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->get_block_for_node(mach);
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->get_block_for_node(mach->in(j));
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->get_block_for_node(mach);
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->get_block_for_node(b->pred(1)); // 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 == NULL || cfg->get_block_for_node(mach)->_dom_depth < cfg->get_block_for_node(best)->_dom_depth) {
307 best = mach;
308 bidx = vidx;
309 }
310 }
311 // No candidate!
312 if (best == NULL) {
313 return;
314 }
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->get_block_for_node(val);
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->map_node_to_block(val, 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->get_block_for_node(n)->find_remove(n);
334 this->add_inst(n);
335 cfg->map_node_to_block(n, this);
336 }
337 }
338 }
339 }
340 // Hoist the memory candidate up to the end of the test block.
341 Block *old_block = cfg->get_block_for_node(best);
342 old_block->find_remove(best);
343 add_inst(best);
344 cfg->map_node_to_block(best, 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->get_block_for_node(n)->find_remove(n);
356 add_inst(n);
357 cfg->map_node_to_block(n, 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->map_node_to_block(nul_chk, 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->get_block_for_node(use) == 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, PhaseCFG* cfg) {
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 (cfg->get_block_for_node(m) == this) {
538 set_next_call(m, next_call, cfg);
539 }
540 }
541 }
542
543 //------------------------------needed_for_next_call---------------------------
544 // Set the flag 'next_call' for each Node that is needed for the next call to
545 // be scheduled. This flag lets me bias scheduling so Nodes needed for the
546 // next subroutine call get priority - basically it moves things NOT needed
547 // for the next call till after the call. This prevents me from trying to
548 // carry lots of stuff live across a call.
549 void Block::needed_for_next_call(Node *this_call, VectorSet &next_call, PhaseCFG* cfg) {
550 // Find the next control-defining Node in this block
551 Node* call = NULL;
552 for (DUIterator_Fast imax, i = this_call->fast_outs(imax); i < imax; i++) {
553 Node* m = this_call->fast_out(i);
554 if(cfg->get_block_for_node(m) == this && // Local-block user
555 m != this_call && // Not self-start node
556 m->is_MachCall() )
557 call = m;
558 break;
559 }
560 if (call == NULL) return; // No next call (e.g., block end is near)
561 // Set next-call for all inputs to this call
562 set_next_call(call, next_call, cfg);
563 }
564
565 //------------------------------add_call_kills-------------------------------------
566 void Block::add_call_kills(MachProjNode *proj, RegMask& regs, const char* save_policy, bool exclude_soe) {
567 // Fill in the kill mask for the call
568 for( OptoReg::Name r = OptoReg::Name(0); r < _last_Mach_Reg; r=OptoReg::add(r,1) ) {
569 if( !regs.Member(r) ) { // Not already defined by the call
570 // Save-on-call register?
571 if ((save_policy[r] == 'C') ||
572 (save_policy[r] == 'A') ||
573 ((save_policy[r] == 'E') && exclude_soe)) {
574 proj->_rout.Insert(r);
575 }
576 }
577 }
578 }
579
580
581 //------------------------------sched_call-------------------------------------
582 uint Block::sched_call( Matcher &matcher, PhaseCFG* cfg, uint node_cnt, Node_List &worklist, GrowableArray<int> &ready_cnt, MachCallNode *mcall, VectorSet &next_call ) {
583 RegMask regs;
584
585 // Schedule all the users of the call right now. All the users are
586 // projection Nodes, so they must be scheduled next to the call.
587 // Collect all the defined registers.
588 for (DUIterator_Fast imax, i = mcall->fast_outs(imax); i < imax; i++) {
589 Node* n = mcall->fast_out(i);
590 assert( n->is_MachProj(), "" );
591 int n_cnt = ready_cnt.at(n->_idx)-1;
592 ready_cnt.at_put(n->_idx, n_cnt);
593 assert( n_cnt == 0, "" );
594 // Schedule next to call
595 _nodes.map(node_cnt++, n);
596 // Collect defined registers
597 regs.OR(n->out_RegMask());
598 // Check for scheduling the next control-definer
599 if( n->bottom_type() == Type::CONTROL )
600 // Warm up next pile of heuristic bits
601 needed_for_next_call(n, next_call, cfg);
602
603 // Children of projections are now all ready
604 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
605 Node* m = n->fast_out(j); // Get user
606 if(cfg->get_block_for_node(m) != this) {
607 continue;
608 }
609 if( m->is_Phi() ) continue;
610 int m_cnt = ready_cnt.at(m->_idx)-1;
611 ready_cnt.at_put(m->_idx, m_cnt);
612 if( m_cnt == 0 )
613 worklist.push(m);
614 }
615
616 }
617
618 // Act as if the call defines the Frame Pointer.
619 // Certainly the FP is alive and well after the call.
620 regs.Insert(matcher.c_frame_pointer());
621
622 // Set all registers killed and not already defined by the call.
623 uint r_cnt = mcall->tf()->range()->cnt();
624 int op = mcall->ideal_Opcode();
625 MachProjNode *proj = new (matcher.C) MachProjNode( mcall, r_cnt+1, RegMask::Empty, MachProjNode::fat_proj );
626 cfg->map_node_to_block(proj, this);
627 _nodes.insert(node_cnt++, proj);
628
629 // Select the right register save policy.
630 const char * save_policy;
631 switch (op) {
632 case Op_CallRuntime:
633 case Op_CallLeaf:
634 case Op_CallLeafNoFP:
635 // Calling C code so use C calling convention
636 save_policy = matcher._c_reg_save_policy;
637 break;
638
639 case Op_CallStaticJava:
640 case Op_CallDynamicJava:
641 // Calling Java code so use Java calling convention
642 save_policy = matcher._register_save_policy;
643 break;
644
645 default:
646 ShouldNotReachHere();
647 }
648
649 // When using CallRuntime mark SOE registers as killed by the call
650 // so values that could show up in the RegisterMap aren't live in a
651 // callee saved register since the register wouldn't know where to
652 // find them. CallLeaf and CallLeafNoFP are ok because they can't
653 // have debug info on them. Strictly speaking this only needs to be
654 // done for oops since idealreg2debugmask takes care of debug info
655 // references but there no way to handle oops differently than other
656 // pointers as far as the kill mask goes.
657 bool exclude_soe = op == Op_CallRuntime;
658
659 // If the call is a MethodHandle invoke, we need to exclude the
660 // register which is used to save the SP value over MH invokes from
661 // the mask. Otherwise this register could be used for
662 // deoptimization information.
663 if (op == Op_CallStaticJava) {
664 MachCallStaticJavaNode* mcallstaticjava = (MachCallStaticJavaNode*) mcall;
665 if (mcallstaticjava->_method_handle_invoke)
666 proj->_rout.OR(Matcher::method_handle_invoke_SP_save_mask());
667 }
668
669 add_call_kills(proj, regs, save_policy, exclude_soe);
670
671 return node_cnt;
672 }
673
674
675 //------------------------------schedule_local---------------------------------
676 // Topological sort within a block. Someday become a real scheduler.
677 bool Block::schedule_local(PhaseCFG *cfg, Matcher &matcher, GrowableArray<int> &ready_cnt, VectorSet &next_call) {
678 // Already "sorted" are the block start Node (as the first entry), and
679 // the block-ending Node and any trailing control projections. We leave
680 // these alone. PhiNodes and ParmNodes are made to follow the block start
681 // Node. Everything else gets topo-sorted.
682
683 #ifndef PRODUCT
684 if (cfg->trace_opto_pipelining()) {
685 tty->print_cr("# --- schedule_local B%d, before: ---", _pre_order);
686 for (uint i = 0;i < _nodes.size();i++) {
687 tty->print("# ");
688 _nodes[i]->fast_dump();
689 }
690 tty->print_cr("#");
691 }
692 #endif
693
694 // RootNode is already sorted
695 if( _nodes.size() == 1 ) return true;
696
697 // Move PhiNodes and ParmNodes from 1 to cnt up to the start
698 uint node_cnt = end_idx();
699 uint phi_cnt = 1;
700 uint i;
701 for( i = 1; i<node_cnt; i++ ) { // Scan for Phi
702 Node *n = _nodes[i];
703 if( n->is_Phi() || // Found a PhiNode or ParmNode
704 (n->is_Proj() && n->in(0) == head()) ) {
705 // Move guy at 'phi_cnt' to the end; makes a hole at phi_cnt
706 _nodes.map(i,_nodes[phi_cnt]);
707 _nodes.map(phi_cnt++,n); // swap Phi/Parm up front
708 } else { // All others
709 // Count block-local inputs to 'n'
710 uint cnt = n->len(); // Input count
711 uint local = 0;
712 for( uint j=0; j<cnt; j++ ) {
713 Node *m = n->in(j);
714 if( m && cfg->get_block_for_node(m) == this && !m->is_top() )
715 local++; // One more block-local input
716 }
717 ready_cnt.at_put(n->_idx, local); // Count em up
718
719 #ifdef ASSERT
720 if( UseConcMarkSweepGC || UseG1GC ) {
721 if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_StoreCM ) {
722 // Check the precedence edges
723 for (uint prec = n->req(); prec < n->len(); prec++) {
724 Node* oop_store = n->in(prec);
725 if (oop_store != NULL) {
726 assert(cfg->get_block_for_node(oop_store)->_dom_depth <= this->_dom_depth, "oop_store must dominate card-mark");
727 }
728 }
729 }
730 }
731 #endif
732
733 // A few node types require changing a required edge to a precedence edge
734 // before allocation.
735 if( n->is_Mach() && n->req() > TypeFunc::Parms &&
736 (n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire ||
737 n->as_Mach()->ideal_Opcode() == Op_MemBarVolatile) ) {
738 // MemBarAcquire could be created without Precedent edge.
739 // del_req() replaces the specified edge with the last input edge
740 // and then removes the last edge. If the specified edge > number of
741 // edges the last edge will be moved outside of the input edges array
742 // and the edge will be lost. This is why this code should be
743 // executed only when Precedent (== TypeFunc::Parms) edge is present.
744 Node *x = n->in(TypeFunc::Parms);
745 n->del_req(TypeFunc::Parms);
746 n->add_prec(x);
747 }
748 }
749 }
750 for(uint i2=i; i2<_nodes.size(); i2++ ) // Trailing guys get zapped count
751 ready_cnt.at_put(_nodes[i2]->_idx, 0);
752
753 // All the prescheduled guys do not hold back internal nodes
754 uint i3;
755 for(i3 = 0; i3<phi_cnt; i3++ ) { // For all pre-scheduled
756 Node *n = _nodes[i3]; // Get pre-scheduled
757 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
758 Node* m = n->fast_out(j);
759 if (cfg->get_block_for_node(m) == this) { // Local-block user
760 int m_cnt = ready_cnt.at(m->_idx)-1;
761 ready_cnt.at_put(m->_idx, m_cnt); // Fix ready count
762 }
763 }
764 }
765
766 Node_List delay;
767 // Make a worklist
768 Node_List worklist;
769 for(uint i4=i3; i4<node_cnt; i4++ ) { // Put ready guys on worklist
770 Node *m = _nodes[i4];
771 if( !ready_cnt.at(m->_idx) ) { // Zero ready count?
772 if (m->is_iteratively_computed()) {
773 // Push induction variable increments last to allow other uses
774 // of the phi to be scheduled first. The select() method breaks
775 // ties in scheduling by worklist order.
776 delay.push(m);
777 } else if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_CreateEx) {
778 // Force the CreateEx to the top of the list so it's processed
779 // first and ends up at the start of the block.
780 worklist.insert(0, m);
781 } else {
782 worklist.push(m); // Then on to worklist!
783 }
784 }
785 }
786 while (delay.size()) {
787 Node* d = delay.pop();
788 worklist.push(d);
789 }
790
791 // Warm up the 'next_call' heuristic bits
792 needed_for_next_call(_nodes[0], next_call, cfg);
793
794 #ifndef PRODUCT
795 if (cfg->trace_opto_pipelining()) {
796 for (uint j=0; j<_nodes.size(); j++) {
797 Node *n = _nodes[j];
798 int idx = n->_idx;
799 tty->print("# ready cnt:%3d ", ready_cnt.at(idx));
800 tty->print("latency:%3d ", cfg->_node_latency->at_grow(idx));
801 tty->print("%4d: %s\n", idx, n->Name());
802 }
803 }
804 #endif
805
806 uint max_idx = (uint)ready_cnt.length();
807 // Pull from worklist and schedule
808 while( worklist.size() ) { // Worklist is not ready
809
810 #ifndef PRODUCT
811 if (cfg->trace_opto_pipelining()) {
812 tty->print("# ready list:");
813 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist
814 Node *n = worklist[i]; // Get Node on worklist
815 tty->print(" %d", n->_idx);
816 }
817 tty->cr();
818 }
819 #endif
820
821 // Select and pop a ready guy from worklist
822 Node* n = select(cfg, worklist, ready_cnt, next_call, phi_cnt);
823 _nodes.map(phi_cnt++,n); // Schedule him next
824
825 #ifndef PRODUCT
826 if (cfg->trace_opto_pipelining()) {
827 tty->print("# select %d: %s", n->_idx, n->Name());
828 tty->print(", latency:%d", cfg->_node_latency->at_grow(n->_idx));
829 n->dump();
830 if (Verbose) {
831 tty->print("# ready list:");
832 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist
833 Node *n = worklist[i]; // Get Node on worklist
834 tty->print(" %d", n->_idx);
835 }
836 tty->cr();
837 }
838 }
839
840 #endif
841 if( n->is_MachCall() ) {
842 MachCallNode *mcall = n->as_MachCall();
843 phi_cnt = sched_call(matcher, cfg, phi_cnt, worklist, ready_cnt, mcall, next_call);
844 continue;
845 }
846
847 if (n->is_Mach() && n->as_Mach()->has_call()) {
848 RegMask regs;
849 regs.Insert(matcher.c_frame_pointer());
850 regs.OR(n->out_RegMask());
851
852 MachProjNode *proj = new (matcher.C) MachProjNode( n, 1, RegMask::Empty, MachProjNode::fat_proj );
853 cfg->map_node_to_block(proj, this);
854 _nodes.insert(phi_cnt++, proj);
855
856 add_call_kills(proj, regs, matcher._c_reg_save_policy, false);
857 }
858
859 // Children are now all ready
860 for (DUIterator_Fast i5max, i5 = n->fast_outs(i5max); i5 < i5max; i5++) {
861 Node* m = n->fast_out(i5); // Get user
862 if (cfg->get_block_for_node(m) != this) {
863 continue;
864 }
865 if( m->is_Phi() ) continue;
866 if (m->_idx >= max_idx) { // new node, skip it
867 assert(m->is_MachProj() && n->is_Mach() && n->as_Mach()->has_call(), "unexpected node types");
868 continue;
869 }
870 int m_cnt = ready_cnt.at(m->_idx)-1;
871 ready_cnt.at_put(m->_idx, m_cnt);
872 if( m_cnt == 0 )
873 worklist.push(m);
874 }
875 }
876
877 if( phi_cnt != end_idx() ) {
878 // did not schedule all. Retry, Bailout, or Die
879 Compile* C = matcher.C;
880 if (C->subsume_loads() == true && !C->failing()) {
881 // Retry with subsume_loads == false
882 // If this is the first failure, the sentinel string will "stick"
883 // to the Compile object, and the C2Compiler will see it and retry.
884 C->record_failure(C2Compiler::retry_no_subsuming_loads());
885 }
886 // assert( phi_cnt == end_idx(), "did not schedule all" );
887 return false;
888 }
889
890 #ifndef PRODUCT
891 if (cfg->trace_opto_pipelining()) {
892 tty->print_cr("#");
893 tty->print_cr("# after schedule_local");
894 for (uint i = 0;i < _nodes.size();i++) {
895 tty->print("# ");
896 _nodes[i]->fast_dump();
897 }
898 tty->cr();
899 }
900 #endif
901
902
903 return true;
904 }
905
906 //--------------------------catch_cleanup_fix_all_inputs-----------------------
907 static void catch_cleanup_fix_all_inputs(Node *use, Node *old_def, Node *new_def) {
908 for (uint l = 0; l < use->len(); l++) {
909 if (use->in(l) == old_def) {
910 if (l < use->req()) {
911 use->set_req(l, new_def);
912 } else {
913 use->rm_prec(l);
914 use->add_prec(new_def);
915 l--;
916 }
917 }
918 }
919 }
920
921 //------------------------------catch_cleanup_find_cloned_def------------------
922 static Node *catch_cleanup_find_cloned_def(Block *use_blk, Node *def, Block *def_blk, PhaseCFG* cfg, int n_clone_idx) {
923 assert( use_blk != def_blk, "Inter-block cleanup only");
924
925 // The use is some block below the Catch. Find and return the clone of the def
926 // that dominates the use. If there is no clone in a dominating block, then
927 // create a phi for the def in a dominating block.
928
929 // Find which successor block dominates this use. The successor
930 // blocks must all be single-entry (from the Catch only; I will have
931 // split blocks to make this so), hence they all dominate.
932 while( use_blk->_dom_depth > def_blk->_dom_depth+1 )
933 use_blk = use_blk->_idom;
934
935 // Find the successor
936 Node *fixup = NULL;
937
938 uint j;
939 for( j = 0; j < def_blk->_num_succs; j++ )
940 if( use_blk == def_blk->_succs[j] )
941 break;
942
943 if( j == def_blk->_num_succs ) {
944 // Block at same level in dom-tree is not a successor. It needs a
945 // PhiNode, the PhiNode uses from the def and IT's uses need fixup.
946 Node_Array inputs = new Node_List(Thread::current()->resource_area());
947 for(uint k = 1; k < use_blk->num_preds(); k++) {
948 Block* block = cfg->get_block_for_node(use_blk->pred(k));
949 inputs.map(k, catch_cleanup_find_cloned_def(block, def, def_blk, cfg, n_clone_idx));
950 }
951
952 // Check to see if the use_blk already has an identical phi inserted.
953 // If it exists, it will be at the first position since all uses of a
954 // def are processed together.
955 Node *phi = use_blk->_nodes[1];
956 if( phi->is_Phi() ) {
957 fixup = phi;
958 for (uint k = 1; k < use_blk->num_preds(); k++) {
959 if (phi->in(k) != inputs[k]) {
960 // Not a match
961 fixup = NULL;
962 break;
963 }
964 }
965 }
966
967 // If an existing PhiNode was not found, make a new one.
968 if (fixup == NULL) {
969 Node *new_phi = PhiNode::make(use_blk->head(), def);
970 use_blk->_nodes.insert(1, new_phi);
971 cfg->map_node_to_block(new_phi, use_blk);
972 for (uint k = 1; k < use_blk->num_preds(); k++) {
973 new_phi->set_req(k, inputs[k]);
974 }
975 fixup = new_phi;
976 }
977
978 } else {
979 // Found the use just below the Catch. Make it use the clone.
980 fixup = use_blk->_nodes[n_clone_idx];
981 }
982
983 return fixup;
984 }
985
986 //--------------------------catch_cleanup_intra_block--------------------------
987 // Fix all input edges in use that reference "def". The use is in the same
988 // block as the def and both have been cloned in each successor block.
989 static void catch_cleanup_intra_block(Node *use, Node *def, Block *blk, int beg, int n_clone_idx) {
990
991 // Both the use and def have been cloned. For each successor block,
992 // get the clone of the use, and make its input the clone of the def
993 // found in that block.
994
995 uint use_idx = blk->find_node(use);
996 uint offset_idx = use_idx - beg;
997 for( uint k = 0; k < blk->_num_succs; k++ ) {
998 // Get clone in each successor block
999 Block *sb = blk->_succs[k];
1000 Node *clone = sb->_nodes[offset_idx+1];
1001 assert( clone->Opcode() == use->Opcode(), "" );
1002
1003 // Make use-clone reference the def-clone
1004 catch_cleanup_fix_all_inputs(clone, def, sb->_nodes[n_clone_idx]);
1005 }
1006 }
1007
1008 //------------------------------catch_cleanup_inter_block---------------------
1009 // Fix all input edges in use that reference "def". The use is in a different
1010 // block than the def.
1011 static void catch_cleanup_inter_block(Node *use, Block *use_blk, Node *def, Block *def_blk, PhaseCFG* cfg, int n_clone_idx) {
1012 if( !use_blk ) return; // Can happen if the use is a precedence edge
1013
1014 Node *new_def = catch_cleanup_find_cloned_def(use_blk, def, def_blk, cfg, n_clone_idx);
1015 catch_cleanup_fix_all_inputs(use, def, new_def);
1016 }
1017
1018 //------------------------------call_catch_cleanup-----------------------------
1019 // If we inserted any instructions between a Call and his CatchNode,
1020 // clone the instructions on all paths below the Catch.
1021 void Block::call_catch_cleanup(PhaseCFG* cfg, Compile* C) {
1022
1023 // End of region to clone
1024 uint end = end_idx();
1025 if( !_nodes[end]->is_Catch() ) return;
1026 // Start of region to clone
1027 uint beg = end;
1028 while(!_nodes[beg-1]->is_MachProj() ||
1029 !_nodes[beg-1]->in(0)->is_MachCall() ) {
1030 beg--;
1031 assert(beg > 0,"Catch cleanup walking beyond block boundary");
1032 }
1033 // Range of inserted instructions is [beg, end)
1034 if( beg == end ) return;
1035
1036 // Clone along all Catch output paths. Clone area between the 'beg' and
1037 // 'end' indices.
1038 for( uint i = 0; i < _num_succs; i++ ) {
1039 Block *sb = _succs[i];
1040 // Clone the entire area; ignoring the edge fixup for now.
1041 for( uint j = end; j > beg; j-- ) {
1042 // It is safe here to clone a node with anti_dependence
1043 // since clones dominate on each path.
1044 Node *clone = _nodes[j-1]->clone();
1045 sb->_nodes.insert( 1, clone );
1046 cfg->map_node_to_block(clone, sb);
1047 }
1048 }
1049
1050
1051 // Fixup edges. Check the def-use info per cloned Node
1052 for(uint i2 = beg; i2 < end; i2++ ) {
1053 uint n_clone_idx = i2-beg+1; // Index of clone of n in each successor block
1054 Node *n = _nodes[i2]; // Node that got cloned
1055 // Need DU safe iterator because of edge manipulation in calls.
1056 Unique_Node_List *out = new Unique_Node_List(Thread::current()->resource_area());
1057 for (DUIterator_Fast j1max, j1 = n->fast_outs(j1max); j1 < j1max; j1++) {
1058 out->push(n->fast_out(j1));
1059 }
1060 uint max = out->size();
1061 for (uint j = 0; j < max; j++) {// For all users
1062 Node *use = out->pop();
1063 Block *buse = cfg->get_block_for_node(use);
1064 if( use->is_Phi() ) {
1065 for( uint k = 1; k < use->req(); k++ )
1066 if( use->in(k) == n ) {
1067 Block* block = cfg->get_block_for_node(buse->pred(k));
1068 Node *fixup = catch_cleanup_find_cloned_def(block, n, this, cfg, n_clone_idx);
1069 use->set_req(k, fixup);
1070 }
1071 } else {
1072 if (this == buse) {
1073 catch_cleanup_intra_block(use, n, this, beg, n_clone_idx);
1074 } else {
1075 catch_cleanup_inter_block(use, buse, n, this, cfg, n_clone_idx);
1076 }
1077 }
1078 } // End for all users
1079
1080 } // End of for all Nodes in cloned area
1081
1082 // Remove the now-dead cloned ops
1083 for(uint i3 = beg; i3 < end; i3++ ) {
1084 _nodes[beg]->disconnect_inputs(NULL, C);
1085 _nodes.remove(beg);
1086 }
1087
1088 // If the successor blocks have a CreateEx node, move it back to the top
1089 for(uint i4 = 0; i4 < _num_succs; i4++ ) {
1090 Block *sb = _succs[i4];
1091 uint new_cnt = end - beg;
1092 // Remove any newly created, but dead, nodes.
1093 for( uint j = new_cnt; j > 0; j-- ) {
1094 Node *n = sb->_nodes[j];
1095 if (n->outcnt() == 0 &&
1096 (!n->is_Proj() || n->as_Proj()->in(0)->outcnt() == 1) ){
1097 n->disconnect_inputs(NULL, C);
1098 sb->_nodes.remove(j);
1099 new_cnt--;
1100 }
1101 }
1102 // If any newly created nodes remain, move the CreateEx node to the top
1103 if (new_cnt > 0) {
1104 Node *cex = sb->_nodes[1+new_cnt];
1105 if( cex->is_Mach() && cex->as_Mach()->ideal_Opcode() == Op_CreateEx ) {
1106 sb->_nodes.remove(1+new_cnt);
1107 sb->_nodes.insert(1,cex);
1108 }
1109 }
1110 }
1111 }