Mercurial > hg > truffle
annotate src/share/vm/opto/loopnode.hpp @ 2248:194c9fdee631
7017240: C2: native memory leak in nsk/regression/b4675027 on windows-x86 in comp mode with G1
Summary: Add ResourceMark into PhaseIdealLoop::build_and_optimize().
Reviewed-by: never
| author | kvn |
|---|---|
| date | Mon, 07 Feb 2011 09:46:01 -0800 |
| parents | f95d63e2154a |
| children | 9dc311b8473e |
| rev | line source |
|---|---|
| 0 | 1 /* |
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2 * Copyright (c) 1998, 2011, 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 * | |
|
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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(arena()), // Thread::resource_area |
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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(arena()), // Thread::resource_area |
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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(arena()), // Thread::resource_area |
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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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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 |