7199742: A lot of C2 OSR compilations of the same method's bci

Summary: Don't clone head of OSR loop.
Reviewed-by: jrose, twisti

src/share/vm/ci/ciTypeFlow.cpp

@@ -2194,6 +2194,10 @@ bool ciTypeFlow::clone_loop_heads(Loop* lp, StateVector* temp_vector, JsrSet* te
     if (head->backedge_copy_count() != 0)
       continue;
 
+    // Don't clone head of OSR loop to get correct types in start block.
+    if (is_osr_flow() && head->start() == start_bci())
+      continue;
+
     // check _no_ shared head below us
     Loop* ch;
     for (ch = lp->child(); ch != NULL && ch->head() != head; ch = ch->sibling());

src/share/vm/opto/parse1.cpp

@@ -372,7 +372,8 @@ void Parse::load_interpreter_state(Node* osr_buf) {
     // in the CFG, which typeflow had previously ignored.
     // E.g., Object x = coldAtFirst() && notReached()? "str": new Integer(123).
     // This x will be typed as Integer if notReached is not yet linked.
-    uncommon_trap(Deoptimization::Reason_unreached,
+    // It could also happen due to a problem in ciTypeFlow analysis.
+    uncommon_trap(Deoptimization::Reason_constraint,
                   Deoptimization::Action_reinterpret);
     set_map(types_are_good);
   }

test/compiler/7199742/Test7199742.java

+/*
+ * Copyright (c) 2012, 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 7199742
+ * @summary A lot of C2 OSR compilations of the same method's bci
+ *
+ * @run main/othervm -Xmx32m -Xbatch Test7199742
+ */
+
+public class Test7199742 {
+  private static final int ITERS  = 10000000;
+  public static void main(String args[]) {
+    Test7199742 t = new Test7199742();
+    for (int i=0; i<10; i++) {
+      test(t, 7);
+    }
+  }
+  static Test7199742 test(Test7199742 t, int m) {
+    int i = -(ITERS/2);
+    if (i == 0) return null;
+    Test7199742 v = null;
+    while(i < ITERS) {
+      if ((i&m) == 0) {
+        v = t;
+      }
+      i++;
+    }
+    return v;
+  }
+}
+