4597 lines
187 KiB
C++
4597 lines
187 KiB
C++
/*
|
|
* Copyright (c) 1997, 2013, 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 "classfile/systemDictionary.hpp"
|
|
#include "compiler/compileLog.hpp"
|
|
#include "memory/allocation.inline.hpp"
|
|
#include "oops/objArrayKlass.hpp"
|
|
#include "opto/addnode.hpp"
|
|
#include "opto/cfgnode.hpp"
|
|
#include "opto/compile.hpp"
|
|
#include "opto/connode.hpp"
|
|
#include "opto/loopnode.hpp"
|
|
#include "opto/machnode.hpp"
|
|
#include "opto/matcher.hpp"
|
|
#include "opto/memnode.hpp"
|
|
#include "opto/mulnode.hpp"
|
|
#include "opto/phaseX.hpp"
|
|
#include "opto/regmask.hpp"
|
|
|
|
// Portions of code courtesy of Clifford Click
|
|
|
|
// Optimization - Graph Style
|
|
|
|
static Node *step_through_mergemem(PhaseGVN *phase, MergeMemNode *mmem, const TypePtr *tp, const TypePtr *adr_check, outputStream *st);
|
|
|
|
//=============================================================================
|
|
uint MemNode::size_of() const { return sizeof(*this); }
|
|
|
|
const TypePtr *MemNode::adr_type() const {
|
|
Node* adr = in(Address);
|
|
const TypePtr* cross_check = NULL;
|
|
DEBUG_ONLY(cross_check = _adr_type);
|
|
return calculate_adr_type(adr->bottom_type(), cross_check);
|
|
}
|
|
|
|
#ifndef PRODUCT
|
|
void MemNode::dump_spec(outputStream *st) const {
|
|
if (in(Address) == NULL) return; // node is dead
|
|
#ifndef ASSERT
|
|
// fake the missing field
|
|
const TypePtr* _adr_type = NULL;
|
|
if (in(Address) != NULL)
|
|
_adr_type = in(Address)->bottom_type()->isa_ptr();
|
|
#endif
|
|
dump_adr_type(this, _adr_type, st);
|
|
|
|
Compile* C = Compile::current();
|
|
if( C->alias_type(_adr_type)->is_volatile() )
|
|
st->print(" Volatile!");
|
|
}
|
|
|
|
void MemNode::dump_adr_type(const Node* mem, const TypePtr* adr_type, outputStream *st) {
|
|
st->print(" @");
|
|
if (adr_type == NULL) {
|
|
st->print("NULL");
|
|
} else {
|
|
adr_type->dump_on(st);
|
|
Compile* C = Compile::current();
|
|
Compile::AliasType* atp = NULL;
|
|
if (C->have_alias_type(adr_type)) atp = C->alias_type(adr_type);
|
|
if (atp == NULL)
|
|
st->print(", idx=?\?;");
|
|
else if (atp->index() == Compile::AliasIdxBot)
|
|
st->print(", idx=Bot;");
|
|
else if (atp->index() == Compile::AliasIdxTop)
|
|
st->print(", idx=Top;");
|
|
else if (atp->index() == Compile::AliasIdxRaw)
|
|
st->print(", idx=Raw;");
|
|
else {
|
|
ciField* field = atp->field();
|
|
if (field) {
|
|
st->print(", name=");
|
|
field->print_name_on(st);
|
|
}
|
|
st->print(", idx=%d;", atp->index());
|
|
}
|
|
}
|
|
}
|
|
|
|
extern void print_alias_types();
|
|
|
|
#endif
|
|
|
|
Node *MemNode::optimize_simple_memory_chain(Node *mchain, const TypeOopPtr *t_oop, Node *load, PhaseGVN *phase) {
|
|
assert((t_oop != NULL), "sanity");
|
|
bool is_instance = t_oop->is_known_instance_field();
|
|
bool is_boxed_value_load = t_oop->is_ptr_to_boxed_value() &&
|
|
(load != NULL) && load->is_Load() &&
|
|
(phase->is_IterGVN() != NULL);
|
|
if (!(is_instance || is_boxed_value_load))
|
|
return mchain; // don't try to optimize non-instance types
|
|
uint instance_id = t_oop->instance_id();
|
|
Node *start_mem = phase->C->start()->proj_out(TypeFunc::Memory);
|
|
Node *prev = NULL;
|
|
Node *result = mchain;
|
|
while (prev != result) {
|
|
prev = result;
|
|
if (result == start_mem)
|
|
break; // hit one of our sentinels
|
|
// 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 == instance_id) {
|
|
break; // hit one of our sentinels
|
|
} else if (proj_in->is_Call()) {
|
|
CallNode *call = proj_in->as_Call();
|
|
if (!call->may_modify(t_oop, phase)) { // returns false for instances
|
|
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 == instance_id)) {
|
|
break;
|
|
}
|
|
if (is_instance) {
|
|
result = proj_in->in(TypeFunc::Memory);
|
|
} else if (is_boxed_value_load) {
|
|
Node* klass = alloc->in(AllocateNode::KlassNode);
|
|
const TypeKlassPtr* tklass = phase->type(klass)->is_klassptr();
|
|
if (tklass->klass_is_exact() && !tklass->klass()->equals(t_oop->klass())) {
|
|
result = proj_in->in(TypeFunc::Memory); // not related allocation
|
|
}
|
|
}
|
|
} else if (proj_in->is_MemBar()) {
|
|
result = proj_in->in(TypeFunc::Memory);
|
|
} else {
|
|
assert(false, "unexpected projection");
|
|
}
|
|
} else if (result->is_ClearArray()) {
|
|
if (!is_instance || !ClearArrayNode::step_through(&result, 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->is_MergeMem()) {
|
|
result = step_through_mergemem(phase, result->as_MergeMem(), t_oop, NULL, tty);
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
Node *MemNode::optimize_memory_chain(Node *mchain, const TypePtr *t_adr, Node *load, PhaseGVN *phase) {
|
|
const TypeOopPtr* t_oop = t_adr->isa_oopptr();
|
|
if (t_oop == NULL)
|
|
return mchain; // don't try to optimize non-oop types
|
|
Node* result = optimize_simple_memory_chain(mchain, t_oop, load, phase);
|
|
bool is_instance = t_oop->is_known_instance_field();
|
|
PhaseIterGVN *igvn = phase->is_IterGVN();
|
|
if (is_instance && igvn != NULL && result->is_Phi()) {
|
|
PhiNode *mphi = result->as_Phi();
|
|
assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
|
|
const TypePtr *t = mphi->adr_type();
|
|
if (t == TypePtr::BOTTOM || t == TypeRawPtr::BOTTOM ||
|
|
t->isa_oopptr() && !t->is_oopptr()->is_known_instance() &&
|
|
t->is_oopptr()->cast_to_exactness(true)
|
|
->is_oopptr()->cast_to_ptr_type(t_oop->ptr())
|
|
->is_oopptr()->cast_to_instance_id(t_oop->instance_id()) == t_oop) {
|
|
// clone the Phi with our address type
|
|
result = mphi->split_out_instance(t_adr, igvn);
|
|
} else {
|
|
assert(phase->C->get_alias_index(t) == phase->C->get_alias_index(t_adr), "correct memory chain");
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
static Node *step_through_mergemem(PhaseGVN *phase, MergeMemNode *mmem, const TypePtr *tp, const TypePtr *adr_check, outputStream *st) {
|
|
uint alias_idx = phase->C->get_alias_index(tp);
|
|
Node *mem = mmem;
|
|
#ifdef ASSERT
|
|
{
|
|
// Check that current type is consistent with the alias index used during graph construction
|
|
assert(alias_idx >= Compile::AliasIdxRaw, "must not be a bad alias_idx");
|
|
bool consistent = adr_check == NULL || adr_check->empty() ||
|
|
phase->C->must_alias(adr_check, alias_idx );
|
|
// Sometimes dead array references collapse to a[-1], a[-2], or a[-3]
|
|
if( !consistent && adr_check != NULL && !adr_check->empty() &&
|
|
tp->isa_aryptr() && tp->offset() == Type::OffsetBot &&
|
|
adr_check->isa_aryptr() && adr_check->offset() != Type::OffsetBot &&
|
|
( adr_check->offset() == arrayOopDesc::length_offset_in_bytes() ||
|
|
adr_check->offset() == oopDesc::klass_offset_in_bytes() ||
|
|
adr_check->offset() == oopDesc::mark_offset_in_bytes() ) ) {
|
|
// don't assert if it is dead code.
|
|
consistent = true;
|
|
}
|
|
if( !consistent ) {
|
|
st->print("alias_idx==%d, adr_check==", alias_idx);
|
|
if( adr_check == NULL ) {
|
|
st->print("NULL");
|
|
} else {
|
|
adr_check->dump();
|
|
}
|
|
st->cr();
|
|
print_alias_types();
|
|
assert(consistent, "adr_check must match alias idx");
|
|
}
|
|
}
|
|
#endif
|
|
// 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.
|
|
const TypeOopPtr *toop = tp->isa_oopptr();
|
|
if( tp->base() != Type::AnyPtr &&
|
|
!(toop &&
|
|
toop->klass() != NULL &&
|
|
toop->klass()->is_java_lang_Object() &&
|
|
toop->offset() == Type::OffsetBot) ) {
|
|
// compress paths and change unreachable cycles to TOP
|
|
// If not, we can update the input infinitely along a MergeMem cycle
|
|
// Equivalent code in PhiNode::Ideal
|
|
Node* m = phase->transform(mmem);
|
|
// If transformed to a MergeMem, get the desired slice
|
|
// Otherwise the returned node represents memory for every slice
|
|
mem = (m->is_MergeMem())? m->as_MergeMem()->memory_at(alias_idx) : m;
|
|
// Update input if it is progress over what we have now
|
|
}
|
|
return mem;
|
|
}
|
|
|
|
//--------------------------Ideal_common---------------------------------------
|
|
// Look for degenerate control and memory inputs. Bypass MergeMem inputs.
|
|
// Unhook non-raw memories from complete (macro-expanded) initializations.
|
|
Node *MemNode::Ideal_common(PhaseGVN *phase, bool can_reshape) {
|
|
// If our control input is a dead region, kill all below the region
|
|
Node *ctl = in(MemNode::Control);
|
|
if (ctl && remove_dead_region(phase, can_reshape))
|
|
return this;
|
|
ctl = in(MemNode::Control);
|
|
// Don't bother trying to transform a dead node
|
|
if (ctl && ctl->is_top()) return NodeSentinel;
|
|
|
|
PhaseIterGVN *igvn = phase->is_IterGVN();
|
|
// Wait if control on the worklist.
|
|
if (ctl && can_reshape && igvn != NULL) {
|
|
Node* bol = NULL;
|
|
Node* cmp = NULL;
|
|
if (ctl->in(0)->is_If()) {
|
|
assert(ctl->is_IfTrue() || ctl->is_IfFalse(), "sanity");
|
|
bol = ctl->in(0)->in(1);
|
|
if (bol->is_Bool())
|
|
cmp = ctl->in(0)->in(1)->in(1);
|
|
}
|
|
if (igvn->_worklist.member(ctl) ||
|
|
(bol != NULL && igvn->_worklist.member(bol)) ||
|
|
(cmp != NULL && igvn->_worklist.member(cmp)) ) {
|
|
// This control path may be dead.
|
|
// Delay this memory node transformation until the control is processed.
|
|
phase->is_IterGVN()->_worklist.push(this);
|
|
return NodeSentinel; // caller will return NULL
|
|
}
|
|
}
|
|
// Ignore if memory is dead, or self-loop
|
|
Node *mem = in(MemNode::Memory);
|
|
if (phase->type( mem ) == Type::TOP) return NodeSentinel; // caller will return NULL
|
|
assert(mem != this, "dead loop in MemNode::Ideal");
|
|
|
|
if (can_reshape && igvn != NULL && igvn->_worklist.member(mem)) {
|
|
// This memory slice may be dead.
|
|
// Delay this mem node transformation until the memory is processed.
|
|
phase->is_IterGVN()->_worklist.push(this);
|
|
return NodeSentinel; // caller will return NULL
|
|
}
|
|
|
|
Node *address = in(MemNode::Address);
|
|
const Type *t_adr = phase->type(address);
|
|
if (t_adr == Type::TOP) return NodeSentinel; // caller will return NULL
|
|
|
|
if (can_reshape && igvn != NULL &&
|
|
(igvn->_worklist.member(address) ||
|
|
igvn->_worklist.size() > 0 && (t_adr != adr_type())) ) {
|
|
// The address's base and type may change when the address is processed.
|
|
// Delay this mem node transformation until the address is processed.
|
|
phase->is_IterGVN()->_worklist.push(this);
|
|
return NodeSentinel; // caller will return NULL
|
|
}
|
|
|
|
// Do NOT remove or optimize the next lines: ensure a new alias index
|
|
// is allocated for an oop pointer type before Escape Analysis.
|
|
// Note: C++ will not remove it since the call has side effect.
|
|
if (t_adr->isa_oopptr()) {
|
|
int alias_idx = phase->C->get_alias_index(t_adr->is_ptr());
|
|
}
|
|
|
|
#ifdef ASSERT
|
|
Node* base = NULL;
|
|
if (address->is_AddP())
|
|
base = address->in(AddPNode::Base);
|
|
if (base != NULL && phase->type(base)->higher_equal(TypePtr::NULL_PTR) &&
|
|
!t_adr->isa_rawptr()) {
|
|
// Note: raw address has TOP base and top->higher_equal(TypePtr::NULL_PTR) is true.
|
|
Compile* C = phase->C;
|
|
tty->cr();
|
|
tty->print_cr("===== NULL+offs not RAW address =====");
|
|
if (C->is_dead_node(this->_idx)) tty->print_cr("'this' is dead");
|
|
if ((ctl != NULL) && C->is_dead_node(ctl->_idx)) tty->print_cr("'ctl' is dead");
|
|
if (C->is_dead_node(mem->_idx)) tty->print_cr("'mem' is dead");
|
|
if (C->is_dead_node(address->_idx)) tty->print_cr("'address' is dead");
|
|
if (C->is_dead_node(base->_idx)) tty->print_cr("'base' is dead");
|
|
tty->cr();
|
|
base->dump(1);
|
|
tty->cr();
|
|
this->dump(2);
|
|
tty->print("this->adr_type(): "); adr_type()->dump(); tty->cr();
|
|
tty->print("phase->type(address): "); t_adr->dump(); tty->cr();
|
|
tty->print("phase->type(base): "); phase->type(address)->dump(); tty->cr();
|
|
tty->cr();
|
|
}
|
|
assert(base == NULL || t_adr->isa_rawptr() ||
|
|
!phase->type(base)->higher_equal(TypePtr::NULL_PTR), "NULL+offs not RAW address?");
|
|
#endif
|
|
|
|
// Avoid independent memory operations
|
|
Node* old_mem = mem;
|
|
|
|
// The code which unhooks non-raw memories from complete (macro-expanded)
|
|
// initializations was removed. After macro-expansion all stores catched
|
|
// by Initialize node became raw stores and there is no information
|
|
// which memory slices they modify. So it is unsafe to move any memory
|
|
// operation above these stores. Also in most cases hooked non-raw memories
|
|
// were already unhooked by using information from detect_ptr_independence()
|
|
// and find_previous_store().
|
|
|
|
if (mem->is_MergeMem()) {
|
|
MergeMemNode* mmem = mem->as_MergeMem();
|
|
const TypePtr *tp = t_adr->is_ptr();
|
|
|
|
mem = step_through_mergemem(phase, mmem, tp, adr_type(), tty);
|
|
}
|
|
|
|
if (mem != old_mem) {
|
|
set_req(MemNode::Memory, mem);
|
|
if (can_reshape && old_mem->outcnt() == 0) {
|
|
igvn->_worklist.push(old_mem);
|
|
}
|
|
if (phase->type( mem ) == Type::TOP) return NodeSentinel;
|
|
return this;
|
|
}
|
|
|
|
// let the subclass continue analyzing...
|
|
return NULL;
|
|
}
|
|
|
|
// Helper function for proving some simple control dominations.
|
|
// Attempt to prove that all control inputs of 'dom' dominate 'sub'.
|
|
// Already assumes that 'dom' is available at 'sub', and that 'sub'
|
|
// is not a constant (dominated by the method's StartNode).
|
|
// Used by MemNode::find_previous_store to prove that the
|
|
// control input of a memory operation predates (dominates)
|
|
// an allocation it wants to look past.
|
|
bool MemNode::all_controls_dominate(Node* dom, Node* sub) {
|
|
if (dom == NULL || dom->is_top() || sub == NULL || sub->is_top())
|
|
return false; // Conservative answer for dead code
|
|
|
|
// Check 'dom'. Skip Proj and CatchProj nodes.
|
|
dom = dom->find_exact_control(dom);
|
|
if (dom == NULL || dom->is_top())
|
|
return false; // Conservative answer for dead code
|
|
|
|
if (dom == sub) {
|
|
// For the case when, for example, 'sub' is Initialize and the original
|
|
// 'dom' is Proj node of the 'sub'.
|
|
return false;
|
|
}
|
|
|
|
if (dom->is_Con() || dom->is_Start() || dom->is_Root() || dom == sub)
|
|
return true;
|
|
|
|
// 'dom' dominates 'sub' if its control edge and control edges
|
|
// of all its inputs dominate or equal to sub's control edge.
|
|
|
|
// Currently 'sub' is either Allocate, Initialize or Start nodes.
|
|
// Or Region for the check in LoadNode::Ideal();
|
|
// 'sub' should have sub->in(0) != NULL.
|
|
assert(sub->is_Allocate() || sub->is_Initialize() || sub->is_Start() ||
|
|
sub->is_Region() || sub->is_Call(), "expecting only these nodes");
|
|
|
|
// Get control edge of 'sub'.
|
|
Node* orig_sub = sub;
|
|
sub = sub->find_exact_control(sub->in(0));
|
|
if (sub == NULL || sub->is_top())
|
|
return false; // Conservative answer for dead code
|
|
|
|
assert(sub->is_CFG(), "expecting control");
|
|
|
|
if (sub == dom)
|
|
return true;
|
|
|
|
if (sub->is_Start() || sub->is_Root())
|
|
return false;
|
|
|
|
{
|
|
// Check all control edges of 'dom'.
|
|
|
|
ResourceMark rm;
|
|
Arena* arena = Thread::current()->resource_area();
|
|
Node_List nlist(arena);
|
|
Unique_Node_List dom_list(arena);
|
|
|
|
dom_list.push(dom);
|
|
bool only_dominating_controls = false;
|
|
|
|
for (uint next = 0; next < dom_list.size(); next++) {
|
|
Node* n = dom_list.at(next);
|
|
if (n == orig_sub)
|
|
return false; // One of dom's inputs dominated by sub.
|
|
if (!n->is_CFG() && n->pinned()) {
|
|
// Check only own control edge for pinned non-control nodes.
|
|
n = n->find_exact_control(n->in(0));
|
|
if (n == NULL || n->is_top())
|
|
return false; // Conservative answer for dead code
|
|
assert(n->is_CFG(), "expecting control");
|
|
dom_list.push(n);
|
|
} else if (n->is_Con() || n->is_Start() || n->is_Root()) {
|
|
only_dominating_controls = true;
|
|
} else if (n->is_CFG()) {
|
|
if (n->dominates(sub, nlist))
|
|
only_dominating_controls = true;
|
|
else
|
|
return false;
|
|
} else {
|
|
// First, own control edge.
|
|
Node* m = n->find_exact_control(n->in(0));
|
|
if (m != NULL) {
|
|
if (m->is_top())
|
|
return false; // Conservative answer for dead code
|
|
dom_list.push(m);
|
|
}
|
|
// Now, the rest of edges.
|
|
uint cnt = n->req();
|
|
for (uint i = 1; i < cnt; i++) {
|
|
m = n->find_exact_control(n->in(i));
|
|
if (m == NULL || m->is_top())
|
|
continue;
|
|
dom_list.push(m);
|
|
}
|
|
}
|
|
}
|
|
return only_dominating_controls;
|
|
}
|
|
}
|
|
|
|
//---------------------detect_ptr_independence---------------------------------
|
|
// Used by MemNode::find_previous_store to prove that two base
|
|
// pointers are never equal.
|
|
// The pointers are accompanied by their associated allocations,
|
|
// if any, which have been previously discovered by the caller.
|
|
bool MemNode::detect_ptr_independence(Node* p1, AllocateNode* a1,
|
|
Node* p2, AllocateNode* a2,
|
|
PhaseTransform* phase) {
|
|
// Attempt to prove that these two pointers cannot be aliased.
|
|
// They may both manifestly be allocations, and they should differ.
|
|
// Or, if they are not both allocations, they can be distinct constants.
|
|
// Otherwise, one is an allocation and the other a pre-existing value.
|
|
if (a1 == NULL && a2 == NULL) { // neither an allocation
|
|
return (p1 != p2) && p1->is_Con() && p2->is_Con();
|
|
} else if (a1 != NULL && a2 != NULL) { // both allocations
|
|
return (a1 != a2);
|
|
} else if (a1 != NULL) { // one allocation a1
|
|
// (Note: p2->is_Con implies p2->in(0)->is_Root, which dominates.)
|
|
return all_controls_dominate(p2, a1);
|
|
} else { //(a2 != NULL) // one allocation a2
|
|
return all_controls_dominate(p1, a2);
|
|
}
|
|
return false;
|
|
}
|
|
|
|
|
|
// The logic for reordering loads and stores uses four steps:
|
|
// (a) Walk carefully past stores and initializations which we
|
|
// can prove are independent of this load.
|
|
// (b) Observe that the next memory state makes an exact match
|
|
// with self (load or store), and locate the relevant store.
|
|
// (c) Ensure that, if we were to wire self directly to the store,
|
|
// the optimizer would fold it up somehow.
|
|
// (d) Do the rewiring, and return, depending on some other part of
|
|
// the optimizer to fold up the load.
|
|
// This routine handles steps (a) and (b). Steps (c) and (d) are
|
|
// specific to loads and stores, so they are handled by the callers.
|
|
// (Currently, only LoadNode::Ideal has steps (c), (d). More later.)
|
|
//
|
|
Node* MemNode::find_previous_store(PhaseTransform* phase) {
|
|
Node* ctrl = in(MemNode::Control);
|
|
Node* adr = in(MemNode::Address);
|
|
intptr_t offset = 0;
|
|
Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
|
|
AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
|
|
|
|
if (offset == Type::OffsetBot)
|
|
return NULL; // cannot unalias unless there are precise offsets
|
|
|
|
const TypeOopPtr *addr_t = adr->bottom_type()->isa_oopptr();
|
|
|
|
intptr_t size_in_bytes = memory_size();
|
|
|
|
Node* mem = in(MemNode::Memory); // start searching here...
|
|
|
|
int cnt = 50; // Cycle limiter
|
|
for (;;) { // While we can dance past unrelated stores...
|
|
if (--cnt < 0) break; // Caught in cycle or a complicated dance?
|
|
|
|
if (mem->is_Store()) {
|
|
Node* st_adr = mem->in(MemNode::Address);
|
|
intptr_t st_offset = 0;
|
|
Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
|
|
if (st_base == NULL)
|
|
break; // inscrutable pointer
|
|
if (st_offset != offset && st_offset != Type::OffsetBot) {
|
|
const int MAX_STORE = BytesPerLong;
|
|
if (st_offset >= offset + size_in_bytes ||
|
|
st_offset <= offset - MAX_STORE ||
|
|
st_offset <= offset - mem->as_Store()->memory_size()) {
|
|
// Success: The offsets are provably independent.
|
|
// (You may ask, why not just test st_offset != offset and be done?
|
|
// The answer is that stores of different sizes can co-exist
|
|
// in the same sequence of RawMem effects. We sometimes initialize
|
|
// a whole 'tile' of array elements with a single jint or jlong.)
|
|
mem = mem->in(MemNode::Memory);
|
|
continue; // (a) advance through independent store memory
|
|
}
|
|
}
|
|
if (st_base != base &&
|
|
detect_ptr_independence(base, alloc,
|
|
st_base,
|
|
AllocateNode::Ideal_allocation(st_base, phase),
|
|
phase)) {
|
|
// Success: The bases are provably independent.
|
|
mem = mem->in(MemNode::Memory);
|
|
continue; // (a) advance through independent store memory
|
|
}
|
|
|
|
// (b) At this point, if the bases or offsets do not agree, we lose,
|
|
// since we have not managed to prove 'this' and 'mem' independent.
|
|
if (st_base == base && st_offset == offset) {
|
|
return mem; // let caller handle steps (c), (d)
|
|
}
|
|
|
|
} else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
|
|
InitializeNode* st_init = mem->in(0)->as_Initialize();
|
|
AllocateNode* st_alloc = st_init->allocation();
|
|
if (st_alloc == NULL)
|
|
break; // something degenerated
|
|
bool known_identical = false;
|
|
bool known_independent = false;
|
|
if (alloc == st_alloc)
|
|
known_identical = true;
|
|
else if (alloc != NULL)
|
|
known_independent = true;
|
|
else if (all_controls_dominate(this, st_alloc))
|
|
known_independent = true;
|
|
|
|
if (known_independent) {
|
|
// The bases are provably independent: Either they are
|
|
// manifestly distinct allocations, or else the control
|
|
// of this load dominates the store's allocation.
|
|
int alias_idx = phase->C->get_alias_index(adr_type());
|
|
if (alias_idx == Compile::AliasIdxRaw) {
|
|
mem = st_alloc->in(TypeFunc::Memory);
|
|
} else {
|
|
mem = st_init->memory(alias_idx);
|
|
}
|
|
continue; // (a) advance through independent store memory
|
|
}
|
|
|
|
// (b) at this point, if we are not looking at a store initializing
|
|
// the same allocation we are loading from, we lose.
|
|
if (known_identical) {
|
|
// From caller, can_see_stored_value will consult find_captured_store.
|
|
return mem; // let caller handle steps (c), (d)
|
|
}
|
|
|
|
} else if (addr_t != NULL && addr_t->is_known_instance_field()) {
|
|
// Can't use optimize_simple_memory_chain() since it needs PhaseGVN.
|
|
if (mem->is_Proj() && mem->in(0)->is_Call()) {
|
|
CallNode *call = mem->in(0)->as_Call();
|
|
if (!call->may_modify(addr_t, phase)) {
|
|
mem = call->in(TypeFunc::Memory);
|
|
continue; // (a) advance through independent call memory
|
|
}
|
|
} else if (mem->is_Proj() && mem->in(0)->is_MemBar()) {
|
|
mem = mem->in(0)->in(TypeFunc::Memory);
|
|
continue; // (a) advance through independent MemBar memory
|
|
} else if (mem->is_ClearArray()) {
|
|
if (ClearArrayNode::step_through(&mem, (uint)addr_t->instance_id(), phase)) {
|
|
// (the call updated 'mem' value)
|
|
continue; // (a) advance through independent allocation memory
|
|
} else {
|
|
// Can not bypass initialization of the instance
|
|
// we are looking for.
|
|
return mem;
|
|
}
|
|
} else if (mem->is_MergeMem()) {
|
|
int alias_idx = phase->C->get_alias_index(adr_type());
|
|
mem = mem->as_MergeMem()->memory_at(alias_idx);
|
|
continue; // (a) advance through independent MergeMem memory
|
|
}
|
|
}
|
|
|
|
// Unless there is an explicit 'continue', we must bail out here,
|
|
// because 'mem' is an inscrutable memory state (e.g., a call).
|
|
break;
|
|
}
|
|
|
|
return NULL; // bail out
|
|
}
|
|
|
|
//----------------------calculate_adr_type-------------------------------------
|
|
// Helper function. Notices when the given type of address hits top or bottom.
|
|
// Also, asserts a cross-check of the type against the expected address type.
|
|
const TypePtr* MemNode::calculate_adr_type(const Type* t, const TypePtr* cross_check) {
|
|
if (t == Type::TOP) return NULL; // does not touch memory any more?
|
|
#ifdef PRODUCT
|
|
cross_check = NULL;
|
|
#else
|
|
if (!VerifyAliases || is_error_reported() || Node::in_dump()) cross_check = NULL;
|
|
#endif
|
|
const TypePtr* tp = t->isa_ptr();
|
|
if (tp == NULL) {
|
|
assert(cross_check == NULL || cross_check == TypePtr::BOTTOM, "expected memory type must be wide");
|
|
return TypePtr::BOTTOM; // touches lots of memory
|
|
} else {
|
|
#ifdef ASSERT
|
|
// %%%% [phh] We don't check the alias index if cross_check is
|
|
// TypeRawPtr::BOTTOM. Needs to be investigated.
|
|
if (cross_check != NULL &&
|
|
cross_check != TypePtr::BOTTOM &&
|
|
cross_check != TypeRawPtr::BOTTOM) {
|
|
// Recheck the alias index, to see if it has changed (due to a bug).
|
|
Compile* C = Compile::current();
|
|
assert(C->get_alias_index(cross_check) == C->get_alias_index(tp),
|
|
"must stay in the original alias category");
|
|
// The type of the address must be contained in the adr_type,
|
|
// disregarding "null"-ness.
|
|
// (We make an exception for TypeRawPtr::BOTTOM, which is a bit bucket.)
|
|
const TypePtr* tp_notnull = tp->join(TypePtr::NOTNULL)->is_ptr();
|
|
assert(cross_check->meet(tp_notnull) == cross_check->remove_speculative(),
|
|
"real address must not escape from expected memory type");
|
|
}
|
|
#endif
|
|
return tp;
|
|
}
|
|
}
|
|
|
|
//------------------------adr_phi_is_loop_invariant----------------------------
|
|
// A helper function for Ideal_DU_postCCP to check if a Phi in a counted
|
|
// loop is loop invariant. Make a quick traversal of Phi and associated
|
|
// CastPP nodes, looking to see if they are a closed group within the loop.
|
|
bool MemNode::adr_phi_is_loop_invariant(Node* adr_phi, Node* cast) {
|
|
// The idea is that the phi-nest must boil down to only CastPP nodes
|
|
// with the same data. This implies that any path into the loop already
|
|
// includes such a CastPP, and so the original cast, whatever its input,
|
|
// must be covered by an equivalent cast, with an earlier control input.
|
|
ResourceMark rm;
|
|
|
|
// The loop entry input of the phi should be the unique dominating
|
|
// node for every Phi/CastPP in the loop.
|
|
Unique_Node_List closure;
|
|
closure.push(adr_phi->in(LoopNode::EntryControl));
|
|
|
|
// Add the phi node and the cast to the worklist.
|
|
Unique_Node_List worklist;
|
|
worklist.push(adr_phi);
|
|
if( cast != NULL ){
|
|
if( !cast->is_ConstraintCast() ) return false;
|
|
worklist.push(cast);
|
|
}
|
|
|
|
// Begin recursive walk of phi nodes.
|
|
while( worklist.size() ){
|
|
// Take a node off the worklist
|
|
Node *n = worklist.pop();
|
|
if( !closure.member(n) ){
|
|
// Add it to the closure.
|
|
closure.push(n);
|
|
// Make a sanity check to ensure we don't waste too much time here.
|
|
if( closure.size() > 20) return false;
|
|
// This node is OK if:
|
|
// - it is a cast of an identical value
|
|
// - or it is a phi node (then we add its inputs to the worklist)
|
|
// Otherwise, the node is not OK, and we presume the cast is not invariant
|
|
if( n->is_ConstraintCast() ){
|
|
worklist.push(n->in(1));
|
|
} else if( n->is_Phi() ) {
|
|
for( uint i = 1; i < n->req(); i++ ) {
|
|
worklist.push(n->in(i));
|
|
}
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Quit when the worklist is empty, and we've found no offending nodes.
|
|
return true;
|
|
}
|
|
|
|
//------------------------------Ideal_DU_postCCP-------------------------------
|
|
// Find any cast-away of null-ness and keep its control. Null cast-aways are
|
|
// going away in this pass and we need to make this memory op depend on the
|
|
// gating null check.
|
|
Node *MemNode::Ideal_DU_postCCP( PhaseCCP *ccp ) {
|
|
return Ideal_common_DU_postCCP(ccp, this, in(MemNode::Address));
|
|
}
|
|
|
|
// I tried to leave the CastPP's in. This makes the graph more accurate in
|
|
// some sense; we get to keep around the knowledge that an oop is not-null
|
|
// after some test. Alas, the CastPP's interfere with GVN (some values are
|
|
// the regular oop, some are the CastPP of the oop, all merge at Phi's which
|
|
// cannot collapse, etc). This cost us 10% on SpecJVM, even when I removed
|
|
// some of the more trivial cases in the optimizer. Removing more useless
|
|
// Phi's started allowing Loads to illegally float above null checks. I gave
|
|
// up on this approach. CNC 10/20/2000
|
|
// This static method may be called not from MemNode (EncodePNode calls it).
|
|
// Only the control edge of the node 'n' might be updated.
|
|
Node *MemNode::Ideal_common_DU_postCCP( PhaseCCP *ccp, Node* n, Node* adr ) {
|
|
Node *skipped_cast = NULL;
|
|
// Need a null check? Regular static accesses do not because they are
|
|
// from constant addresses. Array ops are gated by the range check (which
|
|
// always includes a NULL check). Just check field ops.
|
|
if( n->in(MemNode::Control) == NULL ) {
|
|
// Scan upwards for the highest location we can place this memory op.
|
|
while( true ) {
|
|
switch( adr->Opcode() ) {
|
|
|
|
case Op_AddP: // No change to NULL-ness, so peek thru AddP's
|
|
adr = adr->in(AddPNode::Base);
|
|
continue;
|
|
|
|
case Op_DecodeN: // No change to NULL-ness, so peek thru
|
|
case Op_DecodeNKlass:
|
|
adr = adr->in(1);
|
|
continue;
|
|
|
|
case Op_EncodeP:
|
|
case Op_EncodePKlass:
|
|
// EncodeP node's control edge could be set by this method
|
|
// when EncodeP node depends on CastPP node.
|
|
//
|
|
// Use its control edge for memory op because EncodeP may go away
|
|
// later when it is folded with following or preceding DecodeN node.
|
|
if (adr->in(0) == NULL) {
|
|
// Keep looking for cast nodes.
|
|
adr = adr->in(1);
|
|
continue;
|
|
}
|
|
ccp->hash_delete(n);
|
|
n->set_req(MemNode::Control, adr->in(0));
|
|
ccp->hash_insert(n);
|
|
return n;
|
|
|
|
case Op_CastPP:
|
|
// If the CastPP is useless, just peek on through it.
|
|
if( ccp->type(adr) == ccp->type(adr->in(1)) ) {
|
|
// Remember the cast that we've peeked though. If we peek
|
|
// through more than one, then we end up remembering the highest
|
|
// one, that is, if in a loop, the one closest to the top.
|
|
skipped_cast = adr;
|
|
adr = adr->in(1);
|
|
continue;
|
|
}
|
|
// CastPP is going away in this pass! We need this memory op to be
|
|
// control-dependent on the test that is guarding the CastPP.
|
|
ccp->hash_delete(n);
|
|
n->set_req(MemNode::Control, adr->in(0));
|
|
ccp->hash_insert(n);
|
|
return n;
|
|
|
|
case Op_Phi:
|
|
// Attempt to float above a Phi to some dominating point.
|
|
if (adr->in(0) != NULL && adr->in(0)->is_CountedLoop()) {
|
|
// If we've already peeked through a Cast (which could have set the
|
|
// control), we can't float above a Phi, because the skipped Cast
|
|
// may not be loop invariant.
|
|
if (adr_phi_is_loop_invariant(adr, skipped_cast)) {
|
|
adr = adr->in(1);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
// Intentional fallthrough!
|
|
|
|
// No obvious dominating point. The mem op is pinned below the Phi
|
|
// by the Phi itself. If the Phi goes away (no true value is merged)
|
|
// then the mem op can float, but not indefinitely. It must be pinned
|
|
// behind the controls leading to the Phi.
|
|
case Op_CheckCastPP:
|
|
// These usually stick around to change address type, however a
|
|
// useless one can be elided and we still need to pick up a control edge
|
|
if (adr->in(0) == NULL) {
|
|
// This CheckCastPP node has NO control and is likely useless. But we
|
|
// need check further up the ancestor chain for a control input to keep
|
|
// the node in place. 4959717.
|
|
skipped_cast = adr;
|
|
adr = adr->in(1);
|
|
continue;
|
|
}
|
|
ccp->hash_delete(n);
|
|
n->set_req(MemNode::Control, adr->in(0));
|
|
ccp->hash_insert(n);
|
|
return n;
|
|
|
|
// List of "safe" opcodes; those that implicitly block the memory
|
|
// op below any null check.
|
|
case Op_CastX2P: // no null checks on native pointers
|
|
case Op_Parm: // 'this' pointer is not null
|
|
case Op_LoadP: // Loading from within a klass
|
|
case Op_LoadN: // Loading from within a klass
|
|
case Op_LoadKlass: // Loading from within a klass
|
|
case Op_LoadNKlass: // Loading from within a klass
|
|
case Op_ConP: // Loading from a klass
|
|
case Op_ConN: // Loading from a klass
|
|
case Op_ConNKlass: // Loading from a klass
|
|
case Op_CreateEx: // Sucking up the guts of an exception oop
|
|
case Op_Con: // Reading from TLS
|
|
case Op_CMoveP: // CMoveP is pinned
|
|
case Op_CMoveN: // CMoveN is pinned
|
|
break; // No progress
|
|
|
|
case Op_Proj: // Direct call to an allocation routine
|
|
case Op_SCMemProj: // Memory state from store conditional ops
|
|
#ifdef ASSERT
|
|
{
|
|
assert(adr->as_Proj()->_con == TypeFunc::Parms, "must be return value");
|
|
const Node* call = adr->in(0);
|
|
if (call->is_CallJava()) {
|
|
const CallJavaNode* call_java = call->as_CallJava();
|
|
const TypeTuple *r = call_java->tf()->range();
|
|
assert(r->cnt() > TypeFunc::Parms, "must return value");
|
|
const Type* ret_type = r->field_at(TypeFunc::Parms);
|
|
assert(ret_type && ret_type->isa_ptr(), "must return pointer");
|
|
// We further presume that this is one of
|
|
// new_instance_Java, new_array_Java, or
|
|
// the like, but do not assert for this.
|
|
} else if (call->is_Allocate()) {
|
|
// similar case to new_instance_Java, etc.
|
|
} else if (!call->is_CallLeaf()) {
|
|
// Projections from fetch_oop (OSR) are allowed as well.
|
|
ShouldNotReachHere();
|
|
}
|
|
}
|
|
#endif
|
|
break;
|
|
default:
|
|
ShouldNotReachHere();
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
return NULL; // No progress
|
|
}
|
|
|
|
|
|
//=============================================================================
|
|
uint LoadNode::size_of() const { return sizeof(*this); }
|
|
uint LoadNode::cmp( const Node &n ) const
|
|
{ return !Type::cmp( _type, ((LoadNode&)n)._type ); }
|
|
const Type *LoadNode::bottom_type() const { return _type; }
|
|
uint LoadNode::ideal_reg() const {
|
|
return _type->ideal_reg();
|
|
}
|
|
|
|
#ifndef PRODUCT
|
|
void LoadNode::dump_spec(outputStream *st) const {
|
|
MemNode::dump_spec(st);
|
|
if( !Verbose && !WizardMode ) {
|
|
// standard dump does this in Verbose and WizardMode
|
|
st->print(" #"); _type->dump_on(st);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#ifdef ASSERT
|
|
//----------------------------is_immutable_value-------------------------------
|
|
// Helper function to allow a raw load without control edge for some cases
|
|
bool LoadNode::is_immutable_value(Node* adr) {
|
|
return (adr->is_AddP() && adr->in(AddPNode::Base)->is_top() &&
|
|
adr->in(AddPNode::Address)->Opcode() == Op_ThreadLocal &&
|
|
(adr->in(AddPNode::Offset)->find_intptr_t_con(-1) ==
|
|
in_bytes(JavaThread::osthread_offset())));
|
|
}
|
|
#endif
|
|
|
|
//----------------------------LoadNode::make-----------------------------------
|
|
// Polymorphic factory method:
|
|
Node *LoadNode::make(PhaseGVN& gvn, Node *ctl, Node *mem, Node *adr, const TypePtr* adr_type, const Type *rt, BasicType bt, MemOrd mo) {
|
|
Compile* C = gvn.C;
|
|
|
|
// sanity check the alias category against the created node type
|
|
assert(!(adr_type->isa_oopptr() &&
|
|
adr_type->offset() == oopDesc::klass_offset_in_bytes()),
|
|
"use LoadKlassNode instead");
|
|
assert(!(adr_type->isa_aryptr() &&
|
|
adr_type->offset() == arrayOopDesc::length_offset_in_bytes()),
|
|
"use LoadRangeNode instead");
|
|
// Check control edge of raw loads
|
|
assert( ctl != NULL || C->get_alias_index(adr_type) != Compile::AliasIdxRaw ||
|
|
// oop will be recorded in oop map if load crosses safepoint
|
|
rt->isa_oopptr() || is_immutable_value(adr),
|
|
"raw memory operations should have control edge");
|
|
switch (bt) {
|
|
case T_BOOLEAN: return new (C) LoadUBNode(ctl, mem, adr, adr_type, rt->is_int(), mo);
|
|
case T_BYTE: return new (C) LoadBNode (ctl, mem, adr, adr_type, rt->is_int(), mo);
|
|
case T_INT: return new (C) LoadINode (ctl, mem, adr, adr_type, rt->is_int(), mo);
|
|
case T_CHAR: return new (C) LoadUSNode(ctl, mem, adr, adr_type, rt->is_int(), mo);
|
|
case T_SHORT: return new (C) LoadSNode (ctl, mem, adr, adr_type, rt->is_int(), mo);
|
|
case T_LONG: return new (C) LoadLNode (ctl, mem, adr, adr_type, rt->is_long(), mo);
|
|
case T_FLOAT: return new (C) LoadFNode (ctl, mem, adr, adr_type, rt, mo);
|
|
case T_DOUBLE: return new (C) LoadDNode (ctl, mem, adr, adr_type, rt, mo);
|
|
case T_ADDRESS: return new (C) LoadPNode (ctl, mem, adr, adr_type, rt->is_ptr(), mo);
|
|
case T_OBJECT:
|
|
#ifdef _LP64
|
|
if (adr->bottom_type()->is_ptr_to_narrowoop()) {
|
|
Node* load = gvn.transform(new (C) LoadNNode(ctl, mem, adr, adr_type, rt->make_narrowoop(), mo));
|
|
return new (C) DecodeNNode(load, load->bottom_type()->make_ptr());
|
|
} else
|
|
#endif
|
|
{
|
|
assert(!adr->bottom_type()->is_ptr_to_narrowoop() && !adr->bottom_type()->is_ptr_to_narrowklass(), "should have got back a narrow oop");
|
|
return new (C) LoadPNode(ctl, mem, adr, adr_type, rt->is_oopptr(), mo);
|
|
}
|
|
}
|
|
ShouldNotReachHere();
|
|
return (LoadNode*)NULL;
|
|
}
|
|
|
|
LoadLNode* LoadLNode::make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, const Type* rt, MemOrd mo) {
|
|
bool require_atomic = true;
|
|
return new (C) LoadLNode(ctl, mem, adr, adr_type, rt->is_long(), mo, require_atomic);
|
|
}
|
|
|
|
|
|
|
|
|
|
//------------------------------hash-------------------------------------------
|
|
uint LoadNode::hash() const {
|
|
// unroll addition of interesting fields
|
|
return (uintptr_t)in(Control) + (uintptr_t)in(Memory) + (uintptr_t)in(Address);
|
|
}
|
|
|
|
static bool skip_through_membars(Compile::AliasType* atp, const TypeInstPtr* tp, bool eliminate_boxing) {
|
|
if ((atp != NULL) && (atp->index() >= Compile::AliasIdxRaw)) {
|
|
bool non_volatile = (atp->field() != NULL) && !atp->field()->is_volatile();
|
|
bool is_stable_ary = FoldStableValues &&
|
|
(tp != NULL) && (tp->isa_aryptr() != NULL) &&
|
|
tp->isa_aryptr()->is_stable();
|
|
|
|
return (eliminate_boxing && non_volatile) || is_stable_ary;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
//---------------------------can_see_stored_value------------------------------
|
|
// This routine exists to make sure this set of tests is done the same
|
|
// everywhere. We need to make a coordinated change: first LoadNode::Ideal
|
|
// will change the graph shape in a way which makes memory alive twice at the
|
|
// same time (uses the Oracle model of aliasing), then some
|
|
// LoadXNode::Identity will fold things back to the equivalence-class model
|
|
// of aliasing.
|
|
Node* MemNode::can_see_stored_value(Node* st, PhaseTransform* phase) const {
|
|
Node* ld_adr = in(MemNode::Address);
|
|
intptr_t ld_off = 0;
|
|
AllocateNode* ld_alloc = AllocateNode::Ideal_allocation(ld_adr, phase, ld_off);
|
|
const TypeInstPtr* tp = phase->type(ld_adr)->isa_instptr();
|
|
Compile::AliasType* atp = (tp != NULL) ? phase->C->alias_type(tp) : NULL;
|
|
// This is more general than load from boxing objects.
|
|
if (skip_through_membars(atp, tp, phase->C->eliminate_boxing())) {
|
|
uint alias_idx = atp->index();
|
|
bool final = !atp->is_rewritable();
|
|
Node* result = NULL;
|
|
Node* current = st;
|
|
// Skip through chains of MemBarNodes checking the MergeMems for
|
|
// new states for the slice of this load. Stop once any other
|
|
// kind of node is encountered. Loads from final memory can skip
|
|
// through any kind of MemBar but normal loads shouldn't skip
|
|
// through MemBarAcquire since the could allow them to move out of
|
|
// a synchronized region.
|
|
while (current->is_Proj()) {
|
|
int opc = current->in(0)->Opcode();
|
|
if ((final && (opc == Op_MemBarAcquire ||
|
|
opc == Op_MemBarAcquireLock ||
|
|
opc == Op_LoadFence)) ||
|
|
opc == Op_MemBarRelease ||
|
|
opc == Op_StoreFence ||
|
|
opc == Op_MemBarReleaseLock ||
|
|
opc == Op_MemBarCPUOrder) {
|
|
Node* mem = current->in(0)->in(TypeFunc::Memory);
|
|
if (mem->is_MergeMem()) {
|
|
MergeMemNode* merge = mem->as_MergeMem();
|
|
Node* new_st = merge->memory_at(alias_idx);
|
|
if (new_st == merge->base_memory()) {
|
|
// Keep searching
|
|
current = new_st;
|
|
continue;
|
|
}
|
|
// Save the new memory state for the slice and fall through
|
|
// to exit.
|
|
result = new_st;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
if (result != NULL) {
|
|
st = result;
|
|
}
|
|
}
|
|
|
|
// Loop around twice in the case Load -> Initialize -> Store.
|
|
// (See PhaseIterGVN::add_users_to_worklist, which knows about this case.)
|
|
for (int trip = 0; trip <= 1; trip++) {
|
|
|
|
if (st->is_Store()) {
|
|
Node* st_adr = st->in(MemNode::Address);
|
|
if (!phase->eqv(st_adr, ld_adr)) {
|
|
// Try harder before giving up... Match raw and non-raw pointers.
|
|
intptr_t st_off = 0;
|
|
AllocateNode* alloc = AllocateNode::Ideal_allocation(st_adr, phase, st_off);
|
|
if (alloc == NULL) return NULL;
|
|
if (alloc != ld_alloc) return NULL;
|
|
if (ld_off != st_off) return NULL;
|
|
// At this point we have proven something like this setup:
|
|
// A = Allocate(...)
|
|
// L = LoadQ(, AddP(CastPP(, A.Parm),, #Off))
|
|
// S = StoreQ(, AddP(, A.Parm , #Off), V)
|
|
// (Actually, we haven't yet proven the Q's are the same.)
|
|
// In other words, we are loading from a casted version of
|
|
// the same pointer-and-offset that we stored to.
|
|
// Thus, we are able to replace L by V.
|
|
}
|
|
// Now prove that we have a LoadQ matched to a StoreQ, for some Q.
|
|
if (store_Opcode() != st->Opcode())
|
|
return NULL;
|
|
return st->in(MemNode::ValueIn);
|
|
}
|
|
|
|
// A load from a freshly-created object always returns zero.
|
|
// (This can happen after LoadNode::Ideal resets the load's memory input
|
|
// to find_captured_store, which returned InitializeNode::zero_memory.)
|
|
if (st->is_Proj() && st->in(0)->is_Allocate() &&
|
|
(st->in(0) == ld_alloc) &&
|
|
(ld_off >= st->in(0)->as_Allocate()->minimum_header_size())) {
|
|
// return a zero value for the load's basic type
|
|
// (This is one of the few places where a generic PhaseTransform
|
|
// can create new nodes. Think of it as lazily manifesting
|
|
// virtually pre-existing constants.)
|
|
return phase->zerocon(memory_type());
|
|
}
|
|
|
|
// A load from an initialization barrier can match a captured store.
|
|
if (st->is_Proj() && st->in(0)->is_Initialize()) {
|
|
InitializeNode* init = st->in(0)->as_Initialize();
|
|
AllocateNode* alloc = init->allocation();
|
|
if ((alloc != NULL) && (alloc == ld_alloc)) {
|
|
// examine a captured store value
|
|
st = init->find_captured_store(ld_off, memory_size(), phase);
|
|
if (st != NULL)
|
|
continue; // take one more trip around
|
|
}
|
|
}
|
|
|
|
// Load boxed value from result of valueOf() call is input parameter.
|
|
if (this->is_Load() && ld_adr->is_AddP() &&
|
|
(tp != NULL) && tp->is_ptr_to_boxed_value()) {
|
|
intptr_t ignore = 0;
|
|
Node* base = AddPNode::Ideal_base_and_offset(ld_adr, phase, ignore);
|
|
if (base != NULL && base->is_Proj() &&
|
|
base->as_Proj()->_con == TypeFunc::Parms &&
|
|
base->in(0)->is_CallStaticJava() &&
|
|
base->in(0)->as_CallStaticJava()->is_boxing_method()) {
|
|
return base->in(0)->in(TypeFunc::Parms);
|
|
}
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
//----------------------is_instance_field_load_with_local_phi------------------
|
|
bool LoadNode::is_instance_field_load_with_local_phi(Node* ctrl) {
|
|
if( in(Memory)->is_Phi() && in(Memory)->in(0) == ctrl &&
|
|
in(Address)->is_AddP() ) {
|
|
const TypeOopPtr* t_oop = in(Address)->bottom_type()->isa_oopptr();
|
|
// Only instances and boxed values.
|
|
if( t_oop != NULL &&
|
|
(t_oop->is_ptr_to_boxed_value() ||
|
|
t_oop->is_known_instance_field()) &&
|
|
t_oop->offset() != Type::OffsetBot &&
|
|
t_oop->offset() != Type::OffsetTop) {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
//------------------------------Identity---------------------------------------
|
|
// Loads are identity if previous store is to same address
|
|
Node *LoadNode::Identity( PhaseTransform *phase ) {
|
|
// If the previous store-maker is the right kind of Store, and the store is
|
|
// to the same address, then we are equal to the value stored.
|
|
Node* mem = in(Memory);
|
|
Node* value = can_see_stored_value(mem, phase);
|
|
if( value ) {
|
|
// byte, short & char stores truncate naturally.
|
|
// A load has to load the truncated value which requires
|
|
// some sort of masking operation and that requires an
|
|
// Ideal call instead of an Identity call.
|
|
if (memory_size() < BytesPerInt) {
|
|
// If the input to the store does not fit with the load's result type,
|
|
// it must be truncated via an Ideal call.
|
|
if (!phase->type(value)->higher_equal(phase->type(this)))
|
|
return this;
|
|
}
|
|
// (This works even when value is a Con, but LoadNode::Value
|
|
// usually runs first, producing the singleton type of the Con.)
|
|
return value;
|
|
}
|
|
|
|
// Search for an existing data phi which was generated before for the same
|
|
// instance's field to avoid infinite generation of phis in a loop.
|
|
Node *region = mem->in(0);
|
|
if (is_instance_field_load_with_local_phi(region)) {
|
|
const TypeOopPtr *addr_t = in(Address)->bottom_type()->isa_oopptr();
|
|
int this_index = phase->C->get_alias_index(addr_t);
|
|
int this_offset = addr_t->offset();
|
|
int this_iid = addr_t->instance_id();
|
|
if (!addr_t->is_known_instance() &&
|
|
addr_t->is_ptr_to_boxed_value()) {
|
|
// Use _idx of address base (could be Phi node) for boxed values.
|
|
intptr_t ignore = 0;
|
|
Node* base = AddPNode::Ideal_base_and_offset(in(Address), phase, ignore);
|
|
this_iid = base->_idx;
|
|
}
|
|
const Type* this_type = bottom_type();
|
|
for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
|
|
Node* phi = region->fast_out(i);
|
|
if (phi->is_Phi() && phi != mem &&
|
|
phi->as_Phi()->is_same_inst_field(this_type, this_iid, this_index, this_offset)) {
|
|
return phi;
|
|
}
|
|
}
|
|
}
|
|
|
|
return this;
|
|
}
|
|
|
|
// We're loading from an object which has autobox behaviour.
|
|
// If this object is result of a valueOf call we'll have a phi
|
|
// merging a newly allocated object and a load from the cache.
|
|
// We want to replace this load with the original incoming
|
|
// argument to the valueOf call.
|
|
Node* LoadNode::eliminate_autobox(PhaseGVN* phase) {
|
|
assert(phase->C->eliminate_boxing(), "sanity");
|
|
intptr_t ignore = 0;
|
|
Node* base = AddPNode::Ideal_base_and_offset(in(Address), phase, ignore);
|
|
if ((base == NULL) || base->is_Phi()) {
|
|
// Push the loads from the phi that comes from valueOf up
|
|
// through it to allow elimination of the loads and the recovery
|
|
// of the original value. It is done in split_through_phi().
|
|
return NULL;
|
|
} else if (base->is_Load() ||
|
|
base->is_DecodeN() && base->in(1)->is_Load()) {
|
|
// Eliminate the load of boxed value for integer types from the cache
|
|
// array by deriving the value from the index into the array.
|
|
// Capture the offset of the load and then reverse the computation.
|
|
|
|
// Get LoadN node which loads a boxing object from 'cache' array.
|
|
if (base->is_DecodeN()) {
|
|
base = base->in(1);
|
|
}
|
|
if (!base->in(Address)->is_AddP()) {
|
|
return NULL; // Complex address
|
|
}
|
|
AddPNode* address = base->in(Address)->as_AddP();
|
|
Node* cache_base = address->in(AddPNode::Base);
|
|
if ((cache_base != NULL) && cache_base->is_DecodeN()) {
|
|
// Get ConP node which is static 'cache' field.
|
|
cache_base = cache_base->in(1);
|
|
}
|
|
if ((cache_base != NULL) && cache_base->is_Con()) {
|
|
const TypeAryPtr* base_type = cache_base->bottom_type()->isa_aryptr();
|
|
if ((base_type != NULL) && base_type->is_autobox_cache()) {
|
|
Node* elements[4];
|
|
int shift = exact_log2(type2aelembytes(T_OBJECT));
|
|
int count = address->unpack_offsets(elements, ARRAY_SIZE(elements));
|
|
if ((count > 0) && elements[0]->is_Con() &&
|
|
((count == 1) ||
|
|
(count == 2) && elements[1]->Opcode() == Op_LShiftX &&
|
|
elements[1]->in(2) == phase->intcon(shift))) {
|
|
ciObjArray* array = base_type->const_oop()->as_obj_array();
|
|
// Fetch the box object cache[0] at the base of the array and get its value
|
|
ciInstance* box = array->obj_at(0)->as_instance();
|
|
ciInstanceKlass* ik = box->klass()->as_instance_klass();
|
|
assert(ik->is_box_klass(), "sanity");
|
|
assert(ik->nof_nonstatic_fields() == 1, "change following code");
|
|
if (ik->nof_nonstatic_fields() == 1) {
|
|
// This should be true nonstatic_field_at requires calling
|
|
// nof_nonstatic_fields so check it anyway
|
|
ciConstant c = box->field_value(ik->nonstatic_field_at(0));
|
|
BasicType bt = c.basic_type();
|
|
// Only integer types have boxing cache.
|
|
assert(bt == T_BOOLEAN || bt == T_CHAR ||
|
|
bt == T_BYTE || bt == T_SHORT ||
|
|
bt == T_INT || bt == T_LONG, err_msg_res("wrong type = %s", type2name(bt)));
|
|
jlong cache_low = (bt == T_LONG) ? c.as_long() : c.as_int();
|
|
if (cache_low != (int)cache_low) {
|
|
return NULL; // should not happen since cache is array indexed by value
|
|
}
|
|
jlong offset = arrayOopDesc::base_offset_in_bytes(T_OBJECT) - (cache_low << shift);
|
|
if (offset != (int)offset) {
|
|
return NULL; // should not happen since cache is array indexed by value
|
|
}
|
|
// Add up all the offsets making of the address of the load
|
|
Node* result = elements[0];
|
|
for (int i = 1; i < count; i++) {
|
|
result = phase->transform(new (phase->C) AddXNode(result, elements[i]));
|
|
}
|
|
// Remove the constant offset from the address and then
|
|
result = phase->transform(new (phase->C) AddXNode(result, phase->MakeConX(-(int)offset)));
|
|
// remove the scaling of the offset to recover the original index.
|
|
if (result->Opcode() == Op_LShiftX && result->in(2) == phase->intcon(shift)) {
|
|
// Peel the shift off directly but wrap it in a dummy node
|
|
// since Ideal can't return existing nodes
|
|
result = new (phase->C) RShiftXNode(result->in(1), phase->intcon(0));
|
|
} else if (result->is_Add() && result->in(2)->is_Con() &&
|
|
result->in(1)->Opcode() == Op_LShiftX &&
|
|
result->in(1)->in(2) == phase->intcon(shift)) {
|
|
// We can't do general optimization: ((X<<Z) + Y) >> Z ==> X + (Y>>Z)
|
|
// but for boxing cache access we know that X<<Z will not overflow
|
|
// (there is range check) so we do this optimizatrion by hand here.
|
|
Node* add_con = new (phase->C) RShiftXNode(result->in(2), phase->intcon(shift));
|
|
result = new (phase->C) AddXNode(result->in(1)->in(1), phase->transform(add_con));
|
|
} else {
|
|
result = new (phase->C) RShiftXNode(result, phase->intcon(shift));
|
|
}
|
|
#ifdef _LP64
|
|
if (bt != T_LONG) {
|
|
result = new (phase->C) ConvL2INode(phase->transform(result));
|
|
}
|
|
#else
|
|
if (bt == T_LONG) {
|
|
result = new (phase->C) ConvI2LNode(phase->transform(result));
|
|
}
|
|
#endif
|
|
return result;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static bool stable_phi(PhiNode* phi, PhaseGVN *phase) {
|
|
Node* region = phi->in(0);
|
|
if (region == NULL) {
|
|
return false; // Wait stable graph
|
|
}
|
|
uint cnt = phi->req();
|
|
for (uint i = 1; i < cnt; i++) {
|
|
Node* rc = region->in(i);
|
|
if (rc == NULL || phase->type(rc) == Type::TOP)
|
|
return false; // Wait stable graph
|
|
Node* in = phi->in(i);
|
|
if (in == NULL || phase->type(in) == Type::TOP)
|
|
return false; // Wait stable graph
|
|
}
|
|
return true;
|
|
}
|
|
//------------------------------split_through_phi------------------------------
|
|
// Split instance or boxed field load through Phi.
|
|
Node *LoadNode::split_through_phi(PhaseGVN *phase) {
|
|
Node* mem = in(Memory);
|
|
Node* address = in(Address);
|
|
const TypeOopPtr *t_oop = phase->type(address)->isa_oopptr();
|
|
|
|
assert((t_oop != NULL) &&
|
|
(t_oop->is_known_instance_field() ||
|
|
t_oop->is_ptr_to_boxed_value()), "invalide conditions");
|
|
|
|
Compile* C = phase->C;
|
|
intptr_t ignore = 0;
|
|
Node* base = AddPNode::Ideal_base_and_offset(address, phase, ignore);
|
|
bool base_is_phi = (base != NULL) && base->is_Phi();
|
|
bool load_boxed_values = t_oop->is_ptr_to_boxed_value() && C->aggressive_unboxing() &&
|
|
(base != NULL) && (base == address->in(AddPNode::Base)) &&
|
|
phase->type(base)->higher_equal(TypePtr::NOTNULL);
|
|
|
|
if (!((mem->is_Phi() || base_is_phi) &&
|
|
(load_boxed_values || t_oop->is_known_instance_field()))) {
|
|
return NULL; // memory is not Phi
|
|
}
|
|
|
|
if (mem->is_Phi()) {
|
|
if (!stable_phi(mem->as_Phi(), phase)) {
|
|
return NULL; // Wait stable graph
|
|
}
|
|
uint cnt = mem->req();
|
|
// Check for loop invariant memory.
|
|
if (cnt == 3) {
|
|
for (uint i = 1; i < cnt; i++) {
|
|
Node* in = mem->in(i);
|
|
Node* m = optimize_memory_chain(in, t_oop, this, phase);
|
|
if (m == mem) {
|
|
set_req(Memory, mem->in(cnt - i));
|
|
return this; // made change
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (base_is_phi) {
|
|
if (!stable_phi(base->as_Phi(), phase)) {
|
|
return NULL; // Wait stable graph
|
|
}
|
|
uint cnt = base->req();
|
|
// Check for loop invariant memory.
|
|
if (cnt == 3) {
|
|
for (uint i = 1; i < cnt; i++) {
|
|
if (base->in(i) == base) {
|
|
return NULL; // Wait stable graph
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
bool load_boxed_phi = load_boxed_values && base_is_phi && (base->in(0) == mem->in(0));
|
|
|
|
// Split through Phi (see original code in loopopts.cpp).
|
|
assert(C->have_alias_type(t_oop), "instance should have alias type");
|
|
|
|
// Do nothing here if Identity will find a value
|
|
// (to avoid infinite chain of value phis generation).
|
|
if (!phase->eqv(this, this->Identity(phase)))
|
|
return NULL;
|
|
|
|
// Select Region to split through.
|
|
Node* region;
|
|
if (!base_is_phi) {
|
|
assert(mem->is_Phi(), "sanity");
|
|
region = mem->in(0);
|
|
// Skip if the region dominates some control edge of the address.
|
|
if (!MemNode::all_controls_dominate(address, region))
|
|
return NULL;
|
|
} else if (!mem->is_Phi()) {
|
|
assert(base_is_phi, "sanity");
|
|
region = base->in(0);
|
|
// Skip if the region dominates some control edge of the memory.
|
|
if (!MemNode::all_controls_dominate(mem, region))
|
|
return NULL;
|
|
} else if (base->in(0) != mem->in(0)) {
|
|
assert(base_is_phi && mem->is_Phi(), "sanity");
|
|
if (MemNode::all_controls_dominate(mem, base->in(0))) {
|
|
region = base->in(0);
|
|
} else if (MemNode::all_controls_dominate(address, mem->in(0))) {
|
|
region = mem->in(0);
|
|
} else {
|
|
return NULL; // complex graph
|
|
}
|
|
} else {
|
|
assert(base->in(0) == mem->in(0), "sanity");
|
|
region = mem->in(0);
|
|
}
|
|
|
|
const Type* this_type = this->bottom_type();
|
|
int this_index = C->get_alias_index(t_oop);
|
|
int this_offset = t_oop->offset();
|
|
int this_iid = t_oop->instance_id();
|
|
if (!t_oop->is_known_instance() && load_boxed_values) {
|
|
// Use _idx of address base for boxed values.
|
|
this_iid = base->_idx;
|
|
}
|
|
PhaseIterGVN* igvn = phase->is_IterGVN();
|
|
Node* phi = new (C) PhiNode(region, this_type, NULL, this_iid, this_index, this_offset);
|
|
for (uint i = 1; i < region->req(); i++) {
|
|
Node* x;
|
|
Node* the_clone = NULL;
|
|
if (region->in(i) == C->top()) {
|
|
x = C->top(); // Dead path? Use a dead data op
|
|
} else {
|
|
x = this->clone(); // Else clone up the data op
|
|
the_clone = x; // Remember for possible deletion.
|
|
// Alter data node to use pre-phi inputs
|
|
if (this->in(0) == region) {
|
|
x->set_req(0, region->in(i));
|
|
} else {
|
|
x->set_req(0, NULL);
|
|
}
|
|
if (mem->is_Phi() && (mem->in(0) == region)) {
|
|
x->set_req(Memory, mem->in(i)); // Use pre-Phi input for the clone.
|
|
}
|
|
if (address->is_Phi() && address->in(0) == region) {
|
|
x->set_req(Address, address->in(i)); // Use pre-Phi input for the clone
|
|
}
|
|
if (base_is_phi && (base->in(0) == region)) {
|
|
Node* base_x = base->in(i); // Clone address for loads from boxed objects.
|
|
Node* adr_x = phase->transform(new (C) AddPNode(base_x,base_x,address->in(AddPNode::Offset)));
|
|
x->set_req(Address, adr_x);
|
|
}
|
|
}
|
|
// Check for a 'win' on some paths
|
|
const Type *t = x->Value(igvn);
|
|
|
|
bool singleton = t->singleton();
|
|
|
|
// See comments in PhaseIdealLoop::split_thru_phi().
|
|
if (singleton && t == Type::TOP) {
|
|
singleton &= region->is_Loop() && (i != LoopNode::EntryControl);
|
|
}
|
|
|
|
if (singleton) {
|
|
x = igvn->makecon(t);
|
|
} else {
|
|
// We now call Identity to try to simplify the cloned node.
|
|
// Note that some Identity methods call phase->type(this).
|
|
// Make sure that the type array is big enough for
|
|
// our new node, even though we may throw the node away.
|
|
// (This tweaking with igvn only works because x is a new node.)
|
|
igvn->set_type(x, t);
|
|
// If x is a TypeNode, capture any more-precise type permanently into Node
|
|
// otherwise it will be not updated during igvn->transform since
|
|
// igvn->type(x) is set to x->Value() already.
|
|
x->raise_bottom_type(t);
|
|
Node *y = x->Identity(igvn);
|
|
if (y != x) {
|
|
x = y;
|
|
} else {
|
|
y = igvn->hash_find_insert(x);
|
|
if (y) {
|
|
x = y;
|
|
} else {
|
|
// Else x is a new node we are keeping
|
|
// We do not need register_new_node_with_optimizer
|
|
// because set_type has already been called.
|
|
igvn->_worklist.push(x);
|
|
}
|
|
}
|
|
}
|
|
if (x != the_clone && the_clone != NULL) {
|
|
igvn->remove_dead_node(the_clone);
|
|
}
|
|
phi->set_req(i, x);
|
|
}
|
|
// Record Phi
|
|
igvn->register_new_node_with_optimizer(phi);
|
|
return phi;
|
|
}
|
|
|
|
//------------------------------Ideal------------------------------------------
|
|
// If the load is from Field memory and the pointer is non-null, we can
|
|
// zero out the control input.
|
|
// If the offset is constant and the base is an object allocation,
|
|
// try to hook me up to the exact initializing store.
|
|
Node *LoadNode::Ideal(PhaseGVN *phase, bool can_reshape) {
|
|
Node* p = MemNode::Ideal_common(phase, can_reshape);
|
|
if (p) return (p == NodeSentinel) ? NULL : p;
|
|
|
|
Node* ctrl = in(MemNode::Control);
|
|
Node* address = in(MemNode::Address);
|
|
|
|
// Skip up past a SafePoint control. Cannot do this for Stores because
|
|
// pointer stores & cardmarks must stay on the same side of a SafePoint.
|
|
if( ctrl != NULL && ctrl->Opcode() == Op_SafePoint &&
|
|
phase->C->get_alias_index(phase->type(address)->is_ptr()) != Compile::AliasIdxRaw ) {
|
|
ctrl = ctrl->in(0);
|
|
set_req(MemNode::Control,ctrl);
|
|
}
|
|
|
|
intptr_t ignore = 0;
|
|
Node* base = AddPNode::Ideal_base_and_offset(address, phase, ignore);
|
|
if (base != NULL
|
|
&& phase->C->get_alias_index(phase->type(address)->is_ptr()) != Compile::AliasIdxRaw) {
|
|
// Check for useless control edge in some common special cases
|
|
if (in(MemNode::Control) != NULL
|
|
&& phase->type(base)->higher_equal(TypePtr::NOTNULL)
|
|
&& all_controls_dominate(base, phase->C->start())) {
|
|
// A method-invariant, non-null address (constant or 'this' argument).
|
|
set_req(MemNode::Control, NULL);
|
|
}
|
|
}
|
|
|
|
Node* mem = in(MemNode::Memory);
|
|
const TypePtr *addr_t = phase->type(address)->isa_ptr();
|
|
|
|
if (can_reshape && (addr_t != NULL)) {
|
|
// try to optimize our memory input
|
|
Node* opt_mem = MemNode::optimize_memory_chain(mem, addr_t, this, phase);
|
|
if (opt_mem != mem) {
|
|
set_req(MemNode::Memory, opt_mem);
|
|
if (phase->type( opt_mem ) == Type::TOP) return NULL;
|
|
return this;
|
|
}
|
|
const TypeOopPtr *t_oop = addr_t->isa_oopptr();
|
|
if ((t_oop != NULL) &&
|
|
(t_oop->is_known_instance_field() ||
|
|
t_oop->is_ptr_to_boxed_value())) {
|
|
PhaseIterGVN *igvn = phase->is_IterGVN();
|
|
if (igvn != NULL && igvn->_worklist.member(opt_mem)) {
|
|
// Delay this transformation until memory Phi is processed.
|
|
phase->is_IterGVN()->_worklist.push(this);
|
|
return NULL;
|
|
}
|
|
// Split instance field load through Phi.
|
|
Node* result = split_through_phi(phase);
|
|
if (result != NULL) return result;
|
|
|
|
if (t_oop->is_ptr_to_boxed_value()) {
|
|
Node* result = eliminate_autobox(phase);
|
|
if (result != NULL) return result;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Check for prior store with a different base or offset; make Load
|
|
// independent. Skip through any number of them. Bail out if the stores
|
|
// are in an endless dead cycle and report no progress. This is a key
|
|
// transform for Reflection. However, if after skipping through the Stores
|
|
// we can't then fold up against a prior store do NOT do the transform as
|
|
// this amounts to using the 'Oracle' model of aliasing. It leaves the same
|
|
// array memory alive twice: once for the hoisted Load and again after the
|
|
// bypassed Store. This situation only works if EVERYBODY who does
|
|
// anti-dependence work knows how to bypass. I.e. we need all
|
|
// anti-dependence checks to ask the same Oracle. Right now, that Oracle is
|
|
// the alias index stuff. So instead, peek through Stores and IFF we can
|
|
// fold up, do so.
|
|
Node* prev_mem = find_previous_store(phase);
|
|
// Steps (a), (b): Walk past independent stores to find an exact match.
|
|
if (prev_mem != NULL && prev_mem != in(MemNode::Memory)) {
|
|
// (c) See if we can fold up on the spot, but don't fold up here.
|
|
// Fold-up might require truncation (for LoadB/LoadS/LoadUS) or
|
|
// just return a prior value, which is done by Identity calls.
|
|
if (can_see_stored_value(prev_mem, phase)) {
|
|
// Make ready for step (d):
|
|
set_req(MemNode::Memory, prev_mem);
|
|
return this;
|
|
}
|
|
}
|
|
|
|
return NULL; // No further progress
|
|
}
|
|
|
|
// Helper to recognize certain Klass fields which are invariant across
|
|
// some group of array types (e.g., int[] or all T[] where T < Object).
|
|
const Type*
|
|
LoadNode::load_array_final_field(const TypeKlassPtr *tkls,
|
|
ciKlass* klass) const {
|
|
if (tkls->offset() == in_bytes(Klass::modifier_flags_offset())) {
|
|
// The field is Klass::_modifier_flags. Return its (constant) value.
|
|
// (Folds up the 2nd indirection in aClassConstant.getModifiers().)
|
|
assert(this->Opcode() == Op_LoadI, "must load an int from _modifier_flags");
|
|
return TypeInt::make(klass->modifier_flags());
|
|
}
|
|
if (tkls->offset() == in_bytes(Klass::access_flags_offset())) {
|
|
// The field is Klass::_access_flags. Return its (constant) value.
|
|
// (Folds up the 2nd indirection in Reflection.getClassAccessFlags(aClassConstant).)
|
|
assert(this->Opcode() == Op_LoadI, "must load an int from _access_flags");
|
|
return TypeInt::make(klass->access_flags());
|
|
}
|
|
if (tkls->offset() == in_bytes(Klass::layout_helper_offset())) {
|
|
// The field is Klass::_layout_helper. Return its constant value if known.
|
|
assert(this->Opcode() == Op_LoadI, "must load an int from _layout_helper");
|
|
return TypeInt::make(klass->layout_helper());
|
|
}
|
|
|
|
// No match.
|
|
return NULL;
|
|
}
|
|
|
|
// Try to constant-fold a stable array element.
|
|
static const Type* fold_stable_ary_elem(const TypeAryPtr* ary, int off, BasicType loadbt) {
|
|
assert(ary->is_stable(), "array should be stable");
|
|
|
|
if (ary->const_oop() != NULL) {
|
|
// Decode the results of GraphKit::array_element_address.
|
|
ciArray* aobj = ary->const_oop()->as_array();
|
|
ciConstant con = aobj->element_value_by_offset(off);
|
|
|
|
if (con.basic_type() != T_ILLEGAL && !con.is_null_or_zero()) {
|
|
const Type* con_type = Type::make_from_constant(con);
|
|
if (con_type != NULL) {
|
|
if (con_type->isa_aryptr()) {
|
|
// Join with the array element type, in case it is also stable.
|
|
int dim = ary->stable_dimension();
|
|
con_type = con_type->is_aryptr()->cast_to_stable(true, dim-1);
|
|
}
|
|
if (loadbt == T_NARROWOOP && con_type->isa_oopptr()) {
|
|
con_type = con_type->make_narrowoop();
|
|
}
|
|
#ifndef PRODUCT
|
|
if (TraceIterativeGVN) {
|
|
tty->print("FoldStableValues: array element [off=%d]: con_type=", off);
|
|
con_type->dump(); tty->cr();
|
|
}
|
|
#endif //PRODUCT
|
|
return con_type;
|
|
}
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
//------------------------------Value-----------------------------------------
|
|
const Type *LoadNode::Value( PhaseTransform *phase ) const {
|
|
// Either input is TOP ==> the result is TOP
|
|
Node* mem = in(MemNode::Memory);
|
|
const Type *t1 = phase->type(mem);
|
|
if (t1 == Type::TOP) return Type::TOP;
|
|
Node* adr = in(MemNode::Address);
|
|
const TypePtr* tp = phase->type(adr)->isa_ptr();
|
|
if (tp == NULL || tp->empty()) return Type::TOP;
|
|
int off = tp->offset();
|
|
assert(off != Type::OffsetTop, "case covered by TypePtr::empty");
|
|
Compile* C = phase->C;
|
|
|
|
// Try to guess loaded type from pointer type
|
|
if (tp->isa_aryptr()) {
|
|
const TypeAryPtr* ary = tp->is_aryptr();
|
|
const Type *t = ary->elem();
|
|
|
|
// Determine whether the reference is beyond the header or not, by comparing
|
|
// the offset against the offset of the start of the array's data.
|
|
// Different array types begin at slightly different offsets (12 vs. 16).
|
|
// We choose T_BYTE as an example base type that is least restrictive
|
|
// as to alignment, which will therefore produce the smallest
|
|
// possible base offset.
|
|
const int min_base_off = arrayOopDesc::base_offset_in_bytes(T_BYTE);
|
|
const bool off_beyond_header = ((uint)off >= (uint)min_base_off);
|
|
|
|
// Try to constant-fold a stable array element.
|
|
if (FoldStableValues && ary->is_stable()) {
|
|
// Make sure the reference is not into the header
|
|
if (off_beyond_header && off != Type::OffsetBot) {
|
|
assert(adr->is_AddP() && adr->in(AddPNode::Offset)->is_Con(), "offset is a constant");
|
|
const Type* con_type = fold_stable_ary_elem(ary, off, memory_type());
|
|
if (con_type != NULL) {
|
|
return con_type;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Don't do this for integer types. There is only potential profit if
|
|
// the element type t is lower than _type; that is, for int types, if _type is
|
|
// more restrictive than t. This only happens here if one is short and the other
|
|
// char (both 16 bits), and in those cases we've made an intentional decision
|
|
// to use one kind of load over the other. See AndINode::Ideal and 4965907.
|
|
// Also, do not try to narrow the type for a LoadKlass, regardless of offset.
|
|
//
|
|
// Yes, it is possible to encounter an expression like (LoadKlass p1:(AddP x x 8))
|
|
// where the _gvn.type of the AddP is wider than 8. This occurs when an earlier
|
|
// copy p0 of (AddP x x 8) has been proven equal to p1, and the p0 has been
|
|
// subsumed by p1. If p1 is on the worklist but has not yet been re-transformed,
|
|
// it is possible that p1 will have a type like Foo*[int+]:NotNull*+any.
|
|
// In fact, that could have been the original type of p1, and p1 could have
|
|
// had an original form like p1:(AddP x x (LShiftL quux 3)), where the
|
|
// expression (LShiftL quux 3) independently optimized to the constant 8.
|
|
if ((t->isa_int() == NULL) && (t->isa_long() == NULL)
|
|
&& (_type->isa_vect() == NULL)
|
|
&& Opcode() != Op_LoadKlass && Opcode() != Op_LoadNKlass) {
|
|
// t might actually be lower than _type, if _type is a unique
|
|
// concrete subclass of abstract class t.
|
|
if (off_beyond_header) { // is the offset beyond the header?
|
|
const Type* jt = t->join_speculative(_type);
|
|
// In any case, do not allow the join, per se, to empty out the type.
|
|
if (jt->empty() && !t->empty()) {
|
|
// This can happen if a interface-typed array narrows to a class type.
|
|
jt = _type;
|
|
}
|
|
#ifdef ASSERT
|
|
if (phase->C->eliminate_boxing() && adr->is_AddP()) {
|
|
// The pointers in the autobox arrays are always non-null
|
|
Node* base = adr->in(AddPNode::Base);
|
|
if ((base != NULL) && base->is_DecodeN()) {
|
|
// Get LoadN node which loads IntegerCache.cache field
|
|
base = base->in(1);
|
|
}
|
|
if ((base != NULL) && base->is_Con()) {
|
|
const TypeAryPtr* base_type = base->bottom_type()->isa_aryptr();
|
|
if ((base_type != NULL) && base_type->is_autobox_cache()) {
|
|
// It could be narrow oop
|
|
assert(jt->make_ptr()->ptr() == TypePtr::NotNull,"sanity");
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
return jt;
|
|
}
|
|
}
|
|
} else if (tp->base() == Type::InstPtr) {
|
|
ciEnv* env = C->env();
|
|
const TypeInstPtr* tinst = tp->is_instptr();
|
|
ciKlass* klass = tinst->klass();
|
|
assert( off != Type::OffsetBot ||
|
|
// arrays can be cast to Objects
|
|
tp->is_oopptr()->klass()->is_java_lang_Object() ||
|
|
// unsafe field access may not have a constant offset
|
|
C->has_unsafe_access(),
|
|
"Field accesses must be precise" );
|
|
// For oop loads, we expect the _type to be precise
|
|
if (klass == env->String_klass() &&
|
|
adr->is_AddP() && off != Type::OffsetBot) {
|
|
// For constant Strings treat the final fields as compile time constants.
|
|
Node* base = adr->in(AddPNode::Base);
|
|
const TypeOopPtr* t = phase->type(base)->isa_oopptr();
|
|
if (t != NULL && t->singleton()) {
|
|
ciField* field = env->String_klass()->get_field_by_offset(off, false);
|
|
if (field != NULL && field->is_final()) {
|
|
ciObject* string = t->const_oop();
|
|
ciConstant constant = string->as_instance()->field_value(field);
|
|
if (constant.basic_type() == T_INT) {
|
|
return TypeInt::make(constant.as_int());
|
|
} else if (constant.basic_type() == T_ARRAY) {
|
|
if (adr->bottom_type()->is_ptr_to_narrowoop()) {
|
|
return TypeNarrowOop::make_from_constant(constant.as_object(), true);
|
|
} else {
|
|
return TypeOopPtr::make_from_constant(constant.as_object(), true);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
// Optimizations for constant objects
|
|
ciObject* const_oop = tinst->const_oop();
|
|
if (const_oop != NULL) {
|
|
// For constant Boxed value treat the target field as a compile time constant.
|
|
if (tinst->is_ptr_to_boxed_value()) {
|
|
return tinst->get_const_boxed_value();
|
|
} else
|
|
// For constant CallSites treat the target field as a compile time constant.
|
|
if (const_oop->is_call_site()) {
|
|
ciCallSite* call_site = const_oop->as_call_site();
|
|
ciField* field = call_site->klass()->as_instance_klass()->get_field_by_offset(off, /*is_static=*/ false);
|
|
if (field != NULL && field->is_call_site_target()) {
|
|
ciMethodHandle* target = call_site->get_target();
|
|
if (target != NULL) { // just in case
|
|
ciConstant constant(T_OBJECT, target);
|
|
const Type* t;
|
|
if (adr->bottom_type()->is_ptr_to_narrowoop()) {
|
|
t = TypeNarrowOop::make_from_constant(constant.as_object(), true);
|
|
} else {
|
|
t = TypeOopPtr::make_from_constant(constant.as_object(), true);
|
|
}
|
|
// Add a dependence for invalidation of the optimization.
|
|
if (!call_site->is_constant_call_site()) {
|
|
C->dependencies()->assert_call_site_target_value(call_site, target);
|
|
}
|
|
return t;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} else if (tp->base() == Type::KlassPtr) {
|
|
assert( off != Type::OffsetBot ||
|
|
// arrays can be cast to Objects
|
|
tp->is_klassptr()->klass()->is_java_lang_Object() ||
|
|
// also allow array-loading from the primary supertype
|
|
// array during subtype checks
|
|
Opcode() == Op_LoadKlass,
|
|
"Field accesses must be precise" );
|
|
// For klass/static loads, we expect the _type to be precise
|
|
}
|
|
|
|
const TypeKlassPtr *tkls = tp->isa_klassptr();
|
|
if (tkls != NULL && !StressReflectiveCode) {
|
|
ciKlass* klass = tkls->klass();
|
|
if (klass->is_loaded() && tkls->klass_is_exact()) {
|
|
// We are loading a field from a Klass metaobject whose identity
|
|
// is known at compile time (the type is "exact" or "precise").
|
|
// Check for fields we know are maintained as constants by the VM.
|
|
if (tkls->offset() == in_bytes(Klass::super_check_offset_offset())) {
|
|
// The field is Klass::_super_check_offset. Return its (constant) value.
|
|
// (Folds up type checking code.)
|
|
assert(Opcode() == Op_LoadI, "must load an int from _super_check_offset");
|
|
return TypeInt::make(klass->super_check_offset());
|
|
}
|
|
// Compute index into primary_supers array
|
|
juint depth = (tkls->offset() - in_bytes(Klass::primary_supers_offset())) / sizeof(Klass*);
|
|
// Check for overflowing; use unsigned compare to handle the negative case.
|
|
if( depth < ciKlass::primary_super_limit() ) {
|
|
// The field is an element of Klass::_primary_supers. Return its (constant) value.
|
|
// (Folds up type checking code.)
|
|
assert(Opcode() == Op_LoadKlass, "must load a klass from _primary_supers");
|
|
ciKlass *ss = klass->super_of_depth(depth);
|
|
return ss ? TypeKlassPtr::make(ss) : TypePtr::NULL_PTR;
|
|
}
|
|
const Type* aift = load_array_final_field(tkls, klass);
|
|
if (aift != NULL) return aift;
|
|
if (tkls->offset() == in_bytes(ArrayKlass::component_mirror_offset())
|
|
&& klass->is_array_klass()) {
|
|
// The field is ArrayKlass::_component_mirror. Return its (constant) value.
|
|
// (Folds up aClassConstant.getComponentType, common in Arrays.copyOf.)
|
|
assert(Opcode() == Op_LoadP, "must load an oop from _component_mirror");
|
|
return TypeInstPtr::make(klass->as_array_klass()->component_mirror());
|
|
}
|
|
if (tkls->offset() == in_bytes(Klass::java_mirror_offset())) {
|
|
// The field is Klass::_java_mirror. Return its (constant) value.
|
|
// (Folds up the 2nd indirection in anObjConstant.getClass().)
|
|
assert(Opcode() == Op_LoadP, "must load an oop from _java_mirror");
|
|
return TypeInstPtr::make(klass->java_mirror());
|
|
}
|
|
}
|
|
|
|
// We can still check if we are loading from the primary_supers array at a
|
|
// shallow enough depth. Even though the klass is not exact, entries less
|
|
// than or equal to its super depth are correct.
|
|
if (klass->is_loaded() ) {
|
|
ciType *inner = klass;
|
|
while( inner->is_obj_array_klass() )
|
|
inner = inner->as_obj_array_klass()->base_element_type();
|
|
if( inner->is_instance_klass() &&
|
|
!inner->as_instance_klass()->flags().is_interface() ) {
|
|
// Compute index into primary_supers array
|
|
juint depth = (tkls->offset() - in_bytes(Klass::primary_supers_offset())) / sizeof(Klass*);
|
|
// Check for overflowing; use unsigned compare to handle the negative case.
|
|
if( depth < ciKlass::primary_super_limit() &&
|
|
depth <= klass->super_depth() ) { // allow self-depth checks to handle self-check case
|
|
// The field is an element of Klass::_primary_supers. Return its (constant) value.
|
|
// (Folds up type checking code.)
|
|
assert(Opcode() == Op_LoadKlass, "must load a klass from _primary_supers");
|
|
ciKlass *ss = klass->super_of_depth(depth);
|
|
return ss ? TypeKlassPtr::make(ss) : TypePtr::NULL_PTR;
|
|
}
|
|
}
|
|
}
|
|
|
|
// If the type is enough to determine that the thing is not an array,
|
|
// we can give the layout_helper a positive interval type.
|
|
// This will help short-circuit some reflective code.
|
|
if (tkls->offset() == in_bytes(Klass::layout_helper_offset())
|
|
&& !klass->is_array_klass() // not directly typed as an array
|
|
&& !klass->is_interface() // specifically not Serializable & Cloneable
|
|
&& !klass->is_java_lang_Object() // not the supertype of all T[]
|
|
) {
|
|
// Note: When interfaces are reliable, we can narrow the interface
|
|
// test to (klass != Serializable && klass != Cloneable).
|
|
assert(Opcode() == Op_LoadI, "must load an int from _layout_helper");
|
|
jint min_size = Klass::instance_layout_helper(oopDesc::header_size(), false);
|
|
// The key property of this type is that it folds up tests
|
|
// for array-ness, since it proves that the layout_helper is positive.
|
|
// Thus, a generic value like the basic object layout helper works fine.
|
|
return TypeInt::make(min_size, max_jint, Type::WidenMin);
|
|
}
|
|
}
|
|
|
|
// If we are loading from a freshly-allocated object, produce a zero,
|
|
// if the load is provably beyond the header of the object.
|
|
// (Also allow a variable load from a fresh array to produce zero.)
|
|
const TypeOopPtr *tinst = tp->isa_oopptr();
|
|
bool is_instance = (tinst != NULL) && tinst->is_known_instance_field();
|
|
bool is_boxed_value = (tinst != NULL) && tinst->is_ptr_to_boxed_value();
|
|
if (ReduceFieldZeroing || is_instance || is_boxed_value) {
|
|
Node* value = can_see_stored_value(mem,phase);
|
|
if (value != NULL && value->is_Con()) {
|
|
assert(value->bottom_type()->higher_equal(_type),"sanity");
|
|
return value->bottom_type();
|
|
}
|
|
}
|
|
|
|
if (is_instance) {
|
|
// If we have an instance type and our memory input is the
|
|
// programs's initial memory state, there is no matching store,
|
|
// so just return a zero of the appropriate type
|
|
Node *mem = in(MemNode::Memory);
|
|
if (mem->is_Parm() && mem->in(0)->is_Start()) {
|
|
assert(mem->as_Parm()->_con == TypeFunc::Memory, "must be memory Parm");
|
|
return Type::get_zero_type(_type->basic_type());
|
|
}
|
|
}
|
|
return _type;
|
|
}
|
|
|
|
//------------------------------match_edge-------------------------------------
|
|
// Do we Match on this edge index or not? Match only the address.
|
|
uint LoadNode::match_edge(uint idx) const {
|
|
return idx == MemNode::Address;
|
|
}
|
|
|
|
//--------------------------LoadBNode::Ideal--------------------------------------
|
|
//
|
|
// If the previous store is to the same address as this load,
|
|
// and the value stored was larger than a byte, replace this load
|
|
// with the value stored truncated to a byte. If no truncation is
|
|
// needed, the replacement is done in LoadNode::Identity().
|
|
//
|
|
Node *LoadBNode::Ideal(PhaseGVN *phase, bool can_reshape) {
|
|
Node* mem = in(MemNode::Memory);
|
|
Node* value = can_see_stored_value(mem,phase);
|
|
if( value && !phase->type(value)->higher_equal( _type ) ) {
|
|
Node *result = phase->transform( new (phase->C) LShiftINode(value, phase->intcon(24)) );
|
|
return new (phase->C) RShiftINode(result, phase->intcon(24));
|
|
}
|
|
// Identity call will handle the case where truncation is not needed.
|
|
return LoadNode::Ideal(phase, can_reshape);
|
|
}
|
|
|
|
const Type* LoadBNode::Value(PhaseTransform *phase) const {
|
|
Node* mem = in(MemNode::Memory);
|
|
Node* value = can_see_stored_value(mem,phase);
|
|
if (value != NULL && value->is_Con() &&
|
|
!value->bottom_type()->higher_equal(_type)) {
|
|
// If the input to the store does not fit with the load's result type,
|
|
// it must be truncated. We can't delay until Ideal call since
|
|
// a singleton Value is needed for split_thru_phi optimization.
|
|
int con = value->get_int();
|
|
return TypeInt::make((con << 24) >> 24);
|
|
}
|
|
return LoadNode::Value(phase);
|
|
}
|
|
|
|
//--------------------------LoadUBNode::Ideal-------------------------------------
|
|
//
|
|
// If the previous store is to the same address as this load,
|
|
// and the value stored was larger than a byte, replace this load
|
|
// with the value stored truncated to a byte. If no truncation is
|
|
// needed, the replacement is done in LoadNode::Identity().
|
|
//
|
|
Node* LoadUBNode::Ideal(PhaseGVN* phase, bool can_reshape) {
|
|
Node* mem = in(MemNode::Memory);
|
|
Node* value = can_see_stored_value(mem, phase);
|
|
if (value && !phase->type(value)->higher_equal(_type))
|
|
return new (phase->C) AndINode(value, phase->intcon(0xFF));
|
|
// Identity call will handle the case where truncation is not needed.
|
|
return LoadNode::Ideal(phase, can_reshape);
|
|
}
|
|
|
|
const Type* LoadUBNode::Value(PhaseTransform *phase) const {
|
|
Node* mem = in(MemNode::Memory);
|
|
Node* value = can_see_stored_value(mem,phase);
|
|
if (value != NULL && value->is_Con() &&
|
|
!value->bottom_type()->higher_equal(_type)) {
|
|
// If the input to the store does not fit with the load's result type,
|
|
// it must be truncated. We can't delay until Ideal call since
|
|
// a singleton Value is needed for split_thru_phi optimization.
|
|
int con = value->get_int();
|
|
return TypeInt::make(con & 0xFF);
|
|
}
|
|
return LoadNode::Value(phase);
|
|
}
|
|
|
|
//--------------------------LoadUSNode::Ideal-------------------------------------
|
|
//
|
|
// If the previous store is to the same address as this load,
|
|
// and the value stored was larger than a char, replace this load
|
|
// with the value stored truncated to a char. If no truncation is
|
|
// needed, the replacement is done in LoadNode::Identity().
|
|
//
|
|
Node *LoadUSNode::Ideal(PhaseGVN *phase, bool can_reshape) {
|
|
Node* mem = in(MemNode::Memory);
|
|
Node* value = can_see_stored_value(mem,phase);
|
|
if( value && !phase->type(value)->higher_equal( _type ) )
|
|
return new (phase->C) AndINode(value,phase->intcon(0xFFFF));
|
|
// Identity call will handle the case where truncation is not needed.
|
|
return LoadNode::Ideal(phase, can_reshape);
|
|
}
|
|
|
|
const Type* LoadUSNode::Value(PhaseTransform *phase) const {
|
|
Node* mem = in(MemNode::Memory);
|
|
Node* value = can_see_stored_value(mem,phase);
|
|
if (value != NULL && value->is_Con() &&
|
|
!value->bottom_type()->higher_equal(_type)) {
|
|
// If the input to the store does not fit with the load's result type,
|
|
// it must be truncated. We can't delay until Ideal call since
|
|
// a singleton Value is needed for split_thru_phi optimization.
|
|
int con = value->get_int();
|
|
return TypeInt::make(con & 0xFFFF);
|
|
}
|
|
return LoadNode::Value(phase);
|
|
}
|
|
|
|
//--------------------------LoadSNode::Ideal--------------------------------------
|
|
//
|
|
// If the previous store is to the same address as this load,
|
|
// and the value stored was larger than a short, replace this load
|
|
// with the value stored truncated to a short. If no truncation is
|
|
// needed, the replacement is done in LoadNode::Identity().
|
|
//
|
|
Node *LoadSNode::Ideal(PhaseGVN *phase, bool can_reshape) {
|
|
Node* mem = in(MemNode::Memory);
|
|
Node* value = can_see_stored_value(mem,phase);
|
|
if( value && !phase->type(value)->higher_equal( _type ) ) {
|
|
Node *result = phase->transform( new (phase->C) LShiftINode(value, phase->intcon(16)) );
|
|
return new (phase->C) RShiftINode(result, phase->intcon(16));
|
|
}
|
|
// Identity call will handle the case where truncation is not needed.
|
|
return LoadNode::Ideal(phase, can_reshape);
|
|
}
|
|
|
|
const Type* LoadSNode::Value(PhaseTransform *phase) const {
|
|
Node* mem = in(MemNode::Memory);
|
|
Node* value = can_see_stored_value(mem,phase);
|
|
if (value != NULL && value->is_Con() &&
|
|
!value->bottom_type()->higher_equal(_type)) {
|
|
// If the input to the store does not fit with the load's result type,
|
|
// it must be truncated. We can't delay until Ideal call since
|
|
// a singleton Value is needed for split_thru_phi optimization.
|
|
int con = value->get_int();
|
|
return TypeInt::make((con << 16) >> 16);
|
|
}
|
|
return LoadNode::Value(phase);
|
|
}
|
|
|
|
//=============================================================================
|
|
//----------------------------LoadKlassNode::make------------------------------
|
|
// Polymorphic factory method:
|
|
Node *LoadKlassNode::make( PhaseGVN& gvn, Node *mem, Node *adr, const TypePtr* at, const TypeKlassPtr *tk ) {
|
|
Compile* C = gvn.C;
|
|
Node *ctl = NULL;
|
|
// sanity check the alias category against the created node type
|
|
const TypePtr *adr_type = adr->bottom_type()->isa_ptr();
|
|
assert(adr_type != NULL, "expecting TypeKlassPtr");
|
|
#ifdef _LP64
|
|
if (adr_type->is_ptr_to_narrowklass()) {
|
|
assert(UseCompressedClassPointers, "no compressed klasses");
|
|
Node* load_klass = gvn.transform(new (C) LoadNKlassNode(ctl, mem, adr, at, tk->make_narrowklass(), MemNode::unordered));
|
|
return new (C) DecodeNKlassNode(load_klass, load_klass->bottom_type()->make_ptr());
|
|
}
|
|
#endif
|
|
assert(!adr_type->is_ptr_to_narrowklass() && !adr_type->is_ptr_to_narrowoop(), "should have got back a narrow oop");
|
|
return new (C) LoadKlassNode(ctl, mem, adr, at, tk, MemNode::unordered);
|
|
}
|
|
|
|
//------------------------------Value------------------------------------------
|
|
const Type *LoadKlassNode::Value( PhaseTransform *phase ) const {
|
|
return klass_value_common(phase);
|
|
}
|
|
|
|
const Type *LoadNode::klass_value_common( PhaseTransform *phase ) const {
|
|
// Either input is TOP ==> the result is TOP
|
|
const Type *t1 = phase->type( in(MemNode::Memory) );
|
|
if (t1 == Type::TOP) return Type::TOP;
|
|
Node *adr = in(MemNode::Address);
|
|
const Type *t2 = phase->type( adr );
|
|
if (t2 == Type::TOP) return Type::TOP;
|
|
const TypePtr *tp = t2->is_ptr();
|
|
if (TypePtr::above_centerline(tp->ptr()) ||
|
|
tp->ptr() == TypePtr::Null) return Type::TOP;
|
|
|
|
// Return a more precise klass, if possible
|
|
const TypeInstPtr *tinst = tp->isa_instptr();
|
|
if (tinst != NULL) {
|
|
ciInstanceKlass* ik = tinst->klass()->as_instance_klass();
|
|
int offset = tinst->offset();
|
|
if (ik == phase->C->env()->Class_klass()
|
|
&& (offset == java_lang_Class::klass_offset_in_bytes() ||
|
|
offset == java_lang_Class::array_klass_offset_in_bytes())) {
|
|
// We are loading a special hidden field from a Class mirror object,
|
|
// the field which points to the VM's Klass metaobject.
|
|
ciType* t = tinst->java_mirror_type();
|
|
// java_mirror_type returns non-null for compile-time Class constants.
|
|
if (t != NULL) {
|
|
// constant oop => constant klass
|
|
if (offset == java_lang_Class::array_klass_offset_in_bytes()) {
|
|
if (t->is_void()) {
|
|
// We cannot create a void array. Since void is a primitive type return null
|
|
// klass. Users of this result need to do a null check on the returned klass.
|
|
return TypePtr::NULL_PTR;
|
|
}
|
|
return TypeKlassPtr::make(ciArrayKlass::make(t));
|
|
}
|
|
if (!t->is_klass()) {
|
|
// a primitive Class (e.g., int.class) has NULL for a klass field
|
|
return TypePtr::NULL_PTR;
|
|
}
|
|
// (Folds up the 1st indirection in aClassConstant.getModifiers().)
|
|
return TypeKlassPtr::make(t->as_klass());
|
|
}
|
|
// non-constant mirror, so we can't tell what's going on
|
|
}
|
|
if( !ik->is_loaded() )
|
|
return _type; // Bail out if not loaded
|
|
if (offset == oopDesc::klass_offset_in_bytes()) {
|
|
if (tinst->klass_is_exact()) {
|
|
return TypeKlassPtr::make(ik);
|
|
}
|
|
// See if we can become precise: no subklasses and no interface
|
|
// (Note: We need to support verified interfaces.)
|
|
if (!ik->is_interface() && !ik->has_subklass()) {
|
|
//assert(!UseExactTypes, "this code should be useless with exact types");
|
|
// Add a dependence; if any subclass added we need to recompile
|
|
if (!ik->is_final()) {
|
|
// %%% should use stronger assert_unique_concrete_subtype instead
|
|
phase->C->dependencies()->assert_leaf_type(ik);
|
|
}
|
|
// Return precise klass
|
|
return TypeKlassPtr::make(ik);
|
|
}
|
|
|
|
// Return root of possible klass
|
|
return TypeKlassPtr::make(TypePtr::NotNull, ik, 0/*offset*/);
|
|
}
|
|
}
|
|
|
|
// Check for loading klass from an array
|
|
const TypeAryPtr *tary = tp->isa_aryptr();
|
|
if( tary != NULL ) {
|
|
ciKlass *tary_klass = tary->klass();
|
|
if (tary_klass != NULL // can be NULL when at BOTTOM or TOP
|
|
&& tary->offset() == oopDesc::klass_offset_in_bytes()) {
|
|
if (tary->klass_is_exact()) {
|
|
return TypeKlassPtr::make(tary_klass);
|
|
}
|
|
ciArrayKlass *ak = tary->klass()->as_array_klass();
|
|
// If the klass is an object array, we defer the question to the
|
|
// array component klass.
|
|
if( ak->is_obj_array_klass() ) {
|
|
assert( ak->is_loaded(), "" );
|
|
ciKlass *base_k = ak->as_obj_array_klass()->base_element_klass();
|
|
if( base_k->is_loaded() && base_k->is_instance_klass() ) {
|
|
ciInstanceKlass* ik = base_k->as_instance_klass();
|
|
// See if we can become precise: no subklasses and no interface
|
|
if (!ik->is_interface() && !ik->has_subklass()) {
|
|
//assert(!UseExactTypes, "this code should be useless with exact types");
|
|
// Add a dependence; if any subclass added we need to recompile
|
|
if (!ik->is_final()) {
|
|
phase->C->dependencies()->assert_leaf_type(ik);
|
|
}
|
|
// Return precise array klass
|
|
return TypeKlassPtr::make(ak);
|
|
}
|
|
}
|
|
return TypeKlassPtr::make(TypePtr::NotNull, ak, 0/*offset*/);
|
|
} else { // Found a type-array?
|
|
//assert(!UseExactTypes, "this code should be useless with exact types");
|
|
assert( ak->is_type_array_klass(), "" );
|
|
return TypeKlassPtr::make(ak); // These are always precise
|
|
}
|
|
}
|
|
}
|
|
|
|
// Check for loading klass from an array klass
|
|
const TypeKlassPtr *tkls = tp->isa_klassptr();
|
|
if (tkls != NULL && !StressReflectiveCode) {
|
|
ciKlass* klass = tkls->klass();
|
|
if( !klass->is_loaded() )
|
|
return _type; // Bail out if not loaded
|
|
if( klass->is_obj_array_klass() &&
|
|
tkls->offset() == in_bytes(ObjArrayKlass::element_klass_offset())) {
|
|
ciKlass* elem = klass->as_obj_array_klass()->element_klass();
|
|
// // Always returning precise element type is incorrect,
|
|
// // e.g., element type could be object and array may contain strings
|
|
// return TypeKlassPtr::make(TypePtr::Constant, elem, 0);
|
|
|
|
// The array's TypeKlassPtr was declared 'precise' or 'not precise'
|
|
// according to the element type's subclassing.
|
|
return TypeKlassPtr::make(tkls->ptr(), elem, 0/*offset*/);
|
|
}
|
|
if( klass->is_instance_klass() && tkls->klass_is_exact() &&
|
|
tkls->offset() == in_bytes(Klass::super_offset())) {
|
|
ciKlass* sup = klass->as_instance_klass()->super();
|
|
// The field is Klass::_super. Return its (constant) value.
|
|
// (Folds up the 2nd indirection in aClassConstant.getSuperClass().)
|
|
return sup ? TypeKlassPtr::make(sup) : TypePtr::NULL_PTR;
|
|
}
|
|
}
|
|
|
|
// Bailout case
|
|
return LoadNode::Value(phase);
|
|
}
|
|
|
|
//------------------------------Identity---------------------------------------
|
|
// To clean up reflective code, simplify k.java_mirror.as_klass to plain k.
|
|
// Also feed through the klass in Allocate(...klass...)._klass.
|
|
Node* LoadKlassNode::Identity( PhaseTransform *phase ) {
|
|
return klass_identity_common(phase);
|
|
}
|
|
|
|
Node* LoadNode::klass_identity_common(PhaseTransform *phase ) {
|
|
Node* x = LoadNode::Identity(phase);
|
|
if (x != this) return x;
|
|
|
|
// Take apart the address into an oop and and offset.
|
|
// Return 'this' if we cannot.
|
|
Node* adr = in(MemNode::Address);
|
|
intptr_t offset = 0;
|
|
Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
|
|
if (base == NULL) return this;
|
|
const TypeOopPtr* toop = phase->type(adr)->isa_oopptr();
|
|
if (toop == NULL) return this;
|
|
|
|
// We can fetch the klass directly through an AllocateNode.
|
|
// This works even if the klass is not constant (clone or newArray).
|
|
if (offset == oopDesc::klass_offset_in_bytes()) {
|
|
Node* allocated_klass = AllocateNode::Ideal_klass(base, phase);
|
|
if (allocated_klass != NULL) {
|
|
return allocated_klass;
|
|
}
|
|
}
|
|
|
|
// Simplify k.java_mirror.as_klass to plain k, where k is a Klass*.
|
|
// Simplify ak.component_mirror.array_klass to plain ak, ak an ArrayKlass.
|
|
// See inline_native_Class_query for occurrences of these patterns.
|
|
// Java Example: x.getClass().isAssignableFrom(y)
|
|
// Java Example: Array.newInstance(x.getClass().getComponentType(), n)
|
|
//
|
|
// This improves reflective code, often making the Class
|
|
// mirror go completely dead. (Current exception: Class
|
|
// mirrors may appear in debug info, but we could clean them out by
|
|
// introducing a new debug info operator for Klass*.java_mirror).
|
|
if (toop->isa_instptr() && toop->klass() == phase->C->env()->Class_klass()
|
|
&& (offset == java_lang_Class::klass_offset_in_bytes() ||
|
|
offset == java_lang_Class::array_klass_offset_in_bytes())) {
|
|
// We are loading a special hidden field from a Class mirror,
|
|
// the field which points to its Klass or ArrayKlass metaobject.
|
|
if (base->is_Load()) {
|
|
Node* adr2 = base->in(MemNode::Address);
|
|
const TypeKlassPtr* tkls = phase->type(adr2)->isa_klassptr();
|
|
if (tkls != NULL && !tkls->empty()
|
|
&& (tkls->klass()->is_instance_klass() ||
|
|
tkls->klass()->is_array_klass())
|
|
&& adr2->is_AddP()
|
|
) {
|
|
int mirror_field = in_bytes(Klass::java_mirror_offset());
|
|
if (offset == java_lang_Class::array_klass_offset_in_bytes()) {
|
|
mirror_field = in_bytes(ArrayKlass::component_mirror_offset());
|
|
}
|
|
if (tkls->offset() == mirror_field) {
|
|
return adr2->in(AddPNode::Base);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return this;
|
|
}
|
|
|
|
|
|
//------------------------------Value------------------------------------------
|
|
const Type *LoadNKlassNode::Value( PhaseTransform *phase ) const {
|
|
const Type *t = klass_value_common(phase);
|
|
if (t == Type::TOP)
|
|
return t;
|
|
|
|
return t->make_narrowklass();
|
|
}
|
|
|
|
//------------------------------Identity---------------------------------------
|
|
// To clean up reflective code, simplify k.java_mirror.as_klass to narrow k.
|
|
// Also feed through the klass in Allocate(...klass...)._klass.
|
|
Node* LoadNKlassNode::Identity( PhaseTransform *phase ) {
|
|
Node *x = klass_identity_common(phase);
|
|
|
|
const Type *t = phase->type( x );
|
|
if( t == Type::TOP ) return x;
|
|
if( t->isa_narrowklass()) return x;
|
|
assert (!t->isa_narrowoop(), "no narrow oop here");
|
|
|
|
return phase->transform(new (phase->C) EncodePKlassNode(x, t->make_narrowklass()));
|
|
}
|
|
|
|
//------------------------------Value-----------------------------------------
|
|
const Type *LoadRangeNode::Value( PhaseTransform *phase ) const {
|
|
// Either input is TOP ==> the result is TOP
|
|
const Type *t1 = phase->type( in(MemNode::Memory) );
|
|
if( t1 == Type::TOP ) return Type::TOP;
|
|
Node *adr = in(MemNode::Address);
|
|
const Type *t2 = phase->type( adr );
|
|
if( t2 == Type::TOP ) return Type::TOP;
|
|
const TypePtr *tp = t2->is_ptr();
|
|
if (TypePtr::above_centerline(tp->ptr())) return Type::TOP;
|
|
const TypeAryPtr *tap = tp->isa_aryptr();
|
|
if( !tap ) return _type;
|
|
return tap->size();
|
|
}
|
|
|
|
//-------------------------------Ideal---------------------------------------
|
|
// Feed through the length in AllocateArray(...length...)._length.
|
|
Node *LoadRangeNode::Ideal(PhaseGVN *phase, bool can_reshape) {
|
|
Node* p = MemNode::Ideal_common(phase, can_reshape);
|
|
if (p) return (p == NodeSentinel) ? NULL : p;
|
|
|
|
// Take apart the address into an oop and and offset.
|
|
// Return 'this' if we cannot.
|
|
Node* adr = in(MemNode::Address);
|
|
intptr_t offset = 0;
|
|
Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
|
|
if (base == NULL) return NULL;
|
|
const TypeAryPtr* tary = phase->type(adr)->isa_aryptr();
|
|
if (tary == NULL) return NULL;
|
|
|
|
// We can fetch the length directly through an AllocateArrayNode.
|
|
// This works even if the length is not constant (clone or newArray).
|
|
if (offset == arrayOopDesc::length_offset_in_bytes()) {
|
|
AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(base, phase);
|
|
if (alloc != NULL) {
|
|
Node* allocated_length = alloc->Ideal_length();
|
|
Node* len = alloc->make_ideal_length(tary, phase);
|
|
if (allocated_length != len) {
|
|
// New CastII improves on this.
|
|
return len;
|
|
}
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
//------------------------------Identity---------------------------------------
|
|
// Feed through the length in AllocateArray(...length...)._length.
|
|
Node* LoadRangeNode::Identity( PhaseTransform *phase ) {
|
|
Node* x = LoadINode::Identity(phase);
|
|
if (x != this) return x;
|
|
|
|
// Take apart the address into an oop and and offset.
|
|
// Return 'this' if we cannot.
|
|
Node* adr = in(MemNode::Address);
|
|
intptr_t offset = 0;
|
|
Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
|
|
if (base == NULL) return this;
|
|
const TypeAryPtr* tary = phase->type(adr)->isa_aryptr();
|
|
if (tary == NULL) return this;
|
|
|
|
// We can fetch the length directly through an AllocateArrayNode.
|
|
// This works even if the length is not constant (clone or newArray).
|
|
if (offset == arrayOopDesc::length_offset_in_bytes()) {
|
|
AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(base, phase);
|
|
if (alloc != NULL) {
|
|
Node* allocated_length = alloc->Ideal_length();
|
|
// Do not allow make_ideal_length to allocate a CastII node.
|
|
Node* len = alloc->make_ideal_length(tary, phase, false);
|
|
if (allocated_length == len) {
|
|
// Return allocated_length only if it would not be improved by a CastII.
|
|
return allocated_length;
|
|
}
|
|
}
|
|
}
|
|
|
|
return this;
|
|
|
|
}
|
|
|
|
//=============================================================================
|
|
//---------------------------StoreNode::make-----------------------------------
|
|
// Polymorphic factory method:
|
|
StoreNode* StoreNode::make(PhaseGVN& gvn, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val, BasicType bt, MemOrd mo) {
|
|
assert((mo == unordered || mo == release), "unexpected");
|
|
Compile* C = gvn.C;
|
|
assert(C->get_alias_index(adr_type) != Compile::AliasIdxRaw ||
|
|
ctl != NULL, "raw memory operations should have control edge");
|
|
|
|
switch (bt) {
|
|
case T_BOOLEAN:
|
|
case T_BYTE: return new (C) StoreBNode(ctl, mem, adr, adr_type, val, mo);
|
|
case T_INT: return new (C) StoreINode(ctl, mem, adr, adr_type, val, mo);
|
|
case T_CHAR:
|
|
case T_SHORT: return new (C) StoreCNode(ctl, mem, adr, adr_type, val, mo);
|
|
case T_LONG: return new (C) StoreLNode(ctl, mem, adr, adr_type, val, mo);
|
|
case T_FLOAT: return new (C) StoreFNode(ctl, mem, adr, adr_type, val, mo);
|
|
case T_DOUBLE: return new (C) StoreDNode(ctl, mem, adr, adr_type, val, mo);
|
|
case T_METADATA:
|
|
case T_ADDRESS:
|
|
case T_OBJECT:
|
|
#ifdef _LP64
|
|
if (adr->bottom_type()->is_ptr_to_narrowoop()) {
|
|
val = gvn.transform(new (C) EncodePNode(val, val->bottom_type()->make_narrowoop()));
|
|
return new (C) StoreNNode(ctl, mem, adr, adr_type, val, mo);
|
|
} else if (adr->bottom_type()->is_ptr_to_narrowklass() ||
|
|
(UseCompressedClassPointers && val->bottom_type()->isa_klassptr() &&
|
|
adr->bottom_type()->isa_rawptr())) {
|
|
val = gvn.transform(new (C) EncodePKlassNode(val, val->bottom_type()->make_narrowklass()));
|
|
return new (C) StoreNKlassNode(ctl, mem, adr, adr_type, val, mo);
|
|
}
|
|
#endif
|
|
{
|
|
return new (C) StorePNode(ctl, mem, adr, adr_type, val, mo);
|
|
}
|
|
}
|
|
ShouldNotReachHere();
|
|
return (StoreNode*)NULL;
|
|
}
|
|
|
|
StoreLNode* StoreLNode::make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val, MemOrd mo) {
|
|
bool require_atomic = true;
|
|
return new (C) StoreLNode(ctl, mem, adr, adr_type, val, mo, require_atomic);
|
|
}
|
|
|
|
|
|
//--------------------------bottom_type----------------------------------------
|
|
const Type *StoreNode::bottom_type() const {
|
|
return Type::MEMORY;
|
|
}
|
|
|
|
//------------------------------hash-------------------------------------------
|
|
uint StoreNode::hash() const {
|
|
// unroll addition of interesting fields
|
|
//return (uintptr_t)in(Control) + (uintptr_t)in(Memory) + (uintptr_t)in(Address) + (uintptr_t)in(ValueIn);
|
|
|
|
// Since they are not commoned, do not hash them:
|
|
return NO_HASH;
|
|
}
|
|
|
|
//------------------------------Ideal------------------------------------------
|
|
// Change back-to-back Store(, p, x) -> Store(m, p, y) to Store(m, p, x).
|
|
// When a store immediately follows a relevant allocation/initialization,
|
|
// try to capture it into the initialization, or hoist it above.
|
|
Node *StoreNode::Ideal(PhaseGVN *phase, bool can_reshape) {
|
|
Node* p = MemNode::Ideal_common(phase, can_reshape);
|
|
if (p) return (p == NodeSentinel) ? NULL : p;
|
|
|
|
Node* mem = in(MemNode::Memory);
|
|
Node* address = in(MemNode::Address);
|
|
|
|
// Back-to-back stores to same address? Fold em up. Generally
|
|
// unsafe if I have intervening uses... Also disallowed for StoreCM
|
|
// since they must follow each StoreP operation. Redundant StoreCMs
|
|
// are eliminated just before matching in final_graph_reshape.
|
|
if (mem->is_Store() && mem->in(MemNode::Address)->eqv_uncast(address) &&
|
|
mem->Opcode() != Op_StoreCM) {
|
|
// Looking at a dead closed cycle of memory?
|
|
assert(mem != mem->in(MemNode::Memory), "dead loop in StoreNode::Ideal");
|
|
|
|
assert(Opcode() == mem->Opcode() ||
|
|
phase->C->get_alias_index(adr_type()) == Compile::AliasIdxRaw,
|
|
"no mismatched stores, except on raw memory");
|
|
|
|
if (mem->outcnt() == 1 && // check for intervening uses
|
|
mem->as_Store()->memory_size() <= this->memory_size()) {
|
|
// If anybody other than 'this' uses 'mem', we cannot fold 'mem' away.
|
|
// For example, 'mem' might be the final state at a conditional return.
|
|
// Or, 'mem' might be used by some node which is live at the same time
|
|
// 'this' is live, which might be unschedulable. So, require exactly
|
|
// ONE user, the 'this' store, until such time as we clone 'mem' for
|
|
// each of 'mem's uses (thus making the exactly-1-user-rule hold true).
|
|
if (can_reshape) { // (%%% is this an anachronism?)
|
|
set_req_X(MemNode::Memory, mem->in(MemNode::Memory),
|
|
phase->is_IterGVN());
|
|
} else {
|
|
// It's OK to do this in the parser, since DU info is always accurate,
|
|
// and the parser always refers to nodes via SafePointNode maps.
|
|
set_req(MemNode::Memory, mem->in(MemNode::Memory));
|
|
}
|
|
return this;
|
|
}
|
|
}
|
|
|
|
// Capture an unaliased, unconditional, simple store into an initializer.
|
|
// Or, if it is independent of the allocation, hoist it above the allocation.
|
|
if (ReduceFieldZeroing && /*can_reshape &&*/
|
|
mem->is_Proj() && mem->in(0)->is_Initialize()) {
|
|
InitializeNode* init = mem->in(0)->as_Initialize();
|
|
intptr_t offset = init->can_capture_store(this, phase, can_reshape);
|
|
if (offset > 0) {
|
|
Node* moved = init->capture_store(this, offset, phase, can_reshape);
|
|
// If the InitializeNode captured me, it made a raw copy of me,
|
|
// and I need to disappear.
|
|
if (moved != NULL) {
|
|
// %%% hack to ensure that Ideal returns a new node:
|
|
mem = MergeMemNode::make(phase->C, mem);
|
|
return mem; // fold me away
|
|
}
|
|
}
|
|
}
|
|
|
|
return NULL; // No further progress
|
|
}
|
|
|
|
//------------------------------Value-----------------------------------------
|
|
const Type *StoreNode::Value( PhaseTransform *phase ) const {
|
|
// Either input is TOP ==> the result is TOP
|
|
const Type *t1 = phase->type( in(MemNode::Memory) );
|
|
if( t1 == Type::TOP ) return Type::TOP;
|
|
const Type *t2 = phase->type( in(MemNode::Address) );
|
|
if( t2 == Type::TOP ) return Type::TOP;
|
|
const Type *t3 = phase->type( in(MemNode::ValueIn) );
|
|
if( t3 == Type::TOP ) return Type::TOP;
|
|
return Type::MEMORY;
|
|
}
|
|
|
|
//------------------------------Identity---------------------------------------
|
|
// Remove redundant stores:
|
|
// Store(m, p, Load(m, p)) changes to m.
|
|
// Store(, p, x) -> Store(m, p, x) changes to Store(m, p, x).
|
|
Node *StoreNode::Identity( PhaseTransform *phase ) {
|
|
Node* mem = in(MemNode::Memory);
|
|
Node* adr = in(MemNode::Address);
|
|
Node* val = in(MemNode::ValueIn);
|
|
|
|
// Load then Store? Then the Store is useless
|
|
if (val->is_Load() &&
|
|
val->in(MemNode::Address)->eqv_uncast(adr) &&
|
|
val->in(MemNode::Memory )->eqv_uncast(mem) &&
|
|
val->as_Load()->store_Opcode() == Opcode()) {
|
|
return mem;
|
|
}
|
|
|
|
// Two stores in a row of the same value?
|
|
if (mem->is_Store() &&
|
|
mem->in(MemNode::Address)->eqv_uncast(adr) &&
|
|
mem->in(MemNode::ValueIn)->eqv_uncast(val) &&
|
|
mem->Opcode() == Opcode()) {
|
|
return mem;
|
|
}
|
|
|
|
// Store of zero anywhere into a freshly-allocated object?
|
|
// Then the store is useless.
|
|
// (It must already have been captured by the InitializeNode.)
|
|
if (ReduceFieldZeroing && phase->type(val)->is_zero_type()) {
|
|
// a newly allocated object is already all-zeroes everywhere
|
|
if (mem->is_Proj() && mem->in(0)->is_Allocate()) {
|
|
return mem;
|
|
}
|
|
|
|
// the store may also apply to zero-bits in an earlier object
|
|
Node* prev_mem = find_previous_store(phase);
|
|
// Steps (a), (b): Walk past independent stores to find an exact match.
|
|
if (prev_mem != NULL) {
|
|
Node* prev_val = can_see_stored_value(prev_mem, phase);
|
|
if (prev_val != NULL && phase->eqv(prev_val, val)) {
|
|
// prev_val and val might differ by a cast; it would be good
|
|
// to keep the more informative of the two.
|
|
return mem;
|
|
}
|
|
}
|
|
}
|
|
|
|
return this;
|
|
}
|
|
|
|
//------------------------------match_edge-------------------------------------
|
|
// Do we Match on this edge index or not? Match only memory & value
|
|
uint StoreNode::match_edge(uint idx) const {
|
|
return idx == MemNode::Address || idx == MemNode::ValueIn;
|
|
}
|
|
|
|
//------------------------------cmp--------------------------------------------
|
|
// Do not common stores up together. They generally have to be split
|
|
// back up anyways, so do not bother.
|
|
uint StoreNode::cmp( const Node &n ) const {
|
|
return (&n == this); // Always fail except on self
|
|
}
|
|
|
|
//------------------------------Ideal_masked_input-----------------------------
|
|
// Check for a useless mask before a partial-word store
|
|
// (StoreB ... (AndI valIn conIa) )
|
|
// If (conIa & mask == mask) this simplifies to
|
|
// (StoreB ... (valIn) )
|
|
Node *StoreNode::Ideal_masked_input(PhaseGVN *phase, uint mask) {
|
|
Node *val = in(MemNode::ValueIn);
|
|
if( val->Opcode() == Op_AndI ) {
|
|
const TypeInt *t = phase->type( val->in(2) )->isa_int();
|
|
if( t && t->is_con() && (t->get_con() & mask) == mask ) {
|
|
set_req(MemNode::ValueIn, val->in(1));
|
|
return this;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
|
|
//------------------------------Ideal_sign_extended_input----------------------
|
|
// Check for useless sign-extension before a partial-word store
|
|
// (StoreB ... (RShiftI _ (LShiftI _ valIn conIL ) conIR) )
|
|
// If (conIL == conIR && conIR <= num_bits) this simplifies to
|
|
// (StoreB ... (valIn) )
|
|
Node *StoreNode::Ideal_sign_extended_input(PhaseGVN *phase, int num_bits) {
|
|
Node *val = in(MemNode::ValueIn);
|
|
if( val->Opcode() == Op_RShiftI ) {
|
|
const TypeInt *t = phase->type( val->in(2) )->isa_int();
|
|
if( t && t->is_con() && (t->get_con() <= num_bits) ) {
|
|
Node *shl = val->in(1);
|
|
if( shl->Opcode() == Op_LShiftI ) {
|
|
const TypeInt *t2 = phase->type( shl->in(2) )->isa_int();
|
|
if( t2 && t2->is_con() && (t2->get_con() == t->get_con()) ) {
|
|
set_req(MemNode::ValueIn, shl->in(1));
|
|
return this;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
//------------------------------value_never_loaded-----------------------------------
|
|
// Determine whether there are any possible loads of the value stored.
|
|
// For simplicity, we actually check if there are any loads from the
|
|
// address stored to, not just for loads of the value stored by this node.
|
|
//
|
|
bool StoreNode::value_never_loaded( PhaseTransform *phase) const {
|
|
Node *adr = in(Address);
|
|
const TypeOopPtr *adr_oop = phase->type(adr)->isa_oopptr();
|
|
if (adr_oop == NULL)
|
|
return false;
|
|
if (!adr_oop->is_known_instance_field())
|
|
return false; // if not a distinct instance, there may be aliases of the address
|
|
for (DUIterator_Fast imax, i = adr->fast_outs(imax); i < imax; i++) {
|
|
Node *use = adr->fast_out(i);
|
|
int opc = use->Opcode();
|
|
if (use->is_Load() || use->is_LoadStore()) {
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
//=============================================================================
|
|
//------------------------------Ideal------------------------------------------
|
|
// If the store is from an AND mask that leaves the low bits untouched, then
|
|
// we can skip the AND operation. If the store is from a sign-extension
|
|
// (a left shift, then right shift) we can skip both.
|
|
Node *StoreBNode::Ideal(PhaseGVN *phase, bool can_reshape){
|
|
Node *progress = StoreNode::Ideal_masked_input(phase, 0xFF);
|
|
if( progress != NULL ) return progress;
|
|
|
|
progress = StoreNode::Ideal_sign_extended_input(phase, 24);
|
|
if( progress != NULL ) return progress;
|
|
|
|
// Finally check the default case
|
|
return StoreNode::Ideal(phase, can_reshape);
|
|
}
|
|
|
|
//=============================================================================
|
|
//------------------------------Ideal------------------------------------------
|
|
// If the store is from an AND mask that leaves the low bits untouched, then
|
|
// we can skip the AND operation
|
|
Node *StoreCNode::Ideal(PhaseGVN *phase, bool can_reshape){
|
|
Node *progress = StoreNode::Ideal_masked_input(phase, 0xFFFF);
|
|
if( progress != NULL ) return progress;
|
|
|
|
progress = StoreNode::Ideal_sign_extended_input(phase, 16);
|
|
if( progress != NULL ) return progress;
|
|
|
|
// Finally check the default case
|
|
return StoreNode::Ideal(phase, can_reshape);
|
|
}
|
|
|
|
//=============================================================================
|
|
//------------------------------Identity---------------------------------------
|
|
Node *StoreCMNode::Identity( PhaseTransform *phase ) {
|
|
// No need to card mark when storing a null ptr
|
|
Node* my_store = in(MemNode::OopStore);
|
|
if (my_store->is_Store()) {
|
|
const Type *t1 = phase->type( my_store->in(MemNode::ValueIn) );
|
|
if( t1 == TypePtr::NULL_PTR ) {
|
|
return in(MemNode::Memory);
|
|
}
|
|
}
|
|
return this;
|
|
}
|
|
|
|
//=============================================================================
|
|
//------------------------------Ideal---------------------------------------
|
|
Node *StoreCMNode::Ideal(PhaseGVN *phase, bool can_reshape){
|
|
Node* progress = StoreNode::Ideal(phase, can_reshape);
|
|
if (progress != NULL) return progress;
|
|
|
|
Node* my_store = in(MemNode::OopStore);
|
|
if (my_store->is_MergeMem()) {
|
|
Node* mem = my_store->as_MergeMem()->memory_at(oop_alias_idx());
|
|
set_req(MemNode::OopStore, mem);
|
|
return this;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
//------------------------------Value-----------------------------------------
|
|
const Type *StoreCMNode::Value( PhaseTransform *phase ) const {
|
|
// Either input is TOP ==> the result is TOP
|
|
const Type *t = phase->type( in(MemNode::Memory) );
|
|
if( t == Type::TOP ) return Type::TOP;
|
|
t = phase->type( in(MemNode::Address) );
|
|
if( t == Type::TOP ) return Type::TOP;
|
|
t = phase->type( in(MemNode::ValueIn) );
|
|
if( t == Type::TOP ) return Type::TOP;
|
|
// If extra input is TOP ==> the result is TOP
|
|
t = phase->type( in(MemNode::OopStore) );
|
|
if( t == Type::TOP ) return Type::TOP;
|
|
|
|
return StoreNode::Value( phase );
|
|
}
|
|
|
|
|
|
//=============================================================================
|
|
//----------------------------------SCMemProjNode------------------------------
|
|
const Type * SCMemProjNode::Value( PhaseTransform *phase ) const
|
|
{
|
|
return bottom_type();
|
|
}
|
|
|
|
//=============================================================================
|
|
//----------------------------------LoadStoreNode------------------------------
|
|
LoadStoreNode::LoadStoreNode( Node *c, Node *mem, Node *adr, Node *val, const TypePtr* at, const Type* rt, uint required )
|
|
: Node(required),
|
|
_type(rt),
|
|
_adr_type(at)
|
|
{
|
|
init_req(MemNode::Control, c );
|
|
init_req(MemNode::Memory , mem);
|
|
init_req(MemNode::Address, adr);
|
|
init_req(MemNode::ValueIn, val);
|
|
init_class_id(Class_LoadStore);
|
|
}
|
|
|
|
uint LoadStoreNode::ideal_reg() const {
|
|
return _type->ideal_reg();
|
|
}
|
|
|
|
bool LoadStoreNode::result_not_used() const {
|
|
for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
|
|
Node *x = fast_out(i);
|
|
if (x->Opcode() == Op_SCMemProj) continue;
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
uint LoadStoreNode::size_of() const { return sizeof(*this); }
|
|
|
|
//=============================================================================
|
|
//----------------------------------LoadStoreConditionalNode--------------------
|
|
LoadStoreConditionalNode::LoadStoreConditionalNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex ) : LoadStoreNode(c, mem, adr, val, NULL, TypeInt::BOOL, 5) {
|
|
init_req(ExpectedIn, ex );
|
|
}
|
|
|
|
//=============================================================================
|
|
//-------------------------------adr_type--------------------------------------
|
|
// Do we Match on this edge index or not? Do not match memory
|
|
const TypePtr* ClearArrayNode::adr_type() const {
|
|
Node *adr = in(3);
|
|
return MemNode::calculate_adr_type(adr->bottom_type());
|
|
}
|
|
|
|
//------------------------------match_edge-------------------------------------
|
|
// Do we Match on this edge index or not? Do not match memory
|
|
uint ClearArrayNode::match_edge(uint idx) const {
|
|
return idx > 1;
|
|
}
|
|
|
|
//------------------------------Identity---------------------------------------
|
|
// Clearing a zero length array does nothing
|
|
Node *ClearArrayNode::Identity( PhaseTransform *phase ) {
|
|
return phase->type(in(2))->higher_equal(TypeX::ZERO) ? in(1) : this;
|
|
}
|
|
|
|
//------------------------------Idealize---------------------------------------
|
|
// Clearing a short array is faster with stores
|
|
Node *ClearArrayNode::Ideal(PhaseGVN *phase, bool can_reshape){
|
|
const int unit = BytesPerLong;
|
|
const TypeX* t = phase->type(in(2))->isa_intptr_t();
|
|
if (!t) return NULL;
|
|
if (!t->is_con()) return NULL;
|
|
intptr_t raw_count = t->get_con();
|
|
intptr_t size = raw_count;
|
|
if (!Matcher::init_array_count_is_in_bytes) size *= unit;
|
|
// Clearing nothing uses the Identity call.
|
|
// Negative clears are possible on dead ClearArrays
|
|
// (see jck test stmt114.stmt11402.val).
|
|
if (size <= 0 || size % unit != 0) return NULL;
|
|
intptr_t count = size / unit;
|
|
// Length too long; use fast hardware clear
|
|
if (size > Matcher::init_array_short_size) return NULL;
|
|
Node *mem = in(1);
|
|
if( phase->type(mem)==Type::TOP ) return NULL;
|
|
Node *adr = in(3);
|
|
const Type* at = phase->type(adr);
|
|
if( at==Type::TOP ) return NULL;
|
|
const TypePtr* atp = at->isa_ptr();
|
|
// adjust atp to be the correct array element address type
|
|
if (atp == NULL) atp = TypePtr::BOTTOM;
|
|
else atp = atp->add_offset(Type::OffsetBot);
|
|
// Get base for derived pointer purposes
|
|
if( adr->Opcode() != Op_AddP ) Unimplemented();
|
|
Node *base = adr->in(1);
|
|
|
|
Node *zero = phase->makecon(TypeLong::ZERO);
|
|
Node *off = phase->MakeConX(BytesPerLong);
|
|
mem = new (phase->C) StoreLNode(in(0),mem,adr,atp,zero,MemNode::unordered,false);
|
|
count--;
|
|
while( count-- ) {
|
|
mem = phase->transform(mem);
|
|
adr = phase->transform(new (phase->C) AddPNode(base,adr,off));
|
|
mem = new (phase->C) StoreLNode(in(0),mem,adr,atp,zero,MemNode::unordered,false);
|
|
}
|
|
return mem;
|
|
}
|
|
|
|
//----------------------------step_through----------------------------------
|
|
// Return allocation input memory edge if it is different instance
|
|
// or itself if it is the one we are looking for.
|
|
bool ClearArrayNode::step_through(Node** np, uint instance_id, PhaseTransform* phase) {
|
|
Node* n = *np;
|
|
assert(n->is_ClearArray(), "sanity");
|
|
intptr_t offset;
|
|
AllocateNode* alloc = AllocateNode::Ideal_allocation(n->in(3), phase, offset);
|
|
// This method is called only before Allocate nodes are expanded during
|
|
// macro nodes expansion. Before that ClearArray nodes are only generated
|
|
// in LibraryCallKit::generate_arraycopy() which follows allocations.
|
|
assert(alloc != NULL, "should have allocation");
|
|
if (alloc->_idx == instance_id) {
|
|
// Can not bypass initialization of the instance we are looking for.
|
|
return false;
|
|
}
|
|
// Otherwise skip it.
|
|
InitializeNode* init = alloc->initialization();
|
|
if (init != NULL)
|
|
*np = init->in(TypeFunc::Memory);
|
|
else
|
|
*np = alloc->in(TypeFunc::Memory);
|
|
return true;
|
|
}
|
|
|
|
//----------------------------clear_memory-------------------------------------
|
|
// Generate code to initialize object storage to zero.
|
|
Node* ClearArrayNode::clear_memory(Node* ctl, Node* mem, Node* dest,
|
|
intptr_t start_offset,
|
|
Node* end_offset,
|
|
PhaseGVN* phase) {
|
|
Compile* C = phase->C;
|
|
intptr_t offset = start_offset;
|
|
|
|
int unit = BytesPerLong;
|
|
if ((offset % unit) != 0) {
|
|
Node* adr = new (C) AddPNode(dest, dest, phase->MakeConX(offset));
|
|
adr = phase->transform(adr);
|
|
const TypePtr* atp = TypeRawPtr::BOTTOM;
|
|
mem = StoreNode::make(*phase, ctl, mem, adr, atp, phase->zerocon(T_INT), T_INT, MemNode::unordered);
|
|
mem = phase->transform(mem);
|
|
offset += BytesPerInt;
|
|
}
|
|
assert((offset % unit) == 0, "");
|
|
|
|
// Initialize the remaining stuff, if any, with a ClearArray.
|
|
return clear_memory(ctl, mem, dest, phase->MakeConX(offset), end_offset, phase);
|
|
}
|
|
|
|
Node* ClearArrayNode::clear_memory(Node* ctl, Node* mem, Node* dest,
|
|
Node* start_offset,
|
|
Node* end_offset,
|
|
PhaseGVN* phase) {
|
|
if (start_offset == end_offset) {
|
|
// nothing to do
|
|
return mem;
|
|
}
|
|
|
|
Compile* C = phase->C;
|
|
int unit = BytesPerLong;
|
|
Node* zbase = start_offset;
|
|
Node* zend = end_offset;
|
|
|
|
// Scale to the unit required by the CPU:
|
|
if (!Matcher::init_array_count_is_in_bytes) {
|
|
Node* shift = phase->intcon(exact_log2(unit));
|
|
zbase = phase->transform( new(C) URShiftXNode(zbase, shift) );
|
|
zend = phase->transform( new(C) URShiftXNode(zend, shift) );
|
|
}
|
|
|
|
// Bulk clear double-words
|
|
Node* zsize = phase->transform( new(C) SubXNode(zend, zbase) );
|
|
Node* adr = phase->transform( new(C) AddPNode(dest, dest, start_offset) );
|
|
mem = new (C) ClearArrayNode(ctl, mem, zsize, adr);
|
|
return phase->transform(mem);
|
|
}
|
|
|
|
Node* ClearArrayNode::clear_memory(Node* ctl, Node* mem, Node* dest,
|
|
intptr_t start_offset,
|
|
intptr_t end_offset,
|
|
PhaseGVN* phase) {
|
|
if (start_offset == end_offset) {
|
|
// nothing to do
|
|
return mem;
|
|
}
|
|
|
|
Compile* C = phase->C;
|
|
assert((end_offset % BytesPerInt) == 0, "odd end offset");
|
|
intptr_t done_offset = end_offset;
|
|
if ((done_offset % BytesPerLong) != 0) {
|
|
done_offset -= BytesPerInt;
|
|
}
|
|
if (done_offset > start_offset) {
|
|
mem = clear_memory(ctl, mem, dest,
|
|
start_offset, phase->MakeConX(done_offset), phase);
|
|
}
|
|
if (done_offset < end_offset) { // emit the final 32-bit store
|
|
Node* adr = new (C) AddPNode(dest, dest, phase->MakeConX(done_offset));
|
|
adr = phase->transform(adr);
|
|
const TypePtr* atp = TypeRawPtr::BOTTOM;
|
|
mem = StoreNode::make(*phase, ctl, mem, adr, atp, phase->zerocon(T_INT), T_INT, MemNode::unordered);
|
|
mem = phase->transform(mem);
|
|
done_offset += BytesPerInt;
|
|
}
|
|
assert(done_offset == end_offset, "");
|
|
return mem;
|
|
}
|
|
|
|
//=============================================================================
|
|
// Do not match memory edge.
|
|
uint StrIntrinsicNode::match_edge(uint idx) const {
|
|
return idx == 2 || idx == 3;
|
|
}
|
|
|
|
//------------------------------Ideal------------------------------------------
|
|
// Return a node which is more "ideal" than the current node. Strip out
|
|
// control copies
|
|
Node *StrIntrinsicNode::Ideal(PhaseGVN *phase, bool can_reshape) {
|
|
if (remove_dead_region(phase, can_reshape)) return this;
|
|
// Don't bother trying to transform a dead node
|
|
if (in(0) && in(0)->is_top()) return NULL;
|
|
|
|
if (can_reshape) {
|
|
Node* mem = phase->transform(in(MemNode::Memory));
|
|
// If transformed to a MergeMem, get the desired slice
|
|
uint alias_idx = phase->C->get_alias_index(adr_type());
|
|
mem = mem->is_MergeMem() ? mem->as_MergeMem()->memory_at(alias_idx) : mem;
|
|
if (mem != in(MemNode::Memory)) {
|
|
set_req(MemNode::Memory, mem);
|
|
return this;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
//------------------------------Value------------------------------------------
|
|
const Type *StrIntrinsicNode::Value( PhaseTransform *phase ) const {
|
|
if (in(0) && phase->type(in(0)) == Type::TOP) return Type::TOP;
|
|
return bottom_type();
|
|
}
|
|
|
|
//=============================================================================
|
|
//------------------------------match_edge-------------------------------------
|
|
// Do not match memory edge
|
|
uint EncodeISOArrayNode::match_edge(uint idx) const {
|
|
return idx == 2 || idx == 3; // EncodeISOArray src (Binary dst len)
|
|
}
|
|
|
|
//------------------------------Ideal------------------------------------------
|
|
// Return a node which is more "ideal" than the current node. Strip out
|
|
// control copies
|
|
Node *EncodeISOArrayNode::Ideal(PhaseGVN *phase, bool can_reshape) {
|
|
return remove_dead_region(phase, can_reshape) ? this : NULL;
|
|
}
|
|
|
|
//------------------------------Value------------------------------------------
|
|
const Type *EncodeISOArrayNode::Value(PhaseTransform *phase) const {
|
|
if (in(0) && phase->type(in(0)) == Type::TOP) return Type::TOP;
|
|
return bottom_type();
|
|
}
|
|
|
|
//=============================================================================
|
|
MemBarNode::MemBarNode(Compile* C, int alias_idx, Node* precedent)
|
|
: MultiNode(TypeFunc::Parms + (precedent == NULL? 0: 1)),
|
|
_adr_type(C->get_adr_type(alias_idx))
|
|
{
|
|
init_class_id(Class_MemBar);
|
|
Node* top = C->top();
|
|
init_req(TypeFunc::I_O,top);
|
|
init_req(TypeFunc::FramePtr,top);
|
|
init_req(TypeFunc::ReturnAdr,top);
|
|
if (precedent != NULL)
|
|
init_req(TypeFunc::Parms, precedent);
|
|
}
|
|
|
|
//------------------------------cmp--------------------------------------------
|
|
uint MemBarNode::hash() const { return NO_HASH; }
|
|
uint MemBarNode::cmp( const Node &n ) const {
|
|
return (&n == this); // Always fail except on self
|
|
}
|
|
|
|
//------------------------------make-------------------------------------------
|
|
MemBarNode* MemBarNode::make(Compile* C, int opcode, int atp, Node* pn) {
|
|
switch (opcode) {
|
|
case Op_MemBarAcquire: return new(C) MemBarAcquireNode(C, atp, pn);
|
|
case Op_LoadFence: return new(C) LoadFenceNode(C, atp, pn);
|
|
case Op_MemBarRelease: return new(C) MemBarReleaseNode(C, atp, pn);
|
|
case Op_StoreFence: return new(C) StoreFenceNode(C, atp, pn);
|
|
case Op_MemBarAcquireLock: return new(C) MemBarAcquireLockNode(C, atp, pn);
|
|
case Op_MemBarReleaseLock: return new(C) MemBarReleaseLockNode(C, atp, pn);
|
|
case Op_MemBarVolatile: return new(C) MemBarVolatileNode(C, atp, pn);
|
|
case Op_MemBarCPUOrder: return new(C) MemBarCPUOrderNode(C, atp, pn);
|
|
case Op_Initialize: return new(C) InitializeNode(C, atp, pn);
|
|
case Op_MemBarStoreStore: return new(C) MemBarStoreStoreNode(C, atp, pn);
|
|
default: ShouldNotReachHere(); return NULL;
|
|
}
|
|
}
|
|
|
|
//------------------------------Ideal------------------------------------------
|
|
// Return a node which is more "ideal" than the current node. Strip out
|
|
// control copies
|
|
Node *MemBarNode::Ideal(PhaseGVN *phase, bool can_reshape) {
|
|
if (remove_dead_region(phase, can_reshape)) return this;
|
|
// Don't bother trying to transform a dead node
|
|
if (in(0) && in(0)->is_top()) {
|
|
return NULL;
|
|
}
|
|
|
|
// Eliminate volatile MemBars for scalar replaced objects.
|
|
if (can_reshape && req() == (Precedent+1)) {
|
|
bool eliminate = false;
|
|
int opc = Opcode();
|
|
if ((opc == Op_MemBarAcquire || opc == Op_MemBarVolatile)) {
|
|
// Volatile field loads and stores.
|
|
Node* my_mem = in(MemBarNode::Precedent);
|
|
// The MembarAquire may keep an unused LoadNode alive through the Precedent edge
|
|
if ((my_mem != NULL) && (opc == Op_MemBarAcquire) && (my_mem->outcnt() == 1)) {
|
|
// if the Precedent is a decodeN and its input (a Load) is used at more than one place,
|
|
// replace this Precedent (decodeN) with the Load instead.
|
|
if ((my_mem->Opcode() == Op_DecodeN) && (my_mem->in(1)->outcnt() > 1)) {
|
|
Node* load_node = my_mem->in(1);
|
|
set_req(MemBarNode::Precedent, load_node);
|
|
phase->is_IterGVN()->_worklist.push(my_mem);
|
|
my_mem = load_node;
|
|
} else {
|
|
assert(my_mem->unique_out() == this, "sanity");
|
|
del_req(Precedent);
|
|
phase->is_IterGVN()->_worklist.push(my_mem); // remove dead node later
|
|
my_mem = NULL;
|
|
}
|
|
}
|
|
if (my_mem != NULL && my_mem->is_Mem()) {
|
|
const TypeOopPtr* t_oop = my_mem->in(MemNode::Address)->bottom_type()->isa_oopptr();
|
|
// Check for scalar replaced object reference.
|
|
if( t_oop != NULL && t_oop->is_known_instance_field() &&
|
|
t_oop->offset() != Type::OffsetBot &&
|
|
t_oop->offset() != Type::OffsetTop) {
|
|
eliminate = true;
|
|
}
|
|
}
|
|
} else if (opc == Op_MemBarRelease) {
|
|
// Final field stores.
|
|
Node* alloc = AllocateNode::Ideal_allocation(in(MemBarNode::Precedent), phase);
|
|
if ((alloc != NULL) && alloc->is_Allocate() &&
|
|
alloc->as_Allocate()->_is_non_escaping) {
|
|
// The allocated object does not escape.
|
|
eliminate = true;
|
|
}
|
|
}
|
|
if (eliminate) {
|
|
// Replace MemBar projections by its inputs.
|
|
PhaseIterGVN* igvn = phase->is_IterGVN();
|
|
igvn->replace_node(proj_out(TypeFunc::Memory), in(TypeFunc::Memory));
|
|
igvn->replace_node(proj_out(TypeFunc::Control), in(TypeFunc::Control));
|
|
// Must return either the original node (now dead) or a new node
|
|
// (Do not return a top here, since that would break the uniqueness of top.)
|
|
return new (phase->C) ConINode(TypeInt::ZERO);
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
//------------------------------Value------------------------------------------
|
|
const Type *MemBarNode::Value( PhaseTransform *phase ) const {
|
|
if( !in(0) ) return Type::TOP;
|
|
if( phase->type(in(0)) == Type::TOP )
|
|
return Type::TOP;
|
|
return TypeTuple::MEMBAR;
|
|
}
|
|
|
|
//------------------------------match------------------------------------------
|
|
// Construct projections for memory.
|
|
Node *MemBarNode::match( const ProjNode *proj, const Matcher *m ) {
|
|
switch (proj->_con) {
|
|
case TypeFunc::Control:
|
|
case TypeFunc::Memory:
|
|
return new (m->C) MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj);
|
|
}
|
|
ShouldNotReachHere();
|
|
return NULL;
|
|
}
|
|
|
|
//===========================InitializeNode====================================
|
|
// SUMMARY:
|
|
// This node acts as a memory barrier on raw memory, after some raw stores.
|
|
// The 'cooked' oop value feeds from the Initialize, not the Allocation.
|
|
// The Initialize can 'capture' suitably constrained stores as raw inits.
|
|
// It can coalesce related raw stores into larger units (called 'tiles').
|
|
// It can avoid zeroing new storage for memory units which have raw inits.
|
|
// At macro-expansion, it is marked 'complete', and does not optimize further.
|
|
//
|
|
// EXAMPLE:
|
|
// The object 'new short[2]' occupies 16 bytes in a 32-bit machine.
|
|
// ctl = incoming control; mem* = incoming memory
|
|
// (Note: A star * on a memory edge denotes I/O and other standard edges.)
|
|
// First allocate uninitialized memory and fill in the header:
|
|
// alloc = (Allocate ctl mem* 16 #short[].klass ...)
|
|
// ctl := alloc.Control; mem* := alloc.Memory*
|
|
// rawmem = alloc.Memory; rawoop = alloc.RawAddress
|
|
// Then initialize to zero the non-header parts of the raw memory block:
|
|
// init = (Initialize alloc.Control alloc.Memory* alloc.RawAddress)
|
|
// ctl := init.Control; mem.SLICE(#short[*]) := init.Memory
|
|
// After the initialize node executes, the object is ready for service:
|
|
// oop := (CheckCastPP init.Control alloc.RawAddress #short[])
|
|
// Suppose its body is immediately initialized as {1,2}:
|
|
// store1 = (StoreC init.Control init.Memory (+ oop 12) 1)
|
|
// store2 = (StoreC init.Control store1 (+ oop 14) 2)
|
|
// mem.SLICE(#short[*]) := store2
|
|
//
|
|
// DETAILS:
|
|
// An InitializeNode collects and isolates object initialization after
|
|
// an AllocateNode and before the next possible safepoint. As a
|
|
// memory barrier (MemBarNode), it keeps critical stores from drifting
|
|
// down past any safepoint or any publication of the allocation.
|
|
// Before this barrier, a newly-allocated object may have uninitialized bits.
|
|
// After this barrier, it may be treated as a real oop, and GC is allowed.
|
|
//
|
|
// The semantics of the InitializeNode include an implicit zeroing of
|
|
// the new object from object header to the end of the object.
|
|
// (The object header and end are determined by the AllocateNode.)
|
|
//
|
|
// Certain stores may be added as direct inputs to the InitializeNode.
|
|
// These stores must update raw memory, and they must be to addresses
|
|
// derived from the raw address produced by AllocateNode, and with
|
|
// a constant offset. They must be ordered by increasing offset.
|
|
// The first one is at in(RawStores), the last at in(req()-1).
|
|
// Unlike most memory operations, they are not linked in a chain,
|
|
// but are displayed in parallel as users of the rawmem output of
|
|
// the allocation.
|
|
//
|
|
// (See comments in InitializeNode::capture_store, which continue
|
|
// the example given above.)
|
|
//
|
|
// When the associated Allocate is macro-expanded, the InitializeNode
|
|
// may be rewritten to optimize collected stores. A ClearArrayNode
|
|
// may also be created at that point to represent any required zeroing.
|
|
// The InitializeNode is then marked 'complete', prohibiting further
|
|
// capturing of nearby memory operations.
|
|
//
|
|
// During macro-expansion, all captured initializations which store
|
|
// constant values of 32 bits or smaller are coalesced (if advantageous)
|
|
// into larger 'tiles' 32 or 64 bits. This allows an object to be
|
|
// initialized in fewer memory operations. Memory words which are
|
|
// covered by neither tiles nor non-constant stores are pre-zeroed
|
|
// by explicit stores of zero. (The code shape happens to do all
|
|
// zeroing first, then all other stores, with both sequences occurring
|
|
// in order of ascending offsets.)
|
|
//
|
|
// Alternatively, code may be inserted between an AllocateNode and its
|
|
// InitializeNode, to perform arbitrary initialization of the new object.
|
|
// E.g., the object copying intrinsics insert complex data transfers here.
|
|
// The initialization must then be marked as 'complete' disable the
|
|
// built-in zeroing semantics and the collection of initializing stores.
|
|
//
|
|
// While an InitializeNode is incomplete, reads from the memory state
|
|
// produced by it are optimizable if they match the control edge and
|
|
// new oop address associated with the allocation/initialization.
|
|
// They return a stored value (if the offset matches) or else zero.
|
|
// A write to the memory state, if it matches control and address,
|
|
// and if it is to a constant offset, may be 'captured' by the
|
|
// InitializeNode. It is cloned as a raw memory operation and rewired
|
|
// inside the initialization, to the raw oop produced by the allocation.
|
|
// Operations on addresses which are provably distinct (e.g., to
|
|
// other AllocateNodes) are allowed to bypass the initialization.
|
|
//
|
|
// The effect of all this is to consolidate object initialization
|
|
// (both arrays and non-arrays, both piecewise and bulk) into a
|
|
// single location, where it can be optimized as a unit.
|
|
//
|
|
// Only stores with an offset less than TrackedInitializationLimit words
|
|
// will be considered for capture by an InitializeNode. This puts a
|
|
// reasonable limit on the complexity of optimized initializations.
|
|
|
|
//---------------------------InitializeNode------------------------------------
|
|
InitializeNode::InitializeNode(Compile* C, int adr_type, Node* rawoop)
|
|
: _is_complete(Incomplete), _does_not_escape(false),
|
|
MemBarNode(C, adr_type, rawoop)
|
|
{
|
|
init_class_id(Class_Initialize);
|
|
|
|
assert(adr_type == Compile::AliasIdxRaw, "only valid atp");
|
|
assert(in(RawAddress) == rawoop, "proper init");
|
|
// Note: allocation() can be NULL, for secondary initialization barriers
|
|
}
|
|
|
|
// Since this node is not matched, it will be processed by the
|
|
// register allocator. Declare that there are no constraints
|
|
// on the allocation of the RawAddress edge.
|
|
const RegMask &InitializeNode::in_RegMask(uint idx) const {
|
|
// This edge should be set to top, by the set_complete. But be conservative.
|
|
if (idx == InitializeNode::RawAddress)
|
|
return *(Compile::current()->matcher()->idealreg2spillmask[in(idx)->ideal_reg()]);
|
|
return RegMask::Empty;
|
|
}
|
|
|
|
Node* InitializeNode::memory(uint alias_idx) {
|
|
Node* mem = in(Memory);
|
|
if (mem->is_MergeMem()) {
|
|
return mem->as_MergeMem()->memory_at(alias_idx);
|
|
} else {
|
|
// incoming raw memory is not split
|
|
return mem;
|
|
}
|
|
}
|
|
|
|
bool InitializeNode::is_non_zero() {
|
|
if (is_complete()) return false;
|
|
remove_extra_zeroes();
|
|
return (req() > RawStores);
|
|
}
|
|
|
|
void InitializeNode::set_complete(PhaseGVN* phase) {
|
|
assert(!is_complete(), "caller responsibility");
|
|
_is_complete = Complete;
|
|
|
|
// After this node is complete, it contains a bunch of
|
|
// raw-memory initializations. There is no need for
|
|
// it to have anything to do with non-raw memory effects.
|
|
// Therefore, tell all non-raw users to re-optimize themselves,
|
|
// after skipping the memory effects of this initialization.
|
|
PhaseIterGVN* igvn = phase->is_IterGVN();
|
|
if (igvn) igvn->add_users_to_worklist(this);
|
|
}
|
|
|
|
// convenience function
|
|
// return false if the init contains any stores already
|
|
bool AllocateNode::maybe_set_complete(PhaseGVN* phase) {
|
|
InitializeNode* init = initialization();
|
|
if (init == NULL || init->is_complete()) return false;
|
|
init->remove_extra_zeroes();
|
|
// for now, if this allocation has already collected any inits, bail:
|
|
if (init->is_non_zero()) return false;
|
|
init->set_complete(phase);
|
|
return true;
|
|
}
|
|
|
|
void InitializeNode::remove_extra_zeroes() {
|
|
if (req() == RawStores) return;
|
|
Node* zmem = zero_memory();
|
|
uint fill = RawStores;
|
|
for (uint i = fill; i < req(); i++) {
|
|
Node* n = in(i);
|
|
if (n->is_top() || n == zmem) continue; // skip
|
|
if (fill < i) set_req(fill, n); // compact
|
|
++fill;
|
|
}
|
|
// delete any empty spaces created:
|
|
while (fill < req()) {
|
|
del_req(fill);
|
|
}
|
|
}
|
|
|
|
// Helper for remembering which stores go with which offsets.
|
|
intptr_t InitializeNode::get_store_offset(Node* st, PhaseTransform* phase) {
|
|
if (!st->is_Store()) return -1; // can happen to dead code via subsume_node
|
|
intptr_t offset = -1;
|
|
Node* base = AddPNode::Ideal_base_and_offset(st->in(MemNode::Address),
|
|
phase, offset);
|
|
if (base == NULL) return -1; // something is dead,
|
|
if (offset < 0) return -1; // dead, dead
|
|
return offset;
|
|
}
|
|
|
|
// Helper for proving that an initialization expression is
|
|
// "simple enough" to be folded into an object initialization.
|
|
// Attempts to prove that a store's initial value 'n' can be captured
|
|
// within the initialization without creating a vicious cycle, such as:
|
|
// { Foo p = new Foo(); p.next = p; }
|
|
// True for constants and parameters and small combinations thereof.
|
|
bool InitializeNode::detect_init_independence(Node* n, int& count) {
|
|
if (n == NULL) return true; // (can this really happen?)
|
|
if (n->is_Proj()) n = n->in(0);
|
|
if (n == this) return false; // found a cycle
|
|
if (n->is_Con()) return true;
|
|
if (n->is_Start()) return true; // params, etc., are OK
|
|
if (n->is_Root()) return true; // even better
|
|
|
|
Node* ctl = n->in(0);
|
|
if (ctl != NULL && !ctl->is_top()) {
|
|
if (ctl->is_Proj()) ctl = ctl->in(0);
|
|
if (ctl == this) return false;
|
|
|
|
// If we already know that the enclosing memory op is pinned right after
|
|
// the init, then any control flow that the store has picked up
|
|
// must have preceded the init, or else be equal to the init.
|
|
// Even after loop optimizations (which might change control edges)
|
|
// a store is never pinned *before* the availability of its inputs.
|
|
if (!MemNode::all_controls_dominate(n, this))
|
|
return false; // failed to prove a good control
|
|
}
|
|
|
|
// Check data edges for possible dependencies on 'this'.
|
|
if ((count += 1) > 20) return false; // complexity limit
|
|
for (uint i = 1; i < n->req(); i++) {
|
|
Node* m = n->in(i);
|
|
if (m == NULL || m == n || m->is_top()) continue;
|
|
uint first_i = n->find_edge(m);
|
|
if (i != first_i) continue; // process duplicate edge just once
|
|
if (!detect_init_independence(m, count)) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
// Here are all the checks a Store must pass before it can be moved into
|
|
// an initialization. Returns zero if a check fails.
|
|
// On success, returns the (constant) offset to which the store applies,
|
|
// within the initialized memory.
|
|
intptr_t InitializeNode::can_capture_store(StoreNode* st, PhaseTransform* phase, bool can_reshape) {
|
|
const int FAIL = 0;
|
|
if (st->req() != MemNode::ValueIn + 1)
|
|
return FAIL; // an inscrutable StoreNode (card mark?)
|
|
Node* ctl = st->in(MemNode::Control);
|
|
if (!(ctl != NULL && ctl->is_Proj() && ctl->in(0) == this))
|
|
return FAIL; // must be unconditional after the initialization
|
|
Node* mem = st->in(MemNode::Memory);
|
|
if (!(mem->is_Proj() && mem->in(0) == this))
|
|
return FAIL; // must not be preceded by other stores
|
|
Node* adr = st->in(MemNode::Address);
|
|
intptr_t offset;
|
|
AllocateNode* alloc = AllocateNode::Ideal_allocation(adr, phase, offset);
|
|
if (alloc == NULL)
|
|
return FAIL; // inscrutable address
|
|
if (alloc != allocation())
|
|
return FAIL; // wrong allocation! (store needs to float up)
|
|
Node* val = st->in(MemNode::ValueIn);
|
|
int complexity_count = 0;
|
|
if (!detect_init_independence(val, complexity_count))
|
|
return FAIL; // stored value must be 'simple enough'
|
|
|
|
// The Store can be captured only if nothing after the allocation
|
|
// and before the Store is using the memory location that the store
|
|
// overwrites.
|
|
bool failed = false;
|
|
// If is_complete_with_arraycopy() is true the shape of the graph is
|
|
// well defined and is safe so no need for extra checks.
|
|
if (!is_complete_with_arraycopy()) {
|
|
// We are going to look at each use of the memory state following
|
|
// the allocation to make sure nothing reads the memory that the
|
|
// Store writes.
|
|
const TypePtr* t_adr = phase->type(adr)->isa_ptr();
|
|
int alias_idx = phase->C->get_alias_index(t_adr);
|
|
ResourceMark rm;
|
|
Unique_Node_List mems;
|
|
mems.push(mem);
|
|
Node* unique_merge = NULL;
|
|
for (uint next = 0; next < mems.size(); ++next) {
|
|
Node *m = mems.at(next);
|
|
for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
|
|
Node *n = m->fast_out(j);
|
|
if (n->outcnt() == 0) {
|
|
continue;
|
|
}
|
|
if (n == st) {
|
|
continue;
|
|
} else if (n->in(0) != NULL && n->in(0) != ctl) {
|
|
// If the control of this use is different from the control
|
|
// of the Store which is right after the InitializeNode then
|
|
// this node cannot be between the InitializeNode and the
|
|
// Store.
|
|
continue;
|
|
} else if (n->is_MergeMem()) {
|
|
if (n->as_MergeMem()->memory_at(alias_idx) == m) {
|
|
// We can hit a MergeMemNode (that will likely go away
|
|
// later) that is a direct use of the memory state
|
|
// following the InitializeNode on the same slice as the
|
|
// store node that we'd like to capture. We need to check
|
|
// the uses of the MergeMemNode.
|
|
mems.push(n);
|
|
}
|
|
} else if (n->is_Mem()) {
|
|
Node* other_adr = n->in(MemNode::Address);
|
|
if (other_adr == adr) {
|
|
failed = true;
|
|
break;
|
|
} else {
|
|
const TypePtr* other_t_adr = phase->type(other_adr)->isa_ptr();
|
|
if (other_t_adr != NULL) {
|
|
int other_alias_idx = phase->C->get_alias_index(other_t_adr);
|
|
if (other_alias_idx == alias_idx) {
|
|
// A load from the same memory slice as the store right
|
|
// after the InitializeNode. We check the control of the
|
|
// object/array that is loaded from. If it's the same as
|
|
// the store control then we cannot capture the store.
|
|
assert(!n->is_Store(), "2 stores to same slice on same control?");
|
|
Node* base = other_adr;
|
|
assert(base->is_AddP(), err_msg_res("should be addp but is %s", base->Name()));
|
|
base = base->in(AddPNode::Base);
|
|
if (base != NULL) {
|
|
base = base->uncast();
|
|
if (base->is_Proj() && base->in(0) == alloc) {
|
|
failed = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
failed = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (failed) {
|
|
if (!can_reshape) {
|
|
// We decided we couldn't capture the store during parsing. We
|
|
// should try again during the next IGVN once the graph is
|
|
// cleaner.
|
|
phase->C->record_for_igvn(st);
|
|
}
|
|
return FAIL;
|
|
}
|
|
|
|
return offset; // success
|
|
}
|
|
|
|
// Find the captured store in(i) which corresponds to the range
|
|
// [start..start+size) in the initialized object.
|
|
// If there is one, return its index i. If there isn't, return the
|
|
// negative of the index where it should be inserted.
|
|
// Return 0 if the queried range overlaps an initialization boundary
|
|
// or if dead code is encountered.
|
|
// If size_in_bytes is zero, do not bother with overlap checks.
|
|
int InitializeNode::captured_store_insertion_point(intptr_t start,
|
|
int size_in_bytes,
|
|
PhaseTransform* phase) {
|
|
const int FAIL = 0, MAX_STORE = BytesPerLong;
|
|
|
|
if (is_complete())
|
|
return FAIL; // arraycopy got here first; punt
|
|
|
|
assert(allocation() != NULL, "must be present");
|
|
|
|
// no negatives, no header fields:
|
|
if (start < (intptr_t) allocation()->minimum_header_size()) return FAIL;
|
|
|
|
// after a certain size, we bail out on tracking all the stores:
|
|
intptr_t ti_limit = (TrackedInitializationLimit * HeapWordSize);
|
|
if (start >= ti_limit) return FAIL;
|
|
|
|
for (uint i = InitializeNode::RawStores, limit = req(); ; ) {
|
|
if (i >= limit) return -(int)i; // not found; here is where to put it
|
|
|
|
Node* st = in(i);
|
|
intptr_t st_off = get_store_offset(st, phase);
|
|
if (st_off < 0) {
|
|
if (st != zero_memory()) {
|
|
return FAIL; // bail out if there is dead garbage
|
|
}
|
|
} else if (st_off > start) {
|
|
// ...we are done, since stores are ordered
|
|
if (st_off < start + size_in_bytes) {
|
|
return FAIL; // the next store overlaps
|
|
}
|
|
return -(int)i; // not found; here is where to put it
|
|
} else if (st_off < start) {
|
|
if (size_in_bytes != 0 &&
|
|
start < st_off + MAX_STORE &&
|
|
start < st_off + st->as_Store()->memory_size()) {
|
|
return FAIL; // the previous store overlaps
|
|
}
|
|
} else {
|
|
if (size_in_bytes != 0 &&
|
|
st->as_Store()->memory_size() != size_in_bytes) {
|
|
return FAIL; // mismatched store size
|
|
}
|
|
return i;
|
|
}
|
|
|
|
++i;
|
|
}
|
|
}
|
|
|
|
// Look for a captured store which initializes at the offset 'start'
|
|
// with the given size. If there is no such store, and no other
|
|
// initialization interferes, then return zero_memory (the memory
|
|
// projection of the AllocateNode).
|
|
Node* InitializeNode::find_captured_store(intptr_t start, int size_in_bytes,
|
|
PhaseTransform* phase) {
|
|
assert(stores_are_sane(phase), "");
|
|
int i = captured_store_insertion_point(start, size_in_bytes, phase);
|
|
if (i == 0) {
|
|
return NULL; // something is dead
|
|
} else if (i < 0) {
|
|
return zero_memory(); // just primordial zero bits here
|
|
} else {
|
|
Node* st = in(i); // here is the store at this position
|
|
assert(get_store_offset(st->as_Store(), phase) == start, "sanity");
|
|
return st;
|
|
}
|
|
}
|
|
|
|
// Create, as a raw pointer, an address within my new object at 'offset'.
|
|
Node* InitializeNode::make_raw_address(intptr_t offset,
|
|
PhaseTransform* phase) {
|
|
Node* addr = in(RawAddress);
|
|
if (offset != 0) {
|
|
Compile* C = phase->C;
|
|
addr = phase->transform( new (C) AddPNode(C->top(), addr,
|
|
phase->MakeConX(offset)) );
|
|
}
|
|
return addr;
|
|
}
|
|
|
|
// Clone the given store, converting it into a raw store
|
|
// initializing a field or element of my new object.
|
|
// Caller is responsible for retiring the original store,
|
|
// with subsume_node or the like.
|
|
//
|
|
// From the example above InitializeNode::InitializeNode,
|
|
// here are the old stores to be captured:
|
|
// store1 = (StoreC init.Control init.Memory (+ oop 12) 1)
|
|
// store2 = (StoreC init.Control store1 (+ oop 14) 2)
|
|
//
|
|
// Here is the changed code; note the extra edges on init:
|
|
// alloc = (Allocate ...)
|
|
// rawoop = alloc.RawAddress
|
|
// rawstore1 = (StoreC alloc.Control alloc.Memory (+ rawoop 12) 1)
|
|
// rawstore2 = (StoreC alloc.Control alloc.Memory (+ rawoop 14) 2)
|
|
// init = (Initialize alloc.Control alloc.Memory rawoop
|
|
// rawstore1 rawstore2)
|
|
//
|
|
Node* InitializeNode::capture_store(StoreNode* st, intptr_t start,
|
|
PhaseTransform* phase, bool can_reshape) {
|
|
assert(stores_are_sane(phase), "");
|
|
|
|
if (start < 0) return NULL;
|
|
assert(can_capture_store(st, phase, can_reshape) == start, "sanity");
|
|
|
|
Compile* C = phase->C;
|
|
int size_in_bytes = st->memory_size();
|
|
int i = captured_store_insertion_point(start, size_in_bytes, phase);
|
|
if (i == 0) return NULL; // bail out
|
|
Node* prev_mem = NULL; // raw memory for the captured store
|
|
if (i > 0) {
|
|
prev_mem = in(i); // there is a pre-existing store under this one
|
|
set_req(i, C->top()); // temporarily disconnect it
|
|
// See StoreNode::Ideal 'st->outcnt() == 1' for the reason to disconnect.
|
|
} else {
|
|
i = -i; // no pre-existing store
|
|
prev_mem = zero_memory(); // a slice of the newly allocated object
|
|
if (i > InitializeNode::RawStores && in(i-1) == prev_mem)
|
|
set_req(--i, C->top()); // reuse this edge; it has been folded away
|
|
else
|
|
ins_req(i, C->top()); // build a new edge
|
|
}
|
|
Node* new_st = st->clone();
|
|
new_st->set_req(MemNode::Control, in(Control));
|
|
new_st->set_req(MemNode::Memory, prev_mem);
|
|
new_st->set_req(MemNode::Address, make_raw_address(start, phase));
|
|
new_st = phase->transform(new_st);
|
|
|
|
// At this point, new_st might have swallowed a pre-existing store
|
|
// at the same offset, or perhaps new_st might have disappeared,
|
|
// if it redundantly stored the same value (or zero to fresh memory).
|
|
|
|
// In any case, wire it in:
|
|
set_req(i, new_st);
|
|
|
|
// The caller may now kill the old guy.
|
|
DEBUG_ONLY(Node* check_st = find_captured_store(start, size_in_bytes, phase));
|
|
assert(check_st == new_st || check_st == NULL, "must be findable");
|
|
assert(!is_complete(), "");
|
|
return new_st;
|
|
}
|
|
|
|
static bool store_constant(jlong* tiles, int num_tiles,
|
|
intptr_t st_off, int st_size,
|
|
jlong con) {
|
|
if ((st_off & (st_size-1)) != 0)
|
|
return false; // strange store offset (assume size==2**N)
|
|
address addr = (address)tiles + st_off;
|
|
assert(st_off >= 0 && addr+st_size <= (address)&tiles[num_tiles], "oob");
|
|
switch (st_size) {
|
|
case sizeof(jbyte): *(jbyte*) addr = (jbyte) con; break;
|
|
case sizeof(jchar): *(jchar*) addr = (jchar) con; break;
|
|
case sizeof(jint): *(jint*) addr = (jint) con; break;
|
|
case sizeof(jlong): *(jlong*) addr = (jlong) con; break;
|
|
default: return false; // strange store size (detect size!=2**N here)
|
|
}
|
|
return true; // return success to caller
|
|
}
|
|
|
|
// Coalesce subword constants into int constants and possibly
|
|
// into long constants. The goal, if the CPU permits,
|
|
// is to initialize the object with a small number of 64-bit tiles.
|
|
// Also, convert floating-point constants to bit patterns.
|
|
// Non-constants are not relevant to this pass.
|
|
//
|
|
// In terms of the running example on InitializeNode::InitializeNode
|
|
// and InitializeNode::capture_store, here is the transformation
|
|
// of rawstore1 and rawstore2 into rawstore12:
|
|
// alloc = (Allocate ...)
|
|
// rawoop = alloc.RawAddress
|
|
// tile12 = 0x00010002
|
|
// rawstore12 = (StoreI alloc.Control alloc.Memory (+ rawoop 12) tile12)
|
|
// init = (Initialize alloc.Control alloc.Memory rawoop rawstore12)
|
|
//
|
|
void
|
|
InitializeNode::coalesce_subword_stores(intptr_t header_size,
|
|
Node* size_in_bytes,
|
|
PhaseGVN* phase) {
|
|
Compile* C = phase->C;
|
|
|
|
assert(stores_are_sane(phase), "");
|
|
// Note: After this pass, they are not completely sane,
|
|
// since there may be some overlaps.
|
|
|
|
int old_subword = 0, old_long = 0, new_int = 0, new_long = 0;
|
|
|
|
intptr_t ti_limit = (TrackedInitializationLimit * HeapWordSize);
|
|
intptr_t size_limit = phase->find_intptr_t_con(size_in_bytes, ti_limit);
|
|
size_limit = MIN2(size_limit, ti_limit);
|
|
size_limit = align_size_up(size_limit, BytesPerLong);
|
|
int num_tiles = size_limit / BytesPerLong;
|
|
|
|
// allocate space for the tile map:
|
|
const int small_len = DEBUG_ONLY(true ? 3 :) 30; // keep stack frames small
|
|
jlong tiles_buf[small_len];
|
|
Node* nodes_buf[small_len];
|
|
jlong inits_buf[small_len];
|
|
jlong* tiles = ((num_tiles <= small_len) ? &tiles_buf[0]
|
|
: NEW_RESOURCE_ARRAY(jlong, num_tiles));
|
|
Node** nodes = ((num_tiles <= small_len) ? &nodes_buf[0]
|
|
: NEW_RESOURCE_ARRAY(Node*, num_tiles));
|
|
jlong* inits = ((num_tiles <= small_len) ? &inits_buf[0]
|
|
: NEW_RESOURCE_ARRAY(jlong, num_tiles));
|
|
// tiles: exact bitwise model of all primitive constants
|
|
// nodes: last constant-storing node subsumed into the tiles model
|
|
// inits: which bytes (in each tile) are touched by any initializations
|
|
|
|
//// Pass A: Fill in the tile model with any relevant stores.
|
|
|
|
Copy::zero_to_bytes(tiles, sizeof(tiles[0]) * num_tiles);
|
|
Copy::zero_to_bytes(nodes, sizeof(nodes[0]) * num_tiles);
|
|
Copy::zero_to_bytes(inits, sizeof(inits[0]) * num_tiles);
|
|
Node* zmem = zero_memory(); // initially zero memory state
|
|
for (uint i = InitializeNode::RawStores, limit = req(); i < limit; i++) {
|
|
Node* st = in(i);
|
|
intptr_t st_off = get_store_offset(st, phase);
|
|
|
|
// Figure out the store's offset and constant value:
|
|
if (st_off < header_size) continue; //skip (ignore header)
|
|
if (st->in(MemNode::Memory) != zmem) continue; //skip (odd store chain)
|
|
int st_size = st->as_Store()->memory_size();
|
|
if (st_off + st_size > size_limit) break;
|
|
|
|
// Record which bytes are touched, whether by constant or not.
|
|
if (!store_constant(inits, num_tiles, st_off, st_size, (jlong) -1))
|
|
continue; // skip (strange store size)
|
|
|
|
const Type* val = phase->type(st->in(MemNode::ValueIn));
|
|
if (!val->singleton()) continue; //skip (non-con store)
|
|
BasicType type = val->basic_type();
|
|
|
|
jlong con = 0;
|
|
switch (type) {
|
|
case T_INT: con = val->is_int()->get_con(); break;
|
|
case T_LONG: con = val->is_long()->get_con(); break;
|
|
case T_FLOAT: con = jint_cast(val->getf()); break;
|
|
case T_DOUBLE: con = jlong_cast(val->getd()); break;
|
|
default: continue; //skip (odd store type)
|
|
}
|
|
|
|
if (type == T_LONG && Matcher::isSimpleConstant64(con) &&
|
|
st->Opcode() == Op_StoreL) {
|
|
continue; // This StoreL is already optimal.
|
|
}
|
|
|
|
// Store down the constant.
|
|
store_constant(tiles, num_tiles, st_off, st_size, con);
|
|
|
|
intptr_t j = st_off >> LogBytesPerLong;
|
|
|
|
if (type == T_INT && st_size == BytesPerInt
|
|
&& (st_off & BytesPerInt) == BytesPerInt) {
|
|
jlong lcon = tiles[j];
|
|
if (!Matcher::isSimpleConstant64(lcon) &&
|
|
st->Opcode() == Op_StoreI) {
|
|
// This StoreI is already optimal by itself.
|
|
jint* intcon = (jint*) &tiles[j];
|
|
intcon[1] = 0; // undo the store_constant()
|
|
|
|
// If the previous store is also optimal by itself, back up and
|
|
// undo the action of the previous loop iteration... if we can.
|
|
// But if we can't, just let the previous half take care of itself.
|
|
st = nodes[j];
|
|
st_off -= BytesPerInt;
|
|
con = intcon[0];
|
|
if (con != 0 && st != NULL && st->Opcode() == Op_StoreI) {
|
|
assert(st_off >= header_size, "still ignoring header");
|
|
assert(get_store_offset(st, phase) == st_off, "must be");
|
|
assert(in(i-1) == zmem, "must be");
|
|
DEBUG_ONLY(const Type* tcon = phase->type(st->in(MemNode::ValueIn)));
|
|
assert(con == tcon->is_int()->get_con(), "must be");
|
|
// Undo the effects of the previous loop trip, which swallowed st:
|
|
intcon[0] = 0; // undo store_constant()
|
|
set_req(i-1, st); // undo set_req(i, zmem)
|
|
nodes[j] = NULL; // undo nodes[j] = st
|
|
--old_subword; // undo ++old_subword
|
|
}
|
|
continue; // This StoreI is already optimal.
|
|
}
|
|
}
|
|
|
|
// This store is not needed.
|
|
set_req(i, zmem);
|
|
nodes[j] = st; // record for the moment
|
|
if (st_size < BytesPerLong) // something has changed
|
|
++old_subword; // includes int/float, but who's counting...
|
|
else ++old_long;
|
|
}
|
|
|
|
if ((old_subword + old_long) == 0)
|
|
return; // nothing more to do
|
|
|
|
//// Pass B: Convert any non-zero tiles into optimal constant stores.
|
|
// Be sure to insert them before overlapping non-constant stores.
|
|
// (E.g., byte[] x = { 1,2,y,4 } => x[int 0] = 0x01020004, x[2]=y.)
|
|
for (int j = 0; j < num_tiles; j++) {
|
|
jlong con = tiles[j];
|
|
jlong init = inits[j];
|
|
if (con == 0) continue;
|
|
jint con0, con1; // split the constant, address-wise
|
|
jint init0, init1; // split the init map, address-wise
|
|
{ union { jlong con; jint intcon[2]; } u;
|
|
u.con = con;
|
|
con0 = u.intcon[0];
|
|
con1 = u.intcon[1];
|
|
u.con = init;
|
|
init0 = u.intcon[0];
|
|
init1 = u.intcon[1];
|
|
}
|
|
|
|
Node* old = nodes[j];
|
|
assert(old != NULL, "need the prior store");
|
|
intptr_t offset = (j * BytesPerLong);
|
|
|
|
bool split = !Matcher::isSimpleConstant64(con);
|
|
|
|
if (offset < header_size) {
|
|
assert(offset + BytesPerInt >= header_size, "second int counts");
|
|
assert(*(jint*)&tiles[j] == 0, "junk in header");
|
|
split = true; // only the second word counts
|
|
// Example: int a[] = { 42 ... }
|
|
} else if (con0 == 0 && init0 == -1) {
|
|
split = true; // first word is covered by full inits
|
|
// Example: int a[] = { ... foo(), 42 ... }
|
|
} else if (con1 == 0 && init1 == -1) {
|
|
split = true; // second word is covered by full inits
|
|
// Example: int a[] = { ... 42, foo() ... }
|
|
}
|
|
|
|
// Here's a case where init0 is neither 0 nor -1:
|
|
// byte a[] = { ... 0,0,foo(),0, 0,0,0,42 ... }
|
|
// Assuming big-endian memory, init0, init1 are 0x0000FF00, 0x000000FF.
|
|
// In this case the tile is not split; it is (jlong)42.
|
|
// The big tile is stored down, and then the foo() value is inserted.
|
|
// (If there were foo(),foo() instead of foo(),0, init0 would be -1.)
|
|
|
|
Node* ctl = old->in(MemNode::Control);
|
|
Node* adr = make_raw_address(offset, phase);
|
|
const TypePtr* atp = TypeRawPtr::BOTTOM;
|
|
|
|
// One or two coalesced stores to plop down.
|
|
Node* st[2];
|
|
intptr_t off[2];
|
|
int nst = 0;
|
|
if (!split) {
|
|
++new_long;
|
|
off[nst] = offset;
|
|
st[nst++] = StoreNode::make(*phase, ctl, zmem, adr, atp,
|
|
phase->longcon(con), T_LONG, MemNode::unordered);
|
|
} else {
|
|
// Omit either if it is a zero.
|
|
if (con0 != 0) {
|
|
++new_int;
|
|
off[nst] = offset;
|
|
st[nst++] = StoreNode::make(*phase, ctl, zmem, adr, atp,
|
|
phase->intcon(con0), T_INT, MemNode::unordered);
|
|
}
|
|
if (con1 != 0) {
|
|
++new_int;
|
|
offset += BytesPerInt;
|
|
adr = make_raw_address(offset, phase);
|
|
off[nst] = offset;
|
|
st[nst++] = StoreNode::make(*phase, ctl, zmem, adr, atp,
|
|
phase->intcon(con1), T_INT, MemNode::unordered);
|
|
}
|
|
}
|
|
|
|
// Insert second store first, then the first before the second.
|
|
// Insert each one just before any overlapping non-constant stores.
|
|
while (nst > 0) {
|
|
Node* st1 = st[--nst];
|
|
C->copy_node_notes_to(st1, old);
|
|
st1 = phase->transform(st1);
|
|
offset = off[nst];
|
|
assert(offset >= header_size, "do not smash header");
|
|
int ins_idx = captured_store_insertion_point(offset, /*size:*/0, phase);
|
|
guarantee(ins_idx != 0, "must re-insert constant store");
|
|
if (ins_idx < 0) ins_idx = -ins_idx; // never overlap
|
|
if (ins_idx > InitializeNode::RawStores && in(ins_idx-1) == zmem)
|
|
set_req(--ins_idx, st1);
|
|
else
|
|
ins_req(ins_idx, st1);
|
|
}
|
|
}
|
|
|
|
if (PrintCompilation && WizardMode)
|
|
tty->print_cr("Changed %d/%d subword/long constants into %d/%d int/long",
|
|
old_subword, old_long, new_int, new_long);
|
|
if (C->log() != NULL)
|
|
C->log()->elem("comment that='%d/%d subword/long to %d/%d int/long'",
|
|
old_subword, old_long, new_int, new_long);
|
|
|
|
// Clean up any remaining occurrences of zmem:
|
|
remove_extra_zeroes();
|
|
}
|
|
|
|
// Explore forward from in(start) to find the first fully initialized
|
|
// word, and return its offset. Skip groups of subword stores which
|
|
// together initialize full words. If in(start) is itself part of a
|
|
// fully initialized word, return the offset of in(start). If there
|
|
// are no following full-word stores, or if something is fishy, return
|
|
// a negative value.
|
|
intptr_t InitializeNode::find_next_fullword_store(uint start, PhaseGVN* phase) {
|
|
int int_map = 0;
|
|
intptr_t int_map_off = 0;
|
|
const int FULL_MAP = right_n_bits(BytesPerInt); // the int_map we hope for
|
|
|
|
for (uint i = start, limit = req(); i < limit; i++) {
|
|
Node* st = in(i);
|
|
|
|
intptr_t st_off = get_store_offset(st, phase);
|
|
if (st_off < 0) break; // return conservative answer
|
|
|
|
int st_size = st->as_Store()->memory_size();
|
|
if (st_size >= BytesPerInt && (st_off % BytesPerInt) == 0) {
|
|
return st_off; // we found a complete word init
|
|
}
|
|
|
|
// update the map:
|
|
|
|
intptr_t this_int_off = align_size_down(st_off, BytesPerInt);
|
|
if (this_int_off != int_map_off) {
|
|
// reset the map:
|
|
int_map = 0;
|
|
int_map_off = this_int_off;
|
|
}
|
|
|
|
int subword_off = st_off - this_int_off;
|
|
int_map |= right_n_bits(st_size) << subword_off;
|
|
if ((int_map & FULL_MAP) == FULL_MAP) {
|
|
return this_int_off; // we found a complete word init
|
|
}
|
|
|
|
// Did this store hit or cross the word boundary?
|
|
intptr_t next_int_off = align_size_down(st_off + st_size, BytesPerInt);
|
|
if (next_int_off == this_int_off + BytesPerInt) {
|
|
// We passed the current int, without fully initializing it.
|
|
int_map_off = next_int_off;
|
|
int_map >>= BytesPerInt;
|
|
} else if (next_int_off > this_int_off + BytesPerInt) {
|
|
// We passed the current and next int.
|
|
return this_int_off + BytesPerInt;
|
|
}
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
|
|
// Called when the associated AllocateNode is expanded into CFG.
|
|
// At this point, we may perform additional optimizations.
|
|
// Linearize the stores by ascending offset, to make memory
|
|
// activity as coherent as possible.
|
|
Node* InitializeNode::complete_stores(Node* rawctl, Node* rawmem, Node* rawptr,
|
|
intptr_t header_size,
|
|
Node* size_in_bytes,
|
|
PhaseGVN* phase) {
|
|
assert(!is_complete(), "not already complete");
|
|
assert(stores_are_sane(phase), "");
|
|
assert(allocation() != NULL, "must be present");
|
|
|
|
remove_extra_zeroes();
|
|
|
|
if (ReduceFieldZeroing || ReduceBulkZeroing)
|
|
// reduce instruction count for common initialization patterns
|
|
coalesce_subword_stores(header_size, size_in_bytes, phase);
|
|
|
|
Node* zmem = zero_memory(); // initially zero memory state
|
|
Node* inits = zmem; // accumulating a linearized chain of inits
|
|
#ifdef ASSERT
|
|
intptr_t first_offset = allocation()->minimum_header_size();
|
|
intptr_t last_init_off = first_offset; // previous init offset
|
|
intptr_t last_init_end = first_offset; // previous init offset+size
|
|
intptr_t last_tile_end = first_offset; // previous tile offset+size
|
|
#endif
|
|
intptr_t zeroes_done = header_size;
|
|
|
|
bool do_zeroing = true; // we might give up if inits are very sparse
|
|
int big_init_gaps = 0; // how many large gaps have we seen?
|
|
|
|
if (ZeroTLAB) do_zeroing = false;
|
|
if (!ReduceFieldZeroing && !ReduceBulkZeroing) do_zeroing = false;
|
|
|
|
for (uint i = InitializeNode::RawStores, limit = req(); i < limit; i++) {
|
|
Node* st = in(i);
|
|
intptr_t st_off = get_store_offset(st, phase);
|
|
if (st_off < 0)
|
|
break; // unknown junk in the inits
|
|
if (st->in(MemNode::Memory) != zmem)
|
|
break; // complicated store chains somehow in list
|
|
|
|
int st_size = st->as_Store()->memory_size();
|
|
intptr_t next_init_off = st_off + st_size;
|
|
|
|
if (do_zeroing && zeroes_done < next_init_off) {
|
|
// See if this store needs a zero before it or under it.
|
|
intptr_t zeroes_needed = st_off;
|
|
|
|
if (st_size < BytesPerInt) {
|
|
// Look for subword stores which only partially initialize words.
|
|
// If we find some, we must lay down some word-level zeroes first,
|
|
// underneath the subword stores.
|
|
//
|
|
// Examples:
|
|
// byte[] a = { p,q,r,s } => a[0]=p,a[1]=q,a[2]=r,a[3]=s
|
|
// byte[] a = { x,y,0,0 } => a[0..3] = 0, a[0]=x,a[1]=y
|
|
// byte[] a = { 0,0,z,0 } => a[0..3] = 0, a[2]=z
|
|
//
|
|
// Note: coalesce_subword_stores may have already done this,
|
|
// if it was prompted by constant non-zero subword initializers.
|
|
// But this case can still arise with non-constant stores.
|
|
|
|
intptr_t next_full_store = find_next_fullword_store(i, phase);
|
|
|
|
// In the examples above:
|
|
// in(i) p q r s x y z
|
|
// st_off 12 13 14 15 12 13 14
|
|
// st_size 1 1 1 1 1 1 1
|
|
// next_full_s. 12 16 16 16 16 16 16
|
|
// z's_done 12 16 16 16 12 16 12
|
|
// z's_needed 12 16 16 16 16 16 16
|
|
// zsize 0 0 0 0 4 0 4
|
|
if (next_full_store < 0) {
|
|
// Conservative tack: Zero to end of current word.
|
|
zeroes_needed = align_size_up(zeroes_needed, BytesPerInt);
|
|
} else {
|
|
// Zero to beginning of next fully initialized word.
|
|
// Or, don't zero at all, if we are already in that word.
|
|
assert(next_full_store >= zeroes_needed, "must go forward");
|
|
assert((next_full_store & (BytesPerInt-1)) == 0, "even boundary");
|
|
zeroes_needed = next_full_store;
|
|
}
|
|
}
|
|
|
|
if (zeroes_needed > zeroes_done) {
|
|
intptr_t zsize = zeroes_needed - zeroes_done;
|
|
// Do some incremental zeroing on rawmem, in parallel with inits.
|
|
zeroes_done = align_size_down(zeroes_done, BytesPerInt);
|
|
rawmem = ClearArrayNode::clear_memory(rawctl, rawmem, rawptr,
|
|
zeroes_done, zeroes_needed,
|
|
phase);
|
|
zeroes_done = zeroes_needed;
|
|
if (zsize > Matcher::init_array_short_size && ++big_init_gaps > 2)
|
|
do_zeroing = false; // leave the hole, next time
|
|
}
|
|
}
|
|
|
|
// Collect the store and move on:
|
|
st->set_req(MemNode::Memory, inits);
|
|
inits = st; // put it on the linearized chain
|
|
set_req(i, zmem); // unhook from previous position
|
|
|
|
if (zeroes_done == st_off)
|
|
zeroes_done = next_init_off;
|
|
|
|
assert(!do_zeroing || zeroes_done >= next_init_off, "don't miss any");
|
|
|
|
#ifdef ASSERT
|
|
// Various order invariants. Weaker than stores_are_sane because
|
|
// a large constant tile can be filled in by smaller non-constant stores.
|
|
assert(st_off >= last_init_off, "inits do not reverse");
|
|
last_init_off = st_off;
|
|
const Type* val = NULL;
|
|
if (st_size >= BytesPerInt &&
|
|
(val = phase->type(st->in(MemNode::ValueIn)))->singleton() &&
|
|
(int)val->basic_type() < (int)T_OBJECT) {
|
|
assert(st_off >= last_tile_end, "tiles do not overlap");
|
|
assert(st_off >= last_init_end, "tiles do not overwrite inits");
|
|
last_tile_end = MAX2(last_tile_end, next_init_off);
|
|
} else {
|
|
intptr_t st_tile_end = align_size_up(next_init_off, BytesPerLong);
|
|
assert(st_tile_end >= last_tile_end, "inits stay with tiles");
|
|
assert(st_off >= last_init_end, "inits do not overlap");
|
|
last_init_end = next_init_off; // it's a non-tile
|
|
}
|
|
#endif //ASSERT
|
|
}
|
|
|
|
remove_extra_zeroes(); // clear out all the zmems left over
|
|
add_req(inits);
|
|
|
|
if (!ZeroTLAB) {
|
|
// If anything remains to be zeroed, zero it all now.
|
|
zeroes_done = align_size_down(zeroes_done, BytesPerInt);
|
|
// if it is the last unused 4 bytes of an instance, forget about it
|
|
intptr_t size_limit = phase->find_intptr_t_con(size_in_bytes, max_jint);
|
|
if (zeroes_done + BytesPerLong >= size_limit) {
|
|
assert(allocation() != NULL, "");
|
|
if (allocation()->Opcode() == Op_Allocate) {
|
|
Node* klass_node = allocation()->in(AllocateNode::KlassNode);
|
|
ciKlass* k = phase->type(klass_node)->is_klassptr()->klass();
|
|
if (zeroes_done == k->layout_helper())
|
|
zeroes_done = size_limit;
|
|
}
|
|
}
|
|
if (zeroes_done < size_limit) {
|
|
rawmem = ClearArrayNode::clear_memory(rawctl, rawmem, rawptr,
|
|
zeroes_done, size_in_bytes, phase);
|
|
}
|
|
}
|
|
|
|
set_complete(phase);
|
|
return rawmem;
|
|
}
|
|
|
|
|
|
#ifdef ASSERT
|
|
bool InitializeNode::stores_are_sane(PhaseTransform* phase) {
|
|
if (is_complete())
|
|
return true; // stores could be anything at this point
|
|
assert(allocation() != NULL, "must be present");
|
|
intptr_t last_off = allocation()->minimum_header_size();
|
|
for (uint i = InitializeNode::RawStores; i < req(); i++) {
|
|
Node* st = in(i);
|
|
intptr_t st_off = get_store_offset(st, phase);
|
|
if (st_off < 0) continue; // ignore dead garbage
|
|
if (last_off > st_off) {
|
|
tty->print_cr("*** bad store offset at %d: %d > %d", i, last_off, st_off);
|
|
this->dump(2);
|
|
assert(false, "ascending store offsets");
|
|
return false;
|
|
}
|
|
last_off = st_off + st->as_Store()->memory_size();
|
|
}
|
|
return true;
|
|
}
|
|
#endif //ASSERT
|
|
|
|
|
|
|
|
|
|
//============================MergeMemNode=====================================
|
|
//
|
|
// SEMANTICS OF MEMORY MERGES: A MergeMem is a memory state assembled from several
|
|
// contributing store or call operations. Each contributor provides the memory
|
|
// state for a particular "alias type" (see Compile::alias_type). For example,
|
|
// if a MergeMem has an input X for alias category #6, then any memory reference
|
|
// to alias category #6 may use X as its memory state input, as an exact equivalent
|
|
// to using the MergeMem as a whole.
|
|
// Load<6>( MergeMem(<6>: X, ...), p ) <==> Load<6>(X,p)
|
|
//
|
|
// (Here, the <N> notation gives the index of the relevant adr_type.)
|
|
//
|
|
// In one special case (and more cases in the future), alias categories overlap.
|
|
// The special alias category "Bot" (Compile::AliasIdxBot) includes all memory
|
|
// states. Therefore, if a MergeMem has only one contributing input W for Bot,
|
|
// it is exactly equivalent to that state W:
|
|
// MergeMem(<Bot>: W) <==> W
|
|
//
|
|
// Usually, the merge has more than one input. In that case, where inputs
|
|
// overlap (i.e., one is Bot), the narrower alias type determines the memory
|
|
// state for that type, and the wider alias type (Bot) fills in everywhere else:
|
|
// Load<5>( MergeMem(<Bot>: W, <6>: X), p ) <==> Load<5>(W,p)
|
|
// Load<6>( MergeMem(<Bot>: W, <6>: X), p ) <==> Load<6>(X,p)
|
|
//
|
|
// A merge can take a "wide" memory state as one of its narrow inputs.
|
|
// This simply means that the merge observes out only the relevant parts of
|
|
// the wide input. That is, wide memory states arriving at narrow merge inputs
|
|
// are implicitly "filtered" or "sliced" as necessary. (This is rare.)
|
|
//
|
|
// These rules imply that MergeMem nodes may cascade (via their <Bot> links),
|
|
// and that memory slices "leak through":
|
|
// MergeMem(<Bot>: MergeMem(<Bot>: W, <7>: Y)) <==> MergeMem(<Bot>: W, <7>: Y)
|
|
//
|
|
// But, in such a cascade, repeated memory slices can "block the leak":
|
|
// MergeMem(<Bot>: MergeMem(<Bot>: W, <7>: Y), <7>: Y') <==> MergeMem(<Bot>: W, <7>: Y')
|
|
//
|
|
// In the last example, Y is not part of the combined memory state of the
|
|
// outermost MergeMem. The system must, of course, prevent unschedulable
|
|
// memory states from arising, so you can be sure that the state Y is somehow
|
|
// a precursor to state Y'.
|
|
//
|
|
//
|
|
// REPRESENTATION OF MEMORY MERGES: The indexes used to address the Node::in array
|
|
// of each MergeMemNode array are exactly the numerical alias indexes, including
|
|
// but not limited to AliasIdxTop, AliasIdxBot, and AliasIdxRaw. The functions
|
|
// Compile::alias_type (and kin) produce and manage these indexes.
|
|
//
|
|
// By convention, the value of in(AliasIdxTop) (i.e., in(1)) is always the top node.
|
|
// (Note that this provides quick access to the top node inside MergeMem methods,
|
|
// without the need to reach out via TLS to Compile::current.)
|
|
//
|
|
// As a consequence of what was just described, a MergeMem that represents a full
|
|
// memory state has an edge in(AliasIdxBot) which is a "wide" memory state,
|
|
// containing all alias categories.
|
|
//
|
|
// MergeMem nodes never (?) have control inputs, so in(0) is NULL.
|
|
//
|
|
// All other edges in(N) (including in(AliasIdxRaw), which is in(3)) are either
|
|
// a memory state for the alias type <N>, or else the top node, meaning that
|
|
// there is no particular input for that alias type. Note that the length of
|
|
// a MergeMem is variable, and may be extended at any time to accommodate new
|
|
// memory states at larger alias indexes. When merges grow, they are of course
|
|
// filled with "top" in the unused in() positions.
|
|
//
|
|
// This use of top is named "empty_memory()", or "empty_mem" (no-memory) as a variable.
|
|
// (Top was chosen because it works smoothly with passes like GCM.)
|
|
//
|
|
// For convenience, we hardwire the alias index for TypeRawPtr::BOTTOM. (It is
|
|
// the type of random VM bits like TLS references.) Since it is always the
|
|
// first non-Bot memory slice, some low-level loops use it to initialize an
|
|
// index variable: for (i = AliasIdxRaw; i < req(); i++).
|
|
//
|
|
//
|
|
// ACCESSORS: There is a special accessor MergeMemNode::base_memory which returns
|
|
// the distinguished "wide" state. The accessor MergeMemNode::memory_at(N) returns
|
|
// the memory state for alias type <N>, or (if there is no particular slice at <N>,
|
|
// it returns the base memory. To prevent bugs, memory_at does not accept <Top>
|
|
// or <Bot> indexes. The iterator MergeMemStream provides robust iteration over
|
|
// MergeMem nodes or pairs of such nodes, ensuring that the non-top edges are visited.
|
|
//
|
|
// %%%% We may get rid of base_memory as a separate accessor at some point; it isn't
|
|
// really that different from the other memory inputs. An abbreviation called
|
|
// "bot_memory()" for "memory_at(AliasIdxBot)" would keep code tidy.
|
|
//
|
|
//
|
|
// PARTIAL MEMORY STATES: During optimization, MergeMem nodes may arise that represent
|
|
// partial memory states. When a Phi splits through a MergeMem, the copy of the Phi
|
|
// that "emerges though" the base memory will be marked as excluding the alias types
|
|
// of the other (narrow-memory) copies which "emerged through" the narrow edges:
|
|
//
|
|
// Phi<Bot>(U, MergeMem(<Bot>: W, <8>: Y))
|
|
// ==Ideal=> MergeMem(<Bot>: Phi<Bot-8>(U, W), Phi<8>(U, Y))
|
|
//
|
|
// This strange "subtraction" effect is necessary to ensure IGVN convergence.
|
|
// (It is currently unimplemented.) As you can see, the resulting merge is
|
|
// actually a disjoint union of memory states, rather than an overlay.
|
|
//
|
|
|
|
//------------------------------MergeMemNode-----------------------------------
|
|
Node* MergeMemNode::make_empty_memory() {
|
|
Node* empty_memory = (Node*) Compile::current()->top();
|
|
assert(empty_memory->is_top(), "correct sentinel identity");
|
|
return empty_memory;
|
|
}
|
|
|
|
MergeMemNode::MergeMemNode(Node *new_base) : Node(1+Compile::AliasIdxRaw) {
|
|
init_class_id(Class_MergeMem);
|
|
// all inputs are nullified in Node::Node(int)
|
|
// set_input(0, NULL); // no control input
|
|
|
|
// Initialize the edges uniformly to top, for starters.
|
|
Node* empty_mem = make_empty_memory();
|
|
for (uint i = Compile::AliasIdxTop; i < req(); i++) {
|
|
init_req(i,empty_mem);
|
|
}
|
|
assert(empty_memory() == empty_mem, "");
|
|
|
|
if( new_base != NULL && new_base->is_MergeMem() ) {
|
|
MergeMemNode* mdef = new_base->as_MergeMem();
|
|
assert(mdef->empty_memory() == empty_mem, "consistent sentinels");
|
|
for (MergeMemStream mms(this, mdef); mms.next_non_empty2(); ) {
|
|
mms.set_memory(mms.memory2());
|
|
}
|
|
assert(base_memory() == mdef->base_memory(), "");
|
|
} else {
|
|
set_base_memory(new_base);
|
|
}
|
|
}
|
|
|
|
// Make a new, untransformed MergeMem with the same base as 'mem'.
|
|
// If mem is itself a MergeMem, populate the result with the same edges.
|
|
MergeMemNode* MergeMemNode::make(Compile* C, Node* mem) {
|
|
return new(C) MergeMemNode(mem);
|
|
}
|
|
|
|
//------------------------------cmp--------------------------------------------
|
|
uint MergeMemNode::hash() const { return NO_HASH; }
|
|
uint MergeMemNode::cmp( const Node &n ) const {
|
|
return (&n == this); // Always fail except on self
|
|
}
|
|
|
|
//------------------------------Identity---------------------------------------
|
|
Node* MergeMemNode::Identity(PhaseTransform *phase) {
|
|
// Identity if this merge point does not record any interesting memory
|
|
// disambiguations.
|
|
Node* base_mem = base_memory();
|
|
Node* empty_mem = empty_memory();
|
|
if (base_mem != empty_mem) { // Memory path is not dead?
|
|
for (uint i = Compile::AliasIdxRaw; i < req(); i++) {
|
|
Node* mem = in(i);
|
|
if (mem != empty_mem && mem != base_mem) {
|
|
return this; // Many memory splits; no change
|
|
}
|
|
}
|
|
}
|
|
return base_mem; // No memory splits; ID on the one true input
|
|
}
|
|
|
|
//------------------------------Ideal------------------------------------------
|
|
// This method is invoked recursively on chains of MergeMem nodes
|
|
Node *MergeMemNode::Ideal(PhaseGVN *phase, bool can_reshape) {
|
|
// Remove chain'd MergeMems
|
|
//
|
|
// This is delicate, because the each "in(i)" (i >= Raw) is interpreted
|
|
// relative to the "in(Bot)". Since we are patching both at the same time,
|
|
// we have to be careful to read each "in(i)" relative to the old "in(Bot)",
|
|
// but rewrite each "in(i)" relative to the new "in(Bot)".
|
|
Node *progress = NULL;
|
|
|
|
|
|
Node* old_base = base_memory();
|
|
Node* empty_mem = empty_memory();
|
|
if (old_base == empty_mem)
|
|
return NULL; // Dead memory path.
|
|
|
|
MergeMemNode* old_mbase;
|
|
if (old_base != NULL && old_base->is_MergeMem())
|
|
old_mbase = old_base->as_MergeMem();
|
|
else
|
|
old_mbase = NULL;
|
|
Node* new_base = old_base;
|
|
|
|
// simplify stacked MergeMems in base memory
|
|
if (old_mbase) new_base = old_mbase->base_memory();
|
|
|
|
// the base memory might contribute new slices beyond my req()
|
|
if (old_mbase) grow_to_match(old_mbase);
|
|
|
|
// Look carefully at the base node if it is a phi.
|
|
PhiNode* phi_base;
|
|
if (new_base != NULL && new_base->is_Phi())
|
|
phi_base = new_base->as_Phi();
|
|
else
|
|
phi_base = NULL;
|
|
|
|
Node* phi_reg = NULL;
|
|
uint phi_len = (uint)-1;
|
|
if (phi_base != NULL && !phi_base->is_copy()) {
|
|
// do not examine phi if degraded to a copy
|
|
phi_reg = phi_base->region();
|
|
phi_len = phi_base->req();
|
|
// see if the phi is unfinished
|
|
for (uint i = 1; i < phi_len; i++) {
|
|
if (phi_base->in(i) == NULL) {
|
|
// incomplete phi; do not look at it yet!
|
|
phi_reg = NULL;
|
|
phi_len = (uint)-1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Note: We do not call verify_sparse on entry, because inputs
|
|
// can normalize to the base_memory via subsume_node or similar
|
|
// mechanisms. This method repairs that damage.
|
|
|
|
assert(!old_mbase || old_mbase->is_empty_memory(empty_mem), "consistent sentinels");
|
|
|
|
// Look at each slice.
|
|
for (uint i = Compile::AliasIdxRaw; i < req(); i++) {
|
|
Node* old_in = in(i);
|
|
// calculate the old memory value
|
|
Node* old_mem = old_in;
|
|
if (old_mem == empty_mem) old_mem = old_base;
|
|
assert(old_mem == memory_at(i), "");
|
|
|
|
// maybe update (reslice) the old memory value
|
|
|
|
// simplify stacked MergeMems
|
|
Node* new_mem = old_mem;
|
|
MergeMemNode* old_mmem;
|
|
if (old_mem != NULL && old_mem->is_MergeMem())
|
|
old_mmem = old_mem->as_MergeMem();
|
|
else
|
|
old_mmem = NULL;
|
|
if (old_mmem == this) {
|
|
// This can happen if loops break up and safepoints disappear.
|
|
// A merge of BotPtr (default) with a RawPtr memory derived from a
|
|
// safepoint can be rewritten to a merge of the same BotPtr with
|
|
// the BotPtr phi coming into the loop. If that phi disappears
|
|
// also, we can end up with a self-loop of the mergemem.
|
|
// In general, if loops degenerate and memory effects disappear,
|
|
// a mergemem can be left looking at itself. This simply means
|
|
// that the mergemem's default should be used, since there is
|
|
// no longer any apparent effect on this slice.
|
|
// Note: If a memory slice is a MergeMem cycle, it is unreachable
|
|
// from start. Update the input to TOP.
|
|
new_mem = (new_base == this || new_base == empty_mem)? empty_mem : new_base;
|
|
}
|
|
else if (old_mmem != NULL) {
|
|
new_mem = old_mmem->memory_at(i);
|
|
}
|
|
// else preceding memory was not a MergeMem
|
|
|
|
// replace equivalent phis (unfortunately, they do not GVN together)
|
|
if (new_mem != NULL && new_mem != new_base &&
|
|
new_mem->req() == phi_len && new_mem->in(0) == phi_reg) {
|
|
if (new_mem->is_Phi()) {
|
|
PhiNode* phi_mem = new_mem->as_Phi();
|
|
for (uint i = 1; i < phi_len; i++) {
|
|
if (phi_base->in(i) != phi_mem->in(i)) {
|
|
phi_mem = NULL;
|
|
break;
|
|
}
|
|
}
|
|
if (phi_mem != NULL) {
|
|
// equivalent phi nodes; revert to the def
|
|
new_mem = new_base;
|
|
}
|
|
}
|
|
}
|
|
|
|
// maybe store down a new value
|
|
Node* new_in = new_mem;
|
|
if (new_in == new_base) new_in = empty_mem;
|
|
|
|
if (new_in != old_in) {
|
|
// Warning: Do not combine this "if" with the previous "if"
|
|
// A memory slice might have be be rewritten even if it is semantically
|
|
// unchanged, if the base_memory value has changed.
|
|
set_req(i, new_in);
|
|
progress = this; // Report progress
|
|
}
|
|
}
|
|
|
|
if (new_base != old_base) {
|
|
set_req(Compile::AliasIdxBot, new_base);
|
|
// Don't use set_base_memory(new_base), because we need to update du.
|
|
assert(base_memory() == new_base, "");
|
|
progress = this;
|
|
}
|
|
|
|
if( base_memory() == this ) {
|
|
// a self cycle indicates this memory path is dead
|
|
set_req(Compile::AliasIdxBot, empty_mem);
|
|
}
|
|
|
|
// Resolve external cycles by calling Ideal on a MergeMem base_memory
|
|
// Recursion must occur after the self cycle check above
|
|
if( base_memory()->is_MergeMem() ) {
|
|
MergeMemNode *new_mbase = base_memory()->as_MergeMem();
|
|
Node *m = phase->transform(new_mbase); // Rollup any cycles
|
|
if( m != NULL && (m->is_top() ||
|
|
m->is_MergeMem() && m->as_MergeMem()->base_memory() == empty_mem) ) {
|
|
// propagate rollup of dead cycle to self
|
|
set_req(Compile::AliasIdxBot, empty_mem);
|
|
}
|
|
}
|
|
|
|
if( base_memory() == empty_mem ) {
|
|
progress = this;
|
|
// Cut inputs during Parse phase only.
|
|
// During Optimize phase a dead MergeMem node will be subsumed by Top.
|
|
if( !can_reshape ) {
|
|
for (uint i = Compile::AliasIdxRaw; i < req(); i++) {
|
|
if( in(i) != empty_mem ) { set_req(i, empty_mem); }
|
|
}
|
|
}
|
|
}
|
|
|
|
if( !progress && base_memory()->is_Phi() && can_reshape ) {
|
|
// Check if PhiNode::Ideal's "Split phis through memory merges"
|
|
// transform should be attempted. Look for this->phi->this cycle.
|
|
uint merge_width = req();
|
|
if (merge_width > Compile::AliasIdxRaw) {
|
|
PhiNode* phi = base_memory()->as_Phi();
|
|
for( uint i = 1; i < phi->req(); ++i ) {// For all paths in
|
|
if (phi->in(i) == this) {
|
|
phase->is_IterGVN()->_worklist.push(phi);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
assert(progress || verify_sparse(), "please, no dups of base");
|
|
return progress;
|
|
}
|
|
|
|
//-------------------------set_base_memory-------------------------------------
|
|
void MergeMemNode::set_base_memory(Node *new_base) {
|
|
Node* empty_mem = empty_memory();
|
|
set_req(Compile::AliasIdxBot, new_base);
|
|
assert(memory_at(req()) == new_base, "must set default memory");
|
|
// Clear out other occurrences of new_base:
|
|
if (new_base != empty_mem) {
|
|
for (uint i = Compile::AliasIdxRaw; i < req(); i++) {
|
|
if (in(i) == new_base) set_req(i, empty_mem);
|
|
}
|
|
}
|
|
}
|
|
|
|
//------------------------------out_RegMask------------------------------------
|
|
const RegMask &MergeMemNode::out_RegMask() const {
|
|
return RegMask::Empty;
|
|
}
|
|
|
|
//------------------------------dump_spec--------------------------------------
|
|
#ifndef PRODUCT
|
|
void MergeMemNode::dump_spec(outputStream *st) const {
|
|
st->print(" {");
|
|
Node* base_mem = base_memory();
|
|
for( uint i = Compile::AliasIdxRaw; i < req(); i++ ) {
|
|
Node* mem = memory_at(i);
|
|
if (mem == base_mem) { st->print(" -"); continue; }
|
|
st->print( " N%d:", mem->_idx );
|
|
Compile::current()->get_adr_type(i)->dump_on(st);
|
|
}
|
|
st->print(" }");
|
|
}
|
|
#endif // !PRODUCT
|
|
|
|
|
|
#ifdef ASSERT
|
|
static bool might_be_same(Node* a, Node* b) {
|
|
if (a == b) return true;
|
|
if (!(a->is_Phi() || b->is_Phi())) return false;
|
|
// phis shift around during optimization
|
|
return true; // pretty stupid...
|
|
}
|
|
|
|
// verify a narrow slice (either incoming or outgoing)
|
|
static void verify_memory_slice(const MergeMemNode* m, int alias_idx, Node* n) {
|
|
if (!VerifyAliases) return; // don't bother to verify unless requested
|
|
if (is_error_reported()) return; // muzzle asserts when debugging an error
|
|
if (Node::in_dump()) return; // muzzle asserts when printing
|
|
assert(alias_idx >= Compile::AliasIdxRaw, "must not disturb base_memory or sentinel");
|
|
assert(n != NULL, "");
|
|
// Elide intervening MergeMem's
|
|
while (n->is_MergeMem()) {
|
|
n = n->as_MergeMem()->memory_at(alias_idx);
|
|
}
|
|
Compile* C = Compile::current();
|
|
const TypePtr* n_adr_type = n->adr_type();
|
|
if (n == m->empty_memory()) {
|
|
// Implicit copy of base_memory()
|
|
} else if (n_adr_type != TypePtr::BOTTOM) {
|
|
assert(n_adr_type != NULL, "new memory must have a well-defined adr_type");
|
|
assert(C->must_alias(n_adr_type, alias_idx), "new memory must match selected slice");
|
|
} else {
|
|
// A few places like make_runtime_call "know" that VM calls are narrow,
|
|
// and can be used to update only the VM bits stored as TypeRawPtr::BOTTOM.
|
|
bool expected_wide_mem = false;
|
|
if (n == m->base_memory()) {
|
|
expected_wide_mem = true;
|
|
} else if (alias_idx == Compile::AliasIdxRaw ||
|
|
n == m->memory_at(Compile::AliasIdxRaw)) {
|
|
expected_wide_mem = true;
|
|
} else if (!C->alias_type(alias_idx)->is_rewritable()) {
|
|
// memory can "leak through" calls on channels that
|
|
// are write-once. Allow this also.
|
|
expected_wide_mem = true;
|
|
}
|
|
assert(expected_wide_mem, "expected narrow slice replacement");
|
|
}
|
|
}
|
|
#else // !ASSERT
|
|
#define verify_memory_slice(m,i,n) (void)(0) // PRODUCT version is no-op
|
|
#endif
|
|
|
|
|
|
//-----------------------------memory_at---------------------------------------
|
|
Node* MergeMemNode::memory_at(uint alias_idx) const {
|
|
assert(alias_idx >= Compile::AliasIdxRaw ||
|
|
alias_idx == Compile::AliasIdxBot && Compile::current()->AliasLevel() == 0,
|
|
"must avoid base_memory and AliasIdxTop");
|
|
|
|
// Otherwise, it is a narrow slice.
|
|
Node* n = alias_idx < req() ? in(alias_idx) : empty_memory();
|
|
Compile *C = Compile::current();
|
|
if (is_empty_memory(n)) {
|
|
// the array is sparse; empty slots are the "top" node
|
|
n = base_memory();
|
|
assert(Node::in_dump()
|
|
|| n == NULL || n->bottom_type() == Type::TOP
|
|
|| n->adr_type() == NULL // address is TOP
|
|
|| n->adr_type() == TypePtr::BOTTOM
|
|
|| n->adr_type() == TypeRawPtr::BOTTOM
|
|
|| Compile::current()->AliasLevel() == 0,
|
|
"must be a wide memory");
|
|
// AliasLevel == 0 if we are organizing the memory states manually.
|
|
// See verify_memory_slice for comments on TypeRawPtr::BOTTOM.
|
|
} else {
|
|
// make sure the stored slice is sane
|
|
#ifdef ASSERT
|
|
if (is_error_reported() || Node::in_dump()) {
|
|
} else if (might_be_same(n, base_memory())) {
|
|
// Give it a pass: It is a mostly harmless repetition of the base.
|
|
// This can arise normally from node subsumption during optimization.
|
|
} else {
|
|
verify_memory_slice(this, alias_idx, n);
|
|
}
|
|
#endif
|
|
}
|
|
return n;
|
|
}
|
|
|
|
//---------------------------set_memory_at-------------------------------------
|
|
void MergeMemNode::set_memory_at(uint alias_idx, Node *n) {
|
|
verify_memory_slice(this, alias_idx, n);
|
|
Node* empty_mem = empty_memory();
|
|
if (n == base_memory()) n = empty_mem; // collapse default
|
|
uint need_req = alias_idx+1;
|
|
if (req() < need_req) {
|
|
if (n == empty_mem) return; // already the default, so do not grow me
|
|
// grow the sparse array
|
|
do {
|
|
add_req(empty_mem);
|
|
} while (req() < need_req);
|
|
}
|
|
set_req( alias_idx, n );
|
|
}
|
|
|
|
|
|
|
|
//--------------------------iteration_setup------------------------------------
|
|
void MergeMemNode::iteration_setup(const MergeMemNode* other) {
|
|
if (other != NULL) {
|
|
grow_to_match(other);
|
|
// invariant: the finite support of mm2 is within mm->req()
|
|
#ifdef ASSERT
|
|
for (uint i = req(); i < other->req(); i++) {
|
|
assert(other->is_empty_memory(other->in(i)), "slice left uncovered");
|
|
}
|
|
#endif
|
|
}
|
|
// Replace spurious copies of base_memory by top.
|
|
Node* base_mem = base_memory();
|
|
if (base_mem != NULL && !base_mem->is_top()) {
|
|
for (uint i = Compile::AliasIdxBot+1, imax = req(); i < imax; i++) {
|
|
if (in(i) == base_mem)
|
|
set_req(i, empty_memory());
|
|
}
|
|
}
|
|
}
|
|
|
|
//---------------------------grow_to_match-------------------------------------
|
|
void MergeMemNode::grow_to_match(const MergeMemNode* other) {
|
|
Node* empty_mem = empty_memory();
|
|
assert(other->is_empty_memory(empty_mem), "consistent sentinels");
|
|
// look for the finite support of the other memory
|
|
for (uint i = other->req(); --i >= req(); ) {
|
|
if (other->in(i) != empty_mem) {
|
|
uint new_len = i+1;
|
|
while (req() < new_len) add_req(empty_mem);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
//---------------------------verify_sparse-------------------------------------
|
|
#ifndef PRODUCT
|
|
bool MergeMemNode::verify_sparse() const {
|
|
assert(is_empty_memory(make_empty_memory()), "sane sentinel");
|
|
Node* base_mem = base_memory();
|
|
// The following can happen in degenerate cases, since empty==top.
|
|
if (is_empty_memory(base_mem)) return true;
|
|
for (uint i = Compile::AliasIdxRaw; i < req(); i++) {
|
|
assert(in(i) != NULL, "sane slice");
|
|
if (in(i) == base_mem) return false; // should have been the sentinel value!
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool MergeMemStream::match_memory(Node* mem, const MergeMemNode* mm, int idx) {
|
|
Node* n;
|
|
n = mm->in(idx);
|
|
if (mem == n) return true; // might be empty_memory()
|
|
n = (idx == Compile::AliasIdxBot)? mm->base_memory(): mm->memory_at(idx);
|
|
if (mem == n) return true;
|
|
while (n->is_Phi() && (n = n->as_Phi()->is_copy()) != NULL) {
|
|
if (mem == n) return true;
|
|
if (n == NULL) break;
|
|
}
|
|
return false;
|
|
}
|
|
#endif // !PRODUCT
|