1 /*
2 * Copyright (c) 1998, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "asm/assembler.inline.hpp"
27 #include "asm/macroAssembler.inline.hpp"
28 #include "code/compiledIC.hpp"
29 #include "code/debugInfo.hpp"
30 #include "code/debugInfoRec.hpp"
31 #include "compiler/compileBroker.hpp"
32 #include "compiler/compilerDirectives.hpp"
33 #include "compiler/disassembler.hpp"
34 #include "compiler/oopMap.hpp"
35 #include "gc/shared/barrierSet.hpp"
36 #include "gc/shared/c2/barrierSetC2.hpp"
37 #include "memory/allocation.inline.hpp"
38 #include "opto/ad.hpp"
39 #include "opto/block.hpp"
40 #include "opto/c2compiler.hpp"
41 #include "opto/callnode.hpp"
42 #include "opto/cfgnode.hpp"
43 #include "opto/locknode.hpp"
44 #include "opto/machnode.hpp"
45 #include "opto/node.hpp"
46 #include "opto/optoreg.hpp"
47 #include "opto/output.hpp"
48 #include "opto/regalloc.hpp"
49 #include "opto/runtime.hpp"
50 #include "opto/subnode.hpp"
51 #include "opto/type.hpp"
52 #include "runtime/handles.inline.hpp"
53 #include "runtime/sharedRuntime.hpp"
54 #include "utilities/macros.hpp"
55 #include "utilities/powerOfTwo.hpp"
56 #include "utilities/xmlstream.hpp"
57
58 #ifndef PRODUCT
59 #define DEBUG_ARG(x) , x
60 #else
61 #define DEBUG_ARG(x)
62 #endif
63
64 //------------------------------Scheduling----------------------------------
65 // This class contains all the information necessary to implement instruction
66 // scheduling and bundling.
67 class Scheduling {
68
69 private:
70 // Arena to use
71 Arena *_arena;
72
73 // Control-Flow Graph info
74 PhaseCFG *_cfg;
75
76 // Register Allocation info
77 PhaseRegAlloc *_regalloc;
78
79 // Number of nodes in the method
80 uint _node_bundling_limit;
81
82 // List of scheduled nodes. Generated in reverse order
83 Node_List _scheduled;
84
85 // List of nodes currently available for choosing for scheduling
86 Node_List _available;
87
88 // For each instruction beginning a bundle, the number of following
89 // nodes to be bundled with it.
90 Bundle *_node_bundling_base;
91
92 // Mapping from register to Node
93 Node_List _reg_node;
94
95 // Free list for pinch nodes.
96 Node_List _pinch_free_list;
97
98 // Latency from the beginning of the containing basic block (base 1)
99 // for each node.
100 unsigned short *_node_latency;
101
102 // Number of uses of this node within the containing basic block.
103 short *_uses;
104
105 // Schedulable portion of current block. Skips Region/Phi/CreateEx up
106 // front, branch+proj at end. Also skips Catch/CProj (same as
107 // branch-at-end), plus just-prior exception-throwing call.
108 uint _bb_start, _bb_end;
109
110 // Latency from the end of the basic block as scheduled
111 unsigned short *_current_latency;
112
113 // Remember the next node
114 Node *_next_node;
115
116 // Use this for an unconditional branch delay slot
117 Node *_unconditional_delay_slot;
118
119 // Pointer to a Nop
120 MachNopNode *_nop;
121
122 // Length of the current bundle, in instructions
123 uint _bundle_instr_count;
124
125 // Current Cycle number, for computing latencies and bundling
126 uint _bundle_cycle_number;
127
128 // Bundle information
129 Pipeline_Use_Element _bundle_use_elements[resource_count];
130 Pipeline_Use _bundle_use;
131
132 // Dump the available list
133 void dump_available() const;
134
135 public:
136 Scheduling(Arena *arena, Compile &compile);
137
138 // Destructor
139 NOT_PRODUCT( ~Scheduling(); )
140
141 // Step ahead "i" cycles
142 void step(uint i);
143
144 // Step ahead 1 cycle, and clear the bundle state (for example,
145 // at a branch target)
146 void step_and_clear();
147
148 Bundle* node_bundling(const Node *n) {
149 assert(valid_bundle_info(n), "oob");
150 return (&_node_bundling_base[n->_idx]);
151 }
152
153 bool valid_bundle_info(const Node *n) const {
154 return (_node_bundling_limit > n->_idx);
155 }
156
157 bool starts_bundle(const Node *n) const {
158 return (_node_bundling_limit > n->_idx && _node_bundling_base[n->_idx].starts_bundle());
159 }
160
161 // Do the scheduling
162 void DoScheduling();
163
164 // Compute the local latencies walking forward over the list of
165 // nodes for a basic block
166 void ComputeLocalLatenciesForward(const Block *bb);
167
168 // Compute the register antidependencies within a basic block
169 void ComputeRegisterAntidependencies(Block *bb);
170 void verify_do_def( Node *n, OptoReg::Name def, const char *msg );
171 void verify_good_schedule( Block *b, const char *msg );
172 void anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def );
173 void anti_do_use( Block *b, Node *use, OptoReg::Name use_reg );
174
175 // Add a node to the current bundle
176 void AddNodeToBundle(Node *n, const Block *bb);
177
178 // Add a node to the list of available nodes
179 void AddNodeToAvailableList(Node *n);
180
181 // Compute the local use count for the nodes in a block, and compute
182 // the list of instructions with no uses in the block as available
183 void ComputeUseCount(const Block *bb);
184
185 // Choose an instruction from the available list to add to the bundle
186 Node * ChooseNodeToBundle();
187
188 // See if this Node fits into the currently accumulating bundle
189 bool NodeFitsInBundle(Node *n);
190
191 // Decrement the use count for a node
192 void DecrementUseCounts(Node *n, const Block *bb);
193
194 // Garbage collect pinch nodes for reuse by other blocks.
195 void garbage_collect_pinch_nodes();
196 // Clean up a pinch node for reuse (helper for above).
197 void cleanup_pinch( Node *pinch );
198
199 // Information for statistics gathering
200 #ifndef PRODUCT
201 private:
202 // Gather information on size of nops relative to total
203 uint _branches, _unconditional_delays;
204
205 static uint _total_nop_size, _total_method_size;
206 static uint _total_branches, _total_unconditional_delays;
207 static uint _total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
208
209 public:
210 static void print_statistics();
211
212 static void increment_instructions_per_bundle(uint i) {
213 _total_instructions_per_bundle[i]++;
214 }
215
216 static void increment_nop_size(uint s) {
217 _total_nop_size += s;
218 }
219
220 static void increment_method_size(uint s) {
221 _total_method_size += s;
222 }
223 #endif
224
225 };
226
227
228 PhaseOutput::PhaseOutput()
229 : Phase(Phase::Output),
230 _code_buffer("Compile::Fill_buffer"),
231 _first_block_size(0),
232 _handler_table(),
233 _inc_table(),
234 _oop_map_set(NULL),
235 _scratch_buffer_blob(NULL),
236 _scratch_locs_memory(NULL),
237 _scratch_const_size(-1),
238 _in_scratch_emit_size(false),
239 _frame_slots(0),
240 _code_offsets(),
241 _node_bundling_limit(0),
242 _node_bundling_base(NULL),
243 _orig_pc_slot(0),
244 _orig_pc_slot_offset_in_bytes(0),
245 _buf_sizes(),
246 _block(NULL),
247 _index(0) {
248 C->set_output(this);
249 if (C->stub_name() == NULL) {
250 _orig_pc_slot = C->fixed_slots() - (sizeof(address) / VMRegImpl::stack_slot_size);
251 }
252 }
253
254 PhaseOutput::~PhaseOutput() {
255 C->set_output(NULL);
256 if (_scratch_buffer_blob != NULL) {
257 BufferBlob::free(_scratch_buffer_blob);
258 }
259 }
260
261 void PhaseOutput::perform_mach_node_analysis() {
262 // Late barrier analysis must be done after schedule and bundle
263 // Otherwise liveness based spilling will fail
264 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
265 bs->late_barrier_analysis();
266
267 pd_perform_mach_node_analysis();
268 }
269
270 // Convert Nodes to instruction bits and pass off to the VM
271 void PhaseOutput::Output() {
272 // RootNode goes
273 assert( C->cfg()->get_root_block()->number_of_nodes() == 0, "" );
274
275 // The number of new nodes (mostly MachNop) is proportional to
276 // the number of java calls and inner loops which are aligned.
277 if ( C->check_node_count((NodeLimitFudgeFactor + C->java_calls()*3 +
278 C->inner_loops()*(OptoLoopAlignment-1)),
279 "out of nodes before code generation" ) ) {
280 return;
281 }
282 // Make sure I can find the Start Node
283 Block *entry = C->cfg()->get_block(1);
284 Block *broot = C->cfg()->get_root_block();
285
286 const StartNode *start = entry->head()->as_Start();
287
288 // Replace StartNode with prolog
289 MachPrologNode *prolog = new MachPrologNode();
290 entry->map_node(prolog, 0);
291 C->cfg()->map_node_to_block(prolog, entry);
292 C->cfg()->unmap_node_from_block(start); // start is no longer in any block
293
294 // Virtual methods need an unverified entry point
295
296 if( C->is_osr_compilation() ) {
297 if( PoisonOSREntry ) {
298 // TODO: Should use a ShouldNotReachHereNode...
299 C->cfg()->insert( broot, 0, new MachBreakpointNode() );
300 }
301 } else {
302 if( C->method() && !C->method()->flags().is_static() ) {
303 // Insert unvalidated entry point
304 C->cfg()->insert( broot, 0, new MachUEPNode() );
305 }
306
307 }
308
309 // Break before main entry point
310 if ((C->method() && C->directive()->BreakAtExecuteOption) ||
311 (OptoBreakpoint && C->is_method_compilation()) ||
312 (OptoBreakpointOSR && C->is_osr_compilation()) ||
313 (OptoBreakpointC2R && !C->method()) ) {
314 // checking for C->method() means that OptoBreakpoint does not apply to
315 // runtime stubs or frame converters
316 C->cfg()->insert( entry, 1, new MachBreakpointNode() );
317 }
318
319 // Insert epilogs before every return
320 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
321 Block* block = C->cfg()->get_block(i);
322 if (!block->is_connector() && block->non_connector_successor(0) == C->cfg()->get_root_block()) { // Found a program exit point?
323 Node* m = block->end();
324 if (m->is_Mach() && m->as_Mach()->ideal_Opcode() != Op_Halt) {
325 MachEpilogNode* epilog = new MachEpilogNode(m->as_Mach()->ideal_Opcode() == Op_Return);
326 block->add_inst(epilog);
327 C->cfg()->map_node_to_block(epilog, block);
328 }
329 }
330 }
331
332 // Keeper of sizing aspects
333 _buf_sizes = BufferSizingData();
334
335 // Initialize code buffer
336 estimate_buffer_size(_buf_sizes._const);
337 if (C->failing()) return;
338
339 // Pre-compute the length of blocks and replace
340 // long branches with short if machine supports it.
341 // Must be done before ScheduleAndBundle due to SPARC delay slots
342 uint* blk_starts = NEW_RESOURCE_ARRAY(uint, C->cfg()->number_of_blocks() + 1);
343 blk_starts[0] = 0;
344 shorten_branches(blk_starts);
345
346 ScheduleAndBundle();
347 if (C->failing()) {
348 return;
349 }
350
351 perform_mach_node_analysis();
352
353 // Complete sizing of codebuffer
354 CodeBuffer* cb = init_buffer();
355 if (cb == NULL || C->failing()) {
356 return;
357 }
358
359 BuildOopMaps();
360
361 if (C->failing()) {
362 return;
363 }
364
365 fill_buffer(cb, blk_starts);
366 }
367
368 bool PhaseOutput::need_stack_bang(int frame_size_in_bytes) const {
369 // Determine if we need to generate a stack overflow check.
370 // Do it if the method is not a stub function and
371 // has java calls or has frame size > vm_page_size/8.
372 // The debug VM checks that deoptimization doesn't trigger an
373 // unexpected stack overflow (compiled method stack banging should
374 // guarantee it doesn't happen) so we always need the stack bang in
375 // a debug VM.
376 return (UseStackBanging && C->stub_function() == NULL &&
377 (C->has_java_calls() || frame_size_in_bytes > os::vm_page_size()>>3
378 DEBUG_ONLY(|| true)));
379 }
380
381 bool PhaseOutput::need_register_stack_bang() const {
382 // Determine if we need to generate a register stack overflow check.
383 // This is only used on architectures which have split register
384 // and memory stacks (ie. IA64).
385 // Bang if the method is not a stub function and has java calls
386 return (C->stub_function() == NULL && C->has_java_calls());
387 }
388
389
390 // Compute the size of first NumberOfLoopInstrToAlign instructions at the top
391 // of a loop. When aligning a loop we need to provide enough instructions
392 // in cpu's fetch buffer to feed decoders. The loop alignment could be
393 // avoided if we have enough instructions in fetch buffer at the head of a loop.
394 // By default, the size is set to 999999 by Block's constructor so that
395 // a loop will be aligned if the size is not reset here.
396 //
397 // Note: Mach instructions could contain several HW instructions
398 // so the size is estimated only.
399 //
400 void PhaseOutput::compute_loop_first_inst_sizes() {
401 // The next condition is used to gate the loop alignment optimization.
402 // Don't aligned a loop if there are enough instructions at the head of a loop
403 // or alignment padding is larger then MaxLoopPad. By default, MaxLoopPad
404 // is equal to OptoLoopAlignment-1 except on new Intel cpus, where it is
405 // equal to 11 bytes which is the largest address NOP instruction.
406 if (MaxLoopPad < OptoLoopAlignment - 1) {
407 uint last_block = C->cfg()->number_of_blocks() - 1;
408 for (uint i = 1; i <= last_block; i++) {
409 Block* block = C->cfg()->get_block(i);
410 // Check the first loop's block which requires an alignment.
411 if (block->loop_alignment() > (uint)relocInfo::addr_unit()) {
412 uint sum_size = 0;
413 uint inst_cnt = NumberOfLoopInstrToAlign;
414 inst_cnt = block->compute_first_inst_size(sum_size, inst_cnt, C->regalloc());
415
416 // Check subsequent fallthrough blocks if the loop's first
417 // block(s) does not have enough instructions.
418 Block *nb = block;
419 while(inst_cnt > 0 &&
420 i < last_block &&
421 !C->cfg()->get_block(i + 1)->has_loop_alignment() &&
422 !nb->has_successor(block)) {
423 i++;
424 nb = C->cfg()->get_block(i);
425 inst_cnt = nb->compute_first_inst_size(sum_size, inst_cnt, C->regalloc());
426 } // while( inst_cnt > 0 && i < last_block )
427
428 block->set_first_inst_size(sum_size);
429 } // f( b->head()->is_Loop() )
430 } // for( i <= last_block )
431 } // if( MaxLoopPad < OptoLoopAlignment-1 )
432 }
433
434 // The architecture description provides short branch variants for some long
435 // branch instructions. Replace eligible long branches with short branches.
436 void PhaseOutput::shorten_branches(uint* blk_starts) {
437 // Compute size of each block, method size, and relocation information size
438 uint nblocks = C->cfg()->number_of_blocks();
439
440 uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
441 uint* jmp_size = NEW_RESOURCE_ARRAY(uint,nblocks);
442 int* jmp_nidx = NEW_RESOURCE_ARRAY(int ,nblocks);
443
444 // Collect worst case block paddings
445 int* block_worst_case_pad = NEW_RESOURCE_ARRAY(int, nblocks);
446 memset(block_worst_case_pad, 0, nblocks * sizeof(int));
447
448 DEBUG_ONLY( uint *jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks); )
449 DEBUG_ONLY( uint *jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks); )
450
451 bool has_short_branch_candidate = false;
452
453 // Initialize the sizes to 0
454 int code_size = 0; // Size in bytes of generated code
455 int stub_size = 0; // Size in bytes of all stub entries
456 // Size in bytes of all relocation entries, including those in local stubs.
457 // Start with 2-bytes of reloc info for the unvalidated entry point
458 int reloc_size = 1; // Number of relocation entries
459
460 // Make three passes. The first computes pessimistic blk_starts,
461 // relative jmp_offset and reloc_size information. The second performs
462 // short branch substitution using the pessimistic sizing. The
463 // third inserts nops where needed.
464
465 // Step one, perform a pessimistic sizing pass.
466 uint last_call_adr = max_juint;
467 uint last_avoid_back_to_back_adr = max_juint;
468 uint nop_size = (new MachNopNode())->size(C->regalloc());
469 for (uint i = 0; i < nblocks; i++) { // For all blocks
470 Block* block = C->cfg()->get_block(i);
471 _block = block;
472
473 // During short branch replacement, we store the relative (to blk_starts)
474 // offset of jump in jmp_offset, rather than the absolute offset of jump.
475 // This is so that we do not need to recompute sizes of all nodes when
476 // we compute correct blk_starts in our next sizing pass.
477 jmp_offset[i] = 0;
478 jmp_size[i] = 0;
479 jmp_nidx[i] = -1;
480 DEBUG_ONLY( jmp_target[i] = 0; )
481 DEBUG_ONLY( jmp_rule[i] = 0; )
482
483 // Sum all instruction sizes to compute block size
484 uint last_inst = block->number_of_nodes();
485 uint blk_size = 0;
486 for (uint j = 0; j < last_inst; j++) {
487 _index = j;
488 Node* nj = block->get_node(_index);
489 // Handle machine instruction nodes
490 if (nj->is_Mach()) {
491 MachNode* mach = nj->as_Mach();
492 blk_size += (mach->alignment_required() - 1) * relocInfo::addr_unit(); // assume worst case padding
493 reloc_size += mach->reloc();
494 if (mach->is_MachCall()) {
495 // add size information for trampoline stub
496 // class CallStubImpl is platform-specific and defined in the *.ad files.
497 stub_size += CallStubImpl::size_call_trampoline();
498 reloc_size += CallStubImpl::reloc_call_trampoline();
499
500 MachCallNode *mcall = mach->as_MachCall();
501 // This destination address is NOT PC-relative
502
503 mcall->method_set((intptr_t)mcall->entry_point());
504
505 if (mcall->is_MachCallJava() && mcall->as_MachCallJava()->_method) {
506 stub_size += CompiledStaticCall::to_interp_stub_size();
507 reloc_size += CompiledStaticCall::reloc_to_interp_stub();
508 #if INCLUDE_AOT
509 stub_size += CompiledStaticCall::to_aot_stub_size();
510 reloc_size += CompiledStaticCall::reloc_to_aot_stub();
511 #endif
512 }
513 } else if (mach->is_MachSafePoint()) {
514 // If call/safepoint are adjacent, account for possible
515 // nop to disambiguate the two safepoints.
516 // ScheduleAndBundle() can rearrange nodes in a block,
517 // check for all offsets inside this block.
518 if (last_call_adr >= blk_starts[i]) {
519 blk_size += nop_size;
520 }
521 }
522 if (mach->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
523 // Nop is inserted between "avoid back to back" instructions.
524 // ScheduleAndBundle() can rearrange nodes in a block,
525 // check for all offsets inside this block.
526 if (last_avoid_back_to_back_adr >= blk_starts[i]) {
527 blk_size += nop_size;
528 }
529 }
530 if (mach->may_be_short_branch()) {
531 if (!nj->is_MachBranch()) {
532 #ifndef PRODUCT
533 nj->dump(3);
534 #endif
535 Unimplemented();
536 }
537 assert(jmp_nidx[i] == -1, "block should have only one branch");
538 jmp_offset[i] = blk_size;
539 jmp_size[i] = nj->size(C->regalloc());
540 jmp_nidx[i] = j;
541 has_short_branch_candidate = true;
542 }
543 }
544 blk_size += nj->size(C->regalloc());
545 // Remember end of call offset
546 if (nj->is_MachCall() && !nj->is_MachCallLeaf()) {
547 last_call_adr = blk_starts[i]+blk_size;
548 }
549 // Remember end of avoid_back_to_back offset
550 if (nj->is_Mach() && nj->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
551 last_avoid_back_to_back_adr = blk_starts[i]+blk_size;
552 }
553 }
554
555 // When the next block starts a loop, we may insert pad NOP
556 // instructions. Since we cannot know our future alignment,
557 // assume the worst.
558 if (i < nblocks - 1) {
559 Block* nb = C->cfg()->get_block(i + 1);
560 int max_loop_pad = nb->code_alignment()-relocInfo::addr_unit();
561 if (max_loop_pad > 0) {
562 assert(is_power_of_2(max_loop_pad+relocInfo::addr_unit()), "");
563 // Adjust last_call_adr and/or last_avoid_back_to_back_adr.
564 // If either is the last instruction in this block, bump by
565 // max_loop_pad in lock-step with blk_size, so sizing
566 // calculations in subsequent blocks still can conservatively
567 // detect that it may the last instruction in this block.
568 if (last_call_adr == blk_starts[i]+blk_size) {
569 last_call_adr += max_loop_pad;
570 }
571 if (last_avoid_back_to_back_adr == blk_starts[i]+blk_size) {
572 last_avoid_back_to_back_adr += max_loop_pad;
573 }
574 blk_size += max_loop_pad;
575 block_worst_case_pad[i + 1] = max_loop_pad;
576 }
577 }
578
579 // Save block size; update total method size
580 blk_starts[i+1] = blk_starts[i]+blk_size;
581 }
582
583 // Step two, replace eligible long jumps.
584 bool progress = true;
585 uint last_may_be_short_branch_adr = max_juint;
586 while (has_short_branch_candidate && progress) {
587 progress = false;
588 has_short_branch_candidate = false;
589 int adjust_block_start = 0;
590 for (uint i = 0; i < nblocks; i++) {
591 Block* block = C->cfg()->get_block(i);
592 int idx = jmp_nidx[i];
593 MachNode* mach = (idx == -1) ? NULL: block->get_node(idx)->as_Mach();
594 if (mach != NULL && mach->may_be_short_branch()) {
595 #ifdef ASSERT
596 assert(jmp_size[i] > 0 && mach->is_MachBranch(), "sanity");
597 int j;
598 // Find the branch; ignore trailing NOPs.
599 for (j = block->number_of_nodes()-1; j>=0; j--) {
600 Node* n = block->get_node(j);
601 if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con)
602 break;
603 }
604 assert(j >= 0 && j == idx && block->get_node(j) == (Node*)mach, "sanity");
605 #endif
606 int br_size = jmp_size[i];
607 int br_offs = blk_starts[i] + jmp_offset[i];
608
609 // This requires the TRUE branch target be in succs[0]
610 uint bnum = block->non_connector_successor(0)->_pre_order;
611 int offset = blk_starts[bnum] - br_offs;
612 if (bnum > i) { // adjust following block's offset
613 offset -= adjust_block_start;
614 }
615
616 // This block can be a loop header, account for the padding
617 // in the previous block.
618 int block_padding = block_worst_case_pad[i];
619 assert(i == 0 || block_padding == 0 || br_offs >= block_padding, "Should have at least a padding on top");
620 // In the following code a nop could be inserted before
621 // the branch which will increase the backward distance.
622 bool needs_padding = ((uint)(br_offs - block_padding) == last_may_be_short_branch_adr);
623 assert(!needs_padding || jmp_offset[i] == 0, "padding only branches at the beginning of block");
624
625 if (needs_padding && offset <= 0)
626 offset -= nop_size;
627
628 if (C->matcher()->is_short_branch_offset(mach->rule(), br_size, offset)) {
629 // We've got a winner. Replace this branch.
630 MachNode* replacement = mach->as_MachBranch()->short_branch_version();
631
632 // Update the jmp_size.
633 int new_size = replacement->size(C->regalloc());
634 int diff = br_size - new_size;
635 assert(diff >= (int)nop_size, "short_branch size should be smaller");
636 // Conservatively take into account padding between
637 // avoid_back_to_back branches. Previous branch could be
638 // converted into avoid_back_to_back branch during next
639 // rounds.
640 if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
641 jmp_offset[i] += nop_size;
642 diff -= nop_size;
643 }
644 adjust_block_start += diff;
645 block->map_node(replacement, idx);
646 mach->subsume_by(replacement, C);
647 mach = replacement;
648 progress = true;
649
650 jmp_size[i] = new_size;
651 DEBUG_ONLY( jmp_target[i] = bnum; );
652 DEBUG_ONLY( jmp_rule[i] = mach->rule(); );
653 } else {
654 // The jump distance is not short, try again during next iteration.
655 has_short_branch_candidate = true;
656 }
657 } // (mach->may_be_short_branch())
658 if (mach != NULL && (mach->may_be_short_branch() ||
659 mach->avoid_back_to_back(MachNode::AVOID_AFTER))) {
660 last_may_be_short_branch_adr = blk_starts[i] + jmp_offset[i] + jmp_size[i];
661 }
662 blk_starts[i+1] -= adjust_block_start;
663 }
664 }
665
666 #ifdef ASSERT
667 for (uint i = 0; i < nblocks; i++) { // For all blocks
668 if (jmp_target[i] != 0) {
669 int br_size = jmp_size[i];
670 int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
671 if (!C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
672 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]);
673 }
674 assert(C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset), "Displacement too large for short jmp");
675 }
676 }
677 #endif
678
679 // Step 3, compute the offsets of all blocks, will be done in fill_buffer()
680 // after ScheduleAndBundle().
681
682 // ------------------
683 // Compute size for code buffer
684 code_size = blk_starts[nblocks];
685
686 // Relocation records
687 reloc_size += 1; // Relo entry for exception handler
688
689 // Adjust reloc_size to number of record of relocation info
690 // Min is 2 bytes, max is probably 6 or 8, with a tax up to 25% for
691 // a relocation index.
692 // The CodeBuffer will expand the locs array if this estimate is too low.
693 reloc_size *= 10 / sizeof(relocInfo);
694
695 _buf_sizes._reloc = reloc_size;
696 _buf_sizes._code = code_size;
697 _buf_sizes._stub = stub_size;
698 }
699
700 //------------------------------FillLocArray-----------------------------------
701 // Create a bit of debug info and append it to the array. The mapping is from
702 // Java local or expression stack to constant, register or stack-slot. For
703 // doubles, insert 2 mappings and return 1 (to tell the caller that the next
704 // entry has been taken care of and caller should skip it).
705 static LocationValue *new_loc_value( PhaseRegAlloc *ra, OptoReg::Name regnum, Location::Type l_type ) {
706 // This should never have accepted Bad before
707 assert(OptoReg::is_valid(regnum), "location must be valid");
708 return (OptoReg::is_reg(regnum))
709 ? new LocationValue(Location::new_reg_loc(l_type, OptoReg::as_VMReg(regnum)) )
710 : new LocationValue(Location::new_stk_loc(l_type, ra->reg2offset(regnum)));
711 }
712
713
714 ObjectValue*
715 PhaseOutput::sv_for_node_id(GrowableArray<ScopeValue*> *objs, int id) {
716 for (int i = 0; i < objs->length(); i++) {
717 assert(objs->at(i)->is_object(), "corrupt object cache");
718 ObjectValue* sv = (ObjectValue*) objs->at(i);
719 if (sv->id() == id) {
720 return sv;
721 }
722 }
723 // Otherwise..
724 return NULL;
725 }
726
727 void PhaseOutput::set_sv_for_object_node(GrowableArray<ScopeValue*> *objs,
728 ObjectValue* sv ) {
729 assert(sv_for_node_id(objs, sv->id()) == NULL, "Precondition");
730 objs->append(sv);
731 }
732
733
734 void PhaseOutput::FillLocArray( int idx, MachSafePointNode* sfpt, Node *local,
735 GrowableArray<ScopeValue*> *array,
736 GrowableArray<ScopeValue*> *objs ) {
737 assert( local, "use _top instead of null" );
738 if (array->length() != idx) {
739 assert(array->length() == idx + 1, "Unexpected array count");
740 // Old functionality:
741 // return
742 // New functionality:
743 // Assert if the local is not top. In product mode let the new node
744 // override the old entry.
745 assert(local == C->top(), "LocArray collision");
746 if (local == C->top()) {
747 return;
748 }
749 array->pop();
750 }
751 const Type *t = local->bottom_type();
752
753 // Is it a safepoint scalar object node?
754 if (local->is_SafePointScalarObject()) {
755 SafePointScalarObjectNode* spobj = local->as_SafePointScalarObject();
756
757 ObjectValue* sv = sv_for_node_id(objs, spobj->_idx);
758 if (sv == NULL) {
759 ciKlass* cik = t->is_oopptr()->klass();
760 assert(cik->is_instance_klass() ||
761 cik->is_array_klass(), "Not supported allocation.");
762 sv = new ObjectValue(spobj->_idx,
763 new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
764 set_sv_for_object_node(objs, sv);
765
766 uint first_ind = spobj->first_index(sfpt->jvms());
767 for (uint i = 0; i < spobj->n_fields(); i++) {
768 Node* fld_node = sfpt->in(first_ind+i);
769 (void)FillLocArray(sv->field_values()->length(), sfpt, fld_node, sv->field_values(), objs);
770 }
771 }
772 array->append(sv);
773 return;
774 }
775
776 // Grab the register number for the local
777 OptoReg::Name regnum = C->regalloc()->get_reg_first(local);
778 if( OptoReg::is_valid(regnum) ) {// Got a register/stack?
779 // Record the double as two float registers.
780 // The register mask for such a value always specifies two adjacent
781 // float registers, with the lower register number even.
782 // Normally, the allocation of high and low words to these registers
783 // is irrelevant, because nearly all operations on register pairs
784 // (e.g., StoreD) treat them as a single unit.
785 // Here, we assume in addition that the words in these two registers
786 // stored "naturally" (by operations like StoreD and double stores
787 // within the interpreter) such that the lower-numbered register
788 // is written to the lower memory address. This may seem like
789 // a machine dependency, but it is not--it is a requirement on
790 // the author of the <arch>.ad file to ensure that, for every
791 // even/odd double-register pair to which a double may be allocated,
792 // the word in the even single-register is stored to the first
793 // memory word. (Note that register numbers are completely
794 // arbitrary, and are not tied to any machine-level encodings.)
795 #ifdef _LP64
796 if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon ) {
797 array->append(new ConstantIntValue((jint)0));
798 array->append(new_loc_value( C->regalloc(), regnum, Location::dbl ));
799 } else if ( t->base() == Type::Long ) {
800 array->append(new ConstantIntValue((jint)0));
801 array->append(new_loc_value( C->regalloc(), regnum, Location::lng ));
802 } else if ( t->base() == Type::RawPtr ) {
803 // jsr/ret return address which must be restored into a the full
804 // width 64-bit stack slot.
805 array->append(new_loc_value( C->regalloc(), regnum, Location::lng ));
806 }
807 #else //_LP64
808 if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon || t->base() == Type::Long ) {
809 // Repack the double/long as two jints.
810 // The convention the interpreter uses is that the second local
811 // holds the first raw word of the native double representation.
812 // This is actually reasonable, since locals and stack arrays
813 // grow downwards in all implementations.
814 // (If, on some machine, the interpreter's Java locals or stack
815 // were to grow upwards, the embedded doubles would be word-swapped.)
816 array->append(new_loc_value( C->regalloc(), OptoReg::add(regnum,1), Location::normal ));
817 array->append(new_loc_value( C->regalloc(), regnum , Location::normal ));
818 }
819 #endif //_LP64
820 else if( (t->base() == Type::FloatBot || t->base() == Type::FloatCon) &&
821 OptoReg::is_reg(regnum) ) {
822 array->append(new_loc_value( C->regalloc(), regnum, Matcher::float_in_double()
823 ? Location::float_in_dbl : Location::normal ));
824 } else if( t->base() == Type::Int && OptoReg::is_reg(regnum) ) {
825 array->append(new_loc_value( C->regalloc(), regnum, Matcher::int_in_long
826 ? Location::int_in_long : Location::normal ));
827 } else if( t->base() == Type::NarrowOop ) {
828 array->append(new_loc_value( C->regalloc(), regnum, Location::narrowoop ));
829 } else {
830 array->append(new_loc_value( C->regalloc(), regnum, C->regalloc()->is_oop(local) ? Location::oop : Location::normal ));
831 }
832 return;
833 }
834
835 // No register. It must be constant data.
836 switch (t->base()) {
837 case Type::Half: // Second half of a double
838 ShouldNotReachHere(); // Caller should skip 2nd halves
839 break;
840 case Type::AnyPtr:
841 array->append(new ConstantOopWriteValue(NULL));
842 break;
843 case Type::AryPtr:
844 case Type::InstPtr: // fall through
845 array->append(new ConstantOopWriteValue(t->isa_oopptr()->const_oop()->constant_encoding()));
846 break;
847 case Type::NarrowOop:
848 if (t == TypeNarrowOop::NULL_PTR) {
849 array->append(new ConstantOopWriteValue(NULL));
850 } else {
851 array->append(new ConstantOopWriteValue(t->make_ptr()->isa_oopptr()->const_oop()->constant_encoding()));
852 }
853 break;
854 case Type::Int:
855 array->append(new ConstantIntValue(t->is_int()->get_con()));
856 break;
857 case Type::RawPtr:
858 // A return address (T_ADDRESS).
859 assert((intptr_t)t->is_ptr()->get_con() < (intptr_t)0x10000, "must be a valid BCI");
860 #ifdef _LP64
861 // Must be restored to the full-width 64-bit stack slot.
862 array->append(new ConstantLongValue(t->is_ptr()->get_con()));
863 #else
864 array->append(new ConstantIntValue(t->is_ptr()->get_con()));
865 #endif
866 break;
867 case Type::FloatCon: {
868 float f = t->is_float_constant()->getf();
869 array->append(new ConstantIntValue(jint_cast(f)));
870 break;
871 }
872 case Type::DoubleCon: {
873 jdouble d = t->is_double_constant()->getd();
874 #ifdef _LP64
875 array->append(new ConstantIntValue((jint)0));
876 array->append(new ConstantDoubleValue(d));
877 #else
878 // Repack the double as two jints.
879 // The convention the interpreter uses is that the second local
880 // holds the first raw word of the native double representation.
881 // This is actually reasonable, since locals and stack arrays
882 // grow downwards in all implementations.
883 // (If, on some machine, the interpreter's Java locals or stack
884 // were to grow upwards, the embedded doubles would be word-swapped.)
885 jlong_accessor acc;
886 acc.long_value = jlong_cast(d);
887 array->append(new ConstantIntValue(acc.words[1]));
888 array->append(new ConstantIntValue(acc.words[0]));
889 #endif
890 break;
891 }
892 case Type::Long: {
893 jlong d = t->is_long()->get_con();
894 #ifdef _LP64
895 array->append(new ConstantIntValue((jint)0));
896 array->append(new ConstantLongValue(d));
897 #else
898 // Repack the 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 jlong_accessor acc;
906 acc.long_value = d;
907 array->append(new ConstantIntValue(acc.words[1]));
908 array->append(new ConstantIntValue(acc.words[0]));
909 #endif
910 break;
911 }
912 case Type::Top: // Add an illegal value here
913 array->append(new LocationValue(Location()));
914 break;
915 default:
916 ShouldNotReachHere();
917 break;
918 }
919 }
920
921 // Determine if this node starts a bundle
922 bool PhaseOutput::starts_bundle(const Node *n) const {
923 return (_node_bundling_limit > n->_idx &&
924 _node_bundling_base[n->_idx].starts_bundle());
925 }
926
927 //--------------------------Process_OopMap_Node--------------------------------
928 void PhaseOutput::Process_OopMap_Node(MachNode *mach, int current_offset) {
929 // Handle special safepoint nodes for synchronization
930 MachSafePointNode *sfn = mach->as_MachSafePoint();
931 MachCallNode *mcall;
932
933 int safepoint_pc_offset = current_offset;
934 bool is_method_handle_invoke = false;
935 bool return_oop = false;
936 bool not_global_escape_in_scope = sfn->_not_global_escape_in_scope;
937 bool arg_escape = false;
938
939 // Add the safepoint in the DebugInfoRecorder
940 if( !mach->is_MachCall() ) {
941 mcall = NULL;
942 C->debug_info()->add_safepoint(safepoint_pc_offset, sfn->_oop_map);
943 } else {
944 mcall = mach->as_MachCall();
945
946 // Is the call a MethodHandle call?
947 if (mcall->is_MachCallJava()) {
948 if (mcall->as_MachCallJava()->_method_handle_invoke) {
949 assert(C->has_method_handle_invokes(), "must have been set during call generation");
950 is_method_handle_invoke = true;
951 }
952 arg_escape = mcall->as_MachCallJava()->_arg_escape;
953 }
954
955 // Check if a call returns an object.
956 if (mcall->returns_pointer()) {
957 return_oop = true;
958 }
959 safepoint_pc_offset += mcall->ret_addr_offset();
960 C->debug_info()->add_safepoint(safepoint_pc_offset, mcall->_oop_map);
961 }
962
963 // Loop over the JVMState list to add scope information
964 // Do not skip safepoints with a NULL method, they need monitor info
965 JVMState* youngest_jvms = sfn->jvms();
966 int max_depth = youngest_jvms->depth();
967
968 // Allocate the object pool for scalar-replaced objects -- the map from
969 // small-integer keys (which can be recorded in the local and ostack
970 // arrays) to descriptions of the object state.
971 GrowableArray<ScopeValue*> *objs = new GrowableArray<ScopeValue*>();
972
973 // Visit scopes from oldest to youngest.
974 for (int depth = 1; depth <= max_depth; depth++) {
975 JVMState* jvms = youngest_jvms->of_depth(depth);
976 int idx;
977 ciMethod* method = jvms->has_method() ? jvms->method() : NULL;
978 // Safepoints that do not have method() set only provide oop-map and monitor info
979 // to support GC; these do not support deoptimization.
980 int num_locs = (method == NULL) ? 0 : jvms->loc_size();
981 int num_exps = (method == NULL) ? 0 : jvms->stk_size();
982 int num_mon = jvms->nof_monitors();
983 assert(method == NULL || jvms->bci() < 0 || num_locs == method->max_locals(),
984 "JVMS local count must match that of the method");
985
986 // Add Local and Expression Stack Information
987
988 // Insert locals into the locarray
989 GrowableArray<ScopeValue*> *locarray = new GrowableArray<ScopeValue*>(num_locs);
990 for( idx = 0; idx < num_locs; idx++ ) {
991 FillLocArray( idx, sfn, sfn->local(jvms, idx), locarray, objs );
992 }
993
994 // Insert expression stack entries into the exparray
995 GrowableArray<ScopeValue*> *exparray = new GrowableArray<ScopeValue*>(num_exps);
996 for( idx = 0; idx < num_exps; idx++ ) {
997 FillLocArray( idx, sfn, sfn->stack(jvms, idx), exparray, objs );
998 }
999
1000 // Add in mappings of the monitors
1001 assert( !method ||
1002 !method->is_synchronized() ||
1003 method->is_native() ||
1004 num_mon > 0 ||
1005 !GenerateSynchronizationCode,
1006 "monitors must always exist for synchronized methods");
1007
1008 // Build the growable array of ScopeValues for exp stack
1009 GrowableArray<MonitorValue*> *monarray = new GrowableArray<MonitorValue*>(num_mon);
1010
1011 // Loop over monitors and insert into array
1012 for (idx = 0; idx < num_mon; idx++) {
1013 // Grab the node that defines this monitor
1014 Node* box_node = sfn->monitor_box(jvms, idx);
1015 Node* obj_node = sfn->monitor_obj(jvms, idx);
1016
1017 // Create ScopeValue for object
1018 ScopeValue *scval = NULL;
1019
1020 if (obj_node->is_SafePointScalarObject()) {
1021 SafePointScalarObjectNode* spobj = obj_node->as_SafePointScalarObject();
1022 scval = PhaseOutput::sv_for_node_id(objs, spobj->_idx);
1023 if (scval == NULL) {
1024 const Type *t = spobj->bottom_type();
1025 ciKlass* cik = t->is_oopptr()->klass();
1026 assert(cik->is_instance_klass() ||
1027 cik->is_array_klass(), "Not supported allocation.");
1028 ObjectValue* sv = new ObjectValue(spobj->_idx,
1029 new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
1030 PhaseOutput::set_sv_for_object_node(objs, sv);
1031
1032 uint first_ind = spobj->first_index(youngest_jvms);
1033 for (uint i = 0; i < spobj->n_fields(); i++) {
1034 Node* fld_node = sfn->in(first_ind+i);
1035 (void)FillLocArray(sv->field_values()->length(), sfn, fld_node, sv->field_values(), objs);
1036 }
1037 scval = sv;
1038 }
1039 } else if (!obj_node->is_Con()) {
1040 OptoReg::Name obj_reg = C->regalloc()->get_reg_first(obj_node);
1041 if( obj_node->bottom_type()->base() == Type::NarrowOop ) {
1042 scval = new_loc_value( C->regalloc(), obj_reg, Location::narrowoop );
1043 } else {
1044 scval = new_loc_value( C->regalloc(), obj_reg, Location::oop );
1045 }
1046 } else {
1047 const TypePtr *tp = obj_node->get_ptr_type();
1048 scval = new ConstantOopWriteValue(tp->is_oopptr()->const_oop()->constant_encoding());
1049 }
1050
1051 OptoReg::Name box_reg = BoxLockNode::reg(box_node);
1052 Location basic_lock = Location::new_stk_loc(Location::normal,C->regalloc()->reg2offset(box_reg));
1053 bool eliminated = (box_node->is_BoxLock() && box_node->as_BoxLock()->is_eliminated());
1054 monarray->append(new MonitorValue(scval, basic_lock, eliminated));
1055 }
1056
1057 // We dump the object pool first, since deoptimization reads it in first.
1058 C->debug_info()->dump_object_pool(objs);
1059
1060 // Build first class objects to pass to scope
1061 DebugToken *locvals = C->debug_info()->create_scope_values(locarray);
1062 DebugToken *expvals = C->debug_info()->create_scope_values(exparray);
1063 DebugToken *monvals = C->debug_info()->create_monitor_values(monarray);
1064
1065 // Make method available for all Safepoints
1066 ciMethod* scope_method = method ? method : C->method();
1067 // Describe the scope here
1068 assert(jvms->bci() >= InvocationEntryBci && jvms->bci() <= 0x10000, "must be a valid or entry BCI");
1069 assert(!jvms->should_reexecute() || depth == max_depth, "reexecute allowed only for the youngest");
1070 // Now we can describe the scope.
1071 methodHandle null_mh;
1072 bool rethrow_exception = false;
1073 C->debug_info()->describe_scope(safepoint_pc_offset, null_mh, scope_method, jvms->bci(), jvms->should_reexecute(), rethrow_exception, is_method_handle_invoke, return_oop,
1074 not_global_escape_in_scope, arg_escape,
1075 locvals, expvals, monvals);
1076 } // End jvms loop
1077
1078 // Mark the end of the scope set.
1079 C->debug_info()->end_safepoint(safepoint_pc_offset);
1080 }
1081
1082
1083
1084 // A simplified version of Process_OopMap_Node, to handle non-safepoints.
1085 class NonSafepointEmitter {
1086 Compile* C;
1087 JVMState* _pending_jvms;
1088 int _pending_offset;
1089
1090 void emit_non_safepoint();
1091
1092 public:
1093 NonSafepointEmitter(Compile* compile) {
1094 this->C = compile;
1095 _pending_jvms = NULL;
1096 _pending_offset = 0;
1097 }
1098
1099 void observe_instruction(Node* n, int pc_offset) {
1100 if (!C->debug_info()->recording_non_safepoints()) return;
1101
1102 Node_Notes* nn = C->node_notes_at(n->_idx);
1103 if (nn == NULL || nn->jvms() == NULL) return;
1104 if (_pending_jvms != NULL &&
1105 _pending_jvms->same_calls_as(nn->jvms())) {
1106 // Repeated JVMS? Stretch it up here.
1107 _pending_offset = pc_offset;
1108 } else {
1109 if (_pending_jvms != NULL &&
1110 _pending_offset < pc_offset) {
1111 emit_non_safepoint();
1112 }
1113 _pending_jvms = NULL;
1114 if (pc_offset > C->debug_info()->last_pc_offset()) {
1115 // This is the only way _pending_jvms can become non-NULL:
1116 _pending_jvms = nn->jvms();
1117 _pending_offset = pc_offset;
1118 }
1119 }
1120 }
1121
1122 // Stay out of the way of real safepoints:
1123 void observe_safepoint(JVMState* jvms, int pc_offset) {
1124 if (_pending_jvms != NULL &&
1125 !_pending_jvms->same_calls_as(jvms) &&
1126 _pending_offset < pc_offset) {
1127 emit_non_safepoint();
1128 }
1129 _pending_jvms = NULL;
1130 }
1131
1132 void flush_at_end() {
1133 if (_pending_jvms != NULL) {
1134 emit_non_safepoint();
1135 }
1136 _pending_jvms = NULL;
1137 }
1138 };
1139
1140 void NonSafepointEmitter::emit_non_safepoint() {
1141 JVMState* youngest_jvms = _pending_jvms;
1142 int pc_offset = _pending_offset;
1143
1144 // Clear it now:
1145 _pending_jvms = NULL;
1146
1147 DebugInformationRecorder* debug_info = C->debug_info();
1148 assert(debug_info->recording_non_safepoints(), "sanity");
1149
1150 debug_info->add_non_safepoint(pc_offset);
1151 int max_depth = youngest_jvms->depth();
1152
1153 // Visit scopes from oldest to youngest.
1154 for (int depth = 1; depth <= max_depth; depth++) {
1155 JVMState* jvms = youngest_jvms->of_depth(depth);
1156 ciMethod* method = jvms->has_method() ? jvms->method() : NULL;
1157 assert(!jvms->should_reexecute() || depth==max_depth, "reexecute allowed only for the youngest");
1158 methodHandle null_mh;
1159 debug_info->describe_scope(pc_offset, null_mh, method, jvms->bci(), jvms->should_reexecute());
1160 }
1161
1162 // Mark the end of the scope set.
1163 debug_info->end_non_safepoint(pc_offset);
1164 }
1165
1166 //------------------------------init_buffer------------------------------------
1167 void PhaseOutput::estimate_buffer_size(int& const_req) {
1168
1169 // Set the initially allocated size
1170 const_req = initial_const_capacity;
1171
1172 // The extra spacing after the code is necessary on some platforms.
1173 // Sometimes we need to patch in a jump after the last instruction,
1174 // if the nmethod has been deoptimized. (See 4932387, 4894843.)
1175
1176 // Compute the byte offset where we can store the deopt pc.
1177 if (C->fixed_slots() != 0) {
1178 _orig_pc_slot_offset_in_bytes = C->regalloc()->reg2offset(OptoReg::stack2reg(_orig_pc_slot));
1179 }
1180
1181 // Compute prolog code size
1182 _method_size = 0;
1183 _frame_slots = OptoReg::reg2stack(C->matcher()->_old_SP) + C->regalloc()->_framesize;
1184 #if defined(IA64) && !defined(AIX)
1185 if (save_argument_registers()) {
1186 // 4815101: this is a stub with implicit and unknown precision fp args.
1187 // The usual spill mechanism can only generate stfd's in this case, which
1188 // doesn't work if the fp reg to spill contains a single-precision denorm.
1189 // Instead, we hack around the normal spill mechanism using stfspill's and
1190 // ldffill's in the MachProlog and MachEpilog emit methods. We allocate
1191 // space here for the fp arg regs (f8-f15) we're going to thusly spill.
1192 //
1193 // If we ever implement 16-byte 'registers' == stack slots, we can
1194 // get rid of this hack and have SpillCopy generate stfspill/ldffill
1195 // instead of stfd/stfs/ldfd/ldfs.
1196 _frame_slots += 8*(16/BytesPerInt);
1197 }
1198 #endif
1199 assert(_frame_slots >= 0 && _frame_slots < 1000000, "sanity check");
1200
1201 if (C->has_mach_constant_base_node()) {
1202 uint add_size = 0;
1203 // Fill the constant table.
1204 // Note: This must happen before shorten_branches.
1205 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
1206 Block* b = C->cfg()->get_block(i);
1207
1208 for (uint j = 0; j < b->number_of_nodes(); j++) {
1209 Node* n = b->get_node(j);
1210
1211 // If the node is a MachConstantNode evaluate the constant
1212 // value section.
1213 if (n->is_MachConstant()) {
1214 MachConstantNode* machcon = n->as_MachConstant();
1215 machcon->eval_constant(C);
1216 } else if (n->is_Mach()) {
1217 // On Power there are more nodes that issue constants.
1218 add_size += (n->as_Mach()->ins_num_consts() * 8);
1219 }
1220 }
1221 }
1222
1223 // Calculate the offsets of the constants and the size of the
1224 // constant table (including the padding to the next section).
1225 constant_table().calculate_offsets_and_size();
1226 const_req = constant_table().size() + add_size;
1227 }
1228
1229 // Initialize the space for the BufferBlob used to find and verify
1230 // instruction size in MachNode::emit_size()
1231 init_scratch_buffer_blob(const_req);
1232 }
1233
1234 CodeBuffer* PhaseOutput::init_buffer() {
1235 int stub_req = _buf_sizes._stub;
1236 int code_req = _buf_sizes._code;
1237 int const_req = _buf_sizes._const;
1238
1239 int pad_req = NativeCall::instruction_size;
1240
1241 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1242 stub_req += bs->estimate_stub_size();
1243
1244 // nmethod and CodeBuffer count stubs & constants as part of method's code.
1245 // class HandlerImpl is platform-specific and defined in the *.ad files.
1246 int exception_handler_req = HandlerImpl::size_exception_handler() + MAX_stubs_size; // add marginal slop for handler
1247 int deopt_handler_req = HandlerImpl::size_deopt_handler() + MAX_stubs_size; // add marginal slop for handler
1248 stub_req += MAX_stubs_size; // ensure per-stub margin
1249 code_req += MAX_inst_size; // ensure per-instruction margin
1250
1251 if (StressCodeBuffers)
1252 code_req = const_req = stub_req = exception_handler_req = deopt_handler_req = 0x10; // force expansion
1253
1254 int total_req =
1255 const_req +
1256 code_req +
1257 pad_req +
1258 stub_req +
1259 exception_handler_req +
1260 deopt_handler_req; // deopt handler
1261
1262 if (C->has_method_handle_invokes())
1263 total_req += deopt_handler_req; // deopt MH handler
1264
1265 CodeBuffer* cb = code_buffer();
1266 cb->initialize(total_req, _buf_sizes._reloc);
1267
1268 // Have we run out of code space?
1269 if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
1270 C->record_failure("CodeCache is full");
1271 return NULL;
1272 }
1273 // Configure the code buffer.
1274 cb->initialize_consts_size(const_req);
1275 cb->initialize_stubs_size(stub_req);
1276 cb->initialize_oop_recorder(C->env()->oop_recorder());
1277
1278 // fill in the nop array for bundling computations
1279 MachNode *_nop_list[Bundle::_nop_count];
1280 Bundle::initialize_nops(_nop_list);
1281
1282 return cb;
1283 }
1284
1285 //------------------------------fill_buffer------------------------------------
1286 void PhaseOutput::fill_buffer(CodeBuffer* cb, uint* blk_starts) {
1287 // blk_starts[] contains offsets calculated during short branches processing,
1288 // offsets should not be increased during following steps.
1289
1290 // Compute the size of first NumberOfLoopInstrToAlign instructions at head
1291 // of a loop. It is used to determine the padding for loop alignment.
1292 compute_loop_first_inst_sizes();
1293
1294 // Create oopmap set.
1295 _oop_map_set = new OopMapSet();
1296
1297 // !!!!! This preserves old handling of oopmaps for now
1298 C->debug_info()->set_oopmaps(_oop_map_set);
1299
1300 uint nblocks = C->cfg()->number_of_blocks();
1301 // Count and start of implicit null check instructions
1302 uint inct_cnt = 0;
1303 uint *inct_starts = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1304
1305 // Count and start of calls
1306 uint *call_returns = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1307
1308 uint return_offset = 0;
1309 int nop_size = (new MachNopNode())->size(C->regalloc());
1310
1311 int previous_offset = 0;
1312 int current_offset = 0;
1313 int last_call_offset = -1;
1314 int last_avoid_back_to_back_offset = -1;
1315 #ifdef ASSERT
1316 uint* jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks);
1317 uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
1318 uint* jmp_size = NEW_RESOURCE_ARRAY(uint,nblocks);
1319 uint* jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks);
1320 #endif
1321
1322 // Create an array of unused labels, one for each basic block, if printing is enabled
1323 #if defined(SUPPORT_OPTO_ASSEMBLY)
1324 int *node_offsets = NULL;
1325 uint node_offset_limit = C->unique();
1326
1327 if (C->print_assembly()) {
1328 node_offsets = NEW_RESOURCE_ARRAY(int, node_offset_limit);
1329 }
1330 if (node_offsets != NULL) {
1331 // We need to initialize. Unused array elements may contain garbage and mess up PrintOptoAssembly.
1332 memset(node_offsets, 0, node_offset_limit*sizeof(int));
1333 }
1334 #endif
1335
1336 NonSafepointEmitter non_safepoints(C); // emit non-safepoints lazily
1337
1338 // Emit the constant table.
1339 if (C->has_mach_constant_base_node()) {
1340 constant_table().emit(*cb);
1341 }
1342
1343 // Create an array of labels, one for each basic block
1344 Label *blk_labels = NEW_RESOURCE_ARRAY(Label, nblocks+1);
1345 for (uint i=0; i <= nblocks; i++) {
1346 blk_labels[i].init();
1347 }
1348
1349 // ------------------
1350 // Now fill in the code buffer
1351 Node *delay_slot = NULL;
1352
1353 for (uint i = 0; i < nblocks; i++) {
1354 Block* block = C->cfg()->get_block(i);
1355 _block = block;
1356 Node* head = block->head();
1357
1358 // If this block needs to start aligned (i.e, can be reached other
1359 // than by falling-thru from the previous block), then force the
1360 // start of a new bundle.
1361 if (Pipeline::requires_bundling() && starts_bundle(head)) {
1362 cb->flush_bundle(true);
1363 }
1364
1365 #ifdef ASSERT
1366 if (!block->is_connector()) {
1367 stringStream st;
1368 block->dump_head(C->cfg(), &st);
1369 MacroAssembler(cb).block_comment(st.as_string());
1370 }
1371 jmp_target[i] = 0;
1372 jmp_offset[i] = 0;
1373 jmp_size[i] = 0;
1374 jmp_rule[i] = 0;
1375 #endif
1376 int blk_offset = current_offset;
1377
1378 // Define the label at the beginning of the basic block
1379 MacroAssembler(cb).bind(blk_labels[block->_pre_order]);
1380
1381 uint last_inst = block->number_of_nodes();
1382
1383 // Emit block normally, except for last instruction.
1384 // Emit means "dump code bits into code buffer".
1385 for (uint j = 0; j<last_inst; j++) {
1386 _index = j;
1387
1388 // Get the node
1389 Node* n = block->get_node(j);
1390
1391 // See if delay slots are supported
1392 if (valid_bundle_info(n) && node_bundling(n)->used_in_unconditional_delay()) {
1393 assert(delay_slot == NULL, "no use of delay slot node");
1394 assert(n->size(C->regalloc()) == Pipeline::instr_unit_size(), "delay slot instruction wrong size");
1395
1396 delay_slot = n;
1397 continue;
1398 }
1399
1400 // If this starts a new instruction group, then flush the current one
1401 // (but allow split bundles)
1402 if (Pipeline::requires_bundling() && starts_bundle(n))
1403 cb->flush_bundle(false);
1404
1405 // Special handling for SafePoint/Call Nodes
1406 bool is_mcall = false;
1407 if (n->is_Mach()) {
1408 MachNode *mach = n->as_Mach();
1409 is_mcall = n->is_MachCall();
1410 bool is_sfn = n->is_MachSafePoint();
1411
1412 // If this requires all previous instructions be flushed, then do so
1413 if (is_sfn || is_mcall || mach->alignment_required() != 1) {
1414 cb->flush_bundle(true);
1415 current_offset = cb->insts_size();
1416 }
1417
1418 // A padding may be needed again since a previous instruction
1419 // could be moved to delay slot.
1420
1421 // align the instruction if necessary
1422 int padding = mach->compute_padding(current_offset);
1423 // Make sure safepoint node for polling is distinct from a call's
1424 // return by adding a nop if needed.
1425 if (is_sfn && !is_mcall && padding == 0 && current_offset == last_call_offset) {
1426 padding = nop_size;
1427 }
1428 if (padding == 0 && mach->avoid_back_to_back(MachNode::AVOID_BEFORE) &&
1429 current_offset == last_avoid_back_to_back_offset) {
1430 // Avoid back to back some instructions.
1431 padding = nop_size;
1432 }
1433
1434 if (padding > 0) {
1435 assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
1436 int nops_cnt = padding / nop_size;
1437 MachNode *nop = new MachNopNode(nops_cnt);
1438 block->insert_node(nop, j++);
1439 last_inst++;
1440 C->cfg()->map_node_to_block(nop, block);
1441 // Ensure enough space.
1442 cb->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1443 if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
1444 C->record_failure("CodeCache is full");
1445 return;
1446 }
1447 nop->emit(*cb, C->regalloc());
1448 cb->flush_bundle(true);
1449 current_offset = cb->insts_size();
1450 }
1451
1452 // Remember the start of the last call in a basic block
1453 if (is_mcall) {
1454 MachCallNode *mcall = mach->as_MachCall();
1455
1456 // This destination address is NOT PC-relative
1457 mcall->method_set((intptr_t)mcall->entry_point());
1458
1459 // Save the return address
1460 call_returns[block->_pre_order] = current_offset + mcall->ret_addr_offset();
1461
1462 if (mcall->is_MachCallLeaf()) {
1463 is_mcall = false;
1464 is_sfn = false;
1465 }
1466 }
1467
1468 // sfn will be valid whenever mcall is valid now because of inheritance
1469 if (is_sfn || is_mcall) {
1470
1471 // Handle special safepoint nodes for synchronization
1472 if (!is_mcall) {
1473 MachSafePointNode *sfn = mach->as_MachSafePoint();
1474 // !!!!! Stubs only need an oopmap right now, so bail out
1475 if (sfn->jvms()->method() == NULL) {
1476 // Write the oopmap directly to the code blob??!!
1477 continue;
1478 }
1479 } // End synchronization
1480
1481 non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1482 current_offset);
1483 Process_OopMap_Node(mach, current_offset);
1484 } // End if safepoint
1485
1486 // If this is a null check, then add the start of the previous instruction to the list
1487 else if( mach->is_MachNullCheck() ) {
1488 inct_starts[inct_cnt++] = previous_offset;
1489 }
1490
1491 // If this is a branch, then fill in the label with the target BB's label
1492 else if (mach->is_MachBranch()) {
1493 // This requires the TRUE branch target be in succs[0]
1494 uint block_num = block->non_connector_successor(0)->_pre_order;
1495
1496 // Try to replace long branch if delay slot is not used,
1497 // it is mostly for back branches since forward branch's
1498 // distance is not updated yet.
1499 bool delay_slot_is_used = valid_bundle_info(n) &&
1500 C->output()->node_bundling(n)->use_unconditional_delay();
1501 if (!delay_slot_is_used && mach->may_be_short_branch()) {
1502 assert(delay_slot == NULL, "not expecting delay slot node");
1503 int br_size = n->size(C->regalloc());
1504 int offset = blk_starts[block_num] - current_offset;
1505 if (block_num >= i) {
1506 // Current and following block's offset are not
1507 // finalized yet, adjust distance by the difference
1508 // between calculated and final offsets of current block.
1509 offset -= (blk_starts[i] - blk_offset);
1510 }
1511 // In the following code a nop could be inserted before
1512 // the branch which will increase the backward distance.
1513 bool needs_padding = (current_offset == last_avoid_back_to_back_offset);
1514 if (needs_padding && offset <= 0)
1515 offset -= nop_size;
1516
1517 if (C->matcher()->is_short_branch_offset(mach->rule(), br_size, offset)) {
1518 // We've got a winner. Replace this branch.
1519 MachNode* replacement = mach->as_MachBranch()->short_branch_version();
1520
1521 // Update the jmp_size.
1522 int new_size = replacement->size(C->regalloc());
1523 assert((br_size - new_size) >= (int)nop_size, "short_branch size should be smaller");
1524 // Insert padding between avoid_back_to_back branches.
1525 if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
1526 MachNode *nop = new MachNopNode();
1527 block->insert_node(nop, j++);
1528 C->cfg()->map_node_to_block(nop, block);
1529 last_inst++;
1530 nop->emit(*cb, C->regalloc());
1531 cb->flush_bundle(true);
1532 current_offset = cb->insts_size();
1533 }
1534 #ifdef ASSERT
1535 jmp_target[i] = block_num;
1536 jmp_offset[i] = current_offset - blk_offset;
1537 jmp_size[i] = new_size;
1538 jmp_rule[i] = mach->rule();
1539 #endif
1540 block->map_node(replacement, j);
1541 mach->subsume_by(replacement, C);
1542 n = replacement;
1543 mach = replacement;
1544 }
1545 }
1546 mach->as_MachBranch()->label_set( &blk_labels[block_num], block_num );
1547 } else if (mach->ideal_Opcode() == Op_Jump) {
1548 for (uint h = 0; h < block->_num_succs; h++) {
1549 Block* succs_block = block->_succs[h];
1550 for (uint j = 1; j < succs_block->num_preds(); j++) {
1551 Node* jpn = succs_block->pred(j);
1552 if (jpn->is_JumpProj() && jpn->in(0) == mach) {
1553 uint block_num = succs_block->non_connector()->_pre_order;
1554 Label *blkLabel = &blk_labels[block_num];
1555 mach->add_case_label(jpn->as_JumpProj()->proj_no(), blkLabel);
1556 }
1557 }
1558 }
1559 }
1560 #ifdef ASSERT
1561 // Check that oop-store precedes the card-mark
1562 else if (mach->ideal_Opcode() == Op_StoreCM) {
1563 uint storeCM_idx = j;
1564 int count = 0;
1565 for (uint prec = mach->req(); prec < mach->len(); prec++) {
1566 Node *oop_store = mach->in(prec); // Precedence edge
1567 if (oop_store == NULL) continue;
1568 count++;
1569 uint i4;
1570 for (i4 = 0; i4 < last_inst; ++i4) {
1571 if (block->get_node(i4) == oop_store) {
1572 break;
1573 }
1574 }
1575 // Note: This test can provide a false failure if other precedence
1576 // edges have been added to the storeCMNode.
1577 assert(i4 == last_inst || i4 < storeCM_idx, "CM card-mark executes before oop-store");
1578 }
1579 assert(count > 0, "storeCM expects at least one precedence edge");
1580 }
1581 #endif
1582 else if (!n->is_Proj()) {
1583 // Remember the beginning of the previous instruction, in case
1584 // it's followed by a flag-kill and a null-check. Happens on
1585 // Intel all the time, with add-to-memory kind of opcodes.
1586 previous_offset = current_offset;
1587 }
1588
1589 // Not an else-if!
1590 // If this is a trap based cmp then add its offset to the list.
1591 if (mach->is_TrapBasedCheckNode()) {
1592 inct_starts[inct_cnt++] = current_offset;
1593 }
1594 }
1595
1596 // Verify that there is sufficient space remaining
1597 cb->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1598 if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
1599 C->record_failure("CodeCache is full");
1600 return;
1601 }
1602
1603 // Save the offset for the listing
1604 #if defined(SUPPORT_OPTO_ASSEMBLY)
1605 if ((node_offsets != NULL) && (n->_idx < node_offset_limit)) {
1606 node_offsets[n->_idx] = cb->insts_size();
1607 }
1608 #endif
1609
1610 // "Normal" instruction case
1611 DEBUG_ONLY( uint instr_offset = cb->insts_size(); )
1612 n->emit(*cb, C->regalloc());
1613 current_offset = cb->insts_size();
1614
1615 // Above we only verified that there is enough space in the instruction section.
1616 // However, the instruction may emit stubs that cause code buffer expansion.
1617 // Bail out here if expansion failed due to a lack of code cache space.
1618 if (C->failing()) {
1619 return;
1620 }
1621
1622 #ifdef ASSERT
1623 uint n_size = n->size(C->regalloc());
1624 if (n_size < (current_offset-instr_offset)) {
1625 MachNode* mach = n->as_Mach();
1626 n->dump();
1627 mach->dump_format(C->regalloc(), tty);
1628 tty->print_cr(" n_size (%d), current_offset (%d), instr_offset (%d)", n_size, current_offset, instr_offset);
1629 Disassembler::decode(cb->insts_begin() + instr_offset, cb->insts_begin() + current_offset + 1, tty);
1630 tty->print_cr(" ------------------- ");
1631 BufferBlob* blob = this->scratch_buffer_blob();
1632 address blob_begin = blob->content_begin();
1633 Disassembler::decode(blob_begin, blob_begin + n_size + 1, tty);
1634 assert(false, "wrong size of mach node");
1635 }
1636 #endif
1637 non_safepoints.observe_instruction(n, current_offset);
1638
1639 // mcall is last "call" that can be a safepoint
1640 // record it so we can see if a poll will directly follow it
1641 // in which case we'll need a pad to make the PcDesc sites unique
1642 // see 5010568. This can be slightly inaccurate but conservative
1643 // in the case that return address is not actually at current_offset.
1644 // This is a small price to pay.
1645
1646 if (is_mcall) {
1647 last_call_offset = current_offset;
1648 }
1649
1650 if (n->is_Mach() && n->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
1651 // Avoid back to back some instructions.
1652 last_avoid_back_to_back_offset = current_offset;
1653 }
1654
1655 // See if this instruction has a delay slot
1656 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
1657 guarantee(delay_slot != NULL, "expecting delay slot node");
1658
1659 // Back up 1 instruction
1660 cb->set_insts_end(cb->insts_end() - Pipeline::instr_unit_size());
1661
1662 // Save the offset for the listing
1663 #if defined(SUPPORT_OPTO_ASSEMBLY)
1664 if ((node_offsets != NULL) && (delay_slot->_idx < node_offset_limit)) {
1665 node_offsets[delay_slot->_idx] = cb->insts_size();
1666 }
1667 #endif
1668
1669 // Support a SafePoint in the delay slot
1670 if (delay_slot->is_MachSafePoint()) {
1671 MachNode *mach = delay_slot->as_Mach();
1672 // !!!!! Stubs only need an oopmap right now, so bail out
1673 if (!mach->is_MachCall() && mach->as_MachSafePoint()->jvms()->method() == NULL) {
1674 // Write the oopmap directly to the code blob??!!
1675 delay_slot = NULL;
1676 continue;
1677 }
1678
1679 int adjusted_offset = current_offset - Pipeline::instr_unit_size();
1680 non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1681 adjusted_offset);
1682 // Generate an OopMap entry
1683 Process_OopMap_Node(mach, adjusted_offset);
1684 }
1685
1686 // Insert the delay slot instruction
1687 delay_slot->emit(*cb, C->regalloc());
1688
1689 // Don't reuse it
1690 delay_slot = NULL;
1691 }
1692
1693 } // End for all instructions in block
1694
1695 // If the next block is the top of a loop, pad this block out to align
1696 // the loop top a little. Helps prevent pipe stalls at loop back branches.
1697 if (i < nblocks-1) {
1698 Block *nb = C->cfg()->get_block(i + 1);
1699 int padding = nb->alignment_padding(current_offset);
1700 if( padding > 0 ) {
1701 MachNode *nop = new MachNopNode(padding / nop_size);
1702 block->insert_node(nop, block->number_of_nodes());
1703 C->cfg()->map_node_to_block(nop, block);
1704 nop->emit(*cb, C->regalloc());
1705 current_offset = cb->insts_size();
1706 }
1707 }
1708 // Verify that the distance for generated before forward
1709 // short branches is still valid.
1710 guarantee((int)(blk_starts[i+1] - blk_starts[i]) >= (current_offset - blk_offset), "shouldn't increase block size");
1711
1712 // Save new block start offset
1713 blk_starts[i] = blk_offset;
1714 } // End of for all blocks
1715 blk_starts[nblocks] = current_offset;
1716
1717 non_safepoints.flush_at_end();
1718
1719 // Offset too large?
1720 if (C->failing()) return;
1721
1722 // Define a pseudo-label at the end of the code
1723 MacroAssembler(cb).bind( blk_labels[nblocks] );
1724
1725 // Compute the size of the first block
1726 _first_block_size = blk_labels[1].loc_pos() - blk_labels[0].loc_pos();
1727
1728 #ifdef ASSERT
1729 for (uint i = 0; i < nblocks; i++) { // For all blocks
1730 if (jmp_target[i] != 0) {
1731 int br_size = jmp_size[i];
1732 int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
1733 if (!C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
1734 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]);
1735 assert(false, "Displacement too large for short jmp");
1736 }
1737 }
1738 }
1739 #endif
1740
1741 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1742 bs->emit_stubs(*cb);
1743 if (C->failing()) return;
1744
1745 #ifndef PRODUCT
1746 // Information on the size of the method, without the extraneous code
1747 Scheduling::increment_method_size(cb->insts_size());
1748 #endif
1749
1750 // ------------------
1751 // Fill in exception table entries.
1752 FillExceptionTables(inct_cnt, call_returns, inct_starts, blk_labels);
1753
1754 // Only java methods have exception handlers and deopt handlers
1755 // class HandlerImpl is platform-specific and defined in the *.ad files.
1756 if (C->method()) {
1757 // Emit the exception handler code.
1758 _code_offsets.set_value(CodeOffsets::Exceptions, HandlerImpl::emit_exception_handler(*cb));
1759 if (C->failing()) {
1760 return; // CodeBuffer::expand failed
1761 }
1762 // Emit the deopt handler code.
1763 _code_offsets.set_value(CodeOffsets::Deopt, HandlerImpl::emit_deopt_handler(*cb));
1764
1765 // Emit the MethodHandle deopt handler code (if required).
1766 if (C->has_method_handle_invokes() && !C->failing()) {
1767 // We can use the same code as for the normal deopt handler, we
1768 // just need a different entry point address.
1769 _code_offsets.set_value(CodeOffsets::DeoptMH, HandlerImpl::emit_deopt_handler(*cb));
1770 }
1771 }
1772
1773 // One last check for failed CodeBuffer::expand:
1774 if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
1775 C->record_failure("CodeCache is full");
1776 return;
1777 }
1778
1779 #if defined(SUPPORT_ABSTRACT_ASSEMBLY) || defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_OPTO_ASSEMBLY)
1780 if (C->print_assembly()) {
1781 tty->cr();
1782 tty->print_cr("============================= C2-compiled nmethod ==============================");
1783 }
1784 #endif
1785
1786 #if defined(SUPPORT_OPTO_ASSEMBLY)
1787 // Dump the assembly code, including basic-block numbers
1788 if (C->print_assembly()) {
1789 ttyLocker ttyl; // keep the following output all in one block
1790 if (!VMThread::should_terminate()) { // test this under the tty lock
1791 // This output goes directly to the tty, not the compiler log.
1792 // To enable tools to match it up with the compilation activity,
1793 // be sure to tag this tty output with the compile ID.
1794 if (xtty != NULL) {
1795 xtty->head("opto_assembly compile_id='%d'%s", C->compile_id(),
1796 C->is_osr_compilation() ? " compile_kind='osr'" :
1797 "");
1798 }
1799 if (C->method() != NULL) {
1800 tty->print_cr("----------------------- MetaData before Compile_id = %d ------------------------", C->compile_id());
1801 C->method()->print_metadata();
1802 } else if (C->stub_name() != NULL) {
1803 tty->print_cr("----------------------------- RuntimeStub %s -------------------------------", C->stub_name());
1804 }
1805 tty->cr();
1806 tty->print_cr("------------------------ OptoAssembly for Compile_id = %d -----------------------", C->compile_id());
1807 dump_asm(node_offsets, node_offset_limit);
1808 tty->print_cr("--------------------------------------------------------------------------------");
1809 if (xtty != NULL) {
1810 // print_metadata and dump_asm above may safepoint which makes us loose the ttylock.
1811 // Retake lock too make sure the end tag is coherent, and that xmlStream->pop_tag is done
1812 // thread safe
1813 ttyLocker ttyl2;
1814 xtty->tail("opto_assembly");
1815 }
1816 }
1817 }
1818 #endif
1819 }
1820
1821 void PhaseOutput::FillExceptionTables(uint cnt, uint *call_returns, uint *inct_starts, Label *blk_labels) {
1822 _inc_table.set_size(cnt);
1823
1824 uint inct_cnt = 0;
1825 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
1826 Block* block = C->cfg()->get_block(i);
1827 Node *n = NULL;
1828 int j;
1829
1830 // Find the branch; ignore trailing NOPs.
1831 for (j = block->number_of_nodes() - 1; j >= 0; j--) {
1832 n = block->get_node(j);
1833 if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con) {
1834 break;
1835 }
1836 }
1837
1838 // If we didn't find anything, continue
1839 if (j < 0) {
1840 continue;
1841 }
1842
1843 // Compute ExceptionHandlerTable subtable entry and add it
1844 // (skip empty blocks)
1845 if (n->is_Catch()) {
1846
1847 // Get the offset of the return from the call
1848 uint call_return = call_returns[block->_pre_order];
1849 #ifdef ASSERT
1850 assert( call_return > 0, "no call seen for this basic block" );
1851 while (block->get_node(--j)->is_MachProj()) ;
1852 assert(block->get_node(j)->is_MachCall(), "CatchProj must follow call");
1853 #endif
1854 // last instruction is a CatchNode, find it's CatchProjNodes
1855 int nof_succs = block->_num_succs;
1856 // allocate space
1857 GrowableArray<intptr_t> handler_bcis(nof_succs);
1858 GrowableArray<intptr_t> handler_pcos(nof_succs);
1859 // iterate through all successors
1860 for (int j = 0; j < nof_succs; j++) {
1861 Block* s = block->_succs[j];
1862 bool found_p = false;
1863 for (uint k = 1; k < s->num_preds(); k++) {
1864 Node* pk = s->pred(k);
1865 if (pk->is_CatchProj() && pk->in(0) == n) {
1866 const CatchProjNode* p = pk->as_CatchProj();
1867 found_p = true;
1868 // add the corresponding handler bci & pco information
1869 if (p->_con != CatchProjNode::fall_through_index) {
1870 // p leads to an exception handler (and is not fall through)
1871 assert(s == C->cfg()->get_block(s->_pre_order), "bad numbering");
1872 // no duplicates, please
1873 if (!handler_bcis.contains(p->handler_bci())) {
1874 uint block_num = s->non_connector()->_pre_order;
1875 handler_bcis.append(p->handler_bci());
1876 handler_pcos.append(blk_labels[block_num].loc_pos());
1877 }
1878 }
1879 }
1880 }
1881 assert(found_p, "no matching predecessor found");
1882 // Note: Due to empty block removal, one block may have
1883 // several CatchProj inputs, from the same Catch.
1884 }
1885
1886 // Set the offset of the return from the call
1887 assert(handler_bcis.find(-1) != -1, "must have default handler");
1888 _handler_table.add_subtable(call_return, &handler_bcis, NULL, &handler_pcos);
1889 continue;
1890 }
1891
1892 // Handle implicit null exception table updates
1893 if (n->is_MachNullCheck()) {
1894 uint block_num = block->non_connector_successor(0)->_pre_order;
1895 _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
1896 continue;
1897 }
1898 // Handle implicit exception table updates: trap instructions.
1899 if (n->is_Mach() && n->as_Mach()->is_TrapBasedCheckNode()) {
1900 uint block_num = block->non_connector_successor(0)->_pre_order;
1901 _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
1902 continue;
1903 }
1904 } // End of for all blocks fill in exception table entries
1905 }
1906
1907 // Static Variables
1908 #ifndef PRODUCT
1909 uint Scheduling::_total_nop_size = 0;
1910 uint Scheduling::_total_method_size = 0;
1911 uint Scheduling::_total_branches = 0;
1912 uint Scheduling::_total_unconditional_delays = 0;
1913 uint Scheduling::_total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
1914 #endif
1915
1916 // Initializer for class Scheduling
1917
1918 Scheduling::Scheduling(Arena *arena, Compile &compile)
1919 : _arena(arena),
1920 _cfg(compile.cfg()),
1921 _regalloc(compile.regalloc()),
1922 _scheduled(arena),
1923 _available(arena),
1924 _reg_node(arena),
1925 _pinch_free_list(arena),
1926 _next_node(NULL),
1927 _bundle_instr_count(0),
1928 _bundle_cycle_number(0),
1929 _bundle_use(0, 0, resource_count, &_bundle_use_elements[0])
1930 #ifndef PRODUCT
1931 , _branches(0)
1932 , _unconditional_delays(0)
1933 #endif
1934 {
1935 // Create a MachNopNode
1936 _nop = new MachNopNode();
1937
1938 // Now that the nops are in the array, save the count
1939 // (but allow entries for the nops)
1940 _node_bundling_limit = compile.unique();
1941 uint node_max = _regalloc->node_regs_max_index();
1942
1943 compile.output()->set_node_bundling_limit(_node_bundling_limit);
1944
1945 // This one is persistent within the Compile class
1946 _node_bundling_base = NEW_ARENA_ARRAY(compile.comp_arena(), Bundle, node_max);
1947
1948 // Allocate space for fixed-size arrays
1949 _node_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
1950 _uses = NEW_ARENA_ARRAY(arena, short, node_max);
1951 _current_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
1952
1953 // Clear the arrays
1954 for (uint i = 0; i < node_max; i++) {
1955 ::new (&_node_bundling_base[i]) Bundle();
1956 }
1957 memset(_node_latency, 0, node_max * sizeof(unsigned short));
1958 memset(_uses, 0, node_max * sizeof(short));
1959 memset(_current_latency, 0, node_max * sizeof(unsigned short));
1960
1961 // Clear the bundling information
1962 memcpy(_bundle_use_elements, Pipeline_Use::elaborated_elements, sizeof(Pipeline_Use::elaborated_elements));
1963
1964 // Get the last node
1965 Block* block = _cfg->get_block(_cfg->number_of_blocks() - 1);
1966
1967 _next_node = block->get_node(block->number_of_nodes() - 1);
1968 }
1969
1970 #ifndef PRODUCT
1971 // Scheduling destructor
1972 Scheduling::~Scheduling() {
1973 _total_branches += _branches;
1974 _total_unconditional_delays += _unconditional_delays;
1975 }
1976 #endif
1977
1978 // Step ahead "i" cycles
1979 void Scheduling::step(uint i) {
1980
1981 Bundle *bundle = node_bundling(_next_node);
1982 bundle->set_starts_bundle();
1983
1984 // Update the bundle record, but leave the flags information alone
1985 if (_bundle_instr_count > 0) {
1986 bundle->set_instr_count(_bundle_instr_count);
1987 bundle->set_resources_used(_bundle_use.resourcesUsed());
1988 }
1989
1990 // Update the state information
1991 _bundle_instr_count = 0;
1992 _bundle_cycle_number += i;
1993 _bundle_use.step(i);
1994 }
1995
1996 void Scheduling::step_and_clear() {
1997 Bundle *bundle = node_bundling(_next_node);
1998 bundle->set_starts_bundle();
1999
2000 // Update the bundle record
2001 if (_bundle_instr_count > 0) {
2002 bundle->set_instr_count(_bundle_instr_count);
2003 bundle->set_resources_used(_bundle_use.resourcesUsed());
2004
2005 _bundle_cycle_number += 1;
2006 }
2007
2008 // Clear the bundling information
2009 _bundle_instr_count = 0;
2010 _bundle_use.reset();
2011
2012 memcpy(_bundle_use_elements,
2013 Pipeline_Use::elaborated_elements,
2014 sizeof(Pipeline_Use::elaborated_elements));
2015 }
2016
2017 // Perform instruction scheduling and bundling over the sequence of
2018 // instructions in backwards order.
2019 void PhaseOutput::ScheduleAndBundle() {
2020
2021 // Don't optimize this if it isn't a method
2022 if (!C->method())
2023 return;
2024
2025 // Don't optimize this if scheduling is disabled
2026 if (!C->do_scheduling())
2027 return;
2028
2029 // Scheduling code works only with pairs (8 bytes) maximum.
2030 if (C->max_vector_size() > 8)
2031 return;
2032
2033 Compile::TracePhase tp("isched", &timers[_t_instrSched]);
2034
2035 // Create a data structure for all the scheduling information
2036 Scheduling scheduling(Thread::current()->resource_area(), *C);
2037
2038 // Walk backwards over each basic block, computing the needed alignment
2039 // Walk over all the basic blocks
2040 scheduling.DoScheduling();
2041
2042 #ifndef PRODUCT
2043 if (C->trace_opto_output()) {
2044 tty->print("\n---- After ScheduleAndBundle ----\n");
2045 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
2046 tty->print("\nBB#%03d:\n", i);
2047 Block* block = C->cfg()->get_block(i);
2048 for (uint j = 0; j < block->number_of_nodes(); j++) {
2049 Node* n = block->get_node(j);
2050 OptoReg::Name reg = C->regalloc()->get_reg_first(n);
2051 tty->print(" %-6s ", reg >= 0 && reg < REG_COUNT ? Matcher::regName[reg] : "");
2052 n->dump();
2053 }
2054 }
2055 }
2056 #endif
2057 }
2058
2059 // Compute the latency of all the instructions. This is fairly simple,
2060 // because we already have a legal ordering. Walk over the instructions
2061 // from first to last, and compute the latency of the instruction based
2062 // on the latency of the preceding instruction(s).
2063 void Scheduling::ComputeLocalLatenciesForward(const Block *bb) {
2064 #ifndef PRODUCT
2065 if (_cfg->C->trace_opto_output())
2066 tty->print("# -> ComputeLocalLatenciesForward\n");
2067 #endif
2068
2069 // Walk over all the schedulable instructions
2070 for( uint j=_bb_start; j < _bb_end; j++ ) {
2071
2072 // This is a kludge, forcing all latency calculations to start at 1.
2073 // Used to allow latency 0 to force an instruction to the beginning
2074 // of the bb
2075 uint latency = 1;
2076 Node *use = bb->get_node(j);
2077 uint nlen = use->len();
2078
2079 // Walk over all the inputs
2080 for ( uint k=0; k < nlen; k++ ) {
2081 Node *def = use->in(k);
2082 if (!def)
2083 continue;
2084
2085 uint l = _node_latency[def->_idx] + use->latency(k);
2086 if (latency < l)
2087 latency = l;
2088 }
2089
2090 _node_latency[use->_idx] = latency;
2091
2092 #ifndef PRODUCT
2093 if (_cfg->C->trace_opto_output()) {
2094 tty->print("# latency %4d: ", latency);
2095 use->dump();
2096 }
2097 #endif
2098 }
2099
2100 #ifndef PRODUCT
2101 if (_cfg->C->trace_opto_output())
2102 tty->print("# <- ComputeLocalLatenciesForward\n");
2103 #endif
2104
2105 } // end ComputeLocalLatenciesForward
2106
2107 // See if this node fits into the present instruction bundle
2108 bool Scheduling::NodeFitsInBundle(Node *n) {
2109 uint n_idx = n->_idx;
2110
2111 // If this is the unconditional delay instruction, then it fits
2112 if (n == _unconditional_delay_slot) {
2113 #ifndef PRODUCT
2114 if (_cfg->C->trace_opto_output())
2115 tty->print("# NodeFitsInBundle [%4d]: TRUE; is in unconditional delay slot\n", n->_idx);
2116 #endif
2117 return (true);
2118 }
2119
2120 // If the node cannot be scheduled this cycle, skip it
2121 if (_current_latency[n_idx] > _bundle_cycle_number) {
2122 #ifndef PRODUCT
2123 if (_cfg->C->trace_opto_output())
2124 tty->print("# NodeFitsInBundle [%4d]: FALSE; latency %4d > %d\n",
2125 n->_idx, _current_latency[n_idx], _bundle_cycle_number);
2126 #endif
2127 return (false);
2128 }
2129
2130 const Pipeline *node_pipeline = n->pipeline();
2131
2132 uint instruction_count = node_pipeline->instructionCount();
2133 if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2134 instruction_count = 0;
2135 else if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
2136 instruction_count++;
2137
2138 if (_bundle_instr_count + instruction_count > Pipeline::_max_instrs_per_cycle) {
2139 #ifndef PRODUCT
2140 if (_cfg->C->trace_opto_output())
2141 tty->print("# NodeFitsInBundle [%4d]: FALSE; too many instructions: %d > %d\n",
2142 n->_idx, _bundle_instr_count + instruction_count, Pipeline::_max_instrs_per_cycle);
2143 #endif
2144 return (false);
2145 }
2146
2147 // Don't allow non-machine nodes to be handled this way
2148 if (!n->is_Mach() && instruction_count == 0)
2149 return (false);
2150
2151 // See if there is any overlap
2152 uint delay = _bundle_use.full_latency(0, node_pipeline->resourceUse());
2153
2154 if (delay > 0) {
2155 #ifndef PRODUCT
2156 if (_cfg->C->trace_opto_output())
2157 tty->print("# NodeFitsInBundle [%4d]: FALSE; functional units overlap\n", n_idx);
2158 #endif
2159 return false;
2160 }
2161
2162 #ifndef PRODUCT
2163 if (_cfg->C->trace_opto_output())
2164 tty->print("# NodeFitsInBundle [%4d]: TRUE\n", n_idx);
2165 #endif
2166
2167 return true;
2168 }
2169
2170 Node * Scheduling::ChooseNodeToBundle() {
2171 uint siz = _available.size();
2172
2173 if (siz == 0) {
2174
2175 #ifndef PRODUCT
2176 if (_cfg->C->trace_opto_output())
2177 tty->print("# ChooseNodeToBundle: NULL\n");
2178 #endif
2179 return (NULL);
2180 }
2181
2182 // Fast path, if only 1 instruction in the bundle
2183 if (siz == 1) {
2184 #ifndef PRODUCT
2185 if (_cfg->C->trace_opto_output()) {
2186 tty->print("# ChooseNodeToBundle (only 1): ");
2187 _available[0]->dump();
2188 }
2189 #endif
2190 return (_available[0]);
2191 }
2192
2193 // Don't bother, if the bundle is already full
2194 if (_bundle_instr_count < Pipeline::_max_instrs_per_cycle) {
2195 for ( uint i = 0; i < siz; i++ ) {
2196 Node *n = _available[i];
2197
2198 // Skip projections, we'll handle them another way
2199 if (n->is_Proj())
2200 continue;
2201
2202 // This presupposed that instructions are inserted into the
2203 // available list in a legality order; i.e. instructions that
2204 // must be inserted first are at the head of the list
2205 if (NodeFitsInBundle(n)) {
2206 #ifndef PRODUCT
2207 if (_cfg->C->trace_opto_output()) {
2208 tty->print("# ChooseNodeToBundle: ");
2209 n->dump();
2210 }
2211 #endif
2212 return (n);
2213 }
2214 }
2215 }
2216
2217 // Nothing fits in this bundle, choose the highest priority
2218 #ifndef PRODUCT
2219 if (_cfg->C->trace_opto_output()) {
2220 tty->print("# ChooseNodeToBundle: ");
2221 _available[0]->dump();
2222 }
2223 #endif
2224
2225 return _available[0];
2226 }
2227
2228 void Scheduling::AddNodeToAvailableList(Node *n) {
2229 assert( !n->is_Proj(), "projections never directly made available" );
2230 #ifndef PRODUCT
2231 if (_cfg->C->trace_opto_output()) {
2232 tty->print("# AddNodeToAvailableList: ");
2233 n->dump();
2234 }
2235 #endif
2236
2237 int latency = _current_latency[n->_idx];
2238
2239 // Insert in latency order (insertion sort)
2240 uint i;
2241 for ( i=0; i < _available.size(); i++ )
2242 if (_current_latency[_available[i]->_idx] > latency)
2243 break;
2244
2245 // Special Check for compares following branches
2246 if( n->is_Mach() && _scheduled.size() > 0 ) {
2247 int op = n->as_Mach()->ideal_Opcode();
2248 Node *last = _scheduled[0];
2249 if( last->is_MachIf() && last->in(1) == n &&
2250 ( op == Op_CmpI ||
2251 op == Op_CmpU ||
2252 op == Op_CmpUL ||
2253 op == Op_CmpP ||
2254 op == Op_CmpF ||
2255 op == Op_CmpD ||
2256 op == Op_CmpL ) ) {
2257
2258 // Recalculate position, moving to front of same latency
2259 for ( i=0 ; i < _available.size(); i++ )
2260 if (_current_latency[_available[i]->_idx] >= latency)
2261 break;
2262 }
2263 }
2264
2265 // Insert the node in the available list
2266 _available.insert(i, n);
2267
2268 #ifndef PRODUCT
2269 if (_cfg->C->trace_opto_output())
2270 dump_available();
2271 #endif
2272 }
2273
2274 void Scheduling::DecrementUseCounts(Node *n, const Block *bb) {
2275 for ( uint i=0; i < n->len(); i++ ) {
2276 Node *def = n->in(i);
2277 if (!def) continue;
2278 if( def->is_Proj() ) // If this is a machine projection, then
2279 def = def->in(0); // propagate usage thru to the base instruction
2280
2281 if(_cfg->get_block_for_node(def) != bb) { // Ignore if not block-local
2282 continue;
2283 }
2284
2285 // Compute the latency
2286 uint l = _bundle_cycle_number + n->latency(i);
2287 if (_current_latency[def->_idx] < l)
2288 _current_latency[def->_idx] = l;
2289
2290 // If this does not have uses then schedule it
2291 if ((--_uses[def->_idx]) == 0)
2292 AddNodeToAvailableList(def);
2293 }
2294 }
2295
2296 void Scheduling::AddNodeToBundle(Node *n, const Block *bb) {
2297 #ifndef PRODUCT
2298 if (_cfg->C->trace_opto_output()) {
2299 tty->print("# AddNodeToBundle: ");
2300 n->dump();
2301 }
2302 #endif
2303
2304 // Remove this from the available list
2305 uint i;
2306 for (i = 0; i < _available.size(); i++)
2307 if (_available[i] == n)
2308 break;
2309 assert(i < _available.size(), "entry in _available list not found");
2310 _available.remove(i);
2311
2312 // See if this fits in the current bundle
2313 const Pipeline *node_pipeline = n->pipeline();
2314 const Pipeline_Use& node_usage = node_pipeline->resourceUse();
2315
2316 // Check for instructions to be placed in the delay slot. We
2317 // do this before we actually schedule the current instruction,
2318 // because the delay slot follows the current instruction.
2319 if (Pipeline::_branch_has_delay_slot &&
2320 node_pipeline->hasBranchDelay() &&
2321 !_unconditional_delay_slot) {
2322
2323 uint siz = _available.size();
2324
2325 // Conditional branches can support an instruction that
2326 // is unconditionally executed and not dependent by the
2327 // branch, OR a conditionally executed instruction if
2328 // the branch is taken. In practice, this means that
2329 // the first instruction at the branch target is
2330 // copied to the delay slot, and the branch goes to
2331 // the instruction after that at the branch target
2332 if ( n->is_MachBranch() ) {
2333
2334 assert( !n->is_MachNullCheck(), "should not look for delay slot for Null Check" );
2335 assert( !n->is_Catch(), "should not look for delay slot for Catch" );
2336
2337 #ifndef PRODUCT
2338 _branches++;
2339 #endif
2340
2341 // At least 1 instruction is on the available list
2342 // that is not dependent on the branch
2343 for (uint i = 0; i < siz; i++) {
2344 Node *d = _available[i];
2345 const Pipeline *avail_pipeline = d->pipeline();
2346
2347 // Don't allow safepoints in the branch shadow, that will
2348 // cause a number of difficulties
2349 if ( avail_pipeline->instructionCount() == 1 &&
2350 !avail_pipeline->hasMultipleBundles() &&
2351 !avail_pipeline->hasBranchDelay() &&
2352 Pipeline::instr_has_unit_size() &&
2353 d->size(_regalloc) == Pipeline::instr_unit_size() &&
2354 NodeFitsInBundle(d) &&
2355 !node_bundling(d)->used_in_delay()) {
2356
2357 if (d->is_Mach() && !d->is_MachSafePoint()) {
2358 // A node that fits in the delay slot was found, so we need to
2359 // set the appropriate bits in the bundle pipeline information so
2360 // that it correctly indicates resource usage. Later, when we
2361 // attempt to add this instruction to the bundle, we will skip
2362 // setting the resource usage.
2363 _unconditional_delay_slot = d;
2364 node_bundling(n)->set_use_unconditional_delay();
2365 node_bundling(d)->set_used_in_unconditional_delay();
2366 _bundle_use.add_usage(avail_pipeline->resourceUse());
2367 _current_latency[d->_idx] = _bundle_cycle_number;
2368 _next_node = d;
2369 ++_bundle_instr_count;
2370 #ifndef PRODUCT
2371 _unconditional_delays++;
2372 #endif
2373 break;
2374 }
2375 }
2376 }
2377 }
2378
2379 // No delay slot, add a nop to the usage
2380 if (!_unconditional_delay_slot) {
2381 // See if adding an instruction in the delay slot will overflow
2382 // the bundle.
2383 if (!NodeFitsInBundle(_nop)) {
2384 #ifndef PRODUCT
2385 if (_cfg->C->trace_opto_output())
2386 tty->print("# *** STEP(1 instruction for delay slot) ***\n");
2387 #endif
2388 step(1);
2389 }
2390
2391 _bundle_use.add_usage(_nop->pipeline()->resourceUse());
2392 _next_node = _nop;
2393 ++_bundle_instr_count;
2394 }
2395
2396 // See if the instruction in the delay slot requires a
2397 // step of the bundles
2398 if (!NodeFitsInBundle(n)) {
2399 #ifndef PRODUCT
2400 if (_cfg->C->trace_opto_output())
2401 tty->print("# *** STEP(branch won't fit) ***\n");
2402 #endif
2403 // Update the state information
2404 _bundle_instr_count = 0;
2405 _bundle_cycle_number += 1;
2406 _bundle_use.step(1);
2407 }
2408 }
2409
2410 // Get the number of instructions
2411 uint instruction_count = node_pipeline->instructionCount();
2412 if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2413 instruction_count = 0;
2414
2415 // Compute the latency information
2416 uint delay = 0;
2417
2418 if (instruction_count > 0 || !node_pipeline->mayHaveNoCode()) {
2419 int relative_latency = _current_latency[n->_idx] - _bundle_cycle_number;
2420 if (relative_latency < 0)
2421 relative_latency = 0;
2422
2423 delay = _bundle_use.full_latency(relative_latency, node_usage);
2424
2425 // Does not fit in this bundle, start a new one
2426 if (delay > 0) {
2427 step(delay);
2428
2429 #ifndef PRODUCT
2430 if (_cfg->C->trace_opto_output())
2431 tty->print("# *** STEP(%d) ***\n", delay);
2432 #endif
2433 }
2434 }
2435
2436 // If this was placed in the delay slot, ignore it
2437 if (n != _unconditional_delay_slot) {
2438
2439 if (delay == 0) {
2440 if (node_pipeline->hasMultipleBundles()) {
2441 #ifndef PRODUCT
2442 if (_cfg->C->trace_opto_output())
2443 tty->print("# *** STEP(multiple instructions) ***\n");
2444 #endif
2445 step(1);
2446 }
2447
2448 else if (instruction_count + _bundle_instr_count > Pipeline::_max_instrs_per_cycle) {
2449 #ifndef PRODUCT
2450 if (_cfg->C->trace_opto_output())
2451 tty->print("# *** STEP(%d >= %d instructions) ***\n",
2452 instruction_count + _bundle_instr_count,
2453 Pipeline::_max_instrs_per_cycle);
2454 #endif
2455 step(1);
2456 }
2457 }
2458
2459 if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
2460 _bundle_instr_count++;
2461
2462 // Set the node's latency
2463 _current_latency[n->_idx] = _bundle_cycle_number;
2464
2465 // Now merge the functional unit information
2466 if (instruction_count > 0 || !node_pipeline->mayHaveNoCode())
2467 _bundle_use.add_usage(node_usage);
2468
2469 // Increment the number of instructions in this bundle
2470 _bundle_instr_count += instruction_count;
2471
2472 // Remember this node for later
2473 if (n->is_Mach())
2474 _next_node = n;
2475 }
2476
2477 // It's possible to have a BoxLock in the graph and in the _bbs mapping but
2478 // not in the bb->_nodes array. This happens for debug-info-only BoxLocks.
2479 // 'Schedule' them (basically ignore in the schedule) but do not insert them
2480 // into the block. All other scheduled nodes get put in the schedule here.
2481 int op = n->Opcode();
2482 if( (op == Op_Node && n->req() == 0) || // anti-dependence node OR
2483 (op != Op_Node && // Not an unused antidepedence node and
2484 // not an unallocated boxlock
2485 (OptoReg::is_valid(_regalloc->get_reg_first(n)) || op != Op_BoxLock)) ) {
2486
2487 // Push any trailing projections
2488 if( bb->get_node(bb->number_of_nodes()-1) != n ) {
2489 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2490 Node *foi = n->fast_out(i);
2491 if( foi->is_Proj() )
2492 _scheduled.push(foi);
2493 }
2494 }
2495
2496 // Put the instruction in the schedule list
2497 _scheduled.push(n);
2498 }
2499
2500 #ifndef PRODUCT
2501 if (_cfg->C->trace_opto_output())
2502 dump_available();
2503 #endif
2504
2505 // Walk all the definitions, decrementing use counts, and
2506 // if a definition has a 0 use count, place it in the available list.
2507 DecrementUseCounts(n,bb);
2508 }
2509
2510 // This method sets the use count within a basic block. We will ignore all
2511 // uses outside the current basic block. As we are doing a backwards walk,
2512 // any node we reach that has a use count of 0 may be scheduled. This also
2513 // avoids the problem of cyclic references from phi nodes, as long as phi
2514 // nodes are at the front of the basic block. This method also initializes
2515 // the available list to the set of instructions that have no uses within this
2516 // basic block.
2517 void Scheduling::ComputeUseCount(const Block *bb) {
2518 #ifndef PRODUCT
2519 if (_cfg->C->trace_opto_output())
2520 tty->print("# -> ComputeUseCount\n");
2521 #endif
2522
2523 // Clear the list of available and scheduled instructions, just in case
2524 _available.clear();
2525 _scheduled.clear();
2526
2527 // No delay slot specified
2528 _unconditional_delay_slot = NULL;
2529
2530 #ifdef ASSERT
2531 for( uint i=0; i < bb->number_of_nodes(); i++ )
2532 assert( _uses[bb->get_node(i)->_idx] == 0, "_use array not clean" );
2533 #endif
2534
2535 // Force the _uses count to never go to zero for unscheduable pieces
2536 // of the block
2537 for( uint k = 0; k < _bb_start; k++ )
2538 _uses[bb->get_node(k)->_idx] = 1;
2539 for( uint l = _bb_end; l < bb->number_of_nodes(); l++ )
2540 _uses[bb->get_node(l)->_idx] = 1;
2541
2542 // Iterate backwards over the instructions in the block. Don't count the
2543 // branch projections at end or the block header instructions.
2544 for( uint j = _bb_end-1; j >= _bb_start; j-- ) {
2545 Node *n = bb->get_node(j);
2546 if( n->is_Proj() ) continue; // Projections handled another way
2547
2548 // Account for all uses
2549 for ( uint k = 0; k < n->len(); k++ ) {
2550 Node *inp = n->in(k);
2551 if (!inp) continue;
2552 assert(inp != n, "no cycles allowed" );
2553 if (_cfg->get_block_for_node(inp) == bb) { // Block-local use?
2554 if (inp->is_Proj()) { // Skip through Proj's
2555 inp = inp->in(0);
2556 }
2557 ++_uses[inp->_idx]; // Count 1 block-local use
2558 }
2559 }
2560
2561 // If this instruction has a 0 use count, then it is available
2562 if (!_uses[n->_idx]) {
2563 _current_latency[n->_idx] = _bundle_cycle_number;
2564 AddNodeToAvailableList(n);
2565 }
2566
2567 #ifndef PRODUCT
2568 if (_cfg->C->trace_opto_output()) {
2569 tty->print("# uses: %3d: ", _uses[n->_idx]);
2570 n->dump();
2571 }
2572 #endif
2573 }
2574
2575 #ifndef PRODUCT
2576 if (_cfg->C->trace_opto_output())
2577 tty->print("# <- ComputeUseCount\n");
2578 #endif
2579 }
2580
2581 // This routine performs scheduling on each basic block in reverse order,
2582 // using instruction latencies and taking into account function unit
2583 // availability.
2584 void Scheduling::DoScheduling() {
2585 #ifndef PRODUCT
2586 if (_cfg->C->trace_opto_output())
2587 tty->print("# -> DoScheduling\n");
2588 #endif
2589
2590 Block *succ_bb = NULL;
2591 Block *bb;
2592 Compile* C = Compile::current();
2593
2594 // Walk over all the basic blocks in reverse order
2595 for (int i = _cfg->number_of_blocks() - 1; i >= 0; succ_bb = bb, i--) {
2596 bb = _cfg->get_block(i);
2597
2598 #ifndef PRODUCT
2599 if (_cfg->C->trace_opto_output()) {
2600 tty->print("# Schedule BB#%03d (initial)\n", i);
2601 for (uint j = 0; j < bb->number_of_nodes(); j++) {
2602 bb->get_node(j)->dump();
2603 }
2604 }
2605 #endif
2606
2607 // On the head node, skip processing
2608 if (bb == _cfg->get_root_block()) {
2609 continue;
2610 }
2611
2612 // Skip empty, connector blocks
2613 if (bb->is_connector())
2614 continue;
2615
2616 // If the following block is not the sole successor of
2617 // this one, then reset the pipeline information
2618 if (bb->_num_succs != 1 || bb->non_connector_successor(0) != succ_bb) {
2619 #ifndef PRODUCT
2620 if (_cfg->C->trace_opto_output()) {
2621 tty->print("*** bundle start of next BB, node %d, for %d instructions\n",
2622 _next_node->_idx, _bundle_instr_count);
2623 }
2624 #endif
2625 step_and_clear();
2626 }
2627
2628 // Leave untouched the starting instruction, any Phis, a CreateEx node
2629 // or Top. bb->get_node(_bb_start) is the first schedulable instruction.
2630 _bb_end = bb->number_of_nodes()-1;
2631 for( _bb_start=1; _bb_start <= _bb_end; _bb_start++ ) {
2632 Node *n = bb->get_node(_bb_start);
2633 // Things not matched, like Phinodes and ProjNodes don't get scheduled.
2634 // Also, MachIdealNodes do not get scheduled
2635 if( !n->is_Mach() ) continue; // Skip non-machine nodes
2636 MachNode *mach = n->as_Mach();
2637 int iop = mach->ideal_Opcode();
2638 if( iop == Op_CreateEx ) continue; // CreateEx is pinned
2639 if( iop == Op_Con ) continue; // Do not schedule Top
2640 if( iop == Op_Node && // Do not schedule PhiNodes, ProjNodes
2641 mach->pipeline() == MachNode::pipeline_class() &&
2642 !n->is_SpillCopy() && !n->is_MachMerge() ) // Breakpoints, Prolog, etc
2643 continue;
2644 break; // Funny loop structure to be sure...
2645 }
2646 // Compute last "interesting" instruction in block - last instruction we
2647 // might schedule. _bb_end points just after last schedulable inst. We
2648 // normally schedule conditional branches (despite them being forced last
2649 // in the block), because they have delay slots we can fill. Calls all
2650 // have their delay slots filled in the template expansions, so we don't
2651 // bother scheduling them.
2652 Node *last = bb->get_node(_bb_end);
2653 // Ignore trailing NOPs.
2654 while (_bb_end > 0 && last->is_Mach() &&
2655 last->as_Mach()->ideal_Opcode() == Op_Con) {
2656 last = bb->get_node(--_bb_end);
2657 }
2658 assert(!last->is_Mach() || last->as_Mach()->ideal_Opcode() != Op_Con, "");
2659 if( last->is_Catch() ||
2660 (last->is_Mach() && last->as_Mach()->ideal_Opcode() == Op_Halt) ) {
2661 // There might be a prior call. Skip it.
2662 while (_bb_start < _bb_end && bb->get_node(--_bb_end)->is_MachProj());
2663 } else if( last->is_MachNullCheck() ) {
2664 // Backup so the last null-checked memory instruction is
2665 // outside the schedulable range. Skip over the nullcheck,
2666 // projection, and the memory nodes.
2667 Node *mem = last->in(1);
2668 do {
2669 _bb_end--;
2670 } while (mem != bb->get_node(_bb_end));
2671 } else {
2672 // Set _bb_end to point after last schedulable inst.
2673 _bb_end++;
2674 }
2675
2676 assert( _bb_start <= _bb_end, "inverted block ends" );
2677
2678 // Compute the register antidependencies for the basic block
2679 ComputeRegisterAntidependencies(bb);
2680 if (C->failing()) return; // too many D-U pinch points
2681
2682 // Compute intra-bb latencies for the nodes
2683 ComputeLocalLatenciesForward(bb);
2684
2685 // Compute the usage within the block, and set the list of all nodes
2686 // in the block that have no uses within the block.
2687 ComputeUseCount(bb);
2688
2689 // Schedule the remaining instructions in the block
2690 while ( _available.size() > 0 ) {
2691 Node *n = ChooseNodeToBundle();
2692 guarantee(n != NULL, "no nodes available");
2693 AddNodeToBundle(n,bb);
2694 }
2695
2696 assert( _scheduled.size() == _bb_end - _bb_start, "wrong number of instructions" );
2697 #ifdef ASSERT
2698 for( uint l = _bb_start; l < _bb_end; l++ ) {
2699 Node *n = bb->get_node(l);
2700 uint m;
2701 for( m = 0; m < _bb_end-_bb_start; m++ )
2702 if( _scheduled[m] == n )
2703 break;
2704 assert( m < _bb_end-_bb_start, "instruction missing in schedule" );
2705 }
2706 #endif
2707
2708 // Now copy the instructions (in reverse order) back to the block
2709 for ( uint k = _bb_start; k < _bb_end; k++ )
2710 bb->map_node(_scheduled[_bb_end-k-1], k);
2711
2712 #ifndef PRODUCT
2713 if (_cfg->C->trace_opto_output()) {
2714 tty->print("# Schedule BB#%03d (final)\n", i);
2715 uint current = 0;
2716 for (uint j = 0; j < bb->number_of_nodes(); j++) {
2717 Node *n = bb->get_node(j);
2718 if( valid_bundle_info(n) ) {
2719 Bundle *bundle = node_bundling(n);
2720 if (bundle->instr_count() > 0 || bundle->flags() > 0) {
2721 tty->print("*** Bundle: ");
2722 bundle->dump();
2723 }
2724 n->dump();
2725 }
2726 }
2727 }
2728 #endif
2729 #ifdef ASSERT
2730 verify_good_schedule(bb,"after block local scheduling");
2731 #endif
2732 }
2733
2734 #ifndef PRODUCT
2735 if (_cfg->C->trace_opto_output())
2736 tty->print("# <- DoScheduling\n");
2737 #endif
2738
2739 // Record final node-bundling array location
2740 _regalloc->C->output()->set_node_bundling_base(_node_bundling_base);
2741
2742 } // end DoScheduling
2743
2744 // Verify that no live-range used in the block is killed in the block by a
2745 // wrong DEF. This doesn't verify live-ranges that span blocks.
2746
2747 // Check for edge existence. Used to avoid adding redundant precedence edges.
2748 static bool edge_from_to( Node *from, Node *to ) {
2749 for( uint i=0; i<from->len(); i++ )
2750 if( from->in(i) == to )
2751 return true;
2752 return false;
2753 }
2754
2755 #ifdef ASSERT
2756 void Scheduling::verify_do_def( Node *n, OptoReg::Name def, const char *msg ) {
2757 // Check for bad kills
2758 if( OptoReg::is_valid(def) ) { // Ignore stores & control flow
2759 Node *prior_use = _reg_node[def];
2760 if( prior_use && !edge_from_to(prior_use,n) ) {
2761 tty->print("%s = ",OptoReg::as_VMReg(def)->name());
2762 n->dump();
2763 tty->print_cr("...");
2764 prior_use->dump();
2765 assert(edge_from_to(prior_use,n), "%s", msg);
2766 }
2767 _reg_node.map(def,NULL); // Kill live USEs
2768 }
2769 }
2770
2771 void Scheduling::verify_good_schedule( Block *b, const char *msg ) {
2772
2773 // Zap to something reasonable for the verify code
2774 _reg_node.clear();
2775
2776 // Walk over the block backwards. Check to make sure each DEF doesn't
2777 // kill a live value (other than the one it's supposed to). Add each
2778 // USE to the live set.
2779 for( uint i = b->number_of_nodes()-1; i >= _bb_start; i-- ) {
2780 Node *n = b->get_node(i);
2781 int n_op = n->Opcode();
2782 if( n_op == Op_MachProj && n->ideal_reg() == MachProjNode::fat_proj ) {
2783 // Fat-proj kills a slew of registers
2784 RegMask rm = n->out_RegMask();// Make local copy
2785 while( rm.is_NotEmpty() ) {
2786 OptoReg::Name kill = rm.find_first_elem();
2787 rm.Remove(kill);
2788 verify_do_def( n, kill, msg );
2789 }
2790 } else if( n_op != Op_Node ) { // Avoid brand new antidependence nodes
2791 // Get DEF'd registers the normal way
2792 verify_do_def( n, _regalloc->get_reg_first(n), msg );
2793 verify_do_def( n, _regalloc->get_reg_second(n), msg );
2794 }
2795
2796 // Now make all USEs live
2797 for( uint i=1; i<n->req(); i++ ) {
2798 Node *def = n->in(i);
2799 assert(def != 0, "input edge required");
2800 OptoReg::Name reg_lo = _regalloc->get_reg_first(def);
2801 OptoReg::Name reg_hi = _regalloc->get_reg_second(def);
2802 if( OptoReg::is_valid(reg_lo) ) {
2803 assert(!_reg_node[reg_lo] || edge_from_to(_reg_node[reg_lo],def), "%s", msg);
2804 _reg_node.map(reg_lo,n);
2805 }
2806 if( OptoReg::is_valid(reg_hi) ) {
2807 assert(!_reg_node[reg_hi] || edge_from_to(_reg_node[reg_hi],def), "%s", msg);
2808 _reg_node.map(reg_hi,n);
2809 }
2810 }
2811
2812 }
2813
2814 // Zap to something reasonable for the Antidependence code
2815 _reg_node.clear();
2816 }
2817 #endif
2818
2819 // Conditionally add precedence edges. Avoid putting edges on Projs.
2820 static void add_prec_edge_from_to( Node *from, Node *to ) {
2821 if( from->is_Proj() ) { // Put precedence edge on Proj's input
2822 assert( from->req() == 1 && (from->len() == 1 || from->in(1)==0), "no precedence edges on projections" );
2823 from = from->in(0);
2824 }
2825 if( from != to && // No cycles (for things like LD L0,[L0+4] )
2826 !edge_from_to( from, to ) ) // Avoid duplicate edge
2827 from->add_prec(to);
2828 }
2829
2830 void Scheduling::anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def ) {
2831 if( !OptoReg::is_valid(def_reg) ) // Ignore stores & control flow
2832 return;
2833
2834 Node *pinch = _reg_node[def_reg]; // Get pinch point
2835 if ((pinch == NULL) || _cfg->get_block_for_node(pinch) != b || // No pinch-point yet?
2836 is_def ) { // Check for a true def (not a kill)
2837 _reg_node.map(def_reg,def); // Record def/kill as the optimistic pinch-point
2838 return;
2839 }
2840
2841 Node *kill = def; // Rename 'def' to more descriptive 'kill'
2842 debug_only( def = (Node*)((intptr_t)0xdeadbeef); )
2843
2844 // After some number of kills there _may_ be a later def
2845 Node *later_def = NULL;
2846
2847 Compile* C = Compile::current();
2848
2849 // Finding a kill requires a real pinch-point.
2850 // Check for not already having a pinch-point.
2851 // Pinch points are Op_Node's.
2852 if( pinch->Opcode() != Op_Node ) { // Or later-def/kill as pinch-point?
2853 later_def = pinch; // Must be def/kill as optimistic pinch-point
2854 if ( _pinch_free_list.size() > 0) {
2855 pinch = _pinch_free_list.pop();
2856 } else {
2857 pinch = new Node(1); // Pinch point to-be
2858 }
2859 if (pinch->_idx >= _regalloc->node_regs_max_index()) {
2860 _cfg->C->record_method_not_compilable("too many D-U pinch points");
2861 return;
2862 }
2863 _cfg->map_node_to_block(pinch, b); // Pretend it's valid in this block (lazy init)
2864 _reg_node.map(def_reg,pinch); // Record pinch-point
2865 //regalloc()->set_bad(pinch->_idx); // Already initialized this way.
2866 if( later_def->outcnt() == 0 || later_def->ideal_reg() == MachProjNode::fat_proj ) { // Distinguish def from kill
2867 pinch->init_req(0, C->top()); // set not NULL for the next call
2868 add_prec_edge_from_to(later_def,pinch); // Add edge from kill to pinch
2869 later_def = NULL; // and no later def
2870 }
2871 pinch->set_req(0,later_def); // Hook later def so we can find it
2872 } else { // Else have valid pinch point
2873 if( pinch->in(0) ) // If there is a later-def
2874 later_def = pinch->in(0); // Get it
2875 }
2876
2877 // Add output-dependence edge from later def to kill
2878 if( later_def ) // If there is some original def
2879 add_prec_edge_from_to(later_def,kill); // Add edge from def to kill
2880
2881 // See if current kill is also a use, and so is forced to be the pinch-point.
2882 if( pinch->Opcode() == Op_Node ) {
2883 Node *uses = kill->is_Proj() ? kill->in(0) : kill;
2884 for( uint i=1; i<uses->req(); i++ ) {
2885 if( _regalloc->get_reg_first(uses->in(i)) == def_reg ||
2886 _regalloc->get_reg_second(uses->in(i)) == def_reg ) {
2887 // Yes, found a use/kill pinch-point
2888 pinch->set_req(0,NULL); //
2889 pinch->replace_by(kill); // Move anti-dep edges up
2890 pinch = kill;
2891 _reg_node.map(def_reg,pinch);
2892 return;
2893 }
2894 }
2895 }
2896
2897 // Add edge from kill to pinch-point
2898 add_prec_edge_from_to(kill,pinch);
2899 }
2900
2901 void Scheduling::anti_do_use( Block *b, Node *use, OptoReg::Name use_reg ) {
2902 if( !OptoReg::is_valid(use_reg) ) // Ignore stores & control flow
2903 return;
2904 Node *pinch = _reg_node[use_reg]; // Get pinch point
2905 // Check for no later def_reg/kill in block
2906 if ((pinch != NULL) && _cfg->get_block_for_node(pinch) == b &&
2907 // Use has to be block-local as well
2908 _cfg->get_block_for_node(use) == b) {
2909 if( pinch->Opcode() == Op_Node && // Real pinch-point (not optimistic?)
2910 pinch->req() == 1 ) { // pinch not yet in block?
2911 pinch->del_req(0); // yank pointer to later-def, also set flag
2912 // Insert the pinch-point in the block just after the last use
2913 b->insert_node(pinch, b->find_node(use) + 1);
2914 _bb_end++; // Increase size scheduled region in block
2915 }
2916
2917 add_prec_edge_from_to(pinch,use);
2918 }
2919 }
2920
2921 // We insert antidependences between the reads and following write of
2922 // allocated registers to prevent illegal code motion. Hopefully, the
2923 // number of added references should be fairly small, especially as we
2924 // are only adding references within the current basic block.
2925 void Scheduling::ComputeRegisterAntidependencies(Block *b) {
2926
2927 #ifdef ASSERT
2928 verify_good_schedule(b,"before block local scheduling");
2929 #endif
2930
2931 // A valid schedule, for each register independently, is an endless cycle
2932 // of: a def, then some uses (connected to the def by true dependencies),
2933 // then some kills (defs with no uses), finally the cycle repeats with a new
2934 // def. The uses are allowed to float relative to each other, as are the
2935 // kills. No use is allowed to slide past a kill (or def). This requires
2936 // antidependencies between all uses of a single def and all kills that
2937 // follow, up to the next def. More edges are redundant, because later defs
2938 // & kills are already serialized with true or antidependencies. To keep
2939 // the edge count down, we add a 'pinch point' node if there's more than
2940 // one use or more than one kill/def.
2941
2942 // We add dependencies in one bottom-up pass.
2943
2944 // For each instruction we handle it's DEFs/KILLs, then it's USEs.
2945
2946 // For each DEF/KILL, we check to see if there's a prior DEF/KILL for this
2947 // register. If not, we record the DEF/KILL in _reg_node, the
2948 // register-to-def mapping. If there is a prior DEF/KILL, we insert a
2949 // "pinch point", a new Node that's in the graph but not in the block.
2950 // We put edges from the prior and current DEF/KILLs to the pinch point.
2951 // We put the pinch point in _reg_node. If there's already a pinch point
2952 // we merely add an edge from the current DEF/KILL to the pinch point.
2953
2954 // After doing the DEF/KILLs, we handle USEs. For each used register, we
2955 // put an edge from the pinch point to the USE.
2956
2957 // To be expedient, the _reg_node array is pre-allocated for the whole
2958 // compilation. _reg_node is lazily initialized; it either contains a NULL,
2959 // or a valid def/kill/pinch-point, or a leftover node from some prior
2960 // block. Leftover node from some prior block is treated like a NULL (no
2961 // prior def, so no anti-dependence needed). Valid def is distinguished by
2962 // it being in the current block.
2963 bool fat_proj_seen = false;
2964 uint last_safept = _bb_end-1;
2965 Node* end_node = (_bb_end-1 >= _bb_start) ? b->get_node(last_safept) : NULL;
2966 Node* last_safept_node = end_node;
2967 for( uint i = _bb_end-1; i >= _bb_start; i-- ) {
2968 Node *n = b->get_node(i);
2969 int is_def = n->outcnt(); // def if some uses prior to adding precedence edges
2970 if( n->is_MachProj() && n->ideal_reg() == MachProjNode::fat_proj ) {
2971 // Fat-proj kills a slew of registers
2972 // This can add edges to 'n' and obscure whether or not it was a def,
2973 // hence the is_def flag.
2974 fat_proj_seen = true;
2975 RegMask rm = n->out_RegMask();// Make local copy
2976 while( rm.is_NotEmpty() ) {
2977 OptoReg::Name kill = rm.find_first_elem();
2978 rm.Remove(kill);
2979 anti_do_def( b, n, kill, is_def );
2980 }
2981 } else {
2982 // Get DEF'd registers the normal way
2983 anti_do_def( b, n, _regalloc->get_reg_first(n), is_def );
2984 anti_do_def( b, n, _regalloc->get_reg_second(n), is_def );
2985 }
2986
2987 // Kill projections on a branch should appear to occur on the
2988 // branch, not afterwards, so grab the masks from the projections
2989 // and process them.
2990 if (n->is_MachBranch() || (n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_Jump)) {
2991 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2992 Node* use = n->fast_out(i);
2993 if (use->is_Proj()) {
2994 RegMask rm = use->out_RegMask();// Make local copy
2995 while( rm.is_NotEmpty() ) {
2996 OptoReg::Name kill = rm.find_first_elem();
2997 rm.Remove(kill);
2998 anti_do_def( b, n, kill, false );
2999 }
3000 }
3001 }
3002 }
3003
3004 // Check each register used by this instruction for a following DEF/KILL
3005 // that must occur afterward and requires an anti-dependence edge.
3006 for( uint j=0; j<n->req(); j++ ) {
3007 Node *def = n->in(j);
3008 if( def ) {
3009 assert( !def->is_MachProj() || def->ideal_reg() != MachProjNode::fat_proj, "" );
3010 anti_do_use( b, n, _regalloc->get_reg_first(def) );
3011 anti_do_use( b, n, _regalloc->get_reg_second(def) );
3012 }
3013 }
3014 // Do not allow defs of new derived values to float above GC
3015 // points unless the base is definitely available at the GC point.
3016
3017 Node *m = b->get_node(i);
3018
3019 // Add precedence edge from following safepoint to use of derived pointer
3020 if( last_safept_node != end_node &&
3021 m != last_safept_node) {
3022 for (uint k = 1; k < m->req(); k++) {
3023 const Type *t = m->in(k)->bottom_type();
3024 if( t->isa_oop_ptr() &&
3025 t->is_ptr()->offset() != 0 ) {
3026 last_safept_node->add_prec( m );
3027 break;
3028 }
3029 }
3030 }
3031
3032 if( n->jvms() ) { // Precedence edge from derived to safept
3033 // Check if last_safept_node was moved by pinch-point insertion in anti_do_use()
3034 if( b->get_node(last_safept) != last_safept_node ) {
3035 last_safept = b->find_node(last_safept_node);
3036 }
3037 for( uint j=last_safept; j > i; j-- ) {
3038 Node *mach = b->get_node(j);
3039 if( mach->is_Mach() && mach->as_Mach()->ideal_Opcode() == Op_AddP )
3040 mach->add_prec( n );
3041 }
3042 last_safept = i;
3043 last_safept_node = m;
3044 }
3045 }
3046
3047 if (fat_proj_seen) {
3048 // Garbage collect pinch nodes that were not consumed.
3049 // They are usually created by a fat kill MachProj for a call.
3050 garbage_collect_pinch_nodes();
3051 }
3052 }
3053
3054 // Garbage collect pinch nodes for reuse by other blocks.
3055 //
3056 // The block scheduler's insertion of anti-dependence
3057 // edges creates many pinch nodes when the block contains
3058 // 2 or more Calls. A pinch node is used to prevent a
3059 // combinatorial explosion of edges. If a set of kills for a
3060 // register is anti-dependent on a set of uses (or defs), rather
3061 // than adding an edge in the graph between each pair of kill
3062 // and use (or def), a pinch is inserted between them:
3063 //
3064 // use1 use2 use3
3065 // \ | /
3066 // \ | /
3067 // pinch
3068 // / | \
3069 // / | \
3070 // kill1 kill2 kill3
3071 //
3072 // One pinch node is created per register killed when
3073 // the second call is encountered during a backwards pass
3074 // over the block. Most of these pinch nodes are never
3075 // wired into the graph because the register is never
3076 // used or def'ed in the block.
3077 //
3078 void Scheduling::garbage_collect_pinch_nodes() {
3079 #ifndef PRODUCT
3080 if (_cfg->C->trace_opto_output()) tty->print("Reclaimed pinch nodes:");
3081 #endif
3082 int trace_cnt = 0;
3083 for (uint k = 0; k < _reg_node.Size(); k++) {
3084 Node* pinch = _reg_node[k];
3085 if ((pinch != NULL) && pinch->Opcode() == Op_Node &&
3086 // no predecence input edges
3087 (pinch->req() == pinch->len() || pinch->in(pinch->req()) == NULL) ) {
3088 cleanup_pinch(pinch);
3089 _pinch_free_list.push(pinch);
3090 _reg_node.map(k, NULL);
3091 #ifndef PRODUCT
3092 if (_cfg->C->trace_opto_output()) {
3093 trace_cnt++;
3094 if (trace_cnt > 40) {
3095 tty->print("\n");
3096 trace_cnt = 0;
3097 }
3098 tty->print(" %d", pinch->_idx);
3099 }
3100 #endif
3101 }
3102 }
3103 #ifndef PRODUCT
3104 if (_cfg->C->trace_opto_output()) tty->print("\n");
3105 #endif
3106 }
3107
3108 // Clean up a pinch node for reuse.
3109 void Scheduling::cleanup_pinch( Node *pinch ) {
3110 assert (pinch && pinch->Opcode() == Op_Node && pinch->req() == 1, "just checking");
3111
3112 for (DUIterator_Last imin, i = pinch->last_outs(imin); i >= imin; ) {
3113 Node* use = pinch->last_out(i);
3114 uint uses_found = 0;
3115 for (uint j = use->req(); j < use->len(); j++) {
3116 if (use->in(j) == pinch) {
3117 use->rm_prec(j);
3118 uses_found++;
3119 }
3120 }
3121 assert(uses_found > 0, "must be a precedence edge");
3122 i -= uses_found; // we deleted 1 or more copies of this edge
3123 }
3124 // May have a later_def entry
3125 pinch->set_req(0, NULL);
3126 }
3127
3128 #ifndef PRODUCT
3129
3130 void Scheduling::dump_available() const {
3131 tty->print("#Availist ");
3132 for (uint i = 0; i < _available.size(); i++)
3133 tty->print(" N%d/l%d", _available[i]->_idx,_current_latency[_available[i]->_idx]);
3134 tty->cr();
3135 }
3136
3137 // Print Scheduling Statistics
3138 void Scheduling::print_statistics() {
3139 // Print the size added by nops for bundling
3140 tty->print("Nops added %d bytes to total of %d bytes",
3141 _total_nop_size, _total_method_size);
3142 if (_total_method_size > 0)
3143 tty->print(", for %.2f%%",
3144 ((double)_total_nop_size) / ((double) _total_method_size) * 100.0);
3145 tty->print("\n");
3146
3147 // Print the number of branch shadows filled
3148 if (Pipeline::_branch_has_delay_slot) {
3149 tty->print("Of %d branches, %d had unconditional delay slots filled",
3150 _total_branches, _total_unconditional_delays);
3151 if (_total_branches > 0)
3152 tty->print(", for %.2f%%",
3153 ((double)_total_unconditional_delays) / ((double)_total_branches) * 100.0);
3154 tty->print("\n");
3155 }
3156
3157 uint total_instructions = 0, total_bundles = 0;
3158
3159 for (uint i = 1; i <= Pipeline::_max_instrs_per_cycle; i++) {
3160 uint bundle_count = _total_instructions_per_bundle[i];
3161 total_instructions += bundle_count * i;
3162 total_bundles += bundle_count;
3163 }
3164
3165 if (total_bundles > 0)
3166 tty->print("Average ILP (excluding nops) is %.2f\n",
3167 ((double)total_instructions) / ((double)total_bundles));
3168 }
3169 #endif
3170
3171 //-----------------------init_scratch_buffer_blob------------------------------
3172 // Construct a temporary BufferBlob and cache it for this compile.
3173 void PhaseOutput::init_scratch_buffer_blob(int const_size) {
3174 // If there is already a scratch buffer blob allocated and the
3175 // constant section is big enough, use it. Otherwise free the
3176 // current and allocate a new one.
3177 BufferBlob* blob = scratch_buffer_blob();
3178 if ((blob != NULL) && (const_size <= _scratch_const_size)) {
3179 // Use the current blob.
3180 } else {
3181 if (blob != NULL) {
3182 BufferBlob::free(blob);
3183 }
3184
3185 ResourceMark rm;
3186 _scratch_const_size = const_size;
3187 int size = C2Compiler::initial_code_buffer_size(const_size);
3188 blob = BufferBlob::create("Compile::scratch_buffer", size);
3189 // Record the buffer blob for next time.
3190 set_scratch_buffer_blob(blob);
3191 // Have we run out of code space?
3192 if (scratch_buffer_blob() == NULL) {
3193 // Let CompilerBroker disable further compilations.
3194 C->record_failure("Not enough space for scratch buffer in CodeCache");
3195 return;
3196 }
3197 }
3198
3199 // Initialize the relocation buffers
3200 relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
3201 set_scratch_locs_memory(locs_buf);
3202 }
3203
3204
3205 //-----------------------scratch_emit_size-------------------------------------
3206 // Helper function that computes size by emitting code
3207 uint PhaseOutput::scratch_emit_size(const Node* n) {
3208 // Start scratch_emit_size section.
3209 set_in_scratch_emit_size(true);
3210
3211 // Emit into a trash buffer and count bytes emitted.
3212 // This is a pretty expensive way to compute a size,
3213 // but it works well enough if seldom used.
3214 // All common fixed-size instructions are given a size
3215 // method by the AD file.
3216 // Note that the scratch buffer blob and locs memory are
3217 // allocated at the beginning of the compile task, and
3218 // may be shared by several calls to scratch_emit_size.
3219 // The allocation of the scratch buffer blob is particularly
3220 // expensive, since it has to grab the code cache lock.
3221 BufferBlob* blob = this->scratch_buffer_blob();
3222 assert(blob != NULL, "Initialize BufferBlob at start");
3223 assert(blob->size() > MAX_inst_size, "sanity");
3224 relocInfo* locs_buf = scratch_locs_memory();
3225 address blob_begin = blob->content_begin();
3226 address blob_end = (address)locs_buf;
3227 assert(blob->contains(blob_end), "sanity");
3228 CodeBuffer buf(blob_begin, blob_end - blob_begin);
3229 buf.initialize_consts_size(_scratch_const_size);
3230 buf.initialize_stubs_size(MAX_stubs_size);
3231 assert(locs_buf != NULL, "sanity");
3232 int lsize = MAX_locs_size / 3;
3233 buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
3234 buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
3235 buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
3236 // Mark as scratch buffer.
3237 buf.consts()->set_scratch_emit();
3238 buf.insts()->set_scratch_emit();
3239 buf.stubs()->set_scratch_emit();
3240
3241 // Do the emission.
3242
3243 Label fakeL; // Fake label for branch instructions.
3244 Label* saveL = NULL;
3245 uint save_bnum = 0;
3246 bool is_branch = n->is_MachBranch();
3247 if (is_branch) {
3248 MacroAssembler masm(&buf);
3249 masm.bind(fakeL);
3250 n->as_MachBranch()->save_label(&saveL, &save_bnum);
3251 n->as_MachBranch()->label_set(&fakeL, 0);
3252 }
3253 n->emit(buf, C->regalloc());
3254
3255 // Emitting into the scratch buffer should not fail
3256 assert (!C->failing(), "Must not have pending failure. Reason is: %s", C->failure_reason());
3257
3258 if (is_branch) // Restore label.
3259 n->as_MachBranch()->label_set(saveL, save_bnum);
3260
3261 // End scratch_emit_size section.
3262 set_in_scratch_emit_size(false);
3263
3264 return buf.insts_size();
3265 }
3266
3267 void PhaseOutput::install() {
3268 if (!C->should_install_code()) {
3269 return;
3270 } else if (C->stub_function() != NULL) {
3271 install_stub(C->stub_name(),
3272 C->save_argument_registers());
3273 } else {
3274 install_code(C->method(),
3275 C->entry_bci(),
3276 CompileBroker::compiler2(),
3277 C->has_unsafe_access(),
3278 SharedRuntime::is_wide_vector(C->max_vector_size()),
3279 C->rtm_state());
3280 }
3281 }
3282
3283 void PhaseOutput::install_code(ciMethod* target,
3284 int entry_bci,
3285 AbstractCompiler* compiler,
3286 bool has_unsafe_access,
3287 bool has_wide_vectors,
3288 RTMState rtm_state) {
3289 // Check if we want to skip execution of all compiled code.
3290 {
3291 #ifndef PRODUCT
3292 if (OptoNoExecute) {
3293 C->record_method_not_compilable("+OptoNoExecute"); // Flag as failed
3294 return;
3295 }
3296 #endif
3297 Compile::TracePhase tp("install_code", &timers[_t_registerMethod]);
3298
3299 if (C->is_osr_compilation()) {
3300 _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
3301 _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
3302 } else {
3303 _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
3304 _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
3305 }
3306
3307 C->env()->register_method(target,
3308 entry_bci,
3309 &_code_offsets,
3310 _orig_pc_slot_offset_in_bytes,
3311 code_buffer(),
3312 frame_size_in_words(),
3313 oop_map_set(),
3314 &_handler_table,
3315 inc_table(),
3316 compiler,
3317 has_unsafe_access,
3318 SharedRuntime::is_wide_vector(C->max_vector_size()),
3319 C->rtm_state());
3320
3321 if (C->log() != NULL) { // Print code cache state into compiler log
3322 C->log()->code_cache_state();
3323 }
3324 }
3325 }
3326 void PhaseOutput::install_stub(const char* stub_name,
3327 bool caller_must_gc_arguments) {
3328 // Entry point will be accessed using stub_entry_point();
3329 if (code_buffer() == NULL) {
3330 Matcher::soft_match_failure();
3331 } else {
3332 if (PrintAssembly && (WizardMode || Verbose))
3333 tty->print_cr("### Stub::%s", stub_name);
3334
3335 if (!C->failing()) {
3336 assert(C->fixed_slots() == 0, "no fixed slots used for runtime stubs");
3337
3338 // Make the NMethod
3339 // For now we mark the frame as never safe for profile stackwalking
3340 RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
3341 code_buffer(),
3342 CodeOffsets::frame_never_safe,
3343 // _code_offsets.value(CodeOffsets::Frame_Complete),
3344 frame_size_in_words(),
3345 oop_map_set(),
3346 caller_must_gc_arguments);
3347 assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
3348
3349 C->set_stub_entry_point(rs->entry_point());
3350 }
3351 }
3352 }
3353
3354 // Support for bundling info
3355 Bundle* PhaseOutput::node_bundling(const Node *n) {
3356 assert(valid_bundle_info(n), "oob");
3357 return &_node_bundling_base[n->_idx];
3358 }
3359
3360 bool PhaseOutput::valid_bundle_info(const Node *n) {
3361 return (_node_bundling_limit > n->_idx);
3362 }
3363
3364 //------------------------------frame_size_in_words-----------------------------
3365 // frame_slots in units of words
3366 int PhaseOutput::frame_size_in_words() const {
3367 // shift is 0 in LP32 and 1 in LP64
3368 const int shift = (LogBytesPerWord - LogBytesPerInt);
3369 int words = _frame_slots >> shift;
3370 assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
3371 return words;
3372 }
3373
3374 // To bang the stack of this compiled method we use the stack size
3375 // that the interpreter would need in case of a deoptimization. This
3376 // removes the need to bang the stack in the deoptimization blob which
3377 // in turn simplifies stack overflow handling.
3378 int PhaseOutput::bang_size_in_bytes() const {
3379 return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), C->interpreter_frame_size());
3380 }
3381
3382 //------------------------------dump_asm---------------------------------------
3383 // Dump formatted assembly
3384 #if defined(SUPPORT_OPTO_ASSEMBLY)
3385 void PhaseOutput::dump_asm_on(outputStream* st, int* pcs, uint pc_limit) {
3386
3387 int pc_digits = 3; // #chars required for pc
3388 int sb_chars = 3; // #chars for "start bundle" indicator
3389 int tab_size = 8;
3390 if (pcs != NULL) {
3391 int max_pc = 0;
3392 for (uint i = 0; i < pc_limit; i++) {
3393 max_pc = (max_pc < pcs[i]) ? pcs[i] : max_pc;
3394 }
3395 pc_digits = ((max_pc < 4096) ? 3 : ((max_pc < 65536) ? 4 : ((max_pc < 65536*256) ? 6 : 8))); // #chars required for pc
3396 }
3397 int prefix_len = ((pc_digits + sb_chars + tab_size - 1)/tab_size)*tab_size;
3398
3399 bool cut_short = false;
3400 st->print_cr("#");
3401 st->print("# "); C->tf()->dump_on(st); st->cr();
3402 st->print_cr("#");
3403
3404 // For all blocks
3405 int pc = 0x0; // Program counter
3406 char starts_bundle = ' ';
3407 C->regalloc()->dump_frame();
3408
3409 Node *n = NULL;
3410 for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
3411 if (VMThread::should_terminate()) {
3412 cut_short = true;
3413 break;
3414 }
3415 Block* block = C->cfg()->get_block(i);
3416 if (block->is_connector() && !Verbose) {
3417 continue;
3418 }
3419 n = block->head();
3420 if ((pcs != NULL) && (n->_idx < pc_limit)) {
3421 pc = pcs[n->_idx];
3422 st->print("%*.*x", pc_digits, pc_digits, pc);
3423 }
3424 st->fill_to(prefix_len);
3425 block->dump_head(C->cfg(), st);
3426 if (block->is_connector()) {
3427 st->fill_to(prefix_len);
3428 st->print_cr("# Empty connector block");
3429 } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
3430 st->fill_to(prefix_len);
3431 st->print_cr("# Block is sole successor of call");
3432 }
3433
3434 // For all instructions
3435 Node *delay = NULL;
3436 for (uint j = 0; j < block->number_of_nodes(); j++) {
3437 if (VMThread::should_terminate()) {
3438 cut_short = true;
3439 break;
3440 }
3441 n = block->get_node(j);
3442 if (valid_bundle_info(n)) {
3443 Bundle* bundle = node_bundling(n);
3444 if (bundle->used_in_unconditional_delay()) {
3445 delay = n;
3446 continue;
3447 }
3448 if (bundle->starts_bundle()) {
3449 starts_bundle = '+';
3450 }
3451 }
3452
3453 if (WizardMode) {
3454 n->dump();
3455 }
3456
3457 if( !n->is_Region() && // Dont print in the Assembly
3458 !n->is_Phi() && // a few noisely useless nodes
3459 !n->is_Proj() &&
3460 !n->is_MachTemp() &&
3461 !n->is_SafePointScalarObject() &&
3462 !n->is_Catch() && // Would be nice to print exception table targets
3463 !n->is_MergeMem() && // Not very interesting
3464 !n->is_top() && // Debug info table constants
3465 !(n->is_Con() && !n->is_Mach())// Debug info table constants
3466 ) {
3467 if ((pcs != NULL) && (n->_idx < pc_limit)) {
3468 pc = pcs[n->_idx];
3469 st->print("%*.*x", pc_digits, pc_digits, pc);
3470 } else {
3471 st->fill_to(pc_digits);
3472 }
3473 st->print(" %c ", starts_bundle);
3474 starts_bundle = ' ';
3475 st->fill_to(prefix_len);
3476 n->format(C->regalloc(), st);
3477 st->cr();
3478 }
3479
3480 // If we have an instruction with a delay slot, and have seen a delay,
3481 // then back up and print it
3482 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
3483 // Coverity finding - Explicit null dereferenced.
3484 guarantee(delay != NULL, "no unconditional delay instruction");
3485 if (WizardMode) delay->dump();
3486
3487 if (node_bundling(delay)->starts_bundle())
3488 starts_bundle = '+';
3489 if ((pcs != NULL) && (n->_idx < pc_limit)) {
3490 pc = pcs[n->_idx];
3491 st->print("%*.*x", pc_digits, pc_digits, pc);
3492 } else {
3493 st->fill_to(pc_digits);
3494 }
3495 st->print(" %c ", starts_bundle);
3496 starts_bundle = ' ';
3497 st->fill_to(prefix_len);
3498 delay->format(C->regalloc(), st);
3499 st->cr();
3500 delay = NULL;
3501 }
3502
3503 // Dump the exception table as well
3504 if( n->is_Catch() && (Verbose || WizardMode) ) {
3505 // Print the exception table for this offset
3506 _handler_table.print_subtable_for(pc);
3507 }
3508 st->bol(); // Make sure we start on a new line
3509 }
3510 st->cr(); // one empty line between blocks
3511 assert(cut_short || delay == NULL, "no unconditional delay branch");
3512 } // End of per-block dump
3513
3514 if (cut_short) st->print_cr("*** disassembly is cut short ***");
3515 }
3516 #endif
3517
3518 #ifndef PRODUCT
3519 void PhaseOutput::print_statistics() {
3520 Scheduling::print_statistics();
3521 }
3522 #endif