1 /*
2 * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "asm/assembler.inline.hpp"
27 #include "code/debugInfo.hpp"
28 #include "code/debugInfoRec.hpp"
29 #include "compiler/compileBroker.hpp"
30 #include "compiler/oopMap.hpp"
31 #include "memory/allocation.inline.hpp"
32 #include "opto/callnode.hpp"
33 #include "opto/cfgnode.hpp"
34 #include "opto/locknode.hpp"
35 #include "opto/machnode.hpp"
36 #include "opto/output.hpp"
37 #include "opto/regalloc.hpp"
38 #include "opto/runtime.hpp"
39 #include "opto/subnode.hpp"
40 #include "opto/type.hpp"
41 #include "runtime/handles.inline.hpp"
42 #include "utilities/xmlstream.hpp"
43
44 extern uint size_java_to_interp();
45 extern uint reloc_java_to_interp();
46 extern uint size_exception_handler();
47 extern uint size_deopt_handler();
48
49 #ifndef PRODUCT
50 #define DEBUG_ARG(x) , x
51 #else
52 #define DEBUG_ARG(x)
53 #endif
54
55 extern int emit_exception_handler(CodeBuffer &cbuf);
56 extern int emit_deopt_handler(CodeBuffer &cbuf);
57
58 //------------------------------Output-----------------------------------------
59 // Convert Nodes to instruction bits and pass off to the VM
60 void Compile::Output() {
61 // RootNode goes
62 assert( _cfg->_broot->_nodes.size() == 0, "" );
63
64 // The number of new nodes (mostly MachNop) is proportional to
65 // the number of java calls and inner loops which are aligned.
66 if ( C->check_node_count((NodeLimitFudgeFactor + C->java_calls()*3 +
67 C->inner_loops()*(OptoLoopAlignment-1)),
68 "out of nodes before code generation" ) ) {
69 return;
70 }
71 // Make sure I can find the Start Node
72 Block_Array& bbs = _cfg->_bbs;
73 Block *entry = _cfg->_blocks[1];
74 Block *broot = _cfg->_broot;
75
76 const StartNode *start = entry->_nodes[0]->as_Start();
77
78 // Replace StartNode with prolog
79 MachPrologNode *prolog = new (this) MachPrologNode();
80 entry->_nodes.map( 0, prolog );
81 bbs.map( prolog->_idx, entry );
82 bbs.map( start->_idx, NULL ); // start is no longer in any block
83
84 // Virtual methods need an unverified entry point
85
86 if( is_osr_compilation() ) {
87 if( PoisonOSREntry ) {
88 // TODO: Should use a ShouldNotReachHereNode...
89 _cfg->insert( broot, 0, new (this) MachBreakpointNode() );
90 }
91 } else {
92 if( _method && !_method->flags().is_static() ) {
93 // Insert unvalidated entry point
94 _cfg->insert( broot, 0, new (this) MachUEPNode() );
95 }
96
97 }
98
99
100 // Break before main entry point
101 if( (_method && _method->break_at_execute())
102 #ifndef PRODUCT
103 ||(OptoBreakpoint && is_method_compilation())
104 ||(OptoBreakpointOSR && is_osr_compilation())
105 ||(OptoBreakpointC2R && !_method)
106 #endif
107 ) {
108 // checking for _method means that OptoBreakpoint does not apply to
109 // runtime stubs or frame converters
110 _cfg->insert( entry, 1, new (this) MachBreakpointNode() );
111 }
112
113 // Insert epilogs before every return
114 for( uint i=0; i<_cfg->_num_blocks; i++ ) {
115 Block *b = _cfg->_blocks[i];
116 if( !b->is_connector() && b->non_connector_successor(0) == _cfg->_broot ) { // Found a program exit point?
117 Node *m = b->end();
118 if( m->is_Mach() && m->as_Mach()->ideal_Opcode() != Op_Halt ) {
119 MachEpilogNode *epilog = new (this) MachEpilogNode(m->as_Mach()->ideal_Opcode() == Op_Return);
120 b->add_inst( epilog );
121 bbs.map(epilog->_idx, b);
122 //_regalloc->set_bad(epilog->_idx); // Already initialized this way.
123 }
124 }
125 }
126
127 # ifdef ENABLE_ZAP_DEAD_LOCALS
128 if ( ZapDeadCompiledLocals ) Insert_zap_nodes();
129 # endif
130
131 uint* blk_starts = NEW_RESOURCE_ARRAY(uint,_cfg->_num_blocks+1);
132 blk_starts[0] = 0;
133
134 // Initialize code buffer and process short branches.
135 CodeBuffer* cb = init_buffer(blk_starts);
136
137 if (cb == NULL || failing()) return;
138
139 ScheduleAndBundle();
140
141 #ifndef PRODUCT
142 if (trace_opto_output()) {
143 tty->print("\n---- After ScheduleAndBundle ----\n");
144 for (uint i = 0; i < _cfg->_num_blocks; i++) {
145 tty->print("\nBB#%03d:\n", i);
146 Block *bb = _cfg->_blocks[i];
147 for (uint j = 0; j < bb->_nodes.size(); j++) {
148 Node *n = bb->_nodes[j];
149 OptoReg::Name reg = _regalloc->get_reg_first(n);
150 tty->print(" %-6s ", reg >= 0 && reg < REG_COUNT ? Matcher::regName[reg] : "");
151 n->dump();
152 }
153 }
154 }
155 #endif
156
157 if (failing()) return;
158
159 finalize_offsets_and_shorten(blk_starts);
160
161 BuildOopMaps();
162
163 if (failing()) return;
164
165 fill_buffer(cb, blk_starts);
166 }
167
168 bool Compile::need_stack_bang(int frame_size_in_bytes) const {
169 // Determine if we need to generate a stack overflow check.
170 // Do it if the method is not a stub function and
171 // has java calls or has frame size > vm_page_size/8.
172 return (stub_function() == NULL &&
173 (has_java_calls() || frame_size_in_bytes > os::vm_page_size()>>3));
174 }
175
176 bool Compile::need_register_stack_bang() const {
177 // Determine if we need to generate a register stack overflow check.
178 // This is only used on architectures which have split register
179 // and memory stacks (ie. IA64).
180 // Bang if the method is not a stub function and has java calls
181 return (stub_function() == NULL && has_java_calls());
182 }
183
184 # ifdef ENABLE_ZAP_DEAD_LOCALS
185
186
187 // In order to catch compiler oop-map bugs, we have implemented
188 // a debugging mode called ZapDeadCompilerLocals.
189 // This mode causes the compiler to insert a call to a runtime routine,
190 // "zap_dead_locals", right before each place in compiled code
191 // that could potentially be a gc-point (i.e., a safepoint or oop map point).
192 // The runtime routine checks that locations mapped as oops are really
193 // oops, that locations mapped as values do not look like oops,
194 // and that locations mapped as dead are not used later
195 // (by zapping them to an invalid address).
196
197 int Compile::_CompiledZap_count = 0;
198
199 void Compile::Insert_zap_nodes() {
200 bool skip = false;
201
202
203 // Dink with static counts because code code without the extra
204 // runtime calls is MUCH faster for debugging purposes
205
206 if ( CompileZapFirst == 0 ) ; // nothing special
207 else if ( CompileZapFirst > CompiledZap_count() ) skip = true;
208 else if ( CompileZapFirst == CompiledZap_count() )
209 warning("starting zap compilation after skipping");
210
211 if ( CompileZapLast == -1 ) ; // nothing special
212 else if ( CompileZapLast < CompiledZap_count() ) skip = true;
213 else if ( CompileZapLast == CompiledZap_count() )
214 warning("about to compile last zap");
215
216 ++_CompiledZap_count; // counts skipped zaps, too
217
218 if ( skip ) return;
219
220
221 if ( _method == NULL )
222 return; // no safepoints/oopmaps emitted for calls in stubs,so we don't care
223
224 // Insert call to zap runtime stub before every node with an oop map
225 for( uint i=0; i<_cfg->_num_blocks; i++ ) {
226 Block *b = _cfg->_blocks[i];
227 for ( uint j = 0; j < b->_nodes.size(); ++j ) {
228 Node *n = b->_nodes[j];
229
230 // Determining if we should insert a zap-a-lot node in output.
231 // We do that for all nodes that has oopmap info, except for calls
232 // to allocation. Calls to allocation passes in the old top-of-eden pointer
233 // and expect the C code to reset it. Hence, there can be no safepoints between
234 // the inlined-allocation and the call to new_Java, etc.
235 // We also cannot zap monitor calls, as they must hold the microlock
236 // during the call to Zap, which also wants to grab the microlock.
237 bool insert = n->is_MachSafePoint() && (n->as_MachSafePoint()->oop_map() != NULL);
238 if ( insert ) { // it is MachSafePoint
239 if ( !n->is_MachCall() ) {
240 insert = false;
241 } else if ( n->is_MachCall() ) {
242 MachCallNode* call = n->as_MachCall();
243 if (call->entry_point() == OptoRuntime::new_instance_Java() ||
244 call->entry_point() == OptoRuntime::new_array_Java() ||
245 call->entry_point() == OptoRuntime::multianewarray2_Java() ||
246 call->entry_point() == OptoRuntime::multianewarray3_Java() ||
247 call->entry_point() == OptoRuntime::multianewarray4_Java() ||
248 call->entry_point() == OptoRuntime::multianewarray5_Java() ||
249 call->entry_point() == OptoRuntime::slow_arraycopy_Java() ||
250 call->entry_point() == OptoRuntime::complete_monitor_locking_Java()
251 ) {
252 insert = false;
253 }
254 }
255 if (insert) {
256 Node *zap = call_zap_node(n->as_MachSafePoint(), i);
257 b->_nodes.insert( j, zap );
258 _cfg->_bbs.map( zap->_idx, b );
259 ++j;
260 }
261 }
262 }
263 }
264 }
265
266
267 Node* Compile::call_zap_node(MachSafePointNode* node_to_check, int block_no) {
268 const TypeFunc *tf = OptoRuntime::zap_dead_locals_Type();
269 CallStaticJavaNode* ideal_node =
270 new (this, tf->domain()->cnt()) CallStaticJavaNode( tf,
271 OptoRuntime::zap_dead_locals_stub(_method->flags().is_native()),
272 "call zap dead locals stub", 0, TypePtr::BOTTOM);
273 // We need to copy the OopMap from the site we're zapping at.
274 // We have to make a copy, because the zap site might not be
275 // a call site, and zap_dead is a call site.
276 OopMap* clone = node_to_check->oop_map()->deep_copy();
277
278 // Add the cloned OopMap to the zap node
279 ideal_node->set_oop_map(clone);
280 return _matcher->match_sfpt(ideal_node);
281 }
282
283 //------------------------------is_node_getting_a_safepoint--------------------
284 bool Compile::is_node_getting_a_safepoint( Node* n) {
285 // This code duplicates the logic prior to the call of add_safepoint
286 // below in this file.
287 if( n->is_MachSafePoint() ) return true;
288 return false;
289 }
290
291 # endif // ENABLE_ZAP_DEAD_LOCALS
292
293 //------------------------------compute_loop_first_inst_sizes------------------
294 // Compute the size of first NumberOfLoopInstrToAlign instructions at the top
295 // of a loop. When aligning a loop we need to provide enough instructions
296 // in cpu's fetch buffer to feed decoders. The loop alignment could be
297 // avoided if we have enough instructions in fetch buffer at the head of a loop.
298 // By default, the size is set to 999999 by Block's constructor so that
299 // a loop will be aligned if the size is not reset here.
300 //
301 // Note: Mach instructions could contain several HW instructions
302 // so the size is estimated only.
303 //
304 void Compile::compute_loop_first_inst_sizes() {
305 // The next condition is used to gate the loop alignment optimization.
306 // Don't aligned a loop if there are enough instructions at the head of a loop
307 // or alignment padding is larger then MaxLoopPad. By default, MaxLoopPad
308 // is equal to OptoLoopAlignment-1 except on new Intel cpus, where it is
309 // equal to 11 bytes which is the largest address NOP instruction.
310 if( MaxLoopPad < OptoLoopAlignment-1 ) {
311 uint last_block = _cfg->_num_blocks-1;
312 for( uint i=1; i <= last_block; i++ ) {
313 Block *b = _cfg->_blocks[i];
314 // Check the first loop's block which requires an alignment.
315 if( b->loop_alignment() > (uint)relocInfo::addr_unit() ) {
316 uint sum_size = 0;
317 uint inst_cnt = NumberOfLoopInstrToAlign;
318 inst_cnt = b->compute_first_inst_size(sum_size, inst_cnt, _regalloc);
319
320 // Check subsequent fallthrough blocks if the loop's first
321 // block(s) does not have enough instructions.
322 Block *nb = b;
323 while( inst_cnt > 0 &&
324 i < last_block &&
325 !_cfg->_blocks[i+1]->has_loop_alignment() &&
326 !nb->has_successor(b) ) {
327 i++;
328 nb = _cfg->_blocks[i];
329 inst_cnt = nb->compute_first_inst_size(sum_size, inst_cnt, _regalloc);
330 } // while( inst_cnt > 0 && i < last_block )
331
332 b->set_first_inst_size(sum_size);
333 } // f( b->head()->is_Loop() )
334 } // for( i <= last_block )
335 } // if( MaxLoopPad < OptoLoopAlignment-1 )
336 }
337
338 //----------------------shorten_branches---------------------------------------
339 // The architecture description provides short branch variants for some long
340 // branch instructions. Replace eligible long branches with short branches.
341 void Compile::shorten_branches(uint* blk_starts, int& code_size, int& reloc_size, int& stub_size) {
342
343 // ------------------
344 // Compute size of each block, method size, and relocation information size
345 uint nblocks = _cfg->_num_blocks;
346
347 uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
348 uint* jmp_size = NEW_RESOURCE_ARRAY(uint,nblocks);
349 int* jmp_nidx = NEW_RESOURCE_ARRAY(int ,nblocks);
350 DEBUG_ONLY( uint *jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks); )
351 DEBUG_ONLY( uint *jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks); )
352
353 bool has_short_branch_candidate = false;
354
355 // Initialize the sizes to 0
356 code_size = 0; // Size in bytes of generated code
357 stub_size = 0; // Size in bytes of all stub entries
358 // Size in bytes of all relocation entries, including those in local stubs.
359 // Start with 2-bytes of reloc info for the unvalidated entry point
360 reloc_size = 1; // Number of relocation entries
361
362 // Make three passes. The first computes pessimistic blk_starts,
363 // relative jmp_offset and reloc_size information. The second performs
364 // short branch substitution using the pessimistic sizing. The
365 // third inserts nops where needed.
366
367 // Step one, perform a pessimistic sizing pass.
368 uint last_call_adr = max_uint;
369 uint last_avoid_back_to_back_adr = max_uint;
370 uint nop_size = (new (this) MachNopNode())->size(_regalloc);
371 for (uint i = 0; i < nblocks; i++) { // For all blocks
372 Block *b = _cfg->_blocks[i];
373
374 // During short branch replacement, we store the relative (to blk_starts)
375 // offset of jump in jmp_offset, rather than the absolute offset of jump.
376 // This is so that we do not need to recompute sizes of all nodes when
377 // we compute correct blk_starts in our next sizing pass.
378 jmp_offset[i] = 0;
379 jmp_size[i] = 0;
380 jmp_nidx[i] = -1;
381 DEBUG_ONLY( jmp_target[i] = 0; )
382 DEBUG_ONLY( jmp_rule[i] = 0; )
383
384 // Sum all instruction sizes to compute block size
385 uint last_inst = b->_nodes.size();
386 uint blk_size = 0;
387 for (uint j = 0; j < last_inst; j++) {
388 Node* nj = b->_nodes[j];
389 uint inst_size = nj->size(_regalloc);
390 // Handle machine instruction nodes
391 if (nj->is_Mach()) {
392 MachNode *mach = nj->as_Mach();
393 blk_size += (mach->alignment_required() - 1) * relocInfo::addr_unit(); // assume worst case padding
394 reloc_size += mach->reloc();
395 if( mach->is_MachCall() ) {
396 MachCallNode *mcall = mach->as_MachCall();
397 // This destination address is NOT PC-relative
398
399 mcall->method_set((intptr_t)mcall->entry_point());
400
401 if( mcall->is_MachCallJava() && mcall->as_MachCallJava()->_method ) {
402 stub_size += size_java_to_interp();
403 reloc_size += reloc_java_to_interp();
404 }
405 } else if (mach->is_MachSafePoint()) {
406 // If call/safepoint are adjacent, account for possible
407 // nop to disambiguate the two safepoints.
408 // ScheduleAndBundle() can rearrange nodes in a block,
409 // check for all offsets inside this block.
410 if (last_call_adr >= blk_starts[i]) {
411 blk_size += nop_size;
412 }
413 }
414 if (mach->avoid_back_to_back()) {
415 // Nop is inserted between "avoid back to back" instructions.
416 // ScheduleAndBundle() can rearrange nodes in a block,
417 // check for all offsets inside this block.
418 if (last_avoid_back_to_back_adr >= blk_starts[i]) {
419 blk_size += nop_size;
420 }
421 }
422 if (mach->may_be_short_branch()) {
423 if (!nj->is_MachBranch()) {
424 #ifndef PRODUCT
425 nj->dump(3);
426 #endif
427 Unimplemented();
428 }
429 assert(jmp_nidx[i] == -1, "block should have only one branch");
430 jmp_offset[i] = blk_size;
431 jmp_size[i] = inst_size;
432 jmp_nidx[i] = j;
433 has_short_branch_candidate = true;
434 }
435 }
436 blk_size += inst_size;
437 // Remember end of call offset
438 if (nj->is_MachCall() && !nj->is_MachCallLeaf()) {
439 last_call_adr = blk_starts[i]+blk_size;
440 }
441 // Remember end of avoid_back_to_back offset
442 if (nj->is_Mach() && nj->as_Mach()->avoid_back_to_back()) {
443 last_avoid_back_to_back_adr = blk_starts[i]+blk_size;
444 }
445 }
446
447 // When the next block starts a loop, we may insert pad NOP
448 // instructions. Since we cannot know our future alignment,
449 // assume the worst.
450 if (i< nblocks-1) {
451 Block *nb = _cfg->_blocks[i+1];
452 int max_loop_pad = nb->code_alignment()-relocInfo::addr_unit();
453 if (max_loop_pad > 0) {
454 assert(is_power_of_2(max_loop_pad+relocInfo::addr_unit()), "");
455 blk_size += max_loop_pad;
456 }
457 }
458
459 // Save block size; update total method size
460 blk_starts[i+1] = blk_starts[i]+blk_size;
461 }
462
463 // Step two, replace eligible long jumps.
464 bool progress = true;
465 uint last_may_be_short_branch_adr = max_uint;
466 while (has_short_branch_candidate && progress) {
467 progress = false;
468 has_short_branch_candidate = false;
469 int adjust_block_start = 0;
470 for (uint i = 0; i < nblocks; i++) {
471 Block *b = _cfg->_blocks[i];
472 int idx = jmp_nidx[i];
473 MachNode* mach = (idx == -1) ? NULL: b->_nodes[idx]->as_Mach();
474 if (mach != NULL && mach->may_be_short_branch()) {
475 #ifdef ASSERT
476 assert(jmp_size[i] > 0 && mach->is_MachBranch(), "sanity");
477 int j;
478 // Find the branch; ignore trailing NOPs.
479 for (j = b->_nodes.size()-1; j>=0; j--) {
480 Node* n = b->_nodes[j];
481 if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con)
482 break;
483 }
484 assert(j >= 0 && j == idx && b->_nodes[j] == (Node*)mach, "sanity");
485 #endif
486 int br_size = jmp_size[i];
487 int br_offs = blk_starts[i] + jmp_offset[i];
488
489 // This requires the TRUE branch target be in succs[0]
490 uint bnum = b->non_connector_successor(0)->_pre_order;
491 int offset = blk_starts[bnum] - br_offs;
492 if (bnum > i) { // adjust following block's offset
493 offset -= adjust_block_start;
494 }
495 // In the following code a nop could be inserted before
496 // the branch which will increase the backward distance.
497 bool needs_padding = ((uint)br_offs == last_may_be_short_branch_adr);
498 if (needs_padding && offset <= 0)
499 offset -= nop_size;
500
501 if (_matcher->is_short_branch_offset(mach->rule(), br_size, offset)) {
502 // We've got a winner. Replace this branch.
503 MachNode* replacement = mach->as_MachBranch()->short_branch_version(this);
504
505 // Update the jmp_size.
506 int new_size = replacement->size(_regalloc);
507 int diff = br_size - new_size;
508 assert(diff >= (int)nop_size, "short_branch size should be smaller");
509 // Conservatively take into accound padding between
510 // avoid_back_to_back branches. Previous branch could be
511 // converted into avoid_back_to_back branch during next
512 // rounds.
513 if (needs_padding && replacement->avoid_back_to_back()) {
514 jmp_offset[i] += nop_size;
515 diff -= nop_size;
516 }
517 adjust_block_start += diff;
518 b->_nodes.map(idx, replacement);
519 mach->subsume_by(replacement);
520 mach = replacement;
521 progress = true;
522
523 jmp_size[i] = new_size;
524 DEBUG_ONLY( jmp_target[i] = bnum; );
525 DEBUG_ONLY( jmp_rule[i] = mach->rule(); );
526 } else {
527 // The jump distance is not short, try again during next iteration.
528 has_short_branch_candidate = true;
529 }
530 } // (mach->may_be_short_branch())
531 if (mach != NULL && (mach->may_be_short_branch() ||
532 mach->avoid_back_to_back())) {
533 last_may_be_short_branch_adr = blk_starts[i] + jmp_offset[i] + jmp_size[i];
534 }
535 blk_starts[i+1] -= adjust_block_start;
536 }
537 }
538
539 #ifdef ASSERT
540 for (uint i = 0; i < nblocks; i++) { // For all blocks
541 if (jmp_target[i] != 0) {
542 int br_size = jmp_size[i];
543 int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
544 if (!_matcher->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
545 tty->print_cr("target (%d) - jmp_offset(%d) = offset (%d), jump_size(%d), jmp_block B%d, target_block B%d", blk_starts[jmp_target[i]], blk_starts[i] + jmp_offset[i], offset, br_size, i, jmp_target[i]);
546 }
547 assert(_matcher->is_short_branch_offset(jmp_rule[i], br_size, offset), "Displacement too large for short jmp");
548 }
549 }
550 #endif
551
552 // Step 3, compute the offsets of all blocks, will be done in finalize_offsets_and_shorten()
553 // after ScheduleAndBundle().
554
555 // ------------------
556 // Compute size for code buffer
557 code_size = blk_starts[nblocks];
558
559 // Relocation records
560 reloc_size += 1; // Relo entry for exception handler
561
562 // Adjust reloc_size to number of record of relocation info
563 // Min is 2 bytes, max is probably 6 or 8, with a tax up to 25% for
564 // a relocation index.
565 // The CodeBuffer will expand the locs array if this estimate is too low.
566 reloc_size *= 10 / sizeof(relocInfo);
567 }
568
569 //----------------------finalize_offsets_and_shorten-------------------------
570 void Compile::finalize_offsets_and_shorten(uint* blk_starts) {
571 // blk_starts[] contains offsets calculated during short branches processing,
572 // offsets should not be increased during following steps.
573
574 // Compute the size of first NumberOfLoopInstrToAlign instructions at head
575 // of a loop. It is used to determine the padding for loop alignment.
576 compute_loop_first_inst_sizes();
577
578 uint nblocks = _cfg->_num_blocks;
579 #ifdef ASSERT
580 uint* jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks);
581 uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
582 uint* jmp_size = NEW_RESOURCE_ARRAY(uint,nblocks);
583 uint* jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks);
584 #endif
585
586 // Inserts nops where needed and do final short branches replacement.
587 uint nop_size = (new (this) MachNopNode())->size(_regalloc);
588 uint last_call_adr = max_uint;
589 uint last_avoid_back_to_back_adr = max_uint;
590
591 assert(blk_starts[0] == 0, "sanity");
592 uint current_offset = 0;
593 uint block_alignment_padding = 0;
594
595 for (uint i=0; i < nblocks; i++) { // For all blocks
596 Block *b = _cfg->_blocks[i];
597
598 #ifdef ASSERT
599 jmp_target[i] = 0;
600 jmp_offset[i] = 0;
601 jmp_size[i] = 0;
602 jmp_rule[i] = 0;
603 #endif
604
605 // Maximum alignment was added before loop block during
606 // Step One, as result padding for nodes was not added.
607 // Take this into account for block's size change check
608 // and allow increase block's size by the difference
609 // of maximum and actual alignment paddings.
610 DEBUG_ONLY( uint orig_blk_size = blk_starts[i+1] - blk_starts[i] + block_alignment_padding; )
611 uint blk_offset = current_offset;
612
613 uint last_inst = b->_nodes.size();
614 for (uint j = 0; j<last_inst; j++) {
615 Node* nj = b->_nodes[j];
616
617 if (valid_bundle_info(nj) &&
618 node_bundling(nj)->used_in_unconditional_delay()) {
619 continue; // Skip instruction in delay slot
620 }
621
622 uint inst_size = nj->size(_regalloc);
623 if (nj->is_Mach()) {
624 MachNode *mach = nj->as_Mach();
625 int padding = mach->compute_padding(current_offset);
626
627 // If call/safepoint are adjacent insert a nop (5010568)
628 if (padding == 0 && nj->is_MachSafePoint() && !nj->is_MachCall() &&
629 current_offset == last_call_adr) {
630 padding = nop_size;
631 }
632
633 // Inserted a nop between "avoid back to back" instructions.
634 if (padding == 0 && mach->avoid_back_to_back() &&
635 current_offset == last_avoid_back_to_back_adr) {
636 padding = nop_size;
637 }
638
639 if (padding > 0) {
640 assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
641 int nops_cnt = padding / nop_size;
642 MachNode *nop = new (this) MachNopNode(nops_cnt);
643 b->_nodes.insert(j++, nop);
644 _cfg->_bbs.map(nop->_idx, b);
645 last_inst++;
646 current_offset += padding;
647 }
648
649 // Try to replace long branch if delay slot is not used,
650 // it is mostly for back branches since forward branch's
651 // distance is not updated yet.
652 bool delay_slot_is_used = valid_bundle_info(nj) &&
653 node_bundling(nj)->use_unconditional_delay();
654 if (!delay_slot_is_used && mach->may_be_short_branch()) {
655 int br_size = inst_size;
656
657 // This requires the TRUE branch target be in succs[0]
658 uint bnum = b->non_connector_successor(0)->_pre_order;
659 int offset = blk_starts[bnum] - current_offset;
660 if (bnum >= i) {
661 // Current and following block's offset are not
662 // finilized yet, adjust distance.
663 offset -= (blk_starts[i] - blk_offset);
664 }
665 // In the following code a nop could be inserted before
666 // the branch which will increase the backward distance.
667 bool needs_padding = (current_offset == last_avoid_back_to_back_adr);
668 if (needs_padding && offset <= 0)
669 offset -= nop_size;
670
671 if (_matcher->is_short_branch_offset(mach->rule(), br_size, offset)) {
672 // We've got a winner. Replace this branch.
673 MachNode* replacement = mach->as_MachBranch()->short_branch_version(this);
674
675 // Update the jmp_size.
676 int new_size = replacement->size(_regalloc);
677 assert((br_size - new_size) >= (int)nop_size, "short_branch size should be smaller");
678 // Conservatively take into accound padding between
679 // avoid_back_to_back branches. Previous branch could be
680 // converted into avoid_back_to_back branch during next
681 // rounds.
682 if (needs_padding && replacement->avoid_back_to_back()) {
683 MachNode *nop = new (this) MachNopNode();
684 b->_nodes.insert(j++, nop);
685 _cfg->_bbs.map(nop->_idx, b);
686 last_inst++;
687 current_offset += nop_size;
688 }
689 inst_size = new_size;
690 b->_nodes.map(j, replacement);
691 mach->subsume_by(replacement);
692 nj = replacement;
693 #ifdef ASSERT
694 jmp_target[i] = bnum;
695 jmp_offset[i] = current_offset - blk_offset;
696 jmp_size[i] = new_size;
697 jmp_rule[i] = mach->rule();
698 #endif
699 }
700 }
701 }
702 current_offset += inst_size;
703
704 // Remember end of call offset
705 if (nj->is_MachCall() && !nj->is_MachCallLeaf()) {
706 last_call_adr = current_offset;
707 }
708 // Remember end of avoid_back_to_back offset
709 if (nj->is_Mach() && nj->as_Mach()->avoid_back_to_back()) {
710 last_avoid_back_to_back_adr = current_offset;
711 }
712 }
713 assert(blk_offset <= blk_starts[i], "shouldn't increase distance");
714 blk_starts[i] = blk_offset;
715
716 // When the next block is the top of a loop, we may insert pad NOP
717 // instructions.
718 if (i < nblocks-1) {
719 Block *nb = _cfg->_blocks[i+1];
720 int padding = nb->alignment_padding(current_offset);
721 if (padding > 0) {
722 assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
723 int nops_cnt = padding / nop_size;
724 MachNode *nop = new (this) MachNopNode(nops_cnt);
725 b->_nodes.insert(b->_nodes.size(), nop);
726 _cfg->_bbs.map(nop->_idx, b);
727 current_offset += padding;
728 }
729 int max_loop_pad = nb->code_alignment()-relocInfo::addr_unit();
730 assert(max_loop_pad >= padding, "sanity");
731 block_alignment_padding = max_loop_pad - padding;
732 }
733 assert(orig_blk_size >= (current_offset - blk_offset), "shouldn't increase block size");
734 }
735 blk_starts[nblocks] = current_offset;
736
737 #ifdef ASSERT
738 for (uint i = 0; i < nblocks; i++) { // For all blocks
739 if (jmp_target[i] != 0) {
740 int br_size = jmp_size[i];
741 int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
742 if (!_matcher->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
743 tty->print_cr("target (%d) - jmp_offset(%d) = offset (%d), jump_size(%d), jmp_block B%d, target_block B%d", blk_starts[jmp_target[i]], blk_starts[i] + jmp_offset[i], offset, br_size, i, jmp_target[i]);
744 }
745 assert(_matcher->is_short_branch_offset(jmp_rule[i], br_size, offset), "Displacement too large for short jmp");
746 }
747 }
748 #endif
749 }
750
751 //------------------------------FillLocArray-----------------------------------
752 // Create a bit of debug info and append it to the array. The mapping is from
753 // Java local or expression stack to constant, register or stack-slot. For
754 // doubles, insert 2 mappings and return 1 (to tell the caller that the next
755 // entry has been taken care of and caller should skip it).
756 static LocationValue *new_loc_value( PhaseRegAlloc *ra, OptoReg::Name regnum, Location::Type l_type ) {
757 // This should never have accepted Bad before
758 assert(OptoReg::is_valid(regnum), "location must be valid");
759 return (OptoReg::is_reg(regnum))
760 ? new LocationValue(Location::new_reg_loc(l_type, OptoReg::as_VMReg(regnum)) )
761 : new LocationValue(Location::new_stk_loc(l_type, ra->reg2offset(regnum)));
762 }
763
764
765 ObjectValue*
766 Compile::sv_for_node_id(GrowableArray<ScopeValue*> *objs, int id) {
767 for (int i = 0; i < objs->length(); i++) {
768 assert(objs->at(i)->is_object(), "corrupt object cache");
769 ObjectValue* sv = (ObjectValue*) objs->at(i);
770 if (sv->id() == id) {
771 return sv;
772 }
773 }
774 // Otherwise..
775 return NULL;
776 }
777
778 void Compile::set_sv_for_object_node(GrowableArray<ScopeValue*> *objs,
779 ObjectValue* sv ) {
780 assert(sv_for_node_id(objs, sv->id()) == NULL, "Precondition");
781 objs->append(sv);
782 }
783
784
785 void Compile::FillLocArray( int idx, MachSafePointNode* sfpt, Node *local,
786 GrowableArray<ScopeValue*> *array,
787 GrowableArray<ScopeValue*> *objs ) {
788 assert( local, "use _top instead of null" );
789 if (array->length() != idx) {
790 assert(array->length() == idx + 1, "Unexpected array count");
791 // Old functionality:
792 // return
793 // New functionality:
794 // Assert if the local is not top. In product mode let the new node
795 // override the old entry.
796 assert(local == top(), "LocArray collision");
797 if (local == top()) {
798 return;
799 }
800 array->pop();
801 }
802 const Type *t = local->bottom_type();
803
804 // Is it a safepoint scalar object node?
805 if (local->is_SafePointScalarObject()) {
806 SafePointScalarObjectNode* spobj = local->as_SafePointScalarObject();
807
808 ObjectValue* sv = Compile::sv_for_node_id(objs, spobj->_idx);
809 if (sv == NULL) {
810 ciKlass* cik = t->is_oopptr()->klass();
811 assert(cik->is_instance_klass() ||
812 cik->is_array_klass(), "Not supported allocation.");
813 sv = new ObjectValue(spobj->_idx,
814 new ConstantOopWriteValue(cik->constant_encoding()));
815 Compile::set_sv_for_object_node(objs, sv);
816
817 uint first_ind = spobj->first_index();
818 for (uint i = 0; i < spobj->n_fields(); i++) {
819 Node* fld_node = sfpt->in(first_ind+i);
820 (void)FillLocArray(sv->field_values()->length(), sfpt, fld_node, sv->field_values(), objs);
821 }
822 }
823 array->append(sv);
824 return;
825 }
826
827 // Grab the register number for the local
828 OptoReg::Name regnum = _regalloc->get_reg_first(local);
829 if( OptoReg::is_valid(regnum) ) {// Got a register/stack?
830 // Record the double as two float registers.
831 // The register mask for such a value always specifies two adjacent
832 // float registers, with the lower register number even.
833 // Normally, the allocation of high and low words to these registers
834 // is irrelevant, because nearly all operations on register pairs
835 // (e.g., StoreD) treat them as a single unit.
836 // Here, we assume in addition that the words in these two registers
837 // stored "naturally" (by operations like StoreD and double stores
838 // within the interpreter) such that the lower-numbered register
839 // is written to the lower memory address. This may seem like
840 // a machine dependency, but it is not--it is a requirement on
841 // the author of the <arch>.ad file to ensure that, for every
842 // even/odd double-register pair to which a double may be allocated,
843 // the word in the even single-register is stored to the first
844 // memory word. (Note that register numbers are completely
845 // arbitrary, and are not tied to any machine-level encodings.)
846 #ifdef _LP64
847 if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon ) {
848 array->append(new ConstantIntValue(0));
849 array->append(new_loc_value( _regalloc, regnum, Location::dbl ));
850 } else if ( t->base() == Type::Long ) {
851 array->append(new ConstantIntValue(0));
852 array->append(new_loc_value( _regalloc, regnum, Location::lng ));
853 } else if ( t->base() == Type::RawPtr ) {
854 // jsr/ret return address which must be restored into a the full
855 // width 64-bit stack slot.
856 array->append(new_loc_value( _regalloc, regnum, Location::lng ));
857 }
858 #else //_LP64
859 #ifdef SPARC
860 if (t->base() == Type::Long && OptoReg::is_reg(regnum)) {
861 // For SPARC we have to swap high and low words for
862 // long values stored in a single-register (g0-g7).
863 array->append(new_loc_value( _regalloc, regnum , Location::normal ));
864 array->append(new_loc_value( _regalloc, OptoReg::add(regnum,1), Location::normal ));
865 } else
866 #endif //SPARC
867 if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon || t->base() == Type::Long ) {
868 // Repack the double/long as two jints.
869 // The convention the interpreter uses is that the second local
870 // holds the first raw word of the native double representation.
871 // This is actually reasonable, since locals and stack arrays
872 // grow downwards in all implementations.
873 // (If, on some machine, the interpreter's Java locals or stack
874 // were to grow upwards, the embedded doubles would be word-swapped.)
875 array->append(new_loc_value( _regalloc, OptoReg::add(regnum,1), Location::normal ));
876 array->append(new_loc_value( _regalloc, regnum , Location::normal ));
877 }
878 #endif //_LP64
879 else if( (t->base() == Type::FloatBot || t->base() == Type::FloatCon) &&
880 OptoReg::is_reg(regnum) ) {
881 array->append(new_loc_value( _regalloc, regnum, Matcher::float_in_double()
882 ? Location::float_in_dbl : Location::normal ));
883 } else if( t->base() == Type::Int && OptoReg::is_reg(regnum) ) {
884 array->append(new_loc_value( _regalloc, regnum, Matcher::int_in_long
885 ? Location::int_in_long : Location::normal ));
886 } else if( t->base() == Type::NarrowOop ) {
887 array->append(new_loc_value( _regalloc, regnum, Location::narrowoop ));
888 } else {
889 array->append(new_loc_value( _regalloc, regnum, _regalloc->is_oop(local) ? Location::oop : Location::normal ));
890 }
891 return;
892 }
893
894 // No register. It must be constant data.
895 switch (t->base()) {
896 case Type::Half: // Second half of a double
897 ShouldNotReachHere(); // Caller should skip 2nd halves
898 break;
899 case Type::AnyPtr:
900 array->append(new ConstantOopWriteValue(NULL));
901 break;
902 case Type::AryPtr:
903 case Type::InstPtr:
904 case Type::KlassPtr: // fall through
905 array->append(new ConstantOopWriteValue(t->isa_oopptr()->const_oop()->constant_encoding()));
906 break;
907 case Type::NarrowOop:
908 if (t == TypeNarrowOop::NULL_PTR) {
909 array->append(new ConstantOopWriteValue(NULL));
910 } else {
911 array->append(new ConstantOopWriteValue(t->make_ptr()->isa_oopptr()->const_oop()->constant_encoding()));
912 }
913 break;
914 case Type::Int:
915 array->append(new ConstantIntValue(t->is_int()->get_con()));
916 break;
917 case Type::RawPtr:
918 // A return address (T_ADDRESS).
919 assert((intptr_t)t->is_ptr()->get_con() < (intptr_t)0x10000, "must be a valid BCI");
920 #ifdef _LP64
921 // Must be restored to the full-width 64-bit stack slot.
922 array->append(new ConstantLongValue(t->is_ptr()->get_con()));
923 #else
924 array->append(new ConstantIntValue(t->is_ptr()->get_con()));
925 #endif
926 break;
927 case Type::FloatCon: {
928 float f = t->is_float_constant()->getf();
929 array->append(new ConstantIntValue(jint_cast(f)));
930 break;
931 }
932 case Type::DoubleCon: {
933 jdouble d = t->is_double_constant()->getd();
934 #ifdef _LP64
935 array->append(new ConstantIntValue(0));
936 array->append(new ConstantDoubleValue(d));
937 #else
938 // Repack the double as two jints.
939 // The convention the interpreter uses is that the second local
940 // holds the first raw word of the native double representation.
941 // This is actually reasonable, since locals and stack arrays
942 // grow downwards in all implementations.
943 // (If, on some machine, the interpreter's Java locals or stack
944 // were to grow upwards, the embedded doubles would be word-swapped.)
945 jint *dp = (jint*)&d;
946 array->append(new ConstantIntValue(dp[1]));
947 array->append(new ConstantIntValue(dp[0]));
948 #endif
949 break;
950 }
951 case Type::Long: {
952 jlong d = t->is_long()->get_con();
953 #ifdef _LP64
954 array->append(new ConstantIntValue(0));
955 array->append(new ConstantLongValue(d));
956 #else
957 // Repack the long as two jints.
958 // The convention the interpreter uses is that the second local
959 // holds the first raw word of the native double representation.
960 // This is actually reasonable, since locals and stack arrays
961 // grow downwards in all implementations.
962 // (If, on some machine, the interpreter's Java locals or stack
963 // were to grow upwards, the embedded doubles would be word-swapped.)
964 jint *dp = (jint*)&d;
965 array->append(new ConstantIntValue(dp[1]));
966 array->append(new ConstantIntValue(dp[0]));
967 #endif
968 break;
969 }
970 case Type::Top: // Add an illegal value here
971 array->append(new LocationValue(Location()));
972 break;
973 default:
974 ShouldNotReachHere();
975 break;
976 }
977 }
978
979 // Determine if this node starts a bundle
980 bool Compile::starts_bundle(const Node *n) const {
981 return (_node_bundling_limit > n->_idx &&
982 _node_bundling_base[n->_idx].starts_bundle());
983 }
984
985 //--------------------------Process_OopMap_Node--------------------------------
986 void Compile::Process_OopMap_Node(MachNode *mach, int current_offset) {
987
988 // Handle special safepoint nodes for synchronization
989 MachSafePointNode *sfn = mach->as_MachSafePoint();
990 MachCallNode *mcall;
991
992 #ifdef ENABLE_ZAP_DEAD_LOCALS
993 assert( is_node_getting_a_safepoint(mach), "logic does not match; false negative");
994 #endif
995
996 int safepoint_pc_offset = current_offset;
997 bool is_method_handle_invoke = false;
998 bool return_oop = false;
999
1000 // Add the safepoint in the DebugInfoRecorder
1001 if( !mach->is_MachCall() ) {
1002 mcall = NULL;
1003 debug_info()->add_safepoint(safepoint_pc_offset, sfn->_oop_map);
1004 } else {
1005 mcall = mach->as_MachCall();
1006
1007 // Is the call a MethodHandle call?
1008 if (mcall->is_MachCallJava()) {
1009 if (mcall->as_MachCallJava()->_method_handle_invoke) {
1010 assert(has_method_handle_invokes(), "must have been set during call generation");
1011 is_method_handle_invoke = true;
1012 }
1013 }
1014
1015 // Check if a call returns an object.
1016 if (mcall->return_value_is_used() &&
1017 mcall->tf()->range()->field_at(TypeFunc::Parms)->isa_ptr()) {
1018 return_oop = true;
1019 }
1020 safepoint_pc_offset += mcall->ret_addr_offset();
1021 debug_info()->add_safepoint(safepoint_pc_offset, mcall->_oop_map);
1022 }
1023
1024 // Loop over the JVMState list to add scope information
1025 // Do not skip safepoints with a NULL method, they need monitor info
1026 JVMState* youngest_jvms = sfn->jvms();
1027 int max_depth = youngest_jvms->depth();
1028
1029 // Allocate the object pool for scalar-replaced objects -- the map from
1030 // small-integer keys (which can be recorded in the local and ostack
1031 // arrays) to descriptions of the object state.
1032 GrowableArray<ScopeValue*> *objs = new GrowableArray<ScopeValue*>();
1033
1034 // Visit scopes from oldest to youngest.
1035 for (int depth = 1; depth <= max_depth; depth++) {
1036 JVMState* jvms = youngest_jvms->of_depth(depth);
1037 int idx;
1038 ciMethod* method = jvms->has_method() ? jvms->method() : NULL;
1039 // Safepoints that do not have method() set only provide oop-map and monitor info
1040 // to support GC; these do not support deoptimization.
1041 int num_locs = (method == NULL) ? 0 : jvms->loc_size();
1042 int num_exps = (method == NULL) ? 0 : jvms->stk_size();
1043 int num_mon = jvms->nof_monitors();
1044 assert(method == NULL || jvms->bci() < 0 || num_locs == method->max_locals(),
1045 "JVMS local count must match that of the method");
1046
1047 // Add Local and Expression Stack Information
1048
1049 // Insert locals into the locarray
1050 GrowableArray<ScopeValue*> *locarray = new GrowableArray<ScopeValue*>(num_locs);
1051 for( idx = 0; idx < num_locs; idx++ ) {
1052 FillLocArray( idx, sfn, sfn->local(jvms, idx), locarray, objs );
1053 }
1054
1055 // Insert expression stack entries into the exparray
1056 GrowableArray<ScopeValue*> *exparray = new GrowableArray<ScopeValue*>(num_exps);
1057 for( idx = 0; idx < num_exps; idx++ ) {
1058 FillLocArray( idx, sfn, sfn->stack(jvms, idx), exparray, objs );
1059 }
1060
1061 // Add in mappings of the monitors
1062 assert( !method ||
1063 !method->is_synchronized() ||
1064 method->is_native() ||
1065 num_mon > 0 ||
1066 !GenerateSynchronizationCode,
1067 "monitors must always exist for synchronized methods");
1068
1069 // Build the growable array of ScopeValues for exp stack
1070 GrowableArray<MonitorValue*> *monarray = new GrowableArray<MonitorValue*>(num_mon);
1071
1072 // Loop over monitors and insert into array
1073 for(idx = 0; idx < num_mon; idx++) {
1074 // Grab the node that defines this monitor
1075 Node* box_node = sfn->monitor_box(jvms, idx);
1076 Node* obj_node = sfn->monitor_obj(jvms, idx);
1077
1078 // Create ScopeValue for object
1079 ScopeValue *scval = NULL;
1080
1081 if( obj_node->is_SafePointScalarObject() ) {
1082 SafePointScalarObjectNode* spobj = obj_node->as_SafePointScalarObject();
1083 scval = Compile::sv_for_node_id(objs, spobj->_idx);
1084 if (scval == NULL) {
1085 const Type *t = obj_node->bottom_type();
1086 ciKlass* cik = t->is_oopptr()->klass();
1087 assert(cik->is_instance_klass() ||
1088 cik->is_array_klass(), "Not supported allocation.");
1089 ObjectValue* sv = new ObjectValue(spobj->_idx,
1090 new ConstantOopWriteValue(cik->constant_encoding()));
1091 Compile::set_sv_for_object_node(objs, sv);
1092
1093 uint first_ind = spobj->first_index();
1094 for (uint i = 0; i < spobj->n_fields(); i++) {
1095 Node* fld_node = sfn->in(first_ind+i);
1096 (void)FillLocArray(sv->field_values()->length(), sfn, fld_node, sv->field_values(), objs);
1097 }
1098 scval = sv;
1099 }
1100 } else if( !obj_node->is_Con() ) {
1101 OptoReg::Name obj_reg = _regalloc->get_reg_first(obj_node);
1102 if( obj_node->bottom_type()->base() == Type::NarrowOop ) {
1103 scval = new_loc_value( _regalloc, obj_reg, Location::narrowoop );
1104 } else {
1105 scval = new_loc_value( _regalloc, obj_reg, Location::oop );
1106 }
1107 } else {
1108 const TypePtr *tp = obj_node->bottom_type()->make_ptr();
1109 scval = new ConstantOopWriteValue(tp->is_oopptr()->const_oop()->constant_encoding());
1110 }
1111
1112 OptoReg::Name box_reg = BoxLockNode::stack_slot(box_node);
1113 Location basic_lock = Location::new_stk_loc(Location::normal,_regalloc->reg2offset(box_reg));
1114 while( !box_node->is_BoxLock() ) box_node = box_node->in(1);
1115 monarray->append(new MonitorValue(scval, basic_lock, box_node->as_BoxLock()->is_eliminated()));
1116 }
1117
1118 // We dump the object pool first, since deoptimization reads it in first.
1119 debug_info()->dump_object_pool(objs);
1120
1121 // Build first class objects to pass to scope
1122 DebugToken *locvals = debug_info()->create_scope_values(locarray);
1123 DebugToken *expvals = debug_info()->create_scope_values(exparray);
1124 DebugToken *monvals = debug_info()->create_monitor_values(monarray);
1125
1126 // Make method available for all Safepoints
1127 ciMethod* scope_method = method ? method : _method;
1128 // Describe the scope here
1129 assert(jvms->bci() >= InvocationEntryBci && jvms->bci() <= 0x10000, "must be a valid or entry BCI");
1130 assert(!jvms->should_reexecute() || depth == max_depth, "reexecute allowed only for the youngest");
1131 // Now we can describe the scope.
1132 debug_info()->describe_scope(safepoint_pc_offset, scope_method, jvms->bci(), jvms->should_reexecute(), is_method_handle_invoke, return_oop, locvals, expvals, monvals);
1133 } // End jvms loop
1134
1135 // Mark the end of the scope set.
1136 debug_info()->end_safepoint(safepoint_pc_offset);
1137 }
1138
1139
1140
1141 // A simplified version of Process_OopMap_Node, to handle non-safepoints.
1142 class NonSafepointEmitter {
1143 Compile* C;
1144 JVMState* _pending_jvms;
1145 int _pending_offset;
1146
1147 void emit_non_safepoint();
1148
1149 public:
1150 NonSafepointEmitter(Compile* compile) {
1151 this->C = compile;
1152 _pending_jvms = NULL;
1153 _pending_offset = 0;
1154 }
1155
1156 void observe_instruction(Node* n, int pc_offset) {
1157 if (!C->debug_info()->recording_non_safepoints()) return;
1158
1159 Node_Notes* nn = C->node_notes_at(n->_idx);
1160 if (nn == NULL || nn->jvms() == NULL) return;
1161 if (_pending_jvms != NULL &&
1162 _pending_jvms->same_calls_as(nn->jvms())) {
1163 // Repeated JVMS? Stretch it up here.
1164 _pending_offset = pc_offset;
1165 } else {
1166 if (_pending_jvms != NULL &&
1167 _pending_offset < pc_offset) {
1168 emit_non_safepoint();
1169 }
1170 _pending_jvms = NULL;
1171 if (pc_offset > C->debug_info()->last_pc_offset()) {
1172 // This is the only way _pending_jvms can become non-NULL:
1173 _pending_jvms = nn->jvms();
1174 _pending_offset = pc_offset;
1175 }
1176 }
1177 }
1178
1179 // Stay out of the way of real safepoints:
1180 void observe_safepoint(JVMState* jvms, int pc_offset) {
1181 if (_pending_jvms != NULL &&
1182 !_pending_jvms->same_calls_as(jvms) &&
1183 _pending_offset < pc_offset) {
1184 emit_non_safepoint();
1185 }
1186 _pending_jvms = NULL;
1187 }
1188
1189 void flush_at_end() {
1190 if (_pending_jvms != NULL) {
1191 emit_non_safepoint();
1192 }
1193 _pending_jvms = NULL;
1194 }
1195 };
1196
1197 void NonSafepointEmitter::emit_non_safepoint() {
1198 JVMState* youngest_jvms = _pending_jvms;
1199 int pc_offset = _pending_offset;
1200
1201 // Clear it now:
1202 _pending_jvms = NULL;
1203
1204 DebugInformationRecorder* debug_info = C->debug_info();
1205 assert(debug_info->recording_non_safepoints(), "sanity");
1206
1207 debug_info->add_non_safepoint(pc_offset);
1208 int max_depth = youngest_jvms->depth();
1209
1210 // Visit scopes from oldest to youngest.
1211 for (int depth = 1; depth <= max_depth; depth++) {
1212 JVMState* jvms = youngest_jvms->of_depth(depth);
1213 ciMethod* method = jvms->has_method() ? jvms->method() : NULL;
1214 assert(!jvms->should_reexecute() || depth==max_depth, "reexecute allowed only for the youngest");
1215 debug_info->describe_scope(pc_offset, method, jvms->bci(), jvms->should_reexecute());
1216 }
1217
1218 // Mark the end of the scope set.
1219 debug_info->end_non_safepoint(pc_offset);
1220 }
1221
1222
1223
1224 // helper for fill_buffer bailout logic
1225 static void turn_off_compiler(Compile* C) {
1226 if (CodeCache::largest_free_block() >= CodeCacheMinimumFreeSpace*10) {
1227 // Do not turn off compilation if a single giant method has
1228 // blown the code cache size.
1229 C->record_failure("excessive request to CodeCache");
1230 } else {
1231 // Let CompilerBroker disable further compilations.
1232 C->record_failure("CodeCache is full");
1233 }
1234 }
1235
1236
1237 //------------------------------init_buffer------------------------------------
1238 CodeBuffer* Compile::init_buffer(uint* blk_starts) {
1239
1240 // Set the initially allocated size
1241 int code_req = initial_code_capacity;
1242 int locs_req = initial_locs_capacity;
1243 int stub_req = TraceJumps ? initial_stub_capacity * 10 : initial_stub_capacity;
1244 int const_req = initial_const_capacity;
1245
1246 int pad_req = NativeCall::instruction_size;
1247 // The extra spacing after the code is necessary on some platforms.
1248 // Sometimes we need to patch in a jump after the last instruction,
1249 // if the nmethod has been deoptimized. (See 4932387, 4894843.)
1250
1251 // Compute the byte offset where we can store the deopt pc.
1252 if (fixed_slots() != 0) {
1253 _orig_pc_slot_offset_in_bytes = _regalloc->reg2offset(OptoReg::stack2reg(_orig_pc_slot));
1254 }
1255
1256 // Compute prolog code size
1257 _method_size = 0;
1258 _frame_slots = OptoReg::reg2stack(_matcher->_old_SP)+_regalloc->_framesize;
1259 #ifdef IA64
1260 if (save_argument_registers()) {
1261 // 4815101: this is a stub with implicit and unknown precision fp args.
1262 // The usual spill mechanism can only generate stfd's in this case, which
1263 // doesn't work if the fp reg to spill contains a single-precision denorm.
1264 // Instead, we hack around the normal spill mechanism using stfspill's and
1265 // ldffill's in the MachProlog and MachEpilog emit methods. We allocate
1266 // space here for the fp arg regs (f8-f15) we're going to thusly spill.
1267 //
1268 // If we ever implement 16-byte 'registers' == stack slots, we can
1269 // get rid of this hack and have SpillCopy generate stfspill/ldffill
1270 // instead of stfd/stfs/ldfd/ldfs.
1271 _frame_slots += 8*(16/BytesPerInt);
1272 }
1273 #endif
1274 assert(_frame_slots >= 0 && _frame_slots < 1000000, "sanity check");
1275
1276 if (has_mach_constant_base_node()) {
1277 // Fill the constant table.
1278 // Note: This must happen before shorten_branches.
1279 for (uint i = 0; i < _cfg->_num_blocks; i++) {
1280 Block* b = _cfg->_blocks[i];
1281
1282 for (uint j = 0; j < b->_nodes.size(); j++) {
1283 Node* n = b->_nodes[j];
1284
1285 // If the node is a MachConstantNode evaluate the constant
1286 // value section.
1287 if (n->is_MachConstant()) {
1288 MachConstantNode* machcon = n->as_MachConstant();
1289 machcon->eval_constant(C);
1290 }
1291 }
1292 }
1293
1294 // Calculate the offsets of the constants and the size of the
1295 // constant table (including the padding to the next section).
1296 constant_table().calculate_offsets_and_size();
1297 const_req = constant_table().size();
1298 }
1299
1300 // Initialize the space for the BufferBlob used to find and verify
1301 // instruction size in MachNode::emit_size()
1302 init_scratch_buffer_blob(const_req);
1303 if (failing()) return NULL; // Out of memory
1304
1305 // Pre-compute the length of blocks and replace
1306 // long branches with short if machine supports it.
1307 shorten_branches(blk_starts, code_req, locs_req, stub_req);
1308
1309 // nmethod and CodeBuffer count stubs & constants as part of method's code.
1310 int exception_handler_req = size_exception_handler();
1311 int deopt_handler_req = size_deopt_handler();
1312 exception_handler_req += MAX_stubs_size; // add marginal slop for handler
1313 deopt_handler_req += MAX_stubs_size; // add marginal slop for handler
1314 stub_req += MAX_stubs_size; // ensure per-stub margin
1315 code_req += MAX_inst_size; // ensure per-instruction margin
1316
1317 if (StressCodeBuffers)
1318 code_req = const_req = stub_req = exception_handler_req = deopt_handler_req = 0x10; // force expansion
1319
1320 int total_req =
1321 const_req +
1322 code_req +
1323 pad_req +
1324 stub_req +
1325 exception_handler_req +
1326 deopt_handler_req; // deopt handler
1327
1328 if (has_method_handle_invokes())
1329 total_req += deopt_handler_req; // deopt MH handler
1330
1331 CodeBuffer* cb = code_buffer();
1332 cb->initialize(total_req, locs_req);
1333
1334 // Have we run out of code space?
1335 if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
1336 turn_off_compiler(this);
1337 return NULL;
1338 }
1339 // Configure the code buffer.
1340 cb->initialize_consts_size(const_req);
1341 cb->initialize_stubs_size(stub_req);
1342 cb->initialize_oop_recorder(env()->oop_recorder());
1343
1344 // fill in the nop array for bundling computations
1345 MachNode *_nop_list[Bundle::_nop_count];
1346 Bundle::initialize_nops(_nop_list, this);
1347
1348 return cb;
1349 }
1350
1351 //------------------------------fill_buffer------------------------------------
1352 void Compile::fill_buffer(CodeBuffer* cb, uint* blk_starts) {
1353
1354 // Create oopmap set.
1355 _oop_map_set = new OopMapSet();
1356
1357 // !!!!! This preserves old handling of oopmaps for now
1358 debug_info()->set_oopmaps(_oop_map_set);
1359
1360 // Count and start of implicit null check instructions
1361 uint inct_cnt = 0;
1362 uint *inct_starts = NEW_RESOURCE_ARRAY(uint, _cfg->_num_blocks+1);
1363
1364 // Count and start of calls
1365 uint *call_returns = NEW_RESOURCE_ARRAY(uint, _cfg->_num_blocks+1);
1366
1367 uint return_offset = 0;
1368 int nop_size = (new (this) MachNopNode())->size(_regalloc);
1369
1370 int previous_offset = 0;
1371 int current_offset = 0;
1372 #ifdef ASSERT
1373 int last_call_offset = -1;
1374 int last_avoid_back_to_back_offset = -1;
1375 #endif
1376 // Create an array of unused labels, one for each basic block, if printing is enabled
1377 #ifndef PRODUCT
1378 int *node_offsets = NULL;
1379 uint node_offset_limit = unique();
1380
1381 if (print_assembly())
1382 node_offsets = NEW_RESOURCE_ARRAY(int, node_offset_limit);
1383 #endif
1384
1385 NonSafepointEmitter non_safepoints(this); // emit non-safepoints lazily
1386
1387 // Emit the constant table.
1388 if (has_mach_constant_base_node()) {
1389 constant_table().emit(*cb);
1390 }
1391
1392 // Create an array of labels, one for each basic block
1393 Label *blk_labels = NEW_RESOURCE_ARRAY(Label, _cfg->_num_blocks+1);
1394 for (uint i=0; i <= _cfg->_num_blocks; i++) {
1395 blk_labels[i].init();
1396 }
1397
1398 // ------------------
1399 // Now fill in the code buffer
1400 Node *delay_slot = NULL;
1401
1402 for (uint i=0; i < _cfg->_num_blocks; i++) {
1403 guarantee(blk_starts[i] == (uint)cb->insts_size(),"should not change size");
1404
1405 Block *b = _cfg->_blocks[i];
1406
1407 Node *head = b->head();
1408
1409 // If this block needs to start aligned (i.e, can be reached other
1410 // than by falling-thru from the previous block), then force the
1411 // start of a new bundle.
1412 if (Pipeline::requires_bundling() && starts_bundle(head))
1413 cb->flush_bundle(true);
1414
1415 #ifdef ASSERT
1416 if (!b->is_connector()) {
1417 stringStream st;
1418 b->dump_head(&_cfg->_bbs, &st);
1419 MacroAssembler(cb).block_comment(st.as_string());
1420 }
1421 #endif
1422
1423 // Define the label at the beginning of the basic block
1424 MacroAssembler(cb).bind(blk_labels[b->_pre_order]);
1425
1426 uint last_inst = b->_nodes.size();
1427
1428 // Emit block normally, except for last instruction.
1429 // Emit means "dump code bits into code buffer".
1430 for (uint j = 0; j<last_inst; j++) {
1431
1432 // Get the node
1433 Node* n = b->_nodes[j];
1434
1435 // See if delay slots are supported
1436 if (valid_bundle_info(n) &&
1437 node_bundling(n)->used_in_unconditional_delay()) {
1438 assert(delay_slot == NULL, "no use of delay slot node");
1439 assert(n->size(_regalloc) == Pipeline::instr_unit_size(), "delay slot instruction wrong size");
1440
1441 delay_slot = n;
1442 continue;
1443 }
1444
1445 // If this starts a new instruction group, then flush the current one
1446 // (but allow split bundles)
1447 if (Pipeline::requires_bundling() && starts_bundle(n))
1448 cb->flush_bundle(false);
1449
1450 // The following logic is duplicated in the code ifdeffed for
1451 // ENABLE_ZAP_DEAD_LOCALS which appears above in this file. It
1452 // should be factored out. Or maybe dispersed to the nodes?
1453
1454 // Special handling for SafePoint/Call Nodes
1455 bool is_mcall = false;
1456 if (n->is_Mach()) {
1457 MachNode *mach = n->as_Mach();
1458 is_mcall = n->is_MachCall();
1459 bool is_sfn = n->is_MachSafePoint();
1460
1461 // If this requires all previous instructions be flushed, then do so
1462 if (is_sfn || is_mcall || mach->alignment_required() != 1) {
1463 cb->flush_bundle(true);
1464 current_offset = cb->insts_size();
1465 }
1466
1467 #ifdef ASSERT
1468 // A padding may be needed again since a previous instruction
1469 // could be moved to delay slot.
1470
1471 // align the instruction if necessary
1472 int padding = mach->compute_padding(current_offset);
1473 // Make sure safepoint node for polling is distinct from a call's
1474 // return by adding a nop if needed.
1475 if (is_sfn && !is_mcall && padding == 0 && current_offset == last_call_offset) {
1476 padding = nop_size;
1477 }
1478 if (padding == 0 && mach->avoid_back_to_back() &&
1479 current_offset == last_avoid_back_to_back_offset) {
1480 // Avoid back to back some instructions.
1481 padding = nop_size;
1482 }
1483 assert(padding == 0, "padding should be added already");
1484 #endif
1485 // Remember the start of the last call in a basic block
1486 if (is_mcall) {
1487 MachCallNode *mcall = mach->as_MachCall();
1488
1489 // This destination address is NOT PC-relative
1490 mcall->method_set((intptr_t)mcall->entry_point());
1491
1492 // Save the return address
1493 call_returns[b->_pre_order] = current_offset + mcall->ret_addr_offset();
1494
1495 if (mcall->is_MachCallLeaf()) {
1496 is_mcall = false;
1497 is_sfn = false;
1498 }
1499 }
1500
1501 // sfn will be valid whenever mcall is valid now because of inheritance
1502 if (is_sfn || is_mcall) {
1503
1504 // Handle special safepoint nodes for synchronization
1505 if (!is_mcall) {
1506 MachSafePointNode *sfn = mach->as_MachSafePoint();
1507 // !!!!! Stubs only need an oopmap right now, so bail out
1508 if (sfn->jvms()->method() == NULL) {
1509 // Write the oopmap directly to the code blob??!!
1510 # ifdef ENABLE_ZAP_DEAD_LOCALS
1511 assert( !is_node_getting_a_safepoint(sfn), "logic does not match; false positive");
1512 # endif
1513 continue;
1514 }
1515 } // End synchronization
1516
1517 non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1518 current_offset);
1519 Process_OopMap_Node(mach, current_offset);
1520 } // End if safepoint
1521
1522 // If this is a null check, then add the start of the previous instruction to the list
1523 else if( mach->is_MachNullCheck() ) {
1524 inct_starts[inct_cnt++] = previous_offset;
1525 }
1526
1527 // If this is a branch, then fill in the label with the target BB's label
1528 else if (mach->is_MachBranch()) {
1529 // This requires the TRUE branch target be in succs[0]
1530 uint block_num = b->non_connector_successor(0)->_pre_order;
1531 mach->as_MachBranch()->label_set( &blk_labels[block_num], block_num );
1532 } else if (mach->ideal_Opcode() == Op_Jump) {
1533 for (uint h = 0; h < b->_num_succs; h++) {
1534 Block* succs_block = b->_succs[h];
1535 for (uint j = 1; j < succs_block->num_preds(); j++) {
1536 Node* jpn = succs_block->pred(j);
1537 if (jpn->is_JumpProj() && jpn->in(0) == mach) {
1538 uint block_num = succs_block->non_connector()->_pre_order;
1539 Label *blkLabel = &blk_labels[block_num];
1540 mach->add_case_label(jpn->as_JumpProj()->proj_no(), blkLabel);
1541 }
1542 }
1543 }
1544 }
1545
1546 #ifdef ASSERT
1547 // Check that oop-store precedes the card-mark
1548 else if (mach->ideal_Opcode() == Op_StoreCM) {
1549 uint storeCM_idx = j;
1550 int count = 0;
1551 for (uint prec = mach->req(); prec < mach->len(); prec++) {
1552 Node *oop_store = mach->in(prec); // Precedence edge
1553 if (oop_store == NULL) continue;
1554 count++;
1555 uint i4;
1556 for( i4 = 0; i4 < last_inst; ++i4 ) {
1557 if( b->_nodes[i4] == oop_store ) break;
1558 }
1559 // Note: This test can provide a false failure if other precedence
1560 // edges have been added to the storeCMNode.
1561 assert( i4 == last_inst || i4 < storeCM_idx, "CM card-mark executes before oop-store");
1562 }
1563 assert(count > 0, "storeCM expects at least one precedence edge");
1564 }
1565 #endif
1566
1567 else if (!n->is_Proj()) {
1568 // Remember the beginning of the previous instruction, in case
1569 // it's followed by a flag-kill and a null-check. Happens on
1570 // Intel all the time, with add-to-memory kind of opcodes.
1571 previous_offset = current_offset;
1572 }
1573 }
1574
1575 // Verify that there is sufficient space remaining
1576 cb->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1577 if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
1578 turn_off_compiler(this);
1579 return;
1580 }
1581
1582 // Save the offset for the listing
1583 #ifndef PRODUCT
1584 if (node_offsets && n->_idx < node_offset_limit)
1585 node_offsets[n->_idx] = cb->insts_size();
1586 #endif
1587
1588 // "Normal" instruction case
1589 DEBUG_ONLY( uint instr_offset = cb->insts_size(); )
1590 n->emit(*cb, _regalloc);
1591 current_offset = cb->insts_size();
1592
1593 #ifdef ASSERT
1594 if (n->size(_regalloc) != (current_offset-instr_offset)) {
1595 n->dump();
1596 assert(n->size(_regalloc) == (current_offset-instr_offset), "wrong size of mach node");
1597 }
1598 #endif
1599 non_safepoints.observe_instruction(n, current_offset);
1600
1601 #ifdef ASSERT
1602 // mcall is last "call" that can be a safepoint
1603 // record it so we can see if a poll will directly follow it
1604 // in which case we'll need a pad to make the PcDesc sites unique
1605 // see 5010568. This can be slightly inaccurate but conservative
1606 // in the case that return address is not actually at current_offset.
1607 // This is a small price to pay.
1608
1609 if (is_mcall) {
1610 last_call_offset = current_offset;
1611 }
1612
1613 if (n->is_Mach() && n->as_Mach()->avoid_back_to_back()) {
1614 // Avoid back to back some instructions.
1615 last_avoid_back_to_back_offset = current_offset;
1616 }
1617 #endif
1618
1619 // See if this instruction has a delay slot
1620 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
1621 assert(delay_slot != NULL, "expecting delay slot node");
1622
1623 // Back up 1 instruction
1624 cb->set_insts_end(cb->insts_end() - Pipeline::instr_unit_size());
1625
1626 // Save the offset for the listing
1627 #ifndef PRODUCT
1628 if (node_offsets && delay_slot->_idx < node_offset_limit)
1629 node_offsets[delay_slot->_idx] = cb->insts_size();
1630 #endif
1631
1632 // Support a SafePoint in the delay slot
1633 if (delay_slot->is_MachSafePoint()) {
1634 MachNode *mach = delay_slot->as_Mach();
1635 // !!!!! Stubs only need an oopmap right now, so bail out
1636 if (!mach->is_MachCall() && mach->as_MachSafePoint()->jvms()->method() == NULL) {
1637 // Write the oopmap directly to the code blob??!!
1638 # ifdef ENABLE_ZAP_DEAD_LOCALS
1639 assert( !is_node_getting_a_safepoint(mach), "logic does not match; false positive");
1640 # endif
1641 delay_slot = NULL;
1642 continue;
1643 }
1644
1645 int adjusted_offset = current_offset - Pipeline::instr_unit_size();
1646 non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1647 adjusted_offset);
1648 // Generate an OopMap entry
1649 Process_OopMap_Node(mach, adjusted_offset);
1650 }
1651
1652 // Insert the delay slot instruction
1653 delay_slot->emit(*cb, _regalloc);
1654
1655 // Don't reuse it
1656 delay_slot = NULL;
1657 }
1658
1659 } // End for all instructions in block
1660 #ifdef ASSERT
1661 // If the next block is the top of a loop, pad this block out to align
1662 // the loop top a little. Helps prevent pipe stalls at loop back branches.
1663 if (i < _cfg->_num_blocks-1) {
1664 Block *nb = _cfg->_blocks[i+1];
1665 uint padding = nb->alignment_padding(current_offset);
1666 assert(padding == 0, "alignment should be added already");
1667 }
1668 #endif
1669 } // End of for all blocks
1670
1671 non_safepoints.flush_at_end();
1672
1673 // Offset too large?
1674 if (failing()) return;
1675
1676 // Define a pseudo-label at the end of the code
1677 MacroAssembler(cb).bind( blk_labels[_cfg->_num_blocks] );
1678
1679 // Compute the size of the first block
1680 _first_block_size = blk_labels[1].loc_pos() - blk_labels[0].loc_pos();
1681
1682 assert(cb->insts_size() < 500000, "method is unreasonably large");
1683
1684 // ------------------
1685
1686 #ifndef PRODUCT
1687 // Information on the size of the method, without the extraneous code
1688 Scheduling::increment_method_size(cb->insts_size());
1689 #endif
1690
1691 // ------------------
1692 // Fill in exception table entries.
1693 FillExceptionTables(inct_cnt, call_returns, inct_starts, blk_labels);
1694
1695 // Only java methods have exception handlers and deopt handlers
1696 if (_method) {
1697 // Emit the exception handler code.
1698 _code_offsets.set_value(CodeOffsets::Exceptions, emit_exception_handler(*cb));
1699 // Emit the deopt handler code.
1700 _code_offsets.set_value(CodeOffsets::Deopt, emit_deopt_handler(*cb));
1701
1702 // Emit the MethodHandle deopt handler code (if required).
1703 if (has_method_handle_invokes()) {
1704 // We can use the same code as for the normal deopt handler, we
1705 // just need a different entry point address.
1706 _code_offsets.set_value(CodeOffsets::DeoptMH, emit_deopt_handler(*cb));
1707 }
1708 }
1709
1710 // One last check for failed CodeBuffer::expand:
1711 if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
1712 turn_off_compiler(this);
1713 return;
1714 }
1715
1716 #ifndef PRODUCT
1717 // Dump the assembly code, including basic-block numbers
1718 if (print_assembly()) {
1719 ttyLocker ttyl; // keep the following output all in one block
1720 if (!VMThread::should_terminate()) { // test this under the tty lock
1721 // This output goes directly to the tty, not the compiler log.
1722 // To enable tools to match it up with the compilation activity,
1723 // be sure to tag this tty output with the compile ID.
1724 if (xtty != NULL) {
1725 xtty->head("opto_assembly compile_id='%d'%s", compile_id(),
1726 is_osr_compilation() ? " compile_kind='osr'" :
1727 "");
1728 }
1729 if (method() != NULL) {
1730 method()->print_oop();
1731 print_codes();
1732 }
1733 dump_asm(node_offsets, node_offset_limit);
1734 if (xtty != NULL) {
1735 xtty->tail("opto_assembly");
1736 }
1737 }
1738 }
1739 #endif
1740
1741 }
1742
1743 void Compile::FillExceptionTables(uint cnt, uint *call_returns, uint *inct_starts, Label *blk_labels) {
1744 _inc_table.set_size(cnt);
1745
1746 uint inct_cnt = 0;
1747 for( uint i=0; i<_cfg->_num_blocks; i++ ) {
1748 Block *b = _cfg->_blocks[i];
1749 Node *n = NULL;
1750 int j;
1751
1752 // Find the branch; ignore trailing NOPs.
1753 for( j = b->_nodes.size()-1; j>=0; j-- ) {
1754 n = b->_nodes[j];
1755 if( !n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con )
1756 break;
1757 }
1758
1759 // If we didn't find anything, continue
1760 if( j < 0 ) continue;
1761
1762 // Compute ExceptionHandlerTable subtable entry and add it
1763 // (skip empty blocks)
1764 if( n->is_Catch() ) {
1765
1766 // Get the offset of the return from the call
1767 uint call_return = call_returns[b->_pre_order];
1768 #ifdef ASSERT
1769 assert( call_return > 0, "no call seen for this basic block" );
1770 while( b->_nodes[--j]->is_MachProj() ) ;
1771 assert( b->_nodes[j]->is_MachCall(), "CatchProj must follow call" );
1772 #endif
1773 // last instruction is a CatchNode, find it's CatchProjNodes
1774 int nof_succs = b->_num_succs;
1775 // allocate space
1776 GrowableArray<intptr_t> handler_bcis(nof_succs);
1777 GrowableArray<intptr_t> handler_pcos(nof_succs);
1778 // iterate through all successors
1779 for (int j = 0; j < nof_succs; j++) {
1780 Block* s = b->_succs[j];
1781 bool found_p = false;
1782 for( uint k = 1; k < s->num_preds(); k++ ) {
1783 Node *pk = s->pred(k);
1784 if( pk->is_CatchProj() && pk->in(0) == n ) {
1785 const CatchProjNode* p = pk->as_CatchProj();
1786 found_p = true;
1787 // add the corresponding handler bci & pco information
1788 if( p->_con != CatchProjNode::fall_through_index ) {
1789 // p leads to an exception handler (and is not fall through)
1790 assert(s == _cfg->_blocks[s->_pre_order],"bad numbering");
1791 // no duplicates, please
1792 if( !handler_bcis.contains(p->handler_bci()) ) {
1793 uint block_num = s->non_connector()->_pre_order;
1794 handler_bcis.append(p->handler_bci());
1795 handler_pcos.append(blk_labels[block_num].loc_pos());
1796 }
1797 }
1798 }
1799 }
1800 assert(found_p, "no matching predecessor found");
1801 // Note: Due to empty block removal, one block may have
1802 // several CatchProj inputs, from the same Catch.
1803 }
1804
1805 // Set the offset of the return from the call
1806 _handler_table.add_subtable(call_return, &handler_bcis, NULL, &handler_pcos);
1807 continue;
1808 }
1809
1810 // Handle implicit null exception table updates
1811 if( n->is_MachNullCheck() ) {
1812 uint block_num = b->non_connector_successor(0)->_pre_order;
1813 _inc_table.append( inct_starts[inct_cnt++], blk_labels[block_num].loc_pos() );
1814 continue;
1815 }
1816 } // End of for all blocks fill in exception table entries
1817 }
1818
1819 // Static Variables
1820 #ifndef PRODUCT
1821 uint Scheduling::_total_nop_size = 0;
1822 uint Scheduling::_total_method_size = 0;
1823 uint Scheduling::_total_branches = 0;
1824 uint Scheduling::_total_unconditional_delays = 0;
1825 uint Scheduling::_total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
1826 #endif
1827
1828 // Initializer for class Scheduling
1829
1830 Scheduling::Scheduling(Arena *arena, Compile &compile)
1831 : _arena(arena),
1832 _cfg(compile.cfg()),
1833 _bbs(compile.cfg()->_bbs),
1834 _regalloc(compile.regalloc()),
1835 _reg_node(arena),
1836 _bundle_instr_count(0),
1837 _bundle_cycle_number(0),
1838 _scheduled(arena),
1839 _available(arena),
1840 _next_node(NULL),
1841 _bundle_use(0, 0, resource_count, &_bundle_use_elements[0]),
1842 _pinch_free_list(arena)
1843 #ifndef PRODUCT
1844 , _branches(0)
1845 , _unconditional_delays(0)
1846 #endif
1847 {
1848 // Create a MachNopNode
1849 _nop = new (&compile) MachNopNode();
1850
1851 // Now that the nops are in the array, save the count
1852 // (but allow entries for the nops)
1853 _node_bundling_limit = compile.unique();
1854 uint node_max = _regalloc->node_regs_max_index();
1855
1856 compile.set_node_bundling_limit(_node_bundling_limit);
1857
1858 // This one is persistent within the Compile class
1859 _node_bundling_base = NEW_ARENA_ARRAY(compile.comp_arena(), Bundle, node_max);
1860
1861 // Allocate space for fixed-size arrays
1862 _node_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
1863 _uses = NEW_ARENA_ARRAY(arena, short, node_max);
1864 _current_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
1865
1866 // Clear the arrays
1867 memset(_node_bundling_base, 0, node_max * sizeof(Bundle));
1868 memset(_node_latency, 0, node_max * sizeof(unsigned short));
1869 memset(_uses, 0, node_max * sizeof(short));
1870 memset(_current_latency, 0, node_max * sizeof(unsigned short));
1871
1872 // Clear the bundling information
1873 memcpy(_bundle_use_elements,
1874 Pipeline_Use::elaborated_elements,
1875 sizeof(Pipeline_Use::elaborated_elements));
1876
1877 // Get the last node
1878 Block *bb = _cfg->_blocks[_cfg->_blocks.size()-1];
1879
1880 _next_node = bb->_nodes[bb->_nodes.size()-1];
1881 }
1882
1883 #ifndef PRODUCT
1884 // Scheduling destructor
1885 Scheduling::~Scheduling() {
1886 _total_branches += _branches;
1887 _total_unconditional_delays += _unconditional_delays;
1888 }
1889 #endif
1890
1891 // Step ahead "i" cycles
1892 void Scheduling::step(uint i) {
1893
1894 Bundle *bundle = node_bundling(_next_node);
1895 bundle->set_starts_bundle();
1896
1897 // Update the bundle record, but leave the flags information alone
1898 if (_bundle_instr_count > 0) {
1899 bundle->set_instr_count(_bundle_instr_count);
1900 bundle->set_resources_used(_bundle_use.resourcesUsed());
1901 }
1902
1903 // Update the state information
1904 _bundle_instr_count = 0;
1905 _bundle_cycle_number += i;
1906 _bundle_use.step(i);
1907 }
1908
1909 void Scheduling::step_and_clear() {
1910 Bundle *bundle = node_bundling(_next_node);
1911 bundle->set_starts_bundle();
1912
1913 // Update the bundle record
1914 if (_bundle_instr_count > 0) {
1915 bundle->set_instr_count(_bundle_instr_count);
1916 bundle->set_resources_used(_bundle_use.resourcesUsed());
1917
1918 _bundle_cycle_number += 1;
1919 }
1920
1921 // Clear the bundling information
1922 _bundle_instr_count = 0;
1923 _bundle_use.reset();
1924
1925 memcpy(_bundle_use_elements,
1926 Pipeline_Use::elaborated_elements,
1927 sizeof(Pipeline_Use::elaborated_elements));
1928 }
1929
1930 //------------------------------ScheduleAndBundle------------------------------
1931 // Perform instruction scheduling and bundling over the sequence of
1932 // instructions in backwards order.
1933 void Compile::ScheduleAndBundle() {
1934
1935 // Don't optimize this if it isn't a method
1936 if (!_method)
1937 return;
1938
1939 // Don't optimize this if scheduling is disabled
1940 if (!do_scheduling())
1941 return;
1942
1943 NOT_PRODUCT( TracePhase t2("isched", &_t_instrSched, TimeCompiler); )
1944
1945 // Create a data structure for all the scheduling information
1946 Scheduling scheduling(Thread::current()->resource_area(), *this);
1947
1948 // Walk backwards over each basic block, computing the needed alignment
1949 // Walk over all the basic blocks
1950 scheduling.DoScheduling();
1951 }
1952
1953 //------------------------------ComputeLocalLatenciesForward-------------------
1954 // Compute the latency of all the instructions. This is fairly simple,
1955 // because we already have a legal ordering. Walk over the instructions
1956 // from first to last, and compute the latency of the instruction based
1957 // on the latency of the preceding instruction(s).
1958 void Scheduling::ComputeLocalLatenciesForward(const Block *bb) {
1959 #ifndef PRODUCT
1960 if (_cfg->C->trace_opto_output())
1961 tty->print("# -> ComputeLocalLatenciesForward\n");
1962 #endif
1963
1964 // Walk over all the schedulable instructions
1965 for( uint j=_bb_start; j < _bb_end; j++ ) {
1966
1967 // This is a kludge, forcing all latency calculations to start at 1.
1968 // Used to allow latency 0 to force an instruction to the beginning
1969 // of the bb
1970 uint latency = 1;
1971 Node *use = bb->_nodes[j];
1972 uint nlen = use->len();
1973
1974 // Walk over all the inputs
1975 for ( uint k=0; k < nlen; k++ ) {
1976 Node *def = use->in(k);
1977 if (!def)
1978 continue;
1979
1980 uint l = _node_latency[def->_idx] + use->latency(k);
1981 if (latency < l)
1982 latency = l;
1983 }
1984
1985 _node_latency[use->_idx] = latency;
1986
1987 #ifndef PRODUCT
1988 if (_cfg->C->trace_opto_output()) {
1989 tty->print("# latency %4d: ", latency);
1990 use->dump();
1991 }
1992 #endif
1993 }
1994
1995 #ifndef PRODUCT
1996 if (_cfg->C->trace_opto_output())
1997 tty->print("# <- ComputeLocalLatenciesForward\n");
1998 #endif
1999
2000 } // end ComputeLocalLatenciesForward
2001
2002 // See if this node fits into the present instruction bundle
2003 bool Scheduling::NodeFitsInBundle(Node *n) {
2004 uint n_idx = n->_idx;
2005
2006 // If this is the unconditional delay instruction, then it fits
2007 if (n == _unconditional_delay_slot) {
2008 #ifndef PRODUCT
2009 if (_cfg->C->trace_opto_output())
2010 tty->print("# NodeFitsInBundle [%4d]: TRUE; is in unconditional delay slot\n", n->_idx);
2011 #endif
2012 return (true);
2013 }
2014
2015 // If the node cannot be scheduled this cycle, skip it
2016 if (_current_latency[n_idx] > _bundle_cycle_number) {
2017 #ifndef PRODUCT
2018 if (_cfg->C->trace_opto_output())
2019 tty->print("# NodeFitsInBundle [%4d]: FALSE; latency %4d > %d\n",
2020 n->_idx, _current_latency[n_idx], _bundle_cycle_number);
2021 #endif
2022 return (false);
2023 }
2024
2025 const Pipeline *node_pipeline = n->pipeline();
2026
2027 uint instruction_count = node_pipeline->instructionCount();
2028 if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2029 instruction_count = 0;
2030 else if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
2031 instruction_count++;
2032
2033 if (_bundle_instr_count + instruction_count > Pipeline::_max_instrs_per_cycle) {
2034 #ifndef PRODUCT
2035 if (_cfg->C->trace_opto_output())
2036 tty->print("# NodeFitsInBundle [%4d]: FALSE; too many instructions: %d > %d\n",
2037 n->_idx, _bundle_instr_count + instruction_count, Pipeline::_max_instrs_per_cycle);
2038 #endif
2039 return (false);
2040 }
2041
2042 // Don't allow non-machine nodes to be handled this way
2043 if (!n->is_Mach() && instruction_count == 0)
2044 return (false);
2045
2046 // See if there is any overlap
2047 uint delay = _bundle_use.full_latency(0, node_pipeline->resourceUse());
2048
2049 if (delay > 0) {
2050 #ifndef PRODUCT
2051 if (_cfg->C->trace_opto_output())
2052 tty->print("# NodeFitsInBundle [%4d]: FALSE; functional units overlap\n", n_idx);
2053 #endif
2054 return false;
2055 }
2056
2057 #ifndef PRODUCT
2058 if (_cfg->C->trace_opto_output())
2059 tty->print("# NodeFitsInBundle [%4d]: TRUE\n", n_idx);
2060 #endif
2061
2062 return true;
2063 }
2064
2065 Node * Scheduling::ChooseNodeToBundle() {
2066 uint siz = _available.size();
2067
2068 if (siz == 0) {
2069
2070 #ifndef PRODUCT
2071 if (_cfg->C->trace_opto_output())
2072 tty->print("# ChooseNodeToBundle: NULL\n");
2073 #endif
2074 return (NULL);
2075 }
2076
2077 // Fast path, if only 1 instruction in the bundle
2078 if (siz == 1) {
2079 #ifndef PRODUCT
2080 if (_cfg->C->trace_opto_output()) {
2081 tty->print("# ChooseNodeToBundle (only 1): ");
2082 _available[0]->dump();
2083 }
2084 #endif
2085 return (_available[0]);
2086 }
2087
2088 // Don't bother, if the bundle is already full
2089 if (_bundle_instr_count < Pipeline::_max_instrs_per_cycle) {
2090 for ( uint i = 0; i < siz; i++ ) {
2091 Node *n = _available[i];
2092
2093 // Skip projections, we'll handle them another way
2094 if (n->is_Proj())
2095 continue;
2096
2097 // This presupposed that instructions are inserted into the
2098 // available list in a legality order; i.e. instructions that
2099 // must be inserted first are at the head of the list
2100 if (NodeFitsInBundle(n)) {
2101 #ifndef PRODUCT
2102 if (_cfg->C->trace_opto_output()) {
2103 tty->print("# ChooseNodeToBundle: ");
2104 n->dump();
2105 }
2106 #endif
2107 return (n);
2108 }
2109 }
2110 }
2111
2112 // Nothing fits in this bundle, choose the highest priority
2113 #ifndef PRODUCT
2114 if (_cfg->C->trace_opto_output()) {
2115 tty->print("# ChooseNodeToBundle: ");
2116 _available[0]->dump();
2117 }
2118 #endif
2119
2120 return _available[0];
2121 }
2122
2123 //------------------------------AddNodeToAvailableList-------------------------
2124 void Scheduling::AddNodeToAvailableList(Node *n) {
2125 assert( !n->is_Proj(), "projections never directly made available" );
2126 #ifndef PRODUCT
2127 if (_cfg->C->trace_opto_output()) {
2128 tty->print("# AddNodeToAvailableList: ");
2129 n->dump();
2130 }
2131 #endif
2132
2133 int latency = _current_latency[n->_idx];
2134
2135 // Insert in latency order (insertion sort)
2136 uint i;
2137 for ( i=0; i < _available.size(); i++ )
2138 if (_current_latency[_available[i]->_idx] > latency)
2139 break;
2140
2141 // Special Check for compares following branches
2142 if( n->is_Mach() && _scheduled.size() > 0 ) {
2143 int op = n->as_Mach()->ideal_Opcode();
2144 Node *last = _scheduled[0];
2145 if( last->is_MachIf() && last->in(1) == n &&
2146 ( op == Op_CmpI ||
2147 op == Op_CmpU ||
2148 op == Op_CmpP ||
2149 op == Op_CmpF ||
2150 op == Op_CmpD ||
2151 op == Op_CmpL ) ) {
2152
2153 // Recalculate position, moving to front of same latency
2154 for ( i=0 ; i < _available.size(); i++ )
2155 if (_current_latency[_available[i]->_idx] >= latency)
2156 break;
2157 }
2158 }
2159
2160 // Insert the node in the available list
2161 _available.insert(i, n);
2162
2163 #ifndef PRODUCT
2164 if (_cfg->C->trace_opto_output())
2165 dump_available();
2166 #endif
2167 }
2168
2169 //------------------------------DecrementUseCounts-----------------------------
2170 void Scheduling::DecrementUseCounts(Node *n, const Block *bb) {
2171 for ( uint i=0; i < n->len(); i++ ) {
2172 Node *def = n->in(i);
2173 if (!def) continue;
2174 if( def->is_Proj() ) // If this is a machine projection, then
2175 def = def->in(0); // propagate usage thru to the base instruction
2176
2177 if( _bbs[def->_idx] != bb ) // Ignore if not block-local
2178 continue;
2179
2180 // Compute the latency
2181 uint l = _bundle_cycle_number + n->latency(i);
2182 if (_current_latency[def->_idx] < l)
2183 _current_latency[def->_idx] = l;
2184
2185 // If this does not have uses then schedule it
2186 if ((--_uses[def->_idx]) == 0)
2187 AddNodeToAvailableList(def);
2188 }
2189 }
2190
2191 //------------------------------AddNodeToBundle--------------------------------
2192 void Scheduling::AddNodeToBundle(Node *n, const Block *bb) {
2193 #ifndef PRODUCT
2194 if (_cfg->C->trace_opto_output()) {
2195 tty->print("# AddNodeToBundle: ");
2196 n->dump();
2197 }
2198 #endif
2199
2200 // Remove this from the available list
2201 uint i;
2202 for (i = 0; i < _available.size(); i++)
2203 if (_available[i] == n)
2204 break;
2205 assert(i < _available.size(), "entry in _available list not found");
2206 _available.remove(i);
2207
2208 // See if this fits in the current bundle
2209 const Pipeline *node_pipeline = n->pipeline();
2210 const Pipeline_Use& node_usage = node_pipeline->resourceUse();
2211
2212 // Check for instructions to be placed in the delay slot. We
2213 // do this before we actually schedule the current instruction,
2214 // because the delay slot follows the current instruction.
2215 if (Pipeline::_branch_has_delay_slot &&
2216 node_pipeline->hasBranchDelay() &&
2217 !_unconditional_delay_slot) {
2218
2219 uint siz = _available.size();
2220
2221 // Conditional branches can support an instruction that
2222 // is unconditionally executed and not dependent by the
2223 // branch, OR a conditionally executed instruction if
2224 // the branch is taken. In practice, this means that
2225 // the first instruction at the branch target is
2226 // copied to the delay slot, and the branch goes to
2227 // the instruction after that at the branch target
2228 if ( n->is_MachBranch() ) {
2229
2230 assert( !n->is_MachNullCheck(), "should not look for delay slot for Null Check" );
2231 assert( !n->is_Catch(), "should not look for delay slot for Catch" );
2232
2233 #ifndef PRODUCT
2234 _branches++;
2235 #endif
2236
2237 // At least 1 instruction is on the available list
2238 // that is not dependent on the branch
2239 for (uint i = 0; i < siz; i++) {
2240 Node *d = _available[i];
2241 const Pipeline *avail_pipeline = d->pipeline();
2242
2243 // Don't allow safepoints in the branch shadow, that will
2244 // cause a number of difficulties
2245 if ( avail_pipeline->instructionCount() == 1 &&
2246 !avail_pipeline->hasMultipleBundles() &&
2247 !avail_pipeline->hasBranchDelay() &&
2248 Pipeline::instr_has_unit_size() &&
2249 d->size(_regalloc) == Pipeline::instr_unit_size() &&
2250 NodeFitsInBundle(d) &&
2251 !node_bundling(d)->used_in_delay()) {
2252
2253 if (d->is_Mach() && !d->is_MachSafePoint()) {
2254 // A node that fits in the delay slot was found, so we need to
2255 // set the appropriate bits in the bundle pipeline information so
2256 // that it correctly indicates resource usage. Later, when we
2257 // attempt to add this instruction to the bundle, we will skip
2258 // setting the resource usage.
2259 _unconditional_delay_slot = d;
2260 node_bundling(n)->set_use_unconditional_delay();
2261 node_bundling(d)->set_used_in_unconditional_delay();
2262 _bundle_use.add_usage(avail_pipeline->resourceUse());
2263 _current_latency[d->_idx] = _bundle_cycle_number;
2264 _next_node = d;
2265 ++_bundle_instr_count;
2266 #ifndef PRODUCT
2267 _unconditional_delays++;
2268 #endif
2269 break;
2270 }
2271 }
2272 }
2273 }
2274
2275 // No delay slot, add a nop to the usage
2276 if (!_unconditional_delay_slot) {
2277 // See if adding an instruction in the delay slot will overflow
2278 // the bundle.
2279 if (!NodeFitsInBundle(_nop)) {
2280 #ifndef PRODUCT
2281 if (_cfg->C->trace_opto_output())
2282 tty->print("# *** STEP(1 instruction for delay slot) ***\n");
2283 #endif
2284 step(1);
2285 }
2286
2287 _bundle_use.add_usage(_nop->pipeline()->resourceUse());
2288 _next_node = _nop;
2289 ++_bundle_instr_count;
2290 }
2291
2292 // See if the instruction in the delay slot requires a
2293 // step of the bundles
2294 if (!NodeFitsInBundle(n)) {
2295 #ifndef PRODUCT
2296 if (_cfg->C->trace_opto_output())
2297 tty->print("# *** STEP(branch won't fit) ***\n");
2298 #endif
2299 // Update the state information
2300 _bundle_instr_count = 0;
2301 _bundle_cycle_number += 1;
2302 _bundle_use.step(1);
2303 }
2304 }
2305
2306 // Get the number of instructions
2307 uint instruction_count = node_pipeline->instructionCount();
2308 if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2309 instruction_count = 0;
2310
2311 // Compute the latency information
2312 uint delay = 0;
2313
2314 if (instruction_count > 0 || !node_pipeline->mayHaveNoCode()) {
2315 int relative_latency = _current_latency[n->_idx] - _bundle_cycle_number;
2316 if (relative_latency < 0)
2317 relative_latency = 0;
2318
2319 delay = _bundle_use.full_latency(relative_latency, node_usage);
2320
2321 // Does not fit in this bundle, start a new one
2322 if (delay > 0) {
2323 step(delay);
2324
2325 #ifndef PRODUCT
2326 if (_cfg->C->trace_opto_output())
2327 tty->print("# *** STEP(%d) ***\n", delay);
2328 #endif
2329 }
2330 }
2331
2332 // If this was placed in the delay slot, ignore it
2333 if (n != _unconditional_delay_slot) {
2334
2335 if (delay == 0) {
2336 if (node_pipeline->hasMultipleBundles()) {
2337 #ifndef PRODUCT
2338 if (_cfg->C->trace_opto_output())
2339 tty->print("# *** STEP(multiple instructions) ***\n");
2340 #endif
2341 step(1);
2342 }
2343
2344 else if (instruction_count + _bundle_instr_count > Pipeline::_max_instrs_per_cycle) {
2345 #ifndef PRODUCT
2346 if (_cfg->C->trace_opto_output())
2347 tty->print("# *** STEP(%d >= %d instructions) ***\n",
2348 instruction_count + _bundle_instr_count,
2349 Pipeline::_max_instrs_per_cycle);
2350 #endif
2351 step(1);
2352 }
2353 }
2354
2355 if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
2356 _bundle_instr_count++;
2357
2358 // Set the node's latency
2359 _current_latency[n->_idx] = _bundle_cycle_number;
2360
2361 // Now merge the functional unit information
2362 if (instruction_count > 0 || !node_pipeline->mayHaveNoCode())
2363 _bundle_use.add_usage(node_usage);
2364
2365 // Increment the number of instructions in this bundle
2366 _bundle_instr_count += instruction_count;
2367
2368 // Remember this node for later
2369 if (n->is_Mach())
2370 _next_node = n;
2371 }
2372
2373 // It's possible to have a BoxLock in the graph and in the _bbs mapping but
2374 // not in the bb->_nodes array. This happens for debug-info-only BoxLocks.
2375 // 'Schedule' them (basically ignore in the schedule) but do not insert them
2376 // into the block. All other scheduled nodes get put in the schedule here.
2377 int op = n->Opcode();
2378 if( (op == Op_Node && n->req() == 0) || // anti-dependence node OR
2379 (op != Op_Node && // Not an unused antidepedence node and
2380 // not an unallocated boxlock
2381 (OptoReg::is_valid(_regalloc->get_reg_first(n)) || op != Op_BoxLock)) ) {
2382
2383 // Push any trailing projections
2384 if( bb->_nodes[bb->_nodes.size()-1] != n ) {
2385 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2386 Node *foi = n->fast_out(i);
2387 if( foi->is_Proj() )
2388 _scheduled.push(foi);
2389 }
2390 }
2391
2392 // Put the instruction in the schedule list
2393 _scheduled.push(n);
2394 }
2395
2396 #ifndef PRODUCT
2397 if (_cfg->C->trace_opto_output())
2398 dump_available();
2399 #endif
2400
2401 // Walk all the definitions, decrementing use counts, and
2402 // if a definition has a 0 use count, place it in the available list.
2403 DecrementUseCounts(n,bb);
2404 }
2405
2406 //------------------------------ComputeUseCount--------------------------------
2407 // This method sets the use count within a basic block. We will ignore all
2408 // uses outside the current basic block. As we are doing a backwards walk,
2409 // any node we reach that has a use count of 0 may be scheduled. This also
2410 // avoids the problem of cyclic references from phi nodes, as long as phi
2411 // nodes are at the front of the basic block. This method also initializes
2412 // the available list to the set of instructions that have no uses within this
2413 // basic block.
2414 void Scheduling::ComputeUseCount(const Block *bb) {
2415 #ifndef PRODUCT
2416 if (_cfg->C->trace_opto_output())
2417 tty->print("# -> ComputeUseCount\n");
2418 #endif
2419
2420 // Clear the list of available and scheduled instructions, just in case
2421 _available.clear();
2422 _scheduled.clear();
2423
2424 // No delay slot specified
2425 _unconditional_delay_slot = NULL;
2426
2427 #ifdef ASSERT
2428 for( uint i=0; i < bb->_nodes.size(); i++ )
2429 assert( _uses[bb->_nodes[i]->_idx] == 0, "_use array not clean" );
2430 #endif
2431
2432 // Force the _uses count to never go to zero for unscheduable pieces
2433 // of the block
2434 for( uint k = 0; k < _bb_start; k++ )
2435 _uses[bb->_nodes[k]->_idx] = 1;
2436 for( uint l = _bb_end; l < bb->_nodes.size(); l++ )
2437 _uses[bb->_nodes[l]->_idx] = 1;
2438
2439 // Iterate backwards over the instructions in the block. Don't count the
2440 // branch projections at end or the block header instructions.
2441 for( uint j = _bb_end-1; j >= _bb_start; j-- ) {
2442 Node *n = bb->_nodes[j];
2443 if( n->is_Proj() ) continue; // Projections handled another way
2444
2445 // Account for all uses
2446 for ( uint k = 0; k < n->len(); k++ ) {
2447 Node *inp = n->in(k);
2448 if (!inp) continue;
2449 assert(inp != n, "no cycles allowed" );
2450 if( _bbs[inp->_idx] == bb ) { // Block-local use?
2451 if( inp->is_Proj() ) // Skip through Proj's
2452 inp = inp->in(0);
2453 ++_uses[inp->_idx]; // Count 1 block-local use
2454 }
2455 }
2456
2457 // If this instruction has a 0 use count, then it is available
2458 if (!_uses[n->_idx]) {
2459 _current_latency[n->_idx] = _bundle_cycle_number;
2460 AddNodeToAvailableList(n);
2461 }
2462
2463 #ifndef PRODUCT
2464 if (_cfg->C->trace_opto_output()) {
2465 tty->print("# uses: %3d: ", _uses[n->_idx]);
2466 n->dump();
2467 }
2468 #endif
2469 }
2470
2471 #ifndef PRODUCT
2472 if (_cfg->C->trace_opto_output())
2473 tty->print("# <- ComputeUseCount\n");
2474 #endif
2475 }
2476
2477 // This routine performs scheduling on each basic block in reverse order,
2478 // using instruction latencies and taking into account function unit
2479 // availability.
2480 void Scheduling::DoScheduling() {
2481 #ifndef PRODUCT
2482 if (_cfg->C->trace_opto_output())
2483 tty->print("# -> DoScheduling\n");
2484 #endif
2485
2486 Block *succ_bb = NULL;
2487 Block *bb;
2488
2489 // Walk over all the basic blocks in reverse order
2490 for( int i=_cfg->_num_blocks-1; i >= 0; succ_bb = bb, i-- ) {
2491 bb = _cfg->_blocks[i];
2492
2493 #ifndef PRODUCT
2494 if (_cfg->C->trace_opto_output()) {
2495 tty->print("# Schedule BB#%03d (initial)\n", i);
2496 for (uint j = 0; j < bb->_nodes.size(); j++)
2497 bb->_nodes[j]->dump();
2498 }
2499 #endif
2500
2501 // On the head node, skip processing
2502 if( bb == _cfg->_broot )
2503 continue;
2504
2505 // Skip empty, connector blocks
2506 if (bb->is_connector())
2507 continue;
2508
2509 // If the following block is not the sole successor of
2510 // this one, then reset the pipeline information
2511 if (bb->_num_succs != 1 || bb->non_connector_successor(0) != succ_bb) {
2512 #ifndef PRODUCT
2513 if (_cfg->C->trace_opto_output()) {
2514 tty->print("*** bundle start of next BB, node %d, for %d instructions\n",
2515 _next_node->_idx, _bundle_instr_count);
2516 }
2517 #endif
2518 step_and_clear();
2519 }
2520
2521 // Leave untouched the starting instruction, any Phis, a CreateEx node
2522 // or Top. bb->_nodes[_bb_start] is the first schedulable instruction.
2523 _bb_end = bb->_nodes.size()-1;
2524 for( _bb_start=1; _bb_start <= _bb_end; _bb_start++ ) {
2525 Node *n = bb->_nodes[_bb_start];
2526 // Things not matched, like Phinodes and ProjNodes don't get scheduled.
2527 // Also, MachIdealNodes do not get scheduled
2528 if( !n->is_Mach() ) continue; // Skip non-machine nodes
2529 MachNode *mach = n->as_Mach();
2530 int iop = mach->ideal_Opcode();
2531 if( iop == Op_CreateEx ) continue; // CreateEx is pinned
2532 if( iop == Op_Con ) continue; // Do not schedule Top
2533 if( iop == Op_Node && // Do not schedule PhiNodes, ProjNodes
2534 mach->pipeline() == MachNode::pipeline_class() &&
2535 !n->is_SpillCopy() ) // Breakpoints, Prolog, etc
2536 continue;
2537 break; // Funny loop structure to be sure...
2538 }
2539 // Compute last "interesting" instruction in block - last instruction we
2540 // might schedule. _bb_end points just after last schedulable inst. We
2541 // normally schedule conditional branches (despite them being forced last
2542 // in the block), because they have delay slots we can fill. Calls all
2543 // have their delay slots filled in the template expansions, so we don't
2544 // bother scheduling them.
2545 Node *last = bb->_nodes[_bb_end];
2546 // Ignore trailing NOPs.
2547 while (_bb_end > 0 && last->is_Mach() &&
2548 last->as_Mach()->ideal_Opcode() == Op_Con) {
2549 last = bb->_nodes[--_bb_end];
2550 }
2551 assert(!last->is_Mach() || last->as_Mach()->ideal_Opcode() != Op_Con, "");
2552 if( last->is_Catch() ||
2553 // Exclude unreachable path case when Halt node is in a separate block.
2554 (_bb_end > 1 && last->is_Mach() && last->as_Mach()->ideal_Opcode() == Op_Halt) ) {
2555 // There must be a prior call. Skip it.
2556 while( !bb->_nodes[--_bb_end]->is_MachCall() ) {
2557 assert( bb->_nodes[_bb_end]->is_MachProj(), "skipping projections after expected call" );
2558 }
2559 } else if( last->is_MachNullCheck() ) {
2560 // Backup so the last null-checked memory instruction is
2561 // outside the schedulable range. Skip over the nullcheck,
2562 // projection, and the memory nodes.
2563 Node *mem = last->in(1);
2564 do {
2565 _bb_end--;
2566 } while (mem != bb->_nodes[_bb_end]);
2567 } else {
2568 // Set _bb_end to point after last schedulable inst.
2569 _bb_end++;
2570 }
2571
2572 assert( _bb_start <= _bb_end, "inverted block ends" );
2573
2574 // Compute the register antidependencies for the basic block
2575 ComputeRegisterAntidependencies(bb);
2576 if (_cfg->C->failing()) return; // too many D-U pinch points
2577
2578 // Compute intra-bb latencies for the nodes
2579 ComputeLocalLatenciesForward(bb);
2580
2581 // Compute the usage within the block, and set the list of all nodes
2582 // in the block that have no uses within the block.
2583 ComputeUseCount(bb);
2584
2585 // Schedule the remaining instructions in the block
2586 while ( _available.size() > 0 ) {
2587 Node *n = ChooseNodeToBundle();
2588 AddNodeToBundle(n,bb);
2589 }
2590
2591 assert( _scheduled.size() == _bb_end - _bb_start, "wrong number of instructions" );
2592 #ifdef ASSERT
2593 for( uint l = _bb_start; l < _bb_end; l++ ) {
2594 Node *n = bb->_nodes[l];
2595 uint m;
2596 for( m = 0; m < _bb_end-_bb_start; m++ )
2597 if( _scheduled[m] == n )
2598 break;
2599 assert( m < _bb_end-_bb_start, "instruction missing in schedule" );
2600 }
2601 #endif
2602
2603 // Now copy the instructions (in reverse order) back to the block
2604 for ( uint k = _bb_start; k < _bb_end; k++ )
2605 bb->_nodes.map(k, _scheduled[_bb_end-k-1]);
2606
2607 #ifndef PRODUCT
2608 if (_cfg->C->trace_opto_output()) {
2609 tty->print("# Schedule BB#%03d (final)\n", i);
2610 uint current = 0;
2611 for (uint j = 0; j < bb->_nodes.size(); j++) {
2612 Node *n = bb->_nodes[j];
2613 if( valid_bundle_info(n) ) {
2614 Bundle *bundle = node_bundling(n);
2615 if (bundle->instr_count() > 0 || bundle->flags() > 0) {
2616 tty->print("*** Bundle: ");
2617 bundle->dump();
2618 }
2619 n->dump();
2620 }
2621 }
2622 }
2623 #endif
2624 #ifdef ASSERT
2625 verify_good_schedule(bb,"after block local scheduling");
2626 #endif
2627 }
2628
2629 #ifndef PRODUCT
2630 if (_cfg->C->trace_opto_output())
2631 tty->print("# <- DoScheduling\n");
2632 #endif
2633
2634 // Record final node-bundling array location
2635 _regalloc->C->set_node_bundling_base(_node_bundling_base);
2636
2637 } // end DoScheduling
2638
2639 //------------------------------verify_good_schedule---------------------------
2640 // Verify that no live-range used in the block is killed in the block by a
2641 // wrong DEF. This doesn't verify live-ranges that span blocks.
2642
2643 // Check for edge existence. Used to avoid adding redundant precedence edges.
2644 static bool edge_from_to( Node *from, Node *to ) {
2645 for( uint i=0; i<from->len(); i++ )
2646 if( from->in(i) == to )
2647 return true;
2648 return false;
2649 }
2650
2651 #ifdef ASSERT
2652 //------------------------------verify_do_def----------------------------------
2653 void Scheduling::verify_do_def( Node *n, OptoReg::Name def, const char *msg ) {
2654 // Check for bad kills
2655 if( OptoReg::is_valid(def) ) { // Ignore stores & control flow
2656 Node *prior_use = _reg_node[def];
2657 if( prior_use && !edge_from_to(prior_use,n) ) {
2658 tty->print("%s = ",OptoReg::as_VMReg(def)->name());
2659 n->dump();
2660 tty->print_cr("...");
2661 prior_use->dump();
2662 assert(edge_from_to(prior_use,n),msg);
2663 }
2664 _reg_node.map(def,NULL); // Kill live USEs
2665 }
2666 }
2667
2668 //------------------------------verify_good_schedule---------------------------
2669 void Scheduling::verify_good_schedule( Block *b, const char *msg ) {
2670
2671 // Zap to something reasonable for the verify code
2672 _reg_node.clear();
2673
2674 // Walk over the block backwards. Check to make sure each DEF doesn't
2675 // kill a live value (other than the one it's supposed to). Add each
2676 // USE to the live set.
2677 for( uint i = b->_nodes.size()-1; i >= _bb_start; i-- ) {
2678 Node *n = b->_nodes[i];
2679 int n_op = n->Opcode();
2680 if( n_op == Op_MachProj && n->ideal_reg() == MachProjNode::fat_proj ) {
2681 // Fat-proj kills a slew of registers
2682 RegMask rm = n->out_RegMask();// Make local copy
2683 while( rm.is_NotEmpty() ) {
2684 OptoReg::Name kill = rm.find_first_elem();
2685 rm.Remove(kill);
2686 verify_do_def( n, kill, msg );
2687 }
2688 } else if( n_op != Op_Node ) { // Avoid brand new antidependence nodes
2689 // Get DEF'd registers the normal way
2690 verify_do_def( n, _regalloc->get_reg_first(n), msg );
2691 verify_do_def( n, _regalloc->get_reg_second(n), msg );
2692 }
2693
2694 // Now make all USEs live
2695 for( uint i=1; i<n->req(); i++ ) {
2696 Node *def = n->in(i);
2697 assert(def != 0, "input edge required");
2698 OptoReg::Name reg_lo = _regalloc->get_reg_first(def);
2699 OptoReg::Name reg_hi = _regalloc->get_reg_second(def);
2700 if( OptoReg::is_valid(reg_lo) ) {
2701 assert(!_reg_node[reg_lo] || edge_from_to(_reg_node[reg_lo],def), msg);
2702 _reg_node.map(reg_lo,n);
2703 }
2704 if( OptoReg::is_valid(reg_hi) ) {
2705 assert(!_reg_node[reg_hi] || edge_from_to(_reg_node[reg_hi],def), msg);
2706 _reg_node.map(reg_hi,n);
2707 }
2708 }
2709
2710 }
2711
2712 // Zap to something reasonable for the Antidependence code
2713 _reg_node.clear();
2714 }
2715 #endif
2716
2717 // Conditionally add precedence edges. Avoid putting edges on Projs.
2718 static void add_prec_edge_from_to( Node *from, Node *to ) {
2719 if( from->is_Proj() ) { // Put precedence edge on Proj's input
2720 assert( from->req() == 1 && (from->len() == 1 || from->in(1)==0), "no precedence edges on projections" );
2721 from = from->in(0);
2722 }
2723 if( from != to && // No cycles (for things like LD L0,[L0+4] )
2724 !edge_from_to( from, to ) ) // Avoid duplicate edge
2725 from->add_prec(to);
2726 }
2727
2728 //------------------------------anti_do_def------------------------------------
2729 void Scheduling::anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def ) {
2730 if( !OptoReg::is_valid(def_reg) ) // Ignore stores & control flow
2731 return;
2732
2733 Node *pinch = _reg_node[def_reg]; // Get pinch point
2734 if( !pinch || _bbs[pinch->_idx] != b || // No pinch-point yet?
2735 is_def ) { // Check for a true def (not a kill)
2736 _reg_node.map(def_reg,def); // Record def/kill as the optimistic pinch-point
2737 return;
2738 }
2739
2740 Node *kill = def; // Rename 'def' to more descriptive 'kill'
2741 debug_only( def = (Node*)0xdeadbeef; )
2742
2743 // After some number of kills there _may_ be a later def
2744 Node *later_def = NULL;
2745
2746 // Finding a kill requires a real pinch-point.
2747 // Check for not already having a pinch-point.
2748 // Pinch points are Op_Node's.
2749 if( pinch->Opcode() != Op_Node ) { // Or later-def/kill as pinch-point?
2750 later_def = pinch; // Must be def/kill as optimistic pinch-point
2751 if ( _pinch_free_list.size() > 0) {
2752 pinch = _pinch_free_list.pop();
2753 } else {
2754 pinch = new (_cfg->C, 1) Node(1); // Pinch point to-be
2755 }
2756 if (pinch->_idx >= _regalloc->node_regs_max_index()) {
2757 _cfg->C->record_method_not_compilable("too many D-U pinch points");
2758 return;
2759 }
2760 _bbs.map(pinch->_idx,b); // Pretend it's valid in this block (lazy init)
2761 _reg_node.map(def_reg,pinch); // Record pinch-point
2762 //_regalloc->set_bad(pinch->_idx); // Already initialized this way.
2763 if( later_def->outcnt() == 0 || later_def->ideal_reg() == MachProjNode::fat_proj ) { // Distinguish def from kill
2764 pinch->init_req(0, _cfg->C->top()); // set not NULL for the next call
2765 add_prec_edge_from_to(later_def,pinch); // Add edge from kill to pinch
2766 later_def = NULL; // and no later def
2767 }
2768 pinch->set_req(0,later_def); // Hook later def so we can find it
2769 } else { // Else have valid pinch point
2770 if( pinch->in(0) ) // If there is a later-def
2771 later_def = pinch->in(0); // Get it
2772 }
2773
2774 // Add output-dependence edge from later def to kill
2775 if( later_def ) // If there is some original def
2776 add_prec_edge_from_to(later_def,kill); // Add edge from def to kill
2777
2778 // See if current kill is also a use, and so is forced to be the pinch-point.
2779 if( pinch->Opcode() == Op_Node ) {
2780 Node *uses = kill->is_Proj() ? kill->in(0) : kill;
2781 for( uint i=1; i<uses->req(); i++ ) {
2782 if( _regalloc->get_reg_first(uses->in(i)) == def_reg ||
2783 _regalloc->get_reg_second(uses->in(i)) == def_reg ) {
2784 // Yes, found a use/kill pinch-point
2785 pinch->set_req(0,NULL); //
2786 pinch->replace_by(kill); // Move anti-dep edges up
2787 pinch = kill;
2788 _reg_node.map(def_reg,pinch);
2789 return;
2790 }
2791 }
2792 }
2793
2794 // Add edge from kill to pinch-point
2795 add_prec_edge_from_to(kill,pinch);
2796 }
2797
2798 //------------------------------anti_do_use------------------------------------
2799 void Scheduling::anti_do_use( Block *b, Node *use, OptoReg::Name use_reg ) {
2800 if( !OptoReg::is_valid(use_reg) ) // Ignore stores & control flow
2801 return;
2802 Node *pinch = _reg_node[use_reg]; // Get pinch point
2803 // Check for no later def_reg/kill in block
2804 if( pinch && _bbs[pinch->_idx] == b &&
2805 // Use has to be block-local as well
2806 _bbs[use->_idx] == b ) {
2807 if( pinch->Opcode() == Op_Node && // Real pinch-point (not optimistic?)
2808 pinch->req() == 1 ) { // pinch not yet in block?
2809 pinch->del_req(0); // yank pointer to later-def, also set flag
2810 // Insert the pinch-point in the block just after the last use
2811 b->_nodes.insert(b->find_node(use)+1,pinch);
2812 _bb_end++; // Increase size scheduled region in block
2813 }
2814
2815 add_prec_edge_from_to(pinch,use);
2816 }
2817 }
2818
2819 //------------------------------ComputeRegisterAntidependences-----------------
2820 // We insert antidependences between the reads and following write of
2821 // allocated registers to prevent illegal code motion. Hopefully, the
2822 // number of added references should be fairly small, especially as we
2823 // are only adding references within the current basic block.
2824 void Scheduling::ComputeRegisterAntidependencies(Block *b) {
2825
2826 #ifdef ASSERT
2827 verify_good_schedule(b,"before block local scheduling");
2828 #endif
2829
2830 // A valid schedule, for each register independently, is an endless cycle
2831 // of: a def, then some uses (connected to the def by true dependencies),
2832 // then some kills (defs with no uses), finally the cycle repeats with a new
2833 // def. The uses are allowed to float relative to each other, as are the
2834 // kills. No use is allowed to slide past a kill (or def). This requires
2835 // antidependencies between all uses of a single def and all kills that
2836 // follow, up to the next def. More edges are redundant, because later defs
2837 // & kills are already serialized with true or antidependencies. To keep
2838 // the edge count down, we add a 'pinch point' node if there's more than
2839 // one use or more than one kill/def.
2840
2841 // We add dependencies in one bottom-up pass.
2842
2843 // For each instruction we handle it's DEFs/KILLs, then it's USEs.
2844
2845 // For each DEF/KILL, we check to see if there's a prior DEF/KILL for this
2846 // register. If not, we record the DEF/KILL in _reg_node, the
2847 // register-to-def mapping. If there is a prior DEF/KILL, we insert a
2848 // "pinch point", a new Node that's in the graph but not in the block.
2849 // We put edges from the prior and current DEF/KILLs to the pinch point.
2850 // We put the pinch point in _reg_node. If there's already a pinch point
2851 // we merely add an edge from the current DEF/KILL to the pinch point.
2852
2853 // After doing the DEF/KILLs, we handle USEs. For each used register, we
2854 // put an edge from the pinch point to the USE.
2855
2856 // To be expedient, the _reg_node array is pre-allocated for the whole
2857 // compilation. _reg_node is lazily initialized; it either contains a NULL,
2858 // or a valid def/kill/pinch-point, or a leftover node from some prior
2859 // block. Leftover node from some prior block is treated like a NULL (no
2860 // prior def, so no anti-dependence needed). Valid def is distinguished by
2861 // it being in the current block.
2862 bool fat_proj_seen = false;
2863 uint last_safept = _bb_end-1;
2864 Node* end_node = (_bb_end-1 >= _bb_start) ? b->_nodes[last_safept] : NULL;
2865 Node* last_safept_node = end_node;
2866 for( uint i = _bb_end-1; i >= _bb_start; i-- ) {
2867 Node *n = b->_nodes[i];
2868 int is_def = n->outcnt(); // def if some uses prior to adding precedence edges
2869 if( n->is_MachProj() && n->ideal_reg() == MachProjNode::fat_proj ) {
2870 // Fat-proj kills a slew of registers
2871 // This can add edges to 'n' and obscure whether or not it was a def,
2872 // hence the is_def flag.
2873 fat_proj_seen = true;
2874 RegMask rm = n->out_RegMask();// Make local copy
2875 while( rm.is_NotEmpty() ) {
2876 OptoReg::Name kill = rm.find_first_elem();
2877 rm.Remove(kill);
2878 anti_do_def( b, n, kill, is_def );
2879 }
2880 } else {
2881 // Get DEF'd registers the normal way
2882 anti_do_def( b, n, _regalloc->get_reg_first(n), is_def );
2883 anti_do_def( b, n, _regalloc->get_reg_second(n), is_def );
2884 }
2885
2886 // Kill projections on a branch should appear to occur on the
2887 // branch, not afterwards, so grab the masks from the projections
2888 // and process them.
2889 if (n->is_MachBranch() || n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_Jump) {
2890 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2891 Node* use = n->fast_out(i);
2892 if (use->is_Proj()) {
2893 RegMask rm = use->out_RegMask();// Make local copy
2894 while( rm.is_NotEmpty() ) {
2895 OptoReg::Name kill = rm.find_first_elem();
2896 rm.Remove(kill);
2897 anti_do_def( b, n, kill, false );
2898 }
2899 }
2900 }
2901 }
2902
2903 // Check each register used by this instruction for a following DEF/KILL
2904 // that must occur afterward and requires an anti-dependence edge.
2905 for( uint j=0; j<n->req(); j++ ) {
2906 Node *def = n->in(j);
2907 if( def ) {
2908 assert( !def->is_MachProj() || def->ideal_reg() != MachProjNode::fat_proj, "" );
2909 anti_do_use( b, n, _regalloc->get_reg_first(def) );
2910 anti_do_use( b, n, _regalloc->get_reg_second(def) );
2911 }
2912 }
2913 // Do not allow defs of new derived values to float above GC
2914 // points unless the base is definitely available at the GC point.
2915
2916 Node *m = b->_nodes[i];
2917
2918 // Add precedence edge from following safepoint to use of derived pointer
2919 if( last_safept_node != end_node &&
2920 m != last_safept_node) {
2921 for (uint k = 1; k < m->req(); k++) {
2922 const Type *t = m->in(k)->bottom_type();
2923 if( t->isa_oop_ptr() &&
2924 t->is_ptr()->offset() != 0 ) {
2925 last_safept_node->add_prec( m );
2926 break;
2927 }
2928 }
2929 }
2930
2931 if( n->jvms() ) { // Precedence edge from derived to safept
2932 // Check if last_safept_node was moved by pinch-point insertion in anti_do_use()
2933 if( b->_nodes[last_safept] != last_safept_node ) {
2934 last_safept = b->find_node(last_safept_node);
2935 }
2936 for( uint j=last_safept; j > i; j-- ) {
2937 Node *mach = b->_nodes[j];
2938 if( mach->is_Mach() && mach->as_Mach()->ideal_Opcode() == Op_AddP )
2939 mach->add_prec( n );
2940 }
2941 last_safept = i;
2942 last_safept_node = m;
2943 }
2944 }
2945
2946 if (fat_proj_seen) {
2947 // Garbage collect pinch nodes that were not consumed.
2948 // They are usually created by a fat kill MachProj for a call.
2949 garbage_collect_pinch_nodes();
2950 }
2951 }
2952
2953 //------------------------------garbage_collect_pinch_nodes-------------------------------
2954
2955 // Garbage collect pinch nodes for reuse by other blocks.
2956 //
2957 // The block scheduler's insertion of anti-dependence
2958 // edges creates many pinch nodes when the block contains
2959 // 2 or more Calls. A pinch node is used to prevent a
2960 // combinatorial explosion of edges. If a set of kills for a
2961 // register is anti-dependent on a set of uses (or defs), rather
2962 // than adding an edge in the graph between each pair of kill
2963 // and use (or def), a pinch is inserted between them:
2964 //
2965 // use1 use2 use3
2966 // \ | /
2967 // \ | /
2968 // pinch
2969 // / | \
2970 // / | \
2971 // kill1 kill2 kill3
2972 //
2973 // One pinch node is created per register killed when
2974 // the second call is encountered during a backwards pass
2975 // over the block. Most of these pinch nodes are never
2976 // wired into the graph because the register is never
2977 // used or def'ed in the block.
2978 //
2979 void Scheduling::garbage_collect_pinch_nodes() {
2980 #ifndef PRODUCT
2981 if (_cfg->C->trace_opto_output()) tty->print("Reclaimed pinch nodes:");
2982 #endif
2983 int trace_cnt = 0;
2984 for (uint k = 0; k < _reg_node.Size(); k++) {
2985 Node* pinch = _reg_node[k];
2986 if (pinch != NULL && pinch->Opcode() == Op_Node &&
2987 // no predecence input edges
2988 (pinch->req() == pinch->len() || pinch->in(pinch->req()) == NULL) ) {
2989 cleanup_pinch(pinch);
2990 _pinch_free_list.push(pinch);
2991 _reg_node.map(k, NULL);
2992 #ifndef PRODUCT
2993 if (_cfg->C->trace_opto_output()) {
2994 trace_cnt++;
2995 if (trace_cnt > 40) {
2996 tty->print("\n");
2997 trace_cnt = 0;
2998 }
2999 tty->print(" %d", pinch->_idx);
3000 }
3001 #endif
3002 }
3003 }
3004 #ifndef PRODUCT
3005 if (_cfg->C->trace_opto_output()) tty->print("\n");
3006 #endif
3007 }
3008
3009 // Clean up a pinch node for reuse.
3010 void Scheduling::cleanup_pinch( Node *pinch ) {
3011 assert (pinch && pinch->Opcode() == Op_Node && pinch->req() == 1, "just checking");
3012
3013 for (DUIterator_Last imin, i = pinch->last_outs(imin); i >= imin; ) {
3014 Node* use = pinch->last_out(i);
3015 uint uses_found = 0;
3016 for (uint j = use->req(); j < use->len(); j++) {
3017 if (use->in(j) == pinch) {
3018 use->rm_prec(j);
3019 uses_found++;
3020 }
3021 }
3022 assert(uses_found > 0, "must be a precedence edge");
3023 i -= uses_found; // we deleted 1 or more copies of this edge
3024 }
3025 // May have a later_def entry
3026 pinch->set_req(0, NULL);
3027 }
3028
3029 //------------------------------print_statistics-------------------------------
3030 #ifndef PRODUCT
3031
3032 void Scheduling::dump_available() const {
3033 tty->print("#Availist ");
3034 for (uint i = 0; i < _available.size(); i++)
3035 tty->print(" N%d/l%d", _available[i]->_idx,_current_latency[_available[i]->_idx]);
3036 tty->cr();
3037 }
3038
3039 // Print Scheduling Statistics
3040 void Scheduling::print_statistics() {
3041 // Print the size added by nops for bundling
3042 tty->print("Nops added %d bytes to total of %d bytes",
3043 _total_nop_size, _total_method_size);
3044 if (_total_method_size > 0)
3045 tty->print(", for %.2f%%",
3046 ((double)_total_nop_size) / ((double) _total_method_size) * 100.0);
3047 tty->print("\n");
3048
3049 // Print the number of branch shadows filled
3050 if (Pipeline::_branch_has_delay_slot) {
3051 tty->print("Of %d branches, %d had unconditional delay slots filled",
3052 _total_branches, _total_unconditional_delays);
3053 if (_total_branches > 0)
3054 tty->print(", for %.2f%%",
3055 ((double)_total_unconditional_delays) / ((double)_total_branches) * 100.0);
3056 tty->print("\n");
3057 }
3058
3059 uint total_instructions = 0, total_bundles = 0;
3060
3061 for (uint i = 1; i <= Pipeline::_max_instrs_per_cycle; i++) {
3062 uint bundle_count = _total_instructions_per_bundle[i];
3063 total_instructions += bundle_count * i;
3064 total_bundles += bundle_count;
3065 }
3066
3067 if (total_bundles > 0)
3068 tty->print("Average ILP (excluding nops) is %.2f\n",
3069 ((double)total_instructions) / ((double)total_bundles));
3070 }
3071 #endif