Wed, 22 Jan 2014 17:42:23 -0800
Merge
1 /*
2 * Copyright (c) 1998, 2013, 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 */
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_32
49 # include "adfiles/ad_ppc_32.hpp"
50 #endif
51 #ifdef TARGET_ARCH_MODEL_ppc_64
52 # include "adfiles/ad_ppc_64.hpp"
53 #endif
55 // Optimization - Graph Style
57 // Check whether val is not-null-decoded compressed oop,
58 // i.e. will grab into the base of the heap if it represents NULL.
59 static bool accesses_heap_base_zone(Node *val) {
60 if (Universe::narrow_oop_base() > 0) { // Implies UseCompressedOops.
61 if (val && val->is_Mach()) {
62 if (val->as_Mach()->ideal_Opcode() == Op_DecodeN) {
63 // This assumes all Decodes with TypePtr::NotNull are matched to nodes that
64 // decode NULL to point to the heap base (Decode_NN).
65 if (val->bottom_type()->is_oopptr()->ptr() == TypePtr::NotNull) {
66 return true;
67 }
68 }
69 // Must recognize load operation with Decode matched in memory operand.
70 // We should not reach here exept for PPC/AIX, as os::zero_page_read_protected()
71 // returns true everywhere else. On PPC, no such memory operands
72 // exist, therefore we did not yet implement a check for such operands.
73 NOT_AIX(Unimplemented());
74 }
75 }
76 return false;
77 }
79 static bool needs_explicit_null_check_for_read(Node *val) {
80 // On some OSes (AIX) the page at address 0 is only write protected.
81 // If so, only Store operations will trap.
82 if (os::zero_page_read_protected()) {
83 return false; // Implicit null check will work.
84 }
85 // Also a read accessing the base of a heap-based compressed heap will trap.
86 if (accesses_heap_base_zone(val) && // Hits the base zone page.
87 Universe::narrow_oop_use_implicit_null_checks()) { // Base zone page is protected.
88 return false;
89 }
91 return true;
92 }
94 //------------------------------implicit_null_check----------------------------
95 // Detect implicit-null-check opportunities. Basically, find NULL checks
96 // with suitable memory ops nearby. Use the memory op to do the NULL check.
97 // I can generate a memory op if there is not one nearby.
98 // The proj is the control projection for the not-null case.
99 // The val is the pointer being checked for nullness or
100 // decodeHeapOop_not_null node if it did not fold into address.
101 void PhaseCFG::implicit_null_check(Block* block, Node *proj, Node *val, int allowed_reasons) {
102 // Assume if null check need for 0 offset then always needed
103 // Intel solaris doesn't support any null checks yet and no
104 // mechanism exists (yet) to set the switches at an os_cpu level
105 if( !ImplicitNullChecks || MacroAssembler::needs_explicit_null_check(0)) return;
107 // Make sure the ptr-is-null path appears to be uncommon!
108 float f = block->end()->as_MachIf()->_prob;
109 if( proj->Opcode() == Op_IfTrue ) f = 1.0f - f;
110 if( f > PROB_UNLIKELY_MAG(4) ) return;
112 uint bidx = 0; // Capture index of value into memop
113 bool was_store; // Memory op is a store op
115 // Get the successor block for if the test ptr is non-null
116 Block* not_null_block; // this one goes with the proj
117 Block* null_block;
118 if (block->get_node(block->number_of_nodes()-1) == proj) {
119 null_block = block->_succs[0];
120 not_null_block = block->_succs[1];
121 } else {
122 assert(block->get_node(block->number_of_nodes()-2) == proj, "proj is one or the other");
123 not_null_block = block->_succs[0];
124 null_block = block->_succs[1];
125 }
126 while (null_block->is_Empty() == Block::empty_with_goto) {
127 null_block = null_block->_succs[0];
128 }
130 // Search the exception block for an uncommon trap.
131 // (See Parse::do_if and Parse::do_ifnull for the reason
132 // we need an uncommon trap. Briefly, we need a way to
133 // detect failure of this optimization, as in 6366351.)
134 {
135 bool found_trap = false;
136 for (uint i1 = 0; i1 < null_block->number_of_nodes(); i1++) {
137 Node* nn = null_block->get_node(i1);
138 if (nn->is_MachCall() &&
139 nn->as_MachCall()->entry_point() == SharedRuntime::uncommon_trap_blob()->entry_point()) {
140 const Type* trtype = nn->in(TypeFunc::Parms)->bottom_type();
141 if (trtype->isa_int() && trtype->is_int()->is_con()) {
142 jint tr_con = trtype->is_int()->get_con();
143 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(tr_con);
144 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(tr_con);
145 assert((int)reason < (int)BitsPerInt, "recode bit map");
146 if (is_set_nth_bit(allowed_reasons, (int) reason)
147 && action != Deoptimization::Action_none) {
148 // This uncommon trap is sure to recompile, eventually.
149 // When that happens, C->too_many_traps will prevent
150 // this transformation from happening again.
151 found_trap = true;
152 }
153 }
154 break;
155 }
156 }
157 if (!found_trap) {
158 // We did not find an uncommon trap.
159 return;
160 }
161 }
163 // Check for decodeHeapOop_not_null node which did not fold into address
164 bool is_decoden = ((intptr_t)val) & 1;
165 val = (Node*)(((intptr_t)val) & ~1);
167 assert(!is_decoden || (val->in(0) == NULL) && val->is_Mach() &&
168 (val->as_Mach()->ideal_Opcode() == Op_DecodeN), "sanity");
170 // Search the successor block for a load or store who's base value is also
171 // the tested value. There may be several.
172 Node_List *out = new Node_List(Thread::current()->resource_area());
173 MachNode *best = NULL; // Best found so far
174 for (DUIterator i = val->outs(); val->has_out(i); i++) {
175 Node *m = val->out(i);
176 if( !m->is_Mach() ) continue;
177 MachNode *mach = m->as_Mach();
178 was_store = false;
179 int iop = mach->ideal_Opcode();
180 switch( iop ) {
181 case Op_LoadB:
182 case Op_LoadUB:
183 case Op_LoadUS:
184 case Op_LoadD:
185 case Op_LoadF:
186 case Op_LoadI:
187 case Op_LoadL:
188 case Op_LoadP:
189 case Op_LoadN:
190 case Op_LoadS:
191 case Op_LoadKlass:
192 case Op_LoadNKlass:
193 case Op_LoadRange:
194 case Op_LoadD_unaligned:
195 case Op_LoadL_unaligned:
196 assert(mach->in(2) == val, "should be address");
197 break;
198 case Op_StoreB:
199 case Op_StoreC:
200 case Op_StoreCM:
201 case Op_StoreD:
202 case Op_StoreF:
203 case Op_StoreI:
204 case Op_StoreL:
205 case Op_StoreP:
206 case Op_StoreN:
207 case Op_StoreNKlass:
208 was_store = true; // Memory op is a store op
209 // Stores will have their address in slot 2 (memory in slot 1).
210 // If the value being nul-checked is in another slot, it means we
211 // are storing the checked value, which does NOT check the value!
212 if( mach->in(2) != val ) continue;
213 break; // Found a memory op?
214 case Op_StrComp:
215 case Op_StrEquals:
216 case Op_StrIndexOf:
217 case Op_AryEq:
218 case Op_EncodeISOArray:
219 // Not a legit memory op for implicit null check regardless of
220 // embedded loads
221 continue;
222 default: // Also check for embedded loads
223 if( !mach->needs_anti_dependence_check() )
224 continue; // Not an memory op; skip it
225 if( must_clone[iop] ) {
226 // Do not move nodes which produce flags because
227 // RA will try to clone it to place near branch and
228 // it will cause recompilation, see clone_node().
229 continue;
230 }
231 {
232 // Check that value is used in memory address in
233 // instructions with embedded load (CmpP val1,(val2+off)).
234 Node* base;
235 Node* index;
236 const MachOper* oper = mach->memory_inputs(base, index);
237 if (oper == NULL || oper == (MachOper*)-1) {
238 continue; // Not an memory op; skip it
239 }
240 if (val == base ||
241 val == index && val->bottom_type()->isa_narrowoop()) {
242 break; // Found it
243 } else {
244 continue; // Skip it
245 }
246 }
247 break;
248 }
250 // On some OSes (AIX) the page at address 0 is only write protected.
251 // If so, only Store operations will trap.
252 // But a read accessing the base of a heap-based compressed heap will trap.
253 if (!was_store && needs_explicit_null_check_for_read(val)) {
254 continue;
255 }
257 // check if the offset is not too high for implicit exception
258 {
259 intptr_t offset = 0;
260 const TypePtr *adr_type = NULL; // Do not need this return value here
261 const Node* base = mach->get_base_and_disp(offset, adr_type);
262 if (base == NULL || base == NodeSentinel) {
263 // Narrow oop address doesn't have base, only index
264 if( val->bottom_type()->isa_narrowoop() &&
265 MacroAssembler::needs_explicit_null_check(offset) )
266 continue; // Give up if offset is beyond page size
267 // cannot reason about it; is probably not implicit null exception
268 } else {
269 const TypePtr* tptr;
270 if (UseCompressedOops && (Universe::narrow_oop_shift() == 0 ||
271 Universe::narrow_klass_shift() == 0)) {
272 // 32-bits narrow oop can be the base of address expressions
273 tptr = base->get_ptr_type();
274 } else {
275 // only regular oops are expected here
276 tptr = base->bottom_type()->is_ptr();
277 }
278 // Give up if offset is not a compile-time constant
279 if( offset == Type::OffsetBot || tptr->_offset == Type::OffsetBot )
280 continue;
281 offset += tptr->_offset; // correct if base is offseted
282 if( MacroAssembler::needs_explicit_null_check(offset) )
283 continue; // Give up is reference is beyond 4K page size
284 }
285 }
287 // Check ctrl input to see if the null-check dominates the memory op
288 Block *cb = get_block_for_node(mach);
289 cb = cb->_idom; // Always hoist at least 1 block
290 if( !was_store ) { // Stores can be hoisted only one block
291 while( cb->_dom_depth > (block->_dom_depth + 1))
292 cb = cb->_idom; // Hoist loads as far as we want
293 // The non-null-block should dominate the memory op, too. Live
294 // range spilling will insert a spill in the non-null-block if it is
295 // needs to spill the memory op for an implicit null check.
296 if (cb->_dom_depth == (block->_dom_depth + 1)) {
297 if (cb != not_null_block) continue;
298 cb = cb->_idom;
299 }
300 }
301 if( cb != block ) continue;
303 // Found a memory user; see if it can be hoisted to check-block
304 uint vidx = 0; // Capture index of value into memop
305 uint j;
306 for( j = mach->req()-1; j > 0; j-- ) {
307 if( mach->in(j) == val ) {
308 vidx = j;
309 // Ignore DecodeN val which could be hoisted to where needed.
310 if( is_decoden ) continue;
311 }
312 // Block of memory-op input
313 Block *inb = get_block_for_node(mach->in(j));
314 Block *b = block; // Start from nul check
315 while( b != inb && b->_dom_depth > inb->_dom_depth )
316 b = b->_idom; // search upwards for input
317 // See if input dominates null check
318 if( b != inb )
319 break;
320 }
321 if( j > 0 )
322 continue;
323 Block *mb = get_block_for_node(mach);
324 // Hoisting stores requires more checks for the anti-dependence case.
325 // Give up hoisting if we have to move the store past any load.
326 if( was_store ) {
327 Block *b = mb; // Start searching here for a local load
328 // mach use (faulting) trying to hoist
329 // n might be blocker to hoisting
330 while( b != block ) {
331 uint k;
332 for( k = 1; k < b->number_of_nodes(); k++ ) {
333 Node *n = b->get_node(k);
334 if( n->needs_anti_dependence_check() &&
335 n->in(LoadNode::Memory) == mach->in(StoreNode::Memory) )
336 break; // Found anti-dependent load
337 }
338 if( k < b->number_of_nodes() )
339 break; // Found anti-dependent load
340 // Make sure control does not do a merge (would have to check allpaths)
341 if( b->num_preds() != 2 ) break;
342 b = get_block_for_node(b->pred(1)); // Move up to predecessor block
343 }
344 if( b != block ) continue;
345 }
347 // Make sure this memory op is not already being used for a NullCheck
348 Node *e = mb->end();
349 if( e->is_MachNullCheck() && e->in(1) == mach )
350 continue; // Already being used as a NULL check
352 // Found a candidate! Pick one with least dom depth - the highest
353 // in the dom tree should be closest to the null check.
354 if (best == NULL || get_block_for_node(mach)->_dom_depth < get_block_for_node(best)->_dom_depth) {
355 best = mach;
356 bidx = vidx;
357 }
358 }
359 // No candidate!
360 if (best == NULL) {
361 return;
362 }
364 // ---- Found an implicit null check
365 extern int implicit_null_checks;
366 implicit_null_checks++;
368 if( is_decoden ) {
369 // Check if we need to hoist decodeHeapOop_not_null first.
370 Block *valb = get_block_for_node(val);
371 if( block != valb && block->_dom_depth < valb->_dom_depth ) {
372 // Hoist it up to the end of the test block.
373 valb->find_remove(val);
374 block->add_inst(val);
375 map_node_to_block(val, block);
376 // DecodeN on x86 may kill flags. Check for flag-killing projections
377 // that also need to be hoisted.
378 for (DUIterator_Fast jmax, j = val->fast_outs(jmax); j < jmax; j++) {
379 Node* n = val->fast_out(j);
380 if( n->is_MachProj() ) {
381 get_block_for_node(n)->find_remove(n);
382 block->add_inst(n);
383 map_node_to_block(n, block);
384 }
385 }
386 }
387 }
388 // Hoist the memory candidate up to the end of the test block.
389 Block *old_block = get_block_for_node(best);
390 old_block->find_remove(best);
391 block->add_inst(best);
392 map_node_to_block(best, block);
394 // Move the control dependence
395 if (best->in(0) && best->in(0) == old_block->head())
396 best->set_req(0, block->head());
398 // Check for flag-killing projections that also need to be hoisted
399 // Should be DU safe because no edge updates.
400 for (DUIterator_Fast jmax, j = best->fast_outs(jmax); j < jmax; j++) {
401 Node* n = best->fast_out(j);
402 if( n->is_MachProj() ) {
403 get_block_for_node(n)->find_remove(n);
404 block->add_inst(n);
405 map_node_to_block(n, block);
406 }
407 }
409 // proj==Op_True --> ne test; proj==Op_False --> eq test.
410 // One of two graph shapes got matched:
411 // (IfTrue (If (Bool NE (CmpP ptr NULL))))
412 // (IfFalse (If (Bool EQ (CmpP ptr NULL))))
413 // NULL checks are always branch-if-eq. If we see a IfTrue projection
414 // then we are replacing a 'ne' test with a 'eq' NULL check test.
415 // We need to flip the projections to keep the same semantics.
416 if( proj->Opcode() == Op_IfTrue ) {
417 // Swap order of projections in basic block to swap branch targets
418 Node *tmp1 = block->get_node(block->end_idx()+1);
419 Node *tmp2 = block->get_node(block->end_idx()+2);
420 block->map_node(tmp2, block->end_idx()+1);
421 block->map_node(tmp1, block->end_idx()+2);
422 Node *tmp = new (C) Node(C->top()); // Use not NULL input
423 tmp1->replace_by(tmp);
424 tmp2->replace_by(tmp1);
425 tmp->replace_by(tmp2);
426 tmp->destruct();
427 }
429 // Remove the existing null check; use a new implicit null check instead.
430 // Since schedule-local needs precise def-use info, we need to correct
431 // it as well.
432 Node *old_tst = proj->in(0);
433 MachNode *nul_chk = new (C) MachNullCheckNode(old_tst->in(0),best,bidx);
434 block->map_node(nul_chk, block->end_idx());
435 map_node_to_block(nul_chk, block);
436 // Redirect users of old_test to nul_chk
437 for (DUIterator_Last i2min, i2 = old_tst->last_outs(i2min); i2 >= i2min; --i2)
438 old_tst->last_out(i2)->set_req(0, nul_chk);
439 // Clean-up any dead code
440 for (uint i3 = 0; i3 < old_tst->req(); i3++)
441 old_tst->set_req(i3, NULL);
443 latency_from_uses(nul_chk);
444 latency_from_uses(best);
445 }
448 //------------------------------select-----------------------------------------
449 // Select a nice fellow from the worklist to schedule next. If there is only
450 // one choice, then use it. Projections take top priority for correctness
451 // reasons - if I see a projection, then it is next. There are a number of
452 // other special cases, for instructions that consume condition codes, et al.
453 // These are chosen immediately. Some instructions are required to immediately
454 // precede the last instruction in the block, and these are taken last. Of the
455 // remaining cases (most), choose the instruction with the greatest latency
456 // (that is, the most number of pseudo-cycles required to the end of the
457 // routine). If there is a tie, choose the instruction with the most inputs.
458 Node* PhaseCFG::select(Block* block, Node_List &worklist, GrowableArray<int> &ready_cnt, VectorSet &next_call, uint sched_slot) {
460 // If only a single entry on the stack, use it
461 uint cnt = worklist.size();
462 if (cnt == 1) {
463 Node *n = worklist[0];
464 worklist.map(0,worklist.pop());
465 return n;
466 }
468 uint choice = 0; // Bigger is most important
469 uint latency = 0; // Bigger is scheduled first
470 uint score = 0; // Bigger is better
471 int idx = -1; // Index in worklist
472 int cand_cnt = 0; // Candidate count
474 for( uint i=0; i<cnt; i++ ) { // Inspect entire worklist
475 // Order in worklist is used to break ties.
476 // See caller for how this is used to delay scheduling
477 // of induction variable increments to after the other
478 // uses of the phi are scheduled.
479 Node *n = worklist[i]; // Get Node on worklist
481 int iop = n->is_Mach() ? n->as_Mach()->ideal_Opcode() : 0;
482 if( n->is_Proj() || // Projections always win
483 n->Opcode()== Op_Con || // So does constant 'Top'
484 iop == Op_CreateEx || // Create-exception must start block
485 iop == Op_CheckCastPP
486 ) {
487 worklist.map(i,worklist.pop());
488 return n;
489 }
491 // Final call in a block must be adjacent to 'catch'
492 Node *e = block->end();
493 if( e->is_Catch() && e->in(0)->in(0) == n )
494 continue;
496 // Memory op for an implicit null check has to be at the end of the block
497 if( e->is_MachNullCheck() && e->in(1) == n )
498 continue;
500 // Schedule IV increment last.
501 if (e->is_Mach() && e->as_Mach()->ideal_Opcode() == Op_CountedLoopEnd &&
502 e->in(1)->in(1) == n && n->is_iteratively_computed())
503 continue;
505 uint n_choice = 2;
507 // See if this instruction is consumed by a branch. If so, then (as the
508 // branch is the last instruction in the basic block) force it to the
509 // end of the basic block
510 if ( must_clone[iop] ) {
511 // See if any use is a branch
512 bool found_machif = false;
514 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
515 Node* use = n->fast_out(j);
517 // The use is a conditional branch, make them adjacent
518 if (use->is_MachIf() && get_block_for_node(use) == block) {
519 found_machif = true;
520 break;
521 }
523 // For nodes that produce a FlagsProj, make the node adjacent to the
524 // use of the FlagsProj
525 if (use->is_FlagsProj() && get_block_for_node(use) == block) {
526 found_machif = true;
527 break;
528 }
530 // More than this instruction pending for successor to be ready,
531 // don't choose this if other opportunities are ready
532 if (ready_cnt.at(use->_idx) > 1)
533 n_choice = 1;
534 }
536 // loop terminated, prefer not to use this instruction
537 if (found_machif)
538 continue;
539 }
541 // See if this has a predecessor that is "must_clone", i.e. sets the
542 // condition code. If so, choose this first
543 for (uint j = 0; j < n->req() ; j++) {
544 Node *inn = n->in(j);
545 if (inn) {
546 if (inn->is_Mach() && must_clone[inn->as_Mach()->ideal_Opcode()] ) {
547 n_choice = 3;
548 break;
549 }
550 }
551 }
553 // MachTemps should be scheduled last so they are near their uses
554 if (n->is_MachTemp()) {
555 n_choice = 1;
556 }
558 uint n_latency = get_latency_for_node(n);
559 uint n_score = n->req(); // Many inputs get high score to break ties
561 // Keep best latency found
562 cand_cnt++;
563 if (choice < n_choice ||
564 (choice == n_choice &&
565 ((StressLCM && Compile::randomized_select(cand_cnt)) ||
566 (!StressLCM &&
567 (latency < n_latency ||
568 (latency == n_latency &&
569 (score < n_score))))))) {
570 choice = n_choice;
571 latency = n_latency;
572 score = n_score;
573 idx = i; // Also keep index in worklist
574 }
575 } // End of for all ready nodes in worklist
577 assert(idx >= 0, "index should be set");
578 Node *n = worklist[(uint)idx]; // Get the winner
580 worklist.map((uint)idx, worklist.pop()); // Compress worklist
581 return n;
582 }
585 //------------------------------set_next_call----------------------------------
586 void PhaseCFG::set_next_call(Block* block, Node* n, VectorSet& next_call) {
587 if( next_call.test_set(n->_idx) ) return;
588 for( uint i=0; i<n->len(); i++ ) {
589 Node *m = n->in(i);
590 if( !m ) continue; // must see all nodes in block that precede call
591 if (get_block_for_node(m) == block) {
592 set_next_call(block, m, next_call);
593 }
594 }
595 }
597 //------------------------------needed_for_next_call---------------------------
598 // Set the flag 'next_call' for each Node that is needed for the next call to
599 // be scheduled. This flag lets me bias scheduling so Nodes needed for the
600 // next subroutine call get priority - basically it moves things NOT needed
601 // for the next call till after the call. This prevents me from trying to
602 // carry lots of stuff live across a call.
603 void PhaseCFG::needed_for_next_call(Block* block, Node* this_call, VectorSet& next_call) {
604 // Find the next control-defining Node in this block
605 Node* call = NULL;
606 for (DUIterator_Fast imax, i = this_call->fast_outs(imax); i < imax; i++) {
607 Node* m = this_call->fast_out(i);
608 if (get_block_for_node(m) == block && // Local-block user
609 m != this_call && // Not self-start node
610 m->is_MachCall()) {
611 call = m;
612 break;
613 }
614 }
615 if (call == NULL) return; // No next call (e.g., block end is near)
616 // Set next-call for all inputs to this call
617 set_next_call(block, call, next_call);
618 }
620 //------------------------------add_call_kills-------------------------------------
621 // helper function that adds caller save registers to MachProjNode
622 static void add_call_kills(MachProjNode *proj, RegMask& regs, const char* save_policy, bool exclude_soe) {
623 // Fill in the kill mask for the call
624 for( OptoReg::Name r = OptoReg::Name(0); r < _last_Mach_Reg; r=OptoReg::add(r,1) ) {
625 if( !regs.Member(r) ) { // Not already defined by the call
626 // Save-on-call register?
627 if ((save_policy[r] == 'C') ||
628 (save_policy[r] == 'A') ||
629 ((save_policy[r] == 'E') && exclude_soe)) {
630 proj->_rout.Insert(r);
631 }
632 }
633 }
634 }
637 //------------------------------sched_call-------------------------------------
638 uint PhaseCFG::sched_call(Block* block, uint node_cnt, Node_List& worklist, GrowableArray<int>& ready_cnt, MachCallNode* mcall, VectorSet& next_call) {
639 RegMask regs;
641 // Schedule all the users of the call right now. All the users are
642 // projection Nodes, so they must be scheduled next to the call.
643 // Collect all the defined registers.
644 for (DUIterator_Fast imax, i = mcall->fast_outs(imax); i < imax; i++) {
645 Node* n = mcall->fast_out(i);
646 assert( n->is_MachProj(), "" );
647 int n_cnt = ready_cnt.at(n->_idx)-1;
648 ready_cnt.at_put(n->_idx, n_cnt);
649 assert( n_cnt == 0, "" );
650 // Schedule next to call
651 block->map_node(n, node_cnt++);
652 // Collect defined registers
653 regs.OR(n->out_RegMask());
654 // Check for scheduling the next control-definer
655 if( n->bottom_type() == Type::CONTROL )
656 // Warm up next pile of heuristic bits
657 needed_for_next_call(block, n, next_call);
659 // Children of projections are now all ready
660 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
661 Node* m = n->fast_out(j); // Get user
662 if(get_block_for_node(m) != block) {
663 continue;
664 }
665 if( m->is_Phi() ) continue;
666 int m_cnt = ready_cnt.at(m->_idx)-1;
667 ready_cnt.at_put(m->_idx, m_cnt);
668 if( m_cnt == 0 )
669 worklist.push(m);
670 }
672 }
674 // Act as if the call defines the Frame Pointer.
675 // Certainly the FP is alive and well after the call.
676 regs.Insert(_matcher.c_frame_pointer());
678 // Set all registers killed and not already defined by the call.
679 uint r_cnt = mcall->tf()->range()->cnt();
680 int op = mcall->ideal_Opcode();
681 MachProjNode *proj = new (C) MachProjNode( mcall, r_cnt+1, RegMask::Empty, MachProjNode::fat_proj );
682 map_node_to_block(proj, block);
683 block->insert_node(proj, node_cnt++);
685 // Select the right register save policy.
686 const char * save_policy;
687 switch (op) {
688 case Op_CallRuntime:
689 case Op_CallLeaf:
690 case Op_CallLeafNoFP:
691 // Calling C code so use C calling convention
692 save_policy = _matcher._c_reg_save_policy;
693 break;
695 case Op_CallStaticJava:
696 case Op_CallDynamicJava:
697 // Calling Java code so use Java calling convention
698 save_policy = _matcher._register_save_policy;
699 break;
701 default:
702 ShouldNotReachHere();
703 }
705 // When using CallRuntime mark SOE registers as killed by the call
706 // so values that could show up in the RegisterMap aren't live in a
707 // callee saved register since the register wouldn't know where to
708 // find them. CallLeaf and CallLeafNoFP are ok because they can't
709 // have debug info on them. Strictly speaking this only needs to be
710 // done for oops since idealreg2debugmask takes care of debug info
711 // references but there no way to handle oops differently than other
712 // pointers as far as the kill mask goes.
713 bool exclude_soe = op == Op_CallRuntime;
715 // If the call is a MethodHandle invoke, we need to exclude the
716 // register which is used to save the SP value over MH invokes from
717 // the mask. Otherwise this register could be used for
718 // deoptimization information.
719 if (op == Op_CallStaticJava) {
720 MachCallStaticJavaNode* mcallstaticjava = (MachCallStaticJavaNode*) mcall;
721 if (mcallstaticjava->_method_handle_invoke)
722 proj->_rout.OR(Matcher::method_handle_invoke_SP_save_mask());
723 }
725 add_call_kills(proj, regs, save_policy, exclude_soe);
727 return node_cnt;
728 }
731 //------------------------------schedule_local---------------------------------
732 // Topological sort within a block. Someday become a real scheduler.
733 bool PhaseCFG::schedule_local(Block* block, GrowableArray<int>& ready_cnt, VectorSet& next_call) {
734 // Already "sorted" are the block start Node (as the first entry), and
735 // the block-ending Node and any trailing control projections. We leave
736 // these alone. PhiNodes and ParmNodes are made to follow the block start
737 // Node. Everything else gets topo-sorted.
739 #ifndef PRODUCT
740 if (trace_opto_pipelining()) {
741 tty->print_cr("# --- schedule_local B%d, before: ---", block->_pre_order);
742 for (uint i = 0;i < block->number_of_nodes(); i++) {
743 tty->print("# ");
744 block->get_node(i)->fast_dump();
745 }
746 tty->print_cr("#");
747 }
748 #endif
750 // RootNode is already sorted
751 if (block->number_of_nodes() == 1) {
752 return true;
753 }
755 // Move PhiNodes and ParmNodes from 1 to cnt up to the start
756 uint node_cnt = block->end_idx();
757 uint phi_cnt = 1;
758 uint i;
759 for( i = 1; i<node_cnt; i++ ) { // Scan for Phi
760 Node *n = block->get_node(i);
761 if( n->is_Phi() || // Found a PhiNode or ParmNode
762 (n->is_Proj() && n->in(0) == block->head()) ) {
763 // Move guy at 'phi_cnt' to the end; makes a hole at phi_cnt
764 block->map_node(block->get_node(phi_cnt), i);
765 block->map_node(n, phi_cnt++); // swap Phi/Parm up front
766 } else { // All others
767 // Count block-local inputs to 'n'
768 uint cnt = n->len(); // Input count
769 uint local = 0;
770 for( uint j=0; j<cnt; j++ ) {
771 Node *m = n->in(j);
772 if( m && get_block_for_node(m) == block && !m->is_top() )
773 local++; // One more block-local input
774 }
775 ready_cnt.at_put(n->_idx, local); // Count em up
777 #ifdef ASSERT
778 if( UseConcMarkSweepGC || UseG1GC ) {
779 if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_StoreCM ) {
780 // Check the precedence edges
781 for (uint prec = n->req(); prec < n->len(); prec++) {
782 Node* oop_store = n->in(prec);
783 if (oop_store != NULL) {
784 assert(get_block_for_node(oop_store)->_dom_depth <= block->_dom_depth, "oop_store must dominate card-mark");
785 }
786 }
787 }
788 }
789 #endif
791 // A few node types require changing a required edge to a precedence edge
792 // before allocation.
793 if( n->is_Mach() && n->req() > TypeFunc::Parms &&
794 (n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire ||
795 n->as_Mach()->ideal_Opcode() == Op_MemBarVolatile) ) {
796 // MemBarAcquire could be created without Precedent edge.
797 // del_req() replaces the specified edge with the last input edge
798 // and then removes the last edge. If the specified edge > number of
799 // edges the last edge will be moved outside of the input edges array
800 // and the edge will be lost. This is why this code should be
801 // executed only when Precedent (== TypeFunc::Parms) edge is present.
802 Node *x = n->in(TypeFunc::Parms);
803 n->del_req(TypeFunc::Parms);
804 n->add_prec(x);
805 }
806 }
807 }
808 for(uint i2=i; i2< block->number_of_nodes(); i2++ ) // Trailing guys get zapped count
809 ready_cnt.at_put(block->get_node(i2)->_idx, 0);
811 // All the prescheduled guys do not hold back internal nodes
812 uint i3;
813 for(i3 = 0; i3<phi_cnt; i3++ ) { // For all pre-scheduled
814 Node *n = block->get_node(i3); // Get pre-scheduled
815 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
816 Node* m = n->fast_out(j);
817 if (get_block_for_node(m) == block) { // Local-block user
818 int m_cnt = ready_cnt.at(m->_idx)-1;
819 ready_cnt.at_put(m->_idx, m_cnt); // Fix ready count
820 }
821 }
822 }
824 Node_List delay;
825 // Make a worklist
826 Node_List worklist;
827 for(uint i4=i3; i4<node_cnt; i4++ ) { // Put ready guys on worklist
828 Node *m = block->get_node(i4);
829 if( !ready_cnt.at(m->_idx) ) { // Zero ready count?
830 if (m->is_iteratively_computed()) {
831 // Push induction variable increments last to allow other uses
832 // of the phi to be scheduled first. The select() method breaks
833 // ties in scheduling by worklist order.
834 delay.push(m);
835 } else if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_CreateEx) {
836 // Force the CreateEx to the top of the list so it's processed
837 // first and ends up at the start of the block.
838 worklist.insert(0, m);
839 } else {
840 worklist.push(m); // Then on to worklist!
841 }
842 }
843 }
844 while (delay.size()) {
845 Node* d = delay.pop();
846 worklist.push(d);
847 }
849 // Warm up the 'next_call' heuristic bits
850 needed_for_next_call(block, block->head(), next_call);
852 #ifndef PRODUCT
853 if (trace_opto_pipelining()) {
854 for (uint j=0; j< block->number_of_nodes(); j++) {
855 Node *n = block->get_node(j);
856 int idx = n->_idx;
857 tty->print("# ready cnt:%3d ", ready_cnt.at(idx));
858 tty->print("latency:%3d ", get_latency_for_node(n));
859 tty->print("%4d: %s\n", idx, n->Name());
860 }
861 }
862 #endif
864 uint max_idx = (uint)ready_cnt.length();
865 // Pull from worklist and schedule
866 while( worklist.size() ) { // Worklist is not ready
868 #ifndef PRODUCT
869 if (trace_opto_pipelining()) {
870 tty->print("# ready list:");
871 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist
872 Node *n = worklist[i]; // Get Node on worklist
873 tty->print(" %d", n->_idx);
874 }
875 tty->cr();
876 }
877 #endif
879 // Select and pop a ready guy from worklist
880 Node* n = select(block, worklist, ready_cnt, next_call, phi_cnt);
881 block->map_node(n, phi_cnt++); // Schedule him next
883 #ifndef PRODUCT
884 if (trace_opto_pipelining()) {
885 tty->print("# select %d: %s", n->_idx, n->Name());
886 tty->print(", latency:%d", get_latency_for_node(n));
887 n->dump();
888 if (Verbose) {
889 tty->print("# ready list:");
890 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist
891 Node *n = worklist[i]; // Get Node on worklist
892 tty->print(" %d", n->_idx);
893 }
894 tty->cr();
895 }
896 }
898 #endif
899 if( n->is_MachCall() ) {
900 MachCallNode *mcall = n->as_MachCall();
901 phi_cnt = sched_call(block, phi_cnt, worklist, ready_cnt, mcall, next_call);
902 continue;
903 }
905 if (n->is_Mach() && n->as_Mach()->has_call()) {
906 RegMask regs;
907 regs.Insert(_matcher.c_frame_pointer());
908 regs.OR(n->out_RegMask());
910 MachProjNode *proj = new (C) MachProjNode( n, 1, RegMask::Empty, MachProjNode::fat_proj );
911 map_node_to_block(proj, block);
912 block->insert_node(proj, phi_cnt++);
914 add_call_kills(proj, regs, _matcher._c_reg_save_policy, false);
915 }
917 // Children are now all ready
918 for (DUIterator_Fast i5max, i5 = n->fast_outs(i5max); i5 < i5max; i5++) {
919 Node* m = n->fast_out(i5); // Get user
920 if (get_block_for_node(m) != block) {
921 continue;
922 }
923 if( m->is_Phi() ) continue;
924 if (m->_idx >= max_idx) { // new node, skip it
925 assert(m->is_MachProj() && n->is_Mach() && n->as_Mach()->has_call(), "unexpected node types");
926 continue;
927 }
928 int m_cnt = ready_cnt.at(m->_idx)-1;
929 ready_cnt.at_put(m->_idx, m_cnt);
930 if( m_cnt == 0 )
931 worklist.push(m);
932 }
933 }
935 if( phi_cnt != block->end_idx() ) {
936 // did not schedule all. Retry, Bailout, or Die
937 if (C->subsume_loads() == true && !C->failing()) {
938 // Retry with subsume_loads == false
939 // If this is the first failure, the sentinel string will "stick"
940 // to the Compile object, and the C2Compiler will see it and retry.
941 C->record_failure(C2Compiler::retry_no_subsuming_loads());
942 }
943 // assert( phi_cnt == end_idx(), "did not schedule all" );
944 return false;
945 }
947 #ifndef PRODUCT
948 if (trace_opto_pipelining()) {
949 tty->print_cr("#");
950 tty->print_cr("# after schedule_local");
951 for (uint i = 0;i < block->number_of_nodes();i++) {
952 tty->print("# ");
953 block->get_node(i)->fast_dump();
954 }
955 tty->cr();
956 }
957 #endif
960 return true;
961 }
963 //--------------------------catch_cleanup_fix_all_inputs-----------------------
964 static void catch_cleanup_fix_all_inputs(Node *use, Node *old_def, Node *new_def) {
965 for (uint l = 0; l < use->len(); l++) {
966 if (use->in(l) == old_def) {
967 if (l < use->req()) {
968 use->set_req(l, new_def);
969 } else {
970 use->rm_prec(l);
971 use->add_prec(new_def);
972 l--;
973 }
974 }
975 }
976 }
978 //------------------------------catch_cleanup_find_cloned_def------------------
979 Node* PhaseCFG::catch_cleanup_find_cloned_def(Block *use_blk, Node *def, Block *def_blk, int n_clone_idx) {
980 assert( use_blk != def_blk, "Inter-block cleanup only");
982 // The use is some block below the Catch. Find and return the clone of the def
983 // that dominates the use. If there is no clone in a dominating block, then
984 // create a phi for the def in a dominating block.
986 // Find which successor block dominates this use. The successor
987 // blocks must all be single-entry (from the Catch only; I will have
988 // split blocks to make this so), hence they all dominate.
989 while( use_blk->_dom_depth > def_blk->_dom_depth+1 )
990 use_blk = use_blk->_idom;
992 // Find the successor
993 Node *fixup = NULL;
995 uint j;
996 for( j = 0; j < def_blk->_num_succs; j++ )
997 if( use_blk == def_blk->_succs[j] )
998 break;
1000 if( j == def_blk->_num_succs ) {
1001 // Block at same level in dom-tree is not a successor. It needs a
1002 // PhiNode, the PhiNode uses from the def and IT's uses need fixup.
1003 Node_Array inputs = new Node_List(Thread::current()->resource_area());
1004 for(uint k = 1; k < use_blk->num_preds(); k++) {
1005 Block* block = get_block_for_node(use_blk->pred(k));
1006 inputs.map(k, catch_cleanup_find_cloned_def(block, def, def_blk, n_clone_idx));
1007 }
1009 // Check to see if the use_blk already has an identical phi inserted.
1010 // If it exists, it will be at the first position since all uses of a
1011 // def are processed together.
1012 Node *phi = use_blk->get_node(1);
1013 if( phi->is_Phi() ) {
1014 fixup = phi;
1015 for (uint k = 1; k < use_blk->num_preds(); k++) {
1016 if (phi->in(k) != inputs[k]) {
1017 // Not a match
1018 fixup = NULL;
1019 break;
1020 }
1021 }
1022 }
1024 // If an existing PhiNode was not found, make a new one.
1025 if (fixup == NULL) {
1026 Node *new_phi = PhiNode::make(use_blk->head(), def);
1027 use_blk->insert_node(new_phi, 1);
1028 map_node_to_block(new_phi, use_blk);
1029 for (uint k = 1; k < use_blk->num_preds(); k++) {
1030 new_phi->set_req(k, inputs[k]);
1031 }
1032 fixup = new_phi;
1033 }
1035 } else {
1036 // Found the use just below the Catch. Make it use the clone.
1037 fixup = use_blk->get_node(n_clone_idx);
1038 }
1040 return fixup;
1041 }
1043 //--------------------------catch_cleanup_intra_block--------------------------
1044 // Fix all input edges in use that reference "def". The use is in the same
1045 // block as the def and both have been cloned in each successor block.
1046 static void catch_cleanup_intra_block(Node *use, Node *def, Block *blk, int beg, int n_clone_idx) {
1048 // Both the use and def have been cloned. For each successor block,
1049 // get the clone of the use, and make its input the clone of the def
1050 // found in that block.
1052 uint use_idx = blk->find_node(use);
1053 uint offset_idx = use_idx - beg;
1054 for( uint k = 0; k < blk->_num_succs; k++ ) {
1055 // Get clone in each successor block
1056 Block *sb = blk->_succs[k];
1057 Node *clone = sb->get_node(offset_idx+1);
1058 assert( clone->Opcode() == use->Opcode(), "" );
1060 // Make use-clone reference the def-clone
1061 catch_cleanup_fix_all_inputs(clone, def, sb->get_node(n_clone_idx));
1062 }
1063 }
1065 //------------------------------catch_cleanup_inter_block---------------------
1066 // Fix all input edges in use that reference "def". The use is in a different
1067 // block than the def.
1068 void PhaseCFG::catch_cleanup_inter_block(Node *use, Block *use_blk, Node *def, Block *def_blk, int n_clone_idx) {
1069 if( !use_blk ) return; // Can happen if the use is a precedence edge
1071 Node *new_def = catch_cleanup_find_cloned_def(use_blk, def, def_blk, n_clone_idx);
1072 catch_cleanup_fix_all_inputs(use, def, new_def);
1073 }
1075 //------------------------------call_catch_cleanup-----------------------------
1076 // If we inserted any instructions between a Call and his CatchNode,
1077 // clone the instructions on all paths below the Catch.
1078 void PhaseCFG::call_catch_cleanup(Block* block) {
1080 // End of region to clone
1081 uint end = block->end_idx();
1082 if( !block->get_node(end)->is_Catch() ) return;
1083 // Start of region to clone
1084 uint beg = end;
1085 while(!block->get_node(beg-1)->is_MachProj() ||
1086 !block->get_node(beg-1)->in(0)->is_MachCall() ) {
1087 beg--;
1088 assert(beg > 0,"Catch cleanup walking beyond block boundary");
1089 }
1090 // Range of inserted instructions is [beg, end)
1091 if( beg == end ) return;
1093 // Clone along all Catch output paths. Clone area between the 'beg' and
1094 // 'end' indices.
1095 for( uint i = 0; i < block->_num_succs; i++ ) {
1096 Block *sb = block->_succs[i];
1097 // Clone the entire area; ignoring the edge fixup for now.
1098 for( uint j = end; j > beg; j-- ) {
1099 // It is safe here to clone a node with anti_dependence
1100 // since clones dominate on each path.
1101 Node *clone = block->get_node(j-1)->clone();
1102 sb->insert_node(clone, 1);
1103 map_node_to_block(clone, sb);
1104 }
1105 }
1108 // Fixup edges. Check the def-use info per cloned Node
1109 for(uint i2 = beg; i2 < end; i2++ ) {
1110 uint n_clone_idx = i2-beg+1; // Index of clone of n in each successor block
1111 Node *n = block->get_node(i2); // Node that got cloned
1112 // Need DU safe iterator because of edge manipulation in calls.
1113 Unique_Node_List *out = new Unique_Node_List(Thread::current()->resource_area());
1114 for (DUIterator_Fast j1max, j1 = n->fast_outs(j1max); j1 < j1max; j1++) {
1115 out->push(n->fast_out(j1));
1116 }
1117 uint max = out->size();
1118 for (uint j = 0; j < max; j++) {// For all users
1119 Node *use = out->pop();
1120 Block *buse = get_block_for_node(use);
1121 if( use->is_Phi() ) {
1122 for( uint k = 1; k < use->req(); k++ )
1123 if( use->in(k) == n ) {
1124 Block* b = get_block_for_node(buse->pred(k));
1125 Node *fixup = catch_cleanup_find_cloned_def(b, n, block, n_clone_idx);
1126 use->set_req(k, fixup);
1127 }
1128 } else {
1129 if (block == buse) {
1130 catch_cleanup_intra_block(use, n, block, beg, n_clone_idx);
1131 } else {
1132 catch_cleanup_inter_block(use, buse, n, block, n_clone_idx);
1133 }
1134 }
1135 } // End for all users
1137 } // End of for all Nodes in cloned area
1139 // Remove the now-dead cloned ops
1140 for(uint i3 = beg; i3 < end; i3++ ) {
1141 block->get_node(beg)->disconnect_inputs(NULL, C);
1142 block->remove_node(beg);
1143 }
1145 // If the successor blocks have a CreateEx node, move it back to the top
1146 for(uint i4 = 0; i4 < block->_num_succs; i4++ ) {
1147 Block *sb = block->_succs[i4];
1148 uint new_cnt = end - beg;
1149 // Remove any newly created, but dead, nodes.
1150 for( uint j = new_cnt; j > 0; j-- ) {
1151 Node *n = sb->get_node(j);
1152 if (n->outcnt() == 0 &&
1153 (!n->is_Proj() || n->as_Proj()->in(0)->outcnt() == 1) ){
1154 n->disconnect_inputs(NULL, C);
1155 sb->remove_node(j);
1156 new_cnt--;
1157 }
1158 }
1159 // If any newly created nodes remain, move the CreateEx node to the top
1160 if (new_cnt > 0) {
1161 Node *cex = sb->get_node(1+new_cnt);
1162 if( cex->is_Mach() && cex->as_Mach()->ideal_Opcode() == Op_CreateEx ) {
1163 sb->remove_node(1+new_cnt);
1164 sb->insert_node(cex, 1);
1165 }
1166 }
1167 }
1168 }