blob: 11023f4a85f59b47b642a0b0972bcf0315b632c6 [file] [log] [blame]
/*
* 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/trace.hh"
#include "cpu/o3/store_set.hh"
StoreSet::StoreSet(int _SSIT_size, int _LFST_size)
: SSIT_size(_SSIT_size), LFST_size(_LFST_size)
{
DPRINTF(StoreSet, "StoreSet: Creating store set object.\n");
DPRINTF(StoreSet, "StoreSet: SSIT size: %i, LFST size: %i.\n",
SSIT_size, LFST_size);
SSIT = new SSID[SSIT_size];
validSSIT.resize(SSIT_size);
for (int i = 0; i < SSIT_size; ++i)
validSSIT[i] = false;
LFST = new InstSeqNum[LFST_size];
validLFST.resize(LFST_size);
SSCounters = new int[LFST_size];
for (int i = 0; i < LFST_size; ++i)
{
validLFST[i] = false;
SSCounters[i] = 0;
}
index_mask = SSIT_size - 1;
offset_bits = 2;
}
void
StoreSet::violation(Addr store_PC, Addr load_PC)
{
int load_index = calcIndex(load_PC);
int store_index = calcIndex(store_PC);
assert(load_index < SSIT_size && store_index < SSIT_size);
bool valid_load_SSID = validSSIT[load_index];
bool valid_store_SSID = validSSIT[store_index];
if (!valid_load_SSID && !valid_store_SSID) {
// Calculate a new SSID here.
SSID new_set = calcSSID(load_PC);
validSSIT[load_index] = true;
SSIT[load_index] = new_set;
validSSIT[store_index] = true;
SSIT[store_index] = new_set;
assert(new_set < LFST_size);
SSCounters[new_set]++;
DPRINTF(StoreSet, "StoreSet: Neither load nor store had a valid "
"storeset, creating a new one: %i for load %#x, store %#x\n",
new_set, load_PC, store_PC);
} else if (valid_load_SSID && !valid_store_SSID) {
SSID load_SSID = SSIT[load_index];
validSSIT[store_index] = true;
SSIT[store_index] = load_SSID;
assert(load_SSID < LFST_size);
SSCounters[load_SSID]++;
DPRINTF(StoreSet, "StoreSet: Load had a valid store set. Adding "
"store to that set: %i for load %#x, store %#x\n",
load_SSID, load_PC, store_PC);
} else if (!valid_load_SSID && valid_store_SSID) {
SSID store_SSID = SSIT[store_index];
validSSIT[load_index] = true;
SSIT[load_index] = store_SSID;
// Because we are having a load point to an already existing set,
// the size of the store set is not incremented.
DPRINTF(StoreSet, "StoreSet: Store had a valid store set: %i for "
"load %#x, store %#x\n",
store_SSID, load_PC, store_PC);
} else {
SSID load_SSID = SSIT[load_index];
SSID store_SSID = SSIT[store_index];
assert(load_SSID < LFST_size && store_SSID < LFST_size);
int load_SS_size = SSCounters[load_SSID];
int store_SS_size = SSCounters[store_SSID];
// If the load has the bigger store set, then assign the store
// to the same store set as the load. Otherwise vice-versa.
if (load_SS_size > store_SS_size) {
SSIT[store_index] = load_SSID;
SSCounters[load_SSID]++;
SSCounters[store_SSID]--;
DPRINTF(StoreSet, "StoreSet: Load had bigger store set: %i; "
"for load %#x, store %#x\n",
load_SSID, load_PC, store_PC);
} else {
SSIT[load_index] = store_SSID;
SSCounters[store_SSID]++;
SSCounters[load_SSID]--;
DPRINTF(StoreSet, "StoreSet: Store had bigger store set: %i; "
"for load %#x, store %#x\n",
store_SSID, load_PC, store_PC);
}
}
}
void
StoreSet::insertLoad(Addr load_PC, InstSeqNum load_seq_num)
{
// Does nothing.
return;
}
void
StoreSet::insertStore(Addr store_PC, InstSeqNum store_seq_num)
{
int index = calcIndex(store_PC);
int store_SSID;
assert(index < SSIT_size);
if (!validSSIT[index]) {
// Do nothing if there's no valid entry.
return;
} else {
store_SSID = SSIT[index];
assert(store_SSID < LFST_size);
// Update the last store that was fetched with the current one.
LFST[store_SSID] = store_seq_num;
validLFST[store_SSID] = 1;
DPRINTF(StoreSet, "Store %#x updated the LFST, SSID: %i\n",
store_PC, store_SSID);
}
}
InstSeqNum
StoreSet::checkInst(Addr PC)
{
int index = calcIndex(PC);
int inst_SSID;
assert(index < SSIT_size);
if (!validSSIT[index]) {
DPRINTF(StoreSet, "Inst %#x with index %i had no SSID\n",
PC, index);
// Return 0 if there's no valid entry.
return 0;
} else {
inst_SSID = SSIT[index];
assert(inst_SSID < LFST_size);
if (!validLFST[inst_SSID]) {
DPRINTF(StoreSet, "Inst %#x with index %i and SSID %i had no "
"dependency\n", PC, index, inst_SSID);
return 0;
} else {
DPRINTF(StoreSet, "Inst %#x with index %i and SSID %i had LFST "
"inum of %i\n", PC, index, inst_SSID, LFST[inst_SSID]);
return LFST[inst_SSID];
}
}
}
void
StoreSet::issued(Addr issued_PC, InstSeqNum issued_seq_num, bool is_store)
{
// This only is updated upon a store being issued.
if (!is_store) {
return;
}
int index = calcIndex(issued_PC);
int store_SSID;
assert(index < SSIT_size);
// Make sure the SSIT still has a valid entry for the issued store.
if (!validSSIT[index]) {
return;
}
store_SSID = SSIT[index];
assert(store_SSID < LFST_size);
// If the last fetched store in the store set refers to the store that
// was just issued, then invalidate the entry.
if (validLFST[store_SSID] && LFST[store_SSID] == issued_seq_num) {
DPRINTF(StoreSet, "StoreSet: store invalidated itself in LFST.\n");
validLFST[store_SSID] = false;
}
}
void
StoreSet::squash(InstSeqNum squashed_num)
{
// Not really sure how to do this well.
// Generally this is small enough that it should be okay; short circuit
// evaluation should take care of invalid entries.
DPRINTF(StoreSet, "StoreSet: Squashing until inum %i\n",
squashed_num);
for (int i = 0; i < LFST_size; ++i) {
if (validLFST[i] && LFST[i] < squashed_num) {
validLFST[i] = false;
}
}
}
void
StoreSet::clear()
{
for (int i = 0; i < SSIT_size; ++i) {
validSSIT[i] = false;
}
for (int i = 0; i < LFST_size; ++i) {
validLFST[i] = false;
}
}