1 /*
2 * Copyright (c) 1998, 2012, 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 "memory/allocation.inline.hpp"
27 #include "opto/block.hpp"
28 #include "opto/c2compiler.hpp"
29 #include "opto/callnode.hpp"
30 #include "opto/cfgnode.hpp"
31 #include "opto/machnode.hpp"
32 #include "opto/runtime.hpp"
33 #ifdef TARGET_ARCH_MODEL_x86_32
34 # include "adfiles/ad_x86_32.hpp"
35 #endif
36 #ifdef TARGET_ARCH_MODEL_x86_64
37 # include "adfiles/ad_x86_64.hpp"
38 #endif
39 #ifdef TARGET_ARCH_MODEL_sparc
40 # include "adfiles/ad_sparc.hpp"
41 #endif
42 #ifdef TARGET_ARCH_MODEL_zero
43 # include "adfiles/ad_zero.hpp"
44 #endif
45 #ifdef TARGET_ARCH_MODEL_arm
46 # include "adfiles/ad_arm.hpp"
47 #endif
48 #ifdef TARGET_ARCH_MODEL_ppc
49 # include "adfiles/ad_ppc.hpp"
50 #endif
51
52 // Optimization - Graph Style
53
54 //------------------------------implicit_null_check----------------------------
55 // Detect implicit-null-check opportunities. Basically, find NULL checks
56 // with suitable memory ops nearby. Use the memory op to do the NULL check.
57 // I can generate a memory op if there is not one nearby.
58 // The proj is the control projection for the not-null case.
59 // The val is the pointer being checked for nullness or
60 // decodeHeapOop_not_null node if it did not fold into address.
61 void Block::implicit_null_check(PhaseCFG *cfg, Node *proj, Node *val, int allowed_reasons) {
62 // Assume if null check need for 0 offset then always needed
63 // Intel solaris doesn't support any null checks yet and no
64 // mechanism exists (yet) to set the switches at an os_cpu level
65 if( !ImplicitNullChecks || MacroAssembler::needs_explicit_null_check(0)) return;
66
67 // Make sure the ptr-is-null path appears to be uncommon!
68 float f = end()->as_MachIf()->_prob;
69 if( proj->Opcode() == Op_IfTrue ) f = 1.0f - f;
70 if( f > PROB_UNLIKELY_MAG(4) ) return;
71
72 uint bidx = 0; // Capture index of value into memop
73 bool was_store; // Memory op is a store op
74
75 // Get the successor block for if the test ptr is non-null
76 Block* not_null_block; // this one goes with the proj
77 Block* null_block;
78 if (_nodes[_nodes.size()-1] == proj) {
79 null_block = _succs[0];
80 not_null_block = _succs[1];
81 } else {
82 assert(_nodes[_nodes.size()-2] == proj, "proj is one or the other");
83 not_null_block = _succs[0];
84 null_block = _succs[1];
85 }
86 while (null_block->is_Empty() == Block::empty_with_goto) {
87 null_block = null_block->_succs[0];
88 }
89
90 // Search the exception block for an uncommon trap.
91 // (See Parse::do_if and Parse::do_ifnull for the reason
92 // we need an uncommon trap. Briefly, we need a way to
93 // detect failure of this optimization, as in 6366351.)
94 {
95 bool found_trap = false;
96 for (uint i1 = 0; i1 < null_block->_nodes.size(); i1++) {
97 Node* nn = null_block->_nodes[i1];
98 if (nn->is_MachCall() &&
99 nn->as_MachCall()->entry_point() == SharedRuntime::uncommon_trap_blob()->entry_point()) {
100 const Type* trtype = nn->in(TypeFunc::Parms)->bottom_type();
101 if (trtype->isa_int() && trtype->is_int()->is_con()) {
102 jint tr_con = trtype->is_int()->get_con();
103 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(tr_con);
104 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(tr_con);
105 assert((int)reason < (int)BitsPerInt, "recode bit map");
106 if (is_set_nth_bit(allowed_reasons, (int) reason)
107 && action != Deoptimization::Action_none) {
108 // This uncommon trap is sure to recompile, eventually.
109 // When that happens, C->too_many_traps will prevent
110 // this transformation from happening again.
111 found_trap = true;
112 }
113 }
114 break;
115 }
116 }
117 if (!found_trap) {
118 // We did not find an uncommon trap.
119 return;
120 }
121 }
122
123 // Check for decodeHeapOop_not_null node which did not fold into address
124 bool is_decoden = ((intptr_t)val) & 1;
125 val = (Node*)(((intptr_t)val) & ~1);
126
127 assert(!is_decoden || (val->in(0) == NULL) && val->is_Mach() &&
128 (val->as_Mach()->ideal_Opcode() == Op_DecodeN), "sanity");
129
130 // Search the successor block for a load or store who's base value is also
131 // the tested value. There may be several.
132 Node_List *out = new Node_List(Thread::current()->resource_area());
133 MachNode *best = NULL; // Best found so far
134 for (DUIterator i = val->outs(); val->has_out(i); i++) {
135 Node *m = val->out(i);
136 if( !m->is_Mach() ) continue;
137 MachNode *mach = m->as_Mach();
138 was_store = false;
139 int iop = mach->ideal_Opcode();
140 switch( iop ) {
141 case Op_LoadB:
142 case Op_LoadUB:
143 case Op_LoadUS:
144 case Op_LoadD:
145 case Op_LoadF:
146 case Op_LoadI:
147 case Op_LoadL:
148 case Op_LoadP:
149 case Op_LoadN:
150 case Op_LoadS:
151 case Op_LoadKlass:
152 case Op_LoadNKlass:
153 case Op_LoadRange:
154 case Op_LoadD_unaligned:
155 case Op_LoadL_unaligned:
156 assert(mach->in(2) == val, "should be address");
157 break;
158 case Op_StoreB:
159 case Op_StoreC:
160 case Op_StoreCM:
161 case Op_StoreD:
162 case Op_StoreF:
163 case Op_StoreI:
164 case Op_StoreL:
165 case Op_StoreP:
166 case Op_StoreN:
167 case Op_StoreNKlass:
168 was_store = true; // Memory op is a store op
169 // Stores will have their address in slot 2 (memory in slot 1).
170 // If the value being nul-checked is in another slot, it means we
171 // are storing the checked value, which does NOT check the value!
172 if( mach->in(2) != val ) continue;
173 break; // Found a memory op?
174 case Op_StrComp:
175 case Op_StrEquals:
176 case Op_StrIndexOf:
177 case Op_AryEq:
178 case Op_EncodeISOArray:
179 // Not a legit memory op for implicit null check regardless of
180 // embedded loads
181 continue;
182 default: // Also check for embedded loads
183 if( !mach->needs_anti_dependence_check() )
184 continue; // Not an memory op; skip it
185 if( must_clone[iop] ) {
186 // Do not move nodes which produce flags because
187 // RA will try to clone it to place near branch and
188 // it will cause recompilation, see clone_node().
189 continue;
190 }
191 {
192 // Check that value is used in memory address in
193 // instructions with embedded load (CmpP val1,(val2+off)).
194 Node* base;
195 Node* index;
196 const MachOper* oper = mach->memory_inputs(base, index);
197 if (oper == NULL || oper == (MachOper*)-1) {
198 continue; // Not an memory op; skip it
199 }
200 if (val == base ||
201 val == index && val->bottom_type()->isa_narrowoop()) {
202 break; // Found it
203 } else {
204 continue; // Skip it
205 }
206 }
207 break;
208 }
209 // check if the offset is not too high for implicit exception
210 {
211 intptr_t offset = 0;
212 const TypePtr *adr_type = NULL; // Do not need this return value here
213 const Node* base = mach->get_base_and_disp(offset, adr_type);
214 if (base == NULL || base == NodeSentinel) {
215 // Narrow oop address doesn't have base, only index
216 if( val->bottom_type()->isa_narrowoop() &&
217 MacroAssembler::needs_explicit_null_check(offset) )
218 continue; // Give up if offset is beyond page size
219 // cannot reason about it; is probably not implicit null exception
220 } else {
221 const TypePtr* tptr;
222 if (UseCompressedOops && (Universe::narrow_oop_shift() == 0 ||
223 Universe::narrow_klass_shift() == 0)) {
224 // 32-bits narrow oop can be the base of address expressions
225 tptr = base->get_ptr_type();
226 } else {
227 // only regular oops are expected here
228 tptr = base->bottom_type()->is_ptr();
229 }
230 // Give up if offset is not a compile-time constant
231 if( offset == Type::OffsetBot || tptr->_offset == Type::OffsetBot )
232 continue;
233 offset += tptr->_offset; // correct if base is offseted
234 if( MacroAssembler::needs_explicit_null_check(offset) )
235 continue; // Give up is reference is beyond 4K page size
236 }
237 }
238
239 // Check ctrl input to see if the null-check dominates the memory op
240 Block *cb = cfg->_bbs[mach->_idx];
241 cb = cb->_idom; // Always hoist at least 1 block
242 if( !was_store ) { // Stores can be hoisted only one block
243 while( cb->_dom_depth > (_dom_depth + 1))
244 cb = cb->_idom; // Hoist loads as far as we want
245 // The non-null-block should dominate the memory op, too. Live
246 // range spilling will insert a spill in the non-null-block if it is
247 // needs to spill the memory op for an implicit null check.
248 if (cb->_dom_depth == (_dom_depth + 1)) {
249 if (cb != not_null_block) continue;
250 cb = cb->_idom;
251 }
252 }
253 if( cb != this ) continue;
254
255 // Found a memory user; see if it can be hoisted to check-block
256 uint vidx = 0; // Capture index of value into memop
257 uint j;
258 for( j = mach->req()-1; j > 0; j-- ) {
259 if( mach->in(j) == val ) {
260 vidx = j;
261 // Ignore DecodeN val which could be hoisted to where needed.
262 if( is_decoden ) continue;
263 }
264 // Block of memory-op input
265 Block *inb = cfg->_bbs[mach->in(j)->_idx];
266 Block *b = this; // Start from nul check
267 while( b != inb && b->_dom_depth > inb->_dom_depth )
268 b = b->_idom; // search upwards for input
269 // See if input dominates null check
270 if( b != inb )
271 break;
272 }
273 if( j > 0 )
274 continue;
275 Block *mb = cfg->_bbs[mach->_idx];
276 // Hoisting stores requires more checks for the anti-dependence case.
277 // Give up hoisting if we have to move the store past any load.
278 if( was_store ) {
279 Block *b = mb; // Start searching here for a local load
280 // mach use (faulting) trying to hoist
281 // n might be blocker to hoisting
282 while( b != this ) {
283 uint k;
284 for( k = 1; k < b->_nodes.size(); k++ ) {
285 Node *n = b->_nodes[k];
286 if( n->needs_anti_dependence_check() &&
287 n->in(LoadNode::Memory) == mach->in(StoreNode::Memory) )
288 break; // Found anti-dependent load
289 }
290 if( k < b->_nodes.size() )
291 break; // Found anti-dependent load
292 // Make sure control does not do a merge (would have to check allpaths)
293 if( b->num_preds() != 2 ) break;
294 b = cfg->_bbs[b->pred(1)->_idx]; // Move up to predecessor block
295 }
296 if( b != this ) continue;
297 }
298
299 // Make sure this memory op is not already being used for a NullCheck
300 Node *e = mb->end();
301 if( e->is_MachNullCheck() && e->in(1) == mach )
302 continue; // Already being used as a NULL check
303
304 // Found a candidate! Pick one with least dom depth - the highest
305 // in the dom tree should be closest to the null check.
306 if( !best ||
307 cfg->_bbs[mach->_idx]->_dom_depth < cfg->_bbs[best->_idx]->_dom_depth ) {
308 best = mach;
309 bidx = vidx;
310
311 }
312 }
313 // No candidate!
314 if( !best ) return;
315
316 // ---- Found an implicit null check
317 extern int implicit_null_checks;
318 implicit_null_checks++;
319
320 if( is_decoden ) {
321 // Check if we need to hoist decodeHeapOop_not_null first.
322 Block *valb = cfg->_bbs[val->_idx];
323 if( this != valb && this->_dom_depth < valb->_dom_depth ) {
324 // Hoist it up to the end of the test block.
325 valb->find_remove(val);
326 this->add_inst(val);
327 cfg->_bbs.map(val->_idx,this);
328 // DecodeN on x86 may kill flags. Check for flag-killing projections
329 // that also need to be hoisted.
330 for (DUIterator_Fast jmax, j = val->fast_outs(jmax); j < jmax; j++) {
331 Node* n = val->fast_out(j);
332 if( n->is_MachProj() ) {
333 cfg->_bbs[n->_idx]->find_remove(n);
334 this->add_inst(n);
335 cfg->_bbs.map(n->_idx,this);
336 }
337 }
338 }
339 }
340 // Hoist the memory candidate up to the end of the test block.
341 Block *old_block = cfg->_bbs[best->_idx];
342 old_block->find_remove(best);
343 add_inst(best);
344 cfg->_bbs.map(best->_idx,this);
345
346 // Move the control dependence
347 if (best->in(0) && best->in(0) == old_block->_nodes[0])
348 best->set_req(0, _nodes[0]);
349
350 // Check for flag-killing projections that also need to be hoisted
351 // Should be DU safe because no edge updates.
352 for (DUIterator_Fast jmax, j = best->fast_outs(jmax); j < jmax; j++) {
353 Node* n = best->fast_out(j);
354 if( n->is_MachProj() ) {
355 cfg->_bbs[n->_idx]->find_remove(n);
356 add_inst(n);
357 cfg->_bbs.map(n->_idx,this);
358 }
359 }
360
361 Compile *C = cfg->C;
362 // proj==Op_True --> ne test; proj==Op_False --> eq test.
363 // One of two graph shapes got matched:
364 // (IfTrue (If (Bool NE (CmpP ptr NULL))))
365 // (IfFalse (If (Bool EQ (CmpP ptr NULL))))
366 // NULL checks are always branch-if-eq. If we see a IfTrue projection
367 // then we are replacing a 'ne' test with a 'eq' NULL check test.
368 // We need to flip the projections to keep the same semantics.
369 if( proj->Opcode() == Op_IfTrue ) {
370 // Swap order of projections in basic block to swap branch targets
371 Node *tmp1 = _nodes[end_idx()+1];
372 Node *tmp2 = _nodes[end_idx()+2];
373 _nodes.map(end_idx()+1, tmp2);
374 _nodes.map(end_idx()+2, tmp1);
375 Node *tmp = new (C) Node(C->top()); // Use not NULL input
376 tmp1->replace_by(tmp);
377 tmp2->replace_by(tmp1);
378 tmp->replace_by(tmp2);
379 tmp->destruct();
380 }
381
382 // Remove the existing null check; use a new implicit null check instead.
383 // Since schedule-local needs precise def-use info, we need to correct
384 // it as well.
385 Node *old_tst = proj->in(0);
386 MachNode *nul_chk = new (C) MachNullCheckNode(old_tst->in(0),best,bidx);
387 _nodes.map(end_idx(),nul_chk);
388 cfg->_bbs.map(nul_chk->_idx,this);
389 // Redirect users of old_test to nul_chk
390 for (DUIterator_Last i2min, i2 = old_tst->last_outs(i2min); i2 >= i2min; --i2)
391 old_tst->last_out(i2)->set_req(0, nul_chk);
392 // Clean-up any dead code
393 for (uint i3 = 0; i3 < old_tst->req(); i3++)
394 old_tst->set_req(i3, NULL);
395
396 cfg->latency_from_uses(nul_chk);
397 cfg->latency_from_uses(best);
398 }
399
400
401 //------------------------------select-----------------------------------------
402 // Select a nice fellow from the worklist to schedule next. If there is only
403 // one choice, then use it. Projections take top priority for correctness
404 // reasons - if I see a projection, then it is next. There are a number of
405 // other special cases, for instructions that consume condition codes, et al.
406 // These are chosen immediately. Some instructions are required to immediately
407 // precede the last instruction in the block, and these are taken last. Of the
408 // remaining cases (most), choose the instruction with the greatest latency
409 // (that is, the most number of pseudo-cycles required to the end of the
410 // routine). If there is a tie, choose the instruction with the most inputs.
411 Node *Block::select(PhaseCFG *cfg, Node_List &worklist, GrowableArray<int> &ready_cnt, VectorSet &next_call, uint sched_slot) {
412
413 // If only a single entry on the stack, use it
414 uint cnt = worklist.size();
415 if (cnt == 1) {
416 Node *n = worklist[0];
417 worklist.map(0,worklist.pop());
418 return n;
419 }
420
421 uint choice = 0; // Bigger is most important
422 uint latency = 0; // Bigger is scheduled first
423 uint score = 0; // Bigger is better
424 int idx = -1; // Index in worklist
425 int cand_cnt = 0; // Candidate count
426
427 for( uint i=0; i<cnt; i++ ) { // Inspect entire worklist
428 // Order in worklist is used to break ties.
429 // See caller for how this is used to delay scheduling
430 // of induction variable increments to after the other
431 // uses of the phi are scheduled.
432 Node *n = worklist[i]; // Get Node on worklist
433
434 int iop = n->is_Mach() ? n->as_Mach()->ideal_Opcode() : 0;
435 if( n->is_Proj() || // Projections always win
436 n->Opcode()== Op_Con || // So does constant 'Top'
437 iop == Op_CreateEx || // Create-exception must start block
438 iop == Op_CheckCastPP
439 ) {
440 worklist.map(i,worklist.pop());
441 return n;
442 }
443
444 // Final call in a block must be adjacent to 'catch'
445 Node *e = end();
446 if( e->is_Catch() && e->in(0)->in(0) == n )
447 continue;
448
449 // Memory op for an implicit null check has to be at the end of the block
450 if( e->is_MachNullCheck() && e->in(1) == n )
451 continue;
452
453 // Schedule IV increment last.
454 if (e->is_Mach() && e->as_Mach()->ideal_Opcode() == Op_CountedLoopEnd &&
455 e->in(1)->in(1) == n && n->is_iteratively_computed())
456 continue;
457
458 uint n_choice = 2;
459
460 // See if this instruction is consumed by a branch. If so, then (as the
461 // branch is the last instruction in the basic block) force it to the
462 // end of the basic block
463 if ( must_clone[iop] ) {
464 // See if any use is a branch
465 bool found_machif = false;
466
467 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
468 Node* use = n->fast_out(j);
469
470 // The use is a conditional branch, make them adjacent
471 if (use->is_MachIf() && cfg->_bbs[use->_idx]==this ) {
472 found_machif = true;
473 break;
474 }
475
476 // More than this instruction pending for successor to be ready,
477 // don't choose this if other opportunities are ready
478 if (ready_cnt.at(use->_idx) > 1)
479 n_choice = 1;
480 }
481
482 // loop terminated, prefer not to use this instruction
483 if (found_machif)
484 continue;
485 }
486
487 // See if this has a predecessor that is "must_clone", i.e. sets the
488 // condition code. If so, choose this first
489 for (uint j = 0; j < n->req() ; j++) {
490 Node *inn = n->in(j);
491 if (inn) {
492 if (inn->is_Mach() && must_clone[inn->as_Mach()->ideal_Opcode()] ) {
493 n_choice = 3;
494 break;
495 }
496 }
497 }
498
499 // MachTemps should be scheduled last so they are near their uses
500 if (n->is_MachTemp()) {
501 n_choice = 1;
502 }
503
504 uint n_latency = cfg->_node_latency->at_grow(n->_idx);
505 uint n_score = n->req(); // Many inputs get high score to break ties
506
507 // Keep best latency found
508 cand_cnt++;
509 if (choice < n_choice ||
510 (choice == n_choice &&
511 ((StressLCM && Compile::randomized_select(cand_cnt)) ||
512 (!StressLCM &&
513 (latency < n_latency ||
514 (latency == n_latency &&
515 (score < n_score))))))) {
516 choice = n_choice;
517 latency = n_latency;
518 score = n_score;
519 idx = i; // Also keep index in worklist
520 }
521 } // End of for all ready nodes in worklist
522
523 assert(idx >= 0, "index should be set");
524 Node *n = worklist[(uint)idx]; // Get the winner
525
526 worklist.map((uint)idx, worklist.pop()); // Compress worklist
527 return n;
528 }
529
530
531 //------------------------------set_next_call----------------------------------
532 void Block::set_next_call( Node *n, VectorSet &next_call, Block_Array &bbs ) {
533 if( next_call.test_set(n->_idx) ) return;
534 for( uint i=0; i<n->len(); i++ ) {
535 Node *m = n->in(i);
536 if( !m ) continue; // must see all nodes in block that precede call
537 if( bbs[m->_idx] == this )
538 set_next_call( m, next_call, bbs );
539 }
540 }
541
542 //------------------------------needed_for_next_call---------------------------
543 // Set the flag 'next_call' for each Node that is needed for the next call to
544 // be scheduled. This flag lets me bias scheduling so Nodes needed for the
545 // next subroutine call get priority - basically it moves things NOT needed
546 // for the next call till after the call. This prevents me from trying to
547 // carry lots of stuff live across a call.
548 void Block::needed_for_next_call(Node *this_call, VectorSet &next_call, Block_Array &bbs) {
549 // Find the next control-defining Node in this block
550 Node* call = NULL;
551 for (DUIterator_Fast imax, i = this_call->fast_outs(imax); i < imax; i++) {
552 Node* m = this_call->fast_out(i);
553 if( bbs[m->_idx] == this && // Local-block user
554 m != this_call && // Not self-start node
555 m->is_MachCall() )
556 call = m;
557 break;
558 }
559 if (call == NULL) return; // No next call (e.g., block end is near)
560 // Set next-call for all inputs to this call
561 set_next_call(call, next_call, bbs);
562 }
563
564 //------------------------------add_call_kills-------------------------------------
565 void Block::add_call_kills(MachProjNode *proj, RegMask& regs, const char* save_policy, bool exclude_soe) {
566 // Fill in the kill mask for the call
567 for( OptoReg::Name r = OptoReg::Name(0); r < _last_Mach_Reg; r=OptoReg::add(r,1) ) {
568 if( !regs.Member(r) ) { // Not already defined by the call
569 // Save-on-call register?
570 if ((save_policy[r] == 'C') ||
571 (save_policy[r] == 'A') ||
572 ((save_policy[r] == 'E') && exclude_soe)) {
573 proj->_rout.Insert(r);
574 }
575 }
576 }
577 }
578
579
580 //------------------------------sched_call-------------------------------------
581 uint Block::sched_call( Matcher &matcher, Block_Array &bbs, uint node_cnt, Node_List &worklist, GrowableArray<int> &ready_cnt, MachCallNode *mcall, VectorSet &next_call ) {
582 RegMask regs;
583
584 // Schedule all the users of the call right now. All the users are
585 // projection Nodes, so they must be scheduled next to the call.
586 // Collect all the defined registers.
587 for (DUIterator_Fast imax, i = mcall->fast_outs(imax); i < imax; i++) {
588 Node* n = mcall->fast_out(i);
589 assert( n->is_MachProj(), "" );
590 int n_cnt = ready_cnt.at(n->_idx)-1;
591 ready_cnt.at_put(n->_idx, n_cnt);
592 assert( n_cnt == 0, "" );
593 // Schedule next to call
594 _nodes.map(node_cnt++, n);
595 // Collect defined registers
596 regs.OR(n->out_RegMask());
597 // Check for scheduling the next control-definer
598 if( n->bottom_type() == Type::CONTROL )
599 // Warm up next pile of heuristic bits
600 needed_for_next_call(n, next_call, bbs);
601
602 // Children of projections are now all ready
603 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
604 Node* m = n->fast_out(j); // Get user
605 if( bbs[m->_idx] != this ) continue;
606 if( m->is_Phi() ) continue;
607 int m_cnt = ready_cnt.at(m->_idx)-1;
608 ready_cnt.at_put(m->_idx, m_cnt);
609 if( m_cnt == 0 )
610 worklist.push(m);
611 }
612
613 }
614
615 // Act as if the call defines the Frame Pointer.
616 // Certainly the FP is alive and well after the call.
617 regs.Insert(matcher.c_frame_pointer());
618
619 // Set all registers killed and not already defined by the call.
620 uint r_cnt = mcall->tf()->range()->cnt();
621 int op = mcall->ideal_Opcode();
622 MachProjNode *proj = new (matcher.C) MachProjNode( mcall, r_cnt+1, RegMask::Empty, MachProjNode::fat_proj );
623 bbs.map(proj->_idx,this);
624 _nodes.insert(node_cnt++, proj);
625
626 // Select the right register save policy.
627 const char * save_policy;
628 switch (op) {
629 case Op_CallRuntime:
630 case Op_CallLeaf:
631 case Op_CallLeafNoFP:
632 // Calling C code so use C calling convention
633 save_policy = matcher._c_reg_save_policy;
634 break;
635
636 case Op_CallStaticJava:
637 case Op_CallDynamicJava:
638 // Calling Java code so use Java calling convention
639 save_policy = matcher._register_save_policy;
640 break;
641
642 default:
643 ShouldNotReachHere();
644 }
645
646 // When using CallRuntime mark SOE registers as killed by the call
647 // so values that could show up in the RegisterMap aren't live in a
648 // callee saved register since the register wouldn't know where to
649 // find them. CallLeaf and CallLeafNoFP are ok because they can't
650 // have debug info on them. Strictly speaking this only needs to be
651 // done for oops since idealreg2debugmask takes care of debug info
652 // references but there no way to handle oops differently than other
653 // pointers as far as the kill mask goes.
654 bool exclude_soe = op == Op_CallRuntime;
655
656 // If the call is a MethodHandle invoke, we need to exclude the
657 // register which is used to save the SP value over MH invokes from
658 // the mask. Otherwise this register could be used for
659 // deoptimization information.
660 if (op == Op_CallStaticJava) {
661 MachCallStaticJavaNode* mcallstaticjava = (MachCallStaticJavaNode*) mcall;
662 if (mcallstaticjava->_method_handle_invoke)
663 proj->_rout.OR(Matcher::method_handle_invoke_SP_save_mask());
664 }
665
666 add_call_kills(proj, regs, save_policy, exclude_soe);
667
668 return node_cnt;
669 }
670
671
672 //------------------------------schedule_local---------------------------------
673 // Topological sort within a block. Someday become a real scheduler.
674 bool Block::schedule_local(PhaseCFG *cfg, Matcher &matcher, GrowableArray<int> &ready_cnt, VectorSet &next_call) {
675 // Already "sorted" are the block start Node (as the first entry), and
676 // the block-ending Node and any trailing control projections. We leave
677 // these alone. PhiNodes and ParmNodes are made to follow the block start
678 // Node. Everything else gets topo-sorted.
679
680 #ifndef PRODUCT
681 if (cfg->trace_opto_pipelining()) {
682 tty->print_cr("# --- schedule_local B%d, before: ---", _pre_order);
683 for (uint i = 0;i < _nodes.size();i++) {
684 tty->print("# ");
685 _nodes[i]->fast_dump();
686 }
687 tty->print_cr("#");
688 }
689 #endif
690
691 // RootNode is already sorted
692 if( _nodes.size() == 1 ) return true;
693
694 // Move PhiNodes and ParmNodes from 1 to cnt up to the start
695 uint node_cnt = end_idx();
696 uint phi_cnt = 1;
697 uint i;
698 for( i = 1; i<node_cnt; i++ ) { // Scan for Phi
699 Node *n = _nodes[i];
700 if( n->is_Phi() || // Found a PhiNode or ParmNode
701 (n->is_Proj() && n->in(0) == head()) ) {
702 // Move guy at 'phi_cnt' to the end; makes a hole at phi_cnt
703 _nodes.map(i,_nodes[phi_cnt]);
704 _nodes.map(phi_cnt++,n); // swap Phi/Parm up front
705 } else { // All others
706 // Count block-local inputs to 'n'
707 uint cnt = n->len(); // Input count
708 uint local = 0;
709 for( uint j=0; j<cnt; j++ ) {
710 Node *m = n->in(j);
711 if( m && cfg->_bbs[m->_idx] == this && !m->is_top() )
712 local++; // One more block-local input
713 }
714 ready_cnt.at_put(n->_idx, local); // Count em up
715
716 #ifdef ASSERT
717 if( UseConcMarkSweepGC || UseG1GC ) {
718 if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_StoreCM ) {
719 // Check the precedence edges
720 for (uint prec = n->req(); prec < n->len(); prec++) {
721 Node* oop_store = n->in(prec);
722 if (oop_store != NULL) {
723 assert(cfg->_bbs[oop_store->_idx]->_dom_depth <= this->_dom_depth, "oop_store must dominate card-mark");
724 }
725 }
726 }
727 }
728 #endif
729
730 // A few node types require changing a required edge to a precedence edge
731 // before allocation.
732 if( n->is_Mach() && n->req() > TypeFunc::Parms &&
733 (n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire ||
734 n->as_Mach()->ideal_Opcode() == Op_MemBarVolatile) ) {
735 // MemBarAcquire could be created without Precedent edge.
736 // del_req() replaces the specified edge with the last input edge
737 // and then removes the last edge. If the specified edge > number of
738 // edges the last edge will be moved outside of the input edges array
739 // and the edge will be lost. This is why this code should be
740 // executed only when Precedent (== TypeFunc::Parms) edge is present.
741 Node *x = n->in(TypeFunc::Parms);
742 n->del_req(TypeFunc::Parms);
743 n->add_prec(x);
744 }
745 }
746 }
747 for(uint i2=i; i2<_nodes.size(); i2++ ) // Trailing guys get zapped count
748 ready_cnt.at_put(_nodes[i2]->_idx, 0);
749
750 // All the prescheduled guys do not hold back internal nodes
751 uint i3;
752 for(i3 = 0; i3<phi_cnt; i3++ ) { // For all pre-scheduled
753 Node *n = _nodes[i3]; // Get pre-scheduled
754 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
755 Node* m = n->fast_out(j);
756 if( cfg->_bbs[m->_idx] ==this ) { // Local-block user
757 int m_cnt = ready_cnt.at(m->_idx)-1;
758 ready_cnt.at_put(m->_idx, m_cnt); // Fix ready count
759 }
760 }
761 }
762
763 Node_List delay;
764 // Make a worklist
765 Node_List worklist;
766 for(uint i4=i3; i4<node_cnt; i4++ ) { // Put ready guys on worklist
767 Node *m = _nodes[i4];
768 if( !ready_cnt.at(m->_idx) ) { // Zero ready count?
769 if (m->is_iteratively_computed()) {
770 // Push induction variable increments last to allow other uses
771 // of the phi to be scheduled first. The select() method breaks
772 // ties in scheduling by worklist order.
773 delay.push(m);
774 } else if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_CreateEx) {
775 // Force the CreateEx to the top of the list so it's processed
776 // first and ends up at the start of the block.
777 worklist.insert(0, m);
778 } else {
779 worklist.push(m); // Then on to worklist!
780 }
781 }
782 }
783 while (delay.size()) {
784 Node* d = delay.pop();
785 worklist.push(d);
786 }
787
788 // Warm up the 'next_call' heuristic bits
789 needed_for_next_call(_nodes[0], next_call, cfg->_bbs);
790
791 #ifndef PRODUCT
792 if (cfg->trace_opto_pipelining()) {
793 for (uint j=0; j<_nodes.size(); j++) {
794 Node *n = _nodes[j];
795 int idx = n->_idx;
796 tty->print("# ready cnt:%3d ", ready_cnt.at(idx));
797 tty->print("latency:%3d ", cfg->_node_latency->at_grow(idx));
798 tty->print("%4d: %s\n", idx, n->Name());
799 }
800 }
801 #endif
802
803 uint max_idx = (uint)ready_cnt.length();
804 // Pull from worklist and schedule
805 while( worklist.size() ) { // Worklist is not ready
806
807 #ifndef PRODUCT
808 if (cfg->trace_opto_pipelining()) {
809 tty->print("# ready list:");
810 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist
811 Node *n = worklist[i]; // Get Node on worklist
812 tty->print(" %d", n->_idx);
813 }
814 tty->cr();
815 }
816 #endif
817
818 // Select and pop a ready guy from worklist
819 Node* n = select(cfg, worklist, ready_cnt, next_call, phi_cnt);
820 _nodes.map(phi_cnt++,n); // Schedule him next
821
822 #ifndef PRODUCT
823 if (cfg->trace_opto_pipelining()) {
824 tty->print("# select %d: %s", n->_idx, n->Name());
825 tty->print(", latency:%d", cfg->_node_latency->at_grow(n->_idx));
826 n->dump();
827 if (Verbose) {
828 tty->print("# ready list:");
829 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist
830 Node *n = worklist[i]; // Get Node on worklist
831 tty->print(" %d", n->_idx);
832 }
833 tty->cr();
834 }
835 }
836
837 #endif
838 if( n->is_MachCall() ) {
839 MachCallNode *mcall = n->as_MachCall();
840 phi_cnt = sched_call(matcher, cfg->_bbs, phi_cnt, worklist, ready_cnt, mcall, next_call);
841 continue;
842 }
843
844 if (n->is_Mach() && n->as_Mach()->has_call()) {
845 RegMask regs;
846 regs.Insert(matcher.c_frame_pointer());
847 regs.OR(n->out_RegMask());
848
849 MachProjNode *proj = new (matcher.C) MachProjNode( n, 1, RegMask::Empty, MachProjNode::fat_proj );
850 cfg->_bbs.map(proj->_idx,this);
851 _nodes.insert(phi_cnt++, proj);
852
853 add_call_kills(proj, regs, matcher._c_reg_save_policy, false);
854 }
855
856 // Children are now all ready
857 for (DUIterator_Fast i5max, i5 = n->fast_outs(i5max); i5 < i5max; i5++) {
858 Node* m = n->fast_out(i5); // Get user
859 if( cfg->_bbs[m->_idx] != this ) continue;
860 if( m->is_Phi() ) continue;
861 if (m->_idx >= max_idx) { // new node, skip it
862 assert(m->is_MachProj() && n->is_Mach() && n->as_Mach()->has_call(), "unexpected node types");
863 continue;
864 }
865 int m_cnt = ready_cnt.at(m->_idx)-1;
866 ready_cnt.at_put(m->_idx, m_cnt);
867 if( m_cnt == 0 )
868 worklist.push(m);
869 }
870 }
871
872 if( phi_cnt != end_idx() ) {
873 // did not schedule all. Retry, Bailout, or Die
874 Compile* C = matcher.C;
875 if (C->subsume_loads() == true && !C->failing()) {
876 // Retry with subsume_loads == false
877 // If this is the first failure, the sentinel string will "stick"
878 // to the Compile object, and the C2Compiler will see it and retry.
879 C->record_failure(C2Compiler::retry_no_subsuming_loads());
880 }
881 // assert( phi_cnt == end_idx(), "did not schedule all" );
882 return false;
883 }
884
885 #ifndef PRODUCT
886 if (cfg->trace_opto_pipelining()) {
887 tty->print_cr("#");
888 tty->print_cr("# after schedule_local");
889 for (uint i = 0;i < _nodes.size();i++) {
890 tty->print("# ");
891 _nodes[i]->fast_dump();
892 }
893 tty->cr();
894 }
895 #endif
896
897
898 return true;
899 }
900
901 //--------------------------catch_cleanup_fix_all_inputs-----------------------
902 static void catch_cleanup_fix_all_inputs(Node *use, Node *old_def, Node *new_def) {
903 for (uint l = 0; l < use->len(); l++) {
904 if (use->in(l) == old_def) {
905 if (l < use->req()) {
906 use->set_req(l, new_def);
907 } else {
908 use->rm_prec(l);
909 use->add_prec(new_def);
910 l--;
911 }
912 }
913 }
914 }
915
916 //------------------------------catch_cleanup_find_cloned_def------------------
917 static Node *catch_cleanup_find_cloned_def(Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) {
918 assert( use_blk != def_blk, "Inter-block cleanup only");
919
920 // The use is some block below the Catch. Find and return the clone of the def
921 // that dominates the use. If there is no clone in a dominating block, then
922 // create a phi for the def in a dominating block.
923
924 // Find which successor block dominates this use. The successor
925 // blocks must all be single-entry (from the Catch only; I will have
926 // split blocks to make this so), hence they all dominate.
927 while( use_blk->_dom_depth > def_blk->_dom_depth+1 )
928 use_blk = use_blk->_idom;
929
930 // Find the successor
931 Node *fixup = NULL;
932
933 uint j;
934 for( j = 0; j < def_blk->_num_succs; j++ )
935 if( use_blk == def_blk->_succs[j] )
936 break;
937
938 if( j == def_blk->_num_succs ) {
939 // Block at same level in dom-tree is not a successor. It needs a
940 // PhiNode, the PhiNode uses from the def and IT's uses need fixup.
941 Node_Array inputs = new Node_List(Thread::current()->resource_area());
942 for(uint k = 1; k < use_blk->num_preds(); k++) {
943 inputs.map(k, catch_cleanup_find_cloned_def(bbs[use_blk->pred(k)->_idx], def, def_blk, bbs, n_clone_idx));
944 }
945
946 // Check to see if the use_blk already has an identical phi inserted.
947 // If it exists, it will be at the first position since all uses of a
948 // def are processed together.
949 Node *phi = use_blk->_nodes[1];
950 if( phi->is_Phi() ) {
951 fixup = phi;
952 for (uint k = 1; k < use_blk->num_preds(); k++) {
953 if (phi->in(k) != inputs[k]) {
954 // Not a match
955 fixup = NULL;
956 break;
957 }
958 }
959 }
960
961 // If an existing PhiNode was not found, make a new one.
962 if (fixup == NULL) {
963 Node *new_phi = PhiNode::make(use_blk->head(), def);
964 use_blk->_nodes.insert(1, new_phi);
965 bbs.map(new_phi->_idx, use_blk);
966 for (uint k = 1; k < use_blk->num_preds(); k++) {
967 new_phi->set_req(k, inputs[k]);
968 }
969 fixup = new_phi;
970 }
971
972 } else {
973 // Found the use just below the Catch. Make it use the clone.
974 fixup = use_blk->_nodes[n_clone_idx];
975 }
976
977 return fixup;
978 }
979
980 //--------------------------catch_cleanup_intra_block--------------------------
981 // Fix all input edges in use that reference "def". The use is in the same
982 // block as the def and both have been cloned in each successor block.
983 static void catch_cleanup_intra_block(Node *use, Node *def, Block *blk, int beg, int n_clone_idx) {
984
985 // Both the use and def have been cloned. For each successor block,
986 // get the clone of the use, and make its input the clone of the def
987 // found in that block.
988
989 uint use_idx = blk->find_node(use);
990 uint offset_idx = use_idx - beg;
991 for( uint k = 0; k < blk->_num_succs; k++ ) {
992 // Get clone in each successor block
993 Block *sb = blk->_succs[k];
994 Node *clone = sb->_nodes[offset_idx+1];
995 assert( clone->Opcode() == use->Opcode(), "" );
996
997 // Make use-clone reference the def-clone
998 catch_cleanup_fix_all_inputs(clone, def, sb->_nodes[n_clone_idx]);
999 }
1000 }
1001
1002 //------------------------------catch_cleanup_inter_block---------------------
1003 // Fix all input edges in use that reference "def". The use is in a different
1004 // block than the def.
1005 static void catch_cleanup_inter_block(Node *use, Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) {
1006 if( !use_blk ) return; // Can happen if the use is a precedence edge
1007
1008 Node *new_def = catch_cleanup_find_cloned_def(use_blk, def, def_blk, bbs, n_clone_idx);
1009 catch_cleanup_fix_all_inputs(use, def, new_def);
1010 }
1011
1012 //------------------------------call_catch_cleanup-----------------------------
1013 // If we inserted any instructions between a Call and his CatchNode,
1014 // clone the instructions on all paths below the Catch.
1015 void Block::call_catch_cleanup(Block_Array &bbs, Compile* C) {
1016
1017 // End of region to clone
1018 uint end = end_idx();
1019 if( !_nodes[end]->is_Catch() ) return;
1020 // Start of region to clone
1021 uint beg = end;
1022 while(!_nodes[beg-1]->is_MachProj() ||
1023 !_nodes[beg-1]->in(0)->is_MachCall() ) {
1024 beg--;
1025 assert(beg > 0,"Catch cleanup walking beyond block boundary");
1026 }
1027 // Range of inserted instructions is [beg, end)
1028 if( beg == end ) return;
1029
1030 // Clone along all Catch output paths. Clone area between the 'beg' and
1031 // 'end' indices.
1032 for( uint i = 0; i < _num_succs; i++ ) {
1033 Block *sb = _succs[i];
1034 // Clone the entire area; ignoring the edge fixup for now.
1035 for( uint j = end; j > beg; j-- ) {
1036 // It is safe here to clone a node with anti_dependence
1037 // since clones dominate on each path.
1038 Node *clone = _nodes[j-1]->clone();
1039 sb->_nodes.insert( 1, clone );
1040 bbs.map(clone->_idx,sb);
1041 }
1042 }
1043
1044
1045 // Fixup edges. Check the def-use info per cloned Node
1046 for(uint i2 = beg; i2 < end; i2++ ) {
1047 uint n_clone_idx = i2-beg+1; // Index of clone of n in each successor block
1048 Node *n = _nodes[i2]; // Node that got cloned
1049 // Need DU safe iterator because of edge manipulation in calls.
1050 Unique_Node_List *out = new Unique_Node_List(Thread::current()->resource_area());
1051 for (DUIterator_Fast j1max, j1 = n->fast_outs(j1max); j1 < j1max; j1++) {
1052 out->push(n->fast_out(j1));
1053 }
1054 uint max = out->size();
1055 for (uint j = 0; j < max; j++) {// For all users
1056 Node *use = out->pop();
1057 Block *buse = bbs[use->_idx];
1058 if( use->is_Phi() ) {
1059 for( uint k = 1; k < use->req(); k++ )
1060 if( use->in(k) == n ) {
1061 Node *fixup = catch_cleanup_find_cloned_def(bbs[buse->pred(k)->_idx], n, this, bbs, n_clone_idx);
1062 use->set_req(k, fixup);
1063 }
1064 } else {
1065 if (this == buse) {
1066 catch_cleanup_intra_block(use, n, this, beg, n_clone_idx);
1067 } else {
1068 catch_cleanup_inter_block(use, buse, n, this, bbs, n_clone_idx);
1069 }
1070 }
1071 } // End for all users
1072
1073 } // End of for all Nodes in cloned area
1074
1075 // Remove the now-dead cloned ops
1076 for(uint i3 = beg; i3 < end; i3++ ) {
1077 _nodes[beg]->disconnect_inputs(NULL, C);
1078 _nodes.remove(beg);
1079 }
1080
1081 // If the successor blocks have a CreateEx node, move it back to the top
1082 for(uint i4 = 0; i4 < _num_succs; i4++ ) {
1083 Block *sb = _succs[i4];
1084 uint new_cnt = end - beg;
1085 // Remove any newly created, but dead, nodes.
1086 for( uint j = new_cnt; j > 0; j-- ) {
1087 Node *n = sb->_nodes[j];
1088 if (n->outcnt() == 0 &&
1089 (!n->is_Proj() || n->as_Proj()->in(0)->outcnt() == 1) ){
1090 n->disconnect_inputs(NULL, C);
1091 sb->_nodes.remove(j);
1092 new_cnt--;
1093 }
1094 }
1095 // If any newly created nodes remain, move the CreateEx node to the top
1096 if (new_cnt > 0) {
1097 Node *cex = sb->_nodes[1+new_cnt];
1098 if( cex->is_Mach() && cex->as_Mach()->ideal_Opcode() == Op_CreateEx ) {
1099 sb->_nodes.remove(1+new_cnt);
1100 sb->_nodes.insert(1,cex);
1101 }
1102 }
1103 }
1104 }