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 "gc/shared/gc_globals.hpp"
37 #include "memory/allocation.hpp"
38 #include "opto/ad.hpp"
39 #include "opto/block.hpp"
40 #include "opto/c2_MacroAssembler.hpp"
41 #include "opto/c2compiler.hpp"
42 #include "opto/callnode.hpp"
43 #include "opto/cfgnode.hpp"
44 #include "opto/locknode.hpp"
45 #include "opto/machnode.hpp"
46 #include "opto/node.hpp"
47 #include "opto/optoreg.hpp"
48 #include "opto/output.hpp"
49 #include "opto/regalloc.hpp"
50 #include "opto/type.hpp"
51 #include "runtime/sharedRuntime.hpp"
52 #include "utilities/macros.hpp"
53 #include "utilities/powerOfTwo.hpp"
54 #include "utilities/xmlstream.hpp"
55
56 #ifndef PRODUCT
57 #define DEBUG_ARG(x) , x
58 #else
59 #define DEBUG_ARG(x)
60 #endif
61
62 //------------------------------Scheduling----------------------------------
63 // This class contains all the information necessary to implement instruction
64 // scheduling and bundling.
65 class Scheduling {
66
67 private:
68 // Arena to use
69 Arena *_arena;
70
71 // Control-Flow Graph info
72 PhaseCFG *_cfg;
73
74 // Register Allocation info
75 PhaseRegAlloc *_regalloc;
76
77 // Number of nodes in the method
78 uint _node_bundling_limit;
79
80 // List of scheduled nodes. Generated in reverse order
81 Node_List _scheduled;
82
83 // List of nodes currently available for choosing for scheduling
84 Node_List _available;
85
86 // For each instruction beginning a bundle, the number of following
87 // nodes to be bundled with it.
88 Bundle *_node_bundling_base;
89
90 // Mapping from register to Node
91 Node_List _reg_node;
92
93 // Free list for pinch nodes.
94 Node_List _pinch_free_list;
95
96 // Number of uses of this node within the containing basic block.
97 short *_uses;
98
99 // Schedulable portion of current block. Skips Region/Phi/CreateEx up
100 // front, branch+proj at end. Also skips Catch/CProj (same as
101 // branch-at-end), plus just-prior exception-throwing call.
102 uint _bb_start, _bb_end;
103
104 // Latency from the end of the basic block as scheduled
105 unsigned short *_current_latency;
106
107 // Remember the next node
108 Node *_next_node;
109
110 // Use this for an unconditional branch delay slot
111 Node *_unconditional_delay_slot;
112
113 // Pointer to a Nop
114 MachNopNode *_nop;
115
116 // Length of the current bundle, in instructions
117 uint _bundle_instr_count;
118
119 // Current Cycle number, for computing latencies and bundling
120 uint _bundle_cycle_number;
121
122 // Bundle information
123 Pipeline_Use_Element _bundle_use_elements[resource_count];
124 Pipeline_Use _bundle_use;
125
126 // Dump the available list
127 void dump_available() const;
128
129 public:
130 Scheduling(Arena *arena, Compile &compile);
131
132 // Destructor
133 NOT_PRODUCT( ~Scheduling(); )
134
135 // Step ahead "i" cycles
136 void step(uint i);
137
138 // Step ahead 1 cycle, and clear the bundle state (for example,
139 // at a branch target)
140 void step_and_clear();
141
142 Bundle* node_bundling(const Node *n) {
143 assert(valid_bundle_info(n), "oob");
144 return (&_node_bundling_base[n->_idx]);
145 }
146
147 bool valid_bundle_info(const Node *n) const {
148 return (_node_bundling_limit > n->_idx);
149 }
150
151 bool starts_bundle(const Node *n) const {
152 return (_node_bundling_limit > n->_idx && _node_bundling_base[n->_idx].starts_bundle());
153 }
154
155 // Do the scheduling
156 void DoScheduling();
157
158 // Compute the register antidependencies within a basic block
159 void ComputeRegisterAntidependencies(Block *bb);
160 void verify_do_def( Node *n, OptoReg::Name def, const char *msg );
161 void verify_good_schedule( Block *b, const char *msg );
162 void anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def );
163 void anti_do_use( Block *b, Node *use, OptoReg::Name use_reg );
164
165 // Add a node to the current bundle
166 void AddNodeToBundle(Node *n, const Block *bb);
167
168 // Return an integer less than, equal to, or greater than zero
169 // if the stack offset of the first argument is respectively
170 // less than, equal to, or greater than the second.
171 int compare_two_spill_nodes(Node* first, Node* second);
172
173 // Add a node to the list of available nodes
174 void AddNodeToAvailableList(Node *n);
175
176 // Compute the local use count for the nodes in a block, and compute
177 // the list of instructions with no uses in the block as available
178 void ComputeUseCount(const Block *bb);
179
180 // Choose an instruction from the available list to add to the bundle
181 Node * ChooseNodeToBundle();
182
183 // See if this Node fits into the currently accumulating bundle
184 bool NodeFitsInBundle(Node *n);
185
186 // Decrement the use count for a node
187 void DecrementUseCounts(Node *n, const Block *bb);
188
189 // Garbage collect pinch nodes for reuse by other blocks.
190 void garbage_collect_pinch_nodes();
191 // Clean up a pinch node for reuse (helper for above).
192 void cleanup_pinch( Node *pinch );
193
194 // Information for statistics gathering
195 #ifndef PRODUCT
196 private:
197 // Gather information on size of nops relative to total
198 uint _branches, _unconditional_delays;
199
200 static uint _total_nop_size, _total_method_size;
201 static uint _total_branches, _total_unconditional_delays;
202 static uint _total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
203
204 public:
205 static void print_statistics();
206
207 static void increment_instructions_per_bundle(uint i) {
208 _total_instructions_per_bundle[i]++;
209 }
210
211 static void increment_nop_size(uint s) {
212 _total_nop_size += s;
213 }
214
215 static void increment_method_size(uint s) {
216 _total_method_size += s;
217 }
218 #endif
219
220 };
221
222 PhaseOutput::PhaseOutput()
223 : Phase(Phase::Output),
224 _code_buffer("Compile::Fill_buffer"),
225 _first_block_size(0),
226 _handler_table(),
227 _inc_table(),
228 _stub_list(),
229 _oop_map_set(nullptr),
230 _scratch_buffer_blob(nullptr),
231 _scratch_locs_memory(nullptr),
232 _scratch_const_size(-1),
233 _in_scratch_emit_size(false),
234 _frame_slots(0),
235 _code_offsets(),
236 _node_bundling_limit(0),
237 _node_bundling_base(nullptr),
238 _orig_pc_slot(0),
239 _orig_pc_slot_offset_in_bytes(0),
240 _buf_sizes(),
241 _block(nullptr),
242 _index(0) {
243 C->set_output(this);
244 if (C->stub_name() == nullptr) {
245 int fixed_slots = C->fixed_slots();
246 if (C->needs_stack_repair()) {
247 fixed_slots -= 2;
248 }
249 // TODO 8284443 Only reserve extra slot if needed
250 if (InlineTypeReturnedAsFields) {
251 fixed_slots -= 2;
252 }
253 _orig_pc_slot = fixed_slots - (sizeof(address) / VMRegImpl::stack_slot_size);
254 }
255 }
256
257 PhaseOutput::~PhaseOutput() {
258 C->set_output(nullptr);
259 if (_scratch_buffer_blob != nullptr) {
260 BufferBlob::free(_scratch_buffer_blob);
261 }
262 }
263
264 void PhaseOutput::perform_mach_node_analysis() {
265 // Late barrier analysis must be done after schedule and bundle
266 // Otherwise liveness based spilling will fail
267 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
268 bs->late_barrier_analysis();
269
270 pd_perform_mach_node_analysis();
271
272 C->print_method(CompilerPhaseType::PHASE_MACH_ANALYSIS, 3);
273 }
274
275 // Convert Nodes to instruction bits and pass off to the VM
276 void PhaseOutput::Output() {
277 // RootNode goes
278 assert( C->cfg()->get_root_block()->number_of_nodes() == 0, "" );
279
280 // The number of new nodes (mostly MachNop) is proportional to
281 // the number of java calls and inner loops which are aligned.
282 if ( C->check_node_count((NodeLimitFudgeFactor + C->java_calls()*3 +
283 C->inner_loops()*(OptoLoopAlignment-1)),
284 "out of nodes before code generation" ) ) {
285 return;
286 }
287 // Make sure I can find the Start Node
288 Block *entry = C->cfg()->get_block(1);
289 Block *broot = C->cfg()->get_root_block();
290
291 const StartNode *start = entry->head()->as_Start();
292
293 // Replace StartNode with prolog
294 Label verified_entry;
295 MachPrologNode* prolog = new MachPrologNode(&verified_entry);
296 entry->map_node(prolog, 0);
297 C->cfg()->map_node_to_block(prolog, entry);
298 C->cfg()->unmap_node_from_block(start); // start is no longer in any block
299
300 // Virtual methods need an unverified entry point
301 if (C->is_osr_compilation()) {
302 if (PoisonOSREntry) {
303 // TODO: Should use a ShouldNotReachHereNode...
304 C->cfg()->insert( broot, 0, new MachBreakpointNode() );
305 }
306 } else {
307 if (C->method()) {
308 if (C->method()->has_scalarized_args()) {
309 // Add entry point to unpack all inline type arguments
310 C->cfg()->insert(broot, 0, new MachVEPNode(&verified_entry, /* verified */ true, /* receiver_only */ false));
311 if (!C->method()->is_static()) {
312 // Add verified/unverified entry points to only unpack inline type receiver at interface calls
313 C->cfg()->insert(broot, 0, new MachVEPNode(&verified_entry, /* verified */ false, /* receiver_only */ false));
314 C->cfg()->insert(broot, 0, new MachVEPNode(&verified_entry, /* verified */ true, /* receiver_only */ true));
315 C->cfg()->insert(broot, 0, new MachVEPNode(&verified_entry, /* verified */ false, /* receiver_only */ true));
316 }
317 } else if (!C->method()->is_static()) {
318 // Insert unvalidated entry point
319 C->cfg()->insert(broot, 0, new MachUEPNode());
320 }
321 }
322 }
323
324 // Break before main entry point
325 if ((C->method() && C->directive()->BreakAtExecuteOption) ||
326 (OptoBreakpoint && C->is_method_compilation()) ||
327 (OptoBreakpointOSR && C->is_osr_compilation()) ||
328 (OptoBreakpointC2R && !C->method()) ) {
329 // checking for C->method() means that OptoBreakpoint does not apply to
330 // runtime stubs or frame converters
331 C->cfg()->insert( entry, 1, new MachBreakpointNode() );
332 }
333
334 // Insert epilogs before every return
335 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
336 Block* block = C->cfg()->get_block(i);
337 if (!block->is_connector() && block->non_connector_successor(0) == C->cfg()->get_root_block()) { // Found a program exit point?
338 Node* m = block->end();
339 if (m->is_Mach() && m->as_Mach()->ideal_Opcode() != Op_Halt) {
340 MachEpilogNode* epilog = new MachEpilogNode(m->as_Mach()->ideal_Opcode() == Op_Return);
341 block->add_inst(epilog);
342 C->cfg()->map_node_to_block(epilog, block);
343 }
344 }
345 }
346
347 // Keeper of sizing aspects
348 _buf_sizes = BufferSizingData();
349
350 // Initialize code buffer
351 estimate_buffer_size(_buf_sizes._const);
352 if (C->failing()) return;
353
354 // Pre-compute the length of blocks and replace
355 // long branches with short if machine supports it.
356 // Must be done before ScheduleAndBundle due to SPARC delay slots
357 uint* blk_starts = NEW_RESOURCE_ARRAY(uint, C->cfg()->number_of_blocks() + 1);
358 blk_starts[0] = 0;
359 shorten_branches(blk_starts);
360
361 if (!C->is_osr_compilation() && C->has_scalarized_args()) {
362 // Compute the offsets of the entry points required by the inline type calling convention
363 if (!C->method()->is_static()) {
364 // We have entries at the beginning of the method, implemented by the first 4 nodes.
365 // Entry (unverified) @ offset 0
366 // Verified_Inline_Entry_RO
367 // Inline_Entry (unverified)
368 // Verified_Inline_Entry
369 uint offset = 0;
370 _code_offsets.set_value(CodeOffsets::Entry, offset);
371
372 offset += ((MachVEPNode*)broot->get_node(0))->size(C->regalloc());
373 _code_offsets.set_value(CodeOffsets::Verified_Inline_Entry_RO, offset);
374
375 offset += ((MachVEPNode*)broot->get_node(1))->size(C->regalloc());
376 _code_offsets.set_value(CodeOffsets::Inline_Entry, offset);
377
378 offset += ((MachVEPNode*)broot->get_node(2))->size(C->regalloc());
379 _code_offsets.set_value(CodeOffsets::Verified_Inline_Entry, offset);
380 } else {
381 _code_offsets.set_value(CodeOffsets::Entry, -1); // will be patched later
382 _code_offsets.set_value(CodeOffsets::Verified_Inline_Entry, 0);
383 }
384 }
385
386 ScheduleAndBundle();
387 if (C->failing()) {
388 return;
389 }
390
391 perform_mach_node_analysis();
392
393 // Complete sizing of codebuffer
394 CodeBuffer* cb = init_buffer();
395 if (cb == nullptr || C->failing()) {
396 return;
397 }
398
399 BuildOopMaps();
400
401 if (C->failing()) {
402 return;
403 }
404
405 C2_MacroAssembler masm(cb);
406 fill_buffer(&masm, blk_starts);
407 }
408
409 bool PhaseOutput::need_stack_bang(int frame_size_in_bytes) const {
410 // Determine if we need to generate a stack overflow check.
411 // Do it if the method is not a stub function and
412 // has java calls or has frame size > vm_page_size/8.
413 // The debug VM checks that deoptimization doesn't trigger an
414 // unexpected stack overflow (compiled method stack banging should
415 // guarantee it doesn't happen) so we always need the stack bang in
416 // a debug VM.
417 return (C->stub_function() == nullptr &&
418 (C->has_java_calls() || frame_size_in_bytes > (int)(os::vm_page_size())>>3
419 DEBUG_ONLY(|| true)));
420 }
421
422 bool PhaseOutput::need_register_stack_bang() const {
423 // Determine if we need to generate a register stack overflow check.
424 // This is only used on architectures which have split register
425 // and memory stacks.
426 // Bang if the method is not a stub function and has java calls
427 return (C->stub_function() == nullptr && C->has_java_calls());
428 }
429
430
431 // Compute the size of first NumberOfLoopInstrToAlign instructions at the top
432 // of a loop. When aligning a loop we need to provide enough instructions
433 // in cpu's fetch buffer to feed decoders. The loop alignment could be
434 // avoided if we have enough instructions in fetch buffer at the head of a loop.
435 // By default, the size is set to 999999 by Block's constructor so that
436 // a loop will be aligned if the size is not reset here.
437 //
438 // Note: Mach instructions could contain several HW instructions
439 // so the size is estimated only.
440 //
441 void PhaseOutput::compute_loop_first_inst_sizes() {
442 // The next condition is used to gate the loop alignment optimization.
443 // Don't aligned a loop if there are enough instructions at the head of a loop
444 // or alignment padding is larger then MaxLoopPad. By default, MaxLoopPad
445 // is equal to OptoLoopAlignment-1 except on new Intel cpus, where it is
446 // equal to 11 bytes which is the largest address NOP instruction.
447 if (MaxLoopPad < OptoLoopAlignment - 1) {
448 uint last_block = C->cfg()->number_of_blocks() - 1;
449 for (uint i = 1; i <= last_block; i++) {
450 Block* block = C->cfg()->get_block(i);
451 // Check the first loop's block which requires an alignment.
452 if (block->loop_alignment() > (uint)relocInfo::addr_unit()) {
453 uint sum_size = 0;
454 uint inst_cnt = NumberOfLoopInstrToAlign;
455 inst_cnt = block->compute_first_inst_size(sum_size, inst_cnt, C->regalloc());
456
457 // Check subsequent fallthrough blocks if the loop's first
458 // block(s) does not have enough instructions.
459 Block *nb = block;
460 while(inst_cnt > 0 &&
461 i < last_block &&
462 !C->cfg()->get_block(i + 1)->has_loop_alignment() &&
463 !nb->has_successor(block)) {
464 i++;
465 nb = C->cfg()->get_block(i);
466 inst_cnt = nb->compute_first_inst_size(sum_size, inst_cnt, C->regalloc());
467 } // while( inst_cnt > 0 && i < last_block )
468
469 block->set_first_inst_size(sum_size);
470 } // f( b->head()->is_Loop() )
471 } // for( i <= last_block )
472 } // if( MaxLoopPad < OptoLoopAlignment-1 )
473 }
474
475 // The architecture description provides short branch variants for some long
476 // branch instructions. Replace eligible long branches with short branches.
477 void PhaseOutput::shorten_branches(uint* blk_starts) {
478
479 Compile::TracePhase tp(_t_shortenBranches);
480
481 // Compute size of each block, method size, and relocation information size
482 uint nblocks = C->cfg()->number_of_blocks();
483
484 uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
485 uint* jmp_size = NEW_RESOURCE_ARRAY(uint,nblocks);
486 int* jmp_nidx = NEW_RESOURCE_ARRAY(int ,nblocks);
487
488 // Collect worst case block paddings
489 int* block_worst_case_pad = NEW_RESOURCE_ARRAY(int, nblocks);
490 memset(block_worst_case_pad, 0, nblocks * sizeof(int));
491
492 DEBUG_ONLY( uint *jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks); )
493 DEBUG_ONLY( uint *jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks); )
494
495 bool has_short_branch_candidate = false;
496
497 // Initialize the sizes to 0
498 int code_size = 0; // Size in bytes of generated code
499 int stub_size = 0; // Size in bytes of all stub entries
500 // Size in bytes of all relocation entries, including those in local stubs.
501 // Start with 2-bytes of reloc info for the unvalidated entry point
502 int reloc_size = 1; // Number of relocation entries
503
504 // Make three passes. The first computes pessimistic blk_starts,
505 // relative jmp_offset and reloc_size information. The second performs
506 // short branch substitution using the pessimistic sizing. The
507 // third inserts nops where needed.
508
509 // Step one, perform a pessimistic sizing pass.
510 uint last_call_adr = max_juint;
511 uint last_avoid_back_to_back_adr = max_juint;
512 uint nop_size = (new MachNopNode())->size(C->regalloc());
513 for (uint i = 0; i < nblocks; i++) { // For all blocks
514 Block* block = C->cfg()->get_block(i);
515 _block = block;
516
517 // During short branch replacement, we store the relative (to blk_starts)
518 // offset of jump in jmp_offset, rather than the absolute offset of jump.
519 // This is so that we do not need to recompute sizes of all nodes when
520 // we compute correct blk_starts in our next sizing pass.
521 jmp_offset[i] = 0;
522 jmp_size[i] = 0;
523 jmp_nidx[i] = -1;
524 DEBUG_ONLY( jmp_target[i] = 0; )
525 DEBUG_ONLY( jmp_rule[i] = 0; )
526
527 // Sum all instruction sizes to compute block size
528 uint last_inst = block->number_of_nodes();
529 uint blk_size = 0;
530 for (uint j = 0; j < last_inst; j++) {
531 _index = j;
532 Node* nj = block->get_node(_index);
533 // Handle machine instruction nodes
534 if (nj->is_Mach()) {
535 MachNode* mach = nj->as_Mach();
536 blk_size += (mach->alignment_required() - 1) * relocInfo::addr_unit(); // assume worst case padding
537 reloc_size += mach->reloc();
538 if (mach->is_MachCall()) {
539 // add size information for trampoline stub
540 // class CallStubImpl is platform-specific and defined in the *.ad files.
541 stub_size += CallStubImpl::size_call_trampoline();
542 reloc_size += CallStubImpl::reloc_call_trampoline();
543
544 MachCallNode *mcall = mach->as_MachCall();
545 // This destination address is NOT PC-relative
546
547 if (mcall->entry_point() != nullptr) {
548 mcall->method_set((intptr_t)mcall->entry_point());
549 }
550
551 if (mcall->is_MachCallJava() && mcall->as_MachCallJava()->_method) {
552 stub_size += CompiledDirectCall::to_interp_stub_size();
553 reloc_size += CompiledDirectCall::reloc_to_interp_stub();
554 }
555 } else if (mach->is_MachSafePoint()) {
556 // If call/safepoint are adjacent, account for possible
557 // nop to disambiguate the two safepoints.
558 // ScheduleAndBundle() can rearrange nodes in a block,
559 // check for all offsets inside this block.
560 if (last_call_adr >= blk_starts[i]) {
561 blk_size += nop_size;
562 }
563 }
564 if (mach->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
565 // Nop is inserted between "avoid back to back" instructions.
566 // ScheduleAndBundle() can rearrange nodes in a block,
567 // check for all offsets inside this block.
568 if (last_avoid_back_to_back_adr >= blk_starts[i]) {
569 blk_size += nop_size;
570 }
571 }
572 if (mach->may_be_short_branch()) {
573 if (!nj->is_MachBranch()) {
574 #ifndef PRODUCT
575 nj->dump(3);
576 #endif
577 Unimplemented();
578 }
579 assert(jmp_nidx[i] == -1, "block should have only one branch");
580 jmp_offset[i] = blk_size;
581 jmp_size[i] = nj->size(C->regalloc());
582 jmp_nidx[i] = j;
583 has_short_branch_candidate = true;
584 }
585 }
586 blk_size += nj->size(C->regalloc());
587 // Remember end of call offset
588 if (nj->is_MachCall() && !nj->is_MachCallLeaf()) {
589 last_call_adr = blk_starts[i]+blk_size;
590 }
591 // Remember end of avoid_back_to_back offset
592 if (nj->is_Mach() && nj->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
593 last_avoid_back_to_back_adr = blk_starts[i]+blk_size;
594 }
595 }
596
597 // When the next block starts a loop, we may insert pad NOP
598 // instructions. Since we cannot know our future alignment,
599 // assume the worst.
600 if (i < nblocks - 1) {
601 Block* nb = C->cfg()->get_block(i + 1);
602 int max_loop_pad = nb->code_alignment()-relocInfo::addr_unit();
603 if (max_loop_pad > 0) {
604 assert(is_power_of_2(max_loop_pad+relocInfo::addr_unit()), "");
605 // Adjust last_call_adr and/or last_avoid_back_to_back_adr.
606 // If either is the last instruction in this block, bump by
607 // max_loop_pad in lock-step with blk_size, so sizing
608 // calculations in subsequent blocks still can conservatively
609 // detect that it may the last instruction in this block.
610 if (last_call_adr == blk_starts[i]+blk_size) {
611 last_call_adr += max_loop_pad;
612 }
613 if (last_avoid_back_to_back_adr == blk_starts[i]+blk_size) {
614 last_avoid_back_to_back_adr += max_loop_pad;
615 }
616 blk_size += max_loop_pad;
617 block_worst_case_pad[i + 1] = max_loop_pad;
618 }
619 }
620
621 // Save block size; update total method size
622 blk_starts[i+1] = blk_starts[i]+blk_size;
623 }
624
625 // Step two, replace eligible long jumps.
626 bool progress = true;
627 uint last_may_be_short_branch_adr = max_juint;
628 while (has_short_branch_candidate && progress) {
629 progress = false;
630 has_short_branch_candidate = false;
631 int adjust_block_start = 0;
632 for (uint i = 0; i < nblocks; i++) {
633 Block* block = C->cfg()->get_block(i);
634 int idx = jmp_nidx[i];
635 MachNode* mach = (idx == -1) ? nullptr: block->get_node(idx)->as_Mach();
636 if (mach != nullptr && mach->may_be_short_branch()) {
637 #ifdef ASSERT
638 assert(jmp_size[i] > 0 && mach->is_MachBranch(), "sanity");
639 int j;
640 // Find the branch; ignore trailing NOPs.
641 for (j = block->number_of_nodes()-1; j>=0; j--) {
642 Node* n = block->get_node(j);
643 if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con)
644 break;
645 }
646 assert(j >= 0 && j == idx && block->get_node(j) == (Node*)mach, "sanity");
647 #endif
648 int br_size = jmp_size[i];
649 int br_offs = blk_starts[i] + jmp_offset[i];
650
651 // This requires the TRUE branch target be in succs[0]
652 uint bnum = block->non_connector_successor(0)->_pre_order;
653 int offset = blk_starts[bnum] - br_offs;
654 if (bnum > i) { // adjust following block's offset
655 offset -= adjust_block_start;
656 }
657
658 // This block can be a loop header, account for the padding
659 // in the previous block.
660 int block_padding = block_worst_case_pad[i];
661 assert(i == 0 || block_padding == 0 || br_offs >= block_padding, "Should have at least a padding on top");
662 // In the following code a nop could be inserted before
663 // the branch which will increase the backward distance.
664 bool needs_padding = ((uint)(br_offs - block_padding) == last_may_be_short_branch_adr);
665 assert(!needs_padding || jmp_offset[i] == 0, "padding only branches at the beginning of block");
666
667 if (needs_padding && offset <= 0)
668 offset -= nop_size;
669
670 if (C->matcher()->is_short_branch_offset(mach->rule(), br_size, offset)) {
671 // We've got a winner. Replace this branch.
672 MachNode* replacement = mach->as_MachBranch()->short_branch_version();
673
674 // Update the jmp_size.
675 int new_size = replacement->size(C->regalloc());
676 int diff = br_size - new_size;
677 assert(diff >= (int)nop_size, "short_branch size should be smaller");
678 // Conservatively take into account padding between
679 // avoid_back_to_back branches. Previous branch could be
680 // converted into avoid_back_to_back branch during next
681 // rounds.
682 if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
683 jmp_offset[i] += nop_size;
684 diff -= nop_size;
685 }
686 adjust_block_start += diff;
687 block->map_node(replacement, idx);
688 mach->subsume_by(replacement, C);
689 mach = replacement;
690 progress = true;
691
692 jmp_size[i] = new_size;
693 DEBUG_ONLY( jmp_target[i] = bnum; );
694 DEBUG_ONLY( jmp_rule[i] = mach->rule(); );
695 } else {
696 // The jump distance is not short, try again during next iteration.
697 has_short_branch_candidate = true;
698 }
699 } // (mach->may_be_short_branch())
700 if (mach != nullptr && (mach->may_be_short_branch() ||
701 mach->avoid_back_to_back(MachNode::AVOID_AFTER))) {
702 last_may_be_short_branch_adr = blk_starts[i] + jmp_offset[i] + jmp_size[i];
703 }
704 blk_starts[i+1] -= adjust_block_start;
705 }
706 }
707
708 #ifdef ASSERT
709 for (uint i = 0; i < nblocks; i++) { // For all blocks
710 if (jmp_target[i] != 0) {
711 int br_size = jmp_size[i];
712 int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
713 if (!C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
714 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]);
715 }
716 assert(C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset), "Displacement too large for short jmp");
717 }
718 }
719 #endif
720
721 // Step 3, compute the offsets of all blocks, will be done in fill_buffer()
722 // after ScheduleAndBundle().
723
724 // ------------------
725 // Compute size for code buffer
726 code_size = blk_starts[nblocks];
727
728 // Relocation records
729 reloc_size += 1; // Relo entry for exception handler
730
731 // Adjust reloc_size to number of record of relocation info
732 // Min is 2 bytes, max is probably 6 or 8, with a tax up to 25% for
733 // a relocation index.
734 // The CodeBuffer will expand the locs array if this estimate is too low.
735 reloc_size *= 10 / sizeof(relocInfo);
736
737 _buf_sizes._reloc = reloc_size;
738 _buf_sizes._code = code_size;
739 _buf_sizes._stub = stub_size;
740 }
741
742 //------------------------------FillLocArray-----------------------------------
743 // Create a bit of debug info and append it to the array. The mapping is from
744 // Java local or expression stack to constant, register or stack-slot. For
745 // doubles, insert 2 mappings and return 1 (to tell the caller that the next
746 // entry has been taken care of and caller should skip it).
747 static LocationValue *new_loc_value( PhaseRegAlloc *ra, OptoReg::Name regnum, Location::Type l_type ) {
748 // This should never have accepted Bad before
749 assert(OptoReg::is_valid(regnum), "location must be valid");
750 return (OptoReg::is_reg(regnum))
751 ? new LocationValue(Location::new_reg_loc(l_type, OptoReg::as_VMReg(regnum)) )
752 : new LocationValue(Location::new_stk_loc(l_type, ra->reg2offset(regnum)));
753 }
754
755
756 ObjectValue*
757 PhaseOutput::sv_for_node_id(GrowableArray<ScopeValue*> *objs, int id) {
758 for (int i = 0; i < objs->length(); i++) {
759 assert(objs->at(i)->is_object(), "corrupt object cache");
760 ObjectValue* sv = objs->at(i)->as_ObjectValue();
761 if (sv->id() == id) {
762 return sv;
763 }
764 }
765 // Otherwise..
766 return nullptr;
767 }
768
769 void PhaseOutput::set_sv_for_object_node(GrowableArray<ScopeValue*> *objs,
770 ObjectValue* sv ) {
771 assert(sv_for_node_id(objs, sv->id()) == nullptr, "Precondition");
772 objs->append(sv);
773 }
774
775
776 void PhaseOutput::FillLocArray( int idx, MachSafePointNode* sfpt, Node *local,
777 GrowableArray<ScopeValue*> *array,
778 GrowableArray<ScopeValue*> *objs ) {
779 assert( local, "use _top instead of null" );
780 if (array->length() != idx) {
781 assert(array->length() == idx + 1, "Unexpected array count");
782 // Old functionality:
783 // return
784 // New functionality:
785 // Assert if the local is not top. In product mode let the new node
786 // override the old entry.
787 assert(local == C->top(), "LocArray collision");
788 if (local == C->top()) {
789 return;
790 }
791 array->pop();
792 }
793 const Type *t = local->bottom_type();
794
795 // Is it a safepoint scalar object node?
796 if (local->is_SafePointScalarObject()) {
797 SafePointScalarObjectNode* spobj = local->as_SafePointScalarObject();
798
799 ObjectValue* sv = sv_for_node_id(objs, spobj->_idx);
800 if (sv == nullptr) {
801 ciKlass* cik = t->is_oopptr()->exact_klass();
802 assert(cik->is_instance_klass() ||
803 cik->is_array_klass(), "Not supported allocation.");
804 uint first_ind = spobj->first_index(sfpt->jvms());
805 // Nullable, scalarized inline types have a null_marker input
806 // that needs to be checked before using the field values.
807 ScopeValue* properties = nullptr;
808 if (cik->is_inlinetype()) {
809 Node* null_marker_node = sfpt->in(first_ind++);
810 assert(null_marker_node != nullptr, "null_marker node not found");
811 if (!null_marker_node->is_top()) {
812 const TypeInt* null_marker_type = null_marker_node->bottom_type()->is_int();
813 if (null_marker_node->is_Con()) {
814 properties = new ConstantIntValue(null_marker_type->get_con());
815 } else {
816 OptoReg::Name null_marker_reg = C->regalloc()->get_reg_first(null_marker_node);
817 properties = new_loc_value(C->regalloc(), null_marker_reg, Location::normal);
818 }
819 }
820 }
821 if (cik->is_array_klass() && !cik->is_type_array_klass()) {
822 jint props = ArrayKlass::ArrayProperties::DEFAULT;
823 if (cik->as_array_klass()->element_klass()->is_inlinetype()) {
824 if (cik->as_array_klass()->is_elem_null_free()) {
825 props |= ArrayKlass::ArrayProperties::NULL_RESTRICTED;
826 }
827 if (!cik->as_array_klass()->is_elem_atomic()) {
828 props |= ArrayKlass::ArrayProperties::NON_ATOMIC;
829 }
830 }
831 properties = new ConstantIntValue(props);
832 }
833 sv = new ObjectValue(spobj->_idx,
834 new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()), true, properties);
835 set_sv_for_object_node(objs, sv);
836
837 for (uint i = 0; i < spobj->n_fields(); i++) {
838 Node* fld_node = sfpt->in(first_ind+i);
839 (void)FillLocArray(sv->field_values()->length(), sfpt, fld_node, sv->field_values(), objs);
840 }
841 }
842 array->append(sv);
843 return;
844 } else if (local->is_SafePointScalarMerge()) {
845 SafePointScalarMergeNode* smerge = local->as_SafePointScalarMerge();
846 ObjectMergeValue* mv = (ObjectMergeValue*) sv_for_node_id(objs, smerge->_idx);
847
848 if (mv == nullptr) {
849 GrowableArray<ScopeValue*> deps;
850
851 int merge_pointer_idx = smerge->merge_pointer_idx(sfpt->jvms());
852 (void)FillLocArray(0, sfpt, sfpt->in(merge_pointer_idx), &deps, objs);
853 assert(deps.length() == 1, "missing value");
854
855 int selector_idx = smerge->selector_idx(sfpt->jvms());
856 (void)FillLocArray(1, nullptr, sfpt->in(selector_idx), &deps, nullptr);
857 assert(deps.length() == 2, "missing value");
858
859 mv = new ObjectMergeValue(smerge->_idx, deps.at(0), deps.at(1));
860 set_sv_for_object_node(objs, mv);
861
862 for (uint i = 1; i < smerge->req(); i++) {
863 Node* obj_node = smerge->in(i);
864 int idx = mv->possible_objects()->length();
865 (void)FillLocArray(idx, sfpt, obj_node, mv->possible_objects(), objs);
866
867 // By default ObjectValues that are in 'possible_objects' are not root objects.
868 // They will be marked as root later if they are directly referenced in a JVMS.
869 assert(mv->possible_objects()->length() > idx, "Didn't add entry to possible_objects?!");
870 assert(mv->possible_objects()->at(idx)->is_object(), "Entries in possible_objects should be ObjectValue.");
871 mv->possible_objects()->at(idx)->as_ObjectValue()->set_root(false);
872 }
873 }
874 array->append(mv);
875 return;
876 }
877
878 // Grab the register number for the local
879 OptoReg::Name regnum = C->regalloc()->get_reg_first(local);
880 if( OptoReg::is_valid(regnum) ) {// Got a register/stack?
881 // Record the double as two float registers.
882 // The register mask for such a value always specifies two adjacent
883 // float registers, with the lower register number even.
884 // Normally, the allocation of high and low words to these registers
885 // is irrelevant, because nearly all operations on register pairs
886 // (e.g., StoreD) treat them as a single unit.
887 // Here, we assume in addition that the words in these two registers
888 // stored "naturally" (by operations like StoreD and double stores
889 // within the interpreter) such that the lower-numbered register
890 // is written to the lower memory address. This may seem like
891 // a machine dependency, but it is not--it is a requirement on
892 // the author of the <arch>.ad file to ensure that, for every
893 // even/odd double-register pair to which a double may be allocated,
894 // the word in the even single-register is stored to the first
895 // memory word. (Note that register numbers are completely
896 // arbitrary, and are not tied to any machine-level encodings.)
897 #ifdef _LP64
898 if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon ) {
899 array->append(new ConstantIntValue((jint)0));
900 array->append(new_loc_value( C->regalloc(), regnum, Location::dbl ));
901 } else if ( t->base() == Type::Long ) {
902 array->append(new ConstantIntValue((jint)0));
903 array->append(new_loc_value( C->regalloc(), regnum, Location::lng ));
904 } else if ( t->base() == Type::RawPtr ) {
905 // jsr/ret return address which must be restored into the full
906 // width 64-bit stack slot.
907 array->append(new_loc_value( C->regalloc(), regnum, Location::lng ));
908 }
909 #else //_LP64
910 if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon || t->base() == Type::Long ) {
911 // Repack the double/long as two jints.
912 // The convention the interpreter uses is that the second local
913 // holds the first raw word of the native double representation.
914 // This is actually reasonable, since locals and stack arrays
915 // grow downwards in all implementations.
916 // (If, on some machine, the interpreter's Java locals or stack
917 // were to grow upwards, the embedded doubles would be word-swapped.)
918 array->append(new_loc_value( C->regalloc(), OptoReg::add(regnum,1), Location::normal ));
919 array->append(new_loc_value( C->regalloc(), regnum , Location::normal ));
920 }
921 #endif //_LP64
922 else if( (t->base() == Type::FloatBot || t->base() == Type::FloatCon) &&
923 OptoReg::is_reg(regnum) ) {
924 array->append(new_loc_value( C->regalloc(), regnum, Matcher::float_in_double()
925 ? Location::float_in_dbl : Location::normal ));
926 } else if( t->base() == Type::Int && OptoReg::is_reg(regnum) ) {
927 array->append(new_loc_value( C->regalloc(), regnum, Matcher::int_in_long
928 ? Location::int_in_long : Location::normal ));
929 } else if( t->base() == Type::NarrowOop ) {
930 array->append(new_loc_value( C->regalloc(), regnum, Location::narrowoop ));
931 } else if (t->base() == Type::VectorA || t->base() == Type::VectorS ||
932 t->base() == Type::VectorD || t->base() == Type::VectorX ||
933 t->base() == Type::VectorY || t->base() == Type::VectorZ) {
934 array->append(new_loc_value( C->regalloc(), regnum, Location::vector ));
935 } else if (C->regalloc()->is_oop(local)) {
936 assert(t->base() == Type::OopPtr || t->base() == Type::InstPtr ||
937 t->base() == Type::AryPtr,
938 "Unexpected type: %s", t->msg());
939 array->append(new_loc_value( C->regalloc(), regnum, Location::oop ));
940 } else {
941 assert(t->base() == Type::Int || t->base() == Type::Half ||
942 t->base() == Type::FloatCon || t->base() == Type::FloatBot,
943 "Unexpected type: %s", t->msg());
944 array->append(new_loc_value( C->regalloc(), regnum, Location::normal ));
945 }
946 return;
947 }
948
949 // No register. It must be constant data.
950 switch (t->base()) {
951 case Type::Half: // Second half of a double
952 ShouldNotReachHere(); // Caller should skip 2nd halves
953 break;
954 case Type::AnyPtr:
955 array->append(new ConstantOopWriteValue(nullptr));
956 break;
957 case Type::AryPtr:
958 case Type::InstPtr: // fall through
959 array->append(new ConstantOopWriteValue(t->isa_oopptr()->const_oop()->constant_encoding()));
960 break;
961 case Type::NarrowOop:
962 if (t == TypeNarrowOop::NULL_PTR) {
963 array->append(new ConstantOopWriteValue(nullptr));
964 } else {
965 array->append(new ConstantOopWriteValue(t->make_ptr()->isa_oopptr()->const_oop()->constant_encoding()));
966 }
967 break;
968 case Type::Int:
969 array->append(new ConstantIntValue(t->is_int()->get_con()));
970 break;
971 case Type::RawPtr:
972 // A return address (T_ADDRESS).
973 assert((intptr_t)t->is_ptr()->get_con() < (intptr_t)0x10000, "must be a valid BCI");
974 #ifdef _LP64
975 // Must be restored to the full-width 64-bit stack slot.
976 array->append(new ConstantLongValue(t->is_ptr()->get_con()));
977 #else
978 array->append(new ConstantIntValue(t->is_ptr()->get_con()));
979 #endif
980 break;
981 case Type::FloatCon: {
982 float f = t->is_float_constant()->getf();
983 array->append(new ConstantIntValue(jint_cast(f)));
984 break;
985 }
986 case Type::DoubleCon: {
987 jdouble d = t->is_double_constant()->getd();
988 #ifdef _LP64
989 array->append(new ConstantIntValue((jint)0));
990 array->append(new ConstantDoubleValue(d));
991 #else
992 // Repack the double as two jints.
993 // The convention the interpreter uses is that the second local
994 // holds the first raw word of the native double representation.
995 // This is actually reasonable, since locals and stack arrays
996 // grow downwards in all implementations.
997 // (If, on some machine, the interpreter's Java locals or stack
998 // were to grow upwards, the embedded doubles would be word-swapped.)
999 jlong_accessor acc;
1000 acc.long_value = jlong_cast(d);
1001 array->append(new ConstantIntValue(acc.words[1]));
1002 array->append(new ConstantIntValue(acc.words[0]));
1003 #endif
1004 break;
1005 }
1006 case Type::Long: {
1007 jlong d = t->is_long()->get_con();
1008 #ifdef _LP64
1009 array->append(new ConstantIntValue((jint)0));
1010 array->append(new ConstantLongValue(d));
1011 #else
1012 // Repack the long as two jints.
1013 // The convention the interpreter uses is that the second local
1014 // holds the first raw word of the native double representation.
1015 // This is actually reasonable, since locals and stack arrays
1016 // grow downwards in all implementations.
1017 // (If, on some machine, the interpreter's Java locals or stack
1018 // were to grow upwards, the embedded doubles would be word-swapped.)
1019 jlong_accessor acc;
1020 acc.long_value = d;
1021 array->append(new ConstantIntValue(acc.words[1]));
1022 array->append(new ConstantIntValue(acc.words[0]));
1023 #endif
1024 break;
1025 }
1026 case Type::Top: // Add an illegal value here
1027 array->append(new LocationValue(Location()));
1028 break;
1029 default:
1030 ShouldNotReachHere();
1031 break;
1032 }
1033 }
1034
1035 // Determine if this node starts a bundle
1036 bool PhaseOutput::starts_bundle(const Node *n) const {
1037 return (_node_bundling_limit > n->_idx &&
1038 _node_bundling_base[n->_idx].starts_bundle());
1039 }
1040
1041 // Determine if there is a monitor that has 'ov' as its owner.
1042 bool PhaseOutput::contains_as_owner(GrowableArray<MonitorValue*> *monarray, ObjectValue *ov) const {
1043 for (int k = 0; k < monarray->length(); k++) {
1044 MonitorValue* mv = monarray->at(k);
1045 if (mv->owner() == ov) {
1046 return true;
1047 }
1048 }
1049
1050 return false;
1051 }
1052
1053 // Determine if there is a scalar replaced object description represented by 'ov'.
1054 bool PhaseOutput::contains_as_scalarized_obj(JVMState* jvms, MachSafePointNode* sfn,
1055 GrowableArray<ScopeValue*>* objs,
1056 ObjectValue* ov) const {
1057 for (int i = 0; i < jvms->scl_size(); i++) {
1058 Node* n = sfn->scalarized_obj(jvms, i);
1059 // Other kinds of nodes that we may encounter here, for instance constants
1060 // representing values of fields of objects scalarized, aren't relevant for
1061 // us, since they don't map to ObjectValue.
1062 if (!n->is_SafePointScalarObject()) {
1063 continue;
1064 }
1065
1066 ObjectValue* other = sv_for_node_id(objs, n->_idx);
1067 if (ov == other) {
1068 return true;
1069 }
1070 }
1071 return false;
1072 }
1073
1074 //--------------------------Process_OopMap_Node--------------------------------
1075 void PhaseOutput::Process_OopMap_Node(MachNode *mach, int current_offset) {
1076 // Handle special safepoint nodes for synchronization
1077 MachSafePointNode *sfn = mach->as_MachSafePoint();
1078 MachCallNode *mcall;
1079
1080 int safepoint_pc_offset = current_offset;
1081 bool is_method_handle_invoke = false;
1082 bool return_oop = false;
1083 bool return_scalarized = false;
1084 bool has_ea_local_in_scope = sfn->_has_ea_local_in_scope;
1085 bool arg_escape = false;
1086
1087 // Add the safepoint in the DebugInfoRecorder
1088 if( !mach->is_MachCall() ) {
1089 mcall = nullptr;
1090 C->debug_info()->add_safepoint(safepoint_pc_offset, sfn->_oop_map);
1091 } else {
1092 mcall = mach->as_MachCall();
1093
1094 // Is the call a MethodHandle call?
1095 if (mcall->is_MachCallJava()) {
1096 if (mcall->as_MachCallJava()->_method_handle_invoke) {
1097 assert(C->has_method_handle_invokes(), "must have been set during call generation");
1098 is_method_handle_invoke = true;
1099 }
1100 arg_escape = mcall->as_MachCallJava()->_arg_escape;
1101 }
1102
1103 // Check if a call returns an object.
1104 if (mcall->returns_pointer() || mcall->returns_scalarized()) {
1105 return_oop = true;
1106 }
1107 if (mcall->returns_scalarized()) {
1108 return_scalarized = true;
1109 }
1110 safepoint_pc_offset += mcall->ret_addr_offset();
1111 C->debug_info()->add_safepoint(safepoint_pc_offset, mcall->_oop_map);
1112 }
1113
1114 // Loop over the JVMState list to add scope information
1115 // Do not skip safepoints with a null method, they need monitor info
1116 JVMState* youngest_jvms = sfn->jvms();
1117 int max_depth = youngest_jvms->depth();
1118
1119 // Allocate the object pool for scalar-replaced objects -- the map from
1120 // small-integer keys (which can be recorded in the local and ostack
1121 // arrays) to descriptions of the object state.
1122 GrowableArray<ScopeValue*> *objs = new GrowableArray<ScopeValue*>();
1123
1124 // Visit scopes from oldest to youngest.
1125 for (int depth = 1; depth <= max_depth; depth++) {
1126 JVMState* jvms = youngest_jvms->of_depth(depth);
1127 int idx;
1128 ciMethod* method = jvms->has_method() ? jvms->method() : nullptr;
1129 // Safepoints that do not have method() set only provide oop-map and monitor info
1130 // to support GC; these do not support deoptimization.
1131 int num_locs = (method == nullptr) ? 0 : jvms->loc_size();
1132 int num_exps = (method == nullptr) ? 0 : jvms->stk_size();
1133 int num_mon = jvms->nof_monitors();
1134 assert(method == nullptr || jvms->bci() < 0 || num_locs == method->max_locals(),
1135 "JVMS local count must match that of the method");
1136
1137 // Add Local and Expression Stack Information
1138
1139 // Insert locals into the locarray
1140 GrowableArray<ScopeValue*> *locarray = new GrowableArray<ScopeValue*>(num_locs);
1141 for( idx = 0; idx < num_locs; idx++ ) {
1142 FillLocArray( idx, sfn, sfn->local(jvms, idx), locarray, objs );
1143 }
1144
1145 // Insert expression stack entries into the exparray
1146 GrowableArray<ScopeValue*> *exparray = new GrowableArray<ScopeValue*>(num_exps);
1147 for( idx = 0; idx < num_exps; idx++ ) {
1148 FillLocArray( idx, sfn, sfn->stack(jvms, idx), exparray, objs );
1149 }
1150
1151 // Add in mappings of the monitors
1152 assert( !method ||
1153 !method->is_synchronized() ||
1154 method->is_native() ||
1155 num_mon > 0 ||
1156 !GenerateSynchronizationCode,
1157 "monitors must always exist for synchronized methods");
1158
1159 // Build the growable array of ScopeValues for exp stack
1160 GrowableArray<MonitorValue*> *monarray = new GrowableArray<MonitorValue*>(num_mon);
1161
1162 // Loop over monitors and insert into array
1163 for (idx = 0; idx < num_mon; idx++) {
1164 // Grab the node that defines this monitor
1165 Node* box_node = sfn->monitor_box(jvms, idx);
1166 Node* obj_node = sfn->monitor_obj(jvms, idx);
1167
1168 // Create ScopeValue for object
1169 ScopeValue *scval = nullptr;
1170
1171 if (obj_node->is_SafePointScalarObject()) {
1172 SafePointScalarObjectNode* spobj = obj_node->as_SafePointScalarObject();
1173 scval = PhaseOutput::sv_for_node_id(objs, spobj->_idx);
1174 if (scval == nullptr) {
1175 const Type *t = spobj->bottom_type();
1176 ciKlass* cik = t->is_oopptr()->exact_klass();
1177 assert(cik->is_instance_klass() ||
1178 cik->is_array_klass(), "Not supported allocation.");
1179 assert(!cik->is_inlinetype(), "Synchronization on value object?");
1180 ScopeValue* properties = nullptr;
1181 if (cik->is_array_klass() && !cik->is_type_array_klass()) {
1182 jint props = ArrayKlass::ArrayProperties::DEFAULT;
1183 if (cik->as_array_klass()->element_klass()->is_inlinetype()) {
1184 if (cik->as_array_klass()->is_elem_null_free()) {
1185 props |= ArrayKlass::ArrayProperties::NULL_RESTRICTED;
1186 }
1187 if (!cik->as_array_klass()->is_elem_atomic()) {
1188 props |= ArrayKlass::ArrayProperties::NON_ATOMIC;
1189 }
1190 }
1191 properties = new ConstantIntValue(props);
1192 }
1193 ObjectValue* sv = new ObjectValue(spobj->_idx,
1194 new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()), true, properties);
1195 PhaseOutput::set_sv_for_object_node(objs, sv);
1196
1197 uint first_ind = spobj->first_index(youngest_jvms);
1198 for (uint i = 0; i < spobj->n_fields(); i++) {
1199 Node* fld_node = sfn->in(first_ind+i);
1200 (void)FillLocArray(sv->field_values()->length(), sfn, fld_node, sv->field_values(), objs);
1201 }
1202 scval = sv;
1203 }
1204 } else if (obj_node->is_SafePointScalarMerge()) {
1205 SafePointScalarMergeNode* smerge = obj_node->as_SafePointScalarMerge();
1206 ObjectMergeValue* mv = (ObjectMergeValue*) sv_for_node_id(objs, smerge->_idx);
1207
1208 if (mv == nullptr) {
1209 GrowableArray<ScopeValue*> deps;
1210
1211 int merge_pointer_idx = smerge->merge_pointer_idx(youngest_jvms);
1212 FillLocArray(0, sfn, sfn->in(merge_pointer_idx), &deps, objs);
1213 assert(deps.length() == 1, "missing value");
1214
1215 int selector_idx = smerge->selector_idx(youngest_jvms);
1216 FillLocArray(1, nullptr, sfn->in(selector_idx), &deps, nullptr);
1217 assert(deps.length() == 2, "missing value");
1218
1219 mv = new ObjectMergeValue(smerge->_idx, deps.at(0), deps.at(1));
1220 set_sv_for_object_node(objs, mv);
1221
1222 for (uint i = 1; i < smerge->req(); i++) {
1223 Node* obj_node = smerge->in(i);
1224 int idx = mv->possible_objects()->length();
1225 (void)FillLocArray(idx, sfn, obj_node, mv->possible_objects(), objs);
1226
1227 // By default ObjectValues that are in 'possible_objects' are not root objects.
1228 // They will be marked as root later if they are directly referenced in a JVMS.
1229 assert(mv->possible_objects()->length() > idx, "Didn't add entry to possible_objects?!");
1230 assert(mv->possible_objects()->at(idx)->is_object(), "Entries in possible_objects should be ObjectValue.");
1231 mv->possible_objects()->at(idx)->as_ObjectValue()->set_root(false);
1232 }
1233 }
1234 scval = mv;
1235 } else if (!obj_node->is_Con()) {
1236 OptoReg::Name obj_reg = C->regalloc()->get_reg_first(obj_node);
1237 if( obj_node->bottom_type()->base() == Type::NarrowOop ) {
1238 scval = new_loc_value( C->regalloc(), obj_reg, Location::narrowoop );
1239 } else {
1240 scval = new_loc_value( C->regalloc(), obj_reg, Location::oop );
1241 }
1242 } else {
1243 const TypePtr *tp = obj_node->get_ptr_type();
1244 scval = new ConstantOopWriteValue(tp->is_oopptr()->const_oop()->constant_encoding());
1245 }
1246
1247 OptoReg::Name box_reg = BoxLockNode::reg(box_node);
1248 Location basic_lock = Location::new_stk_loc(Location::normal,C->regalloc()->reg2offset(box_reg));
1249 bool eliminated = (box_node->is_BoxLock() && box_node->as_BoxLock()->is_eliminated());
1250 monarray->append(new MonitorValue(scval, basic_lock, eliminated));
1251 }
1252
1253 // Mark ObjectValue nodes as root nodes if they are directly
1254 // referenced in the JVMS.
1255 for (int i = 0; i < objs->length(); i++) {
1256 ScopeValue* sv = objs->at(i);
1257 if (sv->is_object_merge()) {
1258 ObjectMergeValue* merge = sv->as_ObjectMergeValue();
1259
1260 for (int j = 0; j< merge->possible_objects()->length(); j++) {
1261 ObjectValue* ov = merge->possible_objects()->at(j)->as_ObjectValue();
1262 if (ov->is_root()) {
1263 // Already flagged as 'root' by something else. We shouldn't change it
1264 // to non-root in a younger JVMS because it may need to be alive in
1265 // a younger JVMS.
1266 } else {
1267 bool is_root = locarray->contains(ov) ||
1268 exparray->contains(ov) ||
1269 contains_as_owner(monarray, ov) ||
1270 contains_as_scalarized_obj(jvms, sfn, objs, ov);
1271 ov->set_root(is_root);
1272 }
1273 }
1274 }
1275 }
1276
1277 // We dump the object pool first, since deoptimization reads it in first.
1278 C->debug_info()->dump_object_pool(objs);
1279
1280 // Build first class objects to pass to scope
1281 DebugToken *locvals = C->debug_info()->create_scope_values(locarray);
1282 DebugToken *expvals = C->debug_info()->create_scope_values(exparray);
1283 DebugToken *monvals = C->debug_info()->create_monitor_values(monarray);
1284
1285 // Make method available for all Safepoints
1286 ciMethod* scope_method = method ? method : C->method();
1287 // Describe the scope here
1288 assert(jvms->bci() >= InvocationEntryBci && jvms->bci() <= 0x10000, "must be a valid or entry BCI");
1289 assert(!jvms->should_reexecute() || depth == max_depth, "reexecute allowed only for the youngest");
1290 // Now we can describe the scope.
1291 methodHandle null_mh;
1292 bool rethrow_exception = false;
1293 C->debug_info()->describe_scope(
1294 safepoint_pc_offset,
1295 null_mh,
1296 scope_method,
1297 jvms->bci(),
1298 jvms->should_reexecute(),
1299 rethrow_exception,
1300 is_method_handle_invoke,
1301 return_oop,
1302 return_scalarized,
1303 has_ea_local_in_scope,
1304 arg_escape,
1305 locvals,
1306 expvals,
1307 monvals
1308 );
1309 } // End jvms loop
1310
1311 // Mark the end of the scope set.
1312 C->debug_info()->end_safepoint(safepoint_pc_offset);
1313 }
1314
1315
1316
1317 // A simplified version of Process_OopMap_Node, to handle non-safepoints.
1318 class NonSafepointEmitter {
1319 Compile* C;
1320 JVMState* _pending_jvms;
1321 int _pending_offset;
1322
1323 void emit_non_safepoint();
1324
1325 public:
1326 NonSafepointEmitter(Compile* compile) {
1327 this->C = compile;
1328 _pending_jvms = nullptr;
1329 _pending_offset = 0;
1330 }
1331
1332 void observe_instruction(Node* n, int pc_offset) {
1333 if (!C->debug_info()->recording_non_safepoints()) return;
1334
1335 Node_Notes* nn = C->node_notes_at(n->_idx);
1336 if (nn == nullptr || nn->jvms() == nullptr) return;
1337 if (_pending_jvms != nullptr &&
1338 _pending_jvms->same_calls_as(nn->jvms())) {
1339 // Repeated JVMS? Stretch it up here.
1340 _pending_offset = pc_offset;
1341 } else {
1342 if (_pending_jvms != nullptr &&
1343 _pending_offset < pc_offset) {
1344 emit_non_safepoint();
1345 }
1346 _pending_jvms = nullptr;
1347 if (pc_offset > C->debug_info()->last_pc_offset()) {
1348 // This is the only way _pending_jvms can become non-null:
1349 _pending_jvms = nn->jvms();
1350 _pending_offset = pc_offset;
1351 }
1352 }
1353 }
1354
1355 // Stay out of the way of real safepoints:
1356 void observe_safepoint(JVMState* jvms, int pc_offset) {
1357 if (_pending_jvms != nullptr &&
1358 !_pending_jvms->same_calls_as(jvms) &&
1359 _pending_offset < pc_offset) {
1360 emit_non_safepoint();
1361 }
1362 _pending_jvms = nullptr;
1363 }
1364
1365 void flush_at_end() {
1366 if (_pending_jvms != nullptr) {
1367 emit_non_safepoint();
1368 }
1369 _pending_jvms = nullptr;
1370 }
1371 };
1372
1373 void NonSafepointEmitter::emit_non_safepoint() {
1374 JVMState* youngest_jvms = _pending_jvms;
1375 int pc_offset = _pending_offset;
1376
1377 // Clear it now:
1378 _pending_jvms = nullptr;
1379
1380 DebugInformationRecorder* debug_info = C->debug_info();
1381 assert(debug_info->recording_non_safepoints(), "sanity");
1382
1383 debug_info->add_non_safepoint(pc_offset);
1384 int max_depth = youngest_jvms->depth();
1385
1386 // Visit scopes from oldest to youngest.
1387 for (int depth = 1; depth <= max_depth; depth++) {
1388 JVMState* jvms = youngest_jvms->of_depth(depth);
1389 ciMethod* method = jvms->has_method() ? jvms->method() : nullptr;
1390 assert(!jvms->should_reexecute() || depth==max_depth, "reexecute allowed only for the youngest");
1391 methodHandle null_mh;
1392 debug_info->describe_scope(pc_offset, null_mh, method, jvms->bci(), jvms->should_reexecute());
1393 }
1394
1395 // Mark the end of the scope set.
1396 debug_info->end_non_safepoint(pc_offset);
1397 }
1398
1399 //------------------------------init_buffer------------------------------------
1400 void PhaseOutput::estimate_buffer_size(int& const_req) {
1401
1402 // Set the initially allocated size
1403 const_req = initial_const_capacity;
1404
1405 // The extra spacing after the code is necessary on some platforms.
1406 // Sometimes we need to patch in a jump after the last instruction,
1407 // if the nmethod has been deoptimized. (See 4932387, 4894843.)
1408
1409 // Compute the byte offset where we can store the deopt pc.
1410 if (C->fixed_slots() != 0) {
1411 _orig_pc_slot_offset_in_bytes = C->regalloc()->reg2offset(OptoReg::stack2reg(_orig_pc_slot));
1412 }
1413
1414 // Compute prolog code size
1415 _frame_slots = OptoReg::reg2stack(C->matcher()->_old_SP) + C->regalloc()->_framesize;
1416 assert(_frame_slots >= 0 && _frame_slots < 1000000, "sanity check");
1417
1418 if (C->has_mach_constant_base_node()) {
1419 uint add_size = 0;
1420 // Fill the constant table.
1421 // Note: This must happen before shorten_branches.
1422 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
1423 Block* b = C->cfg()->get_block(i);
1424
1425 for (uint j = 0; j < b->number_of_nodes(); j++) {
1426 Node* n = b->get_node(j);
1427
1428 // If the node is a MachConstantNode evaluate the constant
1429 // value section.
1430 if (n->is_MachConstant()) {
1431 MachConstantNode* machcon = n->as_MachConstant();
1432 machcon->eval_constant(C);
1433 } else if (n->is_Mach()) {
1434 // On Power there are more nodes that issue constants.
1435 add_size += (n->as_Mach()->ins_num_consts() * 8);
1436 }
1437 }
1438 }
1439
1440 // Calculate the offsets of the constants and the size of the
1441 // constant table (including the padding to the next section).
1442 constant_table().calculate_offsets_and_size();
1443 const_req = constant_table().alignment() + constant_table().size() + add_size;
1444 }
1445
1446 // Initialize the space for the BufferBlob used to find and verify
1447 // instruction size in MachNode::emit_size()
1448 init_scratch_buffer_blob(const_req);
1449 }
1450
1451 CodeBuffer* PhaseOutput::init_buffer() {
1452 int stub_req = _buf_sizes._stub;
1453 int code_req = _buf_sizes._code;
1454 int const_req = _buf_sizes._const;
1455
1456 int pad_req = NativeCall::byte_size();
1457
1458 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1459 stub_req += bs->estimate_stub_size();
1460
1461 // nmethod and CodeBuffer count stubs & constants as part of method's code.
1462 // class HandlerImpl is platform-specific and defined in the *.ad files.
1463 int exception_handler_req = HandlerImpl::size_exception_handler() + MAX_stubs_size; // add marginal slop for handler
1464 int deopt_handler_req = HandlerImpl::size_deopt_handler() + MAX_stubs_size; // add marginal slop for handler
1465 stub_req += MAX_stubs_size; // ensure per-stub margin
1466 code_req += MAX_inst_size; // ensure per-instruction margin
1467
1468 if (StressCodeBuffers)
1469 code_req = const_req = stub_req = exception_handler_req = deopt_handler_req = 0x10; // force expansion
1470
1471 int total_req =
1472 const_req +
1473 code_req +
1474 pad_req +
1475 stub_req +
1476 exception_handler_req +
1477 deopt_handler_req; // deopt handler
1478
1479 if (C->has_method_handle_invokes())
1480 total_req += deopt_handler_req; // deopt MH handler
1481
1482 CodeBuffer* cb = code_buffer();
1483 cb->set_const_section_alignment(constant_table().alignment());
1484 cb->initialize(total_req, _buf_sizes._reloc);
1485
1486 // Have we run out of code space?
1487 if ((cb->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1488 C->record_failure("CodeCache is full");
1489 return nullptr;
1490 }
1491 // Configure the code buffer.
1492 cb->initialize_consts_size(const_req);
1493 cb->initialize_stubs_size(stub_req);
1494 cb->initialize_oop_recorder(C->env()->oop_recorder());
1495
1496 // fill in the nop array for bundling computations
1497 MachNode *_nop_list[Bundle::_nop_count];
1498 Bundle::initialize_nops(_nop_list);
1499
1500 return cb;
1501 }
1502
1503 //------------------------------fill_buffer------------------------------------
1504 void PhaseOutput::fill_buffer(C2_MacroAssembler* masm, uint* blk_starts) {
1505 // blk_starts[] contains offsets calculated during short branches processing,
1506 // offsets should not be increased during following steps.
1507
1508 // Compute the size of first NumberOfLoopInstrToAlign instructions at head
1509 // of a loop. It is used to determine the padding for loop alignment.
1510 Compile::TracePhase tp(_t_fillBuffer);
1511
1512 compute_loop_first_inst_sizes();
1513
1514 // Create oopmap set.
1515 _oop_map_set = new OopMapSet();
1516
1517 // !!!!! This preserves old handling of oopmaps for now
1518 C->debug_info()->set_oopmaps(_oop_map_set);
1519
1520 uint nblocks = C->cfg()->number_of_blocks();
1521 // Count and start of implicit null check instructions
1522 uint inct_cnt = 0;
1523 uint* inct_starts = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1524
1525 // Count and start of calls
1526 uint* call_returns = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1527
1528 uint return_offset = 0;
1529 int nop_size = (new MachNopNode())->size(C->regalloc());
1530
1531 int previous_offset = 0;
1532 int current_offset = 0;
1533 int last_call_offset = -1;
1534 int last_avoid_back_to_back_offset = -1;
1535 #ifdef ASSERT
1536 uint* jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks);
1537 uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
1538 uint* jmp_size = NEW_RESOURCE_ARRAY(uint,nblocks);
1539 uint* jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks);
1540 #endif
1541
1542 // Create an array of unused labels, one for each basic block, if printing is enabled
1543 #if defined(SUPPORT_OPTO_ASSEMBLY)
1544 int* node_offsets = nullptr;
1545 uint node_offset_limit = C->unique();
1546
1547 if (C->print_assembly()) {
1548 node_offsets = NEW_RESOURCE_ARRAY(int, node_offset_limit);
1549 }
1550 if (node_offsets != nullptr) {
1551 // We need to initialize. Unused array elements may contain garbage and mess up PrintOptoAssembly.
1552 memset(node_offsets, 0, node_offset_limit*sizeof(int));
1553 }
1554 #endif
1555
1556 NonSafepointEmitter non_safepoints(C); // emit non-safepoints lazily
1557
1558 // Emit the constant table.
1559 if (C->has_mach_constant_base_node()) {
1560 if (!constant_table().emit(masm)) {
1561 C->record_failure("consts section overflow");
1562 return;
1563 }
1564 }
1565
1566 // Create an array of labels, one for each basic block
1567 Label* blk_labels = NEW_RESOURCE_ARRAY(Label, nblocks+1);
1568 for (uint i = 0; i <= nblocks; i++) {
1569 blk_labels[i].init();
1570 }
1571
1572 // Now fill in the code buffer
1573 Node* delay_slot = nullptr;
1574 for (uint i = 0; i < nblocks; i++) {
1575 Block* block = C->cfg()->get_block(i);
1576 _block = block;
1577 Node* head = block->head();
1578
1579 // If this block needs to start aligned (i.e, can be reached other
1580 // than by falling-thru from the previous block), then force the
1581 // start of a new bundle.
1582 if (Pipeline::requires_bundling() && starts_bundle(head)) {
1583 masm->code()->flush_bundle(true);
1584 }
1585
1586 #ifdef ASSERT
1587 if (!block->is_connector()) {
1588 stringStream st;
1589 block->dump_head(C->cfg(), &st);
1590 masm->block_comment(st.freeze());
1591 }
1592 jmp_target[i] = 0;
1593 jmp_offset[i] = 0;
1594 jmp_size[i] = 0;
1595 jmp_rule[i] = 0;
1596 #endif
1597 int blk_offset = current_offset;
1598
1599 // Define the label at the beginning of the basic block
1600 masm->bind(blk_labels[block->_pre_order]);
1601
1602 uint last_inst = block->number_of_nodes();
1603
1604 // Emit block normally, except for last instruction.
1605 // Emit means "dump code bits into code buffer".
1606 for (uint j = 0; j<last_inst; j++) {
1607 _index = j;
1608
1609 // Get the node
1610 Node* n = block->get_node(j);
1611
1612 // See if delay slots are supported
1613 if (valid_bundle_info(n) && node_bundling(n)->used_in_unconditional_delay()) {
1614 assert(delay_slot == nullptr, "no use of delay slot node");
1615 assert(n->size(C->regalloc()) == Pipeline::instr_unit_size(), "delay slot instruction wrong size");
1616
1617 delay_slot = n;
1618 continue;
1619 }
1620
1621 // If this starts a new instruction group, then flush the current one
1622 // (but allow split bundles)
1623 if (Pipeline::requires_bundling() && starts_bundle(n))
1624 masm->code()->flush_bundle(false);
1625
1626 // Special handling for SafePoint/Call Nodes
1627 bool is_mcall = false;
1628 if (n->is_Mach()) {
1629 MachNode *mach = n->as_Mach();
1630 is_mcall = n->is_MachCall();
1631 bool is_sfn = n->is_MachSafePoint();
1632
1633 // If this requires all previous instructions be flushed, then do so
1634 if (is_sfn || is_mcall || mach->alignment_required() != 1) {
1635 masm->code()->flush_bundle(true);
1636 current_offset = masm->offset();
1637 }
1638
1639 // A padding may be needed again since a previous instruction
1640 // could be moved to delay slot.
1641
1642 // align the instruction if necessary
1643 int padding = mach->compute_padding(current_offset);
1644 // Make sure safepoint node for polling is distinct from a call's
1645 // return by adding a nop if needed.
1646 if (is_sfn && !is_mcall && padding == 0 && current_offset == last_call_offset) {
1647 padding = nop_size;
1648 }
1649 if (padding == 0 && mach->avoid_back_to_back(MachNode::AVOID_BEFORE) &&
1650 current_offset == last_avoid_back_to_back_offset) {
1651 // Avoid back to back some instructions.
1652 padding = nop_size;
1653 }
1654
1655 if (padding > 0) {
1656 assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
1657 int nops_cnt = padding / nop_size;
1658 MachNode *nop = new MachNopNode(nops_cnt);
1659 block->insert_node(nop, j++);
1660 last_inst++;
1661 C->cfg()->map_node_to_block(nop, block);
1662 // Ensure enough space.
1663 masm->code()->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1664 if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1665 C->record_failure("CodeCache is full");
1666 return;
1667 }
1668 nop->emit(masm, C->regalloc());
1669 masm->code()->flush_bundle(true);
1670 current_offset = masm->offset();
1671 }
1672
1673 bool observe_safepoint = is_sfn;
1674 // Remember the start of the last call in a basic block
1675 if (is_mcall) {
1676 MachCallNode *mcall = mach->as_MachCall();
1677
1678 if (mcall->entry_point() != nullptr) {
1679 // This destination address is NOT PC-relative
1680 mcall->method_set((intptr_t)mcall->entry_point());
1681 }
1682
1683 // Save the return address
1684 call_returns[block->_pre_order] = current_offset + mcall->ret_addr_offset();
1685
1686 observe_safepoint = mcall->guaranteed_safepoint();
1687 }
1688
1689 // sfn will be valid whenever mcall is valid now because of inheritance
1690 if (observe_safepoint) {
1691 // Handle special safepoint nodes for synchronization
1692 if (!is_mcall) {
1693 MachSafePointNode *sfn = mach->as_MachSafePoint();
1694 // !!!!! Stubs only need an oopmap right now, so bail out
1695 if (sfn->jvms()->method() == nullptr) {
1696 // Write the oopmap directly to the code blob??!!
1697 continue;
1698 }
1699 } // End synchronization
1700
1701 non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1702 current_offset);
1703 Process_OopMap_Node(mach, current_offset);
1704 } // End if safepoint
1705
1706 // If this is a null check, then add the start of the previous instruction to the list
1707 else if( mach->is_MachNullCheck() ) {
1708 inct_starts[inct_cnt++] = previous_offset;
1709 }
1710
1711 // If this is a branch, then fill in the label with the target BB's label
1712 else if (mach->is_MachBranch()) {
1713 // This requires the TRUE branch target be in succs[0]
1714 uint block_num = block->non_connector_successor(0)->_pre_order;
1715
1716 // Try to replace long branch if delay slot is not used,
1717 // it is mostly for back branches since forward branch's
1718 // distance is not updated yet.
1719 bool delay_slot_is_used = valid_bundle_info(n) &&
1720 C->output()->node_bundling(n)->use_unconditional_delay();
1721 if (!delay_slot_is_used && mach->may_be_short_branch()) {
1722 assert(delay_slot == nullptr, "not expecting delay slot node");
1723 int br_size = n->size(C->regalloc());
1724 int offset = blk_starts[block_num] - current_offset;
1725 if (block_num >= i) {
1726 // Current and following block's offset are not
1727 // finalized yet, adjust distance by the difference
1728 // between calculated and final offsets of current block.
1729 offset -= (blk_starts[i] - blk_offset);
1730 }
1731 // In the following code a nop could be inserted before
1732 // the branch which will increase the backward distance.
1733 bool needs_padding = (current_offset == last_avoid_back_to_back_offset);
1734 if (needs_padding && offset <= 0)
1735 offset -= nop_size;
1736
1737 if (C->matcher()->is_short_branch_offset(mach->rule(), br_size, offset)) {
1738 // We've got a winner. Replace this branch.
1739 MachNode* replacement = mach->as_MachBranch()->short_branch_version();
1740
1741 // Update the jmp_size.
1742 int new_size = replacement->size(C->regalloc());
1743 assert((br_size - new_size) >= (int)nop_size, "short_branch size should be smaller");
1744 // Insert padding between avoid_back_to_back branches.
1745 if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
1746 MachNode *nop = new MachNopNode();
1747 block->insert_node(nop, j++);
1748 C->cfg()->map_node_to_block(nop, block);
1749 last_inst++;
1750 nop->emit(masm, C->regalloc());
1751 masm->code()->flush_bundle(true);
1752 current_offset = masm->offset();
1753 }
1754 #ifdef ASSERT
1755 jmp_target[i] = block_num;
1756 jmp_offset[i] = current_offset - blk_offset;
1757 jmp_size[i] = new_size;
1758 jmp_rule[i] = mach->rule();
1759 #endif
1760 block->map_node(replacement, j);
1761 mach->subsume_by(replacement, C);
1762 n = replacement;
1763 mach = replacement;
1764 }
1765 }
1766 mach->as_MachBranch()->label_set( &blk_labels[block_num], block_num );
1767 } else if (mach->ideal_Opcode() == Op_Jump) {
1768 for (uint h = 0; h < block->_num_succs; h++) {
1769 Block* succs_block = block->_succs[h];
1770 for (uint j = 1; j < succs_block->num_preds(); j++) {
1771 Node* jpn = succs_block->pred(j);
1772 if (jpn->is_JumpProj() && jpn->in(0) == mach) {
1773 uint block_num = succs_block->non_connector()->_pre_order;
1774 Label *blkLabel = &blk_labels[block_num];
1775 mach->add_case_label(jpn->as_JumpProj()->proj_no(), blkLabel);
1776 }
1777 }
1778 }
1779 } else if (!n->is_Proj()) {
1780 // Remember the beginning of the previous instruction, in case
1781 // it's followed by a flag-kill and a null-check. Happens on
1782 // Intel all the time, with add-to-memory kind of opcodes.
1783 previous_offset = current_offset;
1784 }
1785
1786 // Not an else-if!
1787 // If this is a trap based cmp then add its offset to the list.
1788 if (mach->is_TrapBasedCheckNode()) {
1789 inct_starts[inct_cnt++] = current_offset;
1790 }
1791 }
1792
1793 // Verify that there is sufficient space remaining
1794 masm->code()->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1795 if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1796 C->record_failure("CodeCache is full");
1797 return;
1798 }
1799
1800 // Save the offset for the listing
1801 #if defined(SUPPORT_OPTO_ASSEMBLY)
1802 if ((node_offsets != nullptr) && (n->_idx < node_offset_limit)) {
1803 node_offsets[n->_idx] = masm->offset();
1804 }
1805 #endif
1806 assert(!C->failing_internal() || C->failure_is_artificial(), "Should not reach here if failing.");
1807
1808 // "Normal" instruction case
1809 DEBUG_ONLY(uint instr_offset = masm->offset());
1810 n->emit(masm, C->regalloc());
1811 current_offset = masm->offset();
1812
1813 // Above we only verified that there is enough space in the instruction section.
1814 // However, the instruction may emit stubs that cause code buffer expansion.
1815 // Bail out here if expansion failed due to a lack of code cache space.
1816 if (C->failing()) {
1817 return;
1818 }
1819
1820 assert(!is_mcall || (call_returns[block->_pre_order] <= (uint)current_offset),
1821 "ret_addr_offset() not within emitted code");
1822 #ifdef ASSERT
1823 uint n_size = n->size(C->regalloc());
1824 if (n_size < (current_offset-instr_offset)) {
1825 MachNode* mach = n->as_Mach();
1826 n->dump();
1827 mach->dump_format(C->regalloc(), tty);
1828 tty->print_cr(" n_size (%d), current_offset (%d), instr_offset (%d)", n_size, current_offset, instr_offset);
1829 Disassembler::decode(masm->code()->insts_begin() + instr_offset, masm->code()->insts_begin() + current_offset + 1, tty);
1830 tty->print_cr(" ------------------- ");
1831 BufferBlob* blob = this->scratch_buffer_blob();
1832 address blob_begin = blob->content_begin();
1833 Disassembler::decode(blob_begin, blob_begin + n_size + 1, tty);
1834 assert(false, "wrong size of mach node");
1835 }
1836 #endif
1837 non_safepoints.observe_instruction(n, current_offset);
1838
1839 // mcall is last "call" that can be a safepoint
1840 // record it so we can see if a poll will directly follow it
1841 // in which case we'll need a pad to make the PcDesc sites unique
1842 // see 5010568. This can be slightly inaccurate but conservative
1843 // in the case that return address is not actually at current_offset.
1844 // This is a small price to pay.
1845
1846 if (is_mcall) {
1847 last_call_offset = current_offset;
1848 }
1849
1850 if (n->is_Mach() && n->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
1851 // Avoid back to back some instructions.
1852 last_avoid_back_to_back_offset = current_offset;
1853 }
1854
1855 // See if this instruction has a delay slot
1856 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
1857 guarantee(delay_slot != nullptr, "expecting delay slot node");
1858
1859 // Back up 1 instruction
1860 masm->code()->set_insts_end(masm->code()->insts_end() - Pipeline::instr_unit_size());
1861
1862 // Save the offset for the listing
1863 #if defined(SUPPORT_OPTO_ASSEMBLY)
1864 if ((node_offsets != nullptr) && (delay_slot->_idx < node_offset_limit)) {
1865 node_offsets[delay_slot->_idx] = masm->offset();
1866 }
1867 #endif
1868
1869 // Support a SafePoint in the delay slot
1870 if (delay_slot->is_MachSafePoint()) {
1871 MachNode *mach = delay_slot->as_Mach();
1872 // !!!!! Stubs only need an oopmap right now, so bail out
1873 if (!mach->is_MachCall() && mach->as_MachSafePoint()->jvms()->method() == nullptr) {
1874 // Write the oopmap directly to the code blob??!!
1875 delay_slot = nullptr;
1876 continue;
1877 }
1878
1879 int adjusted_offset = current_offset - Pipeline::instr_unit_size();
1880 non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1881 adjusted_offset);
1882 // Generate an OopMap entry
1883 Process_OopMap_Node(mach, adjusted_offset);
1884 }
1885
1886 // Insert the delay slot instruction
1887 delay_slot->emit(masm, C->regalloc());
1888
1889 // Don't reuse it
1890 delay_slot = nullptr;
1891 }
1892
1893 } // End for all instructions in block
1894
1895 // If the next block is the top of a loop, pad this block out to align
1896 // the loop top a little. Helps prevent pipe stalls at loop back branches.
1897 if (i < nblocks-1) {
1898 Block *nb = C->cfg()->get_block(i + 1);
1899 int padding = nb->alignment_padding(current_offset);
1900 if( padding > 0 ) {
1901 MachNode *nop = new MachNopNode(padding / nop_size);
1902 block->insert_node(nop, block->number_of_nodes());
1903 C->cfg()->map_node_to_block(nop, block);
1904 nop->emit(masm, C->regalloc());
1905 current_offset = masm->offset();
1906 }
1907 }
1908 // Verify that the distance for generated before forward
1909 // short branches is still valid.
1910 guarantee((int)(blk_starts[i+1] - blk_starts[i]) >= (current_offset - blk_offset), "shouldn't increase block size");
1911
1912 // Save new block start offset
1913 blk_starts[i] = blk_offset;
1914 } // End of for all blocks
1915 blk_starts[nblocks] = current_offset;
1916
1917 non_safepoints.flush_at_end();
1918
1919 // Offset too large?
1920 if (C->failing()) return;
1921
1922 // Define a pseudo-label at the end of the code
1923 masm->bind( blk_labels[nblocks] );
1924
1925 // Compute the size of the first block
1926 _first_block_size = blk_labels[1].loc_pos() - blk_labels[0].loc_pos();
1927
1928 #ifdef ASSERT
1929 for (uint i = 0; i < nblocks; i++) { // For all blocks
1930 if (jmp_target[i] != 0) {
1931 int br_size = jmp_size[i];
1932 int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
1933 if (!C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
1934 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]);
1935 assert(false, "Displacement too large for short jmp");
1936 }
1937 }
1938 }
1939 #endif
1940
1941 if (!masm->code()->finalize_stubs()) {
1942 C->record_failure("CodeCache is full");
1943 return;
1944 }
1945
1946 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1947 bs->emit_stubs(*masm->code());
1948 if (C->failing()) return;
1949
1950 // Fill in stubs.
1951 assert(masm->inst_mark() == nullptr, "should be.");
1952 _stub_list.emit(*masm);
1953 if (C->failing()) return;
1954
1955 #ifndef PRODUCT
1956 // Information on the size of the method, without the extraneous code
1957 Scheduling::increment_method_size(masm->offset());
1958 #endif
1959
1960 // ------------------
1961 // Fill in exception table entries.
1962 FillExceptionTables(inct_cnt, call_returns, inct_starts, blk_labels);
1963
1964 // Only java methods have exception handlers and deopt handlers
1965 // class HandlerImpl is platform-specific and defined in the *.ad files.
1966 if (C->method()) {
1967 // Emit the exception handler code.
1968 _code_offsets.set_value(CodeOffsets::Exceptions, HandlerImpl::emit_exception_handler(masm));
1969 if (C->failing()) {
1970 return; // CodeBuffer::expand failed
1971 }
1972 // Emit the deopt handler code.
1973 _code_offsets.set_value(CodeOffsets::Deopt, HandlerImpl::emit_deopt_handler(masm));
1974
1975 // Emit the MethodHandle deopt handler code (if required).
1976 if (C->has_method_handle_invokes() && !C->failing()) {
1977 // We can use the same code as for the normal deopt handler, we
1978 // just need a different entry point address.
1979 _code_offsets.set_value(CodeOffsets::DeoptMH, HandlerImpl::emit_deopt_handler(masm));
1980 }
1981 }
1982
1983 // One last check for failed CodeBuffer::expand:
1984 if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1985 C->record_failure("CodeCache is full");
1986 return;
1987 }
1988
1989 #if defined(SUPPORT_ABSTRACT_ASSEMBLY) || defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_OPTO_ASSEMBLY)
1990 if (C->print_assembly()) {
1991 tty->cr();
1992 tty->print_cr("============================= C2-compiled nmethod ==============================");
1993 }
1994 #endif
1995
1996 #if defined(SUPPORT_OPTO_ASSEMBLY)
1997 // Dump the assembly code, including basic-block numbers
1998 if (C->print_assembly()) {
1999 ttyLocker ttyl; // keep the following output all in one block
2000 if (!VMThread::should_terminate()) { // test this under the tty lock
2001 // print_metadata and dump_asm may safepoint which makes us loose the ttylock.
2002 // We call them first and write to a stringStream, then we retake the lock to
2003 // make sure the end tag is coherent, and that xmlStream->pop_tag is done thread safe.
2004 ResourceMark rm;
2005 stringStream method_metadata_str;
2006 if (C->method() != nullptr) {
2007 C->method()->print_metadata(&method_metadata_str);
2008 }
2009 stringStream dump_asm_str;
2010 dump_asm_on(&dump_asm_str, node_offsets, node_offset_limit);
2011
2012 NoSafepointVerifier nsv;
2013 ttyLocker ttyl2;
2014 // This output goes directly to the tty, not the compiler log.
2015 // To enable tools to match it up with the compilation activity,
2016 // be sure to tag this tty output with the compile ID.
2017 if (xtty != nullptr) {
2018 xtty->head("opto_assembly compile_id='%d'%s", C->compile_id(),
2019 C->is_osr_compilation() ? " compile_kind='osr'" : "");
2020 }
2021 if (C->method() != nullptr) {
2022 tty->print_cr("----------------------- MetaData before Compile_id = %d ------------------------", C->compile_id());
2023 tty->print_raw(method_metadata_str.freeze());
2024 } else if (C->stub_name() != nullptr) {
2025 tty->print_cr("----------------------------- RuntimeStub %s -------------------------------", C->stub_name());
2026 }
2027 tty->cr();
2028 tty->print_cr("------------------------ OptoAssembly for Compile_id = %d -----------------------", C->compile_id());
2029 tty->print_raw(dump_asm_str.freeze());
2030 tty->print_cr("--------------------------------------------------------------------------------");
2031 if (xtty != nullptr) {
2032 xtty->tail("opto_assembly");
2033 }
2034 }
2035 }
2036 #endif
2037 }
2038
2039 void PhaseOutput::FillExceptionTables(uint cnt, uint *call_returns, uint *inct_starts, Label *blk_labels) {
2040 _inc_table.set_size(cnt);
2041
2042 uint inct_cnt = 0;
2043 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
2044 Block* block = C->cfg()->get_block(i);
2045 Node *n = nullptr;
2046 int j;
2047
2048 // Find the branch; ignore trailing NOPs.
2049 for (j = block->number_of_nodes() - 1; j >= 0; j--) {
2050 n = block->get_node(j);
2051 if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con) {
2052 break;
2053 }
2054 }
2055
2056 // If we didn't find anything, continue
2057 if (j < 0) {
2058 continue;
2059 }
2060
2061 // Compute ExceptionHandlerTable subtable entry and add it
2062 // (skip empty blocks)
2063 if (n->is_Catch()) {
2064
2065 // Get the offset of the return from the call
2066 uint call_return = call_returns[block->_pre_order];
2067 #ifdef ASSERT
2068 assert( call_return > 0, "no call seen for this basic block" );
2069 while (block->get_node(--j)->is_MachProj()) ;
2070 assert(block->get_node(j)->is_MachCall(), "CatchProj must follow call");
2071 #endif
2072 // last instruction is a CatchNode, find it's CatchProjNodes
2073 int nof_succs = block->_num_succs;
2074 // allocate space
2075 GrowableArray<intptr_t> handler_bcis(nof_succs);
2076 GrowableArray<intptr_t> handler_pcos(nof_succs);
2077 // iterate through all successors
2078 for (int j = 0; j < nof_succs; j++) {
2079 Block* s = block->_succs[j];
2080 bool found_p = false;
2081 for (uint k = 1; k < s->num_preds(); k++) {
2082 Node* pk = s->pred(k);
2083 if (pk->is_CatchProj() && pk->in(0) == n) {
2084 const CatchProjNode* p = pk->as_CatchProj();
2085 found_p = true;
2086 // add the corresponding handler bci & pco information
2087 if (p->_con != CatchProjNode::fall_through_index) {
2088 // p leads to an exception handler (and is not fall through)
2089 assert(s == C->cfg()->get_block(s->_pre_order), "bad numbering");
2090 // no duplicates, please
2091 if (!handler_bcis.contains(p->handler_bci())) {
2092 uint block_num = s->non_connector()->_pre_order;
2093 handler_bcis.append(p->handler_bci());
2094 handler_pcos.append(blk_labels[block_num].loc_pos());
2095 }
2096 }
2097 }
2098 }
2099 assert(found_p, "no matching predecessor found");
2100 // Note: Due to empty block removal, one block may have
2101 // several CatchProj inputs, from the same Catch.
2102 }
2103
2104 // Set the offset of the return from the call
2105 assert(handler_bcis.find(-1) != -1, "must have default handler");
2106 _handler_table.add_subtable(call_return, &handler_bcis, nullptr, &handler_pcos);
2107 continue;
2108 }
2109
2110 // Handle implicit null exception table updates
2111 if (n->is_MachNullCheck()) {
2112 MachNode* access = n->in(1)->as_Mach();
2113 assert(access->barrier_data() == 0 ||
2114 access->is_late_expanded_null_check_candidate(),
2115 "Implicit null checks on memory accesses with barriers are only supported on nodes explicitly marked as null-check candidates");
2116 uint block_num = block->non_connector_successor(0)->_pre_order;
2117 _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
2118 continue;
2119 }
2120 // Handle implicit exception table updates: trap instructions.
2121 if (n->is_Mach() && n->as_Mach()->is_TrapBasedCheckNode()) {
2122 uint block_num = block->non_connector_successor(0)->_pre_order;
2123 _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
2124 continue;
2125 }
2126 } // End of for all blocks fill in exception table entries
2127 }
2128
2129 // Static Variables
2130 #ifndef PRODUCT
2131 uint Scheduling::_total_nop_size = 0;
2132 uint Scheduling::_total_method_size = 0;
2133 uint Scheduling::_total_branches = 0;
2134 uint Scheduling::_total_unconditional_delays = 0;
2135 uint Scheduling::_total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
2136 #endif
2137
2138 // Initializer for class Scheduling
2139
2140 Scheduling::Scheduling(Arena *arena, Compile &compile)
2141 : _arena(arena),
2142 _cfg(compile.cfg()),
2143 _regalloc(compile.regalloc()),
2144 _scheduled(arena),
2145 _available(arena),
2146 _reg_node(arena),
2147 _pinch_free_list(arena),
2148 _next_node(nullptr),
2149 _bundle_instr_count(0),
2150 _bundle_cycle_number(0),
2151 _bundle_use(0, 0, resource_count, &_bundle_use_elements[0])
2152 #ifndef PRODUCT
2153 , _branches(0)
2154 , _unconditional_delays(0)
2155 #endif
2156 {
2157 // Create a MachNopNode
2158 _nop = new MachNopNode();
2159
2160 // Now that the nops are in the array, save the count
2161 // (but allow entries for the nops)
2162 _node_bundling_limit = compile.unique();
2163 uint node_max = _regalloc->node_regs_max_index();
2164
2165 compile.output()->set_node_bundling_limit(_node_bundling_limit);
2166
2167 // This one is persistent within the Compile class
2168 _node_bundling_base = NEW_ARENA_ARRAY(compile.comp_arena(), Bundle, node_max);
2169
2170 // Allocate space for fixed-size arrays
2171 _uses = NEW_ARENA_ARRAY(arena, short, node_max);
2172 _current_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
2173
2174 // Clear the arrays
2175 for (uint i = 0; i < node_max; i++) {
2176 ::new (&_node_bundling_base[i]) Bundle();
2177 }
2178 memset(_uses, 0, node_max * sizeof(short));
2179 memset(_current_latency, 0, node_max * sizeof(unsigned short));
2180
2181 // Clear the bundling information
2182 memcpy(_bundle_use_elements, Pipeline_Use::elaborated_elements, sizeof(Pipeline_Use::elaborated_elements));
2183
2184 // Get the last node
2185 Block* block = _cfg->get_block(_cfg->number_of_blocks() - 1);
2186
2187 _next_node = block->get_node(block->number_of_nodes() - 1);
2188 }
2189
2190 #ifndef PRODUCT
2191 // Scheduling destructor
2192 Scheduling::~Scheduling() {
2193 _total_branches += _branches;
2194 _total_unconditional_delays += _unconditional_delays;
2195 }
2196 #endif
2197
2198 // Step ahead "i" cycles
2199 void Scheduling::step(uint i) {
2200
2201 Bundle *bundle = node_bundling(_next_node);
2202 bundle->set_starts_bundle();
2203
2204 // Update the bundle record, but leave the flags information alone
2205 if (_bundle_instr_count > 0) {
2206 bundle->set_instr_count(_bundle_instr_count);
2207 bundle->set_resources_used(_bundle_use.resourcesUsed());
2208 }
2209
2210 // Update the state information
2211 _bundle_instr_count = 0;
2212 _bundle_cycle_number += i;
2213 _bundle_use.step(i);
2214 }
2215
2216 void Scheduling::step_and_clear() {
2217 Bundle *bundle = node_bundling(_next_node);
2218 bundle->set_starts_bundle();
2219
2220 // Update the bundle record
2221 if (_bundle_instr_count > 0) {
2222 bundle->set_instr_count(_bundle_instr_count);
2223 bundle->set_resources_used(_bundle_use.resourcesUsed());
2224
2225 _bundle_cycle_number += 1;
2226 }
2227
2228 // Clear the bundling information
2229 _bundle_instr_count = 0;
2230 _bundle_use.reset();
2231
2232 memcpy(_bundle_use_elements,
2233 Pipeline_Use::elaborated_elements,
2234 sizeof(Pipeline_Use::elaborated_elements));
2235 }
2236
2237 // Perform instruction scheduling and bundling over the sequence of
2238 // instructions in backwards order.
2239 void PhaseOutput::ScheduleAndBundle() {
2240
2241 // Don't optimize this if it isn't a method
2242 if (!C->method())
2243 return;
2244
2245 // Don't optimize this if scheduling is disabled
2246 if (!C->do_scheduling())
2247 return;
2248
2249 // Scheduling code works only with pairs (8 bytes) maximum.
2250 // And when the scalable vector register is used, we may spill/unspill
2251 // the whole reg regardless of the max vector size.
2252 if (C->max_vector_size() > 8 ||
2253 (C->max_vector_size() > 0 && Matcher::supports_scalable_vector())) {
2254 return;
2255 }
2256
2257 Compile::TracePhase tp(_t_instrSched);
2258
2259 // Create a data structure for all the scheduling information
2260 Scheduling scheduling(Thread::current()->resource_area(), *C);
2261
2262 // Walk backwards over each basic block, computing the needed alignment
2263 // Walk over all the basic blocks
2264 scheduling.DoScheduling();
2265
2266 #ifndef PRODUCT
2267 if (C->trace_opto_output()) {
2268 // Buffer and print all at once
2269 ResourceMark rm;
2270 stringStream ss;
2271 ss.print("\n---- After ScheduleAndBundle ----\n");
2272 print_scheduling(&ss);
2273 tty->print("%s", ss.as_string());
2274 }
2275 #endif
2276 }
2277
2278 #ifndef PRODUCT
2279 // Separated out so that it can be called directly from debugger
2280 void PhaseOutput::print_scheduling() {
2281 print_scheduling(tty);
2282 }
2283
2284 void PhaseOutput::print_scheduling(outputStream* output_stream) {
2285 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
2286 output_stream->print("\nBB#%03d:\n", i);
2287 Block* block = C->cfg()->get_block(i);
2288 for (uint j = 0; j < block->number_of_nodes(); j++) {
2289 Node* n = block->get_node(j);
2290 OptoReg::Name reg = C->regalloc()->get_reg_first(n);
2291 output_stream->print(" %-6s ", reg >= 0 && reg < REG_COUNT ? Matcher::regName[reg] : "");
2292 n->dump("\n", false, output_stream);
2293 }
2294 }
2295 }
2296 #endif
2297
2298 // See if this node fits into the present instruction bundle
2299 bool Scheduling::NodeFitsInBundle(Node *n) {
2300 uint n_idx = n->_idx;
2301
2302 // If this is the unconditional delay instruction, then it fits
2303 if (n == _unconditional_delay_slot) {
2304 #ifndef PRODUCT
2305 if (_cfg->C->trace_opto_output())
2306 tty->print("# NodeFitsInBundle [%4d]: TRUE; is in unconditional delay slot\n", n->_idx);
2307 #endif
2308 return (true);
2309 }
2310
2311 // If the node cannot be scheduled this cycle, skip it
2312 if (_current_latency[n_idx] > _bundle_cycle_number) {
2313 #ifndef PRODUCT
2314 if (_cfg->C->trace_opto_output())
2315 tty->print("# NodeFitsInBundle [%4d]: FALSE; latency %4d > %d\n",
2316 n->_idx, _current_latency[n_idx], _bundle_cycle_number);
2317 #endif
2318 return (false);
2319 }
2320
2321 const Pipeline *node_pipeline = n->pipeline();
2322
2323 uint instruction_count = node_pipeline->instructionCount();
2324 if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2325 instruction_count = 0;
2326 else if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
2327 instruction_count++;
2328
2329 if (_bundle_instr_count + instruction_count > Pipeline::_max_instrs_per_cycle) {
2330 #ifndef PRODUCT
2331 if (_cfg->C->trace_opto_output())
2332 tty->print("# NodeFitsInBundle [%4d]: FALSE; too many instructions: %d > %d\n",
2333 n->_idx, _bundle_instr_count + instruction_count, Pipeline::_max_instrs_per_cycle);
2334 #endif
2335 return (false);
2336 }
2337
2338 // Don't allow non-machine nodes to be handled this way
2339 if (!n->is_Mach() && instruction_count == 0)
2340 return (false);
2341
2342 // See if there is any overlap
2343 uint delay = _bundle_use.full_latency(0, node_pipeline->resourceUse());
2344
2345 if (delay > 0) {
2346 #ifndef PRODUCT
2347 if (_cfg->C->trace_opto_output())
2348 tty->print("# NodeFitsInBundle [%4d]: FALSE; functional units overlap\n", n_idx);
2349 #endif
2350 return false;
2351 }
2352
2353 #ifndef PRODUCT
2354 if (_cfg->C->trace_opto_output())
2355 tty->print("# NodeFitsInBundle [%4d]: TRUE\n", n_idx);
2356 #endif
2357
2358 return true;
2359 }
2360
2361 Node * Scheduling::ChooseNodeToBundle() {
2362 uint siz = _available.size();
2363
2364 if (siz == 0) {
2365
2366 #ifndef PRODUCT
2367 if (_cfg->C->trace_opto_output())
2368 tty->print("# ChooseNodeToBundle: null\n");
2369 #endif
2370 return (nullptr);
2371 }
2372
2373 // Fast path, if only 1 instruction in the bundle
2374 if (siz == 1) {
2375 #ifndef PRODUCT
2376 if (_cfg->C->trace_opto_output()) {
2377 tty->print("# ChooseNodeToBundle (only 1): ");
2378 _available[0]->dump();
2379 }
2380 #endif
2381 return (_available[0]);
2382 }
2383
2384 // Don't bother, if the bundle is already full
2385 if (_bundle_instr_count < Pipeline::_max_instrs_per_cycle) {
2386 for ( uint i = 0; i < siz; i++ ) {
2387 Node *n = _available[i];
2388
2389 // Skip projections, we'll handle them another way
2390 if (n->is_Proj())
2391 continue;
2392
2393 // This presupposed that instructions are inserted into the
2394 // available list in a legality order; i.e. instructions that
2395 // must be inserted first are at the head of the list
2396 if (NodeFitsInBundle(n)) {
2397 #ifndef PRODUCT
2398 if (_cfg->C->trace_opto_output()) {
2399 tty->print("# ChooseNodeToBundle: ");
2400 n->dump();
2401 }
2402 #endif
2403 return (n);
2404 }
2405 }
2406 }
2407
2408 // Nothing fits in this bundle, choose the highest priority
2409 #ifndef PRODUCT
2410 if (_cfg->C->trace_opto_output()) {
2411 tty->print("# ChooseNodeToBundle: ");
2412 _available[0]->dump();
2413 }
2414 #endif
2415
2416 return _available[0];
2417 }
2418
2419 int Scheduling::compare_two_spill_nodes(Node* first, Node* second) {
2420 assert(first->is_MachSpillCopy() && second->is_MachSpillCopy(), "");
2421
2422 OptoReg::Name first_src_lo = _regalloc->get_reg_first(first->in(1));
2423 OptoReg::Name first_dst_lo = _regalloc->get_reg_first(first);
2424 OptoReg::Name second_src_lo = _regalloc->get_reg_first(second->in(1));
2425 OptoReg::Name second_dst_lo = _regalloc->get_reg_first(second);
2426
2427 // Comparison between stack -> reg and stack -> reg
2428 if (OptoReg::is_stack(first_src_lo) && OptoReg::is_stack(second_src_lo) &&
2429 OptoReg::is_reg(first_dst_lo) && OptoReg::is_reg(second_dst_lo)) {
2430 return _regalloc->reg2offset(first_src_lo) - _regalloc->reg2offset(second_src_lo);
2431 }
2432
2433 // Comparison between reg -> stack and reg -> stack
2434 if (OptoReg::is_stack(first_dst_lo) && OptoReg::is_stack(second_dst_lo) &&
2435 OptoReg::is_reg(first_src_lo) && OptoReg::is_reg(second_src_lo)) {
2436 return _regalloc->reg2offset(first_dst_lo) - _regalloc->reg2offset(second_dst_lo);
2437 }
2438
2439 return 0; // Not comparable
2440 }
2441
2442 void Scheduling::AddNodeToAvailableList(Node *n) {
2443 assert( !n->is_Proj(), "projections never directly made available" );
2444 #ifndef PRODUCT
2445 if (_cfg->C->trace_opto_output()) {
2446 tty->print("# AddNodeToAvailableList: ");
2447 n->dump();
2448 }
2449 #endif
2450
2451 int latency = _current_latency[n->_idx];
2452
2453 // Insert in latency order (insertion sort). If two MachSpillCopyNodes
2454 // for stack spilling or unspilling have the same latency, we sort
2455 // them in the order of stack offset. Some ports (e.g. aarch64) may also
2456 // have more opportunities to do ld/st merging
2457 uint i;
2458 for (i = 0; i < _available.size(); i++) {
2459 if (_current_latency[_available[i]->_idx] > latency) {
2460 break;
2461 } else if (_current_latency[_available[i]->_idx] == latency &&
2462 n->is_MachSpillCopy() && _available[i]->is_MachSpillCopy() &&
2463 compare_two_spill_nodes(n, _available[i]) > 0) {
2464 break;
2465 }
2466 }
2467
2468 // Special Check for compares following branches
2469 if( n->is_Mach() && _scheduled.size() > 0 ) {
2470 int op = n->as_Mach()->ideal_Opcode();
2471 Node *last = _scheduled[0];
2472 if( last->is_MachIf() && last->in(1) == n &&
2473 ( op == Op_CmpI ||
2474 op == Op_CmpU ||
2475 op == Op_CmpUL ||
2476 op == Op_CmpP ||
2477 op == Op_CmpF ||
2478 op == Op_CmpD ||
2479 op == Op_CmpL ) ) {
2480
2481 // Recalculate position, moving to front of same latency
2482 for ( i=0 ; i < _available.size(); i++ )
2483 if (_current_latency[_available[i]->_idx] >= latency)
2484 break;
2485 }
2486 }
2487
2488 // Insert the node in the available list
2489 _available.insert(i, n);
2490
2491 #ifndef PRODUCT
2492 if (_cfg->C->trace_opto_output())
2493 dump_available();
2494 #endif
2495 }
2496
2497 void Scheduling::DecrementUseCounts(Node *n, const Block *bb) {
2498 for ( uint i=0; i < n->len(); i++ ) {
2499 Node *def = n->in(i);
2500 if (!def) continue;
2501 if( def->is_Proj() ) // If this is a machine projection, then
2502 def = def->in(0); // propagate usage thru to the base instruction
2503
2504 if(_cfg->get_block_for_node(def) != bb) { // Ignore if not block-local
2505 continue;
2506 }
2507
2508 // Compute the latency
2509 uint l = _bundle_cycle_number + n->latency(i);
2510 if (_current_latency[def->_idx] < l)
2511 _current_latency[def->_idx] = l;
2512
2513 // If this does not have uses then schedule it
2514 if ((--_uses[def->_idx]) == 0)
2515 AddNodeToAvailableList(def);
2516 }
2517 }
2518
2519 void Scheduling::AddNodeToBundle(Node *n, const Block *bb) {
2520 #ifndef PRODUCT
2521 if (_cfg->C->trace_opto_output()) {
2522 tty->print("# AddNodeToBundle: ");
2523 n->dump();
2524 }
2525 #endif
2526
2527 // Remove this from the available list
2528 uint i;
2529 for (i = 0; i < _available.size(); i++)
2530 if (_available[i] == n)
2531 break;
2532 assert(i < _available.size(), "entry in _available list not found");
2533 _available.remove(i);
2534
2535 // See if this fits in the current bundle
2536 const Pipeline *node_pipeline = n->pipeline();
2537 const Pipeline_Use& node_usage = node_pipeline->resourceUse();
2538
2539 // Check for instructions to be placed in the delay slot. We
2540 // do this before we actually schedule the current instruction,
2541 // because the delay slot follows the current instruction.
2542 if (Pipeline::_branch_has_delay_slot &&
2543 node_pipeline->hasBranchDelay() &&
2544 !_unconditional_delay_slot) {
2545
2546 uint siz = _available.size();
2547
2548 // Conditional branches can support an instruction that
2549 // is unconditionally executed and not dependent by the
2550 // branch, OR a conditionally executed instruction if
2551 // the branch is taken. In practice, this means that
2552 // the first instruction at the branch target is
2553 // copied to the delay slot, and the branch goes to
2554 // the instruction after that at the branch target
2555 if ( n->is_MachBranch() ) {
2556
2557 assert( !n->is_MachNullCheck(), "should not look for delay slot for Null Check" );
2558 assert( !n->is_Catch(), "should not look for delay slot for Catch" );
2559
2560 #ifndef PRODUCT
2561 _branches++;
2562 #endif
2563
2564 // At least 1 instruction is on the available list
2565 // that is not dependent on the branch
2566 for (uint i = 0; i < siz; i++) {
2567 Node *d = _available[i];
2568 const Pipeline *avail_pipeline = d->pipeline();
2569
2570 // Don't allow safepoints in the branch shadow, that will
2571 // cause a number of difficulties
2572 if ( avail_pipeline->instructionCount() == 1 &&
2573 !avail_pipeline->hasMultipleBundles() &&
2574 !avail_pipeline->hasBranchDelay() &&
2575 Pipeline::instr_has_unit_size() &&
2576 d->size(_regalloc) == Pipeline::instr_unit_size() &&
2577 NodeFitsInBundle(d) &&
2578 !node_bundling(d)->used_in_delay()) {
2579
2580 if (d->is_Mach() && !d->is_MachSafePoint()) {
2581 // A node that fits in the delay slot was found, so we need to
2582 // set the appropriate bits in the bundle pipeline information so
2583 // that it correctly indicates resource usage. Later, when we
2584 // attempt to add this instruction to the bundle, we will skip
2585 // setting the resource usage.
2586 _unconditional_delay_slot = d;
2587 node_bundling(n)->set_use_unconditional_delay();
2588 node_bundling(d)->set_used_in_unconditional_delay();
2589 _bundle_use.add_usage(avail_pipeline->resourceUse());
2590 _current_latency[d->_idx] = _bundle_cycle_number;
2591 _next_node = d;
2592 ++_bundle_instr_count;
2593 #ifndef PRODUCT
2594 _unconditional_delays++;
2595 #endif
2596 break;
2597 }
2598 }
2599 }
2600 }
2601
2602 // No delay slot, add a nop to the usage
2603 if (!_unconditional_delay_slot) {
2604 // See if adding an instruction in the delay slot will overflow
2605 // the bundle.
2606 if (!NodeFitsInBundle(_nop)) {
2607 #ifndef PRODUCT
2608 if (_cfg->C->trace_opto_output())
2609 tty->print("# *** STEP(1 instruction for delay slot) ***\n");
2610 #endif
2611 step(1);
2612 }
2613
2614 _bundle_use.add_usage(_nop->pipeline()->resourceUse());
2615 _next_node = _nop;
2616 ++_bundle_instr_count;
2617 }
2618
2619 // See if the instruction in the delay slot requires a
2620 // step of the bundles
2621 if (!NodeFitsInBundle(n)) {
2622 #ifndef PRODUCT
2623 if (_cfg->C->trace_opto_output())
2624 tty->print("# *** STEP(branch won't fit) ***\n");
2625 #endif
2626 // Update the state information
2627 _bundle_instr_count = 0;
2628 _bundle_cycle_number += 1;
2629 _bundle_use.step(1);
2630 }
2631 }
2632
2633 // Get the number of instructions
2634 uint instruction_count = node_pipeline->instructionCount();
2635 if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2636 instruction_count = 0;
2637
2638 // Compute the latency information
2639 uint delay = 0;
2640
2641 if (instruction_count > 0 || !node_pipeline->mayHaveNoCode()) {
2642 int relative_latency = _current_latency[n->_idx] - _bundle_cycle_number;
2643 if (relative_latency < 0)
2644 relative_latency = 0;
2645
2646 delay = _bundle_use.full_latency(relative_latency, node_usage);
2647
2648 // Does not fit in this bundle, start a new one
2649 if (delay > 0) {
2650 step(delay);
2651
2652 #ifndef PRODUCT
2653 if (_cfg->C->trace_opto_output())
2654 tty->print("# *** STEP(%d) ***\n", delay);
2655 #endif
2656 }
2657 }
2658
2659 // If this was placed in the delay slot, ignore it
2660 if (n != _unconditional_delay_slot) {
2661
2662 if (delay == 0) {
2663 if (node_pipeline->hasMultipleBundles()) {
2664 #ifndef PRODUCT
2665 if (_cfg->C->trace_opto_output())
2666 tty->print("# *** STEP(multiple instructions) ***\n");
2667 #endif
2668 step(1);
2669 }
2670
2671 else if (instruction_count + _bundle_instr_count > Pipeline::_max_instrs_per_cycle) {
2672 #ifndef PRODUCT
2673 if (_cfg->C->trace_opto_output())
2674 tty->print("# *** STEP(%d >= %d instructions) ***\n",
2675 instruction_count + _bundle_instr_count,
2676 Pipeline::_max_instrs_per_cycle);
2677 #endif
2678 step(1);
2679 }
2680 }
2681
2682 if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
2683 _bundle_instr_count++;
2684
2685 // Set the node's latency
2686 _current_latency[n->_idx] = _bundle_cycle_number;
2687
2688 // Now merge the functional unit information
2689 if (instruction_count > 0 || !node_pipeline->mayHaveNoCode())
2690 _bundle_use.add_usage(node_usage);
2691
2692 // Increment the number of instructions in this bundle
2693 _bundle_instr_count += instruction_count;
2694
2695 // Remember this node for later
2696 if (n->is_Mach())
2697 _next_node = n;
2698 }
2699
2700 // It's possible to have a BoxLock in the graph and in the _bbs mapping but
2701 // not in the bb->_nodes array. This happens for debug-info-only BoxLocks.
2702 // 'Schedule' them (basically ignore in the schedule) but do not insert them
2703 // into the block. All other scheduled nodes get put in the schedule here.
2704 int op = n->Opcode();
2705 if( (op == Op_Node && n->req() == 0) || // anti-dependence node OR
2706 (op != Op_Node && // Not an unused antidepedence node and
2707 // not an unallocated boxlock
2708 (OptoReg::is_valid(_regalloc->get_reg_first(n)) || op != Op_BoxLock)) ) {
2709
2710 // Push any trailing projections
2711 if( bb->get_node(bb->number_of_nodes()-1) != n ) {
2712 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2713 Node *foi = n->fast_out(i);
2714 if( foi->is_Proj() )
2715 _scheduled.push(foi);
2716 }
2717 }
2718
2719 // Put the instruction in the schedule list
2720 _scheduled.push(n);
2721 }
2722
2723 #ifndef PRODUCT
2724 if (_cfg->C->trace_opto_output())
2725 dump_available();
2726 #endif
2727
2728 // Walk all the definitions, decrementing use counts, and
2729 // if a definition has a 0 use count, place it in the available list.
2730 DecrementUseCounts(n,bb);
2731 }
2732
2733 // This method sets the use count within a basic block. We will ignore all
2734 // uses outside the current basic block. As we are doing a backwards walk,
2735 // any node we reach that has a use count of 0 may be scheduled. This also
2736 // avoids the problem of cyclic references from phi nodes, as long as phi
2737 // nodes are at the front of the basic block. This method also initializes
2738 // the available list to the set of instructions that have no uses within this
2739 // basic block.
2740 void Scheduling::ComputeUseCount(const Block *bb) {
2741 #ifndef PRODUCT
2742 if (_cfg->C->trace_opto_output())
2743 tty->print("# -> ComputeUseCount\n");
2744 #endif
2745
2746 // Clear the list of available and scheduled instructions, just in case
2747 _available.clear();
2748 _scheduled.clear();
2749
2750 // No delay slot specified
2751 _unconditional_delay_slot = nullptr;
2752
2753 #ifdef ASSERT
2754 for( uint i=0; i < bb->number_of_nodes(); i++ )
2755 assert( _uses[bb->get_node(i)->_idx] == 0, "_use array not clean" );
2756 #endif
2757
2758 // Force the _uses count to never go to zero for unscheduable pieces
2759 // of the block
2760 for( uint k = 0; k < _bb_start; k++ )
2761 _uses[bb->get_node(k)->_idx] = 1;
2762 for( uint l = _bb_end; l < bb->number_of_nodes(); l++ )
2763 _uses[bb->get_node(l)->_idx] = 1;
2764
2765 // Iterate backwards over the instructions in the block. Don't count the
2766 // branch projections at end or the block header instructions.
2767 for( uint j = _bb_end-1; j >= _bb_start; j-- ) {
2768 Node *n = bb->get_node(j);
2769 if( n->is_Proj() ) continue; // Projections handled another way
2770
2771 // Account for all uses
2772 for ( uint k = 0; k < n->len(); k++ ) {
2773 Node *inp = n->in(k);
2774 if (!inp) continue;
2775 assert(inp != n, "no cycles allowed" );
2776 if (_cfg->get_block_for_node(inp) == bb) { // Block-local use?
2777 if (inp->is_Proj()) { // Skip through Proj's
2778 inp = inp->in(0);
2779 }
2780 ++_uses[inp->_idx]; // Count 1 block-local use
2781 }
2782 }
2783
2784 // If this instruction has a 0 use count, then it is available
2785 if (!_uses[n->_idx]) {
2786 _current_latency[n->_idx] = _bundle_cycle_number;
2787 AddNodeToAvailableList(n);
2788 }
2789
2790 #ifndef PRODUCT
2791 if (_cfg->C->trace_opto_output()) {
2792 tty->print("# uses: %3d: ", _uses[n->_idx]);
2793 n->dump();
2794 }
2795 #endif
2796 }
2797
2798 #ifndef PRODUCT
2799 if (_cfg->C->trace_opto_output())
2800 tty->print("# <- ComputeUseCount\n");
2801 #endif
2802 }
2803
2804 // This routine performs scheduling on each basic block in reverse order,
2805 // using instruction latencies and taking into account function unit
2806 // availability.
2807 void Scheduling::DoScheduling() {
2808 #ifndef PRODUCT
2809 if (_cfg->C->trace_opto_output())
2810 tty->print("# -> DoScheduling\n");
2811 #endif
2812
2813 Block *succ_bb = nullptr;
2814 Block *bb;
2815 Compile* C = Compile::current();
2816
2817 // Walk over all the basic blocks in reverse order
2818 for (int i = _cfg->number_of_blocks() - 1; i >= 0; succ_bb = bb, i--) {
2819 bb = _cfg->get_block(i);
2820
2821 #ifndef PRODUCT
2822 if (_cfg->C->trace_opto_output()) {
2823 tty->print("# Schedule BB#%03d (initial)\n", i);
2824 for (uint j = 0; j < bb->number_of_nodes(); j++) {
2825 bb->get_node(j)->dump();
2826 }
2827 }
2828 #endif
2829
2830 // On the head node, skip processing
2831 if (bb == _cfg->get_root_block()) {
2832 continue;
2833 }
2834
2835 // Skip empty, connector blocks
2836 if (bb->is_connector())
2837 continue;
2838
2839 // If the following block is not the sole successor of
2840 // this one, then reset the pipeline information
2841 if (bb->_num_succs != 1 || bb->non_connector_successor(0) != succ_bb) {
2842 #ifndef PRODUCT
2843 if (_cfg->C->trace_opto_output()) {
2844 tty->print("*** bundle start of next BB, node %d, for %d instructions\n",
2845 _next_node->_idx, _bundle_instr_count);
2846 }
2847 #endif
2848 step_and_clear();
2849 }
2850
2851 // Leave untouched the starting instruction, any Phis, a CreateEx node
2852 // or Top. bb->get_node(_bb_start) is the first schedulable instruction.
2853 _bb_end = bb->number_of_nodes()-1;
2854 for( _bb_start=1; _bb_start <= _bb_end; _bb_start++ ) {
2855 Node *n = bb->get_node(_bb_start);
2856 // Things not matched, like Phinodes and ProjNodes don't get scheduled.
2857 // Also, MachIdealNodes do not get scheduled
2858 if( !n->is_Mach() ) continue; // Skip non-machine nodes
2859 MachNode *mach = n->as_Mach();
2860 int iop = mach->ideal_Opcode();
2861 if( iop == Op_CreateEx ) continue; // CreateEx is pinned
2862 if( iop == Op_Con ) continue; // Do not schedule Top
2863 if( iop == Op_Node && // Do not schedule PhiNodes, ProjNodes
2864 mach->pipeline() == MachNode::pipeline_class() &&
2865 !n->is_SpillCopy() && !n->is_MachMerge() ) // Breakpoints, Prolog, etc
2866 continue;
2867 break; // Funny loop structure to be sure...
2868 }
2869 // Compute last "interesting" instruction in block - last instruction we
2870 // might schedule. _bb_end points just after last schedulable inst. We
2871 // normally schedule conditional branches (despite them being forced last
2872 // in the block), because they have delay slots we can fill. Calls all
2873 // have their delay slots filled in the template expansions, so we don't
2874 // bother scheduling them.
2875 Node *last = bb->get_node(_bb_end);
2876 // Ignore trailing NOPs.
2877 while (_bb_end > 0 && last->is_Mach() &&
2878 last->as_Mach()->ideal_Opcode() == Op_Con) {
2879 last = bb->get_node(--_bb_end);
2880 }
2881 assert(!last->is_Mach() || last->as_Mach()->ideal_Opcode() != Op_Con, "");
2882 if( last->is_Catch() ||
2883 (last->is_Mach() && last->as_Mach()->ideal_Opcode() == Op_Halt) ) {
2884 // There might be a prior call. Skip it.
2885 while (_bb_start < _bb_end && bb->get_node(--_bb_end)->is_MachProj());
2886 } else if( last->is_MachNullCheck() ) {
2887 // Backup so the last null-checked memory instruction is
2888 // outside the schedulable range. Skip over the nullcheck,
2889 // projection, and the memory nodes.
2890 Node *mem = last->in(1);
2891 do {
2892 _bb_end--;
2893 } while (mem != bb->get_node(_bb_end));
2894 } else {
2895 // Set _bb_end to point after last schedulable inst.
2896 _bb_end++;
2897 }
2898
2899 assert( _bb_start <= _bb_end, "inverted block ends" );
2900
2901 // Compute the register antidependencies for the basic block
2902 ComputeRegisterAntidependencies(bb);
2903 if (C->failing()) return; // too many D-U pinch points
2904
2905 // Compute the usage within the block, and set the list of all nodes
2906 // in the block that have no uses within the block.
2907 ComputeUseCount(bb);
2908
2909 // Schedule the remaining instructions in the block
2910 while ( _available.size() > 0 ) {
2911 Node *n = ChooseNodeToBundle();
2912 guarantee(n != nullptr, "no nodes available");
2913 AddNodeToBundle(n,bb);
2914 }
2915
2916 assert( _scheduled.size() == _bb_end - _bb_start, "wrong number of instructions" );
2917 #ifdef ASSERT
2918 for( uint l = _bb_start; l < _bb_end; l++ ) {
2919 Node *n = bb->get_node(l);
2920 uint m;
2921 for( m = 0; m < _bb_end-_bb_start; m++ )
2922 if( _scheduled[m] == n )
2923 break;
2924 assert( m < _bb_end-_bb_start, "instruction missing in schedule" );
2925 }
2926 #endif
2927
2928 // Now copy the instructions (in reverse order) back to the block
2929 for ( uint k = _bb_start; k < _bb_end; k++ )
2930 bb->map_node(_scheduled[_bb_end-k-1], k);
2931
2932 #ifndef PRODUCT
2933 if (_cfg->C->trace_opto_output()) {
2934 tty->print("# Schedule BB#%03d (final)\n", i);
2935 uint current = 0;
2936 for (uint j = 0; j < bb->number_of_nodes(); j++) {
2937 Node *n = bb->get_node(j);
2938 if( valid_bundle_info(n) ) {
2939 Bundle *bundle = node_bundling(n);
2940 if (bundle->instr_count() > 0 || bundle->flags() > 0) {
2941 tty->print("*** Bundle: ");
2942 bundle->dump();
2943 }
2944 n->dump();
2945 }
2946 }
2947 }
2948 #endif
2949 #ifdef ASSERT
2950 verify_good_schedule(bb,"after block local scheduling");
2951 #endif
2952 }
2953
2954 #ifndef PRODUCT
2955 if (_cfg->C->trace_opto_output())
2956 tty->print("# <- DoScheduling\n");
2957 #endif
2958
2959 // Record final node-bundling array location
2960 _regalloc->C->output()->set_node_bundling_base(_node_bundling_base);
2961
2962 } // end DoScheduling
2963
2964 // Verify that no live-range used in the block is killed in the block by a
2965 // wrong DEF. This doesn't verify live-ranges that span blocks.
2966
2967 // Check for edge existence. Used to avoid adding redundant precedence edges.
2968 static bool edge_from_to( Node *from, Node *to ) {
2969 for( uint i=0; i<from->len(); i++ )
2970 if( from->in(i) == to )
2971 return true;
2972 return false;
2973 }
2974
2975 #ifdef ASSERT
2976 void Scheduling::verify_do_def( Node *n, OptoReg::Name def, const char *msg ) {
2977 // Check for bad kills
2978 if( OptoReg::is_valid(def) ) { // Ignore stores & control flow
2979 Node *prior_use = _reg_node[def];
2980 if( prior_use && !edge_from_to(prior_use,n) ) {
2981 tty->print("%s = ",OptoReg::as_VMReg(def)->name());
2982 n->dump();
2983 tty->print_cr("...");
2984 prior_use->dump();
2985 assert(edge_from_to(prior_use,n), "%s", msg);
2986 }
2987 _reg_node.map(def,nullptr); // Kill live USEs
2988 }
2989 }
2990
2991 void Scheduling::verify_good_schedule( Block *b, const char *msg ) {
2992
2993 // Zap to something reasonable for the verify code
2994 _reg_node.clear();
2995
2996 // Walk over the block backwards. Check to make sure each DEF doesn't
2997 // kill a live value (other than the one it's supposed to). Add each
2998 // USE to the live set.
2999 for( uint i = b->number_of_nodes()-1; i >= _bb_start; i-- ) {
3000 Node *n = b->get_node(i);
3001 int n_op = n->Opcode();
3002 if( n_op == Op_MachProj && n->ideal_reg() == MachProjNode::fat_proj ) {
3003 // Fat-proj kills a slew of registers
3004 RegMaskIterator rmi(n->out_RegMask());
3005 while (rmi.has_next()) {
3006 OptoReg::Name kill = rmi.next();
3007 verify_do_def(n, kill, msg);
3008 }
3009 } else if( n_op != Op_Node ) { // Avoid brand new antidependence nodes
3010 // Get DEF'd registers the normal way
3011 verify_do_def( n, _regalloc->get_reg_first(n), msg );
3012 verify_do_def( n, _regalloc->get_reg_second(n), msg );
3013 }
3014
3015 // Now make all USEs live
3016 for( uint i=1; i<n->req(); i++ ) {
3017 Node *def = n->in(i);
3018 assert(def != nullptr, "input edge required");
3019 OptoReg::Name reg_lo = _regalloc->get_reg_first(def);
3020 OptoReg::Name reg_hi = _regalloc->get_reg_second(def);
3021 if( OptoReg::is_valid(reg_lo) ) {
3022 assert(!_reg_node[reg_lo] || edge_from_to(_reg_node[reg_lo],def), "%s", msg);
3023 _reg_node.map(reg_lo,n);
3024 }
3025 if( OptoReg::is_valid(reg_hi) ) {
3026 assert(!_reg_node[reg_hi] || edge_from_to(_reg_node[reg_hi],def), "%s", msg);
3027 _reg_node.map(reg_hi,n);
3028 }
3029 }
3030
3031 }
3032
3033 // Zap to something reasonable for the Antidependence code
3034 _reg_node.clear();
3035 }
3036 #endif
3037
3038 // Conditionally add precedence edges. Avoid putting edges on Projs.
3039 static void add_prec_edge_from_to( Node *from, Node *to ) {
3040 if( from->is_Proj() ) { // Put precedence edge on Proj's input
3041 assert( from->req() == 1 && (from->len() == 1 || from->in(1) == nullptr), "no precedence edges on projections" );
3042 from = from->in(0);
3043 }
3044 if( from != to && // No cycles (for things like LD L0,[L0+4] )
3045 !edge_from_to( from, to ) ) // Avoid duplicate edge
3046 from->add_prec(to);
3047 }
3048
3049 void Scheduling::anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def ) {
3050 if( !OptoReg::is_valid(def_reg) ) // Ignore stores & control flow
3051 return;
3052
3053 if (OptoReg::is_reg(def_reg)) {
3054 VMReg vmreg = OptoReg::as_VMReg(def_reg);
3055 if (vmreg->is_reg() && !vmreg->is_concrete() && !vmreg->prev()->is_concrete()) {
3056 // This is one of the high slots of a vector register.
3057 // ScheduleAndBundle already checked there are no live wide
3058 // vectors in this method so it can be safely ignored.
3059 return;
3060 }
3061 }
3062
3063 Node *pinch = _reg_node[def_reg]; // Get pinch point
3064 if ((pinch == nullptr) || _cfg->get_block_for_node(pinch) != b || // No pinch-point yet?
3065 is_def ) { // Check for a true def (not a kill)
3066 _reg_node.map(def_reg,def); // Record def/kill as the optimistic pinch-point
3067 return;
3068 }
3069
3070 Node *kill = def; // Rename 'def' to more descriptive 'kill'
3071 DEBUG_ONLY( def = (Node*)((intptr_t)0xdeadbeef); )
3072
3073 // After some number of kills there _may_ be a later def
3074 Node *later_def = nullptr;
3075
3076 Compile* C = Compile::current();
3077
3078 // Finding a kill requires a real pinch-point.
3079 // Check for not already having a pinch-point.
3080 // Pinch points are Op_Node's.
3081 if( pinch->Opcode() != Op_Node ) { // Or later-def/kill as pinch-point?
3082 later_def = pinch; // Must be def/kill as optimistic pinch-point
3083 if ( _pinch_free_list.size() > 0) {
3084 pinch = _pinch_free_list.pop();
3085 } else {
3086 pinch = new Node(1); // Pinch point to-be
3087 }
3088 if (pinch->_idx >= _regalloc->node_regs_max_index()) {
3089 DEBUG_ONLY( pinch->dump(); );
3090 assert(false, "too many D-U pinch points: %d >= %d", pinch->_idx, _regalloc->node_regs_max_index());
3091 _cfg->C->record_method_not_compilable("too many D-U pinch points");
3092 return;
3093 }
3094 _cfg->map_node_to_block(pinch, b); // Pretend it's valid in this block (lazy init)
3095 _reg_node.map(def_reg,pinch); // Record pinch-point
3096 //regalloc()->set_bad(pinch->_idx); // Already initialized this way.
3097 if( later_def->outcnt() == 0 || later_def->ideal_reg() == MachProjNode::fat_proj ) { // Distinguish def from kill
3098 pinch->init_req(0, C->top()); // set not null for the next call
3099 add_prec_edge_from_to(later_def,pinch); // Add edge from kill to pinch
3100 later_def = nullptr; // and no later def
3101 }
3102 pinch->set_req(0,later_def); // Hook later def so we can find it
3103 } else { // Else have valid pinch point
3104 if( pinch->in(0) ) // If there is a later-def
3105 later_def = pinch->in(0); // Get it
3106 }
3107
3108 // Add output-dependence edge from later def to kill
3109 if( later_def ) // If there is some original def
3110 add_prec_edge_from_to(later_def,kill); // Add edge from def to kill
3111
3112 // See if current kill is also a use, and so is forced to be the pinch-point.
3113 if( pinch->Opcode() == Op_Node ) {
3114 Node *uses = kill->is_Proj() ? kill->in(0) : kill;
3115 for( uint i=1; i<uses->req(); i++ ) {
3116 if( _regalloc->get_reg_first(uses->in(i)) == def_reg ||
3117 _regalloc->get_reg_second(uses->in(i)) == def_reg ) {
3118 // Yes, found a use/kill pinch-point
3119 pinch->set_req(0,nullptr); //
3120 pinch->replace_by(kill); // Move anti-dep edges up
3121 pinch = kill;
3122 _reg_node.map(def_reg,pinch);
3123 return;
3124 }
3125 }
3126 }
3127
3128 // Add edge from kill to pinch-point
3129 add_prec_edge_from_to(kill,pinch);
3130 }
3131
3132 void Scheduling::anti_do_use( Block *b, Node *use, OptoReg::Name use_reg ) {
3133 if( !OptoReg::is_valid(use_reg) ) // Ignore stores & control flow
3134 return;
3135 Node *pinch = _reg_node[use_reg]; // Get pinch point
3136 // Check for no later def_reg/kill in block
3137 if ((pinch != nullptr) && _cfg->get_block_for_node(pinch) == b &&
3138 // Use has to be block-local as well
3139 _cfg->get_block_for_node(use) == b) {
3140 if( pinch->Opcode() == Op_Node && // Real pinch-point (not optimistic?)
3141 pinch->req() == 1 ) { // pinch not yet in block?
3142 pinch->del_req(0); // yank pointer to later-def, also set flag
3143 // Insert the pinch-point in the block just after the last use
3144 b->insert_node(pinch, b->find_node(use) + 1);
3145 _bb_end++; // Increase size scheduled region in block
3146 }
3147
3148 add_prec_edge_from_to(pinch,use);
3149 }
3150 }
3151
3152 // We insert antidependences between the reads and following write of
3153 // allocated registers to prevent illegal code motion. Hopefully, the
3154 // number of added references should be fairly small, especially as we
3155 // are only adding references within the current basic block.
3156 void Scheduling::ComputeRegisterAntidependencies(Block *b) {
3157
3158 #ifdef ASSERT
3159 verify_good_schedule(b,"before block local scheduling");
3160 #endif
3161
3162 // A valid schedule, for each register independently, is an endless cycle
3163 // of: a def, then some uses (connected to the def by true dependencies),
3164 // then some kills (defs with no uses), finally the cycle repeats with a new
3165 // def. The uses are allowed to float relative to each other, as are the
3166 // kills. No use is allowed to slide past a kill (or def). This requires
3167 // antidependencies between all uses of a single def and all kills that
3168 // follow, up to the next def. More edges are redundant, because later defs
3169 // & kills are already serialized with true or antidependencies. To keep
3170 // the edge count down, we add a 'pinch point' node if there's more than
3171 // one use or more than one kill/def.
3172
3173 // We add dependencies in one bottom-up pass.
3174
3175 // For each instruction we handle it's DEFs/KILLs, then it's USEs.
3176
3177 // For each DEF/KILL, we check to see if there's a prior DEF/KILL for this
3178 // register. If not, we record the DEF/KILL in _reg_node, the
3179 // register-to-def mapping. If there is a prior DEF/KILL, we insert a
3180 // "pinch point", a new Node that's in the graph but not in the block.
3181 // We put edges from the prior and current DEF/KILLs to the pinch point.
3182 // We put the pinch point in _reg_node. If there's already a pinch point
3183 // we merely add an edge from the current DEF/KILL to the pinch point.
3184
3185 // After doing the DEF/KILLs, we handle USEs. For each used register, we
3186 // put an edge from the pinch point to the USE.
3187
3188 // To be expedient, the _reg_node array is pre-allocated for the whole
3189 // compilation. _reg_node is lazily initialized; it either contains a null,
3190 // or a valid def/kill/pinch-point, or a leftover node from some prior
3191 // block. Leftover node from some prior block is treated like a null (no
3192 // prior def, so no anti-dependence needed). Valid def is distinguished by
3193 // it being in the current block.
3194 bool fat_proj_seen = false;
3195 uint last_safept = _bb_end-1;
3196 Node* end_node = (_bb_end-1 >= _bb_start) ? b->get_node(last_safept) : nullptr;
3197 Node* last_safept_node = end_node;
3198 for( uint i = _bb_end-1; i >= _bb_start; i-- ) {
3199 Node *n = b->get_node(i);
3200 int is_def = n->outcnt(); // def if some uses prior to adding precedence edges
3201 if( n->is_MachProj() && n->ideal_reg() == MachProjNode::fat_proj ) {
3202 // Fat-proj kills a slew of registers
3203 // This can add edges to 'n' and obscure whether or not it was a def,
3204 // hence the is_def flag.
3205 fat_proj_seen = true;
3206 RegMaskIterator rmi(n->out_RegMask());
3207 while (rmi.has_next()) {
3208 OptoReg::Name kill = rmi.next();
3209 anti_do_def(b, n, kill, is_def);
3210 }
3211 } else {
3212 // Get DEF'd registers the normal way
3213 anti_do_def( b, n, _regalloc->get_reg_first(n), is_def );
3214 anti_do_def( b, n, _regalloc->get_reg_second(n), is_def );
3215 }
3216
3217 // Kill projections on a branch should appear to occur on the
3218 // branch, not afterwards, so grab the masks from the projections
3219 // and process them.
3220 if (n->is_MachBranch() || (n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_Jump)) {
3221 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3222 Node* use = n->fast_out(i);
3223 if (use->is_Proj()) {
3224 RegMaskIterator rmi(use->out_RegMask());
3225 while (rmi.has_next()) {
3226 OptoReg::Name kill = rmi.next();
3227 anti_do_def(b, n, kill, false);
3228 }
3229 }
3230 }
3231 }
3232
3233 // Check each register used by this instruction for a following DEF/KILL
3234 // that must occur afterward and requires an anti-dependence edge.
3235 for( uint j=0; j<n->req(); j++ ) {
3236 Node *def = n->in(j);
3237 if( def ) {
3238 assert( !def->is_MachProj() || def->ideal_reg() != MachProjNode::fat_proj, "" );
3239 anti_do_use( b, n, _regalloc->get_reg_first(def) );
3240 anti_do_use( b, n, _regalloc->get_reg_second(def) );
3241 }
3242 }
3243 // Do not allow defs of new derived values to float above GC
3244 // points unless the base is definitely available at the GC point.
3245
3246 Node *m = b->get_node(i);
3247
3248 // Add precedence edge from following safepoint to use of derived pointer
3249 if( last_safept_node != end_node &&
3250 m != last_safept_node) {
3251 for (uint k = 1; k < m->req(); k++) {
3252 const Type *t = m->in(k)->bottom_type();
3253 if( t->isa_oop_ptr() &&
3254 t->is_ptr()->offset() != 0 ) {
3255 last_safept_node->add_prec( m );
3256 break;
3257 }
3258 }
3259
3260 // Do not allow a CheckCastPP node whose input is a raw pointer to
3261 // float past a safepoint. This can occur when a buffered inline
3262 // type is allocated in a loop and the CheckCastPP from that
3263 // allocation is reused outside the loop. If the use inside the
3264 // loop is scalarized the CheckCastPP will no longer be connected
3265 // to the loop safepoint. See JDK-8264340.
3266 if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_CheckCastPP) {
3267 Node *def = m->in(1);
3268 if (def != nullptr && def->bottom_type()->base() == Type::RawPtr) {
3269 last_safept_node->add_prec(m);
3270 }
3271 }
3272 }
3273
3274 if( n->jvms() ) { // Precedence edge from derived to safept
3275 // Check if last_safept_node was moved by pinch-point insertion in anti_do_use()
3276 if( b->get_node(last_safept) != last_safept_node ) {
3277 last_safept = b->find_node(last_safept_node);
3278 }
3279 for( uint j=last_safept; j > i; j-- ) {
3280 Node *mach = b->get_node(j);
3281 if( mach->is_Mach() && mach->as_Mach()->ideal_Opcode() == Op_AddP )
3282 mach->add_prec( n );
3283 }
3284 last_safept = i;
3285 last_safept_node = m;
3286 }
3287 }
3288
3289 if (fat_proj_seen) {
3290 // Garbage collect pinch nodes that were not consumed.
3291 // They are usually created by a fat kill MachProj for a call.
3292 garbage_collect_pinch_nodes();
3293 }
3294 }
3295
3296 // Garbage collect pinch nodes for reuse by other blocks.
3297 //
3298 // The block scheduler's insertion of anti-dependence
3299 // edges creates many pinch nodes when the block contains
3300 // 2 or more Calls. A pinch node is used to prevent a
3301 // combinatorial explosion of edges. If a set of kills for a
3302 // register is anti-dependent on a set of uses (or defs), rather
3303 // than adding an edge in the graph between each pair of kill
3304 // and use (or def), a pinch is inserted between them:
3305 //
3306 // use1 use2 use3
3307 // \ | /
3308 // \ | /
3309 // pinch
3310 // / | \
3311 // / | \
3312 // kill1 kill2 kill3
3313 //
3314 // One pinch node is created per register killed when
3315 // the second call is encountered during a backwards pass
3316 // over the block. Most of these pinch nodes are never
3317 // wired into the graph because the register is never
3318 // used or def'ed in the block.
3319 //
3320 void Scheduling::garbage_collect_pinch_nodes() {
3321 #ifndef PRODUCT
3322 if (_cfg->C->trace_opto_output()) tty->print("Reclaimed pinch nodes:");
3323 #endif
3324 int trace_cnt = 0;
3325 for (uint k = 0; k < _reg_node.max(); k++) {
3326 Node* pinch = _reg_node[k];
3327 if ((pinch != nullptr) && pinch->Opcode() == Op_Node &&
3328 // no predecence input edges
3329 (pinch->req() == pinch->len() || pinch->in(pinch->req()) == nullptr) ) {
3330 cleanup_pinch(pinch);
3331 _pinch_free_list.push(pinch);
3332 _reg_node.map(k, nullptr);
3333 #ifndef PRODUCT
3334 if (_cfg->C->trace_opto_output()) {
3335 trace_cnt++;
3336 if (trace_cnt > 40) {
3337 tty->print("\n");
3338 trace_cnt = 0;
3339 }
3340 tty->print(" %d", pinch->_idx);
3341 }
3342 #endif
3343 }
3344 }
3345 #ifndef PRODUCT
3346 if (_cfg->C->trace_opto_output()) tty->print("\n");
3347 #endif
3348 }
3349
3350 // Clean up a pinch node for reuse.
3351 void Scheduling::cleanup_pinch( Node *pinch ) {
3352 assert (pinch && pinch->Opcode() == Op_Node && pinch->req() == 1, "just checking");
3353
3354 for (DUIterator_Last imin, i = pinch->last_outs(imin); i >= imin; ) {
3355 Node* use = pinch->last_out(i);
3356 uint uses_found = 0;
3357 for (uint j = use->req(); j < use->len(); j++) {
3358 if (use->in(j) == pinch) {
3359 use->rm_prec(j);
3360 uses_found++;
3361 }
3362 }
3363 assert(uses_found > 0, "must be a precedence edge");
3364 i -= uses_found; // we deleted 1 or more copies of this edge
3365 }
3366 // May have a later_def entry
3367 pinch->set_req(0, nullptr);
3368 }
3369
3370 #ifndef PRODUCT
3371
3372 void Scheduling::dump_available() const {
3373 tty->print("#Availist ");
3374 for (uint i = 0; i < _available.size(); i++)
3375 tty->print(" N%d/l%d", _available[i]->_idx,_current_latency[_available[i]->_idx]);
3376 tty->cr();
3377 }
3378
3379 // Print Scheduling Statistics
3380 void Scheduling::print_statistics() {
3381 // Print the size added by nops for bundling
3382 tty->print("Nops added %d bytes to total of %d bytes",
3383 _total_nop_size, _total_method_size);
3384 if (_total_method_size > 0)
3385 tty->print(", for %.2f%%",
3386 ((double)_total_nop_size) / ((double) _total_method_size) * 100.0);
3387 tty->print("\n");
3388
3389 // Print the number of branch shadows filled
3390 if (Pipeline::_branch_has_delay_slot) {
3391 tty->print("Of %d branches, %d had unconditional delay slots filled",
3392 _total_branches, _total_unconditional_delays);
3393 if (_total_branches > 0)
3394 tty->print(", for %.2f%%",
3395 ((double)_total_unconditional_delays) / ((double)_total_branches) * 100.0);
3396 tty->print("\n");
3397 }
3398
3399 uint total_instructions = 0, total_bundles = 0;
3400
3401 for (uint i = 1; i <= Pipeline::_max_instrs_per_cycle; i++) {
3402 uint bundle_count = _total_instructions_per_bundle[i];
3403 total_instructions += bundle_count * i;
3404 total_bundles += bundle_count;
3405 }
3406
3407 if (total_bundles > 0)
3408 tty->print("Average ILP (excluding nops) is %.2f\n",
3409 ((double)total_instructions) / ((double)total_bundles));
3410 }
3411 #endif
3412
3413 //-----------------------init_scratch_buffer_blob------------------------------
3414 // Construct a temporary BufferBlob and cache it for this compile.
3415 void PhaseOutput::init_scratch_buffer_blob(int const_size) {
3416 // If there is already a scratch buffer blob allocated and the
3417 // constant section is big enough, use it. Otherwise free the
3418 // current and allocate a new one.
3419 BufferBlob* blob = scratch_buffer_blob();
3420 if ((blob != nullptr) && (const_size <= _scratch_const_size)) {
3421 // Use the current blob.
3422 } else {
3423 if (blob != nullptr) {
3424 BufferBlob::free(blob);
3425 }
3426
3427 ResourceMark rm;
3428 _scratch_const_size = const_size;
3429 int size = C2Compiler::initial_code_buffer_size(const_size);
3430 if (C->has_scalarized_args()) {
3431 // Inline type entry points (MachVEPNodes) require lots of space for GC barriers and oop verification
3432 // when loading object fields from the buffered argument. Increase scratch buffer size accordingly.
3433 ciMethod* method = C->method();
3434 int barrier_size = UseZGC ? 200 : (7 DEBUG_ONLY(+ 37));
3435 int arg_num = 0;
3436 if (!method->is_static()) {
3437 if (method->is_scalarized_arg(arg_num)) {
3438 size += method->holder()->as_inline_klass()->oop_count() * barrier_size;
3439 }
3440 arg_num++;
3441 }
3442 for (ciSignatureStream str(method->signature()); !str.at_return_type(); str.next()) {
3443 if (method->is_scalarized_arg(arg_num)) {
3444 size += str.type()->as_inline_klass()->oop_count() * barrier_size;
3445 }
3446 arg_num++;
3447 }
3448 }
3449 blob = BufferBlob::create("Compile::scratch_buffer", size);
3450 // Record the buffer blob for next time.
3451 set_scratch_buffer_blob(blob);
3452 // Have we run out of code space?
3453 if (scratch_buffer_blob() == nullptr) {
3454 // Let CompilerBroker disable further compilations.
3455 C->record_failure("Not enough space for scratch buffer in CodeCache");
3456 return;
3457 }
3458 }
3459
3460 // Initialize the relocation buffers
3461 relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
3462 set_scratch_locs_memory(locs_buf);
3463 }
3464
3465
3466 //-----------------------scratch_emit_size-------------------------------------
3467 // Helper function that computes size by emitting code
3468 uint PhaseOutput::scratch_emit_size(const Node* n) {
3469 // Start scratch_emit_size section.
3470 set_in_scratch_emit_size(true);
3471
3472 // Emit into a trash buffer and count bytes emitted.
3473 // This is a pretty expensive way to compute a size,
3474 // but it works well enough if seldom used.
3475 // All common fixed-size instructions are given a size
3476 // method by the AD file.
3477 // Note that the scratch buffer blob and locs memory are
3478 // allocated at the beginning of the compile task, and
3479 // may be shared by several calls to scratch_emit_size.
3480 // The allocation of the scratch buffer blob is particularly
3481 // expensive, since it has to grab the code cache lock.
3482 BufferBlob* blob = this->scratch_buffer_blob();
3483 assert(blob != nullptr, "Initialize BufferBlob at start");
3484 assert(blob->size() > MAX_inst_size, "sanity");
3485 relocInfo* locs_buf = scratch_locs_memory();
3486 address blob_begin = blob->content_begin();
3487 address blob_end = (address)locs_buf;
3488 assert(blob->contains(blob_end), "sanity");
3489 CodeBuffer buf(blob_begin, blob_end - blob_begin);
3490 buf.initialize_consts_size(_scratch_const_size);
3491 buf.initialize_stubs_size(MAX_stubs_size);
3492 assert(locs_buf != nullptr, "sanity");
3493 int lsize = MAX_locs_size / 3;
3494 buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
3495 buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
3496 buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
3497 // Mark as scratch buffer.
3498 buf.consts()->set_scratch_emit();
3499 buf.insts()->set_scratch_emit();
3500 buf.stubs()->set_scratch_emit();
3501
3502 // Do the emission.
3503
3504 Label fakeL; // Fake label for branch instructions.
3505 Label* saveL = nullptr;
3506 uint save_bnum = 0;
3507 bool is_branch = n->is_MachBranch();
3508 C2_MacroAssembler masm(&buf);
3509 masm.bind(fakeL);
3510 if (is_branch) {
3511 n->as_MachBranch()->save_label(&saveL, &save_bnum);
3512 n->as_MachBranch()->label_set(&fakeL, 0);
3513 }
3514 n->emit(&masm, C->regalloc());
3515
3516 // Emitting into the scratch buffer should not fail
3517 assert(!C->failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", C->failure_reason());
3518
3519 // Restore label.
3520 if (is_branch) {
3521 n->as_MachBranch()->label_set(saveL, save_bnum);
3522 }
3523
3524 // End scratch_emit_size section.
3525 set_in_scratch_emit_size(false);
3526
3527 return buf.insts_size();
3528 }
3529
3530 void PhaseOutput::install() {
3531 if (!C->should_install_code()) {
3532 return;
3533 } else if (C->stub_function() != nullptr) {
3534 install_stub(C->stub_name());
3535 } else {
3536 install_code(C->method(),
3537 C->entry_bci(),
3538 CompileBroker::compiler2(),
3539 C->has_unsafe_access(),
3540 SharedRuntime::is_wide_vector(C->max_vector_size()));
3541 }
3542 }
3543
3544 void PhaseOutput::install_code(ciMethod* target,
3545 int entry_bci,
3546 AbstractCompiler* compiler,
3547 bool has_unsafe_access,
3548 bool has_wide_vectors) {
3549 // Check if we want to skip execution of all compiled code.
3550 {
3551 #ifndef PRODUCT
3552 if (OptoNoExecute) {
3553 C->record_method_not_compilable("+OptoNoExecute"); // Flag as failed
3554 return;
3555 }
3556 #endif
3557 Compile::TracePhase tp(_t_registerMethod);
3558
3559 if (C->is_osr_compilation()) {
3560 _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
3561 _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
3562 } else {
3563 _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
3564 if (_code_offsets.value(CodeOffsets::Verified_Inline_Entry) == -1) {
3565 _code_offsets.set_value(CodeOffsets::Verified_Inline_Entry, _first_block_size);
3566 }
3567 if (_code_offsets.value(CodeOffsets::Verified_Inline_Entry_RO) == -1) {
3568 _code_offsets.set_value(CodeOffsets::Verified_Inline_Entry_RO, _first_block_size);
3569 }
3570 if (_code_offsets.value(CodeOffsets::Entry) == -1) {
3571 _code_offsets.set_value(CodeOffsets::Entry, _first_block_size);
3572 }
3573 _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
3574 }
3575
3576 C->env()->register_method(target,
3577 entry_bci,
3578 &_code_offsets,
3579 _orig_pc_slot_offset_in_bytes,
3580 code_buffer(),
3581 frame_size_in_words(),
3582 _oop_map_set,
3583 &_handler_table,
3584 inc_table(),
3585 compiler,
3586 has_unsafe_access,
3587 SharedRuntime::is_wide_vector(C->max_vector_size()),
3588 C->has_monitors(),
3589 C->has_scoped_access(),
3590 0);
3591
3592 if (C->log() != nullptr) { // Print code cache state into compiler log
3593 C->log()->code_cache_state();
3594 }
3595 }
3596 }
3597 void PhaseOutput::install_stub(const char* stub_name) {
3598 // Entry point will be accessed using stub_entry_point();
3599 if (code_buffer() == nullptr) {
3600 Matcher::soft_match_failure();
3601 } else {
3602 if (PrintAssembly && (WizardMode || Verbose))
3603 tty->print_cr("### Stub::%s", stub_name);
3604
3605 if (!C->failing()) {
3606 assert(C->fixed_slots() == 0, "no fixed slots used for runtime stubs");
3607
3608 // Make the NMethod
3609 // For now we mark the frame as never safe for profile stackwalking
3610 RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
3611 code_buffer(),
3612 CodeOffsets::frame_never_safe,
3613 // _code_offsets.value(CodeOffsets::Frame_Complete),
3614 frame_size_in_words(),
3615 oop_map_set(),
3616 false,
3617 false);
3618
3619 if (rs == nullptr) {
3620 C->record_failure("CodeCache is full");
3621 } else {
3622 assert(rs->is_runtime_stub(), "sanity check");
3623 C->set_stub_entry_point(rs->entry_point());
3624 AOTCodeCache::store_code_blob(*rs, AOTCodeEntry::C2Blob, C->stub_id(), stub_name);
3625 }
3626 }
3627 }
3628 }
3629
3630 // Support for bundling info
3631 Bundle* PhaseOutput::node_bundling(const Node *n) {
3632 assert(valid_bundle_info(n), "oob");
3633 return &_node_bundling_base[n->_idx];
3634 }
3635
3636 bool PhaseOutput::valid_bundle_info(const Node *n) {
3637 return (_node_bundling_limit > n->_idx);
3638 }
3639
3640 //------------------------------frame_size_in_words-----------------------------
3641 // frame_slots in units of words
3642 int PhaseOutput::frame_size_in_words() const {
3643 // shift is 0 in LP32 and 1 in LP64
3644 const int shift = (LogBytesPerWord - LogBytesPerInt);
3645 int words = _frame_slots >> shift;
3646 assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
3647 return words;
3648 }
3649
3650 // To bang the stack of this compiled method we use the stack size
3651 // that the interpreter would need in case of a deoptimization. This
3652 // removes the need to bang the stack in the deoptimization blob which
3653 // in turn simplifies stack overflow handling.
3654 int PhaseOutput::bang_size_in_bytes() const {
3655 return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), C->interpreter_frame_size());
3656 }
3657
3658 //------------------------------dump_asm---------------------------------------
3659 // Dump formatted assembly
3660 #if defined(SUPPORT_OPTO_ASSEMBLY)
3661 void PhaseOutput::dump_asm_on(outputStream* st, int* pcs, uint pc_limit) {
3662
3663 int pc_digits = 3; // #chars required for pc
3664 int sb_chars = 3; // #chars for "start bundle" indicator
3665 int tab_size = 8;
3666 if (pcs != nullptr) {
3667 int max_pc = 0;
3668 for (uint i = 0; i < pc_limit; i++) {
3669 max_pc = (max_pc < pcs[i]) ? pcs[i] : max_pc;
3670 }
3671 pc_digits = ((max_pc < 4096) ? 3 : ((max_pc < 65536) ? 4 : ((max_pc < 65536*256) ? 6 : 8))); // #chars required for pc
3672 }
3673 int prefix_len = ((pc_digits + sb_chars + tab_size - 1)/tab_size)*tab_size;
3674
3675 bool cut_short = false;
3676 st->print_cr("#");
3677 st->print("# "); C->tf()->dump_on(st); st->cr();
3678 st->print_cr("#");
3679
3680 // For all blocks
3681 int pc = 0x0; // Program counter
3682 char starts_bundle = ' ';
3683 C->regalloc()->dump_frame();
3684
3685 Node *n = nullptr;
3686 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
3687 if (VMThread::should_terminate()) {
3688 cut_short = true;
3689 break;
3690 }
3691 Block* block = C->cfg()->get_block(i);
3692 if (block->is_connector() && !Verbose) {
3693 continue;
3694 }
3695 n = block->head();
3696 if ((pcs != nullptr) && (n->_idx < pc_limit)) {
3697 pc = pcs[n->_idx];
3698 st->print("%*.*x", pc_digits, pc_digits, pc);
3699 }
3700 st->fill_to(prefix_len);
3701 block->dump_head(C->cfg(), st);
3702 if (block->is_connector()) {
3703 st->fill_to(prefix_len);
3704 st->print_cr("# Empty connector block");
3705 } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
3706 st->fill_to(prefix_len);
3707 st->print_cr("# Block is sole successor of call");
3708 }
3709
3710 // For all instructions
3711 Node *delay = nullptr;
3712 for (uint j = 0; j < block->number_of_nodes(); j++) {
3713 if (VMThread::should_terminate()) {
3714 cut_short = true;
3715 break;
3716 }
3717 n = block->get_node(j);
3718 if (valid_bundle_info(n)) {
3719 Bundle* bundle = node_bundling(n);
3720 if (bundle->used_in_unconditional_delay()) {
3721 delay = n;
3722 continue;
3723 }
3724 if (bundle->starts_bundle()) {
3725 starts_bundle = '+';
3726 }
3727 }
3728
3729 if (WizardMode) {
3730 n->dump();
3731 }
3732
3733 if( !n->is_Region() && // Dont print in the Assembly
3734 !n->is_Phi() && // a few noisely useless nodes
3735 !n->is_Proj() &&
3736 !n->is_MachTemp() &&
3737 !n->is_SafePointScalarObject() &&
3738 !n->is_Catch() && // Would be nice to print exception table targets
3739 !n->is_MergeMem() && // Not very interesting
3740 !n->is_top() && // Debug info table constants
3741 !(n->is_Con() && !n->is_Mach())// Debug info table constants
3742 ) {
3743 if ((pcs != nullptr) && (n->_idx < pc_limit)) {
3744 pc = pcs[n->_idx];
3745 st->print("%*.*x", pc_digits, pc_digits, pc);
3746 } else {
3747 st->fill_to(pc_digits);
3748 }
3749 st->print(" %c ", starts_bundle);
3750 starts_bundle = ' ';
3751 st->fill_to(prefix_len);
3752 n->format(C->regalloc(), st);
3753 st->cr();
3754 }
3755
3756 // If we have an instruction with a delay slot, and have seen a delay,
3757 // then back up and print it
3758 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
3759 // Coverity finding - Explicit null dereferenced.
3760 guarantee(delay != nullptr, "no unconditional delay instruction");
3761 if (WizardMode) delay->dump();
3762
3763 if (node_bundling(delay)->starts_bundle())
3764 starts_bundle = '+';
3765 if ((pcs != nullptr) && (n->_idx < pc_limit)) {
3766 pc = pcs[n->_idx];
3767 st->print("%*.*x", pc_digits, pc_digits, pc);
3768 } else {
3769 st->fill_to(pc_digits);
3770 }
3771 st->print(" %c ", starts_bundle);
3772 starts_bundle = ' ';
3773 st->fill_to(prefix_len);
3774 delay->format(C->regalloc(), st);
3775 st->cr();
3776 delay = nullptr;
3777 }
3778
3779 // Dump the exception table as well
3780 if( n->is_Catch() && (Verbose || WizardMode) ) {
3781 // Print the exception table for this offset
3782 _handler_table.print_subtable_for(pc);
3783 }
3784 st->bol(); // Make sure we start on a new line
3785 }
3786 st->cr(); // one empty line between blocks
3787 assert(cut_short || delay == nullptr, "no unconditional delay branch");
3788 } // End of per-block dump
3789
3790 if (cut_short) st->print_cr("*** disassembly is cut short ***");
3791 }
3792 #endif
3793
3794 #ifndef PRODUCT
3795 void PhaseOutput::print_statistics() {
3796 Scheduling::print_statistics();
3797 }
3798 #endif