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