8319764: C2 compilation asserts during incremental inlining because Phi input is out of bounds

Reviewed-by: thartmann, chagedorn

Author: rwestrel

src/hotspot/share/opto/replacednodes.cpp

@@ -152,12 +152,12 @@ void ReplacedNodes::apply(Compile* C, Node* ctl) {
       } else if (n->outcnt() != 0 && n != improved) {
         if (n->is_Phi()) {
           Node* region = n->in(0);
-          Node* prev = stack.node_at(stack.size() - 2);
-          for (uint j = 1; j < region->req(); ++j) {
-            if (n->in(j) == prev) {
-              Node* in = region->in(j);
-              if (in != nullptr && !in->is_top()) {
-                if (is_dominator(ctl, in)) {
+          if (n->req() == region->req()) { // ignore dead phis
+            Node* prev = stack.node_at(stack.size() - 2);
+            for (uint j = 1; j < region->req(); ++j) {
+              if (n->in(j) == prev) {
+                Node* in = region->in(j);
+                if (in != nullptr && !in->is_top() && is_dominator(ctl, in)) {
                   valid_control.set(in->_idx);
                   collect_nodes_to_clone(stack, to_fix);
                 }

test/hotspot/jtreg/compiler/inlining/TestLateInlineReplacedNodesExceptionPath.java

@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2023, Red Hat, 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8319764
+ * @summary C2 compilation asserts during incremental inlining because Phi input is out of bounds
+ * @requires vm.compiler2.enabled
+ * @run main/othervm -XX:-TieredCompilation -XX:-BackgroundCompilation -XX:CompileCommand=dontinline,TestLateInlineReplacedNodesExceptionPath::notInlined
+ *                   -XX:+UnlockDiagnosticVMOptions -XX:+StressIGVN -XX:StressSeed=1246687813 TestLateInlineReplacedNodesExceptionPath
+ * @run main/othervm -XX:-TieredCompilation -XX:-BackgroundCompilation -XX:CompileCommand=dontinline,TestLateInlineReplacedNodesExceptionPath::notInlined
+ *                   -XX:+UnlockDiagnosticVMOptions -XX:+StressIGVN TestLateInlineReplacedNodesExceptionPath
+ */
+
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodType;
+
+public class TestLateInlineReplacedNodesExceptionPath {
+    private static A fieldA;
+    private static C fieldC = new C();
+
+    public static void main(String[] args) throws Throwable {
+        A a = new A();
+        B b = new B();
+        for (int i = 0; i < 20_000; i++) {
+            fieldA = a;
+            test1(true);
+            fieldA = b;
+            test1(true);
+            inlined1(true);
+            inlined1(false);
+            inlined2(true);
+            inlined2(false);
+        }
+    }
+
+    static final MethodHandle mh1;
+    static MethodHandle mh2;
+    static final MethodHandle mh3;
+    static MethodHandle mh4;
+
+    static {
+        try {
+            MethodHandles.Lookup lookup = MethodHandles.lookup();
+            mh1 = lookup.findStatic(TestLateInlineReplacedNodesExceptionPath.class, "lateInlined1", MethodType.methodType(void.class, C.class));
+            mh2 = mh1;
+            mh3 = lookup.findStatic(TestLateInlineReplacedNodesExceptionPath.class, "lateInlined2", MethodType.methodType(void.class, C.class));
+            mh4 = mh3;
+        } catch (NoSuchMethodException | IllegalAccessException e) {
+            e.printStackTrace();
+            throw new RuntimeException("Method handle lookup failed");
+        }
+    }
+
+    private static void lateInlined1(C c) {
+        fieldA.m(c);
+        c.field++;
+        fieldA.m(c);
+    }
+
+    private static void lateInlined2(C c) {
+        c.field++;
+    }
+
+    private static void test1(boolean flag) throws Throwable {
+        final C c = fieldC;
+        MethodHandle mh = null;
+        if (flag) {
+            mh = inlined1(flag);
+        }
+        mh.invokeExact(c);
+        mh = null;
+        if (flag) {
+            mh = inlined2(flag);
+        }
+        mh.invokeExact(c);
+    }
+
+    private static MethodHandle inlined1(boolean flag) {
+        if (flag) {
+            return mh1;
+        }
+        return mh2;
+    }
+
+    private static MethodHandle inlined2(boolean flag) {
+        if (flag) {
+            return mh3;
+        }
+        return mh4;
+    }
+
+    private static void notInlined() {
+    }
+
+    private static class A {
+        public void m(C c) {
+            c.field++;
+            notInlined();
+        }
+
+    }
+
+    private static class B extends A {
+
+        public void m(C c) {
+            notInlined();
+        }
+    }
+
+    private static class C {
+        public int field;
+    }
+}