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diff --git a/sim/cache/lzss_compression.hh b/sim/cache/lzss_compression.hh
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+/*
+ * Copyright (c) 2003 The Regents of The University of Michigan
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __LZSS_COMPRESSION_HH__
+#define __LZSS_COMPRESSION_HH__
+
+/** @file
+ * LZSSCompression declarations.
+ */
+
+#include "host.hh" // for uint8_t
+
+/**
+ * Simple LZSS compression scheme.
+ */
+class LZSSCompression
+{
+    /**
+     * Finds the longest substrings that start at the given offsets.
+     * @param src The source block that we search for substrings.
+     * @param front The smaller offset.
+     * @param back The larger offset.
+     * @param size The size of the source block.
+     * @return The size of the longest substring.
+     */
+    int findSubString(uint8_t *src, int front, int back, int size);
+
+    /**
+     * Emit an encoded byte to the compressed data array. If the 2 high
+     * order bits can be signed extended, use 1 byte encoding, if not use 2
+     * bytes.
+     * @param dest The compressed data.
+     * @param byte The byte to emit.
+     * @return The number of bytes used to encode.
+     */
+    int emitByte(uint8_t *dest, uint8_t byte);
+
+    /**
+     * Emit a string reference to the compressed data array. A string reference
+     * always uses 3 bytes. 1 flag bit, 12 bits for the starting position, and
+     * 11 bits for the length of the string. This allows compression of 4096
+     * byte blocks with string lengths of up to 2048 bytes.
+     * @param dest The compressed data.
+     * @param P The starting position in the uncompressed data.
+     * @param L The length in bytes of the string.
+     */
+    void emitString(uint8_t *dest, uint16_t P, uint16_t L);
+
+  public:
+    /**
+     * Compresses the source block and stores it in the destination block. If
+     * the compressed block grows to larger than the source block, it aborts
+     * and just performs a copy.
+     * @param dest The destination block.
+     * @param src The block to be compressed.
+     * @param size The size of the source block.
+     * @return The size of the compressed block.
+     *
+     * @pre Destination has enough storage to hold the compressed block.
+     */
+    int compress(uint8_t *dest, uint8_t *src, int size);
+
+    /**
+     * Unompresses the source block and stores it in the destination block.
+     * @param dest The destination block.
+     * @param src The block to be uncompressed.
+     * @param size The size of the source block.
+     * @return The size of the uncompressed block.
+     *
+     * @pre Destination has enough storage to hold the uncompressed block.
+     */
+    int uncompress(uint8_t *dest, uint8_t *src, int size);
+};
+
+#endif //__LZSS_COMPRESSION_HH__