1 /*
2 * Copyright 1998-2007 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 // Optimization - Graph Style
26
27 #include "incls/_precompiled.incl"
28 #include "incls/_lcm.cpp.incl"
29
30 //------------------------------implicit_null_check----------------------------
31 // Detect implicit-null-check opportunities. Basically, find NULL checks
32 // with suitable memory ops nearby. Use the memory op to do the NULL check.
33 // I can generate a memory op if there is not one nearby.
34 // The proj is the control projection for the not-null case.
35 // The val is the pointer being checked for nullness.
36 void Block::implicit_null_check(PhaseCFG *cfg, Node *proj, Node *val, int allowed_reasons) {
37 // Assume if null check need for 0 offset then always needed
38 // Intel solaris doesn't support any null checks yet and no
39 // mechanism exists (yet) to set the switches at an os_cpu level
40 if( !ImplicitNullChecks || MacroAssembler::needs_explicit_null_check(0)) return;
41
42 // Make sure the ptr-is-null path appears to be uncommon!
43 float f = end()->as_MachIf()->_prob;
44 if( proj->Opcode() == Op_IfTrue ) f = 1.0f - f;
45 if( f > PROB_UNLIKELY_MAG(4) ) return;
46
47 uint bidx = 0; // Capture index of value into memop
48 bool was_store; // Memory op is a store op
49
50 // Get the successor block for if the test ptr is non-null
51 Block* not_null_block; // this one goes with the proj
52 Block* null_block;
53 if (_nodes[_nodes.size()-1] == proj) {
54 null_block = _succs[0];
55 not_null_block = _succs[1];
56 } else {
57 assert(_nodes[_nodes.size()-2] == proj, "proj is one or the other");
58 not_null_block = _succs[0];
59 null_block = _succs[1];
60 }
61
62 // Search the exception block for an uncommon trap.
63 // (See Parse::do_if and Parse::do_ifnull for the reason
64 // we need an uncommon trap. Briefly, we need a way to
65 // detect failure of this optimization, as in 6366351.)
66 {
67 bool found_trap = false;
68 for (uint i1 = 0; i1 < null_block->_nodes.size(); i1++) {
69 Node* nn = null_block->_nodes[i1];
70 if (nn->is_MachCall() &&
71 nn->as_MachCall()->entry_point() ==
72 SharedRuntime::uncommon_trap_blob()->instructions_begin()) {
73 const Type* trtype = nn->in(TypeFunc::Parms)->bottom_type();
74 if (trtype->isa_int() && trtype->is_int()->is_con()) {
75 jint tr_con = trtype->is_int()->get_con();
76 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(tr_con);
77 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(tr_con);
78 assert((int)reason < (int)BitsPerInt, "recode bit map");
79 if (is_set_nth_bit(allowed_reasons, (int) reason)
80 && action != Deoptimization::Action_none) {
81 // This uncommon trap is sure to recompile, eventually.
82 // When that happens, C->too_many_traps will prevent
83 // this transformation from happening again.
84 found_trap = true;
85 }
86 }
87 break;
88 }
89 }
90 if (!found_trap) {
91 // We did not find an uncommon trap.
92 return;
93 }
94 }
95
96 // Search the successor block for a load or store who's base value is also
97 // the tested value. There may be several.
98 Node_List *out = new Node_List(Thread::current()->resource_area());
99 MachNode *best = NULL; // Best found so far
100 for (DUIterator i = val->outs(); val->has_out(i); i++) {
101 Node *m = val->out(i);
102 if( !m->is_Mach() ) continue;
103 MachNode *mach = m->as_Mach();
104 was_store = false;
105 switch( mach->ideal_Opcode() ) {
106 case Op_LoadB:
107 case Op_LoadC:
108 case Op_LoadD:
109 case Op_LoadF:
110 case Op_LoadI:
111 case Op_LoadL:
112 case Op_LoadP:
113 case Op_LoadS:
114 case Op_LoadKlass:
115 case Op_LoadRange:
116 case Op_LoadD_unaligned:
117 case Op_LoadL_unaligned:
118 break;
119 case Op_StoreB:
120 case Op_StoreC:
121 case Op_StoreCM:
122 case Op_StoreD:
123 case Op_StoreF:
124 case Op_StoreI:
125 case Op_StoreL:
126 case Op_StoreP:
127 was_store = true; // Memory op is a store op
128 // Stores will have their address in slot 2 (memory in slot 1).
129 // If the value being nul-checked is in another slot, it means we
130 // are storing the checked value, which does NOT check the value!
131 if( mach->in(2) != val ) continue;
132 break; // Found a memory op?
133 case Op_StrComp:
134 // Not a legit memory op for implicit null check regardless of
135 // embedded loads
136 continue;
137 default: // Also check for embedded loads
138 if( !mach->needs_anti_dependence_check() )
139 continue; // Not an memory op; skip it
140 break;
141 }
142 // check if the offset is not too high for implicit exception
143 {
144 intptr_t offset = 0;
145 const TypePtr *adr_type = NULL; // Do not need this return value here
146 const Node* base = mach->get_base_and_disp(offset, adr_type);
147 if (base == NULL || base == NodeSentinel) {
148 // cannot reason about it; is probably not implicit null exception
149 } else {
150 const TypePtr* tptr = base->bottom_type()->is_ptr();
151 // Give up if offset is not a compile-time constant
152 if( offset == Type::OffsetBot || tptr->_offset == Type::OffsetBot )
153 continue;
154 offset += tptr->_offset; // correct if base is offseted
155 if( MacroAssembler::needs_explicit_null_check(offset) )
156 continue; // Give up is reference is beyond 4K page size
157 }
158 }
159
160 // Check ctrl input to see if the null-check dominates the memory op
161 Block *cb = cfg->_bbs[mach->_idx];
162 cb = cb->_idom; // Always hoist at least 1 block
163 if( !was_store ) { // Stores can be hoisted only one block
164 while( cb->_dom_depth > (_dom_depth + 1))
165 cb = cb->_idom; // Hoist loads as far as we want
166 // The non-null-block should dominate the memory op, too. Live
167 // range spilling will insert a spill in the non-null-block if it is
168 // needs to spill the memory op for an implicit null check.
169 if (cb->_dom_depth == (_dom_depth + 1)) {
170 if (cb != not_null_block) continue;
171 cb = cb->_idom;
172 }
173 }
174 if( cb != this ) continue;
175
176 // Found a memory user; see if it can be hoisted to check-block
177 uint vidx = 0; // Capture index of value into memop
178 uint j;
179 for( j = mach->req()-1; j > 0; j-- ) {
180 if( mach->in(j) == val ) vidx = j;
181 // Block of memory-op input
182 Block *inb = cfg->_bbs[mach->in(j)->_idx];
183 Block *b = this; // Start from nul check
184 while( b != inb && b->_dom_depth > inb->_dom_depth )
185 b = b->_idom; // search upwards for input
186 // See if input dominates null check
187 if( b != inb )
188 break;
189 }
190 if( j > 0 )
191 continue;
192 Block *mb = cfg->_bbs[mach->_idx];
193 // Hoisting stores requires more checks for the anti-dependence case.
194 // Give up hoisting if we have to move the store past any load.
195 if( was_store ) {
196 Block *b = mb; // Start searching here for a local load
197 // mach use (faulting) trying to hoist
198 // n might be blocker to hoisting
199 while( b != this ) {
200 uint k;
201 for( k = 1; k < b->_nodes.size(); k++ ) {
202 Node *n = b->_nodes[k];
203 if( n->needs_anti_dependence_check() &&
204 n->in(LoadNode::Memory) == mach->in(StoreNode::Memory) )
205 break; // Found anti-dependent load
206 }
207 if( k < b->_nodes.size() )
208 break; // Found anti-dependent load
209 // Make sure control does not do a merge (would have to check allpaths)
210 if( b->num_preds() != 2 ) break;
211 b = cfg->_bbs[b->pred(1)->_idx]; // Move up to predecessor block
212 }
213 if( b != this ) continue;
214 }
215
216 // Make sure this memory op is not already being used for a NullCheck
217 Node *e = mb->end();
218 if( e->is_MachNullCheck() && e->in(1) == mach )
219 continue; // Already being used as a NULL check
220
221 // Found a candidate! Pick one with least dom depth - the highest
222 // in the dom tree should be closest to the null check.
223 if( !best ||
224 cfg->_bbs[mach->_idx]->_dom_depth < cfg->_bbs[best->_idx]->_dom_depth ) {
225 best = mach;
226 bidx = vidx;
227
228 }
229 }
230 // No candidate!
231 if( !best ) return;
232
233 // ---- Found an implicit null check
234 extern int implicit_null_checks;
235 implicit_null_checks++;
236
237 // Hoist the memory candidate up to the end of the test block.
238 Block *old_block = cfg->_bbs[best->_idx];
239 old_block->find_remove(best);
240 add_inst(best);
241 cfg->_bbs.map(best->_idx,this);
242
243 // Move the control dependence
244 if (best->in(0) && best->in(0) == old_block->_nodes[0])
245 best->set_req(0, _nodes[0]);
246
247 // Check for flag-killing projections that also need to be hoisted
248 // Should be DU safe because no edge updates.
249 for (DUIterator_Fast jmax, j = best->fast_outs(jmax); j < jmax; j++) {
250 Node* n = best->fast_out(j);
251 if( n->Opcode() == Op_MachProj ) {
252 cfg->_bbs[n->_idx]->find_remove(n);
253 add_inst(n);
254 cfg->_bbs.map(n->_idx,this);
255 }
256 }
257
258 Compile *C = cfg->C;
259 // proj==Op_True --> ne test; proj==Op_False --> eq test.
260 // One of two graph shapes got matched:
261 // (IfTrue (If (Bool NE (CmpP ptr NULL))))
262 // (IfFalse (If (Bool EQ (CmpP ptr NULL))))
263 // NULL checks are always branch-if-eq. If we see a IfTrue projection
264 // then we are replacing a 'ne' test with a 'eq' NULL check test.
265 // We need to flip the projections to keep the same semantics.
266 if( proj->Opcode() == Op_IfTrue ) {
267 // Swap order of projections in basic block to swap branch targets
268 Node *tmp1 = _nodes[end_idx()+1];
269 Node *tmp2 = _nodes[end_idx()+2];
270 _nodes.map(end_idx()+1, tmp2);
271 _nodes.map(end_idx()+2, tmp1);
272 Node *tmp = new (C, 1) Node(C->top()); // Use not NULL input
273 tmp1->replace_by(tmp);
274 tmp2->replace_by(tmp1);
275 tmp->replace_by(tmp2);
276 tmp->destruct();
277 }
278
279 // Remove the existing null check; use a new implicit null check instead.
280 // Since schedule-local needs precise def-use info, we need to correct
281 // it as well.
282 Node *old_tst = proj->in(0);
283 MachNode *nul_chk = new (C) MachNullCheckNode(old_tst->in(0),best,bidx);
284 _nodes.map(end_idx(),nul_chk);
285 cfg->_bbs.map(nul_chk->_idx,this);
286 // Redirect users of old_test to nul_chk
287 for (DUIterator_Last i2min, i2 = old_tst->last_outs(i2min); i2 >= i2min; --i2)
288 old_tst->last_out(i2)->set_req(0, nul_chk);
289 // Clean-up any dead code
290 for (uint i3 = 0; i3 < old_tst->req(); i3++)
291 old_tst->set_req(i3, NULL);
292
293 cfg->latency_from_uses(nul_chk);
294 cfg->latency_from_uses(best);
295 }
296
297
298 //------------------------------select-----------------------------------------
299 // Select a nice fellow from the worklist to schedule next. If there is only
300 // one choice, then use it. Projections take top priority for correctness
301 // reasons - if I see a projection, then it is next. There are a number of
302 // other special cases, for instructions that consume condition codes, et al.
303 // These are chosen immediately. Some instructions are required to immediately
304 // precede the last instruction in the block, and these are taken last. Of the
305 // remaining cases (most), choose the instruction with the greatest latency
306 // (that is, the most number of pseudo-cycles required to the end of the
307 // routine). If there is a tie, choose the instruction with the most inputs.
308 Node *Block::select(PhaseCFG *cfg, Node_List &worklist, int *ready_cnt, VectorSet &next_call, uint sched_slot) {
309
310 // If only a single entry on the stack, use it
311 uint cnt = worklist.size();
312 if (cnt == 1) {
313 Node *n = worklist[0];
314 worklist.map(0,worklist.pop());
315 return n;
316 }
317
318 uint choice = 0; // Bigger is most important
319 uint latency = 0; // Bigger is scheduled first
320 uint score = 0; // Bigger is better
321 uint idx; // Index in worklist
322
323 for( uint i=0; i<cnt; i++ ) { // Inspect entire worklist
324 // Order in worklist is used to break ties.
325 // See caller for how this is used to delay scheduling
326 // of induction variable increments to after the other
327 // uses of the phi are scheduled.
328 Node *n = worklist[i]; // Get Node on worklist
329
330 int iop = n->is_Mach() ? n->as_Mach()->ideal_Opcode() : 0;
331 if( n->is_Proj() || // Projections always win
332 n->Opcode()== Op_Con || // So does constant 'Top'
333 iop == Op_CreateEx || // Create-exception must start block
334 iop == Op_CheckCastPP
335 ) {
336 worklist.map(i,worklist.pop());
337 return n;
338 }
339
340 // Final call in a block must be adjacent to 'catch'
341 Node *e = end();
342 if( e->is_Catch() && e->in(0)->in(0) == n )
343 continue;
344
345 // Memory op for an implicit null check has to be at the end of the block
346 if( e->is_MachNullCheck() && e->in(1) == n )
347 continue;
348
349 uint n_choice = 2;
350
351 // See if this instruction is consumed by a branch. If so, then (as the
352 // branch is the last instruction in the basic block) force it to the
353 // end of the basic block
354 if ( must_clone[iop] ) {
355 // See if any use is a branch
356 bool found_machif = false;
357
358 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
359 Node* use = n->fast_out(j);
360
361 // The use is a conditional branch, make them adjacent
362 if (use->is_MachIf() && cfg->_bbs[use->_idx]==this ) {
363 found_machif = true;
364 break;
365 }
366
367 // More than this instruction pending for successor to be ready,
368 // don't choose this if other opportunities are ready
369 if (ready_cnt[use->_idx] > 1)
370 n_choice = 1;
371 }
372
373 // loop terminated, prefer not to use this instruction
374 if (found_machif)
375 continue;
376 }
377
378 // See if this has a predecessor that is "must_clone", i.e. sets the
379 // condition code. If so, choose this first
380 for (uint j = 0; j < n->req() ; j++) {
381 Node *inn = n->in(j);
382 if (inn) {
383 if (inn->is_Mach() && must_clone[inn->as_Mach()->ideal_Opcode()] ) {
384 n_choice = 3;
385 break;
386 }
387 }
388 }
389
390 // MachTemps should be scheduled last so they are near their uses
391 if (n->is_MachTemp()) {
392 n_choice = 1;
393 }
394
395 uint n_latency = cfg->_node_latency.at_grow(n->_idx);
396 uint n_score = n->req(); // Many inputs get high score to break ties
397
398 // Keep best latency found
399 if( choice < n_choice ||
400 ( choice == n_choice &&
401 ( latency < n_latency ||
402 ( latency == n_latency &&
403 ( score < n_score ))))) {
404 choice = n_choice;
405 latency = n_latency;
406 score = n_score;
407 idx = i; // Also keep index in worklist
408 }
409 } // End of for all ready nodes in worklist
410
411 Node *n = worklist[idx]; // Get the winner
412
413 worklist.map(idx,worklist.pop()); // Compress worklist
414 return n;
415 }
416
417
418 //------------------------------set_next_call----------------------------------
419 void Block::set_next_call( Node *n, VectorSet &next_call, Block_Array &bbs ) {
420 if( next_call.test_set(n->_idx) ) return;
421 for( uint i=0; i<n->len(); i++ ) {
422 Node *m = n->in(i);
423 if( !m ) continue; // must see all nodes in block that precede call
424 if( bbs[m->_idx] == this )
425 set_next_call( m, next_call, bbs );
426 }
427 }
428
429 //------------------------------needed_for_next_call---------------------------
430 // Set the flag 'next_call' for each Node that is needed for the next call to
431 // be scheduled. This flag lets me bias scheduling so Nodes needed for the
432 // next subroutine call get priority - basically it moves things NOT needed
433 // for the next call till after the call. This prevents me from trying to
434 // carry lots of stuff live across a call.
435 void Block::needed_for_next_call(Node *this_call, VectorSet &next_call, Block_Array &bbs) {
436 // Find the next control-defining Node in this block
437 Node* call = NULL;
438 for (DUIterator_Fast imax, i = this_call->fast_outs(imax); i < imax; i++) {
439 Node* m = this_call->fast_out(i);
440 if( bbs[m->_idx] == this && // Local-block user
441 m != this_call && // Not self-start node
442 m->is_Call() )
443 call = m;
444 break;
445 }
446 if (call == NULL) return; // No next call (e.g., block end is near)
447 // Set next-call for all inputs to this call
448 set_next_call(call, next_call, bbs);
449 }
450
451 //------------------------------sched_call-------------------------------------
452 uint Block::sched_call( Matcher &matcher, Block_Array &bbs, uint node_cnt, Node_List &worklist, int *ready_cnt, MachCallNode *mcall, VectorSet &next_call ) {
453 RegMask regs;
454
455 // Schedule all the users of the call right now. All the users are
456 // projection Nodes, so they must be scheduled next to the call.
457 // Collect all the defined registers.
458 for (DUIterator_Fast imax, i = mcall->fast_outs(imax); i < imax; i++) {
459 Node* n = mcall->fast_out(i);
460 assert( n->Opcode()==Op_MachProj, "" );
461 --ready_cnt[n->_idx];
462 assert( !ready_cnt[n->_idx], "" );
463 // Schedule next to call
464 _nodes.map(node_cnt++, n);
465 // Collect defined registers
466 regs.OR(n->out_RegMask());
467 // Check for scheduling the next control-definer
468 if( n->bottom_type() == Type::CONTROL )
469 // Warm up next pile of heuristic bits
470 needed_for_next_call(n, next_call, bbs);
471
472 // Children of projections are now all ready
473 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
474 Node* m = n->fast_out(j); // Get user
475 if( bbs[m->_idx] != this ) continue;
476 if( m->is_Phi() ) continue;
477 if( !--ready_cnt[m->_idx] )
478 worklist.push(m);
479 }
480
481 }
482
483 // Act as if the call defines the Frame Pointer.
484 // Certainly the FP is alive and well after the call.
485 regs.Insert(matcher.c_frame_pointer());
486
487 // Set all registers killed and not already defined by the call.
488 uint r_cnt = mcall->tf()->range()->cnt();
489 int op = mcall->ideal_Opcode();
490 MachProjNode *proj = new (matcher.C, 1) MachProjNode( mcall, r_cnt+1, RegMask::Empty, MachProjNode::fat_proj );
491 bbs.map(proj->_idx,this);
492 _nodes.insert(node_cnt++, proj);
493
494 // Select the right register save policy.
495 const char * save_policy;
496 switch (op) {
497 case Op_CallRuntime:
498 case Op_CallLeaf:
499 case Op_CallLeafNoFP:
500 // Calling C code so use C calling convention
501 save_policy = matcher._c_reg_save_policy;
502 break;
503
504 case Op_CallStaticJava:
505 case Op_CallDynamicJava:
506 // Calling Java code so use Java calling convention
507 save_policy = matcher._register_save_policy;
508 break;
509
510 default:
511 ShouldNotReachHere();
512 }
513
514 // When using CallRuntime mark SOE registers as killed by the call
515 // so values that could show up in the RegisterMap aren't live in a
516 // callee saved register since the register wouldn't know where to
517 // find them. CallLeaf and CallLeafNoFP are ok because they can't
518 // have debug info on them. Strictly speaking this only needs to be
519 // done for oops since idealreg2debugmask takes care of debug info
520 // references but there no way to handle oops differently than other
521 // pointers as far as the kill mask goes.
522 bool exclude_soe = op == Op_CallRuntime;
523
524 // Fill in the kill mask for the call
525 for( OptoReg::Name r = OptoReg::Name(0); r < _last_Mach_Reg; r=OptoReg::add(r,1) ) {
526 if( !regs.Member(r) ) { // Not already defined by the call
527 // Save-on-call register?
528 if ((save_policy[r] == 'C') ||
529 (save_policy[r] == 'A') ||
530 ((save_policy[r] == 'E') && exclude_soe)) {
531 proj->_rout.Insert(r);
532 }
533 }
534 }
535
536 return node_cnt;
537 }
538
539
540 //------------------------------schedule_local---------------------------------
541 // Topological sort within a block. Someday become a real scheduler.
542 bool Block::schedule_local(PhaseCFG *cfg, Matcher &matcher, int *ready_cnt, VectorSet &next_call) {
543 // Already "sorted" are the block start Node (as the first entry), and
544 // the block-ending Node and any trailing control projections. We leave
545 // these alone. PhiNodes and ParmNodes are made to follow the block start
546 // Node. Everything else gets topo-sorted.
547
548 #ifndef PRODUCT
549 if (cfg->trace_opto_pipelining()) {
550 tty->print_cr("# --- schedule_local B%d, before: ---", _pre_order);
551 for (uint i = 0;i < _nodes.size();i++) {
552 tty->print("# ");
553 _nodes[i]->fast_dump();
554 }
555 tty->print_cr("#");
556 }
557 #endif
558
559 // RootNode is already sorted
560 if( _nodes.size() == 1 ) return true;
561
562 // Move PhiNodes and ParmNodes from 1 to cnt up to the start
563 uint node_cnt = end_idx();
564 uint phi_cnt = 1;
565 uint i;
566 for( i = 1; i<node_cnt; i++ ) { // Scan for Phi
567 Node *n = _nodes[i];
568 if( n->is_Phi() || // Found a PhiNode or ParmNode
569 (n->is_Proj() && n->in(0) == head()) ) {
570 // Move guy at 'phi_cnt' to the end; makes a hole at phi_cnt
571 _nodes.map(i,_nodes[phi_cnt]);
572 _nodes.map(phi_cnt++,n); // swap Phi/Parm up front
573 } else { // All others
574 // Count block-local inputs to 'n'
575 uint cnt = n->len(); // Input count
576 uint local = 0;
577 for( uint j=0; j<cnt; j++ ) {
578 Node *m = n->in(j);
579 if( m && cfg->_bbs[m->_idx] == this && !m->is_top() )
580 local++; // One more block-local input
581 }
582 ready_cnt[n->_idx] = local; // Count em up
583
584 // A few node types require changing a required edge to a precedence edge
585 // before allocation.
586 if( UseConcMarkSweepGC ) {
587 if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_StoreCM ) {
588 // Note: Required edges with an index greater than oper_input_base
589 // are not supported by the allocator.
590 // Note2: Can only depend on unmatched edge being last,
591 // can not depend on its absolute position.
592 Node *oop_store = n->in(n->req() - 1);
593 n->del_req(n->req() - 1);
594 n->add_prec(oop_store);
595 assert(cfg->_bbs[oop_store->_idx]->_dom_depth <= this->_dom_depth, "oop_store must dominate card-mark");
596 }
597 }
598 if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire ) {
599 Node *x = n->in(TypeFunc::Parms);
600 n->del_req(TypeFunc::Parms);
601 n->add_prec(x);
602 }
603 }
604 }
605 for(uint i2=i; i2<_nodes.size(); i2++ ) // Trailing guys get zapped count
606 ready_cnt[_nodes[i2]->_idx] = 0;
607
608 // All the prescheduled guys do not hold back internal nodes
609 uint i3;
610 for(i3 = 0; i3<phi_cnt; i3++ ) { // For all pre-scheduled
611 Node *n = _nodes[i3]; // Get pre-scheduled
612 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
613 Node* m = n->fast_out(j);
614 if( cfg->_bbs[m->_idx] ==this ) // Local-block user
615 ready_cnt[m->_idx]--; // Fix ready count
616 }
617 }
618
619 Node_List delay;
620 // Make a worklist
621 Node_List worklist;
622 for(uint i4=i3; i4<node_cnt; i4++ ) { // Put ready guys on worklist
623 Node *m = _nodes[i4];
624 if( !ready_cnt[m->_idx] ) { // Zero ready count?
625 if (m->is_iteratively_computed()) {
626 // Push induction variable increments last to allow other uses
627 // of the phi to be scheduled first. The select() method breaks
628 // ties in scheduling by worklist order.
629 delay.push(m);
630 } else {
631 worklist.push(m); // Then on to worklist!
632 }
633 }
634 }
635 while (delay.size()) {
636 Node* d = delay.pop();
637 worklist.push(d);
638 }
639
640 // Warm up the 'next_call' heuristic bits
641 needed_for_next_call(_nodes[0], next_call, cfg->_bbs);
642
643 #ifndef PRODUCT
644 if (cfg->trace_opto_pipelining()) {
645 for (uint j=0; j<_nodes.size(); j++) {
646 Node *n = _nodes[j];
647 int idx = n->_idx;
648 tty->print("# ready cnt:%3d ", ready_cnt[idx]);
649 tty->print("latency:%3d ", cfg->_node_latency.at_grow(idx));
650 tty->print("%4d: %s\n", idx, n->Name());
651 }
652 }
653 #endif
654
655 // Pull from worklist and schedule
656 while( worklist.size() ) { // Worklist is not ready
657
658 #ifndef PRODUCT
659 if (cfg->trace_opto_pipelining()) {
660 tty->print("# ready list:");
661 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist
662 Node *n = worklist[i]; // Get Node on worklist
663 tty->print(" %d", n->_idx);
664 }
665 tty->cr();
666 }
667 #endif
668
669 // Select and pop a ready guy from worklist
670 Node* n = select(cfg, worklist, ready_cnt, next_call, phi_cnt);
671 _nodes.map(phi_cnt++,n); // Schedule him next
672
673 #ifndef PRODUCT
674 if (cfg->trace_opto_pipelining()) {
675 tty->print("# select %d: %s", n->_idx, n->Name());
676 tty->print(", latency:%d", cfg->_node_latency.at_grow(n->_idx));
677 n->dump();
678 if (Verbose) {
679 tty->print("# ready list:");
680 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist
681 Node *n = worklist[i]; // Get Node on worklist
682 tty->print(" %d", n->_idx);
683 }
684 tty->cr();
685 }
686 }
687
688 #endif
689 if( n->is_MachCall() ) {
690 MachCallNode *mcall = n->as_MachCall();
691 phi_cnt = sched_call(matcher, cfg->_bbs, phi_cnt, worklist, ready_cnt, mcall, next_call);
692 continue;
693 }
694 // Children are now all ready
695 for (DUIterator_Fast i5max, i5 = n->fast_outs(i5max); i5 < i5max; i5++) {
696 Node* m = n->fast_out(i5); // Get user
697 if( cfg->_bbs[m->_idx] != this ) continue;
698 if( m->is_Phi() ) continue;
699 if( !--ready_cnt[m->_idx] )
700 worklist.push(m);
701 }
702 }
703
704 if( phi_cnt != end_idx() ) {
705 // did not schedule all. Retry, Bailout, or Die
706 Compile* C = matcher.C;
707 if (C->subsume_loads() == true && !C->failing()) {
708 // Retry with subsume_loads == false
709 // If this is the first failure, the sentinel string will "stick"
710 // to the Compile object, and the C2Compiler will see it and retry.
711 C->record_failure(C2Compiler::retry_no_subsuming_loads());
712 }
713 // assert( phi_cnt == end_idx(), "did not schedule all" );
714 return false;
715 }
716
717 #ifndef PRODUCT
718 if (cfg->trace_opto_pipelining()) {
719 tty->print_cr("#");
720 tty->print_cr("# after schedule_local");
721 for (uint i = 0;i < _nodes.size();i++) {
722 tty->print("# ");
723 _nodes[i]->fast_dump();
724 }
725 tty->cr();
726 }
727 #endif
728
729
730 return true;
731 }
732
733 //--------------------------catch_cleanup_fix_all_inputs-----------------------
734 static void catch_cleanup_fix_all_inputs(Node *use, Node *old_def, Node *new_def) {
735 for (uint l = 0; l < use->len(); l++) {
736 if (use->in(l) == old_def) {
737 if (l < use->req()) {
738 use->set_req(l, new_def);
739 } else {
740 use->rm_prec(l);
741 use->add_prec(new_def);
742 l--;
743 }
744 }
745 }
746 }
747
748 //------------------------------catch_cleanup_find_cloned_def------------------
749 static Node *catch_cleanup_find_cloned_def(Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) {
750 assert( use_blk != def_blk, "Inter-block cleanup only");
751
752 // The use is some block below the Catch. Find and return the clone of the def
753 // that dominates the use. If there is no clone in a dominating block, then
754 // create a phi for the def in a dominating block.
755
756 // Find which successor block dominates this use. The successor
757 // blocks must all be single-entry (from the Catch only; I will have
758 // split blocks to make this so), hence they all dominate.
759 while( use_blk->_dom_depth > def_blk->_dom_depth+1 )
760 use_blk = use_blk->_idom;
761
762 // Find the successor
763 Node *fixup = NULL;
764
765 uint j;
766 for( j = 0; j < def_blk->_num_succs; j++ )
767 if( use_blk == def_blk->_succs[j] )
768 break;
769
770 if( j == def_blk->_num_succs ) {
771 // Block at same level in dom-tree is not a successor. It needs a
772 // PhiNode, the PhiNode uses from the def and IT's uses need fixup.
773 Node_Array inputs = new Node_List(Thread::current()->resource_area());
774 for(uint k = 1; k < use_blk->num_preds(); k++) {
775 inputs.map(k, catch_cleanup_find_cloned_def(bbs[use_blk->pred(k)->_idx], def, def_blk, bbs, n_clone_idx));
776 }
777
778 // Check to see if the use_blk already has an identical phi inserted.
779 // If it exists, it will be at the first position since all uses of a
780 // def are processed together.
781 Node *phi = use_blk->_nodes[1];
782 if( phi->is_Phi() ) {
783 fixup = phi;
784 for (uint k = 1; k < use_blk->num_preds(); k++) {
785 if (phi->in(k) != inputs[k]) {
786 // Not a match
787 fixup = NULL;
788 break;
789 }
790 }
791 }
792
793 // If an existing PhiNode was not found, make a new one.
794 if (fixup == NULL) {
795 Node *new_phi = PhiNode::make(use_blk->head(), def);
796 use_blk->_nodes.insert(1, new_phi);
797 bbs.map(new_phi->_idx, use_blk);
798 for (uint k = 1; k < use_blk->num_preds(); k++) {
799 new_phi->set_req(k, inputs[k]);
800 }
801 fixup = new_phi;
802 }
803
804 } else {
805 // Found the use just below the Catch. Make it use the clone.
806 fixup = use_blk->_nodes[n_clone_idx];
807 }
808
809 return fixup;
810 }
811
812 //--------------------------catch_cleanup_intra_block--------------------------
813 // Fix all input edges in use that reference "def". The use is in the same
814 // block as the def and both have been cloned in each successor block.
815 static void catch_cleanup_intra_block(Node *use, Node *def, Block *blk, int beg, int n_clone_idx) {
816
817 // Both the use and def have been cloned. For each successor block,
818 // get the clone of the use, and make its input the clone of the def
819 // found in that block.
820
821 uint use_idx = blk->find_node(use);
822 uint offset_idx = use_idx - beg;
823 for( uint k = 0; k < blk->_num_succs; k++ ) {
824 // Get clone in each successor block
825 Block *sb = blk->_succs[k];
826 Node *clone = sb->_nodes[offset_idx+1];
827 assert( clone->Opcode() == use->Opcode(), "" );
828
829 // Make use-clone reference the def-clone
830 catch_cleanup_fix_all_inputs(clone, def, sb->_nodes[n_clone_idx]);
831 }
832 }
833
834 //------------------------------catch_cleanup_inter_block---------------------
835 // Fix all input edges in use that reference "def". The use is in a different
836 // block than the def.
837 static void catch_cleanup_inter_block(Node *use, Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) {
838 if( !use_blk ) return; // Can happen if the use is a precedence edge
839
840 Node *new_def = catch_cleanup_find_cloned_def(use_blk, def, def_blk, bbs, n_clone_idx);
841 catch_cleanup_fix_all_inputs(use, def, new_def);
842 }
843
844 //------------------------------call_catch_cleanup-----------------------------
845 // If we inserted any instructions between a Call and his CatchNode,
846 // clone the instructions on all paths below the Catch.
847 void Block::call_catch_cleanup(Block_Array &bbs) {
848
849 // End of region to clone
850 uint end = end_idx();
851 if( !_nodes[end]->is_Catch() ) return;
852 // Start of region to clone
853 uint beg = end;
854 while( _nodes[beg-1]->Opcode() != Op_MachProj ||
855 !_nodes[beg-1]->in(0)->is_Call() ) {
856 beg--;
857 assert(beg > 0,"Catch cleanup walking beyond block boundary");
858 }
859 // Range of inserted instructions is [beg, end)
860 if( beg == end ) return;
861
862 // Clone along all Catch output paths. Clone area between the 'beg' and
863 // 'end' indices.
864 for( uint i = 0; i < _num_succs; i++ ) {
865 Block *sb = _succs[i];
866 // Clone the entire area; ignoring the edge fixup for now.
867 for( uint j = end; j > beg; j-- ) {
868 Node *clone = _nodes[j-1]->clone();
869 sb->_nodes.insert( 1, clone );
870 bbs.map(clone->_idx,sb);
871 }
872 }
873
874
875 // Fixup edges. Check the def-use info per cloned Node
876 for(uint i2 = beg; i2 < end; i2++ ) {
877 uint n_clone_idx = i2-beg+1; // Index of clone of n in each successor block
878 Node *n = _nodes[i2]; // Node that got cloned
879 // Need DU safe iterator because of edge manipulation in calls.
880 Unique_Node_List *out = new Unique_Node_List(Thread::current()->resource_area());
881 for (DUIterator_Fast j1max, j1 = n->fast_outs(j1max); j1 < j1max; j1++) {
882 out->push(n->fast_out(j1));
883 }
884 uint max = out->size();
885 for (uint j = 0; j < max; j++) {// For all users
886 Node *use = out->pop();
887 Block *buse = bbs[use->_idx];
888 if( use->is_Phi() ) {
889 for( uint k = 1; k < use->req(); k++ )
890 if( use->in(k) == n ) {
891 Node *fixup = catch_cleanup_find_cloned_def(bbs[buse->pred(k)->_idx], n, this, bbs, n_clone_idx);
892 use->set_req(k, fixup);
893 }
894 } else {
895 if (this == buse) {
896 catch_cleanup_intra_block(use, n, this, beg, n_clone_idx);
897 } else {
898 catch_cleanup_inter_block(use, buse, n, this, bbs, n_clone_idx);
899 }
900 }
901 } // End for all users
902
903 } // End of for all Nodes in cloned area
904
905 // Remove the now-dead cloned ops
906 for(uint i3 = beg; i3 < end; i3++ ) {
907 _nodes[beg]->disconnect_inputs(NULL);
908 _nodes.remove(beg);
909 }
910
911 // If the successor blocks have a CreateEx node, move it back to the top
912 for(uint i4 = 0; i4 < _num_succs; i4++ ) {
913 Block *sb = _succs[i4];
914 uint new_cnt = end - beg;
915 // Remove any newly created, but dead, nodes.
916 for( uint j = new_cnt; j > 0; j-- ) {
917 Node *n = sb->_nodes[j];
918 if (n->outcnt() == 0 &&
919 (!n->is_Proj() || n->as_Proj()->in(0)->outcnt() == 1) ){
920 n->disconnect_inputs(NULL);
921 sb->_nodes.remove(j);
922 new_cnt--;
923 }
924 }
925 // If any newly created nodes remain, move the CreateEx node to the top
926 if (new_cnt > 0) {
927 Node *cex = sb->_nodes[1+new_cnt];
928 if( cex->is_Mach() && cex->as_Mach()->ideal_Opcode() == Op_CreateEx ) {
929 sb->_nodes.remove(1+new_cnt);
930 sb->_nodes.insert(1,cex);
931 }
932 }
933 }
934 }