From 32020ae7d3c1f4f07bfb5c025bc364c5f66ab4b1 Mon Sep 17 00:00:00 2001
From: Christian Hagedorn <christian.hagedorn@oracle.com>
Date: Wed, 13 Sep 2023 14:52:21 +0200
Subject: [PATCH] 8316105: C2: Back to back Parse Predicates from different
 loops but with same deopt reason are wrongly grouped together

---
 src/hotspot/share/opto/predicates.cpp         |  2 +-
 .../TestBackToBackParsePredicates.java        | 85 +++++++++++++++++++
 2 files changed, 86 insertions(+), 1 deletion(-)
 create mode 100644 test/hotspot/jtreg/compiler/predicates/TestBackToBackParsePredicates.java

diff --git a/src/hotspot/share/opto/predicates.cpp b/src/hotspot/share/opto/predicates.cpp
index 63e627070a107..adcacd2f1fb39 100644
--- a/src/hotspot/share/opto/predicates.cpp
+++ b/src/hotspot/share/opto/predicates.cpp
@@ -77,7 +77,7 @@ Deoptimization::DeoptReason RuntimePredicate::uncommon_trap_reason(IfProjNode* i
 }
 
 bool RuntimePredicate::is_success_proj(Node* node, Deoptimization::DeoptReason deopt_reason) {
-  if (node->is_IfProj()) {
+  if (node->is_IfProj() && !node->in(0)->is_ParsePredicate()) {
     return deopt_reason == uncommon_trap_reason(node->as_IfProj());
   } else {
     return false;
diff --git a/test/hotspot/jtreg/compiler/predicates/TestBackToBackParsePredicates.java b/test/hotspot/jtreg/compiler/predicates/TestBackToBackParsePredicates.java
new file mode 100644
index 0000000000000..e61bd0cead3f7
--- /dev/null
+++ b/test/hotspot/jtreg/compiler/predicates/TestBackToBackParsePredicates.java
@@ -0,0 +1,85 @@
+/*
+ * 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.
+ *
+ * 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 8316105
+ * @library /test/lib
+ * @summary Test that back to back Parse Predicates with same deopt reason are not grouped together
+ * @run main/othervm -Xbatch compiler.predicates.TestBackToBackParsePredicates
+ */
+
+package compiler.predicates;
+
+import jdk.test.lib.Asserts;
+
+public class TestBackToBackParsePredicates {
+    static long lFld;
+
+    public static void main(String[] strArr2) {
+        for (int i = -350; i <= 0; i++) {
+            lFld = 30;
+            test(i);
+            check();
+        }
+        lFld = 30;
+        test(1);
+        check();
+    }
+
+    // Inlined
+    static void foo() {
+        for (int i12 = 1; i12 < 5; i12++) { // Loop A
+            lFld += 1; // StoreL
+        }
+    }
+
+    static void test(int x) {
+        foo();
+
+        // After fully unrolling loop A and after next round of IGVN:
+        // We wrongly treat two back to back Loop Limit Check Parse Predicates as single Predicate Block. We therefore
+        // keep the Loop Parse Predicate of loop A:
+        //
+        // Loop Parse Predicate (of A)
+        // Loop Limit Check Parse Predicate (of A)  |
+        //    -> StoreL of lFld pinned here         | Wrongly treated as single Predicate Block
+        // Loop Limit Check Parse Predicate (of B)  |
+        for (int i = 7; i < 212; i++) { // Loop B
+            for (int j = 1; j < 80; j++) {
+                switch (x % 8) {
+                    case 0:
+                    case 2:
+                        break;
+                    case 6:
+                    case 7:
+                }
+            }
+        }
+    }
+
+    static void check() {
+        Asserts.assertEQ(34L, lFld);
+    }
+}