[llvm-mca][View] Improved Retire Control Unit Statistics.
RetireControlUnitStatistics now reports extra information about the ROB and the
avg/maximum number of entries consumed over the entire simulation.
Example:
Retire Control Unit - number of cycles where we saw N instructions retired:
[# retired], [# cycles]
0, 109 (17.9%)
1, 102 (16.7%)
2, 399 (65.4%)
Total ROB Entries: 64
Max Used ROB Entries: 35 ( 54.7% )
Average Used ROB Entries per cy: 32 ( 50.0% )
Documentation in llvm/docs/CommandGuide/llvmn-mca.rst has been updated to
reflect this change.
llvm-svn: 347493
diff --git a/llvm/tools/llvm-mca/Views/RetireControlUnitStatistics.cpp b/llvm/tools/llvm-mca/Views/RetireControlUnitStatistics.cpp
index 7e2fd31..54eb28f 100644
--- a/llvm/tools/llvm-mca/Views/RetireControlUnitStatistics.cpp
+++ b/llvm/tools/llvm-mca/Views/RetireControlUnitStatistics.cpp
@@ -18,9 +18,39 @@
namespace llvm {
namespace mca {
+RetireControlUnitStatistics::RetireControlUnitStatistics(const MCSchedModel &SM)
+ : NumRetired(0), NumCycles(0), EntriesInUse(0), MaxUsedEntries(0),
+ SumOfUsedEntries(0) {
+ TotalROBEntries = SM.MicroOpBufferSize;
+ if (SM.hasExtraProcessorInfo()) {
+ const MCExtraProcessorInfo &EPI = SM.getExtraProcessorInfo();
+ if (EPI.ReorderBufferSize)
+ TotalROBEntries = EPI.ReorderBufferSize;
+ }
+}
+
void RetireControlUnitStatistics::onEvent(const HWInstructionEvent &Event) {
- if (Event.Type == HWInstructionEvent::Retired)
+ if (Event.Type == HWInstructionEvent::Dispatched) {
+ unsigned NumEntries =
+ static_cast<const HWInstructionDispatchedEvent &>(Event).MicroOpcodes;
+ EntriesInUse += NumEntries;
+ }
+
+ if (Event.Type == HWInstructionEvent::Retired) {
+ unsigned ReleasedEntries = Event.IR.getInstruction()->getDesc().NumMicroOps;
+ assert(EntriesInUse >= ReleasedEntries && "Invalid internal state!");
+ EntriesInUse -= ReleasedEntries;
++NumRetired;
+ }
+}
+
+void RetireControlUnitStatistics::onCycleEnd() {
+ // Update histogram
+ RetiredPerCycle[NumRetired]++;
+ NumRetired = 0;
+ ++NumCycles;
+ MaxUsedEntries = std::max(MaxUsedEntries, EntriesInUse);
+ SumOfUsedEntries += EntriesInUse;
}
void RetireControlUnitStatistics::printView(raw_ostream &OS) const {
@@ -41,6 +71,18 @@
<< "%)\n";
}
+ unsigned AvgUsage = (double)SumOfUsedEntries / NumCycles;
+ double MaxUsagePercentage = ((double)MaxUsedEntries / TotalROBEntries) * 100.0;
+ double NormalizedMaxPercentage = floor((MaxUsagePercentage * 10) + 0.5) / 10;
+ double AvgUsagePercentage = ((double)AvgUsage / TotalROBEntries) * 100.0;
+ double NormalizedAvgPercentage = floor((AvgUsagePercentage * 10) + 0.5) / 10;
+
+ TempStream << "\nTotal ROB Entries: " << TotalROBEntries
+ << "\nMax Used ROB Entries: " << MaxUsedEntries
+ << format(" ( %.1f%% )", NormalizedMaxPercentage)
+ << "\nAverage Used ROB Entries per cy: " << AvgUsage
+ << format(" ( %.1f%% )\n", NormalizedAvgPercentage);
+
TempStream.flush();
OS << Buffer;
}