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android / platform / libcore / 423daa00f81 / . / hotspot / src / share / vm / opto / escape.cpp
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/*
* Copyright (c) 2005, 2011, 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 "ci/bcEscapeAnalyzer.hpp"
#include "libadt/vectset.hpp"
#include "memory/allocation.hpp"
#include "opto/c2compiler.hpp"
#include "opto/callnode.hpp"
#include "opto/cfgnode.hpp"
#include "opto/compile.hpp"
#include "opto/escape.hpp"
#include "opto/phaseX.hpp"
#include "opto/rootnode.hpp"
void PointsToNode::add_edge(uint targIdx, PointsToNode::EdgeType et) {
uint v = (targIdx << EdgeShift) + ((uint) et);
if (_edges == NULL) {
Arena *a = Compile::current()->comp_arena();
_edges = new(a) GrowableArray<uint>(a, INITIAL_EDGE_COUNT, 0, 0);
}
_edges->append_if_missing(v);
}
void PointsToNode::remove_edge(uint targIdx, PointsToNode::EdgeType et) {
uint v = (targIdx << EdgeShift) + ((uint) et);
_edges->remove(v);
}
#ifndef PRODUCT
static const char *node_type_names[] = {
"UnknownType",
"JavaObject",
"LocalVar",
"Field"
};
static const char *esc_names[] = {
"UnknownEscape",
"NoEscape",
"ArgEscape",
"GlobalEscape"
};
static const char *edge_type_suffix[] = {
"?", // UnknownEdge
"P", // PointsToEdge
"D", // DeferredEdge
"F" // FieldEdge
};
void PointsToNode::dump(bool print_state) const {
NodeType nt = node_type();
tty->print("%s ", node_type_names[(int) nt]);
if (print_state) {
EscapeState es = escape_state();
tty->print("%s %s ", esc_names[(int) es], _scalar_replaceable ? "":"NSR");
}
tty->print("[[");
for (uint i = 0; i < edge_count(); i++) {
tty->print(" %d%s", edge_target(i), edge_type_suffix[(int) edge_type(i)]);
}
tty->print("]] ");
if (_node == NULL)
tty->print_cr("<null>");
else
_node->dump();
}
#endif
ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
_nodes(C->comp_arena(), C->unique(), C->unique(), PointsToNode()),
_processed(C->comp_arena()),
pt_ptset(C->comp_arena()),
pt_visited(C->comp_arena()),
pt_worklist(C->comp_arena(), 4, 0, 0),
_collecting(true),
_progress(false),
_compile(C),
_igvn(igvn),
_node_map(C->comp_arena()) {
_phantom_object = C->top()->_idx,
add_node(C->top(), PointsToNode::JavaObject, PointsToNode::GlobalEscape,true);
// Add ConP(#NULL) and ConN(#NULL) nodes.
Node* oop_null = igvn->zerocon(T_OBJECT);
_oop_null = oop_null->_idx;
assert(_oop_null < nodes_size(), "should be created already");
add_node(oop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
if (UseCompressedOops) {
Node* noop_null = igvn->zerocon(T_NARROWOOP);
_noop_null = noop_null->_idx;
assert(_noop_null < nodes_size(), "should be created already");
add_node(noop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
} else {
_noop_null = _oop_null; // Should be initialized
}
_pcmp_neq = NULL; // Should be initialized
_pcmp_eq = NULL;
}
void ConnectionGraph::add_pointsto_edge(uint from_i, uint to_i) {
PointsToNode *f = ptnode_adr(from_i);
PointsToNode *t = ptnode_adr(to_i);
assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of PointsTo edge");
assert(t->node_type() == PointsToNode::JavaObject, "invalid destination of PointsTo edge");
if (to_i == _phantom_object) { // Quick test for most common object
if (f->has_unknown_ptr()) {
return;
} else {
f->set_has_unknown_ptr();
}
}
add_edge(f, to_i, PointsToNode::PointsToEdge);
}
void ConnectionGraph::add_deferred_edge(uint from_i, uint to_i) {
PointsToNode *f = ptnode_adr(from_i);
PointsToNode *t = ptnode_adr(to_i);
assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of Deferred edge");
assert(t->node_type() == PointsToNode::LocalVar || t->node_type() == PointsToNode::Field, "invalid destination of Deferred edge");
// don't add a self-referential edge, this can occur during removal of
// deferred edges
if (from_i != to_i)
add_edge(f, to_i, PointsToNode::DeferredEdge);
}
int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
const Type *adr_type = phase->type(adr);
if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
adr->in(AddPNode::Address)->is_Proj() &&
adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
// We are computing a raw address for a store captured by an Initialize
// compute an appropriate address type. AddP cases #3 and #5 (see below).
int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
assert(offs != Type::OffsetBot ||
adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
"offset must be a constant or it is initialization of array");
return offs;
}
const TypePtr *t_ptr = adr_type->isa_ptr();
assert(t_ptr != NULL, "must be a pointer type");
return t_ptr->offset();
}
void ConnectionGraph::add_field_edge(uint from_i, uint to_i, int offset) {
// Don't add fields to NULL pointer.
if (is_null_ptr(from_i))
return;
PointsToNode *f = ptnode_adr(from_i);
PointsToNode *t = ptnode_adr(to_i);
assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
assert(f->node_type() == PointsToNode::JavaObject, "invalid destination of Field edge");
assert(t->node_type() == PointsToNode::Field, "invalid destination of Field edge");
assert (t->offset() == -1 || t->offset() == offset, "conflicting field offsets");
t->set_offset(offset);
add_edge(f, to_i, PointsToNode::FieldEdge);
}
void ConnectionGraph::set_escape_state(uint ni, PointsToNode::EscapeState es) {
// Don't change non-escaping state of NULL pointer.
if (is_null_ptr(ni))
return;
PointsToNode *npt = ptnode_adr(ni);
PointsToNode::EscapeState old_es = npt->escape_state();
if (es > old_es)
npt->set_escape_state(es);
}
void ConnectionGraph::add_node(Node *n, PointsToNode::NodeType nt,
PointsToNode::EscapeState es, bool done) {
PointsToNode* ptadr = ptnode_adr(n->_idx);
ptadr->_node = n;
ptadr->set_node_type(nt);
// inline set_escape_state(idx, es);
PointsToNode::EscapeState old_es = ptadr->escape_state();
if (es > old_es)
ptadr->set_escape_state(es);
if (done)
_processed.set(n->_idx);
}
PointsToNode::EscapeState ConnectionGraph::escape_state(Node *n) {
uint idx = n->_idx;
PointsToNode::EscapeState es;
// If we are still collecting or there were no non-escaping allocations
// we don't know the answer yet
if (_collecting)
return PointsToNode::UnknownEscape;
// if the node was created after the escape computation, return
// UnknownEscape
if (idx >= nodes_size())
return PointsToNode::UnknownEscape;
es = ptnode_adr(idx)->escape_state();
// if we have already computed a value, return it
if (es != PointsToNode::UnknownEscape &&
ptnode_adr(idx)->node_type() == PointsToNode::JavaObject)
return es;
// PointsTo() calls n->uncast() which can return a new ideal node.
if (n->uncast()->_idx >= nodes_size())
return PointsToNode::UnknownEscape;
PointsToNode::EscapeState orig_es = es;
// compute max escape state of anything this node could point to
for(VectorSetI i(PointsTo(n)); i.test() && es != PointsToNode::GlobalEscape; ++i) {
uint pt = i.elem;
PointsToNode::EscapeState pes = ptnode_adr(pt)->escape_state();
if (pes > es)
es = pes;
}
if (orig_es != es) {
// cache the computed escape state
assert(es > orig_es, "should have computed an escape state");
set_escape_state(idx, es);
} // orig_es could be PointsToNode::UnknownEscape
return es;
}
VectorSet* ConnectionGraph::PointsTo(Node * n) {
pt_ptset.Reset();
pt_visited.Reset();
pt_worklist.clear();
#ifdef ASSERT
Node *orig_n = n;
#endif
n = n->uncast();
PointsToNode* npt = ptnode_adr(n->_idx);
// If we have a JavaObject, return just that object
if (npt->node_type() == PointsToNode::JavaObject) {
pt_ptset.set(n->_idx);
return &pt_ptset;
}
#ifdef ASSERT
if (npt->_node == NULL) {
if (orig_n != n)
orig_n->dump();
n->dump();
assert(npt->_node != NULL, "unregistered node");
}
#endif
pt_worklist.push(n->_idx);
while(pt_worklist.length() > 0) {
int ni = pt_worklist.pop();
if (pt_visited.test_set(ni))
continue;
PointsToNode* pn = ptnode_adr(ni);
// ensure that all inputs of a Phi have been processed
assert(!_collecting || !pn->_node->is_Phi() || _processed.test(ni),"");
int edges_processed = 0;
uint e_cnt = pn->edge_count();
for (uint e = 0; e < e_cnt; e++) {
uint etgt = pn->edge_target(e);
PointsToNode::EdgeType et = pn->edge_type(e);
if (et == PointsToNode::PointsToEdge) {
pt_ptset.set(etgt);
edges_processed++;
} else if (et == PointsToNode::DeferredEdge) {
pt_worklist.push(etgt);
edges_processed++;
} else {
assert(false,"neither PointsToEdge or DeferredEdge");
}
}
if (edges_processed == 0) {
// no deferred or pointsto edges found. Assume the value was set
// outside this method. Add the phantom object to the pointsto set.
pt_ptset.set(_phantom_object);
}
}
return &pt_ptset;
}
void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
// This method is most expensive during ConnectionGraph construction.
// Reuse vectorSet and an additional growable array for deferred edges.
deferred_edges->clear();
visited->Reset();
visited->set(ni);
PointsToNode *ptn = ptnode_adr(ni);
assert(ptn->node_type() == PointsToNode::LocalVar ||
ptn->node_type() == PointsToNode::Field, "sanity");
assert(ptn->edge_count() != 0, "should have at least phantom_object");
// Mark current edges as visited and move deferred edges to separate array.
for (uint i = 0; i < ptn->edge_count(); ) {
uint t = ptn->edge_target(i);
#ifdef ASSERT
assert(!visited->test_set(t), "expecting no duplications");
#else
visited->set(t);
#endif
if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
ptn->remove_edge(t, PointsToNode::DeferredEdge);
deferred_edges->append(t);
} else {
i++;
}
}
for (int next = 0; next < deferred_edges->length(); ++next) {
uint t = deferred_edges->at(next);
PointsToNode *ptt = ptnode_adr(t);
uint e_cnt = ptt->edge_count();
assert(e_cnt != 0, "should have at least phantom_object");
for (uint e = 0; e < e_cnt; e++) {
uint etgt = ptt->edge_target(e);
if (visited->test_set(etgt))
continue;
PointsToNode::EdgeType et = ptt->edge_type(e);
if (et == PointsToNode::PointsToEdge) {
add_pointsto_edge(ni, etgt);
} else if (et == PointsToNode::DeferredEdge) {
deferred_edges->append(etgt);
} else {
assert(false,"invalid connection graph");
}
}
}
if (ptn->edge_count() == 0) {
// No pointsto edges found after deferred edges are removed.
// For example, in the next case where call is replaced
// with uncommon trap and as result array's load references
// itself through deferred edges:
//
// A a = b[i];
// if (c!=null) a = c.foo();
// b[i] = a;
//
// Assume the value was set outside this method and
// add edge to phantom object.
add_pointsto_edge(ni, _phantom_object);
}
}
// Add an edge to node given by "to_i" from any field of adr_i whose offset
// matches "offset" A deferred edge is added if to_i is a LocalVar, and
// a pointsto edge is added if it is a JavaObject
void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
// No fields for NULL pointer.
if (is_null_ptr(adr_i)) {
return;
}
PointsToNode* an = ptnode_adr(adr_i);
PointsToNode* to = ptnode_adr(to_i);
bool deferred = (to->node_type() == PointsToNode::LocalVar);
bool escaped = (to_i == _phantom_object) && (offs == Type::OffsetTop);
if (escaped) {
// Values in fields escaped during call.
assert(an->escape_state() >= PointsToNode::ArgEscape, "sanity");
offs = Type::OffsetBot;
}
for (uint fe = 0; fe < an->edge_count(); fe++) {
assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
int fi = an->edge_target(fe);
if (escaped) {
set_escape_state(fi, PointsToNode::GlobalEscape);
}
PointsToNode* pf = ptnode_adr(fi);
int po = pf->offset();
if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
if (deferred)
add_deferred_edge(fi, to_i);
else
add_pointsto_edge(fi, to_i);
}
}
}
// Add a deferred edge from node given by "from_i" to any field of adr_i
// whose offset matches "offset".
void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
// No fields for NULL pointer.
if (is_null_ptr(adr_i)) {
return;
}
if (adr_i == _phantom_object) {
// Add only one edge for unknown object.
add_pointsto_edge(from_i, _phantom_object);
return;
}
PointsToNode* an = ptnode_adr(adr_i);
bool is_alloc = an->_node->is_Allocate();
for (uint fe = 0; fe < an->edge_count(); fe++) {
assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
int fi = an->edge_target(fe);
PointsToNode* pf = ptnode_adr(fi);
int offset = pf->offset();
if (!is_alloc) {
// Assume the field was set outside this method if it is not Allocation
add_pointsto_edge(fi, _phantom_object);
}
if (offset == offs || offset == Type::OffsetBot || offs == Type::OffsetBot) {
add_deferred_edge(from_i, fi);
}
}
// Some fields references (AddP) may still be missing
// until Connection Graph construction is complete.
// For example, loads from RAW pointers with offset 0
// which don't have AddP.
// A reference to phantom_object will be added if
// a field reference is still missing after completing
// Connection Graph (see remove_deferred()).
}
// Helper functions
static Node* get_addp_base(Node *addp) {
assert(addp->is_AddP(), "must be AddP");
//
// AddP cases for Base and Address inputs:
// case #1. Direct object's field reference:
// Allocate
// |
// Proj #5 ( oop result )
// |
// CheckCastPP (cast to instance type)
// | |
// AddP ( base == address )
//
// case #2. Indirect object's field reference:
// Phi
// |
// CastPP (cast to instance type)
// | |
// AddP ( base == address )
//
// case #3. Raw object's field reference for Initialize node:
// Allocate
// |
// Proj #5 ( oop result )
// top |
// \ |
// AddP ( base == top )
//
// case #4. Array's element reference:
// {CheckCastPP | CastPP}
// | | |
// | AddP ( array's element offset )
// | |
// AddP ( array's offset )
//
// case #5. Raw object's field reference for arraycopy stub call:
// The inline_native_clone() case when the arraycopy stub is called
// after the allocation before Initialize and CheckCastPP nodes.
// Allocate
// |
// Proj #5 ( oop result )
// | |
// AddP ( base == address )
//
// case #6. Constant Pool, ThreadLocal, CastX2P or
// Raw object's field reference:
// {ConP, ThreadLocal, CastX2P, raw Load}
// top |
// \ |
// AddP ( base == top )
//
// case #7. Klass's field reference.
// LoadKlass
// | |
// AddP ( base == address )
//
// case #8. narrow Klass's field reference.
// LoadNKlass
// |
// DecodeN
// | |
// AddP ( base == address )
//
Node *base = addp->in(AddPNode::Base)->uncast();
if (base->is_top()) { // The AddP case #3 and #6.
base = addp->in(AddPNode::Address)->uncast();
while (base->is_AddP()) {
// Case #6 (unsafe access) may have several chained AddP nodes.
assert(base->in(AddPNode::Base)->is_top(), "expected unsafe access address only");
base = base->in(AddPNode::Address)->uncast();
}
assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
base->Opcode() == Op_CastX2P || base->is_DecodeN() ||
(base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL) ||
(base->is_Proj() && base->in(0)->is_Allocate()), "sanity");
}
return base;
}
static Node* find_second_addp(Node* addp, Node* n) {
assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
Node* addp2 = addp->raw_out(0);
if (addp->outcnt() == 1 && addp2->is_AddP() &&
addp2->in(AddPNode::Base) == n &&
addp2->in(AddPNode::Address) == addp) {
assert(addp->in(AddPNode::Base) == n, "expecting the same base");
//
// Find array's offset to push it on worklist first and
// as result process an array's element offset first (pushed second)
// to avoid CastPP for the array's offset.
// Otherwise the inserted CastPP (LocalVar) will point to what
// the AddP (Field) points to. Which would be wrong since
// the algorithm expects the CastPP has the same point as
// as AddP's base CheckCastPP (LocalVar).
//
// ArrayAllocation
// |
// CheckCastPP
// |
// memProj (from ArrayAllocation CheckCastPP)
// | ||
// | || Int (element index)
// | || | ConI (log(element size))
// | || | /
// | || LShift
// | || /
// | AddP (array's element offset)
// | |
// | | ConI (array's offset: #12(32-bits) or #24(64-bits))
// | / /
// AddP (array's offset)
// |
// Load/Store (memory operation on array's element)
//
return addp2;
}
return NULL;
}
//
// Adjust the type and inputs of an AddP which computes the
// address of a field of an instance
//
bool ConnectionGraph::split_AddP(Node *addp, Node *base, PhaseGVN *igvn) {
const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
if (t == NULL) {
// We are computing a raw address for a store captured by an Initialize
// compute an appropriate address type (cases #3 and #5).
assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
assert(offs != Type::OffsetBot, "offset must be a constant");
t = base_t->add_offset(offs)->is_oopptr();
}
int inst_id = base_t->instance_id();
assert(!t->is_known_instance() || t->instance_id() == inst_id,
"old type must be non-instance or match new type");
// The type 't' could be subclass of 'base_t'.
// As result t->offset() could be large then base_t's size and it will
// cause the failure in add_offset() with narrow oops since TypeOopPtr()
// constructor verifies correctness of the offset.
//
// It could happened on subclass's branch (from the type profiling
// inlining) which was not eliminated during parsing since the exactness
// of the allocation type was not propagated to the subclass type check.
//
// Or the type 't' could be not related to 'base_t' at all.
// It could happened when CHA type is different from MDO type on a dead path
// (for example, from instanceof check) which is not collapsed during parsing.
//
// Do nothing for such AddP node and don't process its users since
// this code branch will go away.
//
if (!t->is_known_instance() &&
!base_t->klass()->is_subtype_of(t->klass())) {
return false; // bail out
}
const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
// Do NOT remove the next line: ensure a new alias index is allocated
// for the instance type. Note: C++ will not remove it since the call
// has side effect.
int alias_idx = _compile->get_alias_index(tinst);
igvn->set_type(addp, tinst);
// record the allocation in the node map
assert(ptnode_adr(addp->_idx)->_node != NULL, "should be registered");
set_map(addp->_idx, get_map(base->_idx));
// Set addp's Base and Address to 'base'.
Node *abase = addp->in(AddPNode::Base);
Node *adr = addp->in(AddPNode::Address);
if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
adr->in(0)->_idx == (uint)inst_id) {
// Skip AddP cases #3 and #5.
} else {
assert(!abase->is_top(), "sanity"); // AddP case #3
if (abase != base) {
igvn->hash_delete(addp);
addp->set_req(AddPNode::Base, base);
if (abase == adr) {
addp->set_req(AddPNode::Address, base);
} else {
// AddP case #4 (adr is array's element offset AddP node)
#ifdef ASSERT
const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
assert(adr->is_AddP() && atype != NULL &&
atype->instance_id() == inst_id, "array's element offset should be processed first");
#endif
}
igvn->hash_insert(addp);
}
}
// Put on IGVN worklist since at least addp's type was changed above.
record_for_optimizer(addp);
return true;
}
//
// Create a new version of orig_phi if necessary. Returns either the newly
// created phi or an existing phi. Sets create_new to indicate whether a new
// phi was created. Cache the last newly created phi in the node map.
//
PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn, bool &new_created) {
Compile *C = _compile;
new_created = false;
int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
// nothing to do if orig_phi is bottom memory or matches alias_idx
if (phi_alias_idx == alias_idx) {
return orig_phi;
}
// Have we recently created a Phi for this alias index?
PhiNode *result = get_map_phi(orig_phi->_idx);
if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
return result;
}
// Previous check may fail when the same wide memory Phi was split into Phis
// for different memory slices. Search all Phis for this region.
if (result != NULL) {
Node* region = orig_phi->in(0);
for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
Node* phi = region->fast_out(i);
if (phi->is_Phi() &&
C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
return phi->as_Phi();
}
}
}
if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
if (C->do_escape_analysis() == true && !C->failing()) {
// Retry compilation without escape analysis.
// If this is the first failure, the sentinel string will "stick"
// to the Compile object, and the C2Compiler will see it and retry.
C->record_failure(C2Compiler::retry_no_escape_analysis());
}
return NULL;
}
orig_phi_worklist.append_if_missing(orig_phi);
const TypePtr *atype = C->get_adr_type(alias_idx);
result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
C->copy_node_notes_to(result, orig_phi);
igvn->set_type(result, result->bottom_type());
record_for_optimizer(result);
debug_only(Node* pn = ptnode_adr(orig_phi->_idx)->_node;)
assert(pn == NULL || pn == orig_phi, "wrong node");
set_map(orig_phi->_idx, result);
ptnode_adr(orig_phi->_idx)->_node = orig_phi;
new_created = true;
return result;
}
//
// Return a new version of Memory Phi "orig_phi" with the inputs having the
// specified alias index.
//
PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn) {
assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
Compile *C = _compile;
bool new_phi_created;
PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
if (!new_phi_created) {
return result;
}
GrowableArray<PhiNode *> phi_list;
GrowableArray<uint> cur_input;
PhiNode *phi = orig_phi;
uint idx = 1;
bool finished = false;
while(!finished) {
while (idx < phi->req()) {
Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
if (mem != NULL && mem->is_Phi()) {
PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
if (new_phi_created) {
// found an phi for which we created a new split, push current one on worklist and begin
// processing new one
phi_list.push(phi);
cur_input.push(idx);
phi = mem->as_Phi();
result = newphi;
idx = 1;
continue;
} else {
mem = newphi;
}
}
if (C->failing()) {
return NULL;
}
result->set_req(idx++, mem);
}
#ifdef ASSERT
// verify that the new Phi has an input for each input of the original
assert( phi->req() == result->req(), "must have same number of inputs.");
assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
#endif
// Check if all new phi's inputs have specified alias index.
// Otherwise use old phi.
for (uint i = 1; i < phi->req(); i++) {
Node* in = result->in(i);
assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
}
// we have finished processing a Phi, see if there are any more to do
finished = (phi_list.length() == 0 );
if (!finished) {
phi = phi_list.pop();
idx = cur_input.pop();
PhiNode *prev_result = get_map_phi(phi->_idx);
prev_result->set_req(idx++, result);
result = prev_result;
}
}
return result;
}
//
// The next methods are derived from methods in MemNode.
//
static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
Node *mem = mmem;
// TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
// means an array I have not precisely typed yet. Do not do any
// alias stuff with it any time soon.
if( toop->base() != Type::AnyPtr &&
!(toop->klass() != NULL &&
toop->klass()->is_java_lang_Object() &&
toop->offset() == Type::OffsetBot) ) {
mem = mmem->memory_at(alias_idx);
// Update input if it is progress over what we have now
}
return mem;
}
//
// Move memory users to their memory slices.
//
void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis, PhaseGVN *igvn) {
Compile* C = _compile;
const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
assert(tp != NULL, "ptr type");
int alias_idx = C->get_alias_index(tp);
int general_idx = C->get_general_index(alias_idx);
// Move users first
for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
Node* use = n->fast_out(i);
if (use->is_MergeMem()) {
MergeMemNode* mmem = use->as_MergeMem();
assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
continue; // Nothing to do
}
// Replace previous general reference to mem node.
uint orig_uniq = C->unique();
Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
assert(orig_uniq == C->unique(), "no new nodes");
mmem->set_memory_at(general_idx, m);
--imax;
--i;
} else if (use->is_MemBar()) {
assert(!use->is_Initialize(), "initializing stores should not be moved");
if (use->req() > MemBarNode::Precedent &&
use->in(MemBarNode::Precedent) == n) {
// Don't move related membars.
record_for_optimizer(use);
continue;
}
tp = use->as_MemBar()->adr_type()->isa_ptr();
if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
alias_idx == general_idx) {
continue; // Nothing to do
}
// Move to general memory slice.
uint orig_uniq = C->unique();
Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
assert(orig_uniq == C->unique(), "no new nodes");
igvn->hash_delete(use);
imax -= use->replace_edge(n, m);
igvn->hash_insert(use);
record_for_optimizer(use);
--i;
#ifdef ASSERT
} else if (use->is_Mem()) {
if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
// Don't move related cardmark.
continue;
}
// Memory nodes should have new memory input.
tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
assert(tp != NULL, "ptr type");
int idx = C->get_alias_index(tp);
assert(get_map(use->_idx) != NULL || idx == alias_idx,
"Following memory nodes should have new memory input or be on the same memory slice");
} else if (use->is_Phi()) {
// Phi nodes should be split and moved already.
tp = use->as_Phi()->adr_type()->isa_ptr();
assert(tp != NULL, "ptr type");
int idx = C->get_alias_index(tp);
assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
} else {
use->dump();
assert(false, "should not be here");
#endif
}
}
}
//
// Search memory chain of "mem" to find a MemNode whose address
// is the specified alias index.
//
Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis, PhaseGVN *phase) {
if (orig_mem == NULL)
return orig_mem;
Compile* C = phase->C;
const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
bool is_instance = (toop != NULL) && toop->is_known_instance();
Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
Node *prev = NULL;
Node *result = orig_mem;
while (prev != result) {
prev = result;
if (result == start_mem)
break; // hit one of our sentinels
if (result->is_Mem()) {
const Type *at = phase->type(result->in(MemNode::Address));
if (at == Type::TOP)
break; // Dead
assert (at->isa_ptr() != NULL, "pointer type required.");
int idx = C->get_alias_index(at->is_ptr());
if (idx == alias_idx)
break; // Found
if (!is_instance && (at->isa_oopptr() == NULL ||
!at->is_oopptr()->is_known_instance())) {
break; // Do not skip store to general memory slice.
}
result = result->in(MemNode::Memory);
}
if (!is_instance)
continue; // don't search further for non-instance types
// skip over a call which does not affect this memory slice
if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
Node *proj_in = result->in(0);
if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
break; // hit one of our sentinels
} else if (proj_in->is_Call()) {
CallNode *call = proj_in->as_Call();
if (!call->may_modify(toop, phase)) {
result = call->in(TypeFunc::Memory);
}
} else if (proj_in->is_Initialize()) {
AllocateNode* alloc = proj_in->as_Initialize()->allocation();
// Stop if this is the initialization for the object instance which
// which contains this memory slice, otherwise skip over it.
if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
result = proj_in->in(TypeFunc::Memory);
}
} else if (proj_in->is_MemBar()) {
result = proj_in->in(TypeFunc::Memory);
}
} else if (result->is_MergeMem()) {
MergeMemNode *mmem = result->as_MergeMem();
result = step_through_mergemem(mmem, alias_idx, toop);
if (result == mmem->base_memory()) {
// Didn't find instance memory, search through general slice recursively.
result = mmem->memory_at(C->get_general_index(alias_idx));
result = find_inst_mem(result, alias_idx, orig_phis, phase);
if (C->failing()) {
return NULL;
}
mmem->set_memory_at(alias_idx, result);
}
} else if (result->is_Phi() &&
C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
Node *un = result->as_Phi()->unique_input(phase);
if (un != NULL) {
orig_phis.append_if_missing(result->as_Phi());
result = un;
} else {
break;
}
} else if (result->is_ClearArray()) {
if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), phase)) {
// Can not bypass initialization of the instance
// we are looking for.
break;
}
// Otherwise skip it (the call updated 'result' value).
} else if (result->Opcode() == Op_SCMemProj) {
assert(result->in(0)->is_LoadStore(), "sanity");
const Type *at = phase->type(result->in(0)->in(MemNode::Address));
if (at != Type::TOP) {
assert (at->isa_ptr() != NULL, "pointer type required.");
int idx = C->get_alias_index(at->is_ptr());
assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
break;
}
result = result->in(0)->in(MemNode::Memory);
}
}
if (result->is_Phi()) {
PhiNode *mphi = result->as_Phi();
assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
const TypePtr *t = mphi->adr_type();
if (!is_instance) {
// Push all non-instance Phis on the orig_phis worklist to update inputs
// during Phase 4 if needed.
orig_phis.append_if_missing(mphi);
} else if (C->get_alias_index(t) != alias_idx) {
// Create a new Phi with the specified alias index type.
result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
}
}
// the result is either MemNode, PhiNode, InitializeNode.
return result;
}
//
// Convert the types of unescaped object to instance types where possible,
// propagate the new type information through the graph, and update memory
// edges and MergeMem inputs to reflect the new type.
//
// We start with allocations (and calls which may be allocations) on alloc_worklist.
// The processing is done in 4 phases:
//
// Phase 1: Process possible allocations from alloc_worklist. Create instance
// types for the CheckCastPP for allocations where possible.
// Propagate the the new types through users as follows:
// casts and Phi: push users on alloc_worklist
// AddP: cast Base and Address inputs to the instance type
// push any AddP users on alloc_worklist and push any memnode
// users onto memnode_worklist.
// Phase 2: Process MemNode's from memnode_worklist. compute new address type and
// search the Memory chain for a store with the appropriate type
// address type. If a Phi is found, create a new version with
// the appropriate memory slices from each of the Phi inputs.
// For stores, process the users as follows:
// MemNode: push on memnode_worklist
// MergeMem: push on mergemem_worklist
// Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
// moving the first node encountered of each instance type to the
// the input corresponding to its alias index.
// appropriate memory slice.
// Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
//
// In the following example, the CheckCastPP nodes are the cast of allocation
// results and the allocation of node 29 is unescaped and eligible to be an
// instance type.
//
// We start with:
//
// 7 Parm #memory
// 10 ConI "12"
// 19 CheckCastPP "Foo"
// 20 AddP _ 19 19 10 Foo+12 alias_index=4
// 29 CheckCastPP "Foo"
// 30 AddP _ 29 29 10 Foo+12 alias_index=4
//
// 40 StoreP 25 7 20 ... alias_index=4
// 50 StoreP 35 40 30 ... alias_index=4
// 60 StoreP 45 50 20 ... alias_index=4
// 70 LoadP _ 60 30 ... alias_index=4
// 80 Phi 75 50 60 Memory alias_index=4
// 90 LoadP _ 80 30 ... alias_index=4
// 100 LoadP _ 80 20 ... alias_index=4
//
//
// Phase 1 creates an instance type for node 29 assigning it an instance id of 24
// and creating a new alias index for node 30. This gives:
//
// 7 Parm #memory
// 10 ConI "12"
// 19 CheckCastPP "Foo"
// 20 AddP _ 19 19 10 Foo+12 alias_index=4
// 29 CheckCastPP "Foo" iid=24
// 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
//
// 40 StoreP 25 7 20 ... alias_index=4
// 50 StoreP 35 40 30 ... alias_index=6
// 60 StoreP 45 50 20 ... alias_index=4
// 70 LoadP _ 60 30 ... alias_index=6
// 80 Phi 75 50 60 Memory alias_index=4
// 90 LoadP _ 80 30 ... alias_index=6
// 100 LoadP _ 80 20 ... alias_index=4
//
// In phase 2, new memory inputs are computed for the loads and stores,
// And a new version of the phi is created. In phase 4, the inputs to
// node 80 are updated and then the memory nodes are updated with the
// values computed in phase 2. This results in:
//
// 7 Parm #memory
// 10 ConI "12"
// 19 CheckCastPP "Foo"
// 20 AddP _ 19 19 10 Foo+12 alias_index=4
// 29 CheckCastPP "Foo" iid=24
// 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
//
// 40 StoreP 25 7 20 ... alias_index=4
// 50 StoreP 35 7 30 ... alias_index=6
// 60 StoreP 45 40 20 ... alias_index=4
// 70 LoadP _ 50 30 ... alias_index=6
// 80 Phi 75 40 60 Memory alias_index=4
// 120 Phi 75 50 50 Memory alias_index=6
// 90 LoadP _ 120 30 ... alias_index=6
// 100 LoadP _ 80 20 ... alias_index=4
//
void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
GrowableArray<Node *> memnode_worklist;
GrowableArray<PhiNode *> orig_phis;
PhaseIterGVN *igvn = _igvn;
uint new_index_start = (uint) _compile->num_alias_types();
Arena* arena = Thread::current()->resource_area();
VectorSet visited(arena);
// Phase 1: Process possible allocations from alloc_worklist.
// Create instance types for the CheckCastPP for allocations where possible.
//
// (Note: don't forget to change the order of the second AddP node on
// the alloc_worklist if the order of the worklist processing is changed,
// see the comment in find_second_addp().)
//
while (alloc_worklist.length() != 0) {
Node *n = alloc_worklist.pop();
uint ni = n->_idx;
const TypeOopPtr* tinst = NULL;
if (n->is_Call()) {
CallNode *alloc = n->as_Call();
// copy escape information to call node
PointsToNode* ptn = ptnode_adr(alloc->_idx);
PointsToNode::EscapeState es = escape_state(alloc);
// We have an allocation or call which returns a Java object,
// see if it is unescaped.
if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
continue;
// Find CheckCastPP for the allocate or for the return value of a call
n = alloc->result_cast();
if (n == NULL) { // No uses except Initialize node
if (alloc->is_Allocate()) {
// Set the scalar_replaceable flag for allocation
// so it could be eliminated if it has no uses.
alloc->as_Allocate()->_is_scalar_replaceable = true;
}
continue;
}
if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
assert(!alloc->is_Allocate(), "allocation should have unique type");
continue;
}
// The inline code for Object.clone() casts the allocation result to
// java.lang.Object and then to the actual type of the allocated
// object. Detect this case and use the second cast.
// Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
// the allocation result is cast to java.lang.Object and then
// to the actual Array type.
if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
&& (alloc->is_AllocateArray() ||
igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
Node *cast2 = NULL;
for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
Node *use = n->fast_out(i);
if (use->is_CheckCastPP()) {
cast2 = use;
break;
}
}
if (cast2 != NULL) {
n = cast2;
} else {
// Non-scalar replaceable if the allocation type is unknown statically
// (reflection allocation), the object can't be restored during
// deoptimization without precise type.
continue;
}
}
if (alloc->is_Allocate()) {
// Set the scalar_replaceable flag for allocation
// so it could be eliminated.
alloc->as_Allocate()->_is_scalar_replaceable = true;
}
set_escape_state(n->_idx, es); // CheckCastPP escape state
// in order for an object to be scalar-replaceable, it must be:
// - a direct allocation (not a call returning an object)
// - non-escaping
// - eligible to be a unique type
// - not determined to be ineligible by escape analysis
assert(ptnode_adr(alloc->_idx)->_node != NULL &&
ptnode_adr(n->_idx)->_node != NULL, "should be registered");
set_map(alloc->_idx, n);
set_map(n->_idx, alloc);
const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
if (t == NULL)
continue; // not a TypeOopPtr
tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
igvn->hash_delete(n);
igvn->set_type(n, tinst);
n->raise_bottom_type(tinst);
igvn->hash_insert(n);
record_for_optimizer(n);
if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
// First, put on the worklist all Field edges from Connection Graph
// which is more accurate then putting immediate users from Ideal Graph.
for (uint e = 0; e < ptn->edge_count(); e++) {
Node *use = ptnode_adr(ptn->edge_target(e))->_node;
assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),
"only AddP nodes are Field edges in CG");
if (use->outcnt() > 0) { // Don't process dead nodes
Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
if (addp2 != NULL) {
assert(alloc->is_AllocateArray(),"array allocation was expected");
alloc_worklist.append_if_missing(addp2);
}
alloc_worklist.append_if_missing(use);
}
}
// An allocation may have an Initialize which has raw stores. Scan
// the users of the raw allocation result and push AddP users
// on alloc_worklist.
Node *raw_result = alloc->proj_out(TypeFunc::Parms);
assert (raw_result != NULL, "must have an allocation result");
for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
Node *use = raw_result->fast_out(i);
if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
Node* addp2 = find_second_addp(use, raw_result);
if (addp2 != NULL) {
assert(alloc->is_AllocateArray(),"array allocation was expected");
alloc_worklist.append_if_missing(addp2);
}
alloc_worklist.append_if_missing(use);
} else if (use->is_MemBar()) {
memnode_worklist.append_if_missing(use);
}
}
}
} else if (n->is_AddP()) {
VectorSet* ptset = PointsTo(get_addp_base(n));
assert(ptset->Size() == 1, "AddP address is unique");
uint elem = ptset->getelem(); // Allocation node's index
if (elem == _phantom_object) {
assert(false, "escaped allocation");
continue; // Assume the value was set outside this method.
}
Node *base = get_map(elem); // CheckCastPP node
if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
tinst = igvn->type(base)->isa_oopptr();
} else if (n->is_Phi() ||
n->is_CheckCastPP() ||
n->is_EncodeP() ||
n->is_DecodeN() ||
(n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
if (visited.test_set(n->_idx)) {
assert(n->is_Phi(), "loops only through Phi's");
continue; // already processed
}
VectorSet* ptset = PointsTo(n);
if (ptset->Size() == 1) {
uint elem = ptset->getelem(); // Allocation node's index
if (elem == _phantom_object) {
assert(false, "escaped allocation");
continue; // Assume the value was set outside this method.
}
Node *val = get_map(elem); // CheckCastPP node
TypeNode *tn = n->as_Type();
tinst = igvn->type(val)->isa_oopptr();
assert(tinst != NULL && tinst->is_known_instance() &&
(uint)tinst->instance_id() == elem , "instance type expected.");
const Type *tn_type = igvn->type(tn);
const TypeOopPtr *tn_t;
if (tn_type->isa_narrowoop()) {
tn_t = tn_type->make_ptr()->isa_oopptr();
} else {
tn_t = tn_type->isa_oopptr();
}
if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
if (tn_type->isa_narrowoop()) {
tn_type = tinst->make_narrowoop();
} else {
tn_type = tinst;
}
igvn->hash_delete(tn);
igvn->set_type(tn, tn_type);
tn->set_type(tn_type);
igvn->hash_insert(tn);
record_for_optimizer(n);
} else {
assert(tn_type == TypePtr::NULL_PTR ||
tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
"unexpected type");
continue; // Skip dead path with different type
}
}
} else {
debug_only(n->dump();)
assert(false, "EA: unexpected node");
continue;
}
// push allocation's users on appropriate worklist
for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
Node *use = n->fast_out(i);
if(use->is_Mem() && use->in(MemNode::Address) == n) {
// Load/store to instance's field
memnode_worklist.append_if_missing(use);
} else if (use->is_MemBar()) {
memnode_worklist.append_if_missing(use);
} else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
Node* addp2 = find_second_addp(use, n);
if (addp2 != NULL) {
alloc_worklist.append_if_missing(addp2);
}
alloc_worklist.append_if_missing(use);
} else if (use->is_Phi() ||
use->is_CheckCastPP() ||
use->is_EncodeP() ||
use->is_DecodeN() ||
(use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
alloc_worklist.append_if_missing(use);
#ifdef ASSERT
} else if (use->is_Mem()) {
assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
} else if (use->is_MergeMem()) {
assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
} else if (use->is_SafePoint()) {
// Look for MergeMem nodes for calls which reference unique allocation
// (through CheckCastPP nodes) even for debug info.
Node* m = use->in(TypeFunc::Memory);
if (m->is_MergeMem()) {
assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
}
} else {
uint op = use->Opcode();
if (!(op == Op_CmpP || op == Op_Conv2B ||
op == Op_CastP2X || op == Op_StoreCM ||
op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
op == Op_StrEquals || op == Op_StrIndexOf)) {
n->dump();
use->dump();
assert(false, "EA: missing allocation reference path");
}
#endif
}
}
}
// New alias types were created in split_AddP().
uint new_index_end = (uint) _compile->num_alias_types();
// Phase 2: Process MemNode's from memnode_worklist. compute new address type and
// compute new values for Memory inputs (the Memory inputs are not
// actually updated until phase 4.)
if (memnode_worklist.length() == 0)
return; // nothing to do
while (memnode_worklist.length() != 0) {
Node *n = memnode_worklist.pop();
if (visited.test_set(n->_idx))
continue;
if (n->is_Phi() || n->is_ClearArray()) {
// we don't need to do anything, but the users must be pushed
} else if (n->is_MemBar()) { // Initialize, MemBar nodes
// we don't need to do anything, but the users must be pushed
n = n->as_MemBar()->proj_out(TypeFunc::Memory);
if (n == NULL)
continue;
} else {
assert(n->is_Mem(), "memory node required.");
Node *addr = n->in(MemNode::Address);
const Type *addr_t = igvn->type(addr);
if (addr_t == Type::TOP)
continue;
assert (addr_t->isa_ptr() != NULL, "pointer type required.");
int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
assert ((uint)alias_idx < new_index_end, "wrong alias index");
Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
if (_compile->failing()) {
return;
}
if (mem != n->in(MemNode::Memory)) {
// We delay the memory edge update since we need old one in
// MergeMem code below when instances memory slices are separated.
debug_only(Node* pn = ptnode_adr(n->_idx)->_node;)
assert(pn == NULL || pn == n, "wrong node");
set_map(n->_idx, mem);
ptnode_adr(n->_idx)->_node = n;
}
if (n->is_Load()) {
continue; // don't push users
} else if (n->is_LoadStore()) {
// get the memory projection
for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
Node *use = n->fast_out(i);
if (use->Opcode() == Op_SCMemProj) {
n = use;
break;
}
}
assert(n->Opcode() == Op_SCMemProj, "memory projection required");
}
}
// push user on appropriate worklist
for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
Node *use = n->fast_out(i);
if (use->is_Phi() || use->is_ClearArray()) {
memnode_worklist.append_if_missing(use);
} else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
continue;
memnode_worklist.append_if_missing(use);
} else if (use->is_MemBar()) {
memnode_worklist.append_if_missing(use);
#ifdef ASSERT
} else if(use->is_Mem()) {
assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
} else if (use->is_MergeMem()) {
assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
} else {
uint op = use->Opcode();
if (!(op == Op_StoreCM ||
(op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
op == Op_AryEq || op == Op_StrComp ||
op == Op_StrEquals || op == Op_StrIndexOf)) {
n->dump();
use->dump();
assert(false, "EA: missing memory path");
}
#endif
}
}
}
// Phase 3: Process MergeMem nodes from mergemem_worklist.
// Walk each memory slice moving the first node encountered of each
// instance type to the the input corresponding to its alias index.
uint length = _mergemem_worklist.length();
for( uint next = 0; next < length; ++next ) {
MergeMemNode* nmm = _mergemem_worklist.at(next);
assert(!visited.test_set(nmm->_idx), "should not be visited before");
// Note: we don't want to use MergeMemStream here because we only want to
// scan inputs which exist at the start, not ones we add during processing.
// Note 2: MergeMem may already contains instance memory slices added
// during find_inst_mem() call when memory nodes were processed above.
igvn->hash_delete(nmm);
uint nslices = nmm->req();
for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
Node* mem = nmm->in(i);
Node* cur = NULL;
if (mem == NULL || mem->is_top())
continue;
// First, update mergemem by moving memory nodes to corresponding slices
// if their type became more precise since this mergemem was created.
while (mem->is_Mem()) {
const Type *at = igvn->type(mem->in(MemNode::Address));
if (at != Type::TOP) {
assert (at->isa_ptr() != NULL, "pointer type required.");
uint idx = (uint)_compile->get_alias_index(at->is_ptr());
if (idx == i) {
if (cur == NULL)
cur = mem;
} else {
if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
nmm->set_memory_at(idx, mem);
}
}
}
mem = mem->in(MemNode::Memory);
}
nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
// Find any instance of the current type if we haven't encountered
// already a memory slice of the instance along the memory chain.
for (uint ni = new_index_start; ni < new_index_end; ni++) {
if((uint)_compile->get_general_index(ni) == i) {
Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
if (nmm->is_empty_memory(m)) {
Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
if (_compile->failing()) {
return;
}
nmm->set_memory_at(ni, result);
}
}
}
}
// Find the rest of instances values
for (uint ni = new_index_start; ni < new_index_end; ni++) {
const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
Node* result = step_through_mergemem(nmm, ni, tinst);
if (result == nmm->base_memory()) {
// Didn't find instance memory, search through general slice recursively.
result = nmm->memory_at(_compile->get_general_index(ni));
result = find_inst_mem(result, ni, orig_phis, igvn);
if (_compile->failing()) {
return;
}
nmm->set_memory_at(ni, result);
}
}
igvn->hash_insert(nmm);
record_for_optimizer(nmm);
}
// Phase 4: Update the inputs of non-instance memory Phis and
// the Memory input of memnodes
// First update the inputs of any non-instance Phi's from
// which we split out an instance Phi. Note we don't have
// to recursively process Phi's encounted on the input memory
// chains as is done in split_memory_phi() since they will
// also be processed here.
for (int j = 0; j < orig_phis.length(); j++) {
PhiNode *phi = orig_phis.at(j);
int alias_idx = _compile->get_alias_index(phi->adr_type());
igvn->hash_delete(phi);
for (uint i = 1; i < phi->req(); i++) {
Node *mem = phi->in(i);
Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
if (_compile->failing()) {
return;
}
if (mem != new_mem) {
phi->set_req(i, new_mem);
}
}
igvn->hash_insert(phi);
record_for_optimizer(phi);
}
// Update the memory inputs of MemNodes with the value we computed
// in Phase 2 and move stores memory users to corresponding memory slices.
// Disable memory split verification code until the fix for 6984348.
// Currently it produces false negative results since it does not cover all cases.
#if 0 // ifdef ASSERT
visited.Reset();
Node_Stack old_mems(arena, _compile->unique() >> 2);
#endif
for (uint i = 0; i < nodes_size(); i++) {
Node *nmem = get_map(i);
if (nmem != NULL) {
Node *n = ptnode_adr(i)->_node;
assert(n != NULL, "sanity");
if (n->is_Mem()) {
#if 0 // ifdef ASSERT
Node* old_mem = n->in(MemNode::Memory);
if (!visited.test_set(old_mem->_idx)) {
old_mems.push(old_mem, old_mem->outcnt());
}
#endif
assert(n->in(MemNode::Memory) != nmem, "sanity");
if (!n->is_Load()) {
// Move memory users of a store first.
move_inst_mem(n, orig_phis, igvn);
}
// Now update memory input
igvn->hash_delete(n);
n->set_req(MemNode::Memory, nmem);
igvn->hash_insert(n);
record_for_optimizer(n);
} else {
assert(n->is_Allocate() || n->is_CheckCastPP() ||
n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
}
}
}
#if 0 // ifdef ASSERT
// Verify that memory was split correctly
while (old_mems.is_nonempty()) {
Node* old_mem = old_mems.node();
uint old_cnt = old_mems.index();
old_mems.pop();
assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
}
#endif
}
bool ConnectionGraph::has_candidates(Compile *C) {
// EA brings benefits only when the code has allocations and/or locks which
// are represented by ideal Macro nodes.
int cnt = C->macro_count();
for( int i=0; i < cnt; i++ ) {
Node *n = C->macro_node(i);
if ( n->is_Allocate() )
return true;
if( n->is_Lock() ) {
Node* obj = n->as_Lock()->obj_node()->uncast();
if( !(obj->is_Parm() || obj->is_Con()) )
return true;
}
}
return false;
}
void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
// Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
// to create space for them in ConnectionGraph::_nodes[].
Node* oop_null = igvn->zerocon(T_OBJECT);
Node* noop_null = igvn->zerocon(T_NARROWOOP);
ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
// Perform escape analysis
if (congraph->compute_escape()) {
// There are non escaping objects.
C->set_congraph(congraph);
}
// Cleanup.
if (oop_null->outcnt() == 0)
igvn->hash_delete(oop_null);
if (noop_null->outcnt() == 0)
igvn->hash_delete(noop_null);
}
bool ConnectionGraph::compute_escape() {
Compile* C = _compile;
// 1. Populate Connection Graph (CG) with Ideal nodes.
Unique_Node_List worklist_init;
worklist_init.map(C->unique(), NULL); // preallocate space
// Initialize worklist
if (C->root() != NULL) {
worklist_init.push(C->root());
}
GrowableArray<Node*> alloc_worklist;
GrowableArray<Node*> addp_worklist;
GrowableArray<Node*> ptr_cmp_worklist;
GrowableArray<Node*> storestore_worklist;
PhaseGVN* igvn = _igvn;
// Push all useful nodes onto CG list and set their type.
for( uint next = 0; next < worklist_init.size(); ++next ) {
Node* n = worklist_init.at(next);
record_for_escape_analysis(n, igvn);
// Only allocations and java static calls results are checked
// for an escape status. See process_call_result() below.
if (n->is_Allocate() || n->is_CallStaticJava() &&
ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
alloc_worklist.append(n);
} else if(n->is_AddP()) {
// Collect address nodes. Use them during stage 3 below
// to build initial connection graph field edges.
addp_worklist.append(n);
} else if (n->is_MergeMem()) {
// Collect all MergeMem nodes to add memory slices for
// scalar replaceable objects in split_unique_types().
_mergemem_worklist.append(n->as_MergeMem());
} else if (OptimizePtrCompare && n->is_Cmp() &&
(n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
// Compare pointers nodes
ptr_cmp_worklist.append(n);
} else if (n->is_MemBarStoreStore()) {
// Collect all MemBarStoreStore nodes so that depending on the
// escape status of the associated Allocate node some of them
// may be eliminated.
storestore_worklist.append(n);
}
for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
Node* m = n->fast_out(i); // Get user
worklist_init.push(m);
}
}
if (alloc_worklist.length() == 0) {
_collecting = false;
return false; // Nothing to do.
}
// 2. First pass to create simple CG edges (doesn't require to walk CG).
uint delayed_size = _delayed_worklist.size();
for( uint next = 0; next < delayed_size; ++next ) {
Node* n = _delayed_worklist.at(next);
build_connection_graph(n, igvn);
}
// 3. Pass to create initial fields edges (JavaObject -F-> AddP)
// to reduce number of iterations during stage 4 below.
uint addp_length = addp_worklist.length();
for( uint next = 0; next < addp_length; ++next ) {
Node* n = addp_worklist.at(next);
Node* base = get_addp_base(n);
if (base->is_Proj() && base->in(0)->is_Call())
base = base->in(0);
PointsToNode::NodeType nt = ptnode_adr(base->_idx)->node_type();
if (nt == PointsToNode::JavaObject) {
build_connection_graph(n, igvn);
}
}
GrowableArray<int> cg_worklist;
cg_worklist.append(_phantom_object);
GrowableArray<uint> worklist;
// 4. Build Connection Graph which need
// to walk the connection graph.
_progress = false;
for (uint ni = 0; ni < nodes_size(); ni++) {
PointsToNode* ptn = ptnode_adr(ni);
Node *n = ptn->_node;
if (n != NULL) { // Call, AddP, LoadP, StoreP
build_connection_graph(n, igvn);
if (ptn->node_type() != PointsToNode::UnknownType)
cg_worklist.append(n->_idx); // Collect CG nodes
if (!_processed.test(n->_idx))
worklist.append(n->_idx); // Collect C/A/L/S nodes
}
}
// After IGVN user nodes may have smaller _idx than
// their inputs so they will be processed first in
// previous loop. Because of that not all Graph
// edges will be created. Walk over interesting
// nodes again until no new edges are created.
//
// Normally only 1-3 passes needed to build
// Connection Graph depending on graph complexity.
// Observed 8 passes in jvm2008 compiler.compiler.
// Set limit to 20 to catch situation when something
// did go wrong and recompile the method without EA.
#define CG_BUILD_ITER_LIMIT 20
uint length = worklist.length();
int iterations = 0;
while(_progress && (iterations++ < CG_BUILD_ITER_LIMIT)) {
_progress = false;
for( uint next = 0; next < length; ++next ) {
int ni = worklist.at(next);
PointsToNode* ptn = ptnode_adr(ni);
Node* n = ptn->_node;
assert(n != NULL, "should be known node");
build_connection_graph(n, igvn);
}
}
if (iterations >= CG_BUILD_ITER_LIMIT) {
assert(iterations < CG_BUILD_ITER_LIMIT,
err_msg("infinite EA connection graph build with %d nodes and worklist size %d",
nodes_size(), length));
// Possible infinite build_connection_graph loop,
// retry compilation without escape analysis.
C->record_failure(C2Compiler::retry_no_escape_analysis());
_collecting = false;
return false;
}
#undef CG_BUILD_ITER_LIMIT
// 5. Propagate escaped states.
worklist.clear();
// mark all nodes reachable from GlobalEscape nodes
(void)propagate_escape_state(&cg_worklist, &worklist, PointsToNode::GlobalEscape);
// mark all nodes reachable from ArgEscape nodes
bool has_non_escaping_obj = propagate_escape_state(&cg_worklist, &worklist, PointsToNode::ArgEscape);
Arena* arena = Thread::current()->resource_area();
VectorSet visited(arena);
// 6. Find fields initializing values for not escaped allocations
uint alloc_length = alloc_worklist.length();
for (uint next = 0; next < alloc_length; ++next) {
Node* n = alloc_worklist.at(next);
PointsToNode::EscapeState es = ptnode_adr(n->_idx)->escape_state();
if (es == PointsToNode::NoEscape) {
has_non_escaping_obj = true;
if (n->is_Allocate()) {
find_init_values(n, &visited, igvn);
// The object allocated by this Allocate node will never be
// seen by an other thread. Mark it so that when it is
// expanded no MemBarStoreStore is added.
n->as_Allocate()->initialization()->set_does_not_escape();
}
} else if ((es == PointsToNode::ArgEscape) && n->is_Allocate()) {
// Same as above. Mark this Allocate node so that when it is
// expanded no MemBarStoreStore is added.
n->as_Allocate()->initialization()->set_does_not_escape();
}
}
uint cg_length = cg_worklist.length();
// Skip the rest of code if all objects escaped.
if (!has_non_escaping_obj) {
cg_length = 0;
addp_length = 0;
}
for (uint next = 0; next < cg_length; ++next) {
int ni = cg_worklist.at(next);
PointsToNode* ptn = ptnode_adr(ni);
PointsToNode::NodeType nt = ptn->node_type();
if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
if (ptn->edge_count() == 0) {
// No values were found. Assume the value was set
// outside this method - add edge to phantom object.
add_pointsto_edge(ni, _phantom_object);
}
}
}
// 7. Remove deferred edges from the graph.
for (uint next = 0; next < cg_length; ++next) {
int ni = cg_worklist.at(next);
PointsToNode* ptn = ptnode_adr(ni);
PointsToNode::NodeType nt = ptn->node_type();
if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
remove_deferred(ni, &worklist, &visited);
}
}
// 8. Adjust escape state of nonescaping objects.
for (uint next = 0; next < addp_length; ++next) {
Node* n = addp_worklist.at(next);
adjust_escape_state(n);
}
// push all NoEscape nodes on the worklist
worklist.clear();
for( uint next = 0; next < cg_length; ++next ) {
int nk = cg_worklist.at(next);
if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape &&
!is_null_ptr(nk))
worklist.push(nk);
}
alloc_worklist.clear();
// Propagate scalar_replaceable value.
while(worklist.length() > 0) {
uint nk = worklist.pop();
PointsToNode* ptn = ptnode_adr(nk);
Node* n = ptn->_node;
bool scalar_replaceable = ptn->scalar_replaceable();
if (n->is_Allocate() && scalar_replaceable) {
// Push scalar replaceable allocations on alloc_worklist
// for processing in split_unique_types(). Note,
// following code may change scalar_replaceable value.
alloc_worklist.append(n);
}
uint e_cnt = ptn->edge_count();
for (uint ei = 0; ei < e_cnt; ei++) {
uint npi = ptn->edge_target(ei);
if (is_null_ptr(npi))
continue;
PointsToNode *np = ptnode_adr(npi);
if (np->escape_state() < PointsToNode::NoEscape) {
set_escape_state(npi, PointsToNode::NoEscape);
if (!scalar_replaceable) {
np->set_scalar_replaceable(false);
}
worklist.push(npi);
} else if (np->scalar_replaceable() && !scalar_replaceable) {
np->set_scalar_replaceable(false);
worklist.push(npi);
}
}
}
_collecting = false;
assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
assert(ptnode_adr(_oop_null)->escape_state() == PointsToNode::NoEscape &&
ptnode_adr(_oop_null)->edge_count() == 0, "sanity");
if (UseCompressedOops) {
assert(ptnode_adr(_noop_null)->escape_state() == PointsToNode::NoEscape &&
ptnode_adr(_noop_null)->edge_count() == 0, "sanity");
}
if (EliminateLocks && has_non_escaping_obj) {
// Mark locks before changing ideal graph.
int cnt = C->macro_count();
for( int i=0; i < cnt; i++ ) {
Node *n = C->macro_node(i);
if (n->is_AbstractLock()) { // Lock and Unlock nodes
AbstractLockNode* alock = n->as_AbstractLock();
if (!alock->is_non_esc_obj()) {
PointsToNode::EscapeState es = escape_state(alock->obj_node());
assert(es != PointsToNode::UnknownEscape, "should know");
if (es != PointsToNode::UnknownEscape && es != PointsToNode::GlobalEscape) {
assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
// The lock could be marked eliminated by lock coarsening
// code during first IGVN before EA. Replace coarsened flag
// to eliminate all associated locks/unlocks.
alock->set_non_esc_obj();
}
}
}
}
}
if (OptimizePtrCompare && has_non_escaping_obj) {
// Add ConI(#CC_GT) and ConI(#CC_EQ).
_pcmp_neq = igvn->makecon(TypeInt::CC_GT);
_pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
// Optimize objects compare.
while (ptr_cmp_worklist.length() != 0) {
Node *n = ptr_cmp_worklist.pop();
Node *res = optimize_ptr_compare(n);
if (res != NULL) {
#ifndef PRODUCT
if (PrintOptimizePtrCompare) {
tty->print_cr("++++ Replaced: %d %s(%d,%d) --> %s", n->_idx, (n->Opcode() == Op_CmpP ? "CmpP" : "CmpN"), n->in(1)->_idx, n->in(2)->_idx, (res == _pcmp_eq ? "EQ" : "NotEQ"));
if (Verbose) {
n->dump(1);
}
}
#endif
_igvn->replace_node(n, res);
}
}
// cleanup
if (_pcmp_neq->outcnt() == 0)
igvn->hash_delete(_pcmp_neq);
if (_pcmp_eq->outcnt() == 0)
igvn->hash_delete(_pcmp_eq);
}
// For MemBarStoreStore nodes added in library_call.cpp, check
// escape status of associated AllocateNode and optimize out
// MemBarStoreStore node if the allocated object never escapes.
while (storestore_worklist.length() != 0) {
Node *n = storestore_worklist.pop();
MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
PointsToNode::EscapeState es = ptnode_adr(alloc->_idx)->escape_state();
if (es == PointsToNode::NoEscape || es == PointsToNode::ArgEscape) {
MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
_igvn->register_new_node_with_optimizer(mb);
_igvn->replace_node(storestore, mb);
}
}
#ifndef PRODUCT
if (PrintEscapeAnalysis) {
dump(); // Dump ConnectionGraph
}
#endif
bool has_scalar_replaceable_candidates = false;
alloc_length = alloc_worklist.length();
for (uint next = 0; next < alloc_length; ++next) {
Node* n = alloc_worklist.at(next);
PointsToNode* ptn = ptnode_adr(n->_idx);
assert(ptn->escape_state() == PointsToNode::NoEscape, "sanity");
if (ptn->scalar_replaceable()) {
has_scalar_replaceable_candidates = true;
break;
}
}
if ( has_scalar_replaceable_candidates &&
C->AliasLevel() >= 3 && EliminateAllocations ) {
// Now use the escape information to create unique types for
// scalar replaceable objects.
split_unique_types(alloc_worklist);
if (C->failing()) return false;
C->print_method("After Escape Analysis", 2);
#ifdef ASSERT
} else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
tty->print("=== No allocations eliminated for ");
C->method()->print_short_name();
if(!EliminateAllocations) {
tty->print(" since EliminateAllocations is off ===");
} else if(!has_scalar_replaceable_candidates) {
tty->print(" since there are no scalar replaceable candidates ===");
} else if(C->AliasLevel() < 3) {
tty->print(" since AliasLevel < 3 ===");
}
tty->cr();
#endif
}
return has_non_escaping_obj;
}
// Find fields initializing values for allocations.
void ConnectionGraph::find_init_values(Node* alloc, VectorSet* visited, PhaseTransform* phase) {
assert(alloc->is_Allocate(), "Should be called for Allocate nodes only");
PointsToNode* pta = ptnode_adr(alloc->_idx);
assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
InitializeNode* ini = alloc->as_Allocate()->initialization();
Compile* C = _compile;
visited->Reset();
// Check if a oop field's initializing value is recorded and add
// a corresponding NULL field's value if it is not recorded.
// Connection Graph does not record a default initialization by NULL
// captured by Initialize node.
//
uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
uint ae_cnt = pta->edge_count();
bool visited_bottom_offset = false;
for (uint ei = 0; ei < ae_cnt; ei++) {
uint nidx = pta->edge_target(ei); // Field (AddP)
PointsToNode* ptn = ptnode_adr(nidx);
assert(ptn->_node->is_AddP(), "Should be AddP nodes only");
int offset = ptn->offset();
if (offset == Type::OffsetBot) {
if (!visited_bottom_offset) {
visited_bottom_offset = true;
// Check only oop fields.
const Type* adr_type = ptn->_node->as_AddP()->bottom_type();
if (!adr_type->isa_aryptr() ||
(adr_type->isa_aryptr()->klass() == NULL) ||
adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
// OffsetBot is used to reference array's element,
// always add reference to NULL since we don't
// known which element is referenced.
add_edge_from_fields(alloc->_idx, null_idx, offset);
}
}
} else if (offset != oopDesc::klass_offset_in_bytes() &&
!visited->test_set(offset)) {
// Check only oop fields.
const Type* adr_type = ptn->_node->as_AddP()->bottom_type();
BasicType basic_field_type = T_INT;
if (adr_type->isa_instptr()) {
ciField* field = C->alias_type(adr_type->isa_instptr())->field();
if (field != NULL) {
basic_field_type = field->layout_type();
} else {
// Ignore non field load (for example, klass load)
}
} else if (adr_type->isa_aryptr()) {
if (offset != arrayOopDesc::length_offset_in_bytes()) {
const Type* elemtype = adr_type->isa_aryptr()->elem();
basic_field_type = elemtype->array_element_basic_type();
} else {
// Ignore array length load
}
#ifdef ASSERT
} else {
// Raw pointers are used for initializing stores so skip it
// since it should be recorded already
Node* base = get_addp_base(ptn->_node);
assert(adr_type->isa_rawptr() && base->is_Proj() &&
(base->in(0) == alloc),"unexpected pointer type");
#endif
}
if (basic_field_type == T_OBJECT ||
basic_field_type == T_NARROWOOP ||
basic_field_type == T_ARRAY) {
Node* value = NULL;
if (ini != NULL) {
BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
if (store != NULL && store->is_Store()) {
value = store->in(MemNode::ValueIn);
} else if (ptn->edge_count() > 0) { // Are there oop stores?
// Check for a store which follows allocation without branches.
// For example, a volatile field store is not collected
// by Initialize node. TODO: it would be nice to use idom() here.
//
// Search all references to the same field which use different
// AddP nodes, for example, in the next case:
//
// Point p[] = new Point[1];
// if ( x ) { p[0] = new Point(); p[0].x = x; }
// if ( p[0] != null ) { y = p[0].x; } // has CastPP
//
for (uint next = ei; (next < ae_cnt) && (value == NULL); next++) {
uint fpi = pta->edge_target(next); // Field (AddP)
PointsToNode *ptf = ptnode_adr(fpi);
if (ptf->offset() == offset) {
Node* nf = ptf->_node;
for (DUIterator_Fast imax, i = nf->fast_outs(imax); i < imax; i++) {
store = nf->fast_out(i);
if (store->is_Store() && store->in(0) != NULL) {
Node* ctrl = store->in(0);
while(!(ctrl == ini || ctrl == alloc || ctrl == NULL ||
ctrl == C->root() || ctrl == C->top() || ctrl->is_Region() ||
ctrl->is_IfTrue() || ctrl->is_IfFalse())) {
ctrl = ctrl->in(0);
}
if (ctrl == ini || ctrl == alloc) {
value = store->in(MemNode::ValueIn);
break;
}
}
}
}
}
}
}
if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
// A field's initializing value was not recorded. Add NULL.
add_edge_from_fields(alloc->_idx, null_idx, offset);
}
}
}
}
}
// Adjust escape state after Connection Graph is built.
void ConnectionGraph::adjust_escape_state(Node* n) {
PointsToNode* ptn = ptnode_adr(n->_idx);
assert(n->is_AddP(), "Should be called for AddP nodes only");
// Search for objects which are not scalar replaceable
// and mark them to propagate the state to referenced objects.
//
int offset = ptn->offset();
Node* base = get_addp_base(n);
VectorSet* ptset = PointsTo(base);
int ptset_size = ptset->Size();
// An object is not scalar replaceable if the field which may point
// to it has unknown offset (unknown element of an array of objects).
//
if (offset == Type::OffsetBot) {
uint e_cnt = ptn->edge_count();
for (uint ei = 0; ei < e_cnt; ei++) {
uint npi = ptn->edge_target(ei);
ptnode_adr(npi)->set_scalar_replaceable(false);
}
}
// Currently an object is not scalar replaceable if a LoadStore node
// access its field since the field value is unknown after it.
//
bool has_LoadStore = false;
for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
Node *use = n->fast_out(i);
if (use->is_LoadStore()) {
has_LoadStore = true;
break;
}
}
// An object is not scalar replaceable if the address points
// to unknown field (unknown element for arrays, offset is OffsetBot).
//
// Or the address may point to more then one object. This may produce
// the false positive result (set not scalar replaceable)
// since the flow-insensitive escape analysis can't separate
// the case when stores overwrite the field's value from the case
// when stores happened on different control branches.
//
// Note: it will disable scalar replacement in some cases:
//
// Point p[] = new Point[1];
// p[0] = new Point(); // Will be not scalar replaced
//
// but it will save us from incorrect optimizations in next cases:
//
// Point p[] = new Point[1];
// if ( x ) p[0] = new Point(); // Will be not scalar replaced
//
if (ptset_size > 1 || ptset_size != 0 &&
(has_LoadStore || offset == Type::OffsetBot)) {
for( VectorSetI j(ptset); j.test(); ++j ) {
ptnode_adr(j.elem)->set_scalar_replaceable(false);
}
}
}
// Propagate escape states to referenced nodes.
bool ConnectionGraph::propagate_escape_state(GrowableArray<int>* cg_worklist,
GrowableArray<uint>* worklist,
PointsToNode::EscapeState esc_state) {
bool has_java_obj = false;
// push all nodes with the same escape state on the worklist
uint cg_length = cg_worklist->length();
for (uint next = 0; next < cg_length; ++next) {
int nk = cg_worklist->at(next);
if (ptnode_adr(nk)->escape_state() == esc_state)
worklist->push(nk);
}
// mark all reachable nodes
while (worklist->length() > 0) {
int pt = worklist->pop();
PointsToNode* ptn = ptnode_adr(pt);
if (ptn->node_type() == PointsToNode::JavaObject &&
!is_null_ptr(pt)) {
has_java_obj = true;
if (esc_state > PointsToNode::NoEscape) {
// fields values are unknown if object escapes
add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
}
}
uint e_cnt = ptn->edge_count();
for (uint ei = 0; ei < e_cnt; ei++) {
uint npi = ptn->edge_target(ei);
if (is_null_ptr(npi))
continue;
PointsToNode *np = ptnode_adr(npi);
if (np->escape_state() < esc_state) {
set_escape_state(npi, esc_state);
worklist->push(npi);
}
}
}
// Has not escaping java objects
return has_java_obj && (esc_state < PointsToNode::GlobalEscape);
}
// Optimize objects compare.
Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
assert(OptimizePtrCompare, "sanity");
// Clone returned Set since PointsTo() returns pointer
// to the same structure ConnectionGraph.pt_ptset.
VectorSet ptset1 = *PointsTo(n->in(1));
VectorSet ptset2 = *PointsTo(n->in(2));
// Check simple cases first.
if (ptset1.Size() == 1) {
uint pt1 = ptset1.getelem();
PointsToNode* ptn1 = ptnode_adr(pt1);
if (ptn1->escape_state() == PointsToNode::NoEscape) {
if (ptset2.Size() == 1 && ptset2.getelem() == pt1) {
// Comparing the same not escaping object.
return _pcmp_eq;
}
Node* obj = ptn1->_node;
// Comparing not escaping allocation.
if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
!ptset2.test(pt1)) {
return _pcmp_neq; // This includes nullness check.
}
}
} else if (ptset2.Size() == 1) {
uint pt2 = ptset2.getelem();
PointsToNode* ptn2 = ptnode_adr(pt2);
if (ptn2->escape_state() == PointsToNode::NoEscape) {
Node* obj = ptn2->_node;
// Comparing not escaping allocation.
if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
!ptset1.test(pt2)) {
return _pcmp_neq; // This includes nullness check.
}
}
}
if (!ptset1.disjoint(ptset2)) {
return NULL; // Sets are not disjoint
}
// Sets are disjoint.
bool set1_has_unknown_ptr = ptset1.test(_phantom_object) != 0;
bool set2_has_unknown_ptr = ptset2.test(_phantom_object) != 0;
bool set1_has_null_ptr = (ptset1.test(_oop_null) | ptset1.test(_noop_null)) != 0;
bool set2_has_null_ptr = (ptset2.test(_oop_null) | ptset2.test(_noop_null)) != 0;
if (set1_has_unknown_ptr && set2_has_null_ptr ||
set2_has_unknown_ptr && set1_has_null_ptr) {
// Check nullness of unknown object.
return NULL;
}
// Disjointness by itself is not sufficient since
// alias analysis is not complete for escaped objects.
// Disjoint sets are definitely unrelated only when
// at least one set has only not escaping objects.
if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
bool has_only_non_escaping_alloc = true;
for (VectorSetI i(&ptset1); i.test(); ++i) {
uint pt = i.elem;
PointsToNode* ptn = ptnode_adr(pt);
Node* obj = ptn->_node;
if (ptn->escape_state() != PointsToNode::NoEscape ||
!(obj->is_Allocate() || obj->is_CallStaticJava())) {
has_only_non_escaping_alloc = false;
break;
}
}
if (has_only_non_escaping_alloc) {
return _pcmp_neq;
}
}
if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
bool has_only_non_escaping_alloc = true;
for (VectorSetI i(&ptset2); i.test(); ++i) {
uint pt = i.elem;
PointsToNode* ptn = ptnode_adr(pt);
Node* obj = ptn->_node;
if (ptn->escape_state() != PointsToNode::NoEscape ||
!(obj->is_Allocate() || obj->is_CallStaticJava())) {
has_only_non_escaping_alloc = false;
break;
}
}
if (has_only_non_escaping_alloc) {
return _pcmp_neq;
}
}
return NULL;
}
void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
bool is_arraycopy = false;
switch (call->Opcode()) {
#ifdef ASSERT
case Op_Allocate:
case Op_AllocateArray:
case Op_Lock:
case Op_Unlock:
assert(false, "should be done already");
break;
#endif
case Op_CallLeafNoFP:
is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
// fall through
case Op_CallLeaf:
{
// Stub calls, objects do not escape but they are not scale replaceable.
// Adjust escape state for outgoing arguments.
const TypeTuple * d = call->tf()->domain();
bool src_has_oops = false;
for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
const Type* at = d->field_at(i);
Node *arg = call->in(i)->uncast();
const Type *aat = phase->type(arg);
PointsToNode::EscapeState arg_esc = ptnode_adr(arg->_idx)->escape_state();
if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr() &&
(is_arraycopy || arg_esc < PointsToNode::ArgEscape)) {
assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
aat->isa_ptr() != NULL, "expecting an Ptr");
bool arg_has_oops = aat->isa_oopptr() &&
(aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
(aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
if (i == TypeFunc::Parms) {
src_has_oops = arg_has_oops;
}
//
// src or dst could be j.l.Object when other is basic type array:
//
// arraycopy(char[],0,Object*,0,size);
// arraycopy(Object*,0,char[],0,size);
//
// Don't add edges from dst's fields in such cases.
//
bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
arg_has_oops && (i > TypeFunc::Parms);
#ifdef ASSERT
if (!(is_arraycopy ||
call->as_CallLeaf()->_name != NULL &&
(strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
) {
call->dump();
assert(false, "EA: unexpected CallLeaf");
}
#endif
// Always process arraycopy's destination object since
// we need to add all possible edges to references in
// source object.
if (arg_esc >= PointsToNode::ArgEscape &&
!arg_is_arraycopy_dest) {
continue;
}
set_escape_state(arg->_idx, PointsToNode::ArgEscape);
Node* arg_base = arg;
if (arg->is_AddP()) {
//
// The inline_native_clone() case when the arraycopy stub is called
// after the allocation before Initialize and CheckCastPP nodes.
// Or normal arraycopy for object arrays case.
//
// Set AddP's base (Allocate) as not scalar replaceable since
// pointer to the base (with offset) is passed as argument.
//
arg_base = get_addp_base(arg);
}
VectorSet argset = *PointsTo(arg_base); // Clone set
for( VectorSetI j(&argset); j.test(); ++j ) {
uint pd = j.elem; // Destination object
set_escape_state(pd, PointsToNode::ArgEscape);
if (arg_is_arraycopy_dest) {
PointsToNode* ptd = ptnode_adr(pd);
// Conservatively reference an unknown object since
// not all source's fields/elements may be known.
add_edge_from_fields(pd, _phantom_object, Type::OffsetBot);
Node *src = call->in(TypeFunc::Parms)->uncast();
Node* src_base = src;
if (src->is_AddP()) {
src_base = get_addp_base(src);
}
// Create edges from destination's fields to
// everything known source's fields could point to.
for( VectorSetI s(PointsTo(src_base)); s.test(); ++s ) {
uint ps = s.elem;
bool has_bottom_offset = false;
for (uint fd = 0; fd < ptd->edge_count(); fd++) {
assert(ptd->edge_type(fd) == PointsToNode::FieldEdge, "expecting a field edge");
int fdi = ptd->edge_target(fd);
PointsToNode* pfd = ptnode_adr(fdi);
int offset = pfd->offset();
if (offset == Type::OffsetBot)
has_bottom_offset = true;
assert(offset != -1, "offset should be set");
add_deferred_edge_to_fields(fdi, ps, offset);
}
// Destination object may not have access (no field edge)
// to fields which are accessed in source object.
// As result no edges will be created to those source's
// fields and escape state of destination object will
// not be propagated to those fields.
//
// Mark source object as global escape except in
// the case with Type::OffsetBot field (which is
// common case for array elements access) when
// edges are created to all source's fields.
if (!has_bottom_offset) {
set_escape_state(ps, PointsToNode::GlobalEscape);
}
}
}
}
}
}
break;
}
case Op_CallStaticJava:
// For a static call, we know exactly what method is being called.
// Use bytecode estimator to record the call's escape affects
{
ciMethod *meth = call->as_CallJava()->method();
BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
// fall-through if not a Java method or no analyzer information
if (call_analyzer != NULL) {
const TypeTuple * d = call->tf()->domain();
bool copy_dependencies = false;
for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
const Type* at = d->field_at(i);
int k = i - TypeFunc::Parms;
Node *arg = call->in(i)->uncast();
if (at->isa_oopptr() != NULL &&
ptnode_adr(arg->_idx)->escape_state() < PointsToNode::GlobalEscape) {
bool global_escapes = false;
bool fields_escapes = false;
if (!call_analyzer->is_arg_stack(k)) {
// The argument global escapes, mark everything it could point to
set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
global_escapes = true;
} else {
if (!call_analyzer->is_arg_local(k)) {
// The argument itself doesn't escape, but any fields might
fields_escapes = true;
}
set_escape_state(arg->_idx, PointsToNode::ArgEscape);
copy_dependencies = true;
}
for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
uint pt = j.elem;
if (global_escapes) {
// The argument global escapes, mark everything it could point to
set_escape_state(pt, PointsToNode::GlobalEscape);
add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
} else {
set_escape_state(pt, PointsToNode::ArgEscape);
if (fields_escapes) {
// The argument itself doesn't escape, but any fields might.
// Use OffsetTop to indicate such case.
add_edge_from_fields(pt, _phantom_object, Type::OffsetTop);
}
}
}
}
}
if (copy_dependencies)
call_analyzer->copy_dependencies(_compile->dependencies());
break;
}
}
default:
// Fall-through here if not a Java method or no analyzer information
// or some other type of call, assume the worst case: all arguments
// globally escape.
{
// adjust escape state for outgoing arguments
const TypeTuple * d = call->tf()->domain();
for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
const Type* at = d->field_at(i);
if (at->isa_oopptr() != NULL) {
Node *arg = call->in(i)->uncast();
set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
uint pt = j.elem;
set_escape_state(pt, PointsToNode::GlobalEscape);
add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
}
}
}
}
}
}
void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
CallNode *call = resproj->in(0)->as_Call();
uint call_idx = call->_idx;
uint resproj_idx = resproj->_idx;
switch (call->Opcode()) {
case Op_Allocate:
{
Node *k = call->in(AllocateNode::KlassNode);
const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
assert(kt != NULL, "TypeKlassPtr required.");
ciKlass* cik = kt->klass();
PointsToNode::EscapeState es;
uint edge_to;
if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
!cik->is_instance_klass() || // StressReflectiveCode
cik->as_instance_klass()->has_finalizer()) {
es = PointsToNode::GlobalEscape;
edge_to = _phantom_object; // Could not be worse
} else {
es = PointsToNode::NoEscape;
edge_to = call_idx;
assert(ptnode_adr(call_idx)->scalar_replaceable(), "sanity");
}
set_escape_state(call_idx, es);
add_pointsto_edge(resproj_idx, edge_to);
_processed.set(resproj_idx);
break;
}
case Op_AllocateArray:
{
Node *k = call->in(AllocateNode::KlassNode);
const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
assert(kt != NULL, "TypeKlassPtr required.");
ciKlass* cik = kt->klass();
PointsToNode::EscapeState es;
uint edge_to;
if (!cik->is_array_klass()) { // StressReflectiveCode
es = PointsToNode::GlobalEscape;
edge_to = _phantom_object;
} else {
es = PointsToNode::NoEscape;
edge_to = call_idx;
assert(ptnode_adr(call_idx)->scalar_replaceable(), "sanity");
int length = call->in(AllocateNode::ALength)->find_int_con(-1);
if (length < 0 || length > EliminateAllocationArraySizeLimit) {
// Not scalar replaceable if the length is not constant or too big.
ptnode_adr(call_idx)->set_scalar_replaceable(false);
}
}
set_escape_state(call_idx, es);
add_pointsto_edge(resproj_idx, edge_to);
_processed.set(resproj_idx);
break;
}
case Op_CallStaticJava:
// For a static call, we know exactly what method is being called.
// Use bytecode estimator to record whether the call's return value escapes
{
bool done = true;
const TypeTuple *r = call->tf()->range();
const Type* ret_type = NULL;
if (r->cnt() > TypeFunc::Parms)
ret_type = r->field_at(TypeFunc::Parms);
// Note: we use isa_ptr() instead of isa_oopptr() here because the
// _multianewarray functions return a TypeRawPtr.
if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
_processed.set(resproj_idx);
break; // doesn't return a pointer type
}
ciMethod *meth = call->as_CallJava()->method();
const TypeTuple * d = call->tf()->domain();
if (meth == NULL) {
// not a Java method, assume global escape
set_escape_state(call_idx, PointsToNode::GlobalEscape);
add_pointsto_edge(resproj_idx, _phantom_object);
} else {
BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
bool copy_dependencies = false;
if (call_analyzer->is_return_allocated()) {
// Returns a newly allocated unescaped object, simply
// update dependency information.
// Mark it as NoEscape so that objects referenced by
// it's fields will be marked as NoEscape at least.
set_escape_state(call_idx, PointsToNode::NoEscape);
ptnode_adr(call_idx)->set_scalar_replaceable(false);
// Fields values are unknown
add_edge_from_fields(call_idx, _phantom_object, Type::OffsetBot);
add_pointsto_edge(resproj_idx, call_idx);
copy_dependencies = true;
} else {
// determine whether any arguments are returned
set_escape_state(call_idx, PointsToNode::ArgEscape);
bool ret_arg = false;
for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
const Type* at = d->field_at(i);
if (at->isa_oopptr() != NULL) {
Node *arg = call->in(i)->uncast();
if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
ret_arg = true;
PointsToNode *arg_esp = ptnode_adr(arg->_idx);
if (arg_esp->node_type() == PointsToNode::UnknownType)
done = false;
else if (arg_esp->node_type() == PointsToNode::JavaObject)
add_pointsto_edge(resproj_idx, arg->_idx);
else
add_deferred_edge(resproj_idx, arg->_idx);
}
}
}
if (done) {
copy_dependencies = true;
// is_return_local() is true when only arguments are returned.
if (!ret_arg || !call_analyzer->is_return_local()) {
// Returns unknown object.
add_pointsto_edge(resproj_idx, _phantom_object);
}
}
}
if (copy_dependencies)
call_analyzer->copy_dependencies(_compile->dependencies());
}
if (done)
_processed.set(resproj_idx);
break;
}
default:
// Some other type of call, assume the worst case that the
// returned value, if any, globally escapes.
{
const TypeTuple *r = call->tf()->range();
if (r->cnt() > TypeFunc::Parms) {
const Type* ret_type = r->field_at(TypeFunc::Parms);
// Note: we use isa_ptr() instead of isa_oopptr() here because the
// _multianewarray functions return a TypeRawPtr.
if (ret_type->isa_ptr() != NULL) {
set_escape_state(call_idx, PointsToNode::GlobalEscape);
add_pointsto_edge(resproj_idx, _phantom_object);
}
}
_processed.set(resproj_idx);
}
}
}
// Populate Connection Graph with Ideal nodes and create simple
// connection graph edges (do not need to check the node_type of inputs
// or to call PointsTo() to walk the connection graph).
void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
if (_processed.test(n->_idx))
return; // No need to redefine node's state.
if (n->is_Call()) {
// Arguments to allocation and locking don't escape.
if (n->is_Allocate()) {
add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
record_for_optimizer(n);
} else if (n->is_Lock() || n->is_Unlock()) {
// Put Lock and Unlock nodes on IGVN worklist to process them during
// the first IGVN optimization when escape information is still available.
record_for_optimizer(n);
_processed.set(n->_idx);
} else {
// Don't mark as processed since call's arguments have to be processed.
PointsToNode::NodeType nt = PointsToNode::UnknownType;
PointsToNode::EscapeState es = PointsToNode::UnknownEscape;
// Check if a call returns an object.
const TypeTuple *r = n->as_Call()->tf()->range();
if (r->cnt() > TypeFunc::Parms &&
r->field_at(TypeFunc::Parms)->isa_ptr() &&
n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
nt = PointsToNode::JavaObject;
if (!n->is_CallStaticJava()) {
// Since the called mathod is statically unknown assume
// the worst case that the returned value globally escapes.
es = PointsToNode::GlobalEscape;
}
}
add_node(n, nt, es, false);
}
return;
}
// Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
// ThreadLocal has RawPrt type.
switch (n->Opcode()) {
case Op_AddP:
{
add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
break;
}
case Op_CastX2P:
{ // "Unsafe" memory access.
add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
break;
}
case Op_CastPP:
case Op_CheckCastPP:
case Op_EncodeP:
case Op_DecodeN:
{
add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
int ti = n->in(1)->_idx;
PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
if (nt == PointsToNode::UnknownType) {
_delayed_worklist.push(n); // Process it later.
break;
} else if (nt == PointsToNode::JavaObject) {
add_pointsto_edge(n->_idx, ti);
} else {
add_deferred_edge(n->_idx, ti);
}
_processed.set(n->_idx);
break;
}
case Op_ConP:
{
// assume all pointer constants globally escape except for null
PointsToNode::EscapeState es;
if (phase->type(n) == TypePtr::NULL_PTR)
es = PointsToNode::NoEscape;
else
es = PointsToNode::GlobalEscape;
add_node(n, PointsToNode::JavaObject, es, true);
break;
}
case Op_ConN:
{
// assume all narrow oop constants globally escape except for null
PointsToNode::EscapeState es;
if (phase->type(n) == TypeNarrowOop::NULL_PTR)
es = PointsToNode::NoEscape;
else
es = PointsToNode::GlobalEscape;
add_node(n, PointsToNode::JavaObject, es, true);
break;
}
case Op_CreateEx:
{
// assume that all exception objects globally escape
add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
break;
}
case Op_LoadKlass:
case Op_LoadNKlass:
{
add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
break;
}
case Op_LoadP:
case Op_LoadN:
{
const Type *t = phase->type(n);
if (t->make_ptr() == NULL) {
_processed.set(n->_idx);
return;
}
add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
break;
}
case Op_Parm:
{
_processed.set(n->_idx); // No need to redefine it state.
uint con = n->as_Proj()->_con;
if (con < TypeFunc::Parms)
return;
const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
if (t->isa_ptr() == NULL)
return;
// We have to assume all input parameters globally escape
// (Note: passing 'false' since _processed is already set).
add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
break;
}
case Op_PartialSubtypeCheck:
{ // Produces Null or notNull and is used in CmpP.
add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
break;
}
case Op_Phi:
{
const Type *t = n->as_Phi()->type();
if (t->make_ptr() == NULL) {
// nothing to do if not an oop or narrow oop
_processed.set(n->_idx);
return;
}
add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
uint i;
for (i = 1; i < n->req() ; i++) {
Node* in = n->in(i);
if (in == NULL)
continue; // ignore NULL
in = in->uncast();
if (in->is_top() || in == n)
continue; // ignore top or inputs which go back this node
int ti = in->_idx;
PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
if (nt == PointsToNode::UnknownType) {
break;
} else if (nt == PointsToNode::JavaObject) {
add_pointsto_edge(n->_idx, ti);
} else {
add_deferred_edge(n->_idx, ti);
}
}
if (i >= n->req())
_processed.set(n->_idx);
else
_delayed_worklist.push(n);
break;
}
case Op_Proj:
{
// we are only interested in the oop result projection from a call
if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
assert(r->cnt() > TypeFunc::Parms, "sanity");
if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
int ti = n->in(0)->_idx;
// The call may not be registered yet (since not all its inputs are registered)
// if this is the projection from backbranch edge of Phi.
if (ptnode_adr(ti)->node_type() != PointsToNode::UnknownType) {
process_call_result(n->as_Proj(), phase);
}
if (!_processed.test(n->_idx)) {
// The call's result may need to be processed later if the call
// returns it's argument and the argument is not processed yet.
_delayed_worklist.push(n);
}
break;
}
}
_processed.set(n->_idx);
break;
}
case Op_Return:
{
if( n->req() > TypeFunc::Parms &&
phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
// Treat Return value as LocalVar with GlobalEscape escape state.
add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
int ti = n->in(TypeFunc::Parms)->_idx;
PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
if (nt == PointsToNode::UnknownType) {
_delayed_worklist.push(n); // Process it later.
break;
} else if (nt == PointsToNode::JavaObject) {
add_pointsto_edge(n->_idx, ti);
} else {
add_deferred_edge(n->_idx, ti);
}
}
_processed.set(n->_idx);
break;
}
case Op_StoreP:
case Op_StoreN:
{
const Type *adr_type = phase->type(n->in(MemNode::Address));
adr_type = adr_type->make_ptr();
if (adr_type->isa_oopptr()) {
add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
} else {
Node* adr = n->in(MemNode::Address);
if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
adr->in(AddPNode::Address)->is_Proj() &&
adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
// We are computing a raw address for a store captured
// by an Initialize compute an appropriate address type.
int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
assert(offs != Type::OffsetBot, "offset must be a constant");
} else {
_processed.set(n->_idx);
return;
}
}
break;
}
case Op_StorePConditional:
case Op_CompareAndSwapP:
case Op_CompareAndSwapN:
{
const Type *adr_type = phase->type(n->in(MemNode::Address));
adr_type = adr_type->make_ptr();
if (adr_type->isa_oopptr()) {
add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
} else {
_processed.set(n->_idx);
return;
}
break;
}
case Op_AryEq:
case Op_StrComp:
case Op_StrEquals:
case Op_StrIndexOf:
{
// char[] arrays passed to string intrinsics are not scalar replaceable.
add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
break;
}
case Op_ThreadLocal:
{
add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
break;
}
default:
;
// nothing to do
}
return;
}
void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
uint n_idx = n->_idx;
assert(ptnode_adr(n_idx)->_node != NULL, "node should be registered");
// Don't set processed bit for AddP, LoadP, StoreP since
// they may need more then one pass to process.
// Also don't mark as processed Call nodes since their
// arguments may need more then one pass to process.
if (_processed.test(n_idx))
return; // No need to redefine node's state.
if (n->is_Call()) {
CallNode *call = n->as_Call();
process_call_arguments(call, phase);
return;
}
switch (n->Opcode()) {
case Op_AddP:
{
Node *base = get_addp_base(n);
int offset = address_offset(n, phase);
// Create a field edge to this node from everything base could point to.
for( VectorSetI i(PointsTo(base)); i.test(); ++i ) {
uint pt = i.elem;
add_field_edge(pt, n_idx, offset);
}
break;
}
case Op_CastX2P:
{
assert(false, "Op_CastX2P");
break;
}
case Op_CastPP:
case Op_CheckCastPP:
case Op_EncodeP:
case Op_DecodeN:
{
int ti = n->in(1)->_idx;
assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "all nodes should be registered");
if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
add_pointsto_edge(n_idx, ti);
} else {
add_deferred_edge(n_idx, ti);
}
_processed.set(n_idx);
break;
}
case Op_ConP:
{
assert(false, "Op_ConP");
break;
}
case Op_ConN:
{
assert(false, "Op_ConN");
break;
}
case Op_CreateEx:
{
assert(false, "Op_CreateEx");
break;
}
case Op_LoadKlass:
case Op_LoadNKlass:
{
assert(false, "Op_LoadKlass");
break;
}
case Op_LoadP:
case Op_LoadN:
{
const Type *t = phase->type(n);
#ifdef ASSERT
if (t->make_ptr() == NULL)
assert(false, "Op_LoadP");
#endif
Node* adr = n->in(MemNode::Address)->uncast();
Node* adr_base;
if (adr->is_AddP()) {
adr_base = get_addp_base(adr);
} else {
adr_base = adr;
}
// For everything "adr_base" could point to, create a deferred edge from
// this node to each field with the same offset.
int offset = address_offset(adr, phase);
for( VectorSetI i(PointsTo(adr_base)); i.test(); ++i ) {
uint pt = i.elem;
if (adr->is_AddP()) {
// Add field edge if it is missing.
add_field_edge(pt, adr->_idx, offset);
}
add_deferred_edge_to_fields(n_idx, pt, offset);
}
break;
}
case Op_Parm:
{
assert(false, "Op_Parm");
break;
}
case Op_PartialSubtypeCheck:
{
assert(false, "Op_PartialSubtypeCheck");
break;
}
case Op_Phi:
{
#ifdef ASSERT
const Type *t = n->as_Phi()->type();
if (t->make_ptr() == NULL)
assert(false, "Op_Phi");
#endif
for (uint i = 1; i < n->req() ; i++) {
Node* in = n->in(i);
if (in == NULL)
continue; // ignore NULL
in = in->uncast();
if (in->is_top() || in == n)
continue; // ignore top or inputs which go back this node
int ti = in->_idx;
PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
assert(nt != PointsToNode::UnknownType, "all nodes should be known");
if (nt == PointsToNode::JavaObject) {
add_pointsto_edge(n_idx, ti);
} else {
add_deferred_edge(n_idx, ti);
}
}
_processed.set(n_idx);
break;
}
case Op_Proj:
{
// we are only interested in the oop result projection from a call
if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
assert(ptnode_adr(n->in(0)->_idx)->node_type() != PointsToNode::UnknownType,
"all nodes should be registered");
const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
assert(r->cnt() > TypeFunc::Parms, "sanity");
if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
process_call_result(n->as_Proj(), phase);
assert(_processed.test(n_idx), "all call results should be processed");
break;
}
}
assert(false, "Op_Proj");
break;
}
case Op_Return:
{
#ifdef ASSERT
if( n->req() <= TypeFunc::Parms ||
!phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
assert(false, "Op_Return");
}
#endif
int ti = n->in(TypeFunc::Parms)->_idx;
assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "node should be registered");
if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
add_pointsto_edge(n_idx, ti);
} else {
add_deferred_edge(n_idx, ti);
}
_processed.set(n_idx);
break;
}
case Op_StoreP:
case Op_StoreN:
case Op_StorePConditional:
case Op_CompareAndSwapP:
case Op_CompareAndSwapN:
{
Node *adr = n->in(MemNode::Address);
const Type *adr_type = phase->type(adr)->make_ptr();
#ifdef ASSERT
if (!adr_type->isa_oopptr())
assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
#endif
assert(adr->is_AddP(), "expecting an AddP");
Node *adr_base = get_addp_base(adr);
Node *val = n->in(MemNode::ValueIn)->uncast();
int offset = address_offset(adr, phase);
// For everything "adr_base" could point to, create a deferred edge
// to "val" from each field with the same offset.
for( VectorSetI i(PointsTo(adr_base)); i.test(); ++i ) {
uint pt = i.elem;
// Add field edge if it is missing.
add_field_edge(pt, adr->_idx, offset);
add_edge_from_fields(pt, val->_idx, offset);
}
break;
}
case Op_AryEq:
case Op_StrComp:
case Op_StrEquals:
case Op_StrIndexOf:
{
// char[] arrays passed to string intrinsic do not escape but
// they are not scalar replaceable. Adjust escape state for them.
// Start from in(2) edge since in(1) is memory edge.
for (uint i = 2; i < n->req(); i++) {
Node* adr = n->in(i)->uncast();
const Type *at = phase->type(adr);
if (!adr->is_top() && at->isa_ptr()) {
assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
at->isa_ptr() != NULL, "expecting an Ptr");
if (adr->is_AddP()) {
adr = get_addp_base(adr);
}
// Mark as ArgEscape everything "adr" could point to.
set_escape_state(adr->_idx, PointsToNode::ArgEscape);
}
}
_processed.set(n_idx);
break;
}
case Op_ThreadLocal:
{
assert(false, "Op_ThreadLocal");
break;
}
default:
// This method should be called only for EA specific nodes.
ShouldNotReachHere();
}
}
#ifndef PRODUCT
void ConnectionGraph::dump() {
bool first = true;
uint size = nodes_size();
for (uint ni = 0; ni < size; ni++) {
PointsToNode *ptn = ptnode_adr(ni);
PointsToNode::NodeType ptn_type = ptn->node_type();
if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)
continue;
PointsToNode::EscapeState es = escape_state(ptn->_node);
if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
if (first) {
tty->cr();
tty->print("======== Connection graph for ");
_compile->method()->print_short_name();
tty->cr();
first = false;
}
tty->print("%6d ", ni);
ptn->dump();
// Print all locals which reference this allocation
for (uint li = ni; li < size; li++) {
PointsToNode *ptn_loc = ptnode_adr(li);
PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
ptnode_adr(li)->dump(false);
}
}
if (Verbose) {
// Print all fields which reference this allocation
for (uint i = 0; i < ptn->edge_count(); i++) {
uint ei = ptn->edge_target(i);
ptnode_adr(ei)->dump(false);
}
}
tty->cr();
}
}
}
#endif