[GR-41102] Speculative guard movement: do not optimize condition if it will result in an unconditional deopt.

PullRequest: graal/13563

Author: davleopo

compiler/src/org.graalvm.compiler.core.test/src/org/graalvm/compiler/core/test/SpeculativeGuardMovementTrivialDeoptTest.java

@@ -0,0 +1,149 @@
+/*
+ * Copyright (c) 2023, 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 org.graalvm.compiler.core.test;
+
+import java.util.EnumSet;
+
+import org.graalvm.compiler.api.directives.GraalDirectives;
+import org.junit.Test;
+
+import jdk.vm.ci.meta.DeoptimizationReason;
+
+public class SpeculativeGuardMovementTrivialDeoptTest extends GraalCompilerTest {
+
+    static class Node {
+        int val;
+        Node next;
+    }
+
+    private static Node createList(int length) {
+        Node head = new Node();
+        for (int i = 1; i < length; i++) {
+            Node newHead = new Node();
+            newHead.val = i;
+            newHead.next = head;
+            head = newHead;
+        }
+        return head;
+    }
+
+    public static long contradictingAfter(Node head) {
+        Node cur = head;
+        int i = 0;
+        for (; GraalDirectives.injectIterationCount(10000, i < 500); i++) {
+            if (GraalDirectives.injectBranchProbability(0.0001, cur == null)) {
+                // this loop effectively ensures the guard below is never triggered
+                break;
+            }
+            cur = cur.next;
+            GraalDirectives.sideEffect(0);
+            if (i == 123) {
+                GraalDirectives.sideEffect(1);
+            } else {
+                GraalDirectives.sideEffect(2);
+            }
+            if (!(i + 1 < 101)) {
+                GraalDirectives.deoptimizeAndInvalidate();
+            }
+            GraalDirectives.sideEffect(3);
+        }
+        return i;
+    }
+
+    @Test
+    public void testContradicting01() {
+        test(getInitialOptions(), EnumSet.allOf(DeoptimizationReason.class), "contradictingAfter", createList(100));
+    }
+
+    public static long contradictingAfterInnerOuter(Node head, int foo) {
+        Node cur = head;
+
+        int outerPhi = 0;
+        while (outerPhi < foo) {
+            int i = outerPhi;
+            for (; GraalDirectives.injectIterationCount(10000, i < 500); i++) {
+                if (GraalDirectives.injectBranchProbability(0.0001, cur == null)) {
+                    // this loop effectively ensures the guard below is never triggered
+                    break;
+                }
+                cur = cur.next;
+                GraalDirectives.sideEffect(0);
+                if (i == 123) {
+                    GraalDirectives.sideEffect(1);
+                } else {
+                    GraalDirectives.sideEffect(2);
+                }
+                if (!(i + 1 < 101)) {
+                    GraalDirectives.deoptimizeAndInvalidate();
+                }
+                GraalDirectives.sideEffect(3);
+            }
+            outerPhi++;
+        }
+        return outerPhi;
+    }
+
+    @Test
+    public void testContradicting02() {
+        test(getInitialOptions(), EnumSet.allOf(DeoptimizationReason.class), "contradictingAfterInnerOuter", createList(100), 1);
+    }
+
+    public static long contradictingAfterInnerOuter2(Node head, int foo, int bar) {
+        Node cur = head;
+        int outerOuterPhi = 0;
+        while (outerOuterPhi < bar) {
+            int outerPhi = outerOuterPhi;
+            while (outerPhi < foo) {
+                int i = outerPhi;
+                for (; GraalDirectives.injectIterationCount(10000, i < 500); i++) {
+                    if (GraalDirectives.injectBranchProbability(0.0001, cur == null)) {
+                        // this loop effectively ensures the guard below is never triggered
+                        break;
+                    }
+                    cur = cur.next;
+                    GraalDirectives.sideEffect(0);
+                    if (i == 123) {
+                        GraalDirectives.sideEffect(1);
+                    } else {
+                        GraalDirectives.sideEffect(2);
+                    }
+                    if (!(i + 1 < 101)) {
+                        GraalDirectives.deoptimizeAndInvalidate();
+                    }
+                    GraalDirectives.sideEffect(3);
+                }
+                outerPhi++;
+            }
+            outerOuterPhi++;
+        }
+        return outerOuterPhi;
+    }
+
+    @Test
+    public void testContradicting03() {
+        test(getInitialOptions(), EnumSet.allOf(DeoptimizationReason.class), "contradictingAfterInnerOuter2", createList(100), 1, 1);
+    }
+
+}