From 4e3426624557b555c354035ee3961eab7554d81d Mon Sep 17 00:00:00 2001 From: Nathan Binkert Date: Thu, 4 Jun 2009 21:50:20 -0700 Subject: move: put predictor includes and cc files into the same place --HG-- rename : src/cpu/2bit_local_pred.cc => src/cpu/pred/2bit_local.cc rename : src/cpu/o3/2bit_local_pred.hh => src/cpu/pred/2bit_local.hh rename : src/cpu/btb.cc => src/cpu/pred/btb.cc rename : src/cpu/o3/btb.hh => src/cpu/pred/btb.hh rename : src/cpu/ras.cc => src/cpu/pred/ras.cc rename : src/cpu/o3/ras.hh => src/cpu/pred/ras.hh rename : src/cpu/tournament_pred.cc => src/cpu/pred/tournament.cc rename : src/cpu/o3/tournament_pred.hh => src/cpu/pred/tournament.hh --- src/cpu/pred/btb.cc | 134 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 134 insertions(+) create mode 100644 src/cpu/pred/btb.cc (limited to 'src/cpu/pred/btb.cc') diff --git a/src/cpu/pred/btb.cc b/src/cpu/pred/btb.cc new file mode 100644 index 000000000..81676aceb --- /dev/null +++ b/src/cpu/pred/btb.cc @@ -0,0 +1,134 @@ +/* + * 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. + * + * Authors: Kevin Lim + */ + +#include "base/intmath.hh" +#include "base/trace.hh" +#include "cpu/pred/btb.hh" + +DefaultBTB::DefaultBTB(unsigned _numEntries, + unsigned _tagBits, + unsigned _instShiftAmt) + : numEntries(_numEntries), + tagBits(_tagBits), + instShiftAmt(_instShiftAmt) +{ + DPRINTF(Fetch, "BTB: Creating BTB object.\n"); + + if (!isPowerOf2(numEntries)) { + fatal("BTB entries is not a power of 2!"); + } + + btb.resize(numEntries); + + for (int i = 0; i < numEntries; ++i) { + btb[i].valid = false; + } + + idxMask = numEntries - 1; + + tagMask = (1 << tagBits) - 1; + + tagShiftAmt = instShiftAmt + floorLog2(numEntries); +} + +void +DefaultBTB::reset() +{ + for (int i = 0; i < numEntries; ++i) { + btb[i].valid = false; + } +} + +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, ThreadID tid) +{ + 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 + && btb[btb_idx].tid == tid) { + 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, ThreadID tid) +{ + 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 + && btb[btb_idx].tid == tid) { + return btb[btb_idx].target; + } else { + return 0; + } +} + +void +DefaultBTB::update(const Addr &inst_PC, const Addr &target, ThreadID tid) +{ + unsigned btb_idx = getIndex(inst_PC); + + assert(btb_idx < numEntries); + + btb[btb_idx].tid = tid; + btb[btb_idx].valid = true; + btb[btb_idx].target = target; + btb[btb_idx].tag = getTag(inst_PC); +} -- cgit v1.2.3