_call:1, // True if has call safepoint
|
|
289 _has_sfpt:1, // True if has non-call safepoint
|
|
290 _rce_candidate:1; // True if candidate for range check elimination
|
|
291
|
|
292 Node_List* _required_safept; // A inner loop cannot delete these safepts;
|
|
293
|
|
294 IdealLoopTree( PhaseIdealLoop* phase, Node *head, Node *tail )
|
|
295 : _parent(0), _next(0), _child(0),
|
|
296 _head(head), _tail(tail),
|
|
297 _phase(phase),
|
|
298 _required_safept(NULL),
|
|
299 _nest(0), _irreducible(0), _has_call(0), _has_sfpt(0), _rce_candidate(0)
|
|
300 { }
|
|
301
|
|
302 // Is 'l' a member of 'this'?
|
|
303 int is_member( const IdealLoopTree *l ) const; // Test for nested membership
|
|
304
|
|
305 // Set loop nesting depth. Accumulate has_call bits.
|
|
306 int set_nest( uint depth );
|
|
307
|
|
308 // Split out multiple fall-in edges from the loop header. Move them to a
|
|
309 // private RegionNode before the loop. This becomes the loop landing pad.
|
|
310 void split_fall_in( PhaseIdealLoop *phase, int fall_in_cnt );
|
|
311
|
|
312 // Split out the outermost loop from this shared header.
|
|
313 void split_outer_loop( PhaseIdealLoop *phase );
|
|
314
|
|
315 // Merge all the backedges from the shared header into a private Region.
|
|
316 // Feed that region as the one backedge to this loop.
|
|
317 void merge_many_backedges( PhaseIdealLoop *phase );
|
|
318
|
|
319 // Split shared headers and insert loop landing pads.
|
|
320 // Insert a LoopNode to replace the RegionNode.
|
|
321 // Returns TRUE if loop tree is structurally changed.
|
|
322 bool beautify_loops( PhaseIdealLoop *phase );
|
|
323
|
|
324 // Perform iteration-splitting on inner loops. Split iterations to avoid
|
|
325 // range checks or one-shot null checks.
|
|
326 void iteration_split( PhaseIdealLoop *phase, Node_List &old_new );
|
|
327
|
|
328 // Driver for various flavors of iteration splitting
|
|
329 void iteration_split_impl( PhaseIdealLoop *phase, Node_List &old_new );
|
|
330
|
|
331 // Given dominators, try to find loops with calls that must always be
|
|
332 // executed (call dominates loop tail). These loops do not need non-call
|
|
333 // safepoints (ncsfpt).
|
|
334 void check_safepts(VectorSet &visited, Node_List &stack);
|
|
335
|
|
336 // Allpaths backwards scan from loop tail, terminating each path at first safepoint
|
|
337 // encountered.
|
|
338 void allpaths_check_safepts(VectorSet &visited, Node_List &stack);
|
|
339
|
|
340 // Convert to counted loops where possible
|
|
341 void counted_loop( PhaseIdealLoop *phase );
|
|
342
|
|
343 // Check for Node being a loop-breaking test
|
|
344 Node *is_loop_exit(Node *iff) const;
|
|
345
|
|
346 // Returns true if ctrl is executed on every complete iteration
|
|
347 bool dominates_backedge(Node* ctrl);
|
|
348
|
|
349 // Remove simplistic dead code from loop body
|
|
350 void DCE_loop_body();
|
|
351
|
|
352 // Look for loop-exit tests with my 50/50 guesses from the Parsing stage.
|
|
353 // Replace with a 1-in-10 exit guess.
|
|
354 void adjust_loop_exit_prob( PhaseIdealLoop *phase );
|
|
355
|
|
356 // Return TRUE or FALSE if the loop should never be RCE'd or aligned.
|
|
357 // Useful for unrolling loops with NO array accesses.
|
|
358 bool policy_peel_only( PhaseIdealLoop *phase ) const;
|
|
359
|
|
360 // Return TRUE or FALSE if the loop should be unswitched -- clone
|
|
361 // loop with an invariant test
|
|
362 bool policy_unswitching( PhaseIdealLoop *phase ) const;
|
|
363
|
|
364 // Micro-benchmark spamming. Remove empty loops.
|
|
365 bool policy_do_remove_empty_loop( PhaseIdealLoop *phase );
|
|
366
|
|
367 // Return TRUE or FALSE if the loop should be peeled or not. Peel if we can
|
|
368 // make some loop-invariant test (usually a null-check) happen before the
|
|
369 // loop.
|
|
370 bool policy_peeling( PhaseIdealLoop *phase ) const;
|
|
371
|
|
372 // Return TRUE or FALSE if the loop should be maximally unrolled. Stash any
|
|
373 // known trip count in the counted loop node.
|
|
374 bool policy_maximally_unroll( PhaseIdealLoop *phase ) const;
|
|
375
|
|
376 // Return TRUE or FALSE if the loop should be unrolled or not. Unroll if
|
|
377 // the loop is a CountedLoop and the body is small enough.
|
|
378 bool policy_unroll( PhaseIdealLoop *phase ) const;
|
|
379
|
|
380 // Return TRUE or FALSE if the loop should be range-check-eliminated.
|
|
381 // Gather a list of IF tests that are dominated by iteration splitting;
|
|
382 // also gather the end of the first split and the start of the 2nd split.
|
|
383 bool policy_range_check( PhaseIdealLoop *phase ) const;
|
|
384
|
|
385 // Return TRUE or FALSE if the loop should be cache-line aligned.
|
|
386 // Gather the expression that does the alignment. Note that only
|
|
387 // one array base can be aligned in a loop (unless the VM guarentees
|
|
388 // mutual alignment). Note that if we vectorize short memory ops
|
|
389 // into longer memory ops, we may want to increase alignment.
|
|
390 bool policy_align( PhaseIdealLoop *phase ) const;
|
|
391
|
|
392 // Compute loop trip count from profile data
|
|
393 void compute_profile_trip_cnt( PhaseIdealLoop *phase );
|
|
394
|
|
395 // Reassociate invariant expressions.
|
|
396 void reassociate_invariants(PhaseIdealLoop *phase);
|
|
397 // Reassociate invariant add and subtract expressions.
|
|
398 Node* reassociate_add_sub(Node* n1, PhaseIdealLoop *phase);
|
|
399 // Return nonzero index of invariant operand if invariant and variant
|
|
400 // are combined with an Add or Sub. Helper for reassoicate_invariants.
|
|
401 int is_invariant_addition(Node* n, PhaseIdealLoop *phase);
|
|
402
|
|
403 // Return true if n is invariant
|
|
404 bool is_invariant(Node* n) const;
|
|
405
|
|
406 // Put loop body on igvn work list
|
|
407 void record_for_igvn();
|
|
408
|
|
409 bool is_loop() { return !_irreducible && _tail && !_tail->is_top(); }
|
|
410 bool is_inner() { return is_loop() && _child == NULL; }
|
|
411 bool is_counted() { return is_loop() && _head != NULL && _head->is_CountedLoop(); }
|
|
412
|
|
413 #ifndef PRODUCT
|
|
414 void dump_head( ) const; // Dump loop head only
|
|
415 void dump() const; // Dump this loop recursively
|
|
416 void verify_tree(IdealLoopTree *loop, const IdealLoopTree *parent) const;
|
|
417 #endif
|
|
418
|
|
419 };
|
|
420
|
|
421 // -----------------------------PhaseIdealLoop---------------------------------
|
|
422 // Computes the mapping from Nodes to IdealLoopTrees. Organizes IdealLoopTrees into a
|
|
423 // loop tree. Drives the loop-based transformations on the ideal graph.
|
|
424 class PhaseIdealLoop : public PhaseTransform {
|
|
425 friend class IdealLoopTree;
|
|
426 friend class SuperWord;
|
|
427 // Pre-computed def-use info
|
|
428 PhaseIterGVN &_igvn;
|
|
429
|
|
430 // Head of loop tree
|
|
431 IdealLoopTree *_ltree_root;
|
|
432
|
|
433 // Array of pre-order numbers, plus post-visited bit.
|
|
434 // ZERO for not pre-visited. EVEN for pre-visited but not post-visited.
|
|
435 // ODD for post-visited. Other bits are the pre-order number.
|
|
436 uint *_preorders;
|
|
437 uint _max_preorder;
|
|
438
|
|
439 // Allocate _preorders[] array
|
|
440 void allocate_preorders() {
|
|
441 _max_preorder = C->unique()+8;
|
|
442 _preorders = NEW_RESOURCE_ARRAY(uint, _max_preorder);
|
|
443 memset(_preorders, 0, sizeof(uint) * _max_preorder);
|
|
444 }
|
|
445
|
|
446 // Allocate _preorders[] array
|
|
447 void reallocate_preorders() {
|
|
448 if ( _max_preorder < C->unique() ) {
|
|
449 _preorders = REALLOC_RESOURCE_ARRAY(uint, _preorders, _max_preorder, C->unique());
|
|
450 _max_preorder = C->unique();
|
|
451 }
|
|
452 memset(_preorders, 0, sizeof(uint) * _max_preorder);
|
|
453 }
|
|
454
|
|
455 // Check to grow _preorders[] array for the case when build_loop_tree_impl()
|
|
456 // adds new nodes.
|
|
457 void check_grow_preorders( ) {
|
|
458 if ( _max_preorder < C->unique() ) {
|
|
459 uint newsize = _max_preorder<<1; // double size of array
|
|
460 _preorders = REALLOC_RESOURCE_ARRAY(uint, _preorders, _max_preorder, newsize);
|
|
461 memset(&_preorders[_max_preorder],0,sizeof(uint)*(newsize-_max_preorder));
|
|
462 _max_preorder = newsize;
|
|
463 }
|
|
464 }
|
|
465 // Check for pre-visited. Zero for NOT visited; non-zero for visited.
|
|
466 int is_visited( Node *n ) const { return _preorders[n->_idx]; }
|
|
467 // Pre-order numbers are written to the Nodes array as low-bit-set values.
|
|
468 void set_preorder_visited( Node *n, int pre_order ) {
|
|
469 assert( !is_visited( n ), "already set" );
|
|
470 _preorders[n->_idx] = (pre_order<<1);
|
|
471 };
|
|
472 // Return pre-order number.
|
|
473 int get_preorder( Node *n ) const { assert( is_visited(n), "" ); return _preorders[n->_idx]>>1; }
|
|
474
|
|
475 // Check for being post-visited.
|
|
476 // Should be previsited already (checked with assert(is_visited(n))).
|
|
477 int is_postvisited( Node *n ) const { assert( is_visited(n), "" ); return _preorders[n->_idx]&1; }
|
|
478
|
|
479 // Mark as post visited
|
|
480 void set_postvisited( Node *n ) { assert( !is_postvisited( n ), "" ); _preorders[n->_idx] |= 1; }
|
|
481
|
|
482 // Set/get control node out. Set lower bit to distinguish from IdealLoopTree
|
|
483 // Returns true if "n" is a data node, false if it's a control node.
|
|
484 bool has_ctrl( Node *n ) const { return ((intptr_t)_nodes[n->_idx]) & 1; }
|
|
485
|
|
486 // clear out dead code after build_loop_late
|
|
487 Node_List _deadlist;
|
|
488
|
|
489 // Support for faster execution of get_late_ctrl()/dom_lca()
|
|
490 // when a node has many uses and dominator depth is deep.
|
|
491 Node_Array _dom_lca_tags;
|
|
492 void init_dom_lca_tags();
|
|
493 void clear_dom_lca_tags();
|
|
494 // Inline wrapper for frequent cases:
|
|
495 // 1) only one use
|
|
496 // 2) a use is the same as the current LCA passed as 'n1'
|
|
497 Node *dom_lca_for_get_late_ctrl( Node *lca, Node *n, Node *tag ) {
|
|
498 assert( n->is_CFG(), "" );
|
|
499 // Fast-path NULL lca
|
|
500 if( lca != NULL && lca != n ) {
|
|
501 assert( lca->is_CFG(), "" );
|
|
502 // find LCA of all uses
|
|
503 n = dom_lca_for_get_late_ctrl_internal( lca, n, tag );
|
|
504 }
|
|
505 return find_non_split_ctrl(n);
|
|
506 }
|
|
507 Node *dom_lca_for_get_late_ctrl_internal( Node *lca, Node *n, Node *tag );
|
|
508 // true if CFG node d dominates CFG node n
|
|
509 bool is_dominator(Node *d, Node *n);
|
|
510
|
|
511 // Helper function for directing control inputs away from CFG split
|
|
512 // points.
|
|
513 Node *find_non_split_ctrl( Node *ctrl ) const {
|
|
514 if (ctrl != NULL) {
|
|
515 if (ctrl->is_MultiBranch()) {
|
|
516 ctrl = ctrl->in(0);
|
|
517 }
|
|
518 assert(ctrl->is_CFG(), "CFG");
|
|
519 }
|
|
520 return ctrl;
|
|
521 }
|
|
522
|
|
523 public:
|
|
524 bool has_node( Node* n ) const { return _nodes[n->_idx] != NULL; }
|
|
525 // check if transform created new nodes that need _ctrl recorded
|
|
526 Node *get_late_ctrl( Node *n, Node *early );
|
|
527 Node *get_early_ctrl( Node *n );
|
|
528 void set_early_ctrl( Node *n );
|
|
529 void set_subtree_ctrl( Node *root );
|
|
530 void set_ctrl( Node *n, Node *ctrl ) {
|
|
531 assert( !has_node(n) || has_ctrl(n), "" );
|
|
532 assert( ctrl->in(0), "cannot set dead control node" );
|
|
533 assert( ctrl == find_non_split_ctrl(ctrl), "must set legal crtl" );
|
|
534 _nodes.map( n->_idx, (Node*)((intptr_t)ctrl + 1) );
|
|
535 }
|
|
536 // Set control and update loop membership
|
|
537 void set_ctrl_and_loop(Node* n, Node* ctrl) {
|
|
538 IdealLoopTree* old_loop = get_loop(get_ctrl(n));
|
|
539 IdealLoopTree* new_loop = get_loop(ctrl);
|
|
540 if (old_loop != new_loop) {
|
|
541 if (old_loop->_child == NULL) old_loop->_body.yank(n);
|
|
542 if (new_loop->_child == NULL) new_loop->_body.push(n);
|
|
543 }
|
|
544 set_ctrl(n, ctrl);
|
|
545 }
|
|
546 // Control nodes can be replaced or subsumed. During this pass they
|
|
547 // get their replacement Node in slot 1. Instead of updating the block
|
|
548 // location of all Nodes in the subsumed block, we lazily do it. As we
|
|
549 // pull such a subsumed block out of the array, we write back the final
|
|
550 // correct block.
|
|
551 Node *get_ctrl( Node *i ) {
|
|
552 assert(has_node(i), "");
|
|
553 Node *n = get_ctrl_no_update(i);
|
|
554 _nodes.map( i->_idx, (Node*)((intptr_t)n + 1) );
|
|
555 assert(has_node(i) && has_ctrl(i), "");
|
|
556 assert(n == find_non_split_ctrl(n), "must return legal ctrl" );
|
|
557 return n;
|
|
558 }
|
|
559
|
|
560 private:
|
|
561 Node *get_ctrl_no_update( Node *i ) const {
|
|
562 assert( has_ctrl(i), "" );
|
|
563 Node *n = (Node*)(((intptr_t)_nodes[i->_idx]) & ~1);
|
|
564 if (!n->in(0)) {
|
|
565 // Skip dead CFG nodes
|
|
566 do {
|
|
567 n = (Node*)(((intptr_t)_nodes[n->_idx]) & ~1);
|
|
568 } while (!n->in(0));
|
|
569 n = find_non_split_ctrl(n);
|
|
570 }
|
|
571 return n;
|
|
572 }
|
|
573
|
|
574 // Check for loop being set
|
|
575 // "n" must be a control node. Returns true if "n" is known to be in a loop.
|
|
576 bool has_loop( Node *n ) const {
|
|
577 assert(!has_node(n) || !has_ctrl(n), "");
|
|
578 return has_node(n);
|
|
579 }
|
|
580 // Set loop
|
|
581 void set_loop( Node *n, IdealLoopTree *loop ) {
|
|
582 _nodes.map(n->_idx, (Node*)loop);
|
|
583 }
|
|
584 // Lazy-dazy update of 'get_ctrl' and 'idom_at' mechanisms. Replace
|
|
585 // the 'old_node' with 'new_node'. Kill old-node. Add a reference
|
|
586 // from old_node to new_node to support the lazy update. Reference
|
|
587 // replaces loop reference, since that is not neede for dead node.
|
|
588 public:
|
|
589 void lazy_update( Node *old_node, Node *new_node ) {
|
|
590 assert( old_node != new_node, "no cycles please" );
|
|
591 //old_node->set_req( 1, new_node /*NO DU INFO*/ );
|
|
592 // Nodes always have DU info now, so re-use the side array slot
|
|
593 // for this node to provide the forwarding pointer.
|
|
594 _nodes.map( old_node->_idx, (Node*)((intptr_t)new_node + 1) );
|
|
595 }
|
|
596 void lazy_replace( Node *old_node, Node *new_node ) {
|
|
597 _igvn.hash_delete(old_node);
|
|
598 _igvn.subsume_node( old_node, new_node );
|
|
599 lazy_update( old_node, new_node );
|
|
600 }
|
|
601 void lazy_replace_proj( Node *old_node, Node *new_node ) {
|
|
602 assert( old_node->req() == 1, "use this for Projs" );
|
|
603 _igvn.hash_delete(old_node); // Must hash-delete before hacking edges
|
|
604 old_node->add_req( NULL );
|
|
605 lazy_replace( old_node, new_node );
|
|
606 }
|
|
607
|
|
608 private:
|
|
609
|
|
610 // Place 'n' in some loop nest, where 'n' is a CFG node
|
|
611 void build_loop_tree();
|
|
612 int build_loop_tree_impl( Node *n, int pre_order );
|
|
613 // Insert loop into the existing loop tree. 'innermost' is a leaf of the
|
|
614 // loop tree, not the root.
|
|
615 IdealLoopTree *sort( IdealLoopTree *loop, IdealLoopTree *innermost );
|
|
616
|
|
617 // Place Data nodes in some loop nest
|
|
618 void build_loop_early( VectorSet &visited, Node_List &worklist, Node_Stack &nstack, const PhaseIdealLoop *verify_me );
|
|
619 void build_loop_late ( VectorSet &visited, Node_List &worklist, Node_Stack &nstack, const PhaseIdealLoop *verify_me );
|
|
620 void build_loop_late_post ( Node* n, const PhaseIdealLoop *verify_me );
|
|
621
|
|
622 // Array of immediate dominance info for each CFG node indexed by node idx
|
|
623 private:
|
|
624 uint _idom_size;
|
|
625 Node **_idom; // Array of immediate dominators
|
|
626 uint *_dom_depth; // Used for fast LCA test
|
|
627 GrowableArray<uint>* _dom_stk; // For recomputation of dom depth
|
|
628
|
|
629 Node* idom_no_update(Node* d) const {
|
|
630 assert(d->_idx < _idom_size, "oob");
|
|
631 Node* n = _idom[d->_idx];
|
|
632 assert(n != NULL,"Bad immediate dominator info.");
|
|
633 while (n->in(0) == NULL) { // Skip dead CFG nodes
|
|
634 //n = n->in(1);
|
|
635 n = (Node*)(((intptr_t)_nodes[n->_idx]) & ~1);
|
|
636 assert(n != NULL,"Bad immediate dominator info.");
|
|
637 }
|
|
638 return n;
|
|
639 }
|
|
640 Node *idom(Node* d) const {
|
|
641 uint didx = d->_idx;
|
|
642 Node *n = idom_no_update(d);
|
|
643 _idom[didx] = n; // Lazily remove dead CFG nodes from table.
|
|
644 return n;
|
|
645 }
|
|
646 uint dom_depth(Node* d) const {
|
|
647 assert(d->_idx < _idom_size, "");
|
|
648 return _dom_depth[d->_idx];
|
|
649 }
|
|
650 void set_idom(Node* d, Node* n, uint dom_depth);
|
|
651 // Locally compute IDOM using dom_lca call
|
|
652 Node *compute_idom( Node *region ) const;
|
|
653 // Recompute dom_depth
|
|
654 void recompute_dom_depth();
|
|
655
|
|
656 // Is safept not required by an outer loop?
|
|
657 bool is_deleteable_safept(Node* sfpt);
|
|
658
|
|
659 public:
|
|
660 // Dominators for the sea of nodes
|
|
661 void Dominators();
|
|
662 Node *dom_lca( Node *n1, Node *n2 ) const {
|
|
663 return find_non_split_ctrl(dom_lca_internal(n1, n2));
|
|
664 }
|
|
665 Node *dom_lca_internal( Node *n1, Node *n2 ) const;
|
|
666
|
|
667 // Compute the Ideal Node to Loop mapping
|
|
668 PhaseIdealLoop( PhaseIterGVN &igvn, const PhaseIdealLoop *verify_me, bool do_split_ifs );
|
|
669
|
|
670 // True if the method has at least 1 irreducible loop
|
|
671 bool _has_irreducible_loops;
|
|
672
|
|
673 // Per-Node transform
|
|
674 virtual Node *transform( Node *a_node ) { return 0; }
|
|
675
|
|
676 Node *is_counted_loop( Node *x, IdealLoopTree *loop );
|
|
677
|
|
678 // Return a post-walked LoopNode
|
|
679 IdealLoopTree *get_loop( Node *n ) const {
|
|
680 // Dead nodes have no loop, so return the top level loop instead
|
|
681 if (!has_node(n)) return _ltree_root;
|
|
682 assert(!has_ctrl(n), "");
|
|
683 return (IdealLoopTree*)_nodes[n->_idx];
|
|
684 }
|
|
685
|
|
686 // Is 'n' a (nested) member of 'loop'?
|
|
687 int is_member( const IdealLoopTree *loop, Node *n ) const {
|
|
688 return loop->is_member(get_loop(n)); }
|
|
689
|
|
690 // This is the basic building block of the loop optimizations. It clones an
|
|
691 // entire loop body. It makes an old_new loop body mapping; with this
|
|
692 // mapping you can find the new-loop equivalent to an old-loop node. All
|
|
693 // new-loop nodes are exactly equal to their old-loop counterparts, all
|
|
694 // edges are the same. All exits from the old-loop now have a RegionNode
|
|
695 // that merges the equivalent new-loop path. This is true even for the
|
|
696 // normal "loop-exit" condition. All uses of loop-invariant old-loop values
|
|
697 // now come from (one or more) Phis that merge their new-loop equivalents.
|
|
698 // Parameter side_by_side_idom:
|
|
699 // When side_by_size_idom is NULL, the dominator tree is constructed for
|
|
700 // the clone loop to dominate the original. Used in construction of
|
|
701 // pre-main-post loop sequence.
|
|
702 // When nonnull, the clone and original are side-by-side, both are
|
|
703 // dominated by the passed in side_by_side_idom node. Used in
|
|
704 // construction of unswitched loops.
|
|
705 void clone_loop( IdealLoopTree *loop, Node_List &old_new, int dom_depth,
|
|
706 Node* side_by_side_idom = NULL);
|
|
707
|
|
708 // If we got the effect of peeling, either by actually peeling or by
|
|
709 // making a pre-loop which must execute at least once, we can remove
|
|
710 // all loop-invariant dominated tests in the main body.
|
|
711 void peeled_dom_test_elim( IdealLoopTree *loop, Node_List &old_new );
|
|
712
|
|
713 // Generate code to do a loop peel for the given loop (and body).
|
|
714 // old_new is a temp array.
|
|
715 void do_peeling( IdealLoopTree *loop, Node_List &old_new );
|
|
716
|
|
717 // Add pre and post loops around the given loop. These loops are used
|
|
718 // during RCE, unrolling and aligning loops.
|
|
719 void insert_pre_post_loops( IdealLoopTree *loop, Node_List &old_new, bool peel_only );
|
|
720 // If Node n lives in the back_ctrl block, we clone a private version of n
|
|
721 // in preheader_ctrl block and return that, otherwise return n.
|
|
722 Node *clone_up_backedge_goo( Node *back_ctrl, Node *preheader_ctrl, Node *n );
|
|
723
|
|
724 // Take steps to maximally unroll the loop. Peel any odd iterations, then
|
|
725 // unroll to do double iterations. The next round of major loop transforms
|
|
726 // will repeat till the doubled loop body does all remaining iterations in 1
|
|
727 // pass.
|
|
728 void do_maximally_unroll( IdealLoopTree *loop, Node_List &old_new );
|
|
729
|
|
730 // Unroll the loop body one step - make each trip do 2 iterations.
|
|
731 void do_unroll( IdealLoopTree *loop, Node_List &old_new, bool adjust_min_trip );
|
|
732
|
|
733 // Return true if exp is a constant times an induction var
|
|
734 bool is_scaled_iv(Node* exp, Node* iv, int* p_scale);
|
|
735
|
|
736 // Return true if exp is a scaled induction var plus (or minus) constant
|
|
737 bool is_scaled_iv_plus_offset(Node* exp, Node* iv, int* p_scale, Node** p_offset, int depth = 0);
|
|
738
|
|
739 // Eliminate range-checks and other trip-counter vs loop-invariant tests.
|
|
740 void do_range_check( IdealLoopTree *loop, Node_List &old_new );
|
|
741
|
|
742 // Create a slow version of the loop by cloning the loop
|
|
743 // and inserting an if to select fast-slow versions.
|
|
744 ProjNode* create_slow_version_of_loop(IdealLoopTree *loop,
|
|
745 Node_List &old_new);
|
|
746
|
|
747 // Clone loop with an invariant test (that does not exit) and
|
|
748 // insert a clone of the test that selects which version to
|
|
749 // execute.
|
|
750 void do_unswitching (IdealLoopTree *loop, Node_List &old_new);
|
|
751
|
|
752 // Find candidate "if" for unswitching
|
|
753 IfNode* find_unswitching_candidate(const IdealLoopTree *loop) const;
|
|
754
|
|
755 // Range Check Elimination uses this function!
|
|
756 // Constrain the main loop iterations so the affine function:
|
|
757 // scale_con * I + offset < limit
|
|
758 // always holds true. That is, either increase the number of iterations in
|
|
759 // the pre-loop or the post-loop until the condition holds true in the main
|
|
760 // loop. Scale_con, offset and limit are all loop invariant.
|
|
761 void add_constraint( int stride_con, int scale_con, Node *offset, Node *limit, Node *pre_ctrl, Node **pre_limit, Node **main_limit );
|
|
762
|
|
763 // Partially peel loop up through last_peel node.
|
|
764 bool partial_peel( IdealLoopTree *loop, Node_List &old_new );
|
|
765
|
|
766 // Create a scheduled list of nodes control dependent on ctrl set.
|
|
767 void scheduled_nodelist( IdealLoopTree *loop, VectorSet& ctrl, Node_List &sched );
|
|
768 // Has a use in the vector set
|
|
769 bool has_use_in_set( Node* n, VectorSet& vset );
|
|
770 // Has use internal to the vector set (ie. not in a phi at the loop head)
|
|
771 bool has_use_internal_to_set( Node* n, VectorSet& vset, IdealLoopTree *loop );
|
|
772 // clone "n" for uses that are outside of loop
|
|
773 void clone_for_use_outside_loop( IdealLoopTree *loop, Node* n, Node_List& worklist );
|
|
774 // clone "n" for special uses that are in the not_peeled region
|
|
775 void clone_for_special_use_inside_loop( IdealLoopTree *loop, Node* n,
|
|
776 VectorSet& not_peel, Node_List& sink_list, Node_List& worklist );
|
|
777 // Insert phi(lp_entry_val, back_edge_val) at use->in(idx) for loop lp if phi does not already exist
|
|
778 void insert_phi_for_loop( Node* use, uint idx, Node* lp_entry_val, Node* back_edge_val, LoopNode* lp );
|
|
779 #ifdef ASSERT
|
|
780 // Validate the loop partition sets: peel and not_peel
|
|
781 bool is_valid_loop_partition( IdealLoopTree *loop, VectorSet& peel, Node_List& peel_list, VectorSet& not_peel );
|
|
782 // Ensure that uses outside of loop are of the right form
|
|
783 bool is_valid_clone_loop_form( IdealLoopTree *loop, Node_List& peel_list,
|
|
784 uint orig_exit_idx, uint clone_exit_idx);
|
|
785 bool is_valid_clone_loop_exit_use( IdealLoopTree *loop, Node* use, uint exit_idx);
|
|
786 #endif
|
|
787
|
|
788 // Returns nonzero constant stride if-node is a possible iv test (otherwise returns zero.)
|
|
789 int stride_of_possible_iv( Node* iff );
|
|
790 bool is_possible_iv_test( Node* iff ) { return stride_of_possible_iv(iff) != 0; }
|
|
791 // Return the (unique) control output node that's in the loop (if it exists.)
|
|
792 Node* stay_in_loop( Node* n, IdealLoopTree *loop);
|
|
793 // Insert a signed compare loop exit cloned from an unsigned compare.
|
|
794 IfNode* insert_cmpi_loop_exit(IfNode* if_cmpu, IdealLoopTree *loop);
|
|
795 void remove_cmpi_loop_exit(IfNode* if_cmp, IdealLoopTree *loop);
|
|
796 // Utility to register node "n" with PhaseIdealLoop
|
|
797 void register_node(Node* n, IdealLoopTree *loop, Node* pred, int ddepth);
|
|
798 // Utility to create an if-projection
|
|
799 ProjNode* proj_clone(ProjNode* p, IfNode* iff);
|
|
800 // Force the iff control output to be the live_proj
|
|
801 Node* short_circuit_if(IfNode* iff, ProjNode* live_proj);
|
|
802 // Insert a region before an if projection
|
|
803 RegionNode* insert_region_before_proj(ProjNode* proj);
|
|
804 // Insert a new if before an if projection
|
|
805 ProjNode* insert_if_before_proj(Node* left, bool Signed, BoolTest::mask relop, Node* right, ProjNode* proj);
|
|
806
|
|
807 // Passed in a Phi merging (recursively) some nearly equivalent Bool/Cmps.
|
|
808 // "Nearly" because all Nodes have been cloned from the original in the loop,
|
|
809 // but the fall-in edges to the Cmp are different. Clone bool/Cmp pairs
|
|
810 // through the Phi recursively, and return a Bool.
|
|
811 BoolNode *clone_iff( PhiNode *phi, IdealLoopTree *loop );
|
|
812 CmpNode *clone_bool( PhiNode *phi, IdealLoopTree *loop );
|
|
813
|
|
814
|
|
815 // Rework addressing expressions to get the most loop-invariant stuff
|
|
816 // moved out. We'd like to do all associative operators, but it's especially
|
|
817 // important (common) to do address expressions.
|
|
818 Node *remix_address_expressions( Node *n );
|
|
819
|
|
820 // Attempt to use a conditional move instead of a phi/branch
|
|
821 Node *conditional_move( Node *n );
|
|
822
|
|
823 // Reorganize offset computations to lower register pressure.
|
|
824 // Mostly prevent loop-fallout uses of the pre-incremented trip counter
|
|
825 // (which are then alive with the post-incremented trip counter
|
|
826 // forcing an extra register move)
|
|
827 void reorg_offsets( IdealLoopTree *loop );
|
|
828
|
|
829 // Check for aggressive application of 'split-if' optimization,
|
|
830 // using basic block level info.
|
|
831 void split_if_with_blocks ( VectorSet &visited, Node_Stack &nstack );
|
|
832 Node *split_if_with_blocks_pre ( Node *n );
|
|
833 void split_if_with_blocks_post( Node *n );
|
|
834 Node *has_local_phi_input( Node *n );
|
|
835 // Mark an IfNode as being dominated by a prior test,
|
|
836 // without actually altering the CFG (and hence IDOM info).
|
|
837 void dominated_by( Node *prevdom, Node *iff );
|
|
838
|
|
839 // Split Node 'n' through merge point
|
|
840 Node *split_thru_region( Node *n, Node *region );
|
|
841 // Split Node 'n' through merge point if there is enough win.
|
|
842 Node *split_thru_phi( Node *n, Node *region, int policy );
|
|
843 // Found an If getting its condition-code input from a Phi in the
|
|
844 // same block. Split thru the Region.
|
|
845 void do_split_if( Node *iff );
|
|
846
|
|
847 private:
|
|
848 // Return a type based on condition control flow
|
|
849 const TypeInt* filtered_type( Node *n, Node* n_ctrl);
|
|
850 const TypeInt* filtered_type( Node *n ) { return filtered_type(n, NULL); }
|
|
851 // Helpers for filtered type
|
|
852 const TypeInt* filtered_type_from_dominators( Node* val, Node *val_ctrl);
|
|
853
|
|
854 // Helper functions
|
|
855 void register_new_node( Node *n, Node *blk );
|
|
856 Node *spinup( Node *iff, Node *new_false, Node *new_true, Node *region, Node *phi, small_cache *cache );
|
|
857 Node *find_use_block( Node *use, Node *def, Node *old_false, Node *new_false, Node *old_true, Node *new_true );
|
|
858 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 );
|
|
859 bool split_up( Node *n, Node *blk1, Node *blk2 );
|
|
860 void sink_use( Node *use, Node *post_loop );
|
|
861 Node *place_near_use( Node *useblock ) const;
|
|
862
|
|
863 bool _created_loop_node;
|
|
864 public:
|
|
865 void set_created_loop_node() { _created_loop_node = true; }
|
|
866 bool created_loop_node() { return _created_loop_node; }
|
|
867
|
|
868 #ifndef PRODUCT
|
|
869 void dump( ) const;
|
|
870 void dump( IdealLoopTree *loop, uint rpo_idx, Node_List &rpo_list ) const;
|
|
871 void rpo( Node *start, Node_Stack &stk, VectorSet &visited, Node_List &rpo_list ) const;
|
|
872 void verify() const; // Major slow :-)
|
|
873 void verify_compare( Node *n, const PhaseIdealLoop *loop_verify, VectorSet &visited ) const;
|
|
874 IdealLoopTree *get_loop_idx(Node* n) const {
|
|
875 // Dead nodes have no loop, so return the top level loop instead
|
|
876 return _nodes[n->_idx] ? (IdealLoopTree*)_nodes[n->_idx] : _ltree_root;
|
|
877 }
|
|
878 // Print some stats
|
|
879 static void print_statistics();
|
|
880 static int _loop_invokes; // Count of PhaseIdealLoop invokes
|
|
881 static int _loop_work; // Sum of PhaseIdealLoop x _unique
|
|
882 #endif
|
|
883 };
|
|
884
|
|
885 inline Node* IdealLoopTree::tail() {
|
|
886 // Handle lazy update of _tail field
|
|
887 Node *n = _tail;
|
|
888 //while( !n->in(0) ) // Skip dead CFG nodes
|
|
889 //n = n->in(1);
|
|
890 if (n->in(0) == NULL)
|
|
891 n = _phase->get_ctrl(n);
|
|
892 _tail = n;
|
|
893 return n;
|
|
894 }
|
|
895
|
|
896
|
|
897 // Iterate over the loop tree using a preorder, left-to-right traversal.
|
|
898 //
|
|
899 // Example that visits all counted loops from within PhaseIdealLoop
|
|
900 //
|
|
901 // for (LoopTreeIterator iter(_ltree_root); !iter.done(); iter.next()) {
|
|
902 // IdealLoopTree* lpt = iter.current();
|
|
903 // if (!lpt->is_counted()) continue;
|
|
904 // ...
|
|
905 class LoopTreeIterator : public StackObj {
|
|
906 private:
|
|
907 IdealLoopTree* _root;
|
|
908 IdealLoopTree* _curnt;
|
|
909
|
|
910 public:
|
|
911 LoopTreeIterator(IdealLoopTree* root) : _root(root), _curnt(root) {}
|
|
912
|
|
913 bool done() { return _curnt == NULL; } // Finished iterating?
|
|
914
|
|
915 void next(); // Advance to next loop tree
|
|
916
|
|
917 IdealLoopTree* current() { return _curnt; } // Return current value of iterator.
|
|
918 };
|