2
* Copyright (c) 1999, 2024, Oracle and/or its affiliates. All rights reserved.
3
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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.
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).
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.
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
25
#include "precompiled.hpp"
26
#include "c1/c1_Compilation.hpp"
27
#include "c1/c1_FrameMap.hpp"
28
#include "c1/c1_GraphBuilder.hpp"
29
#include "c1/c1_IR.hpp"
30
#include "c1/c1_InstructionPrinter.hpp"
31
#include "c1/c1_Optimizer.hpp"
32
#include "compiler/oopMap.hpp"
33
#include "memory/resourceArea.hpp"
34
#include "utilities/bitMap.inline.hpp"
37
// Implementation of XHandlers
39
// Note: This code could eventually go away if we are
40
// just using the ciExceptionHandlerStream.
42
XHandlers::XHandlers(ciMethod* method) : _list(method->exception_table_length()) {
43
ciExceptionHandlerStream s(method);
44
while (!s.is_done()) {
45
_list.append(new XHandler(s.handler()));
48
assert(s.count() == method->exception_table_length(), "exception table lengths inconsistent");
51
// deep copy of all XHandler contained in list
52
XHandlers::XHandlers(XHandlers* other) :
53
_list(other->length())
55
for (int i = 0; i < other->length(); i++) {
56
_list.append(new XHandler(other->handler_at(i)));
60
// Returns whether a particular exception type can be caught. Also
61
// returns true if klass is unloaded or any exception handler
62
// classes are unloaded. type_is_exact indicates whether the throw
63
// is known to be exactly that class or it might throw a subtype.
64
bool XHandlers::could_catch(ciInstanceKlass* klass, bool type_is_exact) const {
65
// the type is unknown so be conservative
66
if (!klass->is_loaded()) {
70
for (int i = 0; i < length(); i++) {
71
XHandler* handler = handler_at(i);
72
if (handler->is_catch_all()) {
76
ciInstanceKlass* handler_klass = handler->catch_klass();
77
// if it's unknown it might be catchable
78
if (!handler_klass->is_loaded()) {
81
// if the throw type is definitely a subtype of the catch type
82
// then it can be caught.
83
if (klass->is_subtype_of(handler_klass)) {
87
// If the type isn't exactly known then it can also be caught by
88
// catch statements where the inexact type is a subtype of the
90
// given: foo extends bar extends Exception
91
// throw bar can be caught by catch foo, catch bar, and catch
92
// Exception, however it can't be caught by any handlers without
93
// bar in its type hierarchy.
94
if (handler_klass->is_subtype_of(klass)) {
104
bool XHandlers::equals(XHandlers* others) const {
105
if (others == nullptr) return false;
106
if (length() != others->length()) return false;
108
for (int i = 0; i < length(); i++) {
109
if (!handler_at(i)->equals(others->handler_at(i))) return false;
114
bool XHandler::equals(XHandler* other) const {
115
assert(entry_pco() != -1 && other->entry_pco() != -1, "must have entry_pco");
117
if (entry_pco() != other->entry_pco()) return false;
118
if (scope_count() != other->scope_count()) return false;
119
if (_desc != other->_desc) return false;
121
assert(entry_block() == other->entry_block(), "entry_block must be equal when entry_pco is equal");
126
// Implementation of IRScope
127
BlockBegin* IRScope::build_graph(Compilation* compilation, int osr_bci) {
128
GraphBuilder gm(compilation, this);
129
NOT_PRODUCT(if (PrintValueNumbering && Verbose) gm.print_stats());
130
if (compilation->bailed_out()) return nullptr;
135
IRScope::IRScope(Compilation* compilation, IRScope* caller, int caller_bci, ciMethod* method, int osr_bci, bool create_graph)
136
: _compilation(compilation)
138
, _requires_phi_function(method->max_locals())
141
_level = caller == nullptr ? 0 : caller->level() + 1;
143
_xhandlers = new XHandlers(method);
144
_number_of_locks = 0;
145
_monitor_pairing_ok = method->has_balanced_monitors();
146
_wrote_final = false;
147
_wrote_fields = false;
148
_wrote_volatile = false;
152
// selective creation of phi functions is not possibel in osr-methods
153
_requires_phi_function.set_range(0, method->max_locals());
156
assert(method->holder()->is_loaded() , "method holder must be loaded");
158
// build graph if monitor pairing is ok
159
if (create_graph && monitor_pairing_ok()) _start = build_graph(compilation, osr_bci);
163
int IRScope::max_stack() const {
164
int my_max = method()->max_stack();
166
for (int i = 0; i < number_of_callees(); i++) {
167
callee_max = MAX2(callee_max, callee_no(i)->max_stack());
169
return my_max + callee_max;
173
bool IRScopeDebugInfo::should_reexecute() {
174
ciMethod* cur_method = scope()->method();
176
if (cur_method != nullptr && cur_bci != SynchronizationEntryBCI) {
177
Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
178
return Interpreter::bytecode_should_reexecute(code);
184
// Implementation of CodeEmitInfo
186
// Stack must be NON-null
187
CodeEmitInfo::CodeEmitInfo(ValueStack* stack, XHandlers* exception_handlers, bool deoptimize_on_exception)
188
: _scope_debug_info(nullptr)
189
, _scope(stack->scope())
190
, _exception_handlers(exception_handlers)
193
, _is_method_handle_invoke(false)
194
, _deoptimize_on_exception(deoptimize_on_exception)
195
, _force_reexecute(false) {
196
assert(_stack != nullptr, "must be non null");
200
CodeEmitInfo::CodeEmitInfo(CodeEmitInfo* info, ValueStack* stack)
201
: _scope_debug_info(nullptr)
202
, _scope(info->_scope)
203
, _exception_handlers(nullptr)
205
, _stack(stack == nullptr ? info->_stack : stack)
206
, _is_method_handle_invoke(info->_is_method_handle_invoke)
207
, _deoptimize_on_exception(info->_deoptimize_on_exception)
208
, _force_reexecute(info->_force_reexecute) {
210
// deep copy of exception handlers
211
if (info->_exception_handlers != nullptr) {
212
_exception_handlers = new XHandlers(info->_exception_handlers);
217
void CodeEmitInfo::record_debug_info(DebugInformationRecorder* recorder, int pc_offset) {
218
// record the safepoint before recording the debug info for enclosing scopes
219
recorder->add_safepoint(pc_offset, _oop_map->deep_copy());
220
bool reexecute = _force_reexecute || _scope_debug_info->should_reexecute();
221
_scope_debug_info->record_debug_info(recorder, pc_offset, reexecute, _is_method_handle_invoke);
222
recorder->end_safepoint(pc_offset);
226
void CodeEmitInfo::add_register_oop(LIR_Opr opr) {
227
assert(_oop_map != nullptr, "oop map must already exist");
228
assert(opr->is_single_cpu(), "should not call otherwise");
230
VMReg name = frame_map()->regname(opr);
231
_oop_map->set_oop(name);
234
// Mirror the stack size calculation in the deopt code
235
// How much stack space would we need at this point in the program in
236
// case of deoptimization?
237
int CodeEmitInfo::interpreter_frame_size() const {
238
ValueStack* state = _stack;
240
int callee_parameters = 0;
241
int callee_locals = 0;
242
int extra_args = state->scope()->method()->max_stack() - state->stack_size();
244
while (state != nullptr) {
245
int locks = state->locks_size();
246
int temps = state->stack_size();
247
bool is_top_frame = (state == _stack);
248
ciMethod* method = state->scope()->method();
250
int frame_size = BytesPerWord * Interpreter::size_activation(method->max_stack(),
251
temps + callee_parameters,
259
callee_parameters = method->size_of_parameters();
260
callee_locals = method->max_locals();
262
state = state->caller_state();
264
return size + Deoptimization::last_frame_adjust(0, callee_locals) * BytesPerWord;
267
// Implementation of IR
269
IR::IR(Compilation* compilation, ciMethod* method, int osr_bci) :
272
_compilation = compilation;
273
_top_scope = new IRScope(compilation, nullptr, -1, method, osr_bci, true);
278
void IR::optimize_blocks() {
280
if (!compilation()->profile_branches()) {
282
opt.eliminate_conditional_expressions();
284
if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after CEE"); print(true); }
285
if (PrintIR || PrintIR1 ) { tty->print_cr("IR after CEE"); print(false); }
288
if (EliminateBlocks) {
289
opt.eliminate_blocks();
291
if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after block elimination"); print(true); }
292
if (PrintIR || PrintIR1 ) { tty->print_cr("IR after block elimination"); print(false); }
298
void IR::eliminate_null_checks() {
300
if (EliminateNullChecks) {
301
opt.eliminate_null_checks();
303
if (PrintCFG || PrintCFG1) { tty->print_cr("CFG after null check elimination"); print(true); }
304
if (PrintIR || PrintIR1 ) { tty->print_cr("IR after null check elimination"); print(false); }
309
// The functionality of this class is to insert a new block between
310
// the 'from' and 'to' block of a critical edge.
311
// It first collects the block pairs, and then processes them.
313
// Some instructions may introduce more than one edge between two blocks.
314
// By checking if the current 'to' block sets critical_edge_split_flag
315
// (all new blocks set this flag) we can avoid repeated processing.
316
// This is why BlockPair contains the index rather than the original 'to' block.
317
class CriticalEdgeFinder: public BlockClosure {
318
BlockPairList blocks;
321
CriticalEdgeFinder(IR* ir) {
322
ir->iterate_preorder(this);
325
void block_do(BlockBegin* bb) {
326
BlockEnd* be = bb->end();
327
int nos = be->number_of_sux();
329
for (int i = 0; i < nos; i++) {
330
BlockBegin* sux = be->sux_at(i);
331
if (sux->number_of_preds() >= 2) {
332
blocks.append(new BlockPair(bb, i));
339
for (int i = 0; i < blocks.length(); i++) {
340
BlockPair* pair = blocks.at(i);
341
BlockBegin* from = pair->from();
342
int index = pair->index();
343
BlockBegin* to = from->end()->sux_at(index);
344
if (to->is_set(BlockBegin::critical_edge_split_flag)) {
348
BlockBegin* split = from->insert_block_between(to);
350
if ((PrintIR || PrintIR1) && Verbose) {
351
tty->print_cr("Split critical edge B%d -> B%d (new block B%d)",
352
from->block_id(), to->block_id(), split->block_id());
359
void IR::split_critical_edges() {
360
CriticalEdgeFinder cef(this);
365
class UseCountComputer: public ValueVisitor, BlockClosure {
367
void visit(Value* n) {
368
// Local instructions and Phis for expression stack values at the
369
// start of basic blocks are not added to the instruction list
370
if (!(*n)->is_linked() && (*n)->can_be_linked()) {
371
assert(false, "a node was not appended to the graph");
372
Compilation::current()->bailout("a node was not appended to the graph");
374
// use n's input if not visited before
375
if (!(*n)->is_pinned() && !(*n)->has_uses()) {
376
// note: a) if the instruction is pinned, it will be handled by compute_use_count
377
// b) if the instruction has uses, it was touched before
378
// => in both cases we don't need to update n's values
388
max_recurse_depth = 20
391
void uses_do(Value* n) {
393
if (depth > max_recurse_depth) {
394
// don't allow the traversal to recurse too deeply
397
(*n)->input_values_do(this);
398
// special handling for some instructions
399
if ((*n)->as_BlockEnd() != nullptr) {
401
// must 'use' the stack only if the method doesn't
402
// terminate, however, in those cases stack is empty
403
(*n)->state_values_do(this);
409
void block_do(BlockBegin* b) {
411
// process all pinned nodes as the roots of expression trees
412
for (Instruction* n = b; n != nullptr; n = n->next()) {
413
if (n->is_pinned()) uses_do(&n);
415
assert(depth == 0, "should have counted back down");
417
// now process any unpinned nodes which recursed too deeply
418
while (worklist->length() > 0) {
419
Value t = worklist->pop();
420
if (!t->is_pinned()) {
421
// compute the use count
424
// pin the instruction so that LIRGenerator doesn't recurse
425
// too deeply during it's evaluation.
429
assert(depth == 0, "should have counted back down");
433
worklist = new Values();
438
static void compute(BlockList* blocks) {
439
UseCountComputer ucc;
440
blocks->iterate_backward(&ucc);
445
// helper macro for short definition of trace-output inside code
447
#define TRACE_LINEAR_SCAN(level, code) \
448
if (TraceLinearScanLevel >= level) { \
452
#define TRACE_LINEAR_SCAN(level, code)
455
class ComputeLinearScanOrder : public StackObj {
457
int _max_block_id; // the highest block_id of a block
458
int _num_blocks; // total number of blocks (smaller than _max_block_id)
459
int _num_loops; // total number of loops
460
bool _iterative_dominators;// method requires iterative computation of dominatiors
462
BlockList* _linear_scan_order; // the resulting list of blocks in correct order
464
ResourceBitMap _visited_blocks; // used for recursive processing of blocks
465
ResourceBitMap _active_blocks; // used for recursive processing of blocks
466
ResourceBitMap _dominator_blocks; // temporary BitMap used for computation of dominator
467
intArray _forward_branches; // number of incoming forward branches for each block
468
BlockList _loop_end_blocks; // list of all loop end blocks collected during count_edges
469
BitMap2D _loop_map; // two-dimensional bit set: a bit is set if a block is contained in a loop
470
BlockList _work_list; // temporary list (used in mark_loops and compute_order)
471
BlockList _loop_headers;
473
Compilation* _compilation;
475
// accessors for _visited_blocks and _active_blocks
476
void init_visited() { _active_blocks.clear(); _visited_blocks.clear(); }
477
bool is_visited(BlockBegin* b) const { return _visited_blocks.at(b->block_id()); }
478
bool is_active(BlockBegin* b) const { return _active_blocks.at(b->block_id()); }
479
void set_visited(BlockBegin* b) { assert(!is_visited(b), "already set"); _visited_blocks.set_bit(b->block_id()); }
480
void set_active(BlockBegin* b) { assert(!is_active(b), "already set"); _active_blocks.set_bit(b->block_id()); }
481
void clear_active(BlockBegin* b) { assert(is_active(b), "not already"); _active_blocks.clear_bit(b->block_id()); }
483
// accessors for _forward_branches
484
void inc_forward_branches(BlockBegin* b) { _forward_branches.at_put(b->block_id(), _forward_branches.at(b->block_id()) + 1); }
485
int dec_forward_branches(BlockBegin* b) { _forward_branches.at_put(b->block_id(), _forward_branches.at(b->block_id()) - 1); return _forward_branches.at(b->block_id()); }
487
// accessors for _loop_map
488
bool is_block_in_loop (int loop_idx, BlockBegin* b) const { return _loop_map.at(loop_idx, b->block_id()); }
489
void set_block_in_loop (int loop_idx, BlockBegin* b) { _loop_map.set_bit(loop_idx, b->block_id()); }
490
void clear_block_in_loop(int loop_idx, int block_id) { _loop_map.clear_bit(loop_idx, block_id); }
492
// count edges between blocks
493
void count_edges(BlockBegin* cur, BlockBegin* parent);
497
void clear_non_natural_loops(BlockBegin* start_block);
498
void assign_loop_depth(BlockBegin* start_block);
500
// computation of final block order
501
BlockBegin* common_dominator(BlockBegin* a, BlockBegin* b);
502
void compute_dominator(BlockBegin* cur, BlockBegin* parent);
503
void compute_dominator_impl(BlockBegin* cur, BlockBegin* parent);
504
int compute_weight(BlockBegin* cur);
505
bool ready_for_processing(BlockBegin* cur);
506
void sort_into_work_list(BlockBegin* b);
507
void append_block(BlockBegin* cur);
508
void compute_order(BlockBegin* start_block);
510
// fixup of dominators for non-natural loops
511
bool compute_dominators_iter();
512
void compute_dominators();
515
DEBUG_ONLY(void print_blocks();)
516
DEBUG_ONLY(void verify();)
518
Compilation* compilation() const { return _compilation; }
520
ComputeLinearScanOrder(Compilation* c, BlockBegin* start_block);
522
// accessors for final result
523
BlockList* linear_scan_order() const { return _linear_scan_order; }
524
int num_loops() const { return _num_loops; }
528
ComputeLinearScanOrder::ComputeLinearScanOrder(Compilation* c, BlockBegin* start_block) :
529
_max_block_id(BlockBegin::number_of_blocks()),
532
_iterative_dominators(false),
533
_linear_scan_order(nullptr), // initialized later with correct size
534
_visited_blocks(_max_block_id),
535
_active_blocks(_max_block_id),
536
_dominator_blocks(_max_block_id),
537
_forward_branches(_max_block_id, _max_block_id, 0),
539
_loop_map(0), // initialized later with correct size
543
TRACE_LINEAR_SCAN(2, tty->print_cr("***** computing linear-scan block order"));
545
count_edges(start_block, nullptr);
547
if (compilation()->is_profiling()) {
548
ciMethod *method = compilation()->method();
549
if (!method->is_accessor()) {
550
ciMethodData* md = method->method_data_or_null();
551
assert(md != nullptr, "Sanity");
552
md->set_compilation_stats(_num_loops, _num_blocks);
556
if (_num_loops > 0) {
558
clear_non_natural_loops(start_block);
559
assign_loop_depth(start_block);
562
compute_order(start_block);
563
compute_dominators();
565
DEBUG_ONLY(print_blocks());
566
DEBUG_ONLY(verify());
571
// * count total number of blocks
572
// * count all incoming edges and backward incoming edges
573
// * number loop header blocks
574
// * create a list with all loop end blocks
575
void ComputeLinearScanOrder::count_edges(BlockBegin* cur, BlockBegin* parent) {
576
TRACE_LINEAR_SCAN(3, tty->print_cr("Enter count_edges for block B%d coming from B%d", cur->block_id(), parent != nullptr ? parent->block_id() : -1));
577
assert(cur->dominator() == nullptr, "dominator already initialized");
579
if (is_active(cur)) {
580
TRACE_LINEAR_SCAN(3, tty->print_cr("backward branch"));
581
assert(is_visited(cur), "block must be visisted when block is active");
582
assert(parent != nullptr, "must have parent");
584
cur->set(BlockBegin::backward_branch_target_flag);
586
// When a loop header is also the start of an exception handler, then the backward branch is
587
// an exception edge. Because such edges are usually critical edges which cannot be split, the
588
// loop must be excluded here from processing.
589
if (cur->is_set(BlockBegin::exception_entry_flag)) {
590
// Make sure that dominators are correct in this weird situation
591
_iterative_dominators = true;
595
cur->set(BlockBegin::linear_scan_loop_header_flag);
596
parent->set(BlockBegin::linear_scan_loop_end_flag);
598
assert(parent->number_of_sux() == 1 && parent->sux_at(0) == cur,
599
"loop end blocks must have one successor (critical edges are split)");
601
_loop_end_blocks.append(parent);
605
// increment number of incoming forward branches
606
inc_forward_branches(cur);
608
if (is_visited(cur)) {
609
TRACE_LINEAR_SCAN(3, tty->print_cr("block already visited"));
617
// recursive call for all successors
619
for (i = cur->number_of_sux() - 1; i >= 0; i--) {
620
count_edges(cur->sux_at(i), cur);
622
for (i = cur->number_of_exception_handlers() - 1; i >= 0; i--) {
623
count_edges(cur->exception_handler_at(i), cur);
628
// Each loop has a unique number.
629
// When multiple loops are nested, assign_loop_depth assumes that the
630
// innermost loop has the lowest number. This is guaranteed by setting
631
// the loop number after the recursive calls for the successors above
633
if (cur->is_set(BlockBegin::linear_scan_loop_header_flag)) {
634
assert(cur->loop_index() == -1, "cannot set loop-index twice");
635
TRACE_LINEAR_SCAN(3, tty->print_cr("Block B%d is loop header of loop %d", cur->block_id(), _num_loops));
637
cur->set_loop_index(_num_loops);
638
_loop_headers.append(cur);
642
TRACE_LINEAR_SCAN(3, tty->print_cr("Finished count_edges for block B%d", cur->block_id()));
646
void ComputeLinearScanOrder::mark_loops() {
647
TRACE_LINEAR_SCAN(3, tty->print_cr("----- marking loops"));
649
_loop_map = BitMap2D(_num_loops, _max_block_id);
651
for (int i = _loop_end_blocks.length() - 1; i >= 0; i--) {
652
BlockBegin* loop_end = _loop_end_blocks.at(i);
653
BlockBegin* loop_start = loop_end->sux_at(0);
654
int loop_idx = loop_start->loop_index();
656
TRACE_LINEAR_SCAN(3, tty->print_cr("Processing loop from B%d to B%d (loop %d):", loop_start->block_id(), loop_end->block_id(), loop_idx));
657
assert(loop_end->is_set(BlockBegin::linear_scan_loop_end_flag), "loop end flag must be set");
658
assert(loop_end->number_of_sux() == 1, "incorrect number of successors");
659
assert(loop_start->is_set(BlockBegin::linear_scan_loop_header_flag), "loop header flag must be set");
660
assert(loop_idx >= 0 && loop_idx < _num_loops, "loop index not set");
661
assert(_work_list.is_empty(), "work list must be empty before processing");
663
// add the end-block of the loop to the working list
664
_work_list.push(loop_end);
665
set_block_in_loop(loop_idx, loop_end);
667
BlockBegin* cur = _work_list.pop();
669
TRACE_LINEAR_SCAN(3, tty->print_cr(" processing B%d", cur->block_id()));
670
assert(is_block_in_loop(loop_idx, cur), "bit in loop map must be set when block is in work list");
672
// recursive processing of all predecessors ends when start block of loop is reached
673
if (cur != loop_start && !cur->is_set(BlockBegin::osr_entry_flag)) {
674
for (int j = cur->number_of_preds() - 1; j >= 0; j--) {
675
BlockBegin* pred = cur->pred_at(j);
677
if (!is_block_in_loop(loop_idx, pred) /*&& !pred->is_set(BlockBeginosr_entry_flag)*/) {
678
// this predecessor has not been processed yet, so add it to work list
679
TRACE_LINEAR_SCAN(3, tty->print_cr(" pushing B%d", pred->block_id()));
680
_work_list.push(pred);
681
set_block_in_loop(loop_idx, pred);
685
} while (!_work_list.is_empty());
690
// check for non-natural loops (loops where the loop header does not dominate
691
// all other loop blocks = loops with multiple entries).
692
// such loops are ignored
693
void ComputeLinearScanOrder::clear_non_natural_loops(BlockBegin* start_block) {
694
for (int i = _num_loops - 1; i >= 0; i--) {
695
if (is_block_in_loop(i, start_block)) {
696
// loop i contains the entry block of the method
697
// -> this is not a natural loop, so ignore it
698
TRACE_LINEAR_SCAN(2, tty->print_cr("Loop %d is non-natural, so it is ignored", i));
700
BlockBegin *loop_header = _loop_headers.at(i);
701
assert(loop_header->is_set(BlockBegin::linear_scan_loop_header_flag), "Must be loop header");
703
for (int j = 0; j < loop_header->number_of_preds(); j++) {
704
BlockBegin *pred = loop_header->pred_at(j);
705
pred->clear(BlockBegin::linear_scan_loop_end_flag);
708
loop_header->clear(BlockBegin::linear_scan_loop_header_flag);
710
for (int block_id = _max_block_id - 1; block_id >= 0; block_id--) {
711
clear_block_in_loop(i, block_id);
713
_iterative_dominators = true;
718
void ComputeLinearScanOrder::assign_loop_depth(BlockBegin* start_block) {
719
TRACE_LINEAR_SCAN(3, tty->print_cr("----- computing loop-depth and weight"));
722
assert(_work_list.is_empty(), "work list must be empty before processing");
723
_work_list.append(start_block);
726
BlockBegin* cur = _work_list.pop();
728
if (!is_visited(cur)) {
730
TRACE_LINEAR_SCAN(4, tty->print_cr("Computing loop depth for block B%d", cur->block_id()));
732
// compute loop-depth and loop-index for the block
733
assert(cur->loop_depth() == 0, "cannot set loop-depth twice");
736
int min_loop_idx = -1;
737
for (i = _num_loops - 1; i >= 0; i--) {
738
if (is_block_in_loop(i, cur)) {
743
cur->set_loop_depth(loop_depth);
744
cur->set_loop_index(min_loop_idx);
746
// append all unvisited successors to work list
747
for (i = cur->number_of_sux() - 1; i >= 0; i--) {
748
_work_list.append(cur->sux_at(i));
750
for (i = cur->number_of_exception_handlers() - 1; i >= 0; i--) {
751
_work_list.append(cur->exception_handler_at(i));
754
} while (!_work_list.is_empty());
758
BlockBegin* ComputeLinearScanOrder::common_dominator(BlockBegin* a, BlockBegin* b) {
759
assert(a != nullptr && b != nullptr, "must have input blocks");
761
_dominator_blocks.clear();
762
while (a != nullptr) {
763
_dominator_blocks.set_bit(a->block_id());
764
assert(a->dominator() != nullptr || a == _linear_scan_order->at(0), "dominator must be initialized");
767
while (b != nullptr && !_dominator_blocks.at(b->block_id())) {
768
assert(b->dominator() != nullptr || b == _linear_scan_order->at(0), "dominator must be initialized");
772
assert(b != nullptr, "could not find dominator");
776
void ComputeLinearScanOrder::compute_dominator(BlockBegin* cur, BlockBegin* parent) {
778
compute_dominator_impl(cur, parent);
781
void ComputeLinearScanOrder::compute_dominator_impl(BlockBegin* cur, BlockBegin* parent) {
782
// Mark as visited to avoid recursive calls with same parent
785
if (cur->dominator() == nullptr) {
786
TRACE_LINEAR_SCAN(4, tty->print_cr("DOM: initializing dominator of B%d to B%d", cur->block_id(), parent->block_id()));
787
cur->set_dominator(parent);
789
} else if (!(cur->is_set(BlockBegin::linear_scan_loop_header_flag) && parent->is_set(BlockBegin::linear_scan_loop_end_flag))) {
790
TRACE_LINEAR_SCAN(4, tty->print_cr("DOM: computing dominator of B%d: common dominator of B%d and B%d is B%d", cur->block_id(), parent->block_id(), cur->dominator()->block_id(), common_dominator(cur->dominator(), parent)->block_id()));
791
// Does not hold for exception blocks
792
assert(cur->number_of_preds() > 1 || cur->is_set(BlockBegin::exception_entry_flag), "");
793
cur->set_dominator(common_dominator(cur->dominator(), parent));
796
// Additional edge to xhandler of all our successors
797
// range check elimination needs that the state at the end of a
798
// block be valid in every block it dominates so cur must dominate
799
// the exception handlers of its successors.
800
int num_cur_xhandler = cur->number_of_exception_handlers();
801
for (int j = 0; j < num_cur_xhandler; j++) {
802
BlockBegin* xhandler = cur->exception_handler_at(j);
803
if (!is_visited(xhandler)) {
804
compute_dominator_impl(xhandler, parent);
810
int ComputeLinearScanOrder::compute_weight(BlockBegin* cur) {
811
BlockBegin* single_sux = nullptr;
812
if (cur->number_of_sux() == 1) {
813
single_sux = cur->sux_at(0);
816
// limit loop-depth to 15 bit (only for security reason, it will never be so big)
817
int weight = (cur->loop_depth() & 0x7FFF) << 16;
819
// general macro for short definition of weight flags
820
// the first instance of INC_WEIGHT_IF has the highest priority
822
#define INC_WEIGHT_IF(condition) if ((condition)) { weight |= (1 << cur_bit); } cur_bit--;
824
// this is necessary for the (very rare) case that two successive blocks have
825
// the same loop depth, but a different loop index (can happen for endless loops
826
// with exception handlers)
827
INC_WEIGHT_IF(!cur->is_set(BlockBegin::linear_scan_loop_header_flag));
829
// loop end blocks (blocks that end with a backward branch) are added
830
// after all other blocks of the loop.
831
INC_WEIGHT_IF(!cur->is_set(BlockBegin::linear_scan_loop_end_flag));
833
// critical edge split blocks are preferred because than they have a bigger
834
// proability to be completely empty
835
INC_WEIGHT_IF(cur->is_set(BlockBegin::critical_edge_split_flag));
837
// exceptions should not be thrown in normal control flow, so these blocks
838
// are added as late as possible
839
INC_WEIGHT_IF(cur->end()->as_Throw() == nullptr && (single_sux == nullptr || single_sux->end()->as_Throw() == nullptr));
840
INC_WEIGHT_IF(cur->end()->as_Return() == nullptr && (single_sux == nullptr || single_sux->end()->as_Return() == nullptr));
842
// exceptions handlers are added as late as possible
843
INC_WEIGHT_IF(!cur->is_set(BlockBegin::exception_entry_flag));
845
// guarantee that weight is > 0
849
assert(cur_bit >= 0, "too many flags");
850
assert(weight > 0, "weight cannot become negative");
855
bool ComputeLinearScanOrder::ready_for_processing(BlockBegin* cur) {
856
// Discount the edge just traveled.
857
// When the number drops to zero, all forward branches were processed
858
if (dec_forward_branches(cur) != 0) {
862
assert(_linear_scan_order->find(cur) == -1, "block already processed (block can be ready only once)");
863
assert(_work_list.find(cur) == -1, "block already in work-list (block can be ready only once)");
867
void ComputeLinearScanOrder::sort_into_work_list(BlockBegin* cur) {
868
assert(_work_list.find(cur) == -1, "block already in work list");
870
int cur_weight = compute_weight(cur);
872
// the linear_scan_number is used to cache the weight of a block
873
cur->set_linear_scan_number(cur_weight);
876
if (StressLinearScan) {
877
_work_list.insert_before(0, cur);
882
_work_list.append(nullptr); // provide space for new element
884
int insert_idx = _work_list.length() - 1;
885
while (insert_idx > 0 && _work_list.at(insert_idx - 1)->linear_scan_number() > cur_weight) {
886
_work_list.at_put(insert_idx, _work_list.at(insert_idx - 1));
889
_work_list.at_put(insert_idx, cur);
891
TRACE_LINEAR_SCAN(3, tty->print_cr("Sorted B%d into worklist. new worklist:", cur->block_id()));
892
TRACE_LINEAR_SCAN(3, for (int i = 0; i < _work_list.length(); i++) tty->print_cr("%8d B%2d weight:%6x", i, _work_list.at(i)->block_id(), _work_list.at(i)->linear_scan_number()));
895
for (int i = 0; i < _work_list.length(); i++) {
896
assert(_work_list.at(i)->linear_scan_number() > 0, "weight not set");
897
assert(i == 0 || _work_list.at(i - 1)->linear_scan_number() <= _work_list.at(i)->linear_scan_number(), "incorrect order in worklist");
902
void ComputeLinearScanOrder::append_block(BlockBegin* cur) {
903
TRACE_LINEAR_SCAN(3, tty->print_cr("appending block B%d (weight 0x%6x) to linear-scan order", cur->block_id(), cur->linear_scan_number()));
904
assert(_linear_scan_order->find(cur) == -1, "cannot add the same block twice");
906
// currently, the linear scan order and code emit order are equal.
907
// therefore the linear_scan_number and the weight of a block must also
909
cur->set_linear_scan_number(_linear_scan_order->length());
910
_linear_scan_order->append(cur);
913
void ComputeLinearScanOrder::compute_order(BlockBegin* start_block) {
914
TRACE_LINEAR_SCAN(3, tty->print_cr("----- computing final block order"));
916
// the start block is always the first block in the linear scan order
917
_linear_scan_order = new BlockList(_num_blocks);
918
append_block(start_block);
920
assert(start_block->end()->as_Base() != nullptr, "start block must end with Base-instruction");
921
BlockBegin* std_entry = ((Base*)start_block->end())->std_entry();
922
BlockBegin* osr_entry = ((Base*)start_block->end())->osr_entry();
924
BlockBegin* sux_of_osr_entry = nullptr;
925
if (osr_entry != nullptr) {
926
// special handling for osr entry:
927
// ignore the edge between the osr entry and its successor for processing
928
// the osr entry block is added manually below
929
assert(osr_entry->number_of_sux() == 1, "osr entry must have exactly one successor");
930
assert(osr_entry->sux_at(0)->number_of_preds() >= 2, "successor of osr entry must have two predecessors (otherwise it is not present in normal control flow");
932
sux_of_osr_entry = osr_entry->sux_at(0);
933
dec_forward_branches(sux_of_osr_entry);
935
compute_dominator(osr_entry, start_block);
936
_iterative_dominators = true;
938
compute_dominator(std_entry, start_block);
940
// start processing with standard entry block
941
assert(_work_list.is_empty(), "list must be empty before processing");
943
if (ready_for_processing(std_entry)) {
944
sort_into_work_list(std_entry);
946
assert(false, "the std_entry must be ready for processing (otherwise, the method has no start block)");
950
BlockBegin* cur = _work_list.pop();
952
if (cur == sux_of_osr_entry) {
953
// the osr entry block is ignored in normal processing, it is never added to the
954
// work list. Instead, it is added as late as possible manually here.
955
append_block(osr_entry);
956
compute_dominator(cur, osr_entry);
961
int num_sux = cur->number_of_sux();
962
// changed loop order to get "intuitive" order of if- and else-blocks
963
for (i = 0; i < num_sux; i++) {
964
BlockBegin* sux = cur->sux_at(i);
965
compute_dominator(sux, cur);
966
if (ready_for_processing(sux)) {
967
sort_into_work_list(sux);
970
num_sux = cur->number_of_exception_handlers();
971
for (i = 0; i < num_sux; i++) {
972
BlockBegin* sux = cur->exception_handler_at(i);
973
if (ready_for_processing(sux)) {
974
sort_into_work_list(sux);
977
} while (_work_list.length() > 0);
981
bool ComputeLinearScanOrder::compute_dominators_iter() {
982
bool changed = false;
983
int num_blocks = _linear_scan_order->length();
985
assert(_linear_scan_order->at(0)->dominator() == nullptr, "must not have dominator");
986
assert(_linear_scan_order->at(0)->number_of_preds() == 0, "must not have predecessors");
987
for (int i = 1; i < num_blocks; i++) {
988
BlockBegin* block = _linear_scan_order->at(i);
990
BlockBegin* dominator = block->pred_at(0);
991
int num_preds = block->number_of_preds();
993
TRACE_LINEAR_SCAN(4, tty->print_cr("DOM: Processing B%d", block->block_id()));
995
for (int j = 0; j < num_preds; j++) {
997
BlockBegin *pred = block->pred_at(j);
998
TRACE_LINEAR_SCAN(4, tty->print_cr(" DOM: Subrocessing B%d", pred->block_id()));
1000
if (block->is_set(BlockBegin::exception_entry_flag)) {
1001
dominator = common_dominator(dominator, pred);
1002
int num_pred_preds = pred->number_of_preds();
1003
for (int k = 0; k < num_pred_preds; k++) {
1004
dominator = common_dominator(dominator, pred->pred_at(k));
1007
dominator = common_dominator(dominator, pred);
1011
if (dominator != block->dominator()) {
1012
TRACE_LINEAR_SCAN(4, tty->print_cr("DOM: updating dominator of B%d from B%d to B%d", block->block_id(), block->dominator()->block_id(), dominator->block_id()));
1014
block->set_dominator(dominator);
1021
void ComputeLinearScanOrder::compute_dominators() {
1022
TRACE_LINEAR_SCAN(3, tty->print_cr("----- computing dominators (iterative computation reqired: %d)", _iterative_dominators));
1024
// iterative computation of dominators is only required for methods with non-natural loops
1025
// and OSR-methods. For all other methods, the dominators computed when generating the
1026
// linear scan block order are correct.
1027
if (_iterative_dominators) {
1029
TRACE_LINEAR_SCAN(1, tty->print_cr("DOM: next iteration of fix-point calculation"));
1030
} while (compute_dominators_iter());
1033
// check that dominators are correct
1034
assert(!compute_dominators_iter(), "fix point not reached");
1036
// Add Blocks to dominates-Array
1037
int num_blocks = _linear_scan_order->length();
1038
for (int i = 0; i < num_blocks; i++) {
1039
BlockBegin* block = _linear_scan_order->at(i);
1041
BlockBegin *dom = block->dominator();
1043
assert(dom->dominator_depth() != -1, "Dominator must have been visited before");
1044
dom->dominates()->append(block);
1045
block->set_dominator_depth(dom->dominator_depth() + 1);
1047
block->set_dominator_depth(0);
1054
void ComputeLinearScanOrder::print_blocks() {
1055
if (TraceLinearScanLevel >= 2) {
1056
tty->print_cr("----- loop information:");
1057
for (int block_idx = 0; block_idx < _linear_scan_order->length(); block_idx++) {
1058
BlockBegin* cur = _linear_scan_order->at(block_idx);
1060
tty->print("%4d: B%2d: ", cur->linear_scan_number(), cur->block_id());
1061
for (int loop_idx = 0; loop_idx < _num_loops; loop_idx++) {
1062
tty->print ("%d ", is_block_in_loop(loop_idx, cur));
1064
tty->print_cr(" -> loop_index: %2d, loop_depth: %2d", cur->loop_index(), cur->loop_depth());
1068
if (TraceLinearScanLevel >= 1) {
1069
tty->print_cr("----- linear-scan block order:");
1070
for (int block_idx = 0; block_idx < _linear_scan_order->length(); block_idx++) {
1071
BlockBegin* cur = _linear_scan_order->at(block_idx);
1072
tty->print("%4d: B%2d loop: %2d depth: %2d", cur->linear_scan_number(), cur->block_id(), cur->loop_index(), cur->loop_depth());
1074
tty->print(cur->is_set(BlockBegin::exception_entry_flag) ? " ex" : " ");
1075
tty->print(cur->is_set(BlockBegin::critical_edge_split_flag) ? " ce" : " ");
1076
tty->print(cur->is_set(BlockBegin::linear_scan_loop_header_flag) ? " lh" : " ");
1077
tty->print(cur->is_set(BlockBegin::linear_scan_loop_end_flag) ? " le" : " ");
1079
if (cur->dominator() != nullptr) {
1080
tty->print(" dom: B%d ", cur->dominator()->block_id());
1082
tty->print(" dom: null ");
1085
if (cur->number_of_preds() > 0) {
1086
tty->print(" preds: ");
1087
for (int j = 0; j < cur->number_of_preds(); j++) {
1088
BlockBegin* pred = cur->pred_at(j);
1089
tty->print("B%d ", pred->block_id());
1092
if (cur->number_of_sux() > 0) {
1093
tty->print(" sux: ");
1094
for (int j = 0; j < cur->number_of_sux(); j++) {
1095
BlockBegin* sux = cur->sux_at(j);
1096
tty->print("B%d ", sux->block_id());
1099
if (cur->number_of_exception_handlers() > 0) {
1100
tty->print(" ex: ");
1101
for (int j = 0; j < cur->number_of_exception_handlers(); j++) {
1102
BlockBegin* ex = cur->exception_handler_at(j);
1103
tty->print("B%d ", ex->block_id());
1111
void ComputeLinearScanOrder::verify() {
1112
assert(_linear_scan_order->length() == _num_blocks, "wrong number of blocks in list");
1114
if (StressLinearScan) {
1115
// blocks are scrambled when StressLinearScan is used
1119
// check that all successors of a block have a higher linear-scan-number
1120
// and that all predecessors of a block have a lower linear-scan-number
1121
// (only backward branches of loops are ignored)
1123
for (i = 0; i < _linear_scan_order->length(); i++) {
1124
BlockBegin* cur = _linear_scan_order->at(i);
1126
assert(cur->linear_scan_number() == i, "incorrect linear_scan_number");
1127
assert(cur->linear_scan_number() >= 0 && cur->linear_scan_number() == _linear_scan_order->find(cur), "incorrect linear_scan_number");
1130
for (j = cur->number_of_sux() - 1; j >= 0; j--) {
1131
BlockBegin* sux = cur->sux_at(j);
1133
assert(sux->linear_scan_number() >= 0 && sux->linear_scan_number() == _linear_scan_order->find(sux), "incorrect linear_scan_number");
1134
if (!sux->is_set(BlockBegin::backward_branch_target_flag)) {
1135
assert(cur->linear_scan_number() < sux->linear_scan_number(), "invalid order");
1137
if (cur->loop_depth() == sux->loop_depth()) {
1138
assert(cur->loop_index() == sux->loop_index() || sux->is_set(BlockBegin::linear_scan_loop_header_flag), "successive blocks with same loop depth must have same loop index");
1142
for (j = cur->number_of_preds() - 1; j >= 0; j--) {
1143
BlockBegin* pred = cur->pred_at(j);
1145
assert(pred->linear_scan_number() >= 0 && pred->linear_scan_number() == _linear_scan_order->find(pred), "incorrect linear_scan_number");
1146
if (!cur->is_set(BlockBegin::backward_branch_target_flag)) {
1147
assert(cur->linear_scan_number() > pred->linear_scan_number(), "invalid order");
1149
if (cur->loop_depth() == pred->loop_depth()) {
1150
assert(cur->loop_index() == pred->loop_index() || cur->is_set(BlockBegin::linear_scan_loop_header_flag), "successive blocks with same loop depth must have same loop index");
1153
assert(cur->dominator()->linear_scan_number() <= cur->pred_at(j)->linear_scan_number(), "dominator must be before predecessors");
1158
assert(cur->dominator() == nullptr, "first block has no dominator");
1160
assert(cur->dominator() != nullptr, "all but first block must have dominator");
1162
// Assertion does not hold for exception handlers
1163
assert(cur->number_of_preds() != 1 || cur->dominator() == cur->pred_at(0) || cur->is_set(BlockBegin::exception_entry_flag), "Single predecessor must also be dominator");
1166
// check that all loops are continuous
1167
for (int loop_idx = 0; loop_idx < _num_loops; loop_idx++) {
1169
assert(!is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx)), "the first block must not be present in any loop");
1171
// skip blocks before the loop
1172
while (block_idx < _num_blocks && !is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx))) {
1175
// skip blocks of loop
1176
while (block_idx < _num_blocks && is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx))) {
1179
// after the first non-loop block, there must not be another loop-block
1180
while (block_idx < _num_blocks) {
1181
assert(!is_block_in_loop(loop_idx, _linear_scan_order->at(block_idx)), "loop not continuous in linear-scan order");
1189
void IR::compute_code() {
1190
assert(is_valid(), "IR must be valid");
1192
ComputeLinearScanOrder compute_order(compilation(), start());
1193
_num_loops = compute_order.num_loops();
1194
_code = compute_order.linear_scan_order();
1198
void IR::compute_use_counts() {
1199
// make sure all values coming out of this block get evaluated.
1200
int num_blocks = _code->length();
1201
for (int i = 0; i < num_blocks; i++) {
1202
_code->at(i)->end()->state()->pin_stack_for_linear_scan();
1205
// compute use counts
1206
UseCountComputer::compute(_code);
1210
void IR::iterate_preorder(BlockClosure* closure) {
1211
assert(is_valid(), "IR must be valid");
1212
start()->iterate_preorder(closure);
1216
void IR::iterate_postorder(BlockClosure* closure) {
1217
assert(is_valid(), "IR must be valid");
1218
start()->iterate_postorder(closure);
1221
void IR::iterate_linear_scan_order(BlockClosure* closure) {
1222
linear_scan_order()->iterate_forward(closure);
1227
class BlockPrinter: public BlockClosure {
1229
InstructionPrinter* _ip;
1234
BlockPrinter(InstructionPrinter* ip, bool cfg_only, bool live_only = false) {
1236
_cfg_only = cfg_only;
1237
_live_only = live_only;
1240
virtual void block_do(BlockBegin* block) {
1242
_ip->print_instr(block); tty->cr();
1244
block->print_block(*_ip, _live_only);
1250
void IR::print(BlockBegin* start, bool cfg_only, bool live_only) {
1252
InstructionPrinter ip(!cfg_only);
1253
BlockPrinter bp(&ip, cfg_only, live_only);
1254
start->iterate_preorder(&bp);
1258
void IR::print(bool cfg_only, bool live_only) {
1260
print(start(), cfg_only, live_only);
1262
tty->print_cr("invalid IR");
1268
class EndNotNullValidator : public BlockClosure {
1270
virtual void block_do(BlockBegin* block) {
1271
assert(block->end() != nullptr, "Expect block end to exist.");
1275
class XentryFlagValidator : public BlockClosure {
1277
virtual void block_do(BlockBegin* block) {
1278
for (int i = 0; i < block->end()->number_of_sux(); i++) {
1279
assert(!block->end()->sux_at(i)->is_set(BlockBegin::exception_entry_flag), "must not be xhandler");
1281
for (int i = 0; i < block->number_of_exception_handlers(); i++) {
1282
assert(block->exception_handler_at(i)->is_set(BlockBegin::exception_entry_flag), "must be xhandler");
1287
typedef GrowableArray<BlockList*> BlockListList;
1290
// - code() length == blocks length
1291
// - code() contents == blocks content
1292
// - Each block's computed predecessors match sux lists (length)
1293
// - Each block's computed predecessors match sux lists (set content)
1294
class PredecessorAndCodeValidator : public BlockClosure {
1296
BlockListList* _predecessors; // Each index i will hold predecessors of block with id i
1299
static int cmp(BlockBegin** a, BlockBegin** b) {
1300
return (*a)->block_id() - (*b)->block_id();
1304
PredecessorAndCodeValidator(IR* hir) {
1306
_predecessors = new BlockListList(BlockBegin::number_of_blocks(), BlockBegin::number_of_blocks(), nullptr);
1307
_blocks = new BlockList(BlockBegin::number_of_blocks());
1309
hir->start()->iterate_preorder(this);
1310
if (hir->code() != nullptr) {
1311
assert(hir->code()->length() == _blocks->length(), "must match");
1312
for (int i = 0; i < _blocks->length(); i++) {
1313
assert(hir->code()->contains(_blocks->at(i)), "should be in both lists");
1317
for (int i = 0; i < _blocks->length(); i++) {
1318
BlockBegin* block = _blocks->at(i);
1319
verify_block_preds_against_collected_preds(block);
1323
virtual void block_do(BlockBegin* block) {
1324
_blocks->append(block);
1325
collect_predecessors(block);
1329
void collect_predecessors(BlockBegin* block) {
1330
for (int i = 0; i < block->end()->number_of_sux(); i++) {
1331
collect_predecessor(block, block->end()->sux_at(i));
1333
for (int i = 0; i < block->number_of_exception_handlers(); i++) {
1334
collect_predecessor(block, block->exception_handler_at(i));
1338
void collect_predecessor(BlockBegin* const pred, const BlockBegin* sux) {
1339
BlockList* preds = _predecessors->at_grow(sux->block_id(), nullptr);
1340
if (preds == nullptr) {
1341
preds = new BlockList();
1342
_predecessors->at_put(sux->block_id(), preds);
1344
preds->append(pred);
1347
void verify_block_preds_against_collected_preds(const BlockBegin* block) const {
1348
BlockList* preds = _predecessors->at(block->block_id());
1349
if (preds == nullptr) {
1350
assert(block->number_of_preds() == 0, "should be the same");
1353
assert(preds->length() == block->number_of_preds(), "should be the same");
1355
// clone the pred list so we can mutate it
1356
BlockList* pred_copy = new BlockList();
1357
for (int j = 0; j < block->number_of_preds(); j++) {
1358
pred_copy->append(block->pred_at(j));
1360
// sort them in the same order
1362
pred_copy->sort(cmp);
1363
for (int j = 0; j < block->number_of_preds(); j++) {
1364
assert(preds->at(j) == pred_copy->at(j), "must match");
1369
class VerifyBlockBeginField : public BlockClosure {
1371
virtual void block_do(BlockBegin* block) {
1372
for (Instruction* cur = block; cur != nullptr; cur = cur->next()) {
1373
assert(cur->block() == block, "Block begin is not correct");
1378
class ValidateEdgeMutuality : public BlockClosure {
1380
virtual void block_do(BlockBegin* block) {
1381
for (int i = 0; i < block->end()->number_of_sux(); i++) {
1382
assert(block->end()->sux_at(i)->is_predecessor(block), "Block's successor should have it as predecessor");
1385
for (int i = 0; i < block->number_of_exception_handlers(); i++) {
1386
assert(block->exception_handler_at(i)->is_predecessor(block), "Block's exception handler should have it as predecessor");
1389
for (int i = 0; i < block->number_of_preds(); i++) {
1390
assert(block->pred_at(i) != nullptr, "Predecessor must exist");
1391
assert(block->pred_at(i)->end() != nullptr, "Predecessor end must exist");
1392
bool is_sux = block->pred_at(i)->end()->is_sux(block);
1393
bool is_xhandler = block->pred_at(i)->is_exception_handler(block);
1394
assert(is_sux || is_xhandler, "Block's predecessor should have it as successor or xhandler");
1399
void IR::expand_with_neighborhood(BlockList& blocks) {
1400
int original_size = blocks.length();
1401
for (int h = 0; h < original_size; h++) {
1402
BlockBegin* block = blocks.at(h);
1404
for (int i = 0; i < block->end()->number_of_sux(); i++) {
1405
if (!blocks.contains(block->end()->sux_at(i))) {
1406
blocks.append(block->end()->sux_at(i));
1410
for (int i = 0; i < block->number_of_preds(); i++) {
1411
if (!blocks.contains(block->pred_at(i))) {
1412
blocks.append(block->pred_at(i));
1416
for (int i = 0; i < block->number_of_exception_handlers(); i++) {
1417
if (!blocks.contains(block->exception_handler_at(i))) {
1418
blocks.append(block->exception_handler_at(i));
1424
void IR::verify_local(BlockList& blocks) {
1425
EndNotNullValidator ennv;
1426
blocks.iterate_forward(&ennv);
1428
ValidateEdgeMutuality vem;
1429
blocks.iterate_forward(&vem);
1431
VerifyBlockBeginField verifier;
1432
blocks.iterate_forward(&verifier);
1436
XentryFlagValidator xe;
1437
iterate_postorder(&xe);
1439
PredecessorAndCodeValidator pv(this);
1441
EndNotNullValidator ennv;
1442
iterate_postorder(&ennv);
1444
ValidateEdgeMutuality vem;
1445
iterate_postorder(&vem);
1447
VerifyBlockBeginField verifier;
1448
iterate_postorder(&verifier);
1452
void SubstitutionResolver::visit(Value* v) {
1455
Value vs = v0->subst();
1463
class SubstitutionChecker: public ValueVisitor {
1464
void visit(Value* v) {
1467
Value vs = v0->subst();
1468
assert(vs == v0, "missed substitution");
1475
void SubstitutionResolver::block_do(BlockBegin* block) {
1476
Instruction* last = nullptr;
1477
for (Instruction* n = block; n != nullptr;) {
1479
// need to remove this instruction from the instruction stream
1480
if (n->subst() != n) {
1481
guarantee(last != nullptr, "must have last");
1482
last->set_next(n->next());
1490
SubstitutionChecker check_substitute;
1491
if (block->state()) block->state()->values_do(&check_substitute);
1492
block->block_values_do(&check_substitute);
1493
if (block->end() && block->end()->state()) block->end()->state()->values_do(&check_substitute);