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/compiledIC.hpp"
27 #include "code/debugInfo.hpp"
28 #include "code/debugInfoRec.hpp"
29 #include "compiler/compileBroker.hpp"
30 #include "compiler/compilerDirectives.hpp"
31 #include "compiler/disassembler.hpp"
32 #include "compiler/oopMap.hpp"
33 #include "gc/shared/barrierSet.hpp"
34 #include "gc/shared/gc_globals.hpp"
35 #include "gc/shared/c2/barrierSetC2.hpp"
36 #include "memory/allocation.hpp"
37 #include "opto/ad.hpp"
38 #include "opto/block.hpp"
39 #include "opto/c2compiler.hpp"
40 #include "opto/c2_MacroAssembler.hpp"
41 #include "opto/callnode.hpp"
42 #include "opto/cfgnode.hpp"
43 #include "opto/locknode.hpp"
44 #include "opto/machnode.hpp"
45 #include "opto/node.hpp"
46 #include "opto/optoreg.hpp"
47 #include "opto/output.hpp"
48 #include "opto/regalloc.hpp"
49 #include "opto/type.hpp"
50 #include "runtime/sharedRuntime.hpp"
51 #include "utilities/macros.hpp"
52 #include "utilities/powerOfTwo.hpp"
53 #include "utilities/xmlstream.hpp"
54
55 #ifndef PRODUCT
56 #define DEBUG_ARG(x) , x
57 #else
58 #define DEBUG_ARG(x)
59 #endif
60
61 //------------------------------Scheduling----------------------------------
62 // This class contains all the information necessary to implement instruction
63 // scheduling and bundling.
64 class Scheduling {
65
66 private:
67 // Arena to use
68 Arena *_arena;
69
70 // Control-Flow Graph info
71 PhaseCFG *_cfg;
72
73 // Register Allocation info
74 PhaseRegAlloc *_regalloc;
75
76 // Number of nodes in the method
77 uint _node_bundling_limit;
78
79 // List of scheduled nodes. Generated in reverse order
80 Node_List _scheduled;
81
82 // List of nodes currently available for choosing for scheduling
83 Node_List _available;
84
85 // For each instruction beginning a bundle, the number of following
86 // nodes to be bundled with it.
87 Bundle *_node_bundling_base;
88
89 // Mapping from register to Node
90 Node_List _reg_node;
91
92 // Free list for pinch nodes.
93 Node_List _pinch_free_list;
94
95 // Number of uses of this node within the containing basic block.
96 short *_uses;
97
98 // Schedulable portion of current block. Skips Region/Phi/CreateEx up
99 // front, branch+proj at end. Also skips Catch/CProj (same as
100 // branch-at-end), plus just-prior exception-throwing call.
101 uint _bb_start, _bb_end;
102
103 // Latency from the end of the basic block as scheduled
104 unsigned short *_current_latency;
105
106 // Remember the next node
107 Node *_next_node;
108
109 // Use this for an unconditional branch delay slot
110 Node *_unconditional_delay_slot;
111
112 // Pointer to a Nop
113 MachNopNode *_nop;
114
115 // Length of the current bundle, in instructions
116 uint _bundle_instr_count;
117
118 // Current Cycle number, for computing latencies and bundling
119 uint _bundle_cycle_number;
120
121 // Bundle information
122 Pipeline_Use_Element _bundle_use_elements[resource_count];
123 Pipeline_Use _bundle_use;
124
125 // Dump the available list
126 void dump_available() const;
127
128 public:
129 Scheduling(Arena *arena, Compile &compile);
130
131 // Destructor
132 NOT_PRODUCT( ~Scheduling(); )
133
134 // Step ahead "i" cycles
135 void step(uint i);
136
137 // Step ahead 1 cycle, and clear the bundle state (for example,
138 // at a branch target)
139 void step_and_clear();
140
141 Bundle* node_bundling(const Node *n) {
142 assert(valid_bundle_info(n), "oob");
143 return (&_node_bundling_base[n->_idx]);
144 }
145
146 bool valid_bundle_info(const Node *n) const {
147 return (_node_bundling_limit > n->_idx);
148 }
149
150 bool starts_bundle(const Node *n) const {
151 return (_node_bundling_limit > n->_idx && _node_bundling_base[n->_idx].starts_bundle());
152 }
153
154 // Do the scheduling
155 void DoScheduling();
156
157 // Compute the register antidependencies within a basic block
158 void ComputeRegisterAntidependencies(Block *bb);
159 void verify_do_def( Node *n, OptoReg::Name def, const char *msg );
160 void verify_good_schedule( Block *b, const char *msg );
161 void anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def );
162 void anti_do_use( Block *b, Node *use, OptoReg::Name use_reg );
163
164 // Add a node to the current bundle
165 void AddNodeToBundle(Node *n, const Block *bb);
166
167 // Return an integer less than, equal to, or greater than zero
168 // if the stack offset of the first argument is respectively
169 // less than, equal to, or greater than the second.
170 int compare_two_spill_nodes(Node* first, Node* second);
171
172 // Add a node to the list of available nodes
173 void AddNodeToAvailableList(Node *n);
174
175 // Compute the local use count for the nodes in a block, and compute
176 // the list of instructions with no uses in the block as available
177 void ComputeUseCount(const Block *bb);
178
179 // Choose an instruction from the available list to add to the bundle
180 Node * ChooseNodeToBundle();
181
182 // See if this Node fits into the currently accumulating bundle
183 bool NodeFitsInBundle(Node *n);
184
185 // Decrement the use count for a node
186 void DecrementUseCounts(Node *n, const Block *bb);
187
188 // Garbage collect pinch nodes for reuse by other blocks.
189 void garbage_collect_pinch_nodes();
190 // Clean up a pinch node for reuse (helper for above).
191 void cleanup_pinch( Node *pinch );
192
193 // Information for statistics gathering
194 #ifndef PRODUCT
195 private:
196 // Gather information on size of nops relative to total
197 uint _branches, _unconditional_delays;
198
199 static uint _total_nop_size, _total_method_size;
200 static uint _total_branches, _total_unconditional_delays;
201 static uint _total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
202
203 public:
204 static void print_statistics();
205
206 static void increment_instructions_per_bundle(uint i) {
207 _total_instructions_per_bundle[i]++;
208 }
209
210 static void increment_nop_size(uint s) {
211 _total_nop_size += s;
212 }
213
214 static void increment_method_size(uint s) {
215 _total_method_size += s;
216 }
217 #endif
218
219 };
220
221 PhaseOutput::PhaseOutput()
222 : Phase(Phase::Output),
223 _code_buffer("Compile::Fill_buffer"),
224 _first_block_size(0),
225 _handler_table(),
226 _inc_table(),
227 _stub_list(),
228 _oop_map_set(nullptr),
229 _scratch_buffer_blob(nullptr),
230 _scratch_locs_memory(nullptr),
231 _scratch_const_size(-1),
232 _in_scratch_emit_size(false),
233 _frame_slots(0),
234 _code_offsets(),
235 _node_bundling_limit(0),
236 _node_bundling_base(nullptr),
237 _orig_pc_slot(0),
238 _orig_pc_slot_offset_in_bytes(0),
239 _buf_sizes(),
240 _block(nullptr),
241 _index(0) {
242 C->set_output(this);
243 if (C->stub_name() == nullptr) {
244 int fixed_slots = C->fixed_slots();
245 if (C->needs_stack_repair()) {
246 fixed_slots -= 2;
247 }
248 // TODO 8284443 Only reserve extra slot if needed
249 if (InlineTypeReturnedAsFields) {
250 fixed_slots -= 2;
251 }
252 _orig_pc_slot = fixed_slots - (sizeof(address) / VMRegImpl::stack_slot_size);
253 }
254 }
255
256 PhaseOutput::~PhaseOutput() {
257 C->set_output(nullptr);
258 if (_scratch_buffer_blob != nullptr) {
259 BufferBlob::free(_scratch_buffer_blob);
260 }
261 }
262
263 void PhaseOutput::perform_mach_node_analysis() {
264 // Late barrier analysis must be done after schedule and bundle
265 // Otherwise liveness based spilling will fail
266 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
267 bs->late_barrier_analysis();
268
269 pd_perform_mach_node_analysis();
270
271 C->print_method(CompilerPhaseType::PHASE_MACH_ANALYSIS, 3);
272 }
273
274 // Convert Nodes to instruction bits and pass off to the VM
275 void PhaseOutput::Output() {
276 // RootNode goes
277 assert( C->cfg()->get_root_block()->number_of_nodes() == 0, "" );
278
279 // The number of new nodes (mostly MachNop) is proportional to
280 // the number of java calls and inner loops which are aligned.
281 if ( C->check_node_count((NodeLimitFudgeFactor + C->java_calls()*3 +
282 C->inner_loops()*(OptoLoopAlignment-1)),
283 "out of nodes before code generation" ) ) {
284 return;
285 }
286 // Make sure I can find the Start Node
287 Block *entry = C->cfg()->get_block(1);
288 Block *broot = C->cfg()->get_root_block();
289
290 const StartNode *start = entry->head()->as_Start();
291
292 // Replace StartNode with prolog
293 Label verified_entry;
294 MachPrologNode* prolog = new MachPrologNode(&verified_entry);
295 entry->map_node(prolog, 0);
296 C->cfg()->map_node_to_block(prolog, entry);
297 C->cfg()->unmap_node_from_block(start); // start is no longer in any block
298
299 // Virtual methods need an unverified entry point
300 if (C->is_osr_compilation()) {
301 if (PoisonOSREntry) {
302 // TODO: Should use a ShouldNotReachHereNode...
303 C->cfg()->insert( broot, 0, new MachBreakpointNode() );
304 }
305 } else {
306 if (C->method()) {
307 if (C->method()->has_scalarized_args()) {
308 // Add entry point to unpack all inline type arguments
309 C->cfg()->insert(broot, 0, new MachVEPNode(&verified_entry, /* verified */ true, /* receiver_only */ false));
310 if (!C->method()->is_static()) {
311 // Add verified/unverified entry points to only unpack inline type receiver at interface calls
312 C->cfg()->insert(broot, 0, new MachVEPNode(&verified_entry, /* verified */ false, /* receiver_only */ false));
313 C->cfg()->insert(broot, 0, new MachVEPNode(&verified_entry, /* verified */ true, /* receiver_only */ true));
314 C->cfg()->insert(broot, 0, new MachVEPNode(&verified_entry, /* verified */ false, /* receiver_only */ true));
315 }
316 } else if (!C->method()->is_static()) {
317 // Insert unvalidated entry point
318 C->cfg()->insert(broot, 0, new MachUEPNode());
319 }
320 }
321 }
322
323 // Break before main entry point
324 if ((C->method() && C->directive()->BreakAtExecuteOption) ||
325 (OptoBreakpoint && C->is_method_compilation()) ||
326 (OptoBreakpointOSR && C->is_osr_compilation()) ||
327 (OptoBreakpointC2R && !C->method()) ) {
328 // checking for C->method() means that OptoBreakpoint does not apply to
329 // runtime stubs or frame converters
330 C->cfg()->insert( entry, 1, new MachBreakpointNode() );
331 }
332
333 // Insert epilogs before every return
334 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
335 Block* block = C->cfg()->get_block(i);
336 if (!block->is_connector() && block->non_connector_successor(0) == C->cfg()->get_root_block()) { // Found a program exit point?
337 Node* m = block->end();
338 if (m->is_Mach() && m->as_Mach()->ideal_Opcode() != Op_Halt) {
339 MachEpilogNode* epilog = new MachEpilogNode(m->as_Mach()->ideal_Opcode() == Op_Return);
340 block->add_inst(epilog);
341 C->cfg()->map_node_to_block(epilog, block);
342 }
343 }
344 }
345
346 // Keeper of sizing aspects
347 _buf_sizes = BufferSizingData();
348
349 // Initialize code buffer
350 estimate_buffer_size(_buf_sizes._const);
351 if (C->failing()) return;
352
353 // Pre-compute the length of blocks and replace
354 // long branches with short if machine supports it.
355 // Must be done before ScheduleAndBundle due to SPARC delay slots
356 uint* blk_starts = NEW_RESOURCE_ARRAY(uint, C->cfg()->number_of_blocks() + 1);
357 blk_starts[0] = 0;
358 shorten_branches(blk_starts);
359
360 if (!C->is_osr_compilation() && C->has_scalarized_args()) {
361 // Compute the offsets of the entry points required by the inline type calling convention
362 if (!C->method()->is_static()) {
363 // We have entries at the beginning of the method, implemented by the first 4 nodes.
364 // Entry (unverified) @ offset 0
365 // Verified_Inline_Entry_RO
366 // Inline_Entry (unverified)
367 // Verified_Inline_Entry
368 uint offset = 0;
369 _code_offsets.set_value(CodeOffsets::Entry, offset);
370
371 offset += ((MachVEPNode*)broot->get_node(0))->size(C->regalloc());
372 _code_offsets.set_value(CodeOffsets::Verified_Inline_Entry_RO, offset);
373
374 offset += ((MachVEPNode*)broot->get_node(1))->size(C->regalloc());
375 _code_offsets.set_value(CodeOffsets::Inline_Entry, offset);
376
377 offset += ((MachVEPNode*)broot->get_node(2))->size(C->regalloc());
378 _code_offsets.set_value(CodeOffsets::Verified_Inline_Entry, offset);
379 } else {
380 _code_offsets.set_value(CodeOffsets::Entry, -1); // will be patched later
381 _code_offsets.set_value(CodeOffsets::Verified_Inline_Entry, 0);
382 }
383 }
384
385 ScheduleAndBundle();
386 if (C->failing()) {
387 return;
388 }
389
390 perform_mach_node_analysis();
391
392 // Complete sizing of codebuffer
393 CodeBuffer* cb = init_buffer();
394 if (cb == nullptr || C->failing()) {
395 return;
396 }
397
398 BuildOopMaps();
399
400 if (C->failing()) {
401 return;
402 }
403
404 C2_MacroAssembler masm(cb);
405 fill_buffer(&masm, blk_starts);
406 }
407
408 bool PhaseOutput::need_stack_bang(int frame_size_in_bytes) const {
409 // Determine if we need to generate a stack overflow check.
410 // Do it if the method is not a stub function and
411 // has java calls or has frame size > vm_page_size/8.
412 // The debug VM checks that deoptimization doesn't trigger an
413 // unexpected stack overflow (compiled method stack banging should
414 // guarantee it doesn't happen) so we always need the stack bang in
415 // a debug VM.
416 return (C->stub_function() == nullptr &&
417 (C->has_java_calls() || frame_size_in_bytes > (int)(os::vm_page_size())>>3
418 DEBUG_ONLY(|| true)));
419 }
420
421 bool PhaseOutput::need_register_stack_bang() const {
422 // Determine if we need to generate a register stack overflow check.
423 // This is only used on architectures which have split register
424 // and memory stacks.
425 // Bang if the method is not a stub function and has java calls
426 return (C->stub_function() == nullptr && C->has_java_calls());
427 }
428
429
430 // Compute the size of first NumberOfLoopInstrToAlign instructions at the top
431 // of a loop. When aligning a loop we need to provide enough instructions
432 // in cpu's fetch buffer to feed decoders. The loop alignment could be
433 // avoided if we have enough instructions in fetch buffer at the head of a loop.
434 // By default, the size is set to 999999 by Block's constructor so that
435 // a loop will be aligned if the size is not reset here.
436 //
437 // Note: Mach instructions could contain several HW instructions
438 // so the size is estimated only.
439 //
440 void PhaseOutput::compute_loop_first_inst_sizes() {
441 // The next condition is used to gate the loop alignment optimization.
442 // Don't aligned a loop if there are enough instructions at the head of a loop
443 // or alignment padding is larger then MaxLoopPad. By default, MaxLoopPad
444 // is equal to OptoLoopAlignment-1 except on new Intel cpus, where it is
445 // equal to 11 bytes which is the largest address NOP instruction.
446 if (MaxLoopPad < OptoLoopAlignment - 1) {
447 uint last_block = C->cfg()->number_of_blocks() - 1;
448 for (uint i = 1; i <= last_block; i++) {
449 Block* block = C->cfg()->get_block(i);
450 // Check the first loop's block which requires an alignment.
451 if (block->loop_alignment() > (uint)relocInfo::addr_unit()) {
452 uint sum_size = 0;
453 uint inst_cnt = NumberOfLoopInstrToAlign;
454 inst_cnt = block->compute_first_inst_size(sum_size, inst_cnt, C->regalloc());
455
456 // Check subsequent fallthrough blocks if the loop's first
457 // block(s) does not have enough instructions.
458 Block *nb = block;
459 while(inst_cnt > 0 &&
460 i < last_block &&
461 !C->cfg()->get_block(i + 1)->has_loop_alignment() &&
462 !nb->has_successor(block)) {
463 i++;
464 nb = C->cfg()->get_block(i);
465 inst_cnt = nb->compute_first_inst_size(sum_size, inst_cnt, C->regalloc());
466 } // while( inst_cnt > 0 && i < last_block )
467
468 block->set_first_inst_size(sum_size);
469 } // f( b->head()->is_Loop() )
470 } // for( i <= last_block )
471 } // if( MaxLoopPad < OptoLoopAlignment-1 )
472 }
473
474 // The architecture description provides short branch variants for some long
475 // branch instructions. Replace eligible long branches with short branches.
476 void PhaseOutput::shorten_branches(uint* blk_starts) {
477
478 Compile::TracePhase tp(_t_shortenBranches);
479
480 // Compute size of each block, method size, and relocation information size
481 uint nblocks = C->cfg()->number_of_blocks();
482
483 uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
484 uint* jmp_size = NEW_RESOURCE_ARRAY(uint,nblocks);
485 int* jmp_nidx = NEW_RESOURCE_ARRAY(int ,nblocks);
486
487 // Collect worst case block paddings
488 int* block_worst_case_pad = NEW_RESOURCE_ARRAY(int, nblocks);
489 memset(block_worst_case_pad, 0, nblocks * sizeof(int));
490
491 DEBUG_ONLY( uint *jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks); )
492 DEBUG_ONLY( uint *jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks); )
493
494 bool has_short_branch_candidate = false;
495
496 // Initialize the sizes to 0
497 int code_size = 0; // Size in bytes of generated code
498 int stub_size = 0; // Size in bytes of all stub entries
499 // Size in bytes of all relocation entries, including those in local stubs.
500 // Start with 2-bytes of reloc info for the unvalidated entry point
501 int reloc_size = 1; // Number of relocation entries
502
503 // Make three passes. The first computes pessimistic blk_starts,
504 // relative jmp_offset and reloc_size information. The second performs
505 // short branch substitution using the pessimistic sizing. The
506 // third inserts nops where needed.
507
508 // Step one, perform a pessimistic sizing pass.
509 uint last_call_adr = max_juint;
510 uint last_avoid_back_to_back_adr = max_juint;
511 uint nop_size = (new MachNopNode())->size(C->regalloc());
512 for (uint i = 0; i < nblocks; i++) { // For all blocks
513 Block* block = C->cfg()->get_block(i);
514 _block = block;
515
516 // During short branch replacement, we store the relative (to blk_starts)
517 // offset of jump in jmp_offset, rather than the absolute offset of jump.
518 // This is so that we do not need to recompute sizes of all nodes when
519 // we compute correct blk_starts in our next sizing pass.
520 jmp_offset[i] = 0;
521 jmp_size[i] = 0;
522 jmp_nidx[i] = -1;
523 DEBUG_ONLY( jmp_target[i] = 0; )
524 DEBUG_ONLY( jmp_rule[i] = 0; )
525
526 // Sum all instruction sizes to compute block size
527 uint last_inst = block->number_of_nodes();
528 uint blk_size = 0;
529 for (uint j = 0; j < last_inst; j++) {
530 _index = j;
531 Node* nj = block->get_node(_index);
532 // Handle machine instruction nodes
533 if (nj->is_Mach()) {
534 MachNode* mach = nj->as_Mach();
535 blk_size += (mach->alignment_required() - 1) * relocInfo::addr_unit(); // assume worst case padding
536 reloc_size += mach->reloc();
537 if (mach->is_MachCall()) {
538 // add size information for trampoline stub
539 // class CallStubImpl is platform-specific and defined in the *.ad files.
540 stub_size += CallStubImpl::size_call_trampoline();
541 reloc_size += CallStubImpl::reloc_call_trampoline();
542
543 MachCallNode *mcall = mach->as_MachCall();
544 // This destination address is NOT PC-relative
545
546 if (mcall->entry_point() != nullptr) {
547 mcall->method_set((intptr_t)mcall->entry_point());
548 }
549
550 if (mcall->is_MachCallJava() && mcall->as_MachCallJava()->_method) {
551 stub_size += CompiledDirectCall::to_interp_stub_size();
552 reloc_size += CompiledDirectCall::reloc_to_interp_stub();
553 }
554 } else if (mach->is_MachSafePoint()) {
555 // If call/safepoint are adjacent, account for possible
556 // nop to disambiguate the two safepoints.
557 // ScheduleAndBundle() can rearrange nodes in a block,
558 // check for all offsets inside this block.
559 if (last_call_adr >= blk_starts[i]) {
560 blk_size += nop_size;
561 }
562 }
563 if (mach->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
564 // Nop is inserted between "avoid back to back" instructions.
565 // ScheduleAndBundle() can rearrange nodes in a block,
566 // check for all offsets inside this block.
567 if (last_avoid_back_to_back_adr >= blk_starts[i]) {
568 blk_size += nop_size;
569 }
570 }
571 if (mach->may_be_short_branch()) {
572 if (!nj->is_MachBranch()) {
573 #ifndef PRODUCT
574 nj->dump(3);
575 #endif
576 Unimplemented();
577 }
578 assert(jmp_nidx[i] == -1, "block should have only one branch");
579 jmp_offset[i] = blk_size;
580 jmp_size[i] = nj->size(C->regalloc());
581 jmp_nidx[i] = j;
582 has_short_branch_candidate = true;
583 }
584 }
585 blk_size += nj->size(C->regalloc());
586 // Remember end of call offset
587 if (nj->is_MachCall() && !nj->is_MachCallLeaf()) {
588 last_call_adr = blk_starts[i]+blk_size;
589 }
590 // Remember end of avoid_back_to_back offset
591 if (nj->is_Mach() && nj->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
592 last_avoid_back_to_back_adr = blk_starts[i]+blk_size;
593 }
594 }
595
596 // When the next block starts a loop, we may insert pad NOP
597 // instructions. Since we cannot know our future alignment,
598 // assume the worst.
599 if (i < nblocks - 1) {
600 Block* nb = C->cfg()->get_block(i + 1);
601 int max_loop_pad = nb->code_alignment()-relocInfo::addr_unit();
602 if (max_loop_pad > 0) {
603 assert(is_power_of_2(max_loop_pad+relocInfo::addr_unit()), "");
604 // Adjust last_call_adr and/or last_avoid_back_to_back_adr.
605 // If either is the last instruction in this block, bump by
606 // max_loop_pad in lock-step with blk_size, so sizing
607 // calculations in subsequent blocks still can conservatively
608 // detect that it may the last instruction in this block.
609 if (last_call_adr == blk_starts[i]+blk_size) {
610 last_call_adr += max_loop_pad;
611 }
612 if (last_avoid_back_to_back_adr == blk_starts[i]+blk_size) {
613 last_avoid_back_to_back_adr += max_loop_pad;
614 }
615 blk_size += max_loop_pad;
616 block_worst_case_pad[i + 1] = max_loop_pad;
617 }
618 }
619
620 // Save block size; update total method size
621 blk_starts[i+1] = blk_starts[i]+blk_size;
622 }
623
624 // Step two, replace eligible long jumps.
625 bool progress = true;
626 uint last_may_be_short_branch_adr = max_juint;
627 while (has_short_branch_candidate && progress) {
628 progress = false;
629 has_short_branch_candidate = false;
630 int adjust_block_start = 0;
631 for (uint i = 0; i < nblocks; i++) {
632 Block* block = C->cfg()->get_block(i);
633 int idx = jmp_nidx[i];
634 MachNode* mach = (idx == -1) ? nullptr: block->get_node(idx)->as_Mach();
635 if (mach != nullptr && mach->may_be_short_branch()) {
636 #ifdef ASSERT
637 assert(jmp_size[i] > 0 && mach->is_MachBranch(), "sanity");
638 int j;
639 // Find the branch; ignore trailing NOPs.
640 for (j = block->number_of_nodes()-1; j>=0; j--) {
641 Node* n = block->get_node(j);
642 if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con)
643 break;
644 }
645 assert(j >= 0 && j == idx && block->get_node(j) == (Node*)mach, "sanity");
646 #endif
647 int br_size = jmp_size[i];
648 int br_offs = blk_starts[i] + jmp_offset[i];
649
650 // This requires the TRUE branch target be in succs[0]
651 uint bnum = block->non_connector_successor(0)->_pre_order;
652 int offset = blk_starts[bnum] - br_offs;
653 if (bnum > i) { // adjust following block's offset
654 offset -= adjust_block_start;
655 }
656
657 // This block can be a loop header, account for the padding
658 // in the previous block.
659 int block_padding = block_worst_case_pad[i];
660 assert(i == 0 || block_padding == 0 || br_offs >= block_padding, "Should have at least a padding on top");
661 // In the following code a nop could be inserted before
662 // the branch which will increase the backward distance.
663 bool needs_padding = ((uint)(br_offs - block_padding) == last_may_be_short_branch_adr);
664 assert(!needs_padding || jmp_offset[i] == 0, "padding only branches at the beginning of block");
665
666 if (needs_padding && offset <= 0)
667 offset -= nop_size;
668
669 if (C->matcher()->is_short_branch_offset(mach->rule(), br_size, offset)) {
670 // We've got a winner. Replace this branch.
671 MachNode* replacement = mach->as_MachBranch()->short_branch_version();
672
673 // Update the jmp_size.
674 int new_size = replacement->size(C->regalloc());
675 int diff = br_size - new_size;
676 assert(diff >= (int)nop_size, "short_branch size should be smaller");
677 // Conservatively take into account padding between
678 // avoid_back_to_back branches. Previous branch could be
679 // converted into avoid_back_to_back branch during next
680 // rounds.
681 if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
682 jmp_offset[i] += nop_size;
683 diff -= nop_size;
684 }
685 adjust_block_start += diff;
686 block->map_node(replacement, idx);
687 mach->subsume_by(replacement, C);
688 mach = replacement;
689 progress = true;
690
691 jmp_size[i] = new_size;
692 DEBUG_ONLY( jmp_target[i] = bnum; );
693 DEBUG_ONLY( jmp_rule[i] = mach->rule(); );
694 } else {
695 // The jump distance is not short, try again during next iteration.
696 has_short_branch_candidate = true;
697 }
698 } // (mach->may_be_short_branch())
699 if (mach != nullptr && (mach->may_be_short_branch() ||
700 mach->avoid_back_to_back(MachNode::AVOID_AFTER))) {
701 last_may_be_short_branch_adr = blk_starts[i] + jmp_offset[i] + jmp_size[i];
702 }
703 blk_starts[i+1] -= adjust_block_start;
704 }
705 }
706
707 #ifdef ASSERT
708 for (uint i = 0; i < nblocks; i++) { // For all blocks
709 if (jmp_target[i] != 0) {
710 int br_size = jmp_size[i];
711 int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
712 if (!C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
713 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]);
714 }
715 assert(C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset), "Displacement too large for short jmp");
716 }
717 }
718 #endif
719
720 // Step 3, compute the offsets of all blocks, will be done in fill_buffer()
721 // after ScheduleAndBundle().
722
723 // ------------------
724 // Compute size for code buffer
725 code_size = blk_starts[nblocks];
726
727 // Relocation records
728 reloc_size += 1; // Relo entry for exception handler
729
730 // Adjust reloc_size to number of record of relocation info
731 // Min is 2 bytes, max is probably 6 or 8, with a tax up to 25% for
732 // a relocation index.
733 // The CodeBuffer will expand the locs array if this estimate is too low.
734 reloc_size *= 10 / sizeof(relocInfo);
735
736 _buf_sizes._reloc = reloc_size;
737 _buf_sizes._code = code_size;
738 _buf_sizes._stub = stub_size;
739 }
740
741 //------------------------------FillLocArray-----------------------------------
742 // Create a bit of debug info and append it to the array. The mapping is from
743 // Java local or expression stack to constant, register or stack-slot. For
744 // doubles, insert 2 mappings and return 1 (to tell the caller that the next
745 // entry has been taken care of and caller should skip it).
746 static LocationValue *new_loc_value( PhaseRegAlloc *ra, OptoReg::Name regnum, Location::Type l_type ) {
747 // This should never have accepted Bad before
748 assert(OptoReg::is_valid(regnum), "location must be valid");
749 return (OptoReg::is_reg(regnum))
750 ? new LocationValue(Location::new_reg_loc(l_type, OptoReg::as_VMReg(regnum)) )
751 : new LocationValue(Location::new_stk_loc(l_type, ra->reg2offset(regnum)));
752 }
753
754
755 ObjectValue*
756 PhaseOutput::sv_for_node_id(GrowableArray<ScopeValue*> *objs, int id) {
757 for (int i = 0; i < objs->length(); i++) {
758 assert(objs->at(i)->is_object(), "corrupt object cache");
759 ObjectValue* sv = objs->at(i)->as_ObjectValue();
760 if (sv->id() == id) {
761 return sv;
762 }
763 }
764 // Otherwise..
765 return nullptr;
766 }
767
768 void PhaseOutput::set_sv_for_object_node(GrowableArray<ScopeValue*> *objs,
769 ObjectValue* sv ) {
770 assert(sv_for_node_id(objs, sv->id()) == nullptr, "Precondition");
771 objs->append(sv);
772 }
773
774
775 void PhaseOutput::FillLocArray( int idx, MachSafePointNode* sfpt, Node *local,
776 GrowableArray<ScopeValue*> *array,
777 GrowableArray<ScopeValue*> *objs ) {
778 assert( local, "use _top instead of null" );
779 if (array->length() != idx) {
780 assert(array->length() == idx + 1, "Unexpected array count");
781 // Old functionality:
782 // return
783 // New functionality:
784 // Assert if the local is not top. In product mode let the new node
785 // override the old entry.
786 assert(local == C->top(), "LocArray collision");
787 if (local == C->top()) {
788 return;
789 }
790 array->pop();
791 }
792 const Type *t = local->bottom_type();
793
794 // Is it a safepoint scalar object node?
795 if (local->is_SafePointScalarObject()) {
796 SafePointScalarObjectNode* spobj = local->as_SafePointScalarObject();
797
798 ObjectValue* sv = sv_for_node_id(objs, spobj->_idx);
799 if (sv == nullptr) {
800 ciKlass* cik = t->is_oopptr()->exact_klass();
801 assert(cik->is_instance_klass() ||
802 cik->is_array_klass(), "Not supported allocation.");
803 uint first_ind = spobj->first_index(sfpt->jvms());
804 // Nullable, scalarized inline types have an is_init input
805 // that needs to be checked before using the field values.
806 ScopeValue* is_init = nullptr;
807 if (cik->is_inlinetype()) {
808 Node* init_node = sfpt->in(first_ind++);
809 assert(init_node != nullptr, "is_init node not found");
810 if (!init_node->is_top()) {
811 const TypeInt* init_type = init_node->bottom_type()->is_int();
812 if (init_node->is_Con()) {
813 is_init = new ConstantIntValue(init_type->get_con());
814 } else {
815 OptoReg::Name init_reg = C->regalloc()->get_reg_first(init_node);
816 is_init = new_loc_value(C->regalloc(), init_reg, Location::normal);
817 }
818 }
819 }
820 sv = new ObjectValue(spobj->_idx,
821 new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()), true, is_init);
822 set_sv_for_object_node(objs, sv);
823
824 for (uint i = 0; i < spobj->n_fields(); i++) {
825 Node* fld_node = sfpt->in(first_ind+i);
826 (void)FillLocArray(sv->field_values()->length(), sfpt, fld_node, sv->field_values(), objs);
827 }
828 }
829 array->append(sv);
830 return;
831 } else if (local->is_SafePointScalarMerge()) {
832 SafePointScalarMergeNode* smerge = local->as_SafePointScalarMerge();
833 ObjectMergeValue* mv = (ObjectMergeValue*) sv_for_node_id(objs, smerge->_idx);
834
835 if (mv == nullptr) {
836 GrowableArray<ScopeValue*> deps;
837
838 int merge_pointer_idx = smerge->merge_pointer_idx(sfpt->jvms());
839 (void)FillLocArray(0, sfpt, sfpt->in(merge_pointer_idx), &deps, objs);
840 assert(deps.length() == 1, "missing value");
841
842 int selector_idx = smerge->selector_idx(sfpt->jvms());
843 (void)FillLocArray(1, nullptr, sfpt->in(selector_idx), &deps, nullptr);
844 assert(deps.length() == 2, "missing value");
845
846 mv = new ObjectMergeValue(smerge->_idx, deps.at(0), deps.at(1));
847 set_sv_for_object_node(objs, mv);
848
849 for (uint i = 1; i < smerge->req(); i++) {
850 Node* obj_node = smerge->in(i);
851 int idx = mv->possible_objects()->length();
852 (void)FillLocArray(idx, sfpt, obj_node, mv->possible_objects(), objs);
853
854 // By default ObjectValues that are in 'possible_objects' are not root objects.
855 // They will be marked as root later if they are directly referenced in a JVMS.
856 assert(mv->possible_objects()->length() > idx, "Didn't add entry to possible_objects?!");
857 assert(mv->possible_objects()->at(idx)->is_object(), "Entries in possible_objects should be ObjectValue.");
858 mv->possible_objects()->at(idx)->as_ObjectValue()->set_root(false);
859 }
860 }
861 array->append(mv);
862 return;
863 }
864
865 // Grab the register number for the local
866 OptoReg::Name regnum = C->regalloc()->get_reg_first(local);
867 if( OptoReg::is_valid(regnum) ) {// Got a register/stack?
868 // Record the double as two float registers.
869 // The register mask for such a value always specifies two adjacent
870 // float registers, with the lower register number even.
871 // Normally, the allocation of high and low words to these registers
872 // is irrelevant, because nearly all operations on register pairs
873 // (e.g., StoreD) treat them as a single unit.
874 // Here, we assume in addition that the words in these two registers
875 // stored "naturally" (by operations like StoreD and double stores
876 // within the interpreter) such that the lower-numbered register
877 // is written to the lower memory address. This may seem like
878 // a machine dependency, but it is not--it is a requirement on
879 // the author of the <arch>.ad file to ensure that, for every
880 // even/odd double-register pair to which a double may be allocated,
881 // the word in the even single-register is stored to the first
882 // memory word. (Note that register numbers are completely
883 // arbitrary, and are not tied to any machine-level encodings.)
884 #ifdef _LP64
885 if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon ) {
886 array->append(new ConstantIntValue((jint)0));
887 array->append(new_loc_value( C->regalloc(), regnum, Location::dbl ));
888 } else if ( t->base() == Type::Long ) {
889 array->append(new ConstantIntValue((jint)0));
890 array->append(new_loc_value( C->regalloc(), regnum, Location::lng ));
891 } else if ( t->base() == Type::RawPtr ) {
892 // jsr/ret return address which must be restored into the full
893 // width 64-bit stack slot.
894 array->append(new_loc_value( C->regalloc(), regnum, Location::lng ));
895 }
896 #else //_LP64
897 if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon || t->base() == Type::Long ) {
898 // Repack the double/long as two jints.
899 // The convention the interpreter uses is that the second local
900 // holds the first raw word of the native double representation.
901 // This is actually reasonable, since locals and stack arrays
902 // grow downwards in all implementations.
903 // (If, on some machine, the interpreter's Java locals or stack
904 // were to grow upwards, the embedded doubles would be word-swapped.)
905 array->append(new_loc_value( C->regalloc(), OptoReg::add(regnum,1), Location::normal ));
906 array->append(new_loc_value( C->regalloc(), regnum , Location::normal ));
907 }
908 #endif //_LP64
909 else if( (t->base() == Type::FloatBot || t->base() == Type::FloatCon) &&
910 OptoReg::is_reg(regnum) ) {
911 array->append(new_loc_value( C->regalloc(), regnum, Matcher::float_in_double()
912 ? Location::float_in_dbl : Location::normal ));
913 } else if( t->base() == Type::Int && OptoReg::is_reg(regnum) ) {
914 array->append(new_loc_value( C->regalloc(), regnum, Matcher::int_in_long
915 ? Location::int_in_long : Location::normal ));
916 } else if( t->base() == Type::NarrowOop ) {
917 array->append(new_loc_value( C->regalloc(), regnum, Location::narrowoop ));
918 } else if (t->base() == Type::VectorA || t->base() == Type::VectorS ||
919 t->base() == Type::VectorD || t->base() == Type::VectorX ||
920 t->base() == Type::VectorY || t->base() == Type::VectorZ) {
921 array->append(new_loc_value( C->regalloc(), regnum, Location::vector ));
922 } else if (C->regalloc()->is_oop(local)) {
923 assert(t->base() == Type::OopPtr || t->base() == Type::InstPtr ||
924 t->base() == Type::AryPtr,
925 "Unexpected type: %s", t->msg());
926 array->append(new_loc_value( C->regalloc(), regnum, Location::oop ));
927 } else {
928 assert(t->base() == Type::Int || t->base() == Type::Half ||
929 t->base() == Type::FloatCon || t->base() == Type::FloatBot,
930 "Unexpected type: %s", t->msg());
931 array->append(new_loc_value( C->regalloc(), regnum, Location::normal ));
932 }
933 return;
934 }
935
936 // No register. It must be constant data.
937 switch (t->base()) {
938 case Type::Half: // Second half of a double
939 ShouldNotReachHere(); // Caller should skip 2nd halves
940 break;
941 case Type::AnyPtr:
942 array->append(new ConstantOopWriteValue(nullptr));
943 break;
944 case Type::AryPtr:
945 case Type::InstPtr: // fall through
946 array->append(new ConstantOopWriteValue(t->isa_oopptr()->const_oop()->constant_encoding()));
947 break;
948 case Type::NarrowOop:
949 if (t == TypeNarrowOop::NULL_PTR) {
950 array->append(new ConstantOopWriteValue(nullptr));
951 } else {
952 array->append(new ConstantOopWriteValue(t->make_ptr()->isa_oopptr()->const_oop()->constant_encoding()));
953 }
954 break;
955 case Type::Int:
956 array->append(new ConstantIntValue(t->is_int()->get_con()));
957 break;
958 case Type::RawPtr:
959 // A return address (T_ADDRESS).
960 assert((intptr_t)t->is_ptr()->get_con() < (intptr_t)0x10000, "must be a valid BCI");
961 #ifdef _LP64
962 // Must be restored to the full-width 64-bit stack slot.
963 array->append(new ConstantLongValue(t->is_ptr()->get_con()));
964 #else
965 array->append(new ConstantIntValue(t->is_ptr()->get_con()));
966 #endif
967 break;
968 case Type::FloatCon: {
969 float f = t->is_float_constant()->getf();
970 array->append(new ConstantIntValue(jint_cast(f)));
971 break;
972 }
973 case Type::DoubleCon: {
974 jdouble d = t->is_double_constant()->getd();
975 #ifdef _LP64
976 array->append(new ConstantIntValue((jint)0));
977 array->append(new ConstantDoubleValue(d));
978 #else
979 // Repack the double as two jints.
980 // The convention the interpreter uses is that the second local
981 // holds the first raw word of the native double representation.
982 // This is actually reasonable, since locals and stack arrays
983 // grow downwards in all implementations.
984 // (If, on some machine, the interpreter's Java locals or stack
985 // were to grow upwards, the embedded doubles would be word-swapped.)
986 jlong_accessor acc;
987 acc.long_value = jlong_cast(d);
988 array->append(new ConstantIntValue(acc.words[1]));
989 array->append(new ConstantIntValue(acc.words[0]));
990 #endif
991 break;
992 }
993 case Type::Long: {
994 jlong d = t->is_long()->get_con();
995 #ifdef _LP64
996 array->append(new ConstantIntValue((jint)0));
997 array->append(new ConstantLongValue(d));
998 #else
999 // Repack the long as two jints.
1000 // The convention the interpreter uses is that the second local
1001 // holds the first raw word of the native double representation.
1002 // This is actually reasonable, since locals and stack arrays
1003 // grow downwards in all implementations.
1004 // (If, on some machine, the interpreter's Java locals or stack
1005 // were to grow upwards, the embedded doubles would be word-swapped.)
1006 jlong_accessor acc;
1007 acc.long_value = d;
1008 array->append(new ConstantIntValue(acc.words[1]));
1009 array->append(new ConstantIntValue(acc.words[0]));
1010 #endif
1011 break;
1012 }
1013 case Type::Top: // Add an illegal value here
1014 array->append(new LocationValue(Location()));
1015 break;
1016 default:
1017 ShouldNotReachHere();
1018 break;
1019 }
1020 }
1021
1022 // Determine if this node starts a bundle
1023 bool PhaseOutput::starts_bundle(const Node *n) const {
1024 return (_node_bundling_limit > n->_idx &&
1025 _node_bundling_base[n->_idx].starts_bundle());
1026 }
1027
1028 // Determine if there is a monitor that has 'ov' as its owner.
1029 bool PhaseOutput::contains_as_owner(GrowableArray<MonitorValue*> *monarray, ObjectValue *ov) const {
1030 for (int k = 0; k < monarray->length(); k++) {
1031 MonitorValue* mv = monarray->at(k);
1032 if (mv->owner() == ov) {
1033 return true;
1034 }
1035 }
1036
1037 return false;
1038 }
1039
1040 // Determine if there is a scalar replaced object description represented by 'ov'.
1041 bool PhaseOutput::contains_as_scalarized_obj(JVMState* jvms, MachSafePointNode* sfn,
1042 GrowableArray<ScopeValue*>* objs,
1043 ObjectValue* ov) const {
1044 for (int i = 0; i < jvms->scl_size(); i++) {
1045 Node* n = sfn->scalarized_obj(jvms, i);
1046 // Other kinds of nodes that we may encounter here, for instance constants
1047 // representing values of fields of objects scalarized, aren't relevant for
1048 // us, since they don't map to ObjectValue.
1049 if (!n->is_SafePointScalarObject()) {
1050 continue;
1051 }
1052
1053 ObjectValue* other = sv_for_node_id(objs, n->_idx);
1054 if (ov == other) {
1055 return true;
1056 }
1057 }
1058 return false;
1059 }
1060
1061 //--------------------------Process_OopMap_Node--------------------------------
1062 void PhaseOutput::Process_OopMap_Node(MachNode *mach, int current_offset) {
1063 // Handle special safepoint nodes for synchronization
1064 MachSafePointNode *sfn = mach->as_MachSafePoint();
1065 MachCallNode *mcall;
1066
1067 int safepoint_pc_offset = current_offset;
1068 bool is_method_handle_invoke = false;
1069 bool return_oop = false;
1070 bool return_scalarized = false;
1071 bool has_ea_local_in_scope = sfn->_has_ea_local_in_scope;
1072 bool arg_escape = false;
1073
1074 // Add the safepoint in the DebugInfoRecorder
1075 if( !mach->is_MachCall() ) {
1076 mcall = nullptr;
1077 C->debug_info()->add_safepoint(safepoint_pc_offset, sfn->_oop_map);
1078 } else {
1079 mcall = mach->as_MachCall();
1080
1081 // Is the call a MethodHandle call?
1082 if (mcall->is_MachCallJava()) {
1083 if (mcall->as_MachCallJava()->_method_handle_invoke) {
1084 assert(C->has_method_handle_invokes(), "must have been set during call generation");
1085 is_method_handle_invoke = true;
1086 }
1087 arg_escape = mcall->as_MachCallJava()->_arg_escape;
1088 }
1089
1090 // Check if a call returns an object.
1091 if (mcall->returns_pointer() || mcall->returns_scalarized()) {
1092 return_oop = true;
1093 }
1094 if (mcall->returns_scalarized()) {
1095 return_scalarized = true;
1096 }
1097 safepoint_pc_offset += mcall->ret_addr_offset();
1098 C->debug_info()->add_safepoint(safepoint_pc_offset, mcall->_oop_map);
1099 }
1100
1101 // Loop over the JVMState list to add scope information
1102 // Do not skip safepoints with a null method, they need monitor info
1103 JVMState* youngest_jvms = sfn->jvms();
1104 int max_depth = youngest_jvms->depth();
1105
1106 // Allocate the object pool for scalar-replaced objects -- the map from
1107 // small-integer keys (which can be recorded in the local and ostack
1108 // arrays) to descriptions of the object state.
1109 GrowableArray<ScopeValue*> *objs = new GrowableArray<ScopeValue*>();
1110
1111 // Visit scopes from oldest to youngest.
1112 for (int depth = 1; depth <= max_depth; depth++) {
1113 JVMState* jvms = youngest_jvms->of_depth(depth);
1114 int idx;
1115 ciMethod* method = jvms->has_method() ? jvms->method() : nullptr;
1116 // Safepoints that do not have method() set only provide oop-map and monitor info
1117 // to support GC; these do not support deoptimization.
1118 int num_locs = (method == nullptr) ? 0 : jvms->loc_size();
1119 int num_exps = (method == nullptr) ? 0 : jvms->stk_size();
1120 int num_mon = jvms->nof_monitors();
1121 assert(method == nullptr || jvms->bci() < 0 || num_locs == method->max_locals(),
1122 "JVMS local count must match that of the method");
1123
1124 // Add Local and Expression Stack Information
1125
1126 // Insert locals into the locarray
1127 GrowableArray<ScopeValue*> *locarray = new GrowableArray<ScopeValue*>(num_locs);
1128 for( idx = 0; idx < num_locs; idx++ ) {
1129 FillLocArray( idx, sfn, sfn->local(jvms, idx), locarray, objs );
1130 }
1131
1132 // Insert expression stack entries into the exparray
1133 GrowableArray<ScopeValue*> *exparray = new GrowableArray<ScopeValue*>(num_exps);
1134 for( idx = 0; idx < num_exps; idx++ ) {
1135 FillLocArray( idx, sfn, sfn->stack(jvms, idx), exparray, objs );
1136 }
1137
1138 // Add in mappings of the monitors
1139 assert( !method ||
1140 !method->is_synchronized() ||
1141 method->is_native() ||
1142 num_mon > 0 ||
1143 !GenerateSynchronizationCode,
1144 "monitors must always exist for synchronized methods");
1145
1146 // Build the growable array of ScopeValues for exp stack
1147 GrowableArray<MonitorValue*> *monarray = new GrowableArray<MonitorValue*>(num_mon);
1148
1149 // Loop over monitors and insert into array
1150 for (idx = 0; idx < num_mon; idx++) {
1151 // Grab the node that defines this monitor
1152 Node* box_node = sfn->monitor_box(jvms, idx);
1153 Node* obj_node = sfn->monitor_obj(jvms, idx);
1154
1155 // Create ScopeValue for object
1156 ScopeValue *scval = nullptr;
1157
1158 if (obj_node->is_SafePointScalarObject()) {
1159 SafePointScalarObjectNode* spobj = obj_node->as_SafePointScalarObject();
1160 scval = PhaseOutput::sv_for_node_id(objs, spobj->_idx);
1161 if (scval == nullptr) {
1162 const Type *t = spobj->bottom_type();
1163 ciKlass* cik = t->is_oopptr()->exact_klass();
1164 assert(cik->is_instance_klass() ||
1165 cik->is_array_klass(), "Not supported allocation.");
1166 ObjectValue* sv = new ObjectValue(spobj->_idx,
1167 new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
1168 PhaseOutput::set_sv_for_object_node(objs, sv);
1169
1170 uint first_ind = spobj->first_index(youngest_jvms);
1171 for (uint i = 0; i < spobj->n_fields(); i++) {
1172 Node* fld_node = sfn->in(first_ind+i);
1173 (void)FillLocArray(sv->field_values()->length(), sfn, fld_node, sv->field_values(), objs);
1174 }
1175 scval = sv;
1176 }
1177 } else if (obj_node->is_SafePointScalarMerge()) {
1178 SafePointScalarMergeNode* smerge = obj_node->as_SafePointScalarMerge();
1179 ObjectMergeValue* mv = (ObjectMergeValue*) sv_for_node_id(objs, smerge->_idx);
1180
1181 if (mv == nullptr) {
1182 GrowableArray<ScopeValue*> deps;
1183
1184 int merge_pointer_idx = smerge->merge_pointer_idx(youngest_jvms);
1185 FillLocArray(0, sfn, sfn->in(merge_pointer_idx), &deps, objs);
1186 assert(deps.length() == 1, "missing value");
1187
1188 int selector_idx = smerge->selector_idx(youngest_jvms);
1189 FillLocArray(1, nullptr, sfn->in(selector_idx), &deps, nullptr);
1190 assert(deps.length() == 2, "missing value");
1191
1192 mv = new ObjectMergeValue(smerge->_idx, deps.at(0), deps.at(1));
1193 set_sv_for_object_node(objs, mv);
1194
1195 for (uint i = 1; i < smerge->req(); i++) {
1196 Node* obj_node = smerge->in(i);
1197 int idx = mv->possible_objects()->length();
1198 (void)FillLocArray(idx, sfn, obj_node, mv->possible_objects(), objs);
1199
1200 // By default ObjectValues that are in 'possible_objects' are not root objects.
1201 // They will be marked as root later if they are directly referenced in a JVMS.
1202 assert(mv->possible_objects()->length() > idx, "Didn't add entry to possible_objects?!");
1203 assert(mv->possible_objects()->at(idx)->is_object(), "Entries in possible_objects should be ObjectValue.");
1204 mv->possible_objects()->at(idx)->as_ObjectValue()->set_root(false);
1205 }
1206 }
1207 scval = mv;
1208 } else if (!obj_node->is_Con()) {
1209 OptoReg::Name obj_reg = C->regalloc()->get_reg_first(obj_node);
1210 if( obj_node->bottom_type()->base() == Type::NarrowOop ) {
1211 scval = new_loc_value( C->regalloc(), obj_reg, Location::narrowoop );
1212 } else {
1213 scval = new_loc_value( C->regalloc(), obj_reg, Location::oop );
1214 }
1215 } else {
1216 const TypePtr *tp = obj_node->get_ptr_type();
1217 scval = new ConstantOopWriteValue(tp->is_oopptr()->const_oop()->constant_encoding());
1218 }
1219
1220 OptoReg::Name box_reg = BoxLockNode::reg(box_node);
1221 Location basic_lock = Location::new_stk_loc(Location::normal,C->regalloc()->reg2offset(box_reg));
1222 bool eliminated = (box_node->is_BoxLock() && box_node->as_BoxLock()->is_eliminated());
1223 monarray->append(new MonitorValue(scval, basic_lock, eliminated));
1224 }
1225
1226 // Mark ObjectValue nodes as root nodes if they are directly
1227 // referenced in the JVMS.
1228 for (int i = 0; i < objs->length(); i++) {
1229 ScopeValue* sv = objs->at(i);
1230 if (sv->is_object_merge()) {
1231 ObjectMergeValue* merge = sv->as_ObjectMergeValue();
1232
1233 for (int j = 0; j< merge->possible_objects()->length(); j++) {
1234 ObjectValue* ov = merge->possible_objects()->at(j)->as_ObjectValue();
1235 if (ov->is_root()) {
1236 // Already flagged as 'root' by something else. We shouldn't change it
1237 // to non-root in a younger JVMS because it may need to be alive in
1238 // a younger JVMS.
1239 } else {
1240 bool is_root = locarray->contains(ov) ||
1241 exparray->contains(ov) ||
1242 contains_as_owner(monarray, ov) ||
1243 contains_as_scalarized_obj(jvms, sfn, objs, ov);
1244 ov->set_root(is_root);
1245 }
1246 }
1247 }
1248 }
1249
1250 // We dump the object pool first, since deoptimization reads it in first.
1251 C->debug_info()->dump_object_pool(objs);
1252
1253 // Build first class objects to pass to scope
1254 DebugToken *locvals = C->debug_info()->create_scope_values(locarray);
1255 DebugToken *expvals = C->debug_info()->create_scope_values(exparray);
1256 DebugToken *monvals = C->debug_info()->create_monitor_values(monarray);
1257
1258 // Make method available for all Safepoints
1259 ciMethod* scope_method = method ? method : C->method();
1260 // Describe the scope here
1261 assert(jvms->bci() >= InvocationEntryBci && jvms->bci() <= 0x10000, "must be a valid or entry BCI");
1262 assert(!jvms->should_reexecute() || depth == max_depth, "reexecute allowed only for the youngest");
1263 // Now we can describe the scope.
1264 methodHandle null_mh;
1265 bool rethrow_exception = false;
1266 C->debug_info()->describe_scope(
1267 safepoint_pc_offset,
1268 null_mh,
1269 scope_method,
1270 jvms->bci(),
1271 jvms->should_reexecute(),
1272 rethrow_exception,
1273 is_method_handle_invoke,
1274 return_oop,
1275 return_scalarized,
1276 has_ea_local_in_scope,
1277 arg_escape,
1278 locvals,
1279 expvals,
1280 monvals
1281 );
1282 } // End jvms loop
1283
1284 // Mark the end of the scope set.
1285 C->debug_info()->end_safepoint(safepoint_pc_offset);
1286 }
1287
1288
1289
1290 // A simplified version of Process_OopMap_Node, to handle non-safepoints.
1291 class NonSafepointEmitter {
1292 Compile* C;
1293 JVMState* _pending_jvms;
1294 int _pending_offset;
1295
1296 void emit_non_safepoint();
1297
1298 public:
1299 NonSafepointEmitter(Compile* compile) {
1300 this->C = compile;
1301 _pending_jvms = nullptr;
1302 _pending_offset = 0;
1303 }
1304
1305 void observe_instruction(Node* n, int pc_offset) {
1306 if (!C->debug_info()->recording_non_safepoints()) return;
1307
1308 Node_Notes* nn = C->node_notes_at(n->_idx);
1309 if (nn == nullptr || nn->jvms() == nullptr) return;
1310 if (_pending_jvms != nullptr &&
1311 _pending_jvms->same_calls_as(nn->jvms())) {
1312 // Repeated JVMS? Stretch it up here.
1313 _pending_offset = pc_offset;
1314 } else {
1315 if (_pending_jvms != nullptr &&
1316 _pending_offset < pc_offset) {
1317 emit_non_safepoint();
1318 }
1319 _pending_jvms = nullptr;
1320 if (pc_offset > C->debug_info()->last_pc_offset()) {
1321 // This is the only way _pending_jvms can become non-null:
1322 _pending_jvms = nn->jvms();
1323 _pending_offset = pc_offset;
1324 }
1325 }
1326 }
1327
1328 // Stay out of the way of real safepoints:
1329 void observe_safepoint(JVMState* jvms, int pc_offset) {
1330 if (_pending_jvms != nullptr &&
1331 !_pending_jvms->same_calls_as(jvms) &&
1332 _pending_offset < pc_offset) {
1333 emit_non_safepoint();
1334 }
1335 _pending_jvms = nullptr;
1336 }
1337
1338 void flush_at_end() {
1339 if (_pending_jvms != nullptr) {
1340 emit_non_safepoint();
1341 }
1342 _pending_jvms = nullptr;
1343 }
1344 };
1345
1346 void NonSafepointEmitter::emit_non_safepoint() {
1347 JVMState* youngest_jvms = _pending_jvms;
1348 int pc_offset = _pending_offset;
1349
1350 // Clear it now:
1351 _pending_jvms = nullptr;
1352
1353 DebugInformationRecorder* debug_info = C->debug_info();
1354 assert(debug_info->recording_non_safepoints(), "sanity");
1355
1356 debug_info->add_non_safepoint(pc_offset);
1357 int max_depth = youngest_jvms->depth();
1358
1359 // Visit scopes from oldest to youngest.
1360 for (int depth = 1; depth <= max_depth; depth++) {
1361 JVMState* jvms = youngest_jvms->of_depth(depth);
1362 ciMethod* method = jvms->has_method() ? jvms->method() : nullptr;
1363 assert(!jvms->should_reexecute() || depth==max_depth, "reexecute allowed only for the youngest");
1364 methodHandle null_mh;
1365 debug_info->describe_scope(pc_offset, null_mh, method, jvms->bci(), jvms->should_reexecute());
1366 }
1367
1368 // Mark the end of the scope set.
1369 debug_info->end_non_safepoint(pc_offset);
1370 }
1371
1372 //------------------------------init_buffer------------------------------------
1373 void PhaseOutput::estimate_buffer_size(int& const_req) {
1374
1375 // Set the initially allocated size
1376 const_req = initial_const_capacity;
1377
1378 // The extra spacing after the code is necessary on some platforms.
1379 // Sometimes we need to patch in a jump after the last instruction,
1380 // if the nmethod has been deoptimized. (See 4932387, 4894843.)
1381
1382 // Compute the byte offset where we can store the deopt pc.
1383 if (C->fixed_slots() != 0) {
1384 _orig_pc_slot_offset_in_bytes = C->regalloc()->reg2offset(OptoReg::stack2reg(_orig_pc_slot));
1385 }
1386
1387 // Compute prolog code size
1388 _frame_slots = OptoReg::reg2stack(C->matcher()->_old_SP) + C->regalloc()->_framesize;
1389 assert(_frame_slots >= 0 && _frame_slots < 1000000, "sanity check");
1390
1391 if (C->has_mach_constant_base_node()) {
1392 uint add_size = 0;
1393 // Fill the constant table.
1394 // Note: This must happen before shorten_branches.
1395 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
1396 Block* b = C->cfg()->get_block(i);
1397
1398 for (uint j = 0; j < b->number_of_nodes(); j++) {
1399 Node* n = b->get_node(j);
1400
1401 // If the node is a MachConstantNode evaluate the constant
1402 // value section.
1403 if (n->is_MachConstant()) {
1404 MachConstantNode* machcon = n->as_MachConstant();
1405 machcon->eval_constant(C);
1406 } else if (n->is_Mach()) {
1407 // On Power there are more nodes that issue constants.
1408 add_size += (n->as_Mach()->ins_num_consts() * 8);
1409 }
1410 }
1411 }
1412
1413 // Calculate the offsets of the constants and the size of the
1414 // constant table (including the padding to the next section).
1415 constant_table().calculate_offsets_and_size();
1416 const_req = constant_table().alignment() + constant_table().size() + add_size;
1417 }
1418
1419 // Initialize the space for the BufferBlob used to find and verify
1420 // instruction size in MachNode::emit_size()
1421 init_scratch_buffer_blob(const_req);
1422 }
1423
1424 CodeBuffer* PhaseOutput::init_buffer() {
1425 int stub_req = _buf_sizes._stub;
1426 int code_req = _buf_sizes._code;
1427 int const_req = _buf_sizes._const;
1428
1429 int pad_req = NativeCall::byte_size();
1430
1431 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1432 stub_req += bs->estimate_stub_size();
1433
1434 // nmethod and CodeBuffer count stubs & constants as part of method's code.
1435 // class HandlerImpl is platform-specific and defined in the *.ad files.
1436 int exception_handler_req = HandlerImpl::size_exception_handler() + MAX_stubs_size; // add marginal slop for handler
1437 int deopt_handler_req = HandlerImpl::size_deopt_handler() + MAX_stubs_size; // add marginal slop for handler
1438 stub_req += MAX_stubs_size; // ensure per-stub margin
1439 code_req += MAX_inst_size; // ensure per-instruction margin
1440
1441 if (StressCodeBuffers)
1442 code_req = const_req = stub_req = exception_handler_req = deopt_handler_req = 0x10; // force expansion
1443
1444 int total_req =
1445 const_req +
1446 code_req +
1447 pad_req +
1448 stub_req +
1449 exception_handler_req +
1450 deopt_handler_req; // deopt handler
1451
1452 if (C->has_method_handle_invokes())
1453 total_req += deopt_handler_req; // deopt MH handler
1454
1455 CodeBuffer* cb = code_buffer();
1456 cb->set_const_section_alignment(constant_table().alignment());
1457 cb->initialize(total_req, _buf_sizes._reloc);
1458
1459 // Have we run out of code space?
1460 if ((cb->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1461 C->record_failure("CodeCache is full");
1462 return nullptr;
1463 }
1464 // Configure the code buffer.
1465 cb->initialize_consts_size(const_req);
1466 cb->initialize_stubs_size(stub_req);
1467 cb->initialize_oop_recorder(C->env()->oop_recorder());
1468
1469 // fill in the nop array for bundling computations
1470 MachNode *_nop_list[Bundle::_nop_count];
1471 Bundle::initialize_nops(_nop_list);
1472
1473 return cb;
1474 }
1475
1476 //------------------------------fill_buffer------------------------------------
1477 void PhaseOutput::fill_buffer(C2_MacroAssembler* masm, uint* blk_starts) {
1478 // blk_starts[] contains offsets calculated during short branches processing,
1479 // offsets should not be increased during following steps.
1480
1481 // Compute the size of first NumberOfLoopInstrToAlign instructions at head
1482 // of a loop. It is used to determine the padding for loop alignment.
1483 Compile::TracePhase tp(_t_fillBuffer);
1484
1485 compute_loop_first_inst_sizes();
1486
1487 // Create oopmap set.
1488 _oop_map_set = new OopMapSet();
1489
1490 // !!!!! This preserves old handling of oopmaps for now
1491 C->debug_info()->set_oopmaps(_oop_map_set);
1492
1493 uint nblocks = C->cfg()->number_of_blocks();
1494 // Count and start of implicit null check instructions
1495 uint inct_cnt = 0;
1496 uint* inct_starts = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1497
1498 // Count and start of calls
1499 uint* call_returns = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1500
1501 uint return_offset = 0;
1502 int nop_size = (new MachNopNode())->size(C->regalloc());
1503
1504 int previous_offset = 0;
1505 int current_offset = 0;
1506 int last_call_offset = -1;
1507 int last_avoid_back_to_back_offset = -1;
1508 #ifdef ASSERT
1509 uint* jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks);
1510 uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
1511 uint* jmp_size = NEW_RESOURCE_ARRAY(uint,nblocks);
1512 uint* jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks);
1513 #endif
1514
1515 // Create an array of unused labels, one for each basic block, if printing is enabled
1516 #if defined(SUPPORT_OPTO_ASSEMBLY)
1517 int* node_offsets = nullptr;
1518 uint node_offset_limit = C->unique();
1519
1520 if (C->print_assembly()) {
1521 node_offsets = NEW_RESOURCE_ARRAY(int, node_offset_limit);
1522 }
1523 if (node_offsets != nullptr) {
1524 // We need to initialize. Unused array elements may contain garbage and mess up PrintOptoAssembly.
1525 memset(node_offsets, 0, node_offset_limit*sizeof(int));
1526 }
1527 #endif
1528
1529 NonSafepointEmitter non_safepoints(C); // emit non-safepoints lazily
1530
1531 // Emit the constant table.
1532 if (C->has_mach_constant_base_node()) {
1533 if (!constant_table().emit(masm)) {
1534 C->record_failure("consts section overflow");
1535 return;
1536 }
1537 }
1538
1539 // Create an array of labels, one for each basic block
1540 Label* blk_labels = NEW_RESOURCE_ARRAY(Label, nblocks+1);
1541 for (uint i = 0; i <= nblocks; i++) {
1542 blk_labels[i].init();
1543 }
1544
1545 // Now fill in the code buffer
1546 Node* delay_slot = nullptr;
1547 for (uint i = 0; i < nblocks; i++) {
1548 Block* block = C->cfg()->get_block(i);
1549 _block = block;
1550 Node* head = block->head();
1551
1552 // If this block needs to start aligned (i.e, can be reached other
1553 // than by falling-thru from the previous block), then force the
1554 // start of a new bundle.
1555 if (Pipeline::requires_bundling() && starts_bundle(head)) {
1556 masm->code()->flush_bundle(true);
1557 }
1558
1559 #ifdef ASSERT
1560 if (!block->is_connector()) {
1561 stringStream st;
1562 block->dump_head(C->cfg(), &st);
1563 masm->block_comment(st.freeze());
1564 }
1565 jmp_target[i] = 0;
1566 jmp_offset[i] = 0;
1567 jmp_size[i] = 0;
1568 jmp_rule[i] = 0;
1569 #endif
1570 int blk_offset = current_offset;
1571
1572 // Define the label at the beginning of the basic block
1573 masm->bind(blk_labels[block->_pre_order]);
1574
1575 uint last_inst = block->number_of_nodes();
1576
1577 // Emit block normally, except for last instruction.
1578 // Emit means "dump code bits into code buffer".
1579 for (uint j = 0; j<last_inst; j++) {
1580 _index = j;
1581
1582 // Get the node
1583 Node* n = block->get_node(j);
1584
1585 // See if delay slots are supported
1586 if (valid_bundle_info(n) && node_bundling(n)->used_in_unconditional_delay()) {
1587 assert(delay_slot == nullptr, "no use of delay slot node");
1588 assert(n->size(C->regalloc()) == Pipeline::instr_unit_size(), "delay slot instruction wrong size");
1589
1590 delay_slot = n;
1591 continue;
1592 }
1593
1594 // If this starts a new instruction group, then flush the current one
1595 // (but allow split bundles)
1596 if (Pipeline::requires_bundling() && starts_bundle(n))
1597 masm->code()->flush_bundle(false);
1598
1599 // Special handling for SafePoint/Call Nodes
1600 bool is_mcall = false;
1601 if (n->is_Mach()) {
1602 MachNode *mach = n->as_Mach();
1603 is_mcall = n->is_MachCall();
1604 bool is_sfn = n->is_MachSafePoint();
1605
1606 // If this requires all previous instructions be flushed, then do so
1607 if (is_sfn || is_mcall || mach->alignment_required() != 1) {
1608 masm->code()->flush_bundle(true);
1609 current_offset = masm->offset();
1610 }
1611
1612 // A padding may be needed again since a previous instruction
1613 // could be moved to delay slot.
1614
1615 // align the instruction if necessary
1616 int padding = mach->compute_padding(current_offset);
1617 // Make sure safepoint node for polling is distinct from a call's
1618 // return by adding a nop if needed.
1619 if (is_sfn && !is_mcall && padding == 0 && current_offset == last_call_offset) {
1620 padding = nop_size;
1621 }
1622 if (padding == 0 && mach->avoid_back_to_back(MachNode::AVOID_BEFORE) &&
1623 current_offset == last_avoid_back_to_back_offset) {
1624 // Avoid back to back some instructions.
1625 padding = nop_size;
1626 }
1627
1628 if (padding > 0) {
1629 assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
1630 int nops_cnt = padding / nop_size;
1631 MachNode *nop = new MachNopNode(nops_cnt);
1632 block->insert_node(nop, j++);
1633 last_inst++;
1634 C->cfg()->map_node_to_block(nop, block);
1635 // Ensure enough space.
1636 masm->code()->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1637 if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1638 C->record_failure("CodeCache is full");
1639 return;
1640 }
1641 nop->emit(masm, C->regalloc());
1642 masm->code()->flush_bundle(true);
1643 current_offset = masm->offset();
1644 }
1645
1646 bool observe_safepoint = is_sfn;
1647 // Remember the start of the last call in a basic block
1648 if (is_mcall) {
1649 MachCallNode *mcall = mach->as_MachCall();
1650
1651 if (mcall->entry_point() != nullptr) {
1652 // This destination address is NOT PC-relative
1653 mcall->method_set((intptr_t)mcall->entry_point());
1654 }
1655
1656 // Save the return address
1657 call_returns[block->_pre_order] = current_offset + mcall->ret_addr_offset();
1658
1659 observe_safepoint = mcall->guaranteed_safepoint();
1660 }
1661
1662 // sfn will be valid whenever mcall is valid now because of inheritance
1663 if (observe_safepoint) {
1664 // Handle special safepoint nodes for synchronization
1665 if (!is_mcall) {
1666 MachSafePointNode *sfn = mach->as_MachSafePoint();
1667 // !!!!! Stubs only need an oopmap right now, so bail out
1668 if (sfn->jvms()->method() == nullptr) {
1669 // Write the oopmap directly to the code blob??!!
1670 continue;
1671 }
1672 } // End synchronization
1673
1674 non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1675 current_offset);
1676 Process_OopMap_Node(mach, current_offset);
1677 } // End if safepoint
1678
1679 // If this is a null check, then add the start of the previous instruction to the list
1680 else if( mach->is_MachNullCheck() ) {
1681 inct_starts[inct_cnt++] = previous_offset;
1682 }
1683
1684 // If this is a branch, then fill in the label with the target BB's label
1685 else if (mach->is_MachBranch()) {
1686 // This requires the TRUE branch target be in succs[0]
1687 uint block_num = block->non_connector_successor(0)->_pre_order;
1688
1689 // Try to replace long branch if delay slot is not used,
1690 // it is mostly for back branches since forward branch's
1691 // distance is not updated yet.
1692 bool delay_slot_is_used = valid_bundle_info(n) &&
1693 C->output()->node_bundling(n)->use_unconditional_delay();
1694 if (!delay_slot_is_used && mach->may_be_short_branch()) {
1695 assert(delay_slot == nullptr, "not expecting delay slot node");
1696 int br_size = n->size(C->regalloc());
1697 int offset = blk_starts[block_num] - current_offset;
1698 if (block_num >= i) {
1699 // Current and following block's offset are not
1700 // finalized yet, adjust distance by the difference
1701 // between calculated and final offsets of current block.
1702 offset -= (blk_starts[i] - blk_offset);
1703 }
1704 // In the following code a nop could be inserted before
1705 // the branch which will increase the backward distance.
1706 bool needs_padding = (current_offset == last_avoid_back_to_back_offset);
1707 if (needs_padding && offset <= 0)
1708 offset -= nop_size;
1709
1710 if (C->matcher()->is_short_branch_offset(mach->rule(), br_size, offset)) {
1711 // We've got a winner. Replace this branch.
1712 MachNode* replacement = mach->as_MachBranch()->short_branch_version();
1713
1714 // Update the jmp_size.
1715 int new_size = replacement->size(C->regalloc());
1716 assert((br_size - new_size) >= (int)nop_size, "short_branch size should be smaller");
1717 // Insert padding between avoid_back_to_back branches.
1718 if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
1719 MachNode *nop = new MachNopNode();
1720 block->insert_node(nop, j++);
1721 C->cfg()->map_node_to_block(nop, block);
1722 last_inst++;
1723 nop->emit(masm, C->regalloc());
1724 masm->code()->flush_bundle(true);
1725 current_offset = masm->offset();
1726 }
1727 #ifdef ASSERT
1728 jmp_target[i] = block_num;
1729 jmp_offset[i] = current_offset - blk_offset;
1730 jmp_size[i] = new_size;
1731 jmp_rule[i] = mach->rule();
1732 #endif
1733 block->map_node(replacement, j);
1734 mach->subsume_by(replacement, C);
1735 n = replacement;
1736 mach = replacement;
1737 }
1738 }
1739 mach->as_MachBranch()->label_set( &blk_labels[block_num], block_num );
1740 } else if (mach->ideal_Opcode() == Op_Jump) {
1741 for (uint h = 0; h < block->_num_succs; h++) {
1742 Block* succs_block = block->_succs[h];
1743 for (uint j = 1; j < succs_block->num_preds(); j++) {
1744 Node* jpn = succs_block->pred(j);
1745 if (jpn->is_JumpProj() && jpn->in(0) == mach) {
1746 uint block_num = succs_block->non_connector()->_pre_order;
1747 Label *blkLabel = &blk_labels[block_num];
1748 mach->add_case_label(jpn->as_JumpProj()->proj_no(), blkLabel);
1749 }
1750 }
1751 }
1752 } else if (!n->is_Proj()) {
1753 // Remember the beginning of the previous instruction, in case
1754 // it's followed by a flag-kill and a null-check. Happens on
1755 // Intel all the time, with add-to-memory kind of opcodes.
1756 previous_offset = current_offset;
1757 }
1758
1759 // Not an else-if!
1760 // If this is a trap based cmp then add its offset to the list.
1761 if (mach->is_TrapBasedCheckNode()) {
1762 inct_starts[inct_cnt++] = current_offset;
1763 }
1764 }
1765
1766 // Verify that there is sufficient space remaining
1767 masm->code()->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1768 if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1769 C->record_failure("CodeCache is full");
1770 return;
1771 }
1772
1773 // Save the offset for the listing
1774 #if defined(SUPPORT_OPTO_ASSEMBLY)
1775 if ((node_offsets != nullptr) && (n->_idx < node_offset_limit)) {
1776 node_offsets[n->_idx] = masm->offset();
1777 }
1778 #endif
1779 assert(!C->failing_internal() || C->failure_is_artificial(), "Should not reach here if failing.");
1780
1781 // "Normal" instruction case
1782 DEBUG_ONLY(uint instr_offset = masm->offset());
1783 n->emit(masm, C->regalloc());
1784 current_offset = masm->offset();
1785
1786 // Above we only verified that there is enough space in the instruction section.
1787 // However, the instruction may emit stubs that cause code buffer expansion.
1788 // Bail out here if expansion failed due to a lack of code cache space.
1789 if (C->failing()) {
1790 return;
1791 }
1792
1793 assert(!is_mcall || (call_returns[block->_pre_order] <= (uint)current_offset),
1794 "ret_addr_offset() not within emitted code");
1795 #ifdef ASSERT
1796 uint n_size = n->size(C->regalloc());
1797 if (n_size < (current_offset-instr_offset)) {
1798 MachNode* mach = n->as_Mach();
1799 n->dump();
1800 mach->dump_format(C->regalloc(), tty);
1801 tty->print_cr(" n_size (%d), current_offset (%d), instr_offset (%d)", n_size, current_offset, instr_offset);
1802 Disassembler::decode(masm->code()->insts_begin() + instr_offset, masm->code()->insts_begin() + current_offset + 1, tty);
1803 tty->print_cr(" ------------------- ");
1804 BufferBlob* blob = this->scratch_buffer_blob();
1805 address blob_begin = blob->content_begin();
1806 Disassembler::decode(blob_begin, blob_begin + n_size + 1, tty);
1807 assert(false, "wrong size of mach node");
1808 }
1809 #endif
1810 non_safepoints.observe_instruction(n, current_offset);
1811
1812 // mcall is last "call" that can be a safepoint
1813 // record it so we can see if a poll will directly follow it
1814 // in which case we'll need a pad to make the PcDesc sites unique
1815 // see 5010568. This can be slightly inaccurate but conservative
1816 // in the case that return address is not actually at current_offset.
1817 // This is a small price to pay.
1818
1819 if (is_mcall) {
1820 last_call_offset = current_offset;
1821 }
1822
1823 if (n->is_Mach() && n->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
1824 // Avoid back to back some instructions.
1825 last_avoid_back_to_back_offset = current_offset;
1826 }
1827
1828 // See if this instruction has a delay slot
1829 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
1830 guarantee(delay_slot != nullptr, "expecting delay slot node");
1831
1832 // Back up 1 instruction
1833 masm->code()->set_insts_end(masm->code()->insts_end() - Pipeline::instr_unit_size());
1834
1835 // Save the offset for the listing
1836 #if defined(SUPPORT_OPTO_ASSEMBLY)
1837 if ((node_offsets != nullptr) && (delay_slot->_idx < node_offset_limit)) {
1838 node_offsets[delay_slot->_idx] = masm->offset();
1839 }
1840 #endif
1841
1842 // Support a SafePoint in the delay slot
1843 if (delay_slot->is_MachSafePoint()) {
1844 MachNode *mach = delay_slot->as_Mach();
1845 // !!!!! Stubs only need an oopmap right now, so bail out
1846 if (!mach->is_MachCall() && mach->as_MachSafePoint()->jvms()->method() == nullptr) {
1847 // Write the oopmap directly to the code blob??!!
1848 delay_slot = nullptr;
1849 continue;
1850 }
1851
1852 int adjusted_offset = current_offset - Pipeline::instr_unit_size();
1853 non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1854 adjusted_offset);
1855 // Generate an OopMap entry
1856 Process_OopMap_Node(mach, adjusted_offset);
1857 }
1858
1859 // Insert the delay slot instruction
1860 delay_slot->emit(masm, C->regalloc());
1861
1862 // Don't reuse it
1863 delay_slot = nullptr;
1864 }
1865
1866 } // End for all instructions in block
1867
1868 // If the next block is the top of a loop, pad this block out to align
1869 // the loop top a little. Helps prevent pipe stalls at loop back branches.
1870 if (i < nblocks-1) {
1871 Block *nb = C->cfg()->get_block(i + 1);
1872 int padding = nb->alignment_padding(current_offset);
1873 if( padding > 0 ) {
1874 MachNode *nop = new MachNopNode(padding / nop_size);
1875 block->insert_node(nop, block->number_of_nodes());
1876 C->cfg()->map_node_to_block(nop, block);
1877 nop->emit(masm, C->regalloc());
1878 current_offset = masm->offset();
1879 }
1880 }
1881 // Verify that the distance for generated before forward
1882 // short branches is still valid.
1883 guarantee((int)(blk_starts[i+1] - blk_starts[i]) >= (current_offset - blk_offset), "shouldn't increase block size");
1884
1885 // Save new block start offset
1886 blk_starts[i] = blk_offset;
1887 } // End of for all blocks
1888 blk_starts[nblocks] = current_offset;
1889
1890 non_safepoints.flush_at_end();
1891
1892 // Offset too large?
1893 if (C->failing()) return;
1894
1895 // Define a pseudo-label at the end of the code
1896 masm->bind( blk_labels[nblocks] );
1897
1898 // Compute the size of the first block
1899 _first_block_size = blk_labels[1].loc_pos() - blk_labels[0].loc_pos();
1900
1901 #ifdef ASSERT
1902 for (uint i = 0; i < nblocks; i++) { // For all blocks
1903 if (jmp_target[i] != 0) {
1904 int br_size = jmp_size[i];
1905 int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
1906 if (!C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
1907 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]);
1908 assert(false, "Displacement too large for short jmp");
1909 }
1910 }
1911 }
1912 #endif
1913
1914 if (!masm->code()->finalize_stubs()) {
1915 C->record_failure("CodeCache is full");
1916 return;
1917 }
1918
1919 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1920 bs->emit_stubs(*masm->code());
1921 if (C->failing()) return;
1922
1923 // Fill in stubs.
1924 assert(masm->inst_mark() == nullptr, "should be.");
1925 _stub_list.emit(*masm);
1926 if (C->failing()) return;
1927
1928 #ifndef PRODUCT
1929 // Information on the size of the method, without the extraneous code
1930 Scheduling::increment_method_size(masm->offset());
1931 #endif
1932
1933 // ------------------
1934 // Fill in exception table entries.
1935 FillExceptionTables(inct_cnt, call_returns, inct_starts, blk_labels);
1936
1937 // Only java methods have exception handlers and deopt handlers
1938 // class HandlerImpl is platform-specific and defined in the *.ad files.
1939 if (C->method()) {
1940 // Emit the exception handler code.
1941 _code_offsets.set_value(CodeOffsets::Exceptions, HandlerImpl::emit_exception_handler(masm));
1942 if (C->failing()) {
1943 return; // CodeBuffer::expand failed
1944 }
1945 // Emit the deopt handler code.
1946 _code_offsets.set_value(CodeOffsets::Deopt, HandlerImpl::emit_deopt_handler(masm));
1947
1948 // Emit the MethodHandle deopt handler code (if required).
1949 if (C->has_method_handle_invokes() && !C->failing()) {
1950 // We can use the same code as for the normal deopt handler, we
1951 // just need a different entry point address.
1952 _code_offsets.set_value(CodeOffsets::DeoptMH, HandlerImpl::emit_deopt_handler(masm));
1953 }
1954 }
1955
1956 // One last check for failed CodeBuffer::expand:
1957 if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1958 C->record_failure("CodeCache is full");
1959 return;
1960 }
1961
1962 #if defined(SUPPORT_ABSTRACT_ASSEMBLY) || defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_OPTO_ASSEMBLY)
1963 if (C->print_assembly()) {
1964 tty->cr();
1965 tty->print_cr("============================= C2-compiled nmethod ==============================");
1966 }
1967 #endif
1968
1969 #if defined(SUPPORT_OPTO_ASSEMBLY)
1970 // Dump the assembly code, including basic-block numbers
1971 if (C->print_assembly()) {
1972 ttyLocker ttyl; // keep the following output all in one block
1973 if (!VMThread::should_terminate()) { // test this under the tty lock
1974 // print_metadata and dump_asm may safepoint which makes us loose the ttylock.
1975 // We call them first and write to a stringStream, then we retake the lock to
1976 // make sure the end tag is coherent, and that xmlStream->pop_tag is done thread safe.
1977 ResourceMark rm;
1978 stringStream method_metadata_str;
1979 if (C->method() != nullptr) {
1980 C->method()->print_metadata(&method_metadata_str);
1981 }
1982 stringStream dump_asm_str;
1983 dump_asm_on(&dump_asm_str, node_offsets, node_offset_limit);
1984
1985 NoSafepointVerifier nsv;
1986 ttyLocker ttyl2;
1987 // This output goes directly to the tty, not the compiler log.
1988 // To enable tools to match it up with the compilation activity,
1989 // be sure to tag this tty output with the compile ID.
1990 if (xtty != nullptr) {
1991 xtty->head("opto_assembly compile_id='%d'%s", C->compile_id(),
1992 C->is_osr_compilation() ? " compile_kind='osr'" : "");
1993 }
1994 if (C->method() != nullptr) {
1995 tty->print_cr("----------------------- MetaData before Compile_id = %d ------------------------", C->compile_id());
1996 tty->print_raw(method_metadata_str.freeze());
1997 } else if (C->stub_name() != nullptr) {
1998 tty->print_cr("----------------------------- RuntimeStub %s -------------------------------", C->stub_name());
1999 }
2000 tty->cr();
2001 tty->print_cr("------------------------ OptoAssembly for Compile_id = %d -----------------------", C->compile_id());
2002 tty->print_raw(dump_asm_str.freeze());
2003 tty->print_cr("--------------------------------------------------------------------------------");
2004 if (xtty != nullptr) {
2005 xtty->tail("opto_assembly");
2006 }
2007 }
2008 }
2009 #endif
2010 }
2011
2012 void PhaseOutput::FillExceptionTables(uint cnt, uint *call_returns, uint *inct_starts, Label *blk_labels) {
2013 _inc_table.set_size(cnt);
2014
2015 uint inct_cnt = 0;
2016 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
2017 Block* block = C->cfg()->get_block(i);
2018 Node *n = nullptr;
2019 int j;
2020
2021 // Find the branch; ignore trailing NOPs.
2022 for (j = block->number_of_nodes() - 1; j >= 0; j--) {
2023 n = block->get_node(j);
2024 if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con) {
2025 break;
2026 }
2027 }
2028
2029 // If we didn't find anything, continue
2030 if (j < 0) {
2031 continue;
2032 }
2033
2034 // Compute ExceptionHandlerTable subtable entry and add it
2035 // (skip empty blocks)
2036 if (n->is_Catch()) {
2037
2038 // Get the offset of the return from the call
2039 uint call_return = call_returns[block->_pre_order];
2040 #ifdef ASSERT
2041 assert( call_return > 0, "no call seen for this basic block" );
2042 while (block->get_node(--j)->is_MachProj()) ;
2043 assert(block->get_node(j)->is_MachCall(), "CatchProj must follow call");
2044 #endif
2045 // last instruction is a CatchNode, find it's CatchProjNodes
2046 int nof_succs = block->_num_succs;
2047 // allocate space
2048 GrowableArray<intptr_t> handler_bcis(nof_succs);
2049 GrowableArray<intptr_t> handler_pcos(nof_succs);
2050 // iterate through all successors
2051 for (int j = 0; j < nof_succs; j++) {
2052 Block* s = block->_succs[j];
2053 bool found_p = false;
2054 for (uint k = 1; k < s->num_preds(); k++) {
2055 Node* pk = s->pred(k);
2056 if (pk->is_CatchProj() && pk->in(0) == n) {
2057 const CatchProjNode* p = pk->as_CatchProj();
2058 found_p = true;
2059 // add the corresponding handler bci & pco information
2060 if (p->_con != CatchProjNode::fall_through_index) {
2061 // p leads to an exception handler (and is not fall through)
2062 assert(s == C->cfg()->get_block(s->_pre_order), "bad numbering");
2063 // no duplicates, please
2064 if (!handler_bcis.contains(p->handler_bci())) {
2065 uint block_num = s->non_connector()->_pre_order;
2066 handler_bcis.append(p->handler_bci());
2067 handler_pcos.append(blk_labels[block_num].loc_pos());
2068 }
2069 }
2070 }
2071 }
2072 assert(found_p, "no matching predecessor found");
2073 // Note: Due to empty block removal, one block may have
2074 // several CatchProj inputs, from the same Catch.
2075 }
2076
2077 // Set the offset of the return from the call
2078 assert(handler_bcis.find(-1) != -1, "must have default handler");
2079 _handler_table.add_subtable(call_return, &handler_bcis, nullptr, &handler_pcos);
2080 continue;
2081 }
2082
2083 // Handle implicit null exception table updates
2084 if (n->is_MachNullCheck()) {
2085 assert(n->in(1)->as_Mach()->barrier_data() == 0,
2086 "Implicit null checks on memory accesses with barriers are not yet supported");
2087 uint block_num = block->non_connector_successor(0)->_pre_order;
2088 _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
2089 continue;
2090 }
2091 // Handle implicit exception table updates: trap instructions.
2092 if (n->is_Mach() && n->as_Mach()->is_TrapBasedCheckNode()) {
2093 uint block_num = block->non_connector_successor(0)->_pre_order;
2094 _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
2095 continue;
2096 }
2097 } // End of for all blocks fill in exception table entries
2098 }
2099
2100 // Static Variables
2101 #ifndef PRODUCT
2102 uint Scheduling::_total_nop_size = 0;
2103 uint Scheduling::_total_method_size = 0;
2104 uint Scheduling::_total_branches = 0;
2105 uint Scheduling::_total_unconditional_delays = 0;
2106 uint Scheduling::_total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
2107 #endif
2108
2109 // Initializer for class Scheduling
2110
2111 Scheduling::Scheduling(Arena *arena, Compile &compile)
2112 : _arena(arena),
2113 _cfg(compile.cfg()),
2114 _regalloc(compile.regalloc()),
2115 _scheduled(arena),
2116 _available(arena),
2117 _reg_node(arena),
2118 _pinch_free_list(arena),
2119 _next_node(nullptr),
2120 _bundle_instr_count(0),
2121 _bundle_cycle_number(0),
2122 _bundle_use(0, 0, resource_count, &_bundle_use_elements[0])
2123 #ifndef PRODUCT
2124 , _branches(0)
2125 , _unconditional_delays(0)
2126 #endif
2127 {
2128 // Create a MachNopNode
2129 _nop = new MachNopNode();
2130
2131 // Now that the nops are in the array, save the count
2132 // (but allow entries for the nops)
2133 _node_bundling_limit = compile.unique();
2134 uint node_max = _regalloc->node_regs_max_index();
2135
2136 compile.output()->set_node_bundling_limit(_node_bundling_limit);
2137
2138 // This one is persistent within the Compile class
2139 _node_bundling_base = NEW_ARENA_ARRAY(compile.comp_arena(), Bundle, node_max);
2140
2141 // Allocate space for fixed-size arrays
2142 _uses = NEW_ARENA_ARRAY(arena, short, node_max);
2143 _current_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
2144
2145 // Clear the arrays
2146 for (uint i = 0; i < node_max; i++) {
2147 ::new (&_node_bundling_base[i]) Bundle();
2148 }
2149 memset(_uses, 0, node_max * sizeof(short));
2150 memset(_current_latency, 0, node_max * sizeof(unsigned short));
2151
2152 // Clear the bundling information
2153 memcpy(_bundle_use_elements, Pipeline_Use::elaborated_elements, sizeof(Pipeline_Use::elaborated_elements));
2154
2155 // Get the last node
2156 Block* block = _cfg->get_block(_cfg->number_of_blocks() - 1);
2157
2158 _next_node = block->get_node(block->number_of_nodes() - 1);
2159 }
2160
2161 #ifndef PRODUCT
2162 // Scheduling destructor
2163 Scheduling::~Scheduling() {
2164 _total_branches += _branches;
2165 _total_unconditional_delays += _unconditional_delays;
2166 }
2167 #endif
2168
2169 // Step ahead "i" cycles
2170 void Scheduling::step(uint i) {
2171
2172 Bundle *bundle = node_bundling(_next_node);
2173 bundle->set_starts_bundle();
2174
2175 // Update the bundle record, but leave the flags information alone
2176 if (_bundle_instr_count > 0) {
2177 bundle->set_instr_count(_bundle_instr_count);
2178 bundle->set_resources_used(_bundle_use.resourcesUsed());
2179 }
2180
2181 // Update the state information
2182 _bundle_instr_count = 0;
2183 _bundle_cycle_number += i;
2184 _bundle_use.step(i);
2185 }
2186
2187 void Scheduling::step_and_clear() {
2188 Bundle *bundle = node_bundling(_next_node);
2189 bundle->set_starts_bundle();
2190
2191 // Update the bundle record
2192 if (_bundle_instr_count > 0) {
2193 bundle->set_instr_count(_bundle_instr_count);
2194 bundle->set_resources_used(_bundle_use.resourcesUsed());
2195
2196 _bundle_cycle_number += 1;
2197 }
2198
2199 // Clear the bundling information
2200 _bundle_instr_count = 0;
2201 _bundle_use.reset();
2202
2203 memcpy(_bundle_use_elements,
2204 Pipeline_Use::elaborated_elements,
2205 sizeof(Pipeline_Use::elaborated_elements));
2206 }
2207
2208 // Perform instruction scheduling and bundling over the sequence of
2209 // instructions in backwards order.
2210 void PhaseOutput::ScheduleAndBundle() {
2211
2212 // Don't optimize this if it isn't a method
2213 if (!C->method())
2214 return;
2215
2216 // Don't optimize this if scheduling is disabled
2217 if (!C->do_scheduling())
2218 return;
2219
2220 // Scheduling code works only with pairs (8 bytes) maximum.
2221 // And when the scalable vector register is used, we may spill/unspill
2222 // the whole reg regardless of the max vector size.
2223 if (C->max_vector_size() > 8 ||
2224 (C->max_vector_size() > 0 && Matcher::supports_scalable_vector())) {
2225 return;
2226 }
2227
2228 Compile::TracePhase tp(_t_instrSched);
2229
2230 // Create a data structure for all the scheduling information
2231 Scheduling scheduling(Thread::current()->resource_area(), *C);
2232
2233 // Walk backwards over each basic block, computing the needed alignment
2234 // Walk over all the basic blocks
2235 scheduling.DoScheduling();
2236
2237 #ifndef PRODUCT
2238 if (C->trace_opto_output()) {
2239 // Buffer and print all at once
2240 ResourceMark rm;
2241 stringStream ss;
2242 ss.print("\n---- After ScheduleAndBundle ----\n");
2243 print_scheduling(&ss);
2244 tty->print("%s", ss.as_string());
2245 }
2246 #endif
2247 }
2248
2249 #ifndef PRODUCT
2250 // Separated out so that it can be called directly from debugger
2251 void PhaseOutput::print_scheduling() {
2252 print_scheduling(tty);
2253 }
2254
2255 void PhaseOutput::print_scheduling(outputStream* output_stream) {
2256 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
2257 output_stream->print("\nBB#%03d:\n", i);
2258 Block* block = C->cfg()->get_block(i);
2259 for (uint j = 0; j < block->number_of_nodes(); j++) {
2260 Node* n = block->get_node(j);
2261 OptoReg::Name reg = C->regalloc()->get_reg_first(n);
2262 output_stream->print(" %-6s ", reg >= 0 && reg < REG_COUNT ? Matcher::regName[reg] : "");
2263 n->dump("\n", false, output_stream);
2264 }
2265 }
2266 }
2267 #endif
2268
2269 // See if this node fits into the present instruction bundle
2270 bool Scheduling::NodeFitsInBundle(Node *n) {
2271 uint n_idx = n->_idx;
2272
2273 // If this is the unconditional delay instruction, then it fits
2274 if (n == _unconditional_delay_slot) {
2275 #ifndef PRODUCT
2276 if (_cfg->C->trace_opto_output())
2277 tty->print("# NodeFitsInBundle [%4d]: TRUE; is in unconditional delay slot\n", n->_idx);
2278 #endif
2279 return (true);
2280 }
2281
2282 // If the node cannot be scheduled this cycle, skip it
2283 if (_current_latency[n_idx] > _bundle_cycle_number) {
2284 #ifndef PRODUCT
2285 if (_cfg->C->trace_opto_output())
2286 tty->print("# NodeFitsInBundle [%4d]: FALSE; latency %4d > %d\n",
2287 n->_idx, _current_latency[n_idx], _bundle_cycle_number);
2288 #endif
2289 return (false);
2290 }
2291
2292 const Pipeline *node_pipeline = n->pipeline();
2293
2294 uint instruction_count = node_pipeline->instructionCount();
2295 if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2296 instruction_count = 0;
2297 else if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
2298 instruction_count++;
2299
2300 if (_bundle_instr_count + instruction_count > Pipeline::_max_instrs_per_cycle) {
2301 #ifndef PRODUCT
2302 if (_cfg->C->trace_opto_output())
2303 tty->print("# NodeFitsInBundle [%4d]: FALSE; too many instructions: %d > %d\n",
2304 n->_idx, _bundle_instr_count + instruction_count, Pipeline::_max_instrs_per_cycle);
2305 #endif
2306 return (false);
2307 }
2308
2309 // Don't allow non-machine nodes to be handled this way
2310 if (!n->is_Mach() && instruction_count == 0)
2311 return (false);
2312
2313 // See if there is any overlap
2314 uint delay = _bundle_use.full_latency(0, node_pipeline->resourceUse());
2315
2316 if (delay > 0) {
2317 #ifndef PRODUCT
2318 if (_cfg->C->trace_opto_output())
2319 tty->print("# NodeFitsInBundle [%4d]: FALSE; functional units overlap\n", n_idx);
2320 #endif
2321 return false;
2322 }
2323
2324 #ifndef PRODUCT
2325 if (_cfg->C->trace_opto_output())
2326 tty->print("# NodeFitsInBundle [%4d]: TRUE\n", n_idx);
2327 #endif
2328
2329 return true;
2330 }
2331
2332 Node * Scheduling::ChooseNodeToBundle() {
2333 uint siz = _available.size();
2334
2335 if (siz == 0) {
2336
2337 #ifndef PRODUCT
2338 if (_cfg->C->trace_opto_output())
2339 tty->print("# ChooseNodeToBundle: null\n");
2340 #endif
2341 return (nullptr);
2342 }
2343
2344 // Fast path, if only 1 instruction in the bundle
2345 if (siz == 1) {
2346 #ifndef PRODUCT
2347 if (_cfg->C->trace_opto_output()) {
2348 tty->print("# ChooseNodeToBundle (only 1): ");
2349 _available[0]->dump();
2350 }
2351 #endif
2352 return (_available[0]);
2353 }
2354
2355 // Don't bother, if the bundle is already full
2356 if (_bundle_instr_count < Pipeline::_max_instrs_per_cycle) {
2357 for ( uint i = 0; i < siz; i++ ) {
2358 Node *n = _available[i];
2359
2360 // Skip projections, we'll handle them another way
2361 if (n->is_Proj())
2362 continue;
2363
2364 // This presupposed that instructions are inserted into the
2365 // available list in a legality order; i.e. instructions that
2366 // must be inserted first are at the head of the list
2367 if (NodeFitsInBundle(n)) {
2368 #ifndef PRODUCT
2369 if (_cfg->C->trace_opto_output()) {
2370 tty->print("# ChooseNodeToBundle: ");
2371 n->dump();
2372 }
2373 #endif
2374 return (n);
2375 }
2376 }
2377 }
2378
2379 // Nothing fits in this bundle, choose the highest priority
2380 #ifndef PRODUCT
2381 if (_cfg->C->trace_opto_output()) {
2382 tty->print("# ChooseNodeToBundle: ");
2383 _available[0]->dump();
2384 }
2385 #endif
2386
2387 return _available[0];
2388 }
2389
2390 int Scheduling::compare_two_spill_nodes(Node* first, Node* second) {
2391 assert(first->is_MachSpillCopy() && second->is_MachSpillCopy(), "");
2392
2393 OptoReg::Name first_src_lo = _regalloc->get_reg_first(first->in(1));
2394 OptoReg::Name first_dst_lo = _regalloc->get_reg_first(first);
2395 OptoReg::Name second_src_lo = _regalloc->get_reg_first(second->in(1));
2396 OptoReg::Name second_dst_lo = _regalloc->get_reg_first(second);
2397
2398 // Comparison between stack -> reg and stack -> reg
2399 if (OptoReg::is_stack(first_src_lo) && OptoReg::is_stack(second_src_lo) &&
2400 OptoReg::is_reg(first_dst_lo) && OptoReg::is_reg(second_dst_lo)) {
2401 return _regalloc->reg2offset(first_src_lo) - _regalloc->reg2offset(second_src_lo);
2402 }
2403
2404 // Comparison between reg -> stack and reg -> stack
2405 if (OptoReg::is_stack(first_dst_lo) && OptoReg::is_stack(second_dst_lo) &&
2406 OptoReg::is_reg(first_src_lo) && OptoReg::is_reg(second_src_lo)) {
2407 return _regalloc->reg2offset(first_dst_lo) - _regalloc->reg2offset(second_dst_lo);
2408 }
2409
2410 return 0; // Not comparable
2411 }
2412
2413 void Scheduling::AddNodeToAvailableList(Node *n) {
2414 assert( !n->is_Proj(), "projections never directly made available" );
2415 #ifndef PRODUCT
2416 if (_cfg->C->trace_opto_output()) {
2417 tty->print("# AddNodeToAvailableList: ");
2418 n->dump();
2419 }
2420 #endif
2421
2422 int latency = _current_latency[n->_idx];
2423
2424 // Insert in latency order (insertion sort). If two MachSpillCopyNodes
2425 // for stack spilling or unspilling have the same latency, we sort
2426 // them in the order of stack offset. Some ports (e.g. aarch64) may also
2427 // have more opportunities to do ld/st merging
2428 uint i;
2429 for (i = 0; i < _available.size(); i++) {
2430 if (_current_latency[_available[i]->_idx] > latency) {
2431 break;
2432 } else if (_current_latency[_available[i]->_idx] == latency &&
2433 n->is_MachSpillCopy() && _available[i]->is_MachSpillCopy() &&
2434 compare_two_spill_nodes(n, _available[i]) > 0) {
2435 break;
2436 }
2437 }
2438
2439 // Special Check for compares following branches
2440 if( n->is_Mach() && _scheduled.size() > 0 ) {
2441 int op = n->as_Mach()->ideal_Opcode();
2442 Node *last = _scheduled[0];
2443 if( last->is_MachIf() && last->in(1) == n &&
2444 ( op == Op_CmpI ||
2445 op == Op_CmpU ||
2446 op == Op_CmpUL ||
2447 op == Op_CmpP ||
2448 op == Op_CmpF ||
2449 op == Op_CmpD ||
2450 op == Op_CmpL ) ) {
2451
2452 // Recalculate position, moving to front of same latency
2453 for ( i=0 ; i < _available.size(); i++ )
2454 if (_current_latency[_available[i]->_idx] >= latency)
2455 break;
2456 }
2457 }
2458
2459 // Insert the node in the available list
2460 _available.insert(i, n);
2461
2462 #ifndef PRODUCT
2463 if (_cfg->C->trace_opto_output())
2464 dump_available();
2465 #endif
2466 }
2467
2468 void Scheduling::DecrementUseCounts(Node *n, const Block *bb) {
2469 for ( uint i=0; i < n->len(); i++ ) {
2470 Node *def = n->in(i);
2471 if (!def) continue;
2472 if( def->is_Proj() ) // If this is a machine projection, then
2473 def = def->in(0); // propagate usage thru to the base instruction
2474
2475 if(_cfg->get_block_for_node(def) != bb) { // Ignore if not block-local
2476 continue;
2477 }
2478
2479 // Compute the latency
2480 uint l = _bundle_cycle_number + n->latency(i);
2481 if (_current_latency[def->_idx] < l)
2482 _current_latency[def->_idx] = l;
2483
2484 // If this does not have uses then schedule it
2485 if ((--_uses[def->_idx]) == 0)
2486 AddNodeToAvailableList(def);
2487 }
2488 }
2489
2490 void Scheduling::AddNodeToBundle(Node *n, const Block *bb) {
2491 #ifndef PRODUCT
2492 if (_cfg->C->trace_opto_output()) {
2493 tty->print("# AddNodeToBundle: ");
2494 n->dump();
2495 }
2496 #endif
2497
2498 // Remove this from the available list
2499 uint i;
2500 for (i = 0; i < _available.size(); i++)
2501 if (_available[i] == n)
2502 break;
2503 assert(i < _available.size(), "entry in _available list not found");
2504 _available.remove(i);
2505
2506 // See if this fits in the current bundle
2507 const Pipeline *node_pipeline = n->pipeline();
2508 const Pipeline_Use& node_usage = node_pipeline->resourceUse();
2509
2510 // Check for instructions to be placed in the delay slot. We
2511 // do this before we actually schedule the current instruction,
2512 // because the delay slot follows the current instruction.
2513 if (Pipeline::_branch_has_delay_slot &&
2514 node_pipeline->hasBranchDelay() &&
2515 !_unconditional_delay_slot) {
2516
2517 uint siz = _available.size();
2518
2519 // Conditional branches can support an instruction that
2520 // is unconditionally executed and not dependent by the
2521 // branch, OR a conditionally executed instruction if
2522 // the branch is taken. In practice, this means that
2523 // the first instruction at the branch target is
2524 // copied to the delay slot, and the branch goes to
2525 // the instruction after that at the branch target
2526 if ( n->is_MachBranch() ) {
2527
2528 assert( !n->is_MachNullCheck(), "should not look for delay slot for Null Check" );
2529 assert( !n->is_Catch(), "should not look for delay slot for Catch" );
2530
2531 #ifndef PRODUCT
2532 _branches++;
2533 #endif
2534
2535 // At least 1 instruction is on the available list
2536 // that is not dependent on the branch
2537 for (uint i = 0; i < siz; i++) {
2538 Node *d = _available[i];
2539 const Pipeline *avail_pipeline = d->pipeline();
2540
2541 // Don't allow safepoints in the branch shadow, that will
2542 // cause a number of difficulties
2543 if ( avail_pipeline->instructionCount() == 1 &&
2544 !avail_pipeline->hasMultipleBundles() &&
2545 !avail_pipeline->hasBranchDelay() &&
2546 Pipeline::instr_has_unit_size() &&
2547 d->size(_regalloc) == Pipeline::instr_unit_size() &&
2548 NodeFitsInBundle(d) &&
2549 !node_bundling(d)->used_in_delay()) {
2550
2551 if (d->is_Mach() && !d->is_MachSafePoint()) {
2552 // A node that fits in the delay slot was found, so we need to
2553 // set the appropriate bits in the bundle pipeline information so
2554 // that it correctly indicates resource usage. Later, when we
2555 // attempt to add this instruction to the bundle, we will skip
2556 // setting the resource usage.
2557 _unconditional_delay_slot = d;
2558 node_bundling(n)->set_use_unconditional_delay();
2559 node_bundling(d)->set_used_in_unconditional_delay();
2560 _bundle_use.add_usage(avail_pipeline->resourceUse());
2561 _current_latency[d->_idx] = _bundle_cycle_number;
2562 _next_node = d;
2563 ++_bundle_instr_count;
2564 #ifndef PRODUCT
2565 _unconditional_delays++;
2566 #endif
2567 break;
2568 }
2569 }
2570 }
2571 }
2572
2573 // No delay slot, add a nop to the usage
2574 if (!_unconditional_delay_slot) {
2575 // See if adding an instruction in the delay slot will overflow
2576 // the bundle.
2577 if (!NodeFitsInBundle(_nop)) {
2578 #ifndef PRODUCT
2579 if (_cfg->C->trace_opto_output())
2580 tty->print("# *** STEP(1 instruction for delay slot) ***\n");
2581 #endif
2582 step(1);
2583 }
2584
2585 _bundle_use.add_usage(_nop->pipeline()->resourceUse());
2586 _next_node = _nop;
2587 ++_bundle_instr_count;
2588 }
2589
2590 // See if the instruction in the delay slot requires a
2591 // step of the bundles
2592 if (!NodeFitsInBundle(n)) {
2593 #ifndef PRODUCT
2594 if (_cfg->C->trace_opto_output())
2595 tty->print("# *** STEP(branch won't fit) ***\n");
2596 #endif
2597 // Update the state information
2598 _bundle_instr_count = 0;
2599 _bundle_cycle_number += 1;
2600 _bundle_use.step(1);
2601 }
2602 }
2603
2604 // Get the number of instructions
2605 uint instruction_count = node_pipeline->instructionCount();
2606 if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2607 instruction_count = 0;
2608
2609 // Compute the latency information
2610 uint delay = 0;
2611
2612 if (instruction_count > 0 || !node_pipeline->mayHaveNoCode()) {
2613 int relative_latency = _current_latency[n->_idx] - _bundle_cycle_number;
2614 if (relative_latency < 0)
2615 relative_latency = 0;
2616
2617 delay = _bundle_use.full_latency(relative_latency, node_usage);
2618
2619 // Does not fit in this bundle, start a new one
2620 if (delay > 0) {
2621 step(delay);
2622
2623 #ifndef PRODUCT
2624 if (_cfg->C->trace_opto_output())
2625 tty->print("# *** STEP(%d) ***\n", delay);
2626 #endif
2627 }
2628 }
2629
2630 // If this was placed in the delay slot, ignore it
2631 if (n != _unconditional_delay_slot) {
2632
2633 if (delay == 0) {
2634 if (node_pipeline->hasMultipleBundles()) {
2635 #ifndef PRODUCT
2636 if (_cfg->C->trace_opto_output())
2637 tty->print("# *** STEP(multiple instructions) ***\n");
2638 #endif
2639 step(1);
2640 }
2641
2642 else if (instruction_count + _bundle_instr_count > Pipeline::_max_instrs_per_cycle) {
2643 #ifndef PRODUCT
2644 if (_cfg->C->trace_opto_output())
2645 tty->print("# *** STEP(%d >= %d instructions) ***\n",
2646 instruction_count + _bundle_instr_count,
2647 Pipeline::_max_instrs_per_cycle);
2648 #endif
2649 step(1);
2650 }
2651 }
2652
2653 if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
2654 _bundle_instr_count++;
2655
2656 // Set the node's latency
2657 _current_latency[n->_idx] = _bundle_cycle_number;
2658
2659 // Now merge the functional unit information
2660 if (instruction_count > 0 || !node_pipeline->mayHaveNoCode())
2661 _bundle_use.add_usage(node_usage);
2662
2663 // Increment the number of instructions in this bundle
2664 _bundle_instr_count += instruction_count;
2665
2666 // Remember this node for later
2667 if (n->is_Mach())
2668 _next_node = n;
2669 }
2670
2671 // It's possible to have a BoxLock in the graph and in the _bbs mapping but
2672 // not in the bb->_nodes array. This happens for debug-info-only BoxLocks.
2673 // 'Schedule' them (basically ignore in the schedule) but do not insert them
2674 // into the block. All other scheduled nodes get put in the schedule here.
2675 int op = n->Opcode();
2676 if( (op == Op_Node && n->req() == 0) || // anti-dependence node OR
2677 (op != Op_Node && // Not an unused antidepedence node and
2678 // not an unallocated boxlock
2679 (OptoReg::is_valid(_regalloc->get_reg_first(n)) || op != Op_BoxLock)) ) {
2680
2681 // Push any trailing projections
2682 if( bb->get_node(bb->number_of_nodes()-1) != n ) {
2683 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2684 Node *foi = n->fast_out(i);
2685 if( foi->is_Proj() )
2686 _scheduled.push(foi);
2687 }
2688 }
2689
2690 // Put the instruction in the schedule list
2691 _scheduled.push(n);
2692 }
2693
2694 #ifndef PRODUCT
2695 if (_cfg->C->trace_opto_output())
2696 dump_available();
2697 #endif
2698
2699 // Walk all the definitions, decrementing use counts, and
2700 // if a definition has a 0 use count, place it in the available list.
2701 DecrementUseCounts(n,bb);
2702 }
2703
2704 // This method sets the use count within a basic block. We will ignore all
2705 // uses outside the current basic block. As we are doing a backwards walk,
2706 // any node we reach that has a use count of 0 may be scheduled. This also
2707 // avoids the problem of cyclic references from phi nodes, as long as phi
2708 // nodes are at the front of the basic block. This method also initializes
2709 // the available list to the set of instructions that have no uses within this
2710 // basic block.
2711 void Scheduling::ComputeUseCount(const Block *bb) {
2712 #ifndef PRODUCT
2713 if (_cfg->C->trace_opto_output())
2714 tty->print("# -> ComputeUseCount\n");
2715 #endif
2716
2717 // Clear the list of available and scheduled instructions, just in case
2718 _available.clear();
2719 _scheduled.clear();
2720
2721 // No delay slot specified
2722 _unconditional_delay_slot = nullptr;
2723
2724 #ifdef ASSERT
2725 for( uint i=0; i < bb->number_of_nodes(); i++ )
2726 assert( _uses[bb->get_node(i)->_idx] == 0, "_use array not clean" );
2727 #endif
2728
2729 // Force the _uses count to never go to zero for unscheduable pieces
2730 // of the block
2731 for( uint k = 0; k < _bb_start; k++ )
2732 _uses[bb->get_node(k)->_idx] = 1;
2733 for( uint l = _bb_end; l < bb->number_of_nodes(); l++ )
2734 _uses[bb->get_node(l)->_idx] = 1;
2735
2736 // Iterate backwards over the instructions in the block. Don't count the
2737 // branch projections at end or the block header instructions.
2738 for( uint j = _bb_end-1; j >= _bb_start; j-- ) {
2739 Node *n = bb->get_node(j);
2740 if( n->is_Proj() ) continue; // Projections handled another way
2741
2742 // Account for all uses
2743 for ( uint k = 0; k < n->len(); k++ ) {
2744 Node *inp = n->in(k);
2745 if (!inp) continue;
2746 assert(inp != n, "no cycles allowed" );
2747 if (_cfg->get_block_for_node(inp) == bb) { // Block-local use?
2748 if (inp->is_Proj()) { // Skip through Proj's
2749 inp = inp->in(0);
2750 }
2751 ++_uses[inp->_idx]; // Count 1 block-local use
2752 }
2753 }
2754
2755 // If this instruction has a 0 use count, then it is available
2756 if (!_uses[n->_idx]) {
2757 _current_latency[n->_idx] = _bundle_cycle_number;
2758 AddNodeToAvailableList(n);
2759 }
2760
2761 #ifndef PRODUCT
2762 if (_cfg->C->trace_opto_output()) {
2763 tty->print("# uses: %3d: ", _uses[n->_idx]);
2764 n->dump();
2765 }
2766 #endif
2767 }
2768
2769 #ifndef PRODUCT
2770 if (_cfg->C->trace_opto_output())
2771 tty->print("# <- ComputeUseCount\n");
2772 #endif
2773 }
2774
2775 // This routine performs scheduling on each basic block in reverse order,
2776 // using instruction latencies and taking into account function unit
2777 // availability.
2778 void Scheduling::DoScheduling() {
2779 #ifndef PRODUCT
2780 if (_cfg->C->trace_opto_output())
2781 tty->print("# -> DoScheduling\n");
2782 #endif
2783
2784 Block *succ_bb = nullptr;
2785 Block *bb;
2786 Compile* C = Compile::current();
2787
2788 // Walk over all the basic blocks in reverse order
2789 for (int i = _cfg->number_of_blocks() - 1; i >= 0; succ_bb = bb, i--) {
2790 bb = _cfg->get_block(i);
2791
2792 #ifndef PRODUCT
2793 if (_cfg->C->trace_opto_output()) {
2794 tty->print("# Schedule BB#%03d (initial)\n", i);
2795 for (uint j = 0; j < bb->number_of_nodes(); j++) {
2796 bb->get_node(j)->dump();
2797 }
2798 }
2799 #endif
2800
2801 // On the head node, skip processing
2802 if (bb == _cfg->get_root_block()) {
2803 continue;
2804 }
2805
2806 // Skip empty, connector blocks
2807 if (bb->is_connector())
2808 continue;
2809
2810 // If the following block is not the sole successor of
2811 // this one, then reset the pipeline information
2812 if (bb->_num_succs != 1 || bb->non_connector_successor(0) != succ_bb) {
2813 #ifndef PRODUCT
2814 if (_cfg->C->trace_opto_output()) {
2815 tty->print("*** bundle start of next BB, node %d, for %d instructions\n",
2816 _next_node->_idx, _bundle_instr_count);
2817 }
2818 #endif
2819 step_and_clear();
2820 }
2821
2822 // Leave untouched the starting instruction, any Phis, a CreateEx node
2823 // or Top. bb->get_node(_bb_start) is the first schedulable instruction.
2824 _bb_end = bb->number_of_nodes()-1;
2825 for( _bb_start=1; _bb_start <= _bb_end; _bb_start++ ) {
2826 Node *n = bb->get_node(_bb_start);
2827 // Things not matched, like Phinodes and ProjNodes don't get scheduled.
2828 // Also, MachIdealNodes do not get scheduled
2829 if( !n->is_Mach() ) continue; // Skip non-machine nodes
2830 MachNode *mach = n->as_Mach();
2831 int iop = mach->ideal_Opcode();
2832 if( iop == Op_CreateEx ) continue; // CreateEx is pinned
2833 if( iop == Op_Con ) continue; // Do not schedule Top
2834 if( iop == Op_Node && // Do not schedule PhiNodes, ProjNodes
2835 mach->pipeline() == MachNode::pipeline_class() &&
2836 !n->is_SpillCopy() && !n->is_MachMerge() ) // Breakpoints, Prolog, etc
2837 continue;
2838 break; // Funny loop structure to be sure...
2839 }
2840 // Compute last "interesting" instruction in block - last instruction we
2841 // might schedule. _bb_end points just after last schedulable inst. We
2842 // normally schedule conditional branches (despite them being forced last
2843 // in the block), because they have delay slots we can fill. Calls all
2844 // have their delay slots filled in the template expansions, so we don't
2845 // bother scheduling them.
2846 Node *last = bb->get_node(_bb_end);
2847 // Ignore trailing NOPs.
2848 while (_bb_end > 0 && last->is_Mach() &&
2849 last->as_Mach()->ideal_Opcode() == Op_Con) {
2850 last = bb->get_node(--_bb_end);
2851 }
2852 assert(!last->is_Mach() || last->as_Mach()->ideal_Opcode() != Op_Con, "");
2853 if( last->is_Catch() ||
2854 (last->is_Mach() && last->as_Mach()->ideal_Opcode() == Op_Halt) ) {
2855 // There might be a prior call. Skip it.
2856 while (_bb_start < _bb_end && bb->get_node(--_bb_end)->is_MachProj());
2857 } else if( last->is_MachNullCheck() ) {
2858 // Backup so the last null-checked memory instruction is
2859 // outside the schedulable range. Skip over the nullcheck,
2860 // projection, and the memory nodes.
2861 Node *mem = last->in(1);
2862 do {
2863 _bb_end--;
2864 } while (mem != bb->get_node(_bb_end));
2865 } else {
2866 // Set _bb_end to point after last schedulable inst.
2867 _bb_end++;
2868 }
2869
2870 assert( _bb_start <= _bb_end, "inverted block ends" );
2871
2872 // Compute the register antidependencies for the basic block
2873 ComputeRegisterAntidependencies(bb);
2874 if (C->failing()) return; // too many D-U pinch points
2875
2876 // Compute the usage within the block, and set the list of all nodes
2877 // in the block that have no uses within the block.
2878 ComputeUseCount(bb);
2879
2880 // Schedule the remaining instructions in the block
2881 while ( _available.size() > 0 ) {
2882 Node *n = ChooseNodeToBundle();
2883 guarantee(n != nullptr, "no nodes available");
2884 AddNodeToBundle(n,bb);
2885 }
2886
2887 assert( _scheduled.size() == _bb_end - _bb_start, "wrong number of instructions" );
2888 #ifdef ASSERT
2889 for( uint l = _bb_start; l < _bb_end; l++ ) {
2890 Node *n = bb->get_node(l);
2891 uint m;
2892 for( m = 0; m < _bb_end-_bb_start; m++ )
2893 if( _scheduled[m] == n )
2894 break;
2895 assert( m < _bb_end-_bb_start, "instruction missing in schedule" );
2896 }
2897 #endif
2898
2899 // Now copy the instructions (in reverse order) back to the block
2900 for ( uint k = _bb_start; k < _bb_end; k++ )
2901 bb->map_node(_scheduled[_bb_end-k-1], k);
2902
2903 #ifndef PRODUCT
2904 if (_cfg->C->trace_opto_output()) {
2905 tty->print("# Schedule BB#%03d (final)\n", i);
2906 uint current = 0;
2907 for (uint j = 0; j < bb->number_of_nodes(); j++) {
2908 Node *n = bb->get_node(j);
2909 if( valid_bundle_info(n) ) {
2910 Bundle *bundle = node_bundling(n);
2911 if (bundle->instr_count() > 0 || bundle->flags() > 0) {
2912 tty->print("*** Bundle: ");
2913 bundle->dump();
2914 }
2915 n->dump();
2916 }
2917 }
2918 }
2919 #endif
2920 #ifdef ASSERT
2921 verify_good_schedule(bb,"after block local scheduling");
2922 #endif
2923 }
2924
2925 #ifndef PRODUCT
2926 if (_cfg->C->trace_opto_output())
2927 tty->print("# <- DoScheduling\n");
2928 #endif
2929
2930 // Record final node-bundling array location
2931 _regalloc->C->output()->set_node_bundling_base(_node_bundling_base);
2932
2933 } // end DoScheduling
2934
2935 // Verify that no live-range used in the block is killed in the block by a
2936 // wrong DEF. This doesn't verify live-ranges that span blocks.
2937
2938 // Check for edge existence. Used to avoid adding redundant precedence edges.
2939 static bool edge_from_to( Node *from, Node *to ) {
2940 for( uint i=0; i<from->len(); i++ )
2941 if( from->in(i) == to )
2942 return true;
2943 return false;
2944 }
2945
2946 #ifdef ASSERT
2947 void Scheduling::verify_do_def( Node *n, OptoReg::Name def, const char *msg ) {
2948 // Check for bad kills
2949 if( OptoReg::is_valid(def) ) { // Ignore stores & control flow
2950 Node *prior_use = _reg_node[def];
2951 if( prior_use && !edge_from_to(prior_use,n) ) {
2952 tty->print("%s = ",OptoReg::as_VMReg(def)->name());
2953 n->dump();
2954 tty->print_cr("...");
2955 prior_use->dump();
2956 assert(edge_from_to(prior_use,n), "%s", msg);
2957 }
2958 _reg_node.map(def,nullptr); // Kill live USEs
2959 }
2960 }
2961
2962 void Scheduling::verify_good_schedule( Block *b, const char *msg ) {
2963
2964 // Zap to something reasonable for the verify code
2965 _reg_node.clear();
2966
2967 // Walk over the block backwards. Check to make sure each DEF doesn't
2968 // kill a live value (other than the one it's supposed to). Add each
2969 // USE to the live set.
2970 for( uint i = b->number_of_nodes()-1; i >= _bb_start; i-- ) {
2971 Node *n = b->get_node(i);
2972 int n_op = n->Opcode();
2973 if( n_op == Op_MachProj && n->ideal_reg() == MachProjNode::fat_proj ) {
2974 // Fat-proj kills a slew of registers
2975 RegMaskIterator rmi(n->out_RegMask());
2976 while (rmi.has_next()) {
2977 OptoReg::Name kill = rmi.next();
2978 verify_do_def(n, kill, msg);
2979 }
2980 } else if( n_op != Op_Node ) { // Avoid brand new antidependence nodes
2981 // Get DEF'd registers the normal way
2982 verify_do_def( n, _regalloc->get_reg_first(n), msg );
2983 verify_do_def( n, _regalloc->get_reg_second(n), msg );
2984 }
2985
2986 // Now make all USEs live
2987 for( uint i=1; i<n->req(); i++ ) {
2988 Node *def = n->in(i);
2989 assert(def != nullptr, "input edge required");
2990 OptoReg::Name reg_lo = _regalloc->get_reg_first(def);
2991 OptoReg::Name reg_hi = _regalloc->get_reg_second(def);
2992 if( OptoReg::is_valid(reg_lo) ) {
2993 assert(!_reg_node[reg_lo] || edge_from_to(_reg_node[reg_lo],def), "%s", msg);
2994 _reg_node.map(reg_lo,n);
2995 }
2996 if( OptoReg::is_valid(reg_hi) ) {
2997 assert(!_reg_node[reg_hi] || edge_from_to(_reg_node[reg_hi],def), "%s", msg);
2998 _reg_node.map(reg_hi,n);
2999 }
3000 }
3001
3002 }
3003
3004 // Zap to something reasonable for the Antidependence code
3005 _reg_node.clear();
3006 }
3007 #endif
3008
3009 // Conditionally add precedence edges. Avoid putting edges on Projs.
3010 static void add_prec_edge_from_to( Node *from, Node *to ) {
3011 if( from->is_Proj() ) { // Put precedence edge on Proj's input
3012 assert( from->req() == 1 && (from->len() == 1 || from->in(1) == nullptr), "no precedence edges on projections" );
3013 from = from->in(0);
3014 }
3015 if( from != to && // No cycles (for things like LD L0,[L0+4] )
3016 !edge_from_to( from, to ) ) // Avoid duplicate edge
3017 from->add_prec(to);
3018 }
3019
3020 void Scheduling::anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def ) {
3021 if( !OptoReg::is_valid(def_reg) ) // Ignore stores & control flow
3022 return;
3023
3024 if (OptoReg::is_reg(def_reg)) {
3025 VMReg vmreg = OptoReg::as_VMReg(def_reg);
3026 if (vmreg->is_reg() && !vmreg->is_concrete() && !vmreg->prev()->is_concrete()) {
3027 // This is one of the high slots of a vector register.
3028 // ScheduleAndBundle already checked there are no live wide
3029 // vectors in this method so it can be safely ignored.
3030 return;
3031 }
3032 }
3033
3034 Node *pinch = _reg_node[def_reg]; // Get pinch point
3035 if ((pinch == nullptr) || _cfg->get_block_for_node(pinch) != b || // No pinch-point yet?
3036 is_def ) { // Check for a true def (not a kill)
3037 _reg_node.map(def_reg,def); // Record def/kill as the optimistic pinch-point
3038 return;
3039 }
3040
3041 Node *kill = def; // Rename 'def' to more descriptive 'kill'
3042 debug_only( def = (Node*)((intptr_t)0xdeadbeef); )
3043
3044 // After some number of kills there _may_ be a later def
3045 Node *later_def = nullptr;
3046
3047 Compile* C = Compile::current();
3048
3049 // Finding a kill requires a real pinch-point.
3050 // Check for not already having a pinch-point.
3051 // Pinch points are Op_Node's.
3052 if( pinch->Opcode() != Op_Node ) { // Or later-def/kill as pinch-point?
3053 later_def = pinch; // Must be def/kill as optimistic pinch-point
3054 if ( _pinch_free_list.size() > 0) {
3055 pinch = _pinch_free_list.pop();
3056 } else {
3057 pinch = new Node(1); // Pinch point to-be
3058 }
3059 if (pinch->_idx >= _regalloc->node_regs_max_index()) {
3060 DEBUG_ONLY( pinch->dump(); );
3061 assert(false, "too many D-U pinch points: %d >= %d", pinch->_idx, _regalloc->node_regs_max_index());
3062 _cfg->C->record_method_not_compilable("too many D-U pinch points");
3063 return;
3064 }
3065 _cfg->map_node_to_block(pinch, b); // Pretend it's valid in this block (lazy init)
3066 _reg_node.map(def_reg,pinch); // Record pinch-point
3067 //regalloc()->set_bad(pinch->_idx); // Already initialized this way.
3068 if( later_def->outcnt() == 0 || later_def->ideal_reg() == MachProjNode::fat_proj ) { // Distinguish def from kill
3069 pinch->init_req(0, C->top()); // set not null for the next call
3070 add_prec_edge_from_to(later_def,pinch); // Add edge from kill to pinch
3071 later_def = nullptr; // and no later def
3072 }
3073 pinch->set_req(0,later_def); // Hook later def so we can find it
3074 } else { // Else have valid pinch point
3075 if( pinch->in(0) ) // If there is a later-def
3076 later_def = pinch->in(0); // Get it
3077 }
3078
3079 // Add output-dependence edge from later def to kill
3080 if( later_def ) // If there is some original def
3081 add_prec_edge_from_to(later_def,kill); // Add edge from def to kill
3082
3083 // See if current kill is also a use, and so is forced to be the pinch-point.
3084 if( pinch->Opcode() == Op_Node ) {
3085 Node *uses = kill->is_Proj() ? kill->in(0) : kill;
3086 for( uint i=1; i<uses->req(); i++ ) {
3087 if( _regalloc->get_reg_first(uses->in(i)) == def_reg ||
3088 _regalloc->get_reg_second(uses->in(i)) == def_reg ) {
3089 // Yes, found a use/kill pinch-point
3090 pinch->set_req(0,nullptr); //
3091 pinch->replace_by(kill); // Move anti-dep edges up
3092 pinch = kill;
3093 _reg_node.map(def_reg,pinch);
3094 return;
3095 }
3096 }
3097 }
3098
3099 // Add edge from kill to pinch-point
3100 add_prec_edge_from_to(kill,pinch);
3101 }
3102
3103 void Scheduling::anti_do_use( Block *b, Node *use, OptoReg::Name use_reg ) {
3104 if( !OptoReg::is_valid(use_reg) ) // Ignore stores & control flow
3105 return;
3106 Node *pinch = _reg_node[use_reg]; // Get pinch point
3107 // Check for no later def_reg/kill in block
3108 if ((pinch != nullptr) && _cfg->get_block_for_node(pinch) == b &&
3109 // Use has to be block-local as well
3110 _cfg->get_block_for_node(use) == b) {
3111 if( pinch->Opcode() == Op_Node && // Real pinch-point (not optimistic?)
3112 pinch->req() == 1 ) { // pinch not yet in block?
3113 pinch->del_req(0); // yank pointer to later-def, also set flag
3114 // Insert the pinch-point in the block just after the last use
3115 b->insert_node(pinch, b->find_node(use) + 1);
3116 _bb_end++; // Increase size scheduled region in block
3117 }
3118
3119 add_prec_edge_from_to(pinch,use);
3120 }
3121 }
3122
3123 // We insert antidependences between the reads and following write of
3124 // allocated registers to prevent illegal code motion. Hopefully, the
3125 // number of added references should be fairly small, especially as we
3126 // are only adding references within the current basic block.
3127 void Scheduling::ComputeRegisterAntidependencies(Block *b) {
3128
3129 #ifdef ASSERT
3130 verify_good_schedule(b,"before block local scheduling");
3131 #endif
3132
3133 // A valid schedule, for each register independently, is an endless cycle
3134 // of: a def, then some uses (connected to the def by true dependencies),
3135 // then some kills (defs with no uses), finally the cycle repeats with a new
3136 // def. The uses are allowed to float relative to each other, as are the
3137 // kills. No use is allowed to slide past a kill (or def). This requires
3138 // antidependencies between all uses of a single def and all kills that
3139 // follow, up to the next def. More edges are redundant, because later defs
3140 // & kills are already serialized with true or antidependencies. To keep
3141 // the edge count down, we add a 'pinch point' node if there's more than
3142 // one use or more than one kill/def.
3143
3144 // We add dependencies in one bottom-up pass.
3145
3146 // For each instruction we handle it's DEFs/KILLs, then it's USEs.
3147
3148 // For each DEF/KILL, we check to see if there's a prior DEF/KILL for this
3149 // register. If not, we record the DEF/KILL in _reg_node, the
3150 // register-to-def mapping. If there is a prior DEF/KILL, we insert a
3151 // "pinch point", a new Node that's in the graph but not in the block.
3152 // We put edges from the prior and current DEF/KILLs to the pinch point.
3153 // We put the pinch point in _reg_node. If there's already a pinch point
3154 // we merely add an edge from the current DEF/KILL to the pinch point.
3155
3156 // After doing the DEF/KILLs, we handle USEs. For each used register, we
3157 // put an edge from the pinch point to the USE.
3158
3159 // To be expedient, the _reg_node array is pre-allocated for the whole
3160 // compilation. _reg_node is lazily initialized; it either contains a null,
3161 // or a valid def/kill/pinch-point, or a leftover node from some prior
3162 // block. Leftover node from some prior block is treated like a null (no
3163 // prior def, so no anti-dependence needed). Valid def is distinguished by
3164 // it being in the current block.
3165 bool fat_proj_seen = false;
3166 uint last_safept = _bb_end-1;
3167 Node* end_node = (_bb_end-1 >= _bb_start) ? b->get_node(last_safept) : nullptr;
3168 Node* last_safept_node = end_node;
3169 for( uint i = _bb_end-1; i >= _bb_start; i-- ) {
3170 Node *n = b->get_node(i);
3171 int is_def = n->outcnt(); // def if some uses prior to adding precedence edges
3172 if( n->is_MachProj() && n->ideal_reg() == MachProjNode::fat_proj ) {
3173 // Fat-proj kills a slew of registers
3174 // This can add edges to 'n' and obscure whether or not it was a def,
3175 // hence the is_def flag.
3176 fat_proj_seen = true;
3177 RegMaskIterator rmi(n->out_RegMask());
3178 while (rmi.has_next()) {
3179 OptoReg::Name kill = rmi.next();
3180 anti_do_def(b, n, kill, is_def);
3181 }
3182 } else {
3183 // Get DEF'd registers the normal way
3184 anti_do_def( b, n, _regalloc->get_reg_first(n), is_def );
3185 anti_do_def( b, n, _regalloc->get_reg_second(n), is_def );
3186 }
3187
3188 // Kill projections on a branch should appear to occur on the
3189 // branch, not afterwards, so grab the masks from the projections
3190 // and process them.
3191 if (n->is_MachBranch() || (n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_Jump)) {
3192 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3193 Node* use = n->fast_out(i);
3194 if (use->is_Proj()) {
3195 RegMaskIterator rmi(use->out_RegMask());
3196 while (rmi.has_next()) {
3197 OptoReg::Name kill = rmi.next();
3198 anti_do_def(b, n, kill, false);
3199 }
3200 }
3201 }
3202 }
3203
3204 // Check each register used by this instruction for a following DEF/KILL
3205 // that must occur afterward and requires an anti-dependence edge.
3206 for( uint j=0; j<n->req(); j++ ) {
3207 Node *def = n->in(j);
3208 if( def ) {
3209 assert( !def->is_MachProj() || def->ideal_reg() != MachProjNode::fat_proj, "" );
3210 anti_do_use( b, n, _regalloc->get_reg_first(def) );
3211 anti_do_use( b, n, _regalloc->get_reg_second(def) );
3212 }
3213 }
3214 // Do not allow defs of new derived values to float above GC
3215 // points unless the base is definitely available at the GC point.
3216
3217 Node *m = b->get_node(i);
3218
3219 // Add precedence edge from following safepoint to use of derived pointer
3220 if( last_safept_node != end_node &&
3221 m != last_safept_node) {
3222 for (uint k = 1; k < m->req(); k++) {
3223 const Type *t = m->in(k)->bottom_type();
3224 if( t->isa_oop_ptr() &&
3225 t->is_ptr()->offset() != 0 ) {
3226 last_safept_node->add_prec( m );
3227 break;
3228 }
3229 }
3230
3231 // Do not allow a CheckCastPP node whose input is a raw pointer to
3232 // float past a safepoint. This can occur when a buffered inline
3233 // type is allocated in a loop and the CheckCastPP from that
3234 // allocation is reused outside the loop. If the use inside the
3235 // loop is scalarized the CheckCastPP will no longer be connected
3236 // to the loop safepoint. See JDK-8264340.
3237 if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_CheckCastPP) {
3238 Node *def = m->in(1);
3239 if (def != nullptr && def->bottom_type()->base() == Type::RawPtr) {
3240 last_safept_node->add_prec(m);
3241 }
3242 }
3243 }
3244
3245 if( n->jvms() ) { // Precedence edge from derived to safept
3246 // Check if last_safept_node was moved by pinch-point insertion in anti_do_use()
3247 if( b->get_node(last_safept) != last_safept_node ) {
3248 last_safept = b->find_node(last_safept_node);
3249 }
3250 for( uint j=last_safept; j > i; j-- ) {
3251 Node *mach = b->get_node(j);
3252 if( mach->is_Mach() && mach->as_Mach()->ideal_Opcode() == Op_AddP )
3253 mach->add_prec( n );
3254 }
3255 last_safept = i;
3256 last_safept_node = m;
3257 }
3258 }
3259
3260 if (fat_proj_seen) {
3261 // Garbage collect pinch nodes that were not consumed.
3262 // They are usually created by a fat kill MachProj for a call.
3263 garbage_collect_pinch_nodes();
3264 }
3265 }
3266
3267 // Garbage collect pinch nodes for reuse by other blocks.
3268 //
3269 // The block scheduler's insertion of anti-dependence
3270 // edges creates many pinch nodes when the block contains
3271 // 2 or more Calls. A pinch node is used to prevent a
3272 // combinatorial explosion of edges. If a set of kills for a
3273 // register is anti-dependent on a set of uses (or defs), rather
3274 // than adding an edge in the graph between each pair of kill
3275 // and use (or def), a pinch is inserted between them:
3276 //
3277 // use1 use2 use3
3278 // \ | /
3279 // \ | /
3280 // pinch
3281 // / | \
3282 // / | \
3283 // kill1 kill2 kill3
3284 //
3285 // One pinch node is created per register killed when
3286 // the second call is encountered during a backwards pass
3287 // over the block. Most of these pinch nodes are never
3288 // wired into the graph because the register is never
3289 // used or def'ed in the block.
3290 //
3291 void Scheduling::garbage_collect_pinch_nodes() {
3292 #ifndef PRODUCT
3293 if (_cfg->C->trace_opto_output()) tty->print("Reclaimed pinch nodes:");
3294 #endif
3295 int trace_cnt = 0;
3296 for (uint k = 0; k < _reg_node.max(); k++) {
3297 Node* pinch = _reg_node[k];
3298 if ((pinch != nullptr) && pinch->Opcode() == Op_Node &&
3299 // no predecence input edges
3300 (pinch->req() == pinch->len() || pinch->in(pinch->req()) == nullptr) ) {
3301 cleanup_pinch(pinch);
3302 _pinch_free_list.push(pinch);
3303 _reg_node.map(k, nullptr);
3304 #ifndef PRODUCT
3305 if (_cfg->C->trace_opto_output()) {
3306 trace_cnt++;
3307 if (trace_cnt > 40) {
3308 tty->print("\n");
3309 trace_cnt = 0;
3310 }
3311 tty->print(" %d", pinch->_idx);
3312 }
3313 #endif
3314 }
3315 }
3316 #ifndef PRODUCT
3317 if (_cfg->C->trace_opto_output()) tty->print("\n");
3318 #endif
3319 }
3320
3321 // Clean up a pinch node for reuse.
3322 void Scheduling::cleanup_pinch( Node *pinch ) {
3323 assert (pinch && pinch->Opcode() == Op_Node && pinch->req() == 1, "just checking");
3324
3325 for (DUIterator_Last imin, i = pinch->last_outs(imin); i >= imin; ) {
3326 Node* use = pinch->last_out(i);
3327 uint uses_found = 0;
3328 for (uint j = use->req(); j < use->len(); j++) {
3329 if (use->in(j) == pinch) {
3330 use->rm_prec(j);
3331 uses_found++;
3332 }
3333 }
3334 assert(uses_found > 0, "must be a precedence edge");
3335 i -= uses_found; // we deleted 1 or more copies of this edge
3336 }
3337 // May have a later_def entry
3338 pinch->set_req(0, nullptr);
3339 }
3340
3341 #ifndef PRODUCT
3342
3343 void Scheduling::dump_available() const {
3344 tty->print("#Availist ");
3345 for (uint i = 0; i < _available.size(); i++)
3346 tty->print(" N%d/l%d", _available[i]->_idx,_current_latency[_available[i]->_idx]);
3347 tty->cr();
3348 }
3349
3350 // Print Scheduling Statistics
3351 void Scheduling::print_statistics() {
3352 // Print the size added by nops for bundling
3353 tty->print("Nops added %d bytes to total of %d bytes",
3354 _total_nop_size, _total_method_size);
3355 if (_total_method_size > 0)
3356 tty->print(", for %.2f%%",
3357 ((double)_total_nop_size) / ((double) _total_method_size) * 100.0);
3358 tty->print("\n");
3359
3360 // Print the number of branch shadows filled
3361 if (Pipeline::_branch_has_delay_slot) {
3362 tty->print("Of %d branches, %d had unconditional delay slots filled",
3363 _total_branches, _total_unconditional_delays);
3364 if (_total_branches > 0)
3365 tty->print(", for %.2f%%",
3366 ((double)_total_unconditional_delays) / ((double)_total_branches) * 100.0);
3367 tty->print("\n");
3368 }
3369
3370 uint total_instructions = 0, total_bundles = 0;
3371
3372 for (uint i = 1; i <= Pipeline::_max_instrs_per_cycle; i++) {
3373 uint bundle_count = _total_instructions_per_bundle[i];
3374 total_instructions += bundle_count * i;
3375 total_bundles += bundle_count;
3376 }
3377
3378 if (total_bundles > 0)
3379 tty->print("Average ILP (excluding nops) is %.2f\n",
3380 ((double)total_instructions) / ((double)total_bundles));
3381 }
3382 #endif
3383
3384 //-----------------------init_scratch_buffer_blob------------------------------
3385 // Construct a temporary BufferBlob and cache it for this compile.
3386 void PhaseOutput::init_scratch_buffer_blob(int const_size) {
3387 // If there is already a scratch buffer blob allocated and the
3388 // constant section is big enough, use it. Otherwise free the
3389 // current and allocate a new one.
3390 BufferBlob* blob = scratch_buffer_blob();
3391 if ((blob != nullptr) && (const_size <= _scratch_const_size)) {
3392 // Use the current blob.
3393 } else {
3394 if (blob != nullptr) {
3395 BufferBlob::free(blob);
3396 }
3397
3398 ResourceMark rm;
3399 _scratch_const_size = const_size;
3400 int size = C2Compiler::initial_code_buffer_size(const_size);
3401 if (C->has_scalarized_args()) {
3402 // Inline type entry points (MachVEPNodes) require lots of space for GC barriers and oop verification
3403 // when loading object fields from the buffered argument. Increase scratch buffer size accordingly.
3404 ciMethod* method = C->method();
3405 int barrier_size = UseZGC ? 200 : (7 DEBUG_ONLY(+ 37));
3406 int arg_num = 0;
3407 if (!method->is_static()) {
3408 if (method->is_scalarized_arg(arg_num)) {
3409 size += method->holder()->as_inline_klass()->oop_count() * barrier_size;
3410 }
3411 arg_num++;
3412 }
3413 for (ciSignatureStream str(method->signature()); !str.at_return_type(); str.next()) {
3414 if (method->is_scalarized_arg(arg_num)) {
3415 size += str.type()->as_inline_klass()->oop_count() * barrier_size;
3416 }
3417 arg_num++;
3418 }
3419 }
3420 blob = BufferBlob::create("Compile::scratch_buffer", size);
3421 // Record the buffer blob for next time.
3422 set_scratch_buffer_blob(blob);
3423 // Have we run out of code space?
3424 if (scratch_buffer_blob() == nullptr) {
3425 // Let CompilerBroker disable further compilations.
3426 C->record_failure("Not enough space for scratch buffer in CodeCache");
3427 return;
3428 }
3429 }
3430
3431 // Initialize the relocation buffers
3432 relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
3433 set_scratch_locs_memory(locs_buf);
3434 }
3435
3436
3437 //-----------------------scratch_emit_size-------------------------------------
3438 // Helper function that computes size by emitting code
3439 uint PhaseOutput::scratch_emit_size(const Node* n) {
3440 // Start scratch_emit_size section.
3441 set_in_scratch_emit_size(true);
3442
3443 // Emit into a trash buffer and count bytes emitted.
3444 // This is a pretty expensive way to compute a size,
3445 // but it works well enough if seldom used.
3446 // All common fixed-size instructions are given a size
3447 // method by the AD file.
3448 // Note that the scratch buffer blob and locs memory are
3449 // allocated at the beginning of the compile task, and
3450 // may be shared by several calls to scratch_emit_size.
3451 // The allocation of the scratch buffer blob is particularly
3452 // expensive, since it has to grab the code cache lock.
3453 BufferBlob* blob = this->scratch_buffer_blob();
3454 assert(blob != nullptr, "Initialize BufferBlob at start");
3455 assert(blob->size() > MAX_inst_size, "sanity");
3456 relocInfo* locs_buf = scratch_locs_memory();
3457 address blob_begin = blob->content_begin();
3458 address blob_end = (address)locs_buf;
3459 assert(blob->contains(blob_end), "sanity");
3460 CodeBuffer buf(blob_begin, blob_end - blob_begin);
3461 buf.initialize_consts_size(_scratch_const_size);
3462 buf.initialize_stubs_size(MAX_stubs_size);
3463 assert(locs_buf != nullptr, "sanity");
3464 int lsize = MAX_locs_size / 3;
3465 buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
3466 buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
3467 buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
3468 // Mark as scratch buffer.
3469 buf.consts()->set_scratch_emit();
3470 buf.insts()->set_scratch_emit();
3471 buf.stubs()->set_scratch_emit();
3472
3473 // Do the emission.
3474
3475 Label fakeL; // Fake label for branch instructions.
3476 Label* saveL = nullptr;
3477 uint save_bnum = 0;
3478 bool is_branch = n->is_MachBranch();
3479 C2_MacroAssembler masm(&buf);
3480 masm.bind(fakeL);
3481 if (is_branch) {
3482 n->as_MachBranch()->save_label(&saveL, &save_bnum);
3483 n->as_MachBranch()->label_set(&fakeL, 0);
3484 }
3485 n->emit(&masm, C->regalloc());
3486
3487 // Emitting into the scratch buffer should not fail
3488 assert(!C->failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", C->failure_reason());
3489
3490 // Restore label.
3491 if (is_branch) {
3492 n->as_MachBranch()->label_set(saveL, save_bnum);
3493 }
3494
3495 // End scratch_emit_size section.
3496 set_in_scratch_emit_size(false);
3497
3498 return buf.insts_size();
3499 }
3500
3501 void PhaseOutput::install() {
3502 if (!C->should_install_code()) {
3503 return;
3504 } else if (C->stub_function() != nullptr) {
3505 install_stub(C->stub_name());
3506 } else {
3507 install_code(C->method(),
3508 C->entry_bci(),
3509 CompileBroker::compiler2(),
3510 C->has_unsafe_access(),
3511 SharedRuntime::is_wide_vector(C->max_vector_size()));
3512 }
3513 }
3514
3515 void PhaseOutput::install_code(ciMethod* target,
3516 int entry_bci,
3517 AbstractCompiler* compiler,
3518 bool has_unsafe_access,
3519 bool has_wide_vectors) {
3520 // Check if we want to skip execution of all compiled code.
3521 {
3522 #ifndef PRODUCT
3523 if (OptoNoExecute) {
3524 C->record_method_not_compilable("+OptoNoExecute"); // Flag as failed
3525 return;
3526 }
3527 #endif
3528 Compile::TracePhase tp(_t_registerMethod);
3529
3530 if (C->is_osr_compilation()) {
3531 _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
3532 _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
3533 } else {
3534 _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
3535 if (_code_offsets.value(CodeOffsets::Verified_Inline_Entry) == -1) {
3536 _code_offsets.set_value(CodeOffsets::Verified_Inline_Entry, _first_block_size);
3537 }
3538 if (_code_offsets.value(CodeOffsets::Verified_Inline_Entry_RO) == -1) {
3539 _code_offsets.set_value(CodeOffsets::Verified_Inline_Entry_RO, _first_block_size);
3540 }
3541 if (_code_offsets.value(CodeOffsets::Entry) == -1) {
3542 _code_offsets.set_value(CodeOffsets::Entry, _first_block_size);
3543 }
3544 _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
3545 }
3546
3547 C->env()->register_method(target,
3548 entry_bci,
3549 &_code_offsets,
3550 _orig_pc_slot_offset_in_bytes,
3551 code_buffer(),
3552 frame_size_in_words(),
3553 _oop_map_set,
3554 &_handler_table,
3555 inc_table(),
3556 compiler,
3557 has_unsafe_access,
3558 SharedRuntime::is_wide_vector(C->max_vector_size()),
3559 C->has_monitors(),
3560 C->has_scoped_access(),
3561 0);
3562
3563 if (C->log() != nullptr) { // Print code cache state into compiler log
3564 C->log()->code_cache_state();
3565 }
3566 }
3567 }
3568 void PhaseOutput::install_stub(const char* stub_name) {
3569 // Entry point will be accessed using stub_entry_point();
3570 if (code_buffer() == nullptr) {
3571 Matcher::soft_match_failure();
3572 } else {
3573 if (PrintAssembly && (WizardMode || Verbose))
3574 tty->print_cr("### Stub::%s", stub_name);
3575
3576 if (!C->failing()) {
3577 assert(C->fixed_slots() == 0, "no fixed slots used for runtime stubs");
3578
3579 // Make the NMethod
3580 // For now we mark the frame as never safe for profile stackwalking
3581 RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
3582 code_buffer(),
3583 CodeOffsets::frame_never_safe,
3584 // _code_offsets.value(CodeOffsets::Frame_Complete),
3585 frame_size_in_words(),
3586 oop_map_set(),
3587 false,
3588 false);
3589
3590 if (rs == nullptr) {
3591 C->record_failure("CodeCache is full");
3592 } else {
3593 assert(rs->is_runtime_stub(), "sanity check");
3594 C->set_stub_entry_point(rs->entry_point());
3595 }
3596 }
3597 }
3598 }
3599
3600 // Support for bundling info
3601 Bundle* PhaseOutput::node_bundling(const Node *n) {
3602 assert(valid_bundle_info(n), "oob");
3603 return &_node_bundling_base[n->_idx];
3604 }
3605
3606 bool PhaseOutput::valid_bundle_info(const Node *n) {
3607 return (_node_bundling_limit > n->_idx);
3608 }
3609
3610 //------------------------------frame_size_in_words-----------------------------
3611 // frame_slots in units of words
3612 int PhaseOutput::frame_size_in_words() const {
3613 // shift is 0 in LP32 and 1 in LP64
3614 const int shift = (LogBytesPerWord - LogBytesPerInt);
3615 int words = _frame_slots >> shift;
3616 assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
3617 return words;
3618 }
3619
3620 // To bang the stack of this compiled method we use the stack size
3621 // that the interpreter would need in case of a deoptimization. This
3622 // removes the need to bang the stack in the deoptimization blob which
3623 // in turn simplifies stack overflow handling.
3624 int PhaseOutput::bang_size_in_bytes() const {
3625 return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), C->interpreter_frame_size());
3626 }
3627
3628 //------------------------------dump_asm---------------------------------------
3629 // Dump formatted assembly
3630 #if defined(SUPPORT_OPTO_ASSEMBLY)
3631 void PhaseOutput::dump_asm_on(outputStream* st, int* pcs, uint pc_limit) {
3632
3633 int pc_digits = 3; // #chars required for pc
3634 int sb_chars = 3; // #chars for "start bundle" indicator
3635 int tab_size = 8;
3636 if (pcs != nullptr) {
3637 int max_pc = 0;
3638 for (uint i = 0; i < pc_limit; i++) {
3639 max_pc = (max_pc < pcs[i]) ? pcs[i] : max_pc;
3640 }
3641 pc_digits = ((max_pc < 4096) ? 3 : ((max_pc < 65536) ? 4 : ((max_pc < 65536*256) ? 6 : 8))); // #chars required for pc
3642 }
3643 int prefix_len = ((pc_digits + sb_chars + tab_size - 1)/tab_size)*tab_size;
3644
3645 bool cut_short = false;
3646 st->print_cr("#");
3647 st->print("# "); C->tf()->dump_on(st); st->cr();
3648 st->print_cr("#");
3649
3650 // For all blocks
3651 int pc = 0x0; // Program counter
3652 char starts_bundle = ' ';
3653 C->regalloc()->dump_frame();
3654
3655 Node *n = nullptr;
3656 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
3657 if (VMThread::should_terminate()) {
3658 cut_short = true;
3659 break;
3660 }
3661 Block* block = C->cfg()->get_block(i);
3662 if (block->is_connector() && !Verbose) {
3663 continue;
3664 }
3665 n = block->head();
3666 if ((pcs != nullptr) && (n->_idx < pc_limit)) {
3667 pc = pcs[n->_idx];
3668 st->print("%*.*x", pc_digits, pc_digits, pc);
3669 }
3670 st->fill_to(prefix_len);
3671 block->dump_head(C->cfg(), st);
3672 if (block->is_connector()) {
3673 st->fill_to(prefix_len);
3674 st->print_cr("# Empty connector block");
3675 } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
3676 st->fill_to(prefix_len);
3677 st->print_cr("# Block is sole successor of call");
3678 }
3679
3680 // For all instructions
3681 Node *delay = nullptr;
3682 for (uint j = 0; j < block->number_of_nodes(); j++) {
3683 if (VMThread::should_terminate()) {
3684 cut_short = true;
3685 break;
3686 }
3687 n = block->get_node(j);
3688 if (valid_bundle_info(n)) {
3689 Bundle* bundle = node_bundling(n);
3690 if (bundle->used_in_unconditional_delay()) {
3691 delay = n;
3692 continue;
3693 }
3694 if (bundle->starts_bundle()) {
3695 starts_bundle = '+';
3696 }
3697 }
3698
3699 if (WizardMode) {
3700 n->dump();
3701 }
3702
3703 if( !n->is_Region() && // Dont print in the Assembly
3704 !n->is_Phi() && // a few noisely useless nodes
3705 !n->is_Proj() &&
3706 !n->is_MachTemp() &&
3707 !n->is_SafePointScalarObject() &&
3708 !n->is_Catch() && // Would be nice to print exception table targets
3709 !n->is_MergeMem() && // Not very interesting
3710 !n->is_top() && // Debug info table constants
3711 !(n->is_Con() && !n->is_Mach())// Debug info table constants
3712 ) {
3713 if ((pcs != nullptr) && (n->_idx < pc_limit)) {
3714 pc = pcs[n->_idx];
3715 st->print("%*.*x", pc_digits, pc_digits, pc);
3716 } else {
3717 st->fill_to(pc_digits);
3718 }
3719 st->print(" %c ", starts_bundle);
3720 starts_bundle = ' ';
3721 st->fill_to(prefix_len);
3722 n->format(C->regalloc(), st);
3723 st->cr();
3724 }
3725
3726 // If we have an instruction with a delay slot, and have seen a delay,
3727 // then back up and print it
3728 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
3729 // Coverity finding - Explicit null dereferenced.
3730 guarantee(delay != nullptr, "no unconditional delay instruction");
3731 if (WizardMode) delay->dump();
3732
3733 if (node_bundling(delay)->starts_bundle())
3734 starts_bundle = '+';
3735 if ((pcs != nullptr) && (n->_idx < pc_limit)) {
3736 pc = pcs[n->_idx];
3737 st->print("%*.*x", pc_digits, pc_digits, pc);
3738 } else {
3739 st->fill_to(pc_digits);
3740 }
3741 st->print(" %c ", starts_bundle);
3742 starts_bundle = ' ';
3743 st->fill_to(prefix_len);
3744 delay->format(C->regalloc(), st);
3745 st->cr();
3746 delay = nullptr;
3747 }
3748
3749 // Dump the exception table as well
3750 if( n->is_Catch() && (Verbose || WizardMode) ) {
3751 // Print the exception table for this offset
3752 _handler_table.print_subtable_for(pc);
3753 }
3754 st->bol(); // Make sure we start on a new line
3755 }
3756 st->cr(); // one empty line between blocks
3757 assert(cut_short || delay == nullptr, "no unconditional delay branch");
3758 } // End of per-block dump
3759
3760 if (cut_short) st->print_cr("*** disassembly is cut short ***");
3761 }
3762 #endif
3763
3764 #ifndef PRODUCT
3765 void PhaseOutput::print_statistics() {
3766 Scheduling::print_statistics();
3767 }
3768 #endif