changeset 5131:6ae83ea003fd

8043354: OptimizePtrCompare too aggressive when allocations are present Summary: In bcEscapeAnalyzer update the _allocated_escapes flag if a var escapes the method. Reviewed-by: rasbold, kvn
author sgabdura
date Wed, 04 Jun 2014 09:36:15 +0200
parents 699a0d90d7f4
children e293ec39c3a0
files src/share/vm/ci/bcEscapeAnalyzer.cpp test/compiler/EscapeAnalysis/TestAllocatedEscapesPtrComparison.java
diffstat 2 files changed, 110 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/src/share/vm/ci/bcEscapeAnalyzer.cpp	Tue May 27 16:05:29 2014 -0700
+++ b/src/share/vm/ci/bcEscapeAnalyzer.cpp	Wed Jun 04 09:36:15 2014 +0200
@@ -158,6 +158,9 @@
 
 void BCEscapeAnalyzer::set_method_escape(ArgumentMap vars) {
   clear_bits(vars, _arg_local);
+  if (vars.contains_allocated()) {
+    _allocated_escapes = true;
+  }
 }
 
 void BCEscapeAnalyzer::set_global_escape(ArgumentMap vars, bool merge) {
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/compiler/EscapeAnalysis/TestAllocatedEscapesPtrComparison.java	Wed Jun 04 09:36:15 2014 +0200
@@ -0,0 +1,107 @@
+/*
+ * Copyright 2014 Google, 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 8043354
+ * @summary  bcEscapeAnalyzer allocated_escapes not conservative enough
+ * @run main/othervm -XX:CompileOnly=.visitAndPop TestAllocatedEscapesPtrComparison
+ * @author Chuck Rasbold rasbold@google.com
+ */
+
+/*
+ * Test always passes with -XX:-OptmimizePtrCompare
+ */
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class TestAllocatedEscapesPtrComparison {
+
+  static TestAllocatedEscapesPtrComparison dummy;
+
+  class Marker {
+  }
+
+  List<Marker> markerList = new ArrayList<>();
+
+  // Suppress compilation of this method, it must be processed
+  // by the bytecode escape analyzer.
+
+  // Make a new marker and put it on the List
+  Marker getMarker() {
+    // result escapes through markerList
+    final Marker result = new Marker();
+    markerList.add(result);
+    return result;
+  }
+
+  void visit(int depth) {
+    // Make a new marker
+    getMarker();
+
+    // Call visitAndPop every once in a while
+    // Cap the depth of our recursive visits
+    if (depth % 10 == 2) {
+      visitAndPop(depth + 1);
+    } else if (depth < 15) {
+      visit(depth + 1);
+    }
+  }
+
+   void visitAndPop(int depth) {
+    // Random dummy allocation to force EscapeAnalysis to process this method
+    dummy = new TestAllocatedEscapesPtrComparison();
+
+    // Make a new marker
+    Marker marker = getMarker();
+
+    visit(depth + 1);
+
+    // Walk and pop the marker list up to the current marker
+    boolean found = false;
+    for (int i = markerList.size() - 1; i >= 0; i--) {
+      Marker removed = markerList.remove(i);
+
+      // In the failure, EA mistakenly converts this comparison to false
+      if (removed == marker) {
+        found = true;
+        break;
+      }
+    }
+
+    if (!found) {
+      throw new RuntimeException("test fails");
+    }
+  }
+
+
+  public static void main(String args[]) {
+    TestAllocatedEscapesPtrComparison tc = new TestAllocatedEscapesPtrComparison();
+
+    // Warmup and run enough times
+    for (int i = 0; i < 20000; i++) {
+      tc.visit(0);
+    }
+  }
+}