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
assert(is_clean(), "should only go to monomorphic from clean state");
Thread *thread = Thread::current();
if (info._to_interpreter) {
COMPILER2_ONLY(debug_only(CodeBlob* cb = CodeCache::find_blob(info.entry()));)
void CompiledIC::set_to_monomorphic(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_metadata() != NULL && info.cached_metadata()->is_method(), "sanity check");
CompiledStaticCall* csc = compiledStaticCall_at(instruction_address());
methodHandle method (thread, (Method*)info.cached_metadata());
csc->set_to_interpreted(method, info.entry());
if (TraceICs) {
ResourceMark rm(thread);
tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to interpreter: %s",
p2i(instruction_address()),
method->print_value_string());
}
} else {
// Call via method-klass-holder
InlineCacheBuffer::create_transition_stub(this, info.claim_cached_icholder(), info.entry());
if (TraceICs) {
ResourceMark rm(thread);
tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to interpreter via icholder ", p2i(instruction_address()));
}
}
} else {
// Call to compiled code
bool static_bound = info.is_optimized() || (info.cached_metadata() == 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_metadata(), info.entry());
} else {
if (is_optimized()) {
set_ic_destination(info.entry());
} else {
set_ic_destination_and_value(info.entry(), info.cached_metadata());
}
}
if (TraceICs) {
ResourceMark rm(thread);
assert(info.cached_metadata() == NULL || info.cached_metadata()->is_klass(), "must be");
tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to compiled (rcvr klass) %s: %s",
p2i(instruction_address()),
((Klass*)info.cached_metadata())->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) {
nmethod* method_code = method->code();
address entry = NULL;
if (method_code != NULL && method_code->is_in_use()) {
// 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.set_compiled_entry(entry, (static_bound || is_optimized) ? NULL : receiver_klass(), is_optimized);
} 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 Method* 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.
// 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.set_interpreter_entry(method()->get_c2i_entry(), method());
} else {
// Use icholder entry
CompiledICHolder* holder = new CompiledICHolder(method(), receiver_klass());
info.set_icholder_entry(method()->get_c2i_unverified_entry(), holder);
}
}
assert(info.is_optimized() == is_optimized, "must agree");
}
void PltNativeCallWrapper::set_to_interpreted(const methodHandle& method, CompiledICInfo& info) {
assert(!info.to_aot(), "only for nmethod");
CompiledPltStaticCall* csc = CompiledPltStaticCall::at(instruction_address());
csc->set_to_interpreted(method, info.entry());
}
