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/*
* Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "compiler/compileLog.hpp"
#include "interpreter/linkResolver.hpp"
#include "memory/resourceArea.hpp"
#include "oops/method.hpp"
#include "opto/addnode.hpp"
#include "opto/c2compiler.hpp"
#include "opto/castnode.hpp"
#include "opto/idealGraphPrinter.hpp"
#include "opto/locknode.hpp"
#include "opto/memnode.hpp"
#include "opto/opaquenode.hpp"
#include "opto/parse.hpp"
#include "opto/rootnode.hpp"
#include "opto/runtime.hpp"
#include "opto/type.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/safepointMechanism.hpp"
#include "runtime/sharedRuntime.hpp"
#include "utilities/bitMap.inline.hpp"
#include "utilities/copy.hpp"
// Static array so we can figure out which bytecodes stop us from compiling
// the most. Some of the non-static variables are needed in bytecodeInfo.cpp
// and eventually should be encapsulated in a proper class (gri 8/18/98).
#ifndef PRODUCT
int nodes_created = 0;
int methods_parsed = 0;
int methods_seen = 0;
int blocks_parsed = 0;
int blocks_seen = 0;
int explicit_null_checks_inserted = 0;
int explicit_null_checks_elided = 0;
int all_null_checks_found = 0;
int implicit_null_checks = 0;
bool Parse::BytecodeParseHistogram::_initialized = false;
uint Parse::BytecodeParseHistogram::_bytecodes_parsed [Bytecodes::number_of_codes];
uint Parse::BytecodeParseHistogram::_nodes_constructed[Bytecodes::number_of_codes];
uint Parse::BytecodeParseHistogram::_nodes_transformed[Bytecodes::number_of_codes];
uint Parse::BytecodeParseHistogram::_new_values [Bytecodes::number_of_codes];
//------------------------------print_statistics-------------------------------
void Parse::print_statistics() {
tty->print_cr("--- Compiler Statistics ---");
tty->print("Methods seen: %d Methods parsed: %d", methods_seen, methods_parsed);
tty->print(" Nodes created: %d", nodes_created);
tty->cr();
if (methods_seen != methods_parsed) {
tty->print_cr("Reasons for parse failures (NOT cumulative):");
}
tty->print_cr("Blocks parsed: %d Blocks seen: %d", blocks_parsed, blocks_seen);
if (explicit_null_checks_inserted) {
tty->print_cr("%d original NULL checks - %d elided (%2d%%); optimizer leaves %d,",
explicit_null_checks_inserted, explicit_null_checks_elided,
(100*explicit_null_checks_elided)/explicit_null_checks_inserted,
all_null_checks_found);
}
if (all_null_checks_found) {
tty->print_cr("%d made implicit (%2d%%)", implicit_null_checks,
(100*implicit_null_checks)/all_null_checks_found);
}
if (SharedRuntime::_implicit_null_throws) {
tty->print_cr("%d implicit null exceptions at runtime",
SharedRuntime::_implicit_null_throws);
}
if (PrintParseStatistics && BytecodeParseHistogram::initialized()) {
BytecodeParseHistogram::print();
}
}
#endif
//------------------------------ON STACK REPLACEMENT---------------------------
// Construct a node which can be used to get incoming state for
// on stack replacement.
Node *Parse::fetch_interpreter_state(int index,
BasicType bt,
Node *local_addrs,
Node *local_addrs_base) {
Node *mem = memory(Compile::AliasIdxRaw);
Node *adr = basic_plus_adr( local_addrs_base, local_addrs, -index*wordSize );
Node *ctl = control();
// Very similar to LoadNode::make, except we handle un-aligned longs and
// doubles on Sparc. Intel can handle them just fine directly.
Node *l = NULL;
switch (bt) { // Signature is flattened
case T_INT: l = new LoadINode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInt::INT, MemNode::unordered); break;
case T_FLOAT: l = new LoadFNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::FLOAT, MemNode::unordered); break;
case T_ADDRESS: l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, MemNode::unordered); break;
case T_OBJECT: l = new LoadPNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeInstPtr::BOTTOM, MemNode::unordered); break;
case T_LONG:
case T_DOUBLE: {
// Since arguments are in reverse order, the argument address 'adr'
// refers to the back half of the long/double. Recompute adr.
adr = basic_plus_adr(local_addrs_base, local_addrs, -(index+1)*wordSize);
if (Matcher::misaligned_doubles_ok) {
l = (bt == T_DOUBLE)
? (Node*)new LoadDNode(ctl, mem, adr, TypeRawPtr::BOTTOM, Type::DOUBLE, MemNode::unordered)
: (Node*)new LoadLNode(ctl, mem, adr, TypeRawPtr::BOTTOM, TypeLong::LONG, MemNode::unordered);
} else {
l = (bt == T_DOUBLE)
? (Node*)new LoadD_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered)
: (Node*)new LoadL_unalignedNode(ctl, mem, adr, TypeRawPtr::BOTTOM, MemNode::unordered);
}
break;
}
default: ShouldNotReachHere();
}
return _gvn.transform(l);
}
// Helper routine to prevent the interpreter from handing
// unexpected typestate to an OSR method.
// The Node l is a value newly dug out of the interpreter frame.
// The type is the type predicted by ciTypeFlow. Note that it is
// not a general type, but can only come from Type::get_typeflow_type.
// The safepoint is a map which will feed an uncommon trap.
Node* Parse::check_interpreter_type(Node* l, const Type* type,
SafePointNode* &bad_type_exit) {
const TypeOopPtr* tp = type->isa_oopptr();
// TypeFlow may assert null-ness if a type appears unloaded.
if (type == TypePtr::NULL_PTR ||
(tp != NULL && !tp->is_loaded())) {
// Value must be null, not a real oop.
Node* chk = _gvn.transform( new CmpPNode(l, null()) );
Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
IfNode* iff = create_and_map_if(control(), tst, PROB_MAX, COUNT_UNKNOWN);
set_control(_gvn.transform( new IfTrueNode(iff) ));
Node* bad_type = _gvn.transform( new IfFalseNode(iff) );
bad_type_exit->control()->add_req(bad_type);
l = null();
}
// Typeflow can also cut off paths from the CFG, based on
// types which appear unloaded, or call sites which appear unlinked.
// When paths are cut off, values at later merge points can rise
// toward more specific classes. Make sure these specific classes
// are still in effect.
if (tp != NULL && !tp->is_same_java_type_as(TypeInstPtr::BOTTOM)) {
// TypeFlow asserted a specific object type. Value must have that type.
Node* bad_type_ctrl = NULL;
l = gen_checkcast(l, makecon(tp->as_klass_type()->cast_to_exactness(true)), &bad_type_ctrl);
bad_type_exit->control()->add_req(bad_type_ctrl);
}
assert(_gvn.type(l)->higher_equal(type), "must constrain OSR typestate");
return l;
}
// Helper routine which sets up elements of the initial parser map when
// performing a parse for on stack replacement. Add values into map.
// The only parameter contains the address of a interpreter arguments.
void Parse::load_interpreter_state(Node* osr_buf) {
int index;
int max_locals = jvms()->loc_size();
int max_stack = jvms()->stk_size();
// Mismatch between method and jvms can occur since map briefly held
// an OSR entry state (which takes up one RawPtr word).
assert(max_locals == method()->max_locals(), "sanity");
assert(max_stack >= method()->max_stack(), "sanity");
assert((int)jvms()->endoff() == TypeFunc::Parms + max_locals + max_stack, "sanity");
assert((int)jvms()->endoff() == (int)map()->req(), "sanity");
// Find the start block.
Block* osr_block = start_block();
assert(osr_block->start() == osr_bci(), "sanity");
// Set initial BCI.
set_parse_bci(osr_block->start());
// Set initial stack depth.
set_sp(osr_block->start_sp());
// Check bailouts. We currently do not perform on stack replacement
// of loops in catch blocks or loops which branch with a non-empty stack.
if (sp() != 0) {
C->record_method_not_compilable("OSR starts with non-empty stack");
return;
}
// Do not OSR inside finally clauses:
if (osr_block->has_trap_at(osr_block->start())) {
C->record_method_not_compilable("OSR starts with an immediate trap");
return;
}
// Commute monitors from interpreter frame to compiler frame.
assert(jvms()->monitor_depth() == 0, "should be no active locks at beginning of osr");
int mcnt = osr_block->flow()->monitor_count();
Node *monitors_addr = basic_plus_adr(osr_buf, osr_buf, (max_locals+mcnt*2-1)*wordSize);
for (index = 0; index < mcnt; index++) {
// Make a BoxLockNode for the monitor.
Node *box = _gvn.transform(new BoxLockNode(next_monitor()));
// Displaced headers and locked objects are interleaved in the
// temp OSR buffer. We only copy the locked objects out here.
// Fetch the locked object from the OSR temp buffer and copy to our fastlock node.
Node *lock_object = fetch_interpreter_state(index*2, T_OBJECT, monitors_addr, osr_buf);
// Try and copy the displaced header to the BoxNode
Node *displaced_hdr = fetch_interpreter_state((index*2) + 1, T_ADDRESS, monitors_addr, osr_buf);
store_to_memory(control(), box, displaced_hdr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
// Build a bogus FastLockNode (no code will be generated) and push the
// monitor into our debug info.
const FastLockNode *flock = _gvn.transform(new FastLockNode( 0, lock_object, box ))->as_FastLock();
map()->push_monitor(flock);
// If the lock is our method synchronization lock, tuck it away in
// _sync_lock for return and rethrow exit paths.
if (index == 0 && method()->is_synchronized()) {
_synch_lock = flock;
}
}
// Use the raw liveness computation to make sure that unexpected
// values don't propagate into the OSR frame.
MethodLivenessResult live_locals = method()->liveness_at_bci(osr_bci());
if (!live_locals.is_valid()) {
// Degenerate or breakpointed method.
C->record_method_not_compilable("OSR in empty or breakpointed method");
return;
}
// Extract the needed locals from the interpreter frame.
Node *locals_addr = basic_plus_adr(osr_buf, osr_buf, (max_locals-1)*wordSize);
// find all the locals that the interpreter thinks contain live oops
const ResourceBitMap live_oops = method()->live_local_oops_at_bci(osr_bci());
for (index = 0; index < max_locals; index++) {
if (!live_locals.at(index)) {
continue;
}
const Type *type = osr_block->local_type_at(index);
if (type->isa_oopptr() != NULL) {
// 6403625: Verify that the interpreter oopMap thinks that the oop is live
// else we might load a stale oop if the MethodLiveness disagrees with the
// result of the interpreter. If the interpreter says it is dead we agree
// by making the value go to top.
//
if (!live_oops.at(index)) {
if (C->log() != NULL) {
C->log()->elem("OSR_mismatch local_index='%d'",index);
}
set_local(index, null());
// and ignore it for the loads
continue;
}
}
// Filter out TOP, HALF, and BOTTOM. (Cf. ensure_phi.)
if (type == Type::TOP || type == Type::HALF) {
continue;
}
// If the type falls to bottom, then this must be a local that
// is mixing ints and oops or some such. Forcing it to top
// makes it go dead.
if (type == Type::BOTTOM) {
continue;
}
// Construct code to access the appropriate local.
BasicType bt = type->basic_type();
if (type == TypePtr::NULL_PTR) {
// Ptr types are mixed together with T_ADDRESS but NULL is
// really for T_OBJECT types so correct it.
bt = T_OBJECT;
}
Node *value = fetch_interpreter_state(index, bt, locals_addr, osr_buf);
set_local(index, value);
}
// Extract the needed stack entries from the interpreter frame.
for (index = 0; index < sp(); index++) {
const Type *type = osr_block->stack_type_at(index);
if (type != Type::TOP) {
// Currently the compiler bails out when attempting to on stack replace
// at a bci with a non-empty stack. We should not reach here.
ShouldNotReachHere();
}
}
// End the OSR migration
make_runtime_call(RC_LEAF, OptoRuntime::osr_end_Type(),
CAST_FROM_FN_PTR(address, SharedRuntime::OSR_migration_end),
"OSR_migration_end", TypeRawPtr::BOTTOM,
osr_buf);
// Now that the interpreter state is loaded, make sure it will match
// at execution time what the compiler is expecting now:
SafePointNode* bad_type_exit = clone_map();
bad_type_exit->set_control(new RegionNode(1));
assert(osr_block->flow()->jsrs()->size() == 0, "should be no jsrs live at osr point");
for (index = 0; index < max_locals; index++) {
if (stopped()) break;
Node* l = local(index);
if (l->is_top()) continue; // nothing here
const Type *type = osr_block->local_type_at(index);
if (type->isa_oopptr() != NULL) {
if (!live_oops.at(index)) {
// skip type check for dead oops
continue;
}
}
if (osr_block->flow()->local_type_at(index)->is_return_address()) {
// In our current system it's illegal for jsr addresses to be
// live into an OSR entry point because the compiler performs
// inlining of jsrs. ciTypeFlow has a bailout that detect this
// case and aborts the compile if addresses are live into an OSR
// entry point. Because of that we can assume that any address
// locals at the OSR entry point are dead. Method liveness
// isn't precise enough to figure out that they are dead in all
// cases so simply skip checking address locals all
// together. Any type check is guaranteed to fail since the
// interpreter type is the result of a load which might have any
// value and the expected type is a constant.
continue;
}
set_local(index, check_interpreter_type(l, type, bad_type_exit));
}
for (index = 0; index < sp(); index++) {
if (stopped()) break;
Node* l = stack(index);
if (l->is_top()) continue; // nothing here
const Type *type = osr_block->stack_type_at(index);
set_stack(index, check_interpreter_type(l, type, bad_type_exit));
}
if (bad_type_exit->control()->req() > 1) {
// Build an uncommon trap here, if any inputs can be unexpected.
bad_type_exit->set_control(_gvn.transform( bad_type_exit->control() ));
record_for_igvn(bad_type_exit->control());
SafePointNode* types_are_good = map();
set_map(bad_type_exit);
// The unexpected type happens because a new edge is active
// in the CFG, which typeflow had previously ignored.
// E.g., Object x = coldAtFirst() && notReached()? "str": new Integer(123).
// This x will be typed as Integer if notReached is not yet linked.
// It could also happen due to a problem in ciTypeFlow analysis.
uncommon_trap(Deoptimization::Reason_constraint,
Deoptimization::Action_reinterpret);
set_map(types_are_good);
}
}
//------------------------------Parse------------------------------------------
// Main parser constructor.
Parse::Parse(JVMState* caller, ciMethod* parse_method, float expected_uses)
: _exits(caller)
{
// Init some variables
_caller = caller;
_method = parse_method;
_expected_uses = expected_uses;
_depth = 1 + (caller->has_method() ? caller->depth() : 0);
_wrote_final = false;
_wrote_volatile = false;
_wrote_stable = false;
_wrote_fields = false;
_alloc_with_final = NULL;
_entry_bci = InvocationEntryBci;
_tf = NULL;
_block = NULL;
_first_return = true;
_replaced_nodes_for_exceptions = false;
_new_idx = C->unique();
debug_only(_block_count = -1);
debug_only(_blocks = (Block*)-1);
#ifndef PRODUCT
if (PrintCompilation || PrintOpto) {
// Make sure I have an inline tree, so I can print messages about it.
JVMState* ilt_caller = is_osr_parse() ? caller->caller() : caller;
InlineTree::find_subtree_from_root(C->ilt(), ilt_caller, parse_method);
}
_max_switch_depth = 0;
_est_switch_depth = 0;
#endif
if (parse_method->has_reserved_stack_access()) {
C->set_has_reserved_stack_access(true);
}
if (parse_method->is_synchronized()) {
C->set_has_monitors(true);
}
_tf = TypeFunc::make(method());
_iter.reset_to_method(method());
_flow = method()->get_flow_analysis();
if (_flow->failing()) {
C->record_method_not_compilable(_flow->failure_reason());
}
#ifndef PRODUCT
if (_flow->has_irreducible_entry()) {
C->set_parsed_irreducible_loop(true);
}
#endif
C->set_has_loops(C->has_loops() || method()->has_loops());
if (_expected_uses <= 0) {
_prof_factor = 1;
} else {
float prof_total = parse_method->interpreter_invocation_count();
if (prof_total <= _expected_uses) {
_prof_factor = 1;
} else {
_prof_factor = _expected_uses / prof_total;
}
}
CompileLog* log = C->log();
if (log != NULL) {
log->begin_head("parse method='%d' uses='%f'",
log->identify(parse_method), expected_uses);
if (depth() == 1 && C->is_osr_compilation()) {
log->print(" osr_bci='%d'", C->entry_bci());
}
log->stamp();
log->end_head();
}
// Accumulate deoptimization counts.
// (The range_check and store_check counts are checked elsewhere.)
ciMethodData* md = method()->method_data();
for (uint reason = 0; reason < md->trap_reason_limit(); reason++) {
uint md_count = md->trap_count(reason);
if (md_count != 0) {
if (md_count >= md->trap_count_limit()) {
md_count = md->trap_count_limit() + md->overflow_trap_count();
}
uint total_count = C->trap_count(reason);
uint old_count = total_count;
total_count += md_count;
// Saturate the add if it overflows.
if (total_count < old_count || total_count < md_count)
total_count = (uint)-1;
C->set_trap_count(reason, total_count);
if (log != NULL)
log->elem("observe trap='%s' count='%d' total='%d'",
Deoptimization::trap_reason_name(reason),
md_count, total_count);
}
}
// Accumulate total sum of decompilations, also.
C->set_decompile_count(C->decompile_count() + md->decompile_count());
if (log != NULL && method()->has_exception_handlers()) {
log->elem("observe that='has_exception_handlers'");
}
assert(InlineTree::check_can_parse(method()) == NULL, "Can not parse this method, cutout earlier");
assert(method()->has_balanced_monitors(), "Can not parse unbalanced monitors, cutout earlier");
// Always register dependence if JVMTI is enabled, because
// either breakpoint setting or hotswapping of methods may
// cause deoptimization.
if (C->env()->jvmti_can_hotswap_or_post_breakpoint()) {
C->dependencies()->assert_evol_method(method());
}
NOT_PRODUCT(methods_seen++);
// Do some special top-level things.
if (depth() == 1 && C->is_osr_compilation()) {
_entry_bci = C->entry_bci();
_flow = method()->get_osr_flow_analysis(osr_bci());
if (_flow->failing()) {
C->record_method_not_compilable(_flow->failure_reason());
#ifndef PRODUCT
if (PrintOpto && (Verbose || WizardMode)) {
tty->print_cr("OSR @%d type flow bailout: %s", _entry_bci, _flow->failure_reason());
if (Verbose) {
method()->print();
method()->print_codes();
_flow->print();
}
}
#endif
}
_tf = C->tf(); // the OSR entry type is different
}
#ifdef ASSERT
if (depth() == 1) {
assert(C->is_osr_compilation() == this->is_osr_parse(), "OSR in sync");
} else {
assert(!this->is_osr_parse(), "no recursive OSR");
}
#endif
#ifndef PRODUCT
methods_parsed++;
// add method size here to guarantee that inlined methods are added too
if (CITime)
_total_bytes_compiled += method()->code_size();
show_parse_info();
#endif
if (failing()) {
if (log) log->done("parse");
return;
}
gvn().set_type(root(), root()->bottom_type());
gvn().transform(top());
// Import the results of the ciTypeFlow.
init_blocks();
// Merge point for all normal exits
build_exits();
// Setup the initial JVM state map.
SafePointNode* entry_map = create_entry_map();
// Check for bailouts during map initialization
if (failing() || entry_map == NULL) {
if (log) log->done("parse");
return;
}
Node_Notes* caller_nn = C->default_node_notes();
// Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
if (DebugInlinedCalls || depth() == 1) {
C->set_default_node_notes(make_node_notes(caller_nn));
}
if (is_osr_parse()) {
Node* osr_buf = entry_map->in(TypeFunc::Parms+0);
entry_map->set_req(TypeFunc::Parms+0, top());
set_map(entry_map);
load_interpreter_state(osr_buf);
} else {
set_map(entry_map);
do_method_entry();
}
if (depth() == 1 && !failing()) {
if (C->clinit_barrier_on_entry()) {
// Add check to deoptimize the nmethod once the holder class is fully initialized
clinit_deopt();
}
// Add check to deoptimize the nmethod if RTM state was changed
rtm_deopt();
}
// Check for bailouts during method entry or RTM state check setup.
if (failing()) {
if (log) log->done("parse");
C->set_default_node_notes(caller_nn);
return;
}
entry_map = map(); // capture any changes performed by method setup code
assert(jvms()->endoff() == map()->req(), "map matches JVMS layout");
// We begin parsing as if we have just encountered a jump to the
// method entry.
Block* entry_block = start_block();
assert(entry_block->start() == (is_osr_parse() ? osr_bci() : 0), "");
set_map_clone(entry_map);
merge_common(entry_block, entry_block->next_path_num());
#ifndef PRODUCT
BytecodeParseHistogram *parse_histogram_obj = new (C->env()->arena()) BytecodeParseHistogram(this, C);
set_parse_histogram( parse_histogram_obj );
#endif
// Parse all the basic blocks.
do_all_blocks();
C->set_default_node_notes(caller_nn);
// Check for bailouts during conversion to graph
if (failing()) {
if (log) log->done("parse");
return;
}
// Fix up all exiting control flow.
set_map(entry_map);
do_exits();
if (log) log->done("parse nodes='%d' live='%d' memory='" SIZE_FORMAT "'",
C->unique(), C->live_nodes(), C->node_arena()->used());
}
//---------------------------do_all_blocks-------------------------------------
void Parse::do_all_blocks() {
bool has_irreducible = flow()->has_irreducible_entry();
// Walk over all blocks in Reverse Post-Order.
while (true) {
bool progress = false;
for (int rpo = 0; rpo < block_count(); rpo++) {
Block* block = rpo_at(rpo);
if (block->is_parsed()) continue;
if (!block->is_merged()) {
// Dead block, no state reaches this block
continue;
}
// Prepare to parse this block.
load_state_from(block);
if (stopped()) {
// Block is dead.
continue;
}
NOT_PRODUCT(blocks_parsed++);
progress = true;
if (block->is_loop_head() || block->is_handler() || (has_irreducible && !block->is_ready())) {
// Not all preds have been parsed. We must build phis everywhere.
// (Note that dead locals do not get phis built, ever.)
ensure_phis_everywhere();
if (block->is_SEL_head()) {
// Add predicate to single entry (not irreducible) loop head.
assert(!block->has_merged_backedge(), "only entry paths should be merged for now");
// Predicates may have been added after a dominating if
if (!block->has_predicates()) {
// Need correct bci for predicate.
// It is fine to set it here since do_one_block() will set it anyway.
set_parse_bci(block->start());
add_empty_predicates();
}
// Add new region for back branches.
int edges = block->pred_count() - block->preds_parsed() + 1; // +1 for original region
RegionNode *r = new RegionNode(edges+1);
_gvn.set_type(r, Type::CONTROL);
record_for_igvn(r);
r->init_req(edges, control());
set_control(r);
// Add new phis.
ensure_phis_everywhere();
}
// Leave behind an undisturbed copy of the map, for future merges.
set_map(clone_map());
}
if (control()->is_Region() && !block->is_loop_head() && !has_irreducible && !block->is_handler()) {
// In the absence of irreducible loops, the Region and Phis
// associated with a merge that doesn't involve a backedge can
// be simplified now since the RPO parsing order guarantees
// that any path which was supposed to reach here has already
// been parsed or must be dead.
Node* c = control();
Node* result = _gvn.transform_no_reclaim(control());
if (c != result && TraceOptoParse) {
tty->print_cr("Block #%d replace %d with %d", block->rpo(), c->_idx, result->_idx);
}
if (result != top()) {
record_for_igvn(result);
}
}
// Parse the block.
do_one_block();
// Check for bailouts.
if (failing()) return;
}
// with irreducible loops multiple passes might be necessary to parse everything
if (!has_irreducible || !progress) {
break;
}
}
#ifndef PRODUCT
blocks_seen += block_count();
// Make sure there are no half-processed blocks remaining.
// Every remaining unprocessed block is dead and may be ignored now.
for (int rpo = 0; rpo < block_count(); rpo++) {
Block* block = rpo_at(rpo);
if (!block->is_parsed()) {
if (TraceOptoParse) {
tty->print_cr("Skipped dead block %d at bci:%d", rpo, block->start());
}
assert(!block->is_merged(), "no half-processed blocks");
}
}
#endif
}
static Node* mask_int_value(Node* v, BasicType bt, PhaseGVN* gvn) {
switch (bt) {
case T_BYTE:
v = gvn->transform(new LShiftINode(v, gvn->intcon(24)));
v = gvn->transform(new RShiftINode(v, gvn->intcon(24)));
break;
case T_SHORT:
v = gvn->transform(new LShiftINode(v, gvn->intcon(16)));
v = gvn->transform(new RShiftINode(v, gvn->intcon(16)));
break;
case T_CHAR:
v = gvn->transform(new AndINode(v, gvn->intcon(0xFFFF)));
break;
case T_BOOLEAN:
v = gvn->transform(new AndINode(v, gvn->intcon(0x1)));
break;
default:
break;
}
return v;
}
//-------------------------------build_exits----------------------------------
// Build normal and exceptional exit merge points.
void Parse::build_exits() {
// make a clone of caller to prevent sharing of side-effects
_exits.set_map(_exits.clone_map());
_exits.clean_stack(_exits.sp());
_exits.sync_jvms();
RegionNode* region = new RegionNode(1);
record_for_igvn(region);
gvn().set_type_bottom(region);
_exits.set_control(region);
// Note: iophi and memphi are not transformed until do_exits.
Node* iophi = new PhiNode(region, Type::ABIO);
Node* memphi = new PhiNode(region, Type::MEMORY, TypePtr::BOTTOM);
gvn().set_type_bottom(iophi);
gvn().set_type_bottom(memphi);
_exits.set_i_o(iophi);
_exits.set_all_memory(memphi);
// Add a return value to the exit state. (Do not push it yet.)
if (tf()->range()->cnt() > TypeFunc::Parms) {
const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
if (ret_type->isa_int()) {
BasicType ret_bt = method()->return_type()->basic_type();
if (ret_bt == T_BOOLEAN ||
ret_bt == T_CHAR ||
ret_bt == T_BYTE ||
ret_bt == T_SHORT) {
ret_type = TypeInt::INT;
}
}
// Don't "bind" an unloaded return klass to the ret_phi. If the klass
// becomes loaded during the subsequent parsing, the loaded and unloaded
// types will not join when we transform and push in do_exits().
const TypeOopPtr* ret_oop_type = ret_type->isa_oopptr();
if (ret_oop_type && !ret_oop_type->is_loaded()) {
ret_type = TypeOopPtr::BOTTOM;
}
int ret_size = type2size[ret_type->basic_type()];
Node* ret_phi = new PhiNode(region, ret_type);
gvn().set_type_bottom(ret_phi);
_exits.ensure_stack(ret_size);
assert((int)(tf()->range()->cnt() - TypeFunc::Parms) == ret_size, "good tf range");
assert(method()->return_type()->size() == ret_size, "tf agrees w/ method");
_exits.set_argument(0, ret_phi); // here is where the parser finds it
// Note: ret_phi is not yet pushed, until do_exits.
}
}
//----------------------------build_start_state-------------------------------
// Construct a state which contains only the incoming arguments from an
// unknown caller. The method & bci will be NULL & InvocationEntryBci.
JVMState* Compile::build_start_state(StartNode* start, const TypeFunc* tf) {
int arg_size = tf->domain()->cnt();
int max_size = MAX2(arg_size, (int)tf->range()->cnt());
JVMState* jvms = new (this) JVMState(max_size - TypeFunc::Parms);
SafePointNode* map = new SafePointNode(max_size, jvms);
record_for_igvn(map);
assert(arg_size == TypeFunc::Parms + (is_osr_compilation() ? 1 : method()->arg_size()), "correct arg_size");
Node_Notes* old_nn = default_node_notes();
if (old_nn != NULL && has_method()) {
Node_Notes* entry_nn = old_nn->clone(this);
JVMState* entry_jvms = new(this) JVMState(method(), old_nn->jvms());
entry_jvms->set_offsets(0);
entry_jvms->set_bci(entry_bci());
entry_nn->set_jvms(entry_jvms);
set_default_node_notes(entry_nn);
}
uint i;
for (i = 0; i < (uint)arg_size; i++) {
Node* parm = initial_gvn()->transform(new ParmNode(start, i));
map->init_req(i, parm);
// Record all these guys for later GVN.
record_for_igvn(parm);
}
for (; i < map->req(); i++) {
map->init_req(i, top());
}
assert(jvms->argoff() == TypeFunc::Parms, "parser gets arguments here");
set_default_node_notes(old_nn);
jvms->set_map(map);
return jvms;
}
//-----------------------------make_node_notes---------------------------------
Node_Notes* Parse::make_node_notes(Node_Notes* caller_nn) {
if (caller_nn == NULL) return NULL;
Node_Notes* nn = caller_nn->clone(C);
JVMState* caller_jvms = nn->jvms();
JVMState* jvms = new (C) JVMState(method(), caller_jvms);
jvms->set_offsets(0);
jvms->set_bci(_entry_bci);
nn->set_jvms(jvms);
return nn;
}
//--------------------------return_values--------------------------------------
void Compile::return_values(JVMState* jvms) {
GraphKit kit(jvms);
Node* ret = new ReturnNode(TypeFunc::Parms,
kit.control(),
kit.i_o(),
kit.reset_memory(),
kit.frameptr(),
kit.returnadr());
// Add zero or 1 return values
int ret_size = tf()->range()->cnt() - TypeFunc::Parms;
if (ret_size > 0) {
kit.inc_sp(-ret_size); // pop the return value(s)
kit.sync_jvms();
ret->add_req(kit.argument(0));
// Note: The second dummy edge is not needed by a ReturnNode.
}
// bind it to root
root()->add_req(ret);
record_for_igvn(ret);
initial_gvn()->transform_no_reclaim(ret);
}
//------------------------rethrow_exceptions-----------------------------------
// Bind all exception states in the list into a single RethrowNode.
void Compile::rethrow_exceptions(JVMState* jvms) {
GraphKit kit(jvms);
if (!kit.has_exceptions()) return; // nothing to generate
// Load my combined exception state into the kit, with all phis transformed:
SafePointNode* ex_map = kit.combine_and_pop_all_exception_states();
Node* ex_oop = kit.use_exception_state(ex_map);
RethrowNode* exit = new RethrowNode(kit.control(),
kit.i_o(), kit.reset_memory(),
kit.frameptr(), kit.returnadr(),
// like a return but with exception input
ex_oop);
// bind to root
root()->add_req(exit);
record_for_igvn(exit);
initial_gvn()->transform_no_reclaim(exit);
}
//---------------------------do_exceptions-------------------------------------
// Process exceptions arising from the current bytecode.
// Send caught exceptions to the proper handler within this method.
// Unhandled exceptions feed into _exit.
void Parse::do_exceptions() {
if (!has_exceptions()) return;
if (failing()) {
// Pop them all off and throw them away.
while (pop_exception_state() != NULL) ;
return;
}
PreserveJVMState pjvms(this, false);
SafePointNode* ex_map;
while ((ex_map = pop_exception_state()) != NULL) {
if (!method()->has_exception_handlers()) {
// Common case: Transfer control outward.
// Doing it this early allows the exceptions to common up
// even between adjacent method calls.
throw_to_exit(ex_map);
} else {
// Have to look at the exception first.
assert(stopped(), "catch_inline_exceptions trashes the map");
catch_inline_exceptions(ex_map);
stop_and_kill_map(); // we used up this exception state; kill it
}
}
// We now return to our regularly scheduled program:
}
//---------------------------throw_to_exit-------------------------------------
// Merge the given map into an exception exit from this method.
// The exception exit will handle any unlocking of receiver.
// The ex_oop must be saved within the ex_map, unlike merge_exception.
void Parse::throw_to_exit(SafePointNode* ex_map) {
// Pop the JVMS to (a copy of) the caller.
GraphKit caller;
caller.set_map_clone(_caller->map());
caller.set_bci(_caller->bci());
caller.set_sp(_caller->sp());
// Copy out the standard machine state:
for (uint i = 0; i < TypeFunc::Parms; i++) {
caller.map()->set_req(i, ex_map->in(i));
}
if (ex_map->has_replaced_nodes()) {
_replaced_nodes_for_exceptions = true;
}
caller.map()->transfer_replaced_nodes_from(ex_map, _new_idx);
// ...and the exception:
Node* ex_oop = saved_ex_oop(ex_map);
SafePointNode* caller_ex_map = caller.make_exception_state(ex_oop);
// Finally, collect the new exception state in my exits:
_exits.add_exception_state(caller_ex_map);
}
//------------------------------do_exits---------------------------------------
void Parse::do_exits() {
set_parse_bci(InvocationEntryBci);
// Now peephole on the return bits
Node* region = _exits.control();
_exits.set_control(gvn().transform(region));
Node* iophi = _exits.i_o();
_exits.set_i_o(gvn().transform(iophi));
// Figure out if we need to emit the trailing barrier. The barrier is only
// needed in the constructors, and only in three cases:
//
// 1. The constructor wrote a final. The effects of all initializations
// must be committed to memory before any code after the constructor
// publishes the reference to the newly constructed object. Rather
// than wait for the publication, we simply block the writes here.
// Rather than put a barrier on only those writes which are required
// to complete, we force all writes to complete.
//
// 2. Experimental VM option is used to force the barrier if any field
// was written out in the constructor.
//
// 3. On processors which are not CPU_MULTI_COPY_ATOMIC (e.g. PPC64),
// support_IRIW_for_not_multiple_copy_atomic_cpu selects that
// MemBarVolatile is used before volatile load instead of after volatile
// store, so there's no barrier after the store.
// We want to guarantee the same behavior as on platforms with total store
// order, although this is not required by the Java memory model.
// In this case, we want to enforce visibility of volatile field
// initializations which are performed in constructors.
// So as with finals, we add a barrier here.
//
// "All bets are off" unless the first publication occurs after a
// normal return from the constructor. We do not attempt to detect
// such unusual early publications. But no barrier is needed on
// exceptional returns, since they cannot publish normally.
//
if (method()->is_initializer() &&
(wrote_final() ||
(AlwaysSafeConstructors && wrote_fields()) ||
(support_IRIW_for_not_multiple_copy_atomic_cpu && wrote_volatile()))) {
_exits.insert_mem_bar(Op_MemBarRelease, alloc_with_final());
// If Memory barrier is created for final fields write
// and allocation node does not escape the initialize method,
// then barrier introduced by allocation node can be removed.
if (DoEscapeAnalysis && alloc_with_final()) {
AllocateNode *alloc = AllocateNode::Ideal_allocation(alloc_with_final(), &_gvn);
alloc->compute_MemBar_redundancy(method());
}
if (PrintOpto && (Verbose || WizardMode)) {
method()->print_name();
tty->print_cr(" writes finals and needs a memory barrier");
}
}
// Any method can write a @Stable field; insert memory barriers
// after those also. Can't bind predecessor allocation node (if any)
// with barrier because allocation doesn't always dominate
// MemBarRelease.
if (wrote_stable()) {
_exits.insert_mem_bar(Op_MemBarRelease);
if (PrintOpto && (Verbose || WizardMode)) {
method()->print_name();
tty->print_cr(" writes @Stable and needs a memory barrier");
}
}
for (MergeMemStream mms(_exits.merged_memory()); mms.next_non_empty(); ) {
// transform each slice of the original memphi:
mms.set_memory(_gvn.transform(mms.memory()));
}
// Clean up input MergeMems created by transforming the slices
_gvn.transform(_exits.merged_memory());
if (tf()->range()->cnt() > TypeFunc::Parms) {
const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
Node* ret_phi = _gvn.transform( _exits.argument(0) );
if (!_exits.control()->is_top() && _gvn.type(ret_phi)->empty()) {
// If the type we set for the ret_phi in build_exits() is too optimistic and
// the ret_phi is top now, there's an extremely small chance that it may be due to class
// loading. It could also be due to an error, so mark this method as not compilable because
// otherwise this could lead to an infinite compile loop.
// In any case, this code path is rarely (and never in my testing) reached.
C->record_method_not_compilable("Can't determine return type.");
return;
}
if (ret_type->isa_int()) {
BasicType ret_bt = method()->return_type()->basic_type();
ret_phi = mask_int_value(ret_phi, ret_bt, &_gvn);
}
_exits.push_node(ret_type->basic_type(), ret_phi);
}
// Note: Logic for creating and optimizing the ReturnNode is in Compile.
// Unlock along the exceptional paths.
// This is done late so that we can common up equivalent exceptions
// (e.g., null checks) arising from multiple points within this method.
// See GraphKit::add_exception_state, which performs the commoning.
bool do_synch = method()->is_synchronized() && GenerateSynchronizationCode;
// record exit from a method if compiled while Dtrace is turned on.
if (do_synch || C->env()->dtrace_method_probes() || _replaced_nodes_for_exceptions) {
// First move the exception list out of _exits:
GraphKit kit(_exits.transfer_exceptions_into_jvms());
SafePointNode* normal_map = kit.map(); // keep this guy safe
// Now re-collect the exceptions into _exits:
SafePointNode* ex_map;
while ((ex_map = kit.pop_exception_state()) != NULL) {
Node* ex_oop = kit.use_exception_state(ex_map);
// Force the exiting JVM state to have this method at InvocationEntryBci.
// The exiting JVM state is otherwise a copy of the calling JVMS.
JVMState* caller = kit.jvms();
JVMState* ex_jvms = caller->clone_shallow(C);
ex_jvms->bind_map(kit.clone_map());
ex_jvms->set_bci( InvocationEntryBci);
kit.set_jvms(ex_jvms);
if (do_synch) {
// Add on the synchronized-method box/object combo
kit.map()->push_monitor(_synch_lock);
// Unlock!
kit.shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
}
if (C->env()->dtrace_method_probes()) {
kit.make_dtrace_method_exit(method());
}
if (_replaced_nodes_for_exceptions) {
kit.map()->apply_replaced_nodes(_new_idx);
}
// Done with exception-path processing.
ex_map = kit.make_exception_state(ex_oop);
assert(ex_jvms->same_calls_as(ex_map->jvms()), "sanity");
// Pop the last vestige of this method:
caller->clone_shallow(C)->bind_map(ex_map);
_exits.push_exception_state(ex_map);
}
assert(_exits.map() == normal_map, "keep the same return state");
}
{
// Capture very early exceptions (receiver null checks) from caller JVMS
GraphKit caller(_caller);
SafePointNode* ex_map;
while ((ex_map = caller.pop_exception_state()) != NULL) {
_exits.add_exception_state(ex_map);
}
}
_exits.map()->apply_replaced_nodes(_new_idx);
}
//-----------------------------create_entry_map-------------------------------
// Initialize our parser map to contain the types at method entry.
// For OSR, the map contains a single RawPtr parameter.
// Initial monitor locking for sync. methods is performed by do_method_entry.
SafePointNode* Parse::create_entry_map() {
// Check for really stupid bail-out cases.
uint len = TypeFunc::Parms + method()->max_locals() + method()->max_stack();
if (len >= 32760) {
C->record_method_not_compilable("too many local variables");
return NULL;
}
// clear current replaced nodes that are of no use from here on (map was cloned in build_exits).
_caller->map()->delete_replaced_nodes();
// If this is an inlined method, we may have to do a receiver null check.
if (_caller->has_method() && is_normal_parse() && !method()->is_static()) {
GraphKit kit(_caller);
kit.null_check_receiver_before_call(method());
_caller = kit.transfer_exceptions_into_jvms();
if (kit.stopped()) {
_exits.add_exception_states_from(_caller);
_exits.set_jvms(_caller);
return NULL;
}
}
assert(method() != NULL, "parser must have a method");
// Create an initial safepoint to hold JVM state during parsing
JVMState* jvms = new (C) JVMState(method(), _caller->has_method() ? _caller : NULL);
set_map(new SafePointNode(len, jvms));
jvms->set_map(map());
record_for_igvn(map());
assert(jvms->endoff() == len, "correct jvms sizing");
SafePointNode* inmap = _caller->map();
assert(inmap != NULL, "must have inmap");
// In case of null check on receiver above
map()->transfer_replaced_nodes_from(inmap, _new_idx);
uint i;
// Pass thru the predefined input parameters.
for (i = 0; i < TypeFunc::Parms; i++) {
map()->init_req(i, inmap->in(i));
}
if (depth() == 1) {
assert(map()->memory()->Opcode() == Op_Parm, "");
// Insert the memory aliasing node
set_all_memory(reset_memory());
}
assert(merged_memory(), "");
// Now add the locals which are initially bound to arguments:
uint arg_size = tf()->domain()->cnt();
ensure_stack(arg_size - TypeFunc::Parms); // OSR methods have funny args
for (i = TypeFunc::Parms; i < arg_size; i++) {
map()->init_req(i, inmap->argument(_caller, i - TypeFunc::Parms));
}
// Clear out the rest of the map (locals and stack)
for (i = arg_size; i < len; i++) {
map()->init_req(i, top());
}
SafePointNode* entry_map = stop();
return entry_map;
}
//-----------------------------do_method_entry--------------------------------
// Emit any code needed in the pseudo-block before BCI zero.
// The main thing to do is lock the receiver of a synchronized method.
void Parse::do_method_entry() {
set_parse_bci(InvocationEntryBci); // Pseudo-BCP
set_sp(0); // Java Stack Pointer
NOT_PRODUCT( count_compiled_calls(true/*at_method_entry*/, false/*is_inline*/); )
if (C->env()->dtrace_method_probes()) {
make_dtrace_method_entry(method());
}
#ifdef ASSERT
// Narrow receiver type when it is too broad for the method being parsed.
if (!method()->is_static()) {
ciInstanceKlass* callee_holder = method()->holder();
const Type* holder_type = TypeInstPtr::make(TypePtr::BotPTR, callee_holder);
Node* receiver_obj = local(0);
const TypeInstPtr* receiver_type = _gvn.type(receiver_obj)->isa_instptr();
if (receiver_type != NULL && !receiver_type->higher_equal(holder_type)) {
// Receiver should always be a subtype of callee holder.
// But, since C2 type system doesn't properly track interfaces,
// the invariant can't be expressed in the type system for default methods.
// Example: for unrelated C <: I and D <: I, (C `meet` D) = Object </: I.
assert(callee_holder->is_interface(), "missing subtype check");
// Perform dynamic receiver subtype check against callee holder class w/ a halt on failure.
Node* holder_klass = _gvn.makecon(TypeKlassPtr::make(callee_holder));
Node* not_subtype_ctrl = gen_subtype_check(receiver_obj, holder_klass);
assert(!stopped(), "not a subtype");
Node* halt = _gvn.transform(new HaltNode(not_subtype_ctrl, frameptr(), "failed receiver subtype check"));
C->root()->add_req(halt);
}
}
#endif // ASSERT
// If the method is synchronized, we need to construct a lock node, attach
// it to the Start node, and pin it there.
if (method()->is_synchronized()) {
// Insert a FastLockNode right after the Start which takes as arguments
// the current thread pointer, the "this" pointer & the address of the
// stack slot pair used for the lock. The "this" pointer is a projection
// off the start node, but the locking spot has to be constructed by
// creating a ConLNode of 0, and boxing it with a BoxLockNode. The BoxLockNode
// becomes the second argument to the FastLockNode call. The
// FastLockNode becomes the new control parent to pin it to the start.
// Setup Object Pointer
Node *lock_obj = NULL;
if (method()->is_static()) {
ciInstance* mirror = _method->holder()->java_mirror();
const TypeInstPtr *t_lock = TypeInstPtr::make(mirror);
lock_obj = makecon(t_lock);
} else { // Else pass the "this" pointer,
lock_obj = local(0); // which is Parm0 from StartNode
}
// Clear out dead values from the debug info.
kill_dead_locals();
// Build the FastLockNode
_synch_lock = shared_lock(lock_obj);
}
// Feed profiling data for parameters to the type system so it can
// propagate it as speculative types
record_profiled_parameters_for_speculation();
}
//------------------------------init_blocks------------------------------------
// Initialize our parser map to contain the types/monitors at method entry.
void Parse::init_blocks() {
// Create the blocks.
_block_count = flow()->block_count();
_blocks = NEW_RESOURCE_ARRAY(Block, _block_count);
// Initialize the structs.
for (int rpo = 0; rpo < block_count(); rpo++) {
Block* block = rpo_at(rpo);
new(block) Block(this, rpo);
}
// Collect predecessor and successor information.
for (int rpo = 0; rpo < block_count(); rpo++) {
Block* block = rpo_at(rpo);
block->init_graph(this);
}
}
//-------------------------------init_node-------------------------------------
Parse::Block::Block(Parse* outer, int rpo) : _live_locals() {
_flow = outer->flow()->rpo_at(rpo);
_pred_count = 0;
_preds_parsed = 0;
_count = 0;
_is_parsed = false;
_is_handler = false;
_has_merged_backedge = false;
_start_map = NULL;
_has_predicates = false;
_num_successors = 0;
_all_successors = 0;
_successors = NULL;
assert(pred_count() == 0 && preds_parsed() == 0, "sanity");
assert(!(is_merged() || is_parsed() || is_handler() || has_merged_backedge()), "sanity");
assert(_live_locals.size() == 0, "sanity");
// entry point has additional predecessor
if (flow()->is_start()) _pred_count++;
assert(flow()->is_start() == (this == outer->start_block()), "");
}
//-------------------------------init_graph------------------------------------
void Parse::Block::init_graph(Parse* outer) {
// Create the successor list for this parser block.
GrowableArray<ciTypeFlow::Block*>* tfs = flow()->successors();
GrowableArray<ciTypeFlow::Block*>* tfe = flow()->exceptions();
int ns = tfs->length();
int ne = tfe->length();
_num_successors = ns;
_all_successors = ns+ne;
_successors = (ns+ne == 0) ? NULL : NEW_RESOURCE_ARRAY(Block*, ns+ne);
int p = 0;
for (int i = 0; i < ns+ne; i++) {
ciTypeFlow::Block* tf2 = (i < ns) ? tfs->at(i) : tfe->at(i-ns);
Block* block2 = outer->rpo_at(tf2->rpo());
_successors[i] = block2;
// Accumulate pred info for the other block, too.
// Note: We also need to set _pred_count for exception blocks since they could
// also have normal predecessors (reached without athrow by an explicit jump).
// This also means that next_path_num can be called along exception paths.
block2->_pred_count++;
if (i >= ns) {
block2->_is_handler = true;
}
#ifdef ASSERT
// A block's successors must be distinguishable by BCI.
// That is, no bytecode is allowed to branch to two different
// clones of the same code location.
for (int j = 0; j < i; j++) {
Block* block1 = _successors[j];
if (block1 == block2) continue; // duplicates are OK
assert(block1->start() != block2->start(), "successors have unique bcis");
}
#endif
}
}
//---------------------------successor_for_bci---------------------------------
Parse::Block* Parse::Block::successor_for_bci(int bci) {
for (int i = 0; i < all_successors(); i++) {
Block* block2 = successor_at(i);
if (block2->start() == bci) return block2;
}
// We can actually reach here if ciTypeFlow traps out a block
// due to an unloaded class, and concurrently with compilation the
// class is then loaded, so that a later phase of the parser is
// able to see more of the bytecode CFG. Or, the flow pass and
// the parser can have a minor difference of opinion about executability
// of bytecodes. For example, "obj.field = null" is executable even
// if the field's type is an unloaded class; the flow pass used to
// make a trap for such code.
return NULL;
}
//-----------------------------stack_type_at-----------------------------------
const Type* Parse::Block::stack_type_at(int i) const {
return get_type(flow()->stack_type_at(i));
}
//-----------------------------local_type_at-----------------------------------
const Type* Parse::Block::local_type_at(int i) const {
// Make dead locals fall to bottom.
if (_live_locals.size() == 0) {
MethodLivenessResult live_locals = flow()->outer()->method()->liveness_at_bci(start());
// This bitmap can be zero length if we saw a breakpoint.
// In such cases, pretend they are all live.
((Block*)this)->_live_locals = live_locals;
}
if (_live_locals.size() > 0 && !_live_locals.at(i))
return Type::BOTTOM;
return get_type(flow()->local_type_at(i));
}
#ifndef PRODUCT
//----------------------------name_for_bc--------------------------------------
// helper method for BytecodeParseHistogram
static const char* name_for_bc(int i) {
return Bytecodes::is_defined(i) ? Bytecodes::name(Bytecodes::cast(i)) : "xxxunusedxxx";
}
//----------------------------BytecodeParseHistogram------------------------------------
Parse::BytecodeParseHistogram::BytecodeParseHistogram(Parse *p, Compile *c) {
_parser = p;
_compiler = c;
if( ! _initialized ) { _initialized = true; reset(); }
}
//----------------------------current_count------------------------------------
int Parse::BytecodeParseHistogram::current_count(BPHType bph_type) {
switch( bph_type ) {
case BPH_transforms: { return _parser->gvn().made_progress(); }
case BPH_values: { return _parser->gvn().made_new_values(); }
default: { ShouldNotReachHere(); return 0; }
}
}
//----------------------------initialized--------------------------------------
bool Parse::BytecodeParseHistogram::initialized() { return _initialized; }
//----------------------------reset--------------------------------------------
void Parse::BytecodeParseHistogram::reset() {
int i = Bytecodes::number_of_codes;
while (i-- > 0) { _bytecodes_parsed[i] = 0; _nodes_constructed[i] = 0; _nodes_transformed[i] = 0; _new_values[i] = 0; }
}
//----------------------------set_initial_state--------------------------------
// Record info when starting to parse one bytecode
void Parse::BytecodeParseHistogram::set_initial_state( Bytecodes::Code bc ) {
if( PrintParseStatistics && !_parser->is_osr_parse() ) {
_initial_bytecode = bc;
_initial_node_count = _compiler->unique();
_initial_transforms = current_count(BPH_transforms);
_initial_values = current_count(BPH_values);
}
}
//----------------------------record_change--------------------------------
// Record results of parsing one bytecode
void Parse::BytecodeParseHistogram::record_change() {
if( PrintParseStatistics && !_parser->is_osr_parse() ) {
++_bytecodes_parsed[_initial_bytecode];
_nodes_constructed [_initial_bytecode] += (_compiler->unique() - _initial_node_count);
_nodes_transformed [_initial_bytecode] += (current_count(BPH_transforms) - _initial_transforms);
_new_values [_initial_bytecode] += (current_count(BPH_values) - _initial_values);
}
}
//----------------------------print--------------------------------------------
void Parse::BytecodeParseHistogram::print(float cutoff) {
ResourceMark rm;
// print profile
int total = 0;
int i = 0;
for( i = 0; i < Bytecodes::number_of_codes; ++i ) { total += _bytecodes_parsed[i]; }
int abs_sum = 0;
tty->cr(); //0123456789012345678901234567890123456789012345678901234567890123456789
tty->print_cr("Histogram of %d parsed bytecodes:", total);
if( total == 0 ) { return; }
tty->cr();
tty->print_cr("absolute: count of compiled bytecodes of this type");
tty->print_cr("relative: percentage contribution to compiled nodes");
tty->print_cr("nodes : Average number of nodes constructed per bytecode");
tty->print_cr("rnodes : Significance towards total nodes constructed, (nodes*relative)");
tty->print_cr("transforms: Average amount of transform progress per bytecode compiled");
tty->print_cr("values : Average number of node values improved per bytecode");
tty->print_cr("name : Bytecode name");
tty->cr();
tty->print_cr(" absolute relative nodes rnodes transforms values name");
tty->print_cr("----------------------------------------------------------------------");
while (--i > 0) {
int abs = _bytecodes_parsed[i];
float rel = abs * 100.0F / total;
float nodes = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_constructed[i])/_bytecodes_parsed[i];
float rnodes = _bytecodes_parsed[i] == 0 ? 0 : rel * nodes;
float xforms = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_transformed[i])/_bytecodes_parsed[i];
float values = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _new_values [i])/_bytecodes_parsed[i];
if (cutoff <= rel) {
tty->print_cr("%10d %7.2f%% %6.1f %6.2f %6.1f %6.1f %s", abs, rel, nodes, rnodes, xforms, values, name_for_bc(i));
abs_sum += abs;
}
}
tty->print_cr("----------------------------------------------------------------------");
float rel_sum = abs_sum * 100.0F / total;
tty->print_cr("%10d %7.2f%% (cutoff = %.2f%%)", abs_sum, rel_sum, cutoff);
tty->print_cr("----------------------------------------------------------------------");
tty->cr();
}
#endif
//----------------------------load_state_from----------------------------------
// Load block/map/sp. But not do not touch iter/bci.
void Parse::load_state_from(Block* block) {
set_block(block);
// load the block's JVM state:
set_map(block->start_map());
set_sp( block->start_sp());
}
//-----------------------------record_state------------------------------------
void Parse::Block::record_state(Parse* p) {
assert(!is_merged(), "can only record state once, on 1st inflow");
assert(start_sp() == p->sp(), "stack pointer must agree with ciTypeFlow");
set_start_map(p->stop());
}
//------------------------------do_one_block-----------------------------------
void Parse::do_one_block() {
if (TraceOptoParse) {
Block *b = block();
int ns = b->num_successors();
int nt = b->all_successors();
tty->print("Parsing block #%d at bci [%d,%d), successors: ",
block()->rpo(), block()->start(), block()->limit());
for (int i = 0; i < nt; i++) {
tty->print((( i < ns) ? " %d" : " %d(e)"), b->successor_at(i)->rpo());
}
if (b->is_loop_head()) tty->print(" lphd");
tty->cr();
}
assert(block()->is_merged(), "must be merged before being parsed");
block()->mark_parsed();
// Set iterator to start of block.
iter().reset_to_bci(block()->start());
CompileLog* log = C->log();
// Parse bytecodes
while (!stopped() && !failing()) {
iter().next();
// Learn the current bci from the iterator:
set_parse_bci(iter().cur_bci());
if (bci() == block()->limit()) {
// Do not walk into the next block until directed by do_all_blocks.
merge(bci());
break;
}
assert(bci() < block()->limit(), "bci still in block");
if (log != NULL) {
// Output an optional context marker, to help place actions
// that occur during parsing of this BC. If there is no log
// output until the next context string, this context string
// will be silently ignored.
log->set_context("bc code='%d' bci='%d'", (int)bc(), bci());
}
if (block()->has_trap_at(bci())) {
// We must respect the flow pass's traps, because it will refuse
// to produce successors for trapping blocks.
int trap_index = block()->flow()->trap_index();
assert(trap_index != 0, "trap index must be valid");
uncommon_trap(trap_index);
break;
}
NOT_PRODUCT( parse_histogram()->set_initial_state(bc()); );
#ifdef ASSERT
int pre_bc_sp = sp();
int inputs, depth;
bool have_se = !stopped() && compute_stack_effects(inputs, depth);
assert(!have_se || pre_bc_sp >= inputs, "have enough stack to execute this BC: pre_bc_sp=%d, inputs=%d", pre_bc_sp, inputs);
#endif //ASSERT
do_one_bytecode();
assert(!have_se || stopped() || failing() || (sp() - pre_bc_sp) == depth,
"incorrect depth prediction: sp=%d, pre_bc_sp=%d, depth=%d", sp(), pre_bc_sp, depth);
do_exceptions();
NOT_PRODUCT( parse_histogram()->record_change(); );
if (log != NULL)
log->clear_context(); // skip marker if nothing was printed
// Fall into next bytecode. Each bytecode normally has 1 sequential
// successor which is typically made ready by visiting this bytecode.
// If the successor has several predecessors, then it is a merge
// point, starts a new basic block, and is handled like other basic blocks.
}
}
//------------------------------merge------------------------------------------
void Parse::set_parse_bci(int bci) {
set_bci(bci);
Node_Notes* nn = C->default_node_notes();
if (nn == NULL) return;
// Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
if (!DebugInlinedCalls && depth() > 1) {
return;
}
// Update the JVMS annotation, if present.
JVMState* jvms = nn->jvms();
if (jvms != NULL && jvms->bci() != bci) {
// Update the JVMS.
jvms = jvms->clone_shallow(C);
jvms->set_bci(bci);
nn->set_jvms(jvms);
}
}
//------------------------------merge------------------------------------------
// Merge the current mapping into the basic block starting at bci
void Parse::merge(int target_bci) {
Block* target = successor_for_bci(target_bci);
if (target == NULL) { handle_missing_successor(target_bci); return; }
assert(!target->is_ready(), "our arrival must be expected");
int pnum = target->next_path_num();
merge_common(target, pnum);
}
//-------------------------merge_new_path--------------------------------------
// Merge the current mapping into the basic block, using a new path
void Parse::merge_new_path(int target_bci) {
Block* target = successor_for_bci(target_bci);
if (target == NULL) { handle_missing_successor(target_bci); return; }
assert(!target->is_ready(), "new path into frozen graph");
int pnum = target->add_new_path();
merge_common(target, pnum);
}
//-------------------------merge_exception-------------------------------------
// Merge the current mapping into the basic block starting at bci
// The ex_oop must be pushed on the stack, unlike throw_to_exit.
void Parse::merge_exception(int target_bci) {
#ifdef ASSERT
if (target_bci < bci()) {
C->set_exception_backedge();
}
#endif
assert(sp() == 1, "must have only the throw exception on the stack");
Block* target = successor_for_bci(target_bci);
if (target == NULL) { handle_missing_successor(target_bci); return; }
assert(target->is_handler(), "exceptions are handled by special blocks");
int pnum = target->add_new_path();
merge_common(target, pnum);
}
//--------------------handle_missing_successor---------------------------------
void Parse::handle_missing_successor(int target_bci) {
#ifndef PRODUCT
Block* b = block();
int trap_bci = b->flow()->has_trap()? b->flow()->trap_bci(): -1;
tty->print_cr("### Missing successor at bci:%d for block #%d (trap_bci:%d)", target_bci, b->rpo(), trap_bci);
#endif
ShouldNotReachHere();
}
//--------------------------merge_common---------------------------------------
void Parse::merge_common(Parse::Block* target, int pnum) {
if (TraceOptoParse) {
tty->print("Merging state at block #%d bci:%d", target->rpo(), target->start());
}
// Zap extra stack slots to top
assert(sp() == target->start_sp(), "");
clean_stack(sp());
if (!target->is_merged()) { // No prior mapping at this bci
if (TraceOptoParse) { tty->print(" with empty state"); }
// If this path is dead, do not bother capturing it as a merge.
// It is "as if" we had 1 fewer predecessors from the beginning.
if (stopped()) {
if (TraceOptoParse) tty->print_cr(", but path is dead and doesn't count");
return;
}
// Make a region if we know there are multiple or unpredictable inputs.
// (Also, if this is a plain fall-through, we might see another region,
// which must not be allowed into this block's map.)
if (pnum > PhiNode::Input // Known multiple inputs.
|| target->is_handler() // These have unpredictable inputs.
|| target->is_loop_head() // Known multiple inputs
|| control()->is_Region()) { // We must hide this guy.
int current_bci = bci();
set_parse_bci(target->start()); // Set target bci
if (target->is_SEL_head()) {
DEBUG_ONLY( target->mark_merged_backedge(block()); )
if (target->start() == 0) {
// Add loop predicate for the special case when
// there are backbranches to the method entry.
add_empty_predicates();
}
}
// Add a Region to start the new basic block. Phis will be added
// later lazily.
int edges = target->pred_count();
if (edges < pnum) edges = pnum; // might be a new path!
RegionNode *r = new RegionNode(edges+1);
gvn().set_type(r, Type::CONTROL);
record_for_igvn(r);
// zap all inputs to NULL for debugging (done in Node(uint) constructor)
// for (int j = 1; j < edges+1; j++) { r->init_req(j, NULL); }
r->init_req(pnum, control());
set_control(r);
set_parse_bci(current_bci); // Restore bci
}
// Convert the existing Parser mapping into a mapping at this bci.
store_state_to(target);
assert(target->is_merged(), "do not come here twice");
} else { // Prior mapping at this bci
--> --------------------
--> maximum size reached
--> --------------------
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