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/*
* Copyright (c) 2011 Google
* 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.
*
* Authors: Gabe Black
*/
#ifndef __CPU_DECODE_CACHE_HH__
#define __CPU_DECODE_CACHE_HH__
#include "arch/isa_traits.hh"
#include "arch/types.hh"
#include "base/hashmap.hh"
#include "config/the_isa.hh"
#include "cpu/static_inst.hh"
namespace TheISA
{
class Decoder;
}
class DecodeCache
{
private:
typedef TheISA::ExtMachInst ExtMachInst;
/// Hash of decoded instructions.
typedef m5::hash_map<ExtMachInst, StaticInstPtr> InstMap;
InstMap instMap;
struct DecodePage {
StaticInstPtr insts[TheISA::PageBytes];
};
/// A store of DecodePages. Basically a slightly smarter hash_map.
class DecodePages
{
protected:
typedef typename m5::hash_map<Addr, DecodePage *> PageMap;
typedef typename PageMap::iterator PageIt;
PageIt recent[2];
PageMap pageMap;
/// Update the small cache of recent lookups.
/// @param recentest The most recent result;
void update(PageIt recentest);
void addPage(Addr addr, DecodePage *page);
public:
/// Constructor
DecodePages();
/// Attempt to find the DecodePage which goes with a particular
/// address. First check the small cache of recent results, then
/// actually look in the hash_map.
/// @param addr The address to look up.
DecodePage *getPage(Addr addr);
} decodePages;
public:
/// Decode a machine instruction.
/// @param mach_inst The binary instruction to decode.
/// @retval A pointer to the corresponding StaticInst object.
StaticInstPtr decode(TheISA::Decoder * const decoder,
ExtMachInst mach_inst, Addr addr);
};
#endif // __CPU_DECODE_CACHE_HH__
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