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/*
* Copyright 1997-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
#include "incls/_precompiled.incl"
#include "incls/_compiledIC.cpp.incl"
// Every time a compiled IC is changed or its type is being accessed,
// either the CompiledIC_lock must be set or we must be at a safe point.
//-----------------------------------------------------------------------------
// Low-level access to an inline cache. Private, since they might not be
// MT-safe to use.
void CompiledIC::set_cached_oop(oop cache) {
assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
assert (!is_optimized(), "an optimized virtual call does not have a cached oop");
assert (cache == NULL || cache != badOop, "invalid oop");
if (TraceCompiledIC) {
tty->print(" ");
print_compiled_ic();
tty->print_cr(" changing oop to " INTPTR_FORMAT, (address)cache);
}
if (cache == NULL) cache = (oop)Universe::non_oop_word();
*_oop_addr = cache;
// fix up the relocations
RelocIterator iter = _oops;
while (iter.next()) {
if (iter.type() == relocInfo::oop_type) {
oop_Relocation* r = iter.oop_reloc();
if (r->oop_addr() == _oop_addr)
r->fix_oop_relocation();
}
}
return;
}
oop CompiledIC::cached_oop() const {
assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
assert (!is_optimized(), "an optimized virtual call does not have a cached oop");
if (!is_in_transition_state()) {
oop data = *_oop_addr;
// If we let the oop value here be initialized to zero...
assert(data != NULL || Universe::non_oop_word() == NULL,
"no raw nulls in CompiledIC oops, because of patching races");
return (data == (oop)Universe::non_oop_word()) ? (oop)NULL : data;
} else {
return InlineCacheBuffer::cached_oop_for((CompiledIC *)this);
}
}
void CompiledIC::set_ic_destination(address entry_point) {
assert(entry_point != NULL, "must set legal entry point");
assert(CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
if (TraceCompiledIC) {
tty->print(" ");
print_compiled_ic();
tty->print_cr(" changing destination to " INTPTR_FORMAT, entry_point);
}
MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
#ifdef ASSERT
CodeBlob* cb = CodeCache::find_blob_unsafe(_ic_call);
assert(cb != NULL && cb->is_nmethod(), "must be nmethod");
#endif
_ic_call->set_destination_mt_safe(entry_point);
}
address CompiledIC::ic_destination() const {
assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
if (!is_in_transition_state()) {
return _ic_call->destination();
} else {
return InlineCacheBuffer::ic_destination_for((CompiledIC *)this);
}
}
bool CompiledIC::is_in_transition_state() const {
assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
return InlineCacheBuffer::contains(_ic_call->destination());
}
// Returns native address of 'call' instruction in inline-cache. Used by
// the InlineCacheBuffer when it needs to find the stub.
address CompiledIC::stub_address() const {
assert(is_in_transition_state(), "should only be called when we are in a transition state");
return _ic_call->destination();
}
//-----------------------------------------------------------------------------
// High-level access to an inline cache. Guaranteed to be MT-safe.
void CompiledIC::set_to_megamorphic(CallInfo* call_info, Bytecodes::Code bytecode, TRAPS) {
methodHandle method = call_info->selected_method();
bool is_invoke_interface = (bytecode == Bytecodes::_invokeinterface && !call_info->has_vtable_index());
assert(CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
assert(method->is_oop(), "cannot be NULL and must be oop");
assert(!is_optimized(), "cannot set an optimized virtual call to megamorphic");
assert(is_call_to_compiled() || is_call_to_interpreted(), "going directly to megamorphic?");
address entry;
if (is_invoke_interface) {
int index = klassItable::compute_itable_index(call_info->resolved_method()());
entry = VtableStubs::create_stub(false, index, method());
assert(entry != NULL, "entry not computed");
klassOop k = call_info->resolved_method()->method_holder();
assert(Klass::cast(k)->is_interface(), "sanity check");
InlineCacheBuffer::create_transition_stub(this, k, entry);
} else {
// Can be different than method->vtable_index(), due to package-private etc.
int vtable_index = call_info->vtable_index();
entry = VtableStubs::create_stub(true, vtable_index, method());
InlineCacheBuffer::create_transition_stub(this, method(), entry);
}
if (TraceICs) {
ResourceMark rm;
tty->print_cr ("IC@" INTPTR_FORMAT ": to megamorphic %s entry: " INTPTR_FORMAT,
instruction_address(), method->print_value_string(), entry);
}
Events::log("compiledIC " INTPTR_FORMAT " --> megamorphic " INTPTR_FORMAT, this, (address)method());
// We can't check this anymore. With lazy deopt we could have already
// cleaned this IC entry before we even return. This is possible if
// we ran out of space in the inline cache buffer trying to do the
// set_next and we safepointed to free up space. This is a benign
// race because the IC entry was complete when we safepointed so
// cleaning it immediately is harmless.
// assert(is_megamorphic(), "sanity check");
}
// true if destination is megamorphic stub
bool CompiledIC::is_megamorphic() const {
assert(CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
assert(!is_optimized(), "an optimized call cannot be megamorphic");
// Cannot rely on cached_oop. It is either an interface or a method.
return VtableStubs::is_entry_point(ic_destination());
}
bool CompiledIC::is_call_to_compiled() const {
assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
// Use unsafe, since an inline cache might point to a zombie method. However, the zombie
// method is guaranteed to still exist, since we only remove methods after all inline caches
// has been cleaned up
CodeBlob* cb = CodeCache::find_blob_unsafe(ic_destination());
bool is_monomorphic = (cb != NULL && cb->is_nmethod());
// Check that the cached_oop is a klass for non-optimized monomorphic calls
// This assertion is invalid for compiler1: a call that does not look optimized (no static stub) can be used
// for calling directly to vep without using the inline cache (i.e., cached_oop == NULL)
#ifdef ASSERT
#ifdef TIERED
CodeBlob* caller = CodeCache::find_blob_unsafe(instruction_address());
bool is_c1_method = caller->is_compiled_by_c1();
#else
#ifdef COMPILER1
bool is_c1_method = true;
#else
bool is_c1_method = false;
#endif // COMPILER1
#endif // TIERED
assert( is_c1_method ||
!is_monomorphic ||
is_optimized() ||
(cached_oop() != NULL && cached_oop()->is_klass()), "sanity check");
#endif // ASSERT
return is_monomorphic;
}
bool CompiledIC::is_call_to_interpreted() const {
assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
// Call to interpreter if destination is either calling to a stub (if it
// is optimized), or calling to an I2C blob
bool is_call_to_interpreted = false;
if (!is_optimized()) {
// must use unsafe because the destination can be a zombie (and we're cleaning)
// and the print_compiled_ic code wants to know if site (in the non-zombie)
// is to the interpreter.
CodeBlob* cb = CodeCache::find_blob_unsafe(ic_destination());
is_call_to_interpreted = (cb != NULL && cb->is_adapter_blob());
assert(!is_call_to_interpreted || (cached_oop() != NULL && cached_oop()->is_compiledICHolder()), "sanity check");
} else {
// Check if we are calling into our own codeblob (i.e., to a stub)
CodeBlob* cb = CodeCache::find_blob(_ic_call->instruction_address());
address dest = ic_destination();
#ifdef ASSERT
{
CodeBlob* db = CodeCache::find_blob_unsafe(dest);
assert(!db->is_adapter_blob(), "must use stub!");
}
#endif /* ASSERT */
is_call_to_interpreted = cb->contains(dest);
}
return is_call_to_interpreted;
}
void CompiledIC::set_to_clean() {
assert(SafepointSynchronize::is_at_safepoint() || CompiledIC_lock->is_locked() , "MT-unsafe call");
if (TraceInlineCacheClearing || TraceICs) {
tty->print_cr("IC@" INTPTR_FORMAT ": set to clean", instruction_address());
print();
}
address entry;
if (is_optimized()) {
entry = SharedRuntime::get_resolve_opt_virtual_call_stub();
} else {
entry = SharedRuntime::get_resolve_virtual_call_stub();
}
// A zombie transition will always be safe, since the oop has already been set to NULL, so
// we only need to patch the destination
bool safe_transition = is_optimized() || SafepointSynchronize::is_at_safepoint();
if (safe_transition) {
if (!is_optimized()) set_cached_oop(NULL);
// Kill any leftover stub we might have too
if (is_in_transition_state()) {
ICStub* old_stub = ICStub_from_destination_address(stub_address());
old_stub->clear();
}
set_ic_destination(entry);
} else {
// Unsafe transition - create stub.
InlineCacheBuffer::create_transition_stub(this, NULL, entry);
}
// We can't check this anymore. With lazy deopt we could have already
// cleaned this IC entry before we even return. This is possible if
// we ran out of space in the inline cache buffer trying to do the
// set_next and we safepointed to free up space. This is a benign
// race because the IC entry was complete when we safepointed so
// cleaning it immediately is harmless.
// assert(is_clean(), "sanity check");
}
bool CompiledIC::is_clean() const {
assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
bool is_clean = false;
address dest = ic_destination();
is_clean = dest == SharedRuntime::get_resolve_opt_virtual_call_stub() ||
dest == SharedRuntime::get_resolve_virtual_call_stub();
assert(!is_clean || is_optimized() || cached_oop() == NULL, "sanity check");
return is_clean;
}
void CompiledIC::set_to_monomorphic(const CompiledICInfo& info) {
assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
// Updating a cache to the wrong entry can cause bugs that are very hard
// to track down - if cache entry gets invalid - we just clean it. In
// this way it is always the same code path that is responsible for
// updating and resolving an inline cache
//
// The above is no longer true. SharedRuntime::fixup_callers_callsite will change optimized
// callsites. In addition ic_miss code will update a site to monomorphic if it determines
// that an monomorphic call to the interpreter can now be monomorphic to compiled code.
//
// In both of these cases the only thing being modifed is the jump/call target and these
// transitions are mt_safe
Thread *thread = Thread::current();
if (info._to_interpreter) {
// Call to interpreter
if (info.is_optimized() && is_optimized()) {
assert(is_clean(), "unsafe IC path");
MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
// the call analysis (callee structure) specifies that the call is optimized
// (either because of CHA or the static target is final)
// At code generation time, this call has been emitted as static call
// Call via stub
assert(info.cached_oop().not_null() && info.cached_oop()->is_method(), "sanity check");
CompiledStaticCall* csc = compiledStaticCall_at(instruction_address());
methodHandle method (thread, (methodOop)info.cached_oop()());
csc->set_to_interpreted(method, info.entry());
if (TraceICs) {
ResourceMark rm(thread);
tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to interpreter: %s",
instruction_address(),
method->print_value_string());
}
} else {
// Call via method-klass-holder
assert(info.cached_oop().not_null(), "must be set");
InlineCacheBuffer::create_transition_stub(this, info.cached_oop()(), info.entry());
if (TraceICs) {
ResourceMark rm(thread);
tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to interpreter via mkh", instruction_address());
}
}
} else {
// Call to compiled code
bool static_bound = info.is_optimized() || (info.cached_oop().is_null());
#ifdef ASSERT
CodeBlob* cb = CodeCache::find_blob_unsafe(info.entry());
assert (cb->is_nmethod(), "must be compiled!");
#endif /* ASSERT */
// This is MT safe if we come from a clean-cache and go through a
// non-verified entry point
bool safe = SafepointSynchronize::is_at_safepoint() ||
(!is_in_transition_state() && (info.is_optimized() || static_bound || is_clean()));
if (!safe) {
InlineCacheBuffer::create_transition_stub(this, info.cached_oop()(), info.entry());
} else {
set_ic_destination(info.entry());
if (!is_optimized()) set_cached_oop(info.cached_oop()());
}
if (TraceICs) {
ResourceMark rm(thread);
assert(info.cached_oop() == NULL || info.cached_oop()()->is_klass(), "must be");
tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to compiled (rcvr klass) %s: %s",
instruction_address(),
((klassOop)info.cached_oop()())->print_value_string(),
(safe) ? "" : "via stub");
}
}
// We can't check this anymore. With lazy deopt we could have already
// cleaned this IC entry before we even return. This is possible if
// we ran out of space in the inline cache buffer trying to do the
// set_next and we safepointed to free up space. This is a benign
// race because the IC entry was complete when we safepointed so
// cleaning it immediately is harmless.
// assert(is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
}
// is_optimized: Compiler has generated an optimized call (i.e., no inline
// cache) static_bound: The call can be static bound (i.e, no need to use
// inline cache)
void CompiledIC::compute_monomorphic_entry(methodHandle method,
KlassHandle receiver_klass,
bool is_optimized,
bool static_bound,
CompiledICInfo& info,
TRAPS) {
info._is_optimized = is_optimized;
nmethod* method_code = method->code();
address entry = NULL;
if (method_code != NULL) {
// Call to compiled code
if (static_bound || is_optimized) {
entry = method_code->verified_entry_point();
} else {
entry = method_code->entry_point();
}
}
if (entry != NULL) {
// Call to compiled code
info._entry = entry;
if (static_bound || is_optimized) {
info._cached_oop = Handle(THREAD, (oop)NULL);
} else {
info._cached_oop = receiver_klass;
}
info._to_interpreter = false;
} else {
// Note: the following problem exists with Compiler1:
// - at compile time we may or may not know if the destination is final
// - if we know that the destination is final, we will emit an optimized
// virtual call (no inline cache), and need a methodOop to make a call
// to the interpreter
// - if we do not know if the destination is final, we emit a standard
// virtual call, and use CompiledICHolder to call interpreted code
// (no static call stub has been generated)
// However in that case we will now notice it is static_bound
// and convert the call into what looks to be an optimized
// virtual call. This causes problems in verifying the IC because
// it look vanilla but is optimized. Code in is_call_to_interpreted
// is aware of this and weakens its asserts.
info._to_interpreter = true;
// static_bound should imply is_optimized -- otherwise we have a
// performance bug (statically-bindable method is called via
// dynamically-dispatched call note: the reverse implication isn't
// necessarily true -- the call may have been optimized based on compiler
// analysis (static_bound is only based on "final" etc.)
#ifdef COMPILER2
#ifdef TIERED
#if defined(ASSERT)
// can't check the assert because we don't have the CompiledIC with which to
// find the address if the call instruction.
//
// CodeBlob* cb = find_blob_unsafe(instruction_address());
// assert(cb->is_compiled_by_c1() || !static_bound || is_optimized, "static_bound should imply is_optimized");
#endif // ASSERT
#else
assert(!static_bound || is_optimized, "static_bound should imply is_optimized");
#endif // TIERED
#endif // COMPILER2
if (is_optimized) {
// Use stub entry
info._entry = method()->get_c2i_entry();
info._cached_oop = method;
} else {
// Use mkh entry
oop holder = oopFactory::new_compiledICHolder(method, receiver_klass, CHECK);
info._cached_oop = Handle(THREAD, holder);
info._entry = method()->get_c2i_unverified_entry();
}
}
}
inline static RelocIterator parse_ic(CodeBlob* code, address ic_call, oop* &_oop_addr, bool *is_optimized) {
address first_oop = NULL;
// Mergers please note: Sun SC5.x CC insists on an lvalue for a reference parameter.
CodeBlob *code1 = code;
return virtual_call_Relocation::parse_ic(code1, ic_call, first_oop, _oop_addr, is_optimized);
}
CompiledIC::CompiledIC(NativeCall* ic_call)
: _ic_call(ic_call),
_oops(parse_ic(NULL, ic_call->instruction_address(), _oop_addr, &_is_optimized))
{
}
CompiledIC::CompiledIC(Relocation* ic_reloc)
: _ic_call(nativeCall_at(ic_reloc->addr())),
_oops(parse_ic(ic_reloc->code(), ic_reloc->addr(), _oop_addr, &_is_optimized))
{
assert(ic_reloc->type() == relocInfo::virtual_call_type ||
ic_reloc->type() == relocInfo::opt_virtual_call_type, "wrong reloc. info");
}
// ----------------------------------------------------------------------------
void CompiledStaticCall::set_to_clean() {
assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
// Reset call site
MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
#ifdef ASSERT
CodeBlob* cb = CodeCache::find_blob_unsafe(this);
assert(cb != NULL && cb->is_nmethod(), "must be nmethod");
#endif
set_destination_mt_safe(SharedRuntime::get_resolve_static_call_stub());
// Do not reset stub here: It is too expensive to call find_stub.
// Instead, rely on caller (nmethod::clear_inline_caches) to clear
// both the call and its stub.
}
bool CompiledStaticCall::is_clean() const {
return destination() == SharedRuntime::get_resolve_static_call_stub();
}
bool CompiledStaticCall::is_call_to_compiled() const {
return CodeCache::contains(destination());
}
bool CompiledStaticCall::is_call_to_interpreted() const {
// It is a call to interpreted, if it calls to a stub. Hence, the destination
// must be in the stub part of the nmethod that contains the call
nmethod* nm = CodeCache::find_nmethod(instruction_address());
return nm->stub_contains(destination());
}
void CompiledStaticCall::set_to_interpreted(methodHandle callee, address entry) {
address stub=find_stub();
assert(stub!=NULL, "stub not found");
if (TraceICs) {
ResourceMark rm;
tty->print_cr("CompiledStaticCall@" INTPTR_FORMAT ": set_to_interpreted %s",
instruction_address(),
callee->name_and_sig_as_C_string());
}
NativeMovConstReg* method_holder = nativeMovConstReg_at(stub); // creation also verifies the object
NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
assert(method_holder->data() == 0 || method_holder->data() == (intptr_t)callee(), "a) MT-unsafe modification of inline cache");
assert(jump->jump_destination() == (address)-1 || jump->jump_destination() == entry, "b) MT-unsafe modification of inline cache");
// Update stub
method_holder->set_data((intptr_t)callee());
jump->set_jump_destination(entry);
// Update jump to call
set_destination_mt_safe(stub);
}
void CompiledStaticCall::set(const StaticCallInfo& info) {
assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
// Updating a cache to the wrong entry can cause bugs that are very hard
// to track down - if cache entry gets invalid - we just clean it. In
// this way it is always the same code path that is responsible for
// updating and resolving an inline cache
assert(is_clean(), "do not update a call entry - use clean");
if (info._to_interpreter) {
// Call to interpreted code
set_to_interpreted(info.callee(), info.entry());
} else {
if (TraceICs) {
ResourceMark rm;
tty->print_cr("CompiledStaticCall@" INTPTR_FORMAT ": set_to_compiled " INTPTR_FORMAT,
instruction_address(),
info.entry());
}
// Call to compiled code
assert (CodeCache::contains(info.entry()), "wrong entry point");
set_destination_mt_safe(info.entry());
}
}
// Compute settings for a CompiledStaticCall. Since we might have to set
// the stub when calling to the interpreter, we need to return arguments.
void CompiledStaticCall::compute_entry(methodHandle m, StaticCallInfo& info) {
nmethod* m_code = m->code();
info._callee = m;
if (m_code != NULL) {
info._to_interpreter = false;
info._entry = m_code->verified_entry_point();
} else {
// Callee is interpreted code. In any case entering the interpreter
// puts a converter-frame on the stack to save arguments.
info._to_interpreter = true;
info._entry = m()->get_c2i_entry();
}
}
void CompiledStaticCall::set_stub_to_clean(static_stub_Relocation* static_stub) {
assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
// Reset stub
address stub = static_stub->addr();
assert(stub!=NULL, "stub not found");
NativeMovConstReg* method_holder = nativeMovConstReg_at(stub); // creation also verifies the object
NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
method_holder->set_data(0);
jump->set_jump_destination((address)-1);
}
address CompiledStaticCall::find_stub() {
// Find reloc. information containing this call-site
RelocIterator iter((nmethod*)NULL, instruction_address());
while (iter.next()) {
if (iter.addr() == instruction_address()) {
switch(iter.type()) {
case relocInfo::static_call_type:
return iter.static_call_reloc()->static_stub();
// We check here for opt_virtual_call_type, since we reuse the code
// from the CompiledIC implementation
case relocInfo::opt_virtual_call_type:
return iter.opt_virtual_call_reloc()->static_stub();
case relocInfo::poll_type:
case relocInfo::poll_return_type: // A safepoint can't overlap a call.
default:
ShouldNotReachHere();
}
}
}
return NULL;
}
//-----------------------------------------------------------------------------
// Non-product mode code
#ifndef PRODUCT
void CompiledIC::verify() {
// make sure code pattern is actually a call imm32 instruction
_ic_call->verify();
if (os::is_MP()) {
_ic_call->verify_alignment();
}
assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted()
|| is_optimized() || is_megamorphic(), "sanity check");
}
void CompiledIC::print() {
print_compiled_ic();
tty->cr();
}
void CompiledIC::print_compiled_ic() {
tty->print("Inline cache at " INTPTR_FORMAT ", calling %s " INTPTR_FORMAT,
instruction_address(), is_call_to_interpreted() ? "interpreted " : "", ic_destination());
}
void CompiledStaticCall::print() {
tty->print("static call at " INTPTR_FORMAT " -> ", instruction_address());
if (is_clean()) {
tty->print("clean");
} else if (is_call_to_compiled()) {
tty->print("compiled");
} else if (is_call_to_interpreted()) {
tty->print("interpreted");
}
tty->cr();
}
void CompiledStaticCall::verify() {
// Verify call
NativeCall::verify();
if (os::is_MP()) {
verify_alignment();
}
// Verify stub
address stub = find_stub();
assert(stub != NULL, "no stub found for static call");
NativeMovConstReg* method_holder = nativeMovConstReg_at(stub); // creation also verifies the object
NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
// Verify state
assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
}
#endif