view src/share/vm/runtime/simpleThresholdPolicy.inline.hpp @ 9126:bc26f978b0ce

HotSpotResolvedObjectType: implement hasFinalizeSubclass() correctly don't use the (wrong) cached value, but ask the runtime on each request. Fixes regression on xml.* benchmarks @ specjvm2008. The problem was: After the constructor of Object was deoptimized due to an assumption violation, it was recompiled again after some time. However, on recompilation, the value of hasFinalizeSubclass for the class was not updated and it was compiled again with a, now wrong, assumption, which then triggers deoptimization again. This was repeated until it hit the recompilation limit (defined by PerMethodRecompilationCutoff), and therefore only executed by the interpreter from now on, causing the performance regression.
author Bernhard Urban <bernhard.urban@jku.at>
date Mon, 15 Apr 2013 19:54:58 +0200
parents da91efe96a93
children f2bdbfe9201b 600c44255e5f
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/*
 * Copyright (c) 2001, 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
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 */

#ifndef SHARE_VM_RUNTIME_SIMPLETHRESHOLDPOLICY_INLINE_HPP
#define SHARE_VM_RUNTIME_SIMPLETHRESHOLDPOLICY_INLINE_HPP

template<CompLevel level>
bool SimpleThresholdPolicy::call_predicate_helper(int i, int b, double scale) {
  switch(level) {
  case CompLevel_none:
  case CompLevel_limited_profile:
    return (i > Tier3InvocationThreshold * scale) ||
           (i > Tier3MinInvocationThreshold * scale && i + b > Tier3CompileThreshold * scale);
  case CompLevel_full_profile:
   return (i > Tier4InvocationThreshold * scale) ||
          (i > Tier4MinInvocationThreshold * scale && i + b > Tier4CompileThreshold * scale);
  }
  return true;
}

template<CompLevel level>
bool SimpleThresholdPolicy::loop_predicate_helper(int i, int b, double scale) {
  switch(level) {
  case CompLevel_none:
  case CompLevel_limited_profile:
    return b > Tier3BackEdgeThreshold * scale;
  case CompLevel_full_profile:
    return b > Tier4BackEdgeThreshold * scale;
  }
  return true;
}

// Simple methods are as good being compiled with C1 as C2.
// Determine if a given method is such a case.
bool SimpleThresholdPolicy::is_trivial(Method* method) {
  if (method->is_accessor()) return true;
  if (method->code() != NULL) {
    MethodData* mdo = method->method_data();
    if (mdo != NULL && mdo->num_loops() == 0 &&
        (method->code_size() < 5  || (mdo->num_blocks() < 4) && (method->code_size() < 15))) {
      return !mdo->would_profile();
    }
  }
  return false;
}

#endif // SHARE_VM_RUNTIME_SIMPLETHRESHOLDPOLICY_INLINE_HPP