--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/cpu/x86/vm/icache_x86.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,55 @@
+/*
+ * Copyright 1997-2004 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.
+ *
+ */
+
+// Interface for updating the instruction cache.  Whenever the VM modifies
+// code, part of the processor instruction cache potentially has to be flushed.
+
+// On the x86, this is a no-op -- the I-cache is guaranteed to be consistent
+// after the next jump, and the VM never modifies instructions directly ahead
+// of the instruction fetch path.
+
+// [phh] It's not clear that the above comment is correct, because on an MP
+// system where the dcaches are not snooped, only the thread doing the invalidate
+// will see the update.  Even in the snooped case, a memory fence would be
+// necessary if stores weren't ordered.  Fortunately, they are on all known
+// x86 implementations.
+
+class ICache : public AbstractICache {
+ public:
+#ifdef AMD64
+  enum {
+    stub_size      = 64, // Size of the icache flush stub in bytes
+    line_size      = 32, // Icache line size in bytes
+    log2_line_size = 5   // log2(line_size)
+  };
+
+  // Use default implementation
+#else
+  enum {
+    stub_size      = 16,                 // Size of the icache flush stub in bytes
+    line_size      = BytesPerWord,      // conservative
+    log2_line_size = LogBytesPerWord    // log2(line_size)
+  };
+#endif // AMD64
+};