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/*
* Copyright (c) 2004-2005 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 __CPU_O3_CPU_BTB_HH__
#define __CPU_O3_CPU_BTB_HH__
// For Addr type.
#include "arch/isa_traits.hh"
class DefaultBTB
{
private:
struct BTBEntry
{
BTBEntry()
: tag(0), target(0), valid(false)
{
}
Addr tag;
Addr target;
bool valid;
};
public:
DefaultBTB(unsigned numEntries, unsigned tagBits,
unsigned instShiftAmt);
Addr lookup(const Addr &inst_PC);
bool valid(const Addr &inst_PC);
void update(const Addr &inst_PC, const Addr &target_PC);
private:
inline unsigned getIndex(const Addr &inst_PC);
inline Addr getTag(const Addr &inst_PC);
BTBEntry *btb;
unsigned numEntries;
unsigned idxMask;
unsigned tagBits;
unsigned tagMask;
unsigned instShiftAmt;
unsigned tagShiftAmt;
};
#endif // __CPU_O3_CPU_BTB_HH__
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