[GR-51558] Remove OpaqueValueNodes at the end of low tier

PullRequest: graal/17033

compiler/src/jdk.graal.compiler.test/src/jdk/graal/compiler/nodes/test/OpaqueNodeTest.java

@@ -82,4 +82,20 @@ public void testNegWrite() {
         test("writeNegSnippet");
         assertTrue(arr[0] == (byte) -300);
     }
+
+    public static void opaqueClassSnippet() {
+        /*
+         * GR-51558: This would cause an assertion failure in LIR constant load optimization if the
+         * opaque is not removed.
+         */
+        Class<?> c = GraalDirectives.opaque(Object.class);
+        if (c.getResource("resource.txt") == null) {
+            GraalDirectives.deoptimize();
+        }
+    }
+
+    @Test
+    public void testOpaqueClass() {
+        test("opaqueClassSnippet");
+    }
 }

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/core/phases/EconomyLowTier.java

@@ -31,6 +31,7 @@
 import jdk.graal.compiler.phases.common.CanonicalizerPhase;
 import jdk.graal.compiler.phases.common.ExpandLogicPhase;
 import jdk.graal.compiler.phases.common.LowTierLoweringPhase;
+import jdk.graal.compiler.phases.common.RemoveOpaqueValuePhase;
 import jdk.graal.compiler.phases.schedule.SchedulePhase;
 import jdk.graal.compiler.phases.tiers.LowTierContext;
 
@@ -52,6 +53,7 @@ public EconomyLowTier() {
          * backend or the target specific suites provider.
          */
         appendPhase(new PlaceholderPhase<>(AddressLoweringPhase.class));
+        appendPhase(new RemoveOpaqueValuePhase());
         appendPhase(new SchedulePhase(SchedulePhase.SchedulingStrategy.LATEST_OUT_OF_LOOPS));
     }
 }

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/core/phases/LowTier.java

@@ -42,6 +42,7 @@
 import jdk.graal.compiler.phases.common.OptimizeExtendsPhase;
 import jdk.graal.compiler.phases.common.ProfileCompiledMethodsPhase;
 import jdk.graal.compiler.phases.common.PropagateDeoptimizeProbabilityPhase;
+import jdk.graal.compiler.phases.common.RemoveOpaqueValuePhase;
 import jdk.graal.compiler.phases.schedule.SchedulePhase;
 import jdk.graal.compiler.phases.schedule.SchedulePhase.SchedulingStrategy;
 import jdk.graal.compiler.phases.tiers.LowTierContext;
@@ -93,6 +94,8 @@ public LowTier(OptionValues options) {
 
         appendPhase(new OptimizeExtendsPhase());
 
+        appendPhase(new RemoveOpaqueValuePhase());
+
         appendPhase(new SchedulePhase(SchedulePhase.SchedulingStrategy.LATEST_OUT_OF_LOOPS));
     }
 

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/nodes/extended/OpaqueValueNode.java

@@ -24,20 +24,32 @@
  */
 package jdk.graal.compiler.nodes.extended;
 
+import static jdk.graal.compiler.nodeinfo.NodeCycles.CYCLES_0;
+import static jdk.graal.compiler.nodeinfo.NodeSize.SIZE_0;
+
+import jdk.graal.compiler.graph.IterableNodeType;
 import jdk.graal.compiler.graph.NodeClass;
 import jdk.graal.compiler.graph.spi.NodeWithIdentity;
 import jdk.graal.compiler.nodeinfo.InputType;
 import jdk.graal.compiler.nodeinfo.NodeInfo;
 import jdk.graal.compiler.nodes.NodeView;
 import jdk.graal.compiler.nodes.ValueNode;
 import jdk.graal.compiler.nodes.spi.LIRLowerable;
-import jdk.graal.compiler.nodes.spi.NodeLIRBuilderTool;
-
-import static jdk.graal.compiler.nodeinfo.NodeCycles.CYCLES_0;
-import static jdk.graal.compiler.nodeinfo.NodeSize.SIZE_0;
+import jdk.graal.compiler.phases.common.RemoveOpaqueValuePhase;
 
+/**
+ * This node type acts as an optimization barrier between its input node and its usages. For
+ * example, a MulNode with two ConstantNodes as input will be canonicalized to a ConstantNode. This
+ * optimization will be prevented if either of the two constants is wrapped by an OpaqueValueNode.
+ * <p>
+ * </p>
+ * This node is not {@link LIRLowerable}, so it should be removed from the graph before LIR
+ * generation.
+ *
+ * @see RemoveOpaqueValuePhase
+ */
 @NodeInfo(cycles = CYCLES_0, size = SIZE_0)
-public final class OpaqueValueNode extends OpaqueNode implements NodeWithIdentity, LIRLowerable, GuardingNode {
+public final class OpaqueValueNode extends OpaqueNode implements NodeWithIdentity, GuardingNode, IterableNodeType {
     public static final NodeClass<OpaqueValueNode> TYPE = NodeClass.create(OpaqueValueNode.class);
 
     @Input(InputType.Value) private ValueNode value;
@@ -57,9 +69,4 @@ public void setValue(ValueNode value) {
         this.updateUsages(this.value, value);
         this.value = value;
     }
-
-    @Override
-    public void generate(NodeLIRBuilderTool gen) {
-        gen.setResult(this, gen.operand(getValue()));
-    }
 }

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/phases/common/RemoveOpaqueValuePhase.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2012, 2022, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+package jdk.graal.compiler.phases.common;
+
+import java.util.Optional;
+
+import jdk.graal.compiler.nodes.GraphState;
+import jdk.graal.compiler.nodes.StructuredGraph;
+import jdk.graal.compiler.nodes.extended.OpaqueValueNode;
+import jdk.graal.compiler.nodes.spi.CoreProviders;
+import jdk.graal.compiler.phases.BasePhase;
+
+/**
+ * Removes all {@link jdk.graal.compiler.nodes.extended.OpaqueValueNode}s from the graph.
+ */
+public class RemoveOpaqueValuePhase extends BasePhase<CoreProviders> {
+    @Override
+    public Optional<NotApplicable> notApplicableTo(GraphState graphState) {
+        return ALWAYS_APPLICABLE;
+    }
+
+    @Override
+    public boolean shouldApply(StructuredGraph graph) {
+        return graph.hasNode(OpaqueValueNode.TYPE);
+    }
+
+    @Override
+    protected void run(StructuredGraph graph, CoreProviders context) {
+        for (OpaqueValueNode opaque : graph.getNodes(OpaqueValueNode.TYPE)) {
+            opaque.replaceAtUsagesAndDelete(opaque.getValue());
+        }
+    }
+}