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