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8167656: Unstable MethodHandle inlining causing huge performance variations

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Profile calls without a reciever

Reviewed-by: jrose, vlivanov, kvn
This commit is contained in:
Nils Eliasson 2016-11-10 18:08:31 +01:00
parent c372aca124
commit df8bbfafc7
1 changed files with 18 additions and 9 deletions
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27
hotspot/src/share/vm/c1/c1_GraphBuilder.cpp
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@ -2056,17 +2056,26 @@ void GraphBuilder::invoke(Bytecodes::Code code) {
}
#endif
// invokespecial always needs a NULL check. invokevirtual where the target is
// final or where it's not known whether the target is final requires a NULL check.
// Otherwise normal invokevirtual will perform the null check during the lookup
// logic or the unverified entry point. Profiling of calls requires that
// the null check is performed in all cases.
// A null check is required here (when there is a receiver) for any of the following cases
// - invokespecial, always need a null check.
// - invokevirtual, when the target is final and loaded. Calls to final targets will become optimized
// and require null checking. If the target is loaded a null check is emitted here.
// If the target isn't loaded the null check must happen after the call resolution. We achieve that
// by using the target methods unverified entry point (see CompiledIC::compute_monomorphic_entry).
// (The JVM specification requires that LinkageError must be thrown before a NPE. An unloaded target may
// potentially fail, and can't have the null check before the resolution.)
// - A call that will be profiled. (But we can't add a null check when the target is unloaded, by the same
// reason as above, so calls with a receiver to unloaded targets can't be profiled.)
//
// Normal invokevirtual will perform the null check during lookup
bool do_null_check = (recv != NULL) &&
(code == Bytecodes::_invokespecial || (target->is_loaded() && (target->is_final() || (is_profiling() && profile_calls()))));
bool need_null_check = (code == Bytecodes::_invokespecial) ||
(target->is_loaded() && (target->is_final_method() || (is_profiling() && profile_calls())));
if (do_null_check) {
null_check(recv);
if (need_null_check) {
if (recv != NULL) {
null_check(recv);
}
if (is_profiling()) {
// Note that we'd collect profile data in this method if we wanted it.