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Diffstat (limited to 'cpu/o3/btb.cc')
-rw-r--r-- | cpu/o3/btb.cc | 120 |
1 files changed, 0 insertions, 120 deletions
diff --git a/cpu/o3/btb.cc b/cpu/o3/btb.cc deleted file mode 100644 index 2d39c3856..000000000 --- a/cpu/o3/btb.cc +++ /dev/null @@ -1,120 +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. - */ - -#include "base/intmath.hh" -#include "base/trace.hh" -#include "cpu/o3/btb.hh" - -using namespace TheISA; - -DefaultBTB::DefaultBTB(unsigned _numEntries, - unsigned _tagBits, - unsigned _instShiftAmt) - : numEntries(_numEntries), - tagBits(_tagBits), - instShiftAmt(_instShiftAmt) -{ - // @todo Check to make sure num_entries is valid (a power of 2) - - DPRINTF(Fetch, "BTB: Creating BTB object.\n"); - - btb = new BTBEntry[numEntries]; - - for (int i = 0; i < numEntries; ++i) - { - btb[i].valid = false; - } - - idxMask = numEntries - 1; - - tagMask = (1 << tagBits) - 1; - - tagShiftAmt = instShiftAmt + floorLog2(numEntries); -} - -inline -unsigned -DefaultBTB::getIndex(const Addr &inst_PC) -{ - // Need to shift PC over by the word offset. - return (inst_PC >> instShiftAmt) & idxMask; -} - -inline -Addr -DefaultBTB::getTag(const Addr &inst_PC) -{ - return (inst_PC >> tagShiftAmt) & tagMask; -} - -bool -DefaultBTB::valid(const Addr &inst_PC) -{ - unsigned btb_idx = getIndex(inst_PC); - - Addr inst_tag = getTag(inst_PC); - - assert(btb_idx < numEntries); - - if (btb[btb_idx].valid && inst_tag == btb[btb_idx].tag) { - return true; - } else { - return false; - } -} - -// @todo Create some sort of return struct that has both whether or not the -// address is valid, and also the address. For now will just use addr = 0 to -// represent invalid entry. -Addr -DefaultBTB::lookup(const Addr &inst_PC) -{ - unsigned btb_idx = getIndex(inst_PC); - - Addr inst_tag = getTag(inst_PC); - - assert(btb_idx < numEntries); - - if (btb[btb_idx].valid && inst_tag == btb[btb_idx].tag) { - return btb[btb_idx].target; - } else { - return 0; - } -} - -void -DefaultBTB::update(const Addr &inst_PC, const Addr &target) -{ - unsigned btb_idx = getIndex(inst_PC); - - assert(btb_idx < numEntries); - - btb[btb_idx].valid = true; - btb[btb_idx].target = target; - btb[btb_idx].tag = getTag(inst_PC); -} |