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