--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/opto/mathexactnode.cpp	Fri Sep 27 08:39:19 2013 +0200
@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2013, 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "memory/allocation.inline.hpp"
+#include "opto/addnode.hpp"
+#include "opto/machnode.hpp"
+#include "opto/mathexactnode.hpp"
+#include "opto/matcher.hpp"
+#include "opto/subnode.hpp"
+
+MathExactNode::MathExactNode(Node* ctrl, Node* n1, Node* n2) : MultiNode(3) {
+  init_req(0, ctrl);
+  init_req(1, n1);
+  init_req(2, n2);
+}
+
+Node* AddExactINode::match(const ProjNode* proj, const Matcher* m) {
+  uint ideal_reg = proj->ideal_reg();
+  RegMask rm;
+  if (proj->_con == result_proj_node) {
+    rm = m->mathExactI_result_proj_mask();
+  } else {
+    assert(proj->_con == flags_proj_node, "must be result or flags");
+    assert(ideal_reg == Op_RegFlags, "sanity");
+    rm = m->mathExactI_flags_proj_mask();
+  }
+  return new (m->C) MachProjNode(this, proj->_con, rm, ideal_reg);
+}
+
+// If the MathExactNode won't overflow we have to replace the
+// FlagsProjNode and ProjNode that is generated by the MathExactNode
+Node* MathExactNode::no_overflow(PhaseGVN *phase, Node* new_result) {
+  PhaseIterGVN *igvn = phase->is_IterGVN();
+  if (igvn) {
+    ProjNode* result = result_node();
+    ProjNode* flags = flags_node();
+
+    if (result != NULL) {
+      igvn->replace_node(result, new_result);
+    }
+
+    if (flags != NULL) {
+      BoolNode* bolnode = (BoolNode *) flags->unique_out();
+      switch (bolnode->_test._test) {
+        case BoolTest::overflow:
+          // if the check is for overflow - never taken
+          igvn->replace_node(bolnode, phase->intcon(0));
+          break;
+        case BoolTest::no_overflow:
+          // if the check is for no overflow - always taken
+          igvn->replace_node(bolnode, phase->intcon(1));
+          break;
+        default:
+          fatal("Unexpected value of BoolTest");
+          break;
+      }
+      flags->del_req(0);
+    }
+  }
+  return new_result;
+}
+
+Node *AddExactINode::Ideal(PhaseGVN *phase, bool can_reshape) {
+  Node *arg1 = in(1);
+  Node *arg2 = in(2);
+
+  const Type* type1 = phase->type(arg1);
+  const Type* type2 = phase->type(arg2);
+
+  if (type1 != Type::TOP && type1->singleton() &&
+      type2 != Type::TOP && type2->singleton()) {
+    jint val1 = arg1->get_int();
+    jint val2 = arg2->get_int();
+    jint result = val1 + val2;
+    // Hacker's Delight 2-12 Overflow if both arguments have the opposite sign of the result
+    if ( (((val1 ^ result) & (val2 ^ result)) >= 0)) {
+      Node* con_result = ConINode::make(phase->C, result);
+      return no_overflow(phase, con_result);
+    }
+    return NULL;
+  }
+
+  if (type1 == TypeInt::ZERO) { // (Add 0 x) == x
+    Node* add_result = new (phase->C) AddINode(arg1, arg2);
+    return no_overflow(phase, add_result);
+  }
+
+  if (type2 == TypeInt::ZERO) { // (Add x 0) == x
+    Node* add_result = new (phase->C) AddINode(arg1, arg2);
+    return no_overflow(phase, add_result);
+  }
+
+  if (type2->singleton()) {
+    return NULL; // no change - keep constant on the right
+  }
+
+  if (type1->singleton()) {
+    // Make it x + Constant - move constant to the right
+    swap_edges(1, 2);
+    return this;
+  }
+
+  if (arg2->is_Load()) {
+    return NULL; // no change - keep load on the right
+  }
+
+  if (arg1->is_Load()) {
+    // Make it x + Load - move load to the right
+    swap_edges(1, 2);
+    return this;
+  }
+
+  if (arg1->_idx > arg2->_idx) {
+    // Sort the edges
+    swap_edges(1, 2);
+    return this;
+  }
+
+  return NULL;
+}
+