1 /*
2 * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc/shared/barrierSet.hpp"
27 #include "gc/shared/c2/barrierSetC2.hpp"
28 #include "memory/allocation.inline.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "opto/addnode.hpp"
31 #include "opto/callnode.hpp"
32 #include "opto/castnode.hpp"
33 #include "opto/connode.hpp"
34 #include "opto/castnode.hpp"
35 #include "opto/divnode.hpp"
36 #include "opto/loopnode.hpp"
37 #include "opto/matcher.hpp"
38 #include "opto/mulnode.hpp"
39 #include "opto/movenode.hpp"
40 #include "opto/opaquenode.hpp"
41 #include "opto/rootnode.hpp"
42 #include "opto/subnode.hpp"
43 #include "opto/valuetypenode.hpp"
44 #include "utilities/macros.hpp"
45 #if INCLUDE_ZGC
46 #include "gc/z/c2/zBarrierSetC2.hpp"
47 #endif
48
49 //=============================================================================
50 //------------------------------split_thru_phi---------------------------------
51 // Split Node 'n' through merge point if there is enough win.
52 Node *PhaseIdealLoop::split_thru_phi( Node *n, Node *region, int policy ) {
53 if (n->Opcode() == Op_ConvI2L && n->bottom_type() != TypeLong::LONG) {
54 // ConvI2L may have type information on it which is unsafe to push up
55 // so disable this for now
56 return NULL;
57 }
58
59 // Splitting range check CastIIs through a loop induction Phi can
60 // cause new Phis to be created that are left unrelated to the loop
61 // induction Phi and prevent optimizations (vectorization)
62 if (n->Opcode() == Op_CastII && n->as_CastII()->has_range_check() &&
63 region->is_CountedLoop() && n->in(1) == region->as_CountedLoop()->phi()) {
64 return NULL;
65 }
66
67 // Value types should not be split through Phis because they cannot be merged
68 // through Phi nodes but each value input needs to be merged individually.
69 if (n->is_ValueType()) {
70 return NULL;
71 }
72
73 int wins = 0;
74 assert(!n->is_CFG(), "");
75 assert(region->is_Region(), "");
76
77 const Type* type = n->bottom_type();
78 const TypeOopPtr *t_oop = _igvn.type(n)->isa_oopptr();
79 Node *phi;
80 if (t_oop != NULL && t_oop->is_known_instance_field()) {
81 int iid = t_oop->instance_id();
82 int index = C->get_alias_index(t_oop);
83 int offset = t_oop->offset();
84 phi = new PhiNode(region, type, NULL, iid, index, offset);
85 } else {
86 phi = PhiNode::make_blank(region, n);
87 }
88 uint old_unique = C->unique();
89 for (uint i = 1; i < region->req(); i++) {
90 Node *x;
91 Node* the_clone = NULL;
92 if (region->in(i) == C->top()) {
93 x = C->top(); // Dead path? Use a dead data op
94 } else {
95 x = n->clone(); // Else clone up the data op
96 the_clone = x; // Remember for possible deletion.
97 // Alter data node to use pre-phi inputs
98 if (n->in(0) == region)
99 x->set_req( 0, region->in(i) );
100 for (uint j = 1; j < n->req(); j++) {
101 Node *in = n->in(j);
102 if (in->is_Phi() && in->in(0) == region)
103 x->set_req( j, in->in(i) ); // Use pre-Phi input for the clone
104 }
105 }
106 // Check for a 'win' on some paths
107 const Type *t = x->Value(&_igvn);
108
109 bool singleton = t->singleton();
110
111 // A TOP singleton indicates that there are no possible values incoming
112 // along a particular edge. In most cases, this is OK, and the Phi will
113 // be eliminated later in an Ideal call. However, we can't allow this to
114 // happen if the singleton occurs on loop entry, as the elimination of
115 // the PhiNode may cause the resulting node to migrate back to a previous
116 // loop iteration.
117 if (singleton && t == Type::TOP) {
118 // Is_Loop() == false does not confirm the absence of a loop (e.g., an
119 // irreducible loop may not be indicated by an affirmative is_Loop());
120 // therefore, the only top we can split thru a phi is on a backedge of
121 // a loop.
122 singleton &= region->is_Loop() && (i != LoopNode::EntryControl);
123 }
124
125 if (singleton) {
126 wins++;
127 x = ((PhaseGVN&)_igvn).makecon(t);
128 } else {
129 // We now call Identity to try to simplify the cloned node.
130 // Note that some Identity methods call phase->type(this).
131 // Make sure that the type array is big enough for
132 // our new node, even though we may throw the node away.
133 // (Note: This tweaking with igvn only works because x is a new node.)
134 _igvn.set_type(x, t);
135 // If x is a TypeNode, capture any more-precise type permanently into Node
136 // otherwise it will be not updated during igvn->transform since
137 // igvn->type(x) is set to x->Value() already.
138 x->raise_bottom_type(t);
139 Node *y = _igvn.apply_identity(x);
140 if (y != x) {
141 wins++;
142 x = y;
143 } else {
144 y = _igvn.hash_find(x);
145 if (y) {
146 wins++;
147 x = y;
148 } else {
149 // Else x is a new node we are keeping
150 // We do not need register_new_node_with_optimizer
151 // because set_type has already been called.
152 _igvn._worklist.push(x);
153 }
154 }
155 }
156 if (x != the_clone && the_clone != NULL)
157 _igvn.remove_dead_node(the_clone);
158 phi->set_req( i, x );
159 }
160 // Too few wins?
161 if (wins <= policy) {
162 _igvn.remove_dead_node(phi);
163 return NULL;
164 }
165
166 // Record Phi
167 register_new_node( phi, region );
168
169 for (uint i2 = 1; i2 < phi->req(); i2++) {
170 Node *x = phi->in(i2);
171 // If we commoned up the cloned 'x' with another existing Node,
172 // the existing Node picks up a new use. We need to make the
173 // existing Node occur higher up so it dominates its uses.
174 Node *old_ctrl;
175 IdealLoopTree *old_loop;
176
177 if (x->is_Con()) {
178 // Constant's control is always root.
179 set_ctrl(x, C->root());
180 continue;
181 }
182 // The occasional new node
183 if (x->_idx >= old_unique) { // Found a new, unplaced node?
184 old_ctrl = NULL;
185 old_loop = NULL; // Not in any prior loop
186 } else {
187 old_ctrl = get_ctrl(x);
188 old_loop = get_loop(old_ctrl); // Get prior loop
189 }
190 // New late point must dominate new use
191 Node *new_ctrl = dom_lca(old_ctrl, region->in(i2));
192 if (new_ctrl == old_ctrl) // Nothing is changed
193 continue;
194
195 IdealLoopTree *new_loop = get_loop(new_ctrl);
196
197 // Don't move x into a loop if its uses are
198 // outside of loop. Otherwise x will be cloned
199 // for each use outside of this loop.
200 IdealLoopTree *use_loop = get_loop(region);
201 if (!new_loop->is_member(use_loop) &&
202 (old_loop == NULL || !new_loop->is_member(old_loop))) {
203 // Take early control, later control will be recalculated
204 // during next iteration of loop optimizations.
205 new_ctrl = get_early_ctrl(x);
206 new_loop = get_loop(new_ctrl);
207 }
208 // Set new location
209 set_ctrl(x, new_ctrl);
210 // If changing loop bodies, see if we need to collect into new body
211 if (old_loop != new_loop) {
212 if (old_loop && !old_loop->_child)
213 old_loop->_body.yank(x);
214 if (!new_loop->_child)
215 new_loop->_body.push(x); // Collect body info
216 }
217 }
218
219 return phi;
220 }
221
222 //------------------------------dominated_by------------------------------------
223 // Replace the dominated test with an obvious true or false. Place it on the
224 // IGVN worklist for later cleanup. Move control-dependent data Nodes on the
225 // live path up to the dominating control.
226 void PhaseIdealLoop::dominated_by( Node *prevdom, Node *iff, bool flip, bool exclude_loop_predicate ) {
227 if (VerifyLoopOptimizations && PrintOpto) { tty->print_cr("dominating test"); }
228
229 // prevdom is the dominating projection of the dominating test.
230 assert( iff->is_If(), "" );
231 assert(iff->Opcode() == Op_If || iff->Opcode() == Op_CountedLoopEnd || iff->Opcode() == Op_RangeCheck, "Check this code when new subtype is added");
232 int pop = prevdom->Opcode();
233 assert( pop == Op_IfFalse || pop == Op_IfTrue, "" );
234 if (flip) {
235 if (pop == Op_IfTrue)
236 pop = Op_IfFalse;
237 else
238 pop = Op_IfTrue;
239 }
240 // 'con' is set to true or false to kill the dominated test.
241 Node *con = _igvn.makecon(pop == Op_IfTrue ? TypeInt::ONE : TypeInt::ZERO);
242 set_ctrl(con, C->root()); // Constant gets a new use
243 // Hack the dominated test
244 _igvn.replace_input_of(iff, 1, con);
245
246 // If I dont have a reachable TRUE and FALSE path following the IfNode then
247 // I can assume this path reaches an infinite loop. In this case it's not
248 // important to optimize the data Nodes - either the whole compilation will
249 // be tossed or this path (and all data Nodes) will go dead.
250 if (iff->outcnt() != 2) return;
251
252 // Make control-dependent data Nodes on the live path (path that will remain
253 // once the dominated IF is removed) become control-dependent on the
254 // dominating projection.
255 Node* dp = iff->as_If()->proj_out_or_null(pop == Op_IfTrue);
256
257 // Loop predicates may have depending checks which should not
258 // be skipped. For example, range check predicate has two checks
259 // for lower and upper bounds.
260 if (dp == NULL)
261 return;
262
263 ProjNode* dp_proj = dp->as_Proj();
264 ProjNode* unc_proj = iff->as_If()->proj_out(1 - dp_proj->_con)->as_Proj();
265 if (exclude_loop_predicate &&
266 (unc_proj->is_uncommon_trap_proj(Deoptimization::Reason_predicate) != NULL ||
267 unc_proj->is_uncommon_trap_proj(Deoptimization::Reason_profile_predicate) != NULL ||
268 unc_proj->is_uncommon_trap_proj(Deoptimization::Reason_range_check) != NULL)) {
269 // If this is a range check (IfNode::is_range_check), do not
270 // reorder because Compile::allow_range_check_smearing might have
271 // changed the check.
272 return; // Let IGVN transformation change control dependence.
273 }
274
275 IdealLoopTree *old_loop = get_loop(dp);
276
277 for (DUIterator_Fast imax, i = dp->fast_outs(imax); i < imax; i++) {
278 Node* cd = dp->fast_out(i); // Control-dependent node
279 if (cd->depends_only_on_test()) {
280 assert(cd->in(0) == dp, "");
281 _igvn.replace_input_of(cd, 0, prevdom);
282 set_early_ctrl(cd);
283 IdealLoopTree *new_loop = get_loop(get_ctrl(cd));
284 if (old_loop != new_loop) {
285 if (!old_loop->_child) old_loop->_body.yank(cd);
286 if (!new_loop->_child) new_loop->_body.push(cd);
287 }
288 --i;
289 --imax;
290 }
291 }
292 }
293
294 //------------------------------has_local_phi_input----------------------------
295 // Return TRUE if 'n' has Phi inputs from its local block and no other
296 // block-local inputs (all non-local-phi inputs come from earlier blocks)
297 Node *PhaseIdealLoop::has_local_phi_input( Node *n ) {
298 Node *n_ctrl = get_ctrl(n);
299 // See if some inputs come from a Phi in this block, or from before
300 // this block.
301 uint i;
302 for( i = 1; i < n->req(); i++ ) {
303 Node *phi = n->in(i);
304 if( phi->is_Phi() && phi->in(0) == n_ctrl )
305 break;
306 }
307 if( i >= n->req() )
308 return NULL; // No Phi inputs; nowhere to clone thru
309
310 // Check for inputs created between 'n' and the Phi input. These
311 // must split as well; they have already been given the chance
312 // (courtesy of a post-order visit) and since they did not we must
313 // recover the 'cost' of splitting them by being very profitable
314 // when splitting 'n'. Since this is unlikely we simply give up.
315 for( i = 1; i < n->req(); i++ ) {
316 Node *m = n->in(i);
317 if( get_ctrl(m) == n_ctrl && !m->is_Phi() ) {
318 // We allow the special case of AddP's with no local inputs.
319 // This allows us to split-up address expressions.
320 if (m->is_AddP() &&
321 get_ctrl(m->in(2)) != n_ctrl &&
322 get_ctrl(m->in(3)) != n_ctrl) {
323 // Move the AddP up to dominating point
324 Node* c = find_non_split_ctrl(idom(n_ctrl));
325 if (c->is_OuterStripMinedLoop()) {
326 c->as_Loop()->verify_strip_mined(1);
327 c = c->in(LoopNode::EntryControl);
328 }
329 set_ctrl_and_loop(m, c);
330 continue;
331 }
332 return NULL;
333 }
334 assert(n->is_Phi() || m->is_Phi() || is_dominator(get_ctrl(m), n_ctrl), "m has strange control");
335 }
336
337 return n_ctrl;
338 }
339
340 //------------------------------remix_address_expressions----------------------
341 // Rework addressing expressions to get the most loop-invariant stuff
342 // moved out. We'd like to do all associative operators, but it's especially
343 // important (common) to do address expressions.
344 Node *PhaseIdealLoop::remix_address_expressions( Node *n ) {
345 if (!has_ctrl(n)) return NULL;
346 Node *n_ctrl = get_ctrl(n);
347 IdealLoopTree *n_loop = get_loop(n_ctrl);
348
349 // See if 'n' mixes loop-varying and loop-invariant inputs and
350 // itself is loop-varying.
351
352 // Only interested in binary ops (and AddP)
353 if( n->req() < 3 || n->req() > 4 ) return NULL;
354
355 Node *n1_ctrl = get_ctrl(n->in( 1));
356 Node *n2_ctrl = get_ctrl(n->in( 2));
357 Node *n3_ctrl = get_ctrl(n->in(n->req() == 3 ? 2 : 3));
358 IdealLoopTree *n1_loop = get_loop( n1_ctrl );
359 IdealLoopTree *n2_loop = get_loop( n2_ctrl );
360 IdealLoopTree *n3_loop = get_loop( n3_ctrl );
361
362 // Does one of my inputs spin in a tighter loop than self?
363 if( (n_loop->is_member( n1_loop ) && n_loop != n1_loop) ||
364 (n_loop->is_member( n2_loop ) && n_loop != n2_loop) ||
365 (n_loop->is_member( n3_loop ) && n_loop != n3_loop) )
366 return NULL; // Leave well enough alone
367
368 // Is at least one of my inputs loop-invariant?
369 if( n1_loop == n_loop &&
370 n2_loop == n_loop &&
371 n3_loop == n_loop )
372 return NULL; // No loop-invariant inputs
373
374
375 int n_op = n->Opcode();
376
377 // Replace expressions like ((V+I) << 2) with (V<<2 + I<<2).
378 if( n_op == Op_LShiftI ) {
379 // Scale is loop invariant
380 Node *scale = n->in(2);
381 Node *scale_ctrl = get_ctrl(scale);
382 IdealLoopTree *scale_loop = get_loop(scale_ctrl );
383 if( n_loop == scale_loop || !scale_loop->is_member( n_loop ) )
384 return NULL;
385 const TypeInt *scale_t = scale->bottom_type()->isa_int();
386 if( scale_t && scale_t->is_con() && scale_t->get_con() >= 16 )
387 return NULL; // Dont bother with byte/short masking
388 // Add must vary with loop (else shift would be loop-invariant)
389 Node *add = n->in(1);
390 Node *add_ctrl = get_ctrl(add);
391 IdealLoopTree *add_loop = get_loop(add_ctrl);
392 //assert( n_loop == add_loop, "" );
393 if( n_loop != add_loop ) return NULL; // happens w/ evil ZKM loops
394
395 // Convert I-V into I+ (0-V); same for V-I
396 if( add->Opcode() == Op_SubI &&
397 _igvn.type( add->in(1) ) != TypeInt::ZERO ) {
398 Node *zero = _igvn.intcon(0);
399 set_ctrl(zero, C->root());
400 Node *neg = new SubINode( _igvn.intcon(0), add->in(2) );
401 register_new_node( neg, get_ctrl(add->in(2) ) );
402 add = new AddINode( add->in(1), neg );
403 register_new_node( add, add_ctrl );
404 }
405 if( add->Opcode() != Op_AddI ) return NULL;
406 // See if one add input is loop invariant
407 Node *add_var = add->in(1);
408 Node *add_var_ctrl = get_ctrl(add_var);
409 IdealLoopTree *add_var_loop = get_loop(add_var_ctrl );
410 Node *add_invar = add->in(2);
411 Node *add_invar_ctrl = get_ctrl(add_invar);
412 IdealLoopTree *add_invar_loop = get_loop(add_invar_ctrl );
413 if( add_var_loop == n_loop ) {
414 } else if( add_invar_loop == n_loop ) {
415 // Swap to find the invariant part
416 add_invar = add_var;
417 add_invar_ctrl = add_var_ctrl;
418 add_invar_loop = add_var_loop;
419 add_var = add->in(2);
420 Node *add_var_ctrl = get_ctrl(add_var);
421 IdealLoopTree *add_var_loop = get_loop(add_var_ctrl );
422 } else // Else neither input is loop invariant
423 return NULL;
424 if( n_loop == add_invar_loop || !add_invar_loop->is_member( n_loop ) )
425 return NULL; // No invariant part of the add?
426
427 // Yes! Reshape address expression!
428 Node *inv_scale = new LShiftINode( add_invar, scale );
429 Node *inv_scale_ctrl =
430 dom_depth(add_invar_ctrl) > dom_depth(scale_ctrl) ?
431 add_invar_ctrl : scale_ctrl;
432 register_new_node( inv_scale, inv_scale_ctrl );
433 Node *var_scale = new LShiftINode( add_var, scale );
434 register_new_node( var_scale, n_ctrl );
435 Node *var_add = new AddINode( var_scale, inv_scale );
436 register_new_node( var_add, n_ctrl );
437 _igvn.replace_node( n, var_add );
438 return var_add;
439 }
440
441 // Replace (I+V) with (V+I)
442 if( n_op == Op_AddI ||
443 n_op == Op_AddL ||
444 n_op == Op_AddF ||
445 n_op == Op_AddD ||
446 n_op == Op_MulI ||
447 n_op == Op_MulL ||
448 n_op == Op_MulF ||
449 n_op == Op_MulD ) {
450 if( n2_loop == n_loop ) {
451 assert( n1_loop != n_loop, "" );
452 n->swap_edges(1, 2);
453 }
454 }
455
456 // Replace ((I1 +p V) +p I2) with ((I1 +p I2) +p V),
457 // but not if I2 is a constant.
458 if( n_op == Op_AddP ) {
459 if( n2_loop == n_loop && n3_loop != n_loop ) {
460 if( n->in(2)->Opcode() == Op_AddP && !n->in(3)->is_Con() ) {
461 Node *n22_ctrl = get_ctrl(n->in(2)->in(2));
462 Node *n23_ctrl = get_ctrl(n->in(2)->in(3));
463 IdealLoopTree *n22loop = get_loop( n22_ctrl );
464 IdealLoopTree *n23_loop = get_loop( n23_ctrl );
465 if( n22loop != n_loop && n22loop->is_member(n_loop) &&
466 n23_loop == n_loop ) {
467 Node *add1 = new AddPNode( n->in(1), n->in(2)->in(2), n->in(3) );
468 // Stuff new AddP in the loop preheader
469 register_new_node( add1, n_loop->_head->in(LoopNode::EntryControl) );
470 Node *add2 = new AddPNode( n->in(1), add1, n->in(2)->in(3) );
471 register_new_node( add2, n_ctrl );
472 _igvn.replace_node( n, add2 );
473 return add2;
474 }
475 }
476 }
477
478 // Replace (I1 +p (I2 + V)) with ((I1 +p I2) +p V)
479 if (n2_loop != n_loop && n3_loop == n_loop) {
480 if (n->in(3)->Opcode() == Op_AddX) {
481 Node *V = n->in(3)->in(1);
482 Node *I = n->in(3)->in(2);
483 if (is_member(n_loop,get_ctrl(V))) {
484 } else {
485 Node *tmp = V; V = I; I = tmp;
486 }
487 if (!is_member(n_loop,get_ctrl(I))) {
488 Node *add1 = new AddPNode(n->in(1), n->in(2), I);
489 // Stuff new AddP in the loop preheader
490 register_new_node(add1, n_loop->_head->in(LoopNode::EntryControl));
491 Node *add2 = new AddPNode(n->in(1), add1, V);
492 register_new_node(add2, n_ctrl);
493 _igvn.replace_node(n, add2);
494 return add2;
495 }
496 }
497 }
498 }
499
500 return NULL;
501 }
502
503 // Optimize ((in1[2*i] * in2[2*i]) + (in1[2*i+1] * in2[2*i+1]))
504 Node *PhaseIdealLoop::convert_add_to_muladd(Node* n) {
505 assert(n->Opcode() == Op_AddI, "sanity");
506 Node * nn = NULL;
507 Node * in1 = n->in(1);
508 Node * in2 = n->in(2);
509 if (in1->Opcode() == Op_MulI && in2->Opcode() == Op_MulI) {
510 IdealLoopTree* loop_n = get_loop(get_ctrl(n));
511 if (loop_n->_head->as_Loop()->is_valid_counted_loop() &&
512 Matcher::match_rule_supported(Op_MulAddS2I) &&
513 Matcher::match_rule_supported(Op_MulAddVS2VI)) {
514 Node* mul_in1 = in1->in(1);
515 Node* mul_in2 = in1->in(2);
516 Node* mul_in3 = in2->in(1);
517 Node* mul_in4 = in2->in(2);
518 if (mul_in1->Opcode() == Op_LoadS &&
519 mul_in2->Opcode() == Op_LoadS &&
520 mul_in3->Opcode() == Op_LoadS &&
521 mul_in4->Opcode() == Op_LoadS) {
522 IdealLoopTree* loop1 = get_loop(get_ctrl(mul_in1));
523 IdealLoopTree* loop2 = get_loop(get_ctrl(mul_in2));
524 IdealLoopTree* loop3 = get_loop(get_ctrl(mul_in3));
525 IdealLoopTree* loop4 = get_loop(get_ctrl(mul_in4));
526 IdealLoopTree* loop5 = get_loop(get_ctrl(in1));
527 IdealLoopTree* loop6 = get_loop(get_ctrl(in2));
528 // All nodes should be in the same counted loop.
529 if (loop_n == loop1 && loop_n == loop2 && loop_n == loop3 &&
530 loop_n == loop4 && loop_n == loop5 && loop_n == loop6) {
531 Node* adr1 = mul_in1->in(MemNode::Address);
532 Node* adr2 = mul_in2->in(MemNode::Address);
533 Node* adr3 = mul_in3->in(MemNode::Address);
534 Node* adr4 = mul_in4->in(MemNode::Address);
535 if (adr1->is_AddP() && adr2->is_AddP() && adr3->is_AddP() && adr4->is_AddP()) {
536 if ((adr1->in(AddPNode::Base) == adr3->in(AddPNode::Base)) &&
537 (adr2->in(AddPNode::Base) == adr4->in(AddPNode::Base))) {
538 nn = new MulAddS2INode(mul_in1, mul_in2, mul_in3, mul_in4);
539 register_new_node(nn, get_ctrl(n));
540 _igvn.replace_node(n, nn);
541 return nn;
542 } else if ((adr1->in(AddPNode::Base) == adr4->in(AddPNode::Base)) &&
543 (adr2->in(AddPNode::Base) == adr3->in(AddPNode::Base))) {
544 nn = new MulAddS2INode(mul_in1, mul_in2, mul_in4, mul_in3);
545 register_new_node(nn, get_ctrl(n));
546 _igvn.replace_node(n, nn);
547 return nn;
548 }
549 }
550 }
551 }
552 }
553 }
554 return nn;
555 }
556
557 //------------------------------conditional_move-------------------------------
558 // Attempt to replace a Phi with a conditional move. We have some pretty
559 // strict profitability requirements. All Phis at the merge point must
560 // be converted, so we can remove the control flow. We need to limit the
561 // number of c-moves to a small handful. All code that was in the side-arms
562 // of the CFG diamond is now speculatively executed. This code has to be
563 // "cheap enough". We are pretty much limited to CFG diamonds that merge
564 // 1 or 2 items with a total of 1 or 2 ops executed speculatively.
565 Node *PhaseIdealLoop::conditional_move( Node *region ) {
566
567 assert(region->is_Region(), "sanity check");
568 if (region->req() != 3) return NULL;
569
570 // Check for CFG diamond
571 Node *lp = region->in(1);
572 Node *rp = region->in(2);
573 if (!lp || !rp) return NULL;
574 Node *lp_c = lp->in(0);
575 if (lp_c == NULL || lp_c != rp->in(0) || !lp_c->is_If()) return NULL;
576 IfNode *iff = lp_c->as_If();
577
578 // Check for ops pinned in an arm of the diamond.
579 // Can't remove the control flow in this case
580 if (lp->outcnt() > 1) return NULL;
581 if (rp->outcnt() > 1) return NULL;
582
583 IdealLoopTree* r_loop = get_loop(region);
584 assert(r_loop == get_loop(iff), "sanity");
585 // Always convert to CMOVE if all results are used only outside this loop.
586 bool used_inside_loop = (r_loop == _ltree_root);
587
588 // Check profitability
589 int cost = 0;
590 int phis = 0;
591 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
592 Node *out = region->fast_out(i);
593 if (!out->is_Phi()) continue; // Ignore other control edges, etc
594 phis++;
595 PhiNode* phi = out->as_Phi();
596 BasicType bt = phi->type()->basic_type();
597 switch (bt) {
598 case T_DOUBLE:
599 case T_FLOAT:
600 if (C->use_cmove()) {
601 continue; //TODO: maybe we want to add some cost
602 }
603 cost += Matcher::float_cmove_cost(); // Could be very expensive
604 break;
605 case T_LONG: {
606 cost += Matcher::long_cmove_cost(); // May encodes as 2 CMOV's
607 }
608 case T_INT: // These all CMOV fine
609 case T_ADDRESS: { // (RawPtr)
610 cost++;
611 break;
612 }
613 case T_NARROWOOP: // Fall through
614 case T_OBJECT: { // Base oops are OK, but not derived oops
615 const TypeOopPtr *tp = phi->type()->make_ptr()->isa_oopptr();
616 // Derived pointers are Bad (tm): what's the Base (for GC purposes) of a
617 // CMOVE'd derived pointer? It's a CMOVE'd derived base. Thus
618 // CMOVE'ing a derived pointer requires we also CMOVE the base. If we
619 // have a Phi for the base here that we convert to a CMOVE all is well
620 // and good. But if the base is dead, we'll not make a CMOVE. Later
621 // the allocator will have to produce a base by creating a CMOVE of the
622 // relevant bases. This puts the allocator in the business of
623 // manufacturing expensive instructions, generally a bad plan.
624 // Just Say No to Conditionally-Moved Derived Pointers.
625 if (tp && tp->offset() != 0)
626 return NULL;
627 cost++;
628 break;
629 }
630 default:
631 return NULL; // In particular, can't do memory or I/O
632 }
633 // Add in cost any speculative ops
634 for (uint j = 1; j < region->req(); j++) {
635 Node *proj = region->in(j);
636 Node *inp = phi->in(j);
637 if (get_ctrl(inp) == proj) { // Found local op
638 cost++;
639 // Check for a chain of dependent ops; these will all become
640 // speculative in a CMOV.
641 for (uint k = 1; k < inp->req(); k++)
642 if (get_ctrl(inp->in(k)) == proj)
643 cost += ConditionalMoveLimit; // Too much speculative goo
644 }
645 }
646 // See if the Phi is used by a Cmp or Narrow oop Decode/Encode.
647 // This will likely Split-If, a higher-payoff operation.
648 for (DUIterator_Fast kmax, k = phi->fast_outs(kmax); k < kmax; k++) {
649 Node* use = phi->fast_out(k);
650 if (use->is_Cmp() || use->is_DecodeNarrowPtr() || use->is_EncodeNarrowPtr())
651 cost += ConditionalMoveLimit;
652 // Is there a use inside the loop?
653 // Note: check only basic types since CMoveP is pinned.
654 if (!used_inside_loop && is_java_primitive(bt)) {
655 IdealLoopTree* u_loop = get_loop(has_ctrl(use) ? get_ctrl(use) : use);
656 if (r_loop == u_loop || r_loop->is_member(u_loop)) {
657 used_inside_loop = true;
658 }
659 }
660 }
661 }//for
662 Node* bol = iff->in(1);
663 assert(bol->Opcode() == Op_Bool, "");
664 int cmp_op = bol->in(1)->Opcode();
665 // It is expensive to generate flags from a float compare.
666 // Avoid duplicated float compare.
667 if (phis > 1 && (cmp_op == Op_CmpF || cmp_op == Op_CmpD)) return NULL;
668
669 float infrequent_prob = PROB_UNLIKELY_MAG(3);
670 // Ignore cost and blocks frequency if CMOVE can be moved outside the loop.
671 if (used_inside_loop) {
672 if (cost >= ConditionalMoveLimit) return NULL; // Too much goo
673
674 // BlockLayoutByFrequency optimization moves infrequent branch
675 // from hot path. No point in CMOV'ing in such case (110 is used
676 // instead of 100 to take into account not exactness of float value).
677 if (BlockLayoutByFrequency) {
678 infrequent_prob = MAX2(infrequent_prob, (float)BlockLayoutMinDiamondPercentage/110.0f);
679 }
680 }
681 // Check for highly predictable branch. No point in CMOV'ing if
682 // we are going to predict accurately all the time.
683 if (C->use_cmove() && (cmp_op == Op_CmpF || cmp_op == Op_CmpD)) {
684 //keep going
685 } else if (iff->_prob < infrequent_prob ||
686 iff->_prob > (1.0f - infrequent_prob))
687 return NULL;
688
689 // --------------
690 // Now replace all Phis with CMOV's
691 Node *cmov_ctrl = iff->in(0);
692 uint flip = (lp->Opcode() == Op_IfTrue);
693 Node_List wq;
694 while (1) {
695 PhiNode* phi = NULL;
696 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
697 Node *out = region->fast_out(i);
698 if (out->is_Phi()) {
699 phi = out->as_Phi();
700 break;
701 }
702 }
703 if (phi == NULL) break;
704 if (PrintOpto && VerifyLoopOptimizations) { tty->print_cr("CMOV"); }
705 // Move speculative ops
706 wq.push(phi);
707 while (wq.size() > 0) {
708 Node *n = wq.pop();
709 for (uint j = 1; j < n->req(); j++) {
710 Node* m = n->in(j);
711 if (m != NULL && !is_dominator(get_ctrl(m), cmov_ctrl)) {
712 #ifndef PRODUCT
713 if (PrintOpto && VerifyLoopOptimizations) {
714 tty->print(" speculate: ");
715 m->dump();
716 }
717 #endif
718 set_ctrl(m, cmov_ctrl);
719 wq.push(m);
720 }
721 }
722 }
723 Node *cmov = CMoveNode::make(cmov_ctrl, iff->in(1), phi->in(1+flip), phi->in(2-flip), _igvn.type(phi));
724 register_new_node( cmov, cmov_ctrl );
725 _igvn.replace_node( phi, cmov );
726 #ifndef PRODUCT
727 if (TraceLoopOpts) {
728 tty->print("CMOV ");
729 r_loop->dump_head();
730 if (Verbose) {
731 bol->in(1)->dump(1);
732 cmov->dump(1);
733 }
734 }
735 if (VerifyLoopOptimizations) verify();
736 #endif
737 }
738
739 // The useless CFG diamond will fold up later; see the optimization in
740 // RegionNode::Ideal.
741 _igvn._worklist.push(region);
742
743 return iff->in(1);
744 }
745
746 static void enqueue_cfg_uses(Node* m, Unique_Node_List& wq) {
747 for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
748 Node* u = m->fast_out(i);
749 if (u->is_CFG()) {
750 if (u->Opcode() == Op_NeverBranch) {
751 u = ((NeverBranchNode*)u)->proj_out(0);
752 enqueue_cfg_uses(u, wq);
753 } else {
754 wq.push(u);
755 }
756 }
757 }
758 }
759
760 // Try moving a store out of a loop, right before the loop
761 Node* PhaseIdealLoop::try_move_store_before_loop(Node* n, Node *n_ctrl) {
762 // Store has to be first in the loop body
763 IdealLoopTree *n_loop = get_loop(n_ctrl);
764 if (n->is_Store() && n_loop != _ltree_root &&
765 n_loop->is_loop() && n_loop->_head->is_Loop() &&
766 n->in(0) != NULL) {
767 Node* address = n->in(MemNode::Address);
768 Node* value = n->in(MemNode::ValueIn);
769 Node* mem = n->in(MemNode::Memory);
770 IdealLoopTree* address_loop = get_loop(get_ctrl(address));
771 IdealLoopTree* value_loop = get_loop(get_ctrl(value));
772
773 // - address and value must be loop invariant
774 // - memory must be a memory Phi for the loop
775 // - Store must be the only store on this memory slice in the
776 // loop: if there's another store following this one then value
777 // written at iteration i by the second store could be overwritten
778 // at iteration i+n by the first store: it's not safe to move the
779 // first store out of the loop
780 // - nothing must observe the memory Phi: it guarantees no read
781 // before the store, we are also guaranteed the store post
782 // dominates the loop head (ignoring a possible early
783 // exit). Otherwise there would be extra Phi involved between the
784 // loop's Phi and the store.
785 // - there must be no early exit from the loop before the Store
786 // (such an exit most of the time would be an extra use of the
787 // memory Phi but sometimes is a bottom memory Phi that takes the
788 // store as input).
789
790 if (!n_loop->is_member(address_loop) &&
791 !n_loop->is_member(value_loop) &&
792 mem->is_Phi() && mem->in(0) == n_loop->_head &&
793 mem->outcnt() == 1 &&
794 mem->in(LoopNode::LoopBackControl) == n) {
795
796 assert(n_loop->_tail != NULL, "need a tail");
797 assert(is_dominator(n_ctrl, n_loop->_tail), "store control must not be in a branch in the loop");
798
799 // Verify that there's no early exit of the loop before the store.
800 bool ctrl_ok = false;
801 {
802 // Follow control from loop head until n, we exit the loop or
803 // we reach the tail
804 ResourceMark rm;
805 Unique_Node_List wq;
806 wq.push(n_loop->_head);
807
808 for (uint next = 0; next < wq.size(); ++next) {
809 Node *m = wq.at(next);
810 if (m == n->in(0)) {
811 ctrl_ok = true;
812 continue;
813 }
814 assert(!has_ctrl(m), "should be CFG");
815 if (!n_loop->is_member(get_loop(m)) || m == n_loop->_tail) {
816 ctrl_ok = false;
817 break;
818 }
819 enqueue_cfg_uses(m, wq);
820 if (wq.size() > 10) {
821 ctrl_ok = false;
822 break;
823 }
824 }
825 }
826 if (ctrl_ok) {
827 // move the Store
828 _igvn.replace_input_of(mem, LoopNode::LoopBackControl, mem);
829 _igvn.replace_input_of(n, 0, n_loop->_head->as_Loop()->skip_strip_mined()->in(LoopNode::EntryControl));
830 _igvn.replace_input_of(n, MemNode::Memory, mem->in(LoopNode::EntryControl));
831 // Disconnect the phi now. An empty phi can confuse other
832 // optimizations in this pass of loop opts.
833 _igvn.replace_node(mem, mem->in(LoopNode::EntryControl));
834 n_loop->_body.yank(mem);
835
836 set_ctrl_and_loop(n, n->in(0));
837
838 return n;
839 }
840 }
841 }
842 return NULL;
843 }
844
845 // Try moving a store out of a loop, right after the loop
846 void PhaseIdealLoop::try_move_store_after_loop(Node* n) {
847 if (n->is_Store() && n->in(0) != NULL) {
848 Node *n_ctrl = get_ctrl(n);
849 IdealLoopTree *n_loop = get_loop(n_ctrl);
850 // Store must be in a loop
851 if (n_loop != _ltree_root && !n_loop->_irreducible) {
852 Node* address = n->in(MemNode::Address);
853 Node* value = n->in(MemNode::ValueIn);
854 IdealLoopTree* address_loop = get_loop(get_ctrl(address));
855 // address must be loop invariant
856 if (!n_loop->is_member(address_loop)) {
857 // Store must be last on this memory slice in the loop and
858 // nothing in the loop must observe it
859 Node* phi = NULL;
860 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
861 Node* u = n->fast_out(i);
862 if (has_ctrl(u)) { // control use?
863 IdealLoopTree *u_loop = get_loop(get_ctrl(u));
864 if (!n_loop->is_member(u_loop)) {
865 continue;
866 }
867 if (u->is_Phi() && u->in(0) == n_loop->_head) {
868 assert(_igvn.type(u) == Type::MEMORY, "bad phi");
869 // multiple phis on the same slice are possible
870 if (phi != NULL) {
871 return;
872 }
873 phi = u;
874 continue;
875 }
876 }
877 return;
878 }
879 if (phi != NULL) {
880 // Nothing in the loop before the store (next iteration)
881 // must observe the stored value
882 bool mem_ok = true;
883 {
884 ResourceMark rm;
885 Unique_Node_List wq;
886 wq.push(phi);
887 for (uint next = 0; next < wq.size() && mem_ok; ++next) {
888 Node *m = wq.at(next);
889 for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax && mem_ok; i++) {
890 Node* u = m->fast_out(i);
891 if (u->is_Store() || u->is_Phi()) {
892 if (u != n) {
893 wq.push(u);
894 mem_ok = (wq.size() <= 10);
895 }
896 } else {
897 mem_ok = false;
898 break;
899 }
900 }
901 }
902 }
903 if (mem_ok) {
904 // Move the store out of the loop if the LCA of all
905 // users (except for the phi) is outside the loop.
906 Node* hook = new Node(1);
907 _igvn.rehash_node_delayed(phi);
908 int count = phi->replace_edge(n, hook);
909 assert(count > 0, "inconsistent phi");
910
911 // Compute latest point this store can go
912 Node* lca = get_late_ctrl(n, get_ctrl(n));
913 if (n_loop->is_member(get_loop(lca))) {
914 // LCA is in the loop - bail out
915 _igvn.replace_node(hook, n);
916 return;
917 }
918 #ifdef ASSERT
919 if (n_loop->_head->is_Loop() && n_loop->_head->as_Loop()->is_strip_mined()) {
920 assert(n_loop->_head->Opcode() == Op_CountedLoop, "outer loop is a strip mined");
921 n_loop->_head->as_Loop()->verify_strip_mined(1);
922 Node* outer = n_loop->_head->as_CountedLoop()->outer_loop();
923 IdealLoopTree* outer_loop = get_loop(outer);
924 assert(n_loop->_parent == outer_loop, "broken loop tree");
925 assert(get_loop(lca) == outer_loop, "safepoint in outer loop consume all memory state");
926 }
927 #endif
928
929 // Move store out of the loop
930 _igvn.replace_node(hook, n->in(MemNode::Memory));
931 _igvn.replace_input_of(n, 0, lca);
932 set_ctrl_and_loop(n, lca);
933
934 // Disconnect the phi now. An empty phi can confuse other
935 // optimizations in this pass of loop opts..
936 if (phi->in(LoopNode::LoopBackControl) == phi) {
937 _igvn.replace_node(phi, phi->in(LoopNode::EntryControl));
938 n_loop->_body.yank(phi);
939 }
940 }
941 }
942 }
943 }
944 }
945 }
946
947 //------------------------------split_if_with_blocks_pre-----------------------
948 // Do the real work in a non-recursive function. Data nodes want to be
949 // cloned in the pre-order so they can feed each other nicely.
950 Node *PhaseIdealLoop::split_if_with_blocks_pre( Node *n ) {
951 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
952 Node* bs_res = bs->split_if_pre(this, n);
953 if (bs_res != NULL) {
954 return bs_res;
955 }
956 // Cloning these guys is unlikely to win
957 int n_op = n->Opcode();
958 if( n_op == Op_MergeMem ) return n;
959 if( n->is_Proj() ) return n;
960 // Do not clone-up CmpFXXX variations, as these are always
961 // followed by a CmpI
962 if( n->is_Cmp() ) return n;
963 // Attempt to use a conditional move instead of a phi/branch
964 if( ConditionalMoveLimit > 0 && n_op == Op_Region ) {
965 Node *cmov = conditional_move( n );
966 if( cmov ) return cmov;
967 }
968 if( n->is_CFG() || n->is_LoadStore() )
969 return n;
970 if( n_op == Op_Opaque1 || // Opaque nodes cannot be mod'd
971 n_op == Op_Opaque2 ) {
972 if( !C->major_progress() ) // If chance of no more loop opts...
973 _igvn._worklist.push(n); // maybe we'll remove them
974 return n;
975 }
976
977 if( n->is_Con() ) return n; // No cloning for Con nodes
978
979 Node *n_ctrl = get_ctrl(n);
980 if( !n_ctrl ) return n; // Dead node
981
982 Node* res = try_move_store_before_loop(n, n_ctrl);
983 if (res != NULL) {
984 return n;
985 }
986
987 // Attempt to remix address expressions for loop invariants
988 Node *m = remix_address_expressions( n );
989 if( m ) return m;
990
991 if (n_op == Op_AddI) {
992 Node *nn = convert_add_to_muladd( n );
993 if ( nn ) return nn;
994 }
995
996 if (n->is_ConstraintCast()) {
997 Node* dom_cast = n->as_ConstraintCast()->dominating_cast(&_igvn, this);
998 // ConstraintCastNode::dominating_cast() uses node control input to determine domination.
999 // Node control inputs don't necessarily agree with loop control info (due to
1000 // transformations happened in between), thus additional dominance check is needed
1001 // to keep loop info valid.
1002 if (dom_cast != NULL && is_dominator(get_ctrl(dom_cast), get_ctrl(n))) {
1003 _igvn.replace_node(n, dom_cast);
1004 return dom_cast;
1005 }
1006 }
1007
1008 // Determine if the Node has inputs from some local Phi.
1009 // Returns the block to clone thru.
1010 Node *n_blk = has_local_phi_input( n );
1011 if( !n_blk ) return n;
1012
1013 // Do not clone the trip counter through on a CountedLoop
1014 // (messes up the canonical shape).
1015 if( n_blk->is_CountedLoop() && n->Opcode() == Op_AddI ) return n;
1016
1017 // Check for having no control input; not pinned. Allow
1018 // dominating control.
1019 if (n->in(0)) {
1020 Node *dom = idom(n_blk);
1021 if (dom_lca(n->in(0), dom) != n->in(0)) {
1022 return n;
1023 }
1024 }
1025 // Policy: when is it profitable. You must get more wins than
1026 // policy before it is considered profitable. Policy is usually 0,
1027 // so 1 win is considered profitable. Big merges will require big
1028 // cloning, so get a larger policy.
1029 int policy = n_blk->req() >> 2;
1030
1031 // If the loop is a candidate for range check elimination,
1032 // delay splitting through it's phi until a later loop optimization
1033 if (n_blk->is_CountedLoop()) {
1034 IdealLoopTree *lp = get_loop(n_blk);
1035 if (lp && lp->_rce_candidate) {
1036 return n;
1037 }
1038 }
1039
1040 if (must_throttle_split_if()) return n;
1041
1042 // Split 'n' through the merge point if it is profitable
1043 Node *phi = split_thru_phi( n, n_blk, policy );
1044 if (!phi) return n;
1045
1046 // Found a Phi to split thru!
1047 // Replace 'n' with the new phi
1048 _igvn.replace_node( n, phi );
1049 // Moved a load around the loop, 'en-registering' something.
1050 if (n_blk->is_Loop() && n->is_Load() &&
1051 !phi->in(LoopNode::LoopBackControl)->is_Load())
1052 C->set_major_progress();
1053
1054 return phi;
1055 }
1056
1057 static bool merge_point_too_heavy(Compile* C, Node* region) {
1058 // Bail out if the region and its phis have too many users.
1059 int weight = 0;
1060 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
1061 weight += region->fast_out(i)->outcnt();
1062 }
1063 int nodes_left = C->max_node_limit() - C->live_nodes();
1064 if (weight * 8 > nodes_left) {
1065 if (PrintOpto) {
1066 tty->print_cr("*** Split-if bails out: %d nodes, region weight %d", C->unique(), weight);
1067 }
1068 return true;
1069 } else {
1070 return false;
1071 }
1072 }
1073
1074 static bool merge_point_safe(Node* region) {
1075 // 4799512: Stop split_if_with_blocks from splitting a block with a ConvI2LNode
1076 // having a PhiNode input. This sidesteps the dangerous case where the split
1077 // ConvI2LNode may become TOP if the input Value() does not
1078 // overlap the ConvI2L range, leaving a node which may not dominate its
1079 // uses.
1080 // A better fix for this problem can be found in the BugTraq entry, but
1081 // expediency for Mantis demands this hack.
1082 // 6855164: If the merge point has a FastLockNode with a PhiNode input, we stop
1083 // split_if_with_blocks from splitting a block because we could not move around
1084 // the FastLockNode.
1085 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
1086 Node* n = region->fast_out(i);
1087 if (n->is_Phi()) {
1088 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
1089 Node* m = n->fast_out(j);
1090 if (m->is_FastLock())
1091 return false;
1092 #ifdef _LP64
1093 if (m->Opcode() == Op_ConvI2L)
1094 return false;
1095 if (m->is_CastII() && m->isa_CastII()->has_range_check()) {
1096 return false;
1097 }
1098 #endif
1099 }
1100 }
1101 }
1102 return true;
1103 }
1104
1105
1106 //------------------------------place_near_use---------------------------------
1107 // Place some computation next to use but not inside inner loops.
1108 // For inner loop uses move it to the preheader area.
1109 Node *PhaseIdealLoop::place_near_use(Node *useblock) const {
1110 IdealLoopTree *u_loop = get_loop( useblock );
1111 if (u_loop->_irreducible) {
1112 return useblock;
1113 }
1114 if (u_loop->_child) {
1115 if (useblock == u_loop->_head && u_loop->_head->is_OuterStripMinedLoop()) {
1116 return u_loop->_head->in(LoopNode::EntryControl);
1117 }
1118 return useblock;
1119 }
1120 return u_loop->_head->as_Loop()->skip_strip_mined()->in(LoopNode::EntryControl);
1121 }
1122
1123
1124 bool PhaseIdealLoop::identical_backtoback_ifs(Node *n) {
1125 if (!n->is_If() || n->is_CountedLoopEnd()) {
1126 return false;
1127 }
1128 if (!n->in(0)->is_Region()) {
1129 return false;
1130 }
1131 Node* region = n->in(0);
1132 Node* dom = idom(region);
1133 if (!dom->is_If() || dom->in(1) != n->in(1)) {
1134 return false;
1135 }
1136 IfNode* dom_if = dom->as_If();
1137 Node* proj_true = dom_if->proj_out(1);
1138 Node* proj_false = dom_if->proj_out(0);
1139
1140 for (uint i = 1; i < region->req(); i++) {
1141 if (is_dominator(proj_true, region->in(i))) {
1142 continue;
1143 }
1144 if (is_dominator(proj_false, region->in(i))) {
1145 continue;
1146 }
1147 return false;
1148 }
1149
1150 return true;
1151 }
1152
1153
1154 bool PhaseIdealLoop::can_split_if(Node* n_ctrl) {
1155 if (must_throttle_split_if()) {
1156 return false;
1157 }
1158
1159 // Do not do 'split-if' if irreducible loops are present.
1160 if (_has_irreducible_loops) {
1161 return false;
1162 }
1163
1164 if (merge_point_too_heavy(C, n_ctrl)) {
1165 return false;
1166 }
1167
1168 // Do not do 'split-if' if some paths are dead. First do dead code
1169 // elimination and then see if its still profitable.
1170 for (uint i = 1; i < n_ctrl->req(); i++) {
1171 if (n_ctrl->in(i) == C->top()) {
1172 return false;
1173 }
1174 }
1175
1176 // If trying to do a 'Split-If' at the loop head, it is only
1177 // profitable if the cmp folds up on BOTH paths. Otherwise we
1178 // risk peeling a loop forever.
1179
1180 // CNC - Disabled for now. Requires careful handling of loop
1181 // body selection for the cloned code. Also, make sure we check
1182 // for any input path not being in the same loop as n_ctrl. For
1183 // irreducible loops we cannot check for 'n_ctrl->is_Loop()'
1184 // because the alternative loop entry points won't be converted
1185 // into LoopNodes.
1186 IdealLoopTree *n_loop = get_loop(n_ctrl);
1187 for (uint j = 1; j < n_ctrl->req(); j++) {
1188 if (get_loop(n_ctrl->in(j)) != n_loop) {
1189 return false;
1190 }
1191 }
1192
1193 // Check for safety of the merge point.
1194 if (!merge_point_safe(n_ctrl)) {
1195 return false;
1196 }
1197
1198 return true;
1199 }
1200
1201 // Detect if the node is the inner strip-mined loop
1202 // Return: NULL if it's not the case, or the exit of outer strip-mined loop
1203 static Node* is_inner_of_stripmined_loop(const Node* out) {
1204 Node* out_le = NULL;
1205
1206 if (out->is_CountedLoopEnd()) {
1207 const CountedLoopNode* loop = out->as_CountedLoopEnd()->loopnode();
1208
1209 if (loop != NULL && loop->is_strip_mined()) {
1210 out_le = loop->in(LoopNode::EntryControl)->as_OuterStripMinedLoop()->outer_loop_exit();
1211 }
1212 }
1213
1214 return out_le;
1215 }
1216
1217 //------------------------------split_if_with_blocks_post----------------------
1218 // Do the real work in a non-recursive function. CFG hackery wants to be
1219 // in the post-order, so it can dirty the I-DOM info and not use the dirtied
1220 // info.
1221 void PhaseIdealLoop::split_if_with_blocks_post(Node *n) {
1222
1223 // Cloning Cmp through Phi's involves the split-if transform.
1224 // FastLock is not used by an If
1225 if (n->is_Cmp() && !n->is_FastLock()) {
1226 Node *n_ctrl = get_ctrl(n);
1227 // Determine if the Node has inputs from some local Phi.
1228 // Returns the block to clone thru.
1229 Node *n_blk = has_local_phi_input(n);
1230 if (n_blk != n_ctrl) {
1231 return;
1232 }
1233
1234 if (!can_split_if(n_ctrl)) {
1235 return;
1236 }
1237
1238 if (n->outcnt() != 1) {
1239 return; // Multiple bool's from 1 compare?
1240 }
1241 Node *bol = n->unique_out();
1242 assert(bol->is_Bool(), "expect a bool here");
1243 if (bol->outcnt() != 1) {
1244 return;// Multiple branches from 1 compare?
1245 }
1246 Node *iff = bol->unique_out();
1247
1248 // Check some safety conditions
1249 if (iff->is_If()) { // Classic split-if?
1250 if (iff->in(0) != n_ctrl) {
1251 return; // Compare must be in same blk as if
1252 }
1253 } else if (iff->is_CMove()) { // Trying to split-up a CMOVE
1254 // Can't split CMove with different control edge.
1255 if (iff->in(0) != NULL && iff->in(0) != n_ctrl ) {
1256 return;
1257 }
1258 if (get_ctrl(iff->in(2)) == n_ctrl ||
1259 get_ctrl(iff->in(3)) == n_ctrl) {
1260 return; // Inputs not yet split-up
1261 }
1262 if (get_loop(n_ctrl) != get_loop(get_ctrl(iff))) {
1263 return; // Loop-invar test gates loop-varying CMOVE
1264 }
1265 } else {
1266 return; // some other kind of node, such as an Allocate
1267 }
1268
1269 // When is split-if profitable? Every 'win' on means some control flow
1270 // goes dead, so it's almost always a win.
1271 int policy = 0;
1272 // Split compare 'n' through the merge point if it is profitable
1273 Node *phi = split_thru_phi( n, n_ctrl, policy);
1274 if (!phi) {
1275 return;
1276 }
1277
1278 // Found a Phi to split thru!
1279 // Replace 'n' with the new phi
1280 _igvn.replace_node(n, phi);
1281
1282 // Now split the bool up thru the phi
1283 Node *bolphi = split_thru_phi(bol, n_ctrl, -1);
1284 guarantee(bolphi != NULL, "null boolean phi node");
1285
1286 _igvn.replace_node(bol, bolphi);
1287 assert(iff->in(1) == bolphi, "");
1288
1289 if (bolphi->Value(&_igvn)->singleton()) {
1290 return;
1291 }
1292
1293 // Conditional-move? Must split up now
1294 if (!iff->is_If()) {
1295 Node *cmovphi = split_thru_phi(iff, n_ctrl, -1);
1296 _igvn.replace_node(iff, cmovphi);
1297 return;
1298 }
1299
1300 // Now split the IF
1301 do_split_if(iff);
1302 return;
1303 }
1304
1305 // Two identical ifs back to back can be merged
1306 if (identical_backtoback_ifs(n) && can_split_if(n->in(0))) {
1307 Node *n_ctrl = n->in(0);
1308 PhiNode* bolphi = PhiNode::make_blank(n_ctrl, n->in(1));
1309 IfNode* dom_if = idom(n_ctrl)->as_If();
1310 Node* proj_true = dom_if->proj_out(1);
1311 Node* proj_false = dom_if->proj_out(0);
1312 Node* con_true = _igvn.makecon(TypeInt::ONE);
1313 Node* con_false = _igvn.makecon(TypeInt::ZERO);
1314
1315 for (uint i = 1; i < n_ctrl->req(); i++) {
1316 if (is_dominator(proj_true, n_ctrl->in(i))) {
1317 bolphi->init_req(i, con_true);
1318 } else {
1319 assert(is_dominator(proj_false, n_ctrl->in(i)), "bad if");
1320 bolphi->init_req(i, con_false);
1321 }
1322 }
1323 register_new_node(bolphi, n_ctrl);
1324 _igvn.replace_input_of(n, 1, bolphi);
1325
1326 // Now split the IF
1327 do_split_if(n);
1328 return;
1329 }
1330
1331 // Check for an IF ready to split; one that has its
1332 // condition codes input coming from a Phi at the block start.
1333 int n_op = n->Opcode();
1334
1335 // Check for an IF being dominated by another IF same test
1336 if (n_op == Op_If ||
1337 n_op == Op_RangeCheck) {
1338 Node *bol = n->in(1);
1339 uint max = bol->outcnt();
1340 // Check for same test used more than once?
1341 if (max > 1 && bol->is_Bool()) {
1342 // Search up IDOMs to see if this IF is dominated.
1343 Node *cutoff = get_ctrl(bol);
1344
1345 // Now search up IDOMs till cutoff, looking for a dominating test
1346 Node *prevdom = n;
1347 Node *dom = idom(prevdom);
1348 while (dom != cutoff) {
1349 if (dom->req() > 1 && dom->in(1) == bol && prevdom->in(0) == dom) {
1350 // It's invalid to move control dependent data nodes in the inner
1351 // strip-mined loop, because:
1352 // 1) break validation of LoopNode::verify_strip_mined()
1353 // 2) move code with side-effect in strip-mined loop
1354 // Move to the exit of outer strip-mined loop in that case.
1355 Node* out_le = is_inner_of_stripmined_loop(dom);
1356 if (out_le != NULL) {
1357 prevdom = out_le;
1358 }
1359 // Replace the dominated test with an obvious true or false.
1360 // Place it on the IGVN worklist for later cleanup.
1361 C->set_major_progress();
1362 dominated_by(prevdom, n, false, true);
1363 #ifndef PRODUCT
1364 if( VerifyLoopOptimizations ) verify();
1365 #endif
1366 return;
1367 }
1368 prevdom = dom;
1369 dom = idom(prevdom);
1370 }
1371 }
1372 }
1373
1374 // See if a shared loop-varying computation has no loop-varying uses.
1375 // Happens if something is only used for JVM state in uncommon trap exits,
1376 // like various versions of induction variable+offset. Clone the
1377 // computation per usage to allow it to sink out of the loop.
1378 if (has_ctrl(n) && !n->in(0)) {// n not dead and has no control edge (can float about)
1379 Node *n_ctrl = get_ctrl(n);
1380 IdealLoopTree *n_loop = get_loop(n_ctrl);
1381 if( n_loop != _ltree_root ) {
1382 DUIterator_Fast imax, i = n->fast_outs(imax);
1383 for (; i < imax; i++) {
1384 Node* u = n->fast_out(i);
1385 if( !has_ctrl(u) ) break; // Found control user
1386 IdealLoopTree *u_loop = get_loop(get_ctrl(u));
1387 if( u_loop == n_loop ) break; // Found loop-varying use
1388 if( n_loop->is_member( u_loop ) ) break; // Found use in inner loop
1389 if( u->Opcode() == Op_Opaque1 ) break; // Found loop limit, bugfix for 4677003
1390 }
1391 bool did_break = (i < imax); // Did we break out of the previous loop?
1392 if (!did_break && n->outcnt() > 1) { // All uses in outer loops!
1393 Node *late_load_ctrl = NULL;
1394 if (n->is_Load()) {
1395 // If n is a load, get and save the result from get_late_ctrl(),
1396 // to be later used in calculating the control for n's clones.
1397 clear_dom_lca_tags();
1398 late_load_ctrl = get_late_ctrl(n, n_ctrl);
1399 }
1400 // If n is a load, and the late control is the same as the current
1401 // control, then the cloning of n is a pointless exercise, because
1402 // GVN will ensure that we end up where we started.
1403 if (!n->is_Load() || late_load_ctrl != n_ctrl) {
1404 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1405 for (DUIterator_Last jmin, j = n->last_outs(jmin); j >= jmin; ) {
1406 Node *u = n->last_out(j); // Clone private computation per use
1407 _igvn.rehash_node_delayed(u);
1408 Node *x = n->clone(); // Clone computation
1409 Node *x_ctrl = NULL;
1410 if( u->is_Phi() ) {
1411 // Replace all uses of normal nodes. Replace Phi uses
1412 // individually, so the separate Nodes can sink down
1413 // different paths.
1414 uint k = 1;
1415 while( u->in(k) != n ) k++;
1416 u->set_req( k, x );
1417 // x goes next to Phi input path
1418 x_ctrl = u->in(0)->in(k);
1419 --j;
1420 } else { // Normal use
1421 // Replace all uses
1422 for( uint k = 0; k < u->req(); k++ ) {
1423 if( u->in(k) == n ) {
1424 u->set_req( k, x );
1425 --j;
1426 }
1427 }
1428 x_ctrl = get_ctrl(u);
1429 }
1430
1431 // Find control for 'x' next to use but not inside inner loops.
1432 // For inner loop uses get the preheader area.
1433 x_ctrl = place_near_use(x_ctrl);
1434
1435 if (bs->sink_node(this, n, x, x_ctrl, n_ctrl)) {
1436 continue;
1437 }
1438
1439 if (n->is_Load()) {
1440 // For loads, add a control edge to a CFG node outside of the loop
1441 // to force them to not combine and return back inside the loop
1442 // during GVN optimization (4641526).
1443 //
1444 // Because we are setting the actual control input, factor in
1445 // the result from get_late_ctrl() so we respect any
1446 // anti-dependences. (6233005).
1447 x_ctrl = dom_lca(late_load_ctrl, x_ctrl);
1448
1449 // Don't allow the control input to be a CFG splitting node.
1450 // Such nodes should only have ProjNodes as outs, e.g. IfNode
1451 // should only have IfTrueNode and IfFalseNode (4985384).
1452 x_ctrl = find_non_split_ctrl(x_ctrl);
1453 assert(dom_depth(n_ctrl) <= dom_depth(x_ctrl), "n is later than its clone");
1454
1455 x->set_req(0, x_ctrl);
1456 }
1457 register_new_node(x, x_ctrl);
1458
1459 // Some institutional knowledge is needed here: 'x' is
1460 // yanked because if the optimizer runs GVN on it all the
1461 // cloned x's will common up and undo this optimization and
1462 // be forced back in the loop.
1463 // I tried setting control edges on the x's to force them to
1464 // not combine, but the matching gets worried when it tries
1465 // to fold a StoreP and an AddP together (as part of an
1466 // address expression) and the AddP and StoreP have
1467 // different controls.
1468 if (!x->is_Load() && !x->is_DecodeNarrowPtr()) _igvn._worklist.yank(x);
1469 }
1470 _igvn.remove_dead_node(n);
1471 }
1472 }
1473 }
1474 }
1475
1476 try_move_store_after_loop(n);
1477
1478 // Remove multiple allocations of the same value type
1479 if (n->is_ValueType()) {
1480 n->as_ValueType()->remove_redundant_allocations(&_igvn, this);
1481 return; // n is now dead
1482 }
1483
1484 // Check for Opaque2's who's loop has disappeared - who's input is in the
1485 // same loop nest as their output. Remove 'em, they are no longer useful.
1486 if( n_op == Op_Opaque2 &&
1487 n->in(1) != NULL &&
1488 get_loop(get_ctrl(n)) == get_loop(get_ctrl(n->in(1))) ) {
1489 _igvn.replace_node( n, n->in(1) );
1490 }
1491 }
1492
1493 //------------------------------split_if_with_blocks---------------------------
1494 // Check for aggressive application of 'split-if' optimization,
1495 // using basic block level info.
1496 void PhaseIdealLoop::split_if_with_blocks(VectorSet &visited, Node_Stack &nstack) {
1497 Node* root = C->root();
1498 visited.set(root->_idx); // first, mark root as visited
1499 // Do pre-visit work for root
1500 Node* n = split_if_with_blocks_pre(root);
1501 uint cnt = n->outcnt();
1502 uint i = 0;
1503
1504 while (true) {
1505 // Visit all children
1506 if (i < cnt) {
1507 Node* use = n->raw_out(i);
1508 ++i;
1509 if (use->outcnt() != 0 && !visited.test_set(use->_idx)) {
1510 // Now do pre-visit work for this use
1511 use = split_if_with_blocks_pre(use);
1512 nstack.push(n, i); // Save parent and next use's index.
1513 n = use; // Process all children of current use.
1514 cnt = use->outcnt();
1515 i = 0;
1516 }
1517 }
1518 else {
1519 // All of n's children have been processed, complete post-processing.
1520 if (cnt != 0 && !n->is_Con()) {
1521 assert(has_node(n), "no dead nodes");
1522 split_if_with_blocks_post(n);
1523 }
1524 if (must_throttle_split_if()) {
1525 nstack.clear();
1526 }
1527 if (nstack.is_empty()) {
1528 // Finished all nodes on stack.
1529 break;
1530 }
1531 // Get saved parent node and next use's index. Visit the rest of uses.
1532 n = nstack.node();
1533 cnt = n->outcnt();
1534 i = nstack.index();
1535 nstack.pop();
1536 }
1537 }
1538 }
1539
1540
1541 //=============================================================================
1542 //
1543 // C L O N E A L O O P B O D Y
1544 //
1545
1546 //------------------------------clone_iff--------------------------------------
1547 // Passed in a Phi merging (recursively) some nearly equivalent Bool/Cmps.
1548 // "Nearly" because all Nodes have been cloned from the original in the loop,
1549 // but the fall-in edges to the Cmp are different. Clone bool/Cmp pairs
1550 // through the Phi recursively, and return a Bool.
1551 Node* PhaseIdealLoop::clone_iff(PhiNode *phi, IdealLoopTree *loop) {
1552
1553 // Convert this Phi into a Phi merging Bools
1554 uint i;
1555 for (i = 1; i < phi->req(); i++) {
1556 Node *b = phi->in(i);
1557 if (b->is_Phi()) {
1558 _igvn.replace_input_of(phi, i, clone_iff(b->as_Phi(), loop));
1559 } else {
1560 assert(b->is_Bool() || b->Opcode() == Op_Opaque4, "");
1561 }
1562 }
1563
1564 Node* n = phi->in(1);
1565 Node* sample_opaque = NULL;
1566 Node *sample_bool = NULL;
1567 if (n->Opcode() == Op_Opaque4) {
1568 sample_opaque = n;
1569 sample_bool = n->in(1);
1570 assert(sample_bool->is_Bool(), "wrong type");
1571 } else {
1572 sample_bool = n;
1573 }
1574 Node *sample_cmp = sample_bool->in(1);
1575
1576 // Make Phis to merge the Cmp's inputs.
1577 PhiNode *phi1 = new PhiNode(phi->in(0), Type::TOP);
1578 PhiNode *phi2 = new PhiNode(phi->in(0), Type::TOP);
1579 for (i = 1; i < phi->req(); i++) {
1580 Node *n1 = sample_opaque == NULL ? phi->in(i)->in(1)->in(1) : phi->in(i)->in(1)->in(1)->in(1);
1581 Node *n2 = sample_opaque == NULL ? phi->in(i)->in(1)->in(2) : phi->in(i)->in(1)->in(1)->in(2);
1582 phi1->set_req(i, n1);
1583 phi2->set_req(i, n2);
1584 phi1->set_type(phi1->type()->meet_speculative(n1->bottom_type()));
1585 phi2->set_type(phi2->type()->meet_speculative(n2->bottom_type()));
1586 }
1587 // See if these Phis have been made before.
1588 // Register with optimizer
1589 Node *hit1 = _igvn.hash_find_insert(phi1);
1590 if (hit1) { // Hit, toss just made Phi
1591 _igvn.remove_dead_node(phi1); // Remove new phi
1592 assert(hit1->is_Phi(), "" );
1593 phi1 = (PhiNode*)hit1; // Use existing phi
1594 } else { // Miss
1595 _igvn.register_new_node_with_optimizer(phi1);
1596 }
1597 Node *hit2 = _igvn.hash_find_insert(phi2);
1598 if (hit2) { // Hit, toss just made Phi
1599 _igvn.remove_dead_node(phi2); // Remove new phi
1600 assert(hit2->is_Phi(), "" );
1601 phi2 = (PhiNode*)hit2; // Use existing phi
1602 } else { // Miss
1603 _igvn.register_new_node_with_optimizer(phi2);
1604 }
1605 // Register Phis with loop/block info
1606 set_ctrl(phi1, phi->in(0));
1607 set_ctrl(phi2, phi->in(0));
1608 // Make a new Cmp
1609 Node *cmp = sample_cmp->clone();
1610 cmp->set_req(1, phi1);
1611 cmp->set_req(2, phi2);
1612 _igvn.register_new_node_with_optimizer(cmp);
1613 set_ctrl(cmp, phi->in(0));
1614
1615 // Make a new Bool
1616 Node *b = sample_bool->clone();
1617 b->set_req(1,cmp);
1618 _igvn.register_new_node_with_optimizer(b);
1619 set_ctrl(b, phi->in(0));
1620
1621 if (sample_opaque != NULL) {
1622 Node* opaque = sample_opaque->clone();
1623 opaque->set_req(1, b);
1624 _igvn.register_new_node_with_optimizer(opaque);
1625 set_ctrl(opaque, phi->in(0));
1626 return opaque;
1627 }
1628
1629 assert(b->is_Bool(), "");
1630 return b;
1631 }
1632
1633 //------------------------------clone_bool-------------------------------------
1634 // Passed in a Phi merging (recursively) some nearly equivalent Bool/Cmps.
1635 // "Nearly" because all Nodes have been cloned from the original in the loop,
1636 // but the fall-in edges to the Cmp are different. Clone bool/Cmp pairs
1637 // through the Phi recursively, and return a Bool.
1638 CmpNode *PhaseIdealLoop::clone_bool( PhiNode *phi, IdealLoopTree *loop ) {
1639 uint i;
1640 // Convert this Phi into a Phi merging Bools
1641 for( i = 1; i < phi->req(); i++ ) {
1642 Node *b = phi->in(i);
1643 if( b->is_Phi() ) {
1644 _igvn.replace_input_of(phi, i, clone_bool( b->as_Phi(), loop ));
1645 } else {
1646 assert( b->is_Cmp() || b->is_top(), "inputs are all Cmp or TOP" );
1647 }
1648 }
1649
1650 Node *sample_cmp = phi->in(1);
1651
1652 // Make Phis to merge the Cmp's inputs.
1653 PhiNode *phi1 = new PhiNode( phi->in(0), Type::TOP );
1654 PhiNode *phi2 = new PhiNode( phi->in(0), Type::TOP );
1655 for( uint j = 1; j < phi->req(); j++ ) {
1656 Node *cmp_top = phi->in(j); // Inputs are all Cmp or TOP
1657 Node *n1, *n2;
1658 if( cmp_top->is_Cmp() ) {
1659 n1 = cmp_top->in(1);
1660 n2 = cmp_top->in(2);
1661 } else {
1662 n1 = n2 = cmp_top;
1663 }
1664 phi1->set_req( j, n1 );
1665 phi2->set_req( j, n2 );
1666 phi1->set_type(phi1->type()->meet_speculative(n1->bottom_type()));
1667 phi2->set_type(phi2->type()->meet_speculative(n2->bottom_type()));
1668 }
1669
1670 // See if these Phis have been made before.
1671 // Register with optimizer
1672 Node *hit1 = _igvn.hash_find_insert(phi1);
1673 if( hit1 ) { // Hit, toss just made Phi
1674 _igvn.remove_dead_node(phi1); // Remove new phi
1675 assert( hit1->is_Phi(), "" );
1676 phi1 = (PhiNode*)hit1; // Use existing phi
1677 } else { // Miss
1678 _igvn.register_new_node_with_optimizer(phi1);
1679 }
1680 Node *hit2 = _igvn.hash_find_insert(phi2);
1681 if( hit2 ) { // Hit, toss just made Phi
1682 _igvn.remove_dead_node(phi2); // Remove new phi
1683 assert( hit2->is_Phi(), "" );
1684 phi2 = (PhiNode*)hit2; // Use existing phi
1685 } else { // Miss
1686 _igvn.register_new_node_with_optimizer(phi2);
1687 }
1688 // Register Phis with loop/block info
1689 set_ctrl(phi1, phi->in(0));
1690 set_ctrl(phi2, phi->in(0));
1691 // Make a new Cmp
1692 Node *cmp = sample_cmp->clone();
1693 cmp->set_req( 1, phi1 );
1694 cmp->set_req( 2, phi2 );
1695 _igvn.register_new_node_with_optimizer(cmp);
1696 set_ctrl(cmp, phi->in(0));
1697
1698 assert( cmp->is_Cmp(), "" );
1699 return (CmpNode*)cmp;
1700 }
1701
1702 //------------------------------sink_use---------------------------------------
1703 // If 'use' was in the loop-exit block, it now needs to be sunk
1704 // below the post-loop merge point.
1705 void PhaseIdealLoop::sink_use( Node *use, Node *post_loop ) {
1706 if (!use->is_CFG() && get_ctrl(use) == post_loop->in(2)) {
1707 set_ctrl(use, post_loop);
1708 for (DUIterator j = use->outs(); use->has_out(j); j++)
1709 sink_use(use->out(j), post_loop);
1710 }
1711 }
1712
1713 void PhaseIdealLoop::clone_loop_handle_data_uses(Node* old, Node_List &old_new,
1714 IdealLoopTree* loop, IdealLoopTree* outer_loop,
1715 Node_List*& split_if_set, Node_List*& split_bool_set,
1716 Node_List*& split_cex_set, Node_List& worklist,
1717 uint new_counter, CloneLoopMode mode) {
1718 Node* nnn = old_new[old->_idx];
1719 // Copy uses to a worklist, so I can munge the def-use info
1720 // with impunity.
1721 for (DUIterator_Fast jmax, j = old->fast_outs(jmax); j < jmax; j++)
1722 worklist.push(old->fast_out(j));
1723
1724 while( worklist.size() ) {
1725 Node *use = worklist.pop();
1726 if (!has_node(use)) continue; // Ignore dead nodes
1727 if (use->in(0) == C->top()) continue;
1728 IdealLoopTree *use_loop = get_loop( has_ctrl(use) ? get_ctrl(use) : use );
1729 // Check for data-use outside of loop - at least one of OLD or USE
1730 // must not be a CFG node.
1731 #ifdef ASSERT
1732 if (loop->_head->as_Loop()->is_strip_mined() && outer_loop->is_member(use_loop) && !loop->is_member(use_loop) && old_new[use->_idx] == NULL) {
1733 Node* sfpt = loop->_head->as_CountedLoop()->outer_safepoint();
1734 assert(mode == ControlAroundStripMined && use == sfpt, "missed a node");
1735 }
1736 #endif
1737 if (!loop->is_member(use_loop) && !outer_loop->is_member(use_loop) && (!old->is_CFG() || !use->is_CFG())) {
1738
1739 // If the Data use is an IF, that means we have an IF outside of the
1740 // loop that is switching on a condition that is set inside of the
1741 // loop. Happens if people set a loop-exit flag; then test the flag
1742 // in the loop to break the loop, then test is again outside of the
1743 // loop to determine which way the loop exited.
1744 // Loop predicate If node connects to Bool node through Opaque1 node.
1745 if (use->is_If() || use->is_CMove() || C->is_predicate_opaq(use) || use->Opcode() == Op_Opaque4) {
1746 // Since this code is highly unlikely, we lazily build the worklist
1747 // of such Nodes to go split.
1748 if (!split_if_set) {
1749 ResourceArea *area = Thread::current()->resource_area();
1750 split_if_set = new Node_List(area);
1751 }
1752 split_if_set->push(use);
1753 }
1754 if (use->is_Bool()) {
1755 if (!split_bool_set) {
1756 ResourceArea *area = Thread::current()->resource_area();
1757 split_bool_set = new Node_List(area);
1758 }
1759 split_bool_set->push(use);
1760 }
1761 if (use->Opcode() == Op_CreateEx) {
1762 if (!split_cex_set) {
1763 ResourceArea *area = Thread::current()->resource_area();
1764 split_cex_set = new Node_List(area);
1765 }
1766 split_cex_set->push(use);
1767 }
1768
1769
1770 // Get "block" use is in
1771 uint idx = 0;
1772 while( use->in(idx) != old ) idx++;
1773 Node *prev = use->is_CFG() ? use : get_ctrl(use);
1774 assert(!loop->is_member(get_loop(prev)) && !outer_loop->is_member(get_loop(prev)), "" );
1775 Node *cfg = prev->_idx >= new_counter
1776 ? prev->in(2)
1777 : idom(prev);
1778 if( use->is_Phi() ) // Phi use is in prior block
1779 cfg = prev->in(idx); // NOT in block of Phi itself
1780 if (cfg->is_top()) { // Use is dead?
1781 _igvn.replace_input_of(use, idx, C->top());
1782 continue;
1783 }
1784
1785 // If use is referenced through control edge... (idx == 0)
1786 if (mode == IgnoreStripMined && idx == 0) {
1787 LoopNode *head = loop->_head->as_Loop();
1788 if (head->is_strip_mined() && is_dominator(head->outer_loop_exit(), prev)) {
1789 // That node is outside the inner loop, leave it outside the
1790 // outer loop as well to not confuse verification code.
1791 assert(!loop->_parent->is_member(use_loop), "should be out of the outer loop");
1792 _igvn.replace_input_of(use, 0, head->outer_loop_exit());
1793 continue;
1794 }
1795 }
1796
1797 while(!outer_loop->is_member(get_loop(cfg))) {
1798 prev = cfg;
1799 cfg = cfg->_idx >= new_counter ? cfg->in(2) : idom(cfg);
1800 }
1801 // If the use occurs after merging several exits from the loop, then
1802 // old value must have dominated all those exits. Since the same old
1803 // value was used on all those exits we did not need a Phi at this
1804 // merge point. NOW we do need a Phi here. Each loop exit value
1805 // is now merged with the peeled body exit; each exit gets its own
1806 // private Phi and those Phis need to be merged here.
1807 Node *phi;
1808 if( prev->is_Region() ) {
1809 if( idx == 0 ) { // Updating control edge?
1810 phi = prev; // Just use existing control
1811 } else { // Else need a new Phi
1812 phi = PhiNode::make( prev, old );
1813 // Now recursively fix up the new uses of old!
1814 for( uint i = 1; i < prev->req(); i++ ) {
1815 worklist.push(phi); // Onto worklist once for each 'old' input
1816 }
1817 }
1818 } else {
1819 // Get new RegionNode merging old and new loop exits
1820 prev = old_new[prev->_idx];
1821 assert( prev, "just made this in step 7" );
1822 if( idx == 0) { // Updating control edge?
1823 phi = prev; // Just use existing control
1824 } else { // Else need a new Phi
1825 // Make a new Phi merging data values properly
1826 phi = PhiNode::make( prev, old );
1827 phi->set_req( 1, nnn );
1828 }
1829 }
1830 // If inserting a new Phi, check for prior hits
1831 if( idx != 0 ) {
1832 Node *hit = _igvn.hash_find_insert(phi);
1833 if( hit == NULL ) {
1834 _igvn.register_new_node_with_optimizer(phi); // Register new phi
1835 } else { // or
1836 // Remove the new phi from the graph and use the hit
1837 _igvn.remove_dead_node(phi);
1838 phi = hit; // Use existing phi
1839 }
1840 set_ctrl(phi, prev);
1841 }
1842 // Make 'use' use the Phi instead of the old loop body exit value
1843 _igvn.replace_input_of(use, idx, phi);
1844 if( use->_idx >= new_counter ) { // If updating new phis
1845 // Not needed for correctness, but prevents a weak assert
1846 // in AddPNode from tripping (when we end up with different
1847 // base & derived Phis that will become the same after
1848 // IGVN does CSE).
1849 Node *hit = _igvn.hash_find_insert(use);
1850 if( hit ) // Go ahead and re-hash for hits.
1851 _igvn.replace_node( use, hit );
1852 }
1853
1854 // If 'use' was in the loop-exit block, it now needs to be sunk
1855 // below the post-loop merge point.
1856 sink_use( use, prev );
1857 }
1858 }
1859 }
1860
1861 static void clone_outer_loop_helper(Node* n, const IdealLoopTree *loop, const IdealLoopTree* outer_loop,
1862 const Node_List &old_new, Unique_Node_List& wq, PhaseIdealLoop* phase,
1863 bool check_old_new) {
1864 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
1865 Node* u = n->fast_out(j);
1866 assert(check_old_new || old_new[u->_idx] == NULL, "shouldn't have been cloned");
1867 if (!u->is_CFG() && (!check_old_new || old_new[u->_idx] == NULL)) {
1868 Node* c = phase->get_ctrl(u);
1869 IdealLoopTree* u_loop = phase->get_loop(c);
1870 assert(!loop->is_member(u_loop), "can be in outer loop or out of both loops only");
1871 if (outer_loop->is_member(u_loop)) {
1872 wq.push(u);
1873 }
1874 }
1875 }
1876 }
1877
1878 void PhaseIdealLoop::clone_outer_loop(LoopNode* head, CloneLoopMode mode, IdealLoopTree *loop,
1879 IdealLoopTree* outer_loop, int dd, Node_List &old_new,
1880 Node_List& extra_data_nodes) {
1881 if (head->is_strip_mined() && mode != IgnoreStripMined) {
1882 CountedLoopNode* cl = head->as_CountedLoop();
1883 Node* l = cl->outer_loop();
1884 Node* tail = cl->outer_loop_tail();
1885 IfNode* le = cl->outer_loop_end();
1886 Node* sfpt = cl->outer_safepoint();
1887 CountedLoopEndNode* cle = cl->loopexit();
1888 CountedLoopNode* new_cl = old_new[cl->_idx]->as_CountedLoop();
1889 CountedLoopEndNode* new_cle = new_cl->as_CountedLoop()->loopexit_or_null();
1890 Node* cle_out = cle->proj_out(false);
1891
1892 Node* new_sfpt = NULL;
1893 Node* new_cle_out = cle_out->clone();
1894 old_new.map(cle_out->_idx, new_cle_out);
1895 if (mode == CloneIncludesStripMined) {
1896 // clone outer loop body
1897 Node* new_l = l->clone();
1898 Node* new_tail = tail->clone();
1899 IfNode* new_le = le->clone()->as_If();
1900 new_sfpt = sfpt->clone();
1901
1902 set_loop(new_l, outer_loop->_parent);
1903 set_idom(new_l, new_l->in(LoopNode::EntryControl), dd);
1904 set_loop(new_cle_out, outer_loop->_parent);
1905 set_idom(new_cle_out, new_cle, dd);
1906 set_loop(new_sfpt, outer_loop->_parent);
1907 set_idom(new_sfpt, new_cle_out, dd);
1908 set_loop(new_le, outer_loop->_parent);
1909 set_idom(new_le, new_sfpt, dd);
1910 set_loop(new_tail, outer_loop->_parent);
1911 set_idom(new_tail, new_le, dd);
1912 set_idom(new_cl, new_l, dd);
1913
1914 old_new.map(l->_idx, new_l);
1915 old_new.map(tail->_idx, new_tail);
1916 old_new.map(le->_idx, new_le);
1917 old_new.map(sfpt->_idx, new_sfpt);
1918
1919 new_l->set_req(LoopNode::LoopBackControl, new_tail);
1920 new_l->set_req(0, new_l);
1921 new_tail->set_req(0, new_le);
1922 new_le->set_req(0, new_sfpt);
1923 new_sfpt->set_req(0, new_cle_out);
1924 new_cle_out->set_req(0, new_cle);
1925 new_cl->set_req(LoopNode::EntryControl, new_l);
1926
1927 _igvn.register_new_node_with_optimizer(new_l);
1928 _igvn.register_new_node_with_optimizer(new_tail);
1929 _igvn.register_new_node_with_optimizer(new_le);
1930 } else {
1931 Node *newhead = old_new[loop->_head->_idx];
1932 newhead->as_Loop()->clear_strip_mined();
1933 _igvn.replace_input_of(newhead, LoopNode::EntryControl, newhead->in(LoopNode::EntryControl)->in(LoopNode::EntryControl));
1934 set_idom(newhead, newhead->in(LoopNode::EntryControl), dd);
1935 }
1936 // Look at data node that were assigned a control in the outer
1937 // loop: they are kept in the outer loop by the safepoint so start
1938 // from the safepoint node's inputs.
1939 IdealLoopTree* outer_loop = get_loop(l);
1940 Node_Stack stack(2);
1941 stack.push(sfpt, 1);
1942 uint new_counter = C->unique();
1943 while (stack.size() > 0) {
1944 Node* n = stack.node();
1945 uint i = stack.index();
1946 while (i < n->req() &&
1947 (n->in(i) == NULL ||
1948 !has_ctrl(n->in(i)) ||
1949 get_loop(get_ctrl(n->in(i))) != outer_loop ||
1950 (old_new[n->in(i)->_idx] != NULL && old_new[n->in(i)->_idx]->_idx >= new_counter))) {
1951 i++;
1952 }
1953 if (i < n->req()) {
1954 stack.set_index(i+1);
1955 stack.push(n->in(i), 0);
1956 } else {
1957 assert(old_new[n->_idx] == NULL || n == sfpt || old_new[n->_idx]->_idx < new_counter, "no clone yet");
1958 Node* m = n == sfpt ? new_sfpt : n->clone();
1959 if (m != NULL) {
1960 for (uint i = 0; i < n->req(); i++) {
1961 if (m->in(i) != NULL && old_new[m->in(i)->_idx] != NULL) {
1962 m->set_req(i, old_new[m->in(i)->_idx]);
1963 }
1964 }
1965 } else {
1966 assert(n == sfpt && mode != CloneIncludesStripMined, "where's the safepoint clone?");
1967 }
1968 if (n != sfpt) {
1969 extra_data_nodes.push(n);
1970 _igvn.register_new_node_with_optimizer(m);
1971 assert(get_ctrl(n) == cle_out, "what other control?");
1972 set_ctrl(m, new_cle_out);
1973 old_new.map(n->_idx, m);
1974 }
1975 stack.pop();
1976 }
1977 }
1978 if (mode == CloneIncludesStripMined) {
1979 _igvn.register_new_node_with_optimizer(new_sfpt);
1980 _igvn.register_new_node_with_optimizer(new_cle_out);
1981 }
1982 // Some other transformation may have pessimistically assign some
1983 // data nodes to the outer loop. Set their control so they are out
1984 // of the outer loop.
1985 ResourceMark rm;
1986 Unique_Node_List wq;
1987 for (uint i = 0; i < extra_data_nodes.size(); i++) {
1988 Node* old = extra_data_nodes.at(i);
1989 clone_outer_loop_helper(old, loop, outer_loop, old_new, wq, this, true);
1990 }
1991 Node* new_ctrl = cl->outer_loop_exit();
1992 assert(get_loop(new_ctrl) != outer_loop, "must be out of the loop nest");
1993 for (uint i = 0; i < wq.size(); i++) {
1994 Node* n = wq.at(i);
1995 set_ctrl(n, new_ctrl);
1996 clone_outer_loop_helper(n, loop, outer_loop, old_new, wq, this, false);
1997 }
1998 } else {
1999 Node *newhead = old_new[loop->_head->_idx];
2000 set_idom(newhead, newhead->in(LoopNode::EntryControl), dd);
2001 }
2002 }
2003
2004 //------------------------------clone_loop-------------------------------------
2005 //
2006 // C L O N E A L O O P B O D Y
2007 //
2008 // This is the basic building block of the loop optimizations. It clones an
2009 // entire loop body. It makes an old_new loop body mapping; with this mapping
2010 // you can find the new-loop equivalent to an old-loop node. All new-loop
2011 // nodes are exactly equal to their old-loop counterparts, all edges are the
2012 // same. All exits from the old-loop now have a RegionNode that merges the
2013 // equivalent new-loop path. This is true even for the normal "loop-exit"
2014 // condition. All uses of loop-invariant old-loop values now come from (one
2015 // or more) Phis that merge their new-loop equivalents.
2016 //
2017 // This operation leaves the graph in an illegal state: there are two valid
2018 // control edges coming from the loop pre-header to both loop bodies. I'll
2019 // definitely have to hack the graph after running this transform.
2020 //
2021 // From this building block I will further edit edges to perform loop peeling
2022 // or loop unrolling or iteration splitting (Range-Check-Elimination), etc.
2023 //
2024 // Parameter side_by_size_idom:
2025 // When side_by_size_idom is NULL, the dominator tree is constructed for
2026 // the clone loop to dominate the original. Used in construction of
2027 // pre-main-post loop sequence.
2028 // When nonnull, the clone and original are side-by-side, both are
2029 // dominated by the side_by_side_idom node. Used in construction of
2030 // unswitched loops.
2031 void PhaseIdealLoop::clone_loop( IdealLoopTree *loop, Node_List &old_new, int dd,
2032 CloneLoopMode mode, Node* side_by_side_idom) {
2033
2034 LoopNode* head = loop->_head->as_Loop();
2035 head->verify_strip_mined(1);
2036
2037 if (C->do_vector_loop() && PrintOpto) {
2038 const char* mname = C->method()->name()->as_quoted_ascii();
2039 if (mname != NULL) {
2040 tty->print("PhaseIdealLoop::clone_loop: for vectorize method %s\n", mname);
2041 }
2042 }
2043
2044 CloneMap& cm = C->clone_map();
2045 Dict* dict = cm.dict();
2046 if (C->do_vector_loop()) {
2047 cm.set_clone_idx(cm.max_gen()+1);
2048 #ifndef PRODUCT
2049 if (PrintOpto) {
2050 tty->print_cr("PhaseIdealLoop::clone_loop: _clone_idx %d", cm.clone_idx());
2051 loop->dump_head();
2052 }
2053 #endif
2054 }
2055
2056 // Step 1: Clone the loop body. Make the old->new mapping.
2057 uint i;
2058 for( i = 0; i < loop->_body.size(); i++ ) {
2059 Node *old = loop->_body.at(i);
2060 Node *nnn = old->clone();
2061 old_new.map( old->_idx, nnn );
2062 if (C->do_vector_loop()) {
2063 cm.verify_insert_and_clone(old, nnn, cm.clone_idx());
2064 }
2065 _igvn.register_new_node_with_optimizer(nnn);
2066 }
2067
2068 IdealLoopTree* outer_loop = (head->is_strip_mined() && mode != IgnoreStripMined) ? get_loop(head->as_CountedLoop()->outer_loop()) : loop;
2069
2070 // Step 2: Fix the edges in the new body. If the old input is outside the
2071 // loop use it. If the old input is INside the loop, use the corresponding
2072 // new node instead.
2073 for( i = 0; i < loop->_body.size(); i++ ) {
2074 Node *old = loop->_body.at(i);
2075 Node *nnn = old_new[old->_idx];
2076 // Fix CFG/Loop controlling the new node
2077 if (has_ctrl(old)) {
2078 set_ctrl(nnn, old_new[get_ctrl(old)->_idx]);
2079 } else {
2080 set_loop(nnn, outer_loop->_parent);
2081 if (old->outcnt() > 0) {
2082 set_idom( nnn, old_new[idom(old)->_idx], dd );
2083 }
2084 }
2085 // Correct edges to the new node
2086 for( uint j = 0; j < nnn->req(); j++ ) {
2087 Node *n = nnn->in(j);
2088 if( n ) {
2089 IdealLoopTree *old_in_loop = get_loop( has_ctrl(n) ? get_ctrl(n) : n );
2090 if( loop->is_member( old_in_loop ) )
2091 nnn->set_req(j, old_new[n->_idx]);
2092 }
2093 }
2094 _igvn.hash_find_insert(nnn);
2095 }
2096
2097 ResourceArea *area = Thread::current()->resource_area();
2098 Node_List extra_data_nodes(area); // data nodes in the outer strip mined loop
2099 clone_outer_loop(head, mode, loop, outer_loop, dd, old_new, extra_data_nodes);
2100
2101 // Step 3: Now fix control uses. Loop varying control uses have already
2102 // been fixed up (as part of all input edges in Step 2). Loop invariant
2103 // control uses must be either an IfFalse or an IfTrue. Make a merge
2104 // point to merge the old and new IfFalse/IfTrue nodes; make the use
2105 // refer to this.
2106 Node_List worklist(area);
2107 uint new_counter = C->unique();
2108 for( i = 0; i < loop->_body.size(); i++ ) {
2109 Node* old = loop->_body.at(i);
2110 if( !old->is_CFG() ) continue;
2111
2112 // Copy uses to a worklist, so I can munge the def-use info
2113 // with impunity.
2114 for (DUIterator_Fast jmax, j = old->fast_outs(jmax); j < jmax; j++)
2115 worklist.push(old->fast_out(j));
2116
2117 while( worklist.size() ) { // Visit all uses
2118 Node *use = worklist.pop();
2119 if (!has_node(use)) continue; // Ignore dead nodes
2120 IdealLoopTree *use_loop = get_loop( has_ctrl(use) ? get_ctrl(use) : use );
2121 if( !loop->is_member( use_loop ) && use->is_CFG() ) {
2122 // Both OLD and USE are CFG nodes here.
2123 assert( use->is_Proj(), "" );
2124 Node* nnn = old_new[old->_idx];
2125
2126 Node* newuse = NULL;
2127 if (head->is_strip_mined() && mode != IgnoreStripMined) {
2128 CountedLoopNode* cl = head->as_CountedLoop();
2129 CountedLoopEndNode* cle = cl->loopexit();
2130 Node* cle_out = cle->proj_out_or_null(false);
2131 if (use == cle_out) {
2132 IfNode* le = cl->outer_loop_end();
2133 use = le->proj_out(false);
2134 use_loop = get_loop(use);
2135 if (mode == CloneIncludesStripMined) {
2136 nnn = old_new[le->_idx];
2137 } else {
2138 newuse = old_new[cle_out->_idx];
2139 }
2140 }
2141 }
2142 if (newuse == NULL) {
2143 newuse = use->clone();
2144 }
2145
2146 // Clone the loop exit control projection
2147 if (C->do_vector_loop()) {
2148 cm.verify_insert_and_clone(use, newuse, cm.clone_idx());
2149 }
2150 newuse->set_req(0,nnn);
2151 _igvn.register_new_node_with_optimizer(newuse);
2152 set_loop(newuse, use_loop);
2153 set_idom(newuse, nnn, dom_depth(nnn) + 1 );
2154
2155 // We need a Region to merge the exit from the peeled body and the
2156 // exit from the old loop body.
2157 RegionNode *r = new RegionNode(3);
2158 // Map the old use to the new merge point
2159 old_new.map( use->_idx, r );
2160 uint dd_r = MIN2(dom_depth(newuse),dom_depth(use));
2161 assert( dd_r >= dom_depth(dom_lca(newuse,use)), "" );
2162
2163 // The original user of 'use' uses 'r' instead.
2164 for (DUIterator_Last lmin, l = use->last_outs(lmin); l >= lmin;) {
2165 Node* useuse = use->last_out(l);
2166 _igvn.rehash_node_delayed(useuse);
2167 uint uses_found = 0;
2168 if( useuse->in(0) == use ) {
2169 useuse->set_req(0, r);
2170 uses_found++;
2171 if( useuse->is_CFG() ) {
2172 assert( dom_depth(useuse) > dd_r, "" );
2173 set_idom(useuse, r, dom_depth(useuse));
2174 }
2175 }
2176 for( uint k = 1; k < useuse->req(); k++ ) {
2177 if( useuse->in(k) == use ) {
2178 useuse->set_req(k, r);
2179 uses_found++;
2180 if (useuse->is_Loop() && k == LoopNode::EntryControl) {
2181 assert(dom_depth(useuse) > dd_r , "");
2182 set_idom(useuse, r, dom_depth(useuse));
2183 }
2184 }
2185 }
2186 l -= uses_found; // we deleted 1 or more copies of this edge
2187 }
2188
2189 // Now finish up 'r'
2190 r->set_req( 1, newuse );
2191 r->set_req( 2, use );
2192 _igvn.register_new_node_with_optimizer(r);
2193 set_loop(r, use_loop);
2194 set_idom(r, !side_by_side_idom ? newuse->in(0) : side_by_side_idom, dd_r);
2195 } // End of if a loop-exit test
2196 }
2197 }
2198
2199 // Step 4: If loop-invariant use is not control, it must be dominated by a
2200 // loop exit IfFalse/IfTrue. Find "proper" loop exit. Make a Region
2201 // there if needed. Make a Phi there merging old and new used values.
2202 Node_List *split_if_set = NULL;
2203 Node_List *split_bool_set = NULL;
2204 Node_List *split_cex_set = NULL;
2205 for( i = 0; i < loop->_body.size(); i++ ) {
2206 Node* old = loop->_body.at(i);
2207 clone_loop_handle_data_uses(old, old_new, loop, outer_loop, split_if_set,
2208 split_bool_set, split_cex_set, worklist, new_counter,
2209 mode);
2210 }
2211
2212 for (i = 0; i < extra_data_nodes.size(); i++) {
2213 Node* old = extra_data_nodes.at(i);
2214 clone_loop_handle_data_uses(old, old_new, loop, outer_loop, split_if_set,
2215 split_bool_set, split_cex_set, worklist, new_counter,
2216 mode);
2217 }
2218
2219 // Check for IFs that need splitting/cloning. Happens if an IF outside of
2220 // the loop uses a condition set in the loop. The original IF probably
2221 // takes control from one or more OLD Regions (which in turn get from NEW
2222 // Regions). In any case, there will be a set of Phis for each merge point
2223 // from the IF up to where the original BOOL def exists the loop.
2224 if (split_if_set) {
2225 while (split_if_set->size()) {
2226 Node *iff = split_if_set->pop();
2227 if (iff->in(1)->is_Phi()) {
2228 Node *b = clone_iff(iff->in(1)->as_Phi(), loop);
2229 _igvn.replace_input_of(iff, 1, b);
2230 }
2231 }
2232 }
2233 if (split_bool_set) {
2234 while (split_bool_set->size()) {
2235 Node *b = split_bool_set->pop();
2236 Node *phi = b->in(1);
2237 assert(phi->is_Phi(), "");
2238 CmpNode *cmp = clone_bool((PhiNode*)phi, loop);
2239 _igvn.replace_input_of(b, 1, cmp);
2240 }
2241 }
2242 if (split_cex_set) {
2243 while (split_cex_set->size()) {
2244 Node *b = split_cex_set->pop();
2245 assert(b->in(0)->is_Region(), "");
2246 assert(b->in(1)->is_Phi(), "");
2247 assert(b->in(0)->in(0) == b->in(1)->in(0), "");
2248 split_up(b, b->in(0), NULL);
2249 }
2250 }
2251
2252 }
2253
2254
2255 //---------------------- stride_of_possible_iv -------------------------------------
2256 // Looks for an iff/bool/comp with one operand of the compare
2257 // being a cycle involving an add and a phi,
2258 // with an optional truncation (left-shift followed by a right-shift)
2259 // of the add. Returns zero if not an iv.
2260 int PhaseIdealLoop::stride_of_possible_iv(Node* iff) {
2261 Node* trunc1 = NULL;
2262 Node* trunc2 = NULL;
2263 const TypeInt* ttype = NULL;
2264 if (!iff->is_If() || iff->in(1) == NULL || !iff->in(1)->is_Bool()) {
2265 return 0;
2266 }
2267 BoolNode* bl = iff->in(1)->as_Bool();
2268 Node* cmp = bl->in(1);
2269 if (!cmp || (cmp->Opcode() != Op_CmpI && cmp->Opcode() != Op_CmpU)) {
2270 return 0;
2271 }
2272 // Must have an invariant operand
2273 if (is_member(get_loop(iff), get_ctrl(cmp->in(2)))) {
2274 return 0;
2275 }
2276 Node* add2 = NULL;
2277 Node* cmp1 = cmp->in(1);
2278 if (cmp1->is_Phi()) {
2279 // (If (Bool (CmpX phi:(Phi ...(Optional-trunc(AddI phi add2))) )))
2280 Node* phi = cmp1;
2281 for (uint i = 1; i < phi->req(); i++) {
2282 Node* in = phi->in(i);
2283 Node* add = CountedLoopNode::match_incr_with_optional_truncation(in,
2284 &trunc1, &trunc2, &ttype);
2285 if (add && add->in(1) == phi) {
2286 add2 = add->in(2);
2287 break;
2288 }
2289 }
2290 } else {
2291 // (If (Bool (CmpX addtrunc:(Optional-trunc((AddI (Phi ...addtrunc...) add2)) )))
2292 Node* addtrunc = cmp1;
2293 Node* add = CountedLoopNode::match_incr_with_optional_truncation(addtrunc,
2294 &trunc1, &trunc2, &ttype);
2295 if (add && add->in(1)->is_Phi()) {
2296 Node* phi = add->in(1);
2297 for (uint i = 1; i < phi->req(); i++) {
2298 if (phi->in(i) == addtrunc) {
2299 add2 = add->in(2);
2300 break;
2301 }
2302 }
2303 }
2304 }
2305 if (add2 != NULL) {
2306 const TypeInt* add2t = _igvn.type(add2)->is_int();
2307 if (add2t->is_con()) {
2308 return add2t->get_con();
2309 }
2310 }
2311 return 0;
2312 }
2313
2314
2315 //---------------------- stay_in_loop -------------------------------------
2316 // Return the (unique) control output node that's in the loop (if it exists.)
2317 Node* PhaseIdealLoop::stay_in_loop( Node* n, IdealLoopTree *loop) {
2318 Node* unique = NULL;
2319 if (!n) return NULL;
2320 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2321 Node* use = n->fast_out(i);
2322 if (!has_ctrl(use) && loop->is_member(get_loop(use))) {
2323 if (unique != NULL) {
2324 return NULL;
2325 }
2326 unique = use;
2327 }
2328 }
2329 return unique;
2330 }
2331
2332 //------------------------------ register_node -------------------------------------
2333 // Utility to register node "n" with PhaseIdealLoop
2334 void PhaseIdealLoop::register_node(Node* n, IdealLoopTree *loop, Node* pred, int ddepth) {
2335 _igvn.register_new_node_with_optimizer(n);
2336 loop->_body.push(n);
2337 if (n->is_CFG()) {
2338 set_loop(n, loop);
2339 set_idom(n, pred, ddepth);
2340 } else {
2341 set_ctrl(n, pred);
2342 }
2343 }
2344
2345 //------------------------------ proj_clone -------------------------------------
2346 // Utility to create an if-projection
2347 ProjNode* PhaseIdealLoop::proj_clone(ProjNode* p, IfNode* iff) {
2348 ProjNode* c = p->clone()->as_Proj();
2349 c->set_req(0, iff);
2350 return c;
2351 }
2352
2353 //------------------------------ short_circuit_if -------------------------------------
2354 // Force the iff control output to be the live_proj
2355 Node* PhaseIdealLoop::short_circuit_if(IfNode* iff, ProjNode* live_proj) {
2356 guarantee(live_proj != NULL, "null projection");
2357 int proj_con = live_proj->_con;
2358 assert(proj_con == 0 || proj_con == 1, "false or true projection");
2359 Node *con = _igvn.intcon(proj_con);
2360 set_ctrl(con, C->root());
2361 if (iff) {
2362 iff->set_req(1, con);
2363 }
2364 return con;
2365 }
2366
2367 //------------------------------ insert_if_before_proj -------------------------------------
2368 // Insert a new if before an if projection (* - new node)
2369 //
2370 // before
2371 // if(test)
2372 // / \
2373 // v v
2374 // other-proj proj (arg)
2375 //
2376 // after
2377 // if(test)
2378 // / \
2379 // / v
2380 // | * proj-clone
2381 // v |
2382 // other-proj v
2383 // * new_if(relop(cmp[IU](left,right)))
2384 // / \
2385 // v v
2386 // * new-proj proj
2387 // (returned)
2388 //
2389 ProjNode* PhaseIdealLoop::insert_if_before_proj(Node* left, bool Signed, BoolTest::mask relop, Node* right, ProjNode* proj) {
2390 IfNode* iff = proj->in(0)->as_If();
2391 IdealLoopTree *loop = get_loop(proj);
2392 ProjNode *other_proj = iff->proj_out(!proj->is_IfTrue())->as_Proj();
2393 int ddepth = dom_depth(proj);
2394
2395 _igvn.rehash_node_delayed(iff);
2396 _igvn.rehash_node_delayed(proj);
2397
2398 proj->set_req(0, NULL); // temporary disconnect
2399 ProjNode* proj2 = proj_clone(proj, iff);
2400 register_node(proj2, loop, iff, ddepth);
2401
2402 Node* cmp = Signed ? (Node*) new CmpINode(left, right) : (Node*) new CmpUNode(left, right);
2403 register_node(cmp, loop, proj2, ddepth);
2404
2405 BoolNode* bol = new BoolNode(cmp, relop);
2406 register_node(bol, loop, proj2, ddepth);
2407
2408 int opcode = iff->Opcode();
2409 assert(opcode == Op_If || opcode == Op_RangeCheck, "unexpected opcode");
2410 IfNode* new_if = (opcode == Op_If) ? new IfNode(proj2, bol, iff->_prob, iff->_fcnt):
2411 new RangeCheckNode(proj2, bol, iff->_prob, iff->_fcnt);
2412 register_node(new_if, loop, proj2, ddepth);
2413
2414 proj->set_req(0, new_if); // reattach
2415 set_idom(proj, new_if, ddepth);
2416
2417 ProjNode* new_exit = proj_clone(other_proj, new_if)->as_Proj();
2418 guarantee(new_exit != NULL, "null exit node");
2419 register_node(new_exit, get_loop(other_proj), new_if, ddepth);
2420
2421 return new_exit;
2422 }
2423
2424 //------------------------------ insert_region_before_proj -------------------------------------
2425 // Insert a region before an if projection (* - new node)
2426 //
2427 // before
2428 // if(test)
2429 // / |
2430 // v |
2431 // proj v
2432 // other-proj
2433 //
2434 // after
2435 // if(test)
2436 // / |
2437 // v |
2438 // * proj-clone v
2439 // | other-proj
2440 // v
2441 // * new-region
2442 // |
2443 // v
2444 // * dum_if
2445 // / \
2446 // v \
2447 // * dum-proj v
2448 // proj
2449 //
2450 RegionNode* PhaseIdealLoop::insert_region_before_proj(ProjNode* proj) {
2451 IfNode* iff = proj->in(0)->as_If();
2452 IdealLoopTree *loop = get_loop(proj);
2453 ProjNode *other_proj = iff->proj_out(!proj->is_IfTrue())->as_Proj();
2454 int ddepth = dom_depth(proj);
2455
2456 _igvn.rehash_node_delayed(iff);
2457 _igvn.rehash_node_delayed(proj);
2458
2459 proj->set_req(0, NULL); // temporary disconnect
2460 ProjNode* proj2 = proj_clone(proj, iff);
2461 register_node(proj2, loop, iff, ddepth);
2462
2463 RegionNode* reg = new RegionNode(2);
2464 reg->set_req(1, proj2);
2465 register_node(reg, loop, iff, ddepth);
2466
2467 IfNode* dum_if = new IfNode(reg, short_circuit_if(NULL, proj), iff->_prob, iff->_fcnt);
2468 register_node(dum_if, loop, reg, ddepth);
2469
2470 proj->set_req(0, dum_if); // reattach
2471 set_idom(proj, dum_if, ddepth);
2472
2473 ProjNode* dum_proj = proj_clone(other_proj, dum_if);
2474 register_node(dum_proj, loop, dum_if, ddepth);
2475
2476 return reg;
2477 }
2478
2479 //------------------------------ insert_cmpi_loop_exit -------------------------------------
2480 // Clone a signed compare loop exit from an unsigned compare and
2481 // insert it before the unsigned cmp on the stay-in-loop path.
2482 // All new nodes inserted in the dominator tree between the original
2483 // if and it's projections. The original if test is replaced with
2484 // a constant to force the stay-in-loop path.
2485 //
2486 // This is done to make sure that the original if and it's projections
2487 // still dominate the same set of control nodes, that the ctrl() relation
2488 // from data nodes to them is preserved, and that their loop nesting is
2489 // preserved.
2490 //
2491 // before
2492 // if(i <u limit) unsigned compare loop exit
2493 // / |
2494 // v v
2495 // exit-proj stay-in-loop-proj
2496 //
2497 // after
2498 // if(stay-in-loop-const) original if
2499 // / |
2500 // / v
2501 // / if(i < limit) new signed test
2502 // / / |
2503 // / / v
2504 // / / if(i <u limit) new cloned unsigned test
2505 // / / / |
2506 // v v v |
2507 // region |
2508 // | |
2509 // dum-if |
2510 // / | |
2511 // ether | |
2512 // v v
2513 // exit-proj stay-in-loop-proj
2514 //
2515 IfNode* PhaseIdealLoop::insert_cmpi_loop_exit(IfNode* if_cmpu, IdealLoopTree *loop) {
2516 const bool Signed = true;
2517 const bool Unsigned = false;
2518
2519 BoolNode* bol = if_cmpu->in(1)->as_Bool();
2520 if (bol->_test._test != BoolTest::lt) return NULL;
2521 CmpNode* cmpu = bol->in(1)->as_Cmp();
2522 if (cmpu->Opcode() != Op_CmpU) return NULL;
2523 int stride = stride_of_possible_iv(if_cmpu);
2524 if (stride == 0) return NULL;
2525
2526 Node* lp_proj = stay_in_loop(if_cmpu, loop);
2527 guarantee(lp_proj != NULL, "null loop node");
2528
2529 ProjNode* lp_continue = lp_proj->as_Proj();
2530 ProjNode* lp_exit = if_cmpu->proj_out(!lp_continue->is_IfTrue())->as_Proj();
2531
2532 Node* limit = NULL;
2533 if (stride > 0) {
2534 limit = cmpu->in(2);
2535 } else {
2536 limit = _igvn.makecon(TypeInt::ZERO);
2537 set_ctrl(limit, C->root());
2538 }
2539 // Create a new region on the exit path
2540 RegionNode* reg = insert_region_before_proj(lp_exit);
2541 guarantee(reg != NULL, "null region node");
2542
2543 // Clone the if-cmpu-true-false using a signed compare
2544 BoolTest::mask rel_i = stride > 0 ? bol->_test._test : BoolTest::ge;
2545 ProjNode* cmpi_exit = insert_if_before_proj(cmpu->in(1), Signed, rel_i, limit, lp_continue);
2546 reg->add_req(cmpi_exit);
2547
2548 // Clone the if-cmpu-true-false
2549 BoolTest::mask rel_u = bol->_test._test;
2550 ProjNode* cmpu_exit = insert_if_before_proj(cmpu->in(1), Unsigned, rel_u, cmpu->in(2), lp_continue);
2551 reg->add_req(cmpu_exit);
2552
2553 // Force original if to stay in loop.
2554 short_circuit_if(if_cmpu, lp_continue);
2555
2556 return cmpi_exit->in(0)->as_If();
2557 }
2558
2559 //------------------------------ remove_cmpi_loop_exit -------------------------------------
2560 // Remove a previously inserted signed compare loop exit.
2561 void PhaseIdealLoop::remove_cmpi_loop_exit(IfNode* if_cmp, IdealLoopTree *loop) {
2562 Node* lp_proj = stay_in_loop(if_cmp, loop);
2563 assert(if_cmp->in(1)->in(1)->Opcode() == Op_CmpI &&
2564 stay_in_loop(lp_proj, loop)->is_If() &&
2565 stay_in_loop(lp_proj, loop)->in(1)->in(1)->Opcode() == Op_CmpU, "inserted cmpi before cmpu");
2566 Node *con = _igvn.makecon(lp_proj->is_IfTrue() ? TypeInt::ONE : TypeInt::ZERO);
2567 set_ctrl(con, C->root());
2568 if_cmp->set_req(1, con);
2569 }
2570
2571 //------------------------------ scheduled_nodelist -------------------------------------
2572 // Create a post order schedule of nodes that are in the
2573 // "member" set. The list is returned in "sched".
2574 // The first node in "sched" is the loop head, followed by
2575 // nodes which have no inputs in the "member" set, and then
2576 // followed by the nodes that have an immediate input dependence
2577 // on a node in "sched".
2578 void PhaseIdealLoop::scheduled_nodelist( IdealLoopTree *loop, VectorSet& member, Node_List &sched ) {
2579
2580 assert(member.test(loop->_head->_idx), "loop head must be in member set");
2581 Arena *a = Thread::current()->resource_area();
2582 VectorSet visited(a);
2583 Node_Stack nstack(a, loop->_body.size());
2584
2585 Node* n = loop->_head; // top of stack is cached in "n"
2586 uint idx = 0;
2587 visited.set(n->_idx);
2588
2589 // Initially push all with no inputs from within member set
2590 for(uint i = 0; i < loop->_body.size(); i++ ) {
2591 Node *elt = loop->_body.at(i);
2592 if (member.test(elt->_idx)) {
2593 bool found = false;
2594 for (uint j = 0; j < elt->req(); j++) {
2595 Node* def = elt->in(j);
2596 if (def && member.test(def->_idx) && def != elt) {
2597 found = true;
2598 break;
2599 }
2600 }
2601 if (!found && elt != loop->_head) {
2602 nstack.push(n, idx);
2603 n = elt;
2604 assert(!visited.test(n->_idx), "not seen yet");
2605 visited.set(n->_idx);
2606 }
2607 }
2608 }
2609
2610 // traverse out's that are in the member set
2611 while (true) {
2612 if (idx < n->outcnt()) {
2613 Node* use = n->raw_out(idx);
2614 idx++;
2615 if (!visited.test_set(use->_idx)) {
2616 if (member.test(use->_idx)) {
2617 nstack.push(n, idx);
2618 n = use;
2619 idx = 0;
2620 }
2621 }
2622 } else {
2623 // All outputs processed
2624 sched.push(n);
2625 if (nstack.is_empty()) break;
2626 n = nstack.node();
2627 idx = nstack.index();
2628 nstack.pop();
2629 }
2630 }
2631 }
2632
2633
2634 //------------------------------ has_use_in_set -------------------------------------
2635 // Has a use in the vector set
2636 bool PhaseIdealLoop::has_use_in_set( Node* n, VectorSet& vset ) {
2637 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2638 Node* use = n->fast_out(j);
2639 if (vset.test(use->_idx)) {
2640 return true;
2641 }
2642 }
2643 return false;
2644 }
2645
2646
2647 //------------------------------ has_use_internal_to_set -------------------------------------
2648 // Has use internal to the vector set (ie. not in a phi at the loop head)
2649 bool PhaseIdealLoop::has_use_internal_to_set( Node* n, VectorSet& vset, IdealLoopTree *loop ) {
2650 Node* head = loop->_head;
2651 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2652 Node* use = n->fast_out(j);
2653 if (vset.test(use->_idx) && !(use->is_Phi() && use->in(0) == head)) {
2654 return true;
2655 }
2656 }
2657 return false;
2658 }
2659
2660
2661 //------------------------------ clone_for_use_outside_loop -------------------------------------
2662 // clone "n" for uses that are outside of loop
2663 int PhaseIdealLoop::clone_for_use_outside_loop( IdealLoopTree *loop, Node* n, Node_List& worklist ) {
2664 int cloned = 0;
2665 assert(worklist.size() == 0, "should be empty");
2666 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2667 Node* use = n->fast_out(j);
2668 if( !loop->is_member(get_loop(has_ctrl(use) ? get_ctrl(use) : use)) ) {
2669 worklist.push(use);
2670 }
2671 }
2672 while( worklist.size() ) {
2673 Node *use = worklist.pop();
2674 if (!has_node(use) || use->in(0) == C->top()) continue;
2675 uint j;
2676 for (j = 0; j < use->req(); j++) {
2677 if (use->in(j) == n) break;
2678 }
2679 assert(j < use->req(), "must be there");
2680
2681 // clone "n" and insert it between the inputs of "n" and the use outside the loop
2682 Node* n_clone = n->clone();
2683 _igvn.replace_input_of(use, j, n_clone);
2684 cloned++;
2685 Node* use_c;
2686 if (!use->is_Phi()) {
2687 use_c = has_ctrl(use) ? get_ctrl(use) : use->in(0);
2688 } else {
2689 // Use in a phi is considered a use in the associated predecessor block
2690 use_c = use->in(0)->in(j);
2691 }
2692 set_ctrl(n_clone, use_c);
2693 assert(!loop->is_member(get_loop(use_c)), "should be outside loop");
2694 get_loop(use_c)->_body.push(n_clone);
2695 _igvn.register_new_node_with_optimizer(n_clone);
2696 #ifndef PRODUCT
2697 if (TracePartialPeeling) {
2698 tty->print_cr("loop exit cloning old: %d new: %d newbb: %d", n->_idx, n_clone->_idx, get_ctrl(n_clone)->_idx);
2699 }
2700 #endif
2701 }
2702 return cloned;
2703 }
2704
2705
2706 //------------------------------ clone_for_special_use_inside_loop -------------------------------------
2707 // clone "n" for special uses that are in the not_peeled region.
2708 // If these def-uses occur in separate blocks, the code generator
2709 // marks the method as not compilable. For example, if a "BoolNode"
2710 // is in a different basic block than the "IfNode" that uses it, then
2711 // the compilation is aborted in the code generator.
2712 void PhaseIdealLoop::clone_for_special_use_inside_loop( IdealLoopTree *loop, Node* n,
2713 VectorSet& not_peel, Node_List& sink_list, Node_List& worklist ) {
2714 if (n->is_Phi() || n->is_Load()) {
2715 return;
2716 }
2717 assert(worklist.size() == 0, "should be empty");
2718 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2719 Node* use = n->fast_out(j);
2720 if ( not_peel.test(use->_idx) &&
2721 (use->is_If() || use->is_CMove() || use->is_Bool()) &&
2722 use->in(1) == n) {
2723 worklist.push(use);
2724 }
2725 }
2726 if (worklist.size() > 0) {
2727 // clone "n" and insert it between inputs of "n" and the use
2728 Node* n_clone = n->clone();
2729 loop->_body.push(n_clone);
2730 _igvn.register_new_node_with_optimizer(n_clone);
2731 set_ctrl(n_clone, get_ctrl(n));
2732 sink_list.push(n_clone);
2733 not_peel <<= n_clone->_idx; // add n_clone to not_peel set.
2734 #ifndef PRODUCT
2735 if (TracePartialPeeling) {
2736 tty->print_cr("special not_peeled cloning old: %d new: %d", n->_idx, n_clone->_idx);
2737 }
2738 #endif
2739 while( worklist.size() ) {
2740 Node *use = worklist.pop();
2741 _igvn.rehash_node_delayed(use);
2742 for (uint j = 1; j < use->req(); j++) {
2743 if (use->in(j) == n) {
2744 use->set_req(j, n_clone);
2745 }
2746 }
2747 }
2748 }
2749 }
2750
2751
2752 //------------------------------ insert_phi_for_loop -------------------------------------
2753 // Insert phi(lp_entry_val, back_edge_val) at use->in(idx) for loop lp if phi does not already exist
2754 void PhaseIdealLoop::insert_phi_for_loop( Node* use, uint idx, Node* lp_entry_val, Node* back_edge_val, LoopNode* lp ) {
2755 Node *phi = PhiNode::make(lp, back_edge_val);
2756 phi->set_req(LoopNode::EntryControl, lp_entry_val);
2757 // Use existing phi if it already exists
2758 Node *hit = _igvn.hash_find_insert(phi);
2759 if( hit == NULL ) {
2760 _igvn.register_new_node_with_optimizer(phi);
2761 set_ctrl(phi, lp);
2762 } else {
2763 // Remove the new phi from the graph and use the hit
2764 _igvn.remove_dead_node(phi);
2765 phi = hit;
2766 }
2767 _igvn.replace_input_of(use, idx, phi);
2768 }
2769
2770 #ifdef ASSERT
2771 //------------------------------ is_valid_loop_partition -------------------------------------
2772 // Validate the loop partition sets: peel and not_peel
2773 bool PhaseIdealLoop::is_valid_loop_partition( IdealLoopTree *loop, VectorSet& peel, Node_List& peel_list,
2774 VectorSet& not_peel ) {
2775 uint i;
2776 // Check that peel_list entries are in the peel set
2777 for (i = 0; i < peel_list.size(); i++) {
2778 if (!peel.test(peel_list.at(i)->_idx)) {
2779 return false;
2780 }
2781 }
2782 // Check at loop members are in one of peel set or not_peel set
2783 for (i = 0; i < loop->_body.size(); i++ ) {
2784 Node *def = loop->_body.at(i);
2785 uint di = def->_idx;
2786 // Check that peel set elements are in peel_list
2787 if (peel.test(di)) {
2788 if (not_peel.test(di)) {
2789 return false;
2790 }
2791 // Must be in peel_list also
2792 bool found = false;
2793 for (uint j = 0; j < peel_list.size(); j++) {
2794 if (peel_list.at(j)->_idx == di) {
2795 found = true;
2796 break;
2797 }
2798 }
2799 if (!found) {
2800 return false;
2801 }
2802 } else if (not_peel.test(di)) {
2803 if (peel.test(di)) {
2804 return false;
2805 }
2806 } else {
2807 return false;
2808 }
2809 }
2810 return true;
2811 }
2812
2813 //------------------------------ is_valid_clone_loop_exit_use -------------------------------------
2814 // Ensure a use outside of loop is of the right form
2815 bool PhaseIdealLoop::is_valid_clone_loop_exit_use( IdealLoopTree *loop, Node* use, uint exit_idx) {
2816 Node *use_c = has_ctrl(use) ? get_ctrl(use) : use;
2817 return (use->is_Phi() &&
2818 use_c->is_Region() && use_c->req() == 3 &&
2819 (use_c->in(exit_idx)->Opcode() == Op_IfTrue ||
2820 use_c->in(exit_idx)->Opcode() == Op_IfFalse ||
2821 use_c->in(exit_idx)->Opcode() == Op_JumpProj) &&
2822 loop->is_member( get_loop( use_c->in(exit_idx)->in(0) ) ) );
2823 }
2824
2825 //------------------------------ is_valid_clone_loop_form -------------------------------------
2826 // Ensure that all uses outside of loop are of the right form
2827 bool PhaseIdealLoop::is_valid_clone_loop_form( IdealLoopTree *loop, Node_List& peel_list,
2828 uint orig_exit_idx, uint clone_exit_idx) {
2829 uint len = peel_list.size();
2830 for (uint i = 0; i < len; i++) {
2831 Node *def = peel_list.at(i);
2832
2833 for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) {
2834 Node *use = def->fast_out(j);
2835 Node *use_c = has_ctrl(use) ? get_ctrl(use) : use;
2836 if (!loop->is_member(get_loop(use_c))) {
2837 // use is not in the loop, check for correct structure
2838 if (use->in(0) == def) {
2839 // Okay
2840 } else if (!is_valid_clone_loop_exit_use(loop, use, orig_exit_idx)) {
2841 return false;
2842 }
2843 }
2844 }
2845 }
2846 return true;
2847 }
2848 #endif
2849
2850 //------------------------------ partial_peel -------------------------------------
2851 // Partially peel (aka loop rotation) the top portion of a loop (called
2852 // the peel section below) by cloning it and placing one copy just before
2853 // the new loop head and the other copy at the bottom of the new loop.
2854 //
2855 // before after where it came from
2856 //
2857 // stmt1 stmt1
2858 // loop: stmt2 clone
2859 // stmt2 if condA goto exitA clone
2860 // if condA goto exitA new_loop: new
2861 // stmt3 stmt3 clone
2862 // if !condB goto loop if condB goto exitB clone
2863 // exitB: stmt2 orig
2864 // stmt4 if !condA goto new_loop orig
2865 // exitA: goto exitA
2866 // exitB:
2867 // stmt4
2868 // exitA:
2869 //
2870 // Step 1: find the cut point: an exit test on probable
2871 // induction variable.
2872 // Step 2: schedule (with cloning) operations in the peel
2873 // section that can be executed after the cut into
2874 // the section that is not peeled. This may need
2875 // to clone operations into exit blocks. For
2876 // instance, a reference to A[i] in the not-peel
2877 // section and a reference to B[i] in an exit block
2878 // may cause a left-shift of i by 2 to be placed
2879 // in the peel block. This step will clone the left
2880 // shift into the exit block and sink the left shift
2881 // from the peel to the not-peel section.
2882 // Step 3: clone the loop, retarget the control, and insert
2883 // phis for values that are live across the new loop
2884 // head. This is very dependent on the graph structure
2885 // from clone_loop. It creates region nodes for
2886 // exit control and associated phi nodes for values
2887 // flow out of the loop through that exit. The region
2888 // node is dominated by the clone's control projection.
2889 // So the clone's peel section is placed before the
2890 // new loop head, and the clone's not-peel section is
2891 // forms the top part of the new loop. The original
2892 // peel section forms the tail of the new loop.
2893 // Step 4: update the dominator tree and recompute the
2894 // dominator depth.
2895 //
2896 // orig
2897 //
2898 // stmt1
2899 // |
2900 // v
2901 // loop predicate
2902 // |
2903 // v
2904 // loop<----+
2905 // | |
2906 // stmt2 |
2907 // | |
2908 // v |
2909 // ifA |
2910 // / | |
2911 // v v |
2912 // false true ^ <-- last_peel
2913 // / | |
2914 // / ===|==cut |
2915 // / stmt3 | <-- first_not_peel
2916 // / | |
2917 // | v |
2918 // v ifB |
2919 // exitA: / \ |
2920 // / \ |
2921 // v v |
2922 // false true |
2923 // / \ |
2924 // / ----+
2925 // |
2926 // v
2927 // exitB:
2928 // stmt4
2929 //
2930 //
2931 // after clone loop
2932 //
2933 // stmt1
2934 // |
2935 // v
2936 // loop predicate
2937 // / \
2938 // clone / \ orig
2939 // / \
2940 // / \
2941 // v v
2942 // +---->loop loop<----+
2943 // | | | |
2944 // | stmt2 stmt2 |
2945 // | | | |
2946 // | v v |
2947 // | ifA ifA |
2948 // | | \ / | |
2949 // | v v v v |
2950 // ^ true false false true ^ <-- last_peel
2951 // | | ^ \ / | |
2952 // | cut==|== \ \ / ===|==cut |
2953 // | stmt3 \ \ / stmt3 | <-- first_not_peel
2954 // | | dom | | | |
2955 // | v \ 1v v2 v |
2956 // | ifB regionA ifB |
2957 // | / \ | / \ |
2958 // | / \ v / \ |
2959 // | v v exitA: v v |
2960 // | true false false true |
2961 // | / ^ \ / \ |
2962 // +---- \ \ / ----+
2963 // dom \ /
2964 // \ 1v v2
2965 // regionB
2966 // |
2967 // v
2968 // exitB:
2969 // stmt4
2970 //
2971 //
2972 // after partial peel
2973 //
2974 // stmt1
2975 // |
2976 // v
2977 // loop predicate
2978 // /
2979 // clone / orig
2980 // / TOP
2981 // / \
2982 // v v
2983 // TOP->loop loop----+
2984 // | | |
2985 // stmt2 stmt2 |
2986 // | | |
2987 // v v |
2988 // ifA ifA |
2989 // | \ / | |
2990 // v v v v |
2991 // true false false true | <-- last_peel
2992 // | ^ \ / +------|---+
2993 // +->newloop \ \ / === ==cut | |
2994 // | stmt3 \ \ / TOP | |
2995 // | | dom | | stmt3 | | <-- first_not_peel
2996 // | v \ 1v v2 v | |
2997 // | ifB regionA ifB ^ v
2998 // | / \ | / \ | |
2999 // | / \ v / \ | |
3000 // | v v exitA: v v | |
3001 // | true false false true | |
3002 // | / ^ \ / \ | |
3003 // | | \ \ / v | |
3004 // | | dom \ / TOP | |
3005 // | | \ 1v v2 | |
3006 // ^ v regionB | |
3007 // | | | | |
3008 // | | v ^ v
3009 // | | exitB: | |
3010 // | | stmt4 | |
3011 // | +------------>-----------------+ |
3012 // | |
3013 // +-----------------<---------------------+
3014 //
3015 //
3016 // final graph
3017 //
3018 // stmt1
3019 // |
3020 // v
3021 // loop predicate
3022 // |
3023 // v
3024 // stmt2 clone
3025 // |
3026 // v
3027 // ........> ifA clone
3028 // : / |
3029 // dom / |
3030 // : v v
3031 // : false true
3032 // : | |
3033 // : | v
3034 // : | newloop<-----+
3035 // : | | |
3036 // : | stmt3 clone |
3037 // : | | |
3038 // : | v |
3039 // : | ifB |
3040 // : | / \ |
3041 // : | v v |
3042 // : | false true |
3043 // : | | | |
3044 // : | v stmt2 |
3045 // : | exitB: | |
3046 // : | stmt4 v |
3047 // : | ifA orig |
3048 // : | / \ |
3049 // : | / \ |
3050 // : | v v |
3051 // : | false true |
3052 // : | / \ |
3053 // : v v -----+
3054 // RegionA
3055 // |
3056 // v
3057 // exitA
3058 //
3059 bool PhaseIdealLoop::partial_peel( IdealLoopTree *loop, Node_List &old_new ) {
3060
3061 assert(!loop->_head->is_CountedLoop(), "Non-counted loop only");
3062 if (!loop->_head->is_Loop()) {
3063 return false;
3064 }
3065 LoopNode *head = loop->_head->as_Loop();
3066
3067 if (head->is_partial_peel_loop() || head->partial_peel_has_failed()) {
3068 return false;
3069 }
3070
3071 // Check for complex exit control
3072 for (uint ii = 0; ii < loop->_body.size(); ii++) {
3073 Node *n = loop->_body.at(ii);
3074 int opc = n->Opcode();
3075 if (n->is_Call() ||
3076 opc == Op_Catch ||
3077 opc == Op_CatchProj ||
3078 opc == Op_Jump ||
3079 opc == Op_JumpProj) {
3080 #ifndef PRODUCT
3081 if (TracePartialPeeling) {
3082 tty->print_cr("\nExit control too complex: lp: %d", head->_idx);
3083 }
3084 #endif
3085 return false;
3086 }
3087 }
3088
3089 int dd = dom_depth(head);
3090
3091 // Step 1: find cut point
3092
3093 // Walk up dominators to loop head looking for first loop exit
3094 // which is executed on every path thru loop.
3095 IfNode *peel_if = NULL;
3096 IfNode *peel_if_cmpu = NULL;
3097
3098 Node *iff = loop->tail();
3099 while (iff != head) {
3100 if (iff->is_If()) {
3101 Node *ctrl = get_ctrl(iff->in(1));
3102 if (ctrl->is_top()) return false; // Dead test on live IF.
3103 // If loop-varying exit-test, check for induction variable
3104 if (loop->is_member(get_loop(ctrl)) &&
3105 loop->is_loop_exit(iff) &&
3106 is_possible_iv_test(iff)) {
3107 Node* cmp = iff->in(1)->in(1);
3108 if (cmp->Opcode() == Op_CmpI) {
3109 peel_if = iff->as_If();
3110 } else {
3111 assert(cmp->Opcode() == Op_CmpU, "must be CmpI or CmpU");
3112 peel_if_cmpu = iff->as_If();
3113 }
3114 }
3115 }
3116 iff = idom(iff);
3117 }
3118
3119 // Prefer signed compare over unsigned compare.
3120 IfNode* new_peel_if = NULL;
3121 if (peel_if == NULL) {
3122 if (!PartialPeelAtUnsignedTests || peel_if_cmpu == NULL) {
3123 return false; // No peel point found
3124 }
3125 new_peel_if = insert_cmpi_loop_exit(peel_if_cmpu, loop);
3126 if (new_peel_if == NULL) {
3127 return false; // No peel point found
3128 }
3129 peel_if = new_peel_if;
3130 }
3131 Node* last_peel = stay_in_loop(peel_if, loop);
3132 Node* first_not_peeled = stay_in_loop(last_peel, loop);
3133 if (first_not_peeled == NULL || first_not_peeled == head) {
3134 return false;
3135 }
3136
3137 #ifndef PRODUCT
3138 if (TraceLoopOpts) {
3139 tty->print("PartialPeel ");
3140 loop->dump_head();
3141 }
3142
3143 if (TracePartialPeeling) {
3144 tty->print_cr("before partial peel one iteration");
3145 Node_List wl;
3146 Node* t = head->in(2);
3147 while (true) {
3148 wl.push(t);
3149 if (t == head) break;
3150 t = idom(t);
3151 }
3152 while (wl.size() > 0) {
3153 Node* tt = wl.pop();
3154 tt->dump();
3155 if (tt == last_peel) tty->print_cr("-- cut --");
3156 }
3157 }
3158 #endif
3159 ResourceArea *area = Thread::current()->resource_area();
3160 VectorSet peel(area);
3161 VectorSet not_peel(area);
3162 Node_List peel_list(area);
3163 Node_List worklist(area);
3164 Node_List sink_list(area);
3165
3166 if (!may_require_nodes(loop->est_loop_clone_sz(2))) {
3167 return false;
3168 }
3169
3170 // Set of cfg nodes to peel are those that are executable from
3171 // the head through last_peel.
3172 assert(worklist.size() == 0, "should be empty");
3173 worklist.push(head);
3174 peel.set(head->_idx);
3175 while (worklist.size() > 0) {
3176 Node *n = worklist.pop();
3177 if (n != last_peel) {
3178 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
3179 Node* use = n->fast_out(j);
3180 if (use->is_CFG() &&
3181 loop->is_member(get_loop(use)) &&
3182 !peel.test_set(use->_idx)) {
3183 worklist.push(use);
3184 }
3185 }
3186 }
3187 }
3188
3189 // Set of non-cfg nodes to peel are those that are control
3190 // dependent on the cfg nodes.
3191 uint i;
3192 for(i = 0; i < loop->_body.size(); i++ ) {
3193 Node *n = loop->_body.at(i);
3194 Node *n_c = has_ctrl(n) ? get_ctrl(n) : n;
3195 if (peel.test(n_c->_idx)) {
3196 peel.set(n->_idx);
3197 } else {
3198 not_peel.set(n->_idx);
3199 }
3200 }
3201
3202 // Step 2: move operations from the peeled section down into the
3203 // not-peeled section
3204
3205 // Get a post order schedule of nodes in the peel region
3206 // Result in right-most operand.
3207 scheduled_nodelist(loop, peel, peel_list );
3208
3209 assert(is_valid_loop_partition(loop, peel, peel_list, not_peel), "bad partition");
3210
3211 // For future check for too many new phis
3212 uint old_phi_cnt = 0;
3213 for (DUIterator_Fast jmax, j = head->fast_outs(jmax); j < jmax; j++) {
3214 Node* use = head->fast_out(j);
3215 if (use->is_Phi()) old_phi_cnt++;
3216 }
3217
3218 #ifndef PRODUCT
3219 if (TracePartialPeeling) {
3220 tty->print_cr("\npeeled list");
3221 }
3222 #endif
3223
3224 // Evacuate nodes in peel region into the not_peeled region if possible
3225 uint new_phi_cnt = 0;
3226 uint cloned_for_outside_use = 0;
3227 for (i = 0; i < peel_list.size();) {
3228 Node* n = peel_list.at(i);
3229 #ifndef PRODUCT
3230 if (TracePartialPeeling) n->dump();
3231 #endif
3232 bool incr = true;
3233 if ( !n->is_CFG() ) {
3234
3235 if ( has_use_in_set(n, not_peel) ) {
3236
3237 // If not used internal to the peeled region,
3238 // move "n" from peeled to not_peeled region.
3239
3240 if ( !has_use_internal_to_set(n, peel, loop) ) {
3241
3242 // if not pinned and not a load (which maybe anti-dependent on a store)
3243 // and not a CMove (Matcher expects only bool->cmove).
3244 if (n->in(0) == NULL && !n->is_Load() && !n->is_CMove()) {
3245 cloned_for_outside_use += clone_for_use_outside_loop( loop, n, worklist );
3246 sink_list.push(n);
3247 peel >>= n->_idx; // delete n from peel set.
3248 not_peel <<= n->_idx; // add n to not_peel set.
3249 peel_list.remove(i);
3250 incr = false;
3251 #ifndef PRODUCT
3252 if (TracePartialPeeling) {
3253 tty->print_cr("sink to not_peeled region: %d newbb: %d",
3254 n->_idx, get_ctrl(n)->_idx);
3255 }
3256 #endif
3257 }
3258 } else {
3259 // Otherwise check for special def-use cases that span
3260 // the peel/not_peel boundary such as bool->if
3261 clone_for_special_use_inside_loop( loop, n, not_peel, sink_list, worklist );
3262 new_phi_cnt++;
3263 }
3264 }
3265 }
3266 if (incr) i++;
3267 }
3268
3269 if (new_phi_cnt > old_phi_cnt + PartialPeelNewPhiDelta) {
3270 #ifndef PRODUCT
3271 if (TracePartialPeeling) {
3272 tty->print_cr("\nToo many new phis: %d old %d new cmpi: %c",
3273 new_phi_cnt, old_phi_cnt, new_peel_if != NULL?'T':'F');
3274 }
3275 #endif
3276 if (new_peel_if != NULL) {
3277 remove_cmpi_loop_exit(new_peel_if, loop);
3278 }
3279 // Inhibit more partial peeling on this loop
3280 assert(!head->is_partial_peel_loop(), "not partial peeled");
3281 head->mark_partial_peel_failed();
3282 if (cloned_for_outside_use > 0) {
3283 // Terminate this round of loop opts because
3284 // the graph outside this loop was changed.
3285 C->set_major_progress();
3286 return true;
3287 }
3288 return false;
3289 }
3290
3291 // Step 3: clone loop, retarget control, and insert new phis
3292
3293 // Create new loop head for new phis and to hang
3294 // the nodes being moved (sinked) from the peel region.
3295 LoopNode* new_head = new LoopNode(last_peel, last_peel);
3296 new_head->set_unswitch_count(head->unswitch_count()); // Preserve
3297 _igvn.register_new_node_with_optimizer(new_head);
3298 assert(first_not_peeled->in(0) == last_peel, "last_peel <- first_not_peeled");
3299 _igvn.replace_input_of(first_not_peeled, 0, new_head);
3300 set_loop(new_head, loop);
3301 loop->_body.push(new_head);
3302 not_peel.set(new_head->_idx);
3303 set_idom(new_head, last_peel, dom_depth(first_not_peeled));
3304 set_idom(first_not_peeled, new_head, dom_depth(first_not_peeled));
3305
3306 while (sink_list.size() > 0) {
3307 Node* n = sink_list.pop();
3308 set_ctrl(n, new_head);
3309 }
3310
3311 assert(is_valid_loop_partition(loop, peel, peel_list, not_peel), "bad partition");
3312
3313 clone_loop(loop, old_new, dd, IgnoreStripMined);
3314
3315 const uint clone_exit_idx = 1;
3316 const uint orig_exit_idx = 2;
3317 assert(is_valid_clone_loop_form( loop, peel_list, orig_exit_idx, clone_exit_idx ), "bad clone loop");
3318
3319 Node* head_clone = old_new[head->_idx];
3320 LoopNode* new_head_clone = old_new[new_head->_idx]->as_Loop();
3321 Node* orig_tail_clone = head_clone->in(2);
3322
3323 // Add phi if "def" node is in peel set and "use" is not
3324
3325 for(i = 0; i < peel_list.size(); i++ ) {
3326 Node *def = peel_list.at(i);
3327 if (!def->is_CFG()) {
3328 for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) {
3329 Node *use = def->fast_out(j);
3330 if (has_node(use) && use->in(0) != C->top() &&
3331 (!peel.test(use->_idx) ||
3332 (use->is_Phi() && use->in(0) == head)) ) {
3333 worklist.push(use);
3334 }
3335 }
3336 while( worklist.size() ) {
3337 Node *use = worklist.pop();
3338 for (uint j = 1; j < use->req(); j++) {
3339 Node* n = use->in(j);
3340 if (n == def) {
3341
3342 // "def" is in peel set, "use" is not in peel set
3343 // or "use" is in the entry boundary (a phi) of the peel set
3344
3345 Node* use_c = has_ctrl(use) ? get_ctrl(use) : use;
3346
3347 if ( loop->is_member(get_loop( use_c )) ) {
3348 // use is in loop
3349 if (old_new[use->_idx] != NULL) { // null for dead code
3350 Node* use_clone = old_new[use->_idx];
3351 _igvn.replace_input_of(use, j, C->top());
3352 insert_phi_for_loop( use_clone, j, old_new[def->_idx], def, new_head_clone );
3353 }
3354 } else {
3355 assert(is_valid_clone_loop_exit_use(loop, use, orig_exit_idx), "clone loop format");
3356 // use is not in the loop, check if the live range includes the cut
3357 Node* lp_if = use_c->in(orig_exit_idx)->in(0);
3358 if (not_peel.test(lp_if->_idx)) {
3359 assert(j == orig_exit_idx, "use from original loop");
3360 insert_phi_for_loop( use, clone_exit_idx, old_new[def->_idx], def, new_head_clone );
3361 }
3362 }
3363 }
3364 }
3365 }
3366 }
3367 }
3368
3369 // Step 3b: retarget control
3370
3371 // Redirect control to the new loop head if a cloned node in
3372 // the not_peeled region has control that points into the peeled region.
3373 // This necessary because the cloned peeled region will be outside
3374 // the loop.
3375 // from to
3376 // cloned-peeled <---+
3377 // new_head_clone: | <--+
3378 // cloned-not_peeled in(0) in(0)
3379 // orig-peeled
3380
3381 for(i = 0; i < loop->_body.size(); i++ ) {
3382 Node *n = loop->_body.at(i);
3383 if (!n->is_CFG() && n->in(0) != NULL &&
3384 not_peel.test(n->_idx) && peel.test(n->in(0)->_idx)) {
3385 Node* n_clone = old_new[n->_idx];
3386 _igvn.replace_input_of(n_clone, 0, new_head_clone);
3387 }
3388 }
3389
3390 // Backedge of the surviving new_head (the clone) is original last_peel
3391 _igvn.replace_input_of(new_head_clone, LoopNode::LoopBackControl, last_peel);
3392
3393 // Cut first node in original not_peel set
3394 _igvn.rehash_node_delayed(new_head); // Multiple edge updates:
3395 new_head->set_req(LoopNode::EntryControl, C->top()); // use rehash_node_delayed / set_req instead of
3396 new_head->set_req(LoopNode::LoopBackControl, C->top()); // multiple replace_input_of calls
3397
3398 // Copy head_clone back-branch info to original head
3399 // and remove original head's loop entry and
3400 // clone head's back-branch
3401 _igvn.rehash_node_delayed(head); // Multiple edge updates
3402 head->set_req(LoopNode::EntryControl, head_clone->in(LoopNode::LoopBackControl));
3403 head->set_req(LoopNode::LoopBackControl, C->top());
3404 _igvn.replace_input_of(head_clone, LoopNode::LoopBackControl, C->top());
3405
3406 // Similarly modify the phis
3407 for (DUIterator_Fast kmax, k = head->fast_outs(kmax); k < kmax; k++) {
3408 Node* use = head->fast_out(k);
3409 if (use->is_Phi() && use->outcnt() > 0) {
3410 Node* use_clone = old_new[use->_idx];
3411 _igvn.rehash_node_delayed(use); // Multiple edge updates
3412 use->set_req(LoopNode::EntryControl, use_clone->in(LoopNode::LoopBackControl));
3413 use->set_req(LoopNode::LoopBackControl, C->top());
3414 _igvn.replace_input_of(use_clone, LoopNode::LoopBackControl, C->top());
3415 }
3416 }
3417
3418 // Step 4: update dominator tree and dominator depth
3419
3420 set_idom(head, orig_tail_clone, dd);
3421 recompute_dom_depth();
3422
3423 // Inhibit more partial peeling on this loop
3424 new_head_clone->set_partial_peel_loop();
3425 C->set_major_progress();
3426 loop->record_for_igvn();
3427
3428 #ifndef PRODUCT
3429 if (TracePartialPeeling) {
3430 tty->print_cr("\nafter partial peel one iteration");
3431 Node_List wl(area);
3432 Node* t = last_peel;
3433 while (true) {
3434 wl.push(t);
3435 if (t == head_clone) break;
3436 t = idom(t);
3437 }
3438 while (wl.size() > 0) {
3439 Node* tt = wl.pop();
3440 if (tt == head) tty->print_cr("orig head");
3441 else if (tt == new_head_clone) tty->print_cr("new head");
3442 else if (tt == head_clone) tty->print_cr("clone head");
3443 tt->dump();
3444 }
3445 }
3446 #endif
3447 return true;
3448 }
3449
3450 //------------------------------reorg_offsets----------------------------------
3451 // Reorganize offset computations to lower register pressure. Mostly
3452 // prevent loop-fallout uses of the pre-incremented trip counter (which are
3453 // then alive with the post-incremented trip counter forcing an extra
3454 // register move)
3455 void PhaseIdealLoop::reorg_offsets(IdealLoopTree *loop) {
3456 // Perform it only for canonical counted loops.
3457 // Loop's shape could be messed up by iteration_split_impl.
3458 if (!loop->_head->is_CountedLoop())
3459 return;
3460 if (!loop->_head->as_Loop()->is_valid_counted_loop())
3461 return;
3462
3463 CountedLoopNode *cl = loop->_head->as_CountedLoop();
3464 CountedLoopEndNode *cle = cl->loopexit();
3465 Node *exit = cle->proj_out(false);
3466 Node *phi = cl->phi();
3467
3468 // Check for the special case when using the pre-incremented trip-counter on
3469 // the fall-out path (forces the pre-incremented and post-incremented trip
3470 // counter to be live at the same time). Fix this by adjusting to use the
3471 // post-increment trip counter.
3472
3473 bool progress = true;
3474 while (progress) {
3475 progress = false;
3476 for (DUIterator_Fast imax, i = phi->fast_outs(imax); i < imax; i++) {
3477 Node* use = phi->fast_out(i); // User of trip-counter
3478 if (!has_ctrl(use)) continue;
3479 Node *u_ctrl = get_ctrl(use);
3480 if (use->is_Phi()) {
3481 u_ctrl = NULL;
3482 for (uint j = 1; j < use->req(); j++)
3483 if (use->in(j) == phi)
3484 u_ctrl = dom_lca(u_ctrl, use->in(0)->in(j));
3485 }
3486 IdealLoopTree *u_loop = get_loop(u_ctrl);
3487 // Look for loop-invariant use
3488 if (u_loop == loop) continue;
3489 if (loop->is_member(u_loop)) continue;
3490 // Check that use is live out the bottom. Assuming the trip-counter
3491 // update is right at the bottom, uses of of the loop middle are ok.
3492 if (dom_lca(exit, u_ctrl) != exit) continue;
3493 // Hit! Refactor use to use the post-incremented tripcounter.
3494 // Compute a post-increment tripcounter.
3495 Node* c = exit;
3496 if (cl->is_strip_mined()) {
3497 IdealLoopTree* outer_loop = get_loop(cl->outer_loop());
3498 if (!outer_loop->is_member(u_loop)) {
3499 c = cl->outer_loop_exit();
3500 }
3501 }
3502 Node *opaq = new Opaque2Node(C, cle->incr());
3503 register_new_node(opaq, c);
3504 Node *neg_stride = _igvn.intcon(-cle->stride_con());
3505 set_ctrl(neg_stride, C->root());
3506 Node *post = new AddINode(opaq, neg_stride);
3507 register_new_node(post, c);
3508 _igvn.rehash_node_delayed(use);
3509 for (uint j = 1; j < use->req(); j++) {
3510 if (use->in(j) == phi)
3511 use->set_req(j, post);
3512 }
3513 // Since DU info changed, rerun loop
3514 progress = true;
3515 break;
3516 }
3517 }
3518
3519 }