Fri, 11 Jul 2008 12:19:29 -0700
Merge
1 /*
2 * Copyright 1998-2008 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 */
25 // Optimization - Graph Style
27 #include "incls/_precompiled.incl"
28 #include "incls/_lcm.cpp.incl"
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;
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;
47 uint bidx = 0; // Capture index of value into memop
48 bool was_store; // Memory op is a store op
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 }
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 }
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_LoadN:
114 case Op_LoadS:
115 case Op_LoadKlass:
116 case Op_LoadNKlass:
117 case Op_LoadRange:
118 case Op_LoadD_unaligned:
119 case Op_LoadL_unaligned:
120 break;
121 case Op_StoreB:
122 case Op_StoreC:
123 case Op_StoreCM:
124 case Op_StoreD:
125 case Op_StoreF:
126 case Op_StoreI:
127 case Op_StoreL:
128 case Op_StoreP:
129 case Op_StoreN:
130 was_store = true; // Memory op is a store op
131 // Stores will have their address in slot 2 (memory in slot 1).
132 // If the value being nul-checked is in another slot, it means we
133 // are storing the checked value, which does NOT check the value!
134 if( mach->in(2) != val ) continue;
135 break; // Found a memory op?
136 case Op_StrComp:
137 case Op_AryEq:
138 // Not a legit memory op for implicit null check regardless of
139 // embedded loads
140 continue;
141 default: // Also check for embedded loads
142 if( !mach->needs_anti_dependence_check() )
143 continue; // Not an memory op; skip it
144 break;
145 }
146 // check if the offset is not too high for implicit exception
147 {
148 intptr_t offset = 0;
149 const TypePtr *adr_type = NULL; // Do not need this return value here
150 const Node* base = mach->get_base_and_disp(offset, adr_type);
151 if (base == NULL || base == NodeSentinel) {
152 // cannot reason about it; is probably not implicit null exception
153 } else {
154 const TypePtr* tptr = base->bottom_type()->is_ptr();
155 // Give up if offset is not a compile-time constant
156 if( offset == Type::OffsetBot || tptr->_offset == Type::OffsetBot )
157 continue;
158 offset += tptr->_offset; // correct if base is offseted
159 if( MacroAssembler::needs_explicit_null_check(offset) )
160 continue; // Give up is reference is beyond 4K page size
161 }
162 }
164 // Check ctrl input to see if the null-check dominates the memory op
165 Block *cb = cfg->_bbs[mach->_idx];
166 cb = cb->_idom; // Always hoist at least 1 block
167 if( !was_store ) { // Stores can be hoisted only one block
168 while( cb->_dom_depth > (_dom_depth + 1))
169 cb = cb->_idom; // Hoist loads as far as we want
170 // The non-null-block should dominate the memory op, too. Live
171 // range spilling will insert a spill in the non-null-block if it is
172 // needs to spill the memory op for an implicit null check.
173 if (cb->_dom_depth == (_dom_depth + 1)) {
174 if (cb != not_null_block) continue;
175 cb = cb->_idom;
176 }
177 }
178 if( cb != this ) continue;
180 // Found a memory user; see if it can be hoisted to check-block
181 uint vidx = 0; // Capture index of value into memop
182 uint j;
183 for( j = mach->req()-1; j > 0; j-- ) {
184 if( mach->in(j) == val ) vidx = j;
185 // Block of memory-op input
186 Block *inb = cfg->_bbs[mach->in(j)->_idx];
187 Block *b = this; // Start from nul check
188 while( b != inb && b->_dom_depth > inb->_dom_depth )
189 b = b->_idom; // search upwards for input
190 // See if input dominates null check
191 if( b != inb )
192 break;
193 }
194 if( j > 0 )
195 continue;
196 Block *mb = cfg->_bbs[mach->_idx];
197 // Hoisting stores requires more checks for the anti-dependence case.
198 // Give up hoisting if we have to move the store past any load.
199 if( was_store ) {
200 Block *b = mb; // Start searching here for a local load
201 // mach use (faulting) trying to hoist
202 // n might be blocker to hoisting
203 while( b != this ) {
204 uint k;
205 for( k = 1; k < b->_nodes.size(); k++ ) {
206 Node *n = b->_nodes[k];
207 if( n->needs_anti_dependence_check() &&
208 n->in(LoadNode::Memory) == mach->in(StoreNode::Memory) )
209 break; // Found anti-dependent load
210 }
211 if( k < b->_nodes.size() )
212 break; // Found anti-dependent load
213 // Make sure control does not do a merge (would have to check allpaths)
214 if( b->num_preds() != 2 ) break;
215 b = cfg->_bbs[b->pred(1)->_idx]; // Move up to predecessor block
216 }
217 if( b != this ) continue;
218 }
220 // Make sure this memory op is not already being used for a NullCheck
221 Node *e = mb->end();
222 if( e->is_MachNullCheck() && e->in(1) == mach )
223 continue; // Already being used as a NULL check
225 // Found a candidate! Pick one with least dom depth - the highest
226 // in the dom tree should be closest to the null check.
227 if( !best ||
228 cfg->_bbs[mach->_idx]->_dom_depth < cfg->_bbs[best->_idx]->_dom_depth ) {
229 best = mach;
230 bidx = vidx;
232 }
233 }
234 // No candidate!
235 if( !best ) return;
237 // ---- Found an implicit null check
238 extern int implicit_null_checks;
239 implicit_null_checks++;
241 // Hoist the memory candidate up to the end of the test block.
242 Block *old_block = cfg->_bbs[best->_idx];
243 old_block->find_remove(best);
244 add_inst(best);
245 cfg->_bbs.map(best->_idx,this);
247 // Move the control dependence
248 if (best->in(0) && best->in(0) == old_block->_nodes[0])
249 best->set_req(0, _nodes[0]);
251 // Check for flag-killing projections that also need to be hoisted
252 // Should be DU safe because no edge updates.
253 for (DUIterator_Fast jmax, j = best->fast_outs(jmax); j < jmax; j++) {
254 Node* n = best->fast_out(j);
255 if( n->Opcode() == Op_MachProj ) {
256 cfg->_bbs[n->_idx]->find_remove(n);
257 add_inst(n);
258 cfg->_bbs.map(n->_idx,this);
259 }
260 }
262 Compile *C = cfg->C;
263 // proj==Op_True --> ne test; proj==Op_False --> eq test.
264 // One of two graph shapes got matched:
265 // (IfTrue (If (Bool NE (CmpP ptr NULL))))
266 // (IfFalse (If (Bool EQ (CmpP ptr NULL))))
267 // NULL checks are always branch-if-eq. If we see a IfTrue projection
268 // then we are replacing a 'ne' test with a 'eq' NULL check test.
269 // We need to flip the projections to keep the same semantics.
270 if( proj->Opcode() == Op_IfTrue ) {
271 // Swap order of projections in basic block to swap branch targets
272 Node *tmp1 = _nodes[end_idx()+1];
273 Node *tmp2 = _nodes[end_idx()+2];
274 _nodes.map(end_idx()+1, tmp2);
275 _nodes.map(end_idx()+2, tmp1);
276 Node *tmp = new (C, 1) Node(C->top()); // Use not NULL input
277 tmp1->replace_by(tmp);
278 tmp2->replace_by(tmp1);
279 tmp->replace_by(tmp2);
280 tmp->destruct();
281 }
283 // Remove the existing null check; use a new implicit null check instead.
284 // Since schedule-local needs precise def-use info, we need to correct
285 // it as well.
286 Node *old_tst = proj->in(0);
287 MachNode *nul_chk = new (C) MachNullCheckNode(old_tst->in(0),best,bidx);
288 _nodes.map(end_idx(),nul_chk);
289 cfg->_bbs.map(nul_chk->_idx,this);
290 // Redirect users of old_test to nul_chk
291 for (DUIterator_Last i2min, i2 = old_tst->last_outs(i2min); i2 >= i2min; --i2)
292 old_tst->last_out(i2)->set_req(0, nul_chk);
293 // Clean-up any dead code
294 for (uint i3 = 0; i3 < old_tst->req(); i3++)
295 old_tst->set_req(i3, NULL);
297 cfg->latency_from_uses(nul_chk);
298 cfg->latency_from_uses(best);
299 }
302 //------------------------------select-----------------------------------------
303 // Select a nice fellow from the worklist to schedule next. If there is only
304 // one choice, then use it. Projections take top priority for correctness
305 // reasons - if I see a projection, then it is next. There are a number of
306 // other special cases, for instructions that consume condition codes, et al.
307 // These are chosen immediately. Some instructions are required to immediately
308 // precede the last instruction in the block, and these are taken last. Of the
309 // remaining cases (most), choose the instruction with the greatest latency
310 // (that is, the most number of pseudo-cycles required to the end of the
311 // routine). If there is a tie, choose the instruction with the most inputs.
312 Node *Block::select(PhaseCFG *cfg, Node_List &worklist, int *ready_cnt, VectorSet &next_call, uint sched_slot) {
314 // If only a single entry on the stack, use it
315 uint cnt = worklist.size();
316 if (cnt == 1) {
317 Node *n = worklist[0];
318 worklist.map(0,worklist.pop());
319 return n;
320 }
322 uint choice = 0; // Bigger is most important
323 uint latency = 0; // Bigger is scheduled first
324 uint score = 0; // Bigger is better
325 uint idx; // Index in worklist
327 for( uint i=0; i<cnt; i++ ) { // Inspect entire worklist
328 // Order in worklist is used to break ties.
329 // See caller for how this is used to delay scheduling
330 // of induction variable increments to after the other
331 // uses of the phi are scheduled.
332 Node *n = worklist[i]; // Get Node on worklist
334 int iop = n->is_Mach() ? n->as_Mach()->ideal_Opcode() : 0;
335 if( n->is_Proj() || // Projections always win
336 n->Opcode()== Op_Con || // So does constant 'Top'
337 iop == Op_CreateEx || // Create-exception must start block
338 iop == Op_CheckCastPP
339 ) {
340 worklist.map(i,worklist.pop());
341 return n;
342 }
344 // Final call in a block must be adjacent to 'catch'
345 Node *e = end();
346 if( e->is_Catch() && e->in(0)->in(0) == n )
347 continue;
349 // Memory op for an implicit null check has to be at the end of the block
350 if( e->is_MachNullCheck() && e->in(1) == n )
351 continue;
353 uint n_choice = 2;
355 // See if this instruction is consumed by a branch. If so, then (as the
356 // branch is the last instruction in the basic block) force it to the
357 // end of the basic block
358 if ( must_clone[iop] ) {
359 // See if any use is a branch
360 bool found_machif = false;
362 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
363 Node* use = n->fast_out(j);
365 // The use is a conditional branch, make them adjacent
366 if (use->is_MachIf() && cfg->_bbs[use->_idx]==this ) {
367 found_machif = true;
368 break;
369 }
371 // More than this instruction pending for successor to be ready,
372 // don't choose this if other opportunities are ready
373 if (ready_cnt[use->_idx] > 1)
374 n_choice = 1;
375 }
377 // loop terminated, prefer not to use this instruction
378 if (found_machif)
379 continue;
380 }
382 // See if this has a predecessor that is "must_clone", i.e. sets the
383 // condition code. If so, choose this first
384 for (uint j = 0; j < n->req() ; j++) {
385 Node *inn = n->in(j);
386 if (inn) {
387 if (inn->is_Mach() && must_clone[inn->as_Mach()->ideal_Opcode()] ) {
388 n_choice = 3;
389 break;
390 }
391 }
392 }
394 // MachTemps should be scheduled last so they are near their uses
395 if (n->is_MachTemp()) {
396 n_choice = 1;
397 }
399 uint n_latency = cfg->_node_latency.at_grow(n->_idx);
400 uint n_score = n->req(); // Many inputs get high score to break ties
402 // Keep best latency found
403 if( choice < n_choice ||
404 ( choice == n_choice &&
405 ( latency < n_latency ||
406 ( latency == n_latency &&
407 ( score < n_score ))))) {
408 choice = n_choice;
409 latency = n_latency;
410 score = n_score;
411 idx = i; // Also keep index in worklist
412 }
413 } // End of for all ready nodes in worklist
415 Node *n = worklist[idx]; // Get the winner
417 worklist.map(idx,worklist.pop()); // Compress worklist
418 return n;
419 }
422 //------------------------------set_next_call----------------------------------
423 void Block::set_next_call( Node *n, VectorSet &next_call, Block_Array &bbs ) {
424 if( next_call.test_set(n->_idx) ) return;
425 for( uint i=0; i<n->len(); i++ ) {
426 Node *m = n->in(i);
427 if( !m ) continue; // must see all nodes in block that precede call
428 if( bbs[m->_idx] == this )
429 set_next_call( m, next_call, bbs );
430 }
431 }
433 //------------------------------needed_for_next_call---------------------------
434 // Set the flag 'next_call' for each Node that is needed for the next call to
435 // be scheduled. This flag lets me bias scheduling so Nodes needed for the
436 // next subroutine call get priority - basically it moves things NOT needed
437 // for the next call till after the call. This prevents me from trying to
438 // carry lots of stuff live across a call.
439 void Block::needed_for_next_call(Node *this_call, VectorSet &next_call, Block_Array &bbs) {
440 // Find the next control-defining Node in this block
441 Node* call = NULL;
442 for (DUIterator_Fast imax, i = this_call->fast_outs(imax); i < imax; i++) {
443 Node* m = this_call->fast_out(i);
444 if( bbs[m->_idx] == this && // Local-block user
445 m != this_call && // Not self-start node
446 m->is_Call() )
447 call = m;
448 break;
449 }
450 if (call == NULL) return; // No next call (e.g., block end is near)
451 // Set next-call for all inputs to this call
452 set_next_call(call, next_call, bbs);
453 }
455 //------------------------------sched_call-------------------------------------
456 uint Block::sched_call( Matcher &matcher, Block_Array &bbs, uint node_cnt, Node_List &worklist, int *ready_cnt, MachCallNode *mcall, VectorSet &next_call ) {
457 RegMask regs;
459 // Schedule all the users of the call right now. All the users are
460 // projection Nodes, so they must be scheduled next to the call.
461 // Collect all the defined registers.
462 for (DUIterator_Fast imax, i = mcall->fast_outs(imax); i < imax; i++) {
463 Node* n = mcall->fast_out(i);
464 assert( n->Opcode()==Op_MachProj, "" );
465 --ready_cnt[n->_idx];
466 assert( !ready_cnt[n->_idx], "" );
467 // Schedule next to call
468 _nodes.map(node_cnt++, n);
469 // Collect defined registers
470 regs.OR(n->out_RegMask());
471 // Check for scheduling the next control-definer
472 if( n->bottom_type() == Type::CONTROL )
473 // Warm up next pile of heuristic bits
474 needed_for_next_call(n, next_call, bbs);
476 // Children of projections are now all ready
477 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
478 Node* m = n->fast_out(j); // Get user
479 if( bbs[m->_idx] != this ) continue;
480 if( m->is_Phi() ) continue;
481 if( !--ready_cnt[m->_idx] )
482 worklist.push(m);
483 }
485 }
487 // Act as if the call defines the Frame Pointer.
488 // Certainly the FP is alive and well after the call.
489 regs.Insert(matcher.c_frame_pointer());
491 // Set all registers killed and not already defined by the call.
492 uint r_cnt = mcall->tf()->range()->cnt();
493 int op = mcall->ideal_Opcode();
494 MachProjNode *proj = new (matcher.C, 1) MachProjNode( mcall, r_cnt+1, RegMask::Empty, MachProjNode::fat_proj );
495 bbs.map(proj->_idx,this);
496 _nodes.insert(node_cnt++, proj);
498 // Select the right register save policy.
499 const char * save_policy;
500 switch (op) {
501 case Op_CallRuntime:
502 case Op_CallLeaf:
503 case Op_CallLeafNoFP:
504 // Calling C code so use C calling convention
505 save_policy = matcher._c_reg_save_policy;
506 break;
508 case Op_CallStaticJava:
509 case Op_CallDynamicJava:
510 // Calling Java code so use Java calling convention
511 save_policy = matcher._register_save_policy;
512 break;
514 default:
515 ShouldNotReachHere();
516 }
518 // When using CallRuntime mark SOE registers as killed by the call
519 // so values that could show up in the RegisterMap aren't live in a
520 // callee saved register since the register wouldn't know where to
521 // find them. CallLeaf and CallLeafNoFP are ok because they can't
522 // have debug info on them. Strictly speaking this only needs to be
523 // done for oops since idealreg2debugmask takes care of debug info
524 // references but there no way to handle oops differently than other
525 // pointers as far as the kill mask goes.
526 bool exclude_soe = op == Op_CallRuntime;
528 // Fill in the kill mask for the call
529 for( OptoReg::Name r = OptoReg::Name(0); r < _last_Mach_Reg; r=OptoReg::add(r,1) ) {
530 if( !regs.Member(r) ) { // Not already defined by the call
531 // Save-on-call register?
532 if ((save_policy[r] == 'C') ||
533 (save_policy[r] == 'A') ||
534 ((save_policy[r] == 'E') && exclude_soe)) {
535 proj->_rout.Insert(r);
536 }
537 }
538 }
540 return node_cnt;
541 }
544 //------------------------------schedule_local---------------------------------
545 // Topological sort within a block. Someday become a real scheduler.
546 bool Block::schedule_local(PhaseCFG *cfg, Matcher &matcher, int *ready_cnt, VectorSet &next_call) {
547 // Already "sorted" are the block start Node (as the first entry), and
548 // the block-ending Node and any trailing control projections. We leave
549 // these alone. PhiNodes and ParmNodes are made to follow the block start
550 // Node. Everything else gets topo-sorted.
552 #ifndef PRODUCT
553 if (cfg->trace_opto_pipelining()) {
554 tty->print_cr("# --- schedule_local B%d, before: ---", _pre_order);
555 for (uint i = 0;i < _nodes.size();i++) {
556 tty->print("# ");
557 _nodes[i]->fast_dump();
558 }
559 tty->print_cr("#");
560 }
561 #endif
563 // RootNode is already sorted
564 if( _nodes.size() == 1 ) return true;
566 // Move PhiNodes and ParmNodes from 1 to cnt up to the start
567 uint node_cnt = end_idx();
568 uint phi_cnt = 1;
569 uint i;
570 for( i = 1; i<node_cnt; i++ ) { // Scan for Phi
571 Node *n = _nodes[i];
572 if( n->is_Phi() || // Found a PhiNode or ParmNode
573 (n->is_Proj() && n->in(0) == head()) ) {
574 // Move guy at 'phi_cnt' to the end; makes a hole at phi_cnt
575 _nodes.map(i,_nodes[phi_cnt]);
576 _nodes.map(phi_cnt++,n); // swap Phi/Parm up front
577 } else { // All others
578 // Count block-local inputs to 'n'
579 uint cnt = n->len(); // Input count
580 uint local = 0;
581 for( uint j=0; j<cnt; j++ ) {
582 Node *m = n->in(j);
583 if( m && cfg->_bbs[m->_idx] == this && !m->is_top() )
584 local++; // One more block-local input
585 }
586 ready_cnt[n->_idx] = local; // Count em up
588 // A few node types require changing a required edge to a precedence edge
589 // before allocation.
590 if( UseConcMarkSweepGC ) {
591 if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_StoreCM ) {
592 // Note: Required edges with an index greater than oper_input_base
593 // are not supported by the allocator.
594 // Note2: Can only depend on unmatched edge being last,
595 // can not depend on its absolute position.
596 Node *oop_store = n->in(n->req() - 1);
597 n->del_req(n->req() - 1);
598 n->add_prec(oop_store);
599 assert(cfg->_bbs[oop_store->_idx]->_dom_depth <= this->_dom_depth, "oop_store must dominate card-mark");
600 }
601 }
602 if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire ) {
603 Node *x = n->in(TypeFunc::Parms);
604 n->del_req(TypeFunc::Parms);
605 n->add_prec(x);
606 }
607 }
608 }
609 for(uint i2=i; i2<_nodes.size(); i2++ ) // Trailing guys get zapped count
610 ready_cnt[_nodes[i2]->_idx] = 0;
612 // All the prescheduled guys do not hold back internal nodes
613 uint i3;
614 for(i3 = 0; i3<phi_cnt; i3++ ) { // For all pre-scheduled
615 Node *n = _nodes[i3]; // Get pre-scheduled
616 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
617 Node* m = n->fast_out(j);
618 if( cfg->_bbs[m->_idx] ==this ) // Local-block user
619 ready_cnt[m->_idx]--; // Fix ready count
620 }
621 }
623 Node_List delay;
624 // Make a worklist
625 Node_List worklist;
626 for(uint i4=i3; i4<node_cnt; i4++ ) { // Put ready guys on worklist
627 Node *m = _nodes[i4];
628 if( !ready_cnt[m->_idx] ) { // Zero ready count?
629 if (m->is_iteratively_computed()) {
630 // Push induction variable increments last to allow other uses
631 // of the phi to be scheduled first. The select() method breaks
632 // ties in scheduling by worklist order.
633 delay.push(m);
634 } else if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_CreateEx) {
635 // Force the CreateEx to the top of the list so it's processed
636 // first and ends up at the start of the block.
637 worklist.insert(0, m);
638 } else {
639 worklist.push(m); // Then on to worklist!
640 }
641 }
642 }
643 while (delay.size()) {
644 Node* d = delay.pop();
645 worklist.push(d);
646 }
648 // Warm up the 'next_call' heuristic bits
649 needed_for_next_call(_nodes[0], next_call, cfg->_bbs);
651 #ifndef PRODUCT
652 if (cfg->trace_opto_pipelining()) {
653 for (uint j=0; j<_nodes.size(); j++) {
654 Node *n = _nodes[j];
655 int idx = n->_idx;
656 tty->print("# ready cnt:%3d ", ready_cnt[idx]);
657 tty->print("latency:%3d ", cfg->_node_latency.at_grow(idx));
658 tty->print("%4d: %s\n", idx, n->Name());
659 }
660 }
661 #endif
663 // Pull from worklist and schedule
664 while( worklist.size() ) { // Worklist is not ready
666 #ifndef PRODUCT
667 if (cfg->trace_opto_pipelining()) {
668 tty->print("# ready list:");
669 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist
670 Node *n = worklist[i]; // Get Node on worklist
671 tty->print(" %d", n->_idx);
672 }
673 tty->cr();
674 }
675 #endif
677 // Select and pop a ready guy from worklist
678 Node* n = select(cfg, worklist, ready_cnt, next_call, phi_cnt);
679 _nodes.map(phi_cnt++,n); // Schedule him next
681 #ifndef PRODUCT
682 if (cfg->trace_opto_pipelining()) {
683 tty->print("# select %d: %s", n->_idx, n->Name());
684 tty->print(", latency:%d", cfg->_node_latency.at_grow(n->_idx));
685 n->dump();
686 if (Verbose) {
687 tty->print("# ready list:");
688 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist
689 Node *n = worklist[i]; // Get Node on worklist
690 tty->print(" %d", n->_idx);
691 }
692 tty->cr();
693 }
694 }
696 #endif
697 if( n->is_MachCall() ) {
698 MachCallNode *mcall = n->as_MachCall();
699 phi_cnt = sched_call(matcher, cfg->_bbs, phi_cnt, worklist, ready_cnt, mcall, next_call);
700 continue;
701 }
702 // Children are now all ready
703 for (DUIterator_Fast i5max, i5 = n->fast_outs(i5max); i5 < i5max; i5++) {
704 Node* m = n->fast_out(i5); // Get user
705 if( cfg->_bbs[m->_idx] != this ) continue;
706 if( m->is_Phi() ) continue;
707 if( !--ready_cnt[m->_idx] )
708 worklist.push(m);
709 }
710 }
712 if( phi_cnt != end_idx() ) {
713 // did not schedule all. Retry, Bailout, or Die
714 Compile* C = matcher.C;
715 if (C->subsume_loads() == true && !C->failing()) {
716 // Retry with subsume_loads == false
717 // If this is the first failure, the sentinel string will "stick"
718 // to the Compile object, and the C2Compiler will see it and retry.
719 C->record_failure(C2Compiler::retry_no_subsuming_loads());
720 }
721 // assert( phi_cnt == end_idx(), "did not schedule all" );
722 return false;
723 }
725 #ifndef PRODUCT
726 if (cfg->trace_opto_pipelining()) {
727 tty->print_cr("#");
728 tty->print_cr("# after schedule_local");
729 for (uint i = 0;i < _nodes.size();i++) {
730 tty->print("# ");
731 _nodes[i]->fast_dump();
732 }
733 tty->cr();
734 }
735 #endif
738 return true;
739 }
741 //--------------------------catch_cleanup_fix_all_inputs-----------------------
742 static void catch_cleanup_fix_all_inputs(Node *use, Node *old_def, Node *new_def) {
743 for (uint l = 0; l < use->len(); l++) {
744 if (use->in(l) == old_def) {
745 if (l < use->req()) {
746 use->set_req(l, new_def);
747 } else {
748 use->rm_prec(l);
749 use->add_prec(new_def);
750 l--;
751 }
752 }
753 }
754 }
756 //------------------------------catch_cleanup_find_cloned_def------------------
757 static Node *catch_cleanup_find_cloned_def(Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) {
758 assert( use_blk != def_blk, "Inter-block cleanup only");
760 // The use is some block below the Catch. Find and return the clone of the def
761 // that dominates the use. If there is no clone in a dominating block, then
762 // create a phi for the def in a dominating block.
764 // Find which successor block dominates this use. The successor
765 // blocks must all be single-entry (from the Catch only; I will have
766 // split blocks to make this so), hence they all dominate.
767 while( use_blk->_dom_depth > def_blk->_dom_depth+1 )
768 use_blk = use_blk->_idom;
770 // Find the successor
771 Node *fixup = NULL;
773 uint j;
774 for( j = 0; j < def_blk->_num_succs; j++ )
775 if( use_blk == def_blk->_succs[j] )
776 break;
778 if( j == def_blk->_num_succs ) {
779 // Block at same level in dom-tree is not a successor. It needs a
780 // PhiNode, the PhiNode uses from the def and IT's uses need fixup.
781 Node_Array inputs = new Node_List(Thread::current()->resource_area());
782 for(uint k = 1; k < use_blk->num_preds(); k++) {
783 inputs.map(k, catch_cleanup_find_cloned_def(bbs[use_blk->pred(k)->_idx], def, def_blk, bbs, n_clone_idx));
784 }
786 // Check to see if the use_blk already has an identical phi inserted.
787 // If it exists, it will be at the first position since all uses of a
788 // def are processed together.
789 Node *phi = use_blk->_nodes[1];
790 if( phi->is_Phi() ) {
791 fixup = phi;
792 for (uint k = 1; k < use_blk->num_preds(); k++) {
793 if (phi->in(k) != inputs[k]) {
794 // Not a match
795 fixup = NULL;
796 break;
797 }
798 }
799 }
801 // If an existing PhiNode was not found, make a new one.
802 if (fixup == NULL) {
803 Node *new_phi = PhiNode::make(use_blk->head(), def);
804 use_blk->_nodes.insert(1, new_phi);
805 bbs.map(new_phi->_idx, use_blk);
806 for (uint k = 1; k < use_blk->num_preds(); k++) {
807 new_phi->set_req(k, inputs[k]);
808 }
809 fixup = new_phi;
810 }
812 } else {
813 // Found the use just below the Catch. Make it use the clone.
814 fixup = use_blk->_nodes[n_clone_idx];
815 }
817 return fixup;
818 }
820 //--------------------------catch_cleanup_intra_block--------------------------
821 // Fix all input edges in use that reference "def". The use is in the same
822 // block as the def and both have been cloned in each successor block.
823 static void catch_cleanup_intra_block(Node *use, Node *def, Block *blk, int beg, int n_clone_idx) {
825 // Both the use and def have been cloned. For each successor block,
826 // get the clone of the use, and make its input the clone of the def
827 // found in that block.
829 uint use_idx = blk->find_node(use);
830 uint offset_idx = use_idx - beg;
831 for( uint k = 0; k < blk->_num_succs; k++ ) {
832 // Get clone in each successor block
833 Block *sb = blk->_succs[k];
834 Node *clone = sb->_nodes[offset_idx+1];
835 assert( clone->Opcode() == use->Opcode(), "" );
837 // Make use-clone reference the def-clone
838 catch_cleanup_fix_all_inputs(clone, def, sb->_nodes[n_clone_idx]);
839 }
840 }
842 //------------------------------catch_cleanup_inter_block---------------------
843 // Fix all input edges in use that reference "def". The use is in a different
844 // block than the def.
845 static void catch_cleanup_inter_block(Node *use, Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) {
846 if( !use_blk ) return; // Can happen if the use is a precedence edge
848 Node *new_def = catch_cleanup_find_cloned_def(use_blk, def, def_blk, bbs, n_clone_idx);
849 catch_cleanup_fix_all_inputs(use, def, new_def);
850 }
852 //------------------------------call_catch_cleanup-----------------------------
853 // If we inserted any instructions between a Call and his CatchNode,
854 // clone the instructions on all paths below the Catch.
855 void Block::call_catch_cleanup(Block_Array &bbs) {
857 // End of region to clone
858 uint end = end_idx();
859 if( !_nodes[end]->is_Catch() ) return;
860 // Start of region to clone
861 uint beg = end;
862 while( _nodes[beg-1]->Opcode() != Op_MachProj ||
863 !_nodes[beg-1]->in(0)->is_Call() ) {
864 beg--;
865 assert(beg > 0,"Catch cleanup walking beyond block boundary");
866 }
867 // Range of inserted instructions is [beg, end)
868 if( beg == end ) return;
870 // Clone along all Catch output paths. Clone area between the 'beg' and
871 // 'end' indices.
872 for( uint i = 0; i < _num_succs; i++ ) {
873 Block *sb = _succs[i];
874 // Clone the entire area; ignoring the edge fixup for now.
875 for( uint j = end; j > beg; j-- ) {
876 Node *clone = _nodes[j-1]->clone();
877 sb->_nodes.insert( 1, clone );
878 bbs.map(clone->_idx,sb);
879 }
880 }
883 // Fixup edges. Check the def-use info per cloned Node
884 for(uint i2 = beg; i2 < end; i2++ ) {
885 uint n_clone_idx = i2-beg+1; // Index of clone of n in each successor block
886 Node *n = _nodes[i2]; // Node that got cloned
887 // Need DU safe iterator because of edge manipulation in calls.
888 Unique_Node_List *out = new Unique_Node_List(Thread::current()->resource_area());
889 for (DUIterator_Fast j1max, j1 = n->fast_outs(j1max); j1 < j1max; j1++) {
890 out->push(n->fast_out(j1));
891 }
892 uint max = out->size();
893 for (uint j = 0; j < max; j++) {// For all users
894 Node *use = out->pop();
895 Block *buse = bbs[use->_idx];
896 if( use->is_Phi() ) {
897 for( uint k = 1; k < use->req(); k++ )
898 if( use->in(k) == n ) {
899 Node *fixup = catch_cleanup_find_cloned_def(bbs[buse->pred(k)->_idx], n, this, bbs, n_clone_idx);
900 use->set_req(k, fixup);
901 }
902 } else {
903 if (this == buse) {
904 catch_cleanup_intra_block(use, n, this, beg, n_clone_idx);
905 } else {
906 catch_cleanup_inter_block(use, buse, n, this, bbs, n_clone_idx);
907 }
908 }
909 } // End for all users
911 } // End of for all Nodes in cloned area
913 // Remove the now-dead cloned ops
914 for(uint i3 = beg; i3 < end; i3++ ) {
915 _nodes[beg]->disconnect_inputs(NULL);
916 _nodes.remove(beg);
917 }
919 // If the successor blocks have a CreateEx node, move it back to the top
920 for(uint i4 = 0; i4 < _num_succs; i4++ ) {
921 Block *sb = _succs[i4];
922 uint new_cnt = end - beg;
923 // Remove any newly created, but dead, nodes.
924 for( uint j = new_cnt; j > 0; j-- ) {
925 Node *n = sb->_nodes[j];
926 if (n->outcnt() == 0 &&
927 (!n->is_Proj() || n->as_Proj()->in(0)->outcnt() == 1) ){
928 n->disconnect_inputs(NULL);
929 sb->_nodes.remove(j);
930 new_cnt--;
931 }
932 }
933 // If any newly created nodes remain, move the CreateEx node to the top
934 if (new_cnt > 0) {
935 Node *cex = sb->_nodes[1+new_cnt];
936 if( cex->is_Mach() && cex->as_Mach()->ideal_Opcode() == Op_CreateEx ) {
937 sb->_nodes.remove(1+new_cnt);
938 sb->_nodes.insert(1,cex);
939 }
940 }
941 }
942 }