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 bool PhaseOutput::need_register_stack_bang() const {
367 // Determine if we need to generate a register stack overflow check.
368 // This is only used on architectures which have split register
369 // and memory stacks.
370 // Bang if the method is not a stub function and has java calls
371 return (C->stub_function() == nullptr && C->has_java_calls());
372 }
373
374
375 // Compute the size of first NumberOfLoopInstrToAlign instructions at the top
376 // of a loop. When aligning a loop we need to provide enough instructions
377 // in cpu's fetch buffer to feed decoders. The loop alignment could be
378 // avoided if we have enough instructions in fetch buffer at the head of a loop.
379 // By default, the size is set to 999999 by Block's constructor so that
380 // a loop will be aligned if the size is not reset here.
381 //
382 // Note: Mach instructions could contain several HW instructions
383 // so the size is estimated only.
384 //
385 void PhaseOutput::compute_loop_first_inst_sizes() {
386 // The next condition is used to gate the loop alignment optimization.
387 // Don't aligned a loop if there are enough instructions at the head of a loop
388 // or alignment padding is larger then MaxLoopPad. By default, MaxLoopPad
389 // is equal to OptoLoopAlignment-1 except on new Intel cpus, where it is
390 // equal to 11 bytes which is the largest address NOP instruction.
391 if (MaxLoopPad < OptoLoopAlignment - 1) {
392 uint last_block = C->cfg()->number_of_blocks() - 1;
393 for (uint i = 1; i <= last_block; i++) {
394 Block* block = C->cfg()->get_block(i);
395 // Check the first loop's block which requires an alignment.
396 if (block->loop_alignment() > (uint)relocInfo::addr_unit()) {
397 uint sum_size = 0;
398 uint inst_cnt = NumberOfLoopInstrToAlign;
399 inst_cnt = block->compute_first_inst_size(sum_size, inst_cnt, C->regalloc());
400
401 // Check subsequent fallthrough blocks if the loop's first
402 // block(s) does not have enough instructions.
403 Block *nb = block;
404 while(inst_cnt > 0 &&
405 i < last_block &&
406 !C->cfg()->get_block(i + 1)->has_loop_alignment() &&
407 !nb->has_successor(block)) {
408 i++;
409 nb = C->cfg()->get_block(i);
410 inst_cnt = nb->compute_first_inst_size(sum_size, inst_cnt, C->regalloc());
411 } // while( inst_cnt > 0 && i < last_block )
412
413 block->set_first_inst_size(sum_size);
414 } // f( b->head()->is_Loop() )
415 } // for( i <= last_block )
416 } // if( MaxLoopPad < OptoLoopAlignment-1 )
417 }
418
419 // The architecture description provides short branch variants for some long
420 // branch instructions. Replace eligible long branches with short branches.
421 void PhaseOutput::shorten_branches(uint* blk_starts) {
422
423 Compile::TracePhase tp(_t_shortenBranches);
424
425 // Compute size of each block, method size, and relocation information size
426 uint nblocks = C->cfg()->number_of_blocks();
427
428 uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
429 uint* jmp_size = NEW_RESOURCE_ARRAY(uint,nblocks);
430 int* jmp_nidx = NEW_RESOURCE_ARRAY(int ,nblocks);
431
432 // Collect worst case block paddings
433 int* block_worst_case_pad = NEW_RESOURCE_ARRAY(int, nblocks);
434 memset(block_worst_case_pad, 0, nblocks * sizeof(int));
435
436 DEBUG_ONLY( uint *jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks); )
437 DEBUG_ONLY( uint *jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks); )
438
439 bool has_short_branch_candidate = false;
440
441 // Initialize the sizes to 0
442 int code_size = 0; // Size in bytes of generated code
443 int stub_size = 0; // Size in bytes of all stub entries
444 // Size in bytes of all relocation entries, including those in local stubs.
445 // Start with 2-bytes of reloc info for the unvalidated entry point
446 int reloc_size = 1; // Number of relocation entries
447
448 // Make three passes. The first computes pessimistic blk_starts,
449 // relative jmp_offset and reloc_size information. The second performs
450 // short branch substitution using the pessimistic sizing. The
451 // third inserts nops where needed.
452
453 // Step one, perform a pessimistic sizing pass.
454 uint last_call_adr = max_juint;
455 uint last_avoid_back_to_back_adr = max_juint;
456 uint nop_size = (new MachNopNode())->size(C->regalloc());
457 for (uint i = 0; i < nblocks; i++) { // For all blocks
458 Block* block = C->cfg()->get_block(i);
459 _block = block;
460
461 // During short branch replacement, we store the relative (to blk_starts)
462 // offset of jump in jmp_offset, rather than the absolute offset of jump.
463 // This is so that we do not need to recompute sizes of all nodes when
464 // we compute correct blk_starts in our next sizing pass.
465 jmp_offset[i] = 0;
466 jmp_size[i] = 0;
467 jmp_nidx[i] = -1;
468 DEBUG_ONLY( jmp_target[i] = 0; )
469 DEBUG_ONLY( jmp_rule[i] = 0; )
470
471 // Sum all instruction sizes to compute block size
472 uint last_inst = block->number_of_nodes();
473 uint blk_size = 0;
474 for (uint j = 0; j < last_inst; j++) {
475 _index = j;
476 Node* nj = block->get_node(_index);
477 // Handle machine instruction nodes
478 if (nj->is_Mach()) {
479 MachNode* mach = nj->as_Mach();
480 blk_size += (mach->alignment_required() - 1) * relocInfo::addr_unit(); // assume worst case padding
481 reloc_size += mach->reloc();
482 if (mach->is_MachCall()) {
483 // add size information for trampoline stub
484 // class CallStubImpl is platform-specific and defined in the *.ad files.
485 stub_size += CallStubImpl::size_call_trampoline();
486 reloc_size += CallStubImpl::reloc_call_trampoline();
487
488 MachCallNode *mcall = mach->as_MachCall();
489 // This destination address is NOT PC-relative
490
491 mcall->method_set((intptr_t)mcall->entry_point());
492
493 if (mcall->is_MachCallJava() && mcall->as_MachCallJava()->_method) {
494 stub_size += CompiledDirectCall::to_interp_stub_size();
495 reloc_size += CompiledDirectCall::reloc_to_interp_stub();
496 }
497 } else if (mach->is_MachSafePoint()) {
498 // If call/safepoint are adjacent, account for possible
499 // nop to disambiguate the two safepoints.
500 // ScheduleAndBundle() can rearrange nodes in a block,
501 // check for all offsets inside this block.
502 if (last_call_adr >= blk_starts[i]) {
503 blk_size += nop_size;
504 }
505 }
506 if (mach->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
507 // Nop is inserted between "avoid back to back" instructions.
508 // ScheduleAndBundle() can rearrange nodes in a block,
509 // check for all offsets inside this block.
510 if (last_avoid_back_to_back_adr >= blk_starts[i]) {
511 blk_size += nop_size;
512 }
513 }
514 if (mach->may_be_short_branch()) {
515 if (!nj->is_MachBranch()) {
516 #ifndef PRODUCT
517 nj->dump(3);
518 #endif
519 Unimplemented();
520 }
521 assert(jmp_nidx[i] == -1, "block should have only one branch");
522 jmp_offset[i] = blk_size;
523 jmp_size[i] = nj->size(C->regalloc());
524 jmp_nidx[i] = j;
525 has_short_branch_candidate = true;
526 }
527 }
528 blk_size += nj->size(C->regalloc());
529 // Remember end of call offset
530 if (nj->is_MachCall() && !nj->is_MachCallLeaf()) {
531 last_call_adr = blk_starts[i]+blk_size;
532 }
533 // Remember end of avoid_back_to_back offset
534 if (nj->is_Mach() && nj->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
535 last_avoid_back_to_back_adr = blk_starts[i]+blk_size;
536 }
537 }
538
539 // When the next block starts a loop, we may insert pad NOP
540 // instructions. Since we cannot know our future alignment,
541 // assume the worst.
542 if (i < nblocks - 1) {
543 Block* nb = C->cfg()->get_block(i + 1);
544 int max_loop_pad = nb->code_alignment()-relocInfo::addr_unit();
545 if (max_loop_pad > 0) {
546 assert(is_power_of_2(max_loop_pad+relocInfo::addr_unit()), "");
547 // Adjust last_call_adr and/or last_avoid_back_to_back_adr.
548 // If either is the last instruction in this block, bump by
549 // max_loop_pad in lock-step with blk_size, so sizing
550 // calculations in subsequent blocks still can conservatively
551 // detect that it may the last instruction in this block.
552 if (last_call_adr == blk_starts[i]+blk_size) {
553 last_call_adr += max_loop_pad;
554 }
555 if (last_avoid_back_to_back_adr == blk_starts[i]+blk_size) {
556 last_avoid_back_to_back_adr += max_loop_pad;
557 }
558 blk_size += max_loop_pad;
559 block_worst_case_pad[i + 1] = max_loop_pad;
560 }
561 }
562
563 // Save block size; update total method size
564 blk_starts[i+1] = blk_starts[i]+blk_size;
565 }
566
567 // Step two, replace eligible long jumps.
568 bool progress = true;
569 uint last_may_be_short_branch_adr = max_juint;
570 while (has_short_branch_candidate && progress) {
571 progress = false;
572 has_short_branch_candidate = false;
573 int adjust_block_start = 0;
574 for (uint i = 0; i < nblocks; i++) {
575 Block* block = C->cfg()->get_block(i);
576 int idx = jmp_nidx[i];
577 MachNode* mach = (idx == -1) ? nullptr: block->get_node(idx)->as_Mach();
578 if (mach != nullptr && mach->may_be_short_branch()) {
579 #ifdef ASSERT
580 assert(jmp_size[i] > 0 && mach->is_MachBranch(), "sanity");
581 int j;
582 // Find the branch; ignore trailing NOPs.
583 for (j = block->number_of_nodes()-1; j>=0; j--) {
584 Node* n = block->get_node(j);
585 if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con)
586 break;
587 }
588 assert(j >= 0 && j == idx && block->get_node(j) == (Node*)mach, "sanity");
589 #endif
590 int br_size = jmp_size[i];
591 int br_offs = blk_starts[i] + jmp_offset[i];
592
593 // This requires the TRUE branch target be in succs[0]
594 uint bnum = block->non_connector_successor(0)->_pre_order;
595 int offset = blk_starts[bnum] - br_offs;
596 if (bnum > i) { // adjust following block's offset
597 offset -= adjust_block_start;
598 }
599
600 // This block can be a loop header, account for the padding
601 // in the previous block.
602 int block_padding = block_worst_case_pad[i];
603 assert(i == 0 || block_padding == 0 || br_offs >= block_padding, "Should have at least a padding on top");
604 // In the following code a nop could be inserted before
605 // the branch which will increase the backward distance.
606 bool needs_padding = ((uint)(br_offs - block_padding) == last_may_be_short_branch_adr);
607 assert(!needs_padding || jmp_offset[i] == 0, "padding only branches at the beginning of block");
608
609 if (needs_padding && offset <= 0)
610 offset -= nop_size;
611
612 if (C->matcher()->is_short_branch_offset(mach->rule(), br_size, offset)) {
613 // We've got a winner. Replace this branch.
614 MachNode* replacement = mach->as_MachBranch()->short_branch_version();
615
616 // Update the jmp_size.
617 int new_size = replacement->size(C->regalloc());
618 int diff = br_size - new_size;
619 assert(diff >= (int)nop_size, "short_branch size should be smaller");
620 // Conservatively take into account padding between
621 // avoid_back_to_back branches. Previous branch could be
622 // converted into avoid_back_to_back branch during next
623 // rounds.
624 if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
625 jmp_offset[i] += nop_size;
626 diff -= nop_size;
627 }
628 adjust_block_start += diff;
629 block->map_node(replacement, idx);
630 mach->subsume_by(replacement, C);
631 mach = replacement;
632 progress = true;
633
634 jmp_size[i] = new_size;
635 DEBUG_ONLY( jmp_target[i] = bnum; );
636 DEBUG_ONLY( jmp_rule[i] = mach->rule(); );
637 } else {
638 // The jump distance is not short, try again during next iteration.
639 has_short_branch_candidate = true;
640 }
641 } // (mach->may_be_short_branch())
642 if (mach != nullptr && (mach->may_be_short_branch() ||
643 mach->avoid_back_to_back(MachNode::AVOID_AFTER))) {
644 last_may_be_short_branch_adr = blk_starts[i] + jmp_offset[i] + jmp_size[i];
645 }
646 blk_starts[i+1] -= adjust_block_start;
647 }
648 }
649
650 #ifdef ASSERT
651 for (uint i = 0; i < nblocks; i++) { // For all blocks
652 if (jmp_target[i] != 0) {
653 int br_size = jmp_size[i];
654 int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
655 if (!C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
656 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]);
657 }
658 assert(C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset), "Displacement too large for short jmp");
659 }
660 }
661 #endif
662
663 // Step 3, compute the offsets of all blocks, will be done in fill_buffer()
664 // after ScheduleAndBundle().
665
666 // ------------------
667 // Compute size for code buffer
668 code_size = blk_starts[nblocks];
669
670 // Relocation records
671 reloc_size += 1; // Relo entry for exception handler
672
673 // Adjust reloc_size to number of record of relocation info
674 // Min is 2 bytes, max is probably 6 or 8, with a tax up to 25% for
675 // a relocation index.
676 // The CodeBuffer will expand the locs array if this estimate is too low.
677 reloc_size *= 10 / sizeof(relocInfo);
678
679 _buf_sizes._reloc = reloc_size;
680 _buf_sizes._code = code_size;
681 _buf_sizes._stub = stub_size;
682 }
683
684 //------------------------------FillLocArray-----------------------------------
685 // Create a bit of debug info and append it to the array. The mapping is from
686 // Java local or expression stack to constant, register or stack-slot. For
687 // doubles, insert 2 mappings and return 1 (to tell the caller that the next
688 // entry has been taken care of and caller should skip it).
689 static LocationValue *new_loc_value( PhaseRegAlloc *ra, OptoReg::Name regnum, Location::Type l_type ) {
690 // This should never have accepted Bad before
691 assert(OptoReg::is_valid(regnum), "location must be valid");
692 return (OptoReg::is_reg(regnum))
693 ? new LocationValue(Location::new_reg_loc(l_type, OptoReg::as_VMReg(regnum)) )
694 : new LocationValue(Location::new_stk_loc(l_type, ra->reg2offset(regnum)));
695 }
696
697
698 ObjectValue*
699 PhaseOutput::sv_for_node_id(GrowableArray<ScopeValue*> *objs, int id) {
700 for (int i = 0; i < objs->length(); i++) {
701 assert(objs->at(i)->is_object(), "corrupt object cache");
702 ObjectValue* sv = objs->at(i)->as_ObjectValue();
703 if (sv->id() == id) {
704 return sv;
705 }
706 }
707 // Otherwise..
708 return nullptr;
709 }
710
711 void PhaseOutput::set_sv_for_object_node(GrowableArray<ScopeValue*> *objs,
712 ObjectValue* sv ) {
713 assert(sv_for_node_id(objs, sv->id()) == nullptr, "Precondition");
714 objs->append(sv);
715 }
716
717
718 void PhaseOutput::FillLocArray( int idx, MachSafePointNode* sfpt, Node *local,
719 GrowableArray<ScopeValue*> *array,
720 GrowableArray<ScopeValue*> *objs ) {
721 assert( local, "use _top instead of null" );
722 if (array->length() != idx) {
723 assert(array->length() == idx + 1, "Unexpected array count");
724 // Old functionality:
725 // return
726 // New functionality:
727 // Assert if the local is not top. In product mode let the new node
728 // override the old entry.
729 assert(local == C->top(), "LocArray collision");
730 if (local == C->top()) {
731 return;
732 }
733 array->pop();
734 }
735 const Type *t = local->bottom_type();
736
737 // Is it a safepoint scalar object node?
738 if (local->is_SafePointScalarObject()) {
739 SafePointScalarObjectNode* spobj = local->as_SafePointScalarObject();
740
741 ObjectValue* sv = sv_for_node_id(objs, spobj->_idx);
742 if (sv == nullptr) {
743 ciKlass* cik = t->is_oopptr()->exact_klass();
744 assert(cik->is_instance_klass() ||
745 cik->is_array_klass(), "Not supported allocation.");
746 sv = new ObjectValue(spobj->_idx,
747 new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
748 set_sv_for_object_node(objs, sv);
749
750 uint first_ind = spobj->first_index(sfpt->jvms());
751 for (uint i = 0; i < spobj->n_fields(); i++) {
752 Node* fld_node = sfpt->in(first_ind+i);
753 (void)FillLocArray(sv->field_values()->length(), sfpt, fld_node, sv->field_values(), objs);
754 }
755 }
756 array->append(sv);
757 return;
758 } else if (local->is_SafePointScalarMerge()) {
759 SafePointScalarMergeNode* smerge = local->as_SafePointScalarMerge();
760 ObjectMergeValue* mv = (ObjectMergeValue*) sv_for_node_id(objs, smerge->_idx);
761
762 if (mv == nullptr) {
763 GrowableArray<ScopeValue*> deps;
764
765 int merge_pointer_idx = smerge->merge_pointer_idx(sfpt->jvms());
766 (void)FillLocArray(0, sfpt, sfpt->in(merge_pointer_idx), &deps, objs);
767 assert(deps.length() == 1, "missing value");
768
769 int selector_idx = smerge->selector_idx(sfpt->jvms());
770 (void)FillLocArray(1, nullptr, sfpt->in(selector_idx), &deps, nullptr);
771 assert(deps.length() == 2, "missing value");
772
773 mv = new ObjectMergeValue(smerge->_idx, deps.at(0), deps.at(1));
774 set_sv_for_object_node(objs, mv);
775
776 for (uint i = 1; i < smerge->req(); i++) {
777 Node* obj_node = smerge->in(i);
778 int idx = mv->possible_objects()->length();
779 (void)FillLocArray(idx, sfpt, obj_node, mv->possible_objects(), objs);
780
781 // By default ObjectValues that are in 'possible_objects' are not root objects.
782 // They will be marked as root later if they are directly referenced in a JVMS.
783 assert(mv->possible_objects()->length() > idx, "Didn't add entry to possible_objects?!");
784 assert(mv->possible_objects()->at(idx)->is_object(), "Entries in possible_objects should be ObjectValue.");
785 mv->possible_objects()->at(idx)->as_ObjectValue()->set_root(false);
786 }
787 }
788 array->append(mv);
789 return;
790 }
791
792 // Grab the register number for the local
793 OptoReg::Name regnum = C->regalloc()->get_reg_first(local);
794 if( OptoReg::is_valid(regnum) ) {// Got a register/stack?
795 // Record the double as two float registers.
796 // The register mask for such a value always specifies two adjacent
797 // float registers, with the lower register number even.
798 // Normally, the allocation of high and low words to these registers
799 // is irrelevant, because nearly all operations on register pairs
800 // (e.g., StoreD) treat them as a single unit.
801 // Here, we assume in addition that the words in these two registers
802 // stored "naturally" (by operations like StoreD and double stores
803 // within the interpreter) such that the lower-numbered register
804 // is written to the lower memory address. This may seem like
805 // a machine dependency, but it is not--it is a requirement on
806 // the author of the <arch>.ad file to ensure that, for every
807 // even/odd double-register pair to which a double may be allocated,
808 // the word in the even single-register is stored to the first
809 // memory word. (Note that register numbers are completely
810 // arbitrary, and are not tied to any machine-level encodings.)
811 #ifdef _LP64
812 if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon ) {
813 array->append(new ConstantIntValue((jint)0));
814 array->append(new_loc_value( C->regalloc(), regnum, Location::dbl ));
815 } else if ( t->base() == Type::Long ) {
816 array->append(new ConstantIntValue((jint)0));
817 array->append(new_loc_value( C->regalloc(), regnum, Location::lng ));
818 } else if ( t->base() == Type::RawPtr ) {
819 // jsr/ret return address which must be restored into the full
820 // width 64-bit stack slot.
821 array->append(new_loc_value( C->regalloc(), regnum, Location::lng ));
822 }
823 #else //_LP64
824 if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon || t->base() == Type::Long ) {
825 // Repack the double/long as two jints.
826 // The convention the interpreter uses is that the second local
827 // holds the first raw word of the native double representation.
828 // This is actually reasonable, since locals and stack arrays
829 // grow downwards in all implementations.
830 // (If, on some machine, the interpreter's Java locals or stack
831 // were to grow upwards, the embedded doubles would be word-swapped.)
832 array->append(new_loc_value( C->regalloc(), OptoReg::add(regnum,1), Location::normal ));
833 array->append(new_loc_value( C->regalloc(), regnum , Location::normal ));
834 }
835 #endif //_LP64
836 else if( (t->base() == Type::FloatBot || t->base() == Type::FloatCon) &&
837 OptoReg::is_reg(regnum) ) {
838 array->append(new_loc_value( C->regalloc(), regnum, Matcher::float_in_double()
839 ? Location::float_in_dbl : Location::normal ));
840 } else if( t->base() == Type::Int && OptoReg::is_reg(regnum) ) {
841 array->append(new_loc_value( C->regalloc(), regnum, Matcher::int_in_long
842 ? Location::int_in_long : Location::normal ));
843 } else if( t->base() == Type::NarrowOop ) {
844 array->append(new_loc_value( C->regalloc(), regnum, Location::narrowoop ));
845 } else if (t->base() == Type::VectorA || t->base() == Type::VectorS ||
846 t->base() == Type::VectorD || t->base() == Type::VectorX ||
847 t->base() == Type::VectorY || t->base() == Type::VectorZ) {
848 array->append(new_loc_value( C->regalloc(), regnum, Location::vector ));
849 } else if (C->regalloc()->is_oop(local)) {
850 assert(t->base() == Type::OopPtr || t->base() == Type::InstPtr ||
851 t->base() == Type::AryPtr,
852 "Unexpected type: %s", t->msg());
853 array->append(new_loc_value( C->regalloc(), regnum, Location::oop ));
854 } else {
855 assert(t->base() == Type::Int || t->base() == Type::Half ||
856 t->base() == Type::FloatCon || t->base() == Type::FloatBot,
857 "Unexpected type: %s", t->msg());
858 array->append(new_loc_value( C->regalloc(), regnum, Location::normal ));
859 }
860 return;
861 }
862
863 // No register. It must be constant data.
864 switch (t->base()) {
865 case Type::Half: // Second half of a double
866 ShouldNotReachHere(); // Caller should skip 2nd halves
867 break;
868 case Type::AnyPtr:
869 array->append(new ConstantOopWriteValue(nullptr));
870 break;
871 case Type::AryPtr:
872 case Type::InstPtr: // fall through
873 array->append(new ConstantOopWriteValue(t->isa_oopptr()->const_oop()->constant_encoding()));
874 break;
875 case Type::NarrowOop:
876 if (t == TypeNarrowOop::NULL_PTR) {
877 array->append(new ConstantOopWriteValue(nullptr));
878 } else {
879 array->append(new ConstantOopWriteValue(t->make_ptr()->isa_oopptr()->const_oop()->constant_encoding()));
880 }
881 break;
882 case Type::Int:
883 array->append(new ConstantIntValue(t->is_int()->get_con()));
884 break;
885 case Type::RawPtr:
886 // A return address (T_ADDRESS).
887 assert((intptr_t)t->is_ptr()->get_con() < (intptr_t)0x10000, "must be a valid BCI");
888 #ifdef _LP64
889 // Must be restored to the full-width 64-bit stack slot.
890 array->append(new ConstantLongValue(t->is_ptr()->get_con()));
891 #else
892 array->append(new ConstantIntValue(t->is_ptr()->get_con()));
893 #endif
894 break;
895 case Type::FloatCon: {
896 float f = t->is_float_constant()->getf();
897 array->append(new ConstantIntValue(jint_cast(f)));
898 break;
899 }
900 case Type::DoubleCon: {
901 jdouble d = t->is_double_constant()->getd();
902 #ifdef _LP64
903 array->append(new ConstantIntValue((jint)0));
904 array->append(new ConstantDoubleValue(d));
905 #else
906 // Repack the double as two jints.
907 // The convention the interpreter uses is that the second local
908 // holds the first raw word of the native double representation.
909 // This is actually reasonable, since locals and stack arrays
910 // grow downwards in all implementations.
911 // (If, on some machine, the interpreter's Java locals or stack
912 // were to grow upwards, the embedded doubles would be word-swapped.)
913 jlong_accessor acc;
914 acc.long_value = jlong_cast(d);
915 array->append(new ConstantIntValue(acc.words[1]));
916 array->append(new ConstantIntValue(acc.words[0]));
917 #endif
918 break;
919 }
920 case Type::Long: {
921 jlong d = t->is_long()->get_con();
922 #ifdef _LP64
923 array->append(new ConstantIntValue((jint)0));
924 array->append(new ConstantLongValue(d));
925 #else
926 // Repack the long as two jints.
927 // The convention the interpreter uses is that the second local
928 // holds the first raw word of the native double representation.
929 // This is actually reasonable, since locals and stack arrays
930 // grow downwards in all implementations.
931 // (If, on some machine, the interpreter's Java locals or stack
932 // were to grow upwards, the embedded doubles would be word-swapped.)
933 jlong_accessor acc;
934 acc.long_value = d;
935 array->append(new ConstantIntValue(acc.words[1]));
936 array->append(new ConstantIntValue(acc.words[0]));
937 #endif
938 break;
939 }
940 case Type::Top: // Add an illegal value here
941 array->append(new LocationValue(Location()));
942 break;
943 default:
944 ShouldNotReachHere();
945 break;
946 }
947 }
948
949 // Determine if this node starts a bundle
950 bool PhaseOutput::starts_bundle(const Node *n) const {
951 return (_node_bundling_limit > n->_idx &&
952 _node_bundling_base[n->_idx].starts_bundle());
953 }
954
955 // Determine if there is a monitor that has 'ov' as its owner.
956 bool PhaseOutput::contains_as_owner(GrowableArray<MonitorValue*> *monarray, ObjectValue *ov) const {
957 for (int k = 0; k < monarray->length(); k++) {
958 MonitorValue* mv = monarray->at(k);
959 if (mv->owner() == ov) {
960 return true;
961 }
962 }
963
964 return false;
965 }
966
967 // Determine if there is a scalar replaced object description represented by 'ov'.
968 bool PhaseOutput::contains_as_scalarized_obj(JVMState* jvms, MachSafePointNode* sfn,
969 GrowableArray<ScopeValue*>* objs,
970 ObjectValue* ov) const {
971 for (int i = 0; i < jvms->scl_size(); i++) {
972 Node* n = sfn->scalarized_obj(jvms, i);
973 // Other kinds of nodes that we may encounter here, for instance constants
974 // representing values of fields of objects scalarized, aren't relevant for
975 // us, since they don't map to ObjectValue.
976 if (!n->is_SafePointScalarObject()) {
977 continue;
978 }
979
980 ObjectValue* other = sv_for_node_id(objs, n->_idx);
981 if (ov == other) {
982 return true;
983 }
984 }
985 return false;
986 }
987
988 //--------------------------Process_OopMap_Node--------------------------------
989 void PhaseOutput::Process_OopMap_Node(MachNode *mach, int current_offset) {
990 // Handle special safepoint nodes for synchronization
991 MachSafePointNode *sfn = mach->as_MachSafePoint();
992 MachCallNode *mcall;
993
994 int safepoint_pc_offset = current_offset;
995 bool return_oop = false;
996 bool has_ea_local_in_scope = sfn->_has_ea_local_in_scope;
997 bool arg_escape = false;
998
999 // Add the safepoint in the DebugInfoRecorder
1000 if( !mach->is_MachCall() ) {
1001 mcall = nullptr;
1002 C->debug_info()->add_safepoint(safepoint_pc_offset, sfn->_oop_map);
1003 } else {
1004 mcall = mach->as_MachCall();
1005
1006 if (mcall->is_MachCallJava()) {
1007 arg_escape = mcall->as_MachCallJava()->_arg_escape;
1008 }
1009
1010 // Check if a call returns an object.
1011 if (mcall->returns_pointer()) {
1012 return_oop = true;
1013 }
1014 safepoint_pc_offset += mcall->ret_addr_offset();
1015 C->debug_info()->add_safepoint(safepoint_pc_offset, mcall->_oop_map);
1016 }
1017
1018 // Loop over the JVMState list to add scope information
1019 // Do not skip safepoints with a null method, they need monitor info
1020 JVMState* youngest_jvms = sfn->jvms();
1021 int max_depth = youngest_jvms->depth();
1022
1023 // Allocate the object pool for scalar-replaced objects -- the map from
1024 // small-integer keys (which can be recorded in the local and ostack
1025 // arrays) to descriptions of the object state.
1026 GrowableArray<ScopeValue*> *objs = new GrowableArray<ScopeValue*>();
1027
1028 // Visit scopes from oldest to youngest.
1029 for (int depth = 1; depth <= max_depth; depth++) {
1030 JVMState* jvms = youngest_jvms->of_depth(depth);
1031 int idx;
1032 ciMethod* method = jvms->has_method() ? jvms->method() : nullptr;
1033 // Safepoints that do not have method() set only provide oop-map and monitor info
1034 // to support GC; these do not support deoptimization.
1035 int num_locs = (method == nullptr) ? 0 : jvms->loc_size();
1036 int num_exps = (method == nullptr) ? 0 : jvms->stk_size();
1037 int num_mon = jvms->nof_monitors();
1038 assert(method == nullptr || jvms->bci() < 0 || num_locs == method->max_locals(),
1039 "JVMS local count must match that of the method");
1040
1041 // Add Local and Expression Stack Information
1042
1043 // Insert locals into the locarray
1044 GrowableArray<ScopeValue*> *locarray = new GrowableArray<ScopeValue*>(num_locs);
1045 for( idx = 0; idx < num_locs; idx++ ) {
1046 FillLocArray( idx, sfn, sfn->local(jvms, idx), locarray, objs );
1047 }
1048
1049 // Insert expression stack entries into the exparray
1050 GrowableArray<ScopeValue*> *exparray = new GrowableArray<ScopeValue*>(num_exps);
1051 for( idx = 0; idx < num_exps; idx++ ) {
1052 FillLocArray( idx, sfn, sfn->stack(jvms, idx), exparray, objs );
1053 }
1054
1055 // Add in mappings of the monitors
1056 assert( !method ||
1057 !method->is_synchronized() ||
1058 method->is_native() ||
1059 num_mon > 0,
1060 "monitors must always exist for synchronized methods");
1061
1062 // Build the growable array of ScopeValues for exp stack
1063 GrowableArray<MonitorValue*> *monarray = new GrowableArray<MonitorValue*>(num_mon);
1064
1065 // Loop over monitors and insert into array
1066 for (idx = 0; idx < num_mon; idx++) {
1067 // Grab the node that defines this monitor
1068 Node* box_node = sfn->monitor_box(jvms, idx);
1069 Node* obj_node = sfn->monitor_obj(jvms, idx);
1070
1071 // Create ScopeValue for object
1072 ScopeValue *scval = nullptr;
1073
1074 if (obj_node->is_SafePointScalarObject()) {
1075 SafePointScalarObjectNode* spobj = obj_node->as_SafePointScalarObject();
1076 scval = PhaseOutput::sv_for_node_id(objs, spobj->_idx);
1077 if (scval == nullptr) {
1078 const Type *t = spobj->bottom_type();
1079 ciKlass* cik = t->is_oopptr()->exact_klass();
1080 assert(cik->is_instance_klass() ||
1081 cik->is_array_klass(), "Not supported allocation.");
1082 ObjectValue* sv = new ObjectValue(spobj->_idx,
1083 new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
1084 PhaseOutput::set_sv_for_object_node(objs, sv);
1085
1086 uint first_ind = spobj->first_index(youngest_jvms);
1087 for (uint i = 0; i < spobj->n_fields(); i++) {
1088 Node* fld_node = sfn->in(first_ind+i);
1089 (void)FillLocArray(sv->field_values()->length(), sfn, fld_node, sv->field_values(), objs);
1090 }
1091 scval = sv;
1092 }
1093 } else if (obj_node->is_SafePointScalarMerge()) {
1094 SafePointScalarMergeNode* smerge = obj_node->as_SafePointScalarMerge();
1095 ObjectMergeValue* mv = (ObjectMergeValue*) sv_for_node_id(objs, smerge->_idx);
1096
1097 if (mv == nullptr) {
1098 GrowableArray<ScopeValue*> deps;
1099
1100 int merge_pointer_idx = smerge->merge_pointer_idx(youngest_jvms);
1101 FillLocArray(0, sfn, sfn->in(merge_pointer_idx), &deps, objs);
1102 assert(deps.length() == 1, "missing value");
1103
1104 int selector_idx = smerge->selector_idx(youngest_jvms);
1105 FillLocArray(1, nullptr, sfn->in(selector_idx), &deps, nullptr);
1106 assert(deps.length() == 2, "missing value");
1107
1108 mv = new ObjectMergeValue(smerge->_idx, deps.at(0), deps.at(1));
1109 set_sv_for_object_node(objs, mv);
1110
1111 for (uint i = 1; i < smerge->req(); i++) {
1112 Node* obj_node = smerge->in(i);
1113 int idx = mv->possible_objects()->length();
1114 (void)FillLocArray(idx, sfn, obj_node, mv->possible_objects(), objs);
1115
1116 // By default ObjectValues that are in 'possible_objects' are not root objects.
1117 // They will be marked as root later if they are directly referenced in a JVMS.
1118 assert(mv->possible_objects()->length() > idx, "Didn't add entry to possible_objects?!");
1119 assert(mv->possible_objects()->at(idx)->is_object(), "Entries in possible_objects should be ObjectValue.");
1120 mv->possible_objects()->at(idx)->as_ObjectValue()->set_root(false);
1121 }
1122 }
1123 scval = mv;
1124 } else if (!obj_node->is_Con()) {
1125 OptoReg::Name obj_reg = C->regalloc()->get_reg_first(obj_node);
1126 if( obj_node->bottom_type()->base() == Type::NarrowOop ) {
1127 scval = new_loc_value( C->regalloc(), obj_reg, Location::narrowoop );
1128 } else {
1129 scval = new_loc_value( C->regalloc(), obj_reg, Location::oop );
1130 }
1131 } else {
1132 const TypePtr *tp = obj_node->get_ptr_type();
1133 scval = new ConstantOopWriteValue(tp->is_oopptr()->const_oop()->constant_encoding());
1134 }
1135
1136 OptoReg::Name box_reg = BoxLockNode::reg(box_node);
1137 Location basic_lock = Location::new_stk_loc(Location::normal,C->regalloc()->reg2offset(box_reg));
1138 bool eliminated = (box_node->is_BoxLock() && box_node->as_BoxLock()->is_eliminated());
1139 monarray->append(new MonitorValue(scval, basic_lock, eliminated));
1140 }
1141
1142 // Mark ObjectValue nodes as root nodes if they are directly
1143 // referenced in the JVMS.
1144 for (int i = 0; i < objs->length(); i++) {
1145 ScopeValue* sv = objs->at(i);
1146 if (sv->is_object_merge()) {
1147 ObjectMergeValue* merge = sv->as_ObjectMergeValue();
1148
1149 for (int j = 0; j< merge->possible_objects()->length(); j++) {
1150 ObjectValue* ov = merge->possible_objects()->at(j)->as_ObjectValue();
1151 if (ov->is_root()) {
1152 // Already flagged as 'root' by something else. We shouldn't change it
1153 // to non-root in a younger JVMS because it may need to be alive in
1154 // a younger JVMS.
1155 } else {
1156 bool is_root = locarray->contains(ov) ||
1157 exparray->contains(ov) ||
1158 contains_as_owner(monarray, ov) ||
1159 contains_as_scalarized_obj(jvms, sfn, objs, ov);
1160 ov->set_root(is_root);
1161 }
1162 }
1163 }
1164 }
1165
1166 // We dump the object pool first, since deoptimization reads it in first.
1167 C->debug_info()->dump_object_pool(objs);
1168
1169 // Build first class objects to pass to scope
1170 DebugToken *locvals = C->debug_info()->create_scope_values(locarray);
1171 DebugToken *expvals = C->debug_info()->create_scope_values(exparray);
1172 DebugToken *monvals = C->debug_info()->create_monitor_values(monarray);
1173
1174 // Make method available for all Safepoints
1175 ciMethod* scope_method = method ? method : C->method();
1176 // Describe the scope here
1177 assert(jvms->bci() >= InvocationEntryBci && jvms->bci() <= 0x10000, "must be a valid or entry BCI");
1178 assert(!jvms->should_reexecute() || depth == max_depth, "reexecute allowed only for the youngest");
1179 // Now we can describe the scope.
1180 methodHandle null_mh;
1181 bool rethrow_exception = false;
1182 C->debug_info()->describe_scope(
1183 safepoint_pc_offset,
1184 null_mh,
1185 scope_method,
1186 jvms->bci(),
1187 jvms->should_reexecute(),
1188 rethrow_exception,
1189 return_oop,
1190 has_ea_local_in_scope,
1191 arg_escape,
1192 locvals,
1193 expvals,
1194 monvals
1195 );
1196 } // End jvms loop
1197
1198 // Mark the end of the scope set.
1199 C->debug_info()->end_safepoint(safepoint_pc_offset);
1200 }
1201
1202
1203
1204 // A simplified version of Process_OopMap_Node, to handle non-safepoints.
1205 class NonSafepointEmitter {
1206 Compile* C;
1207 JVMState* _pending_jvms;
1208 int _pending_offset;
1209
1210 void emit_non_safepoint();
1211
1212 public:
1213 NonSafepointEmitter(Compile* compile) {
1214 this->C = compile;
1215 _pending_jvms = nullptr;
1216 _pending_offset = 0;
1217 }
1218
1219 void observe_instruction(Node* n, int pc_offset) {
1220 if (!C->debug_info()->recording_non_safepoints()) return;
1221
1222 Node_Notes* nn = C->node_notes_at(n->_idx);
1223 if (nn == nullptr || nn->jvms() == nullptr) return;
1224 if (_pending_jvms != nullptr &&
1225 _pending_jvms->same_calls_as(nn->jvms())) {
1226 // Repeated JVMS? Stretch it up here.
1227 _pending_offset = pc_offset;
1228 } else {
1229 if (_pending_jvms != nullptr &&
1230 _pending_offset < pc_offset) {
1231 emit_non_safepoint();
1232 }
1233 _pending_jvms = nullptr;
1234 if (pc_offset > C->debug_info()->last_pc_offset()) {
1235 // This is the only way _pending_jvms can become non-null:
1236 _pending_jvms = nn->jvms();
1237 _pending_offset = pc_offset;
1238 }
1239 }
1240 }
1241
1242 // Stay out of the way of real safepoints:
1243 void observe_safepoint(JVMState* jvms, int pc_offset) {
1244 if (_pending_jvms != nullptr &&
1245 !_pending_jvms->same_calls_as(jvms) &&
1246 _pending_offset < pc_offset) {
1247 emit_non_safepoint();
1248 }
1249 _pending_jvms = nullptr;
1250 }
1251
1252 void flush_at_end() {
1253 if (_pending_jvms != nullptr) {
1254 emit_non_safepoint();
1255 }
1256 _pending_jvms = nullptr;
1257 }
1258 };
1259
1260 void NonSafepointEmitter::emit_non_safepoint() {
1261 JVMState* youngest_jvms = _pending_jvms;
1262 int pc_offset = _pending_offset;
1263
1264 // Clear it now:
1265 _pending_jvms = nullptr;
1266
1267 DebugInformationRecorder* debug_info = C->debug_info();
1268 assert(debug_info->recording_non_safepoints(), "sanity");
1269
1270 debug_info->add_non_safepoint(pc_offset);
1271 int max_depth = youngest_jvms->depth();
1272
1273 // Visit scopes from oldest to youngest.
1274 for (int depth = 1; depth <= max_depth; depth++) {
1275 JVMState* jvms = youngest_jvms->of_depth(depth);
1276 ciMethod* method = jvms->has_method() ? jvms->method() : nullptr;
1277 assert(!jvms->should_reexecute() || depth==max_depth, "reexecute allowed only for the youngest");
1278 methodHandle null_mh;
1279 debug_info->describe_scope(pc_offset, null_mh, method, jvms->bci(), jvms->should_reexecute());
1280 }
1281
1282 // Mark the end of the scope set.
1283 debug_info->end_non_safepoint(pc_offset);
1284 }
1285
1286 //------------------------------init_buffer------------------------------------
1287 void PhaseOutput::estimate_buffer_size(int& const_req) {
1288
1289 // Set the initially allocated size
1290 const_req = initial_const_capacity;
1291
1292 // The extra spacing after the code is necessary on some platforms.
1293 // Sometimes we need to patch in a jump after the last instruction,
1294 // if the nmethod has been deoptimized. (See 4932387, 4894843.)
1295
1296 // Compute the byte offset where we can store the deopt pc.
1297 if (C->fixed_slots() != 0) {
1298 _orig_pc_slot_offset_in_bytes = C->regalloc()->reg2offset(OptoReg::stack2reg(_orig_pc_slot));
1299 }
1300
1301 // Compute prolog code size
1302 _frame_slots = OptoReg::reg2stack(C->matcher()->_old_SP) + C->regalloc()->_framesize;
1303 assert(_frame_slots >= 0 && _frame_slots < 1000000, "sanity check");
1304
1305 if (C->has_mach_constant_base_node()) {
1306 uint add_size = 0;
1307 // Fill the constant table.
1308 // Note: This must happen before shorten_branches.
1309 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
1310 Block* b = C->cfg()->get_block(i);
1311
1312 for (uint j = 0; j < b->number_of_nodes(); j++) {
1313 Node* n = b->get_node(j);
1314
1315 // If the node is a MachConstantNode evaluate the constant
1316 // value section.
1317 if (n->is_MachConstant()) {
1318 MachConstantNode* machcon = n->as_MachConstant();
1319 machcon->eval_constant(C);
1320 } else if (n->is_Mach()) {
1321 // On Power there are more nodes that issue constants.
1322 add_size += (n->as_Mach()->ins_num_consts() * 8);
1323 }
1324 }
1325 }
1326
1327 // Calculate the offsets of the constants and the size of the
1328 // constant table (including the padding to the next section).
1329 constant_table().calculate_offsets_and_size();
1330 const_req = constant_table().alignment() + constant_table().size() + add_size;
1331 }
1332
1333 // Initialize the space for the BufferBlob used to find and verify
1334 // instruction size in MachNode::emit_size()
1335 init_scratch_buffer_blob(const_req);
1336 }
1337
1338 CodeBuffer* PhaseOutput::init_buffer() {
1339 int stub_req = _buf_sizes._stub;
1340 int code_req = _buf_sizes._code;
1341 int const_req = _buf_sizes._const;
1342
1343 int pad_req = NativeCall::byte_size();
1344
1345 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1346 stub_req += bs->estimate_stub_size();
1347
1348 // nmethod and CodeBuffer count stubs & constants as part of method's code.
1349 // class HandlerImpl is platform-specific and defined in the *.ad files.
1350 int deopt_handler_req = HandlerImpl::size_deopt_handler() + MAX_stubs_size; // add marginal slop for handler
1351 stub_req += MAX_stubs_size; // ensure per-stub margin
1352 code_req += max_inst_size(); // ensure per-instruction margin
1353
1354 if (StressCodeBuffers)
1355 code_req = const_req = stub_req = deopt_handler_req = 0x10; // force expansion
1356
1357 int total_req =
1358 const_req +
1359 code_req +
1360 pad_req +
1361 stub_req +
1362 deopt_handler_req; // deopt handler
1363
1364 CodeBuffer* cb = code_buffer();
1365 cb->set_const_section_alignment(constant_table().alignment());
1366 cb->initialize(total_req, _buf_sizes._reloc);
1367
1368 // Have we run out of code space?
1369 if ((cb->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1370 C->record_failure("CodeCache is full");
1371 return nullptr;
1372 }
1373 // Configure the code buffer.
1374 cb->initialize_consts_size(const_req);
1375 cb->initialize_stubs_size(stub_req);
1376 cb->initialize_oop_recorder(C->env()->oop_recorder());
1377
1378 return cb;
1379 }
1380
1381 //------------------------------fill_buffer------------------------------------
1382 void PhaseOutput::fill_buffer(C2_MacroAssembler* masm, uint* blk_starts) {
1383 // blk_starts[] contains offsets calculated during short branches processing,
1384 // offsets should not be increased during following steps.
1385
1386 // Compute the size of first NumberOfLoopInstrToAlign instructions at head
1387 // of a loop. It is used to determine the padding for loop alignment.
1388 Compile::TracePhase tp(_t_fillBuffer);
1389
1390 compute_loop_first_inst_sizes();
1391
1392 // Create oopmap set.
1393 _oop_map_set = new OopMapSet();
1394
1395 // !!!!! This preserves old handling of oopmaps for now
1396 C->debug_info()->set_oopmaps(_oop_map_set);
1397
1398 uint nblocks = C->cfg()->number_of_blocks();
1399 // Count and start of implicit null check instructions
1400 uint inct_cnt = 0;
1401 uint* inct_starts = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1402
1403 // Count and start of calls
1404 uint* call_returns = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1405
1406 uint return_offset = 0;
1407 int nop_size = (new MachNopNode())->size(C->regalloc());
1408
1409 int previous_offset = 0;
1410 int current_offset = 0;
1411 int last_call_offset = -1;
1412 int last_avoid_back_to_back_offset = -1;
1413 #ifdef ASSERT
1414 uint* jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks);
1415 uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
1416 uint* jmp_size = NEW_RESOURCE_ARRAY(uint,nblocks);
1417 uint* jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks);
1418 #endif
1419
1420 // Create an array of unused labels, one for each basic block, if printing is enabled
1421 #if defined(SUPPORT_OPTO_ASSEMBLY)
1422 int* node_offsets = nullptr;
1423 uint node_offset_limit = C->unique();
1424
1425 if (C->print_assembly()) {
1426 node_offsets = NEW_RESOURCE_ARRAY(int, node_offset_limit);
1427 }
1428 if (node_offsets != nullptr) {
1429 // We need to initialize. Unused array elements may contain garbage and mess up PrintOptoAssembly.
1430 memset(node_offsets, 0, node_offset_limit*sizeof(int));
1431 }
1432 #endif
1433
1434 NonSafepointEmitter non_safepoints(C); // emit non-safepoints lazily
1435
1436 // Emit the constant table.
1437 if (C->has_mach_constant_base_node()) {
1438 if (!constant_table().emit(masm)) {
1439 C->record_failure("consts section overflow");
1440 return;
1441 }
1442 }
1443
1444 // Create an array of labels, one for each basic block
1445 Label* blk_labels = NEW_RESOURCE_ARRAY(Label, nblocks+1);
1446 for (uint i = 0; i <= nblocks; i++) {
1447 blk_labels[i].init();
1448 }
1449
1450 // Now fill in the code buffer
1451 for (uint i = 0; i < nblocks; i++) {
1452 Block* block = C->cfg()->get_block(i);
1453 _block = block;
1454 Node* head = block->head();
1455
1456 // If this block needs to start aligned (i.e, can be reached other
1457 // than by falling-thru from the previous block), then force the
1458 // start of a new bundle.
1459 if (Pipeline::requires_bundling() && starts_bundle(head)) {
1460 masm->code()->flush_bundle(true);
1461 }
1462
1463 #ifdef ASSERT
1464 if (!block->is_connector()) {
1465 stringStream st;
1466 block->dump_head(C->cfg(), &st);
1467 masm->block_comment(st.freeze());
1468 }
1469 jmp_target[i] = 0;
1470 jmp_offset[i] = 0;
1471 jmp_size[i] = 0;
1472 jmp_rule[i] = 0;
1473 #endif
1474 int blk_offset = current_offset;
1475
1476 // Define the label at the beginning of the basic block
1477 masm->bind(blk_labels[block->_pre_order]);
1478
1479 uint last_inst = block->number_of_nodes();
1480
1481 // Emit block normally, except for last instruction.
1482 // Emit means "dump code bits into code buffer".
1483 for (uint j = 0; j<last_inst; j++) {
1484 _index = j;
1485
1486 // Get the node
1487 Node* n = block->get_node(j);
1488
1489 // If this starts a new instruction group, then flush the current one
1490 // (but allow split bundles)
1491 if (Pipeline::requires_bundling() && starts_bundle(n))
1492 masm->code()->flush_bundle(false);
1493
1494 // Special handling for SafePoint/Call Nodes
1495 bool is_mcall = false;
1496 if (n->is_Mach()) {
1497 MachNode *mach = n->as_Mach();
1498 is_mcall = n->is_MachCall();
1499 bool is_sfn = n->is_MachSafePoint();
1500
1501 // If this requires all previous instructions be flushed, then do so
1502 if (is_sfn || is_mcall || mach->alignment_required() != 1) {
1503 masm->code()->flush_bundle(true);
1504 current_offset = masm->offset();
1505 }
1506
1507 // align the instruction if necessary
1508 int padding = mach->compute_padding(current_offset);
1509 // Make sure safepoint node for polling is distinct from a call's
1510 // return by adding a nop if needed.
1511 if (is_sfn && !is_mcall && padding == 0 && current_offset == last_call_offset) {
1512 padding = nop_size;
1513 }
1514 if (padding == 0 && mach->avoid_back_to_back(MachNode::AVOID_BEFORE) &&
1515 current_offset == last_avoid_back_to_back_offset) {
1516 // Avoid back to back some instructions.
1517 padding = nop_size;
1518 }
1519
1520 if (padding > 0) {
1521 assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
1522 int nops_cnt = padding / nop_size;
1523 MachNode *nop = new MachNopNode(nops_cnt);
1524 block->insert_node(nop, j++);
1525 last_inst++;
1526 C->cfg()->map_node_to_block(nop, block);
1527 // Ensure enough space.
1528 masm->code()->insts()->maybe_expand_to_ensure_remaining(max_inst_size());
1529 if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1530 C->record_failure("CodeCache is full");
1531 return;
1532 }
1533 nop->emit(masm, C->regalloc());
1534 masm->code()->flush_bundle(true);
1535 current_offset = masm->offset();
1536 }
1537
1538 bool observe_safepoint = is_sfn;
1539 // Remember the start of the last call in a basic block
1540 if (is_mcall) {
1541 MachCallNode *mcall = mach->as_MachCall();
1542
1543 // This destination address is NOT PC-relative
1544 mcall->method_set((intptr_t)mcall->entry_point());
1545
1546 // Save the return address
1547 call_returns[block->_pre_order] = current_offset + mcall->ret_addr_offset();
1548
1549 observe_safepoint = mcall->guaranteed_safepoint();
1550 }
1551
1552 // sfn will be valid whenever mcall is valid now because of inheritance
1553 if (observe_safepoint) {
1554 // Handle special safepoint nodes for synchronization
1555 if (!is_mcall) {
1556 MachSafePointNode *sfn = mach->as_MachSafePoint();
1557 // !!!!! Stubs only need an oopmap right now, so bail out
1558 if (sfn->jvms()->method() == nullptr) {
1559 // Write the oopmap directly to the code blob??!!
1560 continue;
1561 }
1562 } // End synchronization
1563
1564 non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1565 current_offset);
1566 Process_OopMap_Node(mach, current_offset);
1567 } // End if safepoint
1568
1569 // If this is a null check, then add the start of the previous instruction to the list
1570 else if( mach->is_MachNullCheck() ) {
1571 inct_starts[inct_cnt++] = previous_offset;
1572 }
1573
1574 // If this is a branch, then fill in the label with the target BB's label
1575 else if (mach->is_MachBranch()) {
1576 // This requires the TRUE branch target be in succs[0]
1577 uint block_num = block->non_connector_successor(0)->_pre_order;
1578
1579 // Try to replace long branch,
1580 // it is mostly for back branches since forward branch's
1581 // distance is not updated yet.
1582 if (mach->may_be_short_branch()) {
1583 int br_size = n->size(C->regalloc());
1584 int offset = blk_starts[block_num] - current_offset;
1585 if (block_num >= i) {
1586 // Current and following block's offset are not
1587 // finalized yet, adjust distance by the difference
1588 // between calculated and final offsets of current block.
1589 offset -= (blk_starts[i] - blk_offset);
1590 }
1591 // In the following code a nop could be inserted before
1592 // the branch which will increase the backward distance.
1593 bool needs_padding = (current_offset == last_avoid_back_to_back_offset);
1594 if (needs_padding && offset <= 0)
1595 offset -= nop_size;
1596
1597 if (C->matcher()->is_short_branch_offset(mach->rule(), br_size, offset)) {
1598 // We've got a winner. Replace this branch.
1599 MachNode* replacement = mach->as_MachBranch()->short_branch_version();
1600
1601 // Update the jmp_size.
1602 int new_size = replacement->size(C->regalloc());
1603 assert((br_size - new_size) >= (int)nop_size, "short_branch size should be smaller");
1604 // Insert padding between avoid_back_to_back branches.
1605 if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
1606 MachNode *nop = new MachNopNode();
1607 block->insert_node(nop, j++);
1608 C->cfg()->map_node_to_block(nop, block);
1609 last_inst++;
1610 nop->emit(masm, C->regalloc());
1611 masm->code()->flush_bundle(true);
1612 current_offset = masm->offset();
1613 }
1614 #ifdef ASSERT
1615 jmp_target[i] = block_num;
1616 jmp_offset[i] = current_offset - blk_offset;
1617 jmp_size[i] = new_size;
1618 jmp_rule[i] = mach->rule();
1619 #endif
1620 block->map_node(replacement, j);
1621 mach->subsume_by(replacement, C);
1622 n = replacement;
1623 mach = replacement;
1624 }
1625 }
1626 mach->as_MachBranch()->label_set( &blk_labels[block_num], block_num );
1627 } else if (mach->ideal_Opcode() == Op_Jump) {
1628 for (uint h = 0; h < block->_num_succs; h++) {
1629 Block* succs_block = block->_succs[h];
1630 for (uint j = 1; j < succs_block->num_preds(); j++) {
1631 Node* jpn = succs_block->pred(j);
1632 if (jpn->is_JumpProj() && jpn->in(0) == mach) {
1633 uint block_num = succs_block->non_connector()->_pre_order;
1634 Label *blkLabel = &blk_labels[block_num];
1635 mach->add_case_label(jpn->as_JumpProj()->proj_no(), blkLabel);
1636 }
1637 }
1638 }
1639 } else if (!n->is_Proj()) {
1640 // Remember the beginning of the previous instruction, in case
1641 // it's followed by a flag-kill and a null-check. Happens on
1642 // Intel all the time, with add-to-memory kind of opcodes.
1643 previous_offset = current_offset;
1644 }
1645
1646 // Not an else-if!
1647 // If this is a trap based cmp then add its offset to the list.
1648 if (mach->is_TrapBasedCheckNode()) {
1649 inct_starts[inct_cnt++] = current_offset;
1650 }
1651 }
1652
1653 // Verify that there is sufficient space remaining
1654 masm->code()->insts()->maybe_expand_to_ensure_remaining(max_inst_size());
1655 if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1656 C->record_failure("CodeCache is full");
1657 return;
1658 }
1659
1660 // Save the offset for the listing
1661 #if defined(SUPPORT_OPTO_ASSEMBLY)
1662 if ((node_offsets != nullptr) && (n->_idx < node_offset_limit)) {
1663 node_offsets[n->_idx] = masm->offset();
1664 }
1665 #endif
1666 assert(!C->failing_internal() || C->failure_is_artificial(), "Should not reach here if failing.");
1667
1668 // "Normal" instruction case
1669 DEBUG_ONLY(uint instr_offset = masm->offset());
1670 n->emit(masm, C->regalloc());
1671 current_offset = masm->offset();
1672
1673 // Above we only verified that there is enough space in the instruction section.
1674 // However, the instruction may emit stubs that cause code buffer expansion.
1675 // Bail out here if expansion failed due to a lack of code cache space.
1676 if (C->failing()) {
1677 return;
1678 }
1679
1680 assert(!is_mcall || (call_returns[block->_pre_order] <= (uint)current_offset),
1681 "ret_addr_offset() not within emitted code");
1682
1683 #ifdef ASSERT
1684 uint n_size = n->size(C->regalloc());
1685 if (n_size < (current_offset-instr_offset)) {
1686 MachNode* mach = n->as_Mach();
1687 n->dump();
1688 mach->dump_format(C->regalloc(), tty);
1689 tty->print_cr(" n_size (%d), current_offset (%d), instr_offset (%d)", n_size, current_offset, instr_offset);
1690 Disassembler::decode(masm->code()->insts_begin() + instr_offset, masm->code()->insts_begin() + current_offset + 1, tty);
1691 tty->print_cr(" ------------------- ");
1692 BufferBlob* blob = this->scratch_buffer_blob();
1693 address blob_begin = blob->content_begin();
1694 Disassembler::decode(blob_begin, blob_begin + n_size + 1, tty);
1695 assert(false, "wrong size of mach node");
1696 }
1697 #endif
1698 non_safepoints.observe_instruction(n, current_offset);
1699
1700 // mcall is last "call" that can be a safepoint
1701 // record it so we can see if a poll will directly follow it
1702 // in which case we'll need a pad to make the PcDesc sites unique
1703 // see 5010568. This can be slightly inaccurate but conservative
1704 // in the case that return address is not actually at current_offset.
1705 // This is a small price to pay.
1706
1707 if (is_mcall) {
1708 last_call_offset = current_offset;
1709 }
1710
1711 if (n->is_Mach() && n->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
1712 // Avoid back to back some instructions.
1713 last_avoid_back_to_back_offset = current_offset;
1714 }
1715
1716 } // End for all instructions in block
1717
1718 // If the next block is the top of a loop, pad this block out to align
1719 // the loop top a little. Helps prevent pipe stalls at loop back branches.
1720 if (i < nblocks-1) {
1721 Block *nb = C->cfg()->get_block(i + 1);
1722 int padding = nb->alignment_padding(current_offset);
1723 if( padding > 0 ) {
1724 MachNode *nop = new MachNopNode(padding / nop_size);
1725 block->insert_node(nop, block->number_of_nodes());
1726 C->cfg()->map_node_to_block(nop, block);
1727 nop->emit(masm, C->regalloc());
1728 current_offset = masm->offset();
1729 }
1730 }
1731 // Verify that the distance for generated before forward
1732 // short branches is still valid.
1733 guarantee((int)(blk_starts[i+1] - blk_starts[i]) >= (current_offset - blk_offset), "shouldn't increase block size");
1734
1735 // Save new block start offset
1736 blk_starts[i] = blk_offset;
1737 } // End of for all blocks
1738 blk_starts[nblocks] = current_offset;
1739
1740 non_safepoints.flush_at_end();
1741
1742 // Offset too large?
1743 if (C->failing()) return;
1744
1745 // Define a pseudo-label at the end of the code
1746 masm->bind( blk_labels[nblocks] );
1747
1748 // Compute the size of the first block
1749 _first_block_size = blk_labels[1].loc_pos() - blk_labels[0].loc_pos();
1750
1751 #ifdef ASSERT
1752 for (uint i = 0; i < nblocks; i++) { // For all blocks
1753 if (jmp_target[i] != 0) {
1754 int br_size = jmp_size[i];
1755 int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
1756 if (!C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
1757 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]);
1758 assert(false, "Displacement too large for short jmp");
1759 }
1760 }
1761 }
1762 #endif
1763
1764 if (!masm->code()->finalize_stubs()) {
1765 C->record_failure("CodeCache is full");
1766 return;
1767 }
1768
1769 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1770 bs->emit_stubs(*masm->code());
1771 if (C->failing()) return;
1772
1773 // Fill in stubs.
1774 assert(masm->inst_mark() == nullptr, "should be.");
1775 _stub_list.emit(*masm);
1776 if (C->failing()) return;
1777
1778 #ifndef PRODUCT
1779 // Information on the size of the method, without the extraneous code
1780 Scheduling::increment_method_size(masm->offset());
1781 #endif
1782
1783 // ------------------
1784 // Fill in exception table entries.
1785 FillExceptionTables(inct_cnt, call_returns, inct_starts, blk_labels);
1786
1787 // Only java methods have exception handlers and deopt handlers
1788 // class HandlerImpl is platform-specific and defined in the *.ad files.
1789 if (C->method()) {
1790 if (C->failing()) {
1791 return; // CodeBuffer::expand failed
1792 }
1793 // Emit the deopt handler code.
1794 _code_offsets.set_value(CodeOffsets::Deopt, HandlerImpl::emit_deopt_handler(masm));
1795 }
1796
1797 // One last check for failed CodeBuffer::expand:
1798 if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1799 C->record_failure("CodeCache is full");
1800 return;
1801 }
1802
1803 #if defined(SUPPORT_ABSTRACT_ASSEMBLY) || defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_OPTO_ASSEMBLY)
1804 if (C->print_assembly()) {
1805 tty->cr();
1806 tty->print_cr("============================= C2-compiled nmethod ==============================");
1807 }
1808 #endif
1809
1810 #if defined(SUPPORT_OPTO_ASSEMBLY)
1811 // Dump the assembly code, including basic-block numbers
1812 if (C->print_assembly()) {
1813 if (!VMThread::should_terminate()) {
1814 ResourceMark rm;
1815 stringStream method_metadata_str;
1816 if (C->method() != nullptr) {
1817 C->method()->print_metadata(&method_metadata_str);
1818 }
1819 stringStream dump_asm_str;
1820 dump_asm_on(&dump_asm_str, node_offsets, node_offset_limit);
1821
1822 // Make sure the end tag is coherent, and that xmlStream->pop_tag is done thread safe.
1823 NoSafepointVerifier nsv;
1824 ttyLocker ttyl;
1825 // This output goes directly to the tty, not the compiler log.
1826 // To enable tools to match it up with the compilation activity,
1827 // be sure to tag this tty output with the compile ID.
1828 if (xtty != nullptr) {
1829 xtty->head("opto_assembly compile_id='%d'%s", C->compile_id(),
1830 C->is_osr_compilation() ? " compile_kind='osr'" :
1831 (C->for_preload() ? " compile_kind='AP'" : ""));
1832 }
1833 const char* is_aot = C->env()->is_precompile() ? (C->for_preload() ? "(AP) " : "(A) -") : "-----";
1834 if (C->method() != nullptr) {
1835 tty->print_cr("----------------------- MetaData before Compile_id = %d %s-------------------", C->compile_id(), is_aot);
1836 tty->print_raw(method_metadata_str.freeze());
1837 } else if (C->stub_name() != nullptr) {
1838 tty->print_cr("----------------------------- RuntimeStub %s -------------------------------", C->stub_name());
1839 }
1840 tty->cr();
1841 tty->print_cr("------------------------ OptoAssembly for Compile_id = %d %s------------------", C->compile_id(), is_aot);
1842 tty->print_raw(dump_asm_str.freeze());
1843 tty->print_cr("--------------------------------------------------------------------------------");
1844 if (xtty != nullptr) {
1845 xtty->tail("opto_assembly");
1846 }
1847 }
1848 }
1849 #endif
1850 }
1851
1852 void PhaseOutput::FillExceptionTables(uint cnt, uint *call_returns, uint *inct_starts, Label *blk_labels) {
1853 _inc_table.set_size(cnt);
1854
1855 uint inct_cnt = 0;
1856 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
1857 Block* block = C->cfg()->get_block(i);
1858 Node *n = nullptr;
1859 int j;
1860
1861 // Find the branch; ignore trailing NOPs.
1862 for (j = block->number_of_nodes() - 1; j >= 0; j--) {
1863 n = block->get_node(j);
1864 if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con) {
1865 break;
1866 }
1867 }
1868
1869 // If we didn't find anything, continue
1870 if (j < 0) {
1871 continue;
1872 }
1873
1874 // Compute ExceptionHandlerTable subtable entry and add it
1875 // (skip empty blocks)
1876 if (n->is_Catch()) {
1877
1878 // Get the offset of the return from the call
1879 uint call_return = call_returns[block->_pre_order];
1880 #ifdef ASSERT
1881 assert( call_return > 0, "no call seen for this basic block" );
1882 while (block->get_node(--j)->is_MachProj()) ;
1883 assert(block->get_node(j)->is_MachCall(), "CatchProj must follow call");
1884 #endif
1885 // last instruction is a CatchNode, find it's CatchProjNodes
1886 int nof_succs = block->_num_succs;
1887 // allocate space
1888 GrowableArray<intptr_t> handler_bcis(nof_succs);
1889 GrowableArray<intptr_t> handler_pcos(nof_succs);
1890 // iterate through all successors
1891 for (int j = 0; j < nof_succs; j++) {
1892 Block* s = block->_succs[j];
1893 bool found_p = false;
1894 for (uint k = 1; k < s->num_preds(); k++) {
1895 Node* pk = s->pred(k);
1896 if (pk->is_CatchProj() && pk->in(0) == n) {
1897 const CatchProjNode* p = pk->as_CatchProj();
1898 found_p = true;
1899 // add the corresponding handler bci & pco information
1900 if (p->_con != CatchProjNode::fall_through_index) {
1901 // p leads to an exception handler (and is not fall through)
1902 assert(s == C->cfg()->get_block(s->_pre_order), "bad numbering");
1903 // no duplicates, please
1904 if (!handler_bcis.contains(p->handler_bci())) {
1905 uint block_num = s->non_connector()->_pre_order;
1906 handler_bcis.append(p->handler_bci());
1907 handler_pcos.append(blk_labels[block_num].loc_pos());
1908 }
1909 }
1910 }
1911 }
1912 assert(found_p, "no matching predecessor found");
1913 // Note: Due to empty block removal, one block may have
1914 // several CatchProj inputs, from the same Catch.
1915 }
1916
1917 // Set the offset of the return from the call
1918 assert(handler_bcis.find(-1) != -1, "must have default handler");
1919 _handler_table.add_subtable(call_return, &handler_bcis, nullptr, &handler_pcos);
1920 continue;
1921 }
1922
1923 // Handle implicit null exception table updates
1924 if (n->is_MachNullCheck()) {
1925 MachNode* access = n->in(1)->as_Mach();
1926 assert(access->barrier_data() == 0 ||
1927 access->is_late_expanded_null_check_candidate(),
1928 "Implicit null checks on memory accesses with barriers are only supported on nodes explicitly marked as null-check candidates");
1929 uint block_num = block->non_connector_successor(0)->_pre_order;
1930 _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
1931 continue;
1932 }
1933 // Handle implicit exception table updates: trap instructions.
1934 if (n->is_Mach() && n->as_Mach()->is_TrapBasedCheckNode()) {
1935 uint block_num = block->non_connector_successor(0)->_pre_order;
1936 _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
1937 continue;
1938 }
1939 } // End of for all blocks fill in exception table entries
1940 }
1941
1942 // Static Variables
1943 #ifndef PRODUCT
1944 uint Scheduling::_total_nop_size = 0;
1945 uint Scheduling::_total_method_size = 0;
1946 uint Scheduling::_total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
1947 #endif
1948
1949 // Initializer for class Scheduling
1950
1951 Scheduling::Scheduling(Arena *arena, Compile &compile)
1952 : _arena(arena),
1953 _cfg(compile.cfg()),
1954 _regalloc(compile.regalloc()),
1955 _scheduled(arena),
1956 _available(arena),
1957 _reg_node(arena),
1958 _pinch_free_list(arena),
1959 _next_node(nullptr),
1960 _bundle_instr_count(0),
1961 _bundle_cycle_number(0),
1962 _bundle_use(0, 0, resource_count, &_bundle_use_elements[0])
1963 {
1964 // Save the count
1965 _node_bundling_limit = compile.unique();
1966 uint node_max = _regalloc->node_regs_max_index();
1967
1968 compile.output()->set_node_bundling_limit(_node_bundling_limit);
1969
1970 // This one is persistent within the Compile class
1971 _node_bundling_base = NEW_ARENA_ARRAY(compile.comp_arena(), Bundle, node_max);
1972
1973 // Allocate space for fixed-size arrays
1974 _uses = NEW_ARENA_ARRAY(arena, short, node_max);
1975 _current_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
1976
1977 // Clear the arrays
1978 for (uint i = 0; i < node_max; i++) {
1979 ::new (&_node_bundling_base[i]) Bundle();
1980 }
1981 memset(_uses, 0, node_max * sizeof(short));
1982 memset(_current_latency, 0, node_max * sizeof(unsigned short));
1983
1984 // Clear the bundling information
1985 memcpy(_bundle_use_elements, Pipeline_Use::elaborated_elements, sizeof(Pipeline_Use::elaborated_elements));
1986
1987 // Get the last node
1988 Block* block = _cfg->get_block(_cfg->number_of_blocks() - 1);
1989
1990 _next_node = block->get_node(block->number_of_nodes() - 1);
1991 }
1992
1993 // Step ahead "i" cycles
1994 void Scheduling::step(uint i) {
1995
1996 Bundle *bundle = node_bundling(_next_node);
1997 bundle->set_starts_bundle();
1998
1999 // Update the bundle record, but leave the flags information alone
2000 if (_bundle_instr_count > 0) {
2001 bundle->set_instr_count(_bundle_instr_count);
2002 bundle->set_resources_used(_bundle_use.resourcesUsed());
2003 }
2004
2005 // Update the state information
2006 _bundle_instr_count = 0;
2007 _bundle_cycle_number += i;
2008 _bundle_use.step(i);
2009 }
2010
2011 void Scheduling::step_and_clear() {
2012 Bundle *bundle = node_bundling(_next_node);
2013 bundle->set_starts_bundle();
2014
2015 // Update the bundle record
2016 if (_bundle_instr_count > 0) {
2017 bundle->set_instr_count(_bundle_instr_count);
2018 bundle->set_resources_used(_bundle_use.resourcesUsed());
2019
2020 _bundle_cycle_number += 1;
2021 }
2022
2023 // Clear the bundling information
2024 _bundle_instr_count = 0;
2025 _bundle_use.reset();
2026
2027 memcpy(_bundle_use_elements,
2028 Pipeline_Use::elaborated_elements,
2029 sizeof(Pipeline_Use::elaborated_elements));
2030 }
2031
2032 // Perform instruction scheduling and bundling over the sequence of
2033 // instructions in backwards order.
2034 void PhaseOutput::ScheduleAndBundle() {
2035
2036 // Don't optimize this if it isn't a method
2037 if (!C->method())
2038 return;
2039
2040 // Don't optimize this if scheduling is disabled
2041 if (!C->do_scheduling())
2042 return;
2043
2044 // Scheduling code works only with pairs (8 bytes) maximum.
2045 // And when the scalable vector register is used, we may spill/unspill
2046 // the whole reg regardless of the max vector size.
2047 if (C->max_vector_size() > 8 ||
2048 (C->max_vector_size() > 0 && Matcher::supports_scalable_vector())) {
2049 return;
2050 }
2051
2052 Compile::TracePhase tp(_t_instrSched);
2053
2054 // Create a data structure for all the scheduling information
2055 Scheduling scheduling(Thread::current()->resource_area(), *C);
2056
2057 // Walk backwards over each basic block, computing the needed alignment
2058 // Walk over all the basic blocks
2059 scheduling.DoScheduling();
2060
2061 #ifndef PRODUCT
2062 if (C->trace_opto_output()) {
2063 // Buffer and print all at once
2064 ResourceMark rm;
2065 stringStream ss;
2066 ss.print("\n---- After ScheduleAndBundle ----\n");
2067 print_scheduling(&ss);
2068 tty->print("%s", ss.as_string());
2069 }
2070 #endif
2071 }
2072
2073 #ifndef PRODUCT
2074 // Separated out so that it can be called directly from debugger
2075 void PhaseOutput::print_scheduling() {
2076 print_scheduling(tty);
2077 }
2078
2079 void PhaseOutput::print_scheduling(outputStream* output_stream) {
2080 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
2081 output_stream->print("\nBB#%03d:\n", i);
2082 Block* block = C->cfg()->get_block(i);
2083 for (uint j = 0; j < block->number_of_nodes(); j++) {
2084 Node* n = block->get_node(j);
2085 OptoReg::Name reg = C->regalloc()->get_reg_first(n);
2086 output_stream->print(" %-6s ", reg >= 0 && reg < REG_COUNT ? Matcher::regName[reg] : "");
2087 n->dump("\n", false, output_stream);
2088 }
2089 }
2090 }
2091 #endif
2092
2093 // See if this node fits into the present instruction bundle
2094 bool Scheduling::NodeFitsInBundle(Node *n) {
2095 uint n_idx = n->_idx;
2096
2097 // If the node cannot be scheduled this cycle, skip it
2098 if (_current_latency[n_idx] > _bundle_cycle_number) {
2099 #ifndef PRODUCT
2100 if (_cfg->C->trace_opto_output())
2101 tty->print("# NodeFitsInBundle [%4d]: FALSE; latency %4d > %d\n",
2102 n->_idx, _current_latency[n_idx], _bundle_cycle_number);
2103 #endif
2104 return (false);
2105 }
2106
2107 const Pipeline *node_pipeline = n->pipeline();
2108
2109 uint instruction_count = node_pipeline->instructionCount();
2110 if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2111 instruction_count = 0;
2112
2113 if (_bundle_instr_count + instruction_count > Pipeline::_max_instrs_per_cycle) {
2114 #ifndef PRODUCT
2115 if (_cfg->C->trace_opto_output())
2116 tty->print("# NodeFitsInBundle [%4d]: FALSE; too many instructions: %d > %d\n",
2117 n->_idx, _bundle_instr_count + instruction_count, Pipeline::_max_instrs_per_cycle);
2118 #endif
2119 return (false);
2120 }
2121
2122 // Don't allow non-machine nodes to be handled this way
2123 if (!n->is_Mach() && instruction_count == 0)
2124 return (false);
2125
2126 // See if there is any overlap
2127 uint delay = _bundle_use.full_latency(0, node_pipeline->resourceUse());
2128
2129 if (delay > 0) {
2130 #ifndef PRODUCT
2131 if (_cfg->C->trace_opto_output())
2132 tty->print("# NodeFitsInBundle [%4d]: FALSE; functional units overlap\n", n_idx);
2133 #endif
2134 return false;
2135 }
2136
2137 #ifndef PRODUCT
2138 if (_cfg->C->trace_opto_output())
2139 tty->print("# NodeFitsInBundle [%4d]: TRUE\n", n_idx);
2140 #endif
2141
2142 return true;
2143 }
2144
2145 Node * Scheduling::ChooseNodeToBundle() {
2146 uint siz = _available.size();
2147
2148 if (siz == 0) {
2149
2150 #ifndef PRODUCT
2151 if (_cfg->C->trace_opto_output())
2152 tty->print("# ChooseNodeToBundle: null\n");
2153 #endif
2154 return (nullptr);
2155 }
2156
2157 // Fast path, if only 1 instruction in the bundle
2158 if (siz == 1) {
2159 #ifndef PRODUCT
2160 if (_cfg->C->trace_opto_output()) {
2161 tty->print("# ChooseNodeToBundle (only 1): ");
2162 _available[0]->dump();
2163 }
2164 #endif
2165 return (_available[0]);
2166 }
2167
2168 // Don't bother, if the bundle is already full
2169 if (_bundle_instr_count < Pipeline::_max_instrs_per_cycle) {
2170 for ( uint i = 0; i < siz; i++ ) {
2171 Node *n = _available[i];
2172
2173 // Skip projections, we'll handle them another way
2174 if (n->is_Proj())
2175 continue;
2176
2177 // This presupposed that instructions are inserted into the
2178 // available list in a legality order; i.e. instructions that
2179 // must be inserted first are at the head of the list
2180 if (NodeFitsInBundle(n)) {
2181 #ifndef PRODUCT
2182 if (_cfg->C->trace_opto_output()) {
2183 tty->print("# ChooseNodeToBundle: ");
2184 n->dump();
2185 }
2186 #endif
2187 return (n);
2188 }
2189 }
2190 }
2191
2192 // Nothing fits in this bundle, choose the highest priority
2193 #ifndef PRODUCT
2194 if (_cfg->C->trace_opto_output()) {
2195 tty->print("# ChooseNodeToBundle: ");
2196 _available[0]->dump();
2197 }
2198 #endif
2199
2200 return _available[0];
2201 }
2202
2203 int Scheduling::compare_two_spill_nodes(Node* first, Node* second) {
2204 assert(first->is_MachSpillCopy() && second->is_MachSpillCopy(), "");
2205
2206 OptoReg::Name first_src_lo = _regalloc->get_reg_first(first->in(1));
2207 OptoReg::Name first_dst_lo = _regalloc->get_reg_first(first);
2208 OptoReg::Name second_src_lo = _regalloc->get_reg_first(second->in(1));
2209 OptoReg::Name second_dst_lo = _regalloc->get_reg_first(second);
2210
2211 // Comparison between stack -> reg and stack -> reg
2212 if (OptoReg::is_stack(first_src_lo) && OptoReg::is_stack(second_src_lo) &&
2213 OptoReg::is_reg(first_dst_lo) && OptoReg::is_reg(second_dst_lo)) {
2214 return _regalloc->reg2offset(first_src_lo) - _regalloc->reg2offset(second_src_lo);
2215 }
2216
2217 // Comparison between reg -> stack and reg -> stack
2218 if (OptoReg::is_stack(first_dst_lo) && OptoReg::is_stack(second_dst_lo) &&
2219 OptoReg::is_reg(first_src_lo) && OptoReg::is_reg(second_src_lo)) {
2220 return _regalloc->reg2offset(first_dst_lo) - _regalloc->reg2offset(second_dst_lo);
2221 }
2222
2223 return 0; // Not comparable
2224 }
2225
2226 void Scheduling::AddNodeToAvailableList(Node *n) {
2227 assert( !n->is_Proj(), "projections never directly made available" );
2228 #ifndef PRODUCT
2229 if (_cfg->C->trace_opto_output()) {
2230 tty->print("# AddNodeToAvailableList: ");
2231 n->dump();
2232 }
2233 #endif
2234
2235 int latency = _current_latency[n->_idx];
2236
2237 // Insert in latency order (insertion sort). If two MachSpillCopyNodes
2238 // for stack spilling or unspilling have the same latency, we sort
2239 // them in the order of stack offset. Some ports (e.g. aarch64) may also
2240 // have more opportunities to do ld/st merging
2241 uint i;
2242 for (i = 0; i < _available.size(); i++) {
2243 if (_current_latency[_available[i]->_idx] > latency) {
2244 break;
2245 } else if (_current_latency[_available[i]->_idx] == latency &&
2246 n->is_MachSpillCopy() && _available[i]->is_MachSpillCopy() &&
2247 compare_two_spill_nodes(n, _available[i]) > 0) {
2248 break;
2249 }
2250 }
2251
2252 // Special Check for compares following branches
2253 if( n->is_Mach() && _scheduled.size() > 0 ) {
2254 int op = n->as_Mach()->ideal_Opcode();
2255 Node *last = _scheduled[0];
2256 if( last->is_MachIf() && last->in(1) == n &&
2257 ( op == Op_CmpI ||
2258 op == Op_CmpU ||
2259 op == Op_CmpUL ||
2260 op == Op_CmpP ||
2261 op == Op_CmpF ||
2262 op == Op_CmpD ||
2263 op == Op_CmpL ) ) {
2264
2265 // Recalculate position, moving to front of same latency
2266 for ( i=0 ; i < _available.size(); i++ )
2267 if (_current_latency[_available[i]->_idx] >= latency)
2268 break;
2269 }
2270 }
2271
2272 // Insert the node in the available list
2273 _available.insert(i, n);
2274
2275 #ifndef PRODUCT
2276 if (_cfg->C->trace_opto_output())
2277 dump_available();
2278 #endif
2279 }
2280
2281 void Scheduling::DecrementUseCounts(Node *n, const Block *bb) {
2282 for ( uint i=0; i < n->len(); i++ ) {
2283 Node *def = n->in(i);
2284 if (!def) continue;
2285 if( def->is_Proj() ) // If this is a machine projection, then
2286 def = def->in(0); // propagate usage thru to the base instruction
2287
2288 if(_cfg->get_block_for_node(def) != bb) { // Ignore if not block-local
2289 continue;
2290 }
2291
2292 // Compute the latency
2293 uint l = _bundle_cycle_number + n->latency(i);
2294 if (_current_latency[def->_idx] < l)
2295 _current_latency[def->_idx] = l;
2296
2297 // If this does not have uses then schedule it
2298 if ((--_uses[def->_idx]) == 0)
2299 AddNodeToAvailableList(def);
2300 }
2301 }
2302
2303 void Scheduling::AddNodeToBundle(Node *n, const Block *bb) {
2304 #ifndef PRODUCT
2305 if (_cfg->C->trace_opto_output()) {
2306 tty->print("# AddNodeToBundle: ");
2307 n->dump();
2308 }
2309 #endif
2310
2311 // Remove this from the available list
2312 uint i;
2313 for (i = 0; i < _available.size(); i++)
2314 if (_available[i] == n)
2315 break;
2316 assert(i < _available.size(), "entry in _available list not found");
2317 _available.remove(i);
2318
2319 // See if this fits in the current bundle
2320 const Pipeline *node_pipeline = n->pipeline();
2321 const Pipeline_Use& node_usage = node_pipeline->resourceUse();
2322
2323
2324 // Get the number of instructions
2325 uint instruction_count = node_pipeline->instructionCount();
2326 if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2327 instruction_count = 0;
2328
2329 // Compute the latency information
2330 uint delay = 0;
2331
2332 if (instruction_count > 0 || !node_pipeline->mayHaveNoCode()) {
2333 int relative_latency = _current_latency[n->_idx] - _bundle_cycle_number;
2334 if (relative_latency < 0)
2335 relative_latency = 0;
2336
2337 delay = _bundle_use.full_latency(relative_latency, node_usage);
2338
2339 // Does not fit in this bundle, start a new one
2340 if (delay > 0) {
2341 step(delay);
2342
2343 #ifndef PRODUCT
2344 if (_cfg->C->trace_opto_output())
2345 tty->print("# *** STEP(%d) ***\n", delay);
2346 #endif
2347 }
2348 }
2349
2350 if (delay == 0) {
2351 if (node_pipeline->hasMultipleBundles()) {
2352 #ifndef PRODUCT
2353 if (_cfg->C->trace_opto_output())
2354 tty->print("# *** STEP(multiple instructions) ***\n");
2355 #endif
2356 step(1);
2357 }
2358
2359 else if (instruction_count + _bundle_instr_count > Pipeline::_max_instrs_per_cycle) {
2360 #ifndef PRODUCT
2361 if (_cfg->C->trace_opto_output())
2362 tty->print("# *** STEP(%d >= %d instructions) ***\n",
2363 instruction_count + _bundle_instr_count,
2364 Pipeline::_max_instrs_per_cycle);
2365 #endif
2366 step(1);
2367 }
2368 }
2369
2370 // Set the node's latency
2371 _current_latency[n->_idx] = _bundle_cycle_number;
2372
2373 // Now merge the functional unit information
2374 if (instruction_count > 0 || !node_pipeline->mayHaveNoCode())
2375 _bundle_use.add_usage(node_usage);
2376
2377 // Increment the number of instructions in this bundle
2378 _bundle_instr_count += instruction_count;
2379
2380 // Remember this node for later
2381 if (n->is_Mach())
2382 _next_node = n;
2383
2384 // It's possible to have a BoxLock in the graph and in the _bbs mapping but
2385 // not in the bb->_nodes array. This happens for debug-info-only BoxLocks.
2386 // 'Schedule' them (basically ignore in the schedule) but do not insert them
2387 // into the block. All other scheduled nodes get put in the schedule here.
2388 int op = n->Opcode();
2389 if( (op == Op_Node && n->req() == 0) || // anti-dependence node OR
2390 (op != Op_Node && // Not an unused antidepedence node and
2391 // not an unallocated boxlock
2392 (OptoReg::is_valid(_regalloc->get_reg_first(n)) || op != Op_BoxLock)) ) {
2393
2394 // Push any trailing projections
2395 if( bb->get_node(bb->number_of_nodes()-1) != n ) {
2396 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2397 Node *foi = n->fast_out(i);
2398 if( foi->is_Proj() )
2399 _scheduled.push(foi);
2400 }
2401 }
2402
2403 // Put the instruction in the schedule list
2404 _scheduled.push(n);
2405 }
2406
2407 #ifndef PRODUCT
2408 if (_cfg->C->trace_opto_output())
2409 dump_available();
2410 #endif
2411
2412 // Walk all the definitions, decrementing use counts, and
2413 // if a definition has a 0 use count, place it in the available list.
2414 DecrementUseCounts(n,bb);
2415 }
2416
2417 // This method sets the use count within a basic block. We will ignore all
2418 // uses outside the current basic block. As we are doing a backwards walk,
2419 // any node we reach that has a use count of 0 may be scheduled. This also
2420 // avoids the problem of cyclic references from phi nodes, as long as phi
2421 // nodes are at the front of the basic block. This method also initializes
2422 // the available list to the set of instructions that have no uses within this
2423 // basic block.
2424 void Scheduling::ComputeUseCount(const Block *bb) {
2425 #ifndef PRODUCT
2426 if (_cfg->C->trace_opto_output())
2427 tty->print("# -> ComputeUseCount\n");
2428 #endif
2429
2430 // Clear the list of available and scheduled instructions, just in case
2431 _available.clear();
2432 _scheduled.clear();
2433
2434 #ifdef ASSERT
2435 for( uint i=0; i < bb->number_of_nodes(); i++ )
2436 assert( _uses[bb->get_node(i)->_idx] == 0, "_use array not clean" );
2437 #endif
2438
2439 // Force the _uses count to never go to zero for unscheduable pieces
2440 // of the block
2441 for( uint k = 0; k < _bb_start; k++ )
2442 _uses[bb->get_node(k)->_idx] = 1;
2443 for( uint l = _bb_end; l < bb->number_of_nodes(); l++ )
2444 _uses[bb->get_node(l)->_idx] = 1;
2445
2446 // Iterate backwards over the instructions in the block. Don't count the
2447 // branch projections at end or the block header instructions.
2448 for( uint j = _bb_end-1; j >= _bb_start; j-- ) {
2449 Node *n = bb->get_node(j);
2450 if( n->is_Proj() ) continue; // Projections handled another way
2451
2452 // Account for all uses
2453 for ( uint k = 0; k < n->len(); k++ ) {
2454 Node *inp = n->in(k);
2455 if (!inp) continue;
2456 assert(inp != n, "no cycles allowed" );
2457 if (_cfg->get_block_for_node(inp) == bb) { // Block-local use?
2458 if (inp->is_Proj()) { // Skip through Proj's
2459 inp = inp->in(0);
2460 }
2461 ++_uses[inp->_idx]; // Count 1 block-local use
2462 }
2463 }
2464
2465 // If this instruction has a 0 use count, then it is available
2466 if (!_uses[n->_idx]) {
2467 _current_latency[n->_idx] = _bundle_cycle_number;
2468 AddNodeToAvailableList(n);
2469 }
2470
2471 #ifndef PRODUCT
2472 if (_cfg->C->trace_opto_output()) {
2473 tty->print("# uses: %3d: ", _uses[n->_idx]);
2474 n->dump();
2475 }
2476 #endif
2477 }
2478
2479 #ifndef PRODUCT
2480 if (_cfg->C->trace_opto_output())
2481 tty->print("# <- ComputeUseCount\n");
2482 #endif
2483 }
2484
2485 // This routine performs scheduling on each basic block in reverse order,
2486 // using instruction latencies and taking into account function unit
2487 // availability.
2488 void Scheduling::DoScheduling() {
2489 #ifndef PRODUCT
2490 if (_cfg->C->trace_opto_output())
2491 tty->print("# -> DoScheduling\n");
2492 #endif
2493
2494 Block *succ_bb = nullptr;
2495 Block *bb;
2496 Compile* C = Compile::current();
2497
2498 // Walk over all the basic blocks in reverse order
2499 for (int i = _cfg->number_of_blocks() - 1; i >= 0; succ_bb = bb, i--) {
2500 bb = _cfg->get_block(i);
2501
2502 #ifndef PRODUCT
2503 if (_cfg->C->trace_opto_output()) {
2504 tty->print("# Schedule BB#%03d (initial)\n", i);
2505 for (uint j = 0; j < bb->number_of_nodes(); j++) {
2506 bb->get_node(j)->dump();
2507 }
2508 }
2509 #endif
2510
2511 // On the head node, skip processing
2512 if (bb == _cfg->get_root_block()) {
2513 continue;
2514 }
2515
2516 // Skip empty, connector blocks
2517 if (bb->is_connector())
2518 continue;
2519
2520 // If the following block is not the sole successor of
2521 // this one, then reset the pipeline information
2522 if (bb->_num_succs != 1 || bb->non_connector_successor(0) != succ_bb) {
2523 #ifndef PRODUCT
2524 if (_cfg->C->trace_opto_output()) {
2525 tty->print("*** bundle start of next BB, node %d, for %d instructions\n",
2526 _next_node->_idx, _bundle_instr_count);
2527 }
2528 #endif
2529 step_and_clear();
2530 }
2531
2532 // Leave untouched the starting instruction, any Phis, a CreateEx node
2533 // or Top. bb->get_node(_bb_start) is the first schedulable instruction.
2534 _bb_end = bb->number_of_nodes()-1;
2535 for( _bb_start=1; _bb_start <= _bb_end; _bb_start++ ) {
2536 Node *n = bb->get_node(_bb_start);
2537 // Things not matched, like Phinodes and ProjNodes don't get scheduled.
2538 // Also, MachIdealNodes do not get scheduled
2539 if( !n->is_Mach() ) continue; // Skip non-machine nodes
2540 MachNode *mach = n->as_Mach();
2541 int iop = mach->ideal_Opcode();
2542 if( iop == Op_CreateEx ) continue; // CreateEx is pinned
2543 if( iop == Op_Con ) continue; // Do not schedule Top
2544 if( iop == Op_Node && // Do not schedule PhiNodes, ProjNodes
2545 mach->pipeline() == MachNode::pipeline_class() &&
2546 !n->is_SpillCopy() && !n->is_MachMerge() ) // Breakpoints, Prolog, etc
2547 continue;
2548 break; // Funny loop structure to be sure...
2549 }
2550 // Compute last "interesting" instruction in block - last instruction we
2551 // might schedule. _bb_end points just after last schedulable inst.
2552 Node *last = bb->get_node(_bb_end);
2553 // Ignore trailing NOPs.
2554 while (_bb_end > 0 && last->is_Mach() &&
2555 last->as_Mach()->ideal_Opcode() == Op_Con) {
2556 last = bb->get_node(--_bb_end);
2557 }
2558 assert(!last->is_Mach() || last->as_Mach()->ideal_Opcode() != Op_Con, "");
2559 if( last->is_Catch() ||
2560 (last->is_Mach() && last->as_Mach()->ideal_Opcode() == Op_Halt) ) {
2561 // There might be a prior call. Skip it.
2562 while (_bb_start < _bb_end && bb->get_node(--_bb_end)->is_MachProj());
2563 } else if( last->is_MachNullCheck() ) {
2564 // Backup so the last null-checked memory instruction is
2565 // outside the schedulable range. Skip over the nullcheck,
2566 // projection, and the memory nodes.
2567 Node *mem = last->in(1);
2568 do {
2569 _bb_end--;
2570 } while (mem != bb->get_node(_bb_end));
2571 } else {
2572 // Set _bb_end to point after last schedulable inst.
2573 _bb_end++;
2574 }
2575
2576 assert( _bb_start <= _bb_end, "inverted block ends" );
2577
2578 // Compute the register antidependencies for the basic block
2579 ComputeRegisterAntidependencies(bb);
2580 if (C->failing()) return; // too many D-U pinch points
2581
2582 // Compute the usage within the block, and set the list of all nodes
2583 // in the block that have no uses within the block.
2584 ComputeUseCount(bb);
2585
2586 // Schedule the remaining instructions in the block
2587 while ( _available.size() > 0 ) {
2588 Node *n = ChooseNodeToBundle();
2589 guarantee(n != nullptr, "no nodes available");
2590 AddNodeToBundle(n,bb);
2591 }
2592
2593 assert( _scheduled.size() == _bb_end - _bb_start, "wrong number of instructions" );
2594 #ifdef ASSERT
2595 for( uint l = _bb_start; l < _bb_end; l++ ) {
2596 Node *n = bb->get_node(l);
2597 uint m;
2598 for( m = 0; m < _bb_end-_bb_start; m++ )
2599 if( _scheduled[m] == n )
2600 break;
2601 assert( m < _bb_end-_bb_start, "instruction missing in schedule" );
2602 }
2603 #endif
2604
2605 // Now copy the instructions (in reverse order) back to the block
2606 for ( uint k = _bb_start; k < _bb_end; k++ )
2607 bb->map_node(_scheduled[_bb_end-k-1], k);
2608
2609 #ifndef PRODUCT
2610 if (_cfg->C->trace_opto_output()) {
2611 tty->print("# Schedule BB#%03d (final)\n", i);
2612 uint current = 0;
2613 for (uint j = 0; j < bb->number_of_nodes(); j++) {
2614 Node *n = bb->get_node(j);
2615 if( valid_bundle_info(n) ) {
2616 Bundle *bundle = node_bundling(n);
2617 if (bundle->instr_count() > 0) {
2618 tty->print("*** Bundle: ");
2619 bundle->dump();
2620 }
2621 n->dump();
2622 }
2623 }
2624 }
2625 #endif
2626 #ifdef ASSERT
2627 verify_good_schedule(bb,"after block local scheduling");
2628 #endif
2629 }
2630
2631 #ifndef PRODUCT
2632 if (_cfg->C->trace_opto_output())
2633 tty->print("# <- DoScheduling\n");
2634 #endif
2635
2636 // Record final node-bundling array location
2637 _regalloc->C->output()->set_node_bundling_base(_node_bundling_base);
2638
2639 } // end DoScheduling
2640
2641 // Verify that no live-range used in the block is killed in the block by a
2642 // wrong DEF. This doesn't verify live-ranges that span blocks.
2643
2644 // Check for edge existence. Used to avoid adding redundant precedence edges.
2645 static bool edge_from_to( Node *from, Node *to ) {
2646 for( uint i=0; i<from->len(); i++ )
2647 if( from->in(i) == to )
2648 return true;
2649 return false;
2650 }
2651
2652 #ifdef ASSERT
2653 void Scheduling::verify_do_def( Node *n, OptoReg::Name def, const char *msg ) {
2654 // Check for bad kills
2655 if( OptoReg::is_valid(def) ) { // Ignore stores & control flow
2656 Node *prior_use = _reg_node[def];
2657 if( prior_use && !edge_from_to(prior_use,n) ) {
2658 tty->print("%s = ",OptoReg::as_VMReg(def)->name());
2659 n->dump();
2660 tty->print_cr("...");
2661 prior_use->dump();
2662 assert(edge_from_to(prior_use,n), "%s", msg);
2663 }
2664 _reg_node.map(def,nullptr); // Kill live USEs
2665 }
2666 }
2667
2668 void Scheduling::verify_good_schedule( Block *b, const char *msg ) {
2669
2670 // Zap to something reasonable for the verify code
2671 _reg_node.clear();
2672
2673 // Walk over the block backwards. Check to make sure each DEF doesn't
2674 // kill a live value (other than the one it's supposed to). Add each
2675 // USE to the live set.
2676 for( uint i = b->number_of_nodes()-1; i >= _bb_start; i-- ) {
2677 Node *n = b->get_node(i);
2678 int n_op = n->Opcode();
2679 if( n_op == Op_MachProj && n->ideal_reg() == MachProjNode::fat_proj ) {
2680 // Fat-proj kills a slew of registers
2681 RegMaskIterator rmi(n->out_RegMask());
2682 while (rmi.has_next()) {
2683 OptoReg::Name kill = rmi.next();
2684 verify_do_def(n, kill, msg);
2685 }
2686 } else if( n_op != Op_Node ) { // Avoid brand new antidependence nodes
2687 // Get DEF'd registers the normal way
2688 verify_do_def( n, _regalloc->get_reg_first(n), msg );
2689 verify_do_def( n, _regalloc->get_reg_second(n), msg );
2690 }
2691
2692 // Now make all USEs live
2693 for( uint i=1; i<n->req(); i++ ) {
2694 Node *def = n->in(i);
2695 assert(def != nullptr, "input edge required");
2696 OptoReg::Name reg_lo = _regalloc->get_reg_first(def);
2697 OptoReg::Name reg_hi = _regalloc->get_reg_second(def);
2698 if( OptoReg::is_valid(reg_lo) ) {
2699 assert(!_reg_node[reg_lo] || edge_from_to(_reg_node[reg_lo],def), "%s", msg);
2700 _reg_node.map(reg_lo,n);
2701 }
2702 if( OptoReg::is_valid(reg_hi) ) {
2703 assert(!_reg_node[reg_hi] || edge_from_to(_reg_node[reg_hi],def), "%s", msg);
2704 _reg_node.map(reg_hi,n);
2705 }
2706 }
2707
2708 }
2709
2710 // Zap to something reasonable for the Antidependence code
2711 _reg_node.clear();
2712 }
2713 #endif
2714
2715 // Conditionally add precedence edges. Avoid putting edges on Projs.
2716 static void add_prec_edge_from_to( Node *from, Node *to ) {
2717 if( from->is_Proj() ) { // Put precedence edge on Proj's input
2718 assert( from->req() == 1 && (from->len() == 1 || from->in(1) == nullptr), "no precedence edges on projections" );
2719 from = from->in(0);
2720 }
2721 if( from != to && // No cycles (for things like LD L0,[L0+4] )
2722 !edge_from_to( from, to ) ) // Avoid duplicate edge
2723 from->add_prec(to);
2724 }
2725
2726 void Scheduling::anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def ) {
2727 if( !OptoReg::is_valid(def_reg) ) // Ignore stores & control flow
2728 return;
2729
2730 if (OptoReg::is_reg(def_reg)) {
2731 VMReg vmreg = OptoReg::as_VMReg(def_reg);
2732 if (vmreg->is_reg() && !vmreg->is_concrete() && !vmreg->prev()->is_concrete()) {
2733 // This is one of the high slots of a vector register.
2734 // ScheduleAndBundle already checked there are no live wide
2735 // vectors in this method so it can be safely ignored.
2736 return;
2737 }
2738 }
2739
2740 Node *pinch = _reg_node[def_reg]; // Get pinch point
2741 if ((pinch == nullptr) || _cfg->get_block_for_node(pinch) != b || // No pinch-point yet?
2742 is_def ) { // Check for a true def (not a kill)
2743 _reg_node.map(def_reg,def); // Record def/kill as the optimistic pinch-point
2744 return;
2745 }
2746
2747 Node *kill = def; // Rename 'def' to more descriptive 'kill'
2748 DEBUG_ONLY( def = (Node*)((intptr_t)0xdeadbeef); )
2749
2750 // After some number of kills there _may_ be a later def
2751 Node *later_def = nullptr;
2752
2753 Compile* C = Compile::current();
2754
2755 // Finding a kill requires a real pinch-point.
2756 // Check for not already having a pinch-point.
2757 // Pinch points are Op_Node's.
2758 if( pinch->Opcode() != Op_Node ) { // Or later-def/kill as pinch-point?
2759 later_def = pinch; // Must be def/kill as optimistic pinch-point
2760 if ( _pinch_free_list.size() > 0) {
2761 pinch = _pinch_free_list.pop();
2762 } else {
2763 pinch = new Node(1); // Pinch point to-be
2764 }
2765 if (pinch->_idx >= _regalloc->node_regs_max_index()) {
2766 DEBUG_ONLY( pinch->dump(); );
2767 assert(false, "too many D-U pinch points: %d >= %d", pinch->_idx, _regalloc->node_regs_max_index());
2768 _cfg->C->record_method_not_compilable("too many D-U pinch points");
2769 return;
2770 }
2771 _cfg->map_node_to_block(pinch, b); // Pretend it's valid in this block (lazy init)
2772 _reg_node.map(def_reg,pinch); // Record pinch-point
2773 //regalloc()->set_bad(pinch->_idx); // Already initialized this way.
2774 if( later_def->outcnt() == 0 || later_def->ideal_reg() == MachProjNode::fat_proj ) { // Distinguish def from kill
2775 pinch->init_req(0, C->top()); // set not null for the next call
2776 add_prec_edge_from_to(later_def,pinch); // Add edge from kill to pinch
2777 later_def = nullptr; // and no later def
2778 }
2779 pinch->set_req(0,later_def); // Hook later def so we can find it
2780 } else { // Else have valid pinch point
2781 if( pinch->in(0) ) // If there is a later-def
2782 later_def = pinch->in(0); // Get it
2783 }
2784
2785 // Add output-dependence edge from later def to kill
2786 if( later_def ) // If there is some original def
2787 add_prec_edge_from_to(later_def,kill); // Add edge from def to kill
2788
2789 // See if current kill is also a use, and so is forced to be the pinch-point.
2790 if( pinch->Opcode() == Op_Node ) {
2791 Node *uses = kill->is_Proj() ? kill->in(0) : kill;
2792 for( uint i=1; i<uses->req(); i++ ) {
2793 if( _regalloc->get_reg_first(uses->in(i)) == def_reg ||
2794 _regalloc->get_reg_second(uses->in(i)) == def_reg ) {
2795 // Yes, found a use/kill pinch-point
2796 pinch->set_req(0,nullptr); //
2797 pinch->replace_by(kill); // Move anti-dep edges up
2798 pinch = kill;
2799 _reg_node.map(def_reg,pinch);
2800 return;
2801 }
2802 }
2803 }
2804
2805 // Add edge from kill to pinch-point
2806 add_prec_edge_from_to(kill,pinch);
2807 }
2808
2809 void Scheduling::anti_do_use( Block *b, Node *use, OptoReg::Name use_reg ) {
2810 if( !OptoReg::is_valid(use_reg) ) // Ignore stores & control flow
2811 return;
2812 Node *pinch = _reg_node[use_reg]; // Get pinch point
2813 // Check for no later def_reg/kill in block
2814 if ((pinch != nullptr) && _cfg->get_block_for_node(pinch) == b &&
2815 // Use has to be block-local as well
2816 _cfg->get_block_for_node(use) == b) {
2817 if( pinch->Opcode() == Op_Node && // Real pinch-point (not optimistic?)
2818 pinch->req() == 1 ) { // pinch not yet in block?
2819 pinch->del_req(0); // yank pointer to later-def, also set flag
2820 // Insert the pinch-point in the block just after the last use
2821 b->insert_node(pinch, b->find_node(use) + 1);
2822 _bb_end++; // Increase size scheduled region in block
2823 }
2824
2825 add_prec_edge_from_to(pinch,use);
2826 }
2827 }
2828
2829 // We insert antidependences between the reads and following write of
2830 // allocated registers to prevent illegal code motion. Hopefully, the
2831 // number of added references should be fairly small, especially as we
2832 // are only adding references within the current basic block.
2833 void Scheduling::ComputeRegisterAntidependencies(Block *b) {
2834
2835 #ifdef ASSERT
2836 verify_good_schedule(b,"before block local scheduling");
2837 #endif
2838
2839 // A valid schedule, for each register independently, is an endless cycle
2840 // of: a def, then some uses (connected to the def by true dependencies),
2841 // then some kills (defs with no uses), finally the cycle repeats with a new
2842 // def. The uses are allowed to float relative to each other, as are the
2843 // kills. No use is allowed to slide past a kill (or def). This requires
2844 // antidependencies between all uses of a single def and all kills that
2845 // follow, up to the next def. More edges are redundant, because later defs
2846 // & kills are already serialized with true or antidependencies. To keep
2847 // the edge count down, we add a 'pinch point' node if there's more than
2848 // one use or more than one kill/def.
2849
2850 // We add dependencies in one bottom-up pass.
2851
2852 // For each instruction we handle it's DEFs/KILLs, then it's USEs.
2853
2854 // For each DEF/KILL, we check to see if there's a prior DEF/KILL for this
2855 // register. If not, we record the DEF/KILL in _reg_node, the
2856 // register-to-def mapping. If there is a prior DEF/KILL, we insert a
2857 // "pinch point", a new Node that's in the graph but not in the block.
2858 // We put edges from the prior and current DEF/KILLs to the pinch point.
2859 // We put the pinch point in _reg_node. If there's already a pinch point
2860 // we merely add an edge from the current DEF/KILL to the pinch point.
2861
2862 // After doing the DEF/KILLs, we handle USEs. For each used register, we
2863 // put an edge from the pinch point to the USE.
2864
2865 // To be expedient, the _reg_node array is pre-allocated for the whole
2866 // compilation. _reg_node is lazily initialized; it either contains a null,
2867 // or a valid def/kill/pinch-point, or a leftover node from some prior
2868 // block. Leftover node from some prior block is treated like a null (no
2869 // prior def, so no anti-dependence needed). Valid def is distinguished by
2870 // it being in the current block.
2871 bool fat_proj_seen = false;
2872 uint last_safept = _bb_end-1;
2873 Node* end_node = (_bb_end-1 >= _bb_start) ? b->get_node(last_safept) : nullptr;
2874 Node* last_safept_node = end_node;
2875 for( uint i = _bb_end-1; i >= _bb_start; i-- ) {
2876 Node *n = b->get_node(i);
2877 int is_def = n->outcnt(); // def if some uses prior to adding precedence edges
2878 if( n->is_MachProj() && n->ideal_reg() == MachProjNode::fat_proj ) {
2879 // Fat-proj kills a slew of registers
2880 // This can add edges to 'n' and obscure whether or not it was a def,
2881 // hence the is_def flag.
2882 fat_proj_seen = true;
2883 RegMaskIterator rmi(n->out_RegMask());
2884 while (rmi.has_next()) {
2885 OptoReg::Name kill = rmi.next();
2886 anti_do_def(b, n, kill, is_def);
2887 }
2888 } else {
2889 // Get DEF'd registers the normal way
2890 anti_do_def( b, n, _regalloc->get_reg_first(n), is_def );
2891 anti_do_def( b, n, _regalloc->get_reg_second(n), is_def );
2892 }
2893
2894 // Kill projections on a branch should appear to occur on the
2895 // branch, not afterwards, so grab the masks from the projections
2896 // and process them.
2897 if (n->is_MachBranch() || (n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_Jump)) {
2898 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2899 Node* use = n->fast_out(i);
2900 if (use->is_Proj()) {
2901 RegMaskIterator rmi(use->out_RegMask());
2902 while (rmi.has_next()) {
2903 OptoReg::Name kill = rmi.next();
2904 anti_do_def(b, n, kill, false);
2905 }
2906 }
2907 }
2908 }
2909
2910 // Check each register used by this instruction for a following DEF/KILL
2911 // that must occur afterward and requires an anti-dependence edge.
2912 for( uint j=0; j<n->req(); j++ ) {
2913 Node *def = n->in(j);
2914 if( def ) {
2915 assert( !def->is_MachProj() || def->ideal_reg() != MachProjNode::fat_proj, "" );
2916 anti_do_use( b, n, _regalloc->get_reg_first(def) );
2917 anti_do_use( b, n, _regalloc->get_reg_second(def) );
2918 }
2919 }
2920 // Do not allow defs of new derived values to float above GC
2921 // points unless the base is definitely available at the GC point.
2922
2923 Node *m = b->get_node(i);
2924
2925 // Add precedence edge from following safepoint to use of derived pointer
2926 if( last_safept_node != end_node &&
2927 m != last_safept_node) {
2928 for (uint k = 1; k < m->req(); k++) {
2929 const Type *t = m->in(k)->bottom_type();
2930 if( t->isa_oop_ptr() &&
2931 t->is_ptr()->offset() != 0 ) {
2932 last_safept_node->add_prec( m );
2933 break;
2934 }
2935 }
2936 }
2937
2938 if( n->jvms() ) { // Precedence edge from derived to safept
2939 // Check if last_safept_node was moved by pinch-point insertion in anti_do_use()
2940 if( b->get_node(last_safept) != last_safept_node ) {
2941 last_safept = b->find_node(last_safept_node);
2942 }
2943 for( uint j=last_safept; j > i; j-- ) {
2944 Node *mach = b->get_node(j);
2945 if( mach->is_Mach() && mach->as_Mach()->ideal_Opcode() == Op_AddP )
2946 mach->add_prec( n );
2947 }
2948 last_safept = i;
2949 last_safept_node = m;
2950 }
2951 }
2952
2953 if (fat_proj_seen) {
2954 // Garbage collect pinch nodes that were not consumed.
2955 // They are usually created by a fat kill MachProj for a call.
2956 garbage_collect_pinch_nodes();
2957 }
2958 }
2959
2960 // Garbage collect pinch nodes for reuse by other blocks.
2961 //
2962 // The block scheduler's insertion of anti-dependence
2963 // edges creates many pinch nodes when the block contains
2964 // 2 or more Calls. A pinch node is used to prevent a
2965 // combinatorial explosion of edges. If a set of kills for a
2966 // register is anti-dependent on a set of uses (or defs), rather
2967 // than adding an edge in the graph between each pair of kill
2968 // and use (or def), a pinch is inserted between them:
2969 //
2970 // use1 use2 use3
2971 // \ | /
2972 // \ | /
2973 // pinch
2974 // / | \
2975 // / | \
2976 // kill1 kill2 kill3
2977 //
2978 // One pinch node is created per register killed when
2979 // the second call is encountered during a backwards pass
2980 // over the block. Most of these pinch nodes are never
2981 // wired into the graph because the register is never
2982 // used or def'ed in the block.
2983 //
2984 void Scheduling::garbage_collect_pinch_nodes() {
2985 #ifndef PRODUCT
2986 if (_cfg->C->trace_opto_output()) tty->print("Reclaimed pinch nodes:");
2987 #endif
2988 int trace_cnt = 0;
2989 for (uint k = 0; k < _reg_node.max(); k++) {
2990 Node* pinch = _reg_node[k];
2991 if ((pinch != nullptr) && pinch->Opcode() == Op_Node &&
2992 // no predecence input edges
2993 (pinch->req() == pinch->len() || pinch->in(pinch->req()) == nullptr) ) {
2994 cleanup_pinch(pinch);
2995 _pinch_free_list.push(pinch);
2996 _reg_node.map(k, nullptr);
2997 #ifndef PRODUCT
2998 if (_cfg->C->trace_opto_output()) {
2999 trace_cnt++;
3000 if (trace_cnt > 40) {
3001 tty->print("\n");
3002 trace_cnt = 0;
3003 }
3004 tty->print(" %d", pinch->_idx);
3005 }
3006 #endif
3007 }
3008 }
3009 #ifndef PRODUCT
3010 if (_cfg->C->trace_opto_output()) tty->print("\n");
3011 #endif
3012 }
3013
3014 // Clean up a pinch node for reuse.
3015 void Scheduling::cleanup_pinch( Node *pinch ) {
3016 assert (pinch && pinch->Opcode() == Op_Node && pinch->req() == 1, "just checking");
3017
3018 for (DUIterator_Last imin, i = pinch->last_outs(imin); i >= imin; ) {
3019 Node* use = pinch->last_out(i);
3020 uint uses_found = 0;
3021 for (uint j = use->req(); j < use->len(); j++) {
3022 if (use->in(j) == pinch) {
3023 use->rm_prec(j);
3024 uses_found++;
3025 }
3026 }
3027 assert(uses_found > 0, "must be a precedence edge");
3028 i -= uses_found; // we deleted 1 or more copies of this edge
3029 }
3030 // May have a later_def entry
3031 pinch->set_req(0, nullptr);
3032 }
3033
3034 #ifndef PRODUCT
3035
3036 void Scheduling::dump_available() const {
3037 tty->print("#Availist ");
3038 for (uint i = 0; i < _available.size(); i++)
3039 tty->print(" N%d/l%d", _available[i]->_idx,_current_latency[_available[i]->_idx]);
3040 tty->cr();
3041 }
3042
3043 // Print Scheduling Statistics
3044 void Scheduling::print_statistics() {
3045 // Print the size added by nops for bundling
3046 tty->print("Nops added %d bytes to total of %d bytes",
3047 _total_nop_size, _total_method_size);
3048 if (_total_method_size > 0)
3049 tty->print(", for %.2f%%",
3050 ((double)_total_nop_size) / ((double) _total_method_size) * 100.0);
3051 tty->print("\n");
3052
3053 uint total_instructions = 0, total_bundles = 0;
3054
3055 for (uint i = 1; i <= Pipeline::_max_instrs_per_cycle; i++) {
3056 uint bundle_count = _total_instructions_per_bundle[i];
3057 total_instructions += bundle_count * i;
3058 total_bundles += bundle_count;
3059 }
3060
3061 if (total_bundles > 0)
3062 tty->print("Average ILP (excluding nops) is %.2f\n",
3063 ((double)total_instructions) / ((double)total_bundles));
3064 }
3065 #endif
3066
3067 //-----------------------init_scratch_buffer_blob------------------------------
3068 // Construct a temporary BufferBlob and cache it for this compile.
3069 void PhaseOutput::init_scratch_buffer_blob(int const_size) {
3070 // If there is already a scratch buffer blob allocated and the
3071 // constant section is big enough, use it. Otherwise free the
3072 // current and allocate a new one.
3073 BufferBlob* blob = scratch_buffer_blob();
3074 if ((blob != nullptr) && (const_size <= _scratch_const_size)) {
3075 // Use the current blob.
3076 } else {
3077 if (blob != nullptr) {
3078 BufferBlob::free(blob);
3079 }
3080
3081 ResourceMark rm;
3082 _scratch_const_size = const_size;
3083 int size = C2Compiler::initial_code_buffer_size(const_size);
3084 blob = BufferBlob::create("Compile::scratch_buffer", size);
3085 // Record the buffer blob for next time.
3086 set_scratch_buffer_blob(blob);
3087 // Have we run out of code space?
3088 if (scratch_buffer_blob() == nullptr) {
3089 // Let CompilerBroker disable further compilations.
3090 C->record_failure("Not enough space for scratch buffer in CodeCache");
3091 return;
3092 }
3093 }
3094
3095 // Initialize the relocation buffers
3096 relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
3097 set_scratch_locs_memory(locs_buf);
3098 }
3099
3100
3101 //-----------------------scratch_emit_size-------------------------------------
3102 // Helper function that computes size by emitting code
3103 uint PhaseOutput::scratch_emit_size(const Node* n) {
3104 // Start scratch_emit_size section.
3105 set_in_scratch_emit_size(true);
3106
3107 // Emit into a trash buffer and count bytes emitted.
3108 // This is a pretty expensive way to compute a size,
3109 // but it works well enough if seldom used.
3110 // All common fixed-size instructions are given a size
3111 // method by the AD file.
3112 // Note that the scratch buffer blob and locs memory are
3113 // allocated at the beginning of the compile task, and
3114 // may be shared by several calls to scratch_emit_size.
3115 // The allocation of the scratch buffer blob is particularly
3116 // expensive, since it has to grab the code cache lock.
3117 BufferBlob* blob = this->scratch_buffer_blob();
3118 assert(blob != nullptr, "Initialize BufferBlob at start");
3119 assert(blob->size() > max_inst_size(), "sanity");
3120 relocInfo* locs_buf = scratch_locs_memory();
3121 address blob_begin = blob->content_begin();
3122 address blob_end = (address)locs_buf;
3123 assert(blob->contains(blob_end), "sanity");
3124 CodeBuffer buf(blob_begin, blob_end - blob_begin);
3125 buf.initialize_consts_size(_scratch_const_size);
3126 buf.initialize_stubs_size(MAX_stubs_size);
3127 assert(locs_buf != nullptr, "sanity");
3128 int lsize = MAX_locs_size / 3;
3129 buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
3130 buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
3131 buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
3132 // Mark as scratch buffer.
3133 buf.consts()->set_scratch_emit();
3134 buf.insts()->set_scratch_emit();
3135 buf.stubs()->set_scratch_emit();
3136
3137 // Do the emission.
3138
3139 Label fakeL; // Fake label for branch instructions.
3140 Label* saveL = nullptr;
3141 uint save_bnum = 0;
3142 bool is_branch = n->is_MachBranch();
3143 C2_MacroAssembler masm(&buf);
3144 masm.bind(fakeL);
3145 if (is_branch) {
3146 n->as_MachBranch()->save_label(&saveL, &save_bnum);
3147 n->as_MachBranch()->label_set(&fakeL, 0);
3148 }
3149 n->emit(&masm, C->regalloc());
3150
3151 // Emitting into the scratch buffer should not fail
3152 assert(!C->failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", C->failure_reason());
3153
3154 if (is_branch) // Restore label.
3155 n->as_MachBranch()->label_set(saveL, save_bnum);
3156
3157 // End scratch_emit_size section.
3158 set_in_scratch_emit_size(false);
3159
3160 return buf.insts_size();
3161 }
3162
3163 void PhaseOutput::install() {
3164 if (C->should_install_code() && C->stub_function() != nullptr) {
3165 install_stub(C->stub_name());
3166 } else {
3167 install_code(C->method(),
3168 C->entry_bci(),
3169 CompilerThread::current()->compiler(),
3170 C->has_unsafe_access(),
3171 SharedRuntime::is_wide_vector(C->max_vector_size()));
3172 }
3173 }
3174
3175 void PhaseOutput::install_code(ciMethod* target,
3176 int entry_bci,
3177 AbstractCompiler* compiler,
3178 bool has_unsafe_access,
3179 bool has_wide_vectors) {
3180 // Check if we want to skip execution of all compiled code.
3181 {
3182 #ifndef PRODUCT
3183 if (OptoNoExecute) {
3184 C->record_method_not_compilable("+OptoNoExecute"); // Flag as failed
3185 return;
3186 }
3187 #endif
3188 Compile::TracePhase tp(_t_registerMethod);
3189
3190 if (C->is_osr_compilation()) {
3191 _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
3192 _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
3193 } else {
3194 if (!target->is_static()) {
3195 // The UEP of an nmethod ensures that the VEP is padded. However, the padding of the UEP is placed
3196 // before the inline cache check, so we don't have to execute any nop instructions when dispatching
3197 // through the UEP, yet we can ensure that the VEP is aligned appropriately.
3198 _code_offsets.set_value(CodeOffsets::Entry, _first_block_size - MacroAssembler::ic_check_size());
3199 }
3200 _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
3201 _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
3202 }
3203
3204 C->env()->register_method(target,
3205 entry_bci,
3206 &_code_offsets,
3207 _orig_pc_slot_offset_in_bytes,
3208 code_buffer(),
3209 frame_size_in_words(),
3210 oop_map_set(),
3211 &_handler_table,
3212 inc_table(),
3213 compiler,
3214 C->has_clinit_barriers(),
3215 C->for_preload(),
3216 has_unsafe_access,
3217 SharedRuntime::is_wide_vector(C->max_vector_size()),
3218 C->has_monitors(),
3219 C->has_scoped_access(),
3220 0,
3221 C->should_install_code());
3222
3223 if (C->log() != nullptr) { // Print code cache state into compiler log
3224 C->log()->code_cache_state();
3225 }
3226 assert(!C->has_clinit_barriers() || C->for_preload(), "class init barriers should be only in preload code");
3227 }
3228 }
3229 void PhaseOutput::install_stub(const char* stub_name) {
3230 // Entry point will be accessed using stub_entry_point();
3231 if (code_buffer() == nullptr) {
3232 Matcher::soft_match_failure();
3233 } else {
3234 if (PrintAssembly && (WizardMode || Verbose))
3235 tty->print_cr("### Stub::%s", stub_name);
3236
3237 if (!C->failing()) {
3238 assert(C->fixed_slots() == 0, "no fixed slots used for runtime stubs");
3239
3240 // Make the NMethod
3241 // For now we mark the frame as never safe for profile stackwalking
3242 RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
3243 code_buffer(),
3244 CodeOffsets::frame_never_safe,
3245 // _code_offsets.value(CodeOffsets::Frame_Complete),
3246 frame_size_in_words(),
3247 oop_map_set(),
3248 false,
3249 false);
3250
3251 if (rs == nullptr) {
3252 C->record_failure("CodeCache is full");
3253 } else {
3254 assert(rs->is_runtime_stub(), "sanity check");
3255 C->set_stub_entry_point(rs->entry_point());
3256 BlobId blob_id = StubInfo::blob(C->stub_id());
3257 AOTCodeCache::store_code_blob(*rs, AOTCodeEntry::C2Blob, blob_id);
3258 }
3259 }
3260 }
3261 }
3262
3263 // Support for bundling info
3264 Bundle* PhaseOutput::node_bundling(const Node *n) {
3265 assert(valid_bundle_info(n), "oob");
3266 return &_node_bundling_base[n->_idx];
3267 }
3268
3269 bool PhaseOutput::valid_bundle_info(const Node *n) {
3270 return (_node_bundling_limit > n->_idx);
3271 }
3272
3273 //------------------------------frame_size_in_words-----------------------------
3274 // frame_slots in units of words
3275 int PhaseOutput::frame_size_in_words() const {
3276 // shift is 0 in LP32 and 1 in LP64
3277 const int shift = (LogBytesPerWord - LogBytesPerInt);
3278 int words = _frame_slots >> shift;
3279 assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
3280 return words;
3281 }
3282
3283 // To bang the stack of this compiled method we use the stack size
3284 // that the interpreter would need in case of a deoptimization. This
3285 // removes the need to bang the stack in the deoptimization blob which
3286 // in turn simplifies stack overflow handling.
3287 int PhaseOutput::bang_size_in_bytes() const {
3288 return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), C->interpreter_frame_size());
3289 }
3290
3291 //------------------------------dump_asm---------------------------------------
3292 // Dump formatted assembly
3293 #if defined(SUPPORT_OPTO_ASSEMBLY)
3294 void PhaseOutput::dump_asm_on(outputStream* st, int* pcs, uint pc_limit) {
3295
3296 int pc_digits = 3; // #chars required for pc
3297 int sb_chars = 3; // #chars for "start bundle" indicator
3298 int tab_size = 8;
3299 if (pcs != nullptr) {
3300 int max_pc = 0;
3301 for (uint i = 0; i < pc_limit; i++) {
3302 max_pc = (max_pc < pcs[i]) ? pcs[i] : max_pc;
3303 }
3304 pc_digits = ((max_pc < 4096) ? 3 : ((max_pc < 65536) ? 4 : ((max_pc < 65536*256) ? 6 : 8))); // #chars required for pc
3305 }
3306 int prefix_len = ((pc_digits + sb_chars + tab_size - 1)/tab_size)*tab_size;
3307
3308 bool cut_short = false;
3309 st->print_cr("#");
3310 st->print("# "); C->tf()->dump_on(st); st->cr();
3311 st->print_cr("#");
3312
3313 // For all blocks
3314 int pc = 0x0; // Program counter
3315 char starts_bundle = ' ';
3316 C->regalloc()->dump_frame();
3317
3318 Node *n = nullptr;
3319 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
3320 if (VMThread::should_terminate()) {
3321 cut_short = true;
3322 break;
3323 }
3324 Block* block = C->cfg()->get_block(i);
3325 if (block->is_connector() && !Verbose) {
3326 continue;
3327 }
3328 n = block->head();
3329 if ((pcs != nullptr) && (n->_idx < pc_limit)) {
3330 pc = pcs[n->_idx];
3331 st->print("%*.*x", pc_digits, pc_digits, pc);
3332 }
3333 st->fill_to(prefix_len);
3334 block->dump_head(C->cfg(), st);
3335 if (block->is_connector()) {
3336 st->fill_to(prefix_len);
3337 st->print_cr("# Empty connector block");
3338 } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
3339 st->fill_to(prefix_len);
3340 st->print_cr("# Block is sole successor of call");
3341 }
3342
3343 // For all instructions
3344 for (uint j = 0; j < block->number_of_nodes(); j++) {
3345 if (VMThread::should_terminate()) {
3346 cut_short = true;
3347 break;
3348 }
3349 n = block->get_node(j);
3350 if (valid_bundle_info(n)) {
3351 Bundle* bundle = node_bundling(n);
3352 if (bundle->starts_bundle()) {
3353 starts_bundle = '+';
3354 }
3355 }
3356
3357 if (WizardMode) {
3358 n->dump();
3359 }
3360
3361 if( !n->is_Region() && // Dont print in the Assembly
3362 !n->is_Phi() && // a few noisely useless nodes
3363 !n->is_Proj() &&
3364 !n->is_MachTemp() &&
3365 !n->is_SafePointScalarObject() &&
3366 !n->is_Catch() && // Would be nice to print exception table targets
3367 !n->is_MergeMem() && // Not very interesting
3368 !n->is_top() && // Debug info table constants
3369 !(n->is_Con() && !n->is_Mach())// Debug info table constants
3370 ) {
3371 if ((pcs != nullptr) && (n->_idx < pc_limit)) {
3372 pc = pcs[n->_idx];
3373 st->print("%*.*x", pc_digits, pc_digits, pc);
3374 } else {
3375 st->fill_to(pc_digits);
3376 }
3377 st->print(" %c ", starts_bundle);
3378 starts_bundle = ' ';
3379 st->fill_to(prefix_len);
3380 n->format(C->regalloc(), st);
3381 st->cr();
3382 }
3383
3384 // Dump the exception table as well
3385 if( n->is_Catch() && (Verbose || WizardMode) ) {
3386 // Print the exception table for this offset
3387 _handler_table.print_subtable_for(pc);
3388 }
3389 st->bol(); // Make sure we start on a new line
3390 }
3391 st->cr(); // one empty line between blocks
3392 } // End of per-block dump
3393
3394 if (cut_short) st->print_cr("*** disassembly is cut short ***");
3395 }
3396 #endif
3397
3398 #ifndef PRODUCT
3399 void PhaseOutput::print_statistics() {
3400 Scheduling::print_statistics();
3401 }
3402 #endif
3403
3404 int PhaseOutput::max_inst_size() {
3405 if (AOTCodeCache::maybe_dumping_code()) {
3406 // See the comment in output.hpp.
3407 return 16384;
3408 } else {
3409 return mainline_MAX_inst_size;
3410 }
3411 }
3412
3413 int PhaseOutput::max_inst_gcstub_size() {
3414 assert(mainline_MAX_inst_size <= max_inst_size(), "Sanity");
3415 return mainline_MAX_inst_size;
3416 }