1 /*
2 * Copyright (c) 1998, 2018, 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 "memory/allocation.inline.hpp"
36 #include "opto/ad.hpp"
37 #include "opto/callnode.hpp"
38 #include "opto/cfgnode.hpp"
39 #include "opto/locknode.hpp"
40 #include "opto/machnode.hpp"
41 #include "opto/optoreg.hpp"
42 #include "opto/output.hpp"
43 #include "opto/regalloc.hpp"
44 #include "opto/runtime.hpp"
45 #include "opto/subnode.hpp"
46 #include "opto/type.hpp"
47 #include "runtime/handles.inline.hpp"
48 #include "utilities/xmlstream.hpp"
49
50 #ifndef PRODUCT
51 #define DEBUG_ARG(x) , x
52 #else
53 #define DEBUG_ARG(x)
54 #endif
55
56 // Convert Nodes to instruction bits and pass off to the VM
57 void Compile::Output() {
58 // RootNode goes
59 assert( _cfg->get_root_block()->number_of_nodes() == 0, "" );
60
61 // The number of new nodes (mostly MachNop) is proportional to
62 // the number of java calls and inner loops which are aligned.
63 if ( C->check_node_count((NodeLimitFudgeFactor + C->java_calls()*3 +
64 C->inner_loops()*(OptoLoopAlignment-1)),
65 "out of nodes before code generation" ) ) {
66 return;
67 }
68 // Make sure I can find the Start Node
69 Block *entry = _cfg->get_block(1);
70 Block *broot = _cfg->get_root_block();
71
72 const StartNode *start = entry->head()->as_Start();
73
74 // Replace StartNode with prolog
75 MachPrologNode *prolog = new MachPrologNode();
76 entry->map_node(prolog, 0);
77 _cfg->map_node_to_block(prolog, entry);
78 _cfg->unmap_node_from_block(start); // start is no longer in any block
79
80 // Virtual methods need an unverified entry point
81
82 if( is_osr_compilation() ) {
83 if( PoisonOSREntry ) {
84 // TODO: Should use a ShouldNotReachHereNode...
85 _cfg->insert( broot, 0, new MachBreakpointNode() );
86 }
87 } else {
88 if( _method && !_method->flags().is_static() ) {
89 // Insert unvalidated entry point
90 _cfg->insert( broot, 0, new MachUEPNode() );
91 }
92
93 }
94
95 // Break before main entry point
96 if ((_method && C->directive()->BreakAtExecuteOption) ||
97 (OptoBreakpoint && is_method_compilation()) ||
98 (OptoBreakpointOSR && is_osr_compilation()) ||
99 (OptoBreakpointC2R && !_method) ) {
100 // checking for _method means that OptoBreakpoint does not apply to
101 // runtime stubs or frame converters
102 _cfg->insert( entry, 1, new MachBreakpointNode() );
103 }
104
105 // Insert epilogs before every return
106 for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
107 Block* block = _cfg->get_block(i);
108 if (!block->is_connector() && block->non_connector_successor(0) == _cfg->get_root_block()) { // Found a program exit point?
109 Node* m = block->end();
110 if (m->is_Mach() && m->as_Mach()->ideal_Opcode() != Op_Halt) {
111 MachEpilogNode* epilog = new MachEpilogNode(m->as_Mach()->ideal_Opcode() == Op_Return);
112 block->add_inst(epilog);
113 _cfg->map_node_to_block(epilog, block);
114 }
115 }
116 }
117
118 uint* blk_starts = NEW_RESOURCE_ARRAY(uint, _cfg->number_of_blocks() + 1);
119 blk_starts[0] = 0;
120
121 // Initialize code buffer and process short branches.
122 CodeBuffer* cb = init_buffer(blk_starts);
123
124 if (cb == NULL || failing()) {
125 return;
126 }
127
128 ScheduleAndBundle();
129
130 #ifndef PRODUCT
131 if (trace_opto_output()) {
132 tty->print("\n---- After ScheduleAndBundle ----\n");
133 for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
134 tty->print("\nBB#%03d:\n", i);
135 Block* block = _cfg->get_block(i);
136 for (uint j = 0; j < block->number_of_nodes(); j++) {
137 Node* n = block->get_node(j);
138 OptoReg::Name reg = _regalloc->get_reg_first(n);
139 tty->print(" %-6s ", reg >= 0 && reg < REG_COUNT ? Matcher::regName[reg] : "");
140 n->dump();
141 }
142 }
143 }
144 #endif
145
146 if (failing()) {
147 return;
148 }
149
150 BuildOopMaps();
151
152 if (failing()) {
153 return;
154 }
155
156 fill_buffer(cb, blk_starts);
157 }
158
159 bool Compile::need_stack_bang(int frame_size_in_bytes) const {
160 // Determine if we need to generate a stack overflow check.
161 // Do it if the method is not a stub function and
162 // has java calls or has frame size > vm_page_size/8.
163 // The debug VM checks that deoptimization doesn't trigger an
164 // unexpected stack overflow (compiled method stack banging should
165 // guarantee it doesn't happen) so we always need the stack bang in
166 // a debug VM.
167 return (UseStackBanging && stub_function() == NULL &&
168 (has_java_calls() || frame_size_in_bytes > os::vm_page_size()>>3
169 DEBUG_ONLY(|| true)));
170 }
171
172 bool Compile::need_register_stack_bang() const {
173 // Determine if we need to generate a register stack overflow check.
174 // This is only used on architectures which have split register
175 // and memory stacks (ie. IA64).
176 // Bang if the method is not a stub function and has java calls
177 return (stub_function() == NULL && has_java_calls());
178 }
179
180
181 // Compute the size of first NumberOfLoopInstrToAlign instructions at the top
182 // of a loop. When aligning a loop we need to provide enough instructions
183 // in cpu's fetch buffer to feed decoders. The loop alignment could be
184 // avoided if we have enough instructions in fetch buffer at the head of a loop.
185 // By default, the size is set to 999999 by Block's constructor so that
186 // a loop will be aligned if the size is not reset here.
187 //
188 // Note: Mach instructions could contain several HW instructions
189 // so the size is estimated only.
190 //
191 void Compile::compute_loop_first_inst_sizes() {
192 // The next condition is used to gate the loop alignment optimization.
193 // Don't aligned a loop if there are enough instructions at the head of a loop
194 // or alignment padding is larger then MaxLoopPad. By default, MaxLoopPad
195 // is equal to OptoLoopAlignment-1 except on new Intel cpus, where it is
196 // equal to 11 bytes which is the largest address NOP instruction.
197 if (MaxLoopPad < OptoLoopAlignment - 1) {
198 uint last_block = _cfg->number_of_blocks() - 1;
199 for (uint i = 1; i <= last_block; i++) {
200 Block* block = _cfg->get_block(i);
201 // Check the first loop's block which requires an alignment.
202 if (block->loop_alignment() > (uint)relocInfo::addr_unit()) {
203 uint sum_size = 0;
204 uint inst_cnt = NumberOfLoopInstrToAlign;
205 inst_cnt = block->compute_first_inst_size(sum_size, inst_cnt, _regalloc);
206
207 // Check subsequent fallthrough blocks if the loop's first
208 // block(s) does not have enough instructions.
209 Block *nb = block;
210 while(inst_cnt > 0 &&
211 i < last_block &&
212 !_cfg->get_block(i + 1)->has_loop_alignment() &&
213 !nb->has_successor(block)) {
214 i++;
215 nb = _cfg->get_block(i);
216 inst_cnt = nb->compute_first_inst_size(sum_size, inst_cnt, _regalloc);
217 } // while( inst_cnt > 0 && i < last_block )
218
219 block->set_first_inst_size(sum_size);
220 } // f( b->head()->is_Loop() )
221 } // for( i <= last_block )
222 } // if( MaxLoopPad < OptoLoopAlignment-1 )
223 }
224
225 // The architecture description provides short branch variants for some long
226 // branch instructions. Replace eligible long branches with short branches.
227 void Compile::shorten_branches(uint* blk_starts, int& code_size, int& reloc_size, int& stub_size) {
228 // Compute size of each block, method size, and relocation information size
229 uint nblocks = _cfg->number_of_blocks();
230
231 uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
232 uint* jmp_size = NEW_RESOURCE_ARRAY(uint,nblocks);
233 int* jmp_nidx = NEW_RESOURCE_ARRAY(int ,nblocks);
234
235 // Collect worst case block paddings
236 int* block_worst_case_pad = NEW_RESOURCE_ARRAY(int, nblocks);
237 memset(block_worst_case_pad, 0, nblocks * sizeof(int));
238
239 DEBUG_ONLY( uint *jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks); )
240 DEBUG_ONLY( uint *jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks); )
241
242 bool has_short_branch_candidate = false;
243
244 // Initialize the sizes to 0
245 code_size = 0; // Size in bytes of generated code
246 stub_size = 0; // Size in bytes of all stub entries
247 // Size in bytes of all relocation entries, including those in local stubs.
248 // Start with 2-bytes of reloc info for the unvalidated entry point
249 reloc_size = 1; // Number of relocation entries
250
251 // Make three passes. The first computes pessimistic blk_starts,
252 // relative jmp_offset and reloc_size information. The second performs
253 // short branch substitution using the pessimistic sizing. The
254 // third inserts nops where needed.
255
256 // Step one, perform a pessimistic sizing pass.
257 uint last_call_adr = max_juint;
258 uint last_avoid_back_to_back_adr = max_juint;
259 uint nop_size = (new MachNopNode())->size(_regalloc);
260 for (uint i = 0; i < nblocks; i++) { // For all blocks
261 Block* block = _cfg->get_block(i);
262
263 // During short branch replacement, we store the relative (to blk_starts)
264 // offset of jump in jmp_offset, rather than the absolute offset of jump.
265 // This is so that we do not need to recompute sizes of all nodes when
266 // we compute correct blk_starts in our next sizing pass.
267 jmp_offset[i] = 0;
268 jmp_size[i] = 0;
269 jmp_nidx[i] = -1;
270 DEBUG_ONLY( jmp_target[i] = 0; )
271 DEBUG_ONLY( jmp_rule[i] = 0; )
272
273 // Sum all instruction sizes to compute block size
274 uint last_inst = block->number_of_nodes();
275 uint blk_size = 0;
276 for (uint j = 0; j < last_inst; j++) {
277 Node* nj = block->get_node(j);
278 // Handle machine instruction nodes
279 if (nj->is_Mach()) {
280 MachNode *mach = nj->as_Mach();
281 blk_size += (mach->alignment_required() - 1) * relocInfo::addr_unit(); // assume worst case padding
282 reloc_size += mach->reloc();
283 if (mach->is_MachCall()) {
284 // add size information for trampoline stub
285 // class CallStubImpl is platform-specific and defined in the *.ad files.
286 stub_size += CallStubImpl::size_call_trampoline();
287 reloc_size += CallStubImpl::reloc_call_trampoline();
288
289 MachCallNode *mcall = mach->as_MachCall();
290 // This destination address is NOT PC-relative
291
292 mcall->method_set((intptr_t)mcall->entry_point());
293
294 if (mcall->is_MachCallJava() && mcall->as_MachCallJava()->_method) {
295 stub_size += CompiledStaticCall::to_interp_stub_size();
296 reloc_size += CompiledStaticCall::reloc_to_interp_stub();
297 #if INCLUDE_AOT
298 stub_size += CompiledStaticCall::to_aot_stub_size();
299 reloc_size += CompiledStaticCall::reloc_to_aot_stub();
300 #endif
301 }
302 } else if (mach->is_MachSafePoint()) {
303 // If call/safepoint are adjacent, account for possible
304 // nop to disambiguate the two safepoints.
305 // ScheduleAndBundle() can rearrange nodes in a block,
306 // check for all offsets inside this block.
307 if (last_call_adr >= blk_starts[i]) {
308 blk_size += nop_size;
309 }
310 }
311 if (mach->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
312 // Nop is inserted between "avoid back to back" instructions.
313 // ScheduleAndBundle() can rearrange nodes in a block,
314 // check for all offsets inside this block.
315 if (last_avoid_back_to_back_adr >= blk_starts[i]) {
316 blk_size += nop_size;
317 }
318 }
319 if (mach->may_be_short_branch()) {
320 if (!nj->is_MachBranch()) {
321 #ifndef PRODUCT
322 nj->dump(3);
323 #endif
324 Unimplemented();
325 }
326 assert(jmp_nidx[i] == -1, "block should have only one branch");
327 jmp_offset[i] = blk_size;
328 jmp_size[i] = nj->size(_regalloc);
329 jmp_nidx[i] = j;
330 has_short_branch_candidate = true;
331 }
332 }
333 blk_size += nj->size(_regalloc);
334 // Remember end of call offset
335 if (nj->is_MachCall() && !nj->is_MachCallLeaf()) {
336 last_call_adr = blk_starts[i]+blk_size;
337 }
338 // Remember end of avoid_back_to_back offset
339 if (nj->is_Mach() && nj->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
340 last_avoid_back_to_back_adr = blk_starts[i]+blk_size;
341 }
342 }
343
344 // When the next block starts a loop, we may insert pad NOP
345 // instructions. Since we cannot know our future alignment,
346 // assume the worst.
347 if (i < nblocks - 1) {
348 Block* nb = _cfg->get_block(i + 1);
349 int max_loop_pad = nb->code_alignment()-relocInfo::addr_unit();
350 if (max_loop_pad > 0) {
351 assert(is_power_of_2(max_loop_pad+relocInfo::addr_unit()), "");
352 // Adjust last_call_adr and/or last_avoid_back_to_back_adr.
353 // If either is the last instruction in this block, bump by
354 // max_loop_pad in lock-step with blk_size, so sizing
355 // calculations in subsequent blocks still can conservatively
356 // detect that it may the last instruction in this block.
357 if (last_call_adr == blk_starts[i]+blk_size) {
358 last_call_adr += max_loop_pad;
359 }
360 if (last_avoid_back_to_back_adr == blk_starts[i]+blk_size) {
361 last_avoid_back_to_back_adr += max_loop_pad;
362 }
363 blk_size += max_loop_pad;
364 block_worst_case_pad[i + 1] = max_loop_pad;
365 }
366 }
367
368 // Save block size; update total method size
369 blk_starts[i+1] = blk_starts[i]+blk_size;
370 }
371
372 // Step two, replace eligible long jumps.
373 bool progress = true;
374 uint last_may_be_short_branch_adr = max_juint;
375 while (has_short_branch_candidate && progress) {
376 progress = false;
377 has_short_branch_candidate = false;
378 int adjust_block_start = 0;
379 for (uint i = 0; i < nblocks; i++) {
380 Block* block = _cfg->get_block(i);
381 int idx = jmp_nidx[i];
382 MachNode* mach = (idx == -1) ? NULL: block->get_node(idx)->as_Mach();
383 if (mach != NULL && mach->may_be_short_branch()) {
384 #ifdef ASSERT
385 assert(jmp_size[i] > 0 && mach->is_MachBranch(), "sanity");
386 int j;
387 // Find the branch; ignore trailing NOPs.
388 for (j = block->number_of_nodes()-1; j>=0; j--) {
389 Node* n = block->get_node(j);
390 if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con)
391 break;
392 }
393 assert(j >= 0 && j == idx && block->get_node(j) == (Node*)mach, "sanity");
394 #endif
395 int br_size = jmp_size[i];
396 int br_offs = blk_starts[i] + jmp_offset[i];
397
398 // This requires the TRUE branch target be in succs[0]
399 uint bnum = block->non_connector_successor(0)->_pre_order;
400 int offset = blk_starts[bnum] - br_offs;
401 if (bnum > i) { // adjust following block's offset
402 offset -= adjust_block_start;
403 }
404
405 // This block can be a loop header, account for the padding
406 // in the previous block.
407 int block_padding = block_worst_case_pad[i];
408 assert(i == 0 || block_padding == 0 || br_offs >= block_padding, "Should have at least a padding on top");
409 // In the following code a nop could be inserted before
410 // the branch which will increase the backward distance.
411 bool needs_padding = ((uint)(br_offs - block_padding) == last_may_be_short_branch_adr);
412 assert(!needs_padding || jmp_offset[i] == 0, "padding only branches at the beginning of block");
413
414 if (needs_padding && offset <= 0)
415 offset -= nop_size;
416
417 if (_matcher->is_short_branch_offset(mach->rule(), br_size, offset)) {
418 // We've got a winner. Replace this branch.
419 MachNode* replacement = mach->as_MachBranch()->short_branch_version();
420
421 // Update the jmp_size.
422 int new_size = replacement->size(_regalloc);
423 int diff = br_size - new_size;
424 assert(diff >= (int)nop_size, "short_branch size should be smaller");
425 // Conservatively take into account padding between
426 // avoid_back_to_back branches. Previous branch could be
427 // converted into avoid_back_to_back branch during next
428 // rounds.
429 if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
430 jmp_offset[i] += nop_size;
431 diff -= nop_size;
432 }
433 adjust_block_start += diff;
434 block->map_node(replacement, idx);
435 mach->subsume_by(replacement, C);
436 mach = replacement;
437 progress = true;
438
439 jmp_size[i] = new_size;
440 DEBUG_ONLY( jmp_target[i] = bnum; );
441 DEBUG_ONLY( jmp_rule[i] = mach->rule(); );
442 } else {
443 // The jump distance is not short, try again during next iteration.
444 has_short_branch_candidate = true;
445 }
446 } // (mach->may_be_short_branch())
447 if (mach != NULL && (mach->may_be_short_branch() ||
448 mach->avoid_back_to_back(MachNode::AVOID_AFTER))) {
449 last_may_be_short_branch_adr = blk_starts[i] + jmp_offset[i] + jmp_size[i];
450 }
451 blk_starts[i+1] -= adjust_block_start;
452 }
453 }
454
455 #ifdef ASSERT
456 for (uint i = 0; i < nblocks; i++) { // For all blocks
457 if (jmp_target[i] != 0) {
458 int br_size = jmp_size[i];
459 int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
460 if (!_matcher->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
461 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]);
462 }
463 assert(_matcher->is_short_branch_offset(jmp_rule[i], br_size, offset), "Displacement too large for short jmp");
464 }
465 }
466 #endif
467
468 // Step 3, compute the offsets of all blocks, will be done in fill_buffer()
469 // after ScheduleAndBundle().
470
471 // ------------------
472 // Compute size for code buffer
473 code_size = blk_starts[nblocks];
474
475 // Relocation records
476 reloc_size += 1; // Relo entry for exception handler
477
478 // Adjust reloc_size to number of record of relocation info
479 // Min is 2 bytes, max is probably 6 or 8, with a tax up to 25% for
480 // a relocation index.
481 // The CodeBuffer will expand the locs array if this estimate is too low.
482 reloc_size *= 10 / sizeof(relocInfo);
483 }
484
485 //------------------------------FillLocArray-----------------------------------
486 // Create a bit of debug info and append it to the array. The mapping is from
487 // Java local or expression stack to constant, register or stack-slot. For
488 // doubles, insert 2 mappings and return 1 (to tell the caller that the next
489 // entry has been taken care of and caller should skip it).
490 static LocationValue *new_loc_value( PhaseRegAlloc *ra, OptoReg::Name regnum, Location::Type l_type ) {
491 // This should never have accepted Bad before
492 assert(OptoReg::is_valid(regnum), "location must be valid");
493 return (OptoReg::is_reg(regnum))
494 ? new LocationValue(Location::new_reg_loc(l_type, OptoReg::as_VMReg(regnum)) )
495 : new LocationValue(Location::new_stk_loc(l_type, ra->reg2offset(regnum)));
496 }
497
498
499 ObjectValue*
500 Compile::sv_for_node_id(GrowableArray<ScopeValue*> *objs, int id) {
501 for (int i = 0; i < objs->length(); i++) {
502 assert(objs->at(i)->is_object(), "corrupt object cache");
503 ObjectValue* sv = (ObjectValue*) objs->at(i);
504 if (sv->id() == id) {
505 return sv;
506 }
507 }
508 // Otherwise..
509 return NULL;
510 }
511
512 void Compile::set_sv_for_object_node(GrowableArray<ScopeValue*> *objs,
513 ObjectValue* sv ) {
514 assert(sv_for_node_id(objs, sv->id()) == NULL, "Precondition");
515 objs->append(sv);
516 }
517
518
519 void Compile::FillLocArray( int idx, MachSafePointNode* sfpt, Node *local,
520 GrowableArray<ScopeValue*> *array,
521 GrowableArray<ScopeValue*> *objs ) {
522 assert( local, "use _top instead of null" );
523 if (array->length() != idx) {
524 assert(array->length() == idx + 1, "Unexpected array count");
525 // Old functionality:
526 // return
527 // New functionality:
528 // Assert if the local is not top. In product mode let the new node
529 // override the old entry.
530 assert(local == top(), "LocArray collision");
531 if (local == top()) {
532 return;
533 }
534 array->pop();
535 }
536 const Type *t = local->bottom_type();
537
538 // Is it a safepoint scalar object node?
539 if (local->is_SafePointScalarObject()) {
540 SafePointScalarObjectNode* spobj = local->as_SafePointScalarObject();
541
542 ObjectValue* sv = Compile::sv_for_node_id(objs, spobj->_idx);
543 if (sv == NULL) {
544 ciKlass* cik = t->is_oopptr()->klass();
545 assert(cik->is_instance_klass() ||
546 cik->is_array_klass(), "Not supported allocation.");
547 sv = new ObjectValue(spobj->_idx,
548 new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
549 Compile::set_sv_for_object_node(objs, sv);
550
551 uint first_ind = spobj->first_index(sfpt->jvms());
552 for (uint i = 0; i < spobj->n_fields(); i++) {
553 Node* fld_node = sfpt->in(first_ind+i);
554 (void)FillLocArray(sv->field_values()->length(), sfpt, fld_node, sv->field_values(), objs);
555 }
556 }
557 array->append(sv);
558 return;
559 }
560
561 // Grab the register number for the local
562 OptoReg::Name regnum = _regalloc->get_reg_first(local);
563 if( OptoReg::is_valid(regnum) ) {// Got a register/stack?
564 // Record the double as two float registers.
565 // The register mask for such a value always specifies two adjacent
566 // float registers, with the lower register number even.
567 // Normally, the allocation of high and low words to these registers
568 // is irrelevant, because nearly all operations on register pairs
569 // (e.g., StoreD) treat them as a single unit.
570 // Here, we assume in addition that the words in these two registers
571 // stored "naturally" (by operations like StoreD and double stores
572 // within the interpreter) such that the lower-numbered register
573 // is written to the lower memory address. This may seem like
574 // a machine dependency, but it is not--it is a requirement on
575 // the author of the <arch>.ad file to ensure that, for every
576 // even/odd double-register pair to which a double may be allocated,
577 // the word in the even single-register is stored to the first
578 // memory word. (Note that register numbers are completely
579 // arbitrary, and are not tied to any machine-level encodings.)
580 #ifdef _LP64
581 if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon ) {
582 array->append(new ConstantIntValue((jint)0));
583 array->append(new_loc_value( _regalloc, regnum, Location::dbl ));
584 } else if ( t->base() == Type::Long ) {
585 array->append(new ConstantIntValue((jint)0));
586 array->append(new_loc_value( _regalloc, regnum, Location::lng ));
587 } else if ( t->base() == Type::RawPtr ) {
588 // jsr/ret return address which must be restored into a the full
589 // width 64-bit stack slot.
590 array->append(new_loc_value( _regalloc, regnum, Location::lng ));
591 }
592 #else //_LP64
593 #ifdef SPARC
594 if (t->base() == Type::Long && OptoReg::is_reg(regnum)) {
595 // For SPARC we have to swap high and low words for
596 // long values stored in a single-register (g0-g7).
597 array->append(new_loc_value( _regalloc, regnum , Location::normal ));
598 array->append(new_loc_value( _regalloc, OptoReg::add(regnum,1), Location::normal ));
599 } else
600 #endif //SPARC
601 if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon || t->base() == Type::Long ) {
602 // Repack the double/long as two jints.
603 // The convention the interpreter uses is that the second local
604 // holds the first raw word of the native double representation.
605 // This is actually reasonable, since locals and stack arrays
606 // grow downwards in all implementations.
607 // (If, on some machine, the interpreter's Java locals or stack
608 // were to grow upwards, the embedded doubles would be word-swapped.)
609 array->append(new_loc_value( _regalloc, OptoReg::add(regnum,1), Location::normal ));
610 array->append(new_loc_value( _regalloc, regnum , Location::normal ));
611 }
612 #endif //_LP64
613 else if( (t->base() == Type::FloatBot || t->base() == Type::FloatCon) &&
614 OptoReg::is_reg(regnum) ) {
615 array->append(new_loc_value( _regalloc, regnum, Matcher::float_in_double()
616 ? Location::float_in_dbl : Location::normal ));
617 } else if( t->base() == Type::Int && OptoReg::is_reg(regnum) ) {
618 array->append(new_loc_value( _regalloc, regnum, Matcher::int_in_long
619 ? Location::int_in_long : Location::normal ));
620 } else if( t->base() == Type::NarrowOop ) {
621 array->append(new_loc_value( _regalloc, regnum, Location::narrowoop ));
622 } else {
623 array->append(new_loc_value( _regalloc, regnum, _regalloc->is_oop(local) ? Location::oop : Location::normal ));
624 }
625 return;
626 }
627
628 // No register. It must be constant data.
629 switch (t->base()) {
630 case Type::Half: // Second half of a double
631 ShouldNotReachHere(); // Caller should skip 2nd halves
632 break;
633 case Type::AnyPtr:
634 array->append(new ConstantOopWriteValue(NULL));
635 break;
636 case Type::AryPtr:
637 case Type::InstPtr: // fall through
638 array->append(new ConstantOopWriteValue(t->isa_oopptr()->const_oop()->constant_encoding()));
639 break;
640 case Type::NarrowOop:
641 if (t == TypeNarrowOop::NULL_PTR) {
642 array->append(new ConstantOopWriteValue(NULL));
643 } else {
644 array->append(new ConstantOopWriteValue(t->make_ptr()->isa_oopptr()->const_oop()->constant_encoding()));
645 }
646 break;
647 case Type::Int:
648 array->append(new ConstantIntValue(t->is_int()->get_con()));
649 break;
650 case Type::RawPtr:
651 // A return address (T_ADDRESS).
652 assert((intptr_t)t->is_ptr()->get_con() < (intptr_t)0x10000, "must be a valid BCI");
653 #ifdef _LP64
654 // Must be restored to the full-width 64-bit stack slot.
655 array->append(new ConstantLongValue(t->is_ptr()->get_con()));
656 #else
657 array->append(new ConstantIntValue(t->is_ptr()->get_con()));
658 #endif
659 break;
660 case Type::FloatCon: {
661 float f = t->is_float_constant()->getf();
662 array->append(new ConstantIntValue(jint_cast(f)));
663 break;
664 }
665 case Type::DoubleCon: {
666 jdouble d = t->is_double_constant()->getd();
667 #ifdef _LP64
668 array->append(new ConstantIntValue((jint)0));
669 array->append(new ConstantDoubleValue(d));
670 #else
671 // Repack the double as two jints.
672 // The convention the interpreter uses is that the second local
673 // holds the first raw word of the native double representation.
674 // This is actually reasonable, since locals and stack arrays
675 // grow downwards in all implementations.
676 // (If, on some machine, the interpreter's Java locals or stack
677 // were to grow upwards, the embedded doubles would be word-swapped.)
678 jlong_accessor acc;
679 acc.long_value = jlong_cast(d);
680 array->append(new ConstantIntValue(acc.words[1]));
681 array->append(new ConstantIntValue(acc.words[0]));
682 #endif
683 break;
684 }
685 case Type::Long: {
686 jlong d = t->is_long()->get_con();
687 #ifdef _LP64
688 array->append(new ConstantIntValue((jint)0));
689 array->append(new ConstantLongValue(d));
690 #else
691 // Repack the long as two jints.
692 // The convention the interpreter uses is that the second local
693 // holds the first raw word of the native double representation.
694 // This is actually reasonable, since locals and stack arrays
695 // grow downwards in all implementations.
696 // (If, on some machine, the interpreter's Java locals or stack
697 // were to grow upwards, the embedded doubles would be word-swapped.)
698 jlong_accessor acc;
699 acc.long_value = d;
700 array->append(new ConstantIntValue(acc.words[1]));
701 array->append(new ConstantIntValue(acc.words[0]));
702 #endif
703 break;
704 }
705 case Type::Top: // Add an illegal value here
706 array->append(new LocationValue(Location()));
707 break;
708 default:
709 ShouldNotReachHere();
710 break;
711 }
712 }
713
714 // Determine if this node starts a bundle
715 bool Compile::starts_bundle(const Node *n) const {
716 return (_node_bundling_limit > n->_idx &&
717 _node_bundling_base[n->_idx].starts_bundle());
718 }
719
720 //--------------------------Process_OopMap_Node--------------------------------
721 void Compile::Process_OopMap_Node(MachNode *mach, int current_offset) {
722
723 // Handle special safepoint nodes for synchronization
724 MachSafePointNode *sfn = mach->as_MachSafePoint();
725 MachCallNode *mcall;
726
727 int safepoint_pc_offset = current_offset;
728 bool is_method_handle_invoke = false;
729 bool return_oop = false;
730
731 // Add the safepoint in the DebugInfoRecorder
732 if( !mach->is_MachCall() ) {
733 mcall = NULL;
734 debug_info()->add_safepoint(safepoint_pc_offset, sfn->_oop_map);
735 } else {
736 mcall = mach->as_MachCall();
737
738 // Is the call a MethodHandle call?
739 if (mcall->is_MachCallJava()) {
740 if (mcall->as_MachCallJava()->_method_handle_invoke) {
741 assert(has_method_handle_invokes(), "must have been set during call generation");
742 is_method_handle_invoke = true;
743 }
744 }
745
746 // Check if a call returns an object.
747 if (mcall->returns_pointer()) {
748 return_oop = true;
749 }
750 safepoint_pc_offset += mcall->ret_addr_offset();
751 debug_info()->add_safepoint(safepoint_pc_offset, mcall->_oop_map);
752 }
753
754 // Loop over the JVMState list to add scope information
755 // Do not skip safepoints with a NULL method, they need monitor info
756 JVMState* youngest_jvms = sfn->jvms();
757 int max_depth = youngest_jvms->depth();
758
759 // Allocate the object pool for scalar-replaced objects -- the map from
760 // small-integer keys (which can be recorded in the local and ostack
761 // arrays) to descriptions of the object state.
762 GrowableArray<ScopeValue*> *objs = new GrowableArray<ScopeValue*>();
763
764 // Visit scopes from oldest to youngest.
765 for (int depth = 1; depth <= max_depth; depth++) {
766 JVMState* jvms = youngest_jvms->of_depth(depth);
767 int idx;
768 ciMethod* method = jvms->has_method() ? jvms->method() : NULL;
769 // Safepoints that do not have method() set only provide oop-map and monitor info
770 // to support GC; these do not support deoptimization.
771 int num_locs = (method == NULL) ? 0 : jvms->loc_size();
772 int num_exps = (method == NULL) ? 0 : jvms->stk_size();
773 int num_mon = jvms->nof_monitors();
774 assert(method == NULL || jvms->bci() < 0 || num_locs == method->max_locals(),
775 "JVMS local count must match that of the method");
776
777 // Add Local and Expression Stack Information
778
779 // Insert locals into the locarray
780 GrowableArray<ScopeValue*> *locarray = new GrowableArray<ScopeValue*>(num_locs);
781 for( idx = 0; idx < num_locs; idx++ ) {
782 FillLocArray( idx, sfn, sfn->local(jvms, idx), locarray, objs );
783 }
784
785 // Insert expression stack entries into the exparray
786 GrowableArray<ScopeValue*> *exparray = new GrowableArray<ScopeValue*>(num_exps);
787 for( idx = 0; idx < num_exps; idx++ ) {
788 FillLocArray( idx, sfn, sfn->stack(jvms, idx), exparray, objs );
789 }
790
791 // Add in mappings of the monitors
792 assert( !method ||
793 !method->is_synchronized() ||
794 method->is_native() ||
795 num_mon > 0 ||
796 !GenerateSynchronizationCode,
797 "monitors must always exist for synchronized methods");
798
799 // Build the growable array of ScopeValues for exp stack
800 GrowableArray<MonitorValue*> *monarray = new GrowableArray<MonitorValue*>(num_mon);
801
802 // Loop over monitors and insert into array
803 for (idx = 0; idx < num_mon; idx++) {
804 // Grab the node that defines this monitor
805 Node* box_node = sfn->monitor_box(jvms, idx);
806 Node* obj_node = sfn->monitor_obj(jvms, idx);
807
808 // Create ScopeValue for object
809 ScopeValue *scval = NULL;
810
811 if (obj_node->is_SafePointScalarObject()) {
812 SafePointScalarObjectNode* spobj = obj_node->as_SafePointScalarObject();
813 scval = Compile::sv_for_node_id(objs, spobj->_idx);
814 if (scval == NULL) {
815 const Type *t = spobj->bottom_type();
816 ciKlass* cik = t->is_oopptr()->klass();
817 assert(cik->is_instance_klass() ||
818 cik->is_array_klass(), "Not supported allocation.");
819 ObjectValue* sv = new ObjectValue(spobj->_idx,
820 new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
821 Compile::set_sv_for_object_node(objs, sv);
822
823 uint first_ind = spobj->first_index(youngest_jvms);
824 for (uint i = 0; i < spobj->n_fields(); i++) {
825 Node* fld_node = sfn->in(first_ind+i);
826 (void)FillLocArray(sv->field_values()->length(), sfn, fld_node, sv->field_values(), objs);
827 }
828 scval = sv;
829 }
830 } else if (!obj_node->is_Con()) {
831 OptoReg::Name obj_reg = _regalloc->get_reg_first(obj_node);
832 if( obj_node->bottom_type()->base() == Type::NarrowOop ) {
833 scval = new_loc_value( _regalloc, obj_reg, Location::narrowoop );
834 } else {
835 scval = new_loc_value( _regalloc, obj_reg, Location::oop );
836 }
837 } else {
838 const TypePtr *tp = obj_node->get_ptr_type();
839 scval = new ConstantOopWriteValue(tp->is_oopptr()->const_oop()->constant_encoding());
840 }
841
842 OptoReg::Name box_reg = BoxLockNode::reg(box_node);
843 Location basic_lock = Location::new_stk_loc(Location::normal,_regalloc->reg2offset(box_reg));
844 bool eliminated = (box_node->is_BoxLock() && box_node->as_BoxLock()->is_eliminated());
845 monarray->append(new MonitorValue(scval, basic_lock, eliminated));
846 }
847
848 // We dump the object pool first, since deoptimization reads it in first.
849 debug_info()->dump_object_pool(objs);
850
851 // Build first class objects to pass to scope
852 DebugToken *locvals = debug_info()->create_scope_values(locarray);
853 DebugToken *expvals = debug_info()->create_scope_values(exparray);
854 DebugToken *monvals = debug_info()->create_monitor_values(monarray);
855
856 // Make method available for all Safepoints
857 ciMethod* scope_method = method ? method : _method;
858 // Describe the scope here
859 assert(jvms->bci() >= InvocationEntryBci && jvms->bci() <= 0x10000, "must be a valid or entry BCI");
860 assert(!jvms->should_reexecute() || depth == max_depth, "reexecute allowed only for the youngest");
861 // Now we can describe the scope.
862 methodHandle null_mh;
863 bool rethrow_exception = false;
864 debug_info()->describe_scope(safepoint_pc_offset, null_mh, scope_method, jvms->bci(), jvms->should_reexecute(), rethrow_exception, is_method_handle_invoke, return_oop, locvals, expvals, monvals);
865 } // End jvms loop
866
867 // Mark the end of the scope set.
868 debug_info()->end_safepoint(safepoint_pc_offset);
869 }
870
871
872
873 // A simplified version of Process_OopMap_Node, to handle non-safepoints.
874 class NonSafepointEmitter {
875 Compile* C;
876 JVMState* _pending_jvms;
877 int _pending_offset;
878
879 void emit_non_safepoint();
880
881 public:
882 NonSafepointEmitter(Compile* compile) {
883 this->C = compile;
884 _pending_jvms = NULL;
885 _pending_offset = 0;
886 }
887
888 void observe_instruction(Node* n, int pc_offset) {
889 if (!C->debug_info()->recording_non_safepoints()) return;
890
891 Node_Notes* nn = C->node_notes_at(n->_idx);
892 if (nn == NULL || nn->jvms() == NULL) return;
893 if (_pending_jvms != NULL &&
894 _pending_jvms->same_calls_as(nn->jvms())) {
895 // Repeated JVMS? Stretch it up here.
896 _pending_offset = pc_offset;
897 } else {
898 if (_pending_jvms != NULL &&
899 _pending_offset < pc_offset) {
900 emit_non_safepoint();
901 }
902 _pending_jvms = NULL;
903 if (pc_offset > C->debug_info()->last_pc_offset()) {
904 // This is the only way _pending_jvms can become non-NULL:
905 _pending_jvms = nn->jvms();
906 _pending_offset = pc_offset;
907 }
908 }
909 }
910
911 // Stay out of the way of real safepoints:
912 void observe_safepoint(JVMState* jvms, int pc_offset) {
913 if (_pending_jvms != NULL &&
914 !_pending_jvms->same_calls_as(jvms) &&
915 _pending_offset < pc_offset) {
916 emit_non_safepoint();
917 }
918 _pending_jvms = NULL;
919 }
920
921 void flush_at_end() {
922 if (_pending_jvms != NULL) {
923 emit_non_safepoint();
924 }
925 _pending_jvms = NULL;
926 }
927 };
928
929 void NonSafepointEmitter::emit_non_safepoint() {
930 JVMState* youngest_jvms = _pending_jvms;
931 int pc_offset = _pending_offset;
932
933 // Clear it now:
934 _pending_jvms = NULL;
935
936 DebugInformationRecorder* debug_info = C->debug_info();
937 assert(debug_info->recording_non_safepoints(), "sanity");
938
939 debug_info->add_non_safepoint(pc_offset);
940 int max_depth = youngest_jvms->depth();
941
942 // Visit scopes from oldest to youngest.
943 for (int depth = 1; depth <= max_depth; depth++) {
944 JVMState* jvms = youngest_jvms->of_depth(depth);
945 ciMethod* method = jvms->has_method() ? jvms->method() : NULL;
946 assert(!jvms->should_reexecute() || depth==max_depth, "reexecute allowed only for the youngest");
947 methodHandle null_mh;
948 debug_info->describe_scope(pc_offset, null_mh, method, jvms->bci(), jvms->should_reexecute());
949 }
950
951 // Mark the end of the scope set.
952 debug_info->end_non_safepoint(pc_offset);
953 }
954
955 //------------------------------init_buffer------------------------------------
956 CodeBuffer* Compile::init_buffer(uint* blk_starts) {
957
958 // Set the initially allocated size
959 int code_req = initial_code_capacity;
960 int locs_req = initial_locs_capacity;
961 int stub_req = initial_stub_capacity;
962 int const_req = initial_const_capacity;
963
964 int pad_req = NativeCall::instruction_size;
965 // The extra spacing after the code is necessary on some platforms.
966 // Sometimes we need to patch in a jump after the last instruction,
967 // if the nmethod has been deoptimized. (See 4932387, 4894843.)
968
969 // Compute the byte offset where we can store the deopt pc.
970 if (fixed_slots() != 0) {
971 _orig_pc_slot_offset_in_bytes = _regalloc->reg2offset(OptoReg::stack2reg(_orig_pc_slot));
972 }
973
974 // Compute prolog code size
975 _method_size = 0;
976 _frame_slots = OptoReg::reg2stack(_matcher->_old_SP)+_regalloc->_framesize;
977 #if defined(IA64) && !defined(AIX)
978 if (save_argument_registers()) {
979 // 4815101: this is a stub with implicit and unknown precision fp args.
980 // The usual spill mechanism can only generate stfd's in this case, which
981 // doesn't work if the fp reg to spill contains a single-precision denorm.
982 // Instead, we hack around the normal spill mechanism using stfspill's and
983 // ldffill's in the MachProlog and MachEpilog emit methods. We allocate
984 // space here for the fp arg regs (f8-f15) we're going to thusly spill.
985 //
986 // If we ever implement 16-byte 'registers' == stack slots, we can
987 // get rid of this hack and have SpillCopy generate stfspill/ldffill
988 // instead of stfd/stfs/ldfd/ldfs.
989 _frame_slots += 8*(16/BytesPerInt);
990 }
991 #endif
992 assert(_frame_slots >= 0 && _frame_slots < 1000000, "sanity check");
993
994 if (has_mach_constant_base_node()) {
995 uint add_size = 0;
996 // Fill the constant table.
997 // Note: This must happen before shorten_branches.
998 for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
999 Block* b = _cfg->get_block(i);
1000
1001 for (uint j = 0; j < b->number_of_nodes(); j++) {
1002 Node* n = b->get_node(j);
1003
1004 // If the node is a MachConstantNode evaluate the constant
1005 // value section.
1006 if (n->is_MachConstant()) {
1007 MachConstantNode* machcon = n->as_MachConstant();
1008 machcon->eval_constant(C);
1009 } else if (n->is_Mach()) {
1010 // On Power there are more nodes that issue constants.
1011 add_size += (n->as_Mach()->ins_num_consts() * 8);
1012 }
1013 }
1014 }
1015
1016 // Calculate the offsets of the constants and the size of the
1017 // constant table (including the padding to the next section).
1018 constant_table().calculate_offsets_and_size();
1019 const_req = constant_table().size() + add_size;
1020 }
1021
1022 // Initialize the space for the BufferBlob used to find and verify
1023 // instruction size in MachNode::emit_size()
1024 init_scratch_buffer_blob(const_req);
1025 if (failing()) return NULL; // Out of memory
1026
1027 // Pre-compute the length of blocks and replace
1028 // long branches with short if machine supports it.
1029 shorten_branches(blk_starts, code_req, locs_req, stub_req);
1030
1031 // nmethod and CodeBuffer count stubs & constants as part of method's code.
1032 // class HandlerImpl is platform-specific and defined in the *.ad files.
1033 int exception_handler_req = HandlerImpl::size_exception_handler() + MAX_stubs_size; // add marginal slop for handler
1034 int deopt_handler_req = HandlerImpl::size_deopt_handler() + MAX_stubs_size; // add marginal slop for handler
1035 stub_req += MAX_stubs_size; // ensure per-stub margin
1036 code_req += MAX_inst_size; // ensure per-instruction margin
1037
1038 if (StressCodeBuffers)
1039 code_req = const_req = stub_req = exception_handler_req = deopt_handler_req = 0x10; // force expansion
1040
1041 int total_req =
1042 const_req +
1043 code_req +
1044 pad_req +
1045 stub_req +
1046 exception_handler_req +
1047 deopt_handler_req; // deopt handler
1048
1049 if (has_method_handle_invokes())
1050 total_req += deopt_handler_req; // deopt MH handler
1051
1052 CodeBuffer* cb = code_buffer();
1053 cb->initialize(total_req, locs_req);
1054
1055 // Have we run out of code space?
1056 if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
1057 C->record_failure("CodeCache is full");
1058 return NULL;
1059 }
1060 // Configure the code buffer.
1061 cb->initialize_consts_size(const_req);
1062 cb->initialize_stubs_size(stub_req);
1063 cb->initialize_oop_recorder(env()->oop_recorder());
1064
1065 // fill in the nop array for bundling computations
1066 MachNode *_nop_list[Bundle::_nop_count];
1067 Bundle::initialize_nops(_nop_list);
1068
1069 return cb;
1070 }
1071
1072 //------------------------------fill_buffer------------------------------------
1073 void Compile::fill_buffer(CodeBuffer* cb, uint* blk_starts) {
1074 // blk_starts[] contains offsets calculated during short branches processing,
1075 // offsets should not be increased during following steps.
1076
1077 // Compute the size of first NumberOfLoopInstrToAlign instructions at head
1078 // of a loop. It is used to determine the padding for loop alignment.
1079 compute_loop_first_inst_sizes();
1080
1081 // Create oopmap set.
1082 _oop_map_set = new OopMapSet();
1083
1084 // !!!!! This preserves old handling of oopmaps for now
1085 debug_info()->set_oopmaps(_oop_map_set);
1086
1087 uint nblocks = _cfg->number_of_blocks();
1088 // Count and start of implicit null check instructions
1089 uint inct_cnt = 0;
1090 uint *inct_starts = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1091
1092 // Count and start of calls
1093 uint *call_returns = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1094
1095 uint return_offset = 0;
1096 int nop_size = (new MachNopNode())->size(_regalloc);
1097
1098 int previous_offset = 0;
1099 int current_offset = 0;
1100 int last_call_offset = -1;
1101 int last_avoid_back_to_back_offset = -1;
1102 #ifdef ASSERT
1103 uint* jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks);
1104 uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
1105 uint* jmp_size = NEW_RESOURCE_ARRAY(uint,nblocks);
1106 uint* jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks);
1107 #endif
1108
1109 // Create an array of unused labels, one for each basic block, if printing is enabled
1110 #ifndef PRODUCT
1111 int *node_offsets = NULL;
1112 uint node_offset_limit = unique();
1113
1114 if (print_assembly())
1115 node_offsets = NEW_RESOURCE_ARRAY(int, node_offset_limit);
1116 #endif
1117
1118 NonSafepointEmitter non_safepoints(this); // emit non-safepoints lazily
1119
1120 // Emit the constant table.
1121 if (has_mach_constant_base_node()) {
1122 constant_table().emit(*cb);
1123 }
1124
1125 // Create an array of labels, one for each basic block
1126 Label *blk_labels = NEW_RESOURCE_ARRAY(Label, nblocks+1);
1127 for (uint i=0; i <= nblocks; i++) {
1128 blk_labels[i].init();
1129 }
1130
1131 // ------------------
1132 // Now fill in the code buffer
1133 Node *delay_slot = NULL;
1134
1135 for (uint i = 0; i < nblocks; i++) {
1136 Block* block = _cfg->get_block(i);
1137 Node* head = block->head();
1138
1139 // If this block needs to start aligned (i.e, can be reached other
1140 // than by falling-thru from the previous block), then force the
1141 // start of a new bundle.
1142 if (Pipeline::requires_bundling() && starts_bundle(head)) {
1143 cb->flush_bundle(true);
1144 }
1145
1146 #ifdef ASSERT
1147 if (!block->is_connector()) {
1148 stringStream st;
1149 block->dump_head(_cfg, &st);
1150 MacroAssembler(cb).block_comment(st.as_string());
1151 }
1152 jmp_target[i] = 0;
1153 jmp_offset[i] = 0;
1154 jmp_size[i] = 0;
1155 jmp_rule[i] = 0;
1156 #endif
1157 int blk_offset = current_offset;
1158
1159 // Define the label at the beginning of the basic block
1160 MacroAssembler(cb).bind(blk_labels[block->_pre_order]);
1161
1162 uint last_inst = block->number_of_nodes();
1163
1164 // Emit block normally, except for last instruction.
1165 // Emit means "dump code bits into code buffer".
1166 for (uint j = 0; j<last_inst; j++) {
1167
1168 // Get the node
1169 Node* n = block->get_node(j);
1170
1171 // See if delay slots are supported
1172 if (valid_bundle_info(n) &&
1173 node_bundling(n)->used_in_unconditional_delay()) {
1174 assert(delay_slot == NULL, "no use of delay slot node");
1175 assert(n->size(_regalloc) == Pipeline::instr_unit_size(), "delay slot instruction wrong size");
1176
1177 delay_slot = n;
1178 continue;
1179 }
1180
1181 // If this starts a new instruction group, then flush the current one
1182 // (but allow split bundles)
1183 if (Pipeline::requires_bundling() && starts_bundle(n))
1184 cb->flush_bundle(false);
1185
1186 // Special handling for SafePoint/Call Nodes
1187 bool is_mcall = false;
1188 if (n->is_Mach()) {
1189 MachNode *mach = n->as_Mach();
1190 is_mcall = n->is_MachCall();
1191 bool is_sfn = n->is_MachSafePoint();
1192
1193 // If this requires all previous instructions be flushed, then do so
1194 if (is_sfn || is_mcall || mach->alignment_required() != 1) {
1195 cb->flush_bundle(true);
1196 current_offset = cb->insts_size();
1197 }
1198
1199 // A padding may be needed again since a previous instruction
1200 // could be moved to delay slot.
1201
1202 // align the instruction if necessary
1203 int padding = mach->compute_padding(current_offset);
1204 // Make sure safepoint node for polling is distinct from a call's
1205 // return by adding a nop if needed.
1206 if (is_sfn && !is_mcall && padding == 0 && current_offset == last_call_offset) {
1207 padding = nop_size;
1208 }
1209 if (padding == 0 && mach->avoid_back_to_back(MachNode::AVOID_BEFORE) &&
1210 current_offset == last_avoid_back_to_back_offset) {
1211 // Avoid back to back some instructions.
1212 padding = nop_size;
1213 }
1214
1215 if (padding > 0) {
1216 assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
1217 int nops_cnt = padding / nop_size;
1218 MachNode *nop = new MachNopNode(nops_cnt);
1219 block->insert_node(nop, j++);
1220 last_inst++;
1221 _cfg->map_node_to_block(nop, block);
1222 // Ensure enough space.
1223 cb->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1224 if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
1225 C->record_failure("CodeCache is full");
1226 return;
1227 }
1228 nop->emit(*cb, _regalloc);
1229 cb->flush_bundle(true);
1230 current_offset = cb->insts_size();
1231 }
1232
1233 // Remember the start of the last call in a basic block
1234 if (is_mcall) {
1235 MachCallNode *mcall = mach->as_MachCall();
1236
1237 // This destination address is NOT PC-relative
1238 mcall->method_set((intptr_t)mcall->entry_point());
1239
1240 // Save the return address
1241 call_returns[block->_pre_order] = current_offset + mcall->ret_addr_offset();
1242
1243 if (mcall->is_MachCallLeaf()) {
1244 is_mcall = false;
1245 is_sfn = false;
1246 }
1247 }
1248
1249 // sfn will be valid whenever mcall is valid now because of inheritance
1250 if (is_sfn || is_mcall) {
1251
1252 // Handle special safepoint nodes for synchronization
1253 if (!is_mcall) {
1254 MachSafePointNode *sfn = mach->as_MachSafePoint();
1255 // !!!!! Stubs only need an oopmap right now, so bail out
1256 if (sfn->jvms()->method() == NULL) {
1257 // Write the oopmap directly to the code blob??!!
1258 continue;
1259 }
1260 } // End synchronization
1261
1262 non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1263 current_offset);
1264 Process_OopMap_Node(mach, current_offset);
1265 } // End if safepoint
1266
1267 // If this is a null check, then add the start of the previous instruction to the list
1268 else if( mach->is_MachNullCheck() ) {
1269 inct_starts[inct_cnt++] = previous_offset;
1270 }
1271
1272 // If this is a branch, then fill in the label with the target BB's label
1273 else if (mach->is_MachBranch()) {
1274 // This requires the TRUE branch target be in succs[0]
1275 uint block_num = block->non_connector_successor(0)->_pre_order;
1276
1277 // Try to replace long branch if delay slot is not used,
1278 // it is mostly for back branches since forward branch's
1279 // distance is not updated yet.
1280 bool delay_slot_is_used = valid_bundle_info(n) &&
1281 node_bundling(n)->use_unconditional_delay();
1282 if (!delay_slot_is_used && mach->may_be_short_branch()) {
1283 assert(delay_slot == NULL, "not expecting delay slot node");
1284 int br_size = n->size(_regalloc);
1285 int offset = blk_starts[block_num] - current_offset;
1286 if (block_num >= i) {
1287 // Current and following block's offset are not
1288 // finalized yet, adjust distance by the difference
1289 // between calculated and final offsets of current block.
1290 offset -= (blk_starts[i] - blk_offset);
1291 }
1292 // In the following code a nop could be inserted before
1293 // the branch which will increase the backward distance.
1294 bool needs_padding = (current_offset == last_avoid_back_to_back_offset);
1295 if (needs_padding && offset <= 0)
1296 offset -= nop_size;
1297
1298 if (_matcher->is_short_branch_offset(mach->rule(), br_size, offset)) {
1299 // We've got a winner. Replace this branch.
1300 MachNode* replacement = mach->as_MachBranch()->short_branch_version();
1301
1302 // Update the jmp_size.
1303 int new_size = replacement->size(_regalloc);
1304 assert((br_size - new_size) >= (int)nop_size, "short_branch size should be smaller");
1305 // Insert padding between avoid_back_to_back branches.
1306 if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
1307 MachNode *nop = new MachNopNode();
1308 block->insert_node(nop, j++);
1309 _cfg->map_node_to_block(nop, block);
1310 last_inst++;
1311 nop->emit(*cb, _regalloc);
1312 cb->flush_bundle(true);
1313 current_offset = cb->insts_size();
1314 }
1315 #ifdef ASSERT
1316 jmp_target[i] = block_num;
1317 jmp_offset[i] = current_offset - blk_offset;
1318 jmp_size[i] = new_size;
1319 jmp_rule[i] = mach->rule();
1320 #endif
1321 block->map_node(replacement, j);
1322 mach->subsume_by(replacement, C);
1323 n = replacement;
1324 mach = replacement;
1325 }
1326 }
1327 mach->as_MachBranch()->label_set( &blk_labels[block_num], block_num );
1328 } else if (mach->ideal_Opcode() == Op_Jump) {
1329 for (uint h = 0; h < block->_num_succs; h++) {
1330 Block* succs_block = block->_succs[h];
1331 for (uint j = 1; j < succs_block->num_preds(); j++) {
1332 Node* jpn = succs_block->pred(j);
1333 if (jpn->is_JumpProj() && jpn->in(0) == mach) {
1334 uint block_num = succs_block->non_connector()->_pre_order;
1335 Label *blkLabel = &blk_labels[block_num];
1336 mach->add_case_label(jpn->as_JumpProj()->proj_no(), blkLabel);
1337 }
1338 }
1339 }
1340 }
1341 #ifdef ASSERT
1342 // Check that oop-store precedes the card-mark
1343 else if (mach->ideal_Opcode() == Op_StoreCM) {
1344 uint storeCM_idx = j;
1345 int count = 0;
1346 for (uint prec = mach->req(); prec < mach->len(); prec++) {
1347 Node *oop_store = mach->in(prec); // Precedence edge
1348 if (oop_store == NULL) continue;
1349 count++;
1350 uint i4;
1351 for (i4 = 0; i4 < last_inst; ++i4) {
1352 if (block->get_node(i4) == oop_store) {
1353 break;
1354 }
1355 }
1356 // Note: This test can provide a false failure if other precedence
1357 // edges have been added to the storeCMNode.
1358 assert(i4 == last_inst || i4 < storeCM_idx, "CM card-mark executes before oop-store");
1359 }
1360 assert(count > 0, "storeCM expects at least one precedence edge");
1361 }
1362 #endif
1363 else if (!n->is_Proj()) {
1364 // Remember the beginning of the previous instruction, in case
1365 // it's followed by a flag-kill and a null-check. Happens on
1366 // Intel all the time, with add-to-memory kind of opcodes.
1367 previous_offset = current_offset;
1368 }
1369
1370 // Not an else-if!
1371 // If this is a trap based cmp then add its offset to the list.
1372 if (mach->is_TrapBasedCheckNode()) {
1373 inct_starts[inct_cnt++] = current_offset;
1374 }
1375 }
1376
1377 // Verify that there is sufficient space remaining
1378 cb->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1379 if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
1380 C->record_failure("CodeCache is full");
1381 return;
1382 }
1383
1384 // Save the offset for the listing
1385 #ifndef PRODUCT
1386 if (node_offsets && n->_idx < node_offset_limit)
1387 node_offsets[n->_idx] = cb->insts_size();
1388 #endif
1389
1390 // "Normal" instruction case
1391 DEBUG_ONLY( uint instr_offset = cb->insts_size(); )
1392 n->emit(*cb, _regalloc);
1393 current_offset = cb->insts_size();
1394
1395 // Above we only verified that there is enough space in the instruction section.
1396 // However, the instruction may emit stubs that cause code buffer expansion.
1397 // Bail out here if expansion failed due to a lack of code cache space.
1398 if (failing()) {
1399 return;
1400 }
1401
1402 #ifdef ASSERT
1403 uint n_size = n->size(C->regalloc());
1404 if (n_size < (current_offset-instr_offset)) {
1405 MachNode* mach = n->as_Mach();
1406 n->dump();
1407 mach->dump_format(C->regalloc(), tty);
1408 tty->print_cr(" n_size (%d), current_offset (%d), instr_offset (%d)", n_size, current_offset, instr_offset);
1409 Disassembler::decode(cb->insts_begin() + instr_offset, cb->insts_begin() + current_offset + 1, tty);
1410 tty->print_cr(" ------------------- ");
1411 BufferBlob* blob = this->scratch_buffer_blob();
1412 address blob_begin = blob->content_begin();
1413 Disassembler::decode(blob_begin, blob_begin + n_size + 1, tty);
1414 assert(false, "wrong size of mach node");
1415 }
1416 #endif
1417 non_safepoints.observe_instruction(n, current_offset);
1418
1419 // mcall is last "call" that can be a safepoint
1420 // record it so we can see if a poll will directly follow it
1421 // in which case we'll need a pad to make the PcDesc sites unique
1422 // see 5010568. This can be slightly inaccurate but conservative
1423 // in the case that return address is not actually at current_offset.
1424 // This is a small price to pay.
1425
1426 if (is_mcall) {
1427 last_call_offset = current_offset;
1428 }
1429
1430 if (n->is_Mach() && n->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
1431 // Avoid back to back some instructions.
1432 last_avoid_back_to_back_offset = current_offset;
1433 }
1434
1435 // See if this instruction has a delay slot
1436 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
1437 guarantee(delay_slot != NULL, "expecting delay slot node");
1438
1439 // Back up 1 instruction
1440 cb->set_insts_end(cb->insts_end() - Pipeline::instr_unit_size());
1441
1442 // Save the offset for the listing
1443 #ifndef PRODUCT
1444 if (node_offsets && delay_slot->_idx < node_offset_limit)
1445 node_offsets[delay_slot->_idx] = cb->insts_size();
1446 #endif
1447
1448 // Support a SafePoint in the delay slot
1449 if (delay_slot->is_MachSafePoint()) {
1450 MachNode *mach = delay_slot->as_Mach();
1451 // !!!!! Stubs only need an oopmap right now, so bail out
1452 if (!mach->is_MachCall() && mach->as_MachSafePoint()->jvms()->method() == NULL) {
1453 // Write the oopmap directly to the code blob??!!
1454 delay_slot = NULL;
1455 continue;
1456 }
1457
1458 int adjusted_offset = current_offset - Pipeline::instr_unit_size();
1459 non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1460 adjusted_offset);
1461 // Generate an OopMap entry
1462 Process_OopMap_Node(mach, adjusted_offset);
1463 }
1464
1465 // Insert the delay slot instruction
1466 delay_slot->emit(*cb, _regalloc);
1467
1468 // Don't reuse it
1469 delay_slot = NULL;
1470 }
1471
1472 } // End for all instructions in block
1473
1474 // If the next block is the top of a loop, pad this block out to align
1475 // the loop top a little. Helps prevent pipe stalls at loop back branches.
1476 if (i < nblocks-1) {
1477 Block *nb = _cfg->get_block(i + 1);
1478 int padding = nb->alignment_padding(current_offset);
1479 if( padding > 0 ) {
1480 MachNode *nop = new MachNopNode(padding / nop_size);
1481 block->insert_node(nop, block->number_of_nodes());
1482 _cfg->map_node_to_block(nop, block);
1483 nop->emit(*cb, _regalloc);
1484 current_offset = cb->insts_size();
1485 }
1486 }
1487 // Verify that the distance for generated before forward
1488 // short branches is still valid.
1489 guarantee((int)(blk_starts[i+1] - blk_starts[i]) >= (current_offset - blk_offset), "shouldn't increase block size");
1490
1491 // Save new block start offset
1492 blk_starts[i] = blk_offset;
1493 } // End of for all blocks
1494 blk_starts[nblocks] = current_offset;
1495
1496 non_safepoints.flush_at_end();
1497
1498 // Offset too large?
1499 if (failing()) return;
1500
1501 // Define a pseudo-label at the end of the code
1502 MacroAssembler(cb).bind( blk_labels[nblocks] );
1503
1504 // Compute the size of the first block
1505 _first_block_size = blk_labels[1].loc_pos() - blk_labels[0].loc_pos();
1506
1507 #ifdef ASSERT
1508 for (uint i = 0; i < nblocks; i++) { // For all blocks
1509 if (jmp_target[i] != 0) {
1510 int br_size = jmp_size[i];
1511 int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
1512 if (!_matcher->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
1513 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]);
1514 assert(false, "Displacement too large for short jmp");
1515 }
1516 }
1517 }
1518 #endif
1519
1520 #ifndef PRODUCT
1521 // Information on the size of the method, without the extraneous code
1522 Scheduling::increment_method_size(cb->insts_size());
1523 #endif
1524
1525 // ------------------
1526 // Fill in exception table entries.
1527 FillExceptionTables(inct_cnt, call_returns, inct_starts, blk_labels);
1528
1529 // Only java methods have exception handlers and deopt handlers
1530 // class HandlerImpl is platform-specific and defined in the *.ad files.
1531 if (_method) {
1532 // Emit the exception handler code.
1533 _code_offsets.set_value(CodeOffsets::Exceptions, HandlerImpl::emit_exception_handler(*cb));
1534 if (failing()) {
1535 return; // CodeBuffer::expand failed
1536 }
1537 // Emit the deopt handler code.
1538 _code_offsets.set_value(CodeOffsets::Deopt, HandlerImpl::emit_deopt_handler(*cb));
1539
1540 // Emit the MethodHandle deopt handler code (if required).
1541 if (has_method_handle_invokes() && !failing()) {
1542 // We can use the same code as for the normal deopt handler, we
1543 // just need a different entry point address.
1544 _code_offsets.set_value(CodeOffsets::DeoptMH, HandlerImpl::emit_deopt_handler(*cb));
1545 }
1546 }
1547
1548 // One last check for failed CodeBuffer::expand:
1549 if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
1550 C->record_failure("CodeCache is full");
1551 return;
1552 }
1553
1554 #ifndef PRODUCT
1555 // Dump the assembly code, including basic-block numbers
1556 if (print_assembly()) {
1557 ttyLocker ttyl; // keep the following output all in one block
1558 if (!VMThread::should_terminate()) { // test this under the tty lock
1559 // This output goes directly to the tty, not the compiler log.
1560 // To enable tools to match it up with the compilation activity,
1561 // be sure to tag this tty output with the compile ID.
1562 if (xtty != NULL) {
1563 xtty->head("opto_assembly compile_id='%d'%s", compile_id(),
1564 is_osr_compilation() ? " compile_kind='osr'" :
1565 "");
1566 }
1567 if (method() != NULL) {
1568 method()->print_metadata();
1569 } else if (stub_name() != NULL) {
1570 tty->print_cr("Generating RuntimeStub - %s", stub_name());
1571 }
1572 dump_asm(node_offsets, node_offset_limit);
1573 if (xtty != NULL) {
1574 // print_metadata and dump_asm above may safepoint which makes us loose the ttylock.
1575 // Retake lock too make sure the end tag is coherent, and that xmlStream->pop_tag is done
1576 // thread safe
1577 ttyLocker ttyl2;
1578 xtty->tail("opto_assembly");
1579 }
1580 }
1581 }
1582 #endif
1583
1584 }
1585
1586 void Compile::FillExceptionTables(uint cnt, uint *call_returns, uint *inct_starts, Label *blk_labels) {
1587 _inc_table.set_size(cnt);
1588
1589 uint inct_cnt = 0;
1590 for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
1591 Block* block = _cfg->get_block(i);
1592 Node *n = NULL;
1593 int j;
1594
1595 // Find the branch; ignore trailing NOPs.
1596 for (j = block->number_of_nodes() - 1; j >= 0; j--) {
1597 n = block->get_node(j);
1598 if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con) {
1599 break;
1600 }
1601 }
1602
1603 // If we didn't find anything, continue
1604 if (j < 0) {
1605 continue;
1606 }
1607
1608 // Compute ExceptionHandlerTable subtable entry and add it
1609 // (skip empty blocks)
1610 if (n->is_Catch()) {
1611
1612 // Get the offset of the return from the call
1613 uint call_return = call_returns[block->_pre_order];
1614 #ifdef ASSERT
1615 assert( call_return > 0, "no call seen for this basic block" );
1616 while (block->get_node(--j)->is_MachProj()) ;
1617 assert(block->get_node(j)->is_MachCall(), "CatchProj must follow call");
1618 #endif
1619 // last instruction is a CatchNode, find it's CatchProjNodes
1620 int nof_succs = block->_num_succs;
1621 // allocate space
1622 GrowableArray<intptr_t> handler_bcis(nof_succs);
1623 GrowableArray<intptr_t> handler_pcos(nof_succs);
1624 // iterate through all successors
1625 for (int j = 0; j < nof_succs; j++) {
1626 Block* s = block->_succs[j];
1627 bool found_p = false;
1628 for (uint k = 1; k < s->num_preds(); k++) {
1629 Node* pk = s->pred(k);
1630 if (pk->is_CatchProj() && pk->in(0) == n) {
1631 const CatchProjNode* p = pk->as_CatchProj();
1632 found_p = true;
1633 // add the corresponding handler bci & pco information
1634 if (p->_con != CatchProjNode::fall_through_index) {
1635 // p leads to an exception handler (and is not fall through)
1636 assert(s == _cfg->get_block(s->_pre_order), "bad numbering");
1637 // no duplicates, please
1638 if (!handler_bcis.contains(p->handler_bci())) {
1639 uint block_num = s->non_connector()->_pre_order;
1640 handler_bcis.append(p->handler_bci());
1641 handler_pcos.append(blk_labels[block_num].loc_pos());
1642 }
1643 }
1644 }
1645 }
1646 assert(found_p, "no matching predecessor found");
1647 // Note: Due to empty block removal, one block may have
1648 // several CatchProj inputs, from the same Catch.
1649 }
1650
1651 // Set the offset of the return from the call
1652 assert(handler_bcis.find(-1) != -1, "must have default handler");
1653 _handler_table.add_subtable(call_return, &handler_bcis, NULL, &handler_pcos);
1654 continue;
1655 }
1656
1657 // Handle implicit null exception table updates
1658 if (n->is_MachNullCheck()) {
1659 uint block_num = block->non_connector_successor(0)->_pre_order;
1660 _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
1661 continue;
1662 }
1663 // Handle implicit exception table updates: trap instructions.
1664 if (n->is_Mach() && n->as_Mach()->is_TrapBasedCheckNode()) {
1665 uint block_num = block->non_connector_successor(0)->_pre_order;
1666 _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
1667 continue;
1668 }
1669 } // End of for all blocks fill in exception table entries
1670 }
1671
1672 // Static Variables
1673 #ifndef PRODUCT
1674 uint Scheduling::_total_nop_size = 0;
1675 uint Scheduling::_total_method_size = 0;
1676 uint Scheduling::_total_branches = 0;
1677 uint Scheduling::_total_unconditional_delays = 0;
1678 uint Scheduling::_total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
1679 #endif
1680
1681 // Initializer for class Scheduling
1682
1683 Scheduling::Scheduling(Arena *arena, Compile &compile)
1684 : _arena(arena),
1685 _cfg(compile.cfg()),
1686 _regalloc(compile.regalloc()),
1687 _reg_node(arena),
1688 _bundle_instr_count(0),
1689 _bundle_cycle_number(0),
1690 _scheduled(arena),
1691 _available(arena),
1692 _next_node(NULL),
1693 _bundle_use(0, 0, resource_count, &_bundle_use_elements[0]),
1694 _pinch_free_list(arena)
1695 #ifndef PRODUCT
1696 , _branches(0)
1697 , _unconditional_delays(0)
1698 #endif
1699 {
1700 // Create a MachNopNode
1701 _nop = new MachNopNode();
1702
1703 // Now that the nops are in the array, save the count
1704 // (but allow entries for the nops)
1705 _node_bundling_limit = compile.unique();
1706 uint node_max = _regalloc->node_regs_max_index();
1707
1708 compile.set_node_bundling_limit(_node_bundling_limit);
1709
1710 // This one is persistent within the Compile class
1711 _node_bundling_base = NEW_ARENA_ARRAY(compile.comp_arena(), Bundle, node_max);
1712
1713 // Allocate space for fixed-size arrays
1714 _node_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
1715 _uses = NEW_ARENA_ARRAY(arena, short, node_max);
1716 _current_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
1717
1718 // Clear the arrays
1719 memset(_node_bundling_base, 0, node_max * sizeof(Bundle));
1720 memset(_node_latency, 0, node_max * sizeof(unsigned short));
1721 memset(_uses, 0, node_max * sizeof(short));
1722 memset(_current_latency, 0, node_max * sizeof(unsigned short));
1723
1724 // Clear the bundling information
1725 memcpy(_bundle_use_elements, Pipeline_Use::elaborated_elements, sizeof(Pipeline_Use::elaborated_elements));
1726
1727 // Get the last node
1728 Block* block = _cfg->get_block(_cfg->number_of_blocks() - 1);
1729
1730 _next_node = block->get_node(block->number_of_nodes() - 1);
1731 }
1732
1733 #ifndef PRODUCT
1734 // Scheduling destructor
1735 Scheduling::~Scheduling() {
1736 _total_branches += _branches;
1737 _total_unconditional_delays += _unconditional_delays;
1738 }
1739 #endif
1740
1741 // Step ahead "i" cycles
1742 void Scheduling::step(uint i) {
1743
1744 Bundle *bundle = node_bundling(_next_node);
1745 bundle->set_starts_bundle();
1746
1747 // Update the bundle record, but leave the flags information alone
1748 if (_bundle_instr_count > 0) {
1749 bundle->set_instr_count(_bundle_instr_count);
1750 bundle->set_resources_used(_bundle_use.resourcesUsed());
1751 }
1752
1753 // Update the state information
1754 _bundle_instr_count = 0;
1755 _bundle_cycle_number += i;
1756 _bundle_use.step(i);
1757 }
1758
1759 void Scheduling::step_and_clear() {
1760 Bundle *bundle = node_bundling(_next_node);
1761 bundle->set_starts_bundle();
1762
1763 // Update the bundle record
1764 if (_bundle_instr_count > 0) {
1765 bundle->set_instr_count(_bundle_instr_count);
1766 bundle->set_resources_used(_bundle_use.resourcesUsed());
1767
1768 _bundle_cycle_number += 1;
1769 }
1770
1771 // Clear the bundling information
1772 _bundle_instr_count = 0;
1773 _bundle_use.reset();
1774
1775 memcpy(_bundle_use_elements,
1776 Pipeline_Use::elaborated_elements,
1777 sizeof(Pipeline_Use::elaborated_elements));
1778 }
1779
1780 // Perform instruction scheduling and bundling over the sequence of
1781 // instructions in backwards order.
1782 void Compile::ScheduleAndBundle() {
1783
1784 // Don't optimize this if it isn't a method
1785 if (!_method)
1786 return;
1787
1788 // Don't optimize this if scheduling is disabled
1789 if (!do_scheduling())
1790 return;
1791
1792 // Scheduling code works only with pairs (16 bytes) maximum.
1793 if (max_vector_size() > 16)
1794 return;
1795
1796 TracePhase tp("isched", &timers[_t_instrSched]);
1797
1798 // Create a data structure for all the scheduling information
1799 Scheduling scheduling(Thread::current()->resource_area(), *this);
1800
1801 // Walk backwards over each basic block, computing the needed alignment
1802 // Walk over all the basic blocks
1803 scheduling.DoScheduling();
1804 }
1805
1806 // Compute the latency of all the instructions. This is fairly simple,
1807 // because we already have a legal ordering. Walk over the instructions
1808 // from first to last, and compute the latency of the instruction based
1809 // on the latency of the preceding instruction(s).
1810 void Scheduling::ComputeLocalLatenciesForward(const Block *bb) {
1811 #ifndef PRODUCT
1812 if (_cfg->C->trace_opto_output())
1813 tty->print("# -> ComputeLocalLatenciesForward\n");
1814 #endif
1815
1816 // Walk over all the schedulable instructions
1817 for( uint j=_bb_start; j < _bb_end; j++ ) {
1818
1819 // This is a kludge, forcing all latency calculations to start at 1.
1820 // Used to allow latency 0 to force an instruction to the beginning
1821 // of the bb
1822 uint latency = 1;
1823 Node *use = bb->get_node(j);
1824 uint nlen = use->len();
1825
1826 // Walk over all the inputs
1827 for ( uint k=0; k < nlen; k++ ) {
1828 Node *def = use->in(k);
1829 if (!def)
1830 continue;
1831
1832 uint l = _node_latency[def->_idx] + use->latency(k);
1833 if (latency < l)
1834 latency = l;
1835 }
1836
1837 _node_latency[use->_idx] = latency;
1838
1839 #ifndef PRODUCT
1840 if (_cfg->C->trace_opto_output()) {
1841 tty->print("# latency %4d: ", latency);
1842 use->dump();
1843 }
1844 #endif
1845 }
1846
1847 #ifndef PRODUCT
1848 if (_cfg->C->trace_opto_output())
1849 tty->print("# <- ComputeLocalLatenciesForward\n");
1850 #endif
1851
1852 } // end ComputeLocalLatenciesForward
1853
1854 // See if this node fits into the present instruction bundle
1855 bool Scheduling::NodeFitsInBundle(Node *n) {
1856 uint n_idx = n->_idx;
1857
1858 // If this is the unconditional delay instruction, then it fits
1859 if (n == _unconditional_delay_slot) {
1860 #ifndef PRODUCT
1861 if (_cfg->C->trace_opto_output())
1862 tty->print("# NodeFitsInBundle [%4d]: TRUE; is in unconditional delay slot\n", n->_idx);
1863 #endif
1864 return (true);
1865 }
1866
1867 // If the node cannot be scheduled this cycle, skip it
1868 if (_current_latency[n_idx] > _bundle_cycle_number) {
1869 #ifndef PRODUCT
1870 if (_cfg->C->trace_opto_output())
1871 tty->print("# NodeFitsInBundle [%4d]: FALSE; latency %4d > %d\n",
1872 n->_idx, _current_latency[n_idx], _bundle_cycle_number);
1873 #endif
1874 return (false);
1875 }
1876
1877 const Pipeline *node_pipeline = n->pipeline();
1878
1879 uint instruction_count = node_pipeline->instructionCount();
1880 if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
1881 instruction_count = 0;
1882 else if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
1883 instruction_count++;
1884
1885 if (_bundle_instr_count + instruction_count > Pipeline::_max_instrs_per_cycle) {
1886 #ifndef PRODUCT
1887 if (_cfg->C->trace_opto_output())
1888 tty->print("# NodeFitsInBundle [%4d]: FALSE; too many instructions: %d > %d\n",
1889 n->_idx, _bundle_instr_count + instruction_count, Pipeline::_max_instrs_per_cycle);
1890 #endif
1891 return (false);
1892 }
1893
1894 // Don't allow non-machine nodes to be handled this way
1895 if (!n->is_Mach() && instruction_count == 0)
1896 return (false);
1897
1898 // See if there is any overlap
1899 uint delay = _bundle_use.full_latency(0, node_pipeline->resourceUse());
1900
1901 if (delay > 0) {
1902 #ifndef PRODUCT
1903 if (_cfg->C->trace_opto_output())
1904 tty->print("# NodeFitsInBundle [%4d]: FALSE; functional units overlap\n", n_idx);
1905 #endif
1906 return false;
1907 }
1908
1909 #ifndef PRODUCT
1910 if (_cfg->C->trace_opto_output())
1911 tty->print("# NodeFitsInBundle [%4d]: TRUE\n", n_idx);
1912 #endif
1913
1914 return true;
1915 }
1916
1917 Node * Scheduling::ChooseNodeToBundle() {
1918 uint siz = _available.size();
1919
1920 if (siz == 0) {
1921
1922 #ifndef PRODUCT
1923 if (_cfg->C->trace_opto_output())
1924 tty->print("# ChooseNodeToBundle: NULL\n");
1925 #endif
1926 return (NULL);
1927 }
1928
1929 // Fast path, if only 1 instruction in the bundle
1930 if (siz == 1) {
1931 #ifndef PRODUCT
1932 if (_cfg->C->trace_opto_output()) {
1933 tty->print("# ChooseNodeToBundle (only 1): ");
1934 _available[0]->dump();
1935 }
1936 #endif
1937 return (_available[0]);
1938 }
1939
1940 // Don't bother, if the bundle is already full
1941 if (_bundle_instr_count < Pipeline::_max_instrs_per_cycle) {
1942 for ( uint i = 0; i < siz; i++ ) {
1943 Node *n = _available[i];
1944
1945 // Skip projections, we'll handle them another way
1946 if (n->is_Proj())
1947 continue;
1948
1949 // This presupposed that instructions are inserted into the
1950 // available list in a legality order; i.e. instructions that
1951 // must be inserted first are at the head of the list
1952 if (NodeFitsInBundle(n)) {
1953 #ifndef PRODUCT
1954 if (_cfg->C->trace_opto_output()) {
1955 tty->print("# ChooseNodeToBundle: ");
1956 n->dump();
1957 }
1958 #endif
1959 return (n);
1960 }
1961 }
1962 }
1963
1964 // Nothing fits in this bundle, choose the highest priority
1965 #ifndef PRODUCT
1966 if (_cfg->C->trace_opto_output()) {
1967 tty->print("# ChooseNodeToBundle: ");
1968 _available[0]->dump();
1969 }
1970 #endif
1971
1972 return _available[0];
1973 }
1974
1975 void Scheduling::AddNodeToAvailableList(Node *n) {
1976 assert( !n->is_Proj(), "projections never directly made available" );
1977 #ifndef PRODUCT
1978 if (_cfg->C->trace_opto_output()) {
1979 tty->print("# AddNodeToAvailableList: ");
1980 n->dump();
1981 }
1982 #endif
1983
1984 int latency = _current_latency[n->_idx];
1985
1986 // Insert in latency order (insertion sort)
1987 uint i;
1988 for ( i=0; i < _available.size(); i++ )
1989 if (_current_latency[_available[i]->_idx] > latency)
1990 break;
1991
1992 // Special Check for compares following branches
1993 if( n->is_Mach() && _scheduled.size() > 0 ) {
1994 int op = n->as_Mach()->ideal_Opcode();
1995 Node *last = _scheduled[0];
1996 if( last->is_MachIf() && last->in(1) == n &&
1997 ( op == Op_CmpI ||
1998 op == Op_CmpU ||
1999 op == Op_CmpUL ||
2000 op == Op_CmpP ||
2001 op == Op_CmpF ||
2002 op == Op_CmpD ||
2003 op == Op_CmpL ) ) {
2004
2005 // Recalculate position, moving to front of same latency
2006 for ( i=0 ; i < _available.size(); i++ )
2007 if (_current_latency[_available[i]->_idx] >= latency)
2008 break;
2009 }
2010 }
2011
2012 // Insert the node in the available list
2013 _available.insert(i, n);
2014
2015 #ifndef PRODUCT
2016 if (_cfg->C->trace_opto_output())
2017 dump_available();
2018 #endif
2019 }
2020
2021 void Scheduling::DecrementUseCounts(Node *n, const Block *bb) {
2022 for ( uint i=0; i < n->len(); i++ ) {
2023 Node *def = n->in(i);
2024 if (!def) continue;
2025 if( def->is_Proj() ) // If this is a machine projection, then
2026 def = def->in(0); // propagate usage thru to the base instruction
2027
2028 if(_cfg->get_block_for_node(def) != bb) { // Ignore if not block-local
2029 continue;
2030 }
2031
2032 // Compute the latency
2033 uint l = _bundle_cycle_number + n->latency(i);
2034 if (_current_latency[def->_idx] < l)
2035 _current_latency[def->_idx] = l;
2036
2037 // If this does not have uses then schedule it
2038 if ((--_uses[def->_idx]) == 0)
2039 AddNodeToAvailableList(def);
2040 }
2041 }
2042
2043 void Scheduling::AddNodeToBundle(Node *n, const Block *bb) {
2044 #ifndef PRODUCT
2045 if (_cfg->C->trace_opto_output()) {
2046 tty->print("# AddNodeToBundle: ");
2047 n->dump();
2048 }
2049 #endif
2050
2051 // Remove this from the available list
2052 uint i;
2053 for (i = 0; i < _available.size(); i++)
2054 if (_available[i] == n)
2055 break;
2056 assert(i < _available.size(), "entry in _available list not found");
2057 _available.remove(i);
2058
2059 // See if this fits in the current bundle
2060 const Pipeline *node_pipeline = n->pipeline();
2061 const Pipeline_Use& node_usage = node_pipeline->resourceUse();
2062
2063 // Check for instructions to be placed in the delay slot. We
2064 // do this before we actually schedule the current instruction,
2065 // because the delay slot follows the current instruction.
2066 if (Pipeline::_branch_has_delay_slot &&
2067 node_pipeline->hasBranchDelay() &&
2068 !_unconditional_delay_slot) {
2069
2070 uint siz = _available.size();
2071
2072 // Conditional branches can support an instruction that
2073 // is unconditionally executed and not dependent by the
2074 // branch, OR a conditionally executed instruction if
2075 // the branch is taken. In practice, this means that
2076 // the first instruction at the branch target is
2077 // copied to the delay slot, and the branch goes to
2078 // the instruction after that at the branch target
2079 if ( n->is_MachBranch() ) {
2080
2081 assert( !n->is_MachNullCheck(), "should not look for delay slot for Null Check" );
2082 assert( !n->is_Catch(), "should not look for delay slot for Catch" );
2083
2084 #ifndef PRODUCT
2085 _branches++;
2086 #endif
2087
2088 // At least 1 instruction is on the available list
2089 // that is not dependent on the branch
2090 for (uint i = 0; i < siz; i++) {
2091 Node *d = _available[i];
2092 const Pipeline *avail_pipeline = d->pipeline();
2093
2094 // Don't allow safepoints in the branch shadow, that will
2095 // cause a number of difficulties
2096 if ( avail_pipeline->instructionCount() == 1 &&
2097 !avail_pipeline->hasMultipleBundles() &&
2098 !avail_pipeline->hasBranchDelay() &&
2099 Pipeline::instr_has_unit_size() &&
2100 d->size(_regalloc) == Pipeline::instr_unit_size() &&
2101 NodeFitsInBundle(d) &&
2102 !node_bundling(d)->used_in_delay()) {
2103
2104 if (d->is_Mach() && !d->is_MachSafePoint()) {
2105 // A node that fits in the delay slot was found, so we need to
2106 // set the appropriate bits in the bundle pipeline information so
2107 // that it correctly indicates resource usage. Later, when we
2108 // attempt to add this instruction to the bundle, we will skip
2109 // setting the resource usage.
2110 _unconditional_delay_slot = d;
2111 node_bundling(n)->set_use_unconditional_delay();
2112 node_bundling(d)->set_used_in_unconditional_delay();
2113 _bundle_use.add_usage(avail_pipeline->resourceUse());
2114 _current_latency[d->_idx] = _bundle_cycle_number;
2115 _next_node = d;
2116 ++_bundle_instr_count;
2117 #ifndef PRODUCT
2118 _unconditional_delays++;
2119 #endif
2120 break;
2121 }
2122 }
2123 }
2124 }
2125
2126 // No delay slot, add a nop to the usage
2127 if (!_unconditional_delay_slot) {
2128 // See if adding an instruction in the delay slot will overflow
2129 // the bundle.
2130 if (!NodeFitsInBundle(_nop)) {
2131 #ifndef PRODUCT
2132 if (_cfg->C->trace_opto_output())
2133 tty->print("# *** STEP(1 instruction for delay slot) ***\n");
2134 #endif
2135 step(1);
2136 }
2137
2138 _bundle_use.add_usage(_nop->pipeline()->resourceUse());
2139 _next_node = _nop;
2140 ++_bundle_instr_count;
2141 }
2142
2143 // See if the instruction in the delay slot requires a
2144 // step of the bundles
2145 if (!NodeFitsInBundle(n)) {
2146 #ifndef PRODUCT
2147 if (_cfg->C->trace_opto_output())
2148 tty->print("# *** STEP(branch won't fit) ***\n");
2149 #endif
2150 // Update the state information
2151 _bundle_instr_count = 0;
2152 _bundle_cycle_number += 1;
2153 _bundle_use.step(1);
2154 }
2155 }
2156
2157 // Get the number of instructions
2158 uint instruction_count = node_pipeline->instructionCount();
2159 if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2160 instruction_count = 0;
2161
2162 // Compute the latency information
2163 uint delay = 0;
2164
2165 if (instruction_count > 0 || !node_pipeline->mayHaveNoCode()) {
2166 int relative_latency = _current_latency[n->_idx] - _bundle_cycle_number;
2167 if (relative_latency < 0)
2168 relative_latency = 0;
2169
2170 delay = _bundle_use.full_latency(relative_latency, node_usage);
2171
2172 // Does not fit in this bundle, start a new one
2173 if (delay > 0) {
2174 step(delay);
2175
2176 #ifndef PRODUCT
2177 if (_cfg->C->trace_opto_output())
2178 tty->print("# *** STEP(%d) ***\n", delay);
2179 #endif
2180 }
2181 }
2182
2183 // If this was placed in the delay slot, ignore it
2184 if (n != _unconditional_delay_slot) {
2185
2186 if (delay == 0) {
2187 if (node_pipeline->hasMultipleBundles()) {
2188 #ifndef PRODUCT
2189 if (_cfg->C->trace_opto_output())
2190 tty->print("# *** STEP(multiple instructions) ***\n");
2191 #endif
2192 step(1);
2193 }
2194
2195 else if (instruction_count + _bundle_instr_count > Pipeline::_max_instrs_per_cycle) {
2196 #ifndef PRODUCT
2197 if (_cfg->C->trace_opto_output())
2198 tty->print("# *** STEP(%d >= %d instructions) ***\n",
2199 instruction_count + _bundle_instr_count,
2200 Pipeline::_max_instrs_per_cycle);
2201 #endif
2202 step(1);
2203 }
2204 }
2205
2206 if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
2207 _bundle_instr_count++;
2208
2209 // Set the node's latency
2210 _current_latency[n->_idx] = _bundle_cycle_number;
2211
2212 // Now merge the functional unit information
2213 if (instruction_count > 0 || !node_pipeline->mayHaveNoCode())
2214 _bundle_use.add_usage(node_usage);
2215
2216 // Increment the number of instructions in this bundle
2217 _bundle_instr_count += instruction_count;
2218
2219 // Remember this node for later
2220 if (n->is_Mach())
2221 _next_node = n;
2222 }
2223
2224 // It's possible to have a BoxLock in the graph and in the _bbs mapping but
2225 // not in the bb->_nodes array. This happens for debug-info-only BoxLocks.
2226 // 'Schedule' them (basically ignore in the schedule) but do not insert them
2227 // into the block. All other scheduled nodes get put in the schedule here.
2228 int op = n->Opcode();
2229 if( (op == Op_Node && n->req() == 0) || // anti-dependence node OR
2230 (op != Op_Node && // Not an unused antidepedence node and
2231 // not an unallocated boxlock
2232 (OptoReg::is_valid(_regalloc->get_reg_first(n)) || op != Op_BoxLock)) ) {
2233
2234 // Push any trailing projections
2235 if( bb->get_node(bb->number_of_nodes()-1) != n ) {
2236 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2237 Node *foi = n->fast_out(i);
2238 if( foi->is_Proj() )
2239 _scheduled.push(foi);
2240 }
2241 }
2242
2243 // Put the instruction in the schedule list
2244 _scheduled.push(n);
2245 }
2246
2247 #ifndef PRODUCT
2248 if (_cfg->C->trace_opto_output())
2249 dump_available();
2250 #endif
2251
2252 // Walk all the definitions, decrementing use counts, and
2253 // if a definition has a 0 use count, place it in the available list.
2254 DecrementUseCounts(n,bb);
2255 }
2256
2257 // This method sets the use count within a basic block. We will ignore all
2258 // uses outside the current basic block. As we are doing a backwards walk,
2259 // any node we reach that has a use count of 0 may be scheduled. This also
2260 // avoids the problem of cyclic references from phi nodes, as long as phi
2261 // nodes are at the front of the basic block. This method also initializes
2262 // the available list to the set of instructions that have no uses within this
2263 // basic block.
2264 void Scheduling::ComputeUseCount(const Block *bb) {
2265 #ifndef PRODUCT
2266 if (_cfg->C->trace_opto_output())
2267 tty->print("# -> ComputeUseCount\n");
2268 #endif
2269
2270 // Clear the list of available and scheduled instructions, just in case
2271 _available.clear();
2272 _scheduled.clear();
2273
2274 // No delay slot specified
2275 _unconditional_delay_slot = NULL;
2276
2277 #ifdef ASSERT
2278 for( uint i=0; i < bb->number_of_nodes(); i++ )
2279 assert( _uses[bb->get_node(i)->_idx] == 0, "_use array not clean" );
2280 #endif
2281
2282 // Force the _uses count to never go to zero for unscheduable pieces
2283 // of the block
2284 for( uint k = 0; k < _bb_start; k++ )
2285 _uses[bb->get_node(k)->_idx] = 1;
2286 for( uint l = _bb_end; l < bb->number_of_nodes(); l++ )
2287 _uses[bb->get_node(l)->_idx] = 1;
2288
2289 // Iterate backwards over the instructions in the block. Don't count the
2290 // branch projections at end or the block header instructions.
2291 for( uint j = _bb_end-1; j >= _bb_start; j-- ) {
2292 Node *n = bb->get_node(j);
2293 if( n->is_Proj() ) continue; // Projections handled another way
2294
2295 // Account for all uses
2296 for ( uint k = 0; k < n->len(); k++ ) {
2297 Node *inp = n->in(k);
2298 if (!inp) continue;
2299 assert(inp != n, "no cycles allowed" );
2300 if (_cfg->get_block_for_node(inp) == bb) { // Block-local use?
2301 if (inp->is_Proj()) { // Skip through Proj's
2302 inp = inp->in(0);
2303 }
2304 ++_uses[inp->_idx]; // Count 1 block-local use
2305 }
2306 }
2307
2308 // If this instruction has a 0 use count, then it is available
2309 if (!_uses[n->_idx]) {
2310 _current_latency[n->_idx] = _bundle_cycle_number;
2311 AddNodeToAvailableList(n);
2312 }
2313
2314 #ifndef PRODUCT
2315 if (_cfg->C->trace_opto_output()) {
2316 tty->print("# uses: %3d: ", _uses[n->_idx]);
2317 n->dump();
2318 }
2319 #endif
2320 }
2321
2322 #ifndef PRODUCT
2323 if (_cfg->C->trace_opto_output())
2324 tty->print("# <- ComputeUseCount\n");
2325 #endif
2326 }
2327
2328 // This routine performs scheduling on each basic block in reverse order,
2329 // using instruction latencies and taking into account function unit
2330 // availability.
2331 void Scheduling::DoScheduling() {
2332 #ifndef PRODUCT
2333 if (_cfg->C->trace_opto_output())
2334 tty->print("# -> DoScheduling\n");
2335 #endif
2336
2337 Block *succ_bb = NULL;
2338 Block *bb;
2339
2340 // Walk over all the basic blocks in reverse order
2341 for (int i = _cfg->number_of_blocks() - 1; i >= 0; succ_bb = bb, i--) {
2342 bb = _cfg->get_block(i);
2343
2344 #ifndef PRODUCT
2345 if (_cfg->C->trace_opto_output()) {
2346 tty->print("# Schedule BB#%03d (initial)\n", i);
2347 for (uint j = 0; j < bb->number_of_nodes(); j++) {
2348 bb->get_node(j)->dump();
2349 }
2350 }
2351 #endif
2352
2353 // On the head node, skip processing
2354 if (bb == _cfg->get_root_block()) {
2355 continue;
2356 }
2357
2358 // Skip empty, connector blocks
2359 if (bb->is_connector())
2360 continue;
2361
2362 // If the following block is not the sole successor of
2363 // this one, then reset the pipeline information
2364 if (bb->_num_succs != 1 || bb->non_connector_successor(0) != succ_bb) {
2365 #ifndef PRODUCT
2366 if (_cfg->C->trace_opto_output()) {
2367 tty->print("*** bundle start of next BB, node %d, for %d instructions\n",
2368 _next_node->_idx, _bundle_instr_count);
2369 }
2370 #endif
2371 step_and_clear();
2372 }
2373
2374 // Leave untouched the starting instruction, any Phis, a CreateEx node
2375 // or Top. bb->get_node(_bb_start) is the first schedulable instruction.
2376 _bb_end = bb->number_of_nodes()-1;
2377 for( _bb_start=1; _bb_start <= _bb_end; _bb_start++ ) {
2378 Node *n = bb->get_node(_bb_start);
2379 // Things not matched, like Phinodes and ProjNodes don't get scheduled.
2380 // Also, MachIdealNodes do not get scheduled
2381 if( !n->is_Mach() ) continue; // Skip non-machine nodes
2382 MachNode *mach = n->as_Mach();
2383 int iop = mach->ideal_Opcode();
2384 if( iop == Op_CreateEx ) continue; // CreateEx is pinned
2385 if( iop == Op_Con ) continue; // Do not schedule Top
2386 if( iop == Op_Node && // Do not schedule PhiNodes, ProjNodes
2387 mach->pipeline() == MachNode::pipeline_class() &&
2388 !n->is_SpillCopy() && !n->is_MachMerge() ) // Breakpoints, Prolog, etc
2389 continue;
2390 break; // Funny loop structure to be sure...
2391 }
2392 // Compute last "interesting" instruction in block - last instruction we
2393 // might schedule. _bb_end points just after last schedulable inst. We
2394 // normally schedule conditional branches (despite them being forced last
2395 // in the block), because they have delay slots we can fill. Calls all
2396 // have their delay slots filled in the template expansions, so we don't
2397 // bother scheduling them.
2398 Node *last = bb->get_node(_bb_end);
2399 // Ignore trailing NOPs.
2400 while (_bb_end > 0 && last->is_Mach() &&
2401 last->as_Mach()->ideal_Opcode() == Op_Con) {
2402 last = bb->get_node(--_bb_end);
2403 }
2404 assert(!last->is_Mach() || last->as_Mach()->ideal_Opcode() != Op_Con, "");
2405 if( last->is_Catch() ||
2406 (last->is_Mach() && last->as_Mach()->ideal_Opcode() == Op_Halt) ) {
2407 // There might be a prior call. Skip it.
2408 while (_bb_start < _bb_end && bb->get_node(--_bb_end)->is_MachProj());
2409 } else if( last->is_MachNullCheck() ) {
2410 // Backup so the last null-checked memory instruction is
2411 // outside the schedulable range. Skip over the nullcheck,
2412 // projection, and the memory nodes.
2413 Node *mem = last->in(1);
2414 do {
2415 _bb_end--;
2416 } while (mem != bb->get_node(_bb_end));
2417 } else {
2418 // Set _bb_end to point after last schedulable inst.
2419 _bb_end++;
2420 }
2421
2422 assert( _bb_start <= _bb_end, "inverted block ends" );
2423
2424 // Compute the register antidependencies for the basic block
2425 ComputeRegisterAntidependencies(bb);
2426 if (_cfg->C->failing()) return; // too many D-U pinch points
2427
2428 // Compute intra-bb latencies for the nodes
2429 ComputeLocalLatenciesForward(bb);
2430
2431 // Compute the usage within the block, and set the list of all nodes
2432 // in the block that have no uses within the block.
2433 ComputeUseCount(bb);
2434
2435 // Schedule the remaining instructions in the block
2436 while ( _available.size() > 0 ) {
2437 Node *n = ChooseNodeToBundle();
2438 guarantee(n != NULL, "no nodes available");
2439 AddNodeToBundle(n,bb);
2440 }
2441
2442 assert( _scheduled.size() == _bb_end - _bb_start, "wrong number of instructions" );
2443 #ifdef ASSERT
2444 for( uint l = _bb_start; l < _bb_end; l++ ) {
2445 Node *n = bb->get_node(l);
2446 uint m;
2447 for( m = 0; m < _bb_end-_bb_start; m++ )
2448 if( _scheduled[m] == n )
2449 break;
2450 assert( m < _bb_end-_bb_start, "instruction missing in schedule" );
2451 }
2452 #endif
2453
2454 // Now copy the instructions (in reverse order) back to the block
2455 for ( uint k = _bb_start; k < _bb_end; k++ )
2456 bb->map_node(_scheduled[_bb_end-k-1], k);
2457
2458 #ifndef PRODUCT
2459 if (_cfg->C->trace_opto_output()) {
2460 tty->print("# Schedule BB#%03d (final)\n", i);
2461 uint current = 0;
2462 for (uint j = 0; j < bb->number_of_nodes(); j++) {
2463 Node *n = bb->get_node(j);
2464 if( valid_bundle_info(n) ) {
2465 Bundle *bundle = node_bundling(n);
2466 if (bundle->instr_count() > 0 || bundle->flags() > 0) {
2467 tty->print("*** Bundle: ");
2468 bundle->dump();
2469 }
2470 n->dump();
2471 }
2472 }
2473 }
2474 #endif
2475 #ifdef ASSERT
2476 verify_good_schedule(bb,"after block local scheduling");
2477 #endif
2478 }
2479
2480 #ifndef PRODUCT
2481 if (_cfg->C->trace_opto_output())
2482 tty->print("# <- DoScheduling\n");
2483 #endif
2484
2485 // Record final node-bundling array location
2486 _regalloc->C->set_node_bundling_base(_node_bundling_base);
2487
2488 } // end DoScheduling
2489
2490 // Verify that no live-range used in the block is killed in the block by a
2491 // wrong DEF. This doesn't verify live-ranges that span blocks.
2492
2493 // Check for edge existence. Used to avoid adding redundant precedence edges.
2494 static bool edge_from_to( Node *from, Node *to ) {
2495 for( uint i=0; i<from->len(); i++ )
2496 if( from->in(i) == to )
2497 return true;
2498 return false;
2499 }
2500
2501 #ifdef ASSERT
2502 void Scheduling::verify_do_def( Node *n, OptoReg::Name def, const char *msg ) {
2503 // Check for bad kills
2504 if( OptoReg::is_valid(def) ) { // Ignore stores & control flow
2505 Node *prior_use = _reg_node[def];
2506 if( prior_use && !edge_from_to(prior_use,n) ) {
2507 tty->print("%s = ",OptoReg::as_VMReg(def)->name());
2508 n->dump();
2509 tty->print_cr("...");
2510 prior_use->dump();
2511 assert(edge_from_to(prior_use,n), "%s", msg);
2512 }
2513 _reg_node.map(def,NULL); // Kill live USEs
2514 }
2515 }
2516
2517 void Scheduling::verify_good_schedule( Block *b, const char *msg ) {
2518
2519 // Zap to something reasonable for the verify code
2520 _reg_node.clear();
2521
2522 // Walk over the block backwards. Check to make sure each DEF doesn't
2523 // kill a live value (other than the one it's supposed to). Add each
2524 // USE to the live set.
2525 for( uint i = b->number_of_nodes()-1; i >= _bb_start; i-- ) {
2526 Node *n = b->get_node(i);
2527 int n_op = n->Opcode();
2528 if( n_op == Op_MachProj && n->ideal_reg() == MachProjNode::fat_proj ) {
2529 // Fat-proj kills a slew of registers
2530 RegMask rm = n->out_RegMask();// Make local copy
2531 while( rm.is_NotEmpty() ) {
2532 OptoReg::Name kill = rm.find_first_elem();
2533 rm.Remove(kill);
2534 verify_do_def( n, kill, msg );
2535 }
2536 } else if( n_op != Op_Node ) { // Avoid brand new antidependence nodes
2537 // Get DEF'd registers the normal way
2538 verify_do_def( n, _regalloc->get_reg_first(n), msg );
2539 verify_do_def( n, _regalloc->get_reg_second(n), msg );
2540 }
2541
2542 // Now make all USEs live
2543 for( uint i=1; i<n->req(); i++ ) {
2544 Node *def = n->in(i);
2545 assert(def != 0, "input edge required");
2546 OptoReg::Name reg_lo = _regalloc->get_reg_first(def);
2547 OptoReg::Name reg_hi = _regalloc->get_reg_second(def);
2548 if( OptoReg::is_valid(reg_lo) ) {
2549 assert(!_reg_node[reg_lo] || edge_from_to(_reg_node[reg_lo],def), "%s", msg);
2550 _reg_node.map(reg_lo,n);
2551 }
2552 if( OptoReg::is_valid(reg_hi) ) {
2553 assert(!_reg_node[reg_hi] || edge_from_to(_reg_node[reg_hi],def), "%s", msg);
2554 _reg_node.map(reg_hi,n);
2555 }
2556 }
2557
2558 }
2559
2560 // Zap to something reasonable for the Antidependence code
2561 _reg_node.clear();
2562 }
2563 #endif
2564
2565 // Conditionally add precedence edges. Avoid putting edges on Projs.
2566 static void add_prec_edge_from_to( Node *from, Node *to ) {
2567 if( from->is_Proj() ) { // Put precedence edge on Proj's input
2568 assert( from->req() == 1 && (from->len() == 1 || from->in(1)==0), "no precedence edges on projections" );
2569 from = from->in(0);
2570 }
2571 if( from != to && // No cycles (for things like LD L0,[L0+4] )
2572 !edge_from_to( from, to ) ) // Avoid duplicate edge
2573 from->add_prec(to);
2574 }
2575
2576 void Scheduling::anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def ) {
2577 if( !OptoReg::is_valid(def_reg) ) // Ignore stores & control flow
2578 return;
2579
2580 Node *pinch = _reg_node[def_reg]; // Get pinch point
2581 if ((pinch == NULL) || _cfg->get_block_for_node(pinch) != b || // No pinch-point yet?
2582 is_def ) { // Check for a true def (not a kill)
2583 _reg_node.map(def_reg,def); // Record def/kill as the optimistic pinch-point
2584 return;
2585 }
2586
2587 Node *kill = def; // Rename 'def' to more descriptive 'kill'
2588 debug_only( def = (Node*)((intptr_t)0xdeadbeef); )
2589
2590 // After some number of kills there _may_ be a later def
2591 Node *later_def = NULL;
2592
2593 // Finding a kill requires a real pinch-point.
2594 // Check for not already having a pinch-point.
2595 // Pinch points are Op_Node's.
2596 if( pinch->Opcode() != Op_Node ) { // Or later-def/kill as pinch-point?
2597 later_def = pinch; // Must be def/kill as optimistic pinch-point
2598 if ( _pinch_free_list.size() > 0) {
2599 pinch = _pinch_free_list.pop();
2600 } else {
2601 pinch = new Node(1); // Pinch point to-be
2602 }
2603 if (pinch->_idx >= _regalloc->node_regs_max_index()) {
2604 _cfg->C->record_method_not_compilable("too many D-U pinch points");
2605 return;
2606 }
2607 _cfg->map_node_to_block(pinch, b); // Pretend it's valid in this block (lazy init)
2608 _reg_node.map(def_reg,pinch); // Record pinch-point
2609 //_regalloc->set_bad(pinch->_idx); // Already initialized this way.
2610 if( later_def->outcnt() == 0 || later_def->ideal_reg() == MachProjNode::fat_proj ) { // Distinguish def from kill
2611 pinch->init_req(0, _cfg->C->top()); // set not NULL for the next call
2612 add_prec_edge_from_to(later_def,pinch); // Add edge from kill to pinch
2613 later_def = NULL; // and no later def
2614 }
2615 pinch->set_req(0,later_def); // Hook later def so we can find it
2616 } else { // Else have valid pinch point
2617 if( pinch->in(0) ) // If there is a later-def
2618 later_def = pinch->in(0); // Get it
2619 }
2620
2621 // Add output-dependence edge from later def to kill
2622 if( later_def ) // If there is some original def
2623 add_prec_edge_from_to(later_def,kill); // Add edge from def to kill
2624
2625 // See if current kill is also a use, and so is forced to be the pinch-point.
2626 if( pinch->Opcode() == Op_Node ) {
2627 Node *uses = kill->is_Proj() ? kill->in(0) : kill;
2628 for( uint i=1; i<uses->req(); i++ ) {
2629 if( _regalloc->get_reg_first(uses->in(i)) == def_reg ||
2630 _regalloc->get_reg_second(uses->in(i)) == def_reg ) {
2631 // Yes, found a use/kill pinch-point
2632 pinch->set_req(0,NULL); //
2633 pinch->replace_by(kill); // Move anti-dep edges up
2634 pinch = kill;
2635 _reg_node.map(def_reg,pinch);
2636 return;
2637 }
2638 }
2639 }
2640
2641 // Add edge from kill to pinch-point
2642 add_prec_edge_from_to(kill,pinch);
2643 }
2644
2645 void Scheduling::anti_do_use( Block *b, Node *use, OptoReg::Name use_reg ) {
2646 if( !OptoReg::is_valid(use_reg) ) // Ignore stores & control flow
2647 return;
2648 Node *pinch = _reg_node[use_reg]; // Get pinch point
2649 // Check for no later def_reg/kill in block
2650 if ((pinch != NULL) && _cfg->get_block_for_node(pinch) == b &&
2651 // Use has to be block-local as well
2652 _cfg->get_block_for_node(use) == b) {
2653 if( pinch->Opcode() == Op_Node && // Real pinch-point (not optimistic?)
2654 pinch->req() == 1 ) { // pinch not yet in block?
2655 pinch->del_req(0); // yank pointer to later-def, also set flag
2656 // Insert the pinch-point in the block just after the last use
2657 b->insert_node(pinch, b->find_node(use) + 1);
2658 _bb_end++; // Increase size scheduled region in block
2659 }
2660
2661 add_prec_edge_from_to(pinch,use);
2662 }
2663 }
2664
2665 // We insert antidependences between the reads and following write of
2666 // allocated registers to prevent illegal code motion. Hopefully, the
2667 // number of added references should be fairly small, especially as we
2668 // are only adding references within the current basic block.
2669 void Scheduling::ComputeRegisterAntidependencies(Block *b) {
2670
2671 #ifdef ASSERT
2672 verify_good_schedule(b,"before block local scheduling");
2673 #endif
2674
2675 // A valid schedule, for each register independently, is an endless cycle
2676 // of: a def, then some uses (connected to the def by true dependencies),
2677 // then some kills (defs with no uses), finally the cycle repeats with a new
2678 // def. The uses are allowed to float relative to each other, as are the
2679 // kills. No use is allowed to slide past a kill (or def). This requires
2680 // antidependencies between all uses of a single def and all kills that
2681 // follow, up to the next def. More edges are redundant, because later defs
2682 // & kills are already serialized with true or antidependencies. To keep
2683 // the edge count down, we add a 'pinch point' node if there's more than
2684 // one use or more than one kill/def.
2685
2686 // We add dependencies in one bottom-up pass.
2687
2688 // For each instruction we handle it's DEFs/KILLs, then it's USEs.
2689
2690 // For each DEF/KILL, we check to see if there's a prior DEF/KILL for this
2691 // register. If not, we record the DEF/KILL in _reg_node, the
2692 // register-to-def mapping. If there is a prior DEF/KILL, we insert a
2693 // "pinch point", a new Node that's in the graph but not in the block.
2694 // We put edges from the prior and current DEF/KILLs to the pinch point.
2695 // We put the pinch point in _reg_node. If there's already a pinch point
2696 // we merely add an edge from the current DEF/KILL to the pinch point.
2697
2698 // After doing the DEF/KILLs, we handle USEs. For each used register, we
2699 // put an edge from the pinch point to the USE.
2700
2701 // To be expedient, the _reg_node array is pre-allocated for the whole
2702 // compilation. _reg_node is lazily initialized; it either contains a NULL,
2703 // or a valid def/kill/pinch-point, or a leftover node from some prior
2704 // block. Leftover node from some prior block is treated like a NULL (no
2705 // prior def, so no anti-dependence needed). Valid def is distinguished by
2706 // it being in the current block.
2707 bool fat_proj_seen = false;
2708 uint last_safept = _bb_end-1;
2709 Node* end_node = (_bb_end-1 >= _bb_start) ? b->get_node(last_safept) : NULL;
2710 Node* last_safept_node = end_node;
2711 for( uint i = _bb_end-1; i >= _bb_start; i-- ) {
2712 Node *n = b->get_node(i);
2713 int is_def = n->outcnt(); // def if some uses prior to adding precedence edges
2714 if( n->is_MachProj() && n->ideal_reg() == MachProjNode::fat_proj ) {
2715 // Fat-proj kills a slew of registers
2716 // This can add edges to 'n' and obscure whether or not it was a def,
2717 // hence the is_def flag.
2718 fat_proj_seen = true;
2719 RegMask rm = n->out_RegMask();// Make local copy
2720 while( rm.is_NotEmpty() ) {
2721 OptoReg::Name kill = rm.find_first_elem();
2722 rm.Remove(kill);
2723 anti_do_def( b, n, kill, is_def );
2724 }
2725 } else {
2726 // Get DEF'd registers the normal way
2727 anti_do_def( b, n, _regalloc->get_reg_first(n), is_def );
2728 anti_do_def( b, n, _regalloc->get_reg_second(n), is_def );
2729 }
2730
2731 // Kill projections on a branch should appear to occur on the
2732 // branch, not afterwards, so grab the masks from the projections
2733 // and process them.
2734 if (n->is_MachBranch() || (n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_Jump)) {
2735 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2736 Node* use = n->fast_out(i);
2737 if (use->is_Proj()) {
2738 RegMask rm = use->out_RegMask();// Make local copy
2739 while( rm.is_NotEmpty() ) {
2740 OptoReg::Name kill = rm.find_first_elem();
2741 rm.Remove(kill);
2742 anti_do_def( b, n, kill, false );
2743 }
2744 }
2745 }
2746 }
2747
2748 // Check each register used by this instruction for a following DEF/KILL
2749 // that must occur afterward and requires an anti-dependence edge.
2750 for( uint j=0; j<n->req(); j++ ) {
2751 Node *def = n->in(j);
2752 if( def ) {
2753 assert( !def->is_MachProj() || def->ideal_reg() != MachProjNode::fat_proj, "" );
2754 anti_do_use( b, n, _regalloc->get_reg_first(def) );
2755 anti_do_use( b, n, _regalloc->get_reg_second(def) );
2756 }
2757 }
2758 // Do not allow defs of new derived values to float above GC
2759 // points unless the base is definitely available at the GC point.
2760
2761 Node *m = b->get_node(i);
2762
2763 // Add precedence edge from following safepoint to use of derived pointer
2764 if( last_safept_node != end_node &&
2765 m != last_safept_node) {
2766 for (uint k = 1; k < m->req(); k++) {
2767 const Type *t = m->in(k)->bottom_type();
2768 if( t->isa_oop_ptr() &&
2769 t->is_ptr()->offset() != 0 ) {
2770 last_safept_node->add_prec( m );
2771 break;
2772 }
2773 }
2774 }
2775
2776 if( n->jvms() ) { // Precedence edge from derived to safept
2777 // Check if last_safept_node was moved by pinch-point insertion in anti_do_use()
2778 if( b->get_node(last_safept) != last_safept_node ) {
2779 last_safept = b->find_node(last_safept_node);
2780 }
2781 for( uint j=last_safept; j > i; j-- ) {
2782 Node *mach = b->get_node(j);
2783 if( mach->is_Mach() && mach->as_Mach()->ideal_Opcode() == Op_AddP )
2784 mach->add_prec( n );
2785 }
2786 last_safept = i;
2787 last_safept_node = m;
2788 }
2789 }
2790
2791 if (fat_proj_seen) {
2792 // Garbage collect pinch nodes that were not consumed.
2793 // They are usually created by a fat kill MachProj for a call.
2794 garbage_collect_pinch_nodes();
2795 }
2796 }
2797
2798 // Garbage collect pinch nodes for reuse by other blocks.
2799 //
2800 // The block scheduler's insertion of anti-dependence
2801 // edges creates many pinch nodes when the block contains
2802 // 2 or more Calls. A pinch node is used to prevent a
2803 // combinatorial explosion of edges. If a set of kills for a
2804 // register is anti-dependent on a set of uses (or defs), rather
2805 // than adding an edge in the graph between each pair of kill
2806 // and use (or def), a pinch is inserted between them:
2807 //
2808 // use1 use2 use3
2809 // \ | /
2810 // \ | /
2811 // pinch
2812 // / | \
2813 // / | \
2814 // kill1 kill2 kill3
2815 //
2816 // One pinch node is created per register killed when
2817 // the second call is encountered during a backwards pass
2818 // over the block. Most of these pinch nodes are never
2819 // wired into the graph because the register is never
2820 // used or def'ed in the block.
2821 //
2822 void Scheduling::garbage_collect_pinch_nodes() {
2823 #ifndef PRODUCT
2824 if (_cfg->C->trace_opto_output()) tty->print("Reclaimed pinch nodes:");
2825 #endif
2826 int trace_cnt = 0;
2827 for (uint k = 0; k < _reg_node.Size(); k++) {
2828 Node* pinch = _reg_node[k];
2829 if ((pinch != NULL) && pinch->Opcode() == Op_Node &&
2830 // no predecence input edges
2831 (pinch->req() == pinch->len() || pinch->in(pinch->req()) == NULL) ) {
2832 cleanup_pinch(pinch);
2833 _pinch_free_list.push(pinch);
2834 _reg_node.map(k, NULL);
2835 #ifndef PRODUCT
2836 if (_cfg->C->trace_opto_output()) {
2837 trace_cnt++;
2838 if (trace_cnt > 40) {
2839 tty->print("\n");
2840 trace_cnt = 0;
2841 }
2842 tty->print(" %d", pinch->_idx);
2843 }
2844 #endif
2845 }
2846 }
2847 #ifndef PRODUCT
2848 if (_cfg->C->trace_opto_output()) tty->print("\n");
2849 #endif
2850 }
2851
2852 // Clean up a pinch node for reuse.
2853 void Scheduling::cleanup_pinch( Node *pinch ) {
2854 assert (pinch && pinch->Opcode() == Op_Node && pinch->req() == 1, "just checking");
2855
2856 for (DUIterator_Last imin, i = pinch->last_outs(imin); i >= imin; ) {
2857 Node* use = pinch->last_out(i);
2858 uint uses_found = 0;
2859 for (uint j = use->req(); j < use->len(); j++) {
2860 if (use->in(j) == pinch) {
2861 use->rm_prec(j);
2862 uses_found++;
2863 }
2864 }
2865 assert(uses_found > 0, "must be a precedence edge");
2866 i -= uses_found; // we deleted 1 or more copies of this edge
2867 }
2868 // May have a later_def entry
2869 pinch->set_req(0, NULL);
2870 }
2871
2872 #ifndef PRODUCT
2873
2874 void Scheduling::dump_available() const {
2875 tty->print("#Availist ");
2876 for (uint i = 0; i < _available.size(); i++)
2877 tty->print(" N%d/l%d", _available[i]->_idx,_current_latency[_available[i]->_idx]);
2878 tty->cr();
2879 }
2880
2881 // Print Scheduling Statistics
2882 void Scheduling::print_statistics() {
2883 // Print the size added by nops for bundling
2884 tty->print("Nops added %d bytes to total of %d bytes",
2885 _total_nop_size, _total_method_size);
2886 if (_total_method_size > 0)
2887 tty->print(", for %.2f%%",
2888 ((double)_total_nop_size) / ((double) _total_method_size) * 100.0);
2889 tty->print("\n");
2890
2891 // Print the number of branch shadows filled
2892 if (Pipeline::_branch_has_delay_slot) {
2893 tty->print("Of %d branches, %d had unconditional delay slots filled",
2894 _total_branches, _total_unconditional_delays);
2895 if (_total_branches > 0)
2896 tty->print(", for %.2f%%",
2897 ((double)_total_unconditional_delays) / ((double)_total_branches) * 100.0);
2898 tty->print("\n");
2899 }
2900
2901 uint total_instructions = 0, total_bundles = 0;
2902
2903 for (uint i = 1; i <= Pipeline::_max_instrs_per_cycle; i++) {
2904 uint bundle_count = _total_instructions_per_bundle[i];
2905 total_instructions += bundle_count * i;
2906 total_bundles += bundle_count;
2907 }
2908
2909 if (total_bundles > 0)
2910 tty->print("Average ILP (excluding nops) is %.2f\n",
2911 ((double)total_instructions) / ((double)total_bundles));
2912 }
2913 #endif