1 /*
2 * Copyright (c) 1998, 2025, 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 "asm/assembler.inline.hpp"
26 #include "code/aotCodeCache.hpp"
27 #include "code/compiledIC.hpp"
28 #include "code/debugInfo.hpp"
29 #include "code/debugInfoRec.hpp"
30 #include "compiler/compileBroker.hpp"
31 #include "compiler/compilerDirectives.hpp"
32 #include "compiler/disassembler.hpp"
33 #include "compiler/oopMap.hpp"
34 #include "gc/shared/barrierSet.hpp"
35 #include "gc/shared/c2/barrierSetC2.hpp"
36 #include "memory/allocation.hpp"
37 #include "opto/ad.hpp"
38 #include "opto/block.hpp"
39 #include "opto/c2_MacroAssembler.hpp"
40 #include "opto/c2compiler.hpp"
41 #include "opto/callnode.hpp"
42 #include "opto/cfgnode.hpp"
43 #include "opto/locknode.hpp"
44 #include "opto/machnode.hpp"
45 #include "opto/node.hpp"
46 #include "opto/optoreg.hpp"
47 #include "opto/output.hpp"
48 #include "opto/regalloc.hpp"
49 #include "opto/type.hpp"
50 #include "runtime/sharedRuntime.hpp"
51 #include "utilities/macros.hpp"
52 #include "utilities/powerOfTwo.hpp"
53 #include "utilities/xmlstream.hpp"
54
55 #ifndef PRODUCT
56 #define DEBUG_ARG(x) , x
57 #else
58 #define DEBUG_ARG(x)
59 #endif
60
61 //------------------------------Scheduling----------------------------------
62 // This class contains all the information necessary to implement instruction
63 // scheduling and bundling.
64 class Scheduling {
65
66 private:
67 // Arena to use
68 Arena *_arena;
69
70 // Control-Flow Graph info
71 PhaseCFG *_cfg;
72
73 // Register Allocation info
74 PhaseRegAlloc *_regalloc;
75
76 // Number of nodes in the method
77 uint _node_bundling_limit;
78
79 // List of scheduled nodes. Generated in reverse order
80 Node_List _scheduled;
81
82 // List of nodes currently available for choosing for scheduling
83 Node_List _available;
84
85 // For each instruction beginning a bundle, the number of following
86 // nodes to be bundled with it.
87 Bundle *_node_bundling_base;
88
89 // Mapping from register to Node
90 Node_List _reg_node;
91
92 // Free list for pinch nodes.
93 Node_List _pinch_free_list;
94
95 // Number of uses of this node within the containing basic block.
96 short *_uses;
97
98 // Schedulable portion of current block. Skips Region/Phi/CreateEx up
99 // front, branch+proj at end. Also skips Catch/CProj (same as
100 // branch-at-end), plus just-prior exception-throwing call.
101 uint _bb_start, _bb_end;
102
103 // Latency from the end of the basic block as scheduled
104 unsigned short *_current_latency;
105
106 // Remember the next node
107 Node *_next_node;
108
109 // Length of the current bundle, in instructions
110 uint _bundle_instr_count;
111
112 // Current Cycle number, for computing latencies and bundling
113 uint _bundle_cycle_number;
114
115 // Bundle information
116 Pipeline_Use_Element _bundle_use_elements[resource_count];
117 Pipeline_Use _bundle_use;
118
119 // Dump the available list
120 void dump_available() const;
121
122 public:
123 Scheduling(Arena *arena, Compile &compile);
124
125 // Step ahead "i" cycles
126 void step(uint i);
127
128 // Step ahead 1 cycle, and clear the bundle state (for example,
129 // at a branch target)
130 void step_and_clear();
131
132 Bundle* node_bundling(const Node *n) {
133 assert(valid_bundle_info(n), "oob");
134 return (&_node_bundling_base[n->_idx]);
135 }
136
137 bool valid_bundle_info(const Node *n) const {
138 return (_node_bundling_limit > n->_idx);
139 }
140
141 bool starts_bundle(const Node *n) const {
142 return (_node_bundling_limit > n->_idx && _node_bundling_base[n->_idx].starts_bundle());
143 }
144
145 // Do the scheduling
146 void DoScheduling();
147
148 // Compute the register antidependencies within a basic block
149 void ComputeRegisterAntidependencies(Block *bb);
150 void verify_do_def( Node *n, OptoReg::Name def, const char *msg );
151 void verify_good_schedule( Block *b, const char *msg );
152 void anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def );
153 void anti_do_use( Block *b, Node *use, OptoReg::Name use_reg );
154
155 // Add a node to the current bundle
156 void AddNodeToBundle(Node *n, const Block *bb);
157
158 // Return an integer less than, equal to, or greater than zero
159 // if the stack offset of the first argument is respectively
160 // less than, equal to, or greater than the second.
161 int compare_two_spill_nodes(Node* first, Node* second);
162
163 // Add a node to the list of available nodes
164 void AddNodeToAvailableList(Node *n);
165
166 // Compute the local use count for the nodes in a block, and compute
167 // the list of instructions with no uses in the block as available
168 void ComputeUseCount(const Block *bb);
169
170 // Choose an instruction from the available list to add to the bundle
171 Node * ChooseNodeToBundle();
172
173 // See if this Node fits into the currently accumulating bundle
174 bool NodeFitsInBundle(Node *n);
175
176 // Decrement the use count for a node
177 void DecrementUseCounts(Node *n, const Block *bb);
178
179 // Garbage collect pinch nodes for reuse by other blocks.
180 void garbage_collect_pinch_nodes();
181 // Clean up a pinch node for reuse (helper for above).
182 void cleanup_pinch( Node *pinch );
183
184 // Information for statistics gathering
185 #ifndef PRODUCT
186 private:
187 // Gather information on size of nops relative to total
188 static uint _total_nop_size, _total_method_size;
189 static uint _total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
190
191 public:
192 static void print_statistics();
193
194 static void increment_instructions_per_bundle(uint i) {
195 _total_instructions_per_bundle[i]++;
196 }
197
198 static void increment_nop_size(uint s) {
199 _total_nop_size += s;
200 }
201
202 static void increment_method_size(uint s) {
203 _total_method_size += s;
204 }
205 #endif
206
207 };
208
209 PhaseOutput::PhaseOutput()
210 : Phase(Phase::Output),
211 _code_buffer("Compile::Fill_buffer"),
212 _first_block_size(0),
213 _handler_table(),
214 _inc_table(),
215 _stub_list(),
216 _oop_map_set(nullptr),
217 _scratch_buffer_blob(nullptr),
218 _scratch_locs_memory(nullptr),
219 _scratch_const_size(-1),
220 _in_scratch_emit_size(false),
221 _frame_slots(0),
222 _code_offsets(),
223 _node_bundling_limit(0),
224 _node_bundling_base(nullptr),
225 _orig_pc_slot(0),
226 _orig_pc_slot_offset_in_bytes(0),
227 _buf_sizes(),
228 _block(nullptr),
229 _index(0) {
230 C->set_output(this);
231 if (C->stub_name() == nullptr) {
232 _orig_pc_slot = C->fixed_slots() - (sizeof(address) / VMRegImpl::stack_slot_size);
233 }
234 }
235
236 PhaseOutput::~PhaseOutput() {
237 C->set_output(nullptr);
238 if (_scratch_buffer_blob != nullptr) {
239 BufferBlob::free(_scratch_buffer_blob);
240 }
241 }
242
243 void PhaseOutput::perform_mach_node_analysis() {
244 // Late barrier analysis must be done after schedule and bundle
245 // Otherwise liveness based spilling will fail
246 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
247 bs->late_barrier_analysis();
248
249 pd_perform_mach_node_analysis();
250
251 C->print_method(CompilerPhaseType::PHASE_MACH_ANALYSIS, 3);
252 }
253
254 // Convert Nodes to instruction bits and pass off to the VM
255 void PhaseOutput::Output() {
256 // RootNode goes
257 assert( C->cfg()->get_root_block()->number_of_nodes() == 0, "" );
258
259 // The number of new nodes (mostly MachNop) is proportional to
260 // the number of java calls and inner loops which are aligned.
261 if ( C->check_node_count((NodeLimitFudgeFactor + C->java_calls()*3 +
262 C->inner_loops()*(OptoLoopAlignment-1)),
263 "out of nodes before code generation" ) ) {
264 return;
265 }
266 // Make sure I can find the Start Node
267 Block *entry = C->cfg()->get_block(1);
268 Block *broot = C->cfg()->get_root_block();
269
270 const StartNode *start = entry->head()->as_Start();
271
272 // Replace StartNode with prolog
273 MachPrologNode *prolog = new MachPrologNode();
274 entry->map_node(prolog, 0);
275 C->cfg()->map_node_to_block(prolog, entry);
276 C->cfg()->unmap_node_from_block(start); // start is no longer in any block
277
278 // Virtual methods need an unverified entry point
279
280 if( C->is_osr_compilation() ) {
281 if( PoisonOSREntry ) {
282 // TODO: Should use a ShouldNotReachHereNode...
283 C->cfg()->insert( broot, 0, new MachBreakpointNode() );
284 }
285 } else {
286 if( C->method() && !C->method()->flags().is_static() ) {
287 // Insert unvalidated entry point
288 C->cfg()->insert( broot, 0, new MachUEPNode() );
289 }
290
291 }
292
293 // Break before main entry point
294 if ((C->method() && C->directive()->BreakAtExecuteOption) ||
295 (OptoBreakpoint && C->is_method_compilation()) ||
296 (OptoBreakpointOSR && C->is_osr_compilation()) ||
297 (OptoBreakpointC2R && !C->method()) ) {
298 // checking for C->method() means that OptoBreakpoint does not apply to
299 // runtime stubs or frame converters
300 C->cfg()->insert( entry, 1, new MachBreakpointNode() );
301 }
302
303 // Insert epilogs before every return
304 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
305 Block* block = C->cfg()->get_block(i);
306 if (!block->is_connector() && block->non_connector_successor(0) == C->cfg()->get_root_block()) { // Found a program exit point?
307 Node* m = block->end();
308 if (m->is_Mach() && m->as_Mach()->ideal_Opcode() != Op_Halt) {
309 MachEpilogNode* epilog = new MachEpilogNode(m->as_Mach()->ideal_Opcode() == Op_Return);
310 block->add_inst(epilog);
311 C->cfg()->map_node_to_block(epilog, block);
312 }
313 }
314 }
315
316 // Keeper of sizing aspects
317 _buf_sizes = BufferSizingData();
318
319 // Initialize code buffer
320 estimate_buffer_size(_buf_sizes._const);
321 if (C->failing()) return;
322
323 // Pre-compute the length of blocks and replace
324 // long branches with short if machine supports it.
325 // Must be done before ScheduleAndBundle due to SPARC delay slots
326 uint* blk_starts = NEW_RESOURCE_ARRAY(uint, C->cfg()->number_of_blocks() + 1);
327 blk_starts[0] = 0;
328 shorten_branches(blk_starts);
329
330 ScheduleAndBundle();
331 if (C->failing()) {
332 return;
333 }
334
335 perform_mach_node_analysis();
336
337 // Complete sizing of codebuffer
338 CodeBuffer* cb = init_buffer();
339 if (cb == nullptr || C->failing()) {
340 return;
341 }
342
343 BuildOopMaps();
344
345 if (C->failing()) {
346 return;
347 }
348
349 C2_MacroAssembler masm(cb);
350 fill_buffer(&masm, blk_starts);
351 }
352
353 bool PhaseOutput::need_stack_bang(int frame_size_in_bytes) const {
354 // Determine if we need to generate a stack overflow check.
355 // Do it if the method is not a stub function and
356 // has java calls or has frame size > vm_page_size/8.
357 // The debug VM checks that deoptimization doesn't trigger an
358 // unexpected stack overflow (compiled method stack banging should
359 // guarantee it doesn't happen) so we always need the stack bang in
360 // a debug VM.
361 return (C->stub_function() == nullptr &&
362 (C->has_java_calls() || frame_size_in_bytes > (int)(os::vm_page_size())>>3
363 DEBUG_ONLY(|| true)));
364 }
365
366 // Compute the size of first NumberOfLoopInstrToAlign instructions at the top
367 // of a loop. When aligning a loop we need to provide enough instructions
368 // in cpu's fetch buffer to feed decoders. The loop alignment could be
369 // avoided if we have enough instructions in fetch buffer at the head of a loop.
370 // By default, the size is set to 999999 by Block's constructor so that
371 // a loop will be aligned if the size is not reset here.
372 //
373 // Note: Mach instructions could contain several HW instructions
374 // so the size is estimated only.
375 //
376 void PhaseOutput::compute_loop_first_inst_sizes() {
377 // The next condition is used to gate the loop alignment optimization.
378 // Don't aligned a loop if there are enough instructions at the head of a loop
379 // or alignment padding is larger then MaxLoopPad. By default, MaxLoopPad
380 // is equal to OptoLoopAlignment-1 except on new Intel cpus, where it is
381 // equal to 11 bytes which is the largest address NOP instruction.
382 if (MaxLoopPad < OptoLoopAlignment - 1) {
383 uint last_block = C->cfg()->number_of_blocks() - 1;
384 for (uint i = 1; i <= last_block; i++) {
385 Block* block = C->cfg()->get_block(i);
386 // Check the first loop's block which requires an alignment.
387 if (block->loop_alignment() > (uint)relocInfo::addr_unit()) {
388 uint sum_size = 0;
389 uint inst_cnt = NumberOfLoopInstrToAlign;
390 inst_cnt = block->compute_first_inst_size(sum_size, inst_cnt, C->regalloc());
391
392 // Check subsequent fallthrough blocks if the loop's first
393 // block(s) does not have enough instructions.
394 Block *nb = block;
395 while(inst_cnt > 0 &&
396 i < last_block &&
397 !C->cfg()->get_block(i + 1)->has_loop_alignment() &&
398 !nb->has_successor(block)) {
399 i++;
400 nb = C->cfg()->get_block(i);
401 inst_cnt = nb->compute_first_inst_size(sum_size, inst_cnt, C->regalloc());
402 } // while( inst_cnt > 0 && i < last_block )
403
404 block->set_first_inst_size(sum_size);
405 } // f( b->head()->is_Loop() )
406 } // for( i <= last_block )
407 } // if( MaxLoopPad < OptoLoopAlignment-1 )
408 }
409
410 // The architecture description provides short branch variants for some long
411 // branch instructions. Replace eligible long branches with short branches.
412 void PhaseOutput::shorten_branches(uint* blk_starts) {
413
414 Compile::TracePhase tp(_t_shortenBranches);
415
416 // Compute size of each block, method size, and relocation information size
417 uint nblocks = C->cfg()->number_of_blocks();
418
419 uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
420 uint* jmp_size = NEW_RESOURCE_ARRAY(uint,nblocks);
421 int* jmp_nidx = NEW_RESOURCE_ARRAY(int ,nblocks);
422
423 // Collect worst case block paddings
424 int* block_worst_case_pad = NEW_RESOURCE_ARRAY(int, nblocks);
425 memset(block_worst_case_pad, 0, nblocks * sizeof(int));
426
427 DEBUG_ONLY( uint *jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks); )
428 DEBUG_ONLY( uint *jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks); )
429
430 bool has_short_branch_candidate = false;
431
432 // Initialize the sizes to 0
433 int code_size = 0; // Size in bytes of generated code
434 int stub_size = 0; // Size in bytes of all stub entries
435 // Size in bytes of all relocation entries, including those in local stubs.
436 // Start with 2-bytes of reloc info for the unvalidated entry point
437 int reloc_size = 1; // Number of relocation entries
438
439 // Make three passes. The first computes pessimistic blk_starts,
440 // relative jmp_offset and reloc_size information. The second performs
441 // short branch substitution using the pessimistic sizing. The
442 // third inserts nops where needed.
443
444 // Step one, perform a pessimistic sizing pass.
445 uint last_call_adr = max_juint;
446 uint last_avoid_back_to_back_adr = max_juint;
447 uint nop_size = (new MachNopNode())->size(C->regalloc());
448 for (uint i = 0; i < nblocks; i++) { // For all blocks
449 Block* block = C->cfg()->get_block(i);
450 _block = block;
451
452 // During short branch replacement, we store the relative (to blk_starts)
453 // offset of jump in jmp_offset, rather than the absolute offset of jump.
454 // This is so that we do not need to recompute sizes of all nodes when
455 // we compute correct blk_starts in our next sizing pass.
456 jmp_offset[i] = 0;
457 jmp_size[i] = 0;
458 jmp_nidx[i] = -1;
459 DEBUG_ONLY( jmp_target[i] = 0; )
460 DEBUG_ONLY( jmp_rule[i] = 0; )
461
462 // Sum all instruction sizes to compute block size
463 uint last_inst = block->number_of_nodes();
464 uint blk_size = 0;
465 for (uint j = 0; j < last_inst; j++) {
466 _index = j;
467 Node* nj = block->get_node(_index);
468 // Handle machine instruction nodes
469 if (nj->is_Mach()) {
470 MachNode* mach = nj->as_Mach();
471 blk_size += (mach->alignment_required() - 1) * relocInfo::addr_unit(); // assume worst case padding
472 reloc_size += mach->reloc();
473 if (mach->is_MachCall()) {
474 // add size information for trampoline stub
475 // class CallStubImpl is platform-specific and defined in the *.ad files.
476 stub_size += CallStubImpl::size_call_trampoline();
477 reloc_size += CallStubImpl::reloc_call_trampoline();
478
479 MachCallNode *mcall = mach->as_MachCall();
480 // This destination address is NOT PC-relative
481
482 mcall->method_set((intptr_t)mcall->entry_point());
483
484 if (mcall->is_MachCallJava() && mcall->as_MachCallJava()->_method) {
485 stub_size += CompiledDirectCall::to_interp_stub_size();
486 reloc_size += CompiledDirectCall::reloc_to_interp_stub();
487 }
488 } else if (mach->is_MachSafePoint()) {
489 // If call/safepoint are adjacent, account for possible
490 // nop to disambiguate the two safepoints.
491 // ScheduleAndBundle() can rearrange nodes in a block,
492 // check for all offsets inside this block.
493 if (last_call_adr >= blk_starts[i]) {
494 blk_size += nop_size;
495 }
496 }
497 if (mach->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
498 // Nop is inserted between "avoid back to back" instructions.
499 // ScheduleAndBundle() can rearrange nodes in a block,
500 // check for all offsets inside this block.
501 if (last_avoid_back_to_back_adr >= blk_starts[i]) {
502 blk_size += nop_size;
503 }
504 }
505 if (mach->may_be_short_branch()) {
506 if (!nj->is_MachBranch()) {
507 #ifndef PRODUCT
508 nj->dump(3);
509 #endif
510 Unimplemented();
511 }
512 assert(jmp_nidx[i] == -1, "block should have only one branch");
513 jmp_offset[i] = blk_size;
514 jmp_size[i] = nj->size(C->regalloc());
515 jmp_nidx[i] = j;
516 has_short_branch_candidate = true;
517 }
518 }
519 blk_size += nj->size(C->regalloc());
520 // Remember end of call offset
521 if (nj->is_MachCall() && !nj->is_MachCallLeaf()) {
522 last_call_adr = blk_starts[i]+blk_size;
523 }
524 // Remember end of avoid_back_to_back offset
525 if (nj->is_Mach() && nj->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
526 last_avoid_back_to_back_adr = blk_starts[i]+blk_size;
527 }
528 }
529
530 // When the next block starts a loop, we may insert pad NOP
531 // instructions. Since we cannot know our future alignment,
532 // assume the worst.
533 if (i < nblocks - 1) {
534 Block* nb = C->cfg()->get_block(i + 1);
535 int max_loop_pad = nb->code_alignment()-relocInfo::addr_unit();
536 if (max_loop_pad > 0) {
537 assert(is_power_of_2(max_loop_pad+relocInfo::addr_unit()), "");
538 // Adjust last_call_adr and/or last_avoid_back_to_back_adr.
539 // If either is the last instruction in this block, bump by
540 // max_loop_pad in lock-step with blk_size, so sizing
541 // calculations in subsequent blocks still can conservatively
542 // detect that it may the last instruction in this block.
543 if (last_call_adr == blk_starts[i]+blk_size) {
544 last_call_adr += max_loop_pad;
545 }
546 if (last_avoid_back_to_back_adr == blk_starts[i]+blk_size) {
547 last_avoid_back_to_back_adr += max_loop_pad;
548 }
549 blk_size += max_loop_pad;
550 block_worst_case_pad[i + 1] = max_loop_pad;
551 }
552 }
553
554 // Save block size; update total method size
555 blk_starts[i+1] = blk_starts[i]+blk_size;
556 }
557
558 // Step two, replace eligible long jumps.
559 bool progress = true;
560 uint last_may_be_short_branch_adr = max_juint;
561 while (has_short_branch_candidate && progress) {
562 progress = false;
563 has_short_branch_candidate = false;
564 int adjust_block_start = 0;
565 for (uint i = 0; i < nblocks; i++) {
566 Block* block = C->cfg()->get_block(i);
567 int idx = jmp_nidx[i];
568 MachNode* mach = (idx == -1) ? nullptr: block->get_node(idx)->as_Mach();
569 if (mach != nullptr && mach->may_be_short_branch()) {
570 #ifdef ASSERT
571 assert(jmp_size[i] > 0 && mach->is_MachBranch(), "sanity");
572 int j;
573 // Find the branch; ignore trailing NOPs.
574 for (j = block->number_of_nodes()-1; j>=0; j--) {
575 Node* n = block->get_node(j);
576 if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con)
577 break;
578 }
579 assert(j >= 0 && j == idx && block->get_node(j) == (Node*)mach, "sanity");
580 #endif
581 int br_size = jmp_size[i];
582 int br_offs = blk_starts[i] + jmp_offset[i];
583
584 // This requires the TRUE branch target be in succs[0]
585 uint bnum = block->non_connector_successor(0)->_pre_order;
586 int offset = blk_starts[bnum] - br_offs;
587 if (bnum > i) { // adjust following block's offset
588 offset -= adjust_block_start;
589 }
590
591 // This block can be a loop header, account for the padding
592 // in the previous block.
593 int block_padding = block_worst_case_pad[i];
594 assert(i == 0 || block_padding == 0 || br_offs >= block_padding, "Should have at least a padding on top");
595 // In the following code a nop could be inserted before
596 // the branch which will increase the backward distance.
597 bool needs_padding = ((uint)(br_offs - block_padding) == last_may_be_short_branch_adr);
598 assert(!needs_padding || jmp_offset[i] == 0, "padding only branches at the beginning of block");
599
600 if (needs_padding && offset <= 0)
601 offset -= nop_size;
602
603 if (C->matcher()->is_short_branch_offset(mach->rule(), br_size, offset)) {
604 // We've got a winner. Replace this branch.
605 MachNode* replacement = mach->as_MachBranch()->short_branch_version();
606
607 // Update the jmp_size.
608 int new_size = replacement->size(C->regalloc());
609 int diff = br_size - new_size;
610 assert(diff >= (int)nop_size, "short_branch size should be smaller");
611 // Conservatively take into account padding between
612 // avoid_back_to_back branches. Previous branch could be
613 // converted into avoid_back_to_back branch during next
614 // rounds.
615 if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
616 jmp_offset[i] += nop_size;
617 diff -= nop_size;
618 }
619 adjust_block_start += diff;
620 block->map_node(replacement, idx);
621 mach->subsume_by(replacement, C);
622 mach = replacement;
623 progress = true;
624
625 jmp_size[i] = new_size;
626 DEBUG_ONLY( jmp_target[i] = bnum; );
627 DEBUG_ONLY( jmp_rule[i] = mach->rule(); );
628 } else {
629 // The jump distance is not short, try again during next iteration.
630 has_short_branch_candidate = true;
631 }
632 } // (mach->may_be_short_branch())
633 if (mach != nullptr && (mach->may_be_short_branch() ||
634 mach->avoid_back_to_back(MachNode::AVOID_AFTER))) {
635 last_may_be_short_branch_adr = blk_starts[i] + jmp_offset[i] + jmp_size[i];
636 }
637 blk_starts[i+1] -= adjust_block_start;
638 }
639 }
640
641 #ifdef ASSERT
642 for (uint i = 0; i < nblocks; i++) { // For all blocks
643 if (jmp_target[i] != 0) {
644 int br_size = jmp_size[i];
645 int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
646 if (!C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
647 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]);
648 }
649 assert(C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset), "Displacement too large for short jmp");
650 }
651 }
652 #endif
653
654 // Step 3, compute the offsets of all blocks, will be done in fill_buffer()
655 // after ScheduleAndBundle().
656
657 // ------------------
658 // Compute size for code buffer
659 code_size = blk_starts[nblocks];
660
661 // Relocation records
662 reloc_size += 1; // Relo entry for exception handler
663
664 // Adjust reloc_size to number of record of relocation info
665 // Min is 2 bytes, max is probably 6 or 8, with a tax up to 25% for
666 // a relocation index.
667 // The CodeBuffer will expand the locs array if this estimate is too low.
668 reloc_size *= 10 / sizeof(relocInfo);
669
670 _buf_sizes._reloc = reloc_size;
671 _buf_sizes._code = code_size;
672 _buf_sizes._stub = stub_size;
673 }
674
675 //------------------------------FillLocArray-----------------------------------
676 // Create a bit of debug info and append it to the array. The mapping is from
677 // Java local or expression stack to constant, register or stack-slot. For
678 // doubles, insert 2 mappings and return 1 (to tell the caller that the next
679 // entry has been taken care of and caller should skip it).
680 static LocationValue *new_loc_value( PhaseRegAlloc *ra, OptoReg::Name regnum, Location::Type l_type ) {
681 // This should never have accepted Bad before
682 assert(OptoReg::is_valid(regnum), "location must be valid");
683 return (OptoReg::is_reg(regnum))
684 ? new LocationValue(Location::new_reg_loc(l_type, OptoReg::as_VMReg(regnum)) )
685 : new LocationValue(Location::new_stk_loc(l_type, ra->reg2offset(regnum)));
686 }
687
688
689 ObjectValue*
690 PhaseOutput::sv_for_node_id(GrowableArray<ScopeValue*> *objs, int id) {
691 for (int i = 0; i < objs->length(); i++) {
692 assert(objs->at(i)->is_object(), "corrupt object cache");
693 ObjectValue* sv = objs->at(i)->as_ObjectValue();
694 if (sv->id() == id) {
695 return sv;
696 }
697 }
698 // Otherwise..
699 return nullptr;
700 }
701
702 void PhaseOutput::set_sv_for_object_node(GrowableArray<ScopeValue*> *objs,
703 ObjectValue* sv ) {
704 assert(sv_for_node_id(objs, sv->id()) == nullptr, "Precondition");
705 objs->append(sv);
706 }
707
708
709 void PhaseOutput::FillLocArray( int idx, MachSafePointNode* sfpt, Node *local,
710 GrowableArray<ScopeValue*> *array,
711 GrowableArray<ScopeValue*> *objs ) {
712 assert( local, "use _top instead of null" );
713 if (array->length() != idx) {
714 assert(array->length() == idx + 1, "Unexpected array count");
715 // Old functionality:
716 // return
717 // New functionality:
718 // Assert if the local is not top. In product mode let the new node
719 // override the old entry.
720 assert(local == C->top(), "LocArray collision");
721 if (local == C->top()) {
722 return;
723 }
724 array->pop();
725 }
726 const Type *t = local->bottom_type();
727
728 // Is it a safepoint scalar object node?
729 if (local->is_SafePointScalarObject()) {
730 SafePointScalarObjectNode* spobj = local->as_SafePointScalarObject();
731
732 ObjectValue* sv = sv_for_node_id(objs, spobj->_idx);
733 if (sv == nullptr) {
734 ciKlass* cik = t->is_oopptr()->exact_klass();
735 assert(cik->is_instance_klass() ||
736 cik->is_array_klass(), "Not supported allocation.");
737 sv = new ObjectValue(spobj->_idx,
738 new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
739 set_sv_for_object_node(objs, sv);
740
741 uint first_ind = spobj->first_index(sfpt->jvms());
742 for (uint i = 0; i < spobj->n_fields(); i++) {
743 Node* fld_node = sfpt->in(first_ind+i);
744 (void)FillLocArray(sv->field_values()->length(), sfpt, fld_node, sv->field_values(), objs);
745 }
746 }
747 array->append(sv);
748 return;
749 } else if (local->is_SafePointScalarMerge()) {
750 SafePointScalarMergeNode* smerge = local->as_SafePointScalarMerge();
751 ObjectMergeValue* mv = (ObjectMergeValue*) sv_for_node_id(objs, smerge->_idx);
752
753 if (mv == nullptr) {
754 GrowableArray<ScopeValue*> deps;
755
756 int merge_pointer_idx = smerge->merge_pointer_idx(sfpt->jvms());
757 (void)FillLocArray(0, sfpt, sfpt->in(merge_pointer_idx), &deps, objs);
758 assert(deps.length() == 1, "missing value");
759
760 int selector_idx = smerge->selector_idx(sfpt->jvms());
761 (void)FillLocArray(1, nullptr, sfpt->in(selector_idx), &deps, nullptr);
762 assert(deps.length() == 2, "missing value");
763
764 mv = new ObjectMergeValue(smerge->_idx, deps.at(0), deps.at(1));
765 set_sv_for_object_node(objs, mv);
766
767 for (uint i = 1; i < smerge->req(); i++) {
768 Node* obj_node = smerge->in(i);
769 int idx = mv->possible_objects()->length();
770 (void)FillLocArray(idx, sfpt, obj_node, mv->possible_objects(), objs);
771
772 // By default ObjectValues that are in 'possible_objects' are not root objects.
773 // They will be marked as root later if they are directly referenced in a JVMS.
774 assert(mv->possible_objects()->length() > idx, "Didn't add entry to possible_objects?!");
775 assert(mv->possible_objects()->at(idx)->is_object(), "Entries in possible_objects should be ObjectValue.");
776 mv->possible_objects()->at(idx)->as_ObjectValue()->set_root(false);
777 }
778 }
779 array->append(mv);
780 return;
781 }
782
783 // Grab the register number for the local
784 OptoReg::Name regnum = C->regalloc()->get_reg_first(local);
785 if( OptoReg::is_valid(regnum) ) {// Got a register/stack?
786 // Record the double as two float registers.
787 // The register mask for such a value always specifies two adjacent
788 // float registers, with the lower register number even.
789 // Normally, the allocation of high and low words to these registers
790 // is irrelevant, because nearly all operations on register pairs
791 // (e.g., StoreD) treat them as a single unit.
792 // Here, we assume in addition that the words in these two registers
793 // stored "naturally" (by operations like StoreD and double stores
794 // within the interpreter) such that the lower-numbered register
795 // is written to the lower memory address. This may seem like
796 // a machine dependency, but it is not--it is a requirement on
797 // the author of the <arch>.ad file to ensure that, for every
798 // even/odd double-register pair to which a double may be allocated,
799 // the word in the even single-register is stored to the first
800 // memory word. (Note that register numbers are completely
801 // arbitrary, and are not tied to any machine-level encodings.)
802 #ifdef _LP64
803 if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon ) {
804 array->append(new ConstantIntValue((jint)0));
805 array->append(new_loc_value( C->regalloc(), regnum, Location::dbl ));
806 } else if ( t->base() == Type::Long ) {
807 array->append(new ConstantIntValue((jint)0));
808 array->append(new_loc_value( C->regalloc(), regnum, Location::lng ));
809 } else if ( t->base() == Type::RawPtr ) {
810 // jsr/ret return address which must be restored into the full
811 // width 64-bit stack slot.
812 array->append(new_loc_value( C->regalloc(), regnum, Location::lng ));
813 }
814 #else //_LP64
815 if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon || t->base() == Type::Long ) {
816 // Repack the double/long as two jints.
817 // The convention the interpreter uses is that the second local
818 // holds the first raw word of the native double representation.
819 // This is actually reasonable, since locals and stack arrays
820 // grow downwards in all implementations.
821 // (If, on some machine, the interpreter's Java locals or stack
822 // were to grow upwards, the embedded doubles would be word-swapped.)
823 array->append(new_loc_value( C->regalloc(), OptoReg::add(regnum,1), Location::normal ));
824 array->append(new_loc_value( C->regalloc(), regnum , Location::normal ));
825 }
826 #endif //_LP64
827 else if( (t->base() == Type::FloatBot || t->base() == Type::FloatCon) &&
828 OptoReg::is_reg(regnum) ) {
829 array->append(new_loc_value( C->regalloc(), regnum, Matcher::float_in_double()
830 ? Location::float_in_dbl : Location::normal ));
831 } else if( t->base() == Type::Int && OptoReg::is_reg(regnum) ) {
832 array->append(new_loc_value( C->regalloc(), regnum, Matcher::int_in_long
833 ? Location::int_in_long : Location::normal ));
834 } else if( t->base() == Type::NarrowOop ) {
835 array->append(new_loc_value( C->regalloc(), regnum, Location::narrowoop ));
836 } else if (t->base() == Type::VectorA || t->base() == Type::VectorS ||
837 t->base() == Type::VectorD || t->base() == Type::VectorX ||
838 t->base() == Type::VectorY || t->base() == Type::VectorZ) {
839 array->append(new_loc_value( C->regalloc(), regnum, Location::vector ));
840 } else if (C->regalloc()->is_oop(local)) {
841 assert(t->base() == Type::OopPtr || t->base() == Type::InstPtr ||
842 t->base() == Type::AryPtr,
843 "Unexpected type: %s", t->msg());
844 array->append(new_loc_value( C->regalloc(), regnum, Location::oop ));
845 } else {
846 assert(t->base() == Type::Int || t->base() == Type::Half ||
847 t->base() == Type::FloatCon || t->base() == Type::FloatBot,
848 "Unexpected type: %s", t->msg());
849 array->append(new_loc_value( C->regalloc(), regnum, Location::normal ));
850 }
851 return;
852 }
853
854 // No register. It must be constant data.
855 switch (t->base()) {
856 case Type::Half: // Second half of a double
857 ShouldNotReachHere(); // Caller should skip 2nd halves
858 break;
859 case Type::AnyPtr:
860 array->append(new ConstantOopWriteValue(nullptr));
861 break;
862 case Type::AryPtr:
863 case Type::InstPtr: // fall through
864 array->append(new ConstantOopWriteValue(t->isa_oopptr()->const_oop()->constant_encoding()));
865 break;
866 case Type::NarrowOop:
867 if (t == TypeNarrowOop::NULL_PTR) {
868 array->append(new ConstantOopWriteValue(nullptr));
869 } else {
870 array->append(new ConstantOopWriteValue(t->make_ptr()->isa_oopptr()->const_oop()->constant_encoding()));
871 }
872 break;
873 case Type::Int:
874 array->append(new ConstantIntValue(t->is_int()->get_con()));
875 break;
876 case Type::RawPtr:
877 // A return address (T_ADDRESS).
878 assert((intptr_t)t->is_ptr()->get_con() < (intptr_t)0x10000, "must be a valid BCI");
879 #ifdef _LP64
880 // Must be restored to the full-width 64-bit stack slot.
881 array->append(new ConstantLongValue(t->is_ptr()->get_con()));
882 #else
883 array->append(new ConstantIntValue(t->is_ptr()->get_con()));
884 #endif
885 break;
886 case Type::FloatCon: {
887 float f = t->is_float_constant()->getf();
888 array->append(new ConstantIntValue(jint_cast(f)));
889 break;
890 }
891 case Type::DoubleCon: {
892 jdouble d = t->is_double_constant()->getd();
893 #ifdef _LP64
894 array->append(new ConstantIntValue((jint)0));
895 array->append(new ConstantDoubleValue(d));
896 #else
897 // Repack the double as two jints.
898 // The convention the interpreter uses is that the second local
899 // holds the first raw word of the native double representation.
900 // This is actually reasonable, since locals and stack arrays
901 // grow downwards in all implementations.
902 // (If, on some machine, the interpreter's Java locals or stack
903 // were to grow upwards, the embedded doubles would be word-swapped.)
904 jlong_accessor acc;
905 acc.long_value = jlong_cast(d);
906 array->append(new ConstantIntValue(acc.words[1]));
907 array->append(new ConstantIntValue(acc.words[0]));
908 #endif
909 break;
910 }
911 case Type::Long: {
912 jlong d = t->is_long()->get_con();
913 #ifdef _LP64
914 array->append(new ConstantIntValue((jint)0));
915 array->append(new ConstantLongValue(d));
916 #else
917 // Repack the long as two jints.
918 // The convention the interpreter uses is that the second local
919 // holds the first raw word of the native double representation.
920 // This is actually reasonable, since locals and stack arrays
921 // grow downwards in all implementations.
922 // (If, on some machine, the interpreter's Java locals or stack
923 // were to grow upwards, the embedded doubles would be word-swapped.)
924 jlong_accessor acc;
925 acc.long_value = d;
926 array->append(new ConstantIntValue(acc.words[1]));
927 array->append(new ConstantIntValue(acc.words[0]));
928 #endif
929 break;
930 }
931 case Type::Top: // Add an illegal value here
932 array->append(new LocationValue(Location()));
933 break;
934 default:
935 ShouldNotReachHere();
936 break;
937 }
938 }
939
940 // Determine if this node starts a bundle
941 bool PhaseOutput::starts_bundle(const Node *n) const {
942 return (_node_bundling_limit > n->_idx &&
943 _node_bundling_base[n->_idx].starts_bundle());
944 }
945
946 // Determine if there is a monitor that has 'ov' as its owner.
947 bool PhaseOutput::contains_as_owner(GrowableArray<MonitorValue*> *monarray, ObjectValue *ov) const {
948 for (int k = 0; k < monarray->length(); k++) {
949 MonitorValue* mv = monarray->at(k);
950 if (mv->owner() == ov) {
951 return true;
952 }
953 }
954
955 return false;
956 }
957
958 // Determine if there is a scalar replaced object description represented by 'ov'.
959 bool PhaseOutput::contains_as_scalarized_obj(JVMState* jvms, MachSafePointNode* sfn,
960 GrowableArray<ScopeValue*>* objs,
961 ObjectValue* ov) const {
962 for (int i = 0; i < jvms->scl_size(); i++) {
963 Node* n = sfn->scalarized_obj(jvms, i);
964 // Other kinds of nodes that we may encounter here, for instance constants
965 // representing values of fields of objects scalarized, aren't relevant for
966 // us, since they don't map to ObjectValue.
967 if (!n->is_SafePointScalarObject()) {
968 continue;
969 }
970
971 ObjectValue* other = sv_for_node_id(objs, n->_idx);
972 if (ov == other) {
973 return true;
974 }
975 }
976 return false;
977 }
978
979 //--------------------------Process_OopMap_Node--------------------------------
980 void PhaseOutput::Process_OopMap_Node(MachNode *mach, int current_offset) {
981 // Handle special safepoint nodes for synchronization
982 MachSafePointNode *sfn = mach->as_MachSafePoint();
983 MachCallNode *mcall;
984
985 int safepoint_pc_offset = current_offset;
986 bool return_oop = false;
987 bool has_ea_local_in_scope = sfn->_has_ea_local_in_scope;
988 bool arg_escape = false;
989
990 // Add the safepoint in the DebugInfoRecorder
991 if( !mach->is_MachCall() ) {
992 mcall = nullptr;
993 C->debug_info()->add_safepoint(safepoint_pc_offset, sfn->_oop_map);
994 } else {
995 mcall = mach->as_MachCall();
996
997 if (mcall->is_MachCallJava()) {
998 arg_escape = mcall->as_MachCallJava()->_arg_escape;
999 }
1000
1001 // Check if a call returns an object.
1002 if (mcall->returns_pointer()) {
1003 return_oop = true;
1004 }
1005 safepoint_pc_offset += mcall->ret_addr_offset();
1006 C->debug_info()->add_safepoint(safepoint_pc_offset, mcall->_oop_map);
1007 }
1008
1009 // Loop over the JVMState list to add scope information
1010 // Do not skip safepoints with a null method, they need monitor info
1011 JVMState* youngest_jvms = sfn->jvms();
1012 int max_depth = youngest_jvms->depth();
1013
1014 // Allocate the object pool for scalar-replaced objects -- the map from
1015 // small-integer keys (which can be recorded in the local and ostack
1016 // arrays) to descriptions of the object state.
1017 GrowableArray<ScopeValue*> *objs = new GrowableArray<ScopeValue*>();
1018
1019 // Visit scopes from oldest to youngest.
1020 for (int depth = 1; depth <= max_depth; depth++) {
1021 JVMState* jvms = youngest_jvms->of_depth(depth);
1022 int idx;
1023 ciMethod* method = jvms->has_method() ? jvms->method() : nullptr;
1024 // Safepoints that do not have method() set only provide oop-map and monitor info
1025 // to support GC; these do not support deoptimization.
1026 int num_locs = (method == nullptr) ? 0 : jvms->loc_size();
1027 int num_exps = (method == nullptr) ? 0 : jvms->stk_size();
1028 int num_mon = jvms->nof_monitors();
1029 assert(method == nullptr || jvms->bci() < 0 || num_locs == method->max_locals(),
1030 "JVMS local count must match that of the method");
1031
1032 // Add Local and Expression Stack Information
1033
1034 // Insert locals into the locarray
1035 GrowableArray<ScopeValue*> *locarray = new GrowableArray<ScopeValue*>(num_locs);
1036 for( idx = 0; idx < num_locs; idx++ ) {
1037 FillLocArray( idx, sfn, sfn->local(jvms, idx), locarray, objs );
1038 }
1039
1040 // Insert expression stack entries into the exparray
1041 GrowableArray<ScopeValue*> *exparray = new GrowableArray<ScopeValue*>(num_exps);
1042 for( idx = 0; idx < num_exps; idx++ ) {
1043 FillLocArray( idx, sfn, sfn->stack(jvms, idx), exparray, objs );
1044 }
1045
1046 // Add in mappings of the monitors
1047 assert( !method ||
1048 !method->is_synchronized() ||
1049 method->is_native() ||
1050 num_mon > 0,
1051 "monitors must always exist for synchronized methods");
1052
1053 // Build the growable array of ScopeValues for exp stack
1054 GrowableArray<MonitorValue*> *monarray = new GrowableArray<MonitorValue*>(num_mon);
1055
1056 // Loop over monitors and insert into array
1057 for (idx = 0; idx < num_mon; idx++) {
1058 // Grab the node that defines this monitor
1059 Node* box_node = sfn->monitor_box(jvms, idx);
1060 Node* obj_node = sfn->monitor_obj(jvms, idx);
1061
1062 // Create ScopeValue for object
1063 ScopeValue *scval = nullptr;
1064
1065 if (obj_node->is_SafePointScalarObject()) {
1066 SafePointScalarObjectNode* spobj = obj_node->as_SafePointScalarObject();
1067 scval = PhaseOutput::sv_for_node_id(objs, spobj->_idx);
1068 if (scval == nullptr) {
1069 const Type *t = spobj->bottom_type();
1070 ciKlass* cik = t->is_oopptr()->exact_klass();
1071 assert(cik->is_instance_klass() ||
1072 cik->is_array_klass(), "Not supported allocation.");
1073 ObjectValue* sv = new ObjectValue(spobj->_idx,
1074 new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
1075 PhaseOutput::set_sv_for_object_node(objs, sv);
1076
1077 uint first_ind = spobj->first_index(youngest_jvms);
1078 for (uint i = 0; i < spobj->n_fields(); i++) {
1079 Node* fld_node = sfn->in(first_ind+i);
1080 (void)FillLocArray(sv->field_values()->length(), sfn, fld_node, sv->field_values(), objs);
1081 }
1082 scval = sv;
1083 }
1084 } else if (obj_node->is_SafePointScalarMerge()) {
1085 SafePointScalarMergeNode* smerge = obj_node->as_SafePointScalarMerge();
1086 ObjectMergeValue* mv = (ObjectMergeValue*) sv_for_node_id(objs, smerge->_idx);
1087
1088 if (mv == nullptr) {
1089 GrowableArray<ScopeValue*> deps;
1090
1091 int merge_pointer_idx = smerge->merge_pointer_idx(youngest_jvms);
1092 FillLocArray(0, sfn, sfn->in(merge_pointer_idx), &deps, objs);
1093 assert(deps.length() == 1, "missing value");
1094
1095 int selector_idx = smerge->selector_idx(youngest_jvms);
1096 FillLocArray(1, nullptr, sfn->in(selector_idx), &deps, nullptr);
1097 assert(deps.length() == 2, "missing value");
1098
1099 mv = new ObjectMergeValue(smerge->_idx, deps.at(0), deps.at(1));
1100 set_sv_for_object_node(objs, mv);
1101
1102 for (uint i = 1; i < smerge->req(); i++) {
1103 Node* obj_node = smerge->in(i);
1104 int idx = mv->possible_objects()->length();
1105 (void)FillLocArray(idx, sfn, obj_node, mv->possible_objects(), objs);
1106
1107 // By default ObjectValues that are in 'possible_objects' are not root objects.
1108 // They will be marked as root later if they are directly referenced in a JVMS.
1109 assert(mv->possible_objects()->length() > idx, "Didn't add entry to possible_objects?!");
1110 assert(mv->possible_objects()->at(idx)->is_object(), "Entries in possible_objects should be ObjectValue.");
1111 mv->possible_objects()->at(idx)->as_ObjectValue()->set_root(false);
1112 }
1113 }
1114 scval = mv;
1115 } else if (!obj_node->is_Con()) {
1116 OptoReg::Name obj_reg = C->regalloc()->get_reg_first(obj_node);
1117 if( obj_node->bottom_type()->base() == Type::NarrowOop ) {
1118 scval = new_loc_value( C->regalloc(), obj_reg, Location::narrowoop );
1119 } else {
1120 scval = new_loc_value( C->regalloc(), obj_reg, Location::oop );
1121 }
1122 } else {
1123 const TypePtr *tp = obj_node->get_ptr_type();
1124 scval = new ConstantOopWriteValue(tp->is_oopptr()->const_oop()->constant_encoding());
1125 }
1126
1127 OptoReg::Name box_reg = BoxLockNode::reg(box_node);
1128 Location basic_lock = Location::new_stk_loc(Location::normal,C->regalloc()->reg2offset(box_reg));
1129 bool eliminated = (box_node->is_BoxLock() && box_node->as_BoxLock()->is_eliminated());
1130 monarray->append(new MonitorValue(scval, basic_lock, eliminated));
1131 }
1132
1133 // Mark ObjectValue nodes as root nodes if they are directly
1134 // referenced in the JVMS.
1135 for (int i = 0; i < objs->length(); i++) {
1136 ScopeValue* sv = objs->at(i);
1137 if (sv->is_object_merge()) {
1138 ObjectMergeValue* merge = sv->as_ObjectMergeValue();
1139
1140 for (int j = 0; j< merge->possible_objects()->length(); j++) {
1141 ObjectValue* ov = merge->possible_objects()->at(j)->as_ObjectValue();
1142 if (ov->is_root()) {
1143 // Already flagged as 'root' by something else. We shouldn't change it
1144 // to non-root in a younger JVMS because it may need to be alive in
1145 // a younger JVMS.
1146 } else {
1147 bool is_root = locarray->contains(ov) ||
1148 exparray->contains(ov) ||
1149 contains_as_owner(monarray, ov) ||
1150 contains_as_scalarized_obj(jvms, sfn, objs, ov);
1151 ov->set_root(is_root);
1152 }
1153 }
1154 }
1155 }
1156
1157 // We dump the object pool first, since deoptimization reads it in first.
1158 C->debug_info()->dump_object_pool(objs);
1159
1160 // Build first class objects to pass to scope
1161 DebugToken *locvals = C->debug_info()->create_scope_values(locarray);
1162 DebugToken *expvals = C->debug_info()->create_scope_values(exparray);
1163 DebugToken *monvals = C->debug_info()->create_monitor_values(monarray);
1164
1165 // Make method available for all Safepoints
1166 ciMethod* scope_method = method ? method : C->method();
1167 // Describe the scope here
1168 assert(jvms->bci() >= InvocationEntryBci && jvms->bci() <= 0x10000, "must be a valid or entry BCI");
1169 assert(!jvms->should_reexecute() || depth == max_depth, "reexecute allowed only for the youngest");
1170 // Now we can describe the scope.
1171 methodHandle null_mh;
1172 bool rethrow_exception = false;
1173 C->debug_info()->describe_scope(
1174 safepoint_pc_offset,
1175 null_mh,
1176 scope_method,
1177 jvms->bci(),
1178 jvms->should_reexecute(),
1179 rethrow_exception,
1180 return_oop,
1181 has_ea_local_in_scope,
1182 arg_escape,
1183 locvals,
1184 expvals,
1185 monvals
1186 );
1187 } // End jvms loop
1188
1189 // Mark the end of the scope set.
1190 C->debug_info()->end_safepoint(safepoint_pc_offset);
1191 }
1192
1193
1194
1195 // A simplified version of Process_OopMap_Node, to handle non-safepoints.
1196 class NonSafepointEmitter {
1197 Compile* C;
1198 JVMState* _pending_jvms;
1199 int _pending_offset;
1200
1201 void emit_non_safepoint();
1202
1203 public:
1204 NonSafepointEmitter(Compile* compile) {
1205 this->C = compile;
1206 _pending_jvms = nullptr;
1207 _pending_offset = 0;
1208 }
1209
1210 void observe_instruction(Node* n, int pc_offset) {
1211 if (!C->debug_info()->recording_non_safepoints()) return;
1212
1213 Node_Notes* nn = C->node_notes_at(n->_idx);
1214 if (nn == nullptr || nn->jvms() == nullptr) return;
1215 if (_pending_jvms != nullptr &&
1216 _pending_jvms->same_calls_as(nn->jvms())) {
1217 // Repeated JVMS? Stretch it up here.
1218 _pending_offset = pc_offset;
1219 } else {
1220 if (_pending_jvms != nullptr &&
1221 _pending_offset < pc_offset) {
1222 emit_non_safepoint();
1223 }
1224 _pending_jvms = nullptr;
1225 if (pc_offset > C->debug_info()->last_pc_offset()) {
1226 // This is the only way _pending_jvms can become non-null:
1227 _pending_jvms = nn->jvms();
1228 _pending_offset = pc_offset;
1229 }
1230 }
1231 }
1232
1233 // Stay out of the way of real safepoints:
1234 void observe_safepoint(JVMState* jvms, int pc_offset) {
1235 if (_pending_jvms != nullptr &&
1236 !_pending_jvms->same_calls_as(jvms) &&
1237 _pending_offset < pc_offset) {
1238 emit_non_safepoint();
1239 }
1240 _pending_jvms = nullptr;
1241 }
1242
1243 void flush_at_end() {
1244 if (_pending_jvms != nullptr) {
1245 emit_non_safepoint();
1246 }
1247 _pending_jvms = nullptr;
1248 }
1249 };
1250
1251 void NonSafepointEmitter::emit_non_safepoint() {
1252 JVMState* youngest_jvms = _pending_jvms;
1253 int pc_offset = _pending_offset;
1254
1255 // Clear it now:
1256 _pending_jvms = nullptr;
1257
1258 DebugInformationRecorder* debug_info = C->debug_info();
1259 assert(debug_info->recording_non_safepoints(), "sanity");
1260
1261 debug_info->add_non_safepoint(pc_offset);
1262 int max_depth = youngest_jvms->depth();
1263
1264 // Visit scopes from oldest to youngest.
1265 for (int depth = 1; depth <= max_depth; depth++) {
1266 JVMState* jvms = youngest_jvms->of_depth(depth);
1267 ciMethod* method = jvms->has_method() ? jvms->method() : nullptr;
1268 assert(!jvms->should_reexecute() || depth==max_depth, "reexecute allowed only for the youngest");
1269 methodHandle null_mh;
1270 debug_info->describe_scope(pc_offset, null_mh, method, jvms->bci(), jvms->should_reexecute());
1271 }
1272
1273 // Mark the end of the scope set.
1274 debug_info->end_non_safepoint(pc_offset);
1275 }
1276
1277 //------------------------------init_buffer------------------------------------
1278 void PhaseOutput::estimate_buffer_size(int& const_req) {
1279
1280 // Set the initially allocated size
1281 const_req = initial_const_capacity;
1282
1283 // The extra spacing after the code is necessary on some platforms.
1284 // Sometimes we need to patch in a jump after the last instruction,
1285 // if the nmethod has been deoptimized. (See 4932387, 4894843.)
1286
1287 // Compute the byte offset where we can store the deopt pc.
1288 if (C->fixed_slots() != 0) {
1289 _orig_pc_slot_offset_in_bytes = C->regalloc()->reg2offset(OptoReg::stack2reg(_orig_pc_slot));
1290 }
1291
1292 // Compute prolog code size
1293 _frame_slots = OptoReg::reg2stack(C->matcher()->_old_SP) + C->regalloc()->_framesize;
1294 assert(_frame_slots >= 0 && _frame_slots < 1000000, "sanity check");
1295
1296 if (C->has_mach_constant_base_node()) {
1297 uint add_size = 0;
1298 // Fill the constant table.
1299 // Note: This must happen before shorten_branches.
1300 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
1301 Block* b = C->cfg()->get_block(i);
1302
1303 for (uint j = 0; j < b->number_of_nodes(); j++) {
1304 Node* n = b->get_node(j);
1305
1306 // If the node is a MachConstantNode evaluate the constant
1307 // value section.
1308 if (n->is_MachConstant()) {
1309 MachConstantNode* machcon = n->as_MachConstant();
1310 machcon->eval_constant(C);
1311 } else if (n->is_Mach()) {
1312 // On Power there are more nodes that issue constants.
1313 add_size += (n->as_Mach()->ins_num_consts() * 8);
1314 }
1315 }
1316 }
1317
1318 // Calculate the offsets of the constants and the size of the
1319 // constant table (including the padding to the next section).
1320 constant_table().calculate_offsets_and_size();
1321 const_req = constant_table().alignment() + constant_table().size() + add_size;
1322 }
1323
1324 // Initialize the space for the BufferBlob used to find and verify
1325 // instruction size in MachNode::emit_size()
1326 init_scratch_buffer_blob(const_req);
1327 }
1328
1329 CodeBuffer* PhaseOutput::init_buffer() {
1330 int stub_req = _buf_sizes._stub;
1331 int code_req = _buf_sizes._code;
1332 int const_req = _buf_sizes._const;
1333
1334 int pad_req = NativeCall::byte_size();
1335
1336 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1337 stub_req += bs->estimate_stub_size();
1338
1339 // nmethod and CodeBuffer count stubs & constants as part of method's code.
1340 // class HandlerImpl is platform-specific and defined in the *.ad files.
1341 int deopt_handler_req = HandlerImpl::size_deopt_handler() + MAX_stubs_size; // add marginal slop for handler
1342 stub_req += MAX_stubs_size; // ensure per-stub margin
1343 code_req += MAX_inst_size; // ensure per-instruction margin
1344
1345 if (StressCodeBuffers)
1346 code_req = const_req = stub_req = deopt_handler_req = 0x10; // force expansion
1347
1348 int total_req =
1349 const_req +
1350 code_req +
1351 pad_req +
1352 stub_req +
1353 deopt_handler_req; // deopt handler
1354
1355 CodeBuffer* cb = code_buffer();
1356 cb->set_const_section_alignment(constant_table().alignment());
1357 cb->initialize(total_req, _buf_sizes._reloc);
1358
1359 // Have we run out of code space?
1360 if ((cb->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1361 C->record_failure("CodeCache is full");
1362 return nullptr;
1363 }
1364 // Configure the code buffer.
1365 cb->initialize_consts_size(const_req);
1366 cb->initialize_stubs_size(stub_req);
1367 cb->initialize_oop_recorder(C->env()->oop_recorder());
1368
1369 return cb;
1370 }
1371
1372 //------------------------------fill_buffer------------------------------------
1373 void PhaseOutput::fill_buffer(C2_MacroAssembler* masm, uint* blk_starts) {
1374 // blk_starts[] contains offsets calculated during short branches processing,
1375 // offsets should not be increased during following steps.
1376
1377 // Compute the size of first NumberOfLoopInstrToAlign instructions at head
1378 // of a loop. It is used to determine the padding for loop alignment.
1379 Compile::TracePhase tp(_t_fillBuffer);
1380
1381 compute_loop_first_inst_sizes();
1382
1383 // Create oopmap set.
1384 _oop_map_set = new OopMapSet();
1385
1386 // !!!!! This preserves old handling of oopmaps for now
1387 C->debug_info()->set_oopmaps(_oop_map_set);
1388
1389 uint nblocks = C->cfg()->number_of_blocks();
1390 // Count and start of implicit null check instructions
1391 uint inct_cnt = 0;
1392 uint* inct_starts = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1393
1394 // Count and start of calls
1395 uint* call_returns = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1396
1397 uint return_offset = 0;
1398 int nop_size = (new MachNopNode())->size(C->regalloc());
1399
1400 int previous_offset = 0;
1401 int current_offset = 0;
1402 int last_call_offset = -1;
1403 int last_avoid_back_to_back_offset = -1;
1404 #ifdef ASSERT
1405 uint* jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks);
1406 uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
1407 uint* jmp_size = NEW_RESOURCE_ARRAY(uint,nblocks);
1408 uint* jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks);
1409 #endif
1410
1411 // Create an array of unused labels, one for each basic block, if printing is enabled
1412 #if defined(SUPPORT_OPTO_ASSEMBLY)
1413 int* node_offsets = nullptr;
1414 uint node_offset_limit = C->unique();
1415
1416 if (C->print_assembly()) {
1417 node_offsets = NEW_RESOURCE_ARRAY(int, node_offset_limit);
1418 }
1419 if (node_offsets != nullptr) {
1420 // We need to initialize. Unused array elements may contain garbage and mess up PrintOptoAssembly.
1421 memset(node_offsets, 0, node_offset_limit*sizeof(int));
1422 }
1423 #endif
1424
1425 NonSafepointEmitter non_safepoints(C); // emit non-safepoints lazily
1426
1427 // Emit the constant table.
1428 if (C->has_mach_constant_base_node()) {
1429 if (!constant_table().emit(masm)) {
1430 C->record_failure("consts section overflow");
1431 return;
1432 }
1433 }
1434
1435 // Create an array of labels, one for each basic block
1436 Label* blk_labels = NEW_RESOURCE_ARRAY(Label, nblocks+1);
1437 for (uint i = 0; i <= nblocks; i++) {
1438 blk_labels[i].init();
1439 }
1440
1441 // Now fill in the code buffer
1442 for (uint i = 0; i < nblocks; i++) {
1443 Block* block = C->cfg()->get_block(i);
1444 _block = block;
1445 Node* head = block->head();
1446
1447 // If this block needs to start aligned (i.e, can be reached other
1448 // than by falling-thru from the previous block), then force the
1449 // start of a new bundle.
1450 if (Pipeline::requires_bundling() && starts_bundle(head)) {
1451 masm->code()->flush_bundle(true);
1452 }
1453
1454 #ifdef ASSERT
1455 if (!block->is_connector()) {
1456 stringStream st;
1457 block->dump_head(C->cfg(), &st);
1458 masm->block_comment(st.freeze());
1459 }
1460 jmp_target[i] = 0;
1461 jmp_offset[i] = 0;
1462 jmp_size[i] = 0;
1463 jmp_rule[i] = 0;
1464 #endif
1465 int blk_offset = current_offset;
1466
1467 // Define the label at the beginning of the basic block
1468 masm->bind(blk_labels[block->_pre_order]);
1469
1470 uint last_inst = block->number_of_nodes();
1471
1472 // Emit block normally, except for last instruction.
1473 // Emit means "dump code bits into code buffer".
1474 for (uint j = 0; j<last_inst; j++) {
1475 _index = j;
1476
1477 // Get the node
1478 Node* n = block->get_node(j);
1479
1480 // If this starts a new instruction group, then flush the current one
1481 // (but allow split bundles)
1482 if (Pipeline::requires_bundling() && starts_bundle(n))
1483 masm->code()->flush_bundle(false);
1484
1485 // Special handling for SafePoint/Call Nodes
1486 bool is_mcall = false;
1487 if (n->is_Mach()) {
1488 MachNode *mach = n->as_Mach();
1489 is_mcall = n->is_MachCall();
1490 bool is_sfn = n->is_MachSafePoint();
1491
1492 // If this requires all previous instructions be flushed, then do so
1493 if (is_sfn || is_mcall || mach->alignment_required() != 1) {
1494 masm->code()->flush_bundle(true);
1495 current_offset = masm->offset();
1496 }
1497
1498 // align the instruction if necessary
1499 int padding = mach->compute_padding(current_offset);
1500 // Make sure safepoint node for polling is distinct from a call's
1501 // return by adding a nop if needed.
1502 if (is_sfn && !is_mcall && padding == 0 && current_offset == last_call_offset) {
1503 padding = nop_size;
1504 }
1505 if (padding == 0 && mach->avoid_back_to_back(MachNode::AVOID_BEFORE) &&
1506 current_offset == last_avoid_back_to_back_offset) {
1507 // Avoid back to back some instructions.
1508 padding = nop_size;
1509 }
1510
1511 if (padding > 0) {
1512 assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
1513 int nops_cnt = padding / nop_size;
1514 MachNode *nop = new MachNopNode(nops_cnt);
1515 block->insert_node(nop, j++);
1516 last_inst++;
1517 C->cfg()->map_node_to_block(nop, block);
1518 // Ensure enough space.
1519 masm->code()->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1520 if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1521 C->record_failure("CodeCache is full");
1522 return;
1523 }
1524 nop->emit(masm, C->regalloc());
1525 masm->code()->flush_bundle(true);
1526 current_offset = masm->offset();
1527 }
1528
1529 bool observe_safepoint = is_sfn;
1530 // Remember the start of the last call in a basic block
1531 if (is_mcall) {
1532 MachCallNode *mcall = mach->as_MachCall();
1533
1534 // This destination address is NOT PC-relative
1535 mcall->method_set((intptr_t)mcall->entry_point());
1536
1537 // Save the return address
1538 call_returns[block->_pre_order] = current_offset + mcall->ret_addr_offset();
1539
1540 observe_safepoint = mcall->guaranteed_safepoint();
1541 }
1542
1543 // sfn will be valid whenever mcall is valid now because of inheritance
1544 if (observe_safepoint) {
1545 // Handle special safepoint nodes for synchronization
1546 if (!is_mcall) {
1547 MachSafePointNode *sfn = mach->as_MachSafePoint();
1548 // !!!!! Stubs only need an oopmap right now, so bail out
1549 if (sfn->jvms()->method() == nullptr) {
1550 // Write the oopmap directly to the code blob??!!
1551 continue;
1552 }
1553 } // End synchronization
1554
1555 non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1556 current_offset);
1557 Process_OopMap_Node(mach, current_offset);
1558 } // End if safepoint
1559
1560 // If this is a null check, then add the start of the previous instruction to the list
1561 else if( mach->is_MachNullCheck() ) {
1562 inct_starts[inct_cnt++] = previous_offset;
1563 }
1564
1565 // If this is a branch, then fill in the label with the target BB's label
1566 else if (mach->is_MachBranch()) {
1567 // This requires the TRUE branch target be in succs[0]
1568 uint block_num = block->non_connector_successor(0)->_pre_order;
1569
1570 // Try to replace long branch,
1571 // it is mostly for back branches since forward branch's
1572 // distance is not updated yet.
1573 if (mach->may_be_short_branch()) {
1574 int br_size = n->size(C->regalloc());
1575 int offset = blk_starts[block_num] - current_offset;
1576 if (block_num >= i) {
1577 // Current and following block's offset are not
1578 // finalized yet, adjust distance by the difference
1579 // between calculated and final offsets of current block.
1580 offset -= (blk_starts[i] - blk_offset);
1581 }
1582 // In the following code a nop could be inserted before
1583 // the branch which will increase the backward distance.
1584 bool needs_padding = (current_offset == last_avoid_back_to_back_offset);
1585 if (needs_padding && offset <= 0)
1586 offset -= nop_size;
1587
1588 if (C->matcher()->is_short_branch_offset(mach->rule(), br_size, offset)) {
1589 // We've got a winner. Replace this branch.
1590 MachNode* replacement = mach->as_MachBranch()->short_branch_version();
1591
1592 // Update the jmp_size.
1593 int new_size = replacement->size(C->regalloc());
1594 assert((br_size - new_size) >= (int)nop_size, "short_branch size should be smaller");
1595 // Insert padding between avoid_back_to_back branches.
1596 if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
1597 MachNode *nop = new MachNopNode();
1598 block->insert_node(nop, j++);
1599 C->cfg()->map_node_to_block(nop, block);
1600 last_inst++;
1601 nop->emit(masm, C->regalloc());
1602 masm->code()->flush_bundle(true);
1603 current_offset = masm->offset();
1604 }
1605 #ifdef ASSERT
1606 jmp_target[i] = block_num;
1607 jmp_offset[i] = current_offset - blk_offset;
1608 jmp_size[i] = new_size;
1609 jmp_rule[i] = mach->rule();
1610 #endif
1611 block->map_node(replacement, j);
1612 mach->subsume_by(replacement, C);
1613 n = replacement;
1614 mach = replacement;
1615 }
1616 }
1617 mach->as_MachBranch()->label_set( &blk_labels[block_num], block_num );
1618 } else if (mach->ideal_Opcode() == Op_Jump) {
1619 for (uint h = 0; h < block->_num_succs; h++) {
1620 Block* succs_block = block->_succs[h];
1621 for (uint j = 1; j < succs_block->num_preds(); j++) {
1622 Node* jpn = succs_block->pred(j);
1623 if (jpn->is_JumpProj() && jpn->in(0) == mach) {
1624 uint block_num = succs_block->non_connector()->_pre_order;
1625 Label *blkLabel = &blk_labels[block_num];
1626 mach->add_case_label(jpn->as_JumpProj()->proj_no(), blkLabel);
1627 }
1628 }
1629 }
1630 } else if (!n->is_Proj()) {
1631 // Remember the beginning of the previous instruction, in case
1632 // it's followed by a flag-kill and a null-check. Happens on
1633 // Intel all the time, with add-to-memory kind of opcodes.
1634 previous_offset = current_offset;
1635 }
1636
1637 // Not an else-if!
1638 // If this is a trap based cmp then add its offset to the list.
1639 if (mach->is_TrapBasedCheckNode()) {
1640 inct_starts[inct_cnt++] = current_offset;
1641 }
1642 }
1643
1644 // Verify that there is sufficient space remaining
1645 masm->code()->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1646 if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1647 C->record_failure("CodeCache is full");
1648 return;
1649 }
1650
1651 // Save the offset for the listing
1652 #if defined(SUPPORT_OPTO_ASSEMBLY)
1653 if ((node_offsets != nullptr) && (n->_idx < node_offset_limit)) {
1654 node_offsets[n->_idx] = masm->offset();
1655 }
1656 #endif
1657 assert(!C->failing_internal() || C->failure_is_artificial(), "Should not reach here if failing.");
1658
1659 // "Normal" instruction case
1660 DEBUG_ONLY(uint instr_offset = masm->offset());
1661 n->emit(masm, C->regalloc());
1662 current_offset = masm->offset();
1663
1664 // Above we only verified that there is enough space in the instruction section.
1665 // However, the instruction may emit stubs that cause code buffer expansion.
1666 // Bail out here if expansion failed due to a lack of code cache space.
1667 if (C->failing()) {
1668 return;
1669 }
1670
1671 assert(!is_mcall || (call_returns[block->_pre_order] <= (uint)current_offset),
1672 "ret_addr_offset() not within emitted code");
1673
1674 #ifdef ASSERT
1675 uint n_size = n->size(C->regalloc());
1676 if (n_size < (current_offset-instr_offset)) {
1677 MachNode* mach = n->as_Mach();
1678 n->dump();
1679 mach->dump_format(C->regalloc(), tty);
1680 tty->print_cr(" n_size (%d), current_offset (%d), instr_offset (%d)", n_size, current_offset, instr_offset);
1681 Disassembler::decode(masm->code()->insts_begin() + instr_offset, masm->code()->insts_begin() + current_offset + 1, tty);
1682 tty->print_cr(" ------------------- ");
1683 BufferBlob* blob = this->scratch_buffer_blob();
1684 address blob_begin = blob->content_begin();
1685 Disassembler::decode(blob_begin, blob_begin + n_size + 1, tty);
1686 assert(false, "wrong size of mach node");
1687 }
1688 #endif
1689 non_safepoints.observe_instruction(n, current_offset);
1690
1691 // mcall is last "call" that can be a safepoint
1692 // record it so we can see if a poll will directly follow it
1693 // in which case we'll need a pad to make the PcDesc sites unique
1694 // see 5010568. This can be slightly inaccurate but conservative
1695 // in the case that return address is not actually at current_offset.
1696 // This is a small price to pay.
1697
1698 if (is_mcall) {
1699 last_call_offset = current_offset;
1700 }
1701
1702 if (n->is_Mach() && n->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
1703 // Avoid back to back some instructions.
1704 last_avoid_back_to_back_offset = current_offset;
1705 }
1706
1707 } // End for all instructions in block
1708
1709 // If the next block is the top of a loop, pad this block out to align
1710 // the loop top a little. Helps prevent pipe stalls at loop back branches.
1711 if (i < nblocks-1) {
1712 Block *nb = C->cfg()->get_block(i + 1);
1713 int padding = nb->alignment_padding(current_offset);
1714 if( padding > 0 ) {
1715 MachNode *nop = new MachNopNode(padding / nop_size);
1716 block->insert_node(nop, block->number_of_nodes());
1717 C->cfg()->map_node_to_block(nop, block);
1718 nop->emit(masm, C->regalloc());
1719 current_offset = masm->offset();
1720 }
1721 }
1722 // Verify that the distance for generated before forward
1723 // short branches is still valid.
1724 guarantee((int)(blk_starts[i+1] - blk_starts[i]) >= (current_offset - blk_offset), "shouldn't increase block size");
1725
1726 // Save new block start offset
1727 blk_starts[i] = blk_offset;
1728 } // End of for all blocks
1729 blk_starts[nblocks] = current_offset;
1730
1731 non_safepoints.flush_at_end();
1732
1733 // Offset too large?
1734 if (C->failing()) return;
1735
1736 // Define a pseudo-label at the end of the code
1737 masm->bind( blk_labels[nblocks] );
1738
1739 // Compute the size of the first block
1740 _first_block_size = blk_labels[1].loc_pos() - blk_labels[0].loc_pos();
1741
1742 #ifdef ASSERT
1743 for (uint i = 0; i < nblocks; i++) { // For all blocks
1744 if (jmp_target[i] != 0) {
1745 int br_size = jmp_size[i];
1746 int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
1747 if (!C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
1748 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]);
1749 assert(false, "Displacement too large for short jmp");
1750 }
1751 }
1752 }
1753 #endif
1754
1755 if (!masm->code()->finalize_stubs()) {
1756 C->record_failure("CodeCache is full");
1757 return;
1758 }
1759
1760 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1761 bs->emit_stubs(*masm->code());
1762 if (C->failing()) return;
1763
1764 // Fill in stubs.
1765 assert(masm->inst_mark() == nullptr, "should be.");
1766 _stub_list.emit(*masm);
1767 if (C->failing()) return;
1768
1769 #ifndef PRODUCT
1770 // Information on the size of the method, without the extraneous code
1771 Scheduling::increment_method_size(masm->offset());
1772 #endif
1773
1774 // ------------------
1775 // Fill in exception table entries.
1776 FillExceptionTables(inct_cnt, call_returns, inct_starts, blk_labels);
1777
1778 // Only java methods have exception handlers and deopt handlers
1779 // class HandlerImpl is platform-specific and defined in the *.ad files.
1780 if (C->method()) {
1781 if (C->failing()) {
1782 return; // CodeBuffer::expand failed
1783 }
1784 // Emit the deopt handler code.
1785 _code_offsets.set_value(CodeOffsets::Deopt, HandlerImpl::emit_deopt_handler(masm));
1786 }
1787
1788 // One last check for failed CodeBuffer::expand:
1789 if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1790 C->record_failure("CodeCache is full");
1791 return;
1792 }
1793
1794 #if defined(SUPPORT_ABSTRACT_ASSEMBLY) || defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_OPTO_ASSEMBLY)
1795 if (C->print_assembly()) {
1796 tty->cr();
1797 tty->print_cr("============================= C2-compiled nmethod ==============================");
1798 }
1799 #endif
1800
1801 #if defined(SUPPORT_OPTO_ASSEMBLY)
1802 // Dump the assembly code, including basic-block numbers
1803 if (C->print_assembly()) {
1804 if (!VMThread::should_terminate()) {
1805 ResourceMark rm;
1806 stringStream method_metadata_str;
1807 if (C->method() != nullptr) {
1808 C->method()->print_metadata(&method_metadata_str);
1809 }
1810 stringStream dump_asm_str;
1811 dump_asm_on(&dump_asm_str, node_offsets, node_offset_limit);
1812
1813 // Make sure the end tag is coherent, and that xmlStream->pop_tag is done thread safe.
1814 NoSafepointVerifier nsv;
1815 ttyLocker ttyl;
1816 // This output goes directly to the tty, not the compiler log.
1817 // To enable tools to match it up with the compilation activity,
1818 // be sure to tag this tty output with the compile ID.
1819 if (xtty != nullptr) {
1820 xtty->head("opto_assembly compile_id='%d'%s", C->compile_id(),
1821 C->is_osr_compilation() ? " compile_kind='osr'" :
1822 (C->for_preload() ? " compile_kind='AP'" : ""));
1823 }
1824 const char* is_aot = C->env()->is_aot_compile() ? (C->for_preload() ? "(AP) " : "(A) -") : "-----";
1825 if (C->method() != nullptr) {
1826 tty->print_cr("----------------------- MetaData before Compile_id = %d %s-------------------", C->compile_id(), is_aot);
1827 tty->print_raw(method_metadata_str.freeze());
1828 } else if (C->stub_name() != nullptr) {
1829 tty->print_cr("----------------------------- RuntimeStub %s -------------------------------", C->stub_name());
1830 }
1831 tty->cr();
1832 tty->print_cr("------------------------ OptoAssembly for Compile_id = %d %s------------------", C->compile_id(), is_aot);
1833 tty->print_raw(dump_asm_str.freeze());
1834 tty->print_cr("--------------------------------------------------------------------------------");
1835 if (xtty != nullptr) {
1836 xtty->tail("opto_assembly");
1837 }
1838 }
1839 }
1840 #endif
1841 }
1842
1843 void PhaseOutput::FillExceptionTables(uint cnt, uint *call_returns, uint *inct_starts, Label *blk_labels) {
1844 _inc_table.set_size(cnt);
1845
1846 uint inct_cnt = 0;
1847 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
1848 Block* block = C->cfg()->get_block(i);
1849 Node *n = nullptr;
1850 int j;
1851
1852 // Find the branch; ignore trailing NOPs.
1853 for (j = block->number_of_nodes() - 1; j >= 0; j--) {
1854 n = block->get_node(j);
1855 if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con) {
1856 break;
1857 }
1858 }
1859
1860 // If we didn't find anything, continue
1861 if (j < 0) {
1862 continue;
1863 }
1864
1865 // Compute ExceptionHandlerTable subtable entry and add it
1866 // (skip empty blocks)
1867 if (n->is_Catch()) {
1868
1869 // Get the offset of the return from the call
1870 uint call_return = call_returns[block->_pre_order];
1871 #ifdef ASSERT
1872 assert( call_return > 0, "no call seen for this basic block" );
1873 while (block->get_node(--j)->is_MachProj()) ;
1874 assert(block->get_node(j)->is_MachCall(), "CatchProj must follow call");
1875 #endif
1876 // last instruction is a CatchNode, find it's CatchProjNodes
1877 int nof_succs = block->_num_succs;
1878 // allocate space
1879 GrowableArray<intptr_t> handler_bcis(nof_succs);
1880 GrowableArray<intptr_t> handler_pcos(nof_succs);
1881 // iterate through all successors
1882 for (int j = 0; j < nof_succs; j++) {
1883 Block* s = block->_succs[j];
1884 bool found_p = false;
1885 for (uint k = 1; k < s->num_preds(); k++) {
1886 Node* pk = s->pred(k);
1887 if (pk->is_CatchProj() && pk->in(0) == n) {
1888 const CatchProjNode* p = pk->as_CatchProj();
1889 found_p = true;
1890 // add the corresponding handler bci & pco information
1891 if (p->_con != CatchProjNode::fall_through_index) {
1892 // p leads to an exception handler (and is not fall through)
1893 assert(s == C->cfg()->get_block(s->_pre_order), "bad numbering");
1894 // no duplicates, please
1895 if (!handler_bcis.contains(p->handler_bci())) {
1896 uint block_num = s->non_connector()->_pre_order;
1897 handler_bcis.append(p->handler_bci());
1898 handler_pcos.append(blk_labels[block_num].loc_pos());
1899 }
1900 }
1901 }
1902 }
1903 assert(found_p, "no matching predecessor found");
1904 // Note: Due to empty block removal, one block may have
1905 // several CatchProj inputs, from the same Catch.
1906 }
1907
1908 // Set the offset of the return from the call
1909 assert(handler_bcis.find(-1) != -1, "must have default handler");
1910 _handler_table.add_subtable(call_return, &handler_bcis, nullptr, &handler_pcos);
1911 continue;
1912 }
1913
1914 // Handle implicit null exception table updates
1915 if (n->is_MachNullCheck()) {
1916 MachNode* access = n->in(1)->as_Mach();
1917 assert(access->barrier_data() == 0 ||
1918 access->is_late_expanded_null_check_candidate(),
1919 "Implicit null checks on memory accesses with barriers are only supported on nodes explicitly marked as null-check candidates");
1920 uint block_num = block->non_connector_successor(0)->_pre_order;
1921 _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
1922 continue;
1923 }
1924 // Handle implicit exception table updates: trap instructions.
1925 if (n->is_Mach() && n->as_Mach()->is_TrapBasedCheckNode()) {
1926 uint block_num = block->non_connector_successor(0)->_pre_order;
1927 _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
1928 continue;
1929 }
1930 } // End of for all blocks fill in exception table entries
1931 }
1932
1933 // Static Variables
1934 #ifndef PRODUCT
1935 uint Scheduling::_total_nop_size = 0;
1936 uint Scheduling::_total_method_size = 0;
1937 uint Scheduling::_total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
1938 #endif
1939
1940 // Initializer for class Scheduling
1941
1942 Scheduling::Scheduling(Arena *arena, Compile &compile)
1943 : _arena(arena),
1944 _cfg(compile.cfg()),
1945 _regalloc(compile.regalloc()),
1946 _scheduled(arena),
1947 _available(arena),
1948 _reg_node(arena),
1949 _pinch_free_list(arena),
1950 _next_node(nullptr),
1951 _bundle_instr_count(0),
1952 _bundle_cycle_number(0),
1953 _bundle_use(0, 0, resource_count, &_bundle_use_elements[0])
1954 {
1955 // Save the count
1956 _node_bundling_limit = compile.unique();
1957 uint node_max = _regalloc->node_regs_max_index();
1958
1959 compile.output()->set_node_bundling_limit(_node_bundling_limit);
1960
1961 // This one is persistent within the Compile class
1962 _node_bundling_base = NEW_ARENA_ARRAY(compile.comp_arena(), Bundle, node_max);
1963
1964 // Allocate space for fixed-size arrays
1965 _uses = NEW_ARENA_ARRAY(arena, short, node_max);
1966 _current_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
1967
1968 // Clear the arrays
1969 for (uint i = 0; i < node_max; i++) {
1970 ::new (&_node_bundling_base[i]) Bundle();
1971 }
1972 memset(_uses, 0, node_max * sizeof(short));
1973 memset(_current_latency, 0, node_max * sizeof(unsigned short));
1974
1975 // Clear the bundling information
1976 memcpy(_bundle_use_elements, Pipeline_Use::elaborated_elements, sizeof(Pipeline_Use::elaborated_elements));
1977
1978 // Get the last node
1979 Block* block = _cfg->get_block(_cfg->number_of_blocks() - 1);
1980
1981 _next_node = block->get_node(block->number_of_nodes() - 1);
1982 }
1983
1984 // Step ahead "i" cycles
1985 void Scheduling::step(uint i) {
1986
1987 Bundle *bundle = node_bundling(_next_node);
1988 bundle->set_starts_bundle();
1989
1990 // Update the bundle record, but leave the flags information alone
1991 if (_bundle_instr_count > 0) {
1992 bundle->set_instr_count(_bundle_instr_count);
1993 bundle->set_resources_used(_bundle_use.resourcesUsed());
1994 }
1995
1996 // Update the state information
1997 _bundle_instr_count = 0;
1998 _bundle_cycle_number += i;
1999 _bundle_use.step(i);
2000 }
2001
2002 void Scheduling::step_and_clear() {
2003 Bundle *bundle = node_bundling(_next_node);
2004 bundle->set_starts_bundle();
2005
2006 // Update the bundle record
2007 if (_bundle_instr_count > 0) {
2008 bundle->set_instr_count(_bundle_instr_count);
2009 bundle->set_resources_used(_bundle_use.resourcesUsed());
2010
2011 _bundle_cycle_number += 1;
2012 }
2013
2014 // Clear the bundling information
2015 _bundle_instr_count = 0;
2016 _bundle_use.reset();
2017
2018 memcpy(_bundle_use_elements,
2019 Pipeline_Use::elaborated_elements,
2020 sizeof(Pipeline_Use::elaborated_elements));
2021 }
2022
2023 // Perform instruction scheduling and bundling over the sequence of
2024 // instructions in backwards order.
2025 void PhaseOutput::ScheduleAndBundle() {
2026
2027 // Don't optimize this if it isn't a method
2028 if (!C->method())
2029 return;
2030
2031 // Don't optimize this if scheduling is disabled
2032 if (!C->do_scheduling())
2033 return;
2034
2035 // Scheduling code works only with pairs (8 bytes) maximum.
2036 // And when the scalable vector register is used, we may spill/unspill
2037 // the whole reg regardless of the max vector size.
2038 if (C->max_vector_size() > 8 ||
2039 (C->max_vector_size() > 0 && Matcher::supports_scalable_vector())) {
2040 return;
2041 }
2042
2043 Compile::TracePhase tp(_t_instrSched);
2044
2045 // Create a data structure for all the scheduling information
2046 Scheduling scheduling(Thread::current()->resource_area(), *C);
2047
2048 // Walk backwards over each basic block, computing the needed alignment
2049 // Walk over all the basic blocks
2050 scheduling.DoScheduling();
2051
2052 #ifndef PRODUCT
2053 if (C->trace_opto_output()) {
2054 // Buffer and print all at once
2055 ResourceMark rm;
2056 stringStream ss;
2057 ss.print("\n---- After ScheduleAndBundle ----\n");
2058 print_scheduling(&ss);
2059 tty->print("%s", ss.as_string());
2060 }
2061 #endif
2062 }
2063
2064 #ifndef PRODUCT
2065 // Separated out so that it can be called directly from debugger
2066 void PhaseOutput::print_scheduling() {
2067 print_scheduling(tty);
2068 }
2069
2070 void PhaseOutput::print_scheduling(outputStream* output_stream) {
2071 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
2072 output_stream->print("\nBB#%03d:\n", i);
2073 Block* block = C->cfg()->get_block(i);
2074 for (uint j = 0; j < block->number_of_nodes(); j++) {
2075 Node* n = block->get_node(j);
2076 OptoReg::Name reg = C->regalloc()->get_reg_first(n);
2077 output_stream->print(" %-6s ", reg >= 0 && reg < REG_COUNT ? Matcher::regName[reg] : "");
2078 n->dump("\n", false, output_stream);
2079 }
2080 }
2081 }
2082 #endif
2083
2084 // See if this node fits into the present instruction bundle
2085 bool Scheduling::NodeFitsInBundle(Node *n) {
2086 uint n_idx = n->_idx;
2087
2088 // If the node cannot be scheduled this cycle, skip it
2089 if (_current_latency[n_idx] > _bundle_cycle_number) {
2090 #ifndef PRODUCT
2091 if (_cfg->C->trace_opto_output())
2092 tty->print("# NodeFitsInBundle [%4d]: FALSE; latency %4d > %d\n",
2093 n->_idx, _current_latency[n_idx], _bundle_cycle_number);
2094 #endif
2095 return (false);
2096 }
2097
2098 const Pipeline *node_pipeline = n->pipeline();
2099
2100 uint instruction_count = node_pipeline->instructionCount();
2101 if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2102 instruction_count = 0;
2103
2104 if (_bundle_instr_count + instruction_count > Pipeline::_max_instrs_per_cycle) {
2105 #ifndef PRODUCT
2106 if (_cfg->C->trace_opto_output())
2107 tty->print("# NodeFitsInBundle [%4d]: FALSE; too many instructions: %d > %d\n",
2108 n->_idx, _bundle_instr_count + instruction_count, Pipeline::_max_instrs_per_cycle);
2109 #endif
2110 return (false);
2111 }
2112
2113 // Don't allow non-machine nodes to be handled this way
2114 if (!n->is_Mach() && instruction_count == 0)
2115 return (false);
2116
2117 // See if there is any overlap
2118 uint delay = _bundle_use.full_latency(0, node_pipeline->resourceUse());
2119
2120 if (delay > 0) {
2121 #ifndef PRODUCT
2122 if (_cfg->C->trace_opto_output())
2123 tty->print("# NodeFitsInBundle [%4d]: FALSE; functional units overlap\n", n_idx);
2124 #endif
2125 return false;
2126 }
2127
2128 #ifndef PRODUCT
2129 if (_cfg->C->trace_opto_output())
2130 tty->print("# NodeFitsInBundle [%4d]: TRUE\n", n_idx);
2131 #endif
2132
2133 return true;
2134 }
2135
2136 Node * Scheduling::ChooseNodeToBundle() {
2137 uint siz = _available.size();
2138
2139 if (siz == 0) {
2140
2141 #ifndef PRODUCT
2142 if (_cfg->C->trace_opto_output())
2143 tty->print("# ChooseNodeToBundle: null\n");
2144 #endif
2145 return (nullptr);
2146 }
2147
2148 // Fast path, if only 1 instruction in the bundle
2149 if (siz == 1) {
2150 #ifndef PRODUCT
2151 if (_cfg->C->trace_opto_output()) {
2152 tty->print("# ChooseNodeToBundle (only 1): ");
2153 _available[0]->dump();
2154 }
2155 #endif
2156 return (_available[0]);
2157 }
2158
2159 // Don't bother, if the bundle is already full
2160 if (_bundle_instr_count < Pipeline::_max_instrs_per_cycle) {
2161 for ( uint i = 0; i < siz; i++ ) {
2162 Node *n = _available[i];
2163
2164 // Skip projections, we'll handle them another way
2165 if (n->is_Proj())
2166 continue;
2167
2168 // This presupposed that instructions are inserted into the
2169 // available list in a legality order; i.e. instructions that
2170 // must be inserted first are at the head of the list
2171 if (NodeFitsInBundle(n)) {
2172 #ifndef PRODUCT
2173 if (_cfg->C->trace_opto_output()) {
2174 tty->print("# ChooseNodeToBundle: ");
2175 n->dump();
2176 }
2177 #endif
2178 return (n);
2179 }
2180 }
2181 }
2182
2183 // Nothing fits in this bundle, choose the highest priority
2184 #ifndef PRODUCT
2185 if (_cfg->C->trace_opto_output()) {
2186 tty->print("# ChooseNodeToBundle: ");
2187 _available[0]->dump();
2188 }
2189 #endif
2190
2191 return _available[0];
2192 }
2193
2194 int Scheduling::compare_two_spill_nodes(Node* first, Node* second) {
2195 assert(first->is_MachSpillCopy() && second->is_MachSpillCopy(), "");
2196
2197 OptoReg::Name first_src_lo = _regalloc->get_reg_first(first->in(1));
2198 OptoReg::Name first_dst_lo = _regalloc->get_reg_first(first);
2199 OptoReg::Name second_src_lo = _regalloc->get_reg_first(second->in(1));
2200 OptoReg::Name second_dst_lo = _regalloc->get_reg_first(second);
2201
2202 // Comparison between stack -> reg and stack -> reg
2203 if (OptoReg::is_stack(first_src_lo) && OptoReg::is_stack(second_src_lo) &&
2204 OptoReg::is_reg(first_dst_lo) && OptoReg::is_reg(second_dst_lo)) {
2205 return _regalloc->reg2offset(first_src_lo) - _regalloc->reg2offset(second_src_lo);
2206 }
2207
2208 // Comparison between reg -> stack and reg -> stack
2209 if (OptoReg::is_stack(first_dst_lo) && OptoReg::is_stack(second_dst_lo) &&
2210 OptoReg::is_reg(first_src_lo) && OptoReg::is_reg(second_src_lo)) {
2211 return _regalloc->reg2offset(first_dst_lo) - _regalloc->reg2offset(second_dst_lo);
2212 }
2213
2214 return 0; // Not comparable
2215 }
2216
2217 void Scheduling::AddNodeToAvailableList(Node *n) {
2218 assert( !n->is_Proj(), "projections never directly made available" );
2219 #ifndef PRODUCT
2220 if (_cfg->C->trace_opto_output()) {
2221 tty->print("# AddNodeToAvailableList: ");
2222 n->dump();
2223 }
2224 #endif
2225
2226 int latency = _current_latency[n->_idx];
2227
2228 // Insert in latency order (insertion sort). If two MachSpillCopyNodes
2229 // for stack spilling or unspilling have the same latency, we sort
2230 // them in the order of stack offset. Some ports (e.g. aarch64) may also
2231 // have more opportunities to do ld/st merging
2232 uint i;
2233 for (i = 0; i < _available.size(); i++) {
2234 if (_current_latency[_available[i]->_idx] > latency) {
2235 break;
2236 } else if (_current_latency[_available[i]->_idx] == latency &&
2237 n->is_MachSpillCopy() && _available[i]->is_MachSpillCopy() &&
2238 compare_two_spill_nodes(n, _available[i]) > 0) {
2239 break;
2240 }
2241 }
2242
2243 // Special Check for compares following branches
2244 if( n->is_Mach() && _scheduled.size() > 0 ) {
2245 int op = n->as_Mach()->ideal_Opcode();
2246 Node *last = _scheduled[0];
2247 if( last->is_MachIf() && last->in(1) == n &&
2248 ( op == Op_CmpI ||
2249 op == Op_CmpU ||
2250 op == Op_CmpUL ||
2251 op == Op_CmpP ||
2252 op == Op_CmpF ||
2253 op == Op_CmpD ||
2254 op == Op_CmpL ) ) {
2255
2256 // Recalculate position, moving to front of same latency
2257 for ( i=0 ; i < _available.size(); i++ )
2258 if (_current_latency[_available[i]->_idx] >= latency)
2259 break;
2260 }
2261 }
2262
2263 // Insert the node in the available list
2264 _available.insert(i, n);
2265
2266 #ifndef PRODUCT
2267 if (_cfg->C->trace_opto_output())
2268 dump_available();
2269 #endif
2270 }
2271
2272 void Scheduling::DecrementUseCounts(Node *n, const Block *bb) {
2273 for ( uint i=0; i < n->len(); i++ ) {
2274 Node *def = n->in(i);
2275 if (!def) continue;
2276 if( def->is_Proj() ) // If this is a machine projection, then
2277 def = def->in(0); // propagate usage thru to the base instruction
2278
2279 if(_cfg->get_block_for_node(def) != bb) { // Ignore if not block-local
2280 continue;
2281 }
2282
2283 // Compute the latency
2284 uint l = _bundle_cycle_number + n->latency(i);
2285 if (_current_latency[def->_idx] < l)
2286 _current_latency[def->_idx] = l;
2287
2288 // If this does not have uses then schedule it
2289 if ((--_uses[def->_idx]) == 0)
2290 AddNodeToAvailableList(def);
2291 }
2292 }
2293
2294 void Scheduling::AddNodeToBundle(Node *n, const Block *bb) {
2295 #ifndef PRODUCT
2296 if (_cfg->C->trace_opto_output()) {
2297 tty->print("# AddNodeToBundle: ");
2298 n->dump();
2299 }
2300 #endif
2301
2302 // Remove this from the available list
2303 uint i;
2304 for (i = 0; i < _available.size(); i++)
2305 if (_available[i] == n)
2306 break;
2307 assert(i < _available.size(), "entry in _available list not found");
2308 _available.remove(i);
2309
2310 // See if this fits in the current bundle
2311 const Pipeline *node_pipeline = n->pipeline();
2312 const Pipeline_Use& node_usage = node_pipeline->resourceUse();
2313
2314
2315 // Get the number of instructions
2316 uint instruction_count = node_pipeline->instructionCount();
2317 if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2318 instruction_count = 0;
2319
2320 // Compute the latency information
2321 uint delay = 0;
2322
2323 if (instruction_count > 0 || !node_pipeline->mayHaveNoCode()) {
2324 int relative_latency = _current_latency[n->_idx] - _bundle_cycle_number;
2325 if (relative_latency < 0)
2326 relative_latency = 0;
2327
2328 delay = _bundle_use.full_latency(relative_latency, node_usage);
2329
2330 // Does not fit in this bundle, start a new one
2331 if (delay > 0) {
2332 step(delay);
2333
2334 #ifndef PRODUCT
2335 if (_cfg->C->trace_opto_output())
2336 tty->print("# *** STEP(%d) ***\n", delay);
2337 #endif
2338 }
2339 }
2340
2341 if (delay == 0) {
2342 if (node_pipeline->hasMultipleBundles()) {
2343 #ifndef PRODUCT
2344 if (_cfg->C->trace_opto_output())
2345 tty->print("# *** STEP(multiple instructions) ***\n");
2346 #endif
2347 step(1);
2348 }
2349
2350 else if (instruction_count + _bundle_instr_count > Pipeline::_max_instrs_per_cycle) {
2351 #ifndef PRODUCT
2352 if (_cfg->C->trace_opto_output())
2353 tty->print("# *** STEP(%d >= %d instructions) ***\n",
2354 instruction_count + _bundle_instr_count,
2355 Pipeline::_max_instrs_per_cycle);
2356 #endif
2357 step(1);
2358 }
2359 }
2360
2361 // Set the node's latency
2362 _current_latency[n->_idx] = _bundle_cycle_number;
2363
2364 // Now merge the functional unit information
2365 if (instruction_count > 0 || !node_pipeline->mayHaveNoCode())
2366 _bundle_use.add_usage(node_usage);
2367
2368 // Increment the number of instructions in this bundle
2369 _bundle_instr_count += instruction_count;
2370
2371 // Remember this node for later
2372 if (n->is_Mach())
2373 _next_node = n;
2374
2375 // It's possible to have a BoxLock in the graph and in the _bbs mapping but
2376 // not in the bb->_nodes array. This happens for debug-info-only BoxLocks.
2377 // 'Schedule' them (basically ignore in the schedule) but do not insert them
2378 // into the block. All other scheduled nodes get put in the schedule here.
2379 int op = n->Opcode();
2380 if( (op == Op_Node && n->req() == 0) || // anti-dependence node OR
2381 (op != Op_Node && // Not an unused antidepedence node and
2382 // not an unallocated boxlock
2383 (OptoReg::is_valid(_regalloc->get_reg_first(n)) || op != Op_BoxLock)) ) {
2384
2385 // Push any trailing projections
2386 if( bb->get_node(bb->number_of_nodes()-1) != n ) {
2387 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2388 Node *foi = n->fast_out(i);
2389 if( foi->is_Proj() )
2390 _scheduled.push(foi);
2391 }
2392 }
2393
2394 // Put the instruction in the schedule list
2395 _scheduled.push(n);
2396 }
2397
2398 #ifndef PRODUCT
2399 if (_cfg->C->trace_opto_output())
2400 dump_available();
2401 #endif
2402
2403 // Walk all the definitions, decrementing use counts, and
2404 // if a definition has a 0 use count, place it in the available list.
2405 DecrementUseCounts(n,bb);
2406 }
2407
2408 // This method sets the use count within a basic block. We will ignore all
2409 // uses outside the current basic block. As we are doing a backwards walk,
2410 // any node we reach that has a use count of 0 may be scheduled. This also
2411 // avoids the problem of cyclic references from phi nodes, as long as phi
2412 // nodes are at the front of the basic block. This method also initializes
2413 // the available list to the set of instructions that have no uses within this
2414 // basic block.
2415 void Scheduling::ComputeUseCount(const Block *bb) {
2416 #ifndef PRODUCT
2417 if (_cfg->C->trace_opto_output())
2418 tty->print("# -> ComputeUseCount\n");
2419 #endif
2420
2421 // Clear the list of available and scheduled instructions, just in case
2422 _available.clear();
2423 _scheduled.clear();
2424
2425 #ifdef ASSERT
2426 for( uint i=0; i < bb->number_of_nodes(); i++ )
2427 assert( _uses[bb->get_node(i)->_idx] == 0, "_use array not clean" );
2428 #endif
2429
2430 // Force the _uses count to never go to zero for unscheduable pieces
2431 // of the block
2432 for( uint k = 0; k < _bb_start; k++ )
2433 _uses[bb->get_node(k)->_idx] = 1;
2434 for( uint l = _bb_end; l < bb->number_of_nodes(); l++ )
2435 _uses[bb->get_node(l)->_idx] = 1;
2436
2437 // Iterate backwards over the instructions in the block. Don't count the
2438 // branch projections at end or the block header instructions.
2439 for( uint j = _bb_end-1; j >= _bb_start; j-- ) {
2440 Node *n = bb->get_node(j);
2441 if( n->is_Proj() ) continue; // Projections handled another way
2442
2443 // Account for all uses
2444 for ( uint k = 0; k < n->len(); k++ ) {
2445 Node *inp = n->in(k);
2446 if (!inp) continue;
2447 assert(inp != n, "no cycles allowed" );
2448 if (_cfg->get_block_for_node(inp) == bb) { // Block-local use?
2449 if (inp->is_Proj()) { // Skip through Proj's
2450 inp = inp->in(0);
2451 }
2452 ++_uses[inp->_idx]; // Count 1 block-local use
2453 }
2454 }
2455
2456 // If this instruction has a 0 use count, then it is available
2457 if (!_uses[n->_idx]) {
2458 _current_latency[n->_idx] = _bundle_cycle_number;
2459 AddNodeToAvailableList(n);
2460 }
2461
2462 #ifndef PRODUCT
2463 if (_cfg->C->trace_opto_output()) {
2464 tty->print("# uses: %3d: ", _uses[n->_idx]);
2465 n->dump();
2466 }
2467 #endif
2468 }
2469
2470 #ifndef PRODUCT
2471 if (_cfg->C->trace_opto_output())
2472 tty->print("# <- ComputeUseCount\n");
2473 #endif
2474 }
2475
2476 // This routine performs scheduling on each basic block in reverse order,
2477 // using instruction latencies and taking into account function unit
2478 // availability.
2479 void Scheduling::DoScheduling() {
2480 #ifndef PRODUCT
2481 if (_cfg->C->trace_opto_output())
2482 tty->print("# -> DoScheduling\n");
2483 #endif
2484
2485 Block *succ_bb = nullptr;
2486 Block *bb;
2487 Compile* C = Compile::current();
2488
2489 // Walk over all the basic blocks in reverse order
2490 for (int i = _cfg->number_of_blocks() - 1; i >= 0; succ_bb = bb, i--) {
2491 bb = _cfg->get_block(i);
2492
2493 #ifndef PRODUCT
2494 if (_cfg->C->trace_opto_output()) {
2495 tty->print("# Schedule BB#%03d (initial)\n", i);
2496 for (uint j = 0; j < bb->number_of_nodes(); j++) {
2497 bb->get_node(j)->dump();
2498 }
2499 }
2500 #endif
2501
2502 // On the head node, skip processing
2503 if (bb == _cfg->get_root_block()) {
2504 continue;
2505 }
2506
2507 // Skip empty, connector blocks
2508 if (bb->is_connector())
2509 continue;
2510
2511 // If the following block is not the sole successor of
2512 // this one, then reset the pipeline information
2513 if (bb->_num_succs != 1 || bb->non_connector_successor(0) != succ_bb) {
2514 #ifndef PRODUCT
2515 if (_cfg->C->trace_opto_output()) {
2516 tty->print("*** bundle start of next BB, node %d, for %d instructions\n",
2517 _next_node->_idx, _bundle_instr_count);
2518 }
2519 #endif
2520 step_and_clear();
2521 }
2522
2523 // Leave untouched the starting instruction, any Phis, a CreateEx node
2524 // or Top. bb->get_node(_bb_start) is the first schedulable instruction.
2525 _bb_end = bb->number_of_nodes()-1;
2526 for( _bb_start=1; _bb_start <= _bb_end; _bb_start++ ) {
2527 Node *n = bb->get_node(_bb_start);
2528 // Things not matched, like Phinodes and ProjNodes don't get scheduled.
2529 // Also, MachIdealNodes do not get scheduled
2530 if( !n->is_Mach() ) continue; // Skip non-machine nodes
2531 MachNode *mach = n->as_Mach();
2532 int iop = mach->ideal_Opcode();
2533 if( iop == Op_CreateEx ) continue; // CreateEx is pinned
2534 if( iop == Op_Con ) continue; // Do not schedule Top
2535 if( iop == Op_Node && // Do not schedule PhiNodes, ProjNodes
2536 mach->pipeline() == MachNode::pipeline_class() &&
2537 !n->is_SpillCopy() && !n->is_MachMerge() ) // Breakpoints, Prolog, etc
2538 continue;
2539 break; // Funny loop structure to be sure...
2540 }
2541 // Compute last "interesting" instruction in block - last instruction we
2542 // might schedule. _bb_end points just after last schedulable inst.
2543 Node *last = bb->get_node(_bb_end);
2544 // Ignore trailing NOPs.
2545 while (_bb_end > 0 && last->is_Mach() &&
2546 last->as_Mach()->ideal_Opcode() == Op_Con) {
2547 last = bb->get_node(--_bb_end);
2548 }
2549 assert(!last->is_Mach() || last->as_Mach()->ideal_Opcode() != Op_Con, "");
2550 if( last->is_Catch() ||
2551 (last->is_Mach() && last->as_Mach()->ideal_Opcode() == Op_Halt) ) {
2552 // There might be a prior call. Skip it.
2553 while (_bb_start < _bb_end && bb->get_node(--_bb_end)->is_MachProj());
2554 } else if( last->is_MachNullCheck() ) {
2555 // Backup so the last null-checked memory instruction is
2556 // outside the schedulable range. Skip over the nullcheck,
2557 // projection, and the memory nodes.
2558 Node *mem = last->in(1);
2559 do {
2560 _bb_end--;
2561 } while (mem != bb->get_node(_bb_end));
2562 } else {
2563 // Set _bb_end to point after last schedulable inst.
2564 _bb_end++;
2565 }
2566
2567 assert( _bb_start <= _bb_end, "inverted block ends" );
2568
2569 // Compute the register antidependencies for the basic block
2570 ComputeRegisterAntidependencies(bb);
2571 if (C->failing()) return; // too many D-U pinch points
2572
2573 // Compute the usage within the block, and set the list of all nodes
2574 // in the block that have no uses within the block.
2575 ComputeUseCount(bb);
2576
2577 // Schedule the remaining instructions in the block
2578 while ( _available.size() > 0 ) {
2579 Node *n = ChooseNodeToBundle();
2580 guarantee(n != nullptr, "no nodes available");
2581 AddNodeToBundle(n,bb);
2582 }
2583
2584 assert( _scheduled.size() == _bb_end - _bb_start, "wrong number of instructions" );
2585 #ifdef ASSERT
2586 for( uint l = _bb_start; l < _bb_end; l++ ) {
2587 Node *n = bb->get_node(l);
2588 uint m;
2589 for( m = 0; m < _bb_end-_bb_start; m++ )
2590 if( _scheduled[m] == n )
2591 break;
2592 assert( m < _bb_end-_bb_start, "instruction missing in schedule" );
2593 }
2594 #endif
2595
2596 // Now copy the instructions (in reverse order) back to the block
2597 for ( uint k = _bb_start; k < _bb_end; k++ )
2598 bb->map_node(_scheduled[_bb_end-k-1], k);
2599
2600 #ifndef PRODUCT
2601 if (_cfg->C->trace_opto_output()) {
2602 tty->print("# Schedule BB#%03d (final)\n", i);
2603 uint current = 0;
2604 for (uint j = 0; j < bb->number_of_nodes(); j++) {
2605 Node *n = bb->get_node(j);
2606 if( valid_bundle_info(n) ) {
2607 Bundle *bundle = node_bundling(n);
2608 if (bundle->instr_count() > 0) {
2609 tty->print("*** Bundle: ");
2610 bundle->dump();
2611 }
2612 n->dump();
2613 }
2614 }
2615 }
2616 #endif
2617 #ifdef ASSERT
2618 verify_good_schedule(bb,"after block local scheduling");
2619 #endif
2620 }
2621
2622 #ifndef PRODUCT
2623 if (_cfg->C->trace_opto_output())
2624 tty->print("# <- DoScheduling\n");
2625 #endif
2626
2627 // Record final node-bundling array location
2628 _regalloc->C->output()->set_node_bundling_base(_node_bundling_base);
2629
2630 } // end DoScheduling
2631
2632 // Verify that no live-range used in the block is killed in the block by a
2633 // wrong DEF. This doesn't verify live-ranges that span blocks.
2634
2635 // Check for edge existence. Used to avoid adding redundant precedence edges.
2636 static bool edge_from_to( Node *from, Node *to ) {
2637 for( uint i=0; i<from->len(); i++ )
2638 if( from->in(i) == to )
2639 return true;
2640 return false;
2641 }
2642
2643 #ifdef ASSERT
2644 void Scheduling::verify_do_def( Node *n, OptoReg::Name def, const char *msg ) {
2645 // Check for bad kills
2646 if( OptoReg::is_valid(def) ) { // Ignore stores & control flow
2647 Node *prior_use = _reg_node[def];
2648 if( prior_use && !edge_from_to(prior_use,n) ) {
2649 tty->print("%s = ",OptoReg::as_VMReg(def)->name());
2650 n->dump();
2651 tty->print_cr("...");
2652 prior_use->dump();
2653 assert(edge_from_to(prior_use,n), "%s", msg);
2654 }
2655 _reg_node.map(def,nullptr); // Kill live USEs
2656 }
2657 }
2658
2659 void Scheduling::verify_good_schedule( Block *b, const char *msg ) {
2660
2661 // Zap to something reasonable for the verify code
2662 _reg_node.clear();
2663
2664 // Walk over the block backwards. Check to make sure each DEF doesn't
2665 // kill a live value (other than the one it's supposed to). Add each
2666 // USE to the live set.
2667 for( uint i = b->number_of_nodes()-1; i >= _bb_start; i-- ) {
2668 Node *n = b->get_node(i);
2669 int n_op = n->Opcode();
2670 if( n_op == Op_MachProj && n->ideal_reg() == MachProjNode::fat_proj ) {
2671 // Fat-proj kills a slew of registers
2672 RegMaskIterator rmi(n->out_RegMask());
2673 while (rmi.has_next()) {
2674 OptoReg::Name kill = rmi.next();
2675 verify_do_def(n, kill, msg);
2676 }
2677 } else if( n_op != Op_Node ) { // Avoid brand new antidependence nodes
2678 // Get DEF'd registers the normal way
2679 verify_do_def( n, _regalloc->get_reg_first(n), msg );
2680 verify_do_def( n, _regalloc->get_reg_second(n), msg );
2681 }
2682
2683 // Now make all USEs live
2684 for( uint i=1; i<n->req(); i++ ) {
2685 Node *def = n->in(i);
2686 assert(def != nullptr, "input edge required");
2687 OptoReg::Name reg_lo = _regalloc->get_reg_first(def);
2688 OptoReg::Name reg_hi = _regalloc->get_reg_second(def);
2689 if( OptoReg::is_valid(reg_lo) ) {
2690 assert(!_reg_node[reg_lo] || edge_from_to(_reg_node[reg_lo],def), "%s", msg);
2691 _reg_node.map(reg_lo,n);
2692 }
2693 if( OptoReg::is_valid(reg_hi) ) {
2694 assert(!_reg_node[reg_hi] || edge_from_to(_reg_node[reg_hi],def), "%s", msg);
2695 _reg_node.map(reg_hi,n);
2696 }
2697 }
2698
2699 }
2700
2701 // Zap to something reasonable for the Antidependence code
2702 _reg_node.clear();
2703 }
2704 #endif
2705
2706 // Conditionally add precedence edges. Avoid putting edges on Projs.
2707 static void add_prec_edge_from_to( Node *from, Node *to ) {
2708 if( from->is_Proj() ) { // Put precedence edge on Proj's input
2709 assert( from->req() == 1 && (from->len() == 1 || from->in(1) == nullptr), "no precedence edges on projections" );
2710 from = from->in(0);
2711 }
2712 if( from != to && // No cycles (for things like LD L0,[L0+4] )
2713 !edge_from_to( from, to ) ) // Avoid duplicate edge
2714 from->add_prec(to);
2715 }
2716
2717 void Scheduling::anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def ) {
2718 if( !OptoReg::is_valid(def_reg) ) // Ignore stores & control flow
2719 return;
2720
2721 if (OptoReg::is_reg(def_reg)) {
2722 VMReg vmreg = OptoReg::as_VMReg(def_reg);
2723 if (vmreg->is_reg() && !vmreg->is_concrete() && !vmreg->prev()->is_concrete()) {
2724 // This is one of the high slots of a vector register.
2725 // ScheduleAndBundle already checked there are no live wide
2726 // vectors in this method so it can be safely ignored.
2727 return;
2728 }
2729 }
2730
2731 Node *pinch = _reg_node[def_reg]; // Get pinch point
2732 if ((pinch == nullptr) || _cfg->get_block_for_node(pinch) != b || // No pinch-point yet?
2733 is_def ) { // Check for a true def (not a kill)
2734 _reg_node.map(def_reg,def); // Record def/kill as the optimistic pinch-point
2735 return;
2736 }
2737
2738 Node *kill = def; // Rename 'def' to more descriptive 'kill'
2739 DEBUG_ONLY( def = (Node*)((intptr_t)0xdeadbeef); )
2740
2741 // After some number of kills there _may_ be a later def
2742 Node *later_def = nullptr;
2743
2744 Compile* C = Compile::current();
2745
2746 // Finding a kill requires a real pinch-point.
2747 // Check for not already having a pinch-point.
2748 // Pinch points are Op_Node's.
2749 if( pinch->Opcode() != Op_Node ) { // Or later-def/kill as pinch-point?
2750 later_def = pinch; // Must be def/kill as optimistic pinch-point
2751 if ( _pinch_free_list.size() > 0) {
2752 pinch = _pinch_free_list.pop();
2753 } else {
2754 pinch = new Node(1); // Pinch point to-be
2755 }
2756 if (pinch->_idx >= _regalloc->node_regs_max_index()) {
2757 DEBUG_ONLY( pinch->dump(); );
2758 assert(false, "too many D-U pinch points: %d >= %d", pinch->_idx, _regalloc->node_regs_max_index());
2759 _cfg->C->record_method_not_compilable("too many D-U pinch points");
2760 return;
2761 }
2762 _cfg->map_node_to_block(pinch, b); // Pretend it's valid in this block (lazy init)
2763 _reg_node.map(def_reg,pinch); // Record pinch-point
2764 //regalloc()->set_bad(pinch->_idx); // Already initialized this way.
2765 if( later_def->outcnt() == 0 || later_def->ideal_reg() == MachProjNode::fat_proj ) { // Distinguish def from kill
2766 pinch->init_req(0, C->top()); // set not null for the next call
2767 add_prec_edge_from_to(later_def,pinch); // Add edge from kill to pinch
2768 later_def = nullptr; // and no later def
2769 }
2770 pinch->set_req(0,later_def); // Hook later def so we can find it
2771 } else { // Else have valid pinch point
2772 if( pinch->in(0) ) // If there is a later-def
2773 later_def = pinch->in(0); // Get it
2774 }
2775
2776 // Add output-dependence edge from later def to kill
2777 if( later_def ) // If there is some original def
2778 add_prec_edge_from_to(later_def,kill); // Add edge from def to kill
2779
2780 // See if current kill is also a use, and so is forced to be the pinch-point.
2781 if( pinch->Opcode() == Op_Node ) {
2782 Node *uses = kill->is_Proj() ? kill->in(0) : kill;
2783 for( uint i=1; i<uses->req(); i++ ) {
2784 if( _regalloc->get_reg_first(uses->in(i)) == def_reg ||
2785 _regalloc->get_reg_second(uses->in(i)) == def_reg ) {
2786 // Yes, found a use/kill pinch-point
2787 pinch->set_req(0,nullptr); //
2788 pinch->replace_by(kill); // Move anti-dep edges up
2789 pinch = kill;
2790 _reg_node.map(def_reg,pinch);
2791 return;
2792 }
2793 }
2794 }
2795
2796 // Add edge from kill to pinch-point
2797 add_prec_edge_from_to(kill,pinch);
2798 }
2799
2800 void Scheduling::anti_do_use( Block *b, Node *use, OptoReg::Name use_reg ) {
2801 if( !OptoReg::is_valid(use_reg) ) // Ignore stores & control flow
2802 return;
2803 Node *pinch = _reg_node[use_reg]; // Get pinch point
2804 // Check for no later def_reg/kill in block
2805 if ((pinch != nullptr) && _cfg->get_block_for_node(pinch) == b &&
2806 // Use has to be block-local as well
2807 _cfg->get_block_for_node(use) == b) {
2808 if( pinch->Opcode() == Op_Node && // Real pinch-point (not optimistic?)
2809 pinch->req() == 1 ) { // pinch not yet in block?
2810 pinch->del_req(0); // yank pointer to later-def, also set flag
2811 // Insert the pinch-point in the block just after the last use
2812 b->insert_node(pinch, b->find_node(use) + 1);
2813 _bb_end++; // Increase size scheduled region in block
2814 }
2815
2816 add_prec_edge_from_to(pinch,use);
2817 }
2818 }
2819
2820 // We insert antidependences between the reads and following write of
2821 // allocated registers to prevent illegal code motion. Hopefully, the
2822 // number of added references should be fairly small, especially as we
2823 // are only adding references within the current basic block.
2824 void Scheduling::ComputeRegisterAntidependencies(Block *b) {
2825
2826 #ifdef ASSERT
2827 verify_good_schedule(b,"before block local scheduling");
2828 #endif
2829
2830 // A valid schedule, for each register independently, is an endless cycle
2831 // of: a def, then some uses (connected to the def by true dependencies),
2832 // then some kills (defs with no uses), finally the cycle repeats with a new
2833 // def. The uses are allowed to float relative to each other, as are the
2834 // kills. No use is allowed to slide past a kill (or def). This requires
2835 // antidependencies between all uses of a single def and all kills that
2836 // follow, up to the next def. More edges are redundant, because later defs
2837 // & kills are already serialized with true or antidependencies. To keep
2838 // the edge count down, we add a 'pinch point' node if there's more than
2839 // one use or more than one kill/def.
2840
2841 // We add dependencies in one bottom-up pass.
2842
2843 // For each instruction we handle it's DEFs/KILLs, then it's USEs.
2844
2845 // For each DEF/KILL, we check to see if there's a prior DEF/KILL for this
2846 // register. If not, we record the DEF/KILL in _reg_node, the
2847 // register-to-def mapping. If there is a prior DEF/KILL, we insert a
2848 // "pinch point", a new Node that's in the graph but not in the block.
2849 // We put edges from the prior and current DEF/KILLs to the pinch point.
2850 // We put the pinch point in _reg_node. If there's already a pinch point
2851 // we merely add an edge from the current DEF/KILL to the pinch point.
2852
2853 // After doing the DEF/KILLs, we handle USEs. For each used register, we
2854 // put an edge from the pinch point to the USE.
2855
2856 // To be expedient, the _reg_node array is pre-allocated for the whole
2857 // compilation. _reg_node is lazily initialized; it either contains a null,
2858 // or a valid def/kill/pinch-point, or a leftover node from some prior
2859 // block. Leftover node from some prior block is treated like a null (no
2860 // prior def, so no anti-dependence needed). Valid def is distinguished by
2861 // it being in the current block.
2862 bool fat_proj_seen = false;
2863 uint last_safept = _bb_end-1;
2864 Node* end_node = (_bb_end-1 >= _bb_start) ? b->get_node(last_safept) : nullptr;
2865 Node* last_safept_node = end_node;
2866 for( uint i = _bb_end-1; i >= _bb_start; i-- ) {
2867 Node *n = b->get_node(i);
2868 int is_def = n->outcnt(); // def if some uses prior to adding precedence edges
2869 if( n->is_MachProj() && n->ideal_reg() == MachProjNode::fat_proj ) {
2870 // Fat-proj kills a slew of registers
2871 // This can add edges to 'n' and obscure whether or not it was a def,
2872 // hence the is_def flag.
2873 fat_proj_seen = true;
2874 RegMaskIterator rmi(n->out_RegMask());
2875 while (rmi.has_next()) {
2876 OptoReg::Name kill = rmi.next();
2877 anti_do_def(b, n, kill, is_def);
2878 }
2879 } else {
2880 // Get DEF'd registers the normal way
2881 anti_do_def( b, n, _regalloc->get_reg_first(n), is_def );
2882 anti_do_def( b, n, _regalloc->get_reg_second(n), is_def );
2883 }
2884
2885 // Kill projections on a branch should appear to occur on the
2886 // branch, not afterwards, so grab the masks from the projections
2887 // and process them.
2888 if (n->is_MachBranch() || (n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_Jump)) {
2889 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2890 Node* use = n->fast_out(i);
2891 if (use->is_Proj()) {
2892 RegMaskIterator rmi(use->out_RegMask());
2893 while (rmi.has_next()) {
2894 OptoReg::Name kill = rmi.next();
2895 anti_do_def(b, n, kill, false);
2896 }
2897 }
2898 }
2899 }
2900
2901 // Check each register used by this instruction for a following DEF/KILL
2902 // that must occur afterward and requires an anti-dependence edge.
2903 for( uint j=0; j<n->req(); j++ ) {
2904 Node *def = n->in(j);
2905 if( def ) {
2906 assert( !def->is_MachProj() || def->ideal_reg() != MachProjNode::fat_proj, "" );
2907 anti_do_use( b, n, _regalloc->get_reg_first(def) );
2908 anti_do_use( b, n, _regalloc->get_reg_second(def) );
2909 }
2910 }
2911 // Do not allow defs of new derived values to float above GC
2912 // points unless the base is definitely available at the GC point.
2913
2914 Node *m = b->get_node(i);
2915
2916 // Add precedence edge from following safepoint to use of derived pointer
2917 if( last_safept_node != end_node &&
2918 m != last_safept_node) {
2919 for (uint k = 1; k < m->req(); k++) {
2920 const Type *t = m->in(k)->bottom_type();
2921 if( t->isa_oop_ptr() &&
2922 t->is_ptr()->offset() != 0 ) {
2923 last_safept_node->add_prec( m );
2924 break;
2925 }
2926 }
2927 }
2928
2929 if( n->jvms() ) { // Precedence edge from derived to safept
2930 // Check if last_safept_node was moved by pinch-point insertion in anti_do_use()
2931 if( b->get_node(last_safept) != last_safept_node ) {
2932 last_safept = b->find_node(last_safept_node);
2933 }
2934 for( uint j=last_safept; j > i; j-- ) {
2935 Node *mach = b->get_node(j);
2936 if( mach->is_Mach() && mach->as_Mach()->ideal_Opcode() == Op_AddP )
2937 mach->add_prec( n );
2938 }
2939 last_safept = i;
2940 last_safept_node = m;
2941 }
2942 }
2943
2944 if (fat_proj_seen) {
2945 // Garbage collect pinch nodes that were not consumed.
2946 // They are usually created by a fat kill MachProj for a call.
2947 garbage_collect_pinch_nodes();
2948 }
2949 }
2950
2951 // Garbage collect pinch nodes for reuse by other blocks.
2952 //
2953 // The block scheduler's insertion of anti-dependence
2954 // edges creates many pinch nodes when the block contains
2955 // 2 or more Calls. A pinch node is used to prevent a
2956 // combinatorial explosion of edges. If a set of kills for a
2957 // register is anti-dependent on a set of uses (or defs), rather
2958 // than adding an edge in the graph between each pair of kill
2959 // and use (or def), a pinch is inserted between them:
2960 //
2961 // use1 use2 use3
2962 // \ | /
2963 // \ | /
2964 // pinch
2965 // / | \
2966 // / | \
2967 // kill1 kill2 kill3
2968 //
2969 // One pinch node is created per register killed when
2970 // the second call is encountered during a backwards pass
2971 // over the block. Most of these pinch nodes are never
2972 // wired into the graph because the register is never
2973 // used or def'ed in the block.
2974 //
2975 void Scheduling::garbage_collect_pinch_nodes() {
2976 #ifndef PRODUCT
2977 if (_cfg->C->trace_opto_output()) tty->print("Reclaimed pinch nodes:");
2978 #endif
2979 int trace_cnt = 0;
2980 for (uint k = 0; k < _reg_node.max(); k++) {
2981 Node* pinch = _reg_node[k];
2982 if ((pinch != nullptr) && pinch->Opcode() == Op_Node &&
2983 // no predecence input edges
2984 (pinch->req() == pinch->len() || pinch->in(pinch->req()) == nullptr) ) {
2985 cleanup_pinch(pinch);
2986 _pinch_free_list.push(pinch);
2987 _reg_node.map(k, nullptr);
2988 #ifndef PRODUCT
2989 if (_cfg->C->trace_opto_output()) {
2990 trace_cnt++;
2991 if (trace_cnt > 40) {
2992 tty->print("\n");
2993 trace_cnt = 0;
2994 }
2995 tty->print(" %d", pinch->_idx);
2996 }
2997 #endif
2998 }
2999 }
3000 #ifndef PRODUCT
3001 if (_cfg->C->trace_opto_output()) tty->print("\n");
3002 #endif
3003 }
3004
3005 // Clean up a pinch node for reuse.
3006 void Scheduling::cleanup_pinch( Node *pinch ) {
3007 assert (pinch && pinch->Opcode() == Op_Node && pinch->req() == 1, "just checking");
3008
3009 for (DUIterator_Last imin, i = pinch->last_outs(imin); i >= imin; ) {
3010 Node* use = pinch->last_out(i);
3011 uint uses_found = 0;
3012 for (uint j = use->req(); j < use->len(); j++) {
3013 if (use->in(j) == pinch) {
3014 use->rm_prec(j);
3015 uses_found++;
3016 }
3017 }
3018 assert(uses_found > 0, "must be a precedence edge");
3019 i -= uses_found; // we deleted 1 or more copies of this edge
3020 }
3021 // May have a later_def entry
3022 pinch->set_req(0, nullptr);
3023 }
3024
3025 #ifndef PRODUCT
3026
3027 void Scheduling::dump_available() const {
3028 tty->print("#Availist ");
3029 for (uint i = 0; i < _available.size(); i++)
3030 tty->print(" N%d/l%d", _available[i]->_idx,_current_latency[_available[i]->_idx]);
3031 tty->cr();
3032 }
3033
3034 // Print Scheduling Statistics
3035 void Scheduling::print_statistics() {
3036 // Print the size added by nops for bundling
3037 tty->print("Nops added %d bytes to total of %d bytes",
3038 _total_nop_size, _total_method_size);
3039 if (_total_method_size > 0)
3040 tty->print(", for %.2f%%",
3041 ((double)_total_nop_size) / ((double) _total_method_size) * 100.0);
3042 tty->print("\n");
3043
3044 uint total_instructions = 0, total_bundles = 0;
3045
3046 for (uint i = 1; i <= Pipeline::_max_instrs_per_cycle; i++) {
3047 uint bundle_count = _total_instructions_per_bundle[i];
3048 total_instructions += bundle_count * i;
3049 total_bundles += bundle_count;
3050 }
3051
3052 if (total_bundles > 0)
3053 tty->print("Average ILP (excluding nops) is %.2f\n",
3054 ((double)total_instructions) / ((double)total_bundles));
3055 }
3056 #endif
3057
3058 //-----------------------init_scratch_buffer_blob------------------------------
3059 // Construct a temporary BufferBlob and cache it for this compile.
3060 void PhaseOutput::init_scratch_buffer_blob(int const_size) {
3061 // If there is already a scratch buffer blob allocated and the
3062 // constant section is big enough, use it. Otherwise free the
3063 // current and allocate a new one.
3064 BufferBlob* blob = scratch_buffer_blob();
3065 if ((blob != nullptr) && (const_size <= _scratch_const_size)) {
3066 // Use the current blob.
3067 } else {
3068 if (blob != nullptr) {
3069 BufferBlob::free(blob);
3070 }
3071
3072 ResourceMark rm;
3073 _scratch_const_size = const_size;
3074 int size = C2Compiler::initial_code_buffer_size(const_size);
3075 blob = BufferBlob::create("Compile::scratch_buffer", size);
3076 // Record the buffer blob for next time.
3077 set_scratch_buffer_blob(blob);
3078 // Have we run out of code space?
3079 if (scratch_buffer_blob() == nullptr) {
3080 // Let CompilerBroker disable further compilations.
3081 C->record_failure("Not enough space for scratch buffer in CodeCache");
3082 return;
3083 }
3084 }
3085
3086 // Initialize the relocation buffers
3087 relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
3088 set_scratch_locs_memory(locs_buf);
3089 }
3090
3091
3092 //-----------------------scratch_emit_size-------------------------------------
3093 // Helper function that computes size by emitting code
3094 uint PhaseOutput::scratch_emit_size(const Node* n) {
3095 // Start scratch_emit_size section.
3096 set_in_scratch_emit_size(true);
3097
3098 // Emit into a trash buffer and count bytes emitted.
3099 // This is a pretty expensive way to compute a size,
3100 // but it works well enough if seldom used.
3101 // All common fixed-size instructions are given a size
3102 // method by the AD file.
3103 // Note that the scratch buffer blob and locs memory are
3104 // allocated at the beginning of the compile task, and
3105 // may be shared by several calls to scratch_emit_size.
3106 // The allocation of the scratch buffer blob is particularly
3107 // expensive, since it has to grab the code cache lock.
3108 BufferBlob* blob = this->scratch_buffer_blob();
3109 assert(blob != nullptr, "Initialize BufferBlob at start");
3110 assert(blob->size() > MAX_inst_size, "sanity");
3111 relocInfo* locs_buf = scratch_locs_memory();
3112 address blob_begin = blob->content_begin();
3113 address blob_end = (address)locs_buf;
3114 assert(blob->contains(blob_end), "sanity");
3115 CodeBuffer buf(blob_begin, blob_end - blob_begin);
3116 buf.initialize_consts_size(_scratch_const_size);
3117 buf.initialize_stubs_size(MAX_stubs_size);
3118 assert(locs_buf != nullptr, "sanity");
3119 int lsize = MAX_locs_size / 3;
3120 buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
3121 buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
3122 buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
3123 // Mark as scratch buffer.
3124 buf.consts()->set_scratch_emit();
3125 buf.insts()->set_scratch_emit();
3126 buf.stubs()->set_scratch_emit();
3127
3128 // Do the emission.
3129
3130 Label fakeL; // Fake label for branch instructions.
3131 Label* saveL = nullptr;
3132 uint save_bnum = 0;
3133 bool is_branch = n->is_MachBranch();
3134 C2_MacroAssembler masm(&buf);
3135 masm.bind(fakeL);
3136 if (is_branch) {
3137 n->as_MachBranch()->save_label(&saveL, &save_bnum);
3138 n->as_MachBranch()->label_set(&fakeL, 0);
3139 }
3140 n->emit(&masm, C->regalloc());
3141
3142 // Emitting into the scratch buffer should not fail
3143 assert(!C->failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", C->failure_reason());
3144
3145 if (is_branch) // Restore label.
3146 n->as_MachBranch()->label_set(saveL, save_bnum);
3147
3148 // End scratch_emit_size section.
3149 set_in_scratch_emit_size(false);
3150
3151 return buf.insts_size();
3152 }
3153
3154 void PhaseOutput::install() {
3155 if (C->should_install_code() && C->stub_function() != nullptr) {
3156 install_stub(C->stub_name());
3157 } else {
3158 install_code(C->method(),
3159 C->entry_bci(),
3160 CompilerThread::current()->compiler(),
3161 C->has_unsafe_access(),
3162 SharedRuntime::is_wide_vector(C->max_vector_size()));
3163 }
3164 }
3165
3166 void PhaseOutput::install_code(ciMethod* target,
3167 int entry_bci,
3168 AbstractCompiler* compiler,
3169 bool has_unsafe_access,
3170 bool has_wide_vectors) {
3171 // Check if we want to skip execution of all compiled code.
3172 {
3173 #ifndef PRODUCT
3174 if (OptoNoExecute) {
3175 C->record_method_not_compilable("+OptoNoExecute"); // Flag as failed
3176 return;
3177 }
3178 #endif
3179 Compile::TracePhase tp(_t_registerMethod);
3180
3181 if (C->is_osr_compilation()) {
3182 _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
3183 _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
3184 } else {
3185 if (!target->is_static()) {
3186 // The UEP of an nmethod ensures that the VEP is padded. However, the padding of the UEP is placed
3187 // before the inline cache check, so we don't have to execute any nop instructions when dispatching
3188 // through the UEP, yet we can ensure that the VEP is aligned appropriately.
3189 _code_offsets.set_value(CodeOffsets::Entry, _first_block_size - MacroAssembler::ic_check_size());
3190 }
3191 _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
3192 _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
3193 }
3194
3195 C->env()->register_method(target,
3196 entry_bci,
3197 &_code_offsets,
3198 _orig_pc_slot_offset_in_bytes,
3199 code_buffer(),
3200 frame_size_in_words(),
3201 oop_map_set(),
3202 &_handler_table,
3203 inc_table(),
3204 compiler,
3205 C->has_clinit_barriers(),
3206 C->for_preload(),
3207 has_unsafe_access,
3208 SharedRuntime::is_wide_vector(C->max_vector_size()),
3209 C->has_monitors(),
3210 C->has_scoped_access(),
3211 0,
3212 C->should_install_code());
3213
3214 if (C->log() != nullptr) { // Print code cache state into compiler log
3215 C->log()->code_cache_state();
3216 }
3217 assert(!C->has_clinit_barriers() || C->for_preload(), "class init barriers should be only in preload code");
3218 }
3219 }
3220 void PhaseOutput::install_stub(const char* stub_name) {
3221 // Entry point will be accessed using stub_entry_point();
3222 if (code_buffer() == nullptr) {
3223 Matcher::soft_match_failure();
3224 } else {
3225 if (PrintAssembly && (WizardMode || Verbose))
3226 tty->print_cr("### Stub::%s", stub_name);
3227
3228 if (!C->failing()) {
3229 assert(C->fixed_slots() == 0, "no fixed slots used for runtime stubs");
3230
3231 // Make the NMethod
3232 // For now we mark the frame as never safe for profile stackwalking
3233 RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
3234 code_buffer(),
3235 CodeOffsets::frame_never_safe,
3236 // _code_offsets.value(CodeOffsets::Frame_Complete),
3237 frame_size_in_words(),
3238 oop_map_set(),
3239 false,
3240 false);
3241
3242 if (rs == nullptr) {
3243 C->record_failure("CodeCache is full");
3244 } else {
3245 assert(rs->is_runtime_stub(), "sanity check");
3246 C->set_stub_entry_point(rs->entry_point());
3247 BlobId blob_id = StubInfo::blob(C->stub_id());
3248 AOTCodeCache::store_code_blob(*rs, AOTCodeEntry::C2Blob, blob_id);
3249 }
3250 }
3251 }
3252 }
3253
3254 // Support for bundling info
3255 Bundle* PhaseOutput::node_bundling(const Node *n) {
3256 assert(valid_bundle_info(n), "oob");
3257 return &_node_bundling_base[n->_idx];
3258 }
3259
3260 bool PhaseOutput::valid_bundle_info(const Node *n) {
3261 return (_node_bundling_limit > n->_idx);
3262 }
3263
3264 //------------------------------frame_size_in_words-----------------------------
3265 // frame_slots in units of words
3266 int PhaseOutput::frame_size_in_words() const {
3267 // shift is 0 in LP32 and 1 in LP64
3268 const int shift = (LogBytesPerWord - LogBytesPerInt);
3269 int words = _frame_slots >> shift;
3270 assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
3271 return words;
3272 }
3273
3274 // To bang the stack of this compiled method we use the stack size
3275 // that the interpreter would need in case of a deoptimization. This
3276 // removes the need to bang the stack in the deoptimization blob which
3277 // in turn simplifies stack overflow handling.
3278 int PhaseOutput::bang_size_in_bytes() const {
3279 return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), C->interpreter_frame_size());
3280 }
3281
3282 //------------------------------dump_asm---------------------------------------
3283 // Dump formatted assembly
3284 #if defined(SUPPORT_OPTO_ASSEMBLY)
3285 void PhaseOutput::dump_asm_on(outputStream* st, int* pcs, uint pc_limit) {
3286
3287 int pc_digits = 3; // #chars required for pc
3288 int sb_chars = 3; // #chars for "start bundle" indicator
3289 int tab_size = 8;
3290 if (pcs != nullptr) {
3291 int max_pc = 0;
3292 for (uint i = 0; i < pc_limit; i++) {
3293 max_pc = (max_pc < pcs[i]) ? pcs[i] : max_pc;
3294 }
3295 pc_digits = ((max_pc < 4096) ? 3 : ((max_pc < 65536) ? 4 : ((max_pc < 65536*256) ? 6 : 8))); // #chars required for pc
3296 }
3297 int prefix_len = ((pc_digits + sb_chars + tab_size - 1)/tab_size)*tab_size;
3298
3299 bool cut_short = false;
3300 st->print_cr("#");
3301 st->print("# "); C->tf()->dump_on(st); st->cr();
3302 st->print_cr("#");
3303
3304 // For all blocks
3305 int pc = 0x0; // Program counter
3306 char starts_bundle = ' ';
3307 C->regalloc()->dump_frame();
3308
3309 Node *n = nullptr;
3310 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
3311 if (VMThread::should_terminate()) {
3312 cut_short = true;
3313 break;
3314 }
3315 Block* block = C->cfg()->get_block(i);
3316 if (block->is_connector() && !Verbose) {
3317 continue;
3318 }
3319 n = block->head();
3320 if ((pcs != nullptr) && (n->_idx < pc_limit)) {
3321 pc = pcs[n->_idx];
3322 st->print("%*.*x", pc_digits, pc_digits, pc);
3323 }
3324 st->fill_to(prefix_len);
3325 block->dump_head(C->cfg(), st);
3326 if (block->is_connector()) {
3327 st->fill_to(prefix_len);
3328 st->print_cr("# Empty connector block");
3329 } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
3330 st->fill_to(prefix_len);
3331 st->print_cr("# Block is sole successor of call");
3332 }
3333
3334 // For all instructions
3335 for (uint j = 0; j < block->number_of_nodes(); j++) {
3336 if (VMThread::should_terminate()) {
3337 cut_short = true;
3338 break;
3339 }
3340 n = block->get_node(j);
3341 if (valid_bundle_info(n)) {
3342 Bundle* bundle = node_bundling(n);
3343 if (bundle->starts_bundle()) {
3344 starts_bundle = '+';
3345 }
3346 }
3347
3348 if (WizardMode) {
3349 n->dump();
3350 }
3351
3352 if( !n->is_Region() && // Dont print in the Assembly
3353 !n->is_Phi() && // a few noisely useless nodes
3354 !n->is_Proj() &&
3355 !n->is_MachTemp() &&
3356 !n->is_SafePointScalarObject() &&
3357 !n->is_Catch() && // Would be nice to print exception table targets
3358 !n->is_MergeMem() && // Not very interesting
3359 !n->is_top() && // Debug info table constants
3360 !(n->is_Con() && !n->is_Mach())// Debug info table constants
3361 ) {
3362 if ((pcs != nullptr) && (n->_idx < pc_limit)) {
3363 pc = pcs[n->_idx];
3364 st->print("%*.*x", pc_digits, pc_digits, pc);
3365 } else {
3366 st->fill_to(pc_digits);
3367 }
3368 st->print(" %c ", starts_bundle);
3369 starts_bundle = ' ';
3370 st->fill_to(prefix_len);
3371 n->format(C->regalloc(), st);
3372 st->cr();
3373 }
3374
3375 // Dump the exception table as well
3376 if( n->is_Catch() && (Verbose || WizardMode) ) {
3377 // Print the exception table for this offset
3378 _handler_table.print_subtable_for(pc);
3379 }
3380 st->bol(); // Make sure we start on a new line
3381 }
3382 st->cr(); // one empty line between blocks
3383 } // End of per-block dump
3384
3385 if (cut_short) st->print_cr("*** disassembly is cut short ***");
3386 }
3387 #endif
3388
3389 #ifndef PRODUCT
3390 void PhaseOutput::print_statistics() {
3391 Scheduling::print_statistics();
3392 }
3393 #endif