gem5
v20.1.0.0
mem
cache
tags
indexing_policies
base.cc
Go to the documentation of this file.
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/*
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* Copyright (c) 2018 Inria
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* Copyright (c) 2012-2014,2017 ARM Limited
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* All rights reserved.
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*
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* The license below extends only to copyright in the software and shall
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* not be construed as granting a license to any other intellectual
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* property including but not limited to intellectual property relating
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* to a hardware implementation of the functionality of the software
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* licensed hereunder. You may use the software subject to the license
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* terms below provided that you ensure that this notice is replicated
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* unmodified and in its entirety in all distributions of the software,
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* modified or unmodified, in source code or in binary form.
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*
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* Copyright (c) 2003-2005,2014 The Regents of The University of Michigan
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met: redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer;
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* redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution;
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "
mem/cache/tags/indexing_policies/base.hh
"
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#include <cstdlib>
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#include "
base/intmath.hh
"
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#include "
base/logging.hh
"
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#include "
mem/cache/replacement_policies/replaceable_entry.hh
"
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BaseIndexingPolicy::BaseIndexingPolicy
(
const
Params
*
p
)
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:
SimObject
(
p
), assoc(
p
->assoc),
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numSets(
p
->size / (
p
->entry_size * assoc)),
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setShift(
floorLog2
(
p
->entry_size)), setMask(numSets - 1), sets(numSets),
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tagShift(setShift +
floorLog2
(numSets))
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{
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fatal_if
(!
isPowerOf2
(
numSets
),
"# of sets must be non-zero and a power "
\
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"of 2"
);
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fatal_if
(
assoc
<= 0,
"associativity must be greater than zero"
);
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// Make space for the entries
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for
(uint32_t
i
= 0;
i
<
numSets
; ++
i
) {
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sets
[
i
].resize(
assoc
);
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}
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}
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ReplaceableEntry
*
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BaseIndexingPolicy::getEntry
(
const
uint32_t set,
const
uint32_t way)
const
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{
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return
sets
[set][way];
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}
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void
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BaseIndexingPolicy::setEntry
(
ReplaceableEntry
* entry,
const
uint64_t
index
)
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{
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// Calculate set and way from entry index
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const
std::lldiv_t div_result = std::div((
long
long
)
index
,
assoc
);
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const
uint32_t set = div_result.quot;
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const
uint32_t way = div_result.rem;
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// Sanity check
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assert(set <
numSets
);
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// Assign a free pointer
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sets
[set][way] = entry;
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// Inform the entry its position
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entry->
setPosition
(set, way);
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}
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Addr
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BaseIndexingPolicy::extractTag
(
const
Addr
addr
)
const
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{
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return
(
addr
>>
tagShift
);
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}
ReplaceableEntry
A replaceable entry is a basic entry in a 2d table-like structure that needs to have replacement func...
Definition:
replaceable_entry.hh:53
MipsISA::index
Bitfield< 30, 0 > index
Definition:
pra_constants.hh:44
ArmISA::i
Bitfield< 7 > i
Definition:
miscregs_types.hh:63
BaseIndexingPolicy::getEntry
ReplaceableEntry * getEntry(const uint32_t set, const uint32_t way) const
Get an entry based on its set and way.
Definition:
base.cc:72
floorLog2
std::enable_if< std::is_integral< T >::value, int >::type floorLog2(T x)
Definition:
intmath.hh:63
BaseIndexingPolicy::sets
std::vector< std::vector< ReplaceableEntry * > > sets
The cache sets.
Definition:
base.hh:89
base.hh
replaceable_entry.hh
BaseIndexingPolicy::BaseIndexingPolicy
BaseIndexingPolicy(const Params *p)
Construct and initialize this policy.
Definition:
base.cc:55
ReplaceableEntry::setPosition
virtual void setPosition(const uint32_t set, const uint32_t way)
Set both the set and way.
Definition:
replaceable_entry.hh:83
BaseIndexingPolicy::setEntry
void setEntry(ReplaceableEntry *entry, const uint64_t index)
Associate a pointer to an entry to its physical counterpart.
Definition:
base.cc:78
BaseIndexingPolicy::extractTag
virtual Addr extractTag(const Addr addr) const
Generate the tag from the given address.
Definition:
base.cc:96
Addr
uint64_t Addr
Address type This will probably be moved somewhere else in the near future.
Definition:
types.hh:142
BaseIndexingPolicy::tagShift
const int tagShift
The amount to shift the address to get the tag.
Definition:
base.hh:94
BaseIndexingPolicy::Params
BaseIndexingPolicyParams Params
Convenience typedef.
Definition:
base.hh:100
addr
ip6_addr_t addr
Definition:
inet.hh:423
BaseIndexingPolicy::assoc
const unsigned assoc
The associativity.
Definition:
base.hh:69
logging.hh
MipsISA::p
Bitfield< 0 > p
Definition:
pra_constants.hh:323
intmath.hh
fatal_if
#define fatal_if(cond,...)
Conditional fatal macro that checks the supplied condition and only causes a fatal error if the condi...
Definition:
logging.hh:219
BaseIndexingPolicy::numSets
const uint32_t numSets
The number of sets in the cache.
Definition:
base.hh:74
isPowerOf2
bool isPowerOf2(const T &n)
Definition:
intmath.hh:102
SimObject
Abstract superclass for simulation objects.
Definition:
sim_object.hh:92
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