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-rw-r--r--src/cpu/o3/alpha_cpu_builder.cc9
-rw-r--r--src/cpu/o3/alpha_params.hh3
-rw-r--r--src/cpu/o3/iew.hh57
-rw-r--r--src/cpu/o3/iew_impl.hh17
-rw-r--r--src/cpu/o3/inst_queue_impl.hh2
-rw-r--r--src/cpu/o3/lsq_unit_impl.hh1
6 files changed, 80 insertions, 9 deletions
diff --git a/src/cpu/o3/alpha_cpu_builder.cc b/src/cpu/o3/alpha_cpu_builder.cc
index b1e141ff4..4f5dd0465 100644
--- a/src/cpu/o3/alpha_cpu_builder.cc
+++ b/src/cpu/o3/alpha_cpu_builder.cc
@@ -91,7 +91,10 @@ Param<unsigned> renameWidth;
Param<unsigned> commitToIEWDelay;
Param<unsigned> renameToIEWDelay;
Param<unsigned> issueToExecuteDelay;
+Param<unsigned> dispatchWidth;
Param<unsigned> issueWidth;
+Param<unsigned> wbWidth;
+Param<unsigned> wbDepth;
SimObjectParam<FUPool *> fuPool;
Param<unsigned> iewToCommitDelay;
@@ -207,7 +210,10 @@ BEGIN_INIT_SIM_OBJECT_PARAMS(DerivAlphaO3CPU)
"Issue/Execute/Writeback delay"),
INIT_PARAM(issueToExecuteDelay, "Issue to execute delay (internal"
"to the IEW stage)"),
+ INIT_PARAM(dispatchWidth, "Dispatch width"),
INIT_PARAM(issueWidth, "Issue width"),
+ INIT_PARAM(wbWidth, "Writeback width"),
+ INIT_PARAM(wbDepth, "Writeback depth (number of cycles it can buffer)"),
INIT_PARAM_DFLT(fuPool, "Functional unit pool", NULL),
INIT_PARAM(iewToCommitDelay, "Issue/Execute/Writeback to commit "
@@ -333,7 +339,10 @@ CREATE_SIM_OBJECT(DerivAlphaO3CPU)
params->commitToIEWDelay = commitToIEWDelay;
params->renameToIEWDelay = renameToIEWDelay;
params->issueToExecuteDelay = issueToExecuteDelay;
+ params->dispatchWidth = dispatchWidth;
params->issueWidth = issueWidth;
+ params->wbWidth = wbWidth;
+ params->wbDepth = wbDepth;
params->fuPool = fuPool;
params->iewToCommitDelay = iewToCommitDelay;
diff --git a/src/cpu/o3/alpha_params.hh b/src/cpu/o3/alpha_params.hh
index f0732733e..78246e353 100644
--- a/src/cpu/o3/alpha_params.hh
+++ b/src/cpu/o3/alpha_params.hh
@@ -104,7 +104,10 @@ class AlphaSimpleParams : public BaseO3CPU::Params
unsigned commitToIEWDelay;
unsigned renameToIEWDelay;
unsigned issueToExecuteDelay;
+ unsigned dispatchWidth;
unsigned issueWidth;
+ unsigned wbWidth;
+ unsigned wbDepth;
FUPool *fuPool;
//
diff --git a/src/cpu/o3/iew.hh b/src/cpu/o3/iew.hh
index 2af68d8fc..9627609c2 100644
--- a/src/cpu/o3/iew.hh
+++ b/src/cpu/o3/iew.hh
@@ -204,6 +204,45 @@ class DefaultIEW
/** Returns if the LSQ has any stores to writeback. */
bool hasStoresToWB() { return ldstQueue.hasStoresToWB(); }
+ void incrWb(InstSeqNum &sn)
+ {
+ if (++wbOutstanding == wbMax)
+ ableToIssue = false;
+ DPRINTF(IEW, "wbOutstanding: %i\n", wbOutstanding);
+#if DEBUG
+ wbList.insert(sn);
+#endif
+ }
+
+ void decrWb(InstSeqNum &sn)
+ {
+ if (wbOutstanding-- == wbMax)
+ ableToIssue = true;
+ DPRINTF(IEW, "wbOutstanding: %i\n", wbOutstanding);
+#if DEBUG
+ assert(wbList.find(sn) != wbList.end());
+ wbList.erase(sn);
+#endif
+ }
+
+#if DEBUG
+ std::set<InstSeqNum> wbList;
+
+ void dumpWb()
+ {
+ std::set<InstSeqNum>::iterator wb_it = wbList.begin();
+ while (wb_it != wbList.end()) {
+ cprintf("[sn:%lli]\n",
+ (*wb_it));
+ wb_it++;
+ }
+ }
+#endif
+
+ bool canIssue() { return ableToIssue; }
+
+ bool ableToIssue;
+
private:
/** Sends commit proper information for a squash due to a branch
* mispredict.
@@ -384,11 +423,8 @@ class DefaultIEW
*/
unsigned issueToExecuteDelay;
- /** Width of issue's read path, in instructions. The read path is both
- * the skid buffer and the rename instruction queue.
- * Note to self: is this really different than issueWidth?
- */
- unsigned issueReadWidth;
+ /** Width of dispatch, in instructions. */
+ unsigned dispatchWidth;
/** Width of issue, in instructions. */
unsigned issueWidth;
@@ -403,6 +439,17 @@ class DefaultIEW
*/
unsigned wbCycle;
+ /** Number of instructions in flight that will writeback. */
+ unsigned wbOutstanding;
+
+ /** Writeback width. */
+ unsigned wbWidth;
+
+ /** Writeback width * writeback depth, where writeback depth is
+ * the number of cycles of writing back instructions that can be
+ * buffered. */
+ unsigned wbMax;
+
/** Number of active threads. */
unsigned numThreads;
diff --git a/src/cpu/o3/iew_impl.hh b/src/cpu/o3/iew_impl.hh
index 8e6fd46a1..118038b65 100644
--- a/src/cpu/o3/iew_impl.hh
+++ b/src/cpu/o3/iew_impl.hh
@@ -50,8 +50,10 @@ DefaultIEW<Impl>::DefaultIEW(Params *params)
commitToIEWDelay(params->commitToIEWDelay),
renameToIEWDelay(params->renameToIEWDelay),
issueToExecuteDelay(params->issueToExecuteDelay),
- issueReadWidth(params->issueWidth),
+ dispatchWidth(params->dispatchWidth),
issueWidth(params->issueWidth),
+ wbOutstanding(0),
+ wbWidth(params->wbWidth),
numThreads(params->numberOfThreads),
switchedOut(false)
{
@@ -74,8 +76,12 @@ DefaultIEW<Impl>::DefaultIEW(Params *params)
fetchRedirect[i] = false;
}
+ wbMax = wbWidth * params->wbDepth;
+
updateLSQNextCycle = false;
+ ableToIssue = true;
+
skidBufferMax = (3 * (renameToIEWDelay * params->renameWidth)) + issueWidth;
}
@@ -559,12 +565,12 @@ DefaultIEW<Impl>::instToCommit(DynInstPtr &inst)
// free slot.
while ((*iewQueue)[wbCycle].insts[wbNumInst]) {
++wbNumInst;
- if (wbNumInst == issueWidth) {
+ if (wbNumInst == wbWidth) {
++wbCycle;
wbNumInst = 0;
}
- assert(wbCycle < 5);
+ assert((wbCycle * wbWidth + wbNumInst) < wbMax);
}
// Add finished instruction to queue to commit.
@@ -937,7 +943,7 @@ DefaultIEW<Impl>::dispatchInsts(unsigned tid)
// Loop through the instructions, putting them in the instruction
// queue.
for ( ; dis_num_inst < insts_to_add &&
- dis_num_inst < issueReadWidth;
+ dis_num_inst < dispatchWidth;
++dis_num_inst)
{
inst = insts_to_dispatch.front();
@@ -1189,6 +1195,7 @@ DefaultIEW<Impl>::executeInsts()
++iewExecSquashedInsts;
+ decrWb(inst->seqNum);
continue;
}
@@ -1351,6 +1358,8 @@ DefaultIEW<Impl>::writebackInsts()
}
writebackCount[tid]++;
}
+
+ decrWb(inst->seqNum);
}
}
diff --git a/src/cpu/o3/inst_queue_impl.hh b/src/cpu/o3/inst_queue_impl.hh
index 1ef1b2cff..61c04cc2b 100644
--- a/src/cpu/o3/inst_queue_impl.hh
+++ b/src/cpu/o3/inst_queue_impl.hh
@@ -686,6 +686,7 @@ InstructionQueue<Impl>::scheduleReadyInsts()
int total_issued = 0;
while (total_issued < totalWidth &&
+ iewStage->canIssue() &&
order_it != order_end_it) {
OpClass op_class = (*order_it).queueType;
@@ -783,6 +784,7 @@ InstructionQueue<Impl>::scheduleReadyInsts()
listOrder.erase(order_it++);
statIssuedInstType[tid][op_class]++;
+ iewStage->incrWb(issuing_inst->seqNum);
} else {
statFuBusy[op_class]++;
fuBusy[tid]++;
diff --git a/src/cpu/o3/lsq_unit_impl.hh b/src/cpu/o3/lsq_unit_impl.hh
index 714acb2ef..bb3da7eec 100644
--- a/src/cpu/o3/lsq_unit_impl.hh
+++ b/src/cpu/o3/lsq_unit_impl.hh
@@ -77,6 +77,7 @@ LSQUnit<Impl>::completeDataAccess(PacketPtr pkt)
//iewStage->ldstQueue.removeMSHR(inst->threadNumber,inst->seqNum);
if (isSwitchedOut() || inst->isSquashed()) {
+ iewStage->decrWb(inst->seqNum);
delete state;
delete pkt;
return;
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-23 10:37:44 +0000