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