--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/os/windows/vm/chaitin_windows.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,77 @@
+/*
+ * Copyright 1999-2006 Sun Microsystems, 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_chaitin_windows.cpp.incl"
+
+// Disallow the use of the frame pointer (EBP) for implicit null exceptions
+// on win95/98.  If we do not do this, the OS gets confused and gives a stack
+// error.
+void PhaseRegAlloc::pd_preallocate_hook() {
+#ifndef _WIN64
+  if (ImplicitNullChecks && !os::win32::is_nt()) {
+    for (uint block_num=1; block_num<_cfg._num_blocks; block_num++) {
+      Block *block = _cfg._blocks[block_num];
+
+      Node *block_end = block->end();
+      if (block_end->is_MachNullCheck() &&
+          block_end->as_Mach()->ideal_Opcode() != Op_Con) {
+        // The last instruction in the block is an implicit null check.
+        // Fix its input so that it does not load into the frame pointer.
+        _matcher.pd_implicit_null_fixup(block_end->in(1)->as_Mach(),
+                                        block_end->as_MachNullCheck()->_vidx);
+      }
+    }
+  }
+#else
+  // WIN64==itanium on XP
+#endif
+}
+
+#ifdef ASSERT
+// Verify that no implicit null check uses the frame pointer (EBP) as
+// its register on win95/98.  Use of the frame pointer in an implicit
+// null check confuses the OS, yielding a stack error.
+void PhaseRegAlloc::pd_postallocate_verify_hook() {
+#ifndef _WIN64
+  if (ImplicitNullChecks && !os::win32::is_nt()) {
+    for (uint block_num=1; block_num<_cfg._num_blocks; block_num++) {
+      Block *block = _cfg._blocks[block_num];
+
+      Node *block_end = block->_nodes[block->_nodes.size()-1];
+      if (block_end->is_MachNullCheck() && block_end->as_Mach()->ideal_Opcode() != Op_Con) {
+        // The last instruction in the block is an implicit
+        // null check.  Verify that this instruction does not
+        // use the frame pointer.
+        int reg = get_reg_first(block_end->in(1)->in(block_end->as_MachNullCheck()->_vidx));
+        assert(reg != EBP_num,
+               "implicit null check using frame pointer on win95/98");
+      }
+    }
+  }
+#else
+  // WIN64==itanium on XP
+#endif
+}
+#endif