This patch closes PR#32216: Better testing of schedule model instruction latencies/throughputs.

The details are here: https://reviews.llvm.org/D30941

llvm-svn: 300311

1 files changed, 70 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/TargetSchedule.cpp b/llvm/lib/CodeGen/TargetSchedule.cpp
index 04edf0e6285..0df34ce4311 100644
--- a/llvm/lib/CodeGen/TargetSchedule.cpp
+++ b/llvm/lib/CodeGen/TargetSchedule.cpp
@@ -277,7 +277,11 @@ unsigned TargetSchedModel::computeInstrLatency(unsigned Opcode) const {
   if (SCDesc->isValid() && !SCDesc->isVariant())
     return computeInstrLatency(*SCDesc);
 
-  llvm_unreachable("No MI sched latency");
+  if (SCDesc->isValid()) {
+    assert (!SCDesc->isVariant() && "No MI sched latency: SCDesc->isVariant()");
+    return computeInstrLatency(*SCDesc);
+  }
+  return 0;
 }
 
 unsigned
@@ -331,3 +335,68 @@ computeOutputLatency(const MachineInstr *DefMI, unsigned DefOperIdx,
   }
   return 0;
 }
+
+static Optional<double>
+getRTroughputFromItineraries(unsigned schedClass,
+                             const InstrItineraryData *IID){
+  double Unknown = std::numeric_limits<double>::infinity();
+  double Throughput = Unknown;
+
+  for (const InstrStage *IS = IID->beginStage(schedClass),
+                        *E = IID->endStage(schedClass);
+       IS != E; ++IS) {
+    unsigned Cycles = IS->getCycles();
+    if (!Cycles)
+      continue;
+    Throughput =
+        std::min(Throughput, countPopulation(IS->getUnits()) * 1.0 / Cycles);
+  }
+  // We need reciprocal throughput that's why we return such value.
+  return 1 / Throughput;
+}
+
+static Optional<double>
+getRTroughputFromInstrSchedModel(const MCSchedClassDesc *SCDesc,
+                                 const TargetSubtargetInfo *STI,
+                                 const MCSchedModel &SchedModel) {
+  double Unknown = std::numeric_limits<double>::infinity();
+  double Throughput = Unknown;
+
+  for (const MCWriteProcResEntry *WPR = STI->getWriteProcResBegin(SCDesc),
+                                 *WEnd = STI->getWriteProcResEnd(SCDesc);
+       WPR != WEnd; ++WPR) {
+    unsigned Cycles = WPR->Cycles;
+    if (!Cycles)
+      return Optional<double>();
+
+    unsigned NumUnits =
+        SchedModel.getProcResource(WPR->ProcResourceIdx)->NumUnits;
+    Throughput = std::min(Throughput, NumUnits * 1.0 / Cycles);
+  }
+  // We need reciprocal throughput that's why we return such value.
+  return 1 / Throughput;
+}
+
+Optional<double>
+TargetSchedModel::computeInstrRThroughput(const MachineInstr *MI) const {
+  if (hasInstrItineraries())
+    return getRTroughputFromItineraries(MI->getDesc().getSchedClass(),
+                                        getInstrItineraries());
+  if (hasInstrSchedModel())
+    return getRTroughputFromInstrSchedModel(resolveSchedClass(MI), STI,
+                                            SchedModel);
+  return Optional<double>();
+}
+
+Optional<double>
+TargetSchedModel::computeInstrRThroughput(unsigned Opcode) const {
+  unsigned SchedClass = TII->get(Opcode).getSchedClass();
+  if (hasInstrItineraries())
+    return getRTroughputFromItineraries(SchedClass, getInstrItineraries());
+  if (hasInstrSchedModel()) {
+    const MCSchedClassDesc *SCDesc = SchedModel.getSchedClassDesc(SchedClass);
+    if (SCDesc->isValid() && !SCDesc->isVariant())
+      return getRTroughputFromInstrSchedModel(SCDesc, STI, SchedModel);
+  }
+  return Optional<double>();
+}