8071302: assert(!_reg_node[reg_lo] || edge_from_to(_reg_node[reg_lo], def)) failed: after block local
Summary: Add merge nodes to node to block mapping
Reviewed-by: kvn, vlivanov
/*
* Copyright (c) 1997, 2014, 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 "asm/macroAssembler.hpp"
#include "asm/macroAssembler.inline.hpp"
#include "ci/ciReplay.hpp"
#include "classfile/systemDictionary.hpp"
#include "code/exceptionHandlerTable.hpp"
#include "code/nmethod.hpp"
#include "compiler/compileBroker.hpp"
#include "compiler/compileLog.hpp"
#include "compiler/disassembler.hpp"
#include "compiler/oopMap.hpp"
#include "opto/addnode.hpp"
#include "opto/block.hpp"
#include "opto/c2compiler.hpp"
#include "opto/callGenerator.hpp"
#include "opto/callnode.hpp"
#include "opto/cfgnode.hpp"
#include "opto/chaitin.hpp"
#include "opto/compile.hpp"
#include "opto/connode.hpp"
#include "opto/divnode.hpp"
#include "opto/escape.hpp"
#include "opto/idealGraphPrinter.hpp"
#include "opto/loopnode.hpp"
#include "opto/machnode.hpp"
#include "opto/macro.hpp"
#include "opto/matcher.hpp"
#include "opto/mathexactnode.hpp"
#include "opto/memnode.hpp"
#include "opto/mulnode.hpp"
#include "opto/narrowptrnode.hpp"
#include "opto/node.hpp"
#include "opto/opcodes.hpp"
#include "opto/output.hpp"
#include "opto/parse.hpp"
#include "opto/phaseX.hpp"
#include "opto/rootnode.hpp"
#include "opto/runtime.hpp"
#include "opto/stringopts.hpp"
#include "opto/type.hpp"
#include "opto/vectornode.hpp"
#include "runtime/arguments.hpp"
#include "runtime/signature.hpp"
#include "runtime/stubRoutines.hpp"
#include "runtime/timer.hpp"
#include "utilities/copy.hpp"
// -------------------- Compile::mach_constant_base_node -----------------------
// Constant table base node singleton.
MachConstantBaseNode* Compile::mach_constant_base_node() {
if (_mach_constant_base_node == NULL) {
_mach_constant_base_node = new MachConstantBaseNode();
_mach_constant_base_node->add_req(C->root());
}
return _mach_constant_base_node;
}
/// Support for intrinsics.
// Return the index at which m must be inserted (or already exists).
// The sort order is by the address of the ciMethod, with is_virtual as minor key.
int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
#ifdef ASSERT
for (int i = 1; i < _intrinsics->length(); i++) {
CallGenerator* cg1 = _intrinsics->at(i-1);
CallGenerator* cg2 = _intrinsics->at(i);
assert(cg1->method() != cg2->method()
? cg1->method() < cg2->method()
: cg1->is_virtual() < cg2->is_virtual(),
"compiler intrinsics list must stay sorted");
}
#endif
// Binary search sorted list, in decreasing intervals [lo, hi].
int lo = 0, hi = _intrinsics->length()-1;
while (lo <= hi) {
int mid = (uint)(hi + lo) / 2;
ciMethod* mid_m = _intrinsics->at(mid)->method();
if (m < mid_m) {
hi = mid-1;
} else if (m > mid_m) {
lo = mid+1;
} else {
// look at minor sort key
bool mid_virt = _intrinsics->at(mid)->is_virtual();
if (is_virtual < mid_virt) {
hi = mid-1;
} else if (is_virtual > mid_virt) {
lo = mid+1;
} else {
return mid; // exact match
}
}
}
return lo; // inexact match
}
void Compile::register_intrinsic(CallGenerator* cg) {
if (_intrinsics == NULL) {
_intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
}
// This code is stolen from ciObjectFactory::insert.
// Really, GrowableArray should have methods for
// insert_at, remove_at, and binary_search.
int len = _intrinsics->length();
int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
if (index == len) {
_intrinsics->append(cg);
} else {
#ifdef ASSERT
CallGenerator* oldcg = _intrinsics->at(index);
assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
#endif
_intrinsics->append(_intrinsics->at(len-1));
int pos;
for (pos = len-2; pos >= index; pos--) {
_intrinsics->at_put(pos+1,_intrinsics->at(pos));
}
_intrinsics->at_put(index, cg);
}
assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
}
CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
assert(m->is_loaded(), "don't try this on unloaded methods");
if (_intrinsics != NULL) {
int index = intrinsic_insertion_index(m, is_virtual);
if (index < _intrinsics->length()
&& _intrinsics->at(index)->method() == m
&& _intrinsics->at(index)->is_virtual() == is_virtual) {
return _intrinsics->at(index);
}
}
// Lazily create intrinsics for intrinsic IDs well-known in the runtime.
if (m->intrinsic_id() != vmIntrinsics::_none &&
m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
if (cg != NULL) {
// Save it for next time:
register_intrinsic(cg);
return cg;
} else {
gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
}
}
return NULL;
}
// Compile:: register_library_intrinsics and make_vm_intrinsic are defined
// in library_call.cpp.
#ifndef PRODUCT
// statistics gathering...
juint Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
int oflags = _intrinsic_hist_flags[id];
assert(flags != 0, "what happened?");
if (is_virtual) {
flags |= _intrinsic_virtual;
}
bool changed = (flags != oflags);
if ((flags & _intrinsic_worked) != 0) {
juint count = (_intrinsic_hist_count[id] += 1);
if (count == 1) {
changed = true; // first time
}
// increment the overall count also:
_intrinsic_hist_count[vmIntrinsics::_none] += 1;
}
if (changed) {
if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
// Something changed about the intrinsic's virtuality.
if ((flags & _intrinsic_virtual) != 0) {
// This is the first use of this intrinsic as a virtual call.
if (oflags != 0) {
// We already saw it as a non-virtual, so note both cases.
flags |= _intrinsic_both;
}
} else if ((oflags & _intrinsic_both) == 0) {
// This is the first use of this intrinsic as a non-virtual
flags |= _intrinsic_both;
}
}
_intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
}
// update the overall flags also:
_intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
return changed;
}
static char* format_flags(int flags, char* buf) {
buf[0] = 0;
if ((flags & Compile::_intrinsic_worked) != 0) strcat(buf, ",worked");
if ((flags & Compile::_intrinsic_failed) != 0) strcat(buf, ",failed");
if ((flags & Compile::_intrinsic_disabled) != 0) strcat(buf, ",disabled");
if ((flags & Compile::_intrinsic_virtual) != 0) strcat(buf, ",virtual");
if ((flags & Compile::_intrinsic_both) != 0) strcat(buf, ",nonvirtual");
if (buf[0] == 0) strcat(buf, ",");
assert(buf[0] == ',', "must be");
return &buf[1];
}
void Compile::print_intrinsic_statistics() {
char flagsbuf[100];
ttyLocker ttyl;
if (xtty != NULL) xtty->head("statistics type='intrinsic'");
tty->print_cr("Compiler intrinsic usage:");
juint total = _intrinsic_hist_count[vmIntrinsics::_none];
if (total == 0) total = 1; // avoid div0 in case of no successes
#define PRINT_STAT_LINE(name, c, f) \
tty->print_cr(" %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
vmIntrinsics::ID id = (vmIntrinsics::ID) index;
int flags = _intrinsic_hist_flags[id];
juint count = _intrinsic_hist_count[id];
if ((flags | count) != 0) {
PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
}
}
PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
if (xtty != NULL) xtty->tail("statistics");
}
void Compile::print_statistics() {
{ ttyLocker ttyl;
if (xtty != NULL) xtty->head("statistics type='opto'");
Parse::print_statistics();
PhaseCCP::print_statistics();
PhaseRegAlloc::print_statistics();
Scheduling::print_statistics();
PhasePeephole::print_statistics();
PhaseIdealLoop::print_statistics();
if (xtty != NULL) xtty->tail("statistics");
}
if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
// put this under its own <statistics> element.
print_intrinsic_statistics();
}
}
#endif //PRODUCT
// Support for bundling info
Bundle* Compile::node_bundling(const Node *n) {
assert(valid_bundle_info(n), "oob");
return &_node_bundling_base[n->_idx];
}
bool Compile::valid_bundle_info(const Node *n) {
return (_node_bundling_limit > n->_idx);
}
void Compile::gvn_replace_by(Node* n, Node* nn) {
for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
Node* use = n->last_out(i);
bool is_in_table = initial_gvn()->hash_delete(use);
uint uses_found = 0;
for (uint j = 0; j < use->len(); j++) {
if (use->in(j) == n) {
if (j < use->req())
use->set_req(j, nn);
else
use->set_prec(j, nn);
uses_found++;
}
}
if (is_in_table) {
// reinsert into table
initial_gvn()->hash_find_insert(use);
}
record_for_igvn(use);
i -= uses_found; // we deleted 1 or more copies of this edge
}
}
static inline bool not_a_node(const Node* n) {
if (n == NULL) return true;
if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
if (*(address*)n == badAddress) return true; // kill by Node::destruct
return false;
}
// Identify all nodes that are reachable from below, useful.
// Use breadth-first pass that records state in a Unique_Node_List,
// recursive traversal is slower.
void Compile::identify_useful_nodes(Unique_Node_List &useful) {
int estimated_worklist_size = unique();
useful.map( estimated_worklist_size, NULL ); // preallocate space
// Initialize worklist
if (root() != NULL) { useful.push(root()); }
// If 'top' is cached, declare it useful to preserve cached node
if( cached_top_node() ) { useful.push(cached_top_node()); }
// Push all useful nodes onto the list, breadthfirst
for( uint next = 0; next < useful.size(); ++next ) {
assert( next < unique(), "Unique useful nodes < total nodes");
Node *n = useful.at(next);
uint max = n->len();
for( uint i = 0; i < max; ++i ) {
Node *m = n->in(i);
if (not_a_node(m)) continue;
useful.push(m);
}
}
}
// Update dead_node_list with any missing dead nodes using useful
// list. Consider all non-useful nodes to be useless i.e., dead nodes.
void Compile::update_dead_node_list(Unique_Node_List &useful) {
uint max_idx = unique();
VectorSet& useful_node_set = useful.member_set();
for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
// If node with index node_idx is not in useful set,
// mark it as dead in dead node list.
if (! useful_node_set.test(node_idx) ) {
record_dead_node(node_idx);
}
}
}
void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
int shift = 0;
for (int i = 0; i < inlines->length(); i++) {
CallGenerator* cg = inlines->at(i);
CallNode* call = cg->call_node();
if (shift > 0) {
inlines->at_put(i-shift, cg);
}
if (!useful.member(call)) {
shift++;
}
}
inlines->trunc_to(inlines->length()-shift);
}
// Disconnect all useless nodes by disconnecting those at the boundary.
void Compile::remove_useless_nodes(Unique_Node_List &useful) {
uint next = 0;
while (next < useful.size()) {
Node *n = useful.at(next++);
if (n->is_SafePoint()) {
// We're done with a parsing phase. Replaced nodes are not valid
// beyond that point.
n->as_SafePoint()->delete_replaced_nodes();
}
// Use raw traversal of out edges since this code removes out edges
int max = n->outcnt();
for (int j = 0; j < max; ++j) {
Node* child = n->raw_out(j);
if (! useful.member(child)) {
assert(!child->is_top() || child != top(),
"If top is cached in Compile object it is in useful list");
// Only need to remove this out-edge to the useless node
n->raw_del_out(j);
--j;
--max;
}
}
if (n->outcnt() == 1 && n->has_special_unique_user()) {
record_for_igvn(n->unique_out());
}
}
// Remove useless macro and predicate opaq nodes
for (int i = C->macro_count()-1; i >= 0; i--) {
Node* n = C->macro_node(i);
if (!useful.member(n)) {
remove_macro_node(n);
}
}
// Remove useless expensive node
for (int i = C->expensive_count()-1; i >= 0; i--) {
Node* n = C->expensive_node(i);
if (!useful.member(n)) {
remove_expensive_node(n);
}
}
// clean up the late inline lists
remove_useless_late_inlines(&_string_late_inlines, useful);
remove_useless_late_inlines(&_boxing_late_inlines, useful);
remove_useless_late_inlines(&_late_inlines, useful);
debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
}
//------------------------------frame_size_in_words-----------------------------
// frame_slots in units of words
int Compile::frame_size_in_words() const {
// shift is 0 in LP32 and 1 in LP64
const int shift = (LogBytesPerWord - LogBytesPerInt);
int words = _frame_slots >> shift;
assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
return words;
}
// To bang the stack of this compiled method we use the stack size
// that the interpreter would need in case of a deoptimization. This
// removes the need to bang the stack in the deoptimization blob which
// in turn simplifies stack overflow handling.
int Compile::bang_size_in_bytes() const {
return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), _interpreter_frame_size);
}
// ============================================================================
//------------------------------CompileWrapper---------------------------------
class CompileWrapper : public StackObj {
Compile *const _compile;
public:
CompileWrapper(Compile* compile);
~CompileWrapper();
};
CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
// the Compile* pointer is stored in the current ciEnv:
ciEnv* env = compile->env();
assert(env == ciEnv::current(), "must already be a ciEnv active");
assert(env->compiler_data() == NULL, "compile already active?");
env->set_compiler_data(compile);
assert(compile == Compile::current(), "sanity");
compile->set_type_dict(NULL);
compile->set_type_hwm(NULL);
compile->set_type_last_size(0);
compile->set_last_tf(NULL, NULL);
compile->set_indexSet_arena(NULL);
compile->set_indexSet_free_block_list(NULL);
compile->init_type_arena();
Type::Initialize(compile);
_compile->set_scratch_buffer_blob(NULL);
_compile->begin_method();
}
CompileWrapper::~CompileWrapper() {
_compile->end_method();
if (_compile->scratch_buffer_blob() != NULL)
BufferBlob::free(_compile->scratch_buffer_blob());
_compile->env()->set_compiler_data(NULL);
}
//----------------------------print_compile_messages---------------------------
void Compile::print_compile_messages() {
#ifndef PRODUCT
// Check if recompiling
if (_subsume_loads == false && PrintOpto) {
// Recompiling without allowing machine instructions to subsume loads
tty->print_cr("*********************************************************");
tty->print_cr("** Bailout: Recompile without subsuming loads **");
tty->print_cr("*********************************************************");
}
if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
// Recompiling without escape analysis
tty->print_cr("*********************************************************");
tty->print_cr("** Bailout: Recompile without escape analysis **");
tty->print_cr("*********************************************************");
}
if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
// Recompiling without boxing elimination
tty->print_cr("*********************************************************");
tty->print_cr("** Bailout: Recompile without boxing elimination **");
tty->print_cr("*********************************************************");
}
if (env()->break_at_compile()) {
// Open the debugger when compiling this method.
tty->print("### Breaking when compiling: ");
method()->print_short_name();
tty->cr();
BREAKPOINT;
}
if( PrintOpto ) {
if (is_osr_compilation()) {
tty->print("[OSR]%3d", _compile_id);
} else {
tty->print("%3d", _compile_id);
}
}
#endif
}
//-----------------------init_scratch_buffer_blob------------------------------
// Construct a temporary BufferBlob and cache it for this compile.
void Compile::init_scratch_buffer_blob(int const_size) {
// If there is already a scratch buffer blob allocated and the
// constant section is big enough, use it. Otherwise free the
// current and allocate a new one.
BufferBlob* blob = scratch_buffer_blob();
if ((blob != NULL) && (const_size <= _scratch_const_size)) {
// Use the current blob.
} else {
if (blob != NULL) {
BufferBlob::free(blob);
}
ResourceMark rm;
_scratch_const_size = const_size;
int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
blob = BufferBlob::create("Compile::scratch_buffer", size);
// Record the buffer blob for next time.
set_scratch_buffer_blob(blob);
// Have we run out of code space?
if (scratch_buffer_blob() == NULL) {
// Let CompilerBroker disable further compilations.
record_failure("Not enough space for scratch buffer in CodeCache");
return;
}
}
// Initialize the relocation buffers
relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
set_scratch_locs_memory(locs_buf);
}
//-----------------------scratch_emit_size-------------------------------------
// Helper function that computes size by emitting code
uint Compile::scratch_emit_size(const Node* n) {
// Start scratch_emit_size section.
set_in_scratch_emit_size(true);
// Emit into a trash buffer and count bytes emitted.
// This is a pretty expensive way to compute a size,
// but it works well enough if seldom used.
// All common fixed-size instructions are given a size
// method by the AD file.
// Note that the scratch buffer blob and locs memory are
// allocated at the beginning of the compile task, and
// may be shared by several calls to scratch_emit_size.
// The allocation of the scratch buffer blob is particularly
// expensive, since it has to grab the code cache lock.
BufferBlob* blob = this->scratch_buffer_blob();
assert(blob != NULL, "Initialize BufferBlob at start");
assert(blob->size() > MAX_inst_size, "sanity");
relocInfo* locs_buf = scratch_locs_memory();
address blob_begin = blob->content_begin();
address blob_end = (address)locs_buf;
assert(blob->content_contains(blob_end), "sanity");
CodeBuffer buf(blob_begin, blob_end - blob_begin);
buf.initialize_consts_size(_scratch_const_size);
buf.initialize_stubs_size(MAX_stubs_size);
assert(locs_buf != NULL, "sanity");
int lsize = MAX_locs_size / 3;
buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
// Do the emission.
Label fakeL; // Fake label for branch instructions.
Label* saveL = NULL;
uint save_bnum = 0;
bool is_branch = n->is_MachBranch();
if (is_branch) {
MacroAssembler masm(&buf);
masm.bind(fakeL);
n->as_MachBranch()->save_label(&saveL, &save_bnum);
n->as_MachBranch()->label_set(&fakeL, 0);
}
n->emit(buf, this->regalloc());
if (is_branch) // Restore label.
n->as_MachBranch()->label_set(saveL, save_bnum);
// End scratch_emit_size section.
set_in_scratch_emit_size(false);
return buf.insts_size();
}
// ============================================================================
//------------------------------Compile standard-------------------------------
debug_only( int Compile::_debug_idx = 100000; )
// Compile a method. entry_bci is -1 for normal compilations and indicates
// the continuation bci for on stack replacement.
Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
: Phase(Compiler),
_env(ci_env),
_log(ci_env->log()),
_compile_id(ci_env->compile_id()),
_save_argument_registers(false),
_stub_name(NULL),
_stub_function(NULL),
_stub_entry_point(NULL),
_method(target),
_entry_bci(osr_bci),
_initial_gvn(NULL),
_for_igvn(NULL),
_warm_calls(NULL),
_subsume_loads(subsume_loads),
_do_escape_analysis(do_escape_analysis),
_eliminate_boxing(eliminate_boxing),
_failure_reason(NULL),
_code_buffer("Compile::Fill_buffer"),
_orig_pc_slot(0),
_orig_pc_slot_offset_in_bytes(0),
_has_method_handle_invokes(false),
_mach_constant_base_node(NULL),
_node_bundling_limit(0),
_node_bundling_base(NULL),
_java_calls(0),
_inner_loops(0),
_scratch_const_size(-1),
_in_scratch_emit_size(false),
_dead_node_list(comp_arena()),
_dead_node_count(0),
#ifndef PRODUCT
_trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
_in_dump_cnt(0),
_printer(IdealGraphPrinter::printer()),
#endif
_congraph(NULL),
_comp_arena(mtCompiler),
_node_arena(mtCompiler),
_old_arena(mtCompiler),
_Compile_types(mtCompiler),
_replay_inline_data(NULL),
_late_inlines(comp_arena(), 2, 0, NULL),
_string_late_inlines(comp_arena(), 2, 0, NULL),
_boxing_late_inlines(comp_arena(), 2, 0, NULL),
_late_inlines_pos(0),
_number_of_mh_late_inlines(0),
_inlining_progress(false),
_inlining_incrementally(false),
_print_inlining_list(NULL),
_print_inlining_stream(NULL),
_print_inlining_idx(0),
_print_inlining_output(NULL),
_interpreter_frame_size(0),
_max_node_limit(MaxNodeLimit) {
C = this;
CompileWrapper cw(this);
if (CITimeVerbose) {
tty->print(" ");
target->holder()->name()->print();
tty->print(".");
target->print_short_name();
tty->print(" ");
}
TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
#ifndef PRODUCT
bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
if (!print_opto_assembly) {
bool print_assembly = (PrintAssembly || _method->should_print_assembly());
if (print_assembly && !Disassembler::can_decode()) {
tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
print_opto_assembly = true;
}
}
set_print_assembly(print_opto_assembly);
set_parsed_irreducible_loop(false);
if (method()->has_option("ReplayInline")) {
_replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
}
#endif
set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
// Make sure the method being compiled gets its own MDO,
// so we can at least track the decompile_count().
// Need MDO to record RTM code generation state.
method()->ensure_method_data();
}
Init(::AliasLevel);
print_compile_messages();
_ilt = InlineTree::build_inline_tree_root();
// Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
assert(num_alias_types() >= AliasIdxRaw, "");
#define MINIMUM_NODE_HASH 1023
// Node list that Iterative GVN will start with
Unique_Node_List for_igvn(comp_arena());
set_for_igvn(&for_igvn);
// GVN that will be run immediately on new nodes
uint estimated_size = method()->code_size()*4+64;
estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
PhaseGVN gvn(node_arena(), estimated_size);
set_initial_gvn(&gvn);
print_inlining_init();
{ // Scope for timing the parser
TracePhase tp("parse", &timers[_t_parser]);
// Put top into the hash table ASAP.
initial_gvn()->transform_no_reclaim(top());
// Set up tf(), start(), and find a CallGenerator.
CallGenerator* cg = NULL;
if (is_osr_compilation()) {
const TypeTuple *domain = StartOSRNode::osr_domain();
const TypeTuple *range = TypeTuple::make_range(method()->signature());
init_tf(TypeFunc::make(domain, range));
StartNode* s = new StartOSRNode(root(), domain);
initial_gvn()->set_type_bottom(s);
init_start(s);
cg = CallGenerator::for_osr(method(), entry_bci());
} else {
// Normal case.
init_tf(TypeFunc::make(method()));
StartNode* s = new StartNode(root(), tf()->domain());
initial_gvn()->set_type_bottom(s);
init_start(s);
if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
// With java.lang.ref.reference.get() we must go through the
// intrinsic when G1 is enabled - even when get() is the root
// method of the compile - so that, if necessary, the value in
// the referent field of the reference object gets recorded by
// the pre-barrier code.
// Specifically, if G1 is enabled, the value in the referent
// field is recorded by the G1 SATB pre barrier. This will
// result in the referent being marked live and the reference
// object removed from the list of discovered references during
// reference processing.
cg = find_intrinsic(method(), false);
}
if (cg == NULL) {
float past_uses = method()->interpreter_invocation_count();
float expected_uses = past_uses;
cg = CallGenerator::for_inline(method(), expected_uses);
}
}
if (failing()) return;
if (cg == NULL) {
record_method_not_compilable_all_tiers("cannot parse method");
return;
}
JVMState* jvms = build_start_state(start(), tf());
if ((jvms = cg->generate(jvms)) == NULL) {
if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
record_method_not_compilable("method parse failed");
}
return;
}
GraphKit kit(jvms);
if (!kit.stopped()) {
// Accept return values, and transfer control we know not where.
// This is done by a special, unique ReturnNode bound to root.
return_values(kit.jvms());
}
if (kit.has_exceptions()) {
// Any exceptions that escape from this call must be rethrown
// to whatever caller is dynamically above us on the stack.
// This is done by a special, unique RethrowNode bound to root.
rethrow_exceptions(kit.transfer_exceptions_into_jvms());
}
assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
inline_string_calls(true);
}
if (failing()) return;
print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
// Remove clutter produced by parsing.
if (!failing()) {
ResourceMark rm;
PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
}
}
// Note: Large methods are capped off in do_one_bytecode().
if (failing()) return;
// After parsing, node notes are no longer automagic.
// They must be propagated by register_new_node_with_optimizer(),
// clone(), or the like.
set_default_node_notes(NULL);
for (;;) {
int successes = Inline_Warm();
if (failing()) return;
if (successes == 0) break;
}
// Drain the list.
Finish_Warm();
#ifndef PRODUCT
if (_printer && _printer->should_print(_method)) {
_printer->print_inlining(this);
}
#endif
if (failing()) return;
NOT_PRODUCT( verify_graph_edges(); )
// Now optimize
Optimize();
if (failing()) return;
NOT_PRODUCT( verify_graph_edges(); )
#ifndef PRODUCT
if (PrintIdeal) {
ttyLocker ttyl; // keep the following output all in one block
// This output goes directly to the tty, not the compiler log.
// To enable tools to match it up with the compilation activity,
// be sure to tag this tty output with the compile ID.
if (xtty != NULL) {
xtty->head("ideal compile_id='%d'%s", compile_id(),
is_osr_compilation() ? " compile_kind='osr'" :
"");
}
root()->dump(9999);
if (xtty != NULL) {
xtty->tail("ideal");
}
}
#endif
NOT_PRODUCT( verify_barriers(); )
// Dump compilation data to replay it.
if (method()->has_option("DumpReplay")) {
env()->dump_replay_data(_compile_id);
}
if (method()->has_option("DumpInline") && (ilt() != NULL)) {
env()->dump_inline_data(_compile_id);
}
// Now that we know the size of all the monitors we can add a fixed slot
// for the original deopt pc.
_orig_pc_slot = fixed_slots();
int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
set_fixed_slots(next_slot);
// Compute when to use implicit null checks. Used by matching trap based
// nodes and NullCheck optimization.
set_allowed_deopt_reasons();
// Now generate code
Code_Gen();
if (failing()) return;
// Check if we want to skip execution of all compiled code.
{
#ifndef PRODUCT
if (OptoNoExecute) {
record_method_not_compilable("+OptoNoExecute"); // Flag as failed
return;
}
#endif
TracePhase tp("install_code", &timers[_t_registerMethod]);
if (is_osr_compilation()) {
_code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
_code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
} else {
_code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
_code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
}
env()->register_method(_method, _entry_bci,
&_code_offsets,
_orig_pc_slot_offset_in_bytes,
code_buffer(),
frame_size_in_words(), _oop_map_set,
&_handler_table, &_inc_table,
compiler,
env()->comp_level(),
has_unsafe_access(),
SharedRuntime::is_wide_vector(max_vector_size()),
rtm_state()
);
if (log() != NULL) // Print code cache state into compiler log
log()->code_cache_state();
}
}
//------------------------------Compile----------------------------------------
// Compile a runtime stub
Compile::Compile( ciEnv* ci_env,
TypeFunc_generator generator,
address stub_function,
const char *stub_name,
int is_fancy_jump,
bool pass_tls,
bool save_arg_registers,
bool return_pc )
: Phase(Compiler),
_env(ci_env),
_log(ci_env->log()),
_compile_id(0),
_save_argument_registers(save_arg_registers),
_method(NULL),
_stub_name(stub_name),
_stub_function(stub_function),
_stub_entry_point(NULL),
_entry_bci(InvocationEntryBci),
_initial_gvn(NULL),
_for_igvn(NULL),
_warm_calls(NULL),
_orig_pc_slot(0),
_orig_pc_slot_offset_in_bytes(0),
_subsume_loads(true),
_do_escape_analysis(false),
_eliminate_boxing(false),
_failure_reason(NULL),
_code_buffer("Compile::Fill_buffer"),
_has_method_handle_invokes(false),
_mach_constant_base_node(NULL),
_node_bundling_limit(0),
_node_bundling_base(NULL),
_java_calls(0),
_inner_loops(0),
#ifndef PRODUCT
_trace_opto_output(TraceOptoOutput),
_in_dump_cnt(0),
_printer(NULL),
#endif
_comp_arena(mtCompiler),
_node_arena(mtCompiler),
_old_arena(mtCompiler),
_Compile_types(mtCompiler),
_dead_node_list(comp_arena()),
_dead_node_count(0),
_congraph(NULL),
_replay_inline_data(NULL),
_number_of_mh_late_inlines(0),
_inlining_progress(false),
_inlining_incrementally(false),
_print_inlining_list(NULL),
_print_inlining_stream(NULL),
_print_inlining_idx(0),
_print_inlining_output(NULL),
_allowed_reasons(0),
_interpreter_frame_size(0),
_max_node_limit(MaxNodeLimit) {
C = this;
TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
#ifndef PRODUCT
set_print_assembly(PrintFrameConverterAssembly);
set_parsed_irreducible_loop(false);
#endif
set_has_irreducible_loop(false); // no loops
CompileWrapper cw(this);
Init(/*AliasLevel=*/ 0);
init_tf((*generator)());
{
// The following is a dummy for the sake of GraphKit::gen_stub
Unique_Node_List for_igvn(comp_arena());
set_for_igvn(&for_igvn); // not used, but some GraphKit guys push on this
PhaseGVN gvn(Thread::current()->resource_area(),255);
set_initial_gvn(&gvn); // not significant, but GraphKit guys use it pervasively
gvn.transform_no_reclaim(top());
GraphKit kit;
kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
}
NOT_PRODUCT( verify_graph_edges(); )
Code_Gen();
if (failing()) return;
// Entry point will be accessed using compile->stub_entry_point();
if (code_buffer() == NULL) {
Matcher::soft_match_failure();
} else {
if (PrintAssembly && (WizardMode || Verbose))
tty->print_cr("### Stub::%s", stub_name);
if (!failing()) {
assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
// Make the NMethod
// For now we mark the frame as never safe for profile stackwalking
RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
code_buffer(),
CodeOffsets::frame_never_safe,
// _code_offsets.value(CodeOffsets::Frame_Complete),
frame_size_in_words(),
_oop_map_set,
save_arg_registers);
assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
_stub_entry_point = rs->entry_point();
}
}
}
//------------------------------Init-------------------------------------------
// Prepare for a single compilation
void Compile::Init(int aliaslevel) {
_unique = 0;
_regalloc = NULL;
_tf = NULL; // filled in later
_top = NULL; // cached later
_matcher = NULL; // filled in later
_cfg = NULL; // filled in later
set_24_bit_selection_and_mode(Use24BitFP, false);
_node_note_array = NULL;
_default_node_notes = NULL;
DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
_immutable_memory = NULL; // filled in at first inquiry
// Globally visible Nodes
// First set TOP to NULL to give safe behavior during creation of RootNode
set_cached_top_node(NULL);
set_root(new RootNode());
// Now that you have a Root to point to, create the real TOP
set_cached_top_node( new ConNode(Type::TOP) );
set_recent_alloc(NULL, NULL);
// Create Debug Information Recorder to record scopes, oopmaps, etc.
env()->set_oop_recorder(new OopRecorder(env()->arena()));
env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
env()->set_dependencies(new Dependencies(env()));
_fixed_slots = 0;
set_has_split_ifs(false);
set_has_loops(has_method() && method()->has_loops()); // first approximation
set_has_stringbuilder(false);
set_has_boxed_value(false);
_trap_can_recompile = false; // no traps emitted yet
_major_progress = true; // start out assuming good things will happen
set_has_unsafe_access(false);
set_max_vector_size(0);
Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
set_decompile_count(0);
set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
set_num_loop_opts(LoopOptsCount);
set_do_inlining(Inline);
set_max_inline_size(MaxInlineSize);
set_freq_inline_size(FreqInlineSize);
set_do_scheduling(OptoScheduling);
set_do_count_invocations(false);
set_do_method_data_update(false);
set_age_code(has_method() && method()->profile_aging());
set_rtm_state(NoRTM); // No RTM lock eliding by default
method_has_option_value("MaxNodeLimit", _max_node_limit);
#if INCLUDE_RTM_OPT
if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
int rtm_state = method()->method_data()->rtm_state();
if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
// Don't generate RTM lock eliding code.
set_rtm_state(NoRTM);
} else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
// Generate RTM lock eliding code without abort ratio calculation code.
set_rtm_state(UseRTM);
} else if (UseRTMDeopt) {
// Generate RTM lock eliding code and include abort ratio calculation
// code if UseRTMDeopt is on.
set_rtm_state(ProfileRTM);
}
}
#endif
if (debug_info()->recording_non_safepoints()) {
set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
(comp_arena(), 8, 0, NULL));
set_default_node_notes(Node_Notes::make(this));
}
// // -- Initialize types before each compile --
// // Update cached type information
// if( _method && _method->constants() )
// Type::update_loaded_types(_method, _method->constants());
// Init alias_type map.
if (!_do_escape_analysis && aliaslevel == 3)
aliaslevel = 2; // No unique types without escape analysis
_AliasLevel = aliaslevel;
const int grow_ats = 16;
_max_alias_types = grow_ats;
_alias_types = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, grow_ats);
Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
{
for (int i = 0; i < grow_ats; i++) _alias_types[i] = &ats[i];
}
// Initialize the first few types.
_alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
_alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
_alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
_num_alias_types = AliasIdxRaw+1;
// Zero out the alias type cache.
Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
// A NULL adr_type hits in the cache right away. Preload the right answer.
probe_alias_cache(NULL)->_index = AliasIdxTop;
_intrinsics = NULL;
_macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
_predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
_expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
register_library_intrinsics();
}
//---------------------------init_start----------------------------------------
// Install the StartNode on this compile object.
void Compile::init_start(StartNode* s) {
if (failing())
return; // already failing
assert(s == start(), "");
}
/**
* Return the 'StartNode'. We must not have a pending failure, since the ideal graph
* can be in an inconsistent state, i.e., we can get segmentation faults when traversing
* the ideal graph.
*/
StartNode* Compile::start() const {
assert (!failing(), err_msg_res("Must not have pending failure. Reason is: %s", failure_reason()));
for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
Node* start = root()->fast_out(i);
if (start->is_Start()) {
return start->as_Start();
}
}
fatal("Did not find Start node!");
return NULL;
}
//-------------------------------immutable_memory-------------------------------------
// Access immutable memory
Node* Compile::immutable_memory() {
if (_immutable_memory != NULL) {
return _immutable_memory;
}
StartNode* s = start();
for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
Node *p = s->fast_out(i);
if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
_immutable_memory = p;
return _immutable_memory;
}
}
ShouldNotReachHere();
return NULL;
}
//----------------------set_cached_top_node------------------------------------
// Install the cached top node, and make sure Node::is_top works correctly.
void Compile::set_cached_top_node(Node* tn) {
if (tn != NULL) verify_top(tn);
Node* old_top = _top;
_top = tn;
// Calling Node::setup_is_top allows the nodes the chance to adjust
// their _out arrays.
if (_top != NULL) _top->setup_is_top();
if (old_top != NULL) old_top->setup_is_top();
assert(_top == NULL || top()->is_top(), "");
}
#ifdef ASSERT
uint Compile::count_live_nodes_by_graph_walk() {
Unique_Node_List useful(comp_arena());
// Get useful node list by walking the graph.
identify_useful_nodes(useful);
return useful.size();
}
void Compile::print_missing_nodes() {
// Return if CompileLog is NULL and PrintIdealNodeCount is false.
if ((_log == NULL) && (! PrintIdealNodeCount)) {
return;
}
// This is an expensive function. It is executed only when the user
// specifies VerifyIdealNodeCount option or otherwise knows the
// additional work that needs to be done to identify reachable nodes
// by walking the flow graph and find the missing ones using
// _dead_node_list.
Unique_Node_List useful(comp_arena());
// Get useful node list by walking the graph.
identify_useful_nodes(useful);
uint l_nodes = C->live_nodes();
uint l_nodes_by_walk = useful.size();
if (l_nodes != l_nodes_by_walk) {
if (_log != NULL) {
_log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
_log->stamp();
_log->end_head();
}
VectorSet& useful_member_set = useful.member_set();
int last_idx = l_nodes_by_walk;
for (int i = 0; i < last_idx; i++) {
if (useful_member_set.test(i)) {
if (_dead_node_list.test(i)) {
if (_log != NULL) {
_log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
}
if (PrintIdealNodeCount) {
// Print the log message to tty
tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
useful.at(i)->dump();
}
}
}
else if (! _dead_node_list.test(i)) {
if (_log != NULL) {
_log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
}
if (PrintIdealNodeCount) {
// Print the log message to tty
tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
}
}
}
if (_log != NULL) {
_log->tail("mismatched_nodes");
}
}
}
void Compile::record_modified_node(Node* n) {
if (_modified_nodes != NULL && !_inlining_incrementally &&
n->outcnt() != 0 && !n->is_Con()) {
_modified_nodes->push(n);
}
}
void Compile::remove_modified_node(Node* n) {
if (_modified_nodes != NULL) {
_modified_nodes->remove(n);
}
}
#endif
#ifndef PRODUCT
void Compile::verify_top(Node* tn) const {
if (tn != NULL) {
assert(tn->is_Con(), "top node must be a constant");
assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
assert(tn->in(0) != NULL, "must have live top node");
}
}
#endif
///-------------------Managing Per-Node Debug & Profile Info-------------------
void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
guarantee(arr != NULL, "");
int num_blocks = arr->length();
if (grow_by < num_blocks) grow_by = num_blocks;
int num_notes = grow_by * _node_notes_block_size;
Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
while (num_notes > 0) {
arr->append(notes);
notes += _node_notes_block_size;
num_notes -= _node_notes_block_size;
}
assert(num_notes == 0, "exact multiple, please");
}
bool Compile::copy_node_notes_to(Node* dest, Node* source) {
if (source == NULL || dest == NULL) return false;
if (dest->is_Con())
return false; // Do not push debug info onto constants.
#ifdef ASSERT
// Leave a bread crumb trail pointing to the original node:
if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
dest->set_debug_orig(source);
}
#endif
if (node_note_array() == NULL)
return false; // Not collecting any notes now.
// This is a copy onto a pre-existing node, which may already have notes.
// If both nodes have notes, do not overwrite any pre-existing notes.
Node_Notes* source_notes = node_notes_at(source->_idx);
if (source_notes == NULL || source_notes->is_clear()) return false;
Node_Notes* dest_notes = node_notes_at(dest->_idx);
if (dest_notes == NULL || dest_notes->is_clear()) {
return set_node_notes_at(dest->_idx, source_notes);
}
Node_Notes merged_notes = (*source_notes);
// The order of operations here ensures that dest notes will win...
merged_notes.update_from(dest_notes);
return set_node_notes_at(dest->_idx, &merged_notes);
}
//--------------------------allow_range_check_smearing-------------------------
// Gating condition for coalescing similar range checks.
// Sometimes we try 'speculatively' replacing a series of a range checks by a
// single covering check that is at least as strong as any of them.
// If the optimization succeeds, the simplified (strengthened) range check
// will always succeed. If it fails, we will deopt, and then give up
// on the optimization.
bool Compile::allow_range_check_smearing() const {
// If this method has already thrown a range-check,
// assume it was because we already tried range smearing
// and it failed.
uint already_trapped = trap_count(Deoptimization::Reason_range_check);
return !already_trapped;
}
//------------------------------flatten_alias_type-----------------------------
const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
int offset = tj->offset();
TypePtr::PTR ptr = tj->ptr();
// Known instance (scalarizable allocation) alias only with itself.
bool is_known_inst = tj->isa_oopptr() != NULL &&
tj->is_oopptr()->is_known_instance();
// Process weird unsafe references.
if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
tj = TypeOopPtr::BOTTOM;
ptr = tj->ptr();
offset = tj->offset();
}
// Array pointers need some flattening
const TypeAryPtr *ta = tj->isa_aryptr();
if (ta && ta->is_stable()) {
// Erase stability property for alias analysis.
tj = ta = ta->cast_to_stable(false);
}
if( ta && is_known_inst ) {
if ( offset != Type::OffsetBot &&
offset > arrayOopDesc::length_offset_in_bytes() ) {
offset = Type::OffsetBot; // Flatten constant access into array body only
tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
}
} else if( ta && _AliasLevel >= 2 ) {
// For arrays indexed by constant indices, we flatten the alias
// space to include all of the array body. Only the header, klass
// and array length can be accessed un-aliased.
if( offset != Type::OffsetBot ) {
if( ta->const_oop() ) { // MethodData* or Method*
offset = Type::OffsetBot; // Flatten constant access into array body
tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
} else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
// range is OK as-is.
tj = ta = TypeAryPtr::RANGE;
} else if( offset == oopDesc::klass_offset_in_bytes() ) {
tj = TypeInstPtr::KLASS; // all klass loads look alike
ta = TypeAryPtr::RANGE; // generic ignored junk
ptr = TypePtr::BotPTR;
} else if( offset == oopDesc::mark_offset_in_bytes() ) {
tj = TypeInstPtr::MARK;
ta = TypeAryPtr::RANGE; // generic ignored junk
ptr = TypePtr::BotPTR;
} else { // Random constant offset into array body
offset = Type::OffsetBot; // Flatten constant access into array body
tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
}
}
// Arrays of fixed size alias with arrays of unknown size.
if (ta->size() != TypeInt::POS) {
const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
}
// Arrays of known objects become arrays of unknown objects.
if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
}
if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
}
// Arrays of bytes and of booleans both use 'bastore' and 'baload' so
// cannot be distinguished by bytecode alone.
if (ta->elem() == TypeInt::BOOL) {
const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
}
// During the 2nd round of IterGVN, NotNull castings are removed.
// Make sure the Bottom and NotNull variants alias the same.
// Also, make sure exact and non-exact variants alias the same.
if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
}
}
// Oop pointers need some flattening
const TypeInstPtr *to = tj->isa_instptr();
if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
ciInstanceKlass *k = to->klass()->as_instance_klass();
if( ptr == TypePtr::Constant ) {
if (to->klass() != ciEnv::current()->Class_klass() ||
offset < k->size_helper() * wordSize) {
// No constant oop pointers (such as Strings); they alias with
// unknown strings.
assert(!is_known_inst, "not scalarizable allocation");
tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
}
} else if( is_known_inst ) {
tj = to; // Keep NotNull and klass_is_exact for instance type
} else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
// During the 2nd round of IterGVN, NotNull castings are removed.
// Make sure the Bottom and NotNull variants alias the same.
// Also, make sure exact and non-exact variants alias the same.
tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
}
if (to->speculative() != NULL) {
tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
}
// Canonicalize the holder of this field
if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
// First handle header references such as a LoadKlassNode, even if the
// object's klass is unloaded at compile time (4965979).
if (!is_known_inst) { // Do it only for non-instance types
tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
}
} else if (offset < 0 || offset >= k->size_helper() * wordSize) {
// Static fields are in the space above the normal instance
// fields in the java.lang.Class instance.
if (to->klass() != ciEnv::current()->Class_klass()) {
to = NULL;
tj = TypeOopPtr::BOTTOM;
offset = tj->offset();
}
} else {
ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
if (!k->equals(canonical_holder) || tj->offset() != offset) {
if( is_known_inst ) {
tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
} else {
tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
}
}
}
}
// Klass pointers to object array klasses need some flattening
const TypeKlassPtr *tk = tj->isa_klassptr();
if( tk ) {
// If we are referencing a field within a Klass, we need
// to assume the worst case of an Object. Both exact and
// inexact types must flatten to the same alias class so
// use NotNull as the PTR.
if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
TypeKlassPtr::OBJECT->klass(),
offset);
}
ciKlass* klass = tk->klass();
if( klass->is_obj_array_klass() ) {
ciKlass* k = TypeAryPtr::OOPS->klass();
if( !k || !k->is_loaded() ) // Only fails for some -Xcomp runs
k = TypeInstPtr::BOTTOM->klass();
tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
}
// Check for precise loads from the primary supertype array and force them
// to the supertype cache alias index. Check for generic array loads from
// the primary supertype array and also force them to the supertype cache
// alias index. Since the same load can reach both, we need to merge
// these 2 disparate memories into the same alias class. Since the
// primary supertype array is read-only, there's no chance of confusion
// where we bypass an array load and an array store.
int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
if (offset == Type::OffsetBot ||
(offset >= primary_supers_offset &&
offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
offset = in_bytes(Klass::secondary_super_cache_offset());
tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
}
}
// Flatten all Raw pointers together.
if (tj->base() == Type::RawPtr)
tj = TypeRawPtr::BOTTOM;
if (tj->base() == Type::AnyPtr)
tj = TypePtr::BOTTOM; // An error, which the caller must check for.
// Flatten all to bottom for now
switch( _AliasLevel ) {
case 0:
tj = TypePtr::BOTTOM;
break;
case 1: // Flatten to: oop, static, field or array
switch (tj->base()) {
//case Type::AryPtr: tj = TypeAryPtr::RANGE; break;
case Type::RawPtr: tj = TypeRawPtr::BOTTOM; break;
case Type::AryPtr: // do not distinguish arrays at all
case Type::InstPtr: tj = TypeInstPtr::BOTTOM; break;
case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
case Type::AnyPtr: tj = TypePtr::BOTTOM; break; // caller checks it
default: ShouldNotReachHere();
}
break;
case 2: // No collapsing at level 2; keep all splits
case 3: // No collapsing at level 3; keep all splits
break;
default:
Unimplemented();
}
offset = tj->offset();
assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
(offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
(offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
(offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
(offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
(offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
(offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr) ,
"For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
assert( tj->ptr() != TypePtr::TopPTR &&
tj->ptr() != TypePtr::AnyNull &&
tj->ptr() != TypePtr::Null, "No imprecise addresses" );
// assert( tj->ptr() != TypePtr::Constant ||
// tj->base() == Type::RawPtr ||
// tj->base() == Type::KlassPtr, "No constant oop addresses" );
return tj;
}
void Compile::AliasType::Init(int i, const TypePtr* at) {
_index = i;
_adr_type = at;
_field = NULL;
_element = NULL;
_is_rewritable = true; // default
const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
if (atoop != NULL && atoop->is_known_instance()) {
const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
_general_index = Compile::current()->get_alias_index(gt);
} else {
_general_index = 0;
}
}
//---------------------------------print_on------------------------------------
#ifndef PRODUCT
void Compile::AliasType::print_on(outputStream* st) {
if (index() < 10)
st->print("@ <%d> ", index());
else st->print("@ <%d>", index());
st->print(is_rewritable() ? " " : " RO");
int offset = adr_type()->offset();
if (offset == Type::OffsetBot)
st->print(" +any");
else st->print(" +%-3d", offset);
st->print(" in ");
adr_type()->dump_on(st);
const TypeOopPtr* tjp = adr_type()->isa_oopptr();
if (field() != NULL && tjp) {
if (tjp->klass() != field()->holder() ||
tjp->offset() != field()->offset_in_bytes()) {
st->print(" != ");
field()->print();
st->print(" ***");
}
}
}
void print_alias_types() {
Compile* C = Compile::current();
tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
C->alias_type(idx)->print_on(tty);
tty->cr();
}
}
#endif
//----------------------------probe_alias_cache--------------------------------
Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
intptr_t key = (intptr_t) adr_type;
key ^= key >> logAliasCacheSize;
return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
}
//-----------------------------grow_alias_types--------------------------------
void Compile::grow_alias_types() {
const int old_ats = _max_alias_types; // how many before?
const int new_ats = old_ats; // how many more?
const int grow_ats = old_ats+new_ats; // how many now?
_max_alias_types = grow_ats;
_alias_types = REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
for (int i = 0; i < new_ats; i++) _alias_types[old_ats+i] = &ats[i];
}
//--------------------------------find_alias_type------------------------------
Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
if (_AliasLevel == 0)
return alias_type(AliasIdxBot);
AliasCacheEntry* ace = probe_alias_cache(adr_type);
if (ace->_adr_type == adr_type) {
return alias_type(ace->_index);
}
// Handle special cases.
if (adr_type == NULL) return alias_type(AliasIdxTop);
if (adr_type == TypePtr::BOTTOM) return alias_type(AliasIdxBot);
// Do it the slow way.
const TypePtr* flat = flatten_alias_type(adr_type);
#ifdef ASSERT
assert(flat == flatten_alias_type(flat), "idempotent");
assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr");
if (flat->isa_oopptr() && !flat->isa_klassptr()) {
const TypeOopPtr* foop = flat->is_oopptr();
// Scalarizable allocations have exact klass always.
bool exact = !foop->klass_is_exact() || foop->is_known_instance();
const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
}
assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
#endif
int idx = AliasIdxTop;
for (int i = 0; i < num_alias_types(); i++) {
if (alias_type(i)->adr_type() == flat) {
idx = i;
break;
}
}
if (idx == AliasIdxTop) {
if (no_create) return NULL;
// Grow the array if necessary.
if (_num_alias_types == _max_alias_types) grow_alias_types();
// Add a new alias type.
idx = _num_alias_types++;
_alias_types[idx]->Init(idx, flat);
if (flat == TypeInstPtr::KLASS) alias_type(idx)->set_rewritable(false);
if (flat == TypeAryPtr::RANGE) alias_type(idx)->set_rewritable(false);
if (flat->isa_instptr()) {
if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
&& flat->is_instptr()->klass() == env()->Class_klass())
alias_type(idx)->set_rewritable(false);
}
if (flat->isa_aryptr()) {
#ifdef ASSERT
const int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
// (T_BYTE has the weakest alignment and size restrictions...)
assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
#endif
if (flat->offset() == TypePtr::OffsetBot) {
alias_type(idx)->set_element(flat->is_aryptr()->elem());
}
}
if (flat->isa_klassptr()) {
if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
alias_type(idx)->set_rewritable(false);
if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
alias_type(idx)->set_rewritable(false);
if (flat->offset() == in_bytes(Klass::access_flags_offset()))
alias_type(idx)->set_rewritable(false);
if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
alias_type(idx)->set_rewritable(false);
}
// %%% (We would like to finalize JavaThread::threadObj_offset(),
// but the base pointer type is not distinctive enough to identify
// references into JavaThread.)
// Check for final fields.
const TypeInstPtr* tinst = flat->isa_instptr();
if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
ciField* field;
if (tinst->const_oop() != NULL &&
tinst->klass() == ciEnv::current()->Class_klass() &&
tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
// static field
ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
field = k->get_field_by_offset(tinst->offset(), true);
} else {
ciInstanceKlass *k = tinst->klass()->as_instance_klass();
field = k->get_field_by_offset(tinst->offset(), false);
}
assert(field == NULL ||
original_field == NULL ||
(field->holder() == original_field->holder() &&
field->offset() == original_field->offset() &&
field->is_static() == original_field->is_static()), "wrong field?");
// Set field() and is_rewritable() attributes.
if (field != NULL) alias_type(idx)->set_field(field);
}
}
// Fill the cache for next time.
ace->_adr_type = adr_type;
ace->_index = idx;
assert(alias_type(adr_type) == alias_type(idx), "type must be installed");
// Might as well try to fill the cache for the flattened version, too.
AliasCacheEntry* face = probe_alias_cache(flat);
if (face->_adr_type == NULL) {
face->_adr_type = flat;
face->_index = idx;
assert(alias_type(flat) == alias_type(idx), "flat type must work too");
}
return alias_type(idx);
}
Compile::AliasType* Compile::alias_type(ciField* field) {
const TypeOopPtr* t;
if (field->is_static())
t = TypeInstPtr::make(field->holder()->java_mirror());
else
t = TypeOopPtr::make_from_klass_raw(field->holder());
AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
return atp;
}
//------------------------------have_alias_type--------------------------------
bool Compile::have_alias_type(const TypePtr* adr_type) {
AliasCacheEntry* ace = probe_alias_cache(adr_type);
if (ace->_adr_type == adr_type) {
return true;
}
// Handle special cases.
if (adr_type == NULL) return true;
if (adr_type == TypePtr::BOTTOM) return true;
return find_alias_type(adr_type, true, NULL) != NULL;
}
//-----------------------------must_alias--------------------------------------
// True if all values of the given address type are in the given alias category.
bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
if (alias_idx == AliasIdxBot) return true; // the universal category
if (adr_type == NULL) return true; // NULL serves as TypePtr::TOP
if (alias_idx == AliasIdxTop) return false; // the empty category
if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
// the only remaining possible overlap is identity
int adr_idx = get_alias_index(adr_type);
assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
assert(adr_idx == alias_idx ||
(alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
&& adr_type != TypeOopPtr::BOTTOM),
"should not be testing for overlap with an unsafe pointer");
return adr_idx == alias_idx;
}
//------------------------------can_alias--------------------------------------
// True if any values of the given address type are in the given alias category.
bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
if (alias_idx == AliasIdxTop) return false; // the empty category
if (adr_type == NULL) return false; // NULL serves as TypePtr::TOP
if (alias_idx == AliasIdxBot) return true; // the universal category
if (adr_type->base() == Type::AnyPtr) return true; // TypePtr::BOTTOM or its twins
// the only remaining possible overlap is identity
int adr_idx = get_alias_index(adr_type);
assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
return adr_idx == alias_idx;
}
//---------------------------pop_warm_call-------------------------------------
WarmCallInfo* Compile::pop_warm_call() {
WarmCallInfo* wci = _warm_calls;
if (wci != NULL) _warm_calls = wci->remove_from(wci);
return wci;
}
//----------------------------Inline_Warm--------------------------------------
int Compile::Inline_Warm() {
// If there is room, try to inline some more warm call sites.
// %%% Do a graph index compaction pass when we think we're out of space?
if (!InlineWarmCalls) return 0;
int calls_made_hot = 0;
int room_to_grow = NodeCountInliningCutoff - unique();
int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
int amount_grown = 0;
WarmCallInfo* call;
while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
int est_size = (int)call->size();
if (est_size > (room_to_grow - amount_grown)) {
// This one won't fit anyway. Get rid of it.
call->make_cold();
continue;
}
call->make_hot();
calls_made_hot++;
amount_grown += est_size;
amount_to_grow -= est_size;
}
if (calls_made_hot > 0) set_major_progress();
return calls_made_hot;
}
//----------------------------Finish_Warm--------------------------------------
void Compile::Finish_Warm() {
if (!InlineWarmCalls) return;
if (failing()) return;
if (warm_calls() == NULL) return;
// Clean up loose ends, if we are out of space for inlining.
WarmCallInfo* call;
while ((call = pop_warm_call()) != NULL) {
call->make_cold();
}
}
//---------------------cleanup_loop_predicates-----------------------
// Remove the opaque nodes that protect the predicates so that all unused
// checks and uncommon_traps will be eliminated from the ideal graph
void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
if (predicate_count()==0) return;
for (int i = predicate_count(); i > 0; i--) {
Node * n = predicate_opaque1_node(i-1);
assert(n->Opcode() == Op_Opaque1, "must be");
igvn.replace_node(n, n->in(1));
}
assert(predicate_count()==0, "should be clean!");
}
// StringOpts and late inlining of string methods
void Compile::inline_string_calls(bool parse_time) {
{
// remove useless nodes to make the usage analysis simpler
ResourceMark rm;
PhaseRemoveUseless pru(initial_gvn(), for_igvn());
}
{
ResourceMark rm;
print_method(PHASE_BEFORE_STRINGOPTS, 3);
PhaseStringOpts pso(initial_gvn(), for_igvn());
print_method(PHASE_AFTER_STRINGOPTS, 3);
}
// now inline anything that we skipped the first time around
if (!parse_time) {
_late_inlines_pos = _late_inlines.length();
}
while (_string_late_inlines.length() > 0) {
CallGenerator* cg = _string_late_inlines.pop();
cg->do_late_inline();
if (failing()) return;
}
_string_late_inlines.trunc_to(0);
}
// Late inlining of boxing methods
void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
if (_boxing_late_inlines.length() > 0) {
assert(has_boxed_value(), "inconsistent");
PhaseGVN* gvn = initial_gvn();
set_inlining_incrementally(true);
assert( igvn._worklist.size() == 0, "should be done with igvn" );
for_igvn()->clear();
gvn->replace_with(&igvn);
_late_inlines_pos = _late_inlines.length();
while (_boxing_late_inlines.length() > 0) {
CallGenerator* cg = _boxing_late_inlines.pop();
cg->do_late_inline();
if (failing()) return;
}
_boxing_late_inlines.trunc_to(0);
{
ResourceMark rm;
PhaseRemoveUseless pru(gvn, for_igvn());
}
igvn = PhaseIterGVN(gvn);
igvn.optimize();
set_inlining_progress(false);
set_inlining_incrementally(false);
}
}
void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
assert(IncrementalInline, "incremental inlining should be on");
PhaseGVN* gvn = initial_gvn();
set_inlining_progress(false);
for_igvn()->clear();
gvn->replace_with(&igvn);
{
TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
int i = 0;
for (; i <_late_inlines.length() && !inlining_progress(); i++) {
CallGenerator* cg = _late_inlines.at(i);
_late_inlines_pos = i+1;
cg->do_late_inline();
if (failing()) return;
}
int j = 0;
for (; i < _late_inlines.length(); i++, j++) {
_late_inlines.at_put(j, _late_inlines.at(i));
}
_late_inlines.trunc_to(j);
}
{
TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
ResourceMark rm;
PhaseRemoveUseless pru(gvn, for_igvn());
}
{
TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
igvn = PhaseIterGVN(gvn);
}
}
// Perform incremental inlining until bound on number of live nodes is reached
void Compile::inline_incrementally(PhaseIterGVN& igvn) {
TracePhase tp("incrementalInline", &timers[_t_incrInline]);
PhaseGVN* gvn = initial_gvn();
set_inlining_incrementally(true);
set_inlining_progress(true);
uint low_live_nodes = 0;
while(inlining_progress() && _late_inlines.length() > 0) {
if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
// PhaseIdealLoop is expensive so we only try it once we are
// out of live nodes and we only try it again if the previous
// helped got the number of nodes down significantly
PhaseIdealLoop ideal_loop( igvn, false, true );
if (failing()) return;
low_live_nodes = live_nodes();
_major_progress = true;
}
if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
break;
}
}
inline_incrementally_one(igvn);
if (failing()) return;
{
TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
igvn.optimize();
}
if (failing()) return;
}
assert( igvn._worklist.size() == 0, "should be done with igvn" );
if (_string_late_inlines.length() > 0) {
assert(has_stringbuilder(), "inconsistent");
for_igvn()->clear();
initial_gvn()->replace_with(&igvn);
inline_string_calls(false);
if (failing()) return;
{
TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
ResourceMark rm;
PhaseRemoveUseless pru(initial_gvn(), for_igvn());
}
{
TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
igvn = PhaseIterGVN(gvn);
igvn.optimize();
}
}
set_inlining_incrementally(false);
}
//------------------------------Optimize---------------------------------------
// Given a graph, optimize it.
void Compile::Optimize() {
TracePhase tp("optimizer", &timers[_t_optimizer]);
#ifndef PRODUCT
if (env()->break_at_compile()) {
BREAKPOINT;
}
#endif
ResourceMark rm;
int loop_opts_cnt;
print_inlining_reinit();
NOT_PRODUCT( verify_graph_edges(); )
print_method(PHASE_AFTER_PARSING);
{
// Iterative Global Value Numbering, including ideal transforms
// Initialize IterGVN with types and values from parse-time GVN
PhaseIterGVN igvn(initial_gvn());
#ifdef ASSERT
_modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
#endif
{
TracePhase tp("iterGVN", &timers[_t_iterGVN]);
igvn.optimize();
}
print_method(PHASE_ITER_GVN1, 2);
if (failing()) return;
inline_incrementally(igvn);
print_method(PHASE_INCREMENTAL_INLINE, 2);
if (failing()) return;
if (eliminate_boxing()) {
// Inline valueOf() methods now.
inline_boxing_calls(igvn);
if (AlwaysIncrementalInline) {
inline_incrementally(igvn);
}
print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
if (failing()) return;
}
// Remove the speculative part of types and clean up the graph from
// the extra CastPP nodes whose only purpose is to carry them. Do
// that early so that optimizations are not disrupted by the extra
// CastPP nodes.
remove_speculative_types(igvn);
// No more new expensive nodes will be added to the list from here
// so keep only the actual candidates for optimizations.
cleanup_expensive_nodes(igvn);
// Perform escape analysis
if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
if (has_loops()) {
// Cleanup graph (remove dead nodes).
TracePhase tp("idealLoop", &timers[_t_idealLoop]);
PhaseIdealLoop ideal_loop( igvn, false, true );
if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
if (failing()) return;
}
ConnectionGraph::do_analysis(this, &igvn);
if (failing()) return;
// Optimize out fields loads from scalar replaceable allocations.
igvn.optimize();
print_method(PHASE_ITER_GVN_AFTER_EA, 2);
if (failing()) return;
if (congraph() != NULL && macro_count() > 0) {
TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
PhaseMacroExpand mexp(igvn);
mexp.eliminate_macro_nodes();
igvn.set_delay_transform(false);
igvn.optimize();
print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
if (failing()) return;
}
}
// Loop transforms on the ideal graph. Range Check Elimination,
// peeling, unrolling, etc.
// Set loop opts counter
loop_opts_cnt = num_loop_opts();
if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
{
TracePhase tp("idealLoop", &timers[_t_idealLoop]);
PhaseIdealLoop ideal_loop( igvn, true );
loop_opts_cnt--;
if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
if (failing()) return;
}
// Loop opts pass if partial peeling occurred in previous pass
if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
TracePhase tp("idealLoop", &timers[_t_idealLoop]);
PhaseIdealLoop ideal_loop( igvn, false );
loop_opts_cnt--;
if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
if (failing()) return;
}
// Loop opts pass for loop-unrolling before CCP
if(major_progress() && (loop_opts_cnt > 0)) {
TracePhase tp("idealLoop", &timers[_t_idealLoop]);
PhaseIdealLoop ideal_loop( igvn, false );
loop_opts_cnt--;
if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
}
if (!failing()) {
// Verify that last round of loop opts produced a valid graph
TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
PhaseIdealLoop::verify(igvn);
}
}
if (failing()) return;
// Conditional Constant Propagation;
PhaseCCP ccp( &igvn );
assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
{
TracePhase tp("ccp", &timers[_t_ccp]);
ccp.do_transform();
}
print_method(PHASE_CPP1, 2);
assert( true, "Break here to ccp.dump_old2new_map()");
// Iterative Global Value Numbering, including ideal transforms
{
TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
igvn = ccp;
igvn.optimize();
}
print_method(PHASE_ITER_GVN2, 2);
if (failing()) return;
// Loop transforms on the ideal graph. Range Check Elimination,
// peeling, unrolling, etc.
if(loop_opts_cnt > 0) {
debug_only( int cnt = 0; );
while(major_progress() && (loop_opts_cnt > 0)) {
TracePhase tp("idealLoop", &timers[_t_idealLoop]);
assert( cnt++ < 40, "infinite cycle in loop optimization" );
PhaseIdealLoop ideal_loop( igvn, true);
loop_opts_cnt--;
if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
if (failing()) return;
}
}
{
// Verify that all previous optimizations produced a valid graph
// at least to this point, even if no loop optimizations were done.
TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
PhaseIdealLoop::verify(igvn);
}
{
TracePhase tp("macroExpand", &timers[_t_macroExpand]);
PhaseMacroExpand mex(igvn);
if (mex.expand_macro_nodes()) {
assert(failing(), "must bail out w/ explicit message");
return;
}
}
DEBUG_ONLY( _modified_nodes = NULL; )
} // (End scope of igvn; run destructor if necessary for asserts.)
process_print_inlining();
// A method with only infinite loops has no edges entering loops from root
{
TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
if (final_graph_reshaping()) {
assert(failing(), "must bail out w/ explicit message");
return;
}
}
print_method(PHASE_OPTIMIZE_FINISHED, 2);
}
//------------------------------Code_Gen---------------------------------------
// Given a graph, generate code for it
void Compile::Code_Gen() {
if (failing()) {
return;
}
// Perform instruction selection. You might think we could reclaim Matcher
// memory PDQ, but actually the Matcher is used in generating spill code.
// Internals of the Matcher (including some VectorSets) must remain live
// for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
// set a bit in reclaimed memory.
// In debug mode can dump m._nodes.dump() for mapping of ideal to machine
// nodes. Mapping is only valid at the root of each matched subtree.
NOT_PRODUCT( verify_graph_edges(); )
Matcher matcher;
_matcher = &matcher;
{
TracePhase tp("matcher", &timers[_t_matcher]);
matcher.match();
}
// In debug mode can dump m._nodes.dump() for mapping of ideal to machine
// nodes. Mapping is only valid at the root of each matched subtree.
NOT_PRODUCT( verify_graph_edges(); )
// If you have too many nodes, or if matching has failed, bail out
check_node_count(0, "out of nodes matching instructions");
if (failing()) {
return;
}
// Build a proper-looking CFG
PhaseCFG cfg(node_arena(), root(), matcher);
_cfg = &cfg;
{
TracePhase tp("scheduler", &timers[_t_scheduler]);
bool success = cfg.do_global_code_motion();
if (!success) {
return;
}
print_method(PHASE_GLOBAL_CODE_MOTION, 2);
NOT_PRODUCT( verify_graph_edges(); )
debug_only( cfg.verify(); )
}
PhaseChaitin regalloc(unique(), cfg, matcher);
_regalloc = ®alloc;
{
TracePhase tp("regalloc", &timers[_t_registerAllocation]);
// Perform register allocation. After Chaitin, use-def chains are
// no longer accurate (at spill code) and so must be ignored.
// Node->LRG->reg mappings are still accurate.
_regalloc->Register_Allocate();
// Bail out if the allocator builds too many nodes
if (failing()) {
return;
}
}
// Prior to register allocation we kept empty basic blocks in case the
// the allocator needed a place to spill. After register allocation we
// are not adding any new instructions. If any basic block is empty, we
// can now safely remove it.
{
TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
cfg.remove_empty_blocks();
if (do_freq_based_layout()) {
PhaseBlockLayout layout(cfg);
} else {
cfg.set_loop_alignment();
}
cfg.fixup_flow();
}
// Apply peephole optimizations
if( OptoPeephole ) {
TracePhase tp("peephole", &timers[_t_peephole]);
PhasePeephole peep( _regalloc, cfg);
peep.do_transform();
}
// Do late expand if CPU requires this.
if (Matcher::require_postalloc_expand) {
TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
cfg.postalloc_expand(_regalloc);
}
// Convert Nodes to instruction bits in a buffer
{
TraceTime tp("output", &timers[_t_output], CITime);
Output();
}
print_method(PHASE_FINAL_CODE);
// He's dead, Jim.
_cfg = (PhaseCFG*)0xdeadbeef;
_regalloc = (PhaseChaitin*)0xdeadbeef;
}
//------------------------------dump_asm---------------------------------------
// Dump formatted assembly
#ifndef PRODUCT
void Compile::dump_asm(int *pcs, uint pc_limit) {
bool cut_short = false;
tty->print_cr("#");
tty->print("# "); _tf->dump(); tty->cr();
tty->print_cr("#");
// For all blocks
int pc = 0x0; // Program counter
char starts_bundle = ' ';
_regalloc->dump_frame();
Node *n = NULL;
for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
if (VMThread::should_terminate()) {
cut_short = true;
break;
}
Block* block = _cfg->get_block(i);
if (block->is_connector() && !Verbose) {
continue;
}
n = block->head();
if (pcs && n->_idx < pc_limit) {
tty->print("%3.3x ", pcs[n->_idx]);
} else {
tty->print(" ");
}
block->dump_head(_cfg);
if (block->is_connector()) {
tty->print_cr(" # Empty connector block");
} else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
tty->print_cr(" # Block is sole successor of call");
}
// For all instructions
Node *delay = NULL;
for (uint j = 0; j < block->number_of_nodes(); j++) {
if (VMThread::should_terminate()) {
cut_short = true;
break;
}
n = block->get_node(j);
if (valid_bundle_info(n)) {
Bundle* bundle = node_bundling(n);
if (bundle->used_in_unconditional_delay()) {
delay = n;
continue;
}
if (bundle->starts_bundle()) {
starts_bundle = '+';
}
}
if (WizardMode) {
n->dump();
}
if( !n->is_Region() && // Dont print in the Assembly
!n->is_Phi() && // a few noisely useless nodes
!n->is_Proj() &&
!n->is_MachTemp() &&
!n->is_SafePointScalarObject() &&
!n->is_Catch() && // Would be nice to print exception table targets
!n->is_MergeMem() && // Not very interesting
!n->is_top() && // Debug info table constants
!(n->is_Con() && !n->is_Mach())// Debug info table constants
) {
if (pcs && n->_idx < pc_limit)
tty->print("%3.3x", pcs[n->_idx]);
else
tty->print(" ");
tty->print(" %c ", starts_bundle);
starts_bundle = ' ';
tty->print("\t");
n->format(_regalloc, tty);
tty->cr();
}
// If we have an instruction with a delay slot, and have seen a delay,
// then back up and print it
if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
assert(delay != NULL, "no unconditional delay instruction");
if (WizardMode) delay->dump();
if (node_bundling(delay)->starts_bundle())
starts_bundle = '+';
if (pcs && n->_idx < pc_limit)
tty->print("%3.3x", pcs[n->_idx]);
else
tty->print(" ");
tty->print(" %c ", starts_bundle);
starts_bundle = ' ';
tty->print("\t");
delay->format(_regalloc, tty);
tty->cr();
delay = NULL;
}
// Dump the exception table as well
if( n->is_Catch() && (Verbose || WizardMode) ) {
// Print the exception table for this offset
_handler_table.print_subtable_for(pc);
}
}
if (pcs && n->_idx < pc_limit)
tty->print_cr("%3.3x", pcs[n->_idx]);
else
tty->cr();
assert(cut_short || delay == NULL, "no unconditional delay branch");
} // End of per-block dump
tty->cr();
if (cut_short) tty->print_cr("*** disassembly is cut short ***");
}
#endif
//------------------------------Final_Reshape_Counts---------------------------
// This class defines counters to help identify when a method
// may/must be executed using hardware with only 24-bit precision.
struct Final_Reshape_Counts : public StackObj {
int _call_count; // count non-inlined 'common' calls
int _float_count; // count float ops requiring 24-bit precision
int _double_count; // count double ops requiring more precision
int _java_call_count; // count non-inlined 'java' calls
int _inner_loop_count; // count loops which need alignment
VectorSet _visited; // Visitation flags
Node_List _tests; // Set of IfNodes & PCTableNodes
Final_Reshape_Counts() :
_call_count(0), _float_count(0), _double_count(0),
_java_call_count(0), _inner_loop_count(0),
_visited( Thread::current()->resource_area() ) { }
void inc_call_count () { _call_count ++; }
void inc_float_count () { _float_count ++; }
void inc_double_count() { _double_count++; }
void inc_java_call_count() { _java_call_count++; }
void inc_inner_loop_count() { _inner_loop_count++; }
int get_call_count () const { return _call_count ; }
int get_float_count () const { return _float_count ; }
int get_double_count() const { return _double_count; }
int get_java_call_count() const { return _java_call_count; }
int get_inner_loop_count() const { return _inner_loop_count; }
};
#ifdef ASSERT
static bool oop_offset_is_sane(const TypeInstPtr* tp) {
ciInstanceKlass *k = tp->klass()->as_instance_klass();
// Make sure the offset goes inside the instance layout.
return k->contains_field_offset(tp->offset());
// Note that OffsetBot and OffsetTop are very negative.
}
#endif
// Eliminate trivially redundant StoreCMs and accumulate their
// precedence edges.
void Compile::eliminate_redundant_card_marks(Node* n) {
assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
if (n->in(MemNode::Address)->outcnt() > 1) {
// There are multiple users of the same address so it might be
// possible to eliminate some of the StoreCMs
Node* mem = n->in(MemNode::Memory);
Node* adr = n->in(MemNode::Address);
Node* val = n->in(MemNode::ValueIn);
Node* prev = n;
bool done = false;
// Walk the chain of StoreCMs eliminating ones that match. As
// long as it's a chain of single users then the optimization is
// safe. Eliminating partially redundant StoreCMs would require
// cloning copies down the other paths.
while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
if (adr == mem->in(MemNode::Address) &&
val == mem->in(MemNode::ValueIn)) {
// redundant StoreCM
if (mem->req() > MemNode::OopStore) {
// Hasn't been processed by this code yet.
n->add_prec(mem->in(MemNode::OopStore));
} else {
// Already converted to precedence edge
for (uint i = mem->req(); i < mem->len(); i++) {
// Accumulate any precedence edges
if (mem->in(i) != NULL) {
n->add_prec(mem->in(i));
}
}
// Everything above this point has been processed.
done = true;
}
// Eliminate the previous StoreCM
prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
assert(mem->outcnt() == 0, "should be dead");
mem->disconnect_inputs(NULL, this);
} else {
prev = mem;
}
mem = prev->in(MemNode::Memory);
}
}
}
//------------------------------final_graph_reshaping_impl----------------------
// Implement items 1-5 from final_graph_reshaping below.
void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
if ( n->outcnt() == 0 ) return; // dead node
uint nop = n->Opcode();
// Check for 2-input instruction with "last use" on right input.
// Swap to left input. Implements item (2).
if( n->req() == 3 && // two-input instruction
n->in(1)->outcnt() > 1 && // left use is NOT a last use
(!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
n->in(2)->outcnt() == 1 &&// right use IS a last use
!n->in(2)->is_Con() ) { // right use is not a constant
// Check for commutative opcode
switch( nop ) {
case Op_AddI: case Op_AddF: case Op_AddD: case Op_AddL:
case Op_MaxI: case Op_MinI:
case Op_MulI: case Op_MulF: case Op_MulD: case Op_MulL:
case Op_AndL: case Op_XorL: case Op_OrL:
case Op_AndI: case Op_XorI: case Op_OrI: {
// Move "last use" input to left by swapping inputs
n->swap_edges(1, 2);
break;
}
default:
break;
}
}
#ifdef ASSERT
if( n->is_Mem() ) {
int alias_idx = get_alias_index(n->as_Mem()->adr_type());
assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
// oop will be recorded in oop map if load crosses safepoint
n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
LoadNode::is_immutable_value(n->in(MemNode::Address))),
"raw memory operations should have control edge");
}
#endif
// Count FPU ops and common calls, implements item (3)
switch( nop ) {
// Count all float operations that may use FPU
case Op_AddF:
case Op_SubF:
case Op_MulF:
case Op_DivF:
case Op_NegF:
case Op_ModF:
case Op_ConvI2F:
case Op_ConF:
case Op_CmpF:
case Op_CmpF3:
// case Op_ConvL2F: // longs are split into 32-bit halves
frc.inc_float_count();
break;
case Op_ConvF2D:
case Op_ConvD2F:
frc.inc_float_count();
frc.inc_double_count();
break;
// Count all double operations that may use FPU
case Op_AddD:
case Op_SubD:
case Op_MulD:
case Op_DivD:
case Op_NegD:
case Op_ModD:
case Op_ConvI2D:
case Op_ConvD2I:
// case Op_ConvL2D: // handled by leaf call
// case Op_ConvD2L: // handled by leaf call
case Op_ConD:
case Op_CmpD:
case Op_CmpD3:
frc.inc_double_count();
break;
case Op_Opaque1: // Remove Opaque Nodes before matching
case Op_Opaque2: // Remove Opaque Nodes before matching
case Op_Opaque3:
n->subsume_by(n->in(1), this);
break;
case Op_CallStaticJava:
case Op_CallJava:
case Op_CallDynamicJava:
frc.inc_java_call_count(); // Count java call site;
case Op_CallRuntime:
case Op_CallLeaf:
case Op_CallLeafNoFP: {
assert( n->is_Call(), "" );
CallNode *call = n->as_Call();
// Count call sites where the FP mode bit would have to be flipped.
// Do not count uncommon runtime calls:
// uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
// _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
frc.inc_call_count(); // Count the call site
} else { // See if uncommon argument is shared
Node *n = call->in(TypeFunc::Parms);
int nop = n->Opcode();
// Clone shared simple arguments to uncommon calls, item (1).
if( n->outcnt() > 1 &&
!n->is_Proj() &&
nop != Op_CreateEx &&
nop != Op_CheckCastPP &&
nop != Op_DecodeN &&
nop != Op_DecodeNKlass &&
!n->is_Mem() ) {
Node *x = n->clone();
call->set_req( TypeFunc::Parms, x );
}
}
break;
}
case Op_StoreD:
case Op_LoadD:
case Op_LoadD_unaligned:
frc.inc_double_count();
goto handle_mem;
case Op_StoreF:
case Op_LoadF:
frc.inc_float_count();
goto handle_mem;
case Op_StoreCM:
{
// Convert OopStore dependence into precedence edge
Node* prec = n->in(MemNode::OopStore);
n->del_req(MemNode::OopStore);
n->add_prec(prec);
eliminate_redundant_card_marks(n);
}
// fall through
case Op_StoreB:
case Op_StoreC:
case Op_StorePConditional:
case Op_StoreI:
case Op_StoreL:
case Op_StoreIConditional:
case Op_StoreLConditional:
case Op_CompareAndSwapI:
case Op_CompareAndSwapL:
case Op_CompareAndSwapP:
case Op_CompareAndSwapN:
case Op_GetAndAddI:
case Op_GetAndAddL:
case Op_GetAndSetI:
case Op_GetAndSetL:
case Op_GetAndSetP:
case Op_GetAndSetN:
case Op_StoreP:
case Op_StoreN:
case Op_StoreNKlass:
case Op_LoadB:
case Op_LoadUB:
case Op_LoadUS:
case Op_LoadI:
case Op_LoadKlass:
case Op_LoadNKlass:
case Op_LoadL:
case Op_LoadL_unaligned:
case Op_LoadPLocked:
case Op_LoadP:
case Op_LoadN:
case Op_LoadRange:
case Op_LoadS: {
handle_mem:
#ifdef ASSERT
if( VerifyOptoOopOffsets ) {
assert( n->is_Mem(), "" );
MemNode *mem = (MemNode*)n;
// Check to see if address types have grounded out somehow.
const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
assert( !tp || oop_offset_is_sane(tp), "" );
}
#endif
break;
}
case Op_AddP: { // Assert sane base pointers
Node *addp = n->in(AddPNode::Address);
assert( !addp->is_AddP() ||
addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
addp->in(AddPNode::Base) == n->in(AddPNode::Base),
"Base pointers must match" );
#ifdef _LP64
if ((UseCompressedOops || UseCompressedClassPointers) &&
addp->Opcode() == Op_ConP &&
addp == n->in(AddPNode::Base) &&
n->in(AddPNode::Offset)->is_Con()) {
// Use addressing with narrow klass to load with offset on x86.
// On sparc loading 32-bits constant and decoding it have less
// instructions (4) then load 64-bits constant (7).
// Do this transformation here since IGVN will convert ConN back to ConP.
const Type* t = addp->bottom_type();
if (t->isa_oopptr() || t->isa_klassptr()) {
Node* nn = NULL;
int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
// Look for existing ConN node of the same exact type.
Node* r = root();
uint cnt = r->outcnt();
for (uint i = 0; i < cnt; i++) {
Node* m = r->raw_out(i);
if (m!= NULL && m->Opcode() == op &&
m->bottom_type()->make_ptr() == t) {
nn = m;
break;
}
}
if (nn != NULL) {
// Decode a narrow oop to match address
// [R12 + narrow_oop_reg<<3 + offset]
if (t->isa_oopptr()) {
nn = new DecodeNNode(nn, t);
} else {
nn = new DecodeNKlassNode(nn, t);
}
n->set_req(AddPNode::Base, nn);
n->set_req(AddPNode::Address, nn);
if (addp->outcnt() == 0) {
addp->disconnect_inputs(NULL, this);
}
}
}
}
#endif
break;
}
#ifdef _LP64
case Op_CastPP:
if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
Node* in1 = n->in(1);
const Type* t = n->bottom_type();
Node* new_in1 = in1->clone();
new_in1->as_DecodeN()->set_type(t);
if (!Matcher::narrow_oop_use_complex_address()) {
//
// x86, ARM and friends can handle 2 adds in addressing mode
// and Matcher can fold a DecodeN node into address by using
// a narrow oop directly and do implicit NULL check in address:
//
// [R12 + narrow_oop_reg<<3 + offset]
// NullCheck narrow_oop_reg
//
// On other platforms (Sparc) we have to keep new DecodeN node and
// use it to do implicit NULL check in address:
//
// decode_not_null narrow_oop_reg, base_reg
// [base_reg + offset]
// NullCheck base_reg
//
// Pin the new DecodeN node to non-null path on these platform (Sparc)
// to keep the information to which NULL check the new DecodeN node
// corresponds to use it as value in implicit_null_check().
//
new_in1->set_req(0, n->in(0));
}
n->subsume_by(new_in1, this);
if (in1->outcnt() == 0) {
in1->disconnect_inputs(NULL, this);
}
}
break;
case Op_CmpP:
// Do this transformation here to preserve CmpPNode::sub() and
// other TypePtr related Ideal optimizations (for example, ptr nullness).
if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
Node* in1 = n->in(1);
Node* in2 = n->in(2);
if (!in1->is_DecodeNarrowPtr()) {
in2 = in1;
in1 = n->in(2);
}
assert(in1->is_DecodeNarrowPtr(), "sanity");
Node* new_in2 = NULL;
if (in2->is_DecodeNarrowPtr()) {
assert(in2->Opcode() == in1->Opcode(), "must be same node type");
new_in2 = in2->in(1);
} else if (in2->Opcode() == Op_ConP) {
const Type* t = in2->bottom_type();
if (t == TypePtr::NULL_PTR) {
assert(in1->is_DecodeN(), "compare klass to null?");
// Don't convert CmpP null check into CmpN if compressed
// oops implicit null check is not generated.
// This will allow to generate normal oop implicit null check.
if (Matcher::gen_narrow_oop_implicit_null_checks())
new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
//
// This transformation together with CastPP transformation above
// will generated code for implicit NULL checks for compressed oops.
//
// The original code after Optimize()
//
// LoadN memory, narrow_oop_reg
// decode narrow_oop_reg, base_reg
// CmpP base_reg, NULL
// CastPP base_reg // NotNull
// Load [base_reg + offset], val_reg
//
// after these transformations will be
//
// LoadN memory, narrow_oop_reg
// CmpN narrow_oop_reg, NULL
// decode_not_null narrow_oop_reg, base_reg
// Load [base_reg + offset], val_reg
//
// and the uncommon path (== NULL) will use narrow_oop_reg directly
// since narrow oops can be used in debug info now (see the code in
// final_graph_reshaping_walk()).
//
// At the end the code will be matched to
// on x86:
//
// Load_narrow_oop memory, narrow_oop_reg
// Load [R12 + narrow_oop_reg<<3 + offset], val_reg
// NullCheck narrow_oop_reg
//
// and on sparc:
//
// Load_narrow_oop memory, narrow_oop_reg
// decode_not_null narrow_oop_reg, base_reg
// Load [base_reg + offset], val_reg
// NullCheck base_reg
//
} else if (t->isa_oopptr()) {
new_in2 = ConNode::make(t->make_narrowoop());
} else if (t->isa_klassptr()) {
new_in2 = ConNode::make(t->make_narrowklass());
}
}
if (new_in2 != NULL) {
Node* cmpN = new CmpNNode(in1->in(1), new_in2);
n->subsume_by(cmpN, this);
if (in1->outcnt() == 0) {
in1->disconnect_inputs(NULL, this);
}
if (in2->outcnt() == 0) {
in2->disconnect_inputs(NULL, this);
}
}
}
break;
case Op_DecodeN:
case Op_DecodeNKlass:
assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
// DecodeN could be pinned when it can't be fold into
// an address expression, see the code for Op_CastPP above.
assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
break;
case Op_EncodeP:
case Op_EncodePKlass: {
Node* in1 = n->in(1);
if (in1->is_DecodeNarrowPtr()) {
n->subsume_by(in1->in(1), this);
} else if (in1->Opcode() == Op_ConP) {
const Type* t = in1->bottom_type();
if (t == TypePtr::NULL_PTR) {
assert(t->isa_oopptr(), "null klass?");
n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
} else if (t->isa_oopptr()) {
n->subsume_by(ConNode::make(t->make_narrowoop()), this);
} else if (t->isa_klassptr()) {
n->subsume_by(ConNode::make(t->make_narrowklass()), this);
}
}
if (in1->outcnt() == 0) {
in1->disconnect_inputs(NULL, this);
}
break;
}
case Op_Proj: {
if (OptimizeStringConcat) {
ProjNode* p = n->as_Proj();
if (p->_is_io_use) {
// Separate projections were used for the exception path which
// are normally removed by a late inline. If it wasn't inlined
// then they will hang around and should just be replaced with
// the original one.
Node* proj = NULL;
// Replace with just one
for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
Node *use = i.get();
if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
proj = use;
break;
}
}
assert(proj != NULL, "must be found");
p->subsume_by(proj, this);
}
}
break;
}
case Op_Phi:
if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
// The EncodeP optimization may create Phi with the same edges
// for all paths. It is not handled well by Register Allocator.
Node* unique_in = n->in(1);
assert(unique_in != NULL, "");
uint cnt = n->req();
for (uint i = 2; i < cnt; i++) {
Node* m = n->in(i);
assert(m != NULL, "");
if (unique_in != m)
unique_in = NULL;
}
if (unique_in != NULL) {
n->subsume_by(unique_in, this);
}
}
break;
#endif
case Op_ModI:
if (UseDivMod) {
// Check if a%b and a/b both exist
Node* d = n->find_similar(Op_DivI);
if (d) {
// Replace them with a fused divmod if supported
if (Matcher::has_match_rule(Op_DivModI)) {
DivModINode* divmod = DivModINode::make(n);
d->subsume_by(divmod->div_proj(), this);
n->subsume_by(divmod->mod_proj(), this);
} else {
// replace a%b with a-((a/b)*b)
Node* mult = new MulINode(d, d->in(2));
Node* sub = new SubINode(d->in(1), mult);
n->subsume_by(sub, this);
}
}
}
break;
case Op_ModL:
if (UseDivMod) {
// Check if a%b and a/b both exist
Node* d = n->find_similar(Op_DivL);
if (d) {
// Replace them with a fused divmod if supported
if (Matcher::has_match_rule(Op_DivModL)) {
DivModLNode* divmod = DivModLNode::make(n);
d->subsume_by(divmod->div_proj(), this);
n->subsume_by(divmod->mod_proj(), this);
} else {
// replace a%b with a-((a/b)*b)
Node* mult = new MulLNode(d, d->in(2));
Node* sub = new SubLNode(d->in(1), mult);
n->subsume_by(sub, this);
}
}
}
break;
case Op_LoadVector:
case Op_StoreVector:
break;
case Op_PackB:
case Op_PackS:
case Op_PackI:
case Op_PackF:
case Op_PackL:
case Op_PackD:
if (n->req()-1 > 2) {
// Replace many operand PackNodes with a binary tree for matching
PackNode* p = (PackNode*) n;
Node* btp = p->binary_tree_pack(1, n->req());
n->subsume_by(btp, this);
}
break;
case Op_Loop:
case Op_CountedLoop:
if (n->as_Loop()->is_inner_loop()) {
frc.inc_inner_loop_count();
}
break;
case Op_LShiftI:
case Op_RShiftI:
case Op_URShiftI:
case Op_LShiftL:
case Op_RShiftL:
case Op_URShiftL:
if (Matcher::need_masked_shift_count) {
// The cpu's shift instructions don't restrict the count to the
// lower 5/6 bits. We need to do the masking ourselves.
Node* in2 = n->in(2);
juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
const TypeInt* t = in2->find_int_type();
if (t != NULL && t->is_con()) {
juint shift = t->get_con();
if (shift > mask) { // Unsigned cmp
n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
}
} else {
if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
n->set_req(2, shift);
}
}
if (in2->outcnt() == 0) { // Remove dead node
in2->disconnect_inputs(NULL, this);
}
}
break;
case Op_MemBarStoreStore:
case Op_MemBarRelease:
// Break the link with AllocateNode: it is no longer useful and
// confuses register allocation.
if (n->req() > MemBarNode::Precedent) {
n->set_req(MemBarNode::Precedent, top());
}
break;
default:
assert( !n->is_Call(), "" );
assert( !n->is_Mem(), "" );
break;
}
// Collect CFG split points
if (n->is_MultiBranch())
frc._tests.push(n);
}
//------------------------------final_graph_reshaping_walk---------------------
// Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
// requires that the walk visits a node's inputs before visiting the node.
void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
ResourceArea *area = Thread::current()->resource_area();
Unique_Node_List sfpt(area);
frc._visited.set(root->_idx); // first, mark node as visited
uint cnt = root->req();
Node *n = root;
uint i = 0;
while (true) {
if (i < cnt) {
// Place all non-visited non-null inputs onto stack
Node* m = n->in(i);
++i;
if (m != NULL && !frc._visited.test_set(m->_idx)) {
if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
// compute worst case interpreter size in case of a deoptimization
update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
sfpt.push(m);
}
cnt = m->req();
nstack.push(n, i); // put on stack parent and next input's index
n = m;
i = 0;
}
} else {
// Now do post-visit work
final_graph_reshaping_impl( n, frc );
if (nstack.is_empty())
break; // finished
n = nstack.node(); // Get node from stack
cnt = n->req();
i = nstack.index();
nstack.pop(); // Shift to the next node on stack
}
}
// Skip next transformation if compressed oops are not used.
if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
(!UseCompressedOops && !UseCompressedClassPointers))
return;
// Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
// It could be done for an uncommon traps or any safepoints/calls
// if the DecodeN/DecodeNKlass node is referenced only in a debug info.
while (sfpt.size() > 0) {
n = sfpt.pop();
JVMState *jvms = n->as_SafePoint()->jvms();
assert(jvms != NULL, "sanity");
int start = jvms->debug_start();
int end = n->req();
bool is_uncommon = (n->is_CallStaticJava() &&
n->as_CallStaticJava()->uncommon_trap_request() != 0);
for (int j = start; j < end; j++) {
Node* in = n->in(j);
if (in->is_DecodeNarrowPtr()) {
bool safe_to_skip = true;
if (!is_uncommon ) {
// Is it safe to skip?
for (uint i = 0; i < in->outcnt(); i++) {
Node* u = in->raw_out(i);
if (!u->is_SafePoint() ||
u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
safe_to_skip = false;
}
}
}
if (safe_to_skip) {
n->set_req(j, in->in(1));
}
if (in->outcnt() == 0) {
in->disconnect_inputs(NULL, this);
}
}
}
}
}
//------------------------------final_graph_reshaping--------------------------
// Final Graph Reshaping.
//
// (1) Clone simple inputs to uncommon calls, so they can be scheduled late
// and not commoned up and forced early. Must come after regular
// optimizations to avoid GVN undoing the cloning. Clone constant
// inputs to Loop Phis; these will be split by the allocator anyways.
// Remove Opaque nodes.
// (2) Move last-uses by commutative operations to the left input to encourage
// Intel update-in-place two-address operations and better register usage
// on RISCs. Must come after regular optimizations to avoid GVN Ideal
// calls canonicalizing them back.
// (3) Count the number of double-precision FP ops, single-precision FP ops
// and call sites. On Intel, we can get correct rounding either by
// forcing singles to memory (requires extra stores and loads after each
// FP bytecode) or we can set a rounding mode bit (requires setting and
// clearing the mode bit around call sites). The mode bit is only used
// if the relative frequency of single FP ops to calls is low enough.
// This is a key transform for SPEC mpeg_audio.
// (4) Detect infinite loops; blobs of code reachable from above but not
// below. Several of the Code_Gen algorithms fail on such code shapes,
// so we simply bail out. Happens a lot in ZKM.jar, but also happens
// from time to time in other codes (such as -Xcomp finalizer loops, etc).
// Detection is by looking for IfNodes where only 1 projection is
// reachable from below or CatchNodes missing some targets.
// (5) Assert for insane oop offsets in debug mode.
bool Compile::final_graph_reshaping() {
// an infinite loop may have been eliminated by the optimizer,
// in which case the graph will be empty.
if (root()->req() == 1) {
record_method_not_compilable("trivial infinite loop");
return true;
}
// Expensive nodes have their control input set to prevent the GVN
// from freely commoning them. There's no GVN beyond this point so
// no need to keep the control input. We want the expensive nodes to
// be freely moved to the least frequent code path by gcm.
assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
for (int i = 0; i < expensive_count(); i++) {
_expensive_nodes->at(i)->set_req(0, NULL);
}
Final_Reshape_Counts frc;
// Visit everybody reachable!
// Allocate stack of size C->unique()/2 to avoid frequent realloc
Node_Stack nstack(unique() >> 1);
final_graph_reshaping_walk(nstack, root(), frc);
// Check for unreachable (from below) code (i.e., infinite loops).
for( uint i = 0; i < frc._tests.size(); i++ ) {
MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
// Get number of CFG targets.
// Note that PCTables include exception targets after calls.
uint required_outcnt = n->required_outcnt();
if (n->outcnt() != required_outcnt) {
// Check for a few special cases. Rethrow Nodes never take the
// 'fall-thru' path, so expected kids is 1 less.
if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
if (n->in(0)->in(0)->is_Call()) {
CallNode *call = n->in(0)->in(0)->as_Call();
if (call->entry_point() == OptoRuntime::rethrow_stub()) {
required_outcnt--; // Rethrow always has 1 less kid
} else if (call->req() > TypeFunc::Parms &&
call->is_CallDynamicJava()) {
// Check for null receiver. In such case, the optimizer has
// detected that the virtual call will always result in a null
// pointer exception. The fall-through projection of this CatchNode
// will not be populated.
Node *arg0 = call->in(TypeFunc::Parms);
if (arg0->is_Type() &&
arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
required_outcnt--;
}
} else if (call->entry_point() == OptoRuntime::new_array_Java() &&
call->req() > TypeFunc::Parms+1 &&
call->is_CallStaticJava()) {
// Check for negative array length. In such case, the optimizer has
// detected that the allocation attempt will always result in an
// exception. There is no fall-through projection of this CatchNode .
Node *arg1 = call->in(TypeFunc::Parms+1);
if (arg1->is_Type() &&
arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
required_outcnt--;
}
}
}
}
// Recheck with a better notion of 'required_outcnt'
if (n->outcnt() != required_outcnt) {
record_method_not_compilable("malformed control flow");
return true; // Not all targets reachable!
}
}
// Check that I actually visited all kids. Unreached kids
// must be infinite loops.
for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
if (!frc._visited.test(n->fast_out(j)->_idx)) {
record_method_not_compilable("infinite loop");
return true; // Found unvisited kid; must be unreach
}
}
// If original bytecodes contained a mixture of floats and doubles
// check if the optimizer has made it homogenous, item (3).
if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
frc.get_float_count() > 32 &&
frc.get_double_count() == 0 &&
(10 * frc.get_call_count() < frc.get_float_count()) ) {
set_24_bit_selection_and_mode( false, true );
}
set_java_calls(frc.get_java_call_count());
set_inner_loops(frc.get_inner_loop_count());
// No infinite loops, no reason to bail out.
return false;
}
//-----------------------------too_many_traps----------------------------------
// Report if there are too many traps at the current method and bci.
// Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
bool Compile::too_many_traps(ciMethod* method,
int bci,
Deoptimization::DeoptReason reason) {
ciMethodData* md = method->method_data();
if (md->is_empty()) {
// Assume the trap has not occurred, or that it occurred only
// because of a transient condition during start-up in the interpreter.
return false;
}
ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
if (md->has_trap_at(bci, m, reason) != 0) {
// Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
// Also, if there are multiple reasons, or if there is no per-BCI record,
// assume the worst.
if (log())
log()->elem("observe trap='%s' count='%d'",
Deoptimization::trap_reason_name(reason),
md->trap_count(reason));
return true;
} else {
// Ignore method/bci and see if there have been too many globally.
return too_many_traps(reason, md);
}
}
// Less-accurate variant which does not require a method and bci.
bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
ciMethodData* logmd) {
if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
// Too many traps globally.
// Note that we use cumulative trap_count, not just md->trap_count.
if (log()) {
int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
Deoptimization::trap_reason_name(reason),
mcount, trap_count(reason));
}
return true;
} else {
// The coast is clear.
return false;
}
}
//--------------------------too_many_recompiles--------------------------------
// Report if there are too many recompiles at the current method and bci.
// Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
// Is not eager to return true, since this will cause the compiler to use
// Action_none for a trap point, to avoid too many recompilations.
bool Compile::too_many_recompiles(ciMethod* method,
int bci,
Deoptimization::DeoptReason reason) {
ciMethodData* md = method->method_data();
if (md->is_empty()) {
// Assume the trap has not occurred, or that it occurred only
// because of a transient condition during start-up in the interpreter.
return false;
}
// Pick a cutoff point well within PerBytecodeRecompilationCutoff.
uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
uint m_cutoff = (uint) PerMethodRecompilationCutoff / 2 + 1; // not zero
Deoptimization::DeoptReason per_bc_reason
= Deoptimization::reason_recorded_per_bytecode_if_any(reason);
ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
if ((per_bc_reason == Deoptimization::Reason_none
|| md->has_trap_at(bci, m, reason) != 0)
// The trap frequency measure we care about is the recompile count:
&& md->trap_recompiled_at(bci, m)
&& md->overflow_recompile_count() >= bc_cutoff) {
// Do not emit a trap here if it has already caused recompilations.
// Also, if there are multiple reasons, or if there is no per-BCI record,
// assume the worst.
if (log())
log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
Deoptimization::trap_reason_name(reason),
md->trap_count(reason),
md->overflow_recompile_count());
return true;
} else if (trap_count(reason) != 0
&& decompile_count() >= m_cutoff) {
// Too many recompiles globally, and we have seen this sort of trap.
// Use cumulative decompile_count, not just md->decompile_count.
if (log())
log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
Deoptimization::trap_reason_name(reason),
md->trap_count(reason), trap_count(reason),
md->decompile_count(), decompile_count());
return true;
} else {
// The coast is clear.
return false;
}
}
// Compute when not to trap. Used by matching trap based nodes and
// NullCheck optimization.
void Compile::set_allowed_deopt_reasons() {
_allowed_reasons = 0;
if (is_method_compilation()) {
for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
assert(rs < BitsPerInt, "recode bit map");
if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
_allowed_reasons |= nth_bit(rs);
}
}
}
}
#ifndef PRODUCT
//------------------------------verify_graph_edges---------------------------
// Walk the Graph and verify that there is a one-to-one correspondence
// between Use-Def edges and Def-Use edges in the graph.
void Compile::verify_graph_edges(bool no_dead_code) {
if (VerifyGraphEdges) {
ResourceArea *area = Thread::current()->resource_area();
Unique_Node_List visited(area);
// Call recursive graph walk to check edges
_root->verify_edges(visited);
if (no_dead_code) {
// Now make sure that no visited node is used by an unvisited node.
bool dead_nodes = false;
Unique_Node_List checked(area);
while (visited.size() > 0) {
Node* n = visited.pop();
checked.push(n);
for (uint i = 0; i < n->outcnt(); i++) {
Node* use = n->raw_out(i);
if (checked.member(use)) continue; // already checked
if (visited.member(use)) continue; // already in the graph
if (use->is_Con()) continue; // a dead ConNode is OK
// At this point, we have found a dead node which is DU-reachable.
if (!dead_nodes) {
tty->print_cr("*** Dead nodes reachable via DU edges:");
dead_nodes = true;
}
use->dump(2);
tty->print_cr("---");
checked.push(use); // No repeats; pretend it is now checked.
}
}
assert(!dead_nodes, "using nodes must be reachable from root");
}
}
}
// Verify GC barriers consistency
// Currently supported:
// - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
void Compile::verify_barriers() {
if (UseG1GC) {
// Verify G1 pre-barriers
const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
ResourceArea *area = Thread::current()->resource_area();
Unique_Node_List visited(area);
Node_List worklist(area);
// We're going to walk control flow backwards starting from the Root
worklist.push(_root);
while (worklist.size() > 0) {
Node* x = worklist.pop();
if (x == NULL || x == top()) continue;
if (visited.member(x)) {
continue;
} else {
visited.push(x);
}
if (x->is_Region()) {
for (uint i = 1; i < x->req(); i++) {
worklist.push(x->in(i));
}
} else {
worklist.push(x->in(0));
// We are looking for the pattern:
// /->ThreadLocal
// If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
// \->ConI(0)
// We want to verify that the If and the LoadB have the same control
// See GraphKit::g1_write_barrier_pre()
if (x->is_If()) {
IfNode *iff = x->as_If();
if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
&& cmp->in(1)->is_Load()) {
LoadNode* load = cmp->in(1)->as_Load();
if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
&& load->in(2)->in(3)->is_Con()
&& load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
Node* if_ctrl = iff->in(0);
Node* load_ctrl = load->in(0);
if (if_ctrl != load_ctrl) {
// Skip possible CProj->NeverBranch in infinite loops
if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
&& (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
if_ctrl = if_ctrl->in(0)->in(0);
}
}
assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
}
}
}
}
}
}
}
}
#endif
// The Compile object keeps track of failure reasons separately from the ciEnv.
// This is required because there is not quite a 1-1 relation between the
// ciEnv and its compilation task and the Compile object. Note that one
// ciEnv might use two Compile objects, if C2Compiler::compile_method decides
// to backtrack and retry without subsuming loads. Other than this backtracking
// behavior, the Compile's failure reason is quietly copied up to the ciEnv
// by the logic in C2Compiler.
void Compile::record_failure(const char* reason) {
if (log() != NULL) {
log()->elem("failure reason='%s' phase='compile'", reason);
}
if (_failure_reason == NULL) {
// Record the first failure reason.
_failure_reason = reason;
}
if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
C->print_method(PHASE_FAILURE);
}
_root = NULL; // flush the graph, too
}
Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
: TraceTime(name, accumulator, CITime, CITimeVerbose),
_phase_name(name), _dolog(CITimeVerbose)
{
if (_dolog) {
C = Compile::current();
_log = C->log();
} else {
C = NULL;
_log = NULL;
}
if (_log != NULL) {
_log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
_log->stamp();
_log->end_head();
}
}
Compile::TracePhase::~TracePhase() {
C = Compile::current();
if (_dolog) {
_log = C->log();
} else {
_log = NULL;
}
#ifdef ASSERT
if (PrintIdealNodeCount) {
tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
_phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
}
if (VerifyIdealNodeCount) {
Compile::current()->print_missing_nodes();
}
#endif
if (_log != NULL) {
_log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
}
}
//=============================================================================
// Two Constant's are equal when the type and the value are equal.
bool Compile::Constant::operator==(const Constant& other) {
if (type() != other.type() ) return false;
if (can_be_reused() != other.can_be_reused()) return false;
// For floating point values we compare the bit pattern.
switch (type()) {
case T_FLOAT: return (_v._value.i == other._v._value.i);
case T_LONG:
case T_DOUBLE: return (_v._value.j == other._v._value.j);
case T_OBJECT:
case T_ADDRESS: return (_v._value.l == other._v._value.l);
case T_VOID: return (_v._value.l == other._v._value.l); // jump-table entries
case T_METADATA: return (_v._metadata == other._v._metadata);
default: ShouldNotReachHere();
}
return false;
}
static int type_to_size_in_bytes(BasicType t) {
switch (t) {
case T_LONG: return sizeof(jlong );
case T_FLOAT: return sizeof(jfloat );
case T_DOUBLE: return sizeof(jdouble);
case T_METADATA: return sizeof(Metadata*);
// We use T_VOID as marker for jump-table entries (labels) which
// need an internal word relocation.
case T_VOID:
case T_ADDRESS:
case T_OBJECT: return sizeof(jobject);
}
ShouldNotReachHere();
return -1;
}
int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
// sort descending
if (a->freq() > b->freq()) return -1;
if (a->freq() < b->freq()) return 1;
return 0;
}
void Compile::ConstantTable::calculate_offsets_and_size() {
// First, sort the array by frequencies.
_constants.sort(qsort_comparator);
#ifdef ASSERT
// Make sure all jump-table entries were sorted to the end of the
// array (they have a negative frequency).
bool found_void = false;
for (int i = 0; i < _constants.length(); i++) {
Constant con = _constants.at(i);
if (con.type() == T_VOID)
found_void = true; // jump-tables
else
assert(!found_void, "wrong sorting");
}
#endif
int offset = 0;
for (int i = 0; i < _constants.length(); i++) {
Constant* con = _constants.adr_at(i);
// Align offset for type.
int typesize = type_to_size_in_bytes(con->type());
offset = align_size_up(offset, typesize);
con->set_offset(offset); // set constant's offset
if (con->type() == T_VOID) {
MachConstantNode* n = (MachConstantNode*) con->get_jobject();
offset = offset + typesize * n->outcnt(); // expand jump-table
} else {
offset = offset + typesize;
}
}
// Align size up to the next section start (which is insts; see
// CodeBuffer::align_at_start).
assert(_size == -1, "already set?");
_size = align_size_up(offset, CodeEntryAlignment);
}
void Compile::ConstantTable::emit(CodeBuffer& cb) {
MacroAssembler _masm(&cb);
for (int i = 0; i < _constants.length(); i++) {
Constant con = _constants.at(i);
address constant_addr;
switch (con.type()) {
case T_LONG: constant_addr = _masm.long_constant( con.get_jlong() ); break;
case T_FLOAT: constant_addr = _masm.float_constant( con.get_jfloat() ); break;
case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
case T_OBJECT: {
jobject obj = con.get_jobject();
int oop_index = _masm.oop_recorder()->find_index(obj);
constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
break;
}
case T_ADDRESS: {
address addr = (address) con.get_jobject();
constant_addr = _masm.address_constant(addr);
break;
}
// We use T_VOID as marker for jump-table entries (labels) which
// need an internal word relocation.
case T_VOID: {
MachConstantNode* n = (MachConstantNode*) con.get_jobject();
// Fill the jump-table with a dummy word. The real value is
// filled in later in fill_jump_table.
address dummy = (address) n;
constant_addr = _masm.address_constant(dummy);
// Expand jump-table
for (uint i = 1; i < n->outcnt(); i++) {
address temp_addr = _masm.address_constant(dummy + i);
assert(temp_addr, "consts section too small");
}
break;
}
case T_METADATA: {
Metadata* obj = con.get_metadata();
int metadata_index = _masm.oop_recorder()->find_index(obj);
constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
break;
}
default: ShouldNotReachHere();
}
assert(constant_addr, "consts section too small");
assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
}
}
int Compile::ConstantTable::find_offset(Constant& con) const {
int idx = _constants.find(con);
assert(idx != -1, "constant must be in constant table");
int offset = _constants.at(idx).offset();
assert(offset != -1, "constant table not emitted yet?");
return offset;
}
void Compile::ConstantTable::add(Constant& con) {
if (con.can_be_reused()) {
int idx = _constants.find(con);
if (idx != -1 && _constants.at(idx).can_be_reused()) {
_constants.adr_at(idx)->inc_freq(con.freq()); // increase the frequency by the current value
return;
}
}
(void) _constants.append(con);
}
Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
Block* b = Compile::current()->cfg()->get_block_for_node(n);
Constant con(type, value, b->_freq);
add(con);
return con;
}
Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
Constant con(metadata);
add(con);
return con;
}
Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
jvalue value;
BasicType type = oper->type()->basic_type();
switch (type) {
case T_LONG: value.j = oper->constantL(); break;
case T_FLOAT: value.f = oper->constantF(); break;
case T_DOUBLE: value.d = oper->constantD(); break;
case T_OBJECT:
case T_ADDRESS: value.l = (jobject) oper->constant(); break;
case T_METADATA: return add((Metadata*)oper->constant()); break;
default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
}
return add(n, type, value);
}
Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
jvalue value;
// We can use the node pointer here to identify the right jump-table
// as this method is called from Compile::Fill_buffer right before
// the MachNodes are emitted and the jump-table is filled (means the
// MachNode pointers do not change anymore).
value.l = (jobject) n;
Constant con(T_VOID, value, next_jump_table_freq(), false); // Labels of a jump-table cannot be reused.
add(con);
return con;
}
void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
// If called from Compile::scratch_emit_size do nothing.
if (Compile::current()->in_scratch_emit_size()) return;
assert(labels.is_nonempty(), "must be");
assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
// Since MachConstantNode::constant_offset() also contains
// table_base_offset() we need to subtract the table_base_offset()
// to get the plain offset into the constant table.
int offset = n->constant_offset() - table_base_offset();
MacroAssembler _masm(&cb);
address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
for (uint i = 0; i < n->outcnt(); i++) {
address* constant_addr = &jump_table_base[i];
assert(*constant_addr == (((address) n) + i), err_msg_res("all jump-table entries must contain adjusted node pointer: " INTPTR_FORMAT " == " INTPTR_FORMAT, p2i(*constant_addr), p2i(((address) n) + i)));
*constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
}
}
//----------------------------static_subtype_check-----------------------------
// Shortcut important common cases when superklass is exact:
// (0) superklass is java.lang.Object (can occur in reflective code)
// (1) subklass is already limited to a subtype of superklass => always ok
// (2) subklass does not overlap with superklass => always fail
// (3) superklass has NO subtypes and we can check with a simple compare.
int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
if (StressReflectiveCode) {
return SSC_full_test; // Let caller generate the general case.
}
if (superk == env()->Object_klass()) {
return SSC_always_true; // (0) this test cannot fail
}
ciType* superelem = superk;
if (superelem->is_array_klass())
superelem = superelem->as_array_klass()->base_element_type();
if (!subk->is_interface()) { // cannot trust static interface types yet
if (subk->is_subtype_of(superk)) {
return SSC_always_true; // (1) false path dead; no dynamic test needed
}
if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
!superk->is_subtype_of(subk)) {
return SSC_always_false;
}
}
// If casting to an instance klass, it must have no subtypes
if (superk->is_interface()) {
// Cannot trust interfaces yet.
// %%% S.B. superk->nof_implementors() == 1
} else if (superelem->is_instance_klass()) {
ciInstanceKlass* ik = superelem->as_instance_klass();
if (!ik->has_subklass() && !ik->is_interface()) {
if (!ik->is_final()) {
// Add a dependency if there is a chance of a later subclass.
dependencies()->assert_leaf_type(ik);
}
return SSC_easy_test; // (3) caller can do a simple ptr comparison
}
} else {
// A primitive array type has no subtypes.
return SSC_easy_test; // (3) caller can do a simple ptr comparison
}
return SSC_full_test;
}
// The message about the current inlining is accumulated in
// _print_inlining_stream and transfered into the _print_inlining_list
// once we know whether inlining succeeds or not. For regular
// inlining, messages are appended to the buffer pointed by
// _print_inlining_idx in the _print_inlining_list. For late inlining,
// a new buffer is added after _print_inlining_idx in the list. This
// way we can update the inlining message for late inlining call site
// when the inlining is attempted again.
void Compile::print_inlining_init() {
if (print_inlining() || print_intrinsics()) {
_print_inlining_stream = new stringStream();
_print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
}
}
void Compile::print_inlining_reinit() {
if (print_inlining() || print_intrinsics()) {
// Re allocate buffer when we change ResourceMark
_print_inlining_stream = new stringStream();
}
}
void Compile::print_inlining_reset() {
_print_inlining_stream->reset();
}
void Compile::print_inlining_commit() {
assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
// Transfer the message from _print_inlining_stream to the current
// _print_inlining_list buffer and clear _print_inlining_stream.
_print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
print_inlining_reset();
}
void Compile::print_inlining_push() {
// Add new buffer to the _print_inlining_list at current position
_print_inlining_idx++;
_print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
}
Compile::PrintInliningBuffer& Compile::print_inlining_current() {
return _print_inlining_list->at(_print_inlining_idx);
}
void Compile::print_inlining_update(CallGenerator* cg) {
if (print_inlining() || print_intrinsics()) {
if (!cg->is_late_inline()) {
if (print_inlining_current().cg() != NULL) {
print_inlining_push();
}
print_inlining_commit();
} else {
if (print_inlining_current().cg() != cg &&
(print_inlining_current().cg() != NULL ||
print_inlining_current().ss()->size() != 0)) {
print_inlining_push();
}
print_inlining_commit();
print_inlining_current().set_cg(cg);
}
}
}
void Compile::print_inlining_move_to(CallGenerator* cg) {
// We resume inlining at a late inlining call site. Locate the
// corresponding inlining buffer so that we can update it.
if (print_inlining()) {
for (int i = 0; i < _print_inlining_list->length(); i++) {
if (_print_inlining_list->adr_at(i)->cg() == cg) {
_print_inlining_idx = i;
return;
}
}
ShouldNotReachHere();
}
}
void Compile::print_inlining_update_delayed(CallGenerator* cg) {
if (print_inlining()) {
assert(_print_inlining_stream->size() > 0, "missing inlining msg");
assert(print_inlining_current().cg() == cg, "wrong entry");
// replace message with new message
_print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
print_inlining_commit();
print_inlining_current().set_cg(cg);
}
}
void Compile::print_inlining_assert_ready() {
assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
}
void Compile::process_print_inlining() {
bool do_print_inlining = print_inlining() || print_intrinsics();
if (do_print_inlining || log() != NULL) {
// Print inlining message for candidates that we couldn't inline
// for lack of space
for (int i = 0; i < _late_inlines.length(); i++) {
CallGenerator* cg = _late_inlines.at(i);
if (!cg->is_mh_late_inline()) {
const char* msg = "live nodes > LiveNodeCountInliningCutoff";
if (do_print_inlining) {
cg->print_inlining_late(msg);
}
log_late_inline_failure(cg, msg);
}
}
}
if (do_print_inlining) {
ResourceMark rm;
stringStream ss;
for (int i = 0; i < _print_inlining_list->length(); i++) {
ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
}
size_t end = ss.size();
_print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
strncpy(_print_inlining_output, ss.base(), end+1);
_print_inlining_output[end] = 0;
}
}
void Compile::dump_print_inlining() {
if (_print_inlining_output != NULL) {
tty->print_raw(_print_inlining_output);
}
}
void Compile::log_late_inline(CallGenerator* cg) {
if (log() != NULL) {
log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
cg->unique_id());
JVMState* p = cg->call_node()->jvms();
while (p != NULL) {
log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
p = p->caller();
}
log()->tail("late_inline");
}
}
void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
log_late_inline(cg);
if (log() != NULL) {
log()->inline_fail(msg);
}
}
void Compile::log_inline_id(CallGenerator* cg) {
if (log() != NULL) {
// The LogCompilation tool needs a unique way to identify late
// inline call sites. This id must be unique for this call site in
// this compilation. Try to have it unique across compilations as
// well because it can be convenient when grepping through the log
// file.
// Distinguish OSR compilations from others in case CICountOSR is
// on.
jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
cg->set_unique_id(id);
log()->elem("inline_id id='" JLONG_FORMAT "'", id);
}
}
void Compile::log_inline_failure(const char* msg) {
if (C->log() != NULL) {
C->log()->inline_fail(msg);
}
}
// Dump inlining replay data to the stream.
// Don't change thread state and acquire any locks.
void Compile::dump_inline_data(outputStream* out) {
InlineTree* inl_tree = ilt();
if (inl_tree != NULL) {
out->print(" inline %d", inl_tree->count());
inl_tree->dump_replay_data(out);
}
}
int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
if (n1->Opcode() < n2->Opcode()) return -1;
else if (n1->Opcode() > n2->Opcode()) return 1;
assert(n1->req() == n2->req(), err_msg_res("can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req()));
for (uint i = 1; i < n1->req(); i++) {
if (n1->in(i) < n2->in(i)) return -1;
else if (n1->in(i) > n2->in(i)) return 1;
}
return 0;
}
int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
Node* n1 = *n1p;
Node* n2 = *n2p;
return cmp_expensive_nodes(n1, n2);
}
void Compile::sort_expensive_nodes() {
if (!expensive_nodes_sorted()) {
_expensive_nodes->sort(cmp_expensive_nodes);
}
}
bool Compile::expensive_nodes_sorted() const {
for (int i = 1; i < _expensive_nodes->length(); i++) {
if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
return false;
}
}
return true;
}
bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
if (_expensive_nodes->length() == 0) {
return false;
}
assert(OptimizeExpensiveOps, "optimization off?");
// Take this opportunity to remove dead nodes from the list
int j = 0;
for (int i = 0; i < _expensive_nodes->length(); i++) {
Node* n = _expensive_nodes->at(i);
if (!n->is_unreachable(igvn)) {
assert(n->is_expensive(), "should be expensive");
_expensive_nodes->at_put(j, n);
j++;
}
}
_expensive_nodes->trunc_to(j);
// Then sort the list so that similar nodes are next to each other
// and check for at least two nodes of identical kind with same data
// inputs.
sort_expensive_nodes();
for (int i = 0; i < _expensive_nodes->length()-1; i++) {
if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
return true;
}
}
return false;
}
void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
if (_expensive_nodes->length() == 0) {
return;
}
assert(OptimizeExpensiveOps, "optimization off?");
// Sort to bring similar nodes next to each other and clear the
// control input of nodes for which there's only a single copy.
sort_expensive_nodes();
int j = 0;
int identical = 0;
int i = 0;
bool modified = false;
for (; i < _expensive_nodes->length()-1; i++) {
assert(j <= i, "can't write beyond current index");
if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
identical++;
_expensive_nodes->at_put(j++, _expensive_nodes->at(i));
continue;
}
if (identical > 0) {
_expensive_nodes->at_put(j++, _expensive_nodes->at(i));
identical = 0;
} else {
Node* n = _expensive_nodes->at(i);
igvn.replace_input_of(n, 0, NULL);
igvn.hash_insert(n);
modified = true;
}
}
if (identical > 0) {
_expensive_nodes->at_put(j++, _expensive_nodes->at(i));
} else if (_expensive_nodes->length() >= 1) {
Node* n = _expensive_nodes->at(i);
igvn.replace_input_of(n, 0, NULL);
igvn.hash_insert(n);
modified = true;
}
_expensive_nodes->trunc_to(j);
if (modified) {
igvn.optimize();
}
}
void Compile::add_expensive_node(Node * n) {
assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
assert(n->is_expensive(), "expensive nodes with non-null control here only");
assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
if (OptimizeExpensiveOps) {
_expensive_nodes->append(n);
} else {
// Clear control input and let IGVN optimize expensive nodes if
// OptimizeExpensiveOps is off.
n->set_req(0, NULL);
}
}
/**
* Remove the speculative part of types and clean up the graph
*/
void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
if (UseTypeSpeculation) {
Unique_Node_List worklist;
worklist.push(root());
int modified = 0;
// Go over all type nodes that carry a speculative type, drop the
// speculative part of the type and enqueue the node for an igvn
// which may optimize it out.
for (uint next = 0; next < worklist.size(); ++next) {
Node *n = worklist.at(next);
if (n->is_Type()) {
TypeNode* tn = n->as_Type();
const Type* t = tn->type();
const Type* t_no_spec = t->remove_speculative();
if (t_no_spec != t) {
bool in_hash = igvn.hash_delete(n);
assert(in_hash, "node should be in igvn hash table");
tn->set_type(t_no_spec);
igvn.hash_insert(n);
igvn._worklist.push(n); // give it a chance to go away
modified++;
}
}
uint max = n->len();
for( uint i = 0; i < max; ++i ) {
Node *m = n->in(i);
if (not_a_node(m)) continue;
worklist.push(m);
}
}
// Drop the speculative part of all types in the igvn's type table
igvn.remove_speculative_types();
if (modified > 0) {
igvn.optimize();
}
#ifdef ASSERT
// Verify that after the IGVN is over no speculative type has resurfaced
worklist.clear();
worklist.push(root());
for (uint next = 0; next < worklist.size(); ++next) {
Node *n = worklist.at(next);
const Type* t = igvn.type_or_null(n);
assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
if (n->is_Type()) {
t = n->as_Type()->type();
assert(t == t->remove_speculative(), "no more speculative types");
}
uint max = n->len();
for( uint i = 0; i < max; ++i ) {
Node *m = n->in(i);
if (not_a_node(m)) continue;
worklist.push(m);
}
}
igvn.check_no_speculative_types();
#endif
}
}
// Auxiliary method to support randomized stressing/fuzzing.
//
// This method can be called the arbitrary number of times, with current count
// as the argument. The logic allows selecting a single candidate from the
// running list of candidates as follows:
// int count = 0;
// Cand* selected = null;
// while(cand = cand->next()) {
// if (randomized_select(++count)) {
// selected = cand;
// }
// }
//
// Including count equalizes the chances any candidate is "selected".
// This is useful when we don't have the complete list of candidates to choose
// from uniformly. In this case, we need to adjust the randomicity of the
// selection, or else we will end up biasing the selection towards the latter
// candidates.
//
// Quick back-envelope calculation shows that for the list of n candidates
// the equal probability for the candidate to persist as "best" can be
// achieved by replacing it with "next" k-th candidate with the probability
// of 1/k. It can be easily shown that by the end of the run, the
// probability for any candidate is converged to 1/n, thus giving the
// uniform distribution among all the candidates.
//
// We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
#define RANDOMIZED_DOMAIN_POW 29
#define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
#define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
bool Compile::randomized_select(int count) {
assert(count > 0, "only positive");
return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
}