Skip to content
This repository has been archived by the owner. It is now read-only.
Permalink
Browse files
8268371: C2: assert(_gvn.type(obj)->higher_equal(tjp)) failed: cast_u…
…p is no longer needed

Reviewed-by: roland, kvn
  • Loading branch information
Vladimir Ivanov committed Jun 17, 2021
1 parent 8545269 commit 9130b8a9d7ebd943108f01d41ed777e080f34c4d
Showing with 204 additions and 18 deletions.
  1. +29 −18 src/hotspot/share/opto/graphKit.cpp
  2. +175 −0 test/hotspot/jtreg/compiler/c2/UpcastTest.java
@@ -2946,7 +2946,6 @@ Node* GraphKit::gen_subtype_check(Node* obj_or_subklass, Node* superklass) {
return n;
}

const TypePtr* adr_type = TypeKlassPtr::make(TypePtr::NotNull, C->env()->Object_klass(), Type::OffsetBot);
Node* check = _gvn.transform(new SubTypeCheckNode(C, obj_or_subklass, superklass));
Node* bol = _gvn.transform(new BoolNode(check, BoolTest::eq));
IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN);
@@ -2958,23 +2957,30 @@ Node* GraphKit::gen_subtype_check(Node* obj_or_subklass, Node* superklass) {
Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
float prob,
Node* *casted_receiver) {
assert(!klass->is_interface(), "no exact type check on interfaces");

const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
Node* recv_klass = load_object_klass(receiver);
Node* want_klass = makecon(tklass);
Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass) );
Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
Node* cmp = _gvn.transform(new CmpPNode(recv_klass, want_klass));
Node* bol = _gvn.transform(new BoolNode(cmp, BoolTest::eq));
IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
set_control( _gvn.transform( new IfTrueNode (iff) ));
Node* fail = _gvn.transform( new IfFalseNode(iff) );

const TypeOopPtr* recv_xtype = tklass->as_instance_type();
assert(recv_xtype->klass_is_exact(), "");

// Subsume downstream occurrences of receiver with a cast to
// recv_xtype, since now we know what the type will be.
Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
(*casted_receiver) = _gvn.transform(cast);
// (User must make the replace_in_map call.)
set_control( _gvn.transform(new IfTrueNode (iff)));
Node* fail = _gvn.transform(new IfFalseNode(iff));

if (!stopped()) {
const TypeOopPtr* receiver_type = _gvn.type(receiver)->isa_oopptr();
const TypeOopPtr* recvx_type = tklass->as_instance_type();
assert(recvx_type->klass_is_exact(), "");

if (!receiver_type->higher_equal(recvx_type)) { // ignore redundant casts
// Subsume downstream occurrences of receiver with a cast to
// recv_xtype, since now we know what the type will be.
Node* cast = new CheckCastPPNode(control(), receiver, recvx_type);
(*casted_receiver) = _gvn.transform(cast);
// (User must make the replace_in_map call.)
}
}

return fail;
}
@@ -2987,10 +2993,15 @@ Node* GraphKit::subtype_check_receiver(Node* receiver, ciKlass* klass,

Node* slow_ctl = gen_subtype_check(receiver, want_klass);

// Cast receiver after successful check
const TypeOopPtr* recv_type = tklass->cast_to_exactness(false)->is_klassptr()->as_instance_type();
Node* cast = new CheckCastPPNode(control(), receiver, recv_type);
(*casted_receiver) = _gvn.transform(cast);
// Ignore interface type information until interface types are properly tracked.
if (!stopped() && !klass->is_interface()) {
const TypeOopPtr* receiver_type = _gvn.type(receiver)->isa_oopptr();
const TypeOopPtr* recv_type = tklass->cast_to_exactness(false)->is_klassptr()->as_instance_type();
if (!receiver_type->higher_equal(recv_type)) { // ignore redundant casts
Node* cast = new CheckCastPPNode(control(), receiver, recv_type);
(*casted_receiver) = _gvn.transform(cast);
}
}

return slow_ctl;
}
@@ -0,0 +1,175 @@
/*
* Copyright (c) 2021, 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.
*/

/**
* @test
* @requires vm.flavor == "server"
*
* @run main/othervm -Xbatch -XX:-TieredCompilation -XX:+PrintCompilation -XX:+UnlockDiagnosticVMOptions -XX:+PrintInlining
* -XX:CompileCommand=quiet -XX:CompileCommand=compileonly,*::test
* compiler.c2.UpcastTest
*/

package compiler.c2;

public class UpcastTest {
static class Test1 {
interface I { void m(); }

static abstract class AC implements I {
public void m() {}
}

static class T extends AC {
int i = 0;

static {
// Run the test while T is not fully initialized yet.
for (int i = 0; i < 20_000; i++) {
test(new T(){});
test(new T(){});
test(new T(){});
}
}
}

static void test(T t) {
// Interface I has unique implementor AC.
// CHA reports AC::m and the callee is guarded by a type check against its holder (AC).

((I)t).m(); // invokeinterface I.m w/ polluted profile

// No upcasts (to class AC) on t after the call.
// Otherwise, field access fires an assert.
t.i = 1;
}
}

static class Test2 {
interface I { void m(); }
interface J extends I {
default void m() {}
}

static abstract class AC implements I {
}

static abstract class T extends AC {
int i = 0;

static {
// Run the test while T is not fully initialized yet.
for (int i = 0; i < 20_000; i++) {
test(new T1(){});
test(new T2(){});
test(new T3(){});
}
}
}

static class T1 extends T implements J {}
static class T2 extends T implements J {}
static class T3 extends T implements J {}

static void test(T t) {
// Interface I has unique implementor AC.
// CHA reports J::m and the callee is guarded by a type check against its holder (J).

((I)t).m(); // invokeinterface I.m w/ polluted profile

// No upcasts (to interface J) on t after the call.
// Otherwise, field access fires an assert.
t.i = 1;
}
}

static class Test3 {
interface I {
default void m1() { m2(); }
void m2();
}
interface J extends I {
default void m2() {}
}

static abstract class AC implements I {}

static class T extends AC implements J {
int i = 0;
}

static void test(T t) {
t.m1(); // invokeinterface I.m w/ polluted profile

// No upcasts (to interface J) on t after the call.
// Otherwise, field access fires an assert.
t.i = 1;
}

static void run() {
for (int i = 0; i < 20_000; i++) {
test(new T() {});
test(new T() {});
test(new T() {});
}
}
}

static class Test4 {
interface I { default void m() {}}

static class T {
int i = 0;
}

static class D extends T implements I {}

static void test(T t) {
if (t instanceof I) {
((I)t).m();

// No upcasts (to interface J) on t after the call.
// Otherwise, field access fires an assert.

t.i = 1;
} else {
throw new InternalError();
}
}

static void run() {
for (int i = 0; i < 20_000; i++) {
test(new D() {});
test(new D() {});
test(new D() {});
}
}
}

public static void main(String[] args) {
new Test1.T(); // trigger initialization of class T
new Test2.T1(); // trigger initialization of class T
Test3.run();
Test4.run();
}
}

1 comment on commit 9130b8a

@openjdk-notifier

This comment has been minimized.

Copy link

@openjdk-notifier openjdk-notifier bot commented on 9130b8a Jun 17, 2021

Please sign in to comment.