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Diffstat (limited to 'cpu/o3/btb.hh')
-rw-r--r-- | cpu/o3/btb.hh | 127 |
1 files changed, 0 insertions, 127 deletions
diff --git a/cpu/o3/btb.hh b/cpu/o3/btb.hh deleted file mode 100644 index b9ff42573..000000000 --- a/cpu/o3/btb.hh +++ /dev/null @@ -1,127 +0,0 @@ -/* - * 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_BTB_HH__ -#define __CPU_O3_BTB_HH__ - -// For Addr type. -#include "arch/isa_traits.hh" - -class DefaultBTB -{ - private: - struct BTBEntry - { - BTBEntry() - : tag(0), target(0), valid(false) - { - } - - /** The entry's tag. */ - Addr tag; - - /** The entry's target. */ - Addr target; - - /** The entry's thread id. */ - unsigned tid; - - /** Whether or not the entry is valid. */ - bool valid; - }; - - public: - /** Creates a BTB with the given number of entries, number of bits per - * tag, and instruction offset amount. - * @param numEntries Number of entries for the BTB. - * @param tagBits Number of bits for each tag in the BTB. - * @param instShiftAmt Offset amount for instructions to ignore alignment. - */ - DefaultBTB(unsigned numEntries, unsigned tagBits, - unsigned instShiftAmt); - - void reset(); - - /** Looks up an address in the BTB. Must call valid() first on the address. - * @param inst_PC The address of the branch to look up. - * @param tid The thread id. - * @return Returns the target of the branch. - */ - Addr lookup(const Addr &inst_PC, unsigned tid); - - /** Checks if a branch is in the BTB. - * @param inst_PC The address of the branch to look up. - * @param tid The thread id. - * @return Whether or not the branch exists in the BTB. - */ - bool valid(const Addr &inst_PC, unsigned tid); - - /** Updates the BTB with the target of a branch. - * @param inst_PC The address of the branch being updated. - * @param target_PC The target address of the branch. - * @param tid The thread id. - */ - void update(const Addr &inst_PC, const Addr &target_PC, - unsigned tid); - - private: - /** Returns the index into the BTB, based on the branch's PC. - * @param inst_PC The branch to look up. - * @return Returns the index into the BTB. - */ - inline unsigned getIndex(const Addr &inst_PC); - - /** Returns the tag bits of a given address. - * @param inst_PC The branch's address. - * @return Returns the tag bits. - */ - inline Addr getTag(const Addr &inst_PC); - - /** The actual BTB. */ - std::vector<BTBEntry> btb; - - /** The number of entries in the BTB. */ - unsigned numEntries; - - /** The index mask. */ - unsigned idxMask; - - /** The number of tag bits per entry. */ - unsigned tagBits; - - /** The tag mask. */ - unsigned tagMask; - - /** Number of bits to shift PC when calculating index. */ - unsigned instShiftAmt; - - /** Number of bits to shift PC when calculating tag. */ - unsigned tagShiftAmt; -}; - -#endif // __CPU_O3_BTB_HH__ |