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